Introduction
This directory contains Device Tree overlays. Device Tree makes it possible to support many hardware configurations with a single kernel and without the need to explicitly load or blacklist kernel modules. Note that this isn't a "pure" Device Tree configuration (c.f. MACH_BCM2835) - some on-board devices are still configured by the board support code, but the intention is to eventually reach that goal.
On Raspberry Pi, Device Tree usage is controlled from /boot/config.txt. By default, the Raspberry Pi kernel boots with device tree enabled. You can completely disable DT usage (for now) by adding:
device_tree=
to your config.txt, which should cause your Pi to revert to the old way of doing things after a reboot.
In /boot you will find a .dtb for each base platform. This describes the hardware that is part of the Raspberry Pi board. The loader (start.elf and its siblings) selects the .dtb file appropriate for the platform by name, and reads it into memory. At this point, all of the optional interfaces (i2c, i2s, spi) are disabled, but they can be enabled using Device Tree parameters:
dtparam=i2c=on,i2s=on,spi=on
However, this shouldn't be necessary in many use cases because loading an overlay that requires one of those interfaces will cause it to be enabled automatically, and it is advisable to only enable interfaces if they are needed.
Configuring additional, optional hardware is done using Device Tree overlays (see below).
GPIO numbering uses the hardware pin numbering scheme (aka BCM scheme) and not the physical pin numbers.
raspi-config
The Advanced Options section of the raspi-config utility can enable and disable Device Tree use, as well as toggling the I2C and SPI interfaces. Note that it is possible to both enable an interface and blacklist the driver, if for some reason you should want to defer the loading.
Modules
As well as describing the hardware, Device Tree also gives enough information to allow suitable driver modules to be located and loaded, with the corollary that unneeded modules are not loaded. As a result it should be possible to remove lines from /etc/modules, and /etc/modprobe.d/raspi-blacklist.conf can have its contents deleted (or commented out).
Using Overlays
Overlays are loaded using the "dtoverlay" config.txt setting. As an example, consider I2C Real Time Clock drivers. In the pre-DT world these would be loaded by writing a magic string comprising a device identifier and an I2C address to a special file in /sys/class/i2c-adapter, having first loaded the driver for the I2C interface and the RTC device - something like this:
modprobe i2c-bcm2835
modprobe rtc-ds1307
echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device
With DT enabled, this becomes a line in config.txt:
dtoverlay=i2c-rtc,ds1307
This causes the file /boot/overlays/i2c-rtc.dtbo to be loaded and a "node" describing the DS1307 I2C device to be added to the Device Tree for the Pi. By default it usees address 0x68, but this can be modified with an additional DT parameter:
dtoverlay=i2c-rtc,ds1307,addr=0x68
Parameters usually have default values, although certain parameters are mandatory. See the list of overlays below for a description of the parameters and their defaults.
Making new Overlays based on existing Overlays
Recent overlays have been designed in a more general way, so that they can be adapted to hardware by changing their parameters. When you have additional hardware with more than one device of a kind, you end up using the same overlay multiple times with other parameters, e.g.
# 2 CAN FD interfaces on spi but with different pins
dtoverlay=mcp251xfd,spi0-0,interrupt=25
dtoverlay=mcp251xfd,spi0-1,interrupt=24
# a realtime clock on i2c
dtoverlay=i2c-rtc,pcf85063
While this approach does work, it requires knowledge about the hardware design. It is more feasible to simplify things for the end user by providing a single overlay as it is done the traditional way.
A new overlay can be generated by using ovmerge utility. https://github.com/raspberrypi/utils/blob/master/ovmerge/ovmerge
To generate an overlay for the above configuration we pass the configuration to ovmerge and add the -c flag.
ovmerge -c mcp251xfd-overlay.dts,spi0-0,interrupt=25 \
mcp251xfd-overlay.dts,spi0-1,interrupt=24 \
i2c-rtc-overlay.dts,pcf85063 \
>> merged-overlay.dts
The -c option writes the command above as a comment into the overlay as a marker that this overlay is generated and how it was generated. After compiling the overlay it can be loaded in a single line.
dtoverlay=merged
It does the same as the original configuration but without parameters.
The Overlay and Parameter Reference
N.B. When editing this file, please preserve the indentation levels to make it simple to parse programmatically. NO HARD TABS.
Name: Info: Configures the base Raspberry Pi hardware Load: Params: ant1 Select antenna 1 (default). CM4 only.
ant2 Select antenna 2. CM4 only.
noant Disable both antennas. CM4 only.
audio Set to "on" to enable the onboard ALSA audio
interface (default "off")
axiperf Set to "on" to enable the AXI bus performance
monitors.
See /sys/kernel/debug/raspberrypi_axi_monitor
for the results.
bdaddr Set an alternative Bluetooth address (BDADDR).
The value should be a 6-byte hexadecimal value,
with or without colon separators, written least-
significant-byte first. For example,
bdaddr=06:05:04:03:02:01
will set the BDADDR to 01:02:03:04:05:06.
button_debounce Set the debounce delay (in ms) on the power/
shutdown button (default 50ms)
cam0_reg Enables CAM 0 regulator.
Only required on CM1 & 3.
cam0_reg_gpio Set GPIO for CAM 0 regulator.
Default 31 on CM1, 3, and 4S.
Default of GPIO expander 5 on CM4, but override
switches to normal GPIO.
cam1_reg Enables CAM 1 regulator.
Only required on CM1 & 3.
cam1_reg_gpio Set GPIO for CAM 1 regulator.
Default 3 on CM1, 3, and 4S.
Default of GPIO expander 5 on CM4, but override
switches to normal GPIO.
cooling_fan Enables the Pi 5 cooling fan (enabled
automatically by the firmware)
eee Enable Energy Efficient Ethernet support for
compatible devices (default "on"). See also
"tx_lpi_timer". Pi3B+ only.
eth_downshift_after Set the number of auto-negotiation failures
after which the 1000Mbps modes are disabled.
Legal values are 2, 3, 4, 5 and 0, where
0 means never downshift (default 2). Pi3B+ only.
eth_led0 Set mode of LED0 - amber on Pi3B+ (default "1"),
green on Pi4 (default "0").
The legal values are:
Pi3B+
0=link/activity 1=link1000/activity
2=link100/activity 3=link10/activity
4=link100/1000/activity 5=link10/1000/activity
6=link10/100/activity 14=off 15=on
Pi4
0=Speed/Activity 1=Speed
2=Flash activity 3=FDX
4=Off 5=On
6=Alt 7=Speed/Flash
8=Link 9=Activity
eth_led1 Set mode of LED1 - green on Pi3B+ (default "6"),
amber on Pi4 (default "8"). See eth_led0 for
legal values.
eth_max_speed Set the maximum speed a link is allowed
to negotiate. Legal values are 10, 100 and
1000 (default 1000). Pi3B+ only.
hdmi Set to "off" to disable the HDMI interface
(default "on")
i2c An alias for i2c_arm
i2c_arm Set to "on" to enable the ARM's i2c interface
(default "off")
i2c_arm_baudrate Set the baudrate of the ARM's i2c interface
(default "100000")
i2c_baudrate An alias for i2c_arm_baudrate
i2c_csi_dsi Set to "on" to enable the i2c_csi_dsi interface
i2c_csi_dsi0 Set to "on" to enable the i2c_csi_dsi0 interface
i2c_csi_dsi1 Set to "on" to enable the i2c_csi_dsi1 interface
i2c_vc Set to "on" to enable the i2c interface
usually reserved for the VideoCore processor
(default "off")
i2c_vc_baudrate Set the baudrate of the VideoCore i2c interface
(default "100000")
i2s Set to "on" to enable the i2s interface
(default "off")
i2s_dma4 Use to enable 40-bit DMA on the i2s interface
(the assigned value doesn't matter)
(2711 only)
krnbt Set to "off" to disable autoprobing of Bluetooth
driver without need of hciattach/btattach
(default "on")
krnbt_baudrate Set the baudrate of the PL011 UART when used
with krnbt=on
nvme Alias for "pciex1" (2712 only)
pcie Set to "off" to disable the PCIe interface
(default "on")
(2711 only, but not applicable on CM4S)
N.B. USB-A ports on 4B are subsequently disabled
pciex1 Set to "on" to enable the external PCIe link
(2712 only, default "off")
pciex1_gen Sets the PCIe "GEN"/speed for the external PCIe
link (2712 only, default "2")
pciex1_no_l0s Set to "on" to disable ASPM L0s on the external
PCIe link for devices that have broken
implementations (2712 only, default "off")
spi Set to "on" to enable the spi interfaces
(default "off")
spi_dma4 Use to enable 40-bit DMA on spi interfaces
(the assigned value doesn't matter)
(2711 only)
random Set to "on" to enable the hardware random
number generator (default "on")
rtc_bbat_vchg Set the RTC backup battery charging voltage in
microvolts. If set to 0 or not specified, the
trickle charger is disabled.
(2712 only, default "0")
sd Set to "off" to disable the SD card (or eMMC on
non-lite SKU of CM4).
(default "on")
sd_overclock Clock (in MHz) to use when the MMC framework
requests 50MHz
sd_poll_once Looks for a card once after booting. Useful
for network booting scenarios to avoid the
overhead of continuous polling. N.B. Using
this option restricts the system to using a
single card per boot (or none at all).
(default off)
sd_force_pio Disable DMA support for SD driver (default off)
sd_pio_limit Number of blocks above which to use DMA for
SD card (default 1)
sd_debug Enable debug output from SD driver (default off)
sdio_overclock Clock (in MHz) to use when the MMC framework
requests 50MHz for the SDIO/WLAN interface.
suspend Make the power button trigger a suspend rather
than a power-off (2712 only, default "off")
tx_lpi_timer Set the delay in microseconds between going idle
and entering the low power state (default 600).
Requires EEE to be enabled - see "eee".
uart0 Set to "off" to disable uart0 (default "on")
uart0_console Move the kernel boot console to UART0 on pins
6, 8 and 10 of the 40-way header (2712 only,
default "off")
uart1 Set to "on" or "off" to enable or disable uart1
(default varies)
watchdog Set to "on" to enable the hardware watchdog
(default "off")
wifiaddr Set an alternative WiFi MAC address.
The value should be a 6-byte hexadecimal value,
with or without colon separators, written in the
natural (big-endian) order.
act_led_trigger Choose which activity the LED tracks.
Use "heartbeat" for a nice load indicator.
(default "mmc")
act_led_activelow Set to "on" to invert the sense of the LED
(default "off")
N.B. For Pi 3B, 3B+, 3A+ and 4B, use the act-led
overlay.
act_led_gpio Set which GPIO to use for the activity LED
(in case you want to connect it to an external
device)
(default "16" on a non-Plus board, "47" on a
Plus or Pi 2)
N.B. For Pi 3B, 3B+, 3A+ and 4B, use the act-led
overlay.
pwr_led_trigger
pwr_led_activelow
pwr_led_gpio
As for act_led_*, but using the PWR LED.
Not available on Model A/B boards.
N.B. It is recommended to only enable those interfaces that are needed.
Leaving all interfaces enabled can lead to unwanted behaviour (i2c_vc
interfering with Pi Camera, I2S and SPI hogging GPIO pins, etc.)
Note also that i2c, i2c_arm and i2c_vc are aliases for the physical
interfaces i2c0 and i2c1. Use of the numeric variants is still possible
but deprecated because the ARM/VC assignments differ between board
revisions. The same board-specific mapping applies to i2c_baudrate,
and the other i2c baudrate parameters.
Name: act-led Info: Pi 3B, 3B+, 3A+ and 4B use a GPIO expander to drive the LEDs which can only be accessed from the VPU. There is a special driver for this with a separate DT node, which has the unfortunate consequence of breaking the act_led_gpio and act_led_activelow dtparams. This overlay changes the GPIO controller back to the standard one and restores the dtparams. Load: dtoverlay=act-led,= Params: activelow Set to "on" to invert the sense of the LED (default "off")
gpio Set which GPIO to use for the activity LED
(in case you want to connect it to an external
device)
REQUIRED
Name: adafruit-st7735r Info: Overlay for the SPI-connected Adafruit 1.8" 160x128 or 128x128 displays, based on the ST7735R chip. This overlay uses the newer DRM/KMS "Tiny" driver. Load: dtoverlay=adafruit-st7735r,= Params: 128x128 Select the 128x128 driver (default 160x128) rotate Display rotation {0,90,180,270} (default 90) speed SPI bus speed in Hz (default 4000000) dc_pin GPIO pin for D/C (default 24) reset_pin GPIO pin for RESET (default 25) led_pin GPIO used to control backlight (default 18)
Name: adafruit18 Info: Overlay for the SPI-connected Adafruit 1.8" display (based on the ST7735R chip). It includes support for the "green tab" version. This overlay uses the older fbtft driver. Load: dtoverlay=adafruit18,= Params: green Use the adafruit18_green variant. rotate Display rotation {0,90,180,270} speed SPI bus speed in Hz (default 4000000) fps Display frame rate in Hz bgr Enable BGR mode (default off) debug Debug output level {0-7} dc_pin GPIO pin for D/C (default 24) reset_pin GPIO pin for RESET (default 25) led_pin GPIO used to control backlight (default 18)
Name: adau1977-adc
Info: Overlay for activation of ADAU1977 ADC codec over I2C for control
and I2S for data.
Load: dtoverlay=adau1977-adc
Params:
Name: adau7002-simple Info: Overlay for the activation of ADAU7002 stereo PDM to I2S converter. Load: dtoverlay=adau7002-simple,= Params: card-name Override the default, "adau7002", card name.
Name: ads1015 Info: Overlay for activation of Texas Instruments ADS1015 ADC over I2C Load: dtoverlay=ads1015,= Params: addr I2C bus address of device. Set based on how the addr pin is wired. (default=0x48 assumes addr is pulled to GND) cha_enable Enable virtual channel a. (default=true) cha_cfg Set the configuration for virtual channel a. (default=4 configures this channel for the voltage at A0 with respect to GND) cha_datarate Set the datarate (samples/sec) for this channel. (default=4 sets 1600 sps) cha_gain Set the gain of the Programmable Gain Amplifier for this channel. (default=2 sets the full scale of the channel to 2.048 Volts)
Channel (ch) parameters can be set for each enabled channel.
A maximum of 4 channels can be enabled (letters a thru d).
For more information refer to the device datasheet at:
http://www.ti.com/lit/ds/symlink/ads1015.pdf
Name: ads1115 Info: Texas Instruments ADS1115 ADC Load: dtoverlay=ads1115,[=] Params: addr I2C bus address of device. Set based on how the addr pin is wired. (default=0x48 assumes addr is pulled to GND) cha_enable Enable virtual channel a. cha_cfg Set the configuration for virtual channel a. (default=4 configures this channel for the voltage at A0 with respect to GND) cha_datarate Set the datarate (samples/sec) for this channel. (default=7 sets 860 sps) cha_gain Set the gain of the Programmable Gain Amplifier for this channel. (Default 1 sets the full scale of the channel to 4.096 Volts)
Channel parameters can be set for each enabled channel.
A maximum of 4 channels can be enabled (letters a thru d).
For more information refer to the device datasheet at:
http://www.ti.com/lit/ds/symlink/ads1115.pdf
Name: ads7846 Info: ADS7846 Touch controller Load: dtoverlay=ads7846,= Params: cs SPI bus Chip Select (default 1) speed SPI bus speed (default 2MHz, max 3.25MHz) penirq GPIO used for PENIRQ. REQUIRED penirq_pull Set GPIO pull (default 0=none, 2=pullup) swapxy Swap x and y axis xmin Minimum value on the X axis (default 0) ymin Minimum value on the Y axis (default 0) xmax Maximum value on the X axis (default 4095) ymax Maximum value on the Y axis (default 4095) pmin Minimum reported pressure value (default 0) pmax Maximum reported pressure value (default 65535) xohms Touchpanel sensitivity (X-plate resistance) (default 400)
penirq is required and usually xohms (60-100) has to be set as well.
Apart from that, pmax (255) and swapxy are also common.
The rest of the calibration can be done with xinput-calibrator.
See: github.com/notro/fbtft/wiki/FBTFT-on-Raspian
Device Tree binding document:
www.kernel.org/doc/Documentation/devicetree/bindings/input/ads7846.txt
Name: adv7282m Info: Analog Devices ADV7282M analogue video to CSI2 bridge. Uses Unicam1, which is the standard camera connector on most Pi variants. Load: dtoverlay=adv7282m,= Params: addr Overrides the I2C address (default 0x21) media-controller Configure use of Media Controller API for configuring the sensor (default off)
Name: adv728x-m Info: Analog Devices ADV728[0|1|2]-M analogue video to CSI2 bridges. This is a wrapper for adv7282m, and defaults to ADV7282M. Load: dtoverlay=adv728x-m,= Params: addr Overrides the I2C address (default 0x21) adv7280m Select ADV7280-M. adv7281m Select ADV7281-M. adv7281ma Select ADV7281-MA. media-controller Configure use of Media Controller API for configuring the sensor (default off)
Name: akkordion-iqdacplus Info: Configures the Digital Dreamtime Akkordion Music Player (based on the OEM IQAudIO DAC+ or DAC Zero module). Load: dtoverlay=akkordion-iqdacplus,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with dtoverlay=akkordion-iqdacplus,24db_digital_gain (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24db_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!)
Name: allo-boss-dac-pcm512x-audio Info: Configures the Allo Boss DAC audio cards. Load: dtoverlay=allo-boss-dac-pcm512x-audio, Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with "dtoverlay=allo-boss-dac-pcm512x-audio, 24db_digital_gain" (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24db_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!) slave Force Boss DAC into slave mode, using Pi a master for bit clock and frame clock. Enable with "dtoverlay=allo-boss-dac-pcm512x-audio, slave"
Name: allo-boss2-dac-audio
Info: Configures the Allo Boss2 DAC audio card
Load: dtoverlay=allo-boss2-dac-audio
Params:
Name: allo-digione
Info: Configures the Allo Digione audio card
Load: dtoverlay=allo-digione
Params:
Name: allo-katana-dac-audio
Info: Configures the Allo Katana DAC audio card
Load: dtoverlay=allo-katana-dac-audio
Params:
Name: allo-piano-dac-pcm512x-audio Info: Configures the Allo Piano DAC (2.0/2.1) audio cards. (NB. This initial support is for 2.0 channel audio ONLY! ie. stereo. The subwoofer outputs on the Piano 2.1 are not currently supported!) Load: dtoverlay=allo-piano-dac-pcm512x-audio, Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24db_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!)
