diff mbox series

[1/5] cec-gpio.txt: add v5-gpios for testing the 5V line

Message ID 20180717132909.92158-2-hverkuil@xs4all.nl
State Not Applicable, archived
Headers show
Series cec/cec-gpio: add support for 5V testing | expand

Commit Message

Hans Verkuil July 17, 2018, 1:29 p.m. UTC
From: Hans Verkuil <hans.verkuil@cisco.com>

In order to debug the HDMI 5V line we need to add a new v5-gpios
property.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 .../devicetree/bindings/media/cec-gpio.txt      | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

Comments

Rob Herring July 20, 2018, 6:05 p.m. UTC | #1
On Tue, Jul 17, 2018 at 03:29:05PM +0200, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> In order to debug the HDMI 5V line we need to add a new v5-gpios
> property.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  .../devicetree/bindings/media/cec-gpio.txt      | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/media/cec-gpio.txt b/Documentation/devicetree/bindings/media/cec-gpio.txt
> index 12fcd55ed153..1d53ce89da74 100644
> --- a/Documentation/devicetree/bindings/media/cec-gpio.txt
> +++ b/Documentation/devicetree/bindings/media/cec-gpio.txt
> @@ -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
>  hooked up to another GPIO line.
>  
> -Please note: the maximum voltage for the CEC line is 3.63V, for the HPD
> -line it is 5.3V. So you may need some sort of level conversion circuitry
> +Please note: the maximum voltage for the CEC line is 3.63V, for the HPD and
> +5V lines it is 5.3V. So you may need some sort of level conversion circuitry
>  when connecting them to a GPIO line.
>  
>  Required properties:
> @@ -22,15 +22,18 @@ 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.
> +  - v5-gpios: gpio that the 5V line is connected to.

This is a bit strange without the context of debugging. So can you 
mention that here.

With that,

Reviewed-by: Rob Herring <robh@kernel.org>

>  
>  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 (some level shifter is needed for this!):
> +pin 26 aka BCM7 aka CE1 on the GPIO pin header, the HPD line is
> +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>
>  
>  cec-gpio {
> -       compatible = "cec-gpio";
> -       cec-gpios = <&gpio 7 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
> -       hpd-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>;
> +	compatible = "cec-gpio";
> +	cec-gpios = <&gpio 7 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
> +	hpd-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>;
> +	v5-gpios = <&gpio 22 GPIO_ACTIVE_HIGH>;
>  };
> -- 
> 2.18.0
> 
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diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/media/cec-gpio.txt b/Documentation/devicetree/bindings/media/cec-gpio.txt
index 12fcd55ed153..1d53ce89da74 100644
--- a/Documentation/devicetree/bindings/media/cec-gpio.txt
+++ b/Documentation/devicetree/bindings/media/cec-gpio.txt
@@ -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
 hooked up to another GPIO line.
 
-Please note: the maximum voltage for the CEC line is 3.63V, for the HPD
-line it is 5.3V. So you may need some sort of level conversion circuitry
+Please note: the maximum voltage for the CEC line is 3.63V, for the HPD and
+5V lines it is 5.3V. So you may need some sort of level conversion circuitry
 when connecting them to a GPIO line.
 
 Required properties:
@@ -22,15 +22,18 @@  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.
+  - v5-gpios: gpio that the 5V 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 (some level shifter is needed for this!):
+pin 26 aka BCM7 aka CE1 on the GPIO pin header, the HPD line is
+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>
 
 cec-gpio {
-       compatible = "cec-gpio";
-       cec-gpios = <&gpio 7 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
-       hpd-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>;
+	compatible = "cec-gpio";
+	cec-gpios = <&gpio 7 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>;
+	hpd-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>;
+	v5-gpios = <&gpio 22 GPIO_ACTIVE_HIGH>;
 };