rhoering
commented
1 year ago 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=onHowever, 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_deviceWith DT enabled, this becomes a line in config.txt:
dtoverlay=i2c-rtc,ds1307This 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=0x68Parameters 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,pcf85063While 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.dtsThe -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=mergedIt 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:
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.
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.
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_arm Set to "on" to enable the ARM's i2c interface
(default "off")
i2c_vc Set to "on" to enable the i2c interface
usually reserved for the VideoCore processor
(default "off")
i2c An alias for i2c_arm
i2c_arm_baudrate Set the baudrate of the ARM's i2c interface
(default "100000")
i2c_vc_baudrate Set the baudrate of the VideoCore i2c interface
(default "100000")
i2c_baudrate An alias for i2c_arm_baudrate
i2s Set to "on" to enable the i2s interface
(default "off")
krnbt Set to "on" to enable autoprobing of Bluetooth
driver without need of hciattach/btattach
(default "off")
krnbt_baudrate Set the baudrate of the PL011 UART when used
with krnbt=on
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
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")
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.
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")
uart1 Set to "on" or "off" to enable or disable uart1
(default varies)
watchdog Set to "on" to enable the hardware watchdog
(default "off")
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,=
gpio Set which GPIO to use for the activity LED
(in case you want to connect it to an external
device)
REQUIREDName: 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,=
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,=
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,=
Name: ads1015
Info: Overlay for activation of Texas Instruments ADS1015 ADC over I2C
Load: dtoverlay=ads1015,=
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.pdfName: ads1115
Info: Texas Instruments ADS1115 ADC
Load: dtoverlay=ads1115,[=
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.pdfName: ads7846
Info: ADS7846 Touch controller
Load: dtoverlay=ads7846,=
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.txtName: 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,=
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,=
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,=
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,=
Name: apds9960
Info: Configures the AVAGO APDS9960 digital proximity, ambient light, RGB and
gesture sensor
Load: dtoverlay=apds9960,=
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,=
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,=
Name: at86rf233
Info: Configures the Atmel AT86RF233 802.15.4 low-power WPAN transceiver,
connected to spi0.0
Load: dtoverlay=at86rf233,=
Name: audioinjector-addons
Info: Configures the audioinjector.net audio add on soundcards
Load: dtoverlay=audioinjector-addons,=
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,=
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,=
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,=
Name: cap1106
Info: Enables the ability to use the cap1106 touch sensor as a keyboard
Load: dtoverlay=cap1106,=
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,=
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,=
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,=
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,=
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,=
Name: disable-bt
Info: Disable onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W, restoring
UART0/ttyAMA0 over GPIOs 14 & 15.
N.B. To disable the systemd service that initialises the modem so it
doesn't use the UART, use 'sudo systemctl disable hciuart'.
Load: dtoverlay=disable-bt
Params:
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 Pi 3B, 3B+, 3A+, 4B and Zero W.
Load: dtoverlay=disable-wifi
Params:
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 = 3300spsLoad: dtoverlay=draws,=
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,=
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 on the CSI/DSI I2C interface.
This works with the Raspberry Pi 7" touchscreen when not being polled
by the firmware.
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,=
Name: enc28j60
Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
Load: dtoverlay=enc28j60,=
speed SPI bus speed (default 12000000)Name: enc28j60-spi2
Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
Load: dtoverlay=enc28j60-spi2,=
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,=
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,=
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 backlightName: 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,=
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,=
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,=
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,=
Name: googlevoicehat-soundcard
Info: Configures the Google voiceHAT soundcard
Load: dtoverlay=googlevoicehat-soundcard
Params:
Name: gpio-fan
Info: Configure a GPIO pin to control a cooling fan.
Load: dtoverlay=gpio-fan,=
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,=
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,=
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,=
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,=
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.rstLoad: dtoverlay=gpio-led,=
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,=
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,=
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,=
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 charactersName: 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,=
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,=
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,=
Name: hifiberry-dacplusadc
Info: Configures the HifiBerry DAC+ADC audio card
Load: dtoverlay=hifiberry-dacplusadc,=
Name: hifiberry-dacplusadcpro
Info: Configures the HifiBerry DAC+ADC PRO audio card
Load: dtoverlay=hifiberry-dacplusadcpro,=
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,=
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 backlightName: hy28b
Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
Default values match Texy's display shield
Load: dtoverlay=hy28b,=
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 backlightName: 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,=
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 backlightName: 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,=
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)
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,=
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,=
pca9545 Select the NXP PCA9545 device
pca9548 Select the NXP PCA9548 device
addr Change I2C address of the device (default 0x70)[ 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,=
Name: i2c-rtc
Info: Adds support for a number of I2C Real Time Clock devices
Load: dtoverlay=i2c-rtc,=
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, RV1805, RV3028)
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 only)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,=
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, RV1805, RV3028)
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 only)
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,=
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
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.
sht3x Select the Sensiron SHT3x temperature and
humidity sensor. 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,=
Name: i2c0-bcm2708
Info: Deprecated, legacy version of i2c0.
Load:
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,=
Name: i2c1-bcm2708
Info: Deprecated, legacy version of i2c1.
