Add DT binding for led-backlight.
Signed-off-by: Jean-Jacques Hiblot <[email protected]>
---
.../bindings/leds/backlight/led-backlight.txt | 28 +++++++++++++++++++
1 file changed, 28 insertions(+)
create mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
diff --git a/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt b/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
new file mode 100644
index 000000000000..0444eec8efe1
--- /dev/null
+++ b/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
@@ -0,0 +1,28 @@
+led-backlight bindings
+
+This binding is used to describe a basic backlight device made of LEDs.
+It can also be used to describe a backlight device controlled by the output of
+a LED driver.
+
+Required properties:
+ - compatible: "led-backlight"
+ - leds: a list of LEDs
+
+Optional properties:
+ - brightness-levels: Array of distinct brightness levels. The levels must be
+ in the range accepted by the underlying LED devices.
+ This is used to translate a backlight brightness level
+ into a LED brightness level. if not provided, the
+ identity mapping is used.
+
+ - default-brightness-level: The default brightness level.
+
+Example:
+
+ backlight {
+ compatible = "led-backlight";
+
+ leds = <&led1>, <&led2>;
+ brightness-levels = <0 4 8 16 32 64 128 255>;
+ default-brightness-level = <6>;
+ };
--
2.17.1
On Wed 2019-07-10 14:39:31, Jean-Jacques Hiblot wrote:
> Add DT binding for led-backlight.
>
> Signed-off-by: Jean-Jacques Hiblot <[email protected]>
> ---
> .../bindings/leds/backlight/led-backlight.txt | 28 +++++++++++++++++++
> 1 file changed, 28 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
>
> diff --git a/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt b/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
> new file mode 100644
> index 000000000000..0444eec8efe1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
> @@ -0,0 +1,28 @@
> +led-backlight bindings
> +
> +This binding is used to describe a basic backlight device made of
> LEDs.
Ok.
> +It can also be used to describe a backlight device controlled by the output of
> +a LED driver.
? The LED driver should better be driving some LEDs...
> +Required properties:
> + - compatible: "led-backlight"
> + - leds: a list of LEDs
> +
> +Optional properties:
> + - brightness-levels: Array of distinct brightness levels. The levels must be
> + in the range accepted by the underlying LED devices.
> + This is used to translate a backlight brightness level
> + into a LED brightness level. if not provided, the
> + identity mapping is used.
"If it is not"
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
Pavel,
On 10/07/2019 21:13, Pavel Machek wrote:
> On Wed 2019-07-10 14:39:31, Jean-Jacques Hiblot wrote:
>> Add DT binding for led-backlight.
>>
>> Signed-off-by: Jean-Jacques Hiblot <[email protected]>
>> ---
>> .../bindings/leds/backlight/led-backlight.txt | 28 +++++++++++++++++++
>> 1 file changed, 28 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
>>
>> diff --git a/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt b/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
>> new file mode 100644
>> index 000000000000..0444eec8efe1
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
>> @@ -0,0 +1,28 @@
>> +led-backlight bindings
>> +
>> +This binding is used to describe a basic backlight device made of
>> LEDs.
> Ok.
>
>> +It can also be used to describe a backlight device controlled by the output of
>> +a LED driver.
> ? The LED driver should better be driving some LEDs...
Well. we are dependent of the board design. If a board designer decided
to control a backlight with a LED-controller, then we have to deal with it.
In practice there are a lot of LED drivers that actually drive the LEDs
using PWMs and can be used for this purpose.
JJ
>
>> +Required properties:
>> + - compatible: "led-backlight"
>> + - leds: a list of LEDs
>> +
>> +Optional properties:
>> + - brightness-levels: Array of distinct brightness levels. The levels must be
>> + in the range accepted by the underlying LED devices.
>> + This is used to translate a backlight brightness level
>> + into a LED brightness level. if not provided, the
>> + identity mapping is used.
> "If it is not"
> Pavel