4 This directory contains Device Tree overlays. Device Tree makes it possible
5 to support many hardware configurations with a single kernel and without the
6 need to explicitly load or blacklist kernel modules. Note that this isn't a
7 "pure" Device Tree configuration (c.f. MACH_BCM2835) - some on-board devices
8 are still configured by the board support code, but the intention is to
9 eventually reach that goal.
11 On Raspberry Pi, Device Tree usage is controlled from /boot/config.txt. By
12 default, the Raspberry Pi kernel boots with device tree enabled. You can
13 completely disable DT usage (for now) by adding:
17 to your config.txt, which should cause your Pi to revert to the old way of
18 doing things after a reboot.
20 In /boot you will find a .dtb for each base platform. This describes the
21 hardware that is part of the Raspberry Pi board. The loader (start.elf and its
22 siblings) selects the .dtb file appropriate for the platform by name, and reads
23 it into memory. At this point, all of the optional interfaces (i2c, i2s, spi)
24 are disabled, but they can be enabled using Device Tree parameters:
26 dtparam=i2c=on,i2s=on,spi=on
28 However, this shouldn't be necessary in many use cases because loading an
29 overlay that requires one of those interfaces will cause it to be enabled
30 automatically, and it is advisable to only enable interfaces if they are
33 Configuring additional, optional hardware is done using Device Tree overlays
36 GPIO numbering uses the hardware pin numbering scheme (aka BCM scheme) and
37 not the physical pin numbers.
42 The Advanced Options section of the raspi-config utility can enable and disable
43 Device Tree use, as well as toggling the I2C and SPI interfaces. Note that it
44 is possible to both enable an interface and blacklist the driver, if for some
45 reason you should want to defer the loading.
50 As well as describing the hardware, Device Tree also gives enough information
51 to allow suitable driver modules to be located and loaded, with the corollary
52 that unneeded modules are not loaded. As a result it should be possible to
53 remove lines from /etc/modules, and /etc/modprobe.d/raspi-blacklist.conf can
54 have its contents deleted (or commented out).
59 Overlays are loaded using the "dtoverlay" config.txt setting. As an example,
60 consider I2C Real Time Clock drivers. In the pre-DT world these would be loaded
61 by writing a magic string comprising a device identifier and an I2C address to
62 a special file in /sys/class/i2c-adapter, having first loaded the driver for
63 the I2C interface and the RTC device - something like this:
67 echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device
69 With DT enabled, this becomes a line in config.txt:
71 dtoverlay=i2c-rtc,ds1307
73 This causes the file /boot/overlays/i2c-rtc.dtbo to be loaded and a "node"
74 describing the DS1307 I2C device to be added to the Device Tree for the Pi. By
75 default it usees address 0x68, but this can be modified with an additional DT
78 dtoverlay=i2c-rtc,ds1307,addr=0x68
80 Parameters usually have default values, although certain parameters are
81 mandatory. See the list of overlays below for a description of the parameters
84 Making new Overlays based on existing Overlays
85 ==============================================
87 Recent overlays have been designed in a more general way, so that they can be
88 adapted to hardware by changing their parameters. When you have additional
89 hardware with more than one device of a kind, you end up using the same overlay
90 multiple times with other parameters, e.g.
92 # 2 CAN FD interfaces on spi but with different pins
93 dtoverlay=mcp251xfd,spi0-0,interrupt=25
94 dtoverlay=mcp251xfd,spi0-1,interrupt=24
96 # a realtime clock on i2c
97 dtoverlay=i2c-rtc,pcf85063
99 While this approach does work, it requires knowledge about the hardware design.
100 It is more feasible to simplify things for the end user by providing a single
101 overlay as it is done the traditional way.
103 A new overlay can be generated by using ovmerge utility.
104 https://github.com/raspberrypi/utils/blob/master/ovmerge/ovmerge
106 To generate an overlay for the above configuration we pass the configuration
107 to ovmerge and add the -c flag.
109 ovmerge -c mcp251xfd-overlay.dts,spi0-0,interrupt=25 \
110 mcp251xfd-overlay.dts,spi0-1,interrupt=24 \
111 i2c-rtc-overlay.dts,pcf85063 \
112 >> merged-overlay.dts
114 The -c option writes the command above as a comment into the overlay as
115 a marker that this overlay is generated and how it was generated.
116 After compiling the overlay it can be loaded in a single line.
120 It does the same as the original configuration but without parameters.
122 The Overlay and Parameter Reference
123 ===================================
125 N.B. When editing this file, please preserve the indentation levels to make it
126 simple to parse programmatically. NO HARD TABS.
130 Info: Configures the base Raspberry Pi hardware
131 Load: <loaded automatically>
133 ant1 Select antenna 1 (default). CM4 only.
135 ant2 Select antenna 2. CM4 only.
137 noant Disable both antennas. CM4 only.
139 audio Set to "on" to enable the onboard ALSA audio
140 interface (default "off")
142 axiperf Set to "on" to enable the AXI bus performance
144 See /sys/kernel/debug/raspberrypi_axi_monitor
147 cam0_reg Enables CAM 0 regulator. CM1 & 3 only.
149 cam0_reg_gpio Set GPIO for CAM 0 regulator. Default 30.
152 cam1_reg Enables CAM 1 regulator. CM1 & 3 only.
154 cam1_reg_gpio Set GPIO for CAM 1 regulator. Default 2.
157 eee Enable Energy Efficient Ethernet support for
158 compatible devices (default "on"). See also
159 "tx_lpi_timer". Pi3B+ only.
161 eth_downshift_after Set the number of auto-negotiation failures
162 after which the 1000Mbps modes are disabled.
163 Legal values are 2, 3, 4, 5 and 0, where
164 0 means never downshift (default 2). Pi3B+ only.
166 eth_led0 Set mode of LED0 - amber on Pi3B+ (default "1"),
167 green on Pi4 (default "0").
168 The legal values are:
172 0=link/activity 1=link1000/activity
173 2=link100/activity 3=link10/activity
174 4=link100/1000/activity 5=link10/1000/activity
175 6=link10/100/activity 14=off 15=on
179 0=Speed/Activity 1=Speed
180 2=Flash activity 3=FDX
185 eth_led1 Set mode of LED1 - green on Pi3B+ (default "6"),
186 amber on Pi4 (default "8"). See eth_led0 for
189 eth_max_speed Set the maximum speed a link is allowed
190 to negotiate. Legal values are 10, 100 and
191 1000 (default 1000). Pi3B+ only.
193 i2c_arm Set to "on" to enable the ARM's i2c interface
196 i2c_vc Set to "on" to enable the i2c interface
197 usually reserved for the VideoCore processor
200 i2c An alias for i2c_arm
202 i2c_arm_baudrate Set the baudrate of the ARM's i2c interface
205 i2c_vc_baudrate Set the baudrate of the VideoCore i2c interface
208 i2c_baudrate An alias for i2c_arm_baudrate
210 i2s Set to "on" to enable the i2s interface
213 krnbt Set to "on" to enable autoprobing of Bluetooth
214 driver without need of hciattach/btattach
217 krnbt_baudrate Set the baudrate of the PL011 UART when used
220 spi Set to "on" to enable the spi interfaces
223 spi_dma4 Use to enable 40-bit DMA on spi interfaces
224 (the assigned value doesn't matter)
227 random Set to "on" to enable the hardware random
228 number generator (default "on")
230 sd_overclock Clock (in MHz) to use when the MMC framework
233 sd_poll_once Looks for a card once after booting. Useful
234 for network booting scenarios to avoid the
235 overhead of continuous polling. N.B. Using
236 this option restricts the system to using a
237 single card per boot (or none at all).
240 sd_force_pio Disable DMA support for SD driver (default off)
242 sd_pio_limit Number of blocks above which to use DMA for
245 sd_debug Enable debug output from SD driver (default off)
247 sdio_overclock Clock (in MHz) to use when the MMC framework
248 requests 50MHz for the SDIO/WLAN interface.
250 tx_lpi_timer Set the delay in microseconds between going idle
251 and entering the low power state (default 600).
252 Requires EEE to be enabled - see "eee".
254 uart0 Set to "off" to disable uart0 (default "on")
256 uart1 Set to "on" or "off" to enable or disable uart1
259 watchdog Set to "on" to enable the hardware watchdog
262 act_led_trigger Choose which activity the LED tracks.
263 Use "heartbeat" for a nice load indicator.
266 act_led_activelow Set to "on" to invert the sense of the LED
268 N.B. For Pi 3B, 3B+, 3A+ and 4B, use the act-led
271 act_led_gpio Set which GPIO to use for the activity LED
272 (in case you want to connect it to an external
274 (default "16" on a non-Plus board, "47" on a
276 N.B. For Pi 3B, 3B+, 3A+ and 4B, use the act-led
282 As for act_led_*, but using the PWR LED.
283 Not available on Model A/B boards.
285 N.B. It is recommended to only enable those interfaces that are needed.
286 Leaving all interfaces enabled can lead to unwanted behaviour (i2c_vc
287 interfering with Pi Camera, I2S and SPI hogging GPIO pins, etc.)
288 Note also that i2c, i2c_arm and i2c_vc are aliases for the physical
289 interfaces i2c0 and i2c1. Use of the numeric variants is still possible
290 but deprecated because the ARM/VC assignments differ between board
291 revisions. The same board-specific mapping applies to i2c_baudrate,
292 and the other i2c baudrate parameters.
296 Info: Pi 3B, 3B+, 3A+ and 4B use a GPIO expander to drive the LEDs which can
297 only be accessed from the VPU. There is a special driver for this with a
298 separate DT node, which has the unfortunate consequence of breaking the
299 act_led_gpio and act_led_activelow dtparams.
300 This overlay changes the GPIO controller back to the standard one and
301 restores the dtparams.
302 Load: dtoverlay=act-led,<param>=<val>
303 Params: activelow Set to "on" to invert the sense of the LED
306 gpio Set which GPIO to use for the activity LED
307 (in case you want to connect it to an external
312 Name: adafruit-st7735r
313 Info: Overlay for the SPI-connected Adafruit 1.8" 160x128 or 128x128 displays,
314 based on the ST7735R chip.
315 This overlay uses the newer DRM/KMS "Tiny" driver.
316 Load: dtoverlay=adafruit-st7735r,<param>=<val>
317 Params: 128x128 Select the 128x128 driver (default 160x128)
318 rotate Display rotation {0,90,180,270} (default 90)
319 speed SPI bus speed in Hz (default 4000000)
320 dc_pin GPIO pin for D/C (default 24)
321 reset_pin GPIO pin for RESET (default 25)
322 led_pin GPIO used to control backlight (default 18)
326 Info: Overlay for the SPI-connected Adafruit 1.8" display (based on the
327 ST7735R chip). It includes support for the "green tab" version.
328 This overlay uses the older fbtft driver.
329 Load: dtoverlay=adafruit18,<param>=<val>
330 Params: green Use the adafruit18_green variant.
331 rotate Display rotation {0,90,180,270}
332 speed SPI bus speed in Hz (default 4000000)
333 fps Display frame rate in Hz
334 bgr Enable BGR mode (default off)
335 debug Debug output level {0-7}
336 dc_pin GPIO pin for D/C (default 24)
337 reset_pin GPIO pin for RESET (default 25)
338 led_pin GPIO used to control backlight (default 18)
342 Info: Overlay for activation of ADAU1977 ADC codec over I2C for control
344 Load: dtoverlay=adau1977-adc
348 Name: adau7002-simple
349 Info: Overlay for the activation of ADAU7002 stereo PDM to I2S converter.
350 Load: dtoverlay=adau7002-simple,<param>=<val>
351 Params: card-name Override the default, "adau7002", card name.
355 Info: Overlay for activation of Texas Instruments ADS1015 ADC over I2C
356 Load: dtoverlay=ads1015,<param>=<val>
357 Params: addr I2C bus address of device. Set based on how the
358 addr pin is wired. (default=0x48 assumes addr
360 cha_enable Enable virtual channel a. (default=true)
361 cha_cfg Set the configuration for virtual channel a.
362 (default=4 configures this channel for the
363 voltage at A0 with respect to GND)
364 cha_datarate Set the datarate (samples/sec) for this channel.
365 (default=4 sets 1600 sps)
366 cha_gain Set the gain of the Programmable Gain
367 Amplifier for this channel. (default=2 sets the
368 full scale of the channel to 2.048 Volts)
370 Channel (ch) parameters can be set for each enabled channel.
371 A maximum of 4 channels can be enabled (letters a thru d).
372 For more information refer to the device datasheet at:
373 http://www.ti.com/lit/ds/symlink/ads1015.pdf
377 Info: Texas Instruments ADS1115 ADC
378 Load: dtoverlay=ads1115,<param>[=<val>]
379 Params: addr I2C bus address of device. Set based on how the
380 addr pin is wired. (default=0x48 assumes addr
382 cha_enable Enable virtual channel a.
383 cha_cfg Set the configuration for virtual channel a.
384 (default=4 configures this channel for the
385 voltage at A0 with respect to GND)
386 cha_datarate Set the datarate (samples/sec) for this channel.
387 (default=7 sets 860 sps)
388 cha_gain Set the gain of the Programmable Gain
389 Amplifier for this channel. (Default 1 sets the
390 full scale of the channel to 4.096 Volts)
392 Channel parameters can be set for each enabled channel.
393 A maximum of 4 channels can be enabled (letters a thru d).
394 For more information refer to the device datasheet at:
395 http://www.ti.com/lit/ds/symlink/ads1115.pdf
399 Info: ADS7846 Touch controller
400 Load: dtoverlay=ads7846,<param>=<val>
401 Params: cs SPI bus Chip Select (default 1)
402 speed SPI bus speed (default 2MHz, max 3.25MHz)
403 penirq GPIO used for PENIRQ. REQUIRED
404 penirq_pull Set GPIO pull (default 0=none, 2=pullup)
405 swapxy Swap x and y axis
406 xmin Minimum value on the X axis (default 0)
407 ymin Minimum value on the Y axis (default 0)
408 xmax Maximum value on the X axis (default 4095)
409 ymax Maximum value on the Y axis (default 4095)
410 pmin Minimum reported pressure value (default 0)
411 pmax Maximum reported pressure value (default 65535)
412 xohms Touchpanel sensitivity (X-plate resistance)
415 penirq is required and usually xohms (60-100) has to be set as well.
416 Apart from that, pmax (255) and swapxy are also common.
417 The rest of the calibration can be done with xinput-calibrator.
418 See: github.com/notro/fbtft/wiki/FBTFT-on-Raspian
419 Device Tree binding document:
420 www.kernel.org/doc/Documentation/devicetree/bindings/input/ads7846.txt
424 Info: Analog Devices ADV7282M analogue video to CSI2 bridge.
425 Uses Unicam1, which is the standard camera connector on most Pi
427 Load: dtoverlay=adv7282m,<param>=<val>
428 Params: addr Overrides the I2C address (default 0x21)
429 media-controller Configure use of Media Controller API for
430 configuring the sensor (default off)
434 Info: Analog Devices ADV728[0|1|2]-M analogue video to CSI2 bridges.
435 This is a wrapper for adv7282m, and defaults to ADV7282M.
436 Load: dtoverlay=adv728x-m,<param>=<val>
437 Params: addr Overrides the I2C address (default 0x21)
438 adv7280m Select ADV7280-M.
439 adv7281m Select ADV7281-M.
440 adv7281ma Select ADV7281-MA.
441 media-controller Configure use of Media Controller API for
442 configuring the sensor (default off)
445 Name: akkordion-iqdacplus
446 Info: Configures the Digital Dreamtime Akkordion Music Player (based on the
447 OEM IQAudIO DAC+ or DAC Zero module).
448 Load: dtoverlay=akkordion-iqdacplus,<param>=<val>
449 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
450 Digital volume control. Enable with
451 dtoverlay=akkordion-iqdacplus,24db_digital_gain
452 (The default behaviour is that the Digital
453 volume control is limited to a maximum of
454 0dB. ie. it can attenuate but not provide
455 gain. For most users, this will be desired
456 as it will prevent clipping. By appending
457 the 24db_digital_gain parameter, the Digital
458 volume control will allow up to 24dB of
459 gain. If this parameter is enabled, it is the
460 responsibility of the user to ensure that
461 the Digital volume control is set to a value
462 that does not result in clipping/distortion!)
465 Name: allo-boss-dac-pcm512x-audio
466 Info: Configures the Allo Boss DAC audio cards.
467 Load: dtoverlay=allo-boss-dac-pcm512x-audio,<param>
468 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
469 Digital volume control. Enable with
470 "dtoverlay=allo-boss-dac-pcm512x-audio,
472 (The default behaviour is that the Digital
473 volume control is limited to a maximum of
474 0dB. ie. it can attenuate but not provide
475 gain. For most users, this will be desired
476 as it will prevent clipping. By appending
477 the 24db_digital_gain parameter, the Digital
478 volume control will allow up to 24dB of
479 gain. If this parameter is enabled, it is the
480 responsibility of the user to ensure that
481 the Digital volume control is set to a value
482 that does not result in clipping/distortion!)
