Commit Graph

5 Commits

Author SHA1 Message Date
Hans Verkuil
76e464888b media: cec-gpio: support 5v testing
Add support for the new (optional) 5V gpio in order to debug 5V
changes. Some displays turn off CEC if the 5V is not detected,
so it is useful to be able to monitor this line.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-07-25 07:12:36 -04:00
Hans Verkuil
f6b6631478 media: cec-gpio: use GPIOD_OUT_HIGH_OPEN_DRAIN
This driver needs a pull up output GPIO, but devm_gpiod_get() is called
with GPIOD_IN. This apparently works fine for the RPi3 where the DT
correctly specifies a pull up GPIO, but on the i.MX6 it also needs to
be specified with devm_gpiod_get().

Reported-by: Henrik Mau <Henrik.Mau@linn.co.uk>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-05-09 16:15:06 -04:00
Hans Verkuil
ddddfa78ac media: add SPDX license info
Replace the old license information with the corresponding SPDX
license for the remaining media drivers that Cisco authored.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2018-02-14 13:17:03 -05:00
Hans Verkuil
5b2c8da1b0 [media] cec-gpio: don't generate spurious HPD events
Only send HPD_LOW/HIGH event if the gpio actually changed value.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
2017-10-04 17:04:18 -03:00
Hans Verkuil
1e33936d3b media: cec-gpio: add HDMI CEC GPIO driver
Add a simple HDMI CEC GPIO driver that sits on top of the cec-pin framework.

While I have heard of SoCs that use the GPIO pin for CEC (apparently an
early RockChip SoC used that), the main use-case of this driver is to
function as a debugging tool.

By connecting the CEC line to a GPIO pin on a Raspberry Pi 3 for example
it turns it into a CEC debugger and protocol analyzer.

With 'cec-ctl --monitor-pin' the CEC traffic can be analyzed.

But of course it can also be used with any hardware project where the
HDMI CEC line is hooked up to a pull-up gpio line.

In addition this has (optional) support for tracing HPD changes if the
HPD is connected to a GPIO.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
2017-09-23 07:51:44 -04:00