path: root/drivers/gpu/drm/i915/intel_drv.h
diff options
authorJani Nikula <jani.nikula@intel.com>2014-06-24 18:27:40 +0300
committerDaniel Vetter <daniel.vetter@ffwll.ch>2014-07-23 07:07:18 +0200
commit6dda730e55f412a6dfb181cae6784822ba463847 (patch)
tree8af4bf0685d6f1e23bcb26ecb59daa658b70a763 /drivers/gpu/drm/i915/intel_drv.h
parent1de6068eb755cf8f87b985277fc396903d6bccd2 (diff)
drm/i915: respect the VBT minimum backlight brightness
Historically we've exposed the full backlight PWM duty cycle range to the userspace, in the name of "mechanism, not policy". However, it turns out there are both panels and board designs where there is a minimum duty cycle that is required for proper operation. The minimum duty cycle is available in the VBT. The backlight class sysfs interface does not make any promises to the userspace about the physical meaning of the range 0..max_brightness. Specifically there is no guarantee that 0 means off; indeed for acpi_backlight 0 usually is not off, but the minimum acceptable value. Respect the minimum backlight, and expose the range acceptable to the hardware as 0..max_brightness to the userspace via the backlight class device; 0 means the minimum acceptable enabled value. To switch off the backlight, the user must disable the encoder. As a side effect, make the backlight class device max brightness and physical PWM modulation frequency (i.e. max duty cycle) independent. This allows a follow-up patch to virtualize the max value exposed to the userspace. Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org> [danvet: s/BUG_ON/WARN_ON/] Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_drv.h')
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 8fc68c783228..bb9042bde7dd 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -165,6 +165,7 @@ struct intel_panel {
struct {
bool present;
u32 level;
+ u32 min;
u32 max;
bool enabled;
bool combination_mode; /* gen 2/4 only */
@@ -969,8 +970,8 @@ void intel_pch_panel_fitting(struct intel_crtc *crtc,
void intel_gmch_panel_fitting(struct intel_crtc *crtc,
struct intel_crtc_config *pipe_config,
int fitting_mode);
-void intel_panel_set_backlight(struct intel_connector *connector, u32 level,
- u32 max);
+void intel_panel_set_backlight_acpi(struct intel_connector *connector,
+ u32 level, u32 max);
int intel_panel_setup_backlight(struct drm_connector *connector);
void intel_panel_enable_backlight(struct intel_connector *connector);
void intel_panel_disable_backlight(struct intel_connector *connector);