+Introduction
+============
+
+This directory contains Device Tree overlays. Device Tree makes it possible
+to support many hardware configurations with a single kernel and without the
+need to explicitly load or blacklist kernel modules. Note that this isn't a
+"pure" Device Tree configuration (c.f. MACH_BCM2835) - some on-board devices
+are still configured by the board support code, but the intention is to
+eventually reach that goal.
+
+On Raspberry Pi, Device Tree usage is controlled from /boot/config.txt. By
+default, the Raspberry Pi kernel boots with device tree enabled. You can
+completely disable DT usage (for now) by adding:
+
+ device_tree=
+
+to your config.txt, which should cause your Pi to revert to the old way of
+doing things after a reboot.
+
+In /boot you will find a .dtb for each base platform. This describes the
+hardware that is part of the Raspberry Pi board. The loader (start.elf and its
+siblings) selects the .dtb file appropriate for the platform by name, and reads
+it into memory. At this point, all of the optional interfaces (i2c, i2s, spi)
+are disabled, but they can be enabled using Device Tree parameters:
+
+ dtparam=i2c=on,i2s=on,spi=on
+
+However, this shouldn't be necessary in many use cases because loading an
+overlay that requires one of those interfaces will cause it to be enabled
+automatically, and it is advisable to only enable interfaces if they are
+needed.
+
+Configuring additional, optional hardware is done using Device Tree overlays
+(see below).
+
+GPIO numbering uses the hardware pin numbering scheme (aka BCM scheme) and
+not the physical pin numbers.
+
+raspi-config
+============
+
+The Advanced Options section of the raspi-config utility can enable and disable
+Device Tree use, as well as toggling the I2C and SPI interfaces. Note that it
+is possible to both enable an interface and blacklist the driver, if for some
+reason you should want to defer the loading.
+
+Modules
+=======
+
+As well as describing the hardware, Device Tree also gives enough information
+to allow suitable driver modules to be located and loaded, with the corollary
+that unneeded modules are not loaded. As a result it should be possible to
+remove lines from /etc/modules, and /etc/modprobe.d/raspi-blacklist.conf can
+have its contents deleted (or commented out).
+
+Using Overlays
+==============
+
+Overlays are loaded using the "dtoverlay" config.txt setting. As an example,
+consider I2C Real Time Clock drivers. In the pre-DT world these would be loaded
+by writing a magic string comprising a device identifier and an I2C address to
+a special file in /sys/class/i2c-adapter, having first loaded the driver for
+the I2C interface and the RTC device - something like this:
+
+ modprobe i2c-bcm2835
+ modprobe rtc-ds1307
+ echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device
+
+With DT enabled, this becomes a line in config.txt:
+
+ dtoverlay=i2c-rtc,ds1307
+
+This causes the file /boot/overlays/i2c-rtc.dtbo to be loaded and a "node"
+describing the DS1307 I2C device to be added to the Device Tree for the Pi. By
+default it usees address 0x68, but this can be modified with an additional DT
+parameter:
+
+ dtoverlay=i2c-rtc,ds1307,addr=0x68
+
+Parameters usually have default values, although certain parameters are
+mandatory. See the list of overlays below for a description of the parameters
+and their defaults.
+
+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: <The base DTB>
+Info: Configures the base Raspberry Pi hardware
+Load: <loaded automatically>
+Params:
+ 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.
+
+ eee Enable Energy Efficient Ethernet support for
+ compatible devices (default "on"). See also
+ "tx_lpi_timer".
+
+ 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).
+
+ eth_led0 Set mode of LED0 (usually orange) (default
+ "1"). The legal values are:
+ 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
+
+ eth_led1 Set mode of LED1 (usually green) (default
+ "6"). 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).
+
+ 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")
+
+ spi Set to "on" to enable the spi interfaces
+ (default "off")
+
+ random Set to "on" to enable the hardware random
+ number generator (default "on")
+
+ sd_overclock Clock (in MHz) to use when the MMC framework
+ requests 50MHz
+
+ 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/WiFi 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,<param>=<val>
+Params: activelow Set to "on" to invert the sense of the LED
+ (default "off")
+
+ gpio Set which GPIO to use for the activity LED
+ (in case you want to connect it to an external
+ device)
+ REQUIRED
+
+
+Name: adau1977-adc
+Info: Overlay for activation of ADAU1977 ADC codec over I2C for control
+ and I2S for data.
+Load: dtoverlay=adau1977-adc
+Params: <None>
+
+
+Name: adau7002-simple
+Info: Overlay for the activation of ADAU7002 stereo PDM to I2S converter.
+Load: dtoverlay=adau7002-simple,<param>=<val>
+Params: card-name Override the default, "adau7002", card name.
+
+
+Name: ads1015
+Info: Overlay for activation of Texas Instruments ADS1015 ADC over I2C
+Load: dtoverlay=ads1015,<param>=<val>
+Params: addr I2C bus address of device. Set based on how the
+ addr pin is wired. (default=0x48 assumes addr
+ is pulled to GND)
+ cha_enable Enable virtual channel a. (default=true)
+ cha_cfg Set the configuration for virtual channel a.
+ (default=4 configures this channel for the
+ voltage at A0 with respect to GND)
+ cha_datarate Set the datarate (samples/sec) for this channel.
+ (default=4 sets 1600 sps)
+ cha_gain Set the gain of the Programmable Gain
+ Amplifier for this channel. (default=2 sets the
+ full scale of the channel to 2.048 Volts)
+
+ Channel (ch) parameters can be set for each enabled channel.
+ A maximum of 4 channels can be enabled (letters a thru d).
+ For more information refer to the device datasheet at:
+ http://www.ti.com/lit/ds/symlink/ads1015.pdf
+
+
+Name: ads1115
+Info: Texas Instruments ADS1115 ADC
+Load: dtoverlay=ads1115,<param>[=<val>]
+Params: addr I2C bus address of device. Set based on how the
+ addr pin is wired. (default=0x48 assumes addr
+ is pulled to GND)
+ cha_enable Enable virtual channel a.
+ cha_cfg Set the configuration for virtual channel a.
+ (default=4 configures this channel for the
+ voltage at A0 with respect to GND)
+ cha_datarate Set the datarate (samples/sec) for this channel.
+ (default=7 sets 860 sps)
+ cha_gain Set the gain of the Programmable Gain
+ Amplifier for this channel. (Default 1 sets the
+ full scale of the channel to 4.096 Volts)
+
+ Channel parameters can be set for each enabled channel.
+ A maximum of 4 channels can be enabled (letters a thru d).
+ For more information refer to the device datasheet at:
+ http://www.ti.com/lit/ds/symlink/ads1115.pdf
+
+
+Name: ads7846
+Info: ADS7846 Touch controller
+Load: dtoverlay=ads7846,<param>=<val>
+Params: cs SPI bus Chip Select (default 1)
+ speed SPI bus speed (default 2MHz, max 3.25MHz)
+ penirq GPIO used for PENIRQ. REQUIRED
+ penirq_pull Set GPIO pull (default 0=none, 2=pullup)
+ swapxy Swap x and y axis
+ xmin Minimum value on the X axis (default 0)
+ ymin Minimum value on the Y axis (default 0)
+ xmax Maximum value on the X axis (default 4095)
+ ymax Maximum value on the Y axis (default 4095)
+ pmin Minimum reported pressure value (default 0)
+ pmax Maximum reported pressure value (default 65535)
+ xohms Touchpanel sensitivity (X-plate resistance)
+ (default 400)
+
+ penirq is required and usually xohms (60-100) has to be set as well.
+ Apart from that, pmax (255) and swapxy are also common.
+ The rest of the calibration can be done with xinput-calibrator.
+ See: github.com/notro/fbtft/wiki/FBTFT-on-Raspian
+ Device Tree binding document:
+ www.kernel.org/doc/Documentation/devicetree/bindings/input/ads7846.txt
+
+
+Name: adv7282m
+Info: Analog Devices ADV7282M analogue video to CSI2 bridge.
+ Uses Unicam1, which is the standard camera connector on most Pi
+ variants.
+Load: dtoverlay=adv7282m,<param>=<val>
+Params: i2c_pins_0_1 Use pins 0&1 for the I2C instead of 44&45.