Name: allo-piano-dac-plus-pcm512x-audio Info: Configures the Allo Piano DAC (2.1) audio cards. Load: dtoverlay=allo-piano-dac-plus-pcm512x-audio, Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24db_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!) glb_mclk This option is only with Kali board. If enabled, MCLK for Kali is used and PLL is disabled for better voice quality. (default Off)
Name: anyspi Info: Universal device tree overlay for SPI devices
Just specify the SPI address and device name ("compatible" property).
This overlay lacks any device-specific parameter support!
For devices on spi1 or spi2, the interfaces should be enabled
with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
Examples:
1. SPI NOR flash on spi0.1, maximum SPI clock frequency 45MHz:
dtoverlay=anyspi:spi0-1,dev="jedec,spi-nor",speed=45000000
2. MCP3204 ADC on spi1.2, maximum SPI clock frequency 500kHz:
dtoverlay=anyspi:spi1-2,dev="microchip,mcp3204" Load: dtoverlay=anyspi,<param>=<val> Params: spi<n>-<m> Configure device at spi<n>, cs<m>
(boolean, required)
dev Set device name to search compatible module
(string, required)
speed Set SPI clock frequency in Hz
(integer, optional, default 500000)
Name: apds9960 Info: Configures the AVAGO APDS9960 digital proximity, ambient light, RGB and gesture sensor Load: dtoverlay=apds9960,= Params: gpiopin GPIO used for INT (default 4) noints Disable the interrupt GPIO line.
Name: applepi-dac
Info: Configures the Orchard Audio ApplePi-DAC audio card
Load: dtoverlay=applepi-dac
Params:
Name: arducam-64mp Info: Arducam 64MP camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=arducam-64mp,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 0) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg). vcm Select lens driver state. Default is enabled, but vcm=off will disable.
Name: arducam-pivariety Info: Arducam Pivariety camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=arducam-pivariety,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 0) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: at86rf233 Info: Configures the Atmel AT86RF233 802.15.4 low-power WPAN transceiver, connected to spi0.0 Load: dtoverlay=at86rf233,= Params: interrupt GPIO used for INT (default 23) reset GPIO used for Reset (default 24) sleep GPIO used for Sleep (default 25) speed SPI bus speed in Hz (default 3000000) trim Fine tuning of the internal capacitance arrays (0=+0pF, 15=+4.5pF, default 15)
Name: audioinjector-addons Info: Configures the audioinjector.net audio add on soundcards Load: dtoverlay=audioinjector-addons,= Params: non-stop-clocks Keeps the clocks running even when the stream is paused or stopped (default off)
Name: audioinjector-bare-i2s
Info: Configures the audioinjector.net audio bare i2s soundcard
Load: dtoverlay=audioinjector-bare-i2s
Params:
Name: audioinjector-isolated-soundcard
Info: Configures the audioinjector.net isolated soundcard
Load: dtoverlay=audioinjector-isolated-soundcard
Params:
Name: audioinjector-ultra
Info: Configures the audioinjector.net ultra soundcard
Load: dtoverlay=audioinjector-ultra
Params:
Name: audioinjector-wm8731-audio
Info: Configures the audioinjector.net audio add on soundcard
Load: dtoverlay=audioinjector-wm8731-audio
Params:
Name: audiosense-pi
Info: Configures the audiosense-pi add on soundcard
For more information refer to
https://gitlab.com/kakar0t/audiosense-pi
Load: dtoverlay=audiosense-pi
Params:
Name: audremap Info: Switches PWM sound output to GPIOs on the 40-pin header Load: dtoverlay=audremap,= Params: swap_lr Reverse the channel allocation, which will also swap the audio jack outputs (default off) enable_jack Don't switch off the audio jack output. Does nothing on BCM2711 (default off) pins_12_13 Select GPIOs 12 & 13 (default) pins_18_19 Select GPIOs 18 & 19 pins_40_41 Select GPIOs 40 & 41 (not available on CM4, used for other purposes) pins_40_45 Select GPIOs 40 & 45 (don't use on BCM2711 - the pins are on different controllers)
Name: balena-fin
Info: Overlay that enables WLAN, Bluetooth and the GPIO expander on the
balenaFin carrier board for the Raspberry Pi Compute Module 3/3+ Lite.
Load: dtoverlay=balena-fin
Params:
Name: bmp085_i2c-sensor Info: This overlay is now deprecated - see i2c-sensor Load:
Name: camera-mux-2port Info: Configures a 2 port camera multiplexer Note that currently ALL IMX290 modules share a common clock, therefore all modules will need to have the same clock frequency. Load: dtoverlay=camera-mux-2port,= Params: cam0-arducam-64mp Select Arducam64MP for camera on port 0 cam0-imx219 Select IMX219 for camera on port 0 cam0-imx258 Select IMX258 for camera on port 0 cam0-imx290 Select IMX290 for camera on port 0 cam0-imx477 Select IMX477 for camera on port 0 cam0-imx519 Select IMX519 for camera on port 0 cam0-imx708 Select IMX708 for camera on port 0 cam0-ov2311 Select OV2311 for camera on port 0 cam0-ov5647 Select OV5647 for camera on port 0 cam0-ov7251 Select OV7251 for camera on port 0 cam0-ov9281 Select OV9281 for camera on port 0 cam0-imx290-clk-freq Set clock frequency for an IMX290 on port 0 cam1-arducam-64mp Select Arducam64MP for camera on port 1 cam1-imx219 Select IMX219 for camera on port 1 cam1-imx258 Select IMX258 for camera on port 1 cam1-imx290 Select IMX290 for camera on port 1 cam1-imx477 Select IMX477 for camera on port 1 cam1-imx519 Select IMX519 for camera on port 1 cam1-imx708 Select IMX708 for camera on port 1 cam1-ov2311 Select OV2311 for camera on port 1 cam1-ov5647 Select OV5647 for camera on port 1 cam1-ov7251 Select OV7251 for camera on port 1 cam1-ov9281 Select OV9281 for camera on port 1 cam1-imx290-clk-freq Set clock frequency for an IMX290 on port 1
Name: camera-mux-4port Info: Configures a 4 port camera multiplexer Note that currently ALL IMX290 modules share a common clock, therefore all modules will need to have the same clock frequency. Load: dtoverlay=camera-mux-4port,= Params: cam0-arducam-64mp Select Arducam64MP for camera on port 0 cam0-imx219 Select IMX219 for camera on port 0 cam0-imx258 Select IMX258 for camera on port 0 cam0-imx290 Select IMX290 for camera on port 0 cam0-imx477 Select IMX477 for camera on port 0 cam0-imx519 Select IMX519 for camera on port 0 cam0-imx708 Select IMX708 for camera on port 0 cam0-ov2311 Select OV2311 for camera on port 0 cam0-ov5647 Select OV5647 for camera on port 0 cam0-ov7251 Select OV7251 for camera on port 0 cam0-ov9281 Select OV9281 for camera on port 0 cam0-imx290-clk-freq Set clock frequency for an IMX290 on port 0 cam1-arducam-64mp Select Arducam64MP for camera on port 1 cam1-imx219 Select IMX219 for camera on port 1 cam1-imx258 Select IMX258 for camera on port 1 cam1-imx290 Select IMX290 for camera on port 1 cam1-imx477 Select IMX477 for camera on port 1 cam1-imx519 Select IMX519 for camera on port 1 cam1-imx708 Select IMX708 for camera on port 1 cam1-ov2311 Select OV2311 for camera on port 1 cam1-ov5647 Select OV5647 for camera on port 1 cam1-ov7251 Select OV7251 for camera on port 1 cam1-ov9281 Select OV9281 for camera on port 1 cam1-imx290-clk-freq Set clock frequency for an IMX290 on port 1 cam2-arducam-64mp Select Arducam64MP for camera on port 2 cam2-imx219 Select IMX219 for camera on port 2 cam2-imx258 Select IMX258 for camera on port 2 cam2-imx290 Select IMX290 for camera on port 2 cam2-imx477 Select IMX477 for camera on port 2 cam2-imx519 Select IMX519 for camera on port 2 cam2-imx708 Select IMX708 for camera on port 2 cam2-ov2311 Select OV2311 for camera on port 2 cam2-ov5647 Select OV5647 for camera on port 2 cam2-ov7251 Select OV7251 for camera on port 2 cam2-ov9281 Select OV9281 for camera on port 2 cam2-imx290-clk-freq Set clock frequency for an IMX290 on port 2 cam3-arducam-64mp Select Arducam64MP for camera on port 3 cam3-imx219 Select IMX219 for camera on port 3 cam3-imx258 Select IMX258 for camera on port 3 cam3-imx290 Select IMX290 for camera on port 3 cam3-imx477 Select IMX477 for camera on port 3 cam3-imx519 Select IMX519 for camera on port 3 cam3-imx708 Select IMX708 for camera on port 3 cam3-ov2311 Select OV2311 for camera on port 3 cam3-ov5647 Select OV5647 for camera on port 3 cam3-ov7251 Select OV7251 for camera on port 3 cam3-ov9281 Select OV9281 for camera on port 3 cam3-imx290-clk-freq Set clock frequency for an IMX290 on port 3
Name: cap1106 Info: Enables the ability to use the cap1106 touch sensor as a keyboard Load: dtoverlay=cap1106,= Params: int_pin GPIO pin for interrupt signal (default 23)
Name: chipdip-dac
Info: Configures Chip Dip audio cards.
Load: dtoverlay=chipdip-dac
Params:
Name: cirrus-wm5102
Info: Configures the Cirrus Logic Audio Card
Load: dtoverlay=cirrus-wm5102
Params:
Name: cm-swap-i2c0 Info: Largely for Compute Modules 1&3 where the original instructions for adding a camera used GPIOs 0&1 for CAM1 and 28&29 for CAM0, whilst all other platforms use 28&29 (or 44&45) for CAM1. The default assignment through using this overlay is for i2c0 to use 28&29, and i2c10 (aka i2c_csi_dsi) to use 28&29, but the overrides allow this to be changed. Load: dtoverlay=cm-swap-i2c0,= Params: i2c0-gpio0 Use GPIOs 0&1 for i2c0 i2c0-gpio28 Use GPIOs 28&29 for i2c0 (default) i2c0-gpio44 Use GPIOs 44&45 for i2c0 i2c10-gpio0 Use GPIOs 0&1 for i2c0 (default) i2c10-gpio28 Use GPIOs 28&29 for i2c0 i2c10-gpio44 Use GPIOs 44&45 for i2c0
Name: cma Info: Set custom CMA sizes, only use if you know what you are doing, might clash with other overlays like vc4-fkms-v3d and vc4-kms-v3d. Load: dtoverlay=cma,= Params: cma-512 CMA is 512MB (needs 1GB) cma-448 CMA is 448MB (needs 1GB) cma-384 CMA is 384MB (needs 1GB) cma-320 CMA is 320MB (needs 1GB) cma-256 CMA is 256MB (needs 1GB) cma-192 CMA is 192MB (needs 1GB) cma-128 CMA is 128MB cma-96 CMA is 96MB cma-64 CMA is 64MB cma-size CMA size in bytes, 4MB aligned cma-default Use upstream's default value
Name: crystalfontz-cfa050_pi_m Info: Configures the Crystalfontz CFA050-PI-M series of Raspberry Pi CM4 based modules using the CFA7201280A0_050Tx 7" TFT LCD displays, with or without capacitive touch screen. Requires use of vc4-kms-v3d. Load: dtoverlay=crystalfontz-cfa050_pi_m,= Params: captouch Enable capacitive touch display
Name: cutiepi-panel
Info: 8" TFT LCD display and touch panel used by cutiepi.io
Load: dtoverlay=cutiepi-panel
Params:
Name: dacberry400
Info: Configures the dacberry400 add on soundcard
Load: dtoverlay=dacberry400
Params:
Name: dht11 Info: Overlay for the DHT11/DHT21/DHT22 humidity/temperature sensors Also sometimes found with the part number(s) AM230x. Load: dtoverlay=dht11,= Params: gpiopin GPIO connected to the sensor's DATA output. (default 4)
Name: dionaudio-kiwi
Info: Configures the Dion Audio KIWI STREAMER
Load: dtoverlay=dionaudio-kiwi
Params:
Name: dionaudio-loco
Info: Configures the Dion Audio LOCO DAC-AMP
Load: dtoverlay=dionaudio-loco
Params:
Name: dionaudio-loco-v2 Info: Configures the Dion Audio LOCO-V2 DAC-AMP Load: dtoverlay=dionaudio-loco-v2,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with "dtoverlay=hifiberry-dacplus,24db_digital_gain" (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24dB_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!)
Name: disable-bt
Info: Disable onboard Bluetooth on Bluetooth-capable Raspberry Pis. On Pis
prior to Pi 5 this restores UART0/ttyAMA0 over GPIOs 14 & 15.
Load: dtoverlay=disable-bt
Params:
Name: disable-bt-pi5 Info: See disable-bt
Name: disable-emmc2
Info: Disable EMMC2 controller on BCM2711.
The allows the onboard EMMC storage on Compute Module 4 to be disabled
e.g. if a fault has occurred.
Load: dtoverlay=disable-emmc2
Params:
Name: disable-wifi
Info: Disable onboard WLAN on WiFi-capable Raspberry Pis.
Load: dtoverlay=disable-wifi
Params:
Name: disable-wifi-pi5 Info: See disable-wifi
Name: dpi18
Info: Overlay for a generic 18-bit DPI display
This uses GPIOs 0-21 (so no I2C, uart etc.), and activates the output
2-3 seconds after the kernel has started.
Load: dtoverlay=dpi18
Params:
Name: dpi18cpadhi
Info: Overlay for a generic 18-bit DPI display (in 'mode 6' connection scheme)
This uses GPIOs 0-9,12-17,20-25 (so no I2C, uart etc.), and activates
the output 3-3 seconds after the kernel has started.
Load: dtoverlay=dpi18cpadhi
Params:
Name: dpi24
Info: Overlay for a generic 24-bit DPI display
This uses GPIOs 0-27 (so no I2C, uart etc.), and activates the output
2-3 seconds after the kernel has started.
Load: dtoverlay=dpi24
Params:
Name: draws Info: Configures the NW Digital Radio DRAWS Hat
The board includes an ADC to measure various board values and also
provides two analog user inputs on the expansion header. The ADC
can be configured for various sample rates and gain values to adjust
the input range. Tables describing the two parameters follow.
ADC Gain Values:
0 = +/- 6.144V
1 = +/- 4.096V
2 = +/- 2.048V
3 = +/- 1.024V
4 = +/- 0.512V
5 = +/- 0.256V
6 = +/- 0.256V
7 = +/- 0.256V
ADC Datarate Values:
0 = 128sps
1 = 250sps
2 = 490sps
3 = 920sps
4 = 1600sps (default)
5 = 2400sps
6 = 3300sps
7 = 3300sps Load: dtoverlay=draws,<param>=<val> Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
input voltage sensor (default 1)
draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
sensor
draws_adc_ch5_gain Sets the full scale resolution of the ADCs
5V rail voltage sensor (default 1)
draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
sensor
draws_adc_ch6_gain Sets the full scale resolution of the ADCs
AIN2 input (default 2)
draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
draws_adc_ch7_gain Sets the full scale resolution of the ADCs
AIN3 input (default 2)
draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
alsaname Name of the ALSA audio device (default "draws")
Name: dwc-otg
Info: Selects the dwc_otg USB controller driver which has fiq support. This
is the default on all except the Pi Zero which defaults to dwc2.
Load: dtoverlay=dwc-otg
Params:
Name: dwc2 Info: Selects the dwc2 USB controller driver Load: dtoverlay=dwc2,= Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
g-rx-fifo-size Size of rx fifo size in gadget mode
g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
mode
[ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
Name: edt-ft5406 Info: Overlay for the EDT FT5406 touchscreen. This works with the Raspberry Pi 7" touchscreen when not being polled by the firmware. By default the overlay uses the i2c_csi_dsi I2C interface, but this can be overridden You MUST use either "disable_touchscreen=1" or "ignore_lcd=1" in config.txt to stop the firmware polling the touchscreen. Load: dtoverlay=edt-ft5406,= Params: sizex Touchscreen size x (default 800) sizey Touchscreen size y (default 480) invx Touchscreen inverted x axis invy Touchscreen inverted y axis swapxy Touchscreen swapped x y axis i2c0 Choose the I2C0 bus on GPIOs 0&1 i2c1 Choose the I2C1 bus on GPIOs 2&3 i2c3 Choose the I2C3 bus (configure with the i2c3 overlay - BCM2711 only) i2c4 Choose the I2C4 bus (configure with the i2c4 overlay - BCM2711 only) i2c5 Choose the I2C5 bus (configure with the i2c5 overlay - BCM2711 only) i2c6 Choose the I2C6 bus (configure with the i2c6 overlay - BCM2711 only) addr Sets the address for the touch controller. Note that the device must be configured to use the specified address.
Name: enc28j60 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0 Load: dtoverlay=enc28j60,= Params: int_pin GPIO used for INT (default 25)
speed SPI bus speed (default 12000000)
Name: enc28j60-spi2 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2 Load: dtoverlay=enc28j60-spi2,= Params: int_pin GPIO used for INT (default 39)
speed SPI bus speed (default 12000000)
Name: exc3000 Info: Enables I2C connected EETI EXC3000 multiple touch controller using GPIO 4 (pin 7 on GPIO header) for interrupt. Load: dtoverlay=exc3000,= Params: interrupt GPIO used for interrupt (default 4) sizex Touchscreen size x (default 4096) sizey Touchscreen size y (default 4096) invx Touchscreen inverted x axis invy Touchscreen inverted y axis swapxy Touchscreen swapped x y axis
Name: fbtft Info: Overlay for SPI-connected displays using the fbtft drivers.
