--- zzzz-none-000/linux-3.10.107/drivers/gpu/drm/i915/intel_panel.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/gpu/drm/i915/intel_panel.c	2021-02-04 17:41:59.000000000 +0000
@@ -30,455 +30,1783 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/kernel.h>
 #include <linux/moduleparam.h>
+#include <linux/pwm.h>
 #include "intel_drv.h"
 
-#define PCI_LBPC 0xf4 /* legacy/combination backlight modes */
+#define CRC_PMIC_PWM_PERIOD_NS	21333
 
 void
-intel_fixed_panel_mode(struct drm_display_mode *fixed_mode,
+intel_fixed_panel_mode(const struct drm_display_mode *fixed_mode,
 		       struct drm_display_mode *adjusted_mode)
 {
-	adjusted_mode->hdisplay = fixed_mode->hdisplay;
-	adjusted_mode->hsync_start = fixed_mode->hsync_start;
-	adjusted_mode->hsync_end = fixed_mode->hsync_end;
-	adjusted_mode->htotal = fixed_mode->htotal;
-
-	adjusted_mode->vdisplay = fixed_mode->vdisplay;
-	adjusted_mode->vsync_start = fixed_mode->vsync_start;
-	adjusted_mode->vsync_end = fixed_mode->vsync_end;
-	adjusted_mode->vtotal = fixed_mode->vtotal;
+	drm_mode_copy(adjusted_mode, fixed_mode);
 
-	adjusted_mode->clock = fixed_mode->clock;
+	drm_mode_set_crtcinfo(adjusted_mode, 0);
+}
+
+/**
+ * intel_find_panel_downclock - find the reduced downclock for LVDS in EDID
+ * @dev: drm device
+ * @fixed_mode : panel native mode
+ * @connector: LVDS/eDP connector
+ *
+ * Return downclock_avail
+ * Find the reduced downclock for LVDS/eDP in EDID.
+ */
+struct drm_display_mode *
+intel_find_panel_downclock(struct drm_device *dev,
+			struct drm_display_mode *fixed_mode,
+			struct drm_connector *connector)
+{
+	struct drm_display_mode *scan, *tmp_mode;
+	int temp_downclock;
+
+	temp_downclock = fixed_mode->clock;
+	tmp_mode = NULL;
+
+	list_for_each_entry(scan, &connector->probed_modes, head) {
+		/*
+		 * If one mode has the same resolution with the fixed_panel
+		 * mode while they have the different refresh rate, it means
+		 * that the reduced downclock is found. In such
+		 * case we can set the different FPx0/1 to dynamically select
+		 * between low and high frequency.
+		 */
+		if (scan->hdisplay == fixed_mode->hdisplay &&
+		    scan->hsync_start == fixed_mode->hsync_start &&
+		    scan->hsync_end == fixed_mode->hsync_end &&
+		    scan->htotal == fixed_mode->htotal &&
+		    scan->vdisplay == fixed_mode->vdisplay &&
+		    scan->vsync_start == fixed_mode->vsync_start &&
+		    scan->vsync_end == fixed_mode->vsync_end &&
+		    scan->vtotal == fixed_mode->vtotal) {
+			if (scan->clock < temp_downclock) {
+				/*
+				 * The downclock is already found. But we
+				 * expect to find the lower downclock.
+				 */
+				temp_downclock = scan->clock;
+				tmp_mode = scan;
+			}
+		}
+	}
+
+	if (temp_downclock < fixed_mode->clock)
+		return drm_mode_duplicate(dev, tmp_mode);
+	else
+		return NULL;
 }
 
 /* adjusted_mode has been preset to be the panel's fixed mode */
 void
-intel_pch_panel_fitting(struct drm_device *dev,
-			int fitting_mode,
-			const struct drm_display_mode *mode,
-			struct drm_display_mode *adjusted_mode)
+intel_pch_panel_fitting(struct intel_crtc *intel_crtc,
+			struct intel_crtc_state *pipe_config,
+			int fitting_mode)
 {
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	int x, y, width, height;
-
-	x = y = width = height = 0;
+	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
+	int x = 0, y = 0, width = 0, height = 0;
 
 	/* Native modes don't need fitting */
-	if (adjusted_mode->hdisplay == mode->hdisplay &&
-	    adjusted_mode->vdisplay == mode->vdisplay)
+	if (adjusted_mode->crtc_hdisplay == pipe_config->pipe_src_w &&
+	    adjusted_mode->crtc_vdisplay == pipe_config->pipe_src_h)
 		goto done;
 
 	switch (fitting_mode) {
 	case DRM_MODE_SCALE_CENTER:
-		width = mode->hdisplay;
-		height = mode->vdisplay;
-		x = (adjusted_mode->hdisplay - width + 1)/2;
-		y = (adjusted_mode->vdisplay - height + 1)/2;
+		width = pipe_config->pipe_src_w;
+		height = pipe_config->pipe_src_h;
+		x = (adjusted_mode->crtc_hdisplay - width + 1)/2;
+		y = (adjusted_mode->crtc_vdisplay - height + 1)/2;
 		break;
 
