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-bare-i2s
605 Info: Configures the audioinjector.net audio bare i2s soundcard
606 Load: dtoverlay=audioinjector-bare-i2s
610 Name: audioinjector-isolated-soundcard
611 Info: Configures the audioinjector.net isolated soundcard
612 Load: dtoverlay=audioinjector-isolated-soundcard
616 Name: audioinjector-ultra
617 Info: Configures the audioinjector.net ultra soundcard
618 Load: dtoverlay=audioinjector-ultra
622 Name: audioinjector-wm8731-audio
623 Info: Configures the audioinjector.net audio add on soundcard
624 Load: dtoverlay=audioinjector-wm8731-audio
629 Info: Configures the audiosense-pi add on soundcard
630 For more information refer to
631 https://gitlab.com/kakar0t/audiosense-pi
632 Load: dtoverlay=audiosense-pi
637 Info: Switches PWM sound output to GPIOs on the 40-pin header
638 Load: dtoverlay=audremap,<param>=<val>
639 Params: swap_lr Reverse the channel allocation, which will also
640 swap the audio jack outputs (default off)
641 enable_jack Don't switch off the audio jack output
643 pins_12_13 Select GPIOs 12 & 13 (default)
644 pins_18_19 Select GPIOs 18 & 19
648 Info: Overlay that enables WLAN, Bluetooth and the GPIO expander on the
649 balenaFin carrier board for the Raspberry Pi Compute Module 3/3+ Lite.
650 Load: dtoverlay=balena-fin
654 Name: bmp085_i2c-sensor
655 Info: This overlay is now deprecated - see i2c-sensor
660 Info: Enables the ability to use the cap1106 touch sensor as a keyboard
661 Load: dtoverlay=cap1106,<param>=<val>
662 Params: int_pin GPIO pin for interrupt signal (default 23)
666 Info: Configures Chip Dip audio cards.
667 Load: dtoverlay=chipdip-dac
672 Info: Set custom CMA sizes, only use if you know what you are doing, might
673 clash with other overlays like vc4-fkms-v3d and vc4-kms-v3d.
674 Load: dtoverlay=cma,<param>=<val>
675 Params: cma-512 CMA is 512MB (needs 1GB)
676 cma-448 CMA is 448MB (needs 1GB)
677 cma-384 CMA is 384MB (needs 1GB)
678 cma-320 CMA is 320MB (needs 1GB)
679 cma-256 CMA is 256MB (needs 1GB)
680 cma-192 CMA is 192MB (needs 1GB)
684 cma-size CMA size in bytes, 4MB aligned
685 cma-default Use upstream's default value
689 Info: 8" TFT LCD display and touch panel used by cutiepi.io
690 Load: dtoverlay=cutiepi-panel
695 Info: Overlay for the DHT11/DHT21/DHT22 humidity/temperature sensors
696 Also sometimes found with the part number(s) AM230x.
697 Load: dtoverlay=dht11,<param>=<val>
698 Params: gpiopin GPIO connected to the sensor's DATA output.
703 Info: Configures the Dion Audio LOCO DAC-AMP
704 Load: dtoverlay=dionaudio-loco
708 Name: dionaudio-loco-v2
709 Info: Configures the Dion Audio LOCO-V2 DAC-AMP
710 Load: dtoverlay=dionaudio-loco-v2,<param>=<val>
711 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
712 Digital volume control. Enable with
713 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
714 (The default behaviour is that the Digital
715 volume control is limited to a maximum of
716 0dB. ie. it can attenuate but not provide
717 gain. For most users, this will be desired
718 as it will prevent clipping. By appending
719 the 24dB_digital_gain parameter, the Digital
720 volume control will allow up to 24dB of
721 gain. If this parameter is enabled, it is the
722 responsibility of the user to ensure that
723 the Digital volume control is set to a value
724 that does not result in clipping/distortion!)
728 Info: Disable onboard Bluetooth on Pi 3B, 3B+, 3A+, 4B and Zero W, restoring
729 UART0/ttyAMA0 over GPIOs 14 & 15.
730 N.B. To disable the systemd service that initialises the modem so it
731 doesn't use the UART, use 'sudo systemctl disable hciuart'.
732 Load: dtoverlay=disable-bt
737 Info: Disable onboard WLAN on Pi 3B, 3B+, 3A+, 4B and Zero W.
738 Load: dtoverlay=disable-wifi
743 Info: Overlay for a generic 18-bit DPI display
744 This uses GPIOs 0-21 (so no I2C, uart etc.), and activates the output
745 2-3 seconds after the kernel has started.
746 Load: dtoverlay=dpi18
751 Info: Overlay for a generic 18-bit DPI display (in 'mode 6' connection scheme)
752 This uses GPIOs 0-9,12-17,20-25 (so no I2C, uart etc.), and activates
753 the output 3-3 seconds after the kernel has started.
754 Load: dtoverlay=dpi18cpadhi
759 Info: Overlay for a generic 24-bit DPI display
760 This uses GPIOs 0-27 (so no I2C, uart etc.), and activates the output
761 2-3 seconds after the kernel has started.
762 Load: dtoverlay=dpi24
767 Info: Configures the NW Digital Radio DRAWS Hat
769 The board includes an ADC to measure various board values and also
770 provides two analog user inputs on the expansion header. The ADC
771 can be configured for various sample rates and gain values to adjust
772 the input range. Tables describing the two parameters follow.
789 4 = 1600sps (default)
793 Load: dtoverlay=draws,<param>=<val>
794 Params: draws_adc_ch4_gain Sets the full scale resolution of the ADCs
795 input voltage sensor (default 1)
797 draws_adc_ch4_datarate Sets the datarate of the ADCs input voltage
800 draws_adc_ch5_gain Sets the full scale resolution of the ADCs
801 5V rail voltage sensor (default 1)
803 draws_adc_ch5_datarate Sets the datarate of the ADCs 4V rail voltage
806 draws_adc_ch6_gain Sets the full scale resolution of the ADCs
807 AIN2 input (default 2)
809 draws_adc_ch6_datarate Sets the datarate of the ADCs AIN2 input
811 draws_adc_ch7_gain Sets the full scale resolution of the ADCs
812 AIN3 input (default 2)
814 draws_adc_ch7_datarate Sets the datarate of the ADCs AIN3 input
816 alsaname Name of the ALSA audio device (default "draws")
820 Info: Selects the dwc_otg USB controller driver which has fiq support. This
821 is the default on all except the Pi Zero which defaults to dwc2.
822 Load: dtoverlay=dwc-otg
827 Info: Selects the dwc2 USB controller driver
828 Load: dtoverlay=dwc2,<param>=<val>
829 Params: dr_mode Dual role mode: "host", "peripheral" or "otg"
831 g-rx-fifo-size Size of rx fifo size in gadget mode
833 g-np-tx-fifo-size Size of non-periodic tx fifo size in gadget
837 [ The ds1307-rtc overlay has been deleted. See i2c-rtc. ]
841 Info: Overlay for the EDT FT5406 touchscreen on the CSI/DSI I2C interface.
842 This works with the Raspberry Pi 7" touchscreen when not being polled
844 You MUST use either "disable_touchscreen=1" or "ignore_lcd=1" in
845 config.txt to stop the firmware polling the touchscreen.
846 Load: dtoverlay=edt-ft5406,<param>=<val>
847 Params: sizex Touchscreen size x (default 800)
848 sizey Touchscreen size y (default 480)
849 invx Touchscreen inverted x axis
850 invy Touchscreen inverted y axis
851 swapxy Touchscreen swapped x y axis
855 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI0
856 Load: dtoverlay=enc28j60,<param>=<val>
857 Params: int_pin GPIO used for INT (default 25)
859 speed SPI bus speed (default 12000000)
863 Info: Overlay for the Microchip ENC28J60 Ethernet Controller on SPI2
864 Load: dtoverlay=enc28j60-spi2,<param>=<val>
865 Params: int_pin GPIO used for INT (default 39)
867 speed SPI bus speed (default 12000000)
871 Info: Enables I2C connected EETI EXC3000 multiple touch controller using
872 GPIO 4 (pin 7 on GPIO header) for interrupt.
873 Load: dtoverlay=exc3000,<param>=<val>
874 Params: interrupt GPIO used for interrupt (default 4)
875 sizex Touchscreen size x (default 4096)
876 sizey Touchscreen size y (default 4096)
877 invx Touchscreen inverted x axis
878 invy Touchscreen inverted y axis
879 swapxy Touchscreen swapped x y axis
883 Info: Overlay for SPI-connected displays using the fbtft drivers.
885 This overlay seeks to replace the functionality provided by fbtft_device
886 which is now gone from the kernel.
888 Most displays from fbtft_device have been ported over.
890 dtoverlay=fbtft,spi0-0,rpi-display,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
892 It is also possible to specify the controller (this will use the default
893 init sequence in the driver).
895 dtoverlay=fbtft,spi0-0,ili9341,bgr,reset_pin=23,dc_pin=24,led_pin=18,rotate=270
897 For devices on spi1 or spi2, the interfaces should be enabled
898 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
900 The following features of fbtft_device have not been ported over:
901 - parallel bus is not supported
902 - the init property which overrides the controller initialization
903 sequence is not supported as a parameter due to memory limitations in
904 the bootloader responsible for applying the overlay.
906 See https://github.com/notro/fbtft/wiki/FBTFT-RPI-overlays for how to
909 Load: dtoverlay=fbtft,<param>=<val>
911 spi<n>-<m> Configure device at spi<n>, cs<m>
913 speed SPI bus speed in Hz (default 32000000)
914 cpha Shifted clock phase (CPHA) mode
915 cpol Inverse clock polarity (CPOL) mode
917 adafruit18 Adafruit 1.8
918 adafruit22 Adafruit 2.2 (old)
919 adafruit22a Adafruit 2.2
920 adafruit28 Adafruit 2.8
921 adafruit13m Adafruit 1.3 OLED
922 admatec_c-berry28 C-Berry28
924 er_tftm050_2 ER-TFTM070-2
925 er_tftm070_5 ER-TFTM070-5
927 ew24ha0_9bit EW24HA0 in 9-bit mode
928 freetronicsoled128 Freetronics OLED128
931 itdb28_spi ITDB02-2.8 with SPI interface circuit
932 mi0283qt-2 Watterott MI0283QT-2
933 mi0283qt-9a Watterott MI0283QT-9A
935 nokia3310a Nokia 3310a
938 pitft Adafruit PiTFT 2.8
940 rpi-display Watterott rpi-display
941 sainsmart18 Sainsmart 1.8
942 sainsmart32_spi Sainsmart 3.2 with SPI interfce circuit
943 tinylcd35 TinyLCD 3.5
944 tm022hdh26 Tianma TM022HDH26
945 tontec35_9481 Tontect 3.5 with ILI9481 controller
946 tontec35_9486 Tontect 3.5 with ILI9486 controller
947 waveshare32b Waveshare 3.2
948 waveshare22 Waveshare 2.2
950 bd663474 BD663474 display controller
951 hx8340bn HX8340BN display controller
952 hx8347d HX8347D display controller
953 hx8353d HX8353D display controller
954 hx8357d HX8357D display controller
955 ili9163 ILI9163 display controller
956 ili9320 ILI9320 display controller
957 ili9325 ILI9325 display controller
958 ili9340 ILI9340 display controller
959 ili9341 ILI9341 display controller
960 ili9481 ILI9481 display controller
961 ili9486 ILI9486 display controller
962 pcd8544 PCD8544 display controller
963 ra8875 RA8875 display controller
964 s6d02a1 S6D02A1 display controller
965 s6d1121 S6D1121 display controller
966 seps525 SEPS525 display controller
967 sh1106 SH1106 display controller
968 ssd1289 SSD1289 display controller
969 ssd1305 SSD1305 display controller
970 ssd1306 SSD1306 display controller
971 ssd1325 SSD1325 display controller
972 ssd1331 SSD1331 display controller
973 ssd1351 SSD1351 display controller
974 st7735r ST7735R display controller
975 st7789v ST7789V display controller
976 tls8204 TLS8204 display controller
977 uc1611 UC1611 display controller
978 uc1701 UC1701 display controller
979 upd161704 UPD161704 display controller
981 width Display width in pixels
982 height Display height in pixels
983 regwidth Display controller register width (default is
985 buswidth Display bus interface width (default 8)
986 debug Debug output level {0-7}
987 rotate Display rotation {0, 90, 180, 270} (counter
988 clockwise). Not supported by all drivers.
989 bgr Enable BGR mode (default off). Use if Red and
990 Blue are swapped. Not supported by all drivers.
991 fps Frames per second (default 30). In effect this
992 states how long the driver will wait after video
993 memory has been changed until display update
995 txbuflen Length of the FBTFT transmit buffer
997 startbyte Sets the Start byte used by fb_ili9320,
998 fb_ili9325 and fb_hx8347d. Common value is 0x70.
999 gamma String representation of Gamma Curve(s). Driver
1000 specific. Not supported by all drivers.
1001 reset_pin GPIO pin for RESET
1002 dc_pin GPIO pin for D/C
1003 led_pin GPIO pin for LED backlight
1007 Info: Configures the Fe-Pi Audio Sound Card
1008 Load: dtoverlay=fe-pi-audio
1013 Info: A demonstration of the gpio-fsm driver. The GPIOs are chosen to work
1014 nicely with a "traffic-light" display of red, amber and green LEDs on
1015 GPIOs 7, 8 and 25 respectively.
1016 Load: dtoverlay=fsm-demo,<param>=<val>
1017 Params: fsm_debug Enable debug logging (default off)
1021 Info: An overlay for the Ghost amplifier.
1022 Load: dtoverlay=ghost-amp,<param>=<val>
1023 Params: fsm_debug Enable debug logging of the GPIO FSM (default
1028 Info: Enables I2C connected Goodix gt9271 multiple touch controller using
1029 GPIOs 4 and 17 (pins 7 and 11 on GPIO header) for interrupt and reset.
1030 Load: dtoverlay=goodix,<param>=<val>
1031 Params: interrupt GPIO used for interrupt (default 4)
1032 reset GPIO used for reset (default 17)
1035 Name: googlevoicehat-soundcard
1036 Info: Configures the Google voiceHAT soundcard
1037 Load: dtoverlay=googlevoicehat-soundcard
1042 Info: Configure a GPIO pin to control a cooling fan.
1043 Load: dtoverlay=gpio-fan,<param>=<val>
1044 Params: gpiopin GPIO used to control the fan (default 12)
1045 temp Temperature at which the fan switches on, in
1046 millicelcius (default 55000)
1050 Info: Use GPIO pin as rc-core style infrared receiver input. The rc-core-
1051 based gpio_ir_recv driver maps received keys directly to a
1052 /dev/input/event* device, all decoding is done by the kernel - LIRC is
1053 not required! The key mapping and other decoding parameters can be
1054 configured by "ir-keytable" tool.
1055 Load: dtoverlay=gpio-ir,<param>=<val>
1056 Params: gpio_pin Input pin number. Default is 18.
1058 gpio_pull Desired pull-up/down state (off, down, up)
1061 invert "1" = invert the input (active-low signalling).
1062 "0" = non-inverted input (active-high
1063 signalling). Default is "1".
1065 rc-map-name Default rc keymap (can also be changed by
1066 ir-keytable), defaults to "rc-rc6-mce"
1070 Info: Use GPIO pin as bit-banged infrared transmitter output.
1071 This is an alternative to "pwm-ir-tx". gpio-ir-tx doesn't require
1072 a PWM so it can be used together with onboard analog audio.
1073 Load: dtoverlay=gpio-ir-tx,<param>=<val>
1074 Params: gpio_pin Output GPIO (default 18)
1076 invert "1" = invert the output (make it active-low).
