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Diffstat (limited to 'Documentation/admin-guide/media/cec.rst')
| -rw-r--r-- | Documentation/admin-guide/media/cec.rst | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/Documentation/admin-guide/media/cec.rst b/Documentation/admin-guide/media/cec.rst index 6b30e355cf23..92690e1f2183 100644 --- a/Documentation/admin-guide/media/cec.rst +++ b/Documentation/admin-guide/media/cec.rst @@ -42,10 +42,14 @@ dongles): ``persistent_config``: by default this is off, but when set to 1 the driver will store the current settings to the device's internal eeprom and restore it the next time the device is connected to the USB port. + - RainShadow Tech. Note: this driver does not support the persistent_config module option of the Pulse-Eight driver. The hardware supports it, but I have no plans to add this feature. But I accept patches :-) +- Extron DA HD 4K PLUS HDMI Distribution Amplifier. See + :ref:`extron_da_hd_4k_plus` for more information. + Miscellaneous: - vivid: emulates a CEC receiver and CEC transmitter. @@ -378,3 +382,86 @@ it later using ``--analyze-pin``. You can also use this as a full-fledged CEC device by configuring it using ``cec-ctl --tv -p0.0.0.0`` or ``cec-ctl --playback -p1.0.0.0``. + +.. _extron_da_hd_4k_plus: + +Extron DA HD 4K PLUS CEC Adapter driver +======================================= + +This driver is for the Extron DA HD 4K PLUS series of HDMI Distribution +Amplifiers: https://www.extron.com/product/dahd4kplusseries + +The 2, 4 and 6 port models are supported. + +Firmware version 1.02.0001 or higher is required. + +Note that older Extron hardware revisions have a problem with the CEC voltage, +which may mean that CEC will not work. This is fixed in hardware revisions +E34814 and up. + +The CEC support has two modes: the first is a manual mode where userspace has +to manually control CEC for the HDMI Input and all HDMI Outputs. While this gives +full control, it is also complicated. + +The second mode is an automatic mode, which is selected if the module option +``vendor_id`` is set. In that case the driver controls CEC and CEC messages +received in the input will be distributed to the outputs. It is still possible +to use the /dev/cecX devices to talk to the connected devices directly, but it is +the driver that configures everything and deals with things like Hotplug Detect +changes. + +The driver also takes care of the EDIDs: /dev/videoX devices are created to +read the EDIDs and (for the HDMI Input port) to set the EDID. + +By default userspace is responsible to set the EDID for the HDMI Input +according to the EDIDs of the connected displays. But if the ``manufacturer_name`` +module option is set, then the driver will take care of setting the EDID +of the HDMI Input based on the supported resolutions of the connected displays. +Currently the driver only supports resolutions 1080p60 and 4kp60: if all connected +displays support 4kp60, then it will advertise 4kp60 on the HDMI input, otherwise +it will fall back to an EDID that just reports 1080p60. + +The status of the Extron is reported in ``/sys/kernel/debug/cec/cecX/status``. + +The extron-da-hd-4k-plus driver implements the following module options: + +``debug`` +--------- + +If set to 1, then all serial port traffic is shown. + +``vendor_id`` +------------- + +The CEC Vendor ID to report to connected displays. + +If set, then the driver will take care of distributing CEC messages received +on the input to the HDMI outputs. This is done for the following CEC messages: + +- <Standby> +- <Image View On> and <Text View On> +- <Give Device Power Status> +- <Set System Audio Mode> +- <Request Current Latency> + +If not set, then userspace is responsible for this, and it will have to +configure the CEC devices for HDMI Input and the HDMI Outputs manually. + +``manufacturer_name`` +--------------------- + +A three character manufacturer name that is used in the EDID for the HDMI +Input. If not set, then userspace is reponsible for configuring an EDID. +If set, then the driver will update the EDID automatically based on the +resolutions supported by the connected displays, and it will not be possible +anymore to manually set the EDID for the HDMI Input. + +``hpd_never_low`` +----------------- + +If set, then the Hotplug Detect pin of the HDMI Input will always be high, +even if nothing is connected to the HDMI Outputs. If not set (the default) +then the Hotplug Detect pin of the HDMI input will go low if all the detected +Hotplug Detect pins of the HDMI Outputs are also low. + +This option may be changed dynamically. |