+ Useful on Compute Modules.
+ i2c_pins_28_29 Use pins 28&29 for the I2C instead of 44&45.
+ This is required for Pi B+, 2, 0, and 0W.
+ addr Overrides the I2C address (default 0x21)
+
+
+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,<param>=<val>
+Params: i2c_pins_0_1 Use pins 0&1 for the I2C instead of 44&45.
+ Useful on Compute Modules.
+ i2c_pins_28_29 Use pins 28&29 for the I2C instead of 44&45.
+ This is required for Pi B+, 2, 0, and 0W.
+ addr Overrides the I2C address (default 0x21)
+ adv7280m Select ADV7280-M.
+ adv7281m Select ADV7281-M.
+ adv7281ma Select ADV7281-MA.
+
+
+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,<param>=<val>
+Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
+ Digital volume control. Enable with
+ dtoverlay=akkordion-iqdacplus,24db_digital_gain
+ (The default behaviour is that the Digital
+ volume control is limited to a maximum of
+ 0dB. ie. it can attenuate but not provide
+ gain. For most users, this will be desired
+ as it will prevent clipping. By appending
+ the 24db_digital_gain parameter, the Digital
+ volume control will allow up to 24dB of
+ gain. If this parameter is enabled, it is the
+ responsibility of the user to ensure that
+ the Digital volume control is set to a value
+ that does not result in clipping/distortion!)
+
+
+Name: allo-boss-dac-pcm512x-audio
+Info: Configures the Allo Boss DAC audio cards.
+Load: dtoverlay=allo-boss-dac-pcm512x-audio,<param>
+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-digione
+Info: Configures the Allo Digione audio card
+Load: dtoverlay=allo-digione
+Params: <None>
+
+
+Name: allo-katana-dac-audio
+Info: Configures the Allo Katana DAC audio card
+Load: dtoverlay=allo-katana-dac-audio
+Params: <None>
+
+
+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,<param>
+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,<param>
+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: applepi-dac
+Info: Configures the Orchard Audio ApplePi-DAC audio card
+Load: dtoverlay=applepi-dac
+Params: <None>
+
+
+Name: at86rf233
+Info: Configures the Atmel AT86RF233 802.15.4 low-power WPAN transceiver,
+ connected to spi0.0
+Load: dtoverlay=at86rf233,<param>=<val>
+Params: interrupt GPIO used for INT (default 23)
+ reset GPIO used for Reset (default 24)
+ sleep GPIO used for Sleep (default 25)
+ speed SPI bus speed in Hz (default 3000000)
+ trim Fine tuning of the internal capacitance
+ arrays (0=+0pF, 15=+4.5pF, default 15)
+
+
+Name: audioinjector-addons
+Info: Configures the audioinjector.net audio add on soundcards
+Load: dtoverlay=audioinjector-addons,<param>=<val>
+Params: non-stop-clocks Keeps the clocks running even when the stream
+ is paused or stopped (default off)
+
+
+Name: audioinjector-ultra
+Info: Configures the audioinjector.net ultra soundcard
+Load: dtoverlay=audioinjector-ultra
+Params: <None>
+
+
+Name: audioinjector-wm8731-audio
+Info: Configures the audioinjector.net audio add on soundcard
+Load: dtoverlay=audioinjector-wm8731-audio
+Params: <None>
+
+
+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: <None>
+
+
+Name: audremap
+Info: Switches PWM sound output to GPIOs on the 40-pin header
+Load: dtoverlay=audremap,<param>=<val>
+Params: swap_lr Reverse the channel allocation, which will also
+ swap the audio jack outputs (default off)
+ enable_jack Don't switch off the audio jack output
+ (default off)
+ pins_12_13 Select GPIOs 12 & 13 (default)
+ pins_18_19 Select GPIOs 18 & 19
+
+
+Name: balena-fin
+Info: Overlay that enables WiFi, Bluetooth and the GPIO expander on the
+ balenaFin carrier board for the Raspberry Pi Compute Module 3/3+ Lite.
+Load: dtoverlay=balena-fin
+Params: <None>
+
+
+Name: bmp085_i2c-sensor
+Info: This overlay is now deprecated - see i2c-sensor
+Load: <Deprecated>
+
+
+Name: dht11
+Info: Overlay for the DHT11/DHT21/DHT22 humidity/temperature sensors
+ Also sometimes found with the part number(s) AM230x.
+Load: dtoverlay=dht11,<param>=<val>
+Params: gpiopin GPIO connected to the sensor's DATA output.
+ (default 4)
+
+
+Name: dionaudio-loco
+Info: Configures the Dion Audio LOCO DAC-AMP
+Load: dtoverlay=dionaudio-loco
+Params: <None>
+
+
+Name: dionaudio-loco-v2
+Info: Configures the Dion Audio LOCO-V2 DAC-AMP
+Load: dtoverlay=dionaudio-loco-v2,<param>=<val>
+Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
+ Digital volume control. Enable with
+ "dtoverlay=hifiberry-dacplus,24db_digital_gain"
+ (The default behaviour is that the Digital
+ volume control is limited to a maximum of
+ 0dB. ie. it can attenuate but not provide
+ gain. For most users, this will be desired
+ as it will prevent clipping. By appending
+ the 24dB_digital_gain parameter, the Digital
+ volume control will allow up to 24dB of
+ gain. If this parameter is enabled, it is the
+ responsibility of the user to ensure that
+ the Digital volume control is set to a value
+ that does not result in clipping/distortion!)
+
+
+Name: disable-bt
+Info: Disable onboard Bluetooth on 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: <None>
+
+
+Name: disable-wifi
+Info: Disable onboard WiFi on Pi 3B, 3B+, 3A+, 4B and Zero W.
+Load: dtoverlay=disable-wifi
+Params: <None>
+
+
+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: <None>
+
+
+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: <None>
+
+
+Name: draws
+Info: Configures the NW Digital Radio DRAWS Hat
+
+ The board includes an ADC to measure various board values and also
+ provides two analog user inputs on the expansion header. The ADC
+ can be configured for various sample rates and gain values to adjust
+ the input range. Tables describing the two parameters follow.
+
+ ADC Gain Values:
+ 0 = +/- 6.144V
+ 1 = +/- 4.096V
+ 2 = +/- 2.048V
+ 3 = +/- 1.024V
+ 4 = +/- 0.512V
+ 5 = +/- 0.256V
+ 6 = +/- 0.256V
+ 7 = +/- 0.256V
+
+ ADC Datarate Values:
+ 0 = 128sps
+ 1 = 250sps
+ 2 = 490sps
+ 3 = 920sps
+ 4 = 1600sps (default)
+ 5 = 2400sps
+ 6 = 3300sps
+ 7 = 3300sps
+Load: dtoverlay=draws,<param>=<val>
+Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
+ input voltage sensor (default 1)
+
+ draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
+ sensor
+
+ draws_adc_ch5_gain Sets the full scale resolution of the ADCs
+ 5V rail voltage sensor (default 1)
+
+ draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
+ sensor
+
+ draws_adc_ch6_gain Sets the full scale resolution of the ADCs
+ AIN2 input (default 2)
+
+ draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
+
+ draws_adc_ch7_gain Sets the full scale resolution of the ADCs
+ AIN3 input (default 2)
+
+ draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
+
+ alsaname Name of the ALSA audio device (default "draws")
+
+
+Name: dwc-otg
+Info: Selects the dwc_otg USB controller driver which has fiq support. This
+ is the default on all except the Pi Zero which defaults to dwc2.
+Load: dtoverlay=dwc-otg
+Params: <None>
+
+
+Name: dwc2
+Info: Selects the dwc2 USB controller driver
+Load: dtoverlay=dwc2,<param>=<val>
+Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
+
+ g-rx-fifo-size Size of rx fifo size in gadget mode
+
+ g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
+ mode
+
+
+[ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
+
+
+Name: enc28j60
+Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
+Load: dtoverlay=enc28j60,<param>=<val>
+Params: int_pin GPIO used for INT (default 25)
+
+ speed SPI bus speed (default 12000000)
+
+
+Name: enc28j60-spi2
+Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
+Load: dtoverlay=enc28j60-spi2,<param>=<val>
+Params: int_pin GPIO used for INT (default 39)
+
+ speed SPI bus speed (default 12000000)
+
+
+Name: exc3000
+Info: Enables I2C connected EETI EXC3000 multiple touch controller using
+ GPIO 4 (pin 7 on GPIO header) for interrupt.