 	case DRM_MODE_SCALE_ASPECT:
 		/* Scale but preserve the aspect ratio */
 		{
-			u32 scaled_width = adjusted_mode->hdisplay * mode->vdisplay;
-			u32 scaled_height = mode->hdisplay * adjusted_mode->vdisplay;
+			u32 scaled_width = adjusted_mode->crtc_hdisplay
+				* pipe_config->pipe_src_h;
+			u32 scaled_height = pipe_config->pipe_src_w
+				* adjusted_mode->crtc_vdisplay;
 			if (scaled_width > scaled_height) { /* pillar */
-				width = scaled_height / mode->vdisplay;
+				width = scaled_height / pipe_config->pipe_src_h;
 				if (width & 1)
 					width++;
-				x = (adjusted_mode->hdisplay - width + 1) / 2;
+				x = (adjusted_mode->crtc_hdisplay - width + 1) / 2;
 				y = 0;
-				height = adjusted_mode->vdisplay;
+				height = adjusted_mode->crtc_vdisplay;
 			} else if (scaled_width < scaled_height) { /* letter */
-				height = scaled_width / mode->hdisplay;
+				height = scaled_width / pipe_config->pipe_src_w;
 				if (height & 1)
 				    height++;
-				y = (adjusted_mode->vdisplay - height + 1) / 2;
+				y = (adjusted_mode->crtc_vdisplay - height + 1) / 2;
 				x = 0;
-				width = adjusted_mode->hdisplay;
+				width = adjusted_mode->crtc_hdisplay;
 			} else {
 				x = y = 0;
-				width = adjusted_mode->hdisplay;
-				height = adjusted_mode->vdisplay;
+				width = adjusted_mode->crtc_hdisplay;
+				height = adjusted_mode->crtc_vdisplay;
 			}
 		}
 		break;
 
-	default:
 	case DRM_MODE_SCALE_FULLSCREEN:
 		x = y = 0;
-		width = adjusted_mode->hdisplay;
-		height = adjusted_mode->vdisplay;
+		width = adjusted_mode->crtc_hdisplay;
+		height = adjusted_mode->crtc_vdisplay;
 		break;
+
+	default:
+		WARN(1, "bad panel fit mode: %d\n", fitting_mode);
+		return;
 	}
 
 done:
-	dev_priv->pch_pf_pos = (x << 16) | y;
-	dev_priv->pch_pf_size = (width << 16) | height;
+	pipe_config->pch_pfit.pos = (x << 16) | y;
+	pipe_config->pch_pfit.size = (width << 16) | height;
+	pipe_config->pch_pfit.enabled = pipe_config->pch_pfit.size != 0;
 }
 
-static int is_backlight_combination_mode(struct drm_device *dev)
+static void
+centre_horizontally(struct drm_display_mode *adjusted_mode,
+		    int width)
 {
-	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 border, sync_pos, blank_width, sync_width;
 
-	if (INTEL_INFO(dev)->gen >= 4)
-		return I915_READ(BLC_PWM_CTL2) & BLM_COMBINATION_MODE;
+	/* keep the hsync and hblank widths constant */
+	sync_width = adjusted_mode->crtc_hsync_end - adjusted_mode->crtc_hsync_start;
+	blank_width = adjusted_mode->crtc_hblank_end - adjusted_mode->crtc_hblank_start;
+	sync_pos = (blank_width - sync_width + 1) / 2;
 
-	if (IS_GEN2(dev))
-		return I915_READ(BLC_PWM_CTL) & BLM_LEGACY_MODE;
+	border = (adjusted_mode->crtc_hdisplay - width + 1) / 2;
+	border += border & 1; /* make the border even */
 
-	return 0;
+	adjusted_mode->crtc_hdisplay = width;
+	adjusted_mode->crtc_hblank_start = width + border;
+	adjusted_mode->crtc_hblank_end = adjusted_mode->crtc_hblank_start + blank_width;
+
+	adjusted_mode->crtc_hsync_start = adjusted_mode->crtc_hblank_start + sync_pos;
+	adjusted_mode->crtc_hsync_end = adjusted_mode->crtc_hsync_start + sync_width;
 }
 
-static u32 i915_read_blc_pwm_ctl(struct drm_device *dev)
+static void
+centre_vertically(struct drm_display_mode *adjusted_mode,
+		  int height)
 {
-	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32 val;
+	u32 border, sync_pos, blank_width, sync_width;
+
+	/* keep the vsync and vblank widths constant */
+	sync_width = adjusted_mode->crtc_vsync_end - adjusted_mode->crtc_vsync_start;
+	blank_width = adjusted_mode->crtc_vblank_end - adjusted_mode->crtc_vblank_start;
+	sync_pos = (blank_width - sync_width + 1) / 2;
 
-	/* Restore the CTL value if it lost, e.g. GPU reset */
+	border = (adjusted_mode->crtc_vdisplay - height + 1) / 2;
 
