| Message ID | 20210824140042.3083-1-shawn.c.lee@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/i915/dsi: Retrieve max brightness level from VBT | expand |
On Tue, 24 Aug 2021, Lee Shawn C <shawn.c.lee@intel.com> wrote: > So far, DCS backlight driver hardcode (0xFF) for max brightness level. > MIPI DCS spec allow max 0xFFFF for set_display_brightness (51h) command. > And VBT brightness precision bits can support 8 ~ 16 bits. > > We should set correct precision bits in VBT that meet panel's request. > Driver can refer to this setting then configure max brightness level > in DCS backlight driver properly. > > v2: modify variable name brightness_precision_bits instead of > max_brightness_level. > > Cc: Ville Syrjala <ville.syrjala@linux.intel.com> > Cc: Jani Nikula <jani.nikula@linux.intel.com> > Cc: Vandita Kulkarni <vandita.kulkarni@intel.com> > Cc: Cooper Chiou <cooper.chiou@intel.com> > Cc: William Tseng <william.tseng@intel.com> > Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com> > --- > drivers/gpu/drm/i915/display/intel_bios.c | 3 +++ > drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c | 8 ++++++-- > drivers/gpu/drm/i915/i915_drv.h | 1 + > 3 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c > index e86e6ed2d3bf..ccaf0a3100f7 100644 > --- a/drivers/gpu/drm/i915/display/intel_bios.c > +++ b/drivers/gpu/drm/i915/display/intel_bios.c > @@ -483,6 +483,9 @@ parse_lfp_backlight(struct drm_i915_private *i915, > level = 255; > } > i915->vbt.backlight.min_brightness = min_level; > + > + i915->vbt.backlight.brightness_precision_bits = > + backlight_data->brightness_precision_bits[panel_type]; > } else { > level = backlight_data->level[panel_type]; > i915->vbt.backlight.min_brightness = entry->min_brightness; > diff --git a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > index 584c14c4cbd0..21ab9e1acb57 100644 > --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c > @@ -147,10 +147,14 @@ static void dcs_enable_backlight(const struct intel_crtc_state *crtc_state, > static int dcs_setup_backlight(struct intel_connector *connector, > enum pipe unused) > { > + struct drm_device *dev = connector->base.dev; > + struct drm_i915_private *dev_priv = to_i915(dev); > struct intel_panel *panel = &connector->panel; > > - panel->backlight.max = PANEL_PWM_MAX_VALUE; > - panel->backlight.level = PANEL_PWM_MAX_VALUE; > + panel->backlight.max = (dev_priv->vbt.backlight.brightness_precision_bits > 8) \ > + ? (1 << dev_priv->vbt.backlight.brightness_precision_bits) - 1 \ > + : PANEL_PWM_MAX_VALUE; > + panel->backlight.level = panel->backlight.max; If the precision is < 8, why would max be 0xff? Use GENMASK() perhaps? BR, Jani. > > return 0; > } > diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h > index 005b1cec7007..1b42e39a7cd4 100644 > --- a/drivers/gpu/drm/i915/i915_drv.h > +++ b/drivers/gpu/drm/i915/i915_drv.h > @@ -706,6 +706,7 @@ struct intel_vbt_data { > > struct { > u16 pwm_freq_hz; > + u16 brightness_precision_bits; > bool present; > bool active_low_pwm; > u8 min_brightness; /* min_brightness/255 of max */
On Tue, 24 Aug 2021, Jani Nikula <jani.nikula@linux.intel.com> wrote: >On Tue, 24 Aug 2021, Lee Shawn C <shawn.c.lee@intel.com> wrote: >> So far, DCS backlight driver hardcode (0xFF) for max brightness level. >> MIPI DCS spec allow max 0xFFFF for set_display_brightness (51h) command. >> And VBT brightness precision bits can support 8 ~ 16 bits. >> >> We should set correct precision bits in VBT that meet panel's request. >> Driver can refer to this setting then configure max brightness level >> in DCS backlight driver properly. >> >> v2: modify variable name brightness_precision_bits instead of >> max_brightness_level. >> >> Cc: Ville Syrjala <ville.syrjala@linux.intel.com> >> Cc: Jani Nikula <jani.nikula@linux.intel.com> >> Cc: Vandita Kulkarni <vandita.kulkarni@intel.com> >> Cc: Cooper Chiou <cooper.chiou@intel.com> >> Cc: William Tseng <william.tseng@intel.com> >> Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com> >> --- >> drivers/gpu/drm/i915/display/intel_bios.c | 3 +++ >> drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c | 8 ++++++-- >> drivers/gpu/drm/i915/i915_drv.h | 1 + >> 3 files changed, 10 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c >> b/drivers/gpu/drm/i915/display/intel_bios.c >> index e86e6ed2d3bf..ccaf0a3100f7 100644 >> --- a/drivers/gpu/drm/i915/display/intel_bios.c >> +++ b/drivers/gpu/drm/i915/display/intel_bios.c >> @@ -483,6 +483,9 @@ parse_lfp_backlight(struct drm_i915_private *i915, >> level = 255; >> } >> i915->vbt.backlight.min_brightness = min_level; >> + >> + i915->vbt.backlight.brightness_precision_bits = >> + backlight_data->brightness_precision_bits[panel_type]; >> } else { >> level = backlight_data->level[panel_type]; >> i915->vbt.backlight.min_brightness = entry->min_brightness; diff >> --git a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c >> b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c >> index 584c14c4cbd0..21ab9e1acb57 100644 >> --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c >> +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c >> @@ -147,10 +147,14 @@ static void dcs_enable_backlight(const struct >> intel_crtc_state *crtc_state, static int dcs_setup_backlight(struct intel_connector *connector, >> enum pipe unused) >> { >> + struct drm_device *dev = connector->base.dev; >> + struct drm_i915_private *dev_priv = to_i915(dev); >> struct intel_panel *panel = &connector->panel; >> >> - panel->backlight.max = PANEL_PWM_MAX_VALUE; >> - panel->backlight.level = PANEL_PWM_MAX_VALUE; >> + panel->backlight.max = (dev_priv->vbt.backlight.brightness_precision_bits > 8) \ >> + ? (1 << dev_priv->vbt.backlight.brightness_precision_bits) - 1 \ >> + : PANEL_PWM_MAX_VALUE; >> + panel->backlight.level = panel->backlight.max; > >If the precision is < 8, why would max be 0xff? Use GENMASK() perhaps? > >BR, >Jani. > On vbt structure version 234 and later, vbt support brightness_precision_bits for MIPI display. And its value will be 8~16 that defined in bpsec #20149. If vbt version before 234 without this parameter, vbt.backlight.brightness_precision_bits will be "0". Driver don't know panel required 8 bits or more bits for brightness control. So assign PANEL_PWM_MAX_VALUE (0xFF) to backlight.max. And driver assign the same value when precision_bits is "8" (support max level 255). Best regards, Shawn > >> >> return 0; >> } >> diff --git a/drivers/gpu/drm/i915/i915_drv.h >> b/drivers/gpu/drm/i915/i915_drv.h index 005b1cec7007..1b42e39a7cd4 >> 100644 >> --- a/drivers/gpu/drm/i915/i915_drv.h >> +++ b/drivers/gpu/drm/i915/i915_drv.h >> @@ -706,6 +706,7 @@ struct intel_vbt_data { >> >> struct { >> u16 pwm_freq_hz; >> + u16 brightness_precision_bits; >> bool present; >> bool active_low_pwm; >> u8 min_brightness; /* min_brightness/255 of max */ > >-- >Jani Nikula, Intel Open Source Graphics Center >
diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c index e86e6ed2d3bf..ccaf0a3100f7 100644 --- a/drivers/gpu/drm/i915/display/intel_bios.c +++ b/drivers/gpu/drm/i915/display/intel_bios.c @@ -483,6 +483,9 @@ parse_lfp_backlight(struct drm_i915_private *i915, level = 255; } i915->vbt.backlight.min_brightness = min_level; + + i915->vbt.backlight.brightness_precision_bits = + backlight_data->brightness_precision_bits[panel_type]; } else { level = backlight_data->level[panel_type]; i915->vbt.backlight.min_brightness = entry->min_brightness; diff --git a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c index 584c14c4cbd0..21ab9e1acb57 100644 --- a/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c @@ -147,10 +147,14 @@ static void dcs_enable_backlight(const struct intel_crtc_state *crtc_state, static int dcs_setup_backlight(struct intel_connector *connector, enum pipe unused) { + struct drm_device *dev = connector->base.dev; + struct drm_i915_private *dev_priv = to_i915(dev); struct intel_panel *panel = &connector->panel; - panel->backlight.max = PANEL_PWM_MAX_VALUE; - panel->backlight.level = PANEL_PWM_MAX_VALUE; + panel->backlight.max = (dev_priv->vbt.backlight.brightness_precision_bits > 8) \ + ? (1 << dev_priv->vbt.backlight.brightness_precision_bits) - 1 \ + : PANEL_PWM_MAX_VALUE; + panel->backlight.level = panel->backlight.max; return 0; } diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 005b1cec7007..1b42e39a7cd4 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -706,6 +706,7 @@ struct intel_vbt_data { struct { u16 pwm_freq_hz; + u16 brightness_precision_bits; bool present; bool active_low_pwm; u8 min_brightness; /* min_brightness/255 of max */
So far, DCS backlight driver hardcode (0xFF) for max brightness level. MIPI DCS spec allow max 0xFFFF for set_display_brightness (51h) command. And VBT brightness precision bits can support 8 ~ 16 bits. We should set correct precision bits in VBT that meet panel's request. Driver can refer to this setting then configure max brightness level in DCS backlight driver properly. v2: modify variable name brightness_precision_bits instead of max_brightness_level. Cc: Ville Syrjala <ville.syrjala@linux.intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Vandita Kulkarni <vandita.kulkarni@intel.com> Cc: Cooper Chiou <cooper.chiou@intel.com> Cc: William Tseng <william.tseng@intel.com> Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com> --- drivers/gpu/drm/i915/display/intel_bios.c | 3 +++ drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c | 8 ++++++-- drivers/gpu/drm/i915/i915_drv.h | 1 + 3 files changed, 10 insertions(+), 2 deletions(-)