+Load: dtoverlay=exc3000,<param>=<val>
+Params: interrupt GPIO used for interrupt (default 4)
+ sizex Touchscreen size x (default 4096)
+ sizey Touchscreen size y (default 4096)
+ invx Touchscreen inverted x axis
+ invy Touchscreen inverted y axis
+ swapxy Touchscreen swapped x y axis
+
+
+Name: fe-pi-audio
+Info: Configures the Fe-Pi Audio Sound Card
+Load: dtoverlay=fe-pi-audio
+Params: <None>
+
+
+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,<param>=<val>
+Params: interrupt GPIO used for interrupt (default 4)
+ reset GPIO used for reset (default 17)
+
+
+Name: googlevoicehat-soundcard
+Info: Configures the Google voiceHAT soundcard
+Load: dtoverlay=googlevoicehat-soundcard
+Params: <None>
+
+
+Name: gpio-fan
+Info: Configure a GPIO pin to control a cooling fan.
+Load: dtoverlay=gpio-fan,<param>=<val>
+Params: gpiopin GPIO used to control the fan (default 12)
+ temp Temperature at which the fan switches on, in
+ millicelcius (default 55000)
+
+
+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,<param>=<val>
+Params: gpio_pin Input pin number. Default is 18.
+
+ gpio_pull Desired pull-up/down state (off, down, up)
+ Default is "up".
+
+ 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,<param>=<val>
+Params: gpio_pin Output GPIO (default 18)
+
+ invert "1" = invert the output (make it active-low).
+ Default is "0" (active-high).
+
+
+Name: gpio-key
+Info: This is a generic overlay for activating GPIO keypresses using
+ the gpio-keys library and this dtoverlay. Multiple keys can be
+ set up using multiple calls to the overlay for configuring
+ additional buttons or joysticks. You can see available keycodes
+ at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
+ linux/input-event-codes.h#L64
+Load: dtoverlay=gpio-key,<param>=<val>
+Params: gpio GPIO pin to trigger on (default 3)
+ active_low When this is 1 (active low), a falling
+ edge generates a key down event and a
+ rising edge generates a key up event.
+ When this is 0 (active high), this is
+ reversed. The default is 1 (active low)
+ gpio_pull Desired pull-up/down state (off, down, up)
+ Default is "up". Note that the default pin
+ (GPIO3) has an external pullup
+ label Set a label for the key
+ keycode Set the key code for the button
+
+
+Name: gpio-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: <None>
+
+
+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: <None>
+
+
+Name: gpio-poweroff
+Info: Drives a GPIO high or low on poweroff (including halt). Enabling this
+ overlay will prevent the ability to boot by driving GPIO3 low.
+Load: dtoverlay=gpio-poweroff,<param>=<val>
+Params: gpiopin GPIO for signalling (default 26)
+
+ active_low Set if the power control device requires a
+ high->low transition to trigger a power-down.
+ Note that this will require the support of a
+ custom dt-blob.bin to prevent a power-down
+ during the boot process, and that a reboot
+ will also cause the pin to go low.
+ input Set if the gpio pin should be configured as
+ an input.
+ export Set to export the configured pin to sysfs
+
+
+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"
+
+ 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.
+Load: dtoverlay=gpio-shutdown,<param>=<val>
+Params: gpio_pin GPIO pin to trigger on (default 3)
+
+ active_low When this is 1 (active low), a falling
+ edge generates a key down event and a
+ rising edge generates a key up event.
+ When this is 0 (active high), this is
+ reversed. The default is 1 (active low).
+
+ gpio_pull Desired pull-up/down state (off, down, up)
+ Default is "up".
+
+ Note that the default pin (GPIO3) has an
+ external pullup.
+
+ 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,<param>=<val>
+Params: pin_d4 GPIO pin for data pin D4 (default 6)
+
+ pin_d5 GPIO pin for data pin D5 (default 13)
+
+ pin_d6 GPIO pin for data pin D6 (default 19)
+
+ pin_d7 GPIO pin for data pin D7 (default 26)
+
+ pin_en GPIO pin for "Enable" (default 21)
+
+ pin_rs GPIO pin for "Register Select" (default 20)
+
+ pin_bl Optional pin for enabling/disabling the
+ display backlight. (default disabled)
+
+ display_height Height of the display in characters
+
+ display_width Width of the display in characters
+
+
+Name: hifiberry-amp
+Info: Configures the HifiBerry Amp and Amp+ audio cards
+Load: dtoverlay=hifiberry-amp
+Params: <None>
+
+
+Name: hifiberry-dac
+Info: Configures the HifiBerry DAC audio card
+Load: dtoverlay=hifiberry-dac
+Params: <None>
+
+
+Name: hifiberry-dacplus
+Info: Configures the HifiBerry DAC+ audio card
+Load: dtoverlay=hifiberry-dacplus,<param>=<val>
+Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
+ Digital volume control. Enable with
+ "dtoverlay=hifiberry-dacplus,24db_digital_gain"
+ (The default behaviour is that the Digital
+ volume control is limited to a maximum of
+ 0dB. ie. it can attenuate but not provide
+ gain. For most users, this will be desired
+ as it will prevent clipping. By appending
+ the 24dB_digital_gain parameter, the Digital
+ volume control will allow up to 24dB of
+ gain. If this parameter is enabled, it is the
+ responsibility of the user to ensure that
+ the Digital volume control is set to a value
+ that does not result in clipping/distortion!)
+ slave Force DAC+ Pro into slave mode, using Pi as
+ master for bit clock and frame clock.
+
+
+Name: hifiberry-dacplusadc
+Info: Configures the HifiBerry DAC+ADC audio card
+Load: dtoverlay=hifiberry-dacplusadc,<param>=<val>
+Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
+ Digital volume control. Enable with
+ "dtoverlay=hifiberry-dacplus,24db_digital_gain"
+ (The default behaviour is that the Digital
+ volume control is limited to a maximum of
+ 0dB. ie. it can attenuate but not provide
+ gain. For most users, this will be desired
+ as it will prevent clipping. By appending
+ the 24dB_digital_gain parameter, the Digital
+ volume control will allow up to 24dB of
+ gain. If this parameter is enabled, it is the
+ responsibility of the user to ensure that
+ the Digital volume control is set to a value
+ that does not result in clipping/distortion!)
+ slave Force DAC+ Pro into slave mode, using Pi as
+ master for bit clock and frame clock.
+
+
+Name: hifiberry-dacplusadcpro
+Info: Configures the HifiBerry DAC+ADC PRO audio card
+Load: dtoverlay=hifiberry-dacplusadcpro,<param>=<val>
+Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
+ Digital volume control. Enable with
+ "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain"
+ (The default behaviour is that the Digital
+ volume control is limited to a maximum of
+ 0dB. ie. it can attenuate but not provide
+ gain. For most users, this will be desired
+ as it will prevent clipping. By appending
+ the 24dB_digital_gain parameter, the Digital
+ volume control will allow up to 24dB of
+ gain. If this parameter is enabled, it is the
+ responsibility of the user to ensure that
+ the Digital volume control is set to a value
+ that does not result in clipping/distortion!)
+ slave Force DAC+ADC Pro into slave mode, using Pi as
+ master for bit clock and frame clock.