This overlay seeks to replace the functionality provided by fbtft_device
which is now gone from the kernel.
Most displays from fbtft_device have been ported over.
Example:
dtoverlay=fbtft,spi0-0,rpi-display,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
It is also possible to specify the controller (this will use the default
init sequence in the driver).
Example:
dtoverlay=fbtft,spi0-0,ili9341,bgr,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
For devices on spi1 or spi2, the interfaces should be enabled
with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
The following features of fbtft_device have not been ported over:
- parallel bus is not supported
- the init property which overrides the controller initialization
sequence is not supported as a parameter due to memory limitations in
the bootloader responsible for applying the overlay.
See https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays for how to
create an overlay.
Load: dtoverlay=fbtft,= Params: spi- Configure device at spi, cs (boolean, required) speed SPI bus speed in Hz (default 32000000) cpha Shifted clock phase (CPHA) mode cpol Inverse clock polarity (CPOL) mode
adafruit18 Adafruit 1.8
adafruit22 Adafruit 2.2 (old)
adafruit22a Adafruit 2.2
adafruit28 Adafruit 2.8
adafruit13m Adafruit 1.3 OLED
admatec_c-berry28 C-Berry28
dogs102 EA DOGS102
er_tftm050_2 ER-TFTM070-2
er_tftm070_5 ER-TFTM070-5
ew24ha0 EW24HA0
ew24ha0_9bit EW24HA0 in 9-bit mode
freetronicsoled128 Freetronics OLED128
hy28a HY28A
hy28b HY28B
itdb28_spi ITDB02-2.8 with SPI interface circuit
mi0283qt-2 Watterott MI0283QT-2
mi0283qt-9a Watterott MI0283QT-9A
nokia3310 Nokia 3310
nokia3310a Nokia 3310a
nokia5110 Nokia 5110
piscreen PiScreen
pitft Adafruit PiTFT 2.8
pioled ILSoft OLED
rpi-display Watterott rpi-display
sainsmart18 Sainsmart 1.8
sainsmart32_spi Sainsmart 3.2 with SPI interfce circuit
tinylcd35 TinyLCD 3.5
tm022hdh26 Tianma TM022HDH26
tontec35_9481 Tontect 3.5 with ILI9481 controller
tontec35_9486 Tontect 3.5 with ILI9486 controller
waveshare32b Waveshare 3.2
waveshare22 Waveshare 2.2
bd663474 BD663474 display controller
hx8340bn HX8340BN display controller
hx8347d HX8347D display controller
hx8353d HX8353D display controller
hx8357d HX8357D display controller
ili9163 ILI9163 display controller
ili9320 ILI9320 display controller
ili9325 ILI9325 display controller
ili9340 ILI9340 display controller
ili9341 ILI9341 display controller
ili9481 ILI9481 display controller
ili9486 ILI9486 display controller
pcd8544 PCD8544 display controller
ra8875 RA8875 display controller
s6d02a1 S6D02A1 display controller
s6d1121 S6D1121 display controller
seps525 SEPS525 display controller
sh1106 SH1106 display controller
ssd1289 SSD1289 display controller
ssd1305 SSD1305 display controller
ssd1306 SSD1306 display controller
ssd1325 SSD1325 display controller
ssd1331 SSD1331 display controller
ssd1351 SSD1351 display controller
st7735r ST7735R display controller
st7789v ST7789V display controller
tls8204 TLS8204 display controller
uc1611 UC1611 display controller
uc1701 UC1701 display controller
upd161704 UPD161704 display controller
width Display width in pixels
height Display height in pixels
regwidth Display controller register width (default is
driver specific)
buswidth Display bus interface width (default 8)
debug Debug output level {0-7}
rotate Display rotation {0, 90, 180, 270} (counter
clockwise). Not supported by all drivers.
bgr Enable BGR mode (default off). Use if Red and
Blue are swapped. Not supported by all drivers.
fps Frames per second (default 30). In effect this
states how long the driver will wait after video
memory has been changed until display update
transfer is started.
txbuflen Length of the FBTFT transmit buffer
(default 4096)
startbyte Sets the Start byte used by fb_ili9320,
fb_ili9325 and fb_hx8347d. Common value is 0x70.
gamma String representation of Gamma Curve(s). Driver
specific. Not supported by all drivers.
reset_pin GPIO pin for RESET
dc_pin GPIO pin for D/C
led_pin GPIO pin for LED backlight
Name: fe-pi-audio
Info: Configures the Fe-Pi Audio Sound Card
Load: dtoverlay=fe-pi-audio
Params:
Name: fsm-demo Info: A demonstration of the gpio-fsm driver. The GPIOs are chosen to work nicely with a "traffic-light" display of red, amber and green LEDs on GPIOs 7, 8 and 25 respectively. Load: dtoverlay=fsm-demo,= Params: fsm_debug Enable debug logging (default off)
Name: gc9a01 Info: Enables GalaxyCore's GC9A01 single chip driver based displays on SPI0 as fb1, using GPIOs DC=25, RST=27 and BL=18 (physical GPIO header pins 22, 13 and 12 respectively) in addition to the SPI0 pins DIN=10, CLK=11 and CS=8 (physical GPIO header pins 19, 23 and 24 respectively). Load: dtoverlay=gc9a01,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
width Width of the display
height Height of the display
fps Delay between frame updates
debug Debug output level {0-7}
Name: ghost-amp Info: An overlay for the Ghost amplifier. Load: dtoverlay=ghost-amp,= Params: fsm_debug Enable debug logging of the GPIO FSM (default off)
Name: goodix Info: Enables I2C connected Goodix gt9271 multiple touch controller using GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset. Load: dtoverlay=goodix,= Params: interrupt GPIO used for interrupt (default 4) reset GPIO used for reset (default 17)
Name: googlevoicehat-soundcard
Info: Configures the Google voiceHAT soundcard
Load: dtoverlay=googlevoicehat-soundcard
Params:
Name: gpio-charger Info: This is a generic overlay for detecting charger with GPIO. Load: dtoverlay=gpio-charger,= Params: gpio GPIO pin to trigger on (default 4) active_low When this is 1 (active low), a falling edge generates a charging event and a rising edge generates a discharging event. When this is 0 (active high), this is reversed. The default is 0 (active high) gpio_pull Desired pull-up/down state (off, down, up) Default is "down". type Set a charger type for the pin. (Default: mains)
Name: gpio-fan Info: Configure a GPIO pin to control a cooling fan. Load: dtoverlay=gpio-fan,= Params: gpiopin GPIO used to control the fan (default 12) temp Temperature at which the fan switches on, in millicelcius (default 55000) hyst Temperature delta (in millicelcius) below temp at which the fan will drop to minrpm (default 10000)
Name: gpio-hog Info: Activate a "hog" for a GPIO - request that the kernel configures it as an output, driven low or high as indicated by the presence or absence of the active_low parameter. Note that a hogged GPIO is not available to other drivers or for gpioset/gpioget. Load: dtoverlay=gpio-hog,= Params: gpio GPIO pin to hog (default 26) active_low If set, the hog drives the GPIO low (defaults to off - the GPIO is driven high)
Name: gpio-ir Info: Use GPIO pin as rc-core style infrared receiver input. The rc-core- based gpio_ir_recv driver maps received keys directly to a /dev/input/event* device, all decoding is done by the kernel - LIRC is not required! The key mapping and other decoding parameters can be configured by "ir-keytable" tool. Load: dtoverlay=gpio-ir,= Params: gpio_pin Input pin number. Default is 18.
gpio_pull Desired pull-up/down state (off, down, up)
Default is "up".
invert "1" = invert the input (active-low signalling).
"0" = non-inverted input (active-high
signalling). Default is "1".
rc-map-name Default rc keymap (can also be changed by
ir-keytable), defaults to "rc-rc6-mce"
Name: gpio-ir-tx Info: Use GPIO pin as bit-banged infrared transmitter output. This is an alternative to "pwm-ir-tx". gpio-ir-tx doesn't require a PWM so it can be used together with onboard analog audio. Load: dtoverlay=gpio-ir-tx,= Params: gpio_pin Output GPIO (default 18)
invert "1" = invert the output (make it active-low).
Default is "0" (active-high).
Name: gpio-key Info: This is a generic overlay for activating GPIO keypresses using the gpio-keys library and this dtoverlay. Multiple keys can be set up using multiple calls to the overlay for configuring additional buttons or joysticks. You can see available keycodes at https://github.com/torvalds/linux/blob/v4.12/include/uapi/ linux/input-event-codes.h#L64 Load: dtoverlay=gpio-key,= Params: gpio GPIO pin to trigger on (default 3) active_low When this is 1 (active low), a falling edge generates a key down event and a rising edge generates a key up event. When this is 0 (active high), this is reversed. The default is 1 (active low) gpio_pull Desired pull-up/down state (off, down, up) Default is "up". Note that the default pin (GPIO3) has an external pullup label Set a label for the key keycode Set the key code for the button
Name: gpio-led Info: This is a generic overlay for activating LEDs (or any other component) by a GPIO pin. Multiple LEDs can be set up using multiple calls to the overlay. While there are many existing methods to activate LEDs on the RPi, this method offers some advantages: 1) Does not require any userspace programs. 2) LEDs can be connected to the kernel's led-trigger framework, and drive the LED based on triggers such as cpu load, heartbeat, kernel panic, key input, timers and others. 3) LED can be tied to the input state of another GPIO pin. 4) The LED is setup early during the kernel boot process (useful for cpu/heartbeat/panic triggers).
Typical electrical connection is:
RPI-GPIO.19 -> LED -> 300ohm resister -> RPI-GND
The GPIO pin number can be changed with the 'gpio=' parameter.
To control an LED from userspace, write a 0 or 1 value:
echo 1 > /sys/class/leds/myled1/brightness
The 'myled1' name can be changed with the 'label=' parameter.
To connect the LED to a kernel trigger from userspace:
echo cpu > /sys/class/leds/myled1/trigger
echo heartbeat > /sys/class/leds/myled1/trigger
echo none > /sys/class/leds/myled1/trigger
To connect the LED to GPIO.26 pin (physical pin 37):
echo gpio > /sys/class/leds/myled1/trigger
echo 26 > /sys/class/leds/myled1/gpio
Available triggers:
cat /sys/class/leds/myled1/trigger
More information about the Linux kernel LED/Trigger system:
https://www.kernel.org/doc/Documentation/leds/leds-class.rst
https://www.kernel.org/doc/Documentation/leds/ledtrig-oneshot.rst Load: dtoverlay=gpio-led,<param>=<val> Params: gpio GPIO pin connected to the LED (default 19)
label The label for this LED. It will appear under
/sys/class/leds/<label> . Default 'myled1'.
trigger Set the led-trigger to connect to this LED.
default 'none' (LED is user-controlled).
Some possible triggers:
cpu - CPU load (all CPUs)
cpu0 - CPU load of first CPU.
mmc - disk activity (all disks)
panic - turn on on kernel panic
heartbeat - indicate system health
gpio - connect to a GPIO input pin (note:
currently the GPIO PIN can not be set
using overlay parameters, must be
done in userspace, see examples above.
active_low Set to 1 to turn invert the LED control
(writing 0 to /sys/class/leds/XXX/brightness
will turn on the GPIO/LED). Default '0'.
Name: gpio-no-bank0-irq
Info: Use this overlay to disable GPIO interrupts for GPIOs in bank 0 (0-27),
which can be useful for UIO drivers.
N.B. Using this overlay will trigger a kernel WARN during booting, but
this can safely be ignored - the system should work as expected.
Load: dtoverlay=gpio-no-bank0-irq
Params:
Name: gpio-no-irq
Info: Use this overlay to disable all GPIO interrupts, which can be useful
for user-space GPIO edge detection systems.
Load: dtoverlay=gpio-no-irq
Params:
Name: gpio-poweroff Info: Drives a GPIO high or low on poweroff (including halt). Using this overlay interferes with the normal power-down sequence, preventing the kernel from resetting the SoC (a necessary step in a normal power-off or reboot). This also disables the ability to trigger a boot by driving GPIO3 low.
The GPIO starts in an inactive state. At poweroff time it is driven
active for 100ms, then inactive for 100ms, then active again. It is
safe to remove the power at any point after the initial activation of
the GPIO.
Users of this overlay are required to provide an external mechanism to
switch off the power supply when signalled - failure to do so results
in a kernel BUG, increased power consumption and undefined behaviour. Load: dtoverlay=gpio-poweroff,<param>=<val> Params: gpiopin GPIO for signalling (default 26)
active_low Set if the power control device requires a
high->low transition to trigger a power-down.
Note that this will require the support of a
custom dt-blob.bin to prevent a power-down
during the boot process, and that a reboot
will also cause the pin to go low.
input Set if the gpio pin should be configured as
an input.
export Set to export the configured pin to sysfs
active_delay_ms Initial GPIO active period (default 100)
inactive_delay_ms Subsequent GPIO inactive period (default 100)
timeout_ms Specify (in ms) how long the kernel waits for
power-down before issuing a WARN (default 3000).
Name: gpio-shutdown Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin is configured as an input key that generates KEY_POWER events.
This event is handled by systemd-logind by initiating a
shutdown. Systemd versions older than 225 need an udev rule
enable listening to the input device:
ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
ATTRS{keys}=="116", TAG+="power-switch"
Alternatively this event can be handled also on systems without
systemd, just by traditional SysV init daemon. KEY_POWER event
(keycode 116) needs to be mapped to KeyboardSignal on console
and then kb::kbrequest inittab action which is triggered by
KeyboardSignal from console can be configured to issue system
shutdown. Steps for this configuration are:
Add following lines to the /etc/console-setup/remap.inc file:
# Key Power as special keypress
keycode 116 = KeyboardSignal
Then add following lines to /etc/inittab file:
# Action on special keypress (Key Power)
kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
And finally reload configuration by calling following commands:
# dpkg-reconfigure console-setup
# service console-setup reload
# init q
This overlay only handles shutdown. After shutdown, the system
can be powered up again by driving GPIO3 low. The default
configuration uses GPIO3 with a pullup, so if you connect a
button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
you get a shutdown and power-up button. Please note that
Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3. Load: dtoverlay=gpio-shutdown,<param>=<val> Params: gpio_pin GPIO pin to trigger on (default 3)
For Raspberry Pi 1 Model B rev 1 set this
explicitly to value 1, e.g.:
dtoverlay=gpio-shutdown,gpio_pin=1
active_low When this is 1 (active low), a falling
edge generates a key down event and a
rising edge generates a key up event.
When this is 0 (active high), this is
reversed. The default is 1 (active low).
gpio_pull Desired pull-up/down state (off, down, up)
Default is "up".
Note that the default pin (GPIO3) has an
external pullup. Same applies for GPIO1
on Raspberry Pi 1 Model B rev 1.
debounce Specify the debounce interval in milliseconds
(default 100)
Name: hd44780-lcd Info: Configures an HD44780 compatible LCD display. Uses 4 gpio pins for data, 2 gpio pins for enable and register select and 1 optional pin for enabling/disabling the backlight display. Load: dtoverlay=hd44780-lcd,= Params: pin_d4 GPIO pin for data pin D4 (default 6)
pin_d5 GPIO pin for data pin D5 (default 13)
pin_d6 GPIO pin for data pin D6 (default 19)
pin_d7 GPIO pin for data pin D7 (default 26)
pin_en GPIO pin for "Enable" (default 21)
pin_rs GPIO pin for "Register Select" (default 20)
pin_bl Optional pin for enabling/disabling the
display backlight. (default disabled)
display_height Height of the display in characters
display_width Width of the display in characters
Name: hdmi-backlight-hwhack-gpio Info: Devicetree overlay for GPIO based backlight on/off capability. Use this if you have one of those HDMI displays whose backlight cannot be controlled via DPMS over HDMI and plan to do a little soldering to use an RPi gpio pin for on/off switching. See: https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control Load: dtoverlay=hdmi-backlight-hwhack-gpio,= Params: gpio_pin GPIO pin used (default 17) active_low Set this to 1 if the display backlight is switched on when the wire goes low. Leave the default (value 0) if the backlight expects a high to switch it on.
Name: hifiberry-amp
Info: Configures the HifiBerry Amp and Amp+ audio cards
Load: dtoverlay=hifiberry-amp
Params:
Name: hifiberry-amp100 Info: Configures the HifiBerry AMP100 audio card Load: dtoverlay=hifiberry-amp100,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with "dtoverlay=hifiberry-amp100,24db_digital_gain" (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24dB_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!) slave Force DAC+ Pro into slave mode, using Pi as master for bit clock and frame clock. leds_off If set to 'true' the onboard indicator LEDs are switched off at all times. auto_mute If set to 'true' the amplifier is automatically muted when the DAC is not playing. mute_ext_ctl The amplifier's HW mute control is enabled in ALSA mixer and set to . Will be overwritten by ALSA user settings.
Name: hifiberry-amp3
Info: Configures the HifiBerry Amp3 audio card
Load: dtoverlay=hifiberry-amp3
Params:
Name: hifiberry-dac
Info: Configures the HifiBerry DAC audio cards
Load: dtoverlay=hifiberry-dac
Params:
Name: hifiberry-dacplus Info: Configures the HifiBerry DAC+ audio card Load: dtoverlay=hifiberry-dacplus,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with "dtoverlay=hifiberry-dacplus,24db_digital_gain" (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24dB_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!) slave Force DAC+ Pro into slave mode, using Pi as master for bit clock and frame clock. leds_off If set to 'true' the onboard indicator LEDs are switched off at all times.