483 slave Force Boss DAC into slave mode, using Pi a
484 master for bit clock and frame clock. Enable
485 with "dtoverlay=allo-boss-dac-pcm512x-audio,
489 Name: allo-boss2-dac-audio
490 Info: Configures the Allo Boss2 DAC audio card
491 Load: dtoverlay=allo-boss2-dac-audio
496 Info: Configures the Allo Digione audio card
497 Load: dtoverlay=allo-digione
501 Name: allo-katana-dac-audio
502 Info: Configures the Allo Katana DAC audio card
503 Load: dtoverlay=allo-katana-dac-audio
507 Name: allo-piano-dac-pcm512x-audio
508 Info: Configures the Allo Piano DAC (2.0/2.1) audio cards.
509 (NB. This initial support is for 2.0 channel audio ONLY! ie. stereo.
510 The subwoofer outputs on the Piano 2.1 are not currently supported!)
511 Load: dtoverlay=allo-piano-dac-pcm512x-audio,<param>
512 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
513 Digital volume control.
514 (The default behaviour is that the Digital
515 volume control is limited to a maximum of
516 0dB. ie. it can attenuate but not provide
517 gain. For most users, this will be desired
518 as it will prevent clipping. By appending
519 the 24db_digital_gain parameter, the Digital
520 volume control will allow up to 24dB of
521 gain. If this parameter is enabled, it is the
522 responsibility of the user to ensure that
523 the Digital volume control is set to a value
524 that does not result in clipping/distortion!)
527 Name: allo-piano-dac-plus-pcm512x-audio
528 Info: Configures the Allo Piano DAC (2.1) audio cards.
529 Load: dtoverlay=allo-piano-dac-plus-pcm512x-audio,<param>
530 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
531 Digital volume control.
532 (The default behaviour is that the Digital
533 volume control is limited to a maximum of
534 0dB. ie. it can attenuate but not provide
535 gain. For most users, this will be desired
536 as it will prevent clipping. By appending
537 the 24db_digital_gain parameter, the Digital
538 volume control will allow up to 24dB of
539 gain. If this parameter is enabled, it is the
540 responsibility of the user to ensure that
541 the Digital volume control is set to a value
542 that does not result in clipping/distortion!)
543 glb_mclk This option is only with Kali board. If enabled,
544 MCLK for Kali is used and PLL is disabled for
545 better voice quality. (default Off)
549 Info: Universal device tree overlay for SPI devices
551 Just specify the SPI address and device name ("compatible" property).
552 This overlay lacks any device-specific parameter support!
554 For devices on spi1 or spi2, the interfaces should be enabled
555 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
558 1. SPI NOR flash on spi0.1, maximum SPI clock frequency 45MHz:
559 dtoverlay=anyspi:spi0-1,dev="jedec,spi-nor",speed=45000000
560 2. MCP3204 ADC on spi1.2, maximum SPI clock frequency 500kHz:
561 dtoverlay=anyspi:spi1-2,dev="microchip,mcp3204"
562 Load: dtoverlay=anyspi,<param>=<val>
563 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
565 dev Set device name to search compatible module
567 speed Set SPI clock frequency in Hz
568 (integer, optional, default 500000)
572 Info: Configures the AVAGO APDS9960 digital proximity, ambient light, RGB and
574 Load: dtoverlay=apds9960,<param>=<val>
575 Params: gpiopin GPIO used for INT (default 4)
576 noints Disable the interrupt GPIO line.
580 Info: Configures the Orchard Audio ApplePi-DAC audio card
581 Load: dtoverlay=applepi-dac
586 Info: Configures the Atmel AT86RF233 802.15.4 low-power WPAN transceiver,
588 Load: dtoverlay=at86rf233,<param>=<val>
589 Params: interrupt GPIO used for INT (default 23)
590 reset GPIO used for Reset (default 24)
591 sleep GPIO used for Sleep (default 25)
592 speed SPI bus speed in Hz (default 3000000)
593 trim Fine tuning of the internal capacitance
594 arrays (0=+0pF, 15=+4.5pF, default 15)
597 Name: audioinjector-addons
598 Info: Configures the audioinjector.net audio add on soundcards
599 Load: dtoverlay=audioinjector-addons,<param>=<val>
600 Params: non-stop-clocks Keeps the clocks running even when the stream
601 is paused or stopped (default off)
604 Name: audioinjector-isolated-soundcard
605 Info: Configures the audioinjector.net isolated soundcard
606 Load: dtoverlay=audioinjector-isolated-soundcard
610 Name: audioinjector-ultra
611 Info: Configures the audioinjector.net ultra soundcard
612 Load: dtoverlay=audioinjector-ultra
616 Name: audioinjector-wm8731-audio
617 Info: Configures the audioinjector.net audio add on soundcard
618 Load: dtoverlay=audioinjector-wm8731-audio
623 Info: Configures the audiosense-pi add on soundcard
624 For more information refer to
625 https://gitlab.com/kakar0t/audiosense-pi
626 Load: dtoverlay=audiosense-pi
631 Info: Switches PWM sound output to GPIOs on the 40-pin header
632 Load: dtoverlay=audremap,<param>=<val>
633 Params: swap_lr Reverse the channel allocation, which will also
634 swap the audio jack outputs (default off)
635 enable_jack Don't switch off the audio jack output
637 pins_12_13 Select GPIOs 12 & 13 (default)
638 pins_18_19 Select GPIOs 18 & 19
642 Info: Overlay that enables WLAN, Bluetooth and the GPIO expander on the
643 balenaFin carrier board for the Raspberry Pi Compute Module 3/3+ Lite.
644 Load: dtoverlay=balena-fin
648 Name: bmp085_i2c-sensor
649 Info: This overlay is now deprecated - see i2c-sensor
654 Info: Enables the ability to use the cap1106 touch sensor as a keyboard
655 Load: dtoverlay=cap1106,<param>=<val>
656 Params: int_pin GPIO pin for interrupt signal (default 23)
660 Info: Configures Chip Dip audio cards.
661 Load: dtoverlay=chipdip-dac
666 Info: Set custom CMA sizes, only use if you know what you are doing, might
667 clash with other overlays like vc4-fkms-v3d and vc4-kms-v3d.
668 Load: dtoverlay=cma,<param>=<val>
669 Params: cma-512 CMA is 512MB (needs 1GB)
670 cma-448 CMA is 448MB (needs 1GB)
671 cma-384 CMA is 384MB (needs 1GB)
672 cma-320 CMA is 320MB (needs 1GB)
673 cma-256 CMA is 256MB (needs 1GB)
674 cma-192 CMA is 192MB (needs 1GB)
678 cma-size CMA size in bytes, 4MB aligned
679 cma-default Use upstream's default value
683 Info: 8" TFT LCD display and touch panel used by cutiepi.io
684 Load: dtoverlay=cutiepi-panel
689 Info: Overlay for the DHT11/DHT21/DHT22 humidity/temperature sensors
690 Also sometimes found with the part number(s) AM230x.
691 Load: dtoverlay=dht11,<param>=<val>
692 Params: gpiopin GPIO connected to the sensor's DATA output.
697 Info: Configures the Dion Audio LOCO DAC-AMP
698 Load: dtoverlay=dionaudio-loco
702 Name: dionaudio-loco-v2
703 Info: Configures the Dion Audio LOCO-V2 DAC-AMP
704 Load: dtoverlay=dionaudio-loco-v2,<param>=<val>
705 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
706 Digital volume control. Enable with
707 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
708 (The default behaviour is that the Digital
709 volume control is limited to a maximum of
710 0dB. ie. it can attenuate but not provide
711 gain. For most users, this will be desired
712 as it will prevent clipping. By appending
713 the 24dB_digital_gain parameter, the Digital
714 volume control will allow up to 24dB of
715 gain. If this parameter is enabled, it is the
716 responsibility of the user to ensure that
717 the Digital volume control is set to a value
718 that does not result in clipping/distortion!)
722 Info: Disable onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W, restoring
723 UART0/ttyAMA0 over GPIOs 14 & 15.
724 N.B. To disable the systemd service that initialises the modem so it
725 doesn't use the UART, use 'sudo systemctl disable hciuart'.
726 Load: dtoverlay=disable-bt
731 Info: Disable onboard WLAN on Pi 3B, 3B+, 3A+, 4B and Zero W.
732 Load: dtoverlay=disable-wifi
737 Info: Overlay for a generic 18-bit DPI display
738 This uses GPIOs 0-21 (so no I2C, uart etc.), and activates the output
739 2-3 seconds after the kernel has started.
740 Load: dtoverlay=dpi18
745 Info: Overlay for a generic 18-bit DPI display (in 'mode 6' connection scheme)
746 This uses GPIOs 0-9,12-17,20-25 (so no I2C, uart etc.), and activates
747 the output 3-3 seconds after the kernel has started.
748 Load: dtoverlay=dpi18cpadhi
753 Info: Overlay for a generic 24-bit DPI display
754 This uses GPIOs 0-27 (so no I2C, uart etc.), and activates the output
755 2-3 seconds after the kernel has started.
756 Load: dtoverlay=dpi24
761 Info: Configures the NW Digital Radio DRAWS Hat
763 The board includes an ADC to measure various board values and also
764 provides two analog user inputs on the expansion header. The ADC
765 can be configured for various sample rates and gain values to adjust
766 the input range. Tables describing the two parameters follow.
783 4 = 1600sps (default)
787 Load: dtoverlay=draws,<param>=<val>
788 Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
789 input voltage sensor (default 1)
791 draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
794 draws_adc_ch5_gain Sets the full scale resolution of the ADCs
795 5V rail voltage sensor (default 1)
797 draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
800 draws_adc_ch6_gain Sets the full scale resolution of the ADCs
801 AIN2 input (default 2)
803 draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
805 draws_adc_ch7_gain Sets the full scale resolution of the ADCs
806 AIN3 input (default 2)
808 draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
810 alsaname Name of the ALSA audio device (default "draws")
814 Info: Selects the dwc_otg USB controller driver which has fiq support. This
815 is the default on all except the Pi Zero which defaults to dwc2.
816 Load: dtoverlay=dwc-otg
821 Info: Selects the dwc2 USB controller driver
822 Load: dtoverlay=dwc2,<param>=<val>
823 Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
825 g-rx-fifo-size Size of rx fifo size in gadget mode
827 g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
831 [ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
835 Info: Overlay for the EDT FT5406 touchscreen on the CSI/DSI I2C interface.
836 This works with the Raspberry Pi 7" touchscreen when not being polled
838 You MUST use either "disable_touchscreen=1" or "ignore_lcd=1" in
839 config.txt to stop the firmware polling the touchscreen.
840 Load: dtoverlay=edt-ft5406,<param>=<val>
841 Params: sizex Touchscreen size x (default 800)
842 sizey Touchscreen size y (default 480)
843 invx Touchscreen inverted x axis
844 invy Touchscreen inverted y axis
845 swapxy Touchscreen swapped x y axis
849 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
850 Load: dtoverlay=enc28j60,<param>=<val>
851 Params: int_pin GPIO used for INT (default 25)
853 speed SPI bus speed (default 12000000)
857 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
858 Load: dtoverlay=enc28j60-spi2,<param>=<val>
859 Params: int_pin GPIO used for INT (default 39)
861 speed SPI bus speed (default 12000000)
865 Info: Enables I2C connected EETI EXC3000 multiple touch controller using
866 GPIO 4 (pin 7 on GPIO header) for interrupt.
867 Load: dtoverlay=exc3000,<param>=<val>
868 Params: interrupt GPIO used for interrupt (default 4)
869 sizex Touchscreen size x (default 4096)
870 sizey Touchscreen size y (default 4096)
871 invx Touchscreen inverted x axis
872 invy Touchscreen inverted y axis
873 swapxy Touchscreen swapped x y axis
877 Info: Overlay for SPI-connected displays using the fbtft drivers.
879 This overlay seeks to replace the functionality provided by fbtft_device
880 which is now gone from the kernel.
882 Most displays from fbtft_device have been ported over.
884 dtoverlay=fbtft,spi0-0,rpi-display,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
886 It is also possible to specify the controller (this will use the default
887 init sequence in the driver).
889 dtoverlay=fbtft,spi0-0,ili9341,bgr,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
891 For devices on spi1 or spi2, the interfaces should be enabled
892 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
894 The following features of fbtft_device have not been ported over:
895 - parallel bus is not supported
896 - the init property which overrides the controller initialization
897 sequence is not supported as a parameter due to memory limitations in
898 the bootloader responsible for applying the overlay.
900 See https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays for how to
903 Load: dtoverlay=fbtft,<param>=<val>
905 spi<n>-<m> Configure device at spi<n>, cs<m>
907 speed SPI bus speed in Hz (default 32000000)
908 cpha Shifted clock phase (CPHA) mode
909 cpol Inverse clock polarity (CPOL) mode
911 adafruit18 Adafruit 1.8
912 adafruit22 Adafruit 2.2 (old)
913 adafruit22a Adafruit 2.2
914 adafruit28 Adafruit 2.8
915 adafruit13m Adafruit 1.3 OLED
916 admatec_c-berry28 C-Berry28
918 er_tftm050_2 ER-TFTM070-2
919 er_tftm070_5 ER-TFTM070-5
921 ew24ha0_9bit EW24HA0 in 9-bit mode
922 freetronicsoled128 Freetronics OLED128
925 itdb28_spi ITDB02-2.8 with SPI interface circuit
926 mi0283qt-2 Watterott MI0283QT-2
927 mi0283qt-9a Watterott MI0283QT-9A
929 nokia3310a Nokia 3310a
932 pitft Adafruit PiTFT 2.8
934 rpi-display Watterott rpi-display
935 sainsmart18 Sainsmart 1.8
936 sainsmart32_spi Sainsmart 3.2 with SPI interfce circuit
937 tinylcd35 TinyLCD 3.5
938 tm022hdh26 Tianma TM022HDH26
939 tontec35_9481 Tontect 3.5 with ILI9481 controller
940 tontec35_9486 Tontect 3.5 with ILI9486 controller
941 waveshare32b Waveshare 3.2
942 waveshare22 Waveshare 2.2
944 bd663474 BD663474 display controller
945 hx8340bn HX8340BN display controller
946 hx8347d HX8347D display controller
947 hx8353d HX8353D display controller
948 hx8357d HX8357D display controller
949 ili9163 ILI9163 display controller
950 ili9320 ILI9320 display controller
951 ili9325 ILI9325 display controller
952 ili9340 ILI9340 display controller
953 ili9341 ILI9341 display controller
954 ili9481 ILI9481 display controller
955 ili9486 ILI9486 display controller
956 pcd8544 PCD8544 display controller
957 ra8875 RA8875 display controller
958 s6d02a1 S6D02A1 display controller
959 s6d1121 S6D1121 display controller
960 seps525 SEPS525 display controller
961 sh1106 SH1106 display controller
962 ssd1289 SSD1289 display controller
963 ssd1305 SSD1305 display controller
964 ssd1306 SSD1306 display controller
965 ssd1325 SSD1325 display controller
966 ssd1331 SSD1331 display controller
967 ssd1351 SSD1351 display controller
968 st7735r ST7735R display controller
969 st7789v ST7789V display controller
970 tls8204 TLS8204 display controller
971 uc1611 UC1611 display controller
972 uc1701 UC1701 display controller
973 upd161704 UPD161704 display controller
975 width Display width in pixels
976 height Display height in pixels
977 regwidth Display controller register width (default is
979 buswidth Display bus interface width (default 8)
980 debug Debug output level {0-7}
981 rotate Display rotation {0, 90, 180, 270} (counter
982 clockwise). Not supported by all drivers.
983 bgr Enable BGR mode (default off). Use if Red and
984 Blue are swapped. Not supported by all drivers.
985 fps Frames per second (default 30). In effect this
986 states how long the driver will wait after video
987 memory has been changed until display update
989 txbuflen Length of the FBTFT transmit buffer
991 startbyte Sets the Start byte used by fb_ili9320,
992 fb_ili9325 and fb_hx8347d. Common value is 0x70.
993 gamma String representation of Gamma Curve(s). Driver
994 specific. Not supported by all drivers.
995 reset_pin GPIO pin for RESET
996 dc_pin GPIO pin for D/C
997 led_pin GPIO pin for LED backlight
1001 Info: Configures the Fe-Pi Audio Sound Card
1002 Load: dtoverlay=fe-pi-audio
1007 Info: A demonstration of the gpio-fsm driver. The GPIOs are chosen to work
1008 nicely with a "traffic-light" display of red, amber and green LEDs on
1009 GPIOs 7, 8 and 25 respectively.
1010 Load: dtoverlay=fsm-demo,<param>=<val>
1011 Params: fsm_debug Enable debug logging (default off)
1015 Info: An overlay for the Ghost amplifier.
1016 Load: dtoverlay=ghost-amp,<param>=<val>
1017 Params: fsm_debug Enable debug logging of the GPIO FSM (default
1022 Info: Enables I2C connected Goodix gt9271 multiple touch controller using
1023 GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset.
1024 Load: dtoverlay=goodix,<param>=<val>
1025 Params: interrupt GPIO used for interrupt (default 4)
1026 reset GPIO used for reset (default 17)
1029 Name: googlevoicehat-soundcard
1030 Info: Configures the Google voiceHAT soundcard
1031 Load: dtoverlay=googlevoicehat-soundcard
1036 Info: Configure a GPIO pin to control a cooling fan.
1037 Load: dtoverlay=gpio-fan,<param>=<val>
1038 Params: gpiopin GPIO used to control the fan (default 12)
1039 temp Temperature at which the fan switches on, in
1040 millicelcius (default 55000)
1044 Info: Use GPIO pin as rc-core style infrared receiver input. The rc-core-
1045 based gpio_ir_recv driver maps received keys directly to a
1046 /dev/input/event* device, all decoding is done by the kernel - LIRC is
1047 not required! The key mapping and other decoding parameters can be
1048 configured by "ir-keytable" tool.