+
+
+Name: hifiberry-dacplusdsp
+Info: Configures the HifiBerry DAC+DSP audio card
+Load: dtoverlay=hifiberry-dacplusdsp
+Params: <None>
+
+
+Name: hifiberry-digi
+Info: Configures the HifiBerry Digi and Digi+ audio card
+Load: dtoverlay=hifiberry-digi
+Params: <None>
+
+
+Name: hifiberry-digi-pro
+Info: Configures the HifiBerry Digi+ Pro audio card
+Load: dtoverlay=hifiberry-digi-pro
+Params: <None>
+
+
+Name: hy28a
+Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics
+ Default values match Texy's display shield
+Load: dtoverlay=hy28a,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ debug Debug output level {0-7}
+
+ xohms Touchpanel sensitivity (X-plate resistance)
+
+ resetgpio GPIO used to reset controller
+
+ ledgpio GPIO used to control backlight
+
+
+Name: hy28b
+Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
+ Default values match Texy's display shield
+Load: dtoverlay=hy28b,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ debug Debug output level {0-7}
+
+ xohms Touchpanel sensitivity (X-plate resistance)
+
+ resetgpio GPIO used to reset controller
+
+ ledgpio GPIO used to control backlight
+
+
+Name: hy28b-2017
+Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics
+ Default values match Texy's display shield
+Load: dtoverlay=hy28b-2017,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ debug Debug output level {0-7}
+
+ xohms Touchpanel sensitivity (X-plate resistance)
+
+ resetgpio GPIO used to reset controller
+
+ ledgpio GPIO used to control backlight
+
+
+Name: i-sabre-q2m
+Info: Configures the Audiophonics I-SABRE Q2M DAC
+Load: dtoverlay=i-sabre-q2m
+Params: <None>
+
+
+Name: i2c-bcm2708
+Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
+Load: dtoverlay=i2c-bcm2708
+Params: <None>
+
+
+Name: i2c-gpio
+Info: Adds support for software i2c controller on gpio pins
+Load: dtoverlay=i2c-gpio,<param>=<val>
+Params: i2c_gpio_sda GPIO used for I2C data (default "23")
+
+ i2c_gpio_scl GPIO used for I2C clock (default "24")
+
+ i2c_gpio_delay_us Clock delay in microseconds
+ (default "2" = ~100kHz)
+
+ bus Set to a unique, non-zero value if wanting
+ multiple i2c-gpio busses. If set, will be used
+ as the preferred bus number (/dev/i2c-<n>). If
+ not set, the default value is 0, but the bus
+ number will be dynamically assigned - probably
+ 3.
+
+
+Name: i2c-mux
+Info: Adds support for a number of I2C bus multiplexers on i2c_arm
+Load: dtoverlay=i2c-mux,<param>=<val>
+Params: pca9542 Select the NXP PCA9542 device
+
+ pca9545 Select the NXP PCA9545 device
+
+ pca9548 Select the NXP PCA9548 device
+
+ addr Change I2C address of the device (default 0x70)
+
+
+[ 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,<param>=<val>
+Params: addr I2C address of PCA9685A (default 0x40)
+
+
+Name: i2c-rtc
+Info: Adds support for a number of I2C Real Time Clock devices
+Load: dtoverlay=i2c-rtc,<param>=<val>
+Params: abx80x Select one of the ABx80x family:
+ AB0801, AB0803, AB0804, AB0805,
+ AB1801, AB1803, AB1804, AB1805
+
+ ds1307 Select the DS1307 device
+
+ ds1339 Select the DS1339 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
+
+ pcf8523 Select the PCF8523 device
+
+ pcf8563 Select the PCF8563 device
+
+ rv3028 Select the Micro Crystal RV3028 device
+
+ addr Sets the address for the RTC. Note that the
+ device must be configured to use the specified
+ address.
+
+ trickle-diode-type Diode type for trickle charge - "standard" or
+ "schottky" (ABx80x only)
+
+ trickle-resistor-ohms Resistor value for trickle charge (DS1339,
+ ABx80x, 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,<param>=<val>
+Params: abx80x Select one of the ABx80x family:
+ AB0801, AB0803, AB0804, AB0805,
+ AB1801, AB1803, AB1804, AB1805
+
+ ds1307 Select the DS1307 device
+
+ ds1339 Select the DS1339 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
+
+ pcf8523 Select the PCF8523 device
+
+ pcf8563 Select the PCF8563 device
+
+ rv3028 Select the Micro Crystal RV3028 device
+
+ addr Sets the address for the RTC. Note that the
+ device must be configured to use the specified
+ address.
+
+ trickle-diode-type Diode type for trickle charge - "standard" or
+ "schottky" (ABx80x only)
+
+ trickle-resistor-ohms Resistor value for trickle charge (DS1339,
+ ABx80x, 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 and temperature
+ sensors on i2c_arm
+Load: dtoverlay=i2c-sensor,<param>=<val>
+Params: addr Set the address for the BME280, BMP280, DS1621,
+ HDC100X, LM75, SHT3x or TMP102
+
+ bme280 Select the Bosch Sensortronic BME280
+ 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
+
+ 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
+
+ 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
+
+ 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
+
+ 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
+
+
+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.
+Load: dtoverlay=i2c0,<param>=<val>
+Params: pins_0_1 Use pins 0 and 1 (default)
+ pins_28_29 Use pins 28 and 29
+ pins_44_45 Use pins 44 and 45
+ pins_46_47 Use pins 46 and 47
+ combine Allow transactions to be combined (default
+ "yes")
+
+
+Name: i2c0-bcm2708
+Info: Deprecated, legacy version of i2c0, from which it inherits its
+ parameters, just adding the explicit individual pin specifiers.
+Load: <Deprecated>
+Params: sda0_pin GPIO pin for SDA0 (deprecated - use pins_*)
+ scl0_pin GPIO pin for SCL0 (deprecated - use pins_*)
+
+
+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,<param>=<val>
+Params: pins_2_3 Use pins 2 and 3 (default)
+ pins_44_45 Use pins 44 and 45
+ combine Allow transactions to be combined (default
+ "yes")
+
+
+Name: i2c1-bcm2708
+Info: Deprecated, legacy version of i2c1, from which it inherits its
+ parameters, just adding the explicit individual pin specifiers.
+Load: <Deprecated>
+Params: sda1_pin GPIO pin for SDA1 (2 or 44 - default 2)
+ scl1_pin GPIO pin for SCL1 (3 or 45 - default 3)
+ pin_func Alternative pin function (4 (alt0), 6 (alt2) -
+ default 4)
+
+
+Name: i2c3
+Info: Enable the i2c3 bus
+Load: dtoverlay=i2c3,<param>
+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
+Load: dtoverlay=i2c4,<param>
+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
+Load: dtoverlay=i2c5,<param>
+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
+Load: dtoverlay=i2c6,<param>
+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-gpio28-31
+Info: move I2S function block to GPIO 28 to 31
+Load: dtoverlay=i2s-gpio28-31
+Params: <None>
+
+
+Name: ilitek251x
+Info: Enables I2C connected Ilitek 251x multiple touch controller using
+ GPIO 4 (pin 7 on GPIO header) for interrupt.
+Load: dtoverlay=ilitek251x,<param>=<val>
+Params: interrupt GPIO used for interrupt (default 4)
+ sizex Touchscreen size x, horizontal resolution of
+ touchscreen (in pixels)
+ sizey Touchscreen size y, vertical resolution of
+ touchscreen (in pixels)
+
+
+Name: imx219
+Info: Sony IMX219 camera module.
+ Uses Unicam 1, which is the standard camera connector on most Pi
+ variants.
+Load: dtoverlay=imx219,<param>=<val>
+Params: i2c_pins_0_1 Use pins 0&1 for the I2C instead of 44&45.
+ Useful on Compute Modules.
+
+ i2c_pins_28_29 Use pins 28&29 for the I2C instead of 44&45.
+ This is required for Pi B+, 2, 0, and 0W.
+
+
+Name: iqaudio-codec
+Info: Configures the IQaudio Codec audio card
+Load: dtoverlay=iqaudio-codec
+Params: <None>
+
+
+Name: iqaudio-dac
+Info: Configures the IQaudio DAC audio card
+Load: dtoverlay=iqaudio-dac,<param>
+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,<param>=<val>
+Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
+ Digital volume control. Enable with
+ "dtoverlay=iqaudio-dacplus,24db_digital_gain"
+ (The default behaviour is that the Digital
+ volume control is limited to a maximum of
+ 0dB. ie. it can attenuate but not provide
+ gain. For most users, this will be desired
+ as it will prevent clipping. By appending
+ the 24db_digital_gain parameter, the Digital
+ volume control will allow up to 24dB of
+ gain. If this parameter is enabled, it is the
+ responsibility of the user to ensure that
+ the Digital volume control is set to a value
+ that does not result in clipping/distortion!)
