Re: [PATCH] video: ARM CLCD: Added dt support to set tim2 register

[Pawel Moll <pawel.moll@arm.com>]

On Wed, 2015-02-25 at 21:01 +0000, Arun Ramamurthy wrote:
> Added code based on linaro tree:
> http://git.linaro.org/kernel/linux-linaro-stable.git
> with commit id:6846e7822c4cab5a84672baace3b768c2d0db142
> at drivers/video/amba-clcd.c. This lets the driver set
> certain tim2 register bits after reading them from
> device tree.
> 
> Reviewed-by: Ray Jui <rjui@broadcom.com>
> Reviewed-by: Scott Branden <sbranden@broadcom.com>
> Signed-off-by: Arun Ramamurthy <arun.ramamurthy@broadcom.com>
> ---
>  .../devicetree/bindings/video/arm,pl11x.txt        | 17 ++++++++-
>  drivers/video/fbdev/amba-clcd.c                    | 41 ++++++++++++++++++++++
>  2 files changed, 57 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/video/arm,pl11x.txt b/Documentation/devicetree/bindings/video/arm,pl11x.txt
> index 3e3039a..14d6f87 100644
> --- a/Documentation/devicetree/bindings/video/arm,pl11x.txt
> +++ b/Documentation/devicetree/bindings/video/arm,pl11x.txt
> @@ -35,6 +35,21 @@ Optional properties:
>  	cell's memory interface can handle; if not present, the memory
>  	interface is fast enough to handle all possible video modes
>  
> +- tim2: Used to set certain bits in LCDTiming2 register.
> +	It can be TIM2_CLKSEL or TIM2_IOE or both
> +
> +	TIM2_CLKSEL: This bit drives the CLCDCLKSEL signal. It is the select
> +	signal for the external LCD clock multiplexor.
> +
> +	TIM2_IOE: Invert output enable:
> +	0 = CLAC output pin is active HIGH in TFT mode
> +	1 = CLAC output pin is active LOW in TFT mode.
> +	This bit selects the active polarity of the output enable signal in
> +	TFT mode. In this mode, the CLAC pin is an enable that indicates to
> +	the LCD panel when valid display data is available. In active
> +	display mode, data is driven onto the LCD data lines at the
> +	programmed edge of CLCP when CLAC is in its active state.
> +

The existing bindings intentionally avoided quoting internal registers -
they are supposed to describe how the hardware is wired up...

So how about something like "arm,pl11x,tft-invert-clac"? Then the driver
sets the bit or not, depending on the property existance?

Pawel