1049 Load: dtoverlay=gpio-ir,<param>=<val>
1050 Params: gpio_pin Input pin number. Default is 18.
1052 gpio_pull Desired pull-up/down state (off, down, up)
1055 invert "1" = invert the input (active-low signalling).
1056 "0" = non-inverted input (active-high
1057 signalling). Default is "1".
1059 rc-map-name Default rc keymap (can also be changed by
1060 ir-keytable), defaults to "rc-rc6-mce"
1064 Info: Use GPIO pin as bit-banged infrared transmitter output.
1065 This is an alternative to "pwm-ir-tx". gpio-ir-tx doesn't require
1066 a PWM so it can be used together with onboard analog audio.
1067 Load: dtoverlay=gpio-ir-tx,<param>=<val>
1068 Params: gpio_pin Output GPIO (default 18)
1070 invert "1" = invert the output (make it active-low).
1071 Default is "0" (active-high).
1075 Info: This is a generic overlay for activating GPIO keypresses using
1076 the gpio-keys library and this dtoverlay. Multiple keys can be
1077 set up using multiple calls to the overlay for configuring
1078 additional buttons or joysticks. You can see available keycodes
1079 at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
1080 linux/input-event-codes.h#L64
1081 Load: dtoverlay=gpio-key,<param>=<val>
1082 Params: gpio GPIO pin to trigger on (default 3)
1083 active_low When this is 1 (active low), a falling
1084 edge generates a key down event and a
1085 rising edge generates a key up event.
1086 When this is 0 (active high), this is
1087 reversed. The default is 1 (active low)
1088 gpio_pull Desired pull-up/down state (off, down, up)
1089 Default is "up". Note that the default pin
1090 (GPIO3) has an external pullup
1091 label Set a label for the key
1092 keycode Set the key code for the button
1097 Info: This is a generic overlay for activating LEDs (or any other component)
1098 by a GPIO pin. Multiple LEDs can be set up using multiple calls to the
1099 overlay. While there are many existing methods to activate LEDs on the
1100 RPi, this method offers some advantages:
1101 1) Does not require any userspace programs.
1102 2) LEDs can be connected to the kernel's led-trigger framework,
1103 and drive the LED based on triggers such as cpu load, heartbeat,
1104 kernel panic, key input, timers and others.
1105 3) LED can be tied to the input state of another GPIO pin.
1106 4) The LED is setup early during the kernel boot process (useful
1107 for cpu/heartbeat/panic triggers).
1109 Typical electrical connection is:
1110 RPI-GPIO.19 -> LED -> 300ohm resister -> RPI-GND
1111 The GPIO pin number can be changed with the 'gpio=' parameter.
1113 To control an LED from userspace, write a 0 or 1 value:
1114 echo 1 > /sys/class/leds/myled1/brightness
1115 The 'myled1' name can be changed with the 'label=' parameter.
1117 To connect the LED to a kernel trigger from userspace:
1118 echo cpu > /sys/class/leds/myled1/trigger
1119 echo heartbeat > /sys/class/leds/myled1/trigger
1120 echo none > /sys/class/leds/myled1/trigger
1121 To connect the LED to GPIO.26 pin (physical pin 37):
1122 echo gpio > /sys/class/leds/myled1/trigger
1123 echo 26 > /sys/class/leds/myled1/gpio
1125 cat /sys/class/leds/myled1/trigger
1127 More information about the Linux kernel LED/Trigger system:
1128 https://www.kernel.org/doc/Documentation/leds/leds-class.rst
1129 https://www.kernel.org/doc/Documentation/leds/ledtrig-oneshot.rst
1130 Load: dtoverlay=gpio-led,<param>=<val>
1131 Params: gpio GPIO pin connected to the LED (default 19)
1132 label The label for this LED. It will appear under
1133 /sys/class/leds/<label> . Default 'myled1'.
1134 trigger Set the led-trigger to connect to this LED.
1135 default 'none' (LED is user-controlled).
1136 Some possible triggers:
1137 cpu - CPU load (all CPUs)
1138 cpu0 - CPU load of first CPU.
1139 mmc - disk activity (all disks)
1140 panic - turn on on kernel panic
1141 heartbeat - indicate system health
1142 gpio - connect to a GPIO input pin (note:
1143 currently the GPIO PIN can not be set
1144 using overlay parameters, must be
1145 done in userspace, see examples above.
1146 active_low Set to 1 to turn invert the LED control
1147 (writing 0 to /sys/class/leds/XXX/brightness
1148 will turn on the GPIO/LED). Default '0'.
1151 Name: gpio-no-bank0-irq
1152 Info: Use this overlay to disable GPIO interrupts for GPIOs in bank 0 (0-27),
1153 which can be useful for UIO drivers.
1154 N.B. Using this overlay will trigger a kernel WARN during booting, but
1155 this can safely be ignored - the system should work as expected.
1156 Load: dtoverlay=gpio-no-bank0-irq
1161 Info: Use this overlay to disable all GPIO interrupts, which can be useful
1162 for user-space GPIO edge detection systems.
1163 Load: dtoverlay=gpio-no-irq
1168 Info: Drives a GPIO high or low on poweroff (including halt). Using this
1169 overlay interferes with the normal power-down sequence, preventing the
1170 kernel from resetting the SoC (a necessary step in a normal power-off
1171 or reboot). This also disables the ability to trigger a boot by driving
1174 The GPIO starts in an inactive state. At poweroff time it is driven
1175 active for 100ms, then inactive for 100ms, then active again. It is
1176 safe to remove the power at any point after the initial activation of
1179 Users of this overlay are required to provide an external mechanism to
1180 switch off the power supply when signalled - failure to do so results
1181 in a kernel BUG, increased power consumption and undefined behaviour.
1182 Load: dtoverlay=gpio-poweroff,<param>=<val>
1183 Params: gpiopin GPIO for signalling (default 26)
1185 active_low Set if the power control device requires a
1186 high->low transition to trigger a power-down.
1187 Note that this will require the support of a
1188 custom dt-blob.bin to prevent a power-down
1189 during the boot process, and that a reboot
1190 will also cause the pin to go low.
1191 input Set if the gpio pin should be configured as
1193 export Set to export the configured pin to sysfs
1194 active_delay_ms Initial GPIO active period (default 100)
1195 inactive_delay_ms Subsequent GPIO inactive period (default 100)
1196 timeout_ms Specify (in ms) how long the kernel waits for
1197 power-down before issuing a WARN (default 3000).
1201 Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin
1202 is configured as an input key that generates KEY_POWER events.
1204 This event is handled by systemd-logind by initiating a
1205 shutdown. Systemd versions older than 225 need an udev rule
1206 enable listening to the input device:
1208 ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
1209 SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
1210 ATTRS{keys}=="116", TAG+="power-switch"
1212 Alternatively this event can be handled also on systems without
1213 systemd, just by traditional SysV init daemon. KEY_POWER event
1214 (keycode 116) needs to be mapped to KeyboardSignal on console
1215 and then kb::kbrequest inittab action which is triggered by
1216 KeyboardSignal from console can be configured to issue system
1217 shutdown. Steps for this configuration are:
1219 Add following lines to the /etc/console-setup/remap.inc file:
1221 # Key Power as special keypress
1222 keycode 116 = KeyboardSignal
1224 Then add following lines to /etc/inittab file:
1226 # Action on special keypress (Key Power)
1227 kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
1229 And finally reload configuration by calling following commands:
1231 # dpkg-reconfigure console-setup
1232 # service console-setup reload
1235 This overlay only handles shutdown. After shutdown, the system
1236 can be powered up again by driving GPIO3 low. The default
1237 configuration uses GPIO3 with a pullup, so if you connect a
1238 button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
1239 you get a shutdown and power-up button. Please note that
1240 Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.
1241 Load: dtoverlay=gpio-shutdown,<param>=<val>
1242 Params: gpio_pin GPIO pin to trigger on (default 3)
1243 For Raspberry Pi 1 Model B rev 1 set this
1244 explicitly to value 1, e.g.:
1246 dtoverlay=gpio-shutdown,gpio_pin=1
1248 active_low When this is 1 (active low), a falling
1249 edge generates a key down event and a
1250 rising edge generates a key up event.
1251 When this is 0 (active high), this is
1252 reversed. The default is 1 (active low).
1254 gpio_pull Desired pull-up/down state (off, down, up)
1257 Note that the default pin (GPIO3) has an
1258 external pullup. Same applies for GPIO1
1259 on Raspberry Pi 1 Model B rev 1.
1261 debounce Specify the debounce interval in milliseconds
1266 Info: Configures an HD44780 compatible LCD display. Uses 4 gpio pins for
1267 data, 2 gpio pins for enable and register select and 1 optional pin
1268 for enabling/disabling the backlight display.
1269 Load: dtoverlay=hd44780-lcd,<param>=<val>
1270 Params: pin_d4 GPIO pin for data pin D4 (default 6)
1272 pin_d5 GPIO pin for data pin D5 (default 13)
1274 pin_d6 GPIO pin for data pin D6 (default 19)
1276 pin_d7 GPIO pin for data pin D7 (default 26)
1278 pin_en GPIO pin for "Enable" (default 21)
1280 pin_rs GPIO pin for "Register Select" (default 20)
1282 pin_bl Optional pin for enabling/disabling the
1283 display backlight. (default disabled)
1285 display_height Height of the display in characters
1287 display_width Width of the display in characters
1290 Name: hdmi-backlight-hwhack-gpio
1291 Info: Devicetree overlay for GPIO based backlight on/off capability.
1292 Use this if you have one of those HDMI displays whose backlight cannot
1293 be controlled via DPMS over HDMI and plan to do a little soldering to
1294 use an RPi gpio pin for on/off switching. See:
1295 https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control
1296 Load: dtoverlay=hdmi-backlight-hwhack-gpio,<param>=<val>
1297 Params: gpio_pin GPIO pin used (default 17)
1298 active_low Set this to 1 if the display backlight is
1299 switched on when the wire goes low.
1300 Leave the default (value 0) if the backlight
1301 expects a high to switch it on.
1305 Info: Configures the HifiBerry Amp and Amp+ audio cards
1306 Load: dtoverlay=hifiberry-amp
1310 Name: hifiberry-amp100
1311 Info: Configures the HifiBerry AMP100 audio card
1312 Load: dtoverlay=hifiberry-amp100,<param>=<val>
1313 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1314 Digital volume control. Enable with
1315 "dtoverlay=hifiberry-amp100,24db_digital_gain"
1316 (The default behaviour is that the Digital
1317 volume control is limited to a maximum of
1318 0dB. ie. it can attenuate but not provide
1319 gain. For most users, this will be desired
1320 as it will prevent clipping. By appending
1321 the 24dB_digital_gain parameter, the Digital
1322 volume control will allow up to 24dB of
1323 gain. If this parameter is enabled, it is the
1324 responsibility of the user to ensure that
1325 the Digital volume control is set to a value
1326 that does not result in clipping/distortion!)
1327 slave Force DAC+ Pro into slave mode, using Pi as
1328 master for bit clock and frame clock.
1329 leds_off If set to 'true' the onboard indicator LEDs
1330 are switched off at all times.
1331 auto_mute If set to 'true' the amplifier is automatically
1332 muted when the DAC is not playing.
1333 mute_ext_ctl The amplifier's HW mute control is enabled
1334 in ALSA mixer and set to <val>.
1335 Will be overwritten by ALSA user settings.
1339 Info: Configures the HifiBerry DAC audio cards
1340 Load: dtoverlay=hifiberry-dac
1344 Name: hifiberry-dacplus
1345 Info: Configures the HifiBerry DAC+ audio card
1346 Load: dtoverlay=hifiberry-dacplus,<param>=<val>
1347 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1348 Digital volume control. Enable with
1349 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1350 (The default behaviour is that the Digital
1351 volume control is limited to a maximum of
1352 0dB. ie. it can attenuate but not provide
1353 gain. For most users, this will be desired
1354 as it will prevent clipping. By appending
1355 the 24dB_digital_gain parameter, the Digital
1356 volume control will allow up to 24dB of
1357 gain. If this parameter is enabled, it is the
1358 responsibility of the user to ensure that
1359 the Digital volume control is set to a value
1360 that does not result in clipping/distortion!)
1361 slave Force DAC+ Pro into slave mode, using Pi as
1362 master for bit clock and frame clock.
1363 leds_off If set to 'true' the onboard indicator LEDs
1364 are switched off at all times.
1367 Name: hifiberry-dacplusadc
1368 Info: Configures the HifiBerry DAC+ADC audio card
1369 Load: dtoverlay=hifiberry-dacplusadc,<param>=<val>
1370 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1371 Digital volume control. Enable with
1372 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1373 (The default behaviour is that the Digital
1374 volume control is limited to a maximum of
1375 0dB. ie. it can attenuate but not provide
1376 gain. For most users, this will be desired
1377 as it will prevent clipping. By appending
1378 the 24dB_digital_gain parameter, the Digital
1379 volume control will allow up to 24dB of
1380 gain. If this parameter is enabled, it is the
1381 responsibility of the user to ensure that
1382 the Digital volume control is set to a value
1383 that does not result in clipping/distortion!)
1384 slave Force DAC+ Pro into slave mode, using Pi as
1385 master for bit clock and frame clock.
1386 leds_off If set to 'true' the onboard indicator LEDs
1387 are switched off at all times.
1390 Name: hifiberry-dacplusadcpro
1391 Info: Configures the HifiBerry DAC+ADC PRO audio card
1392 Load: dtoverlay=hifiberry-dacplusadcpro,<param>=<val>
1393 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1394 Digital volume control. Enable with
1395 "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain"
1396 (The default behaviour is that the Digital
1397 volume control is limited to a maximum of
1398 0dB. ie. it can attenuate but not provide
1399 gain. For most users, this will be desired
1400 as it will prevent clipping. By appending
1401 the 24dB_digital_gain parameter, the Digital
1402 volume control will allow up to 24dB of
1403 gain. If this parameter is enabled, it is the
1404 responsibility of the user to ensure that
1405 the Digital volume control is set to a value
1406 that does not result in clipping/distortion!)
1407 slave Force DAC+ADC Pro into slave mode, using Pi as
1408 master for bit clock and frame clock.
1409 leds_off If set to 'true' the onboard indicator LEDs
1410 are switched off at all times.
