Messages in this thread | | | Subject | Re: [PATCH v3 3/4] dt-bindings: backlight: Add led-backlight binding | From | Jean-Jacques Hiblot <> | Date | Fri, 12 Jul 2019 15:57:20 +0200 |
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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 <jjhiblot@ti.com> >> --- >> .../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
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