+ auto_mute_amp If specified, unmute/mute the IQaudIO amp when
+ starting/stopping audio playback.
+ unmute_amp If specified, unmute the IQaudIO amp once when
+ the DAC driver module loads.
+
+
+Name: iqaudio-digi-wm8804-audio
+Info: Configures the IQAudIO Digi WM8804 audio card
+Load: dtoverlay=iqaudio-digi-wm8804-audio,<param>=<val>
+Params: card_name Override the default, "IQAudIODigi", card name.
+ dai_name Override the default, "IQAudIO Digi", dai name.
+ dai_stream_name Override the default, "IQAudIO Digi HiFi",
+ dai stream name.
+
+
+Name: irs1125
+Info: Infineon irs1125 TOF camera module.
+ Uses Unicam 1, which is the standard camera connector on most Pi
+ variants.
+Load: dtoverlay=irs1125,<param>=<val>
+Params: i2c_pins_0_1 Use pins 0&1 for the I2C instead of 44&45.
+ Useful on Compute Modules.
+
+ i2c_pins_28_29 Use pins 28&29 for the I2C instead of 44&45.
+ This is required for Pi B+, 2, 0, and 0W.
+
+
+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,<param>=<val>
+Params: flash-spi<n>-<m> Enables flash device on SPI<n>, CS#<m>.
+ flash-fastr-spi<n>-<m> Enables flash device with fast read capability
+ on SPI<n>, CS#<m>.
+
+
+Name: justboom-dac
+Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
+ cards
+Load: dtoverlay=justboom-dac,<param>=<val>
+Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
+ Digital volume control. Enable with
+ "dtoverlay=justboom-dac,24db_digital_gain"
+ (The default behaviour is that the Digital
+ volume control is limited to a maximum of
+ 0dB. ie. it can attenuate but not provide
+ gain. For most users, this will be desired
+ as it will prevent clipping. By appending
+ the 24dB_digital_gain parameter, the Digital
+ volume control will allow up to 24dB of
+ gain. If this parameter is enabled, it is the
+ responsibility of the user to ensure that
+ the Digital volume control is set to a value
+ that does not result in clipping/distortion!)
+
+
+Name: justboom-digi
+Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
+Load: dtoverlay=justboom-digi
+Params: <None>
+
+
+Name: lirc-rpi
+Info: This overlay has been deprecated and removed - see gpio-ir
+Load: <Deprecated>
+
+
+Name: ltc294x
+Info: Adds support for the ltc294x family of battery gauges
+Load: dtoverlay=ltc294x,<param>=<val>
+Params: ltc2941 Select the ltc2941 device
+
+ ltc2942 Select the ltc2942 device
+
+ ltc2943 Select the ltc2943 device
+
+ ltc2944 Select the ltc2944 device
+
+ resistor-sense The sense resistor value in milli-ohms.
+ Can be a 32-bit negative value when the battery
+ has been connected to the wrong end of the
+ resistor.
+
+ prescaler-exponent Range and accuracy of the gauge. The value is
+ programmed into the chip only if it differs
+ from the current setting.
+ For LTC2941 only:
+ - Default value is 128
+ - the exponent is in the range 0-7 (default 7)
+ See the datasheet for more information.
+
+
+Name: max98357a
+Info: Configures the Maxim MAX98357A I2S DAC
+Load: dtoverlay=max98357a,<param>=<val>
+Params: no-sdmode Driver does not manage the state of the DAC's
+ SD_MODE pin (i.e. chip is always on).
+ sdmode-pin integer, GPIO pin connected to the SD_MODE input
+ of the DAC (default GPIO4 if parameter omitted).
+
+
+Name: mbed-dac
+Info: Configures the mbed AudioCODEC (TLV320AIC23B)
+Load: dtoverlay=mbed-dac
+Params: <None>
+
+
+Name: mcp23017
+Info: Configures the MCP23017 I2C GPIO expander
+Load: dtoverlay=mcp23017,<param>=<val>
+Params: gpiopin Gpio pin connected to the INTA output of the
+ MCP23017 (default: 4)
+
+ addr I2C address of the MCP23017 (default: 0x20)
+
+ mcp23008 Configure an MCP23008 instead.
+ noints Disable the interrupt GPIO line.
+
+
+Name: mcp23s17
+Info: Configures the MCP23S08/17 SPI GPIO expanders.
+ If devices are present on SPI1 or SPI2, those interfaces must be enabled
+ with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
+ If interrupts are enabled for a device on a given CS# on a SPI bus, that
+ device must be the only one present on that SPI bus/CS#.
+Load: dtoverlay=mcp23s17,<param>=<val>
+Params: s08-spi<n>-<m>-present 4-bit integer, bitmap indicating MCP23S08
+ devices present on SPI<n>, CS#<m>
+
+ 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-can0
+Info: Configures the MCP2515 CAN controller on spi0.0
+Load: dtoverlay=mcp2515-can0,<param>=<val>
+Params: oscillator Clock frequency for the CAN controller (Hz)
+
+ spimaxfrequency Maximum SPI frequence (Hz)
+
+ interrupt GPIO for interrupt signal
+
+
+Name: mcp2515-can1
+Info: Configures the MCP2515 CAN controller on spi0.1
+Load: dtoverlay=mcp2515-can1,<param>=<val>
+Params: oscillator Clock frequency for the CAN controller (Hz)
+
+ spimaxfrequency Maximum SPI frequence (Hz)
+
+ interrupt GPIO for interrupt signal
+
+
+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,<param>[=<val>]
+Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
+ spi<n>-<m>-speed integer, set the spi bus speed for this device
+
+
+Name: mcp3202
+Info: Configures MCP3202 A/D converters
+ For devices on spi1 or spi2, the interfaces should be enabled
+ with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
+Load: dtoverlay=mcp3202,<param>[=<val>]
+Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
+ spi<n>-<m>-speed integer, set the spi bus speed for this device
+
+
+Name: mcp342x
+Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
+Load: dtoverlay=mcp342x,<param>=<val>
+Params: addr I2C bus address of device, for devices with
+ addresses that are configurable, e.g. by
+ hardware links (default=0x68)
+ mcp3421 The device is an MCP3421
+ mcp3422 The device is an MCP3422
+ mcp3423 The device is an MCP3423
+ mcp3424 The device is an MCP3424
+ mcp3425 The device is an MCP3425
+ mcp3426 The device is an MCP3426
+ mcp3427 The device is an MCP3427
+ mcp3428 The device is an MCP3428
+
+
+Name: media-center
+Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
+Load: dtoverlay=media-center,<param>=<val>
+Params: speed Display SPI bus speed
+ rotate Display rotation {0,90,180,270}
+ fps Delay between frame updates
+ xohms Touchpanel sensitivity (X-plate resistance)
+ swapxy Swap x and y axis
+ backlight Change backlight GPIO pin {e.g. 12, 18}
+ gpio_out_pin GPIO for output (default "17")
+ gpio_in_pin GPIO for input (default "18")
+ gpio_in_pull Pull up/down/off on the input pin
+ (default "down")
+ sense Override the IR receive auto-detection logic:
+ "0" = force active-high
+ "1" = force active-low
+ "-1" = use auto-detection
+ (default "-1")
+ softcarrier Turn the software carrier "on" or "off"
+ (default "on")
+ invert "on" = invert the output pin (default "off")
+ debug "on" = enable additional debug messages
+ (default "off")
+
+
+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: <None>
+
+
+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: <None>
+
+
+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 &
+ 15. 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: <None>
+
+
+Name: mmc
+Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock
+Load: dtoverlay=mmc,<param>=<val>
+Params: overclock_50 Clock (in MHz) to use when the MMC framework
+ requests 50MHz
+
+
+Name: mpu6050
+Info: Overlay for i2c connected mpu6050 imu
+Load: dtoverlay=mpu6050,<param>=<val>
+Params: interrupt GPIO pin for interrupt (default 4)
+
+
+Name: mz61581
+Info: MZ61581 display by Tontec
+Load: dtoverlay=mz61581,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ txbuflen Transmit buffer length (default 32768)
+
+ debug Debug output level {0-7}
+
+ xohms Touchpanel sensitivity (X-plate resistance)
+
+
+Name: ov5647
+Info: Omnivision OV5647 camera module.