1077 Default is "0" (active-high).
1081 Info: This is a generic overlay for activating GPIO keypresses using
1082 the gpio-keys library and this dtoverlay. Multiple keys can be
1083 set up using multiple calls to the overlay for configuring
1084 additional buttons or joysticks. You can see available keycodes
1085 at https://github.com/torvalds/linux/blob/v4.12/include/uapi/
1086 linux/input-event-codes.h#L64
1087 Load: dtoverlay=gpio-key,<param>=<val>
1088 Params: gpio GPIO pin to trigger on (default 3)
1089 active_low When this is 1 (active low), a falling
1090 edge generates a key down event and a
1091 rising edge generates a key up event.
1092 When this is 0 (active high), this is
1093 reversed. The default is 1 (active low)
1094 gpio_pull Desired pull-up/down state (off, down, up)
1095 Default is "up". Note that the default pin
1096 (GPIO3) has an external pullup
1097 label Set a label for the key
1098 keycode Set the key code for the button
1103 Info: This is a generic overlay for activating LEDs (or any other component)
1104 by a GPIO pin. Multiple LEDs can be set up using multiple calls to the
1105 overlay. While there are many existing methods to activate LEDs on the
1106 RPi, this method offers some advantages:
1107 1) Does not require any userspace programs.
1108 2) LEDs can be connected to the kernel's led-trigger framework,
1109 and drive the LED based on triggers such as cpu load, heartbeat,
1110 kernel panic, key input, timers and others.
1111 3) LED can be tied to the input state of another GPIO pin.
1112 4) The LED is setup early during the kernel boot process (useful
1113 for cpu/heartbeat/panic triggers).
1115 Typical electrical connection is:
1116 RPI-GPIO.19 -> LED -> 300ohm resister -> RPI-GND
1117 The GPIO pin number can be changed with the 'gpio=' parameter.
1119 To control an LED from userspace, write a 0 or 1 value:
1120 echo 1 > /sys/class/leds/myled1/brightness
1121 The 'myled1' name can be changed with the 'label=' parameter.
1123 To connect the LED to a kernel trigger from userspace:
1124 echo cpu > /sys/class/leds/myled1/trigger
1125 echo heartbeat > /sys/class/leds/myled1/trigger
1126 echo none > /sys/class/leds/myled1/trigger
1127 To connect the LED to GPIO.26 pin (physical pin 37):
1128 echo gpio > /sys/class/leds/myled1/trigger
1129 echo 26 > /sys/class/leds/myled1/gpio
1131 cat /sys/class/leds/myled1/trigger
1133 More information about the Linux kernel LED/Trigger system:
1134 https://www.kernel.org/doc/Documentation/leds/leds-class.rst
1135 https://www.kernel.org/doc/Documentation/leds/ledtrig-oneshot.rst
1136 Load: dtoverlay=gpio-led,<param>=<val>
1137 Params: gpio GPIO pin connected to the LED (default 19)
1138 label The label for this LED. It will appear under
1139 /sys/class/leds/<label> . Default 'myled1'.
1140 trigger Set the led-trigger to connect to this LED.
1141 default 'none' (LED is user-controlled).
1142 Some possible triggers:
1143 cpu - CPU load (all CPUs)
1144 cpu0 - CPU load of first CPU.
1145 mmc - disk activity (all disks)
1146 panic - turn on on kernel panic
1147 heartbeat - indicate system health
1148 gpio - connect to a GPIO input pin (note:
1149 currently the GPIO PIN can not be set
1150 using overlay parameters, must be
1151 done in userspace, see examples above.
1152 active_low Set to 1 to turn invert the LED control
1153 (writing 0 to /sys/class/leds/XXX/brightness
1154 will turn on the GPIO/LED). Default '0'.
1157 Name: gpio-no-bank0-irq
1158 Info: Use this overlay to disable GPIO interrupts for GPIOs in bank 0 (0-27),
1159 which can be useful for UIO drivers.
1160 N.B. Using this overlay will trigger a kernel WARN during booting, but
1161 this can safely be ignored - the system should work as expected.
1162 Load: dtoverlay=gpio-no-bank0-irq
1167 Info: Use this overlay to disable all GPIO interrupts, which can be useful
1168 for user-space GPIO edge detection systems.
1169 Load: dtoverlay=gpio-no-irq
1174 Info: Drives a GPIO high or low on poweroff (including halt). Using this
1175 overlay interferes with the normal power-down sequence, preventing the
1176 kernel from resetting the SoC (a necessary step in a normal power-off
1177 or reboot). This also disables the ability to trigger a boot by driving
1180 The GPIO starts in an inactive state. At poweroff time it is driven
1181 active for 100ms, then inactive for 100ms, then active again. It is
1182 safe to remove the power at any point after the initial activation of
1185 Users of this overlay are required to provide an external mechanism to
1186 switch off the power supply when signalled - failure to do so results
1187 in a kernel BUG, increased power consumption and undefined behaviour.
1188 Load: dtoverlay=gpio-poweroff,<param>=<val>
1189 Params: gpiopin GPIO for signalling (default 26)
1191 active_low Set if the power control device requires a
1192 high->low transition to trigger a power-down.
1193 Note that this will require the support of a
1194 custom dt-blob.bin to prevent a power-down
1195 during the boot process, and that a reboot
1196 will also cause the pin to go low.
1197 input Set if the gpio pin should be configured as
1199 export Set to export the configured pin to sysfs
1200 active_delay_ms Initial GPIO active period (default 100)
1201 inactive_delay_ms Subsequent GPIO inactive period (default 100)
1202 timeout_ms Specify (in ms) how long the kernel waits for
1203 power-down before issuing a WARN (default 3000).
1207 Info: Initiates a shutdown when GPIO pin changes. The given GPIO pin
1208 is configured as an input key that generates KEY_POWER events.
1210 This event is handled by systemd-logind by initiating a
1211 shutdown. Systemd versions older than 225 need an udev rule
1212 enable listening to the input device:
1214 ACTION!="REMOVE", SUBSYSTEM=="input", KERNEL=="event*", \
1215 SUBSYSTEMS=="platform", DRIVERS=="gpio-keys", \
1216 ATTRS{keys}=="116", TAG+="power-switch"
1218 Alternatively this event can be handled also on systems without
1219 systemd, just by traditional SysV init daemon. KEY_POWER event
1220 (keycode 116) needs to be mapped to KeyboardSignal on console
1221 and then kb::kbrequest inittab action which is triggered by
1222 KeyboardSignal from console can be configured to issue system
1223 shutdown. Steps for this configuration are:
1225 Add following lines to the /etc/console-setup/remap.inc file:
1227 # Key Power as special keypress
1228 keycode 116 = KeyboardSignal
1230 Then add following lines to /etc/inittab file:
1232 # Action on special keypress (Key Power)
1233 kb::kbrequest:/sbin/shutdown -t1 -a -h -P now
1235 And finally reload configuration by calling following commands:
1237 # dpkg-reconfigure console-setup
1238 # service console-setup reload
1241 This overlay only handles shutdown. After shutdown, the system
1242 can be powered up again by driving GPIO3 low. The default
1243 configuration uses GPIO3 with a pullup, so if you connect a
1244 button between GPIO3 and GND (pin 5 and 6 on the 40-pin header),
1245 you get a shutdown and power-up button. Please note that
1246 Raspberry Pi 1 Model B rev 1 uses GPIO1 instead of GPIO3.
1247 Load: dtoverlay=gpio-shutdown,<param>=<val>
1248 Params: gpio_pin GPIO pin to trigger on (default 3)
1249 For Raspberry Pi 1 Model B rev 1 set this
1250 explicitly to value 1, e.g.:
1252 dtoverlay=gpio-shutdown,gpio_pin=1
1254 active_low When this is 1 (active low), a falling
1255 edge generates a key down event and a
1256 rising edge generates a key up event.
1257 When this is 0 (active high), this is
1258 reversed. The default is 1 (active low).
1260 gpio_pull Desired pull-up/down state (off, down, up)
1263 Note that the default pin (GPIO3) has an
1264 external pullup. Same applies for GPIO1
1265 on Raspberry Pi 1 Model B rev 1.
1267 debounce Specify the debounce interval in milliseconds
1272 Info: Configures an HD44780 compatible LCD display. Uses 4 gpio pins for
1273 data, 2 gpio pins for enable and register select and 1 optional pin
1274 for enabling/disabling the backlight display.
1275 Load: dtoverlay=hd44780-lcd,<param>=<val>
1276 Params: pin_d4 GPIO pin for data pin D4 (default 6)
1278 pin_d5 GPIO pin for data pin D5 (default 13)
1280 pin_d6 GPIO pin for data pin D6 (default 19)
1282 pin_d7 GPIO pin for data pin D7 (default 26)
1284 pin_en GPIO pin for "Enable" (default 21)
1286 pin_rs GPIO pin for "Register Select" (default 20)
1288 pin_bl Optional pin for enabling/disabling the
1289 display backlight. (default disabled)
1291 display_height Height of the display in characters
1293 display_width Width of the display in characters
1296 Name: hdmi-backlight-hwhack-gpio
1297 Info: Devicetree overlay for GPIO based backlight on/off capability.
1298 Use this if you have one of those HDMI displays whose backlight cannot
1299 be controlled via DPMS over HDMI and plan to do a little soldering to
1300 use an RPi gpio pin for on/off switching. See:
1301 https://www.waveshare.com/wiki/7inch_HDMI_LCD_(C)#Backlight_Control
1302 Load: dtoverlay=hdmi-backlight-hwhack-gpio,<param>=<val>
1303 Params: gpio_pin GPIO pin used (default 17)
1304 active_low Set this to 1 if the display backlight is
1305 switched on when the wire goes low.
1306 Leave the default (value 0) if the backlight
1307 expects a high to switch it on.
1311 Info: Configures the HifiBerry Amp and Amp+ audio cards
1312 Load: dtoverlay=hifiberry-amp
1316 Name: hifiberry-amp100
1317 Info: Configures the HifiBerry AMP100 audio card
1318 Load: dtoverlay=hifiberry-amp100,<param>=<val>
1319 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1320 Digital volume control. Enable with
1321 "dtoverlay=hifiberry-amp100,24db_digital_gain"
1322 (The default behaviour is that the Digital
1323 volume control is limited to a maximum of
1324 0dB. ie. it can attenuate but not provide
1325 gain. For most users, this will be desired
1326 as it will prevent clipping. By appending
1327 the 24dB_digital_gain parameter, the Digital
1328 volume control will allow up to 24dB of
1329 gain. If this parameter is enabled, it is the
1330 responsibility of the user to ensure that
1331 the Digital volume control is set to a value
1332 that does not result in clipping/distortion!)
1333 slave Force DAC+ Pro into slave mode, using Pi as
1334 master for bit clock and frame clock.
1335 leds_off If set to 'true' the onboard indicator LEDs
1336 are switched off at all times.
1337 auto_mute If set to 'true' the amplifier is automatically
1338 muted when the DAC is not playing.
1339 mute_ext_ctl The amplifier's HW mute control is enabled
1340 in ALSA mixer and set to <val>.
1341 Will be overwritten by ALSA user settings.
1345 Info: Configures the HifiBerry DAC audio cards
1346 Load: dtoverlay=hifiberry-dac
1350 Name: hifiberry-dacplus
1351 Info: Configures the HifiBerry DAC+ audio card
1352 Load: dtoverlay=hifiberry-dacplus,<param>=<val>
1353 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1354 Digital volume control. Enable with
1355 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1356 (The default behaviour is that the Digital
1357 volume control is limited to a maximum of
1358 0dB. ie. it can attenuate but not provide
1359 gain. For most users, this will be desired
1360 as it will prevent clipping. By appending
1361 the 24dB_digital_gain parameter, the Digital
1362 volume control will allow up to 24dB of
1363 gain. If this parameter is enabled, it is the
1364 responsibility of the user to ensure that
1365 the Digital volume control is set to a value
1366 that does not result in clipping/distortion!)
1367 slave Force DAC+ Pro into slave mode, using Pi as
1368 master for bit clock and frame clock.
1369 leds_off If set to 'true' the onboard indicator LEDs
1370 are switched off at all times.
1373 Name: hifiberry-dacplusadc
1374 Info: Configures the HifiBerry DAC+ADC audio card
1375 Load: dtoverlay=hifiberry-dacplusadc,<param>=<val>
1376 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1377 Digital volume control. Enable with
1378 "dtoverlay=hifiberry-dacplus,24db_digital_gain"
1379 (The default behaviour is that the Digital
1380 volume control is limited to a maximum of
1381 0dB. ie. it can attenuate but not provide
1382 gain. For most users, this will be desired
1383 as it will prevent clipping. By appending
1384 the 24dB_digital_gain parameter, the Digital
1385 volume control will allow up to 24dB of
1386 gain. If this parameter is enabled, it is the
1387 responsibility of the user to ensure that
1388 the Digital volume control is set to a value
1389 that does not result in clipping/distortion!)
1390 slave Force DAC+ Pro into slave mode, using Pi as
1391 master for bit clock and frame clock.
1392 leds_off If set to 'true' the onboard indicator LEDs
1393 are switched off at all times.
1396 Name: hifiberry-dacplusadcpro
1397 Info: Configures the HifiBerry DAC+ADC PRO audio card
1398 Load: dtoverlay=hifiberry-dacplusadcpro,<param>=<val>
1399 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1400 Digital volume control. Enable with
1401 "dtoverlay=hifiberry-dacplusadcpro,24db_digital_gain"
1402 (The default behaviour is that the Digital
1403 volume control is limited to a maximum of
1404 0dB. ie. it can attenuate but not provide
1405 gain. For most users, this will be desired
1406 as it will prevent clipping. By appending
1407 the 24dB_digital_gain parameter, the Digital
1408 volume control will allow up to 24dB of
1409 gain. If this parameter is enabled, it is the
1410 responsibility of the user to ensure that
1411 the Digital volume control is set to a value
1412 that does not result in clipping/distortion!)
1413 slave Force DAC+ADC Pro into slave mode, using Pi as
1414 master for bit clock and frame clock.
1415 leds_off If set to 'true' the onboard indicator LEDs
1416 are switched off at all times.