Name: hifiberry-dacplusadc Info: Configures the HifiBerry DAC+ADC audio card Load: dtoverlay=hifiberry-dacplusadc,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with "dtoverlay=hifiberry-dacplus,24db_digital_gain" (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24dB_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!) slave Force DAC+ Pro into slave mode, using Pi as master for bit clock and frame clock. leds_off If set to 'true' the onboard indicator LEDs are switched off at all times.
Name: hifiberry-dacplusadcpro Info: Configures the HifiBerry DAC+ADC PRO audio card Load: dtoverlay=hifiberry-dacplusadcpro,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain" (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24dB_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!) slave Force DAC+ADC Pro into slave mode, using Pi as master for bit clock and frame clock. leds_off If set to 'true' the onboard indicator LEDs are switched off at all times.
Name: hifiberry-dacplusdsp
Info: Configures the HifiBerry DAC+DSP audio card
Load: dtoverlay=hifiberry-dacplusdsp
Params:
Name: hifiberry-dacplushd
Info: Configures the HifiBerry DAC+ HD audio card
Load: dtoverlay=hifiberry-dacplushd
Params:
Name: hifiberry-digi
Info: Configures the HifiBerry Digi and Digi+ audio card
Load: dtoverlay=hifiberry-digi
Params:
Name: hifiberry-digi-pro
Info: Configures the HifiBerry Digi+ Pro and Digi2 Pro audio card
Load: dtoverlay=hifiberry-digi-pro
Params:
Name: highperi
Info: Enables "High Peripheral" mode
Load: dtoverlay=highperi
Params:
Name: hy28a Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics Default values match Texy's display shield Load: dtoverlay=hy28a,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
debug Debug output level {0-7}
xohms Touchpanel sensitivity (X-plate resistance)
resetgpio GPIO used to reset controller
ledgpio GPIO used to control backlight
Name: hy28b Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics Default values match Texy's display shield Load: dtoverlay=hy28b,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
debug Debug output level {0-7}
xohms Touchpanel sensitivity (X-plate resistance)
resetgpio GPIO used to reset controller
ledgpio GPIO used to control backlight
Name: hy28b-2017 Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics Default values match Texy's display shield Load: dtoverlay=hy28b-2017,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
debug Debug output level {0-7}
xohms Touchpanel sensitivity (X-plate resistance)
resetgpio GPIO used to reset controller
ledgpio GPIO used to control backlight
Name: i-sabre-q2m
Info: Configures the Audiophonics I-SABRE Q2M DAC
Load: dtoverlay=i-sabre-q2m
Params:
Name: i2c-bcm2708
Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
Load: dtoverlay=i2c-bcm2708
Params:
Name: i2c-fan Info: Adds support for a number of I2C fan controllers Load: dtoverlay=i2c-fan,= Params: addr Sets the address for the fan controller. Note that the device must be configured to use the specified address.
i2c0 Choose the I2C0 bus on GPIOs 0&1
i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
i2c3 Choose the I2C3 bus (configure with the i2c3
overlay - BCM2711 only)
i2c4 Choose the I2C4 bus (configure with the i2c4
overlay - BCM2711 only)
i2c5 Choose the I2C5 bus (configure with the i2c5
overlay - BCM2711 only)
i2c6 Choose the I2C6 bus (configure with the i2c6
overlay - BCM2711 only)
minpwm PWM setting for the fan when the SoC is below
mintemp (range 0-255. default 0)
maxpwm PWM setting for the fan when the SoC is above
maxtemp (range 0-255. default 255)
midtemp Temperature (in millicelcius) at which the fan
begins to speed up (default 50000)
midtemp_hyst Temperature delta (in millicelcius) below
mintemp at which the fan will drop to minrpm
(default 2000)
maxtemp Temperature (in millicelcius) at which the fan
will be held at maxrpm (default 70000)
maxtemp_hyst Temperature delta (in millicelcius) below
maxtemp at which the fan begins to slow down
(default 2000)
emc2301 Select the Microchip EMC230x controller family
- EMC2301, EMC2302, EMC2303, EMC2305.
Name: i2c-gpio Info: Adds support for software i2c controller on gpio pins Load: dtoverlay=i2c-gpio,= Params: i2c_gpio_sda GPIO used for I2C data (default "23")
i2c_gpio_scl GPIO used for I2C clock (default "24")
i2c_gpio_delay_us Clock delay in microseconds
(default "2" = ~100kHz)
bus Set to a unique, non-zero value if wanting
multiple i2c-gpio busses. If set, will be used
as the preferred bus number (/dev/i2c-<n>). If
not set, the default value is 0, but the bus
number will be dynamically assigned - probably
3.
Name: i2c-mux Info: Adds support for a number of I2C bus multiplexers on i2c_arm Load: dtoverlay=i2c-mux,= Params: pca9542 Select the NXP PCA9542 device
pca9545 Select the NXP PCA9545 device
pca9548 Select the NXP PCA9548 device
addr Change I2C address of the device (default 0x70)
i2c0 Choose the I2C0 bus on GPIOs 0&1
i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
i2c3 Choose the I2C3 bus (configure with the i2c3
overlay - BCM2711 only)
i2c4 Choose the I2C3 bus (configure with the i2c3
overlay - BCM2711 only)
i2c5 Choose the I2C5 bus (configure with the i2c4
overlay - BCM2711 only)
i2c6 Choose the I2C6 bus (configure with the i2c6
overlay - BCM2711 only)
[ The i2c-mux-pca9548a overlay has been deleted. See i2c-mux. ]
Name: i2c-pwm-pca9685a Info: Adds support for an NXP PCA9685A I2C PWM controller on i2c_arm Load: dtoverlay=i2c-pwm-pca9685a,= Params: addr I2C address of PCA9685A (default 0x40) i2c0 Choose the I2C0 bus on GPIOs 0&1 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45 i2c3 Choose the I2C3 bus (configure with the i2c3 overlay - BCM2711 only) i2c4 Choose the I2C3 bus (configure with the i2c3 overlay - BCM2711 only) i2c5 Choose the I2C5 bus (configure with the i2c4 overlay - BCM2711 only) i2c6 Choose the I2C6 bus (configure with the i2c6 overlay - BCM2711 only)
Name: i2c-rtc Info: Adds support for a number of I2C Real Time Clock devices Load: dtoverlay=i2c-rtc,= Params: abx80x Select one of the ABx80x family: AB0801, AB0803, AB0804, AB0805, AB1801, AB1803, AB1804, AB1805
bq32000 Select the TI BQ32000 device
ds1307 Select the DS1307 device
ds1339 Select the DS1339 device
ds1340 Select the DS1340 device
ds3231 Select the DS3231 device
m41t62 Select the M41T62 device
mcp7940x Select the MCP7940x device
mcp7941x Select the MCP7941x device
pcf2127 Select the PCF2127 device
pcf2129 Select the PCF2129 device
pcf85063 Select the PCF85063 device
pcf85063a Select the PCF85063A device
pcf8523 Select the PCF8523 device
pcf85363 Select the PCF85363 device
pcf8563 Select the PCF8563 device
rv1805 Select the Micro Crystal RV1805 device
rv3028 Select the Micro Crystal RV3028 device
rv3032 Select the Micro Crystal RV3032 device
rv8803 Select the Micro Crystal RV8803 device
sd3078 Select the ZXW Shenzhen whwave SD3078 device
s35390a Select the ABLIC S35390A device
i2c0 Choose the I2C0 bus on GPIOs 0&1
i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
i2c3 Choose the I2C3 bus (configure with the i2c3
overlay - BCM2711 only)
i2c4 Choose the I2C3 bus (configure with the i2c3
overlay - BCM2711 only)
i2c5 Choose the I2C5 bus (configure with the i2c4
overlay - BCM2711 only)
i2c6 Choose the I2C6 bus (configure with the i2c6
overlay - BCM2711 only)
addr Sets the address for the RTC. Note that the
device must be configured to use the specified
address.
trickle-diode-disable Do not use the internal trickle charger diode
(BQ32000 only)
trickle-diode-type Diode type for trickle charge - "standard" or
"schottky" (ABx80x and RV1805 only)
trickle-resistor-ohms Resistor value for trickle charge (DS1339,
ABx80x, BQ32000, RV1805, RV3028, RV3032)
trickle-voltage-mv Charge pump voltage for trickle charge (RV3032)
wakeup-source Specify that the RTC can be used as a wakeup
source
backup-switchover-mode Backup power supply switch mode. Must be 0 for
off or 1 for Vdd < VBackup (RV3028, RV3032)
Name: i2c-rtc-gpio Info: Adds support for a number of I2C Real Time Clock devices using the software i2c controller Load: dtoverlay=i2c-rtc-gpio,= Params: abx80x Select one of the ABx80x family: AB0801, AB0803, AB0804, AB0805, AB1801, AB1803, AB1804, AB1805
bq32000 Select the TI BQ32000 device
ds1307 Select the DS1307 device
ds1339 Select the DS1339 device
ds1340 Select the DS1340 device
ds3231 Select the DS3231 device
m41t62 Select the M41T62 device
mcp7940x Select the MCP7940x device
mcp7941x Select the MCP7941x device
pcf2127 Select the PCF2127 device
pcf2129 Select the PCF2129 device
pcf85063 Select the PCF85063 device
pcf85063a Select the PCF85063A device
pcf8523 Select the PCF8523 device
pcf85363 Select the PCF85363 device
pcf8563 Select the PCF8563 device
rv1805 Select the Micro Crystal RV1805 device
rv3028 Select the Micro Crystal RV3028 device
rv3032 Select the Micro Crystal RV3032 device
rv8803 Select the Micro Crystal RV8803 device
sd3078 Select the ZXW Shenzhen whwave SD3078 device
s35390a Select the ABLIC S35390A device
addr Sets the address for the RTC. Note that the
device must be configured to use the specified
address.
trickle-diode-disable Do not use the internal trickle charger diode
(BQ32000 only)
trickle-diode-type Diode type for trickle charge - "standard" or
"schottky" (ABx80x and RV1805 only)
trickle-resistor-ohms Resistor value for trickle charge (DS1339,
ABx80x, BQ32000, RV1805, RV3028, RV3032)
trickle-voltage-mv Charge pump voltage for trickle charge (RV3032)
wakeup-source Specify that the RTC can be used as a wakeup
source
backup-switchover-mode Backup power supply switch mode. Must be 0 for
off or 1 for Vdd < VBackup (RV3028, RV3032)
i2c_gpio_sda GPIO used for I2C data (default "23")
i2c_gpio_scl GPIO used for I2C clock (default "24")
i2c_gpio_delay_us Clock delay in microseconds
(default "2" = ~100kHz)
Name: i2c-sensor Info: Adds support for a number of I2C barometric pressure, temperature, light level and chemical sensors on i2c_arm Load: dtoverlay=i2c-sensor,= Params: addr Set the address for the BH1750, BME280, BME680, BMP280, BMP380, CCS811, DS1621, HDC100X, JC42, LM75, MCP980x, MPU6050, MPU9250, MS5637, MS5803, MS5805, MS5837, MS8607, SHT3x or TMP102
aht10 Select the Aosong AHT10 temperature and humidity
sensor
bh1750 Select the Rohm BH1750 ambient light sensor
Valid addresses 0x23 or 0x5c, default 0x23
bme280 Select the Bosch Sensortronic BME280
Valid addresses 0x76-0x77, default 0x76
bme680 Select the Bosch Sensortronic BME680
Valid addresses 0x76-0x77, default 0x76
bmp085 Select the Bosch Sensortronic BMP085
bmp180 Select the Bosch Sensortronic BMP180
bmp280 Select the Bosch Sensortronic BMP280
Valid addresses 0x76-0x77, default 0x76
bmp380 Select the Bosch Sensortronic BMP380
Valid addresses 0x76-0x77, default 0x76
bno055 Select the Bosch Sensortronic BNO055 IMU
Valid address 0x28-0x29, default 0x29
ccs811 Select the AMS CCS811 digital gas sensor
Valid addresses 0x5a-0x5b, default 0x5b
ds1621 Select the Dallas Semiconductors DS1621 temp
sensor. Valid addresses 0x48-0x4f, default 0x48
hdc100x Select the Texas Instruments HDC100x temp sensor
Valid addresses 0x40-0x43, default 0x40
htu21 Select the HTU21 temperature and humidity sensor
int_pin Set the GPIO to use for interrupts (max30102,
mpu6050 and mpu9250 only)
jc42 Select any of the many JEDEC JC42.4-compliant
temperature sensors, including:
ADT7408, AT30TS00, CAT34TS02, CAT6095,
MAX6604, MCP9804, MCP9805, MCP9808,
MCP98242, MCP98243, MCP98244, MCP9843,
SE97, SE98, STTS424(E), STTS2002, STTS3000,
TSE2002, TSE2004, TS3000, and TS3001.
The default address is 0x18.
lm75 Select the Maxim LM75 temperature sensor
Valid addresses 0x48-0x4f, default 0x4f
lm75addr Deprecated - use addr parameter instead
max17040 Select the Maxim Integrated MAX17040 battery
monitor
max30102 Select the Maxim Integrated MAX30102 heart-rate
and blood-oxygen sensor
mcp980x Select the Maxim MCP980x range of temperature
sensors (i.e. MCP9800, MCP9801, MCP9802 and
MCP9803). N.B. For MCP9804, MCP9805 and MCP9808,
use the "jc42" option.
Valid addresses are 0x18-0x1f (default 0x18)
mpu6050 Select the InvenSense MPU6050 IMU. Valid
valid addresses are 0x68 and 0x69 (default 0x68)
mpu9250 Select the InvenSense MPU9250 IMU. Valid
valid addresses are 0x68 and 0x69 (default 0x68)
ms5637 Select the Measurement Specialities MS5637
pressure and temperature sensor.
ms5803 Select the Measurement Specialities MS5803
pressure and temperature sensor.
ms5805 Select the Measurement Specialities MS5805
pressure and temperature sensor.
ms5837 Select the Measurement Specialities MS5837
pressure and temperature sensor.
ms8607 Select the Measurement Specialities MS8607
pressure and temperature sensor.
no_timeout Disable the SMBUS timeout. N.B. Only supported
by some jc42 devices - using with an
incompatible device can stop it from being
activated.
reset_pin GPIO to be used to reset the device (bno055
only, disabled by default)
sht3x Select the Sensirion SHT3x temperature and
humidity sensors. Valid addresses 0x44-0x45,
default 0x44
sht4x Select the Sensirion SHT4x temperature and
humidity sensors. Valid addresses 0x44-0x45,
default 0x44
si7020 Select the Silicon Labs Si7013/20/21 humidity/
temperature sensor
sps30 Select the Sensirion SPS30 particulate matter
sensor. Fixed address 0x69.
sgp30 Select the Sensirion SGP30 VOC sensor.
Fixed address 0x58.
tmp102 Select the Texas Instruments TMP102 temp sensor
Valid addresses 0x48-0x4b, default 0x48
tsl4531 Select the AMS TSL4531 digital ambient light
sensor
veml6070 Select the Vishay VEML6070 ultraviolet light
sensor
i2c0 Choose the I2C0 bus on GPIOs 0&1
i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
i2c3 Choose the I2C3 bus (configure with the i2c3
overlay - BCM2711 only)
i2c4 Choose the I2C3 bus (configure with the i2c3
overlay - BCM2711 only)
i2c5 Choose the I2C5 bus (configure with the i2c4
overlay - BCM2711 only)
i2c6 Choose the I2C6 bus (configure with the i2c6
overlay - BCM2711 only)
Name: i2c0 Info: Change i2c0 pin usage. Not all pin combinations are usable on all platforms - platforms other then Compute Modules can only use this to disable transaction combining. Do NOT use in conjunction with dtparam=i2c_vc=on. From the 5.4 kernel onwards the base DT includes the use of i2c_mux_pinctrl to expose two muxings of BSC0 - GPIOs 0&1, and whichever combination is used for the camera and display connectors. This overlay disables that mux and configures /dev/i2c0 to point at whichever set of pins is requested. dtparam=i2c_vc=on will try and enable the mux, so combining the two will cause conflicts. Load: dtoverlay=i2c0,= Params: pins_0_1 Use pins 0 and 1 (default) pins_28_29 Use pins 28 and 29 pins_44_45 Use pins 44 and 45 pins_46_47 Use pins 46 and 47 combine Allow transactions to be combined (default "yes")
Name: i2c0-bcm2708 Info: Deprecated, legacy version of i2c0. Load:
Name: i2c0-pi5 Info: Enable i2c0 (Pi 5 only) Load: dtoverlay=i2c0-pi5,= Params: pins_0_1 Use GPIOs 0 and 1 (default) pins_8_9 Use GPIOs 8 and 9 baudrate Set the baudrate for the interface (default "100000")
Name: i2c1 Info: Change i2c1 pin usage. Not all pin combinations are usable on all platforms - platforms other then Compute Modules can only use this to disable transaction combining. Load: dtoverlay=i2c1,= Params: pins_2_3 Use pins 2 and 3 (default) pins_44_45 Use pins 44 and 45 combine Allow transactions to be combined (default "yes")
Name: i2c1-bcm2708 Info: Deprecated, legacy version of i2c1. Load:
Name: i2c1-pi5 Info: Enable i2c1 (Pi 5 only) Load: dtoverlay=i2c1-pi5,= Params: pins_2_3 Use GPIOs 2 and 3 (default) pins_10_11 Use GPIOs 10 and 11 baudrate Set the baudrate for the interface (default "100000")
Name: i2c2-pi5 Info: Enable i2c2 (Pi 5 only) Load: dtoverlay=i2c2-pi5,= Params: pins_4_5 Use GPIOs 4 and 5 (default) pins_12_13 Use GPIOs 12 and 13 baudrate Set the baudrate for the interface (default "100000")
Name: i2c3 Info: Enable the i2c3 bus. BCM2711 only. Load: dtoverlay=i2c3, Params: pins_2_3 Use GPIOs 2 and 3 pins_4_5 Use GPIOs 4 and 5 (default) baudrate Set the baudrate for the interface (default "100000")
Name: i2c3-pi5 Info: Enable i2c3 (Pi 5 only) Load: dtoverlay=i2c3-pi5,= Params: pins_6_7 Use GPIOs 6 and 7 (default) pins_14_15 Use GPIOs 14 and 15 pins_22_23 Use GPIOs 22 and 23 baudrate Set the baudrate for the interface (default "100000")
Name: i2c4 Info: Enable the i2c4 bus. BCM2711 only. Load: dtoverlay=i2c4, Params: pins_6_7 Use GPIOs 6 and 7 pins_8_9 Use GPIOs 8 and 9 (default) baudrate Set the baudrate for the interface (default "100000")
Name: i2c5 Info: Enable the i2c5 bus. BCM2711 only. Load: dtoverlay=i2c5, Params: pins_10_11 Use GPIOs 10 and 11 pins_12_13 Use GPIOs 12 and 13 (default) baudrate Set the baudrate for the interface (default "100000")
Name: i2c6 Info: Enable the i2c6 bus. BCM2711 only. Load: dtoverlay=i2c6, Params: pins_0_1 Use GPIOs 0 and 1 pins_22_23 Use GPIOs 22 and 23 (default) baudrate Set the baudrate for the interface (default "100000")
Name: i2s-dac
Info: Configures any passive I2S DAC soundcard.
