Hi Tomi,
On Wed, Sep 17, 2014 at 9:52 PM, Tomi Valkeinen tomi.valkeinen@ti.com wrote:
On 17/09/14 17:29, Ajay kumar wrote:
Hi Tomi,
Thanks for your comments.
On Wed, Sep 17, 2014 at 5:22 PM, Tomi Valkeinen tomi.valkeinen@ti.com wrote:
On 27/08/14 17:39, Ajay Kumar wrote:
Add documentation for DT properties supported by ps8622/ps8625 eDP-LVDS converter.
Signed-off-by: Ajay Kumar ajaykumar.rs@samsung.com
.../devicetree/bindings/video/bridge/ps8622.txt | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 Documentation/devicetree/bindings/video/bridge/ps8622.txt
diff --git a/Documentation/devicetree/bindings/video/bridge/ps8622.txt b/Documentation/devicetree/bindings/video/bridge/ps8622.txt new file mode 100644 index 0000000..0ec8172 --- /dev/null +++ b/Documentation/devicetree/bindings/video/bridge/ps8622.txt @@ -0,0 +1,20 @@ +ps8622-bridge bindings
+Required properties:
- compatible: "parade,ps8622" or "parade,ps8625"- reg: first i2c address of the bridge- sleep-gpios: OF device-tree gpio specification for PD_ pin.- reset-gpios: OF device-tree gpio specification for RST_ pin.+Optional properties:
- lane-count: number of DP lanes to use- use-external-pwm: backlight will be controlled by an external PWMWhat does this mean? That the backlight support from ps8625 is not used? If so, maybe "disable-pwm" or something?
"use-external-pwm" or "disable-bridge-pwm" would be better.
Well, the properties are about the bridge. "use-external-pwm" means that the bridge uses an external PWM, which, if I understood correctly, is not what the property is about.
"disable-bridge-pwm" is ok, but the "bridge" there is extra. The properties are about the bridge, so it's implicit.
Ok. I will use "disable-pwm".
+Example:
lvds-bridge@48 {compatible = "parade,ps8622";reg = <0x48>;sleep-gpios = <&gpc3 6 1 0 0>;reset-gpios = <&gpc3 1 1 0 0>;lane-count = <1>;};I wish all new display component bindings would use the video ports/endpoints to describe the connections. It will be very difficult to improve the display driver model later if we're missing such critical pieces from the DT bindings.
Why do we need a complex graph when it can be handled using a simple phandle?
Maybe in your case you can handle it with simple phandle. Can you guarantee that it's enough for everyone, on all platforms?
Yes, as of now exynos5420-peach-pit and exynos5250-spring boards use this. In case of both, the phandle to bridge node is passed to the exynos_dp node.
The point of the ports/endpoint graph is to also support more complicated scenarios. If you now create ps8622 bindings that do not support those graphs, the no one else using ps8622 can use ports/endpoint graphs either.
Btw, is there an example how the bridge with these bindings is used in a board's .dts file? I couldn't find any example with a quick search. So it's unclear to me what the "simple phandle" actually is.
Please refer to the following link: https://git.kernel.org/cgit/linux/kernel/git/kgene/linux-samsung.git/tree/ar... Let me know if you still think we would need to describe it as a complex graph!
Ajay