Re: [PATCH v9 4/5] dt-bindings: backlight: Add led-backlight binding

From: Jean-Jacques Hiblot
Date: Tue Oct 08 2019 - 09:30:40 EST


Rob,

On 08/10/2019 14:51, Jean-Jacques Hiblot wrote:
Hi Rob,

On 07/10/2019 18:15, Rob Herring wrote:
Please send DT bindings to DT list or it's never in my queue. IOW,
send patches to the lists that get_maintainers.pl tells you to.

On Mon, Oct 7, 2019 at 7:45 AM Jean-Jacques Hiblot <jjhiblot@xxxxxx> wrote:
Add DT binding for led-backlight.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@xxxxxx>
Reviewed-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
Reviewed-by: Sebastian Reichel <sebastian.reichel@xxxxxxxxxxxxx>
---
 .../bindings/leds/backlight/led-backlight.txt | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/leds/backlight/led-backlight.txt
Please make this a DT schema.

OK.

BTW I used "make dt_binding_check" but had to fix a couple of YAMLs file to get it to work. Do you have a kernel tree with already all the YAML files in good shape ? Or do you want me to post the changes to devicetree@xxxxxxxxxxxxxxx ?



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..4c7dfbe7f67a
--- /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:
+Â - compatible: "led-backlight"
+Â - leds: a list of LEDs
'leds' is already used as a node name and mixing is not ideal.

We already have 'flash-leds' in use and with the same definition, so
lets continue that and use 'backlight-leds'.
OK

I am taking that back. I have added of_get_led() and devm_of_get_led() to the LED core to make it easier to get a LED from the DT. I modeled the interface like it is done for PWM, PHYs or clocks. The property containing list/array of phandle is always named the same. To get one particular PWM/PHY/clock, a identifier (name or integer) must be provided.

So unless there is a strong incentive to do otherwise I's rather keep this name here.


JJ


+
+Optional properties:
+Â - brightness-levels: Array of distinct brightness levels. The levels must be
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ in the range accepted by the underlying LED devices.
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ This is used to translate a backlight brightness level
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ into a LED brightness level. If it is not provided, the
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ identity mapping is used.
+
+Â - default-brightness-level: The default brightness level.
You can just assume these 2 get a common schema at some point. So just
need to define any additional constraints if possible.

Maybe we should keep them until such a common schema is written ?

JJ


Rob