From 84d3d71fe3630c757580dc0c4b7d1c141785fbcc Mon Sep 17 00:00:00 2001 From: Lee Shawn C Date: Wed, 8 Sep 2021 19:56:06 +0800 Subject: drm/i915/dsi: Retrieve max brightness level from VBT 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. v3: fix checkpatch warning. Cc: Ville Syrjala Cc: Jani Nikula Cc: Vandita Kulkarni Cc: Cooper Chiou Cc: William Tseng Signed-off-by: Lee Shawn C Reviewed-by: Jani Nikula Signed-off-by: Vandita Kulkarni Link: https://patchwork.freedesktop.org/patch/msgid/20210908115607.9633-5-shawn.c.lee@intel.com --- drivers/gpu/drm/i915/display/intel_bios.c | 3 +++ drivers/gpu/drm/i915/display/intel_dsi_dcs_backlight.c | 10 ++++++++-- drivers/gpu/drm/i915/i915_drv.h | 1 + 3 files changed, 12 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/i915') diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c index 052f27c0fb0c..3c25926092de 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..567c086602d5 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 +147,16 @@ 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; + if (dev_priv->vbt.backlight.brightness_precision_bits > 8) + panel->backlight.max = (1 << dev_priv->vbt.backlight.brightness_precision_bits) - 1; + else + panel->backlight.max = 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 309a483d1722..a8129153d1db 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -689,6 +689,7 @@ 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 */ -- cgit