Re: [PATCH 1/2] mt9v022: fix pixel clock

[Guennadi Liakhovetski <g.liakhovetski@gmx.de>]

On Wed, 6 Apr 2011, Teresa Gámez wrote:

> Measurements show that the setup of the pixel clock is not correct.
> The 'Invert Pixel Clock' bit has to be set to 1 for falling edge
> and not for rising.

Doesn't seem correct to me. The mt9v022 datasheet says:

<quote>
Invert pixel clock. When set, LINE_VALID,
FRAME_VALID, and DOUT is set up to the rising edge
of pixel clock, PIXCLK. When clear, they are set up to
the falling edge of PIXCLK.
</quote>

and this works for present mt9v022 configurations, which include at least 
two boards: PXA270-based arch/arm/mach-pxa/pcm990-baseboard.c and i.MX31 
based arch/arm/mach-mx3/mach-pcm037.c. If this is different for your 
board, maybe you have to set the SOCAM_SENSOR_INVERT_PCLK flag in your 
"struct soc_camera_link" instance.

Thanks
Guennadi

> Signed-off-by: Teresa Gámez <t.gamez@phytec.de>
> ---
>  drivers/media/video/mt9v022.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/drivers/media/video/mt9v022.c b/drivers/media/video/mt9v022.c
> index 6a784c8..dec2a69 100644
> --- a/drivers/media/video/mt9v022.c
> +++ b/drivers/media/video/mt9v022.c
> @@ -228,7 +228,7 @@ static int mt9v022_set_bus_param(struct soc_camera_device *icd,
>  
>  	flags = soc_camera_apply_sensor_flags(icl, flags);
>  
> -	if (flags & SOCAM_PCLK_SAMPLE_RISING)
> +	if (flags & SOCAM_PCLK_SAMPLE_FALLING)
>  		pixclk |= 0x10;
>  
>  	if (!(flags & SOCAM_HSYNC_ACTIVE_HIGH))
> -- 
> 1.7.0.4
> 
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---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/