admin-guide/media/cec.rst

1 .. SPDX-License-Identifier: GPL-2.0
12 - Exynos4
13 - Exynos5
14 - STIH4xx HDMI CEC
15 - V4L2 adv7511 (same HW, but a different driver from the drm adv7511)
16 - stm32
17 - Allwinner A10 (sun4i)
18 - Raspberry Pi
19 - dw-hdmi (Synopsis IP)
20 - amlogic (meson ao-cec and ao-cec-g12a)
21 - drm adv7511/adv7533
22 - omap4
23 - tegra
24 - rk3288, rk3399
25 - tda998x
26 - DisplayPort CEC-Tunneling-over-AUX on i915, nouveau and amdgpu
27 - ChromeOS EC CEC
28 - CEC for SECO boards (UDOO x86).
29 - Chrontel CH7322
34 - adv7604/11/12
35 - adv7842
36 - tc358743
41 - Pulse-Eight: the pulse8-cec driver implements the following module option:
46 - RainShadow Tech. Note: this driver does not support the persistent_config
47   module option of the Pulse-Eight driver. The hardware supports it, but I
48   have no plans to add this feature. But I accept patches :-)
50 - Extron DA HD 4K PLUS HDMI Distribution Amplifier. See
55 - vivid: emulates a CEC receiver and CEC transmitter.
58 - cec-gpio. If the CEC pin is hooked up to a GPIO pin then
62 - cec-gpio and Allwinner A10 (or any other driver that uses the CEC pin
64   high-resolution timers. These timers are affected by NTP daemons that
75 Utilities are available here: https://git.linuxtv.org/v4l-utils.git
77 ``utils/cec-ctl``: control a CEC device
79 ``utils/cec-compliance``: test compliance of a remote CEC device
81 ``utils/cec-follower``: emulate a CEC follower device
83 Note that ``cec-ctl`` has support for the CEC Hospitality Profile as is
86 Note that the libcec library (https://github.com/Pulse-Eight/libcec) supports
108 To test: hook up your DP-to-HDMI adapter to a CEC capable device
111 	cec-ctl --playback	# Configure the PC as a CEC Playback device
112 	cec-ctl -S		# Show the CEC topology
114 The ``cec-ctl -S`` command should show at least two CEC devices,
121 USB-C to HDMI
122 -------------
124 Samsung Multiport Adapter EE-PW700: https://www.samsung.com/ie/support/model/EE-PW700BBEGWW/
126 Kramer ADC-U31C/HF: https://www.kramerav.com/product/ADC-U31C/HF
128 Club3D CAC-2504: https://www.club-3d.com/en/detail/2449/usb_3.1_type_c_to_hdmi_2.0_uhd_4k_60hz_acti…
131 -------------------
133 Club3D CAC-1080: https://www.club-3d.com/en/detail/2442/displayport_1.4_to_hdmi_2.0b_hdr/
135 …ion (SKU: CD0712): https://www.cablecreation.com/products/active-displayport-to-hdmi-adapter-4k-hdr
137 …I True 4k Adapter (P/N 2JA63AA): https://www.hp.com/us-en/shop/pdp/hp-displayport-to-hdmi-true-4k-…
139 Mini-DisplayPort to HDMI
140 ------------------------
142 Club3D CAC-1180: https://www.club-3d.com/en/detail/2443/mini_displayport_1.4_to_hdmi_2.0b_hdr/
151 whereas with the PS176 it is more hit-and-miss (mostly miss). The PS186 is
160 utility to create the ``/dev/cecX`` devices. Support for the Pulse-Eight
166 …ERNEL=="ttyACM[0-9]*", ATTRS{idVendor}=="2548", ATTRS{idProduct}=="1002", ACTION=="add", TAG+="sys…
167 …ERNEL=="ttyACM[0-9]*", ATTRS{idVendor}=="2548", ATTRS{idProduct}=="1001", ACTION=="add", TAG+="sys…
168 …NEL=="ttyACM[0-9]*", ATTRS{idVendor}=="04d8", ATTRS{idProduct}=="ff59", ACTION=="add", TAG+="syste…
172 For Pulse-Eight make /lib/systemd/system/pulse8-cec-inputattach@.service::
175 	Description=inputattach for pulse8-cec device on %I
179 	ExecStart=/usr/bin/inputattach --pulse8-cec /dev/%I
181 For the RainShadow Tech make /lib/systemd/system/rainshadow-cec-inputattach@.service::
184 	Description=inputattach for rainshadow-cec device on %I
188 	ExecStart=/usr/bin/inputattach --rainshadow-cec /dev/%I
191 For proper suspend/resume support create: /lib/systemd/system/restart-cec-inputattach.service::
199 …-c 'for d in /dev/serial/by-id/usb-Pulse-Eight*; do /usr/bin/inputattach --daemon --pulse8-cec $d;…