1419 Name: hifiberry-dacplusdsp
1420 Info: Configures the HifiBerry DAC+DSP audio card
1421 Load: dtoverlay=hifiberry-dacplusdsp
1425 Name: hifiberry-dacplushd
1426 Info: Configures the HifiBerry DAC+ HD audio card
1427 Load: dtoverlay=hifiberry-dacplushd
1431 Name: hifiberry-digi
1432 Info: Configures the HifiBerry Digi and Digi+ audio card
1433 Load: dtoverlay=hifiberry-digi
1437 Name: hifiberry-digi-pro
1438 Info: Configures the HifiBerry Digi+ Pro audio card
1439 Load: dtoverlay=hifiberry-digi-pro
1444 Info: Enables "High Peripheral" mode
1445 Load: dtoverlay=highperi
1450 Info: HY28A - 2.8" TFT LCD Display Module by HAOYU Electronics
1451 Default values match Texy's display shield
1452 Load: dtoverlay=hy28a,<param>=<val>
1453 Params: speed Display SPI bus speed
1455 rotate Display rotation {0,90,180,270}
1457 fps Delay between frame updates
1459 debug Debug output level {0-7}
1461 xohms Touchpanel sensitivity (X-plate resistance)
1463 resetgpio GPIO used to reset controller
1465 ledgpio GPIO used to control backlight
1469 Info: HY28B - 2.8" TFT LCD Display Module by HAOYU Electronics
1470 Default values match Texy's display shield
1471 Load: dtoverlay=hy28b,<param>=<val>
1472 Params: speed Display SPI bus speed
1474 rotate Display rotation {0,90,180,270}
1476 fps Delay between frame updates
1478 debug Debug output level {0-7}
1480 xohms Touchpanel sensitivity (X-plate resistance)
1482 resetgpio GPIO used to reset controller
1484 ledgpio GPIO used to control backlight
1488 Info: HY28B 2017 version - 2.8" TFT LCD Display Module by HAOYU Electronics
1489 Default values match Texy's display shield
1490 Load: dtoverlay=hy28b-2017,<param>=<val>
1491 Params: speed Display SPI bus speed
1493 rotate Display rotation {0,90,180,270}
1495 fps Delay between frame updates
1497 debug Debug output level {0-7}
1499 xohms Touchpanel sensitivity (X-plate resistance)
1501 resetgpio GPIO used to reset controller
1503 ledgpio GPIO used to control backlight
1507 Info: Configures the Audiophonics I-SABRE Q2M DAC
1508 Load: dtoverlay=i-sabre-q2m
1513 Info: Fall back to the i2c_bcm2708 driver for the i2c_arm bus.
1514 Load: dtoverlay=i2c-bcm2708
1519 Info: Adds support for software i2c controller on gpio pins
1520 Load: dtoverlay=i2c-gpio,<param>=<val>
1521 Params: i2c_gpio_sda GPIO used for I2C data (default "23")
1523 i2c_gpio_scl GPIO used for I2C clock (default "24")
1525 i2c_gpio_delay_us Clock delay in microseconds
1526 (default "2" = ~100kHz)
1528 bus Set to a unique, non-zero value if wanting
1529 multiple i2c-gpio busses. If set, will be used
1530 as the preferred bus number (/dev/i2c-<n>). If
1531 not set, the default value is 0, but the bus
1532 number will be dynamically assigned - probably
1537 Info: Adds support for a number of I2C bus multiplexers on i2c_arm
1538 Load: dtoverlay=i2c-mux,<param>=<val>
1539 Params: pca9542 Select the NXP PCA9542 device
1541 pca9545 Select the NXP PCA9545 device
1543 pca9548 Select the NXP PCA9548 device
1545 addr Change I2C address of the device (default 0x70)
1548 [ The i2c-mux-pca9548a overlay has been deleted. See i2c-mux. ]
1551 Name: i2c-pwm-pca9685a
1552 Info: Adds support for an NXP PCA9685A I2C PWM controller on i2c_arm
1553 Load: dtoverlay=i2c-pwm-pca9685a,<param>=<val>
1554 Params: addr I2C address of PCA9685A (default 0x40)
1558 Info: Adds support for a number of I2C Real Time Clock devices
1559 Load: dtoverlay=i2c-rtc,<param>=<val>
1560 Params: abx80x Select one of the ABx80x family:
1561 AB0801, AB0803, AB0804, AB0805,
1562 AB1801, AB1803, AB1804, AB1805
1564 bq32000 Select the TI BQ32000 device
1566 ds1307 Select the DS1307 device
1568 ds1339 Select the DS1339 device
1570 ds1340 Select the DS1340 device
1572 ds3231 Select the DS3231 device
1574 m41t62 Select the M41T62 device
1576 mcp7940x Select the MCP7940x device
1578 mcp7941x Select the MCP7941x device
1580 pcf2127 Select the PCF2127 device
1582 pcf2129 Select the PCF2129 device
1584 pcf85063 Select the PCF85063 device
1586 pcf85063a Select the PCF85063A device
1588 pcf8523 Select the PCF8523 device
1590 pcf85363 Select the PCF85363 device
1592 pcf8563 Select the PCF8563 device
1594 rv1805 Select the Micro Crystal RV1805 device
1596 rv3028 Select the Micro Crystal RV3028 device
1598 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1600 s35390a Select the ABLIC S35390A device
1602 i2c0 Choose the I2C0 bus on GPIOs 0&1
1604 i2c_csi_dsi Choose the I2C0 bus on GPIOs 44&45
1606 addr Sets the address for the RTC. Note that the
1607 device must be configured to use the specified
1610 trickle-diode-disable Do not use the internal trickle charger diode
1613 trickle-diode-type Diode type for trickle charge - "standard" or
1614 "schottky" (ABx80x and RV1805 only)
1616 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1617 ABx80x, RV1805, RV3028)
1619 wakeup-source Specify that the RTC can be used as a wakeup
1622 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1623 off or 1 for Vdd < VBackup (RV3028 only)
1627 Info: Adds support for a number of I2C Real Time Clock devices
1628 using the software i2c controller
1629 Load: dtoverlay=i2c-rtc-gpio,<param>=<val>
1630 Params: abx80x Select one of the ABx80x family:
1631 AB0801, AB0803, AB0804, AB0805,
1632 AB1801, AB1803, AB1804, AB1805
1634 bq32000 Select the TI BQ32000 device
1636 ds1307 Select the DS1307 device
1638 ds1339 Select the DS1339 device
1640 ds1340 Select the DS1340 device
1642 ds3231 Select the DS3231 device
1644 m41t62 Select the M41T62 device
1646 mcp7940x Select the MCP7940x device
1648 mcp7941x Select the MCP7941x device
1650 pcf2127 Select the PCF2127 device
1652 pcf2129 Select the PCF2129 device
1654 pcf85063 Select the PCF85063 device
1656 pcf85063a Select the PCF85063A device
1658 pcf8523 Select the PCF8523 device
1660 pcf85363 Select the PCF85363 device
1662 pcf8563 Select the PCF8563 device
1664 rv1805 Select the Micro Crystal RV1805 device
1666 rv3028 Select the Micro Crystal RV3028 device
1668 sd3078 Select the ZXW Shenzhen whwave SD3078 device
1670 s35390a Select the ABLIC S35390A device
1672 addr Sets the address for the RTC. Note that the
1673 device must be configured to use the specified
1676 trickle-diode-disable Do not use the internal trickle charger diode
1679 trickle-diode-type Diode type for trickle charge - "standard" or
1680 "schottky" (ABx80x and RV1805 only)
1682 trickle-resistor-ohms Resistor value for trickle charge (DS1339,
1683 ABx80x, RV1805, RV3028)
1685 wakeup-source Specify that the RTC can be used as a wakeup
1688 backup-switchover-mode Backup power supply switch mode. Must be 0 for
1689 off or 1 for Vdd < VBackup (RV3028 only)
1691 i2c_gpio_sda GPIO used for I2C data (default "23")
1693 i2c_gpio_scl GPIO used for I2C clock (default "24")
1695 i2c_gpio_delay_us Clock delay in microseconds
1696 (default "2" = ~100kHz)
1700 Info: Adds support for a number of I2C barometric pressure, temperature,
1701 light level and chemical sensors on i2c_arm
1702 Load: dtoverlay=i2c-sensor,<param>=<val>
1703 Params: addr Set the address for the BH1750, BME280, BME680,
1704 BMP280, CCS811, DS1621, HDC100X, LM75, SHT3x or
1707 bh1750 Select the Rohm BH1750 ambient light sensor
1708 Valid addresses 0x23 or 0x5c, default 0x23
1710 bme280 Select the Bosch Sensortronic BME280
1711 Valid addresses 0x76-0x77, default 0x76
1713 bme680 Select the Bosch Sensortronic BME680
1714 Valid addresses 0x76-0x77, default 0x76
1716 bmp085 Select the Bosch Sensortronic BMP085
1718 bmp180 Select the Bosch Sensortronic BMP180
1720 bmp280 Select the Bosch Sensortronic BMP280
1721 Valid addresses 0x76-0x77, default 0x76
1723 ccs811 Select the AMS CCS811 digital gas sensor
1724 Valid addresses 0x5a-0x5b, default 0x5b
1726 ds1621 Select the Dallas Semiconductors DS1621 temp
1727 sensor. Valid addresses 0x48-0x4f, default 0x48
1729 hdc100x Select the Texas Instruments HDC100x temp sensor
1730 Valid addresses 0x40-0x43, default 0x40
1732 htu21 Select the HTU21 temperature and humidity sensor
1734 int_pin Set the GPIO to use for interrupts (max30102
1737 lm75 Select the Maxim LM75 temperature sensor
1738 Valid addresses 0x48-0x4f, default 0x4f
1740 lm75addr Deprecated - use addr parameter instead
1742 max17040 Select the Maxim Integrated MAX17040 battery
1745 max30102 Select the Maxim Integrated MAX30102 heart-rate
1746 and blood-oxygen sensor
1748 sht3x Select the Sensiron SHT3x temperature and
1749 humidity sensor. Valid addresses 0x44-0x45,
1752 si7020 Select the Silicon Labs Si7013/20/21 humidity/
1755 sps30 Select the Sensirion SPS30 particulate matter
1756 sensor. Fixed address 0x69.
1758 sgp30 Select the Sensirion SGP30 VOC sensor.
1761 tmp102 Select the Texas Instruments TMP102 temp sensor
1762 Valid addresses 0x48-0x4b, default 0x48
1764 tsl4531 Select the AMS TSL4531 digital ambient light
1767 veml6070 Select the Vishay VEML6070 ultraviolet light
1772 Info: Change i2c0 pin usage. Not all pin combinations are usable on all
1773 platforms - platforms other then Compute Modules can only use this
1774 to disable transaction combining.
1775 Do NOT use in conjunction with dtparam=i2c_vc=on. From the 5.4 kernel
1776 onwards the base DT includes the use of i2c_mux_pinctrl to expose two
1777 muxings of BSC0 - GPIOs 0&1, and whichever combination is used for the
1778 camera and display connectors. This overlay disables that mux and
1779 configures /dev/i2c0 to point at whichever set of pins is requested.
1780 dtparam=i2c_vc=on will try and enable the mux, so combining the two
1781 will cause conflicts.
1782 Load: dtoverlay=i2c0,<param>=<val>
1783 Params: pins_0_1 Use pins 0 and 1 (default)
1784 pins_28_29 Use pins 28 and 29
1785 pins_44_45 Use pins 44 and 45
1786 pins_46_47 Use pins 46 and 47
1787 combine Allow transactions to be combined (default
1792 Info: Deprecated, legacy version of i2c0.
1797 Info: Change i2c1 pin usage. Not all pin combinations are usable on all
1798 platforms - platforms other then Compute Modules can only use this
1799 to disable transaction combining.
1800 Load: dtoverlay=i2c1,<param>=<val>
1801 Params: pins_2_3 Use pins 2 and 3 (default)
1802 pins_44_45 Use pins 44 and 45
1803 combine Allow transactions to be combined (default
1808 Info: Deprecated, legacy version of i2c1.
1813 Info: Enable the i2c3 bus. BCM2711 only.
1814 Load: dtoverlay=i2c3,<param>
1815 Params: pins_2_3 Use GPIOs 2 and 3
1816 pins_4_5 Use GPIOs 4 and 5 (default)
1817 baudrate Set the baudrate for the interface (default
1822 Info: Enable the i2c4 bus. BCM2711 only.
1823 Load: dtoverlay=i2c4,<param>
1824 Params: pins_6_7 Use GPIOs 6 and 7
1825 pins_8_9 Use GPIOs 8 and 9 (default)
1826 baudrate Set the baudrate for the interface (default
1831 Info: Enable the i2c5 bus. BCM2711 only.
1832 Load: dtoverlay=i2c5,<param>
1833 Params: pins_10_11 Use GPIOs 10 and 11
1834 pins_12_13 Use GPIOs 12 and 13 (default)
1835 baudrate Set the baudrate for the interface (default
1840 Info: Enable the i2c6 bus. BCM2711 only.
1841 Load: dtoverlay=i2c6,<param>
1842 Params: pins_0_1 Use GPIOs 0 and 1
1843 pins_22_23 Use GPIOs 22 and 23 (default)
1844 baudrate Set the baudrate for the interface (default
1849 Info: move I2S function block to GPIO 28 to 31
1850 Load: dtoverlay=i2s-gpio28-31
1855 Info: Enables I2C connected Ilitek 251x multiple touch controller using
1856 GPIO 4 (pin 7 on GPIO header) for interrupt.
1857 Load: dtoverlay=ilitek251x,<param>=<val>
1858 Params: interrupt GPIO used for interrupt (default 4)
1859 sizex Touchscreen size x, horizontal resolution of
1860 touchscreen (in pixels)
1861 sizey Touchscreen size y, vertical resolution of
1862 touchscreen (in pixels)
1866 Info: Sony IMX219 camera module.
1867 Uses Unicam 1, which is the standard camera connector on most Pi
1869 Load: dtoverlay=imx219,<param>=<val>
1870 Params: rotation Mounting rotation of the camera sensor (0 or
1872 orientation Sensor orientation (0 = front, 1 = rear,
1873 2 = external, default external)
1874 media-controller Configure use of Media Controller API for
1875 configuring the sensor (default on)
1876 cam0 Adopt the default configuration for CAM0 on a
1877 Compute Module (CSI0, i2c_vc, and cam0_reg).
1878 vcm Configure a VCM focus drive on the sensor.
1882 Info: Sony IMX258 camera module.
1883 Uses Unicam 1, which is the standard camera connector on most Pi
1885 Load: dtoverlay=imx258,<param>=<val>
1886 Params: rotation Mounting rotation of the camera sensor (0 or
1888 orientation Sensor orientation (0 = front, 1 = rear,
1889 2 = external, default external)
1890 media-controller Configure use of Media Controller API for
1891 configuring the sensor (default on)
1892 cam0 Adopt the default configuration for CAM0 on a
1893 Compute Module (CSI0, i2c_vc, and cam0_reg).
1894 vcm Configure a VCM focus drive on the sensor.
1895 4lane Enable 4 CSI2 lanes. This requires a Compute
1896 Module (1, 3, or 4).
1900 Info: Sony IMX290 camera module.
1901 Uses Unicam 1, which is the standard camera connector on most Pi
1902 variants. NB This currently uses 4 CSI2 data lanes and therefore will
1904 Load: dtoverlay=imx290,<param>
1905 Params: 4lane Enable 4 CSI2 lanes. This requires a Compute
1906 Module (1, 3, or 4).
1907 clock-frequency Sets the clock frequency to match that used on
1909 Modules from Vision Components use 37.125MHz
1910 (the default), whilst those from Innomaker use
1912 mono Denote that the module is a mono sensor.