Load: dtoverlay=i2s-dac
Params:
Name: i2s-gpio28-31
Info: move I2S function block to GPIO 28 to 31
Load: dtoverlay=i2s-gpio28-31
Params:
Name: ilitek251x Info: Enables I2C connected Ilitek 251x multiple touch controller using GPIO 4 (pin 7 on GPIO header) for interrupt. Load: dtoverlay=ilitek251x,= Params: interrupt GPIO used for interrupt (default 4) sizex Touchscreen size x, horizontal resolution of touchscreen (in pixels) sizey Touchscreen size y, vertical resolution of touchscreen (in pixels)
Name: imx219 Info: Sony IMX219 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=imx219,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 180) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg). vcm Configure a VCM focus drive on the sensor.
Name: imx258 Info: Sony IMX258 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=imx258,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 180) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg). vcm Configure a VCM focus drive on the sensor. 4lane Enable 4 CSI2 lanes. This requires a Compute Module (1, 3, or 4).
Name: imx290 Info: Sony IMX290 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=imx290, Params: 4lane Enable 4 CSI2 lanes. This requires a Compute Module (1, 3, or 4). clock-frequency Sets the clock frequency to match that used on the board. Modules from Vision Components use 37.125MHz (the default), whilst those from Innomaker use 74.25MHz. mono Denote that the module is a mono sensor. orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) rotation Mounting rotation of the camera sensor (0 or 180, default 0) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: imx296 Info: Sony IMX296 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=imx296,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 180) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg). clock-frequency Sets the clock frequency to match that used on the board, which should be one of 54000000 (the default), 37125000 or 74250000.
Name: imx327 Info: Sony IMX327 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=imx327, Params: 4lane Enable 4 CSI2 lanes. This requires a Compute Module (1, 3, or 4). clock-frequency Sets the clock frequency to match that used on the board. Modules from Vision Components use 37.125MHz (the default), whilst those from Innomaker use 74.25MHz. mono Denote that the module is a mono sensor. orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) rotation Mounting rotation of the camera sensor (0 or 180, default 0) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: imx378 Info: Sony IMX378 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=imx378,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 180) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: imx462 Info: Sony IMX462 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=imx462, Params: 4lane Enable 4 CSI2 lanes. This requires a Compute Module (1, 3, or 4). clock-frequency Sets the clock frequency to match that used on the board. Modules from Vision Components use 37.125MHz (the default), whilst those from Innomaker use 74.25MHz. mono Denote that the module is a mono sensor. orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) rotation Mounting rotation of the camera sensor (0 or 180, default 0) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: imx477 Info: Sony IMX477 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=imx477,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 180) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: imx519 Info: Sony IMX519 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=imx519,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 0) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg). vcm Select lens driver state. Default is enabled, but vcm=off will disable.
Name: imx708 Info: Sony IMX708 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=imx708,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 180) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) vcm Select lens driver state. Default is enabled, but vcm=off will disable. media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg). link-frequency Allowable link frequency values to use in Hz: 450000000 (default), 447000000, 453000000.
Name: iqaudio-codec
Info: Configures the IQaudio Codec audio card
Load: dtoverlay=iqaudio-codec
Params:
Name: iqaudio-dac Info: Configures the IQaudio DAC audio card Load: dtoverlay=iqaudio-dac, Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with "dtoverlay=iqaudio-dac,24db_digital_gain" (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24db_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!)
Name: iqaudio-dacplus Info: Configures the IQaudio DAC+ audio card Load: dtoverlay=iqaudio-dacplus,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with "dtoverlay=iqaudio-dacplus,24db_digital_gain" (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24db_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!) auto_mute_amp If specified, unmute/mute the IQaudIO amp when starting/stopping audio playback. unmute_amp If specified, unmute the IQaudIO amp once when the DAC driver module loads.
Name: iqaudio-digi-wm8804-audio Info: Configures the IQAudIO Digi WM8804 audio card Load: dtoverlay=iqaudio-digi-wm8804-audio,= Params: card_name Override the default, "IQAudIODigi", card name. dai_name Override the default, "IQAudIO Digi", dai name. dai_stream_name Override the default, "IQAudIO Digi HiFi", dai stream name.
Name: iqs550 Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller using GPIO 4 (pin 7 on GPIO header) for interrupt. Load: dtoverlay=iqs550,= Params: interrupt GPIO used for interrupt (default 4) reset GPIO used for reset (optional) sizex Touchscreen size x (default 800) sizey Touchscreen size y (default 480) invx Touchscreen inverted x axis invy Touchscreen inverted y axis swapxy Touchscreen swapped x y axis
Name: irs1125 Info: Infineon irs1125 TOF camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=irs1125,= Params: media-controller Configure use of Media Controller API for configuring the sensor (default off) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: jedec-spi-nor Info: Adds support for JEDEC-compliant SPI NOR flash devices. (Note: The "jedec,spi-nor" kernel driver was formerly known as "m25p80".) Load: dtoverlay=jedec-spi-nor,= Params: spi- Enable flash device on SPI, CS# fastr Add fast read capability to the flash device speed Maximum SPI frequency (Hz) flash-spi- Same as spi- (deprecated) flash-fastr-spi- Same as spi->m>,fastr (deprecated)
Name: justboom-both Info: Simultaneous usage of an justboom-dac and justboom-digi based card Load: dtoverlay=justboom-both,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with "dtoverlay=justboom-dac,24db_digital_gain" (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24dB_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!)
Name: justboom-dac Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio cards Load: dtoverlay=justboom-dac,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec Digital volume control. Enable with "dtoverlay=justboom-dac,24db_digital_gain" (The default behaviour is that the Digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24dB_digital_gain parameter, the Digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the Digital volume control is set to a value that does not result in clipping/distortion!)
Name: justboom-digi
Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
Load: dtoverlay=justboom-digi
Params:
Name: lirc-rpi Info: This overlay has been deprecated and removed - see gpio-ir Load:
Name: ltc294x Info: Adds support for the ltc294x family of battery gauges Load: dtoverlay=ltc294x,= Params: ltc2941 Select the ltc2941 device
ltc2942 Select the ltc2942 device
ltc2943 Select the ltc2943 device
ltc2944 Select the ltc2944 device
resistor-sense The sense resistor value in milli-ohms.
Can be a 32-bit negative value when the battery
has been connected to the wrong end of the
resistor.
prescaler-exponent Range and accuracy of the gauge. The value is
programmed into the chip only if it differs
from the current setting.
For LTC2941 only:
- Default value is 128
- the exponent is in the range 0-7 (default 7)
See the datasheet for more information.
Name: max98357a Info: Configures the Maxim MAX98357A I2S DAC Load: dtoverlay=max98357a,= Params: no-sdmode Driver does not manage the state of the DAC's SD_MODE pin (i.e. chip is always on). sdmode-pin integer, GPIO pin connected to the SD_MODE input of the DAC (default GPIO4 if parameter omitted).
Name: maxtherm Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
For devices on spi1 or spi2, the interfaces should be enabled
with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
The overlay expects to disable the relevant spidev node, so also using
e.g. cs0_spidev=off is unnecessary.
Example:
MAX31855 on /dev/spidev0.0
dtoverlay=maxtherm,spi0-0,max31855
MAX31856 using a type J thermocouple on /dev/spidev2.1
dtoverlay=spi2-2cs
dtoverlay=maxtherm,spi2-1,max31856,type_j
Load: dtoverlay=maxtherm,= Params: spi- Configure device at spi, cs (boolean, required) max6675 Enable support for the MAX6675 (default) max31855 Enable support for the MAX31855 max31855e Enable support for the MAX31855E max31855j Enable support for the MAX31855J max31855k Enable support for the MAX31855K max31855n Enable support for the MAX31855N max31855r Enable support for the MAX31855R max31855s Enable support for the MAX31855S max31855t Enable support for the MAX31855T max31856 Enable support for the MAX31856 (with type K) type_b Select a type B sensor for max31856 type_e Select a type E sensor for max31856 type_j Select a type J sensor for max31856 type_k Select a type K sensor for max31856 type_n Select a type N sensor for max31856 type_r Select a type R sensor for max31856 type_s Select a type S sensor for max31856 type_t Select a type T sensor for max31856
Name: mbed-dac
Info: Configures the mbed AudioCODEC (TLV320AIC23B)
Load: dtoverlay=mbed-dac
Params:
Name: mcp23017 Info: Configures the MCP23017 I2C GPIO expander Load: dtoverlay=mcp23017,= Params: gpiopin Gpio pin connected to the INTA output of the MCP23017 (default: 4)
addr I2C address of the MCP23017 (default: 0x20)
mcp23008 Configure an MCP23008 instead.
noints Disable the interrupt GPIO line.
Name: mcp23s17 Info: Configures the MCP23S08/17 SPI GPIO expanders. If devices are present on SPI1 or SPI2, those interfaces must be enabled with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays. If interrupts are enabled for a device on a given CS# on a SPI bus, that device must be the only one present on that SPI bus/CS#. Load: dtoverlay=mcp23s17,= Params: s08-spi--present 4-bit integer, bitmap indicating MCP23S08 devices present on SPI, CS#
s17-spi<n>-<m>-present 8-bit integer, bitmap indicating MCP23S17
devices present on SPI<n>, CS#<m>
s08-spi<n>-<m>-int-gpio integer, enables interrupts on a single
MCP23S08 device on SPI<n>, CS#<m>, specifies
the GPIO pin to which INT output of MCP23S08
is connected.
s17-spi<n>-<m>-int-gpio integer, enables mirrored interrupts on a
single MCP23S17 device on SPI<n>, CS#<m>,
specifies the GPIO pin to which either INTA
or INTB output of MCP23S17 is connected.
Name: mcp2515 Info: Configures the MCP2515 CAN controller on spi0/1/2 For devices on spi1 or spi2, the interfaces should be enabled with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays. Load: dtoverlay=mcp2515,= Params: spi- Configure device at spi, cs (boolean, required)
oscillator Clock frequency for the CAN controller (Hz)
speed Maximum SPI frequence (Hz)
interrupt GPIO for interrupt signal
Name: mcp2515-can0 Info: Configures the MCP2515 CAN controller on spi0.0 Load: dtoverlay=mcp2515-can0,= Params: oscillator Clock frequency for the CAN controller (Hz)
spimaxfrequency Maximum SPI frequence (Hz)
interrupt GPIO for interrupt signal
Name: mcp2515-can1 Info: Configures the MCP2515 CAN controller on spi0.1 Load: dtoverlay=mcp2515-can1,= Params: oscillator Clock frequency for the CAN controller (Hz)
spimaxfrequency Maximum SPI frequence (Hz)
interrupt GPIO for interrupt signal
Name: mcp251xfd Info: Configures the MCP251XFD CAN controller family For devices on spi1 or spi2, the interfaces should be enabled with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays. Load: dtoverlay=mcp251xfd,= Params: spi- Configure device at spi, cs (boolean, required)
oscillator Clock frequency for the CAN controller (Hz)
speed Maximum SPI frequence (Hz)
interrupt GPIO for interrupt signal
rx_interrupt GPIO for RX interrupt signal (nINT1) (optional)
xceiver_enable GPIO for CAN transceiver enable (optional)
xceiver_active_high specifiy if CAN transceiver enable pin is
active high (optional, default: active low)
Name: mcp3008 Info: Configures MCP3008 A/D converters For devices on spi1 or spi2, the interfaces should be enabled with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays. Load: dtoverlay=mcp3008,[=] Params: spi--present boolean, configure device at spi, cs spi--speed integer, set the spi bus speed for this device
Name: mcp3202 Info: Configures MCP3202 A/D converters For devices on spi1 or spi2, the interfaces should be enabled with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays. Load: dtoverlay=mcp3202,[=] Params: spi--present boolean, configure device at spi, cs spi--speed integer, set the spi bus speed for this device
Name: mcp342x Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C Load: dtoverlay=mcp342x,= Params: addr I2C bus address of device, for devices with addresses that are configurable, e.g. by hardware links (default=0x68) mcp3421 The device is an MCP3421 mcp3422 The device is an MCP3422 mcp3423 The device is an MCP3423 mcp3424 The device is an MCP3424 mcp3425 The device is an MCP3425 mcp3426 The device is an MCP3426 mcp3427 The device is an MCP3427 mcp3428 The device is an MCP3428
Name: media-center Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply Load: dtoverlay=media-center,= Params: speed Display SPI bus speed rotate Display rotation {0,90,180,270} fps Delay between frame updates xohms Touchpanel sensitivity (X-plate resistance) swapxy Swap x and y axis backlight Change backlight GPIO pin {e.g. 12, 18} debug "on" = enable additional debug messages (default "off")
Name: merus-amp
Info: Configures the merus-amp audio card
Load: dtoverlay=merus-amp
Params:
Name: midi-uart0
Info: Configures UART0 (ttyAMA0) so that a requested 38.4kbaud actually gets
31.25kbaud, the frequency required for MIDI
Load: dtoverlay=midi-uart0
Params:
Name: midi-uart0-pi5 Info: See midi-uart0 (this is the Pi 5 version)
Name: midi-uart1
Info: Configures UART1 (ttyS0) so that a requested 38.4kbaud actually gets
31.25kbaud, the frequency required for MIDI
Load: dtoverlay=midi-uart1
Params:
Name: midi-uart1-pi5 Info: See midi-uart1 (this is the Pi 5 version)
Name: midi-uart2
Info: Configures UART2 (ttyAMA2) so that a requested 38.4kbaud actually gets
31.25kbaud, the frequency required for MIDI
Load: dtoverlay=midi-uart2
Params:
Name: midi-uart2-pi5 Info: See midi-uart2 (this is the Pi 5 version)
Name: midi-uart3
Info: Configures UART3 (ttyAMA3) so that a requested 38.4kbaud actually gets
31.25kbaud, the frequency required for MIDI
Load: dtoverlay=midi-uart3
Params:
Name: midi-uart3-pi5 Info: See midi-uart3 (this is the Pi 5 version)
Name: midi-uart4
Info: Configures UART4 (ttyAMA4) so that a requested 38.4kbaud actually gets
31.25kbaud, the frequency required for MIDI
Load: dtoverlay=midi-uart4
Params:
Name: midi-uart4-pi5 Info: See midi-uart4 (this is the Pi 5 version)
Name: midi-uart5
Info: Configures UART5 (ttyAMA5) so that a requested 38.4kbaud actually gets
31.25kbaud, the frequency required for MIDI
Load: dtoverlay=midi-uart5
Params:
Name: minipitft13 Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver. Load: dtoverlay=minipitft13,= Params: speed SPI bus speed (default 32000000) rotate Display rotation (0, 90, 180 or 270; default 0) width Display width (default 240) height Display height (default 240) fps Delay between frame updates (default 25) debug Debug output level (0-7; default 0)
Name: miniuart-bt Info: Switch the onboard Bluetooth function of a BT-equipped Raspberry Pi to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 & 15. Note that this option uses a lower baudrate, and should only be used with low-bandwidth peripherals. Load: dtoverlay=miniuart-bt,= Params: krnbt Set to "off" to disable autoprobing of Bluetooth driver without need of hciattach/btattach
Name: mipi-dbi-spi Info: Overlay for SPI-connected MIPI DBI displays using the panel-mipi-dbi driver. The driver will load a file /lib/firmware/panel.bin containing the initialisation commands.
Example:
dtoverlay=mipi-dbi-spi,spi0-0,speed=70000000
dtparam=width=320,height=240
dtparam=reset-gpio=23,dc-gpio=24
dtparam=backlight-gpio=18
Compared to fbtft panel-mipi-dbi runs pixel data at spi-max-frequency
and init commands at 10MHz. This makes it possible to push the envelope
without messing up the controller configuration due to command
transmission errors.
For devices on spi1 or spi2, the interfaces should be enabled
with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
See https://github.com/notro/panel-mipi-dbi/wiki for more info.
Load: dtoverlay=mipi-dbi-spi,= Params: compatible Set the compatible string to load a different firmware file. Both the panel compatible value used to load the firmware file and the value used to load the driver has to be set having a NUL (\0) separator between them. Example: dtparam=compatible=mypanel\0panel-mipi-dbi-spi spi- Configure device at spi, cs (boolean, required) speed SPI bus speed in Hz (default 32000000) cpha Shifted SPI clock phase (CPHA) mode cpol Inverse SPI clock polarity (CPOL) mode write-only Controller is not readable (ie. MISO is not wired up).
width Panel width in pixels (required)
height Panel height in pixels (required)
width-mm Panel width in mm
height-mm Panel height in mm
x-offset Panel x-offset in controller RAM
y-offset Panel y-offset in controller RAM
clock-frequency Panel clock frequency in Hz
(optional, just informational).
reset-gpio GPIO pin to be used for RESET
dc-gpio GPIO pin to be used for D/C
backlight-gpio GPIO pin to be used for backlight control
(default of none).
backlight-pwm PWM channel to be used for backlight control
(default of none). NB Disables audio headphone
output as that also uses PWM.
backlight-pwm-chan Choose channel on &pwm node for backlight
control (default 0).
backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
pwm-2chan for valid options (default 18).
backlight-pwm-func Pin function of GPIO used for the PWM backlight.
