Re: <Query> Reg: Adding a gpio initialization sequence in dts is valid or not

[Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>]

On 08/17/2012 04:37 AM, Leela Krishna Amudala wrote:
> Hello,
> 
> I think you misinterpreted my question.
> 
...
> But I don't bother about enabling regulator and pwm for my panel.
> 
> My panel needs a sequence like
> 1. Pull up a gpio line
> 2. Maintain some delay
> 3. Pull down gpio line
> 4. Maintain some delay and
> 5. Pull up a gpio line.

Yes, I think that kind of thing is exactly what the power sequences
bindings/driver are for.

But ...

> Please find the Image shown in the attachment for better understanding.
> 
> So, to get this done I used your code and created a node like below
> and it worked for me.
> 
> backlight {
>         compatible = "pwm-backlight";
>         brightness-levels = <0 16 32 48 64 80 96 112 128 144 160 176
> 192 208 224 240 255>;
>         default-brightness-level = <12>;
> 
>         enable-gpio1 = <&gpx1 5 1 0 0>;
>         enable-gpio2 = <&gpx3 0 0 0 0>;

In your original email, you mentioned that some of those cells for the
GPIO control the state features such as pull-up/-down and
drive-strength. Those two features should really be configured by
pinctrl not by the GPIO bindings, although that's a comment on the GPIO
bindings itself, and nothing to do with power sequences.