Load:
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: 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,=
Name: imx219
Info: Sony IMX219 camera module.
Uses Unicam 1, which is the standard camera connector on most Pi
variants.
Load: dtoverlay=imx219,=
Name: imx258
Info: Sony IMX258 camera module.
Uses Unicam 1, which is the standard camera connector on most Pi
variants.
Load: dtoverlay=imx258,=
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,=
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,=
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,=
Name: imx519
Info: Sony IMX519 camera module.
Uses Unicam 1, which is the standard camera connector on most Pi
variants.
Load: dtoverlay=imx519,=
Name: imx708
Info: Sony IMX708 camera module.
Uses Unicam 1, which is the standard camera connector on most Pi
variants.
Load: dtoverlay=imx708,=
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,=
Name: iqaudio-digi-wm8804-audio
Info: Configures the IQAudIO Digi WM8804 audio card
Load: dtoverlay=iqaudio-digi-wm8804-audio,=
Name: iqs550
Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller
using GPIO 4 (pin 7 on GPIO header) for interrupt.
Load: dtoverlay=iqs550,=
Name: irs1125
Info: Infineon irs1125 TOF camera module.
Uses Unicam 1, which is the standard camera connector on most Pi
variants.
Load: dtoverlay=irs1125,=
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,=
Name: justboom-both
Info: Simultaneous usage of an justboom-dac and justboom-digi based
card
Load: dtoverlay=justboom-both,=
Name: justboom-dac
Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
cards
Load: dtoverlay=justboom-dac,=
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,=
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,=
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_jLoad: dtoverlay=maxtherm,=
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,=
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,=
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,=
oscillator Clock frequency for the CAN controller (Hz)
speed Maximum SPI frequence (Hz)
interrupt GPIO for interrupt signalName: mcp2515-can0
Info: Configures the MCP2515 CAN controller on spi0.0
Load: dtoverlay=mcp2515-can0,=
spimaxfrequency Maximum SPI frequence (Hz)
interrupt GPIO for interrupt signalName: mcp2515-can1
Info: Configures the MCP2515 CAN controller on spi0.1
Load: dtoverlay=mcp2515-can1,=
spimaxfrequency Maximum SPI frequence (Hz)
interrupt GPIO for interrupt signalName: 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,=
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,[=
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,[=
Name: mcp342x
Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
Load: dtoverlay=mcp342x,=
Name: media-center
Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
Load: dtoverlay=media-center,=
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-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-uart2
Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
31.25kbaud, the frequency required for MIDI
Load: dtoverlay=midi-uart2
Params:
Name: midi-uart3
Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
31.25kbaud, the frequency required for MIDI
Load: dtoverlay=midi-uart3
Params:
Name: midi-uart4
Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
31.25kbaud, the frequency required for MIDI
Load: dtoverlay=midi-uart4
Params:
Name: midi-uart5
Info: Configures UART5 (ttyAMA4) 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,=
Name: miniuart-bt Info: Switch the onboard Bluetooth function on Pi 3B, 3B+, 3A+, 4B and Zero W to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 &
- Note that this may reduce the maximum usable baudrate.
N.B. It is also necessary to edit /lib/systemd/system/hciuart.service
and replace ttyAMA0 with ttyS0, unless using Raspbian or another
distribution with udev rules that create /dev/serial0 and /dev/serial1,
in which case use /dev/serial1 instead because it will always be
correct. Furthermore, you must also set core_freq and core_freq_min to
the same value in config.txt or the miniuart will not work.
Load: dtoverlay=miniuart-bt,=
Params: krnbt Set to "on" to enable 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,=
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,=
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,=
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,=
Name: ov5647
Info: Omnivision OV5647 camera module.
Uses Unicam 1, which is the standard camera connector on most Pi
variants.
Load: dtoverlay=ov5647,=
Name: ov7251
Info: Omnivision OV7251 camera module.
Uses Unicam 1, which is the standard camera connector on most Pi
variants.
Load: dtoverlay=ov7251,=
Name: ov9281
Info: Omnivision OV9281 camera module.
Uses Unicam 1, which is the standard camera connector on most Pi
variants.
Load: dtoverlay=ov9281,=
Name: papirus
Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
Load: dtoverlay=papirus,=
speed Display SPI bus speedName: pca953x
Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
Load: dtoverlay=pca953x,=
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,=
Name: pifacedigital
Info: Configures the PiFace Digital mcp23s17 GPIO port expander.
Load: dtoverlay=pifacedigital,=
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,=
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: piscreen2r
Info: PiScreen 2 with resistive TP display by OzzMaker.com
Load: dtoverlay=piscreen2r,=
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,=
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,=
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 axisName: pitft28-resistive
Info: Adafruit PiTFT 2.8" resistive touch screen
Load: dtoverlay=pitft28-resistive,=
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,=
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,=
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,=
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,=
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,=
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,=
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,=
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,=
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,=
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,=
Name: rotary-encoder
Info: Overlay for GPIO connected rotary encoder.