See pwm-2chan for valid options (default 2).
backlight-def-brightness
Set the default brightness. Normal range 1-16.
(default 16).
Name: mlx90640
Info: Overlay for i2c connected mlx90640 thermal camera
Load: dtoverlay=mlx90640
Params:
Name: mmc Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock Load: dtoverlay=mmc,= Params: overclock_50 Clock (in MHz) to use when the MMC framework requests 50MHz
Name: mpu6050 Info: This overlay has been deprecated - use "dtoverlay=i2c-sensor,mpu6050" instead. Note that "int_pin" is the new name for the "interrupt" parameter. Load:
Name: mz61581 Info: MZ61581 display by Tontec Load: dtoverlay=mz61581,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
txbuflen Transmit buffer length (default 32768)
debug Debug output level {0-7}
xohms Touchpanel sensitivity (X-plate resistance)
Name: ov2311 Info: Omnivision OV2311 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=ov2311,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 0) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: ov5647 Info: Omnivision OV5647 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=ov5647,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 0) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg). vcm Configure a VCM focus drive on the sensor.
Name: ov7251 Info: Omnivision OV7251 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=ov7251,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 0) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default off) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: ov9281 Info: Omnivision OV9281 camera module. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=ov9281,= Params: rotation Mounting rotation of the camera sensor (0 or 180, default 0) orientation Sensor orientation (0 = front, 1 = rear, 2 = external, default external) media-controller Configure use of Media Controller API for configuring the sensor (default on) cam0 Adopt the default configuration for CAM0 on a Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: papirus Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT) Load: dtoverlay=papirus,= Params: panel Display panel (required): 1.44": e1144cs021 2.0": e2200cs021 2.7": e2271cs021
speed Display SPI bus speed
Name: pca953x Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534. Load: dtoverlay=pca953x,= Params: addr I2C address of expander. Default 0x20. pca6416 Select the NXP PCA6416 (16 bit) pca9505 Select the NXP PCA9505 (40 bit) pca9535 Select the NXP PCA9535 (16 bit) pca9536 Select the NXP PCA9536 or TI PCA9536 (4 bit) pca9537 Select the NXP PCA9537 (4 bit) pca9538 Select the NXP PCA9538 (8 bit) pca9539 Select the NXP PCA9539 (16 bit) pca9554 Select the NXP PCA9554 (8 bit) pca9555 Select the NXP PCA9555 (16 bit) pca9556 Select the NXP PCA9556 (8 bit) pca9557 Select the NXP PCA9557 (8 bit) pca9574 Select the NXP PCA9574 (8 bit) pca9575 Select the NXP PCA9575 (16 bit) pca9698 Select the NXP PCA9698 (40 bit) pcal6416 Select the NXP PCAL6416 (16 bit) pcal6524 Select the NXP PCAL6524 (24 bit) pcal9555a Select the NXP PCAL9555A (16 bit) max7310 Select the Maxim MAX7310 (8 bit) max7312 Select the Maxim MAX7312 (16 bit) max7313 Select the Maxim MAX7313 (16 bit) max7315 Select the Maxim MAX7315 (8 bit) pca6107 Select the TI PCA6107 (8 bit) tca6408 Select the TI TCA6408 (8 bit) tca6416 Select the TI TCA6416 (16 bit) tca6424 Select the TI TCA6424 (24 bit) tca9539 Select the TI TCA9539 (16 bit) tca9554 Select the TI TCA9554 (8 bit) cat9554 Select the Onnn CAT9554 (8 bit) pca9654 Select the Onnn PCA9654 (8 bit) xra1202 Select the Exar XRA1202 (8 bit)
Name: pcf857x Info: NXP PCF857x family of I2C GPIO expanders. Load: dtoverlay=pcf857x,= Params: addr I2C address of expander. Default depends on model selected. pcf8574 Select the NXP PCF8574 (8 bit) pcf8574a Select the NXP PCF8574A (8 bit) pcf8575 Select the NXP PCF8575 (16 bit) pca8574 Select the NXP PCA8574 (8 bit)
Name: pcie-32bit-dma
Info: Force PCIe config to support 32bit DMA addresses at the expense of
having to bounce buffers.
Load: dtoverlay=pcie-32bit-dma
Params:
[ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]
[ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]
[ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]
Name: pi3-act-led Info: This overlay has been renamed act-led, keeping pi3-act-led as an alias for backwards compatibility. Load:
Name: pi3-disable-bt Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an alias for backwards compatibility. Load:
Name: pi3-disable-wifi Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as an alias for backwards compatibility. Load:
Name: pi3-miniuart-bt Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as an alias for backwards compatibility. Load:
Name: pibell Info: Configures the pibell audio card. Load: dtoverlay=pibell,= Params: alsaname Set the name as it appears in ALSA (default "PiBell")
Name: pifacedigital Info: Configures the PiFace Digital mcp23s17 GPIO port expander. Load: dtoverlay=pifacedigital,= Params: spi-present-mask 8-bit integer, bitmap indicating MCP23S17 SPI0 CS0 address. PiFace Digital supports addresses 0-3, which can be configured with JP1 and JP2.
Name: pifi-40
Info: Configures the PiFi 40W stereo amplifier
Load: dtoverlay=pifi-40
Params:
Name: pifi-dac-hd
Info: Configures the PiFi DAC HD
Load: dtoverlay=pifi-dac-hd
Params:
Name: pifi-dac-zero
Info: Configures the PiFi DAC Zero
Load: dtoverlay=pifi-dac-zero
Params:
Name: pifi-mini-210
Info: Configures the PiFi Mini stereo amplifier
Load: dtoverlay=pifi-mini-210
Params:
Name: piglow
Info: Configures the PiGlow by pimoroni.com
Load: dtoverlay=piglow
Params:
Name: piscreen Info: PiScreen display by OzzMaker.com Load: dtoverlay=piscreen,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
debug Debug output level {0-7}
xohms Touchpanel sensitivity (X-plate resistance)
drm Select the DRM/KMS driver instead of the FBTFT
one
Name: piscreen2r Info: PiScreen 2 with resistive TP display by OzzMaker.com Load: dtoverlay=piscreen2r,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
debug Debug output level {0-7}
xohms Touchpanel sensitivity (X-plate resistance)
Name: pisound
Info: Configures the Blokas Labs pisound card
Load: dtoverlay=pisound
Params:
Name: pitft22 Info: Adafruit PiTFT 2.2" screen Load: dtoverlay=pitft22,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
debug Debug output level {0-7}
Name: pitft28-capacitive Info: Adafruit PiTFT 2.8" capacitive touch screen Load: dtoverlay=pitft28-capacitive,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
debug Debug output level {0-7}
touch-sizex Touchscreen size x (default 240)
touch-sizey Touchscreen size y (default 320)
touch-invx Touchscreen inverted x axis
touch-invy Touchscreen inverted y axis
touch-swapxy Touchscreen swapped x y axis
Name: pitft28-resistive Info: Adafruit PiTFT 2.8" resistive touch screen Load: dtoverlay=pitft28-resistive,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
debug Debug output level {0-7}
drm Force the use of the mi0283qt DRM driver (by
default the ili9340 framebuffer driver will
be used in preference if available)
Name: pitft35-resistive Info: Adafruit PiTFT 3.5" resistive touch screen Load: dtoverlay=pitft35-resistive,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
debug Debug output level {0-7}
drm Force the use of the hx8357d DRM driver (by
default the fb_hx8357d framebuffer driver will
be used in preference if available)
Name: pps-gpio Info: Configures the pps-gpio (pulse-per-second time signal via GPIO). Load: dtoverlay=pps-gpio,= Params: gpiopin Input GPIO (default "18") assert_falling_edge When present, assert is indicated by a falling edge, rather than by a rising edge (default off) capture_clear Generate clear events on the trailing edge (default off) pull Desired pull-up/down state (off, down, up) Default is "off".
Name: proto-codec
Info: Configures the PROTO Audio Codec card
Load: dtoverlay=proto-codec
Params:
Name: pwm Info: Configures a single PWM channel Legal pin,function combinations for each channel: PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1) PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1) N.B.: 1) Pin 18 is the only one available on all platforms, and it is the one used by the I2S audio interface. Pins 12 and 13 might be better choices on an A+, B+ or Pi2. 2) The onboard analogue audio output uses both PWM channels. 3) So be careful mixing audio and PWM. 4) Currently the clock must have been enabled and configured by other means. Load: dtoverlay=pwm,= Params: pin Output pin (default 18) - see table func Pin function (default 2 = Alt5) - see above clock PWM clock frequency (informational)
Name: pwm-2chan Info: Configures both PWM channels Legal pin,function combinations for each channel: PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1) PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1) N.B.: 1) Pin 18 is the only one available on all platforms, and it is the one used by the I2S audio interface. Pins 12 and 13 might be better choices on an A+, B+ or Pi2. 2) The onboard analogue audio output uses both PWM channels. 3) So be careful mixing audio and PWM. 4) Currently the clock must have been enabled and configured by other means. Load: dtoverlay=pwm-2chan,= Params: pin Output pin (default 18) - see table pin2 Output pin for other channel (default 19) func Pin function (default 2 = Alt5) - see above func2 Function for pin2 (default 2 = Alt5) clock PWM clock frequency (informational)
Name: pwm-ir-tx Info: Use GPIO pin as pwm-assisted infrared transmitter output. This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use of PWM0 to reduce the CPU load during transmission compared to gpio-ir-tx which uses bit-banging. Legal pin,function combinations are: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1) Load: dtoverlay=pwm-ir-tx,= Params: gpio_pin Output GPIO (default 18)
func Pin function (default 2 = Alt5)
Name: pwm1 Info: Configures one or two PWM channel on PWM1 (BCM2711 only) N.B.: 1) The onboard analogue audio output uses both PWM channels. 2) So be careful mixing audio and PWM. Note that even when only one pin is enabled, both channels are available from the PWM driver, so be careful to use the correct one. Load: dtoverlay=pwm1,= Params: clock PWM clock frequency (informational) pins_40 Enable channel 0 (PWM1_0) on GPIO 40 pins_41 Enable channel 1 (PWM1_1) on GPIO 41 pins_40_41 Enable channels 0 (PWM1_0) and 1 (PW1_1) on GPIOs 40 and 41 (default) pull_up Enable pull-ups on the PWM pins (default) pull_down Enable pull-downs on the PWM pins pull_off Disable pulls on the PWM pins
Name: qca7000 Info: in-tech's Evaluation Board for PLC Stamp micro This uses spi0 and a separate GPIO interrupt to connect the QCA7000. Load: dtoverlay=qca7000,= Params: int_pin GPIO pin for interrupt signal (default 23)
speed SPI bus speed (default 12 MHz)
Name: qca7000-uart0 Info: in-tech's Evaluation Board for PLC Stamp micro (UART) This uses uart0/ttyAMA0 over GPIOs 14 & 15 to connect the QCA7000. But it requires disabling of onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W. Load: dtoverlay=qca7000-uart0,= Params: baudrate Set the baudrate for the UART (default "115200")
Name: ramoops Info: Enable the preservation of crash logs across a reboot. With systemd-pstore enabled (as it is on Raspberry Pi OS) the crash logs are moved to /var/lib/systemd/pstore/ on reboot. Load: dtoverlay=ramoops,= Params: base-addr Where to place the capture buffer (default 0x0b000000) total-size How much memory to allocate altogether (in bytes - default 64kB) record-size How much space to use for each capture, i.e. total-size / record-size = number of captures (default 16kB) console-size Size of non-panic dmesg captures (default 0)
Name: ramoops-pi4 Info: The version of the ramoops overlay for the Pi 4 family. It should be loaded automatically if dtoverlay=ramoops is specified on a Pi 4. Load: dtoverlay=ramoops-pi4,= Params: base-addr Where to place the capture buffer (default 0x0b000000) total-size How much memory to allocate altogether (in bytes - default 64kB) record-size How much space to use for each capture, i.e. total-size / record-size = number of captures (default 16kB) console-size Size of non-panic dmesg captures (default 0)
Name: rotary-encoder Info: Overlay for GPIO connected rotary encoder. Load: dtoverlay=rotary-encoder,= Params: pin_a GPIO connected to rotary encoder channel A (default 4). pin_b GPIO connected to rotary encoder channel B (default 17). relative_axis register a relative axis rather than an absolute one. Relative axis will only generate +1/-1 events on the input device, hence no steps need to be passed. linux_axis the input subsystem axis to map to this rotary encoder. Defaults to 0 (ABS_X / REL_X) rollover Automatic rollover when the rotary value becomes greater than the specified steps or smaller than 0. For absolute axis only. steps-per-period Number of steps (stable states) per period. The values have the following meaning: 1: Full-period mode (default) 2: Half-period mode 4: Quarter-period mode steps Number of steps in a full turnaround of the encoder. Only relevant for absolute axis. Defaults to 24 which is a typical value for such devices. wakeup Boolean, rotary encoder can wake up the system. encoding String, the method used to encode steps. Supported are "gray" (the default and more common) and "binary".
Name: rpi-backlight
Info: Raspberry Pi official display backlight driver
Load: dtoverlay=rpi-backlight
Params:
Name: rpi-cirrus-wm5102 Info: This overlay has been renamed to cirrus-wm5102 Load:
Name: rpi-codeczero
Info: Configures the Raspberry Pi Codec Zero sound card
Load: dtoverlay=rpi-codeczero
Params:
Name: rpi-dac Info: This overlay has been renamed to i2s-dac. Load:
Name: rpi-dacplus Info: Configures the Raspberry Pi DAC+ card Load: dtoverlay=rpi-dacplus,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec digital volume control. Enable by adding "dtparam=24db_digital_gain" to config.txt before any "dtoverlay" lines. The default behaviour is that the digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24db_digital_gain parameter, the digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the digital volume control is set to a value that does not result in clipping/distortion!
Name: rpi-dacpro Info: Configures the Raspberry Pi DAC Pro sound card Load: dtoverlay=rpi-dacpro,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec digital volume control. Enable by adding "dtparam=24db_digital_gain" to config.txt before any "dtoverlay" lines. The default behaviour is that the digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24db_digital_gain parameter, the digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the digital volume control is set to a value that does not result in clipping/distortion!
Name: rpi-digiampplus Info: Configures the Raspberry Pi DigiAMP+ sound card Load: dtoverlay=rpi-digiampplus,= Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec digital volume control. Enable by adding "dtparam=24db_digital_gain" to config.txt before any "dtoverlay" lines. The default behaviour is that the digital volume control is limited to a maximum of 0dB. ie. it can attenuate but not provide gain. For most users, this will be desired as it will prevent clipping. By appending the 24db_digital_gain parameter, the digital volume control will allow up to 24dB of gain. If this parameter is enabled, it is the responsibility of the user to ensure that the digital volume control is set to a value that does not result in clipping/distortion! auto_mute_amp If specified, unmute/mute the DigiAMP+ when starting/stopping audio playback (default "on"). unmute_amp If specified, unmute the DigiAMP+ amp once when the DAC driver module loads (default "off").
Name: rpi-display Info: This overlay has been renamed to watterott-display Load:
Name: rpi-ft5406 Info: Official Raspberry Pi display touchscreen Load: dtoverlay=rpi-ft5406,= Params: touchscreen-size-x Touchscreen X resolution (default 800) touchscreen-size-y Touchscreen Y resolution (default 600); touchscreen-inverted-x Invert touchscreen X coordinates (default 0); touchscreen-inverted-y Invert touchscreen Y coordinates (default 0); touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
Name: rpi-poe Info: Raspberry Pi PoE HAT fan Load: dtoverlay=rpi-poe,[=] Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan turns on (default 40000) poe_fan_temp0_hyst Temperature delta (in millicelcius) at which the fan turns off (default 2000) poe_fan_temp1 Temperature (in millicelcius) at which the fan speeds up (default 45000) poe_fan_temp1_hyst Temperature delta (in millicelcius) at which the fan slows down (default 2000) poe_fan_temp2 Temperature (in millicelcius) at which the fan speeds up (default 50000) poe_fan_temp2_hyst Temperature delta (in millicelcius) at which the fan slows down (default 2000) poe_fan_temp3 Temperature (in millicelcius) at which the fan speeds up (default 55000) poe_fan_temp3_hyst Temperature delta (in millicelcius) at which the fan slows down (default 5000) i2c Control the fan via Linux I2C drivers instead of the firmware.
Name: rpi-poe-plus Info: Raspberry Pi PoE+ HAT fan Load: dtoverlay=rpi-poe-plus,[=] Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan turns on (default 40000) poe_fan_temp0_hyst Temperature delta (in millicelcius) at which the fan turns off (default 2000) poe_fan_temp1 Temperature (in millicelcius) at which the fan speeds up (default 45000) poe_fan_temp1_hyst Temperature delta (in millicelcius) at which the fan slows down (default 2000) poe_fan_temp2 Temperature (in millicelcius) at which the fan speeds up (default 50000) poe_fan_temp2_hyst Temperature delta (in millicelcius) at which the fan slows down (default 2000) poe_fan_temp3 Temperature (in millicelcius) at which the fan speeds up (default 55000) poe_fan_temp3_hyst Temperature delta (in millicelcius) at which the fan slows down (default 5000) i2c Control the fan via Linux I2C drivers instead of the firmware.