1413 Name: hifiberry-dacplusdsp
1414 Info: Configures the HifiBerry DAC+DSP audio card
1415 Load: dtoverlay=hifiberry-dacplusdsp
1419 Name: hifiberry-dacplushd
1420 Info: Configures the HifiBerry DAC+ HD audio card
1421 Load: dtoverlay=hifiberry-dacplushd
1425 Name: hifiberry-digi
1426 Info: Configures the HifiBerry Digi and Digi+ audio card
1427 Load: dtoverlay=hifiberry-digi
1431 Name: hifiberry-digi-pro
1432 Info: Configures the HifiBerry Digi+ Pro audio card
1433 Load: dtoverlay=hifiberry-digi-pro
1438 Info: Enables "High Peripheral" mode
1439 Load: dtoverlay=highperi
1444 Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics
1445 Default values match Texy's display shield
1446 Load: dtoverlay=hy28a,<param>=<val>
1447 Params: speed Display SPI bus speed
1449 rotate Display rotation {0,90,180,270}
1451 fps Delay between frame updates
1453 debug Debug output level {0-7}
1455 xohms Touchpanel sensitivity (X-plate resistance)
1457 resetgpio GPIO used to reset controller
1459 ledgpio GPIO used to control backlight
1463 Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
1464 Default values match Texy's display shield
1465 Load: dtoverlay=hy28b,<param>=<val>
1466 Params: speed Display SPI bus speed
1468 rotate Display rotation {0,90,180,270}
1470 fps Delay between frame updates
1472 debug Debug output level {0-7}
1474 xohms Touchpanel sensitivity (X-plate resistance)
1476 resetgpio GPIO used to reset controller
1478 ledgpio GPIO used to control backlight
1482 Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics
1483 Default values match Texy's display shield
1484 Load: dtoverlay=hy28b-2017,<param>=<val>
1485 Params: speed Display SPI bus speed
1487 rotate Display rotation {0,90,180,270}
1489 fps Delay between frame updates
1491 debug Debug output level {0-7}
1493 xohms Touchpanel sensitivity (X-plate resistance)
1495 resetgpio GPIO used to reset controller
1497 ledgpio GPIO used to control backlight
1501 Info: Configures the Audiophonics I-SABRE Q2M DAC
1502 Load: dtoverlay=i-sabre-q2m
1507 Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
1508 Load: dtoverlay=i2c-bcm2708
1513 Info: Adds support for software i2c controller on gpio pins
1514 Load: dtoverlay=i2c-gpio,<param>=<val>
1515 Params: i2c_gpio_sda GPIO used for I2C data (default "23")
1517 i2c_gpio_scl GPIO used for I2C clock (default "24")
1519 i2c_gpio_delay_us Clock delay in microseconds
1520 (default "2" = ~100kHz)
1522 bus Set to a unique, non-zero value if wanting
1523 multiple i2c-gpio busses. If set, will be used
1524 as the preferred bus number (/dev/i2c-<n>). If
1525 not set, the default value is 0, but the bus
1526 number will be dynamically assigned - probably
1531 Info: Adds support for a number of I2C bus multiplexers on i2c_arm
1532 Load: dtoverlay=i2c-mux,<param>=<val>
1533 Params: pca9542 Select the NXP PCA9542 device
1535 pca9545 Select the NXP PCA9545 device
1537 pca9548 Select the NXP PCA9548 device
1539 addr Change I2C address of the device (default 0x70)
1542 [ The i2c-mux-pca9548a overlay has been deleted. See i2c-mux. ]
1545 Name: i2c-pwm-pca9685a
1546 Info: Adds support for an NXP PCA9685A I2C PWM controller on i2c_arm
1547 Load: dtoverlay=i2c-pwm-pca9685a,<param>=<val>
1548 Params: addr I2C address of PCA9685A (default 0x40)
1552 Info: Adds support for a number of I2C Real Time Clock devices
1553 Load: dtoverlay=i2c-rtc,<param>=<val>
1554 Params: abx80x Select one of the ABx80x family:
1555 AB0801, AB0803, AB0804, AB0805,
1556 AB1801, AB1803, AB1804, AB1805
1558 bq32000 Select the TI BQ32000 device
1560 ds1307 Select the DS1307 device
1562 ds1339 Select the DS1339 device
1564 ds1340 Select the DS1340 device
1566 ds3231 Select the DS3231 device
1568 m41t62 Select the M41T62 device
1570 mcp7940x Select the MCP7940x device
1572 mcp7941x Select the MCP7941x device
1574 pcf2127 Select the PCF2127 device
1576 pcf2129 Select the PCF2129 device
1578 pcf85063 Select the PCF85063 device
1580 pcf85063a Select the PCF85063A device
1582 pcf8523 Select the PCF8523 device
1584 pcf85363 Select the PCF85363 device
1586 pcf8563 Select the PCF8563 device
1588 rv1805 Select the Micro Crystal RV1805 device
1590 rv3028 Select the Micro Crystal RV3028 device
1592 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1594 s35390a Select the ABLIC S35390A device
1596 i2c0 Choose the I2C0 bus on GPIOs 0&1
1598 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1600 addr Sets the address for the RTC. Note that the
1601 device must be configured to use the specified
1604 trickle-diode-disable Do not use the internal trickle charger diode
1607 trickle-diode-type Diode type for trickle charge - "standard" or
1608 "schottky" (ABx80x and RV1805 only)
1610 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1611 ABx80x, RV1805, RV3028)
1613 wakeup-source Specify that the RTC can be used as a wakeup
1616 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1617 off or 1 for Vdd < VBackup (RV3028 only)
1621 Info: Adds support for a number of I2C Real Time Clock devices
1622 using the software i2c controller
1623 Load: dtoverlay=i2c-rtc-gpio,<param>=<val>
1624 Params: abx80x Select one of the ABx80x family:
1625 AB0801, AB0803, AB0804, AB0805,
1626 AB1801, AB1803, AB1804, AB1805
1628 bq32000 Select the TI BQ32000 device
1630 ds1307 Select the DS1307 device
1632 ds1339 Select the DS1339 device
1634 ds1340 Select the DS1340 device
1636 ds3231 Select the DS3231 device
1638 m41t62 Select the M41T62 device
1640 mcp7940x Select the MCP7940x device
1642 mcp7941x Select the MCP7941x device
1644 pcf2127 Select the PCF2127 device
1646 pcf2129 Select the PCF2129 device
1648 pcf85063 Select the PCF85063 device
1650 pcf85063a Select the PCF85063A device
1652 pcf8523 Select the PCF8523 device
1654 pcf85363 Select the PCF85363 device
1656 pcf8563 Select the PCF8563 device
1658 rv1805 Select the Micro Crystal RV1805 device
1660 rv3028 Select the Micro Crystal RV3028 device
1662 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1664 s35390a Select the ABLIC S35390A device
1666 addr Sets the address for the RTC. Note that the
1667 device must be configured to use the specified
1670 trickle-diode-disable Do not use the internal trickle charger diode
1673 trickle-diode-type Diode type for trickle charge - "standard" or
1674 "schottky" (ABx80x and RV1805 only)
1676 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1677 ABx80x, RV1805, RV3028)
1679 wakeup-source Specify that the RTC can be used as a wakeup
1682 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1683 off or 1 for Vdd < VBackup (RV3028 only)
1685 i2c_gpio_sda GPIO used for I2C data (default "23")
1687 i2c_gpio_scl GPIO used for I2C clock (default "24")
1689 i2c_gpio_delay_us Clock delay in microseconds
1690 (default "2" = ~100kHz)
1694 Info: Adds support for a number of I2C barometric pressure, temperature,
1695 light level and chemical sensors on i2c_arm
1696 Load: dtoverlay=i2c-sensor,<param>=<val>
1697 Params: addr Set the address for the BH1750, BME280, BME680,
1698 BMP280, CCS811, DS1621, HDC100X, LM75, SHT3x or
1701 bh1750 Select the Rohm BH1750 ambient light sensor
1702 Valid addresses 0x23 or 0x5c, default 0x23
1704 bme280 Select the Bosch Sensortronic BME280
1705 Valid addresses 0x76-0x77, default 0x76
1707 bme680 Select the Bosch Sensortronic BME680
1708 Valid addresses 0x76-0x77, default 0x76
1710 bmp085 Select the Bosch Sensortronic BMP085
1712 bmp180 Select the Bosch Sensortronic BMP180
1714 bmp280 Select the Bosch Sensortronic BMP280
1715 Valid addresses 0x76-0x77, default 0x76
1717 ccs811 Select the AMS CCS811 digital gas sensor
1718 Valid addresses 0x5a-0x5b, default 0x5b
1720 ds1621 Select the Dallas Semiconductors DS1621 temp
1721 sensor. Valid addresses 0x48-0x4f, default 0x48
1723 hdc100x Select the Texas Instruments HDC100x temp sensor
1724 Valid addresses 0x40-0x43, default 0x40
1726 htu21 Select the HTU21 temperature and humidity sensor
1728 int_pin Set the GPIO to use for interrupts (max30102
1731 lm75 Select the Maxim LM75 temperature sensor
1732 Valid addresses 0x48-0x4f, default 0x4f
1734 lm75addr Deprecated - use addr parameter instead
1736 max17040 Select the Maxim Integrated MAX17040 battery
1739 max30102 Select the Maxim Integrated MAX30102 heart-rate
1740 and blood-oxygen sensor
1742 sht3x Select the Sensiron SHT3x temperature and
1743 humidity sensor. Valid addresses 0x44-0x45,
1746 si7020 Select the Silicon Labs Si7013/20/21 humidity/
1749 sps30 Select the Sensirion SPS30 particulate matter
1750 sensor. Fixed address 0x69.
1752 sgp30 Select the Sensirion SGP30 VOC sensor.
1755 tmp102 Select the Texas Instruments TMP102 temp sensor
1756 Valid addresses 0x48-0x4b, default 0x48
1758 tsl4531 Select the AMS TSL4531 digital ambient light
1761 veml6070 Select the Vishay VEML6070 ultraviolet light
1766 Info: Change i2c0 pin usage. Not all pin combinations are usable on all
1767 platforms - platforms other then Compute Modules can only use this
1768 to disable transaction combining.
1769 Do NOT use in conjunction with dtparam=i2c_vc=on. From the 5.4 kernel
1770 onwards the base DT includes the use of i2c_mux_pinctrl to expose two
1771 muxings of BSC0 - GPIOs 0&1, and whichever combination is used for the
1772 camera and display connectors. This overlay disables that mux and
1773 configures /dev/i2c0 to point at whichever set of pins is requested.
1774 dtparam=i2c_vc=on will try and enable the mux, so combining the two
1775 will cause conflicts.
1776 Load: dtoverlay=i2c0,<param>=<val>
1777 Params: pins_0_1 Use pins 0 and 1 (default)
1778 pins_28_29 Use pins 28 and 29
1779 pins_44_45 Use pins 44 and 45
1780 pins_46_47 Use pins 46 and 47
1781 combine Allow transactions to be combined (default
1786 Info: Deprecated, legacy version of i2c0.
1791 Info: Change i2c1 pin usage. Not all pin combinations are usable on all
1792 platforms - platforms other then Compute Modules can only use this
1793 to disable transaction combining.
1794 Load: dtoverlay=i2c1,<param>=<val>
1795 Params: pins_2_3 Use pins 2 and 3 (default)
1796 pins_44_45 Use pins 44 and 45
1797 combine Allow transactions to be combined (default
1802 Info: Deprecated, legacy version of i2c1.
1807 Info: Enable the i2c3 bus. BCM2711 only.
1808 Load: dtoverlay=i2c3,<param>
1809 Params: pins_2_3 Use GPIOs 2 and 3
1810 pins_4_5 Use GPIOs 4 and 5 (default)
1811 baudrate Set the baudrate for the interface (default
1816 Info: Enable the i2c4 bus. BCM2711 only.
1817 Load: dtoverlay=i2c4,<param>
1818 Params: pins_6_7 Use GPIOs 6 and 7
1819 pins_8_9 Use GPIOs 8 and 9 (default)
1820 baudrate Set the baudrate for the interface (default
1825 Info: Enable the i2c5 bus. BCM2711 only.
1826 Load: dtoverlay=i2c5,<param>
1827 Params: pins_10_11 Use GPIOs 10 and 11
1828 pins_12_13 Use GPIOs 12 and 13 (default)
1829 baudrate Set the baudrate for the interface (default
1834 Info: Enable the i2c6 bus. BCM2711 only.
1835 Load: dtoverlay=i2c6,<param>
1836 Params: pins_0_1 Use GPIOs 0 and 1
1837 pins_22_23 Use GPIOs 22 and 23 (default)
1838 baudrate Set the baudrate for the interface (default
1843 Info: move I2S function block to GPIO 28 to 31
1844 Load: dtoverlay=i2s-gpio28-31
1849 Info: Enables I2C connected Ilitek 251x multiple touch controller using
1850 GPIO 4 (pin 7 on GPIO header) for interrupt.
1851 Load: dtoverlay=ilitek251x,<param>=<val>
1852 Params: interrupt GPIO used for interrupt (default 4)
1853 sizex Touchscreen size x, horizontal resolution of
1854 touchscreen (in pixels)
1855 sizey Touchscreen size y, vertical resolution of
1856 touchscreen (in pixels)
1860 Info: Sony IMX219 camera module.
1861 Uses Unicam 1, which is the standard camera connector on most Pi
1863 Load: dtoverlay=imx219,<param>=<val>
1864 Params: rotation Mounting rotation of the camera sensor (0 or
1866 orientation Sensor orientation (0 = front, 1 = rear,
1867 2 = external, default external)
1868 media-controller Configure use of Media Controller API for
1869 configuring the sensor (default on)
1870 cam0 Adopt the default configuration for CAM0 on a
1871 Compute Module (CSI0, i2c_vc, and cam0_reg).
1872 vcm Configure a VCM focus drive on the sensor.
1876 Info: Sony IMX258 camera module.
1877 Uses Unicam 1, which is the standard camera connector on most Pi
1879 Load: dtoverlay=imx258,<param>=<val>
1880 Params: rotation Mounting rotation of the camera sensor (0 or
1882 orientation Sensor orientation (0 = front, 1 = rear,
1883 2 = external, default external)
1884 media-controller Configure use of Media Controller API for
1885 configuring the sensor (default on)
1886 cam0 Adopt the default configuration for CAM0 on a
1887 Compute Module (CSI0, i2c_vc, and cam0_reg).
1888 vcm Configure a VCM focus drive on the sensor.
1889 4lane Enable 4 CSI2 lanes. This requires a Compute
1890 Module (1, 3, or 4).
1894 Info: Sony IMX290 camera module.
1895 Uses Unicam 1, which is the standard camera connector on most Pi
1896 variants. NB This currently uses 4 CSI2 data lanes and therefore will
1898 Load: dtoverlay=imx290,<param>
1899 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
1900 Module (1, 3, or 4).
1901 clock-frequency Sets the clock frequency to match that used on
1903 Modules from Vision Components use 37.125MHz
1904 (the default), whilst those from Innomaker use
1906 mono Denote that the module is a mono sensor.
1907 orientation Sensor orientation (0 = front, 1 = rear,
1908 2 = external, default external)
1909 rotation Mounting rotation of the camera sensor (0 or
1911 media-controller Configure use of Media Controller API for
1912 configuring the sensor (default on)
1913 cam0 Adopt the default configuration for CAM0 on a
1914 Compute Module (CSI0, i2c_vc, and cam0_reg).
1918 Info: Sony IMX378 camera module.
1919 Uses Unicam 1, which is the standard camera connector on most Pi
1921 Load: dtoverlay=imx378,<param>=<val>
1922 Params: rotation Mounting rotation of the camera sensor (0 or
1924 orientation Sensor orientation (0 = front, 1 = rear,
1925 2 = external, default external)
1926 media-controller Configure use of Media Controller API for
1927 configuring the sensor (default on)
1928 cam0 Adopt the default configuration for CAM0 on a
1929 Compute Module (CSI0, i2c_vc, and cam0_reg).
1933 Info: Sony IMX477 camera module.
1934 Uses Unicam 1, which is the standard camera connector on most Pi
1936 Load: dtoverlay=imx477,<param>=<val>
1937 Params: rotation Mounting rotation of the camera sensor (0 or
1939 orientation Sensor orientation (0 = front, 1 = rear,
1940 2 = external, default external)
1941 media-controller Configure use of Media Controller API for
1942 configuring the sensor (default on)
1943 cam0 Adopt the default configuration for CAM0 on a
1944 Compute Module (CSI0, i2c_vc, and cam0_reg).
1948 Info: Sony IMX519 camera module.
1949 Uses Unicam 1, which is the standard camera connector on most Pi
1951 Load: dtoverlay=imx519,<param>=<val>
1952 Params: rotation Mounting rotation of the camera sensor (0 or
1954 orientation Sensor orientation (0 = front, 1 = rear,
1955 2 = external, default external)
1956 media-controller Configure use of Media Controller API for
1957 configuring the sensor (default on)
1958 cam0 Adopt the default configuration for CAM0 on a
1959 Compute Module (CSI0, i2c_vc, and cam0_reg).
1963 Info: Configures the IQaudio Codec audio card
1964 Load: dtoverlay=iqaudio-codec
1969 Info: Configures the IQaudio DAC audio card
1970 Load: dtoverlay=iqaudio-dac,<param>
1971 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1972 Digital volume control. Enable with
1973 "dtoverlay=iqaudio-dac,24db_digital_gain"
1974 (The default behaviour is that the Digital
1975 volume control is limited to a maximum of
1976 0dB. ie. it can attenuate but not provide
1977 gain. For most users, this will be desired
1978 as it will prevent clipping. By appending
1979 the 24db_digital_gain parameter, the Digital
1980 volume control will allow up to 24dB of
1981 gain. If this parameter is enabled, it is the
1982 responsibility of the user to ensure that
1983 the Digital volume control is set to a value
1984 that does not result in clipping/distortion!)
1987 Name: iqaudio-dacplus
1988 Info: Configures the IQaudio DAC+ audio card
1989 Load: dtoverlay=iqaudio-dacplus,<param>=<val>
1990 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1991 Digital volume control. Enable with
1992 "dtoverlay=iqaudio-dacplus,24db_digital_gain"
1993 (The default behaviour is that the Digital
1994 volume control is limited to a maximum of
1995 0dB. ie. it can attenuate but not provide
1996 gain. For most users, this will be desired
1997 as it will prevent clipping. By appending
1998 the 24db_digital_gain parameter, the Digital
1999 volume control will allow up to 24dB of
2000 gain. If this parameter is enabled, it is the
2001 responsibility of the user to ensure that
2002 the Digital volume control is set to a value
2003 that does not result in clipping/distortion!)
2004 auto_mute_amp If specified, unmute/mute the IQaudIO amp when
2005 starting/stopping audio playback.
2006 unmute_amp If specified, unmute the IQaudIO amp once when
2007 the DAC driver module loads.