1913 orientation Sensor orientation (0 = front, 1 = rear,
1914 2 = external, default external)
1915 rotation Mounting rotation of the camera sensor (0 or
1917 media-controller Configure use of Media Controller API for
1918 configuring the sensor (default on)
1919 cam0 Adopt the default configuration for CAM0 on a
1920 Compute Module (CSI0, i2c_vc, and cam0_reg).
1924 Info: Sony IMX378 camera module.
1925 Uses Unicam 1, which is the standard camera connector on most Pi
1927 Load: dtoverlay=imx378,<param>=<val>
1928 Params: rotation Mounting rotation of the camera sensor (0 or
1930 orientation Sensor orientation (0 = front, 1 = rear,
1931 2 = external, default external)
1932 media-controller Configure use of Media Controller API for
1933 configuring the sensor (default on)
1934 cam0 Adopt the default configuration for CAM0 on a
1935 Compute Module (CSI0, i2c_vc, and cam0_reg).
1939 Info: Sony IMX477 camera module.
1940 Uses Unicam 1, which is the standard camera connector on most Pi
1942 Load: dtoverlay=imx477,<param>=<val>
1943 Params: rotation Mounting rotation of the camera sensor (0 or
1945 orientation Sensor orientation (0 = front, 1 = rear,
1946 2 = external, default external)
1947 media-controller Configure use of Media Controller API for
1948 configuring the sensor (default on)
1949 cam0 Adopt the default configuration for CAM0 on a
1950 Compute Module (CSI0, i2c_vc, and cam0_reg).
1954 Info: Sony IMX519 camera module.
1955 Uses Unicam 1, which is the standard camera connector on most Pi
1957 Load: dtoverlay=imx519,<param>=<val>
1958 Params: rotation Mounting rotation of the camera sensor (0 or
1960 orientation Sensor orientation (0 = front, 1 = rear,
1961 2 = external, default external)
1962 media-controller Configure use of Media Controller API for
1963 configuring the sensor (default on)
1964 cam0 Adopt the default configuration for CAM0 on a
1965 Compute Module (CSI0, i2c_vc, and cam0_reg).
1969 Info: Configures the IQaudio Codec audio card
1970 Load: dtoverlay=iqaudio-codec
1975 Info: Configures the IQaudio DAC audio card
1976 Load: dtoverlay=iqaudio-dac,<param>
1977 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1978 Digital volume control. Enable with
1979 "dtoverlay=iqaudio-dac,24db_digital_gain"
1980 (The default behaviour is that the Digital
1981 volume control is limited to a maximum of
1982 0dB. ie. it can attenuate but not provide
1983 gain. For most users, this will be desired
1984 as it will prevent clipping. By appending
1985 the 24db_digital_gain parameter, the Digital
1986 volume control will allow up to 24dB of
1987 gain. If this parameter is enabled, it is the
1988 responsibility of the user to ensure that
1989 the Digital volume control is set to a value
1990 that does not result in clipping/distortion!)
1993 Name: iqaudio-dacplus
1994 Info: Configures the IQaudio DAC+ audio card
1995 Load: dtoverlay=iqaudio-dacplus,<param>=<val>
1996 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
1997 Digital volume control. Enable with
1998 "dtoverlay=iqaudio-dacplus,24db_digital_gain"
1999 (The default behaviour is that the Digital
2000 volume control is limited to a maximum of
2001 0dB. ie. it can attenuate but not provide
2002 gain. For most users, this will be desired
2003 as it will prevent clipping. By appending
2004 the 24db_digital_gain parameter, the Digital
2005 volume control will allow up to 24dB of
2006 gain. If this parameter is enabled, it is the
2007 responsibility of the user to ensure that
2008 the Digital volume control is set to a value
2009 that does not result in clipping/distortion!)
2010 auto_mute_amp If specified, unmute/mute the IQaudIO amp when
2011 starting/stopping audio playback.
2012 unmute_amp If specified, unmute the IQaudIO amp once when
2013 the DAC driver module loads.
2016 Name: iqaudio-digi-wm8804-audio
2017 Info: Configures the IQAudIO Digi WM8804 audio card
2018 Load: dtoverlay=iqaudio-digi-wm8804-audio,<param>=<val>
2019 Params: card_name Override the default, "IQAudIODigi", card name.
2020 dai_name Override the default, "IQAudIO Digi", dai name.
2021 dai_stream_name Override the default, "IQAudIO Digi HiFi",
2026 Info: Enables I2C connected Azoteq IQS550 trackpad/touchscreen controller
2027 using GPIO 4 (pin 7 on GPIO header) for interrupt.
2028 Load: dtoverlay=iqs550,<param>=<val>
2029 Params: interrupt GPIO used for interrupt (default 4)
2030 reset GPIO used for reset (optional)
2031 sizex Touchscreen size x (default 800)
2032 sizey Touchscreen size y (default 480)
2033 invx Touchscreen inverted x axis
2034 invy Touchscreen inverted y axis
2035 swapxy Touchscreen swapped x y axis
2039 Info: Infineon irs1125 TOF camera module.
2040 Uses Unicam 1, which is the standard camera connector on most Pi
2042 Load: dtoverlay=irs1125,<param>=<val>
2043 Params: media-controller Configure use of Media Controller API for
2044 configuring the sensor (default off)
2045 cam0 Adopt the default configuration for CAM0 on a
2046 Compute Module (CSI0, i2c_vc, and cam0_reg).
2050 Info: Adds support for JEDEC-compliant SPI NOR flash devices. (Note: The
2051 "jedec,spi-nor" kernel driver was formerly known as "m25p80".)
2052 Load: dtoverlay=jedec-spi-nor,<param>=<val>
2053 Params: flash-spi<n>-<m> Enables flash device on SPI<n>, CS#<m>.
2054 flash-fastr-spi<n>-<m> Enables flash device with fast read capability
2059 Info: Simultaneous usage of an justboom-dac and justboom-digi based
2061 Load: dtoverlay=justboom-both,<param>=<val>
2062 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2063 Digital volume control. Enable with
2064 "dtoverlay=justboom-dac,24db_digital_gain"
2065 (The default behaviour is that the Digital
2066 volume control is limited to a maximum of
2067 0dB. ie. it can attenuate but not provide
2068 gain. For most users, this will be desired
2069 as it will prevent clipping. By appending
2070 the 24dB_digital_gain parameter, the Digital
2071 volume control will allow up to 24dB of
2072 gain. If this parameter is enabled, it is the
2073 responsibility of the user to ensure that
2074 the Digital volume control is set to a value
2075 that does not result in clipping/distortion!)
2079 Info: Configures the JustBoom DAC HAT, Amp HAT, DAC Zero and Amp Zero audio
2081 Load: dtoverlay=justboom-dac,<param>=<val>
2082 Params: 24db_digital_gain Allow gain to be applied via the PCM512x codec
2083 Digital volume control. Enable with
2084 "dtoverlay=justboom-dac,24db_digital_gain"
2085 (The default behaviour is that the Digital
2086 volume control is limited to a maximum of
2087 0dB. ie. it can attenuate but not provide
2088 gain. For most users, this will be desired
2089 as it will prevent clipping. By appending
2090 the 24dB_digital_gain parameter, the Digital
2091 volume control will allow up to 24dB of
2092 gain. If this parameter is enabled, it is the
2093 responsibility of the user to ensure that
2094 the Digital volume control is set to a value
2095 that does not result in clipping/distortion!)
2099 Info: Configures the JustBoom Digi HAT and Digi Zero audio cards
2100 Load: dtoverlay=justboom-digi
2105 Info: This overlay has been deprecated and removed - see gpio-ir
2110 Info: Adds support for the ltc294x family of battery gauges
2111 Load: dtoverlay=ltc294x,<param>=<val>
2112 Params: ltc2941 Select the ltc2941 device
2114 ltc2942 Select the ltc2942 device
2116 ltc2943 Select the ltc2943 device
2118 ltc2944 Select the ltc2944 device
2120 resistor-sense The sense resistor value in milli-ohms.
2121 Can be a 32-bit negative value when the battery
2122 has been connected to the wrong end of the
2125 prescaler-exponent Range and accuracy of the gauge. The value is
2126 programmed into the chip only if it differs
2127 from the current setting.
2129 - Default value is 128
2130 - the exponent is in the range 0-7 (default 7)
2131 See the datasheet for more information.
2135 Info: Configures the Maxim MAX98357A I2S DAC
2136 Load: dtoverlay=max98357a,<param>=<val>
2137 Params: no-sdmode Driver does not manage the state of the DAC's
2138 SD_MODE pin (i.e. chip is always on).
2139 sdmode-pin integer, GPIO pin connected to the SD_MODE input
2140 of the DAC (default GPIO4 if parameter omitted).
2144 Info: Configure a MAX6675, MAX31855 or MAX31856 thermocouple as an IIO device.
2146 For devices on spi1 or spi2, the interfaces should be enabled
2147 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2148 The overlay expects to disable the relevant spidev node, so also using
2149 e.g. cs0_spidev=off is unnecessary.
2152 MAX31855 on /dev/spidev0.0
2153 dtoverlay=maxtherm,spi0-0,max31855
2154 MAX31856 using a type J thermocouple on /dev/spidev2.1
2156 dtoverlay=maxtherm,spi2-1,max31856,type_j
2158 Load: dtoverlay=maxtherm,<param>=<val>
2159 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2161 max6675 Enable support for the MAX6675 (default)
2162 max31855 Enable support for the MAX31855
2163 max31855e Enable support for the MAX31855E
2164 max31855j Enable support for the MAX31855J
2165 max31855k Enable support for the MAX31855K
2166 max31855n Enable support for the MAX31855N
2167 max31855r Enable support for the MAX31855R
2168 max31855s Enable support for the MAX31855S
2169 max31855t Enable support for the MAX31855T
2170 max31856 Enable support for the MAX31856 (with type K)
2171 type_b Select a type B sensor for max31856
2172 type_e Select a type E sensor for max31856
2173 type_j Select a type J sensor for max31856
2174 type_k Select a type K sensor for max31856
2175 type_n Select a type N sensor for max31856
2176 type_r Select a type R sensor for max31856
2177 type_s Select a type S sensor for max31856
2178 type_t Select a type T sensor for max31856
2182 Info: Configures the mbed AudioCODEC (TLV320AIC23B)
2183 Load: dtoverlay=mbed-dac
2188 Info: Configures the MCP23017 I2C GPIO expander
2189 Load: dtoverlay=mcp23017,<param>=<val>
2190 Params: gpiopin Gpio pin connected to the INTA output of the
2191 MCP23017 (default: 4)
2193 addr I2C address of the MCP23017 (default: 0x20)
2195 mcp23008 Configure an MCP23008 instead.
2196 noints Disable the interrupt GPIO line.
2200 Info: Configures the MCP23S08/17 SPI GPIO expanders.
2201 If devices are present on SPI1 or SPI2, those interfaces must be enabled
2202 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2203 If interrupts are enabled for a device on a given CS# on a SPI bus, that
2204 device must be the only one present on that SPI bus/CS#.
2205 Load: dtoverlay=mcp23s17,<param>=<val>
2206 Params: s08-spi<n>-<m>-present 4-bit integer, bitmap indicating MCP23S08
2207 devices present on SPI<n>, CS#<m>
2209 s17-spi<n>-<m>-present 8-bit integer, bitmap indicating MCP23S17
2210 devices present on SPI<n>, CS#<m>
2212 s08-spi<n>-<m>-int-gpio integer, enables interrupts on a single
2213 MCP23S08 device on SPI<n>, CS#<m>, specifies
2214 the GPIO pin to which INT output of MCP23S08
2217 s17-spi<n>-<m>-int-gpio integer, enables mirrored interrupts on a
2218 single MCP23S17 device on SPI<n>, CS#<m>,
2219 specifies the GPIO pin to which either INTA
2220 or INTB output of MCP23S17 is connected.
2224 Info: Configures the MCP2515 CAN controller on spi0/1/2
2225 For devices on spi1 or spi2, the interfaces should be enabled
2226 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2227 Load: dtoverlay=mcp2515,<param>=<val>
2228 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2231 oscillator Clock frequency for the CAN controller (Hz)
2233 speed Maximum SPI frequence (Hz)
2235 interrupt GPIO for interrupt signal
2239 Info: Configures the MCP2515 CAN controller on spi0.0
2240 Load: dtoverlay=mcp2515-can0,<param>=<val>
2241 Params: oscillator Clock frequency for the CAN controller (Hz)
2243 spimaxfrequency Maximum SPI frequence (Hz)
2245 interrupt GPIO for interrupt signal
2249 Info: Configures the MCP2515 CAN controller on spi0.1
2250 Load: dtoverlay=mcp2515-can1,<param>=<val>
2251 Params: oscillator Clock frequency for the CAN controller (Hz)
2253 spimaxfrequency Maximum SPI frequence (Hz)
2255 interrupt GPIO for interrupt signal
2259 Info: Configures the MCP251XFD CAN controller family
2260 For devices on spi1 or spi2, the interfaces should be enabled
2261 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2262 Load: dtoverlay=mcp251xfd,<param>=<val>
2263 Params: spi<n>-<m> Configure device at spi<n>, cs<m>
2266 oscillator Clock frequency for the CAN controller (Hz)
2268 speed Maximum SPI frequence (Hz)
2270 interrupt GPIO for interrupt signal
2272 rx_interrupt GPIO for RX interrupt signal (nINT1) (optional)
2274 xceiver_enable GPIO for CAN transceiver enable (optional)
2276 xceiver_active_high specifiy if CAN transceiver enable pin is
2277 active high (optional, default: active low)
2281 Info: Configures MCP3008 A/D converters
2282 For devices on spi1 or spi2, the interfaces should be enabled
2283 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2284 Load: dtoverlay=mcp3008,<param>[=<val>]
2285 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2286 spi<n>-<m>-speed integer, set the spi bus speed for this device
2290 Info: Configures MCP3202 A/D converters
2291 For devices on spi1 or spi2, the interfaces should be enabled
2292 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2293 Load: dtoverlay=mcp3202,<param>[=<val>]
2294 Params: spi<n>-<m>-present boolean, configure device at spi<n>, cs<m>
2295 spi<n>-<m>-speed integer, set the spi bus speed for this device
2299 Info: Overlay for activation of Microchip MCP3421-3428 ADCs over I2C
2300 Load: dtoverlay=mcp342x,<param>=<val>
2301 Params: addr I2C bus address of device, for devices with
2302 addresses that are configurable, e.g. by
2303 hardware links (default=0x68)
2304 mcp3421 The device is an MCP3421
2305 mcp3422 The device is an MCP3422
2306 mcp3423 The device is an MCP3423
2307 mcp3424 The device is an MCP3424
2308 mcp3425 The device is an MCP3425
2309 mcp3426 The device is an MCP3426
2310 mcp3427 The device is an MCP3427
2311 mcp3428 The device is an MCP3428
2315 Info: Media Center HAT - 2.83" Touch Display + extras by Pi Supply
2316 Load: dtoverlay=media-center,<param>=<val>
2317 Params: speed Display SPI bus speed
2318 rotate Display rotation {0,90,180,270}
2319 fps Delay between frame updates
2320 xohms Touchpanel sensitivity (X-plate resistance)
2321 swapxy Swap x and y axis
2322 backlight Change backlight GPIO pin {e.g. 12, 18}
2323 gpio_out_pin GPIO for output (default "17")
2324 gpio_in_pin GPIO for input (default "18")
2325 gpio_in_pull Pull up/down/off on the input pin
2327 sense Override the IR receive auto-detection logic:
2328 "0" = force active-high
2329 "1" = force active-low
2330 "-1" = use auto-detection
2332 softcarrier Turn the software carrier "on" or "off"
2334 invert "on" = invert the output pin (default "off")
2335 debug "on" = enable additional debug messages
2340 Info: Configures the merus-amp audio card
2341 Load: dtoverlay=merus-amp
2346 Info: Configures UART0 (ttyAMA0) so that a requested 38.4kbaud actually gets
2347 31.25kbaud, the frequency required for MIDI
2348 Load: dtoverlay=midi-uart0
2353 Info: Configures UART1 (ttyS0) so that a requested 38.4kbaud actually gets
2354 31.25kbaud, the frequency required for MIDI
2355 Load: dtoverlay=midi-uart1
2360 Info: Configures UART2 (ttyAMA1) so that a requested 38.4kbaud actually gets
2361 31.25kbaud, the frequency required for MIDI
2362 Load: dtoverlay=midi-uart2
2367 Info: Configures UART3 (ttyAMA2) so that a requested 38.4kbaud actually gets
2368 31.25kbaud, the frequency required for MIDI
2369 Load: dtoverlay=midi-uart3
2374 Info: Configures UART4 (ttyAMA3) so that a requested 38.4kbaud actually gets
2375 31.25kbaud, the frequency required for MIDI
2376 Load: dtoverlay=midi-uart4
2381 Info: Configures UART5 (ttyAMA4) so that a requested 38.4kbaud actually gets
2382 31.25kbaud, the frequency required for MIDI
2383 Load: dtoverlay=midi-uart5
2388 Info: Overlay for AdaFruit Mini Pi 1.3" TFT via SPI using fbtft driver.
2389 Load: dtoverlay=minipitft13,<param>=<val>
2390 Params: speed SPI bus speed (default 32000000)
2391 rotate Display rotation (0, 90, 180 or 270; default 0)
2392 width Display width (default 240)
2393 height Display height (default 240)
2394 fps Delay between frame updates (default 25)
2395 debug Debug output level (0-7; default 0)
2399 Info: Switch the onboard Bluetooth function on Pi 3B, 3B+, 3A+, 4B and Zero W
2400 to use the mini-UART (ttyS0) and restore UART0/ttyAMA0 over GPIOs 14 &
2401 15. Note that this may reduce the maximum usable baudrate.