+ Uses Unicam 1, which is the standard camera connector on most Pi
+ variants.
+Load: dtoverlay=ov5647,<param>=<val>
+Params: i2c_pins_0_1 Use pins 0&1 for the I2C instead of 44&45.
+ Useful on Compute Modules.
+
+ i2c_pins_28_29 Use pins 28&29 for the I2C instead of 44&45.
+ This is required for Pi B+, 2, 0, and 0W.
+
+
+Name: papirus
+Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
+Load: dtoverlay=papirus,<param>=<val>
+Params: panel Display panel (required):
+ 1.44": e1144cs021
+ 2.0": e2200cs021
+ 2.7": e2271cs021
+
+ speed Display SPI bus speed
+
+
+[ 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: <Deprecated>
+
+
+Name: pi3-disable-bt
+Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
+ alias for backwards compatibility.
+Load: <Deprecated>
+
+
+Name: pi3-disable-wifi
+Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
+ an alias for backwards compatibility.
+Load: <Deprecated>
+
+
+Name: pi3-miniuart-bt
+Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
+ an alias for backwards compatibility.
+Load: <Deprecated>
+
+
+Name: pibell
+Info: Configures the pibell audio card.
+Load: dtoverlay=pibell,<param>=<val>
+Params: alsaname Set the name as it appears in ALSA (default
+ "PiBell")
+
+
+Name: piglow
+Info: Configures the PiGlow by pimoroni.com
+Load: dtoverlay=piglow
+Params: <None>
+
+
+Name: piscreen
+Info: PiScreen display by OzzMaker.com
+Load: dtoverlay=piscreen,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ debug Debug output level {0-7}
+
+ xohms Touchpanel sensitivity (X-plate resistance)
+
+
+Name: piscreen2r
+Info: PiScreen 2 with resistive TP display by OzzMaker.com
+Load: dtoverlay=piscreen2r,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ debug Debug output level {0-7}
+
+ xohms Touchpanel sensitivity (X-plate resistance)
+
+
+Name: pisound
+Info: Configures the Blokas Labs pisound card
+Load: dtoverlay=pisound
+Params: <None>
+
+
+Name: pitft22
+Info: Adafruit PiTFT 2.2" screen
+Load: dtoverlay=pitft22,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ debug Debug output level {0-7}
+
+
+Name: pitft28-capacitive
+Info: Adafruit PiTFT 2.8" capacitive touch screen
+Load: dtoverlay=pitft28-capacitive,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ debug Debug output level {0-7}
+
+ touch-sizex Touchscreen size x (default 240)
+
+ touch-sizey Touchscreen size y (default 320)
+
+ touch-invx Touchscreen inverted x axis
+
+ touch-invy Touchscreen inverted y axis
+
+ touch-swapxy Touchscreen swapped x y axis
+
+
+Name: pitft28-resistive
+Info: Adafruit PiTFT 2.8" resistive touch screen
+Load: dtoverlay=pitft28-resistive,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ debug Debug output level {0-7}
+
+
+Name: pitft35-resistive
+Info: Adafruit PiTFT 3.5" resistive touch screen
+Load: dtoverlay=pitft35-resistive,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ debug Debug output level {0-7}
+
+
+Name: pps-gpio
+Info: Configures the pps-gpio (pulse-per-second time signal via GPIO).
+Load: dtoverlay=pps-gpio,<param>=<val>
+Params: gpiopin Input GPIO (default "18")
+ assert_falling_edge When present, assert is indicated by a falling
+ edge, rather than by a rising edge (default
+ off)
+ capture_clear Generate clear events on the trailing edge
+ (default off)
+
+
+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,<param>=<val>
+Params: pin Output pin (default 18) - see table
+ func Pin function (default 2 = Alt5) - see above
+ clock PWM clock frequency (informational)
+
+
+Name: pwm-2chan
+Info: Configures both PWM channels
+ Legal pin,function combinations for each channel:
+ PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
+ PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
+ N.B.:
+ 1) Pin 18 is the only one available on all platforms, and
+ it is the one used by the I2S audio interface.
+ Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
+ 2) The onboard analogue audio output uses both PWM channels.
+ 3) So be careful mixing audio and PWM.
+ 4) Currently the clock must have been enabled and configured
+ by other means.
+Load: dtoverlay=pwm-2chan,<param>=<val>
+Params: pin Output pin (default 18) - see table
+ pin2 Output pin for other channel (default 19)
+ func Pin function (default 2 = Alt5) - see above
+ func2 Function for pin2 (default 2 = Alt5)
+ clock PWM clock frequency (informational)
+
+
+Name: pwm-ir-tx
+Info: Use GPIO pin as pwm-assisted infrared transmitter output.
+ This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
+ of PWM0 to reduce the CPU load during transmission compared to
+ gpio-ir-tx which uses bit-banging.
+ Legal pin,function combinations are:
+ 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
+Load: dtoverlay=pwm-ir-tx,<param>=<val>
+Params: gpio_pin Output GPIO (default 18)
+
+ func Pin function (default 2 = Alt5)
+
+
+Name: qca7000
+Info: I2SE's Evaluation Board for PLC Stamp micro
+Load: dtoverlay=qca7000,<param>=<val>
+Params: int_pin GPIO pin for interrupt signal (default 23)
+
+ speed SPI bus speed (default 12 MHz)
+
+
+Name: rotary-encoder
+Info: Overlay for GPIO connected rotary encoder.
+Load: dtoverlay=rotary-encoder,<param>=<val>
+Params: pin_a GPIO connected to rotary encoder channel A
+ (default 4).
+ pin_b GPIO connected to rotary encoder channel B
+ (default 17).
+ relative_axis register a relative axis rather than an
+ absolute one. Relative axis will only
+ generate +1/-1 events on the input device,
+ hence no steps need to be passed.
+ linux_axis the input subsystem axis to map to this
+ rotary encoder. Defaults to 0 (ABS_X / REL_X)
+ rollover Automatic rollover when the rotary value
+ becomes greater than the specified steps or
+ smaller than 0. For absolute axis only.
+ steps-per-period Number of steps (stable states) per period.
+ The values have the following meaning:
+ 1: Full-period mode (default)
+ 2: Half-period mode
+ 4: Quarter-period mode
+ steps Number of steps in a full turnaround of the
+ encoder. Only relevant for absolute axis.
+ Defaults to 24 which is a typical value for
+ such devices.
+ wakeup Boolean, rotary encoder can wake up the
+ system.
+ encoding String, the method used to encode steps.
+ Supported are "gray" (the default and more
+ common) and "binary".
+
+
+Name: rpi-backlight
+Info: Raspberry Pi official display backlight driver
+Load: dtoverlay=rpi-backlight
+Params: <None>
+
+
+Name: rpi-cirrus-wm5102
+Info: Configures the Cirrus Logic Audio Card
+Load: dtoverlay=rpi-cirrus-wm5102
+Params: <None>
+
+
+Name: rpi-dac
+Info: Configures the RPi DAC audio card
+Load: dtoverlay=rpi-dac
+Params: <None>
+
+
+Name: rpi-display
+Info: RPi-Display - 2.8" Touch Display by Watterott
+Load: dtoverlay=rpi-display,<param>=<val>
+Params: speed Display SPI bus speed
+ rotate Display rotation {0,90,180,270}
+ fps Delay between frame updates
+ debug Debug output level {0-7}
+ xohms Touchpanel sensitivity (X-plate resistance)
+ swapxy Swap x and y axis
+ backlight Change backlight GPIO pin {e.g. 12, 18}
+
+
+Name: rpi-ft5406
+Info: Official Raspberry Pi display touchscreen
+Load: dtoverlay=rpi-ft5406,<param>=<val>
+Params: touchscreen-size-x Touchscreen X resolution (default 800)
+ touchscreen-size-y Touchscreen Y resolution (default 600);
+ touchscreen-inverted-x Invert touchscreen X coordinates (default 0);
+ touchscreen-inverted-y Invert touchscreen Y coordinates (default 0);
+ touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
+
+
+Name: rpi-poe
+Info: Raspberry Pi PoE HAT fan
+Load: dtoverlay=rpi-poe,<param>[=<val>]
+Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
+ turns on (default 50000)
+ poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
+ the fan turns off (default 5000)
+ poe_fan_temp1 Temperature (in millicelcius) at which the fan
+ speeds up (default 55000)
+ poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
+ the fan slows down (default 5000)
+
+
+Name: rpi-proto
+Info: Configures the RPi Proto audio card
+Load: dtoverlay=rpi-proto
+Params: <None>
+
+
+Name: rpi-sense
+Info: Raspberry Pi Sense HAT
+Load: dtoverlay=rpi-sense
+Params: <None>
+
+
+Name: rpi-tv
+Info: Raspberry Pi TV HAT
+Load: dtoverlay=rpi-tv
+Params: <None>
+
+
+Name: rra-digidac1-wm8741-audio
+Info: Configures the Red Rocks Audio DigiDAC1 soundcard
+Load: dtoverlay=rra-digidac1-wm8741-audio
+Params: <None>
+
+
+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,<param>=<val>
+Params: int_pin GPIO used for IRQ (default 24)
+ addr Address (default 0x48)
+ xtal On-board crystal frequency (default 14745600)
+
+
+Name: sc16is752-i2c
+Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface
+ Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
+ select another address, please refer to table 10 in reference manual.