2010 Name: iqaudio-digi-wm8804-audio
2011 Info: Configures the IQAudIO Digi WM8804 audio card
2012 Load: dtoverlay=iqaudio-digi-wm8804-audio,<param>=<val>
2013 Params: card_name Override the default, "IQAudIODigi", card name.
2014 dai_name Override the default, "IQAudIO Digi", dai name.
2015 dai_stream_name Override the default, "IQAudIO Digi HiFi",
2020 Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller
2021 using GPIO 4 (pin 7 on GPIO header) for interrupt.
2022 Load: dtoverlay=iqs550,<param>=<val>
2023 Params: interrupt GPIO used for interrupt (default 4)
2024 reset GPIO used for reset (optional)
2025 sizex Touchscreen size x (default 800)
2026 sizey Touchscreen size y (default 480)
2027 invx Touchscreen inverted x axis
2028 invy Touchscreen inverted y axis
2029 swapxy Touchscreen swapped x y axis
2033 Info: Infineon irs1125 TOF camera module.
2034 Uses Unicam 1, which is the standard camera connector on most Pi
2036 Load: dtoverlay=irs1125,<param>=<val>
2037 Params: media-controller Configure use of Media Controller API for
2038 configuring the sensor (default off)
2039 cam0 Adopt the default configuration for CAM0 on a
2040 Compute Module (CSI0, i2c_vc, and cam0_reg).
2044 Info: Adds support for JEDEC-compliant SPI NOR flash devices. (Note: The
2045 "jedec,spi-nor" kernel driver was formerly known as "m25p80".)
2046 Load: dtoverlay=jedec-spi-nor,<param>=<val>
2047 Params: flash-spi<n>-<m> Enables flash device on SPI<n>, CS#<m>.
2048 flash-fastr-spi<n>-<m> Enables flash device with fast read capability
2053 Info: Simultaneous usage of an justboom-dac and justboom-digi based
2055 Load: dtoverlay=justboom-both,<param>=<val>
2056 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2057 Digital volume control. Enable with
2058 "dtoverlay=justboom-dac,24db_digital_gain"
2059 (The default behaviour is that the Digital
2060 volume control is limited to a maximum of
2061 0dB. ie. it can attenuate but not provide
2062 gain. For most users, this will be desired
2063 as it will prevent clipping. By appending
2064 the 24dB_digital_gain parameter, the Digital
2065 volume control will allow up to 24dB of
2066 gain. If this parameter is enabled, it is the
2067 responsibility of the user to ensure that
2068 the Digital volume control is set to a value
2069 that does not result in clipping/distortion!)
2073 Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
2075 Load: dtoverlay=justboom-dac,<param>=<val>
2076 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2077 Digital volume control. Enable with
2078 "dtoverlay=justboom-dac,24db_digital_gain"
2079 (The default behaviour is that the Digital
2080 volume control is limited to a maximum of
2081 0dB. ie. it can attenuate but not provide
2082 gain. For most users, this will be desired
2083 as it will prevent clipping. By appending
2084 the 24dB_digital_gain parameter, the Digital
2085 volume control will allow up to 24dB of
2086 gain. If this parameter is enabled, it is the
2087 responsibility of the user to ensure that
2088 the Digital volume control is set to a value
2089 that does not result in clipping/distortion!)
2093 Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
2094 Load: dtoverlay=justboom-digi
2099 Info: This overlay has been deprecated and removed - see gpio-ir
2104 Info: Adds support for the ltc294x family of battery gauges
2105 Load: dtoverlay=ltc294x,<param>=<val>
2106 Params: ltc2941 Select the ltc2941 device
2108 ltc2942 Select the ltc2942 device
2110 ltc2943 Select the ltc2943 device
2112 ltc2944 Select the ltc2944 device
2114 resistor-sense The sense resistor value in milli-ohms.
2115 Can be a 32-bit negative value when the battery
2116 has been connected to the wrong end of the
2119 prescaler-exponent Range and accuracy of the gauge. The value is
2120 programmed into the chip only if it differs
2121 from the current setting.
2123 - Default value is 128
2124 - the exponent is in the range 0-7 (default 7)
2125 See the datasheet for more information.
2129 Info: Configures the Maxim MAX98357A I2S DAC
2130 Load: dtoverlay=max98357a,<param>=<val>
2131 Params: no-sdmode Driver does not manage the state of the DAC's
2132 SD_MODE pin (i.e. chip is always on).
2133 sdmode-pin integer, GPIO pin connected to the SD_MODE input
2134 of the DAC (default GPIO4 if parameter omitted).
2138 Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
2140 For devices on spi1 or spi2, the interfaces should be enabled
2141 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2142 The overlay expects to disable the relevant spidev node, so also using
2143 e.g. cs0_spidev=off is unnecessary.
2146 MAX31855 on /dev/spidev0.0
2147 dtoverlay=maxtherm,spi0-0,max31855
2148 MAX31856 using a type J thermocouple on /dev/spidev2.1
2150 dtoverlay=maxtherm,spi2-1,max31856,type_j
2152 Load: dtoverlay=maxtherm,<param>=<val>
2153 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2155 max6675 Enable support for the MAX6675 (default)
2156 max31855 Enable support for the MAX31855
2157 max31855e Enable support for the MAX31855E
2158 max31855j Enable support for the MAX31855J
2159 max31855k Enable support for the MAX31855K
2160 max31855n Enable support for the MAX31855N
2161 max31855r Enable support for the MAX31855R
2162 max31855s Enable support for the MAX31855S
2163 max31855t Enable support for the MAX31855T
2164 max31856 Enable support for the MAX31856 (with type K)
2165 type_b Select a type B sensor for max31856
2166 type_e Select a type E sensor for max31856
2167 type_j Select a type J sensor for max31856
2168 type_k Select a type K sensor for max31856
2169 type_n Select a type N sensor for max31856
2170 type_r Select a type R sensor for max31856
2171 type_s Select a type S sensor for max31856
2172 type_t Select a type T sensor for max31856
2176 Info: Configures the mbed AudioCODEC (TLV320AIC23B)
2177 Load: dtoverlay=mbed-dac
2182 Info: Configures the MCP23017 I2C GPIO expander
2183 Load: dtoverlay=mcp23017,<param>=<val>
2184 Params: gpiopin Gpio pin connected to the INTA output of the
2185 MCP23017 (default: 4)
2187 addr I2C address of the MCP23017 (default: 0x20)
2189 mcp23008 Configure an MCP23008 instead.
2190 noints Disable the interrupt GPIO line.
2194 Info: Configures the MCP23S08/17 SPI GPIO expanders.
2195 If devices are present on SPI1 or SPI2, those interfaces must be enabled
2196 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2197 If interrupts are enabled for a device on a given CS# on a SPI bus, that
2198 device must be the only one present on that SPI bus/CS#.
2199 Load: dtoverlay=mcp23s17,<param>=<val>
2200 Params: s08-spi<n>-<m>-present 4-bit integer, bitmap indicating MCP23S08
2201 devices present on SPI<n>, CS#<m>
2203 s17-spi<n>-<m>-present 8-bit integer, bitmap indicating MCP23S17
2204 devices present on SPI<n>, CS#<m>
2206 s08-spi<n>-<m>-int-gpio integer, enables interrupts on a single
2207 MCP23S08 device on SPI<n>, CS#<m>, specifies
2208 the GPIO pin to which INT output of MCP23S08
2211 s17-spi<n>-<m>-int-gpio integer, enables mirrored interrupts on a
2212 single MCP23S17 device on SPI<n>, CS#<m>,
2213 specifies the GPIO pin to which either INTA
2214 or INTB output of MCP23S17 is connected.
2218 Info: Configures the MCP2515 CAN controller on spi0/1/2
2219 For devices on spi1 or spi2, the interfaces should be enabled
2220 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2221 Load: dtoverlay=mcp2515,<param>=<val>
2222 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2225 oscillator Clock frequency for the CAN controller (Hz)
2227 speed Maximum SPI frequence (Hz)
2229 interrupt GPIO for interrupt signal
2233 Info: Configures the MCP2515 CAN controller on spi0.0
2234 Load: dtoverlay=mcp2515-can0,<param>=<val>
2235 Params: oscillator Clock frequency for the CAN controller (Hz)
2237 spimaxfrequency Maximum SPI frequence (Hz)
2239 interrupt GPIO for interrupt signal
2243 Info: Configures the MCP2515 CAN controller on spi0.1
2244 Load: dtoverlay=mcp2515-can1,<param>=<val>
2245 Params: oscillator Clock frequency for the CAN controller (Hz)
2247 spimaxfrequency Maximum SPI frequence (Hz)
2249 interrupt GPIO for interrupt signal
2253 Info: Configures the MCP251XFD CAN controller family
2254 For devices on spi1 or spi2, the interfaces should be enabled
2255 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2256 Load: dtoverlay=mcp251xfd,<param>=<val>
2257 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2260 oscillator Clock frequency for the CAN controller (Hz)
2262 speed Maximum SPI frequence (Hz)
2264 interrupt GPIO for interrupt signal
2266 rx_interrupt GPIO for RX interrupt signal (nINT1) (optional)
2268 xceiver_enable GPIO for CAN transceiver enable (optional)
2270 xceiver_active_high specifiy if CAN transceiver enable pin is
2271 active high (optional, default: active low)
2275 Info: Configures MCP3008 A/D converters
2276 For devices on spi1 or spi2, the interfaces should be enabled
2277 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2278 Load: dtoverlay=mcp3008,<param>[=<val>]
2279 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2280 spi<n>-<m>-speed integer, set the spi bus speed for this device
2284 Info: Configures MCP3202 A/D converters
2285 For devices on spi1 or spi2, the interfaces should be enabled
2286 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2287 Load: dtoverlay=mcp3202,<param>[=<val>]
2288 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2289 spi<n>-<m>-speed integer, set the spi bus speed for this device
2293 Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
2294 Load: dtoverlay=mcp342x,<param>=<val>
2295 Params: addr I2C bus address of device, for devices with
2296 addresses that are configurable, e.g. by
2297 hardware links (default=0x68)
2298 mcp3421 The device is an MCP3421
2299 mcp3422 The device is an MCP3422
2300 mcp3423 The device is an MCP3423
2301 mcp3424 The device is an MCP3424
2302 mcp3425 The device is an MCP3425
2303 mcp3426 The device is an MCP3426
2304 mcp3427 The device is an MCP3427
2305 mcp3428 The device is an MCP3428
2309 Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
2310 Load: dtoverlay=media-center,<param>=<val>
2311 Params: speed Display SPI bus speed
2312 rotate Display rotation {0,90,180,270}
2313 fps Delay between frame updates
2314 xohms Touchpanel sensitivity (X-plate resistance)
2315 swapxy Swap x and y axis
2316 backlight Change backlight GPIO pin {e.g. 12, 18}
2317 gpio_out_pin GPIO for output (default "17")
2318 gpio_in_pin GPIO for input (default "18")
2319 gpio_in_pull Pull up/down/off on the input pin
2321 sense Override the IR receive auto-detection logic:
2322 "0" = force active-high
2323 "1" = force active-low
2324 "-1" = use auto-detection
2326 softcarrier Turn the software carrier "on" or "off"
2328 invert "on" = invert the output pin (default "off")
2329 debug "on" = enable additional debug messages
2334 Info: Configures the merus-amp audio card
2335 Load: dtoverlay=merus-amp
2340 Info: Configures UART0 (ttyAMA0) so that a requested 38.4kbaud actually gets
2341 31.25kbaud, the frequency required for MIDI
2342 Load: dtoverlay=midi-uart0
2347 Info: Configures UART1 (ttyS0) so that a requested 38.4kbaud actually gets
2348 31.25kbaud, the frequency required for MIDI
2349 Load: dtoverlay=midi-uart1
2354 Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
2355 31.25kbaud, the frequency required for MIDI
2356 Load: dtoverlay=midi-uart2
2361 Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
2362 31.25kbaud, the frequency required for MIDI
2363 Load: dtoverlay=midi-uart3
2368 Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
2369 31.25kbaud, the frequency required for MIDI
2370 Load: dtoverlay=midi-uart4
2375 Info: Configures UART5 (ttyAMA4) so that a requested 38.4kbaud actually gets
2376 31.25kbaud, the frequency required for MIDI
2377 Load: dtoverlay=midi-uart5
2382 Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver.
2383 Load: dtoverlay=minipitft13,<param>=<val>
2384 Params: speed SPI bus speed (default 32000000)
2385 rotate Display rotation (0, 90, 180 or 270; default 0)
2386 width Display width (default 240)
2387 height Display height (default 240)
2388 fps Delay between frame updates (default 25)
2389 debug Debug output level (0-7; default 0)
2393 Info: Switch the onboard Bluetooth function on Pi 3B, 3B+, 3A+, 4B and Zero W
2394 to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 &
2395 15. Note that this may reduce the maximum usable baudrate.
2396 N.B. It is also necessary to edit /lib/systemd/system/hciuart.service
2397 and replace ttyAMA0 with ttyS0, unless using Raspbian or another
2398 distribution with udev rules that create /dev/serial0 and /dev/serial1,
2399 in which case use /dev/serial1 instead because it will always be
2400 correct. Furthermore, you must also set core_freq and core_freq_min to
2401 the same value in config.txt or the miniuart will not work.
2402 Load: dtoverlay=miniuart-bt,<param>=<val>
2403 Params: krnbt Set to "on" to enable autoprobing of Bluetooth
2404 driver without need of hciattach/btattach
2408 Info: Overlay for SPI-connected MIPI DBI displays using the panel-mipi-dbi
2409 driver. The driver will load a file /lib/firmware/panel.bin containing
2410 the initialisation commands.
2413 dtoverlay=mipi-dbi-spi,spi0-0,speed=70000000
2414 dtparam=width=320,height=240
2415 dtparam=reset-gpio=23,dc-gpio=24
2416 dtparam=backlight-gpio=18
2418 Compared to fbtft panel-mipi-dbi runs pixel data at spi-max-frequency
2419 and init commands at 10MHz. This makes it possible to push the envelope
2420 without messing up the controller configuration due to command
2421 transmission errors.
2423 For devices on spi1 or spi2, the interfaces should be enabled
2424 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2426 See https://github.com/notro/panel-mipi-dbi/wiki for more info.
2428 Load: dtoverlay=mipi-dbi-spi,<param>=<val>
2430 compatible Set the compatible string to load a different
2431 firmware file. Both the panel compatible value
2432 used to load the firmware file and the value
2433 used to load the driver has to be set having a
2434 NUL (\0) separator between them.
2436 dtparam=compatible=mypanel\0panel-mipi-dbi-spi
2437 spi<n>-<m> Configure device at spi<n>, cs<m>
2439 speed SPI bus speed in Hz (default 32000000)
2440 cpha Shifted SPI clock phase (CPHA) mode
2441 cpol Inverse SPI clock polarity (CPOL) mode
2442 write-only Controller is not readable
2443 (ie. MISO is not wired up).
2445 width Panel width in pixels (required)
2446 height Panel height in pixels (required)
2447 width-mm Panel width in mm
2448 height-mm Panel height in mm
2449 x-offset Panel x-offset in controller RAM
2450 y-offset Panel y-offset in controller RAM
2452 clock-frequency Panel clock frequency in Hz
2453 (optional, just informational).
2455 reset-gpio GPIO pin to be used for RESET
2456 dc-gpio GPIO pin to be used for D/C
2458 backlight-gpio GPIO pin to be used for backlight control
2460 backlight-pwm PWM channel to be used for backlight control
2461 (default of none). NB Disables audio headphone
2462 output as that also uses PWM.
2463 backlight-pwm-chan Choose channel on &pwm node for backlight
2464 control (default 0).
2465 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
2466 pwm-2chan for valid options (default 18).
2467 backlight-pwm-func Pin function of GPIO used for the PWM backlight.
2468 See pwm-2chan for valid options (default 2).
2469 backlight-def-brightness
2470 Set the default brightness. Normal range 1-16.
2475 Info: Overlay for i2c connected mlx90640 thermal camera
2476 Load: dtoverlay=mlx90640
2481 Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock
2482 Load: dtoverlay=mmc,<param>=<val>
2483 Params: overclock_50 Clock (in MHz) to use when the MMC framework
2488 Info: Overlay for i2c connected mpu6050 imu
2489 Load: dtoverlay=mpu6050,<param>=<val>
2490 Params: interrupt GPIO pin for interrupt (default 4)
2491 addr I2C address of the device (default 0x68)
2495 Info: MZ61581 display by Tontec
2496 Load: dtoverlay=mz61581,<param>=<val>
2497 Params: speed Display SPI bus speed
2499 rotate Display rotation {0,90,180,270}
2501 fps Delay between frame updates
2503 txbuflen Transmit buffer length (default 32768)
2505 debug Debug output level {0-7}
2507 xohms Touchpanel sensitivity (X-plate resistance)
2511 Info: Omnivision OV2311 camera module.
2512 Uses Unicam 1, which is the standard camera connector on most Pi
2514 Load: dtoverlay=ov2311,<param>=<val>
2515 Params: rotation Mounting rotation of the camera sensor (0 or
2517 orientation Sensor orientation (0 = front, 1 = rear,
2518 2 = external, default external)
2519 media-controller Configure use of Media Controller API for
2520 configuring the sensor (default on)
2521 cam0 Adopt the default configuration for CAM0 on a
2522 Compute Module (CSI0, i2c_vc, and cam0_reg).
2526 Info: Omnivision OV5647 camera module.
2527 Uses Unicam 1, which is the standard camera connector on most Pi
2529 Load: dtoverlay=ov5647,<param>=<val>
2530 Params: rotation Mounting rotation of the camera sensor (0 or
2532 orientation Sensor orientation (0 = front, 1 = rear,
2533 2 = external, default external)
2534 media-controller Configure use of Media Controller API for
2535 configuring the sensor (default on)
2536 cam0 Adopt the default configuration for CAM0 on a
2537 Compute Module (CSI0, i2c_vc, and cam0_reg).
2538 vcm Configure a VCM focus drive on the sensor.