2402 N.B. It is also necessary to edit /lib/systemd/system/hciuart.service
2403 and replace ttyAMA0 with ttyS0, unless using Raspbian or another
2404 distribution with udev rules that create /dev/serial0 and /dev/serial1,
2405 in which case use /dev/serial1 instead because it will always be
2406 correct. Furthermore, you must also set core_freq and core_freq_min to
2407 the same value in config.txt or the miniuart will not work.
2408 Load: dtoverlay=miniuart-bt,<param>=<val>
2409 Params: krnbt Set to "on" to enable autoprobing of Bluetooth
2410 driver without need of hciattach/btattach
2414 Info: Overlay for SPI-connected MIPI DBI displays using the panel-mipi-dbi
2415 driver. The driver will load a file /lib/firmware/panel.bin containing
2416 the initialisation commands.
2419 dtoverlay=mipi-dbi-spi,spi0-0,speed=70000000
2420 dtparam=width=320,height=240
2421 dtparam=reset-gpio=23,dc-gpio=24
2422 dtparam=backlight-gpio=18
2424 Compared to fbtft panel-mipi-dbi runs pixel data at spi-max-frequency
2425 and init commands at 10MHz. This makes it possible to push the envelope
2426 without messing up the controller configuration due to command
2427 transmission errors.
2429 For devices on spi1 or spi2, the interfaces should be enabled
2430 with one of the spi1-1/2/3cs and/or spi2-1/2/3cs overlays.
2432 See https://github.com/notro/panel-mipi-dbi/wiki for more info.
2434 Load: dtoverlay=mipi-dbi-spi,<param>=<val>
2436 compatible Set the compatible string to load a different
2437 firmware file. Both the panel compatible value
2438 used to load the firmware file and the value
2439 used to load the driver has to be set having a
2440 NUL (\0) separator between them.
2442 dtparam=compatible=mypanel\0panel-mipi-dbi-spi
2443 spi<n>-<m> Configure device at spi<n>, cs<m>
2445 speed SPI bus speed in Hz (default 32000000)
2446 cpha Shifted SPI clock phase (CPHA) mode
2447 cpol Inverse SPI clock polarity (CPOL) mode
2448 write-only Controller is not readable
2449 (ie. MISO is not wired up).
2451 width Panel width in pixels (required)
2452 height Panel height in pixels (required)
2453 width-mm Panel width in mm
2454 height-mm Panel height in mm
2455 x-offset Panel x-offset in controller RAM
2456 y-offset Panel y-offset in controller RAM
2458 clock-frequency Panel clock frequency in Hz
2459 (optional, just informational).
2461 reset-gpio GPIO pin to be used for RESET
2462 dc-gpio GPIO pin to be used for D/C
2464 backlight-gpio GPIO pin to be used for backlight control
2466 backlight-pwm PWM channel to be used for backlight control
2467 (default of none). NB Disables audio headphone
2468 output as that also uses PWM.
2469 backlight-pwm-chan Choose channel on &pwm node for backlight
2470 control (default 0).
2471 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
2472 pwm-2chan for valid options (default 18).
2473 backlight-pwm-func Pin function of GPIO used for the PWM backlight.
2474 See pwm-2chan for valid options (default 2).
2475 backlight-def-brightness
2476 Set the default brightness. Normal range 1-16.
2481 Info: Overlay for i2c connected mlx90640 thermal camera
2482 Load: dtoverlay=mlx90640
2487 Info: Selects the bcm2835-mmc SD/MMC driver, optionally with overclock
2488 Load: dtoverlay=mmc,<param>=<val>
2489 Params: overclock_50 Clock (in MHz) to use when the MMC framework
2494 Info: Overlay for i2c connected mpu6050 imu
2495 Load: dtoverlay=mpu6050,<param>=<val>
2496 Params: interrupt GPIO pin for interrupt (default 4)
2497 addr I2C address of the device (default 0x68)
2501 Info: MZ61581 display by Tontec
2502 Load: dtoverlay=mz61581,<param>=<val>
2503 Params: speed Display SPI bus speed
2505 rotate Display rotation {0,90,180,270}
2507 fps Delay between frame updates
2509 txbuflen Transmit buffer length (default 32768)
2511 debug Debug output level {0-7}
2513 xohms Touchpanel sensitivity (X-plate resistance)
2517 Info: Omnivision OV2311 camera module.
2518 Uses Unicam 1, which is the standard camera connector on most Pi
2520 Load: dtoverlay=ov2311,<param>=<val>
2521 Params: rotation Mounting rotation of the camera sensor (0 or
2523 orientation Sensor orientation (0 = front, 1 = rear,
2524 2 = external, default external)
2525 media-controller Configure use of Media Controller API for
2526 configuring the sensor (default on)
2527 cam0 Adopt the default configuration for CAM0 on a
2528 Compute Module (CSI0, i2c_vc, and cam0_reg).
2532 Info: Omnivision OV5647 camera module.
2533 Uses Unicam 1, which is the standard camera connector on most Pi
2535 Load: dtoverlay=ov5647,<param>=<val>
2536 Params: rotation Mounting rotation of the camera sensor (0 or
2538 orientation Sensor orientation (0 = front, 1 = rear,
2539 2 = external, default external)
2540 media-controller Configure use of Media Controller API for
2541 configuring the sensor (default on)
2542 cam0 Adopt the default configuration for CAM0 on a
2543 Compute Module (CSI0, i2c_vc, and cam0_reg).
2544 vcm Configure a VCM focus drive on the sensor.
2548 Info: Omnivision OV7251 camera module.
2549 Uses Unicam 1, which is the standard camera connector on most Pi
2551 Load: dtoverlay=ov7251,<param>=<val>
2552 Params: rotation Mounting rotation of the camera sensor (0 or
2554 orientation Sensor orientation (0 = front, 1 = rear,
2555 2 = external, default external)
2556 media-controller Configure use of Media Controller API for
2557 configuring the sensor (default off)
2558 cam0 Adopt the default configuration for CAM0 on a
2559 Compute Module (CSI0, i2c_vc, and cam0_reg).
2563 Info: Omnivision OV9281 camera module.
2564 Uses Unicam 1, which is the standard camera connector on most Pi
2566 Load: dtoverlay=ov9281,<param>=<val>
2567 Params: rotation Mounting rotation of the camera sensor (0 or
2569 orientation Sensor orientation (0 = front, 1 = rear,
2570 2 = external, default external)
2571 media-controller Configure use of Media Controller API for
2572 configuring the sensor (default on)
2573 cam0 Adopt the default configuration for CAM0 on a
2574 Compute Module (CSI0, i2c_vc, and cam0_reg).
2578 Info: PaPiRus ePaper Screen by Pi Supply (both HAT and pHAT)
2579 Load: dtoverlay=papirus,<param>=<val>
2580 Params: panel Display panel (required):
2585 speed Display SPI bus speed
2589 Info: TI PCA953x family of I2C GPIO expanders. Default is for NXP PCA9534.
2590 Load: dtoverlay=pca953x,<param>=<val>
2591 Params: addr I2C address of expander. Default 0x20.
2592 pca6416 Select the NXP PCA6416 (16 bit)
2593 pca9505 Select the NXP PCA9505 (40 bit)
2594 pca9535 Select the NXP PCA9535 (16 bit)
2595 pca9536 Select the NXP PCA9536 or TI PCA9536 (4 bit)
2596 pca9537 Select the NXP PCA9537 (4 bit)
2597 pca9538 Select the NXP PCA9538 (8 bit)
2598 pca9539 Select the NXP PCA9539 (16 bit)
2599 pca9554 Select the NXP PCA9554 (8 bit)
2600 pca9555 Select the NXP PCA9555 (16 bit)
2601 pca9556 Select the NXP PCA9556 (8 bit)
2602 pca9557 Select the NXP PCA9557 (8 bit)
2603 pca9574 Select the NXP PCA9574 (8 bit)
2604 pca9575 Select the NXP PCA9575 (16 bit)
2605 pca9698 Select the NXP PCA9698 (40 bit)
2606 pca16416 Select the NXP PCA16416 (16 bit)
2607 pca16524 Select the NXP PCA16524 (24 bit)
2608 pca19555a Select the NXP PCA19555A (16 bit)
2609 max7310 Select the Maxim MAX7310 (8 bit)
2610 max7312 Select the Maxim MAX7312 (16 bit)
2611 max7313 Select the Maxim MAX7313 (16 bit)
2612 max7315 Select the Maxim MAX7315 (8 bit)
2613 pca6107 Select the TI PCA6107 (8 bit)
2614 tca6408 Select the TI TCA6408 (8 bit)
2615 tca6416 Select the TI TCA6416 (16 bit)
2616 tca6424 Select the TI TCA6424 (24 bit)
2617 tca9539 Select the TI TCA9539 (16 bit)
2618 tca9554 Select the TI TCA9554 (8 bit)
2619 cat9554 Select the Onnn CAT9554 (8 bit)
2620 pca9654 Select the Onnn PCA9654 (8 bit)
2621 xra1202 Select the Exar XRA1202 (8 bit)
2624 Name: pcie-32bit-dma
2625 Info: Force PCIe config to support 32bit DMA addresses at the expense of
2626 having to bounce buffers.
2627 Load: dtoverlay=pcie-32bit-dma
2631 [ The pcf2127-rtc overlay has been deleted. See i2c-rtc. ]
2634 [ The pcf8523-rtc overlay has been deleted. See i2c-rtc. ]
2637 [ The pcf8563-rtc overlay has been deleted. See i2c-rtc. ]
2641 Info: This overlay has been renamed act-led, keeping pi3-act-led as an alias
2642 for backwards compatibility.
2646 Name: pi3-disable-bt
2647 Info: This overlay has been renamed disable-bt, keeping pi3-disable-bt as an
2648 alias for backwards compatibility.
2652 Name: pi3-disable-wifi
2653 Info: This overlay has been renamed disable-wifi, keeping pi3-disable-wifi as
2654 an alias for backwards compatibility.
2658 Name: pi3-miniuart-bt
2659 Info: This overlay has been renamed miniuart-bt, keeping pi3-miniuart-bt as
2660 an alias for backwards compatibility.
2665 Info: Configures the pibell audio card.
2666 Load: dtoverlay=pibell,<param>=<val>
2667 Params: alsaname Set the name as it appears in ALSA (default
2672 Info: Configures the PiFace Digital mcp23s17 GPIO port expander.
2673 Load: dtoverlay=pifacedigital,<param>=<val>
2674 Params: spi-present-mask 8-bit integer, bitmap indicating MCP23S17 SPI0
2675 CS0 address. PiFace Digital supports addresses
2676 0-3, which can be configured with JP1 and JP2.
2680 Info: Configures the PiFi 40W stereo amplifier
2681 Load: dtoverlay=pifi-40
2686 Info: Configures the PiFi DAC HD
2687 Load: dtoverlay=pifi-dac-hd
2692 Info: Configures the PiFi DAC Zero
2693 Load: dtoverlay=pifi-dac-zero
2698 Info: Configures the PiFi Mini stereo amplifier
2699 Load: dtoverlay=pifi-mini-210
2704 Info: Configures the PiGlow by pimoroni.com
2705 Load: dtoverlay=piglow
2710 Info: PiScreen display by OzzMaker.com
2711 Load: dtoverlay=piscreen,<param>=<val>
2712 Params: speed Display SPI bus speed
2714 rotate Display rotation {0,90,180,270}
2716 fps Delay between frame updates
2718 debug Debug output level {0-7}
2720 xohms Touchpanel sensitivity (X-plate resistance)
2724 Info: PiScreen 2 with resistive TP display by OzzMaker.com
2725 Load: dtoverlay=piscreen2r,<param>=<val>
2726 Params: speed Display SPI bus speed
2728 rotate Display rotation {0,90,180,270}
2730 fps Delay between frame updates
2732 debug Debug output level {0-7}
2734 xohms Touchpanel sensitivity (X-plate resistance)
2738 Info: Configures the Blokas Labs pisound card
2739 Load: dtoverlay=pisound
2744 Info: Adafruit PiTFT 2.2" screen
2745 Load: dtoverlay=pitft22,<param>=<val>
2746 Params: speed Display SPI bus speed
2748 rotate Display rotation {0,90,180,270}
2750 fps Delay between frame updates
2752 debug Debug output level {0-7}
2755 Name: pitft28-capacitive
2756 Info: Adafruit PiTFT 2.8" capacitive touch screen
2757 Load: dtoverlay=pitft28-capacitive,<param>=<val>
2758 Params: speed Display SPI bus speed
2760 rotate Display rotation {0,90,180,270}
2762 fps Delay between frame updates
2764 debug Debug output level {0-7}
2766 touch-sizex Touchscreen size x (default 240)
2768 touch-sizey Touchscreen size y (default 320)
2770 touch-invx Touchscreen inverted x axis
2772 touch-invy Touchscreen inverted y axis
2774 touch-swapxy Touchscreen swapped x y axis
2777 Name: pitft28-resistive
2778 Info: Adafruit PiTFT 2.8" resistive touch screen
2779 Load: dtoverlay=pitft28-resistive,<param>=<val>
2780 Params: speed Display SPI bus speed
2782 rotate Display rotation {0,90,180,270}
2784 fps Delay between frame updates
2786 debug Debug output level {0-7}
2788 drm Force the use of the mi0283qt DRM driver (by
2789 default the ili9340 framebuffer driver will
2790 be used in preference if available)
2793 Name: pitft35-resistive
2794 Info: Adafruit PiTFT 3.5" resistive touch screen
2795 Load: dtoverlay=pitft35-resistive,<param>=<val>
2796 Params: speed Display SPI bus speed
2798 rotate Display rotation {0,90,180,270}
2800 fps Delay between frame updates
2802 debug Debug output level {0-7}
2804 drm Force the use of the hx8357d DRM driver (by
2805 default the fb_hx8357d framebuffer driver will
2806 be used in preference if available)
2810 Info: Configures the pps-gpio (pulse-per-second time signal via GPIO).
2811 Load: dtoverlay=pps-gpio,<param>=<val>
2812 Params: gpiopin Input GPIO (default "18")
2813 assert_falling_edge When present, assert is indicated by a falling
2814 edge, rather than by a rising edge (default
2816 capture_clear Generate clear events on the trailing edge
2821 Info: Configures a single PWM channel
2822 Legal pin,function combinations for each channel:
2823 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2824 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
2826 1) Pin 18 is the only one available on all platforms, and
2827 it is the one used by the I2S audio interface.
2828 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
2829 2) The onboard analogue audio output uses both PWM channels.
2830 3) So be careful mixing audio and PWM.