+Load: dtoverlay=sc16is752-i2c,<param>=<val>
+Params: int_pin GPIO used for IRQ (default 24)
+ addr Address (default 0x48)
+ xtal On-board crystal frequency (default 14745600)
+
+
+Name: sc16is752-spi1
+Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
+ Enables the chip on SPI1.
+ N.B.: spi1 is only accessible on devices with a 40pin header, eg:
+ A+, B+, Zero and PI2 B; as well as the Compute Module.
+
+Load: dtoverlay=sc16is752-spi1,<param>=<val>
+Params: int_pin GPIO used for IRQ (default 24)
+
+
+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
+ WiFi 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,<param>=<val>
+Params: overclock_50 Clock (in MHz) to use when the MMC framework
+ requests 50MHz
+
+ force_pio Disable DMA support (default off)
+
+ pio_limit Number of blocks above which to use DMA
+ (default 1)
+
+ debug Enable debug output (default off)
+
+
+Name: sdio
+Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
+ and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
+ "dtoverlay=sdio,bus_width=1,gpios_22_25"
+Load: dtoverlay=sdio,<param>=<val>
+Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC
+ framework requests 50MHz
+
+ poll_once Disable SDIO-device polling every second
+ (default on: polling once at boot-time)
+
+ bus_width Set the SDIO host bus width (default 4 bits)
+
+ gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
+ with bus_width=1. This replaces the sdio-1bit
+ overlay, which is now deprecated.
+
+ gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
+ with bus_width=1.
+
+ gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
+ with bus_width=4 (the default).
+
+
+Name: sdio-1bit
+Info: This overlay is now deprecated. Use
+ "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
+Load: <Deprecated>
+
+
+Name: sdtweak
+Info: Tunes the bcm2835-sdhost SD/MMC driver
+ N.B. This functionality is now available via the sd_* dtparams in the
+ base DTB.
+Load: dtoverlay=sdtweak,<param>=<val>
+Params: overclock_50 Clock (in MHz) to use when the MMC framework
+ requests 50MHz
+
+ force_pio Disable DMA support (default off)
+
+ pio_limit Number of blocks above which to use DMA
+ (default 1)
+
+ debug Enable debug output (default off)
+
+ 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)
+
+ enable Set to off to completely disable the interface
+ (default on)
+
+
+Name: smi
+Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
+Load: dtoverlay=smi
+Params: <None>
+
+
+Name: smi-dev
+Info: Enables the userspace interface for the SMI driver
+Load: dtoverlay=smi-dev
+Params: <None>
+
+
+Name: smi-nand
+Info: Enables access to NAND flash via the SMI interface
+Load: dtoverlay=smi-nand
+Params: <None>
+
+
+Name: spi-gpio35-39
+Info: Move SPI function block to GPIO 35 to 39
+Load: dtoverlay=spi-gpio35-39
+Params: <None>
+
+
+Name: spi-gpio40-45
+Info: Move SPI function block to GPIOs 40 to 45
+Load: dtoverlay=spi-gpio40-45
+Params: <None>
+
+
+Name: spi-rtc
+Info: Adds support for a number of SPI Real Time Clock devices
+Load: dtoverlay=spi-rtc,<param>=<val>
+Params: pcf2123 Select the PCF2123 device
+
+
+Name: spi0-cs
+Info: Allows the (software) CS pins for SPI0 to be changed
+Load: dtoverlay=spi0-cs,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 8)
+ cs1_pin GPIO pin for CS1 (default 7)
+
+
+Name: spi0-hw-cs
+Info: Re-enables hardware CS/CE (chip selects) for SPI0
+Load: dtoverlay=spi0-hw-cs
+Params: <None>
+
+
+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,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
+ cs0_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev1.0 (default
+ is 'okay' or enabled).
+
+
+Name: spi1-2cs
+Info: Enables spi1 with two chip select (CS) lines and associated spidev
+ dev nodes. The gpio pin numbers for the CS lines and spidev device node
+ creation are configurable.
+ N.B.: spi1 is 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,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
+ cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
+ cs0_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev1.0 (default
+ is 'okay' or enabled).
+ cs1_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev1.1 (default
+ is 'okay' or enabled).
+
+
+Name: spi1-3cs
+Info: Enables spi1 with three chip select (CS) lines and associated spidev
+ dev nodes. The gpio pin numbers for the CS lines and spidev device node
+ creation are configurable.
+ N.B.: spi1 is 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,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
+ cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
+ cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
+ cs0_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev1.0 (default
+ is 'okay' or enabled).
+ cs1_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev1.1 (default
+ is 'okay' or enabled).
+ cs2_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev1.2 (default
+ is 'okay' or enabled).
+
+
+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,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
+ cs0_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev2.0 (default
+ is 'okay' or enabled).
+
+
+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,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
+ cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
+ cs0_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev2.0 (default
+ is 'okay' or enabled).
+ cs1_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev2.1 (default
+ is 'okay' or enabled).
+
+
+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,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
+ cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
+ cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
+ cs0_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev2.0 (default
+ is 'okay' or enabled).
+ cs1_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev2.1 (default
+ is 'okay' or enabled).
+ cs2_spidev Set to 'disabled' to stop the creation of a
+ userspace device node /dev/spidev2.2 (default
+ is 'okay' or enabled).
+
+
+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.
+Load: dtoverlay=spi3-1cs,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
+ cs0_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev3.0 (default
+ is 'on' or enabled).
+
+
+Name: spi3-2cs
+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.
+Load: dtoverlay=spi3-2cs,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
+ cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
+ cs0_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev3.0 (default
+ is 'on' or enabled).
+ cs1_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev3.1 (default
+ is 'on' or enabled).
+
+
+Name: 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.
+Load: dtoverlay=spi4-1cs,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
+ cs0_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev4.0 (default
+ is 'on' or enabled).
+
+
+Name: spi4-2cs
+Info: Enables spi4 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.
+Load: dtoverlay=spi4-2cs,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
+ cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
+ cs0_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev4.0 (default
+ is 'on' or enabled).
+ cs1_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev4.1 (default
+ is 'on' or enabled).
+
+
+Name: spi5-1cs
+Info: Enables spi5 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.
+Load: dtoverlay=spi5-1cs,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
+ cs0_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev5.0 (default
+ is 'on' or enabled).
+
+
+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.
+Load: dtoverlay=spi5-2cs,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
+ cs1_pin GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
+ cs0_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev5.0 (default
+ is 'on' or enabled).
+ cs1_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev5.1 (default
+ is 'on' or enabled).
+
+
+Name: 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.
+Load: dtoverlay=spi6-1cs,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
+ cs0_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev6.0 (default
+ is 'on' or enabled).
+
+
+Name: spi6-2cs
+Info: Enables spi6 with two chip select (CS) lines and associated spidev
+ dev nodes. The gpio pin numbers for the CS lines and spidev device node
+ creation are configurable.
