diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_panel.c | 160 |
1 files changed, 143 insertions, 17 deletions
diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c index 12b02fe1d0ae..59b028f0b1e8 100644 --- a/drivers/gpu/drm/i915/intel_panel.c +++ b/drivers/gpu/drm/i915/intel_panel.c @@ -398,6 +398,69 @@ intel_panel_detect(struct drm_device *dev) } } +/** + * scale - scale values from one range to another + * + * @source_val: value in range [@source_min..@source_max] + * + * Return @source_val in range [@source_min..@source_max] scaled to range + * [@target_min..@target_max]. + */ +static uint32_t scale(uint32_t source_val, + uint32_t source_min, uint32_t source_max, + uint32_t target_min, uint32_t target_max) +{ + uint64_t target_val; + + WARN_ON(source_min > source_max); + WARN_ON(target_min > target_max); + + /* defensive */ + source_val = clamp(source_val, source_min, source_max); + + /* avoid overflows */ + target_val = (uint64_t)(source_val - source_min) * + (target_max - target_min); + do_div(target_val, source_max - source_min); + target_val += target_min; + + return target_val; +} + +/* Scale user_level in range [0..user_max] to [hw_min..hw_max]. */ +static inline u32 scale_user_to_hw(struct intel_connector *connector, + u32 user_level, u32 user_max) +{ + struct intel_panel *panel = &connector->panel; + + return scale(user_level, 0, user_max, + panel->backlight.min, panel->backlight.max); +} + +/* Scale user_level in range [0..user_max] to [0..hw_max], clamping the result + * to [hw_min..hw_max]. */ +static inline u32 clamp_user_to_hw(struct intel_connector *connector, + u32 user_level, u32 user_max) +{ + struct intel_panel *panel = &connector->panel; + u32 hw_level; + + hw_level = scale(user_level, 0, user_max, 0, panel->backlight.max); + hw_level = clamp(hw_level, panel->backlight.min, panel->backlight.max); + + return hw_level; +} + +/* Scale hw_level in range [hw_min..hw_max] to [0..user_max]. */ +static inline u32 scale_hw_to_user(struct intel_connector *connector, + u32 hw_level, u32 user_max) +{ + struct intel_panel *panel = &connector->panel; + + return scale(hw_level, panel->backlight.min, panel->backlight.max, + 0, user_max); +} + static u32 intel_panel_compute_brightness(struct intel_connector *connector, u32 val) { @@ -557,17 +620,16 @@ intel_panel_actually_set_backlight(struct intel_connector *connector, u32 level) dev_priv->display.set_backlight(connector, level); } -/* set backlight brightness to level in range [0..max] */ -void intel_panel_set_backlight(struct intel_connector *connector, u32 level, - u32 max) +/* set backlight brightness to level in range [0..max], scaling wrt hw min */ +static void intel_panel_set_backlight(struct intel_connector *connector, + u32 user_level, u32 user_max) { struct drm_device *dev = connector->base.dev; struct drm_i915_private *dev_priv = dev->dev_private; struct intel_panel *panel = &connector->panel; enum pipe pipe = intel_get_pipe_from_connector(connector); - u32 freq; + u32 hw_level; unsigned long flags; - u64 n; if (!panel->backlight.present || pipe == INVALID_PIPE) return; @@ -576,18 +638,46 @@ void intel_panel_set_backlight(struct intel_connector *connector, u32 level, WARN_ON(panel->backlight.max == 0); - /* scale to hardware max, but be careful to not overflow */ - freq = panel->backlight.max; - n = (u64)level * freq; - do_div(n, max); - level = n; + hw_level = scale_user_to_hw(connector, user_level, user_max); + panel->backlight.level = hw_level; + + if (panel->backlight.enabled) + intel_panel_actually_set_backlight(connector, hw_level); + + spin_unlock_irqrestore(&dev_priv->backlight_lock, flags); +} + +/* set backlight brightness to level in range [0..max], assuming hw min is + * respected. + */ +void intel_panel_set_backlight_acpi(struct intel_connector *connector, + u32 user_level, u32 user_max) +{ + struct drm_device *dev = connector->base.dev; + struct drm_i915_private *dev_priv = dev->dev_private; + struct intel_panel *panel = &connector->panel; + enum pipe pipe = intel_get_pipe_from_connector(connector); + u32 hw_level; + unsigned long flags; + + if (!panel->backlight.present || pipe == INVALID_PIPE) + return; + + spin_lock_irqsave(&dev_priv->backlight_lock, flags); + + WARN_ON(panel->backlight.max == 0); + + hw_level = clamp_user_to_hw(connector, user_level, user_max); + panel->backlight.level = hw_level; - panel->backlight.level = level; if (panel->backlight.device) - panel->backlight.device->props.brightness = level; + panel->backlight.device->props.brightness = + scale_hw_to_user(connector, + panel->backlight.level, + panel->backlight.device->props.max_brightness); if (panel->backlight.enabled) - intel_panel_actually_set_backlight(connector, level); + intel_panel_actually_set_backlight(connector, hw_level); spin_unlock_irqrestore(&dev_priv->backlight_lock, flags); } @@ -860,7 +950,9 @@ void intel_panel_enable_backlight(struct intel_connector *connector) panel->backlight.level = panel->backlight.max; if (panel->backlight.device) panel->backlight.device->props.brightness = - panel->backlight.level; + scale_hw_to_user(connector, + panel->backlight.level, + panel->backlight.device->props.max_brightness); } dev_priv->display.enable_backlight(connector); @@ -889,11 +981,15 @@ static int intel_backlight_device_get_brightness(struct backlight_device *bd) struct intel_connector *connector = bl_get_data(bd); struct drm_device *dev = connector->base.dev; struct drm_i915_private *dev_priv = dev->dev_private; + u32 hw_level; int ret; intel_runtime_pm_get(dev_priv); drm_modeset_lock(&dev->mode_config.connection_mutex, NULL); - ret = intel_panel_get_backlight(connector); + + hw_level = intel_panel_get_backlight(connector); + ret = scale_hw_to_user(connector, hw_level, bd->props.max_brightness); + drm_modeset_unlock(&dev->mode_config.connection_mutex); intel_runtime_pm_put(dev_priv); @@ -913,12 +1009,19 @@ static int intel_backlight_device_register(struct intel_connector *connector) if (WARN_ON(panel->backlight.device)) return -ENODEV; - BUG_ON(panel->backlight.max == 0); + WARN_ON(panel->backlight.max == 0); memset(&props, 0, sizeof(props)); props.type = BACKLIGHT_RAW; - props.brightness = panel->backlight.level; + + /* + * Note: Everything should work even if the backlight device max + * presented to the userspace is arbitrarily chosen. + */ props.max_brightness = panel->backlight.max; + props.brightness = scale_hw_to_user(connector, + panel->backlight.level, + props.max_brightness); /* * Note: using the same name independent of the connector prevents @@ -964,6 +1067,19 @@ static void intel_backlight_device_unregister(struct intel_connector *connector) * XXX: Query mode clock or hardware clock and program PWM modulation frequency * appropriately when it's 0. Use VBT and/or sane defaults. */ +static u32 get_backlight_min_vbt(struct intel_connector *connector) +{ + struct drm_device *dev = connector->base.dev; + struct drm_i915_private *dev_priv = dev->dev_private; + struct intel_panel *panel = &connector->panel; + + WARN_ON(panel->backlight.max == 0); + + /* vbt value is a coefficient in range [0..255] */ + return scale(dev_priv->vbt.backlight.min_brightness, 0, 255, + 0, panel->backlight.max); +} + static int bdw_setup_backlight(struct intel_connector *connector) { struct drm_device *dev = connector->base.dev; @@ -979,6 +1095,8 @@ static int bdw_setup_backlight(struct intel_connector *connector) if (!panel->backlight.max) return -ENODEV; + panel->backlight.min = get_backlight_min_vbt(connector); + val = bdw_get_backlight(connector); panel->backlight.level = intel_panel_compute_brightness(connector, val); @@ -1003,6 +1121,8 @@ static int pch_setup_backlight(struct intel_connector *connector) if (!panel->backlight.max) return -ENODEV; + panel->backlight.min = get_backlight_min_vbt(connector); + val = pch_get_backlight(connector); panel->backlight.level = intel_panel_compute_brightness(connector, val); @@ -1035,6 +1155,8 @@ static int i9xx_setup_backlight(struct intel_connector *connector) if (!panel->backlight.max) return -ENODEV; + panel->backlight.min = get_backlight_min_vbt(connector); + val = i9xx_get_backlight(connector); panel->backlight.level = intel_panel_compute_brightness(connector, val); @@ -1062,6 +1184,8 @@ static int i965_setup_backlight(struct intel_connector *connector) if (!panel->backlight.max) return -ENODEV; + panel->backlight.min = get_backlight_min_vbt(connector); + val = i9xx_get_backlight(connector); panel->backlight.level = intel_panel_compute_brightness(connector, val); @@ -1099,6 +1223,8 @@ static int vlv_setup_backlight(struct intel_connector *connector) if (!panel->backlight.max) return -ENODEV; + panel->backlight.min = get_backlight_min_vbt(connector); + val = _vlv_get_backlight(dev, PIPE_A); panel->backlight.level = intel_panel_compute_brightness(connector, val); |