2831 4) Currently the clock must have been enabled and configured
2833 Load: dtoverlay=pwm,<param>=<val>
2834 Params: pin Output pin (default 18) - see table
2835 func Pin function (default 2 = Alt5) - see above
2836 clock PWM clock frequency (informational)
2840 Info: Configures both PWM channels
2841 Legal pin,function combinations for each channel:
2842 PWM0: 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2843 PWM1: 13,4(Alt0) 19,2(Alt5) 41,4(Alt0) 45,4(Alt0) 53,5(Alt1)
2845 1) Pin 18 is the only one available on all platforms, and
2846 it is the one used by the I2S audio interface.
2847 Pins 12 and 13 might be better choices on an A+, B+ or Pi2.
2848 2) The onboard analogue audio output uses both PWM channels.
2849 3) So be careful mixing audio and PWM.
2850 4) Currently the clock must have been enabled and configured
2852 Load: dtoverlay=pwm-2chan,<param>=<val>
2853 Params: pin Output pin (default 18) - see table
2854 pin2 Output pin for other channel (default 19)
2855 func Pin function (default 2 = Alt5) - see above
2856 func2 Function for pin2 (default 2 = Alt5)
2857 clock PWM clock frequency (informational)
2861 Info: Use GPIO pin as pwm-assisted infrared transmitter output.
2862 This is an alternative to "gpio-ir-tx". pwm-ir-tx makes use
2863 of PWM0 to reduce the CPU load during transmission compared to
2864 gpio-ir-tx which uses bit-banging.
2865 Legal pin,function combinations are:
2866 12,4(Alt0) 18,2(Alt5) 40,4(Alt0) 52,5(Alt1)
2867 Load: dtoverlay=pwm-ir-tx,<param>=<val>
2868 Params: gpio_pin Output GPIO (default 18)
2870 func Pin function (default 2 = Alt5)
2874 Info: in-tech's Evaluation Board for PLC Stamp micro
2875 This uses spi0 and a separate GPIO interrupt to connect the QCA7000.
2876 Load: dtoverlay=qca7000,<param>=<val>
2877 Params: int_pin GPIO pin for interrupt signal (default 23)
2879 speed SPI bus speed (default 12 MHz)
2883 Info: in-tech's Evaluation Board for PLC Stamp micro (UART)
2884 This uses uart0/ttyAMA0 over GPIOs 14 & 15 to connect the QCA7000.
2885 But it requires disabling of onboard Bluetooth on
2886 Pi 3B, 3B+, 3A+, 4B and Zero W.
2887 Load: dtoverlay=qca7000-uart0,<param>=<val>
2888 Params: baudrate Set the baudrate for the UART (default
2892 Name: rotary-encoder
2893 Info: Overlay for GPIO connected rotary encoder.
2894 Load: dtoverlay=rotary-encoder,<param>=<val>
2895 Params: pin_a GPIO connected to rotary encoder channel A
2897 pin_b GPIO connected to rotary encoder channel B
2899 relative_axis register a relative axis rather than an
2900 absolute one. Relative axis will only
2901 generate +1/-1 events on the input device,
2902 hence no steps need to be passed.
2903 linux_axis the input subsystem axis to map to this
2904 rotary encoder. Defaults to 0 (ABS_X / REL_X)
2905 rollover Automatic rollover when the rotary value
2906 becomes greater than the specified steps or
2907 smaller than 0. For absolute axis only.
2908 steps-per-period Number of steps (stable states) per period.
2909 The values have the following meaning:
2910 1: Full-period mode (default)
2912 4: Quarter-period mode
2913 steps Number of steps in a full turnaround of the
2914 encoder. Only relevant for absolute axis.
2915 Defaults to 24 which is a typical value for
2917 wakeup Boolean, rotary encoder can wake up the
2919 encoding String, the method used to encode steps.
2920 Supported are "gray" (the default and more
2921 common) and "binary".
2925 Info: Raspberry Pi official display backlight driver
2926 Load: dtoverlay=rpi-backlight
2930 Name: rpi-cirrus-wm5102
2931 Info: Configures the Cirrus Logic Audio Card
2932 Load: dtoverlay=rpi-cirrus-wm5102
2937 Info: Configures the RPi DAC audio card
2938 Load: dtoverlay=rpi-dac
2943 Info: RPi-Display - 2.8" Touch Display by Watterott
2944 Linux has 2 drivers that support this display and this overlay supports
2948 fbtft/fb_ili9341: dtoverlay=rpi-display
2949 drm/mi0283qt: dtoverlay=rpi-display,drm,backlight-pwm,rotate=180
2951 Some notable differences with the DRM driver compared to fbtft:
2952 - The display is turned on when it's first used and not on driver load
2953 as with fbtft. So if nothing uses the display it stays off.
2954 - Can run with a higher SPI clock increasing framerate. This is possible
2955 since the driver avoids messing up the controller configuration due to
2956 transmission errors by running config commands at 10MHz and only pixel
2957 data at full speed (occasional pixel glitch might occur).
2958 - PWM backlight is supported.
2960 Load: dtoverlay=rpi-display,<param>=<val>
2961 Params: speed Display SPI bus speed
2962 rotate Display rotation {0,90,180,270}
2963 fps Delay between frame updates (fbtft only)
2964 debug Debug output level {0-7} (fbtft only)
2965 xohms Touchpanel sensitivity (X-plate resistance)
2966 swapxy Swap x and y axis
2967 backlight Change backlight GPIO pin {e.g. 12, 18}
2969 drm Use DRM/KMS driver mi0283qt instead of fbtft.
2970 Set the SPI clock to 70MHz.
2971 This has to be the first parameter.
2972 backlight-pwm Use pwm for backlight (drm only). NB: Disables
2973 audio headphone output as that also uses PWM.
2977 Info: Official Raspberry Pi display touchscreen
2978 Load: dtoverlay=rpi-ft5406,<param>=<val>
2979 Params: touchscreen-size-x Touchscreen X resolution (default 800)
2980 touchscreen-size-y Touchscreen Y resolution (default 600);
2981 touchscreen-inverted-x Invert touchscreen X coordinates (default 0);
2982 touchscreen-inverted-y Invert touchscreen Y coordinates (default 0);
2983 touchscreen-swapped-x-y Swap X and Y cordinates (default 0);
2987 Info: Raspberry Pi PoE HAT fan
2988 Load: dtoverlay=rpi-poe,<param>[=<val>]
2989 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
2990 turns on (default 40000)
2991 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
2992 the fan turns off (default 2000)
2993 poe_fan_temp1 Temperature (in millicelcius) at which the fan
2994 speeds up (default 45000)
2995 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
2996 the fan slows down (default 2000)
2997 poe_fan_temp2 Temperature (in millicelcius) at which the fan
2998 speeds up (default 50000)
2999 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3000 the fan slows down (default 2000)
3001 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3002 speeds up (default 55000)
3003 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3004 the fan slows down (default 5000)
3005 i2c Control the fan via Linux I2C drivers instead of
3010 Info: Raspberry Pi PoE+ HAT fan
3011 Load: dtoverlay=rpi-poe-plus,<param>[=<val>]
3012 Params: poe_fan_temp0 Temperature (in millicelcius) at which the fan
3013 turns on (default 40000)
3014 poe_fan_temp0_hyst Temperature delta (in millicelcius) at which
3015 the fan turns off (default 2000)
3016 poe_fan_temp1 Temperature (in millicelcius) at which the fan
3017 speeds up (default 45000)
3018 poe_fan_temp1_hyst Temperature delta (in millicelcius) at which
3019 the fan slows down (default 2000)
3020 poe_fan_temp2 Temperature (in millicelcius) at which the fan
3021 speeds up (default 50000)
3022 poe_fan_temp2_hyst Temperature delta (in millicelcius) at which
3023 the fan slows down (default 2000)
3024 poe_fan_temp3 Temperature (in millicelcius) at which the fan
3025 speeds up (default 55000)
3026 poe_fan_temp3_hyst Temperature delta (in millicelcius) at which
3027 the fan slows down (default 5000)
3028 i2c Control the fan via Linux I2C drivers instead of
3033 Info: Configures the RPi Proto audio card
3034 Load: dtoverlay=rpi-proto
3039 Info: Raspberry Pi Sense HAT
3040 Load: dtoverlay=rpi-sense
3045 Info: Raspberry Pi TV HAT
3046 Load: dtoverlay=rpi-tv
3051 Info: Load the V4L2 stateless video decoder driver for the HEVC block,
3052 disabling the memory mapped devices in the process.
3053 Load: dtoverlay=rpivid-v4l2
3057 Name: rra-digidac1-wm8741-audio
3058 Info: Configures the Red Rocks Audio DigiDAC1 soundcard
3059 Load: dtoverlay=rra-digidac1-wm8741-audio
3064 Info: Overlay for the SPI-connected Sainsmart 1.8" display (based on the
3066 Load: dtoverlay=sainsmart18,<param>=<val>
3067 Params: rotate Display rotation {0,90,180,270}
3068 speed SPI bus speed in Hz (default 4000000)
3069 fps Display frame rate in Hz
3070 bgr Enable BGR mode (default off)
3071 debug Debug output level {0-7}
3072 dc_pin GPIO pin for D/C (default 24)
3073 reset_pin GPIO pin for RESET (default 25)
3077 Info: Overlay for the NXP SC16IS750 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=sc16is750-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)
3087 Info: Overlay for the NXP SC16IS752 dual UART with I2C Interface
3088 Enables the chip on I2C1 at 0x48 (or the "addr" parameter value). To
3089 select another address, please refer to table 10 in reference manual.
3090 Load: dtoverlay=sc16is752-i2c,<param>=<val>
3091 Params: int_pin GPIO used for IRQ (default 24)
3092 addr Address (default 0x48)
3093 xtal On-board crystal frequency (default 14745600)
3096 Name: sc16is752-spi0
3097 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3098 Enables the chip on SPI0.
3099 Load: dtoverlay=sc16is752-spi0,<param>=<val>
3100 Params: int_pin GPIO used for IRQ (default 24)
3101 xtal On-board crystal frequency (default 14745600)
3104 Name: sc16is752-spi1
3105 Info: Overlay for the NXP SC16IS752 Dual UART with SPI Interface
3106 Enables the chip on SPI1.
3107 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3108 A+, B+, Zero and PI2 B; as well as the Compute Module.
3110 Load: dtoverlay=sc16is752-spi1,<param>=<val>
3111 Params: int_pin GPIO used for IRQ (default 24)
3112 xtal On-board crystal frequency (default 14745600)
3116 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock.
3117 N.B. This overlay is designed for situations where the mmc driver is
3118 the default, so it disables the other (mmc) interface - this will kill
3119 WLAN on a Pi3. If this isn't what you want, either use the sdtweak
3120 overlay or the new sd_* dtparams of the base DTBs.
3121 Load: dtoverlay=sdhost,<param>=<val>
3122 Params: overclock_50 Clock (in MHz) to use when the MMC framework
3125 force_pio Disable DMA support (default off)
3127 pio_limit Number of blocks above which to use DMA
3130 debug Enable debug output (default off)
3134 Info: Selects the bcm2835-sdhost SD/MMC driver, optionally with overclock,
3135 and enables SDIO via GPIOs 22-27. An example of use in 1-bit mode is
3136 "dtoverlay=sdio,bus_width=1,gpios_22_25"
3137 Load: dtoverlay=sdio,<param>=<val>
3138 Params: sdio_overclock SDIO Clock (in MHz) to use when the MMC
3139 framework requests 50MHz
3141 poll_once Disable SDIO-device polling every second
3142 (default on: polling once at boot-time)
3144 bus_width Set the SDIO host bus width (default 4 bits)
3146 gpios_22_25 Select GPIOs 22-25 for 1-bit mode. Must be used
3147 with bus_width=1. This replaces the sdio-1bit
3148 overlay, which is now deprecated.
3150 gpios_34_37 Select GPIOs 34-37 for 1-bit mode. Must be used
3153 gpios_34_39 Select GPIOs 34-39 for 4-bit mode. Must be used
3154 with bus_width=4 (the default).
3158 Info: This overlay is now deprecated. Use
3159 "dtoverlay=sdio,bus_width=1,gpios_22_25" instead.
3164 Info: This overlay is now deprecated. Use the sd_* dtparams in the
3165 base DTB, e.g. "dtoverlay=sdtweak,poll_once" becomes
3166 "dtparam=sd_poll_once".
3170 Name: seeed-can-fd-hat-v1
3171 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3172 channels without RTC. Use this overlay if your HAT has no
3174 https://www.seeedstudio.com/2-Channel-CAN-BUS-FD-Shield-for-Raspberry-Pi-p-4072.html
3175 Load: dtoverlay=seeed-can-fd-hat-v1
3179 Name: seeed-can-fd-hat-v2
3180 Info: Overlay for Seeed Studio CAN BUS FD HAT with two CAN FD
3181 channels and an RTC. Use this overlay if your HAT has a
3183 https://www.seeedstudio.com/CAN-BUS-FD-HAT-for-Raspberry-Pi-p-4742.html
3184 Load: dtoverlay=seeed-can-fd-hat-v2
3189 Info: Overlay for SH1106 OLED via SPI using fbtft staging driver.
3190 Load: dtoverlay=sh1106-spi,<param>=<val>
3191 Params: speed SPI bus speed (default 4000000)
3192 rotate Display rotation (0, 90, 180 or 270; default 0)
3193 fps Delay between frame updates (default 25)
3194 debug Debug output level (0-7; default 0)
3195 dc_pin GPIO pin for D/C (default 24)
3196 reset_pin GPIO pin for RESET (default 25)
3197 height Display height (32 or 64; default 64)
3201 Info: Overlay for Si446x UHF Transceiver via SPI using si446x driver.
3202 The driver is currently out-of-tree at
3203 https://github.com/sunipkmukherjee/silabs.git
3204 Load: dtoverlay=si446x-spi0,<param>=<val>
3205 Params: speed SPI bus speed (default 4000000)
3206 int_pin GPIO pin for interrupts (default 17)
3207 reset_pin GPIO pin for RESET (default 27)
3211 Info: Enables the Secondary Memory Interface peripheral. Uses GPIOs 2-25!
3217 Info: Enables the userspace interface for the SMI driver
3218 Load: dtoverlay=smi-dev
3223 Info: Enables access to NAND flash via the SMI interface
3224 Load: dtoverlay=smi-nand
3229 Info: Move SPI function block to GPIO 35 to 39
3230 Load: dtoverlay=spi-gpio35-39
3235 Info: Move SPI function block to GPIOs 40 to 45
3236 Load: dtoverlay=spi-gpio40-45
3241 Info: Adds support for a number of SPI Real Time Clock devices
3242 Load: dtoverlay=spi-rtc,<param>=<val>
3243 Params: ds3232 Select the DS3232 device
3244 ds3234 Select the DS3234 device
3245 pcf2123 Select the PCF2123 device
3247 spi0_0 Use spi0.0 (default)
3253 cs_high This device requires an active-high CS
3257 Info: Don't claim any CS pins for SPI0. Requires a device with its chip
3258 select permanently enabled, but frees a GPIO for e.g. a DPI display.
3259 Load: dtoverlay=spi0-0cs,<param>=<val>
3260 Params: no_miso Don't claim and use the MISO pin (9), freeing
3265 Info: Only use one CS pin for SPI0
3266 Load: dtoverlay=spi0-1cs,<param>=<val>
3267 Params: cs0_pin GPIO pin for CS0 (default 8)
3268 no_miso Don't claim and use the MISO pin (9), freeing
3273 Info: Change the CS pins for SPI0
3274 Load: dtoverlay=spi0-2cs,<param>=<val>
3275 Params: cs0_pin GPIO pin for CS0 (default 8)
3276 cs1_pin GPIO pin for CS1 (default 7)
3277 no_miso Don't claim and use the MISO pin (9), freeing
3282 Info: This overlay has been renamed spi0-2cs, keeping spi0-cs as an
3283 alias for backwards compatibility.