+Load: dtoverlay=spi6-2cs,<param>=<val>
+Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
+ cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
+ cs0_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev6.0 (default
+ is 'on' or enabled).
+ cs1_spidev Set to 'off' to prevent the creation of a
+ userspace device node /dev/spidev6.1 (default
+ is 'on' or enabled).
+
+
+Name: ssd1306
+Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
+Load: dtoverlay=ssd1306,<param>=<val>
+Params: address Location in display memory of first character.
+ (default=0)
+ width Width of display. (default=128)
+ height Height of display. (default=64)
+ offset virtual channel a. (default=0)
+ normal Has no effect on displays tested. (default=not
+ set)
+ sequential Set this if every other scan line is missing.
+ (default=not set)
+ remapped Set this if display is garbled. (default=not
+ set)
+ inverted Set this if display is inverted and mirrored.
+ (default=not set)
+
+ Examples:
+ Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
+
+ Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
+
+ i2c_baudrate=400000 will speed up the display.
+
+ i2c_baudrate=1000000 seems to work even though it's not officially
+ supported by the hardware, and is faster still.
+
+ For more information refer to the device datasheet at:
+ https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
+
+
+Name: superaudioboard
+Info: Configures the SuperAudioBoard sound card
+Load: dtoverlay=superaudioboard,<param>=<val>
+Params: gpiopin GPIO pin for codec reset
+
+
+Name: sx150x
+Info: Configures the Semtech SX150X I2C GPIO expanders.
+Load: dtoverlay=sx150x,<param>=<val>
+Params: sx150<x>-<n>-<m> Enables SX150X device on I2C#<n> with slave
+ address <m>. <x> may be 1-9. <n> may be 0 or 1.
+ Permissible values of <m> (which is denoted in
+ hex) depend on the device variant. For SX1501,
+ SX1502, SX1504 and SX1505, <m> may be 20 or 21.
+ For SX1503 and SX1506, <m> may be 20. For
+ SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
+ For SX1508, <m> may be 20, 21, 22 or 23.
+
+ sx150<x>-<n>-<m>-int-gpio
+ Integer, enables interrupts on SX150X device on
+ I2C#<n> with slave address <m>, specifies
+ the GPIO pin to which NINT output of SX150X is
+ connected.
+
+
+Name: tc358743
+Info: Toshiba TC358743 HDMI to CSI-2 bridge chip.
+ Uses Unicam 1, which is the standard camera connector on most Pi
+ variants.
+Load: dtoverlay=tc358743,<param>=<val>
+Params: 4lane Use 4 lanes (only applicable to Compute Modules
+ CAM1 connector).
+
+ link-frequency Set the link frequency. Only values of 297000000
+ (574Mbit/s) and 486000000 (972Mbit/s - default)
+ are supported by the driver.
+
+ i2c_pins_0_1 Use pins 0&1 for the I2C instead of 44&45.
+ Useful on Compute Modules.
+
+ i2c_pins_28_29 Use pins 28&29 for the I2C instead of 44&45.
+ This is required for Pi B+, 2, 0, and 0W.
+
+
+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,<param>=<val>
+Params: card-name Override the default, "tc358743", card name.
+
+
+Name: tinylcd35
+Info: 3.5" Color TFT Display by www.tinylcd.com
+ Options: Touch, RTC, keypad
+Load: dtoverlay=tinylcd35,<param>=<val>
+Params: speed Display SPI bus speed
+
+ rotate Display rotation {0,90,180,270}
+
+ fps Delay between frame updates
+
+ debug Debug output level {0-7}
+
+ touch Enable touch panel
+
+ touchgpio Touch controller IRQ GPIO
+
+ xohms Touchpanel: Resistance of X-plate in ohms
+
+ rtc-pcf PCF8563 Real Time Clock
+
+ rtc-ds DS1307 Real Time Clock
+
+ keypad Enable keypad
+
+ Examples:
+ Display with touchpanel, PCF8563 RTC and keypad:
+ dtoverlay=tinylcd35,touch,rtc-pcf,keypad
+ Old touch display:
+ dtoverlay=tinylcd35,touch,touchgpio=3
+
+
+Name: tpm-slb9670
+Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
+ boards, which can be used as a secure key storage and hwrng,
+ available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
+Load: dtoverlay=tpm-slb9670
+Params: <None>
+
+
+Name: uart0
+Info: Change the pin usage of uart0
+Load: dtoverlay=uart0,<param>=<val>
+Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
+
+ rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
+
+ pin_func Alternative pin function - 4(Alt0) for 14&15,
+ 7(Alt3) for 32&33, 6(Alt2) for 36&37
+
+
+Name: uart1
+Info: Change the pin usage of uart1
+Load: dtoverlay=uart1,<param>=<val>
+Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
+
+ rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
+
+
+Name: uart2
+Info: Enable uart 2 on GPIOs 0-3
+Load: dtoverlay=uart2,<param>
+Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
+
+
+Name: uart3
+Info: Enable uart 3 on GPIOs 4-7
+Load: dtoverlay=uart3,<param>
+Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
+
+
+Name: uart4
+Info: Enable uart 4 on GPIOs 8-11
+Load: dtoverlay=uart4,<param>
+Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
+
+
+Name: uart5
+Info: Enable uart 5 on GPIOs 12-15
+Load: dtoverlay=uart5,<param>
+Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
+
+
+Name: udrc
+Info: Configures the NW Digital Radio UDRC Hat
+Load: dtoverlay=udrc,<param>=<val>
+Params: alsaname Name of the ALSA audio device (default "udrc")
+
+
+Name: upstream
+Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
+ vc4-kms-v3d and dwc2 overlays.
+Load: dtoverlay=upstream
+Params: <None>
+
+
+Name: upstream-aux-interrupt
+Info: This overlay has been deprecated and removed because it is no longer
+ necessary.
+Load: <Deprecated>
+
+
+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,<param>
+Params: 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
+
+
+Name: vc4-kms-kippah-7inch
+Info: Enable the Adafruit DPI Kippah with the 7" Ontat panel attached.
+ Requires vc4-kms-v3d to be loaded.
+Load: dtoverlay=vc4-kms-kippah-7inch
+Params: <None>
+
+
+Name: vc4-kms-v3d
+Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver. Running startx or
+ booting to GUI while this overlay is in use will cause interesting
+ lockups.
+Load: dtoverlay=vc4-kms-v3d,<param>
+Params: 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
+ audio Enable or disable audio over HDMI (default "on")
+
+
+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.
+Load: dtoverlay=vga666
+Params: <None>
+
+
+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,<param>=<val>
+Params: gpiopin GPIO for I/O (default "4")
+ pullup Now enabled by default (ignored)
+
+
+Name: w1-gpio-pullup
+Info: Configures the w1-gpio Onewire interface module.
+ Use this overlay if you *do* need a GPIO to drive an external pullup.
+Load: dtoverlay=w1-gpio-pullup,<param>=<val>
+Params: gpiopin GPIO for I/O (default "4")
+ extpullup GPIO for external pullup (default "5")
+ pullup Now enabled by default (ignored)
+
+
+Name: w5500
+Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
+Load: dtoverlay=w5500,<param>=<val>
+Params: int_pin GPIO used for INT (default 25)
+
+ speed SPI bus speed (default 30000000)
+
+ cs SPI bus Chip Select (default 0)
+
+
+Name: wittypi
+Info: Configures the wittypi RTC module.
+Load: dtoverlay=wittypi,<param>=<val>
+Params: led_gpio GPIO for LED (default "17")
+ led_trigger Choose which activity the LED tracks (default
+ "default-on")
+
+
+Troubleshooting
+===============
+
+If you are experiencing problems that you think are DT-related, enable DT
+diagnostic output by adding this to /boot/config.txt:
+
+ dtdebug=on
+
+and rebooting. Then run:
+
+ sudo vcdbg log msg
+
+and look for relevant messages.
+
+Further reading
+===============
+
+This is only meant to be a quick introduction to the subject of Device Tree on
+Raspberry Pi. There is a more complete explanation here:
+
+http://www.raspberrypi.org/documentation/configuration/device-tree.md
projects / platform / kernel / linux-rpi.git / commitdiff