2542 Info: Omnivision OV7251 camera module.
2543 Uses Unicam 1, which is the standard camera connector on most Pi
2545 Load: dtoverlay=ov7251,<param>=<val>
2546 Params: rotation Mounting rotation of the camera sensor (0 or
2548 orientation Sensor orientation (0 = front, 1 = rear,
2549 2 = external, default external)
2550 media-controller Configure use of Media Controller API for
2551 configuring the sensor (default off)
2552 cam0 Adopt the default configuration for CAM0 on a
2553 Compute Module (CSI0, i2c_vc, and cam0_reg).
2557 Info: Omnivision OV9281 camera module.
2558 Uses Unicam 1, which is the standard camera connector on most Pi
2560 Load: dtoverlay=ov9281,<param>=<val>
2561 Params: rotation Mounting rotation of the camera sensor (0 or
2563 orientation Sensor orientation (0 = front, 1 = rear,
2564 2 = external, default external)
2565 media-controller Configure use of Media Controller API for
2566 configuring the sensor (default on)
2567 cam0 Adopt the default configuration for CAM0 on a
2568 Compute Module (CSI0, i2c_vc, and cam0_reg).
2572 Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
2573 Load: dtoverlay=papirus,<param>=<val>
2574 Params: panel Display panel (required):
2579 speed Display SPI bus speed
2583 Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
2584 Load: dtoverlay=pca953x,<param>=<val>
2585 Params: addr I2C address of expander. Default 0x20.
2586 pca6416 Select the NXP PCA6416 (16 bit)
2587 pca9505 Select the NXP PCA9505 (40 bit)
2588 pca9535 Select the NXP PCA9535 (16 bit)
2589 pca9536 Select the NXP PCA9536 or TI PCA9536 (4 bit)
2590 pca9537 Select the NXP PCA9537 (4 bit)
2591 pca9538 Select the NXP PCA9538 (8 bit)
2592 pca9539 Select the NXP PCA9539 (16 bit)
2593 pca9554 Select the NXP PCA9554 (8 bit)
2594 pca9555 Select the NXP PCA9555 (16 bit)
2595 pca9556 Select the NXP PCA9556 (8 bit)
2596 pca9557 Select the NXP PCA9557 (8 bit)
2597 pca9574 Select the NXP PCA9574 (8 bit)
2598 pca9575 Select the NXP PCA9575 (16 bit)
2599 pca9698 Select the NXP PCA9698 (40 bit)
2600 pca16416 Select the NXP PCA16416 (16 bit)
2601 pca16524 Select the NXP PCA16524 (24 bit)
2602 pca19555a Select the NXP PCA19555A (16 bit)
2603 max7310 Select the Maxim MAX7310 (8 bit)
2604 max7312 Select the Maxim MAX7312 (16 bit)
2605 max7313 Select the Maxim MAX7313 (16 bit)
2606 max7315 Select the Maxim MAX7315 (8 bit)
2607 pca6107 Select the TI PCA6107 (8 bit)
2608 tca6408 Select the TI TCA6408 (8 bit)
2609 tca6416 Select the TI TCA6416 (16 bit)
2610 tca6424 Select the TI TCA6424 (24 bit)
2611 tca9539 Select the TI TCA9539 (16 bit)
2612 tca9554 Select the TI TCA9554 (8 bit)
2613 cat9554 Select the Onnn CAT9554 (8 bit)
2614 pca9654 Select the Onnn PCA9654 (8 bit)
2615 xra1202 Select the Exar XRA1202 (8 bit)
2618 Name: pcie-32bit-dma
2619 Info: Force PCIe config to support 32bit DMA addresses at the expense of
2620 having to bounce buffers.
2621 Load: dtoverlay=pcie-32bit-dma
2625 [ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]
2628 [ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]
2631 [ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]
2635 Info: This overlay has been renamed act-led, keeping pi3-act-led as an alias
2636 for backwards compatibility.
2640 Name: pi3-disable-bt
2641 Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
2642 alias for backwards compatibility.
2646 Name: pi3-disable-wifi
2647 Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
2648 an alias for backwards compatibility.
2652 Name: pi3-miniuart-bt
2653 Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
2654 an alias for backwards compatibility.
2659 Info: Configures the pibell audio card.
2660 Load: dtoverlay=pibell,<param>=<val>
2661 Params: alsaname Set the name as it appears in ALSA (default
2666 Info: Configures the PiFace Digital mcp23s17 GPIO port expander.
2667 Load: dtoverlay=pifacedigital,<param>=<val>
2668 Params: spi-present-mask 8-bit integer, bitmap indicating MCP23S17 SPI0
2669 CS0 address. PiFace Digital supports addresses
2670 0-3, which can be configured with JP1 and JP2.
2674 Info: Configures the PiFi 40W stereo amplifier
2675 Load: dtoverlay=pifi-40
2680 Info: Configures the PiFi DAC HD
2681 Load: dtoverlay=pifi-dac-hd
2686 Info: Configures the PiFi DAC Zero
2687 Load: dtoverlay=pifi-dac-zero
2692 Info: Configures the PiFi Mini stereo amplifier
2693 Load: dtoverlay=pifi-mini-210
2698 Info: Configures the PiGlow by pimoroni.com
2699 Load: dtoverlay=piglow
2704 Info: PiScreen display by OzzMaker.com
2705 Load: dtoverlay=piscreen,<param>=<val>
2706 Params: speed Display SPI bus speed
2708 rotate Display rotation {0,90,180,270}
2710 fps Delay between frame updates
2712 debug Debug output level {0-7}
2714 xohms Touchpanel sensitivity (X-plate resistance)
2718 Info: PiScreen 2 with resistive TP display by OzzMaker.com
2719 Load: dtoverlay=piscreen2r,<param>=<val>
2720 Params: speed Display SPI bus speed
2722 rotate Display rotation {0,90,180,270}
2724 fps Delay between frame updates
2726 debug Debug output level {0-7}
2728 xohms Touchpanel sensitivity (X-plate resistance)
2732 Info: Configures the Blokas Labs pisound card
2733 Load: dtoverlay=pisound
2738 Info: Adafruit PiTFT 2.2" screen
2739 Load: dtoverlay=pitft22,<param>=<val>
2740 Params: speed Display SPI bus speed
2742 rotate Display rotation {0,90,180,270}
2744 fps Delay between frame updates
2746 debug Debug output level {0-7}
2749 Name: pitft28-capacitive
2750 Info: Adafruit PiTFT 2.8" capacitive touch screen
2751 Load: dtoverlay=pitft28-capacitive,<param>=<val>
2752 Params: speed Display SPI bus speed
2754 rotate Display rotation {0,90,180,270}
2756 fps Delay between frame updates
2758 debug Debug output level {0-7}
2760 touch-sizex Touchscreen size x (default 240)
2762 touch-sizey Touchscreen size y (default 320)
2764 touch-invx Touchscreen inverted x axis
2766 touch-invy Touchscreen inverted y axis
2768 touch-swapxy Touchscreen swapped x y axis
2771 Name: pitft28-resistive
2772 Info: Adafruit PiTFT 2.8" resistive touch screen
2773 Load: dtoverlay=pitft28-resistive,<param>=<val>
2774 Params: speed Display SPI bus speed
2776 rotate Display rotation {0,90,180,270}
2778 fps Delay between frame updates
2780 debug Debug output level {0-7}
2783 Name: pitft35-resistive
2784 Info: Adafruit PiTFT 3.5" resistive touch screen
2785 Load: dtoverlay=pitft35-resistive,<param>=<val>
2786 Params: speed Display SPI bus speed
2788 rotate Display rotation {0,90,180,270}
2790 fps Delay between frame updates
2792 debug Debug output level {0-7}
2794 drm Force the use of the hx8357d DRM driver (by
2795 default the fb_hx8357d framebuffer driver will
2796 be used in preference if available)
2800 Info: Configures the pps-gpio (pulse-per-second time signal via GPIO).
2801 Load: dtoverlay=pps-gpio,<param>=<val>
2802 Params: gpiopin Input GPIO (default "18")
2803 assert_falling_edge When present, assert is indicated by a falling
2804 edge, rather than by a rising edge (default
2806 capture_clear Generate clear events on the trailing edge
2811 Info: Configures a single PWM channel
2812 Legal pin,function combinations for each channel:
2813 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2814 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
2816 1) Pin 18 is the only one available on all platforms, and
2817 it is the one used by the I2S audio interface.
2818 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
2819 2) The onboard analogue audio output uses both PWM channels.
2820 3) So be careful mixing audio and PWM.
2821 4) Currently the clock must have been enabled and configured
2823 Load: dtoverlay=pwm,<param>=<val>
2824 Params: pin Output pin (default 18) - see table
2825 func Pin function (default 2 = Alt5) - see above
2826 clock PWM clock frequency (informational)
2830 Info: Configures both PWM channels
2831 Legal pin,function combinations for each channel:
2832 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2833 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
2835 1) Pin 18 is the only one available on all platforms, and
2836 it is the one used by the I2S audio interface.
2837 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
2838 2) The onboard analogue audio output uses both PWM channels.
2839 3) So be careful mixing audio and PWM.
2840 4) Currently the clock must have been enabled and configured
2842 Load: dtoverlay=pwm-2chan,<param>=<val>
2843 Params: pin Output pin (default 18) - see table
2844 pin2 Output pin for other channel (default 19)
2845 func Pin function (default 2 = Alt5) - see above
2846 func2 Function for pin2 (default 2 = Alt5)
2847 clock PWM clock frequency (informational)
2851 Info: Use GPIO pin as pwm-assisted infrared transmitter output.
2852 This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
2853 of PWM0 to reduce the CPU load during transmission compared to
2854 gpio-ir-tx which uses bit-banging.
2855 Legal pin,function combinations are:
2856 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2857 Load: dtoverlay=pwm-ir-tx,<param>=<val>
2858 Params: gpio_pin Output GPIO (default 18)
2860 func Pin function (default 2 = Alt5)
2864 Info: in-tech's Evaluation Board for PLC Stamp micro
2865 This uses spi0 and a separate GPIO interrupt to connect the QCA7000.
2866 Load: dtoverlay=qca7000,<param>=<val>
2867 Params: int_pin GPIO pin for interrupt signal (default 23)
2869 speed SPI bus speed (default 12 MHz)
2873 Info: in-tech's Evaluation Board for PLC Stamp micro (UART)
2874 This uses uart0/ttyAMA0 over GPIOs 14 & 15 to connect the QCA7000.
2875 But it requires disabling of onboard Bluetooth on
2876 Pi 3B, 3B+, 3A+, 4B and Zero W.
2877 Load: dtoverlay=qca7000-uart0,<param>=<val>
2878 Params: baudrate Set the baudrate for the UART (default
2882 Name: rotary-encoder
2883 Info: Overlay for GPIO connected rotary encoder.
2884 Load: dtoverlay=rotary-encoder,<param>=<val>
2885 Params: pin_a GPIO connected to rotary encoder channel A
2887 pin_b GPIO connected to rotary encoder channel B
2889 relative_axis register a relative axis rather than an
2890 absolute one. Relative axis will only
2891 generate +1/-1 events on the input device,
2892 hence no steps need to be passed.
2893 linux_axis the input subsystem axis to map to this
2894 rotary encoder. Defaults to 0 (ABS_X / REL_X)
2895 rollover Automatic rollover when the rotary value
2896 becomes greater than the specified steps or
2897 smaller than 0. For absolute axis only.
2898 steps-per-period Number of steps (stable states) per period.
2899 The values have the following meaning:
2900 1: Full-period mode (default)
2902 4: Quarter-period mode
2903 steps Number of steps in a full turnaround of the
2904 encoder. Only relevant for absolute axis.
2905 Defaults to 24 which is a typical value for
2907 wakeup Boolean, rotary encoder can wake up the
2909 encoding String, the method used to encode steps.
2910 Supported are "gray" (the default and more
2911 common) and "binary".
2915 Info: Raspberry Pi official display backlight driver
2916 Load: dtoverlay=rpi-backlight
2920 Name: rpi-cirrus-wm5102
2921 Info: Configures the Cirrus Logic Audio Card
2922 Load: dtoverlay=rpi-cirrus-wm5102
2927 Info: Configures the RPi DAC audio card
2928 Load: dtoverlay=rpi-dac
2933 Info: RPi-Display - 2.8" Touch Display by Watterott
2934 Linux has 2 drivers that support this display and this overlay supports
2938 fbtft/fb_ili9341: dtoverlay=rpi-display
2939 drm/mi0283qt: dtoverlay=rpi-display,drm,backlight-pwm,rotate=180
2941 Some notable differences with the DRM driver compared to fbtft:
2942 - The display is turned on when it's first used and not on driver load
2943 as with fbtft. So if nothing uses the display it stays off.
2944 - Can run with a higher SPI clock increasing framerate. This is possible
2945 since the driver avoids messing up the controller configuration due to
2946 transmission errors by running config commands at 10MHz and only pixel
2947 data at full speed (occasional pixel glitch might occur).
2948 - PWM backlight is supported.
2950 Load: dtoverlay=rpi-display,<param>=<val>
2951 Params: speed Display SPI bus speed
2952 rotate Display rotation {0,90,180,270}
2953 fps Delay between frame updates (fbtft only)
2954 debug Debug output level {0-7} (fbtft only)
2955 xohms Touchpanel sensitivity (X-plate resistance)
2956 swapxy Swap x and y axis
2957 backlight Change backlight GPIO pin {e.g. 12, 18}
2959 drm Use DRM/KMS driver mi0283qt instead of fbtft.
2960 Set the SPI clock to 70MHz.
2961 This has to be the first parameter.
2962 backlight-pwm Use pwm for backlight (drm only). NB: Disables
2963 audio headphone output as that also uses PWM.
2967 Info: Official Raspberry Pi display touchscreen
2968 Load: dtoverlay=rpi-ft5406,<param>=<val>
2969 Params: touchscreen-size-x Touchscreen X resolution (default 800)
2970 touchscreen-size-y Touchscreen Y resolution (default 600);
2971 touchscreen-inverted-x Invert touchscreen X coordinates (default 0);
2972 touchscreen-inverted-y Invert touchscreen Y coordinates (default 0);
2973 touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
2977 Info: Raspberry Pi PoE HAT fan
2978 Load: dtoverlay=rpi-poe,<param>[=<val>]
2979 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
2980 turns on (default 40000)
2981 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
2982 the fan turns off (default 2000)
2983 poe_fan_temp1 Temperature (in millicelcius) at which the fan
2984 speeds up (default 45000)
2985 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
2986 the fan slows down (default 2000)
2987 poe_fan_temp2 Temperature (in millicelcius) at which the fan
2988 speeds up (default 50000)
2989 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
2990 the fan slows down (default 2000)
2991 poe_fan_temp3 Temperature (in millicelcius) at which the fan
2992 speeds up (default 55000)
2993 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
2994 the fan slows down (default 5000)
2995 i2c Control the fan via Linux I2C drivers instead of
3000 Info: Raspberry Pi PoE+ HAT fan
3001 Load: dtoverlay=rpi-poe-plus,<param>[=<val>]
3002 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3003 turns on (default 40000)
3004 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3005 the fan turns off (default 2000)
3006 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3007 speeds up (default 45000)
3008 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3009 the fan slows down (default 2000)
3010 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3011 speeds up (default 50000)
3012 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3013 the fan slows down (default 2000)
3014 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3015 speeds up (default 55000)
3016 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3017 the fan slows down (default 5000)
3018 i2c Control the fan via Linux I2C drivers instead of
3023 Info: Configures the RPi Proto audio card
3024 Load: dtoverlay=rpi-proto
3029 Info: Raspberry Pi Sense HAT
3030 Load: dtoverlay=rpi-sense
3035 Info: Raspberry Pi TV HAT
3036 Load: dtoverlay=rpi-tv
3041 Info: Load the V4L2 stateless video decoder driver for the HEVC block,
3042 disabling the memory mapped devices in the process.
