drm/i915: handle backlight through chip specific functions

The backlight code has grown rather hairy, not least because the
hardware registers and bits have repeatedly been shuffled around. And
this isn't expected to get any easier with new hardware. Make things
easier for our (read: my) poor brains, and split the code up into chip
specific functions.

There should be no functional changes.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -351,6 +351,7 @@ struct drm_i915_error_state {
 	enum intel_ring_hangcheck_action hangcheck_action[I915_NUM_RINGS];
 };
 
+struct intel_connector;
 struct intel_crtc_config;
 struct intel_crtc;
 struct intel_limit;
@@ -413,6 +414,14 @@ struct drm_i915_display_funcs {
 	/* render clock increase/decrease */
 	/* display clock increase/decrease */
 	/* pll clock increase/decrease */
+
+	int (*setup_backlight)(struct intel_connector *connector);
+	uint32_t (*get_max_backlight)(struct intel_connector *connector);
+	uint32_t (*get_backlight)(struct intel_connector *connector);
+	void (*set_backlight)(struct intel_connector *connector,
+			      uint32_t level);
+	void (*disable_backlight)(struct intel_connector *connector);
+	void (*enable_backlight)(struct intel_connector *connector);
 };
 
 struct intel_uncore_funcs {

drivers/gpu/drm/i915/intel_display.c

@@ -10418,6 +10418,8 @@ static void intel_init_display(struct drm_device *dev)
 		dev_priv->display.queue_flip = intel_gen7_queue_flip;
 		break;
 	}
+
+	intel_panel_init_backlight_funcs(dev);
 }
 
 /*

drivers/gpu/drm/i915/intel_drv.h

@@ -161,6 +161,7 @@ struct intel_panel {
 	struct {
 		bool present;
 		u32 level;
+		u32 max;
 		bool enabled;
 		struct backlight_device *device;
 	} backlight;
@@ -817,6 +818,7 @@ 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);
 void intel_panel_destroy_backlight(struct drm_connector *connector);
+void intel_panel_init_backlight_funcs(struct drm_device *dev);
 enum drm_connector_status intel_panel_detect(struct drm_device *dev);