3288 Info: This overlay has been deprecated and removed because it is no longer
3289 necessary and has been seen to prevent spi0 from working.
3294 Info: Enables spi1 with a single chip select (CS) line and associated spidev
3295 dev node. The gpio pin number for the CS line and spidev device node
3296 creation are configurable.
3297 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3298 A+, B+, Zero and PI2 B; as well as the Compute Module.
3299 Load: dtoverlay=spi1-1cs,<param>=<val>
3300 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3301 cs0_spidev Set to 'disabled' to stop the creation of a
3302 userspace device node /dev/spidev1.0 (default
3303 is 'okay' or enabled).
3307 Info: Enables spi1 with two chip select (CS) lines and associated spidev
3308 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3309 creation are configurable.
3310 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3311 A+, B+, Zero and PI2 B; as well as the Compute Module.
3312 Load: dtoverlay=spi1-2cs,<param>=<val>
3313 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3314 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3315 cs0_spidev Set to 'disabled' to stop the creation of a
3316 userspace device node /dev/spidev1.0 (default
3317 is 'okay' or enabled).
3318 cs1_spidev Set to 'disabled' to stop the creation of a
3319 userspace device node /dev/spidev1.1 (default
3320 is 'okay' or enabled).
3324 Info: Enables spi1 with three chip select (CS) lines and associated spidev
3325 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3326 creation are configurable.
3327 N.B.: spi1 is only accessible on devices with a 40pin header, eg:
3328 A+, B+, Zero and PI2 B; as well as the Compute Module.
3329 Load: dtoverlay=spi1-3cs,<param>=<val>
3330 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI1_CE0).
3331 cs1_pin GPIO pin for CS1 (default 17 - BCM SPI1_CE1).
3332 cs2_pin GPIO pin for CS2 (default 16 - BCM SPI1_CE2).
3333 cs0_spidev Set to 'disabled' to stop the creation of a
3334 userspace device node /dev/spidev1.0 (default
3335 is 'okay' or enabled).
3336 cs1_spidev Set to 'disabled' to stop the creation of a
3337 userspace device node /dev/spidev1.1 (default
3338 is 'okay' or enabled).
3339 cs2_spidev Set to 'disabled' to stop the creation of a
3340 userspace device node /dev/spidev1.2 (default
3341 is 'okay' or enabled).
3345 Info: Enables spi2 with a single chip select (CS) line and associated spidev
3346 dev node. The gpio pin number for the CS line and spidev device node
3347 creation are configurable.
3348 N.B.: spi2 is only accessible with the Compute Module.
3349 Load: dtoverlay=spi2-1cs,<param>=<val>
3350 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3351 cs0_spidev Set to 'disabled' to stop the creation of a
3352 userspace device node /dev/spidev2.0 (default
3353 is 'okay' or enabled).
3357 Info: Enables spi2 with two chip select (CS) lines and associated spidev
3358 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3359 creation are configurable.
3360 N.B.: spi2 is only accessible with the Compute Module.
3361 Load: dtoverlay=spi2-2cs,<param>=<val>
3362 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3363 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3364 cs0_spidev Set to 'disabled' to stop the creation of a
3365 userspace device node /dev/spidev2.0 (default
3366 is 'okay' or enabled).
3367 cs1_spidev Set to 'disabled' to stop the creation of a
3368 userspace device node /dev/spidev2.1 (default
3369 is 'okay' or enabled).
3373 Info: Enables spi2 with three chip select (CS) lines and associated spidev
3374 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3375 creation are configurable.
3376 N.B.: spi2 is only accessible with the Compute Module.
3377 Load: dtoverlay=spi2-3cs,<param>=<val>
3378 Params: cs0_pin GPIO pin for CS0 (default 43 - BCM SPI2_CE0).
3379 cs1_pin GPIO pin for CS1 (default 44 - BCM SPI2_CE1).
3380 cs2_pin GPIO pin for CS2 (default 45 - BCM SPI2_CE2).
3381 cs0_spidev Set to 'disabled' to stop the creation of a
3382 userspace device node /dev/spidev2.0 (default
3383 is 'okay' or enabled).
3384 cs1_spidev Set to 'disabled' to stop the creation of a
3385 userspace device node /dev/spidev2.1 (default
3386 is 'okay' or enabled).
3387 cs2_spidev Set to 'disabled' to stop the creation of a
3388 userspace device node /dev/spidev2.2 (default
3389 is 'okay' or enabled).
3393 Info: Enables spi3 with a single chip select (CS) line and associated spidev
3394 dev node. The gpio pin number for the CS line and spidev device node
3395 creation are configurable. BCM2711 only.
3396 Load: dtoverlay=spi3-1cs,<param>=<val>
3397 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3398 cs0_spidev Set to 'off' to prevent the creation of a
3399 userspace device node /dev/spidev3.0 (default
3400 is 'on' or enabled).
3404 Info: Enables spi3 with two chip select (CS) lines and associated spidev
3405 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3406 creation are configurable. BCM2711 only.
3407 Load: dtoverlay=spi3-2cs,<param>=<val>
3408 Params: cs0_pin GPIO pin for CS0 (default 0 - BCM SPI3_CE0).
3409 cs1_pin GPIO pin for CS1 (default 24 - BCM SPI3_CE1).
3410 cs0_spidev Set to 'off' to prevent the creation of a
3411 userspace device node /dev/spidev3.0 (default
3412 is 'on' or enabled).
3413 cs1_spidev Set to 'off' to prevent the creation of a
3414 userspace device node /dev/spidev3.1 (default
3415 is 'on' or enabled).
3419 Info: Enables spi4 with a single chip select (CS) line and associated spidev
3420 dev node. The gpio pin number for the CS line and spidev device node
3421 creation are configurable. BCM2711 only.
3422 Load: dtoverlay=spi4-1cs,<param>=<val>
3423 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3424 cs0_spidev Set to 'off' to prevent the creation of a
3425 userspace device node /dev/spidev4.0 (default
3426 is 'on' or enabled).
3430 Info: Enables spi4 with two chip select (CS) lines and associated spidev
3431 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3432 creation are configurable. BCM2711 only.
3433 Load: dtoverlay=spi4-2cs,<param>=<val>
3434 Params: cs0_pin GPIO pin for CS0 (default 4 - BCM SPI4_CE0).
3435 cs1_pin GPIO pin for CS1 (default 25 - BCM SPI4_CE1).
3436 cs0_spidev Set to 'off' to prevent the creation of a
3437 userspace device node /dev/spidev4.0 (default
3438 is 'on' or enabled).
3439 cs1_spidev Set to 'off' to prevent the creation of a
3440 userspace device node /dev/spidev4.1 (default
3441 is 'on' or enabled).
3445 Info: Enables spi5 with a single chip select (CS) line and associated spidev
3446 dev node. The gpio pin numbers for the CS lines and spidev device node
3447 creation are configurable. BCM2711 only.
3448 Load: dtoverlay=spi5-1cs,<param>=<val>
3449 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3450 cs0_spidev Set to 'off' to prevent the creation of a
3451 userspace device node /dev/spidev5.0 (default
3452 is 'on' or enabled).
3456 Info: Enables spi5 with two chip select (CS) lines and associated spidev
3457 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3458 creation are configurable. BCM2711 only.
3459 Load: dtoverlay=spi5-2cs,<param>=<val>
3460 Params: cs0_pin GPIO pin for CS0 (default 12 - BCM SPI5_CE0).
3461 cs1_pin GPIO pin for CS1 (default 26 - BCM SPI5_CE1).
3462 cs0_spidev Set to 'off' to prevent the creation of a
3463 userspace device node /dev/spidev5.0 (default
3464 is 'on' or enabled).
3465 cs1_spidev Set to 'off' to prevent the creation of a
3466 userspace device node /dev/spidev5.1 (default
3467 is 'on' or enabled).
3471 Info: Enables spi6 with a single chip select (CS) line and associated spidev
3472 dev node. The gpio pin number for the CS line and spidev device node
3473 creation are configurable. BCM2711 only.
3474 Load: dtoverlay=spi6-1cs,<param>=<val>
3475 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3476 cs0_spidev Set to 'off' to prevent the creation of a
3477 userspace device node /dev/spidev6.0 (default
3478 is 'on' or enabled).
3482 Info: Enables spi6 with two chip select (CS) lines and associated spidev
3483 dev nodes. The gpio pin numbers for the CS lines and spidev device node
3484 creation are configurable. BCM2711 only.
3485 Load: dtoverlay=spi6-2cs,<param>=<val>
3486 Params: cs0_pin GPIO pin for CS0 (default 18 - BCM SPI6_CE0).
3487 cs1_pin GPIO pin for CS1 (default 27 - BCM SPI6_CE1).
3488 cs0_spidev Set to 'off' to prevent the creation of a
3489 userspace device node /dev/spidev6.0 (default
3490 is 'on' or enabled).
3491 cs1_spidev Set to 'off' to prevent the creation of a
3492 userspace device node /dev/spidev6.1 (default
3493 is 'on' or enabled).
3497 Info: Overlay for activation of SSD1306 over I2C OLED display framebuffer.
3498 Load: dtoverlay=ssd1306,<param>=<val>
3499 Params: address Location in display memory of first character.
3501 width Width of display. (default=128)
3502 height Height of display. (default=64)
3503 offset virtual channel a. (default=0)
3504 normal Has no effect on displays tested. (default=not
3506 sequential Set this if every other scan line is missing.
3508 remapped Set this if display is garbled. (default=not
3510 inverted Set this if display is inverted and mirrored.
3514 Typical usage for 128x64 display: dtoverlay=ssd1306,inverted
3516 Typical usage for 128x32 display: dtoverlay=ssd1306,inverted,sequential
3518 i2c_baudrate=400000 will speed up the display.
3520 i2c_baudrate=1000000 seems to work even though it's not officially
3521 supported by the hardware, and is faster still.
3523 For more information refer to the device datasheet at:
3524 https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
3528 Info: Overlay for SSD1306 OLED via SPI using fbtft staging driver.
3529 Load: dtoverlay=ssd1306-spi,<param>=<val>
3530 Params: speed SPI bus speed (default 10000000)
3531 rotate Display rotation (0, 90, 180 or 270; default 0)
3532 fps Delay between frame updates (default 25)
3533 debug Debug output level (0-7; default 0)
3534 dc_pin GPIO pin for D/C (default 24)
3535 reset_pin GPIO pin for RESET (default 25)
3536 height Display height (32 or 64; default 64)
3540 Info: Overlay for SSD1331 OLED via SPI using fbtft staging driver.
3541 Load: dtoverlay=ssd1331-spi,<param>=<val>
3542 Params: speed SPI bus speed (default 4500000)
3543 rotate Display rotation (0, 90, 180 or 270; default 0)
3544 fps Delay between frame updates (default 25)
3545 debug Debug output level (0-7; default 0)
3546 dc_pin GPIO pin for D/C (default 24)
3547 reset_pin GPIO pin for RESET (default 25)
3551 Info: Overlay for SSD1351 OLED via SPI using fbtft staging driver.
3552 Load: dtoverlay=ssd1351-spi,<param>=<val>
3553 Params: speed SPI bus speed (default 4500000)
3554 rotate Display rotation (0, 90, 180 or 270; default 0)
3555 fps Delay between frame updates (default 25)
3556 debug Debug output level (0-7; default 0)
3557 dc_pin GPIO pin for D/C (default 24)
3558 reset_pin GPIO pin for RESET (default 25)
3561 Name: superaudioboard
3562 Info: Configures the SuperAudioBoard sound card
3563 Load: dtoverlay=superaudioboard,<param>=<val>
3564 Params: gpiopin GPIO pin for codec reset
3568 Info: Configures the Semtech SX150X I2C GPIO expanders.
3569 Load: dtoverlay=sx150x,<param>=<val>
3570 Params: sx150<x>-<n>-<m> Enables SX150X device on I2C#<n> with slave
3571 address <m>. <x> may be 1-9. <n> may be 0 or 1.
3572 Permissible values of <m> (which is denoted in
3573 hex) depend on the device variant. For SX1501,
3574 SX1502, SX1504 and SX1505, <m> may be 20 or 21.
3575 For SX1503 and SX1506, <m> may be 20. For
3576 SX1507 and SX1509, <m> may be 3E, 3F, 70 or 71.
3577 For SX1508, <m> may be 20, 21, 22 or 23.
3579 sx150<x>-<n>-<m>-int-gpio
3580 Integer, enables interrupts on SX150X device on
3581 I2C#<n> with slave address <m>, specifies
3582 the GPIO pin to which NINT output of SX150X is
3587 Info: Toshiba TC358743 HDMI to CSI-2 bridge chip.
3588 Uses Unicam 1, which is the standard camera connector on most Pi
3590 Load: dtoverlay=tc358743,<param>=<val>
3591 Params: 4lane Use 4 lanes (only applicable to Compute Modules
3594 link-frequency Set the link frequency. Only values of 297000000
3595 (574Mbit/s) and 486000000 (972Mbit/s - default)
3596 are supported by the driver.
3597 media-controller Configure use of Media Controller API for
3598 configuring the sensor (default off)
3599 cam0 Adopt the default configuration for CAM0 on a
3600 Compute Module (CSI0, i2c_vc, and cam0_reg).
3603 Name: tc358743-audio
3604 Info: Used in combination with the tc358743-fast overlay to route the audio
3605 from the TC358743 over I2S to the Pi.
3606 Wiring is LRCK/WFS to GPIO 19, BCK/SCK to GPIO 18, and DATA/SD to GPIO
3608 Load: dtoverlay=tc358743-audio,<param>=<val>
3609 Params: card-name Override the default, "tc358743", card name.
3613 Info: 3.5" Color TFT Display by www.tinylcd.com
3614 Options: Touch, RTC, keypad
3615 Load: dtoverlay=tinylcd35,<param>=<val>
3616 Params: speed Display SPI bus speed
3618 rotate Display rotation {0,90,180,270}
3620 fps Delay between frame updates
3622 debug Debug output level {0-7}
3624 touch Enable touch panel
3626 touchgpio Touch controller IRQ GPIO
3628 xohms Touchpanel: Resistance of X-plate in ohms
3630 rtc-pcf PCF8563 Real Time Clock
3632 rtc-ds DS1307 Real Time Clock
3634 keypad Enable keypad
3637 Display with touchpanel, PCF8563 RTC and keypad:
3638 dtoverlay=tinylcd35,touch,rtc-pcf,keypad
3640 dtoverlay=tinylcd35,touch,touchgpio=3
3644 Info: Enables support for Infineon SLB9670 Trusted Platform Module add-on
3645 boards, which can be used as a secure key storage and hwrng,
3646 available as "Iridium SLB9670" by Infineon and "LetsTrust TPM" by pi3g.