3043 Load: dtoverlay=rpivid-v4l2
3047 Name: rra-digidac1-wm8741-audio
3048 Info: Configures the Red Rocks Audio DigiDAC1 soundcard
3049 Load: dtoverlay=rra-digidac1-wm8741-audio
3054 Info: Overlay for the SPI-connected Sainsmart 1.8" display (based on the
3056 Load: dtoverlay=sainsmart18,<param>=<val>
3057 Params: rotate Display rotation {0,90,180,270}
3058 speed SPI bus speed in Hz (default 4000000)
3059 fps Display frame rate in Hz
3060 bgr Enable BGR mode (default off)
3061 debug Debug output level {0-7}
3062 dc_pin GPIO pin for D/C (default 24)
3063 reset_pin GPIO pin for RESET (default 25)
3067 Info: Overlay for the NXP SC16IS750 UART with I2C Interface
3068 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3069 select another address, please refer to table 10 in reference manual.
3070 Load: dtoverlay=sc16is750-i2c,<param>=<val>
3071 Params: int_pin GPIO used for IRQ (default 24)
3072 addr Address (default 0x48)
3073 xtal On-board crystal frequency (default 14745600)
3077 Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface
3078 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3079 select another address, please refer to table 10 in reference manual.
3080 Load: dtoverlay=sc16is752-i2c,<param>=<val>
3081 Params: int_pin GPIO used for IRQ (default 24)
3082 addr Address (default 0x48)
3083 xtal On-board crystal frequency (default 14745600)
3086 Name: sc16is752-spi0
3087 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3088 Enables the chip on SPI0.
3089 Load: dtoverlay=sc16is752-spi0,<param>=<val>
3090 Params: int_pin GPIO used for IRQ (default 24)
3091 xtal On-board crystal frequency (default 14745600)
3094 Name: sc16is752-spi1
3095 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3096 Enables the chip on SPI1.
3097 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3098 A+, B+, Zero and PI2 B; as well as the Compute Module.
3100 Load: dtoverlay=sc16is752-spi1,<param>=<val>
3101 Params: int_pin GPIO used for IRQ (default 24)
3102 xtal On-board crystal frequency (default 14745600)
3106 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
3107 N.B. This overlay is designed for situations where the mmc driver is
3108 the default, so it disables the other (mmc) interface - this will kill
3109 WLAN on a Pi3. If this isn't what you want, either use the sdtweak
3110 overlay or the new sd_* dtparams of the base DTBs.
3111 Load: dtoverlay=sdhost,<param>=<val>
3112 Params: overclock_50 Clock (in MHz) to use when the MMC framework
3115 force_pio Disable DMA support (default off)
3117 pio_limit Number of blocks above which to use DMA
3120 debug Enable debug output (default off)
3124 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
3125 and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
3126 "dtoverlay=sdio,bus_width=1,gpios_22_25"
3127 Load: dtoverlay=sdio,<param>=<val>
3128 Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC
3129 framework requests 50MHz
3131 poll_once Disable SDIO-device polling every second
3132 (default on: polling once at boot-time)
3134 bus_width Set the SDIO host bus width (default 4 bits)
3136 gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
3137 with bus_width=1. This replaces the sdio-1bit
3138 overlay, which is now deprecated.
3140 gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
3143 gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
3144 with bus_width=4 (the default).
3148 Info: This overlay is now deprecated. Use
3149 "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
3154 Info: This overlay is now deprecated. Use the sd_* dtparams in the
3155 base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes
3156 "dtparam=sd_poll_once".
3160 Name: seeed-can-fd-hat-v1
3161 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3162 channels without RTC. Use this overlay if your HAT has no
3164 https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
3165 Load: dtoverlay=seeed-can-fd-hat-v1
3169 Name: seeed-can-fd-hat-v2
3170 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3171 channels and an RTC. Use this overlay if your HAT has a
3173 https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
3174 Load: dtoverlay=seeed-can-fd-hat-v2
3179 Info: Overlay for SH1106 OLED via SPI using fbtft staging driver.
3180 Load: dtoverlay=sh1106-spi,<param>=<val>
3181 Params: speed SPI bus speed (default 4000000)
3182 rotate Display rotation (0, 90, 180 or 270; default 0)
3183 fps Delay between frame updates (default 25)
3184 debug Debug output level (0-7; default 0)
3185 dc_pin GPIO pin for D/C (default 24)
3186 reset_pin GPIO pin for RESET (default 25)
3187 height Display height (32 or 64; default 64)
3191 Info: Overlay for Si446x UHF Transceiver via SPI using si446x driver.
3192 The driver is currently out-of-tree at
3193 https://github.com/sunipkmukherjee/silabs.git
3194 Load: dtoverlay=si446x-spi0,<param>=<val>
3195 Params: speed SPI bus speed (default 4000000)
3196 int_pin GPIO pin for interrupts (default 17)
3197 reset_pin GPIO pin for RESET (default 27)
3201 Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
3207 Info: Enables the userspace interface for the SMI driver
3208 Load: dtoverlay=smi-dev
3213 Info: Enables access to NAND flash via the SMI interface
3214 Load: dtoverlay=smi-nand
3219 Info: Move SPI function block to GPIO 35 to 39
3220 Load: dtoverlay=spi-gpio35-39
3225 Info: Move SPI function block to GPIOs 40 to 45
3226 Load: dtoverlay=spi-gpio40-45
3231 Info: Adds support for a number of SPI Real Time Clock devices
3232 Load: dtoverlay=spi-rtc,<param>=<val>
3233 Params: ds3232 Select the DS3232 device
3234 ds3234 Select the DS3234 device
3235 pcf2123 Select the PCF2123 device
3237 spi0_0 Use spi0.0 (default)
3243 cs_high This device requires an active-high CS
3247 Info: Don't claim any CS pins for SPI0. Requires a device with its chip
3248 select permanently enabled, but frees a GPIO for e.g. a DPI display.
3249 Load: dtoverlay=spi0-0cs,<param>=<val>
3250 Params: no_miso Don't claim and use the MISO pin (9), freeing
3255 Info: Only use one CS pin for SPI0
3256 Load: dtoverlay=spi0-1cs,<param>=<val>
3257 Params: cs0_pin GPIO pin for CS0 (default 8)
3258 no_miso Don't claim and use the MISO pin (9), freeing
3263 Info: Change the CS pins for SPI0
3264 Load: dtoverlay=spi0-2cs,<param>=<val>
3265 Params: cs0_pin GPIO pin for CS0 (default 8)
3266 cs1_pin GPIO pin for CS1 (default 7)
3267 no_miso Don't claim and use the MISO pin (9), freeing
3272 Info: This overlay has been renamed spi0-2cs, keeping spi0-cs as an
3273 alias for backwards compatibility.
3278 Info: This overlay has been deprecated and removed because it is no longer
3279 necessary and has been seen to prevent spi0 from working.
3284 Info: Enables spi1 with a single chip select (CS) line and associated spidev
3285 dev node. The gpio pin number for the CS line and spidev device node
3286 creation are configurable.
3287 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3288 A+, B+, Zero and PI2 B; as well as the Compute Module.
3289 Load: dtoverlay=spi1-1cs,<param>=<val>
3290 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3291 cs0_spidev Set to 'disabled' to stop the creation of a
3292 userspace device node /dev/spidev1.0 (default
3293 is 'okay' or enabled).
3297 Info: Enables spi1 with two chip select (CS) lines and associated spidev
3298 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3299 creation are configurable.
3300 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3301 A+, B+, Zero and PI2 B; as well as the Compute Module.
3302 Load: dtoverlay=spi1-2cs,<param>=<val>
3303 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3304 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3305 cs0_spidev Set to 'disabled' to stop the creation of a
3306 userspace device node /dev/spidev1.0 (default
3307 is 'okay' or enabled).
3308 cs1_spidev Set to 'disabled' to stop the creation of a
3309 userspace device node /dev/spidev1.1 (default
3310 is 'okay' or enabled).
3314 Info: Enables spi1 with three chip select (CS) lines and associated spidev
3315 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3316 creation are configurable.
3317 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3318 A+, B+, Zero and PI2 B; as well as the Compute Module.
3319 Load: dtoverlay=spi1-3cs,<param>=<val>
3320 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3321 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3322 cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
3323 cs0_spidev Set to 'disabled' to stop the creation of a
3324 userspace device node /dev/spidev1.0 (default
3325 is 'okay' or enabled).
3326 cs1_spidev Set to 'disabled' to stop the creation of a
3327 userspace device node /dev/spidev1.1 (default
3328 is 'okay' or enabled).
3329 cs2_spidev Set to 'disabled' to stop the creation of a
3330 userspace device node /dev/spidev1.2 (default
3331 is 'okay' or enabled).
3335 Info: Enables spi2 with a single chip select (CS) line and associated spidev
3336 dev node. The gpio pin number for the CS line and spidev device node
3337 creation are configurable.
3338 N.B.: spi2 is only accessible with the Compute Module.
3339 Load: dtoverlay=spi2-1cs,<param>=<val>
3340 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3341 cs0_spidev Set to 'disabled' to stop the creation of a
3342 userspace device node /dev/spidev2.0 (default
3343 is 'okay' or enabled).
3347 Info: Enables spi2 with two chip select (CS) lines and associated spidev
3348 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3349 creation are configurable.
3350 N.B.: spi2 is only accessible with the Compute Module.
3351 Load: dtoverlay=spi2-2cs,<param>=<val>
3352 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3353 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3354 cs0_spidev Set to 'disabled' to stop the creation of a
3355 userspace device node /dev/spidev2.0 (default
3356 is 'okay' or enabled).
3357 cs1_spidev Set to 'disabled' to stop the creation of a
3358 userspace device node /dev/spidev2.1 (default
3359 is 'okay' or enabled).
3363 Info: Enables spi2 with three chip select (CS) lines and associated spidev
3364 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3365 creation are configurable.
3366 N.B.: spi2 is only accessible with the Compute Module.
3367 Load: dtoverlay=spi2-3cs,<param>=<val>
3368 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3369 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3370 cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
3371 cs0_spidev Set to 'disabled' to stop the creation of a
3372 userspace device node /dev/spidev2.0 (default
3373 is 'okay' or enabled).
3374 cs1_spidev Set to 'disabled' to stop the creation of a
3375 userspace device node /dev/spidev2.1 (default
3376 is 'okay' or enabled).
3377 cs2_spidev Set to 'disabled' to stop the creation of a
3378 userspace device node /dev/spidev2.2 (default
3379 is 'okay' or enabled).
3383 Info: Enables spi3 with a single chip select (CS) line and associated spidev
3384 dev node. The gpio pin number for the CS line and spidev device node
3385 creation are configurable. BCM2711 only.
3386 Load: dtoverlay=spi3-1cs,<param>=<val>
3387 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3388 cs0_spidev Set to 'off' to prevent the creation of a
3389 userspace device node /dev/spidev3.0 (default
3390 is 'on' or enabled).
3394 Info: Enables spi3 with two chip select (CS) lines and associated spidev
3395 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3396 creation are configurable. BCM2711 only.
3397 Load: dtoverlay=spi3-2cs,<param>=<val>
3398 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3399 cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
3400 cs0_spidev Set to 'off' to prevent the creation of a
3401 userspace device node /dev/spidev3.0 (default
3402 is 'on' or enabled).
3403 cs1_spidev Set to 'off' to prevent the creation of a
3404 userspace device node /dev/spidev3.1 (default
3405 is 'on' or enabled).
3409 Info: Enables spi4 with a single chip select (CS) line and associated spidev
3410 dev node. The gpio pin number for the CS line and spidev device node
3411 creation are configurable. BCM2711 only.
3412 Load: dtoverlay=spi4-1cs,<param>=<val>
3413 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3414 cs0_spidev Set to 'off' to prevent the creation of a
3415 userspace device node /dev/spidev4.0 (default
3416 is 'on' or enabled).
3420 Info: Enables spi4 with two chip select (CS) lines and associated spidev
3421 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3422 creation are configurable. BCM2711 only.
3423 Load: dtoverlay=spi4-2cs,<param>=<val>
3424 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3425 cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
3426 cs0_spidev Set to 'off' to prevent the creation of a
3427 userspace device node /dev/spidev4.0 (default
3428 is 'on' or enabled).
3429 cs1_spidev Set to 'off' to prevent the creation of a
3430 userspace device node /dev/spidev4.1 (default
3431 is 'on' or enabled).
3435 Info: Enables spi5 with a single chip select (CS) line and associated spidev
3436 dev node. The gpio pin numbers for the CS lines and spidev device node
3437 creation are configurable. BCM2711 only.
3438 Load: dtoverlay=spi5-1cs,<param>=<val>
3439 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3440 cs0_spidev Set to 'off' to prevent the creation of a
3441 userspace device node /dev/spidev5.0 (default
3442 is 'on' or enabled).
3446 Info: Enables spi5 with two chip select (CS) lines and associated spidev
3447 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3448 creation are configurable. BCM2711 only.
3449 Load: dtoverlay=spi5-2cs,<param>=<val>
3450 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3451 cs1_pin GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
3452 cs0_spidev Set to 'off' to prevent the creation of a
3453 userspace device node /dev/spidev5.0 (default
3454 is 'on' or enabled).
3455 cs1_spidev Set to 'off' to prevent the creation of a
3456 userspace device node /dev/spidev5.1 (default
3457 is 'on' or enabled).
3461 Info: Enables spi6 with a single chip select (CS) line and associated spidev
3462 dev node. The gpio pin number for the CS line and spidev device node
3463 creation are configurable. BCM2711 only.
3464 Load: dtoverlay=spi6-1cs,<param>=<val>
3465 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3466 cs0_spidev Set to 'off' to prevent the creation of a
3467 userspace device node /dev/spidev6.0 (default
3468 is 'on' or enabled).
3472 Info: Enables spi6 with two chip select (CS) lines and associated spidev
3473 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3474 creation are configurable. BCM2711 only.
3475 Load: dtoverlay=spi6-2cs,<param>=<val>
3476 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3477 cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
3478 cs0_spidev Set to 'off' to prevent the creation of a
3479 userspace device node /dev/spidev6.0 (default
3480 is 'on' or enabled).
3481 cs1_spidev Set to 'off' to prevent the creation of a
3482 userspace device node /dev/spidev6.1 (default
3483 is 'on' or enabled).
3487 Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
3488 Load: dtoverlay=ssd1306,<param>=<val>
3489 Params: address Location in display memory of first character.
3491 width Width of display. (default=128)
3492 height Height of display. (default=64)
3493 offset virtual channel a. (default=0)
3494 normal Has no effect on displays tested. (default=not
3496 sequential Set this if every other scan line is missing.
3498 remapped Set this if display is garbled. (default=not
3500 inverted Set this if display is inverted and mirrored.
3504 Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
3506 Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
3508 i2c_baudrate=400000 will speed up the display.
3510 i2c_baudrate=1000000 seems to work even though it's not officially
3511 supported by the hardware, and is faster still.
3513 For more information refer to the device datasheet at:
3514 https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
3518 Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver.
3519 Load: dtoverlay=ssd1306-spi,<param>=<val>
3520 Params: speed SPI bus speed (default 10000000)
3521 rotate Display rotation (0, 90, 180 or 270; default 0)
3522 fps Delay between frame updates (default 25)
3523 debug Debug output level (0-7; default 0)
3524 dc_pin GPIO pin for D/C (default 24)
3525 reset_pin GPIO pin for RESET (default 25)
3526 height Display height (32 or 64; default 64)
3530 Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver.
3531 Load: dtoverlay=ssd1331-spi,<param>=<val>
3532 Params: speed SPI bus speed (default 4500000)
3533 rotate Display rotation (0, 90, 180 or 270; default 0)
3534 fps Delay between frame updates (default 25)
3535 debug Debug output level (0-7; default 0)
3536 dc_pin GPIO pin for D/C (default 24)
3537 reset_pin GPIO pin for RESET (default 25)
3541 Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver.
3542 Load: dtoverlay=ssd1351-spi,<param>=<val>
3543 Params: speed SPI bus speed (default 4500000)
3544 rotate Display rotation (0, 90, 180 or 270; default 0)
3545 fps Delay between frame updates (default 25)
3546 debug Debug output level (0-7; default 0)
3547 dc_pin GPIO pin for D/C (default 24)
3548 reset_pin GPIO pin for RESET (default 25)
3551 Name: superaudioboard
3552 Info: Configures the SuperAudioBoard sound card
3553 Load: dtoverlay=superaudioboard,<param>=<val>
3554 Params: gpiopin GPIO pin for codec reset
3558 Info: Configures the Semtech SX150X I2C GPIO expanders.
3559 Load: dtoverlay=sx150x,<param>=<val>
3560 Params: sx150<x>-<n>-<m> Enables SX150X device on I2C#<n> with slave
3561 address <m>. <x> may be 1-9. <n> may be 0 or 1.
3562 Permissible values of <m> (which is denoted in
3563 hex) depend on the device variant. For SX1501,
3564 SX1502, SX1504 and SX1505, <m> may be 20 or 21.
3565 For SX1503 and SX1506, <m> may be 20. For
3566 SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
3567 For SX1508, <m> may be 20, 21, 22 or 23.
3569 sx150<x>-<n>-<m>-int-gpio
3570 Integer, enables interrupts on SX150X device on
3571 I2C#<n> with slave address <m>, specifies
3572 the GPIO pin to which NINT output of SX150X is
3577 Info: Toshiba TC358743 HDMI to CSI-2 bridge chip.
3578 Uses Unicam 1, which is the standard camera connector on most Pi
3580 Load: dtoverlay=tc358743,<param>=<val>
3581 Params: 4lane Use 4 lanes (only applicable to Compute Modules
3584 link-frequency Set the link frequency. Only values of 297000000
3585 (574Mbit/s) and 486000000 (972Mbit/s - default)
3586 are supported by the driver.