Name: rpi-proto Info: This overlay has been renamed to proto-codec. Load:
Name: rpi-sense
Info: Raspberry Pi Sense HAT
Load: dtoverlay=rpi-sense
Params:
Name: rpi-sense-v2
Info: Raspberry Pi Sense HAT v2
Load: dtoverlay=rpi-sense-v2
Params:
Name: rpi-tv
Info: Raspberry Pi TV HAT
Load: dtoverlay=rpi-tv
Params:
Name: rpivid-v4l2 Info: This overlay has been deprecated and deleted as the V4L2 stateless video decoder driver is enabled by default. Load:
Name: rra-digidac1-wm8741-audio
Info: Configures the Red Rocks Audio DigiDAC1 soundcard
Load: dtoverlay=rra-digidac1-wm8741-audio
Params:
Name: sainsmart18 Info: Overlay for the SPI-connected Sainsmart 1.8" display (based on the ST7735R chip). Load: dtoverlay=sainsmart18,= Params: rotate Display rotation {0,90,180,270} speed SPI bus speed in Hz (default 4000000) fps Display frame rate in Hz bgr Enable BGR mode (default off) debug Debug output level {0-7} dc_pin GPIO pin for D/C (default 24) reset_pin GPIO pin for RESET (default 25)
Name: sc16is750-i2c Info: Overlay for the NXP SC16IS750 UART with I2C Interface Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To select another address, please refer to table 10 in reference manual. Load: dtoverlay=sc16is750-i2c,= Params: int_pin GPIO used for IRQ (default 24) addr Address (default 0x48) xtal On-board crystal frequency (default 14745600)
Name: sc16is752-i2c Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To select another address, please refer to table 10 in reference manual. Load: dtoverlay=sc16is752-i2c,= Params: int_pin GPIO used for IRQ (default 24) addr Address (default 0x48) xtal On-board crystal frequency (default 14745600)
Name: sc16is752-spi0 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface Enables the chip on SPI0. Load: dtoverlay=sc16is752-spi0,= Params: int_pin GPIO used for IRQ (default 24) xtal On-board crystal frequency (default 14745600)
Name: sc16is752-spi1 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface Enables the chip on SPI1. N.B.: spi1 is only accessible on devices with a 40pin header, eg: A+, B+, Zero and PI2 B; as well as the Compute Module.
Load: dtoverlay=sc16is752-spi1,= Params: int_pin GPIO used for IRQ (default 24) xtal On-board crystal frequency (default 14745600)
Name: sdhost Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock. N.B. This overlay is designed for situations where the mmc driver is the default, so it disables the other (mmc) interface - this will kill WLAN on a Pi3. If this isn't what you want, either use the sdtweak overlay or the new sd_* dtparams of the base DTBs. Load: dtoverlay=sdhost,= Params: overclock_50 Clock (in MHz) to use when the MMC framework requests 50MHz
force_pio Disable DMA support (default off)
pio_limit Number of blocks above which to use DMA
(default 1)
debug Enable debug output (default off)
Name: sdio Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock, and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is "dtoverlay=sdio,bus_width=1,gpios_22_25" Load: dtoverlay=sdio,= Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC framework requests 50MHz
poll_once Disable SDIO-device polling every second
(default on: polling once at boot-time)
bus_width Set the SDIO host bus width (default 4 bits)
gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
with bus_width=1. This replaces the sdio-1bit
overlay, which is now deprecated.
gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
with bus_width=1.
gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
with bus_width=4 (the default).
Name: sdio-1bit Info: This overlay is now deprecated. Use "dtoverlay=sdio,bus_width=1,gpios_22_25" instead. Load:
Name: sdtweak Info: This overlay is now deprecated. Use the sd_* dtparams in the base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes "dtparam=sd_poll_once". Load:
Name: seeed-can-fd-hat-v1
Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
channels without RTC. Use this overlay if your HAT has no
battery holder.
https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
Load: dtoverlay=seeed-can-fd-hat-v1
Params:
Name: seeed-can-fd-hat-v2
Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
channels and an RTC. Use this overlay if your HAT has a
battery holder.
https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
Load: dtoverlay=seeed-can-fd-hat-v2
Params:
Name: sh1106-spi Info: Overlay for SH1106 OLED via SPI using fbtft staging driver. Load: dtoverlay=sh1106-spi,= Params: speed SPI bus speed (default 4000000) rotate Display rotation (0, 90, 180 or 270; default 0) fps Delay between frame updates (default 25) debug Debug output level (0-7; default 0) dc_pin GPIO pin for D/C (default 24) reset_pin GPIO pin for RESET (default 25) height Display height (32 or 64; default 64)
Name: si446x-spi0 Info: Overlay for Si446x UHF Transceiver via SPI using si446x driver. The driver is currently out-of-tree at https://github.com/sunipkmukherjee/silabs.git Load: dtoverlay=si446x-spi0,= Params: speed SPI bus speed (default 4000000) int_pin GPIO pin for interrupts (default 17) reset_pin GPIO pin for RESET (default 27)
Name: smi
Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
Load: dtoverlay=smi
Params:
Name: smi-dev
Info: Enables the userspace interface for the SMI driver
Load: dtoverlay=smi-dev
Params:
Name: smi-nand
Info: Enables access to NAND flash via the SMI interface
Load: dtoverlay=smi-nand
Params:
Name: spi-gpio35-39
Info: Move SPI function block to GPIO 35 to 39
Load: dtoverlay=spi-gpio35-39
Params:
Name: spi-gpio40-45
Info: Move SPI function block to GPIOs 40 to 45
Load: dtoverlay=spi-gpio40-45
Params:
Name: spi-rtc Info: Adds support for a number of SPI Real Time Clock devices Load: dtoverlay=spi-rtc,= Params: ds3232 Select the DS3232 device ds3234 Select the DS3234 device pcf2123 Select the PCF2123 device
spi0_0 Use spi0.0 (default)
spi0_1 Use spi0.1
spi1_0 Use spi1.0
spi1_1 Use spi1.1
spi2_0 Use spi2.0
spi2_1 Use spi2.1
cs_high This device requires an active-high CS
Name: spi0-0cs Info: Don't claim any CS pins for SPI0. Requires a device with its chip select permanently enabled, but frees a GPIO for e.g. a DPI display. Load: dtoverlay=spi0-0cs,= Params: no_miso Don't claim and use the MISO pin (9), freeing it for other uses.
Name: spi0-1cs Info: Only use one CS pin for SPI0 Load: dtoverlay=spi0-1cs,= Params: cs0_pin GPIO pin for CS0 (default 8) no_miso Don't claim and use the MISO pin (9), freeing it for other uses.
Name: spi0-2cs Info: Change the CS pins for SPI0 Load: dtoverlay=spi0-2cs,= Params: cs0_pin GPIO pin for CS0 (default 8) cs1_pin GPIO pin for CS1 (default 7) no_miso Don't claim and use the MISO pin (9), freeing it for other uses.
Name: spi0-cs Info: This overlay has been renamed spi0-2cs, keeping spi0-cs as an alias for backwards compatibility. Load:
Name: spi0-hw-cs Info: This overlay has been deprecated and removed because it is no longer necessary and has been seen to prevent spi0 from working. Load:
Name: spi1-1cs Info: Enables spi1 with a single chip select (CS) line and associated spidev dev node. The gpio pin number for the CS line and spidev device node creation are configurable. N.B.: spi1 is not accessible on old Pis without a 40-pin header. Load: dtoverlay=spi1-1cs,= Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0). cs0_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev1.0 (default is 'on' or enabled).
Name: spi1-2cs Info: Enables spi1 with two chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. N.B.: spi1 is not accessible on old Pis without a 40-pin header. Load: dtoverlay=spi1-2cs,= Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0). cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1). cs0_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev1.0 (default is 'on' or enabled). cs1_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev1.1 (default is 'on' or enabled).
Name: spi1-3cs Info: Enables spi1 with three chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. N.B.: spi1 is not accessible on old Pis without a 40-pin header. Load: dtoverlay=spi1-3cs,= Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0). cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1). cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2). cs0_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev1.0 (default is 'on' or enabled). cs1_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev1.1 (default is 'on' or enabled). cs2_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev1.2 (default is 'on' or enabled).
Name: spi2-1cs Info: Enables spi2 on GPIOs 40-42 with a single chip select (CS) line and associated spidev dev node. The gpio pin number for the CS line and spidev device node creation are configurable. spi2-2cs-pi5 is substituted on a Pi 5. N.B.: spi2 is only accessible with the Compute Module or Pi 5. Load: dtoverlay=spi2-1cs,= Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0). cs0_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev2.0 (default is 'on' or enabled).
Name: spi2-1cs-pi5 Info: Enables spi2 on GPIOs 1-3 with a single chip select (CS) line and associated spidev dev node. The gpio pin number for the CS line and spidev device node creation are configurable. Pi 5 only. Load: dtoverlay=spi2-1cs-pi5,= Params: cs0_pin GPIO pin for CS0 (default 0). cs0_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev2.0 (default is 'on' or enabled).
Name: spi2-2cs Info: Enables spi2 on GPIOs 40-42 with two chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. spi2-2cs-pi5 is substituted on a Pi 5. N.B.: spi2 is only accessible with the Compute Module or Pi 5. Load: dtoverlay=spi2-2cs,= Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0). cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1). cs0_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev2.0 (default is 'on' or enabled). cs1_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev2.1 (default is 'on' or enabled).
Name: spi2-2cs-pi5 Info: Enables spi2 on GPIOs 1-3 with two chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. Pi 5 only. Load: dtoverlay=spi2-2cs-pi5,= Params: cs0_pin GPIO pin for CS0 (default 0). cs1_pin GPIO pin for CS1 (default 24). cs0_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev2.0 (default is 'on' or enabled). cs1_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev2.1 (default is 'on' or enabled).
Name: spi2-3cs Info: Enables spi2 on GPIOs 40-42 with three chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. N.B.: spi2 is only accessible with the Compute Module or Pi 5. Load: dtoverlay=spi2-3cs,= Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0). cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1). cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2). cs0_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev2.0 (default is 'on' or enabled). cs1_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev2.1 (default is 'on' or enabled). cs2_spidev Set to 'off' to stop the creation of a userspace device node /dev/spidev2.2 (default is 'on' or enabled).
Name: spi3-1cs Info: Enables spi3 on GPIOs 1-3 with a single chip select (CS) line and associated spidev dev node. The gpio pin number for the CS line and spidev device node creation are configurable. BCM2711 only, spi3-1cs-pi5 is substituted on Pi 5. Load: dtoverlay=spi3-1cs,= Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0). cs0_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev3.0 (default is 'on' or enabled).
Name: spi3-1cs-pi5 Info: Enables spi3 on GPIOs 5-7 with a single chip select (CS) line and associated spidev dev node. The gpio pin number for the CS line and spidev device node creation are configurable. Pi 5 only. Load: dtoverlay=spi3-1cs-pi5,= Params: cs0_pin GPIO pin for CS0 (default 4). cs0_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev3.0 (default is 'on' or enabled).
Name: spi3-2cs Info: Enables spi3 on GPIO2 1-3 with two chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. BCM2711 only, spi3-2cs-pi5 is substituted on Pi 5. Load: dtoverlay=spi3-2cs,= Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0). cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1). cs0_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev3.0 (default is 'on' or enabled). cs1_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev3.1 (default is 'on' or enabled).
Name: spi3-2cs-pi5 Info: Enables spi3 on GPIOs 5-7 with two chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. Pi 5 only. Load: dtoverlay=spi3-2cs-pi5,= Params: cs0_pin GPIO pin for CS0 (default 4). cs1_pin GPIO pin for CS1 (default 25). cs0_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev3.0 (default is 'on' or enabled). cs1_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev3.1 (default is 'on' or enabled).
Name: spi4-1cs Info: Enables spi4 on GPIOs 5-7 with a single chip select (CS) line and associated spidev dev node. The gpio pin number for the CS line and spidev device node creation are configurable. BCM2711 only. Load: dtoverlay=spi4-1cs,= Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0). cs0_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev4.0 (default is 'on' or enabled).
Name: spi4-2cs Info: Enables spi4 on GPIOs 5-6 with two chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. BCM2711 only. Load: dtoverlay=spi4-2cs,= Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0). cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1). cs0_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev4.0 (default is 'on' or enabled). cs1_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev4.1 (default is 'on' or enabled).
Name: spi5-1cs Info: Enables spi5 on GPIOs 13-15 with a single chip select (CS) line and associated spidev dev node. The gpio pin numbers for the CS lines and spidev device node creation are configurable. BCM2711 and Pi 5. Load: dtoverlay=spi5-1cs,= Params: cs0_pin GPIO pin for CS0 (default 12). cs0_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev5.0 (default is 'on' or enabled).
Name: spi5-1cs-pi5 Info: See spi5-1cs
Name: spi5-2cs Info: Enables spi5 on GPIOs 13-15 with two chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. BCM2711 and Pi 5. Load: dtoverlay=spi5-2cs,= Params: cs0_pin GPIO pin for CS0 (default 12). cs1_pin GPIO pin for CS1 (default 26). cs0_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev5.0 (default is 'on' or enabled). cs1_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev5.1 (default is 'on' or enabled).
Name: spi5-2cs-pi5 Info: See spi5-2cs
Name: spi6-1cs Info: Enables spi6 with a single chip select (CS) line and associated spidev dev node. The gpio pin number for the CS line and spidev device node creation are configurable. BCM2711 only. Load: dtoverlay=spi6-1cs,= Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0). cs0_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev6.0 (default is 'on' or enabled).
Name: spi6-2cs Info: Enables spi6 with two chip select (CS) lines and associated spidev dev nodes. The gpio pin numbers for the CS lines and spidev device node creation are configurable. BCM2711 only. Load: dtoverlay=spi6-2cs,= Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0). cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1). cs0_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev6.0 (default is 'on' or enabled). cs1_spidev Set to 'off' to prevent the creation of a userspace device node /dev/spidev6.1 (default is 'on' or enabled).
Name: ssd1306 Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer. Load: dtoverlay=ssd1306,= Params: address Location in display memory of first character. (default=0) width Width of display. (default=128) height Height of display. (default=64) offset virtual channel a. (default=0) normal Has no effect on displays tested. (default=not set) sequential Set this if every other scan line is missing. (default=not set) remapped Set this if display is garbled. (default=not set) inverted Set this if display is inverted and mirrored. (default=not set)
Examples:
Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
i2c_baudrate=400000 will speed up the display.
i2c_baudrate=1000000 seems to work even though it's not officially
supported by the hardware, and is faster still.
For more information refer to the device datasheet at:
https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
Name: ssd1306-spi Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver. Load: dtoverlay=ssd1306-spi,= Params: speed SPI bus speed (default 10000000) rotate Display rotation (0, 90, 180 or 270; default 0) fps Delay between frame updates (default 25) debug Debug output level (0-7; default 0) dc_pin GPIO pin for D/C (default 24) reset_pin GPIO pin for RESET (default 25) height Display height (32 or 64; default 64) inverted Set this if display is inverted and mirrored. (default=not set)
Name: ssd1331-spi Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver. Load: dtoverlay=ssd1331-spi,= Params: speed SPI bus speed (default 4500000) rotate Display rotation (0, 90, 180 or 270; default 0) fps Delay between frame updates (default 25) debug Debug output level (0-7; default 0) dc_pin GPIO pin for D/C (default 24) reset_pin GPIO pin for RESET (default 25)
Name: ssd1351-spi Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver. Load: dtoverlay=ssd1351-spi,= Params: speed SPI bus speed (default 4500000) rotate Display rotation (0, 90, 180 or 270; default 0) fps Delay between frame updates (default 25) debug Debug output level (0-7; default 0) dc_pin GPIO pin for D/C (default 24) reset_pin GPIO pin for RESET (default 25)
Name: superaudioboard Info: Configures the SuperAudioBoard sound card Load: dtoverlay=superaudioboard,= Params: gpiopin GPIO pin for codec reset
Name: sx150x Info: Configures the Semtech SX150X I2C GPIO expanders. Load: dtoverlay=sx150x,= Params: sx150-- Enables SX150X device on I2C# with slave address . may be 1-9. may be 0 or 1. Permissible values of (which is denoted in hex) depend on the device variant. For SX1501, SX1502, SX1504 and SX1505, may be 20 or 21. For SX1503 and SX1506, may be 20. For SX1507 and SX1509, may be 3E, 3F, 70 or 71. For SX1508, may be 20, 21, 22 or 23.
sx150<x>-<n>-<m>-int-gpio
Integer, enables interrupts on SX150X device on
I2C#<n> with slave address <m>, specifies
the GPIO pin to which NINT output of SX150X is
connected.
Name: tc358743 Info: Toshiba TC358743 HDMI to CSI-2 bridge chip. Uses Unicam 1, which is the standard camera connector on most Pi variants. Load: dtoverlay=tc358743,= Params: 4lane Use 4 lanes (only applicable to Compute Modules CAM1 connector).
link-frequency Set the link frequency. Only values of 297000000
(574Mbit/s) and 486000000 (972Mbit/s - default)
are supported by the driver.
media-controller Configure use of Media Controller API for
configuring the sensor (default off)
cam0 Adopt the default configuration for CAM0 on a
Compute Module (CSI0, i2c_vc, and cam0_reg).
Name: tc358743-audio Info: Used in combination with the tc358743-fast overlay to route the audio from the TC358743 over I2S to the Pi. Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO 20. Load: dtoverlay=tc358743-audio,= Params: card-name Override the default, "tc358743", card name.
Name: tinylcd35 Info: 3.5" Color TFT Display by www.tinylcd.com Options: Touch, RTC, keypad Load: dtoverlay=tinylcd35,= Params: speed Display SPI bus speed
rotate Display rotation {0,90,180,270}
fps Delay between frame updates
debug Debug output level {0-7}
touch Enable touch panel
touchgpio Touch controller IRQ GPIO
xohms Touchpanel: Resistance of X-plate in ohms
rtc-pcf PCF8563 Real Time Clock
rtc-ds DS1307 Real Time Clock
keypad Enable keypad
Examples:
Display with touchpanel, PCF8563 RTC and keypad:
dtoverlay=tinylcd35,touch,rtc-pcf,keypad
Old touch display:
dtoverlay=tinylcd35,touch,touchgpio=3
Name: tpm-slb9670
Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
boards, which can be used as a secure key storage and hwrng,
available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
Load: dtoverlay=tpm-slb9670
Params:
Name: tpm-slb9673
Info: Enables support for Infineon SLB9673 Trusted Platform Module add-on
boards, which can be used as a secure key storage and hwrng
via the I2C protocol.
