[PATCHv6,3/5] dt-bindings: document the CEC GPIO bindings

Commit Message

Hans Verkuil Sept. 17, 2017, 10:15 a.m. UTC

From: Hans Verkuil <[e-mail]>

Document the bindings for the cec-gpio module for hardware where the
CEC line and optionally the HPD line are connected to GPIO lines.

Signed-off-by: Hans Verkuil <[e-mail]>
Reviewed-by: Linus Walleij <[e-mail]>
---
 .../devicetree/bindings/media/cec-gpio.txt         | 32 ++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/cec-gpio.txt

Comments

Rob Herring (Arm) Sept. 18, 2017, 8:01 p.m. UTC | #1

On Sun, Sep 17, 2017 at 5:15 AM, Hans Verkuil <[e-mail]> wrote:
> From: Hans Verkuil <[e-mail]>
>
> Document the bindings for the cec-gpio module for hardware where the
> CEC line and optionally the HPD line are connected to GPIO lines.
>
> Signed-off-by: Hans Verkuil <[e-mail]>
> Reviewed-by: Linus Walleij <[e-mail]>
> ---
>  .../devicetree/bindings/media/cec-gpio.txt         | 32 ++++++++++++++++++++++
>  1 file changed, 32 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/media/cec-gpio.txt

Reviewed-by: Rob Herring <[e-mail]>

Patch

diff --git a/Documentation/devicetree/bindings/media/cec-gpio.txt b/Documentation/devicetree/bindings/media/cec-gpio.txt
new file mode 100644
index 000000000000..46a0bac8b3b9
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/cec-gpio.txt
@@ -0,0 +1,32 @@ 
+* HDMI CEC GPIO driver
+
+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
+hooked up to another GPIO line.
+
+Required properties:
+  - compatible: value must be "cec-gpio".
+  - cec-gpios: gpio that the CEC line is connected to. The line should be
+    tagged as open drain.
+
+If the CEC line is associated with an HDMI receiver/transmitter, then the
+following property is also required:
+
+  - hdmi-phandle - phandle to the HDMI controller, see also cec.txt.
+
+If the CEC line is not associated with an HDMI receiver/transmitter, then
+the following property is optional:
+
+  - hpd-gpios: gpio that the HPD 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
+connected to pin 11 aka BCM17:
+
+#include <dt-bindings/gpio/gpio.h>
+
+cec-gpio {
+       compatible = "cec-gpio";
+       cec-gpios = <&gpio 7 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
+       hpd-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>;
+};