204 And run ``systemctl enable restart-cec-inputattach``.
207 EDID changes, you can use ``cec-ctl`` with the ``-E`` option::
209 	cec-ctl -E /sys/class/drm/card0-DP-1/edid
211 This assumes the dongle is connected to the card0-DP-1 output (``xrandr`` will tell
216 ``crontab -e`` and add this line::
218 	@reboot /usr/local/bin/cec-ctl -E /sys/class/drm/card0-DP-1/edid
224 CEC Without HPD
230 adapters can support this. An example is the Odroid-U3 SBC that has a
231 level-shifter that is powered off when the HPD signal is low, thus
232 blocking the CEC pin. Even though the SoC can use CEC without a HPD,
233 the level-shifter will prevent this from functioning.
247 1) Get a Pulse-Eight USB CEC dongle, connect an HDMI cable from your
248    device to the Pulse-Eight, but do not connect the Pulse-Eight to
251    Now configure the Pulse-Eight dongle::
253 	cec-ctl -p0.0.0.0 --tv
257 	sudo cec-ctl -M
261 	cec-ctl --playback
266 	cec-ctl -t0 --image-view-on
268    The Pulse-Eight should see the <Image View On> message. If not,
273    Pulse-Eight to a CEC-enabled display and run the same command
274    on your device: now there is a HPD, so you should see the command
275    arriving at the Pulse-Eight.
277 2) If you have another linux device supporting CEC without HPD, then
279    two HDMI outputs together. You won't have a HPD (which is what we
284 If CEC messages do not come through when there is no HPD, then you
286 or the software powers off the CEC core when the HPD goes low. The
296 have timing issues. This is hard to discover unless you can hook up a low-level
313 your own low-level CEC debugger.
315 The critical component is one of these HDMI female-female passthrough connectors
318 …om/collections/camera/products/hdmi-af-af-v1a-hdmi-type-a-female-to-hdmi-type-a-female-pass-throug…
320 The video quality is variable and certainly not enough to pass-through 4kp60
326 http://www.dx.com/p/diy-40p-male-to-female-male-to-male-female-to-female-dupont-line-wire-3pcs-3560…
328 If you want to monitor the HPD and/or 5V lines as well, then you need one of
340 GPIO 6 and GPIO 7. The optional HPD pin of the HDMI connector should
341 be connected via the level shifter to these pins: GPIO 23 and GPIO 12.
343 level shifter to these pins: GPIO 25 and GPIO 22. Monitoring the HPD and
346 This device tree addition in ``arch/arm/boot/dts/bcm2711-rpi-4-b.dts``
347 will hook up the cec-gpio driver correctly::
350 		compatible = "cec-gpio";
351 		cec-gpios = <&gpio 6 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
352 		hpd-gpios = <&gpio 23 GPIO_ACTIVE_HIGH>;
353 		v5-gpios = <&gpio 25 GPIO_ACTIVE_HIGH>;
357 		compatible = "cec-gpio";
358 		cec-gpios = <&gpio 7 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
359 		hpd-gpios = <&gpio 12 GPIO_ACTIVE_HIGH>;
360 		v5-gpios = <&gpio 22 GPIO_ACTIVE_HIGH>;
363 If you haven't hooked up the HPD and/or 5V lines, then just delete those
366 This dts change will enable two cec GPIO devices: I typically use one to
368 an unconfigured CEC adapter then it will use GPIO interrupts which makes
372 The minimum configuration is one HDMI female-female passthrough connector
373 and two female-female breadboard wires: one for connecting the HDMI ground
375 CEC pin to GPIO 6 on the Raspberry Pi.
379 ``cec-ctl --monitor-pin`` will do low-level CEC bus sniffing and analysis.
380 You can also store the CEC traffic to file using ``--store-pin`` and analyze
381 it later using ``--analyze-pin``.
383 You can also use this as a full-fledged CEC device by configuring it
384 using ``cec-ctl --tv -p0.0.0.0`` or ``cec-ctl --playback -p1.0.0.0``.
426 The extron-da-hd-4k-plus driver implements the following module options:
429 ---------
434 -------------
441 - <Standby>
442 - <Image View On> and <Text View On>
443 - <Give Device Power Status>
444 - <Set System Audio Mode>
445 - <Request Current Latency>
451 ---------------------
460 -----------------