[Intel-gfx] [PATCH RESEND v4 5/6] drm: Add definition for eDP backlight frequency

[Manasi Navare]

On Wed, May 03, 2017 at 03:49:23PM +0300, Jani Nikula wrote:
> On Tue, 02 May 2017, Manasi Navare <manasi.d.navare at intel.com> wrote:
> > On Tue, Apr 18, 2017 at 04:48:23PM -0700, Puthikorn Voravootivat wrote:
> >
> > Since this adds definitions in the DRM layer, you need to copy
> > the dri-devel at lists.freedesktop.org M-L.
> >
> >> 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..9aee65ebc54c 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      (31 << 0)
> 
> For bit masks like this hex is preferred. 0x1f is way more intuitive
> than a decimal number.
> 
> >>  
> >>  #define DP_EDP_BACKLIGHT_CONTROL_STATUS     0x727
> >>  
> >>  #define DP_EDP_BACKLIGHT_FREQ_SET           0x728
> >> +# define DP_EDP_BACKLIGHT_FREQ_BASE         27000000
> >
> > Could you use HEX value to define this? Thats the convention around.
> 
> However I think this is fine as decimal.
> 
> BR,
> Jani.
> 
>

Yea it is the direct representation of 27MHz so I guess decimal
is more intuitive.

Manasi

> >
> > Manasi
> >>  
> >>  #define DP_EDP_BACKLIGHT_FREQ_CAP_MIN_MSB   0x72a
> >>  #define DP_EDP_BACKLIGHT_FREQ_CAP_MIN_MID   0x72b
> >> -- 
> >> 2.12.2.816.g2cccc81164-goog
> >> 
> >> _______________________________________________
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> >> Intel-gfx at lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center