[PATCH 5/7] drm/i915/backlight: Add function to change brightness in nits for VESA

[Murthy, Arun R]

> > Create a function that fills in the value for
> > PANEL_TARGET_LUMINANCE_VALUE which helps in changing the luminance
> in nits using VESA interface.
> >
> > --v2
> > -Prefer using luminance over nits [Jani]
> >
> > Signed-off-by: Suraj Kandpal <suraj.kandpal at intel.com>
> > Tested-by: Ben Kao <ben.kao at intel.com>
> > ---
> Reviewed-by: Arun R Murthy <arun.r.murthy at intel.com>
> 
> Thanks and Regards,
> Arun R Murthy
> --------------------
> 
> >  .../drm/i915/display/intel_dp_aux_backlight.c | 30
> > +++++++++++++++++++
> >  1 file changed, 30 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> > b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> > index a733b5623563..a9facfacac95 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> > @@ -474,6 +474,31 @@ static u32 intel_dp_aux_vesa_get_backlight(struct
> > intel_connector *connector, en
> >  	return connector->panel.backlight.level;  }
> >
> > +static int
> > +intel_dp_aux_vesa_set_luminance(struct intel_connector *connector,
> > +u32
> > +level) {
> > +	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
> > +	u8 buf[3];
> > +	int ret;
> > +
> > +	level = level * 1000;
> > +	level &= 0xffffff;
> > +	buf[0] = (level & 0x0000ff);
> > +	buf[1] = (level & 0x00ff00) >> 8;
> > +	buf[2] = (level & 0xff0000) >> 16;
> > +
> > +	ret = drm_dp_dpcd_write(&intel_dp->aux,
> > DP_EDP_PANEL_TARGET_LUMINANCE_VALUE,
> > +				buf, sizeof(buf));
> > +	if (ret != sizeof(buf)) {
> > +		drm_err(intel_dp->aux.drm_dev,
> > +			"%s: Failed to set VESA Aux Luminance: %d\n",
> > +			intel_dp->aux.name, ret);
> > +		return -EINVAL;
> > +	} else {
> > +		return 0;
> > +	}
> > +}
Can this function be moved to drm core drm_edp_backlight_set_level() ?

Thanks and Regards,
Arun R Murthy
--------------------
> > +
> >  static void
> >  intel_dp_aux_vesa_set_backlight(const struct drm_connector_state
> > *conn_state, u32 level)  { @@ -481,6 +506,11 @@
> > intel_dp_aux_vesa_set_backlight(const struct drm_connector_state
> > *conn_state, u3
> >  	struct intel_panel *panel = &connector->panel;
> >  	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
> >
> > +	if (panel->backlight.edp.vesa.luminance_control_support) {
> > +		if (!intel_dp_aux_vesa_set_luminance(connector, level))
> > +			return;
> > +	}
> > +
> >  	if (!panel->backlight.edp.vesa.info.aux_set) {
> >  		const u32 pwm_level =
> > intel_backlight_level_to_pwm(connector, level);
> >
> > --
> > 2.34.1