3647 Load: dtoverlay=tpm-slb9670
3652 Info: Change the pin usage of uart0
3653 Load: dtoverlay=uart0,<param>=<val>
3654 Params: txd0_pin GPIO pin for TXD0 (14, 32 or 36 - default 14)
3656 rxd0_pin GPIO pin for RXD0 (15, 33 or 37 - default 15)
3658 pin_func Alternative pin function - 4(Alt0) for 14&15,
3659 7(Alt3) for 32&33, 6(Alt2) for 36&37
3663 Info: Change the pin usage of uart1
3664 Load: dtoverlay=uart1,<param>=<val>
3665 Params: txd1_pin GPIO pin for TXD1 (14, 32 or 40 - default 14)
3667 rxd1_pin GPIO pin for RXD1 (15, 33 or 41 - default 15)
3671 Info: Enable uart 2 on GPIOs 0-3. BCM2711 only.
3672 Load: dtoverlay=uart2,<param>
3673 Params: ctsrts Enable CTS/RTS on GPIOs 2-3 (default off)
3677 Info: Enable uart 3 on GPIOs 4-7. BCM2711 only.
3678 Load: dtoverlay=uart3,<param>
3679 Params: ctsrts Enable CTS/RTS on GPIOs 6-7 (default off)
3683 Info: Enable uart 4 on GPIOs 8-11. BCM2711 only.
3684 Load: dtoverlay=uart4,<param>
3685 Params: ctsrts Enable CTS/RTS on GPIOs 10-11 (default off)
3689 Info: Enable uart 5 on GPIOs 12-15. BCM2711 only.
3690 Load: dtoverlay=uart5,<param>
3691 Params: ctsrts Enable CTS/RTS on GPIOs 14-15 (default off)
3695 Info: Configures the NW Digital Radio UDRC Hat
3696 Load: dtoverlay=udrc,<param>=<val>
3697 Params: alsaname Name of the ALSA audio device (default "udrc")
3700 Name: ugreen-dabboard
3701 Info: Configures the ugreen-dabboard I2S overlay
3702 This is a simple overlay based on the simple-audio-card and the dmic
3703 codec. It has the speciality that it is configured to use the codec
3704 as a master I2S device. It works for example with the Si468x DAB
3705 receiver on the uGreen DABBoard.
3706 Load: dtoverlay=ugreen-dabboard,<param>=<val>
3707 Params: card-name Override the default, "dabboard", card name.
3711 Info: Allow usage of downstream .dtb with upstream kernel. Comprises the
3712 vc4-kms-v3d and dwc2 overlays.
3713 Load: dtoverlay=upstream
3717 Name: upstream-aux-interrupt
3718 Info: This overlay has been deprecated and removed because it is no longer
3724 Info: Allow usage of downstream .dtb with upstream kernel on Pi 4. Comprises
3725 the vc4-kms-v3d-pi4 and dwc2 overlays.
3726 Load: dtoverlay=upstream-pi4
3731 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
3733 Load: dtoverlay=vc4-fkms-v3d,<param>
3734 Params: cma-512 CMA is 512MB (needs 1GB)
3735 cma-448 CMA is 448MB (needs 1GB)
3736 cma-384 CMA is 384MB (needs 1GB)
3737 cma-320 CMA is 320MB (needs 1GB)
3738 cma-256 CMA is 256MB (needs 1GB)
3739 cma-192 CMA is 192MB (needs 1GB)
3740 cma-128 CMA is 128MB
3743 cma-size CMA size in bytes, 4MB aligned
3744 cma-default Use upstream's default value
3747 Name: vc4-fkms-v3d-pi4
3748 Info: Enable Eric Anholt's DRM VC4 V3D driver on top of the dispmanx
3750 Load: dtoverlay=vc4-fkms-v3d-pi4,<param>
3751 Params: cma-512 CMA is 512MB (needs 1GB)
3752 cma-448 CMA is 448MB (needs 1GB)
3753 cma-384 CMA is 384MB (needs 1GB)
3754 cma-320 CMA is 320MB (needs 1GB)
3755 cma-256 CMA is 256MB (needs 1GB)
3756 cma-192 CMA is 192MB (needs 1GB)
3757 cma-128 CMA is 128MB
3760 cma-size CMA size in bytes, 4MB aligned
3761 cma-default Use upstream's default value
3764 Name: vc4-kms-dpi-at056tn53v1
3765 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,at056tn53v1
3769 Name: vc4-kms-dpi-generic
3770 Info: Enable a generic DPI display under KMS. Default timings are for the
3771 Adafruit Kippah with 800x480 panel and RGB666 (GPIOs 0-21)
3772 Requires vc4-kms-v3d to be loaded.
3773 Load: dtoverlay=vc4-kms-dpi-generic,<param>=<val>
3774 Params: clock-frequency Display clock frequency (Hz)
3775 hactive Horizontal active pixels
3776 hfp Horizontal front porch
3777 hsync Horizontal sync pulse width
3778 hbp Horizontal back porch
3779 vactive Vertical active lines
3780 vfp Vertical front porch
3781 vsync Vertical sync pulse width
3782 vbp Vertical back porch
3783 hsync-invert Horizontal sync active low
3784 vsync-invert Vertical sync active low
3785 de-invert Data Enable active low
3786 pixclk-invert Negative edge pixel clock
3787 width-mm Define the screen width in mm
3788 height-mm Define the screen height in mm
3789 rgb565 Change to RGB565 output on GPIOs 0-19
3790 rgb565-padhi Change to RGB565 output on GPIOs 0-8, 12-17, and
3792 bgr666 Change to BGR666 output on GPIOs 0-21.
3793 bgr666-padhi Change to BGR666 output on GPIOs 0-9, 12-17, and
3795 rgb666-padhi Change to RGB666 output on GPIOs 0-9, 12-17, and
3797 bgr888 Change to BGR888 output on GPIOs 0-27
3798 rgb888 Change to RGB888 output on GPIOs 0-27
3799 bus-format Override the bus format for a MEDIA_BUS_FMT_*
3800 value. NB also overridden by rgbXXX overrides.
3801 backlight-gpio Defines a GPIO to be used for backlight control
3803 backlight-pwm Defines a PWM channel to be used for backlight
3804 control (default of none). NB Disables audio
3805 headphone output as that also uses PWM.
3806 backlight-pwm-chan Choose channel on &pwm node for backlight
3809 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
3810 pwm-2chan for valid options.
3811 (default 18 - note this can only work with
3813 backlight-pwm-func Pin function of GPIO used for the PWM
3815 See pwm-2chan for valid options.
3817 backlight-def-brightness
3818 Set the default brightness. Normal range 1-16.
3820 rotate Display rotation {0,90,180,270} (default 0)
3823 Name: vc4-kms-dpi-hyperpixel2r
3824 Info: Enable the KMS drivers for the Pimoroni HyperPixel2 Round DPI display.
3825 Requires vc4-kms-v3d to be loaded.
3826 Load: dtoverlay=vc4-kms-dpi-hyperpixel2r,<param>=<val>
3827 Params: disable-touch Disables the touch controller
3828 touchscreen-inverted-x Inverts X direction of touch controller
3829 touchscreen-inverted-y Inverts Y direction of touch controller
3830 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
3831 rotate Display rotation {0,90,180,270} (default 0)
3834 Name: vc4-kms-dpi-hyperpixel4
3835 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 DPI display.
3836 Requires vc4-kms-v3d to be loaded.
3837 Load: dtoverlay=vc4-kms-dpi-hyperpixel4,<param>=<val>
3838 Params: disable-touch Disables the touch controller
3839 touchscreen-inverted-x Inverts X direction of touch controller
3840 touchscreen-inverted-y Inverts Y direction of touch controller
3841 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
3842 rotate Display rotation {0,90,180,270} (default 0)
3845 Name: vc4-kms-dpi-hyperpixel4sq
3846 Info: Enable the KMS drivers for the Pimoroni HyperPixel4 Square DPI display.
3847 Requires vc4-kms-v3d to be loaded.
3848 Load: dtoverlay=vc4-kms-dpi-hyperpixel4sq,<param>=<val>
3849 Params: disable-touch Disables the touch controller
3850 touchscreen-inverted-x Inverts X direction of touch controller
3851 touchscreen-inverted-y Inverts Y direction of touch controller
3852 touchscreen-swapped-x-y Swaps X & Y axes of touch controller
3853 rotate Display rotation {0,90,180,270} (default 0)
3856 Name: vc4-kms-dpi-panel
3857 Info: Enable a preconfigured KMS DPI panel.
3858 Requires vc4-kms-v3d to be loaded.
3859 Load: dtoverlay=vc4-kms-dpi-panel,<param>=<val>
3860 Params: at056tn53v1 Enable an Innolux 5.6in VGA TFT
3861 kippah-7inch Enable an Adafruit Kippah with 7inch panel.
3862 mzp280 Enable a Geekworm MZP280 panel.
3863 backlight-gpio Defines a GPIO to be used for backlight control
3865 backlight-pwm Defines a PWM channel to be used for backlight
3866 control (default of none). NB Disables audio
3867 headphone output as that also uses PWM.
3868 backlight-pwm-chan Choose channel on &pwm node for backlight
3871 backlight-pwm-gpio GPIO pin to be used for the PWM backlight. See
3872 pwm-2chan for valid options.
3873 (default 18 - note this can only work with
3875 backlight-pwm-func Pin function of GPIO used for the PWM
3877 See pwm-2chan for valid options.
3879 backlight-def-brightness
3880 Set the default brightness. Normal range 1-16.
3882 rotate Display rotation {0,90,180,270} (default 0)
3885 Name: vc4-kms-dsi-7inch
3886 Info: Enable the Raspberry Pi DSI 7" screen.
3887 Includes the edt-ft5406 for the touchscreen element.
3888 Requires vc4-kms-v3d to be loaded.
3889 Load: dtoverlay=vc4-kms-dsi-7inch,<param>=<val>
3890 Params: sizex Touchscreen size x (default 800)
3891 sizey Touchscreen size y (default 480)
3892 invx Touchscreen inverted x axis
3893 invy Touchscreen inverted y axis
3894 swapxy Touchscreen swapped x y axis
3895 disable_touch Disables the touch screen overlay driver
3898 Name: vc4-kms-dsi-lt070me05000
3899 Info: Enable a JDI LT070ME05000 DSI display on DSI1.
3900 Note that this is a 4 lane DSI device, so it will only work on a Compute
3902 Requires vc4-kms-v3d to be loaded.
3903 Load: dtoverlay=vc4-kms-dsi-lt070me05000,<param>
3904 Params: reset GPIO for the reset signal (default 17)
3905 enable GPIO for the enable signal (default 4)
3906 dcdc-en GPIO for the DC-DC converter enable (default 5)
3909 Name: vc4-kms-dsi-lt070me05000-v2
3910 Info: Enable a JDI LT070ME05000 DSI display on DSI1 using Harlab's V2
3912 Note that this is a 4 lane DSI device, so it will only work on a Compute
3914 Requires vc4-kms-v3d to be loaded.
3915 Load: dtoverlay=vc4-kms-dsi-lt070me05000-v2
3919 Name: vc4-kms-kippah-7inch
3920 Info: This overlay is now deprecated - see vc4-kms-dpi-panel,kippah-7inch
3925 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver.
3926 Load: dtoverlay=vc4-kms-v3d,<param>
3927 Params: cma-512 CMA is 512MB (needs 1GB)
3928 cma-448 CMA is 448MB (needs 1GB)
3929 cma-384 CMA is 384MB (needs 1GB)
3930 cma-320 CMA is 320MB (needs 1GB)
3931 cma-256 CMA is 256MB (needs 1GB)
3932 cma-192 CMA is 192MB (needs 1GB)
3933 cma-128 CMA is 128MB
3936 cma-size CMA size in bytes, 4MB aligned
3937 cma-default Use upstream's default value
3938 audio Enable or disable audio over HDMI (default "on")
3939 noaudio Disable all HDMI audio (default "off")
3940 composite Enable the composite output (default "off")
3941 N.B. Disables all other outputs on a Pi 4.
3944 Name: vc4-kms-v3d-pi4
3945 Info: Enable Eric Anholt's DRM VC4 HDMI/HVS/V3D driver for Pi4.
3946 Load: dtoverlay=vc4-kms-v3d-pi4,<param>
3947 Params: cma-512 CMA is 512MB
3948 cma-448 CMA is 448MB
3949 cma-384 CMA is 384MB
3950 cma-320 CMA is 320MB
3951 cma-256 CMA is 256MB
3952 cma-192 CMA is 192MB
3953 cma-128 CMA is 128MB
3956 cma-size CMA size in bytes, 4MB aligned
3957 cma-default Use upstream's default value
3958 audio Enable or disable audio over HDMI0 (default
3960 audio1 Enable or disable audio over HDMI1 (default
3962 noaudio Disable all HDMI audio (default "off")
3963 composite Enable the composite output (disables all other
3967 Name: vc4-kms-vga666
3968 Info: Enable the VGA666 (resistor ladder ADC) for the vc4-kms-v3d driver.
3969 Requires vc4-kms-v3d to be loaded.
3970 Load: dtoverlay=vc4-kms-vga666,<param>
3971 Params: ddc Enables GPIOs 0&1 as the I2C to read the EDID
3972 from the display. NB These are NOT 5V tolerant
3973 GPIOs, therefore level shifters are required.
3977 Info: Overlay for the Fen Logic VGA666 board
3978 This uses GPIOs 2-21 (so no I2C), and activates the output 2-3 seconds
3979 after the kernel has started.
3980 NOT for use with vc4-kms-v3d.
3981 Load: dtoverlay=vga666
3986 Info: Overlay to enable a VIA VL805 USB3 controller on CM4 carriers
3987 Will be loaded automatically by up-to-date firmware if "VL805=1" is
3988 set in the EEPROM config.
3989 Load: dtoverlay=vl805
3994 Info: Configures the w1-gpio Onewire interface module.
3995 Use this overlay if you *don't* need a GPIO to drive an external pullup.
3996 Load: dtoverlay=w1-gpio,<param>=<val>
3997 Params: gpiopin GPIO for I/O (default "4")
3998 pullup Now enabled by default (ignored)
4001 Name: w1-gpio-pullup
4002 Info: Configures the w1-gpio Onewire interface module.
4003 Use this overlay if you *do* need a GPIO to drive an external pullup.
4004 Load: dtoverlay=w1-gpio-pullup,<param>=<val>
4005 Params: gpiopin GPIO for I/O (default "4")
4006 extpullup GPIO for external pullup (default "5")
4007 pullup Now enabled by default (ignored)
4011 Info: Overlay for the Wiznet W5500 Ethernet Controller on SPI0
4012 Load: dtoverlay=w5500,<param>=<val>
4013 Params: int_pin GPIO used for INT (default 25)
4015 speed SPI bus speed (default 30000000)
4017 cs SPI bus Chip Select (default 0)
4020 Name: waveshare-can-fd-hat-mode-a
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 A (Default), with can0 on spi0.0
4025 https://www.waveshare.com/2-ch-can-fd-hat.htm
4026 Load: dtoverlay=waveshare-can-fd-hat-mode-a
4030 Name: waveshare-can-fd-hat-mode-b
4031 Info: Overlay for the Waveshare 2-Channel Isolated CAN FD Expansion HAT
4032 for Raspberry Pi, Multi Protections. Use this overlay when the
4033 HAT is configured in Mode B (requires hardware modification), with
4034 can0 on spi0.0 and can1 on spi0.1.
4035 https://www.waveshare.com/2-ch-can-fd-hat.htm
4036 Load: dtoverlay=waveshare-can-fd-hat-mode-b
4041 Info: Configures the wittypi RTC module.
4042 Load: dtoverlay=wittypi,<param>=<val>
4043 Params: led_gpio GPIO for LED (default "17")
4044 led_trigger Choose which activity the LED tracks (default
4048 Name: wm8960-soundcard
4049 Info: Overlay for the Waveshare wm8960 soundcard
4050 Load: dtoverlay=wm8960-soundcard,<param>=<val>
4051 Params: alsaname Changes the card name in ALSA
4052 compatible Changes the codec compatibility
4058 If you are experiencing problems that you think are DT-related, enable DT
4059 diagnostic output by adding this to /boot/config.txt:
4063 and rebooting. Then run:
4067 and look for relevant messages.
4072 This is only meant to be a quick introduction to the subject of Device Tree on
4073 Raspberry Pi. There is a more complete explanation here:
4075 http://www.raspberrypi.org/documentation/configuration/device-tree.md