[Intel-gfx] [PATCH v6 8/9] drm: Add definition for eDP backlight frequency

Pandiyan, Dhinakaran dhinakaran.pandiyan at intel.com
Thu May 11 01:09:49 UTC 2017


On Tue, 2017-05-09 at 16:40 -0700, Puthikorn Voravootivat wrote:
> This patch adds the following definition
> - Bit mask for EDP_PWMGEN_BIT_COUNT and min/max cap
>   register which only use bit 0:4
> - Base frequency (27 MHz) for backlight PWM frequency
>   generator.
> 
> Signed-off-by: Puthikorn Voravootivat <puthik at chromium.org>
> ---
>  include/drm/drm_dp_helper.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
> index c0bd0d7651a9..810b7d5d9f2b 100644
> --- a/include/drm/drm_dp_helper.h
> +++ b/include/drm/drm_dp_helper.h
> @@ -572,10 +572,12 @@
>  #define DP_EDP_PWMGEN_BIT_COUNT             0x724
>  #define DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN     0x725
>  #define DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX     0x726
> +# define  DP_EDP_PWMGEN_BIT_COUNT_MASK      (0x1f << 0)
>  
>  #define DP_EDP_BACKLIGHT_CONTROL_STATUS     0x727
>  
>  #define DP_EDP_BACKLIGHT_FREQ_SET           0x728
> +# define DP_EDP_BACKLIGHT_FREQ_BASE         27000000

I have seen frequency values expressed in kHz in most places within drm,
I think it's best to write this also in kHz to avoid confusion. With the
units addressed,
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>

>  
>  #define DP_EDP_BACKLIGHT_FREQ_CAP_MIN_MSB   0x72a
>  #define DP_EDP_BACKLIGHT_FREQ_CAP_MIN_MID   0x72b



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