3587 media-controller Configure use of Media Controller API for
3588 configuring the sensor (default off)
3589 cam0 Adopt the default configuration for CAM0 on a
3590 Compute Module (CSI0, i2c_vc, and cam0_reg).
3593 Name: tc358743-audio
3594 Info: Used in combination with the tc358743-fast overlay to route the audio
3595 from the TC358743 over I2S to the Pi.
3596 Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO
3598 Load: dtoverlay=tc358743-audio,<param>=<val>
3599 Params: card-name Override the default, "tc358743", card name.
3603 Info: 3.5" Color TFT Display by www.tinylcd.com
3604 Options: Touch, RTC, keypad
3605 Load: dtoverlay=tinylcd35,<param>=<val>
3606 Params: speed Display SPI bus speed
3608 rotate Display rotation {0,90,180,270}
3610 fps Delay between frame updates
3612 debug Debug output level {0-7}
3614 touch Enable touch panel
3616 touchgpio Touch controller IRQ GPIO
3618 xohms Touchpanel: Resistance of X-plate in ohms
3620 rtc-pcf PCF8563 Real Time Clock
3622 rtc-ds DS1307 Real Time Clock
3624 keypad Enable keypad
3627 Display with touchpanel, PCF8563 RTC and keypad:
3628 dtoverlay=tinylcd35,touch,rtc-pcf,keypad
3630 dtoverlay=tinylcd35,touch,touchgpio=3
3634 Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
3635 boards, which can be used as a secure key storage and hwrng,
3636 available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
3637 Load: dtoverlay=tpm-slb9670
3642 Info: Change the pin usage of uart0
3643 Load: dtoverlay=uart0,<param>=<val>
3644 Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
3646 rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
3648 pin_func Alternative pin function - 4(Alt0) for 14&15,
3649 7(Alt3) for 32&33, 6(Alt2) for 36&37
3653 Info: Change the pin usage of uart1
3654 Load: dtoverlay=uart1,<param>=<val>
3655 Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
3657 rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
3661 Info: Enable uart 2 on GPIOs 0-3. BCM2711 only.
3662 Load: dtoverlay=uart2,<param>
3663 Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
3667 Info: Enable uart 3 on GPIOs 4-7. BCM2711 only.
3668 Load: dtoverlay=uart3,<param>
3669 Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
3673 Info: Enable uart 4 on GPIOs 8-11. BCM2711 only.
3674 Load: dtoverlay=uart4,<param>
3675 Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
3679 Info: Enable uart 5 on GPIOs 12-15. BCM2711 only.
3680 Load: dtoverlay=uart5,<param>
3681 Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
3685 Info: Configures the NW Digital Radio UDRC Hat
3686 Load: dtoverlay=udrc,<param>=<val>
3687 Params: alsaname Name of the ALSA audio device (default "udrc")
3690 Name: ugreen-dabboard
3691 Info: Configures the ugreen-dabboard I2S overlay
3692 This is a simple overlay based on the simple-audio-card and the dmic
3693 codec. It has the speciality that it is configured to use the codec
3694 as a master I2S device. It works for example with the Si468x DAB
3695 receiver on the uGreen DABBoard.
3696 Load: dtoverlay=ugreen-dabboard,<param>=<val>
3697 Params: card-name Override the default, "dabboard", card name.
3701 Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
3702 vc4-kms-v3d and dwc2 overlays.
3703 Load: dtoverlay=upstream
3707 Name: upstream-aux-interrupt
3708 Info: This overlay has been deprecated and removed because it is no longer
3714 Info: Allow usage of downstream .dtb with upstream kernel on Pi 4. Comprises
3715 the vc4-kms-v3d-pi4 and dwc2 overlays.
3716 Load: dtoverlay=upstream-pi4
3721 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
3723 Load: dtoverlay=vc4-fkms-v3d,<param>
3724 Params: cma-512 CMA is 512MB (needs 1GB)
3725 cma-448 CMA is 448MB (needs 1GB)
3726 cma-384 CMA is 384MB (needs 1GB)
3727 cma-320 CMA is 320MB (needs 1GB)
3728 cma-256 CMA is 256MB (needs 1GB)
3729 cma-192 CMA is 192MB (needs 1GB)
3730 cma-128 CMA is 128MB
3733 cma-size CMA size in bytes, 4MB aligned
3734 cma-default Use upstream's default value
3737 Name: vc4-fkms-v3d-pi4
3738 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
3740 Load: dtoverlay=vc4-fkms-v3d-pi4,<param>
3741 Params: cma-512 CMA is 512MB (needs 1GB)
3742 cma-448 CMA is 448MB (needs 1GB)
3743 cma-384 CMA is 384MB (needs 1GB)
3744 cma-320 CMA is 320MB (needs 1GB)
3745 cma-256 CMA is 256MB (needs 1GB)
3746 cma-192 CMA is 192MB (needs 1GB)
3747 cma-128 CMA is 128MB
3750 cma-size CMA size in bytes, 4MB aligned
3751 cma-default Use upstream's default value
3754 Name: vc4-kms-dpi-at056tn53v1
3755 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,at056tn53v1
3759 Name: vc4-kms-dpi-generic
3760 Info: Enable a generic DPI display under KMS. Default timings are for the
3761 Adafruit Kippah with 800x480 panel and RGB666 (GPIOs 0-21)
3762 Requires vc4-kms-v3d to be loaded.
3763 Load: dtoverlay=vc4-kms-dpi-generic,<param>=<val>
3764 Params: clock-frequency Display clock frequency (Hz)
3765 hactive Horizontal active pixels
3766 hfp Horizontal front porch
3767 hsync Horizontal sync pulse width
3768 hbp Horizontal back porch
3769 vactive Vertical active lines
3770 vfp Vertical front porch
3771 vsync Vertical sync pulse width
3772 vbp Vertical back porch
3773 hsync-invert Horizontal sync active low
3774 vsync-invert Vertical sync active low
3775 de-invert Data Enable active low
3776 pixclk-invert Negative edge pixel clock
3777 width-mm Define the screen width in mm
3778 height-mm Define the screen height in mm
3779 rgb565 Change to RGB565 output on GPIOs 0-19
3780 rgb565-padhi Change to RGB565 output on GPIOs 0-8, 12-17, and
3782 bgr666 Change to BGR666 output on GPIOs 0-21.
3783 bgr666-padhi Change to BGR666 output on GPIOs 0-9, 12-17, and
3785 rgb666-padhi Change to RGB666 output on GPIOs 0-9, 12-17, and
3787 bgr888 Change to BGR888 output on GPIOs 0-27
3788 rgb888 Change to RGB888 output on GPIOs 0-27
3789 bus-format Override the bus format for a MEDIA_BUS_FMT_*
3790 value. NB also overridden by rgbXXX overrides.
3791 backlight-gpio Defines a GPIO to be used for backlight control
3793 backlight-pwm Defines a PWM channel to be used for backlight
3794 control (default of none). NB Disables audio
3795 headphone output as that also uses PWM.
3796 backlight-pwm-chan Choose channel on &pwm node for backlight
3799 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
3800 pwm-2chan for valid options.
3801 (default 18 - note this can only work with
3803 backlight-pwm-func Pin function of GPIO used for the PWM
3805 See pwm-2chan for valid options.
3807 backlight-def-brightness
3808 Set the default brightness. Normal range 1-16.
3810 rotate Display rotation {0,90,180,270} (default 0)
3813 Name: vc4-kms-dpi-hyperpixel2r
3814 Info: Enable the KMS drivers for the Pimoroni HyperPixel2 Round DPI display.
3815 Requires vc4-kms-v3d to be loaded.
3816 Load: dtoverlay=vc4-kms-dpi-hyperpixel2r,<param>=<val>
3817 Params: disable-touch Disables the touch controller
3818 touchscreen-inverted-x Inverts X direction of touch controller
3819 touchscreen-inverted-y Inverts Y direction of touch controller
3820 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
3821 rotate Display rotation {0,90,180,270} (default 0)
3824 Name: vc4-kms-dpi-hyperpixel4
3825 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 DPI display.
3826 Requires vc4-kms-v3d to be loaded.
3827 Load: dtoverlay=vc4-kms-dpi-hyperpixel4,<param>=<val>
3828 Params: disable-touch Disables the touch controller
3829 touchscreen-inverted-x Inverts X direction of touch controller
3830 touchscreen-inverted-y Inverts Y direction of touch controller
3831 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
3832 rotate Display rotation {0,90,180,270} (default 0)
3835 Name: vc4-kms-dpi-hyperpixel4sq
3836 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 Square DPI display.
3837 Requires vc4-kms-v3d to be loaded.
3838 Load: dtoverlay=vc4-kms-dpi-hyperpixel4sq,<param>=<val>
3839 Params: disable-touch Disables the touch controller
3840 touchscreen-inverted-x Inverts X direction of touch controller
3841 touchscreen-inverted-y Inverts Y direction of touch controller
3842 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
3843 rotate Display rotation {0,90,180,270} (default 0)
3846 Name: vc4-kms-dpi-panel
3847 Info: Enable a preconfigured KMS DPI panel.
3848 Requires vc4-kms-v3d to be loaded.
3849 Load: dtoverlay=vc4-kms-dpi-panel,<param>=<val>
3850 Params: at056tn53v1 Enable an Innolux 5.6in VGA TFT
3851 kippah-7inch Enable an Adafruit Kippah with 7inch panel.
3852 mzp280 Enable a Geekworm MZP280 panel.
3853 backlight-gpio Defines a GPIO to be used for backlight control
3855 backlight-pwm Defines a PWM channel to be used for backlight
3856 control (default of none). NB Disables audio
3857 headphone output as that also uses PWM.
3858 backlight-pwm-chan Choose channel on &pwm node for backlight
3861 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
3862 pwm-2chan for valid options.
3863 (default 18 - note this can only work with
3865 backlight-pwm-func Pin function of GPIO used for the PWM
3867 See pwm-2chan for valid options.
3869 backlight-def-brightness
3870 Set the default brightness. Normal range 1-16.
3872 rotate Display rotation {0,90,180,270} (default 0)
3875 Name: vc4-kms-dsi-7inch
3876 Info: Enable the Raspberry Pi DSI 7" screen.
3877 Includes the edt-ft5406 for the touchscreen element.
3878 Requires vc4-kms-v3d to be loaded.
3879 Load: dtoverlay=vc4-kms-dsi-7inch,<param>=<val>
3880 Params: sizex Touchscreen size x (default 800)
3881 sizey Touchscreen size y (default 480)
3882 invx Touchscreen inverted x axis
3883 invy Touchscreen inverted y axis
3884 swapxy Touchscreen swapped x y axis
3885 disable_touch Disables the touch screen overlay driver
3888 Name: vc4-kms-dsi-lt070me05000
3889 Info: Enable a JDI LT070ME05000 DSI display on DSI1.
3890 Note that this is a 4 lane DSI device, so it will only work on a Compute
3892 Requires vc4-kms-v3d to be loaded.
3893 Load: dtoverlay=vc4-kms-dsi-lt070me05000,<param>
3894 Params: reset GPIO for the reset signal (default 17)
3895 enable GPIO for the enable signal (default 4)
3896 dcdc-en GPIO for the DC-DC converter enable (default 5)
3899 Name: vc4-kms-dsi-lt070me05000-v2
3900 Info: Enable a JDI LT070ME05000 DSI display on DSI1 using Harlab's V2
3902 Note that this is a 4 lane DSI device, so it will only work on a Compute
3904 Requires vc4-kms-v3d to be loaded.
3905 Load: dtoverlay=vc4-kms-dsi-lt070me05000-v2
3909 Name: vc4-kms-kippah-7inch
3910 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,kippah-7inch
3915 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver.
3916 Load: dtoverlay=vc4-kms-v3d,<param>
3917 Params: cma-512 CMA is 512MB (needs 1GB)
3918 cma-448 CMA is 448MB (needs 1GB)
3919 cma-384 CMA is 384MB (needs 1GB)
3920 cma-320 CMA is 320MB (needs 1GB)
3921 cma-256 CMA is 256MB (needs 1GB)
3922 cma-192 CMA is 192MB (needs 1GB)
3923 cma-128 CMA is 128MB
3926 cma-size CMA size in bytes, 4MB aligned
3927 cma-default Use upstream's default value
3928 audio Enable or disable audio over HDMI (default "on")
3929 noaudio Disable all HDMI audio (default "off")
3930 composite Enable the composite output (default "off")
3931 N.B. Disables all other outputs on a Pi 4.
3934 Name: vc4-kms-v3d-pi4
3935 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver for Pi4.
3936 Load: dtoverlay=vc4-kms-v3d-pi4,<param>
3937 Params: cma-512 CMA is 512MB
3938 cma-448 CMA is 448MB
3939 cma-384 CMA is 384MB
3940 cma-320 CMA is 320MB
3941 cma-256 CMA is 256MB
3942 cma-192 CMA is 192MB
3943 cma-128 CMA is 128MB
3946 cma-size CMA size in bytes, 4MB aligned
3947 cma-default Use upstream's default value
3948 audio Enable or disable audio over HDMI0 (default
3950 audio1 Enable or disable audio over HDMI1 (default
3952 noaudio Disable all HDMI audio (default "off")
3953 composite Enable the composite output (disables all other
3957 Name: vc4-kms-vga666
3958 Info: Enable the VGA666 (resistor ladder ADC) for the vc4-kms-v3d driver.
3959 Requires vc4-kms-v3d to be loaded.
3960 Load: dtoverlay=vc4-kms-vga666,<param>
3961 Params: ddc Enables GPIOs 0&1 as the I2C to read the EDID
3962 from the display. NB These are NOT 5V tolerant
3963 GPIOs, therefore level shifters are required.
3967 Info: Overlay for the Fen Logic VGA666 board
3968 This uses GPIOs 2-21 (so no I2C), and activates the output 2-3 seconds
3969 after the kernel has started.
3970 NOT for use with vc4-kms-v3d.
3971 Load: dtoverlay=vga666
3976 Info: Overlay to enable a VIA VL805 USB3 controller on CM4 carriers
3977 Will be loaded automatically by up-to-date firmware if "VL805=1" is
3978 set in the EEPROM config.
3979 Load: dtoverlay=vl805
3984 Info: Configures the w1-gpio Onewire interface module.
3985 Use this overlay if you *don't* need a GPIO to drive an external pullup.
3986 Load: dtoverlay=w1-gpio,<param>=<val>
3987 Params: gpiopin GPIO for I/O (default "4")
3988 pullup Now enabled by default (ignored)
3991 Name: w1-gpio-pullup
3992 Info: Configures the w1-gpio Onewire interface module.
3993 Use this overlay if you *do* need a GPIO to drive an external pullup.
3994 Load: dtoverlay=w1-gpio-pullup,<param>=<val>
3995 Params: gpiopin GPIO for I/O (default "4")
3996 extpullup GPIO for external pullup (default "5")
3997 pullup Now enabled by default (ignored)
4001 Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
4002 Load: dtoverlay=w5500,<param>=<val>
4003 Params: int_pin GPIO used for INT (default 25)
4005 speed SPI bus speed (default 30000000)
4007 cs SPI bus Chip Select (default 0)
4010 Name: waveshare-can-fd-hat-mode-a
4011 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4012 for Raspberry Pi, Multi Protections. Use this overlay when the
4013 HAT is configured in Mode A (Default), with can0 on spi0.0
4015 https://www.waveshare.com/2-ch-can-fd-hat.htm
4016 Load: dtoverlay=waveshare-can-fd-hat-mode-a
4020 Name: waveshare-can-fd-hat-mode-b
4021 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4022 for Raspberry Pi, Multi Protections. Use this overlay when the
4023 HAT is configured in Mode B (requires hardware modification), with
4024 can0 on spi0.0 and can1 on spi0.1.
4025 https://www.waveshare.com/2-ch-can-fd-hat.htm
4026 Load: dtoverlay=waveshare-can-fd-hat-mode-b
4031 Info: Configures the wittypi RTC module.
4032 Load: dtoverlay=wittypi,<param>=<val>
4033 Params: led_gpio GPIO for LED (default "17")
4034 led_trigger Choose which activity the LED tracks (default
4038 Name: wm8960-soundcard
4039 Info: Overlay for the Waveshare wm8960 soundcard
4040 Load: dtoverlay=wm8960-soundcard,<param>=<val>
4041 Params: alsaname Changes the card name in ALSA
4042 compatible Changes the codec compatibility
4048 If you are experiencing problems that you think are DT-related, enable DT
4049 diagnostic output by adding this to /boot/config.txt:
4053 and rebooting. Then run:
4057 and look for relevant messages.
4062 This is only meant to be a quick introduction to the subject of Device Tree on
4063 Raspberry Pi. There is a more complete explanation here:
4065 http://www.raspberrypi.org/documentation/configuration/device-tree.md