Load: dtoverlay=rotary-encoder,=
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,=
Name: rpi-dacpro
Info: Configures the Raspberry Pi DAC Pro sound card
Load: dtoverlay=rpi-dacpro,=
Name: rpi-digiampplus
Info: Configures the Raspberry Pi DigiAMP+ sound card
Load: dtoverlay=rpi-digiampplus,=
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,=
Name: rpi-poe
Info: Raspberry Pi PoE HAT fan
Load: dtoverlay=rpi-poe,[=
Name: rpi-poe-plus
Info: Raspberry Pi PoE+ HAT fan
Load: dtoverlay=rpi-poe-plus,[=
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,=
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,=
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,=
Name: sc16is752-spi0
Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
Enables the chip on SPI0.
Load: dtoverlay=sc16is752-spi0,=
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,=
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,=
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,=
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,=
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,=
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,=
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 CSName: 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,=
Name: spi0-1cs
Info: Only use one CS pin for SPI0
Load: dtoverlay=spi0-1cs,=
Name: spi0-2cs
Info: Change the CS pins for SPI0
Load: dtoverlay=spi0-2cs,=
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 only accessible on devices with a 40pin header, eg:
A+, B+, Zero and PI2 B; as well as the Compute Module.
Load: dtoverlay=spi1-1cs,=
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 only accessible on devices with a 40pin header, eg:
A+, B+, Zero and PI2 B; as well as the Compute Module.
Load: dtoverlay=spi1-2cs,=
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 only accessible on devices with a 40pin header, eg:
A+, B+, Zero and PI2 B; as well as the Compute Module.
Load: dtoverlay=spi1-3cs,=
Name: spi2-1cs
Info: Enables spi2 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.: spi2 is only accessible with the Compute Module.
Load: dtoverlay=spi2-1cs,=
Name: spi2-2cs
Info: Enables spi2 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.: spi2 is only accessible with the Compute Module.
Load: dtoverlay=spi2-2cs,=
Name: spi2-3cs
Info: Enables spi2 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.
Load: dtoverlay=spi2-3cs,=
Name: spi3-1cs
Info: Enables spi3 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=spi3-1cs,=
Name: spi3-2cs
Info: Enables spi3 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=spi3-2cs,=
Name: spi4-1cs
Info: Enables spi4 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,=
Name: spi4-2cs
Info: Enables spi4 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,=
Name: spi5-1cs
Info: Enables spi5 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 only.
Load: dtoverlay=spi5-1cs,=
Name: spi5-2cs
Info: Enables spi5 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=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,=
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,=
Name: ssd1306
Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
Load: dtoverlay=ssd1306,=
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.pdfName: ssd1306-spi
Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver.
Load: dtoverlay=ssd1306-spi,=
Name: ssd1331-spi
Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver.
Load: dtoverlay=ssd1331-spi,=
Name: ssd1351-spi
Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver.
Load: dtoverlay=ssd1351-spi,=
Name: superaudioboard
Info: Configures the SuperAudioBoard sound card
Load: dtoverlay=superaudioboard,=
Name: sx150x
Info: Configures the Semtech SX150X I2C GPIO expanders.
Load: dtoverlay=sx150x,=
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,=
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,=
Name: tinylcd35
Info: 3.5" Color TFT Display by www.tinylcd.com
Options: Touch, RTC, keypad
Load: dtoverlay=tinylcd35,=
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=3Name: 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: uart0
Info: Change the pin usage of uart0
Load: dtoverlay=uart0,=
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&37Name: uart1
Info: Change the pin usage of uart1
Load: dtoverlay=uart1,=
rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)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: 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: 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: 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,=
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,=
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,=
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,=
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,=
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,=
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,=
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,=
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-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-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,=
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,=
Name: w5500
Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
Load: dtoverlay=w5500,=
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,=
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,=
Name: wm8960-soundcard
Info: Overlay for the Waveshare wm8960 soundcard
Load: dtoverlay=wm8960-soundcard,=
Troubleshooting
If you are experiencing problems that you think are DT-related, enable DT diagnostic output by adding this to /boot/config.txt:
dtdebug=onand rebooting. Then run:
sudo vcdbg log msgand 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
jcorporation
rpi-dac / i2s-dac do not show up in the results when running audiohat.sh. They are present in the overlays/README.
myMPDos:/usr/bin# ./audiohat.sh Downloading audio hats description 1) allo-boss-dac-pcm512x-audio 2) allo-boss2-dac-audio 3) allo-digione 4) allo-katana-dac-audio 5) allo-piano-dac-pcm512x-audio 6) allo-piano-dac-plus-pcm512x-audio 7) applepi-dac 8) chipdip-dac 9) hifiberry-amp 10) hifiberry-amp100 11) hifiberry-amp3 12) hifiberry-dac 13) hifiberry-dacplus 14) hifiberry-dacplusadc 15) hifiberry-dacplusadcpro 16) hifiberry-dacplusdsp 17) hifiberry-dacplushd 18) hifiberry-digi 19) hifiberry-digi-pro 20) iqaudio-codec 21) iqaudio-dac 22) iqaudio-dacplus 23) iqaudio-digi-wm8804-audio 24) justboom-digi 25) merus-amp 26) pibell