Commit fbf8ad7e authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab

media: cec-gpio.txt: add v5-gpios for testing the 5V line

In order to debug the HDMI 5V line we need to add a new v5-gpios
property.
Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
parent 23178307
...@@ -4,8 +4,8 @@ The HDMI CEC GPIO module supports CEC implementations where the CEC line ...@@ -4,8 +4,8 @@ The HDMI CEC GPIO module supports CEC implementations where the CEC line
is hooked up to a pull-up GPIO line and - optionally - the HPD line is is hooked up to a pull-up GPIO line and - optionally - the HPD line is
hooked up to another GPIO line. hooked up to another GPIO line.
Please note: the maximum voltage for the CEC line is 3.63V, for the HPD Please note: the maximum voltage for the CEC line is 3.63V, for the HPD and
line it is 5.3V. So you may need some sort of level conversion circuitry 5V lines it is 5.3V. So you may need some sort of level conversion circuitry
when connecting them to a GPIO line. when connecting them to a GPIO line.
Required properties: Required properties:
...@@ -19,18 +19,24 @@ following property is also required: ...@@ -19,18 +19,24 @@ following property is also required:
- hdmi-phandle - phandle to the HDMI controller, see also cec.txt. - hdmi-phandle - phandle to the HDMI controller, see also cec.txt.
If the CEC line is not associated with an HDMI receiver/transmitter, then If the CEC line is not associated with an HDMI receiver/transmitter, then
the following property is optional: the following property is optional and can be used for debugging HPD changes:
- hpd-gpios: gpio that the HPD line is connected to. - hpd-gpios: gpio that the HPD line is connected to.
This property is optional and can be used for debugging changes on the 5V line:
- v5-gpios: gpio that the 5V line is connected to.
Example for the Raspberry Pi 3 where the CEC line is connected to Example for the Raspberry Pi 3 where the CEC line is connected to
pin 26 aka BCM7 aka CE1 on the GPIO pin header and the HPD line is pin 26 aka BCM7 aka CE1 on the GPIO pin header, the HPD line is
connected to pin 11 aka BCM17 (some level shifter is needed for this!): connected to pin 11 aka BCM17 and the 5V line is connected to pin
15 aka BCM22 (some level shifter is needed for the HPD and 5V lines!):
#include <dt-bindings/gpio/gpio.h> #include <dt-bindings/gpio/gpio.h>
cec-gpio { cec-gpio {
compatible = "cec-gpio"; compatible = "cec-gpio";
cec-gpios = <&gpio 7 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>; cec-gpios = <&gpio 7 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
hpd-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>; hpd-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>;
v5-gpios = <&gpio 22 GPIO_ACTIVE_HIGH>;
}; };
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