Load: dtoverlay=tpm-slb9673
Params:
Name: uart0 Info: Change the pin usage of uart0 Load: dtoverlay=uart0,= Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
pin_func Alternative pin function - 4(Alt0) for 14&15,
7(Alt3) for 32&33, 6(Alt2) for 36&37
Name: uart0-pi5 Info: Enable uart 0 on GPIOs 14-15. Pi 5 only. Load: dtoverlay=uart0-pi5, Params: ctsrts Enable CTS/RTS on GPIOs 16-17 (default off)
Name: uart1 Info: Change the pin usage of uart1 Load: dtoverlay=uart1,= Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
Name: uart1-pi5 Info: Enable uart 1 on GPIOs 0-1. Pi 5 only. Load: dtoverlay=uart1-pi5, Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
Name: uart2 Info: Enable uart 2 on GPIOs 0-3. BCM2711 only. Load: dtoverlay=uart2, Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
Name: uart2-pi5 Info: Enable uart 2 on GPIOs 4-5. Pi 5 only. Load: dtoverlay=uart2-pi5, Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
Name: uart3 Info: Enable uart 3 on GPIOs 4-7. BCM2711 only. Load: dtoverlay=uart3, Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
Name: uart3-pi5 Info: Enable uart 3 on GPIOs 8-9. Pi 5 only. Load: dtoverlay=uart3-pi5, Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
Name: uart4 Info: Enable uart 4 on GPIOs 8-11. BCM2711 only. Load: dtoverlay=uart4, Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
Name: uart4-pi5 Info: Enable uart 4 on GPIOs 12-13. Pi 5 only. Load: dtoverlay=uart4-pi5, Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
Name: uart5 Info: Enable uart 5 on GPIOs 12-15. BCM2711 only. Load: dtoverlay=uart5, Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
Name: udrc Info: Configures the NW Digital Radio UDRC Hat Load: dtoverlay=udrc,= Params: alsaname Name of the ALSA audio device (default "udrc")
Name: ugreen-dabboard Info: Configures the ugreen-dabboard I2S overlay This is a simple overlay based on the simple-audio-card and the dmic codec. It has the speciality that it is configured to use the codec as a master I2S device. It works for example with the Si468x DAB receiver on the uGreen DABBoard. Load: dtoverlay=ugreen-dabboard,= Params: card-name Override the default, "dabboard", card name.
Name: upstream
Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
vc4-kms-v3d and dwc2 overlays.
Load: dtoverlay=upstream
Params:
Name: upstream-aux-interrupt Info: This overlay has been deprecated and removed because it is no longer necessary. Load:
Name: upstream-pi4
Info: Allow usage of downstream .dtb with upstream kernel on Pi 4. Comprises
the vc4-kms-v3d-pi4 and dwc2 overlays.
Load: dtoverlay=upstream-pi4
Params:
Name: vc4-fkms-v3d Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx display stack. Load: dtoverlay=vc4-fkms-v3d, Params: cma-512 CMA is 512MB (needs 1GB) cma-448 CMA is 448MB (needs 1GB) cma-384 CMA is 384MB (needs 1GB) cma-320 CMA is 320MB (needs 1GB) cma-256 CMA is 256MB (needs 1GB) cma-192 CMA is 192MB (needs 1GB) cma-128 CMA is 128MB cma-96 CMA is 96MB cma-64 CMA is 64MB cma-size CMA size in bytes, 4MB aligned cma-default Use upstream's default value
Name: vc4-fkms-v3d-pi4 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx display stack. Load: dtoverlay=vc4-fkms-v3d-pi4, Params: cma-512 CMA is 512MB (needs 1GB) cma-448 CMA is 448MB (needs 1GB) cma-384 CMA is 384MB (needs 1GB) cma-320 CMA is 320MB (needs 1GB) cma-256 CMA is 256MB (needs 1GB) cma-192 CMA is 192MB (needs 1GB) cma-128 CMA is 128MB cma-96 CMA is 96MB cma-64 CMA is 64MB cma-size CMA size in bytes, 4MB aligned cma-default Use upstream's default value
Name: vc4-kms-dpi-at056tn53v1 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,at056tn53v1 Load:
Name: vc4-kms-dpi-generic Info: Enable a generic DPI display under KMS. Default timings are for the Adafruit Kippah with 800x480 panel and RGB666 (GPIOs 0-21) Requires vc4-kms-v3d to be loaded. Load: dtoverlay=vc4-kms-dpi-generic,= Params: clock-frequency Display clock frequency (Hz) hactive Horizontal active pixels hfp Horizontal front porch hsync Horizontal sync pulse width hbp Horizontal back porch vactive Vertical active lines vfp Vertical front porch vsync Vertical sync pulse width vbp Vertical back porch hsync-invert Horizontal sync active low vsync-invert Vertical sync active low de-invert Data Enable active low pixclk-invert Negative edge pixel clock width-mm Define the screen width in mm height-mm Define the screen height in mm rgb565 Change to RGB565 output on GPIOs 0-19 rgb565-padhi Change to RGB565 output on GPIOs 0-8, 12-17, and 20-24 bgr666 Change to BGR666 output on GPIOs 0-21. bgr666-padhi Change to BGR666 output on GPIOs 0-9, 12-17, and 20-25 rgb666-padhi Change to RGB666 output on GPIOs 0-9, 12-17, and 20-25 bgr888 Change to BGR888 output on GPIOs 0-27 rgb888 Change to RGB888 output on GPIOs 0-27 bus-format Override the bus format for a MEDIA_BUS_FMT_* value. NB also overridden by rgbXXX overrides. backlight-gpio Defines a GPIO to be used for backlight control (default of none). backlight-pwm Defines a PWM channel to be used for backlight control (default of none). NB Disables audio headphone output as that also uses PWM. backlight-pwm-chan Choose channel on &pwm node for backlight control. (default 0). backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See pwm-2chan for valid options. (default 18 - note this can only work with rgb666-padhi). backlight-pwm-func Pin function of GPIO used for the PWM backlight. See pwm-2chan for valid options. (default 2). backlight-def-brightness Set the default brightness. Normal range 1-16. (default 16). rotate Display rotation {0,90,180,270} (default 0)
Name: vc4-kms-dpi-hyperpixel2r Info: Enable the KMS drivers for the Pimoroni HyperPixel2 Round DPI display. Requires vc4-kms-v3d to be loaded. Load: dtoverlay=vc4-kms-dpi-hyperpixel2r,= Params: disable-touch Disables the touch controller touchscreen-inverted-x Inverts X direction of touch controller touchscreen-inverted-y Inverts Y direction of touch controller touchscreen-swapped-x-y Swaps X & Y axes of touch controller rotate Display rotation {0,90,180,270} (default 0)
Name: vc4-kms-dpi-hyperpixel4 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 DPI display. Requires vc4-kms-v3d to be loaded. Load: dtoverlay=vc4-kms-dpi-hyperpixel4,= Params: disable-touch Disables the touch controller touchscreen-inverted-x Inverts X direction of touch controller touchscreen-inverted-y Inverts Y direction of touch controller touchscreen-swapped-x-y Swaps X & Y axes of touch controller rotate Display rotation {0,90,180,270} (default 0)
Name: vc4-kms-dpi-hyperpixel4sq Info: Enable the KMS drivers for the Pimoroni HyperPixel4 Square DPI display. Requires vc4-kms-v3d to be loaded. Load: dtoverlay=vc4-kms-dpi-hyperpixel4sq,= Params: disable-touch Disables the touch controller touchscreen-inverted-x Inverts X direction of touch controller touchscreen-inverted-y Inverts Y direction of touch controller touchscreen-swapped-x-y Swaps X & Y axes of touch controller rotate Display rotation {0,90,180,270} (default 0)
Name: vc4-kms-dpi-panel Info: Enable a preconfigured KMS DPI panel. Requires vc4-kms-v3d to be loaded. Load: dtoverlay=vc4-kms-dpi-panel,= Params: at056tn53v1 Enable an Innolux 5.6in VGA TFT kippah-7inch Enable an Adafruit Kippah with 7inch panel. mzp280 Enable a Geekworm MZP280 panel. backlight-gpio Defines a GPIO to be used for backlight control (default of none). backlight-pwm Defines a PWM channel to be used for backlight control (default of none). NB Disables audio headphone output as that also uses PWM. backlight-pwm-chan Choose channel on &pwm node for backlight control. (default 0). backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See pwm-2chan for valid options. (default 18 - note this can only work with rgb666-padhi). backlight-pwm-func Pin function of GPIO used for the PWM backlight. See pwm-2chan for valid options. (default 2). backlight-def-brightness Set the default brightness. Normal range 1-16. (default 16). rotate Display rotation {0,90,180,270} (default 0)
Name: vc4-kms-dsi-7inch Info: Enable the Raspberry Pi DSI 7" screen. Includes the edt-ft5406 for the touchscreen element. Requires vc4-kms-v3d to be loaded. Load: dtoverlay=vc4-kms-dsi-7inch,= Params: sizex Touchscreen size x (default 800) sizey Touchscreen size y (default 480) invx Touchscreen inverted x axis invy Touchscreen inverted y axis swapxy Touchscreen swapped x y axis disable_touch Disables the touch screen overlay driver dsi0 Use DSI0 and i2c_csi_dsi0 (rather than the default DSI1 and i2c_csi_dsi).
Name: vc4-kms-dsi-lt070me05000 Info: Enable a JDI LT070ME05000 DSI display on DSI1. Note that this is a 4 lane DSI device, so it will only work on a Compute Module. Requires vc4-kms-v3d to be loaded. Load: dtoverlay=vc4-kms-dsi-lt070me05000, Params: reset GPIO for the reset signal (default 17) enable GPIO for the enable signal (default 4) dcdc-en GPIO for the DC-DC converter enable (default 5)
Name: vc4-kms-dsi-lt070me05000-v2
Info: Enable a JDI LT070ME05000 DSI display on DSI1 using Harlab's V2
interface board.
Note that this is a 4 lane DSI device, so it will only work on a Compute
Module.
Requires vc4-kms-v3d to be loaded.
Load: dtoverlay=vc4-kms-dsi-lt070me05000-v2
Params:
Name: vc4-kms-dsi-waveshare-panel Info: Enable a Waveshare DSI touchscreen Includes the Goodix driver for the touchscreen element. The default is for the display to be using the I2C0 option for control. Use the i2c1 override if using the I2C1 wiring with jumper wires from GPIOs 2&3 (pins 3&5). invx/invy/swapxy should be used with caution as the panel specifier will set the default inversions for that panel. Always use them after the panel specifier, and be aware that you may need to set them as =0, not just adding it. Requires vc4-kms-v3d to be loaded. Load: dtoverlay=vc4-kms-dsi-waveshare-panel,= Params: 2_8_inch 2.8" 480x640 3_4_inch 3.4" 800x800 round 4_0_inch 4.0" 480x800 7_0_inchC 7.0" C 1024x600 7_9_inch 7.9" 400x1280 8_0_inch 8.0" 1280x800 10_1_inch 10.1" 1280x800 11_9_inch 11.9" 320x1480 i2c1 Use i2c-1 with jumper wires from GPIOs 2&3 disable_touch Disable the touch controller rotation Set the panel orientation property invx Touchscreen inverted x axis invy Touchscreen inverted y axis swapxy Touchscreen swapped x y axis dsi0 Use DSI0 and i2c_csi_dsi0 (rather than the default DSI1 and i2c_csi_dsi).
Name: vc4-kms-kippah-7inch Info: This overlay is now deprecated - see vc4-kms-dpi-panel,kippah-7inch Load:
Name: vc4-kms-v3d Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver. Load: dtoverlay=vc4-kms-v3d, Params: cma-512 CMA is 512MB (needs 1GB) cma-448 CMA is 448MB (needs 1GB) cma-384 CMA is 384MB (needs 1GB) cma-320 CMA is 320MB (needs 1GB) cma-256 CMA is 256MB (needs 1GB) cma-192 CMA is 192MB (needs 1GB) cma-128 CMA is 128MB cma-96 CMA is 96MB cma-64 CMA is 64MB cma-size CMA size in bytes, 4MB aligned cma-default Use upstream's default value audio Enable or disable audio over HDMI (default "on") noaudio Disable all HDMI audio (default "off") composite Enable the composite output (default "off") N.B. Disables all other outputs on a Pi 4. nohdmi Disable HDMI output
Name: vc4-kms-v3d-pi4 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver for Pi4. Load: dtoverlay=vc4-kms-v3d-pi4, Params: cma-512 CMA is 512MB cma-448 CMA is 448MB cma-384 CMA is 384MB cma-320 CMA is 320MB cma-256 CMA is 256MB cma-192 CMA is 192MB cma-128 CMA is 128MB cma-96 CMA is 96MB cma-64 CMA is 64MB cma-size CMA size in bytes, 4MB aligned cma-default Use upstream's default value audio Enable or disable audio over HDMI0 (default "on") audio1 Enable or disable audio over HDMI1 (default "on") noaudio Disable all HDMI audio (default "off") composite Enable the composite output (disables all other outputs) nohdmi Disable both HDMI 0 & 1 outputs nohdmi0 Disable HDMI 0 output nohdmi1 Disable HDMI 1 output
Name: vc4-kms-v3d-pi5 Info: See vc4-kms-v3d-pi4 (this is the Pi 5 version)
Name: vc4-kms-vga666 Info: Enable the VGA666 (resistor ladder ADC) for the vc4-kms-v3d driver. Requires vc4-kms-v3d to be loaded. Load: dtoverlay=vc4-kms-vga666, Params: ddc Enables GPIOs 0&1 as the I2C to read the EDID from the display. NB These are NOT 5V tolerant GPIOs, therefore level shifters are required.
Name: vga666
Info: Overlay for the Fen Logic VGA666 board
This uses GPIOs 2-21 (so no I2C), and activates the output 2-3 seconds
after the kernel has started.
NOT for use with vc4-kms-v3d.
Load: dtoverlay=vga666
Params:
Name: vl805
Info: Overlay to enable a VIA VL805 USB3 controller on CM4 carriers
Will be loaded automatically by up-to-date firmware if "VL805=1" is
set in the EEPROM config.
Load: dtoverlay=vl805
Params:
Name: w1-gpio Info: Configures the w1-gpio Onewire interface module. Use this overlay if you don't need a GPIO to drive an external pullup. Load: dtoverlay=w1-gpio,= Params: gpiopin GPIO for I/O (default "4") pullup Now enabled by default (ignored)
Name: w1-gpio-pullup Info: Configures the w1-gpio Onewire interface module. Use this overlay if you do need a GPIO to drive an external pullup. Load: dtoverlay=w1-gpio-pullup,= Params: gpiopin GPIO for I/O (default "4") extpullup GPIO for external pullup (default "5") pullup Now enabled by default (ignored)
Name: w5500 Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0 Load: dtoverlay=w5500,= Params: int_pin GPIO used for INT (default 25)
speed SPI bus speed (default 30000000)
cs SPI bus Chip Select (default 0)
Name: watterott-display Info: Watterott RPi-Display - 2.8" Touch Display Linux has 2 drivers that support this display and this overlay supports both.
Examples:
fbtft/fb_ili9341: dtoverlay=watterott-display
drm/mi0283qt: dtoverlay=watterott-display,drm,backlight-pwm,rotate=180
Some notable differences with the DRM driver compared to fbtft:
- The display is turned on when it's first used and not on driver load
as with fbtft. So if nothing uses the display it stays off.
- Can run with a higher SPI clock increasing framerate. This is possible
since the driver avoids messing up the controller configuration due to
transmission errors by running config commands at 10MHz and only pixel
data at full speed (occasional pixel glitch might occur).
- PWM backlight is supported.
Load: dtoverlay=watterott-display,= Params: speed Display SPI bus speed rotate Display rotation {0,90,180,270} fps Delay between frame updates (fbtft only) debug Debug output level {0-7} (fbtft only) xohms Touchpanel sensitivity (X-plate resistance) swapxy Swap x and y axis backlight Change backlight GPIO pin {e.g. 12, 18} (fbtft only) drm Use DRM/KMS driver mi0283qt instead of fbtft. Set the SPI clock to 70MHz. This has to be the first parameter. backlight-pwm Use pwm for backlight (drm only). NB: Disables audio headphone output as that also uses PWM.
Name: waveshare-can-fd-hat-mode-a
Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
for Raspberry Pi, Multi Protections. Use this overlay when the
HAT is configured in Mode A (Default), with can0 on spi0.0
and can1 on spi1.0.
https://www.waveshare.com/2-ch-can-fd-hat.htm
Load: dtoverlay=waveshare-can-fd-hat-mode-a
Params:
Name: waveshare-can-fd-hat-mode-b
Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
for Raspberry Pi, Multi Protections. Use this overlay when the
HAT is configured in Mode B (requires hardware modification), with
can0 on spi0.0 and can1 on spi0.1.
https://www.waveshare.com/2-ch-can-fd-hat.htm
Load: dtoverlay=waveshare-can-fd-hat-mode-b
Params:
Name: wittypi Info: Configures the wittypi RTC module. Load: dtoverlay=wittypi,= Params: led_gpio GPIO for LED (default "17") led_trigger Choose which activity the LED tracks (default "default-on")
Name: wm8960-soundcard Info: Overlay for the Waveshare wm8960 soundcard Load: dtoverlay=wm8960-soundcard,= Params: alsaname Changes the card name in ALSA compatible Changes the codec compatibility
Troubleshooting
If you are experiencing problems that you think are DT-related, enable DT diagnostic output by adding this to /boot/config.txt:
dtdebug=on
and rebooting. Then run:
sudo vcdbg log msg
and look for relevant messages.
Further reading
This is only meant to be a quick introduction to the subject of Device Tree on Raspberry Pi. There is a more complete explanation here:
http://www.raspberrypi.org/documentation/configuration/device-tree.md