-	if (HAS_PCH_SPLIT(dev_priv->dev)) {
-		val = I915_READ(BLC_PWM_PCH_CTL2);
-		if (dev_priv->regfile.saveBLC_PWM_CTL2 == 0) {
-			dev_priv->regfile.saveBLC_PWM_CTL2 = val;
-		} else if (val == 0) {
-			val = dev_priv->regfile.saveBLC_PWM_CTL2;
-			I915_WRITE(BLC_PWM_PCH_CTL2, val);
+	adjusted_mode->crtc_vdisplay = height;
+	adjusted_mode->crtc_vblank_start = height + border;
+	adjusted_mode->crtc_vblank_end = adjusted_mode->crtc_vblank_start + blank_width;
+
+	adjusted_mode->crtc_vsync_start = adjusted_mode->crtc_vblank_start + sync_pos;
+	adjusted_mode->crtc_vsync_end = adjusted_mode->crtc_vsync_start + sync_width;
+}
+
+static inline u32 panel_fitter_scaling(u32 source, u32 target)
+{
+	/*
+	 * Floating point operation is not supported. So the FACTOR
+	 * is defined, which can avoid the floating point computation
+	 * when calculating the panel ratio.
+	 */
+#define ACCURACY 12
+#define FACTOR (1 << ACCURACY)
+	u32 ratio = source * FACTOR / target;
+	return (FACTOR * ratio + FACTOR/2) / FACTOR;
+}
+
+static void i965_scale_aspect(struct intel_crtc_state *pipe_config,
+			      u32 *pfit_control)
+{
+	const struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
+	u32 scaled_width = adjusted_mode->crtc_hdisplay *
+		pipe_config->pipe_src_h;
+	u32 scaled_height = pipe_config->pipe_src_w *
+		adjusted_mode->crtc_vdisplay;
+
+	/* 965+ is easy, it does everything in hw */
+	if (scaled_width > scaled_height)
+		*pfit_control |= PFIT_ENABLE |
+			PFIT_SCALING_PILLAR;
+	else if (scaled_width < scaled_height)
+		*pfit_control |= PFIT_ENABLE |
+			PFIT_SCALING_LETTER;
+	else if (adjusted_mode->crtc_hdisplay != pipe_config->pipe_src_w)
+		*pfit_control |= PFIT_ENABLE | PFIT_SCALING_AUTO;
+}
+
+static void i9xx_scale_aspect(struct intel_crtc_state *pipe_config,
+			      u32 *pfit_control, u32 *pfit_pgm_ratios,
+			      u32 *border)
+{
+	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
+	u32 scaled_width = adjusted_mode->crtc_hdisplay *
+		pipe_config->pipe_src_h;
+	u32 scaled_height = pipe_config->pipe_src_w *
+		adjusted_mode->crtc_vdisplay;
+	u32 bits;
+
+	/*
+	 * For earlier chips we have to calculate the scaling
+	 * ratio by hand and program it into the
+	 * PFIT_PGM_RATIO register
+	 */
+	if (scaled_width > scaled_height) { /* pillar */
+		centre_horizontally(adjusted_mode,
+				    scaled_height /
+				    pipe_config->pipe_src_h);
+
+		*border = LVDS_BORDER_ENABLE;
+		if (pipe_config->pipe_src_h != adjusted_mode->crtc_vdisplay) {
+			bits = panel_fitter_scaling(pipe_config->pipe_src_h,
+						    adjusted_mode->crtc_vdisplay);
+
+			*pfit_pgm_ratios |= (bits << PFIT_HORIZ_SCALE_SHIFT |
+					     bits << PFIT_VERT_SCALE_SHIFT);
+			*pfit_control |= (PFIT_ENABLE |
+					  VERT_INTERP_BILINEAR |
+					  HORIZ_INTERP_BILINEAR);
+		}
+	} else if (scaled_width < scaled_height) { /* letter */
+		centre_vertically(adjusted_mode,
+				  scaled_width /
+				  pipe_config->pipe_src_w);
+
+		*border = LVDS_BORDER_ENABLE;
+		if (pipe_config->pipe_src_w != adjusted_mode->crtc_hdisplay) {
+			bits = panel_fitter_scaling(pipe_config->pipe_src_w,
+						    adjusted_mode->crtc_hdisplay);
+
+			*pfit_pgm_ratios |= (bits << PFIT_HORIZ_SCALE_SHIFT |
+					     bits << PFIT_VERT_SCALE_SHIFT);
+			*pfit_control |= (PFIT_ENABLE |
+					  VERT_INTERP_BILINEAR |
+					  HORIZ_INTERP_BILINEAR);
 		}
 	} else {
-		val = I915_READ(BLC_PWM_CTL);
-		if (dev_priv->regfile.saveBLC_PWM_CTL == 0) {
-			dev_priv->regfile.saveBLC_PWM_CTL = val;
-			if (INTEL_INFO(dev)->gen >= 4)
-				dev_priv->regfile.saveBLC_PWM_CTL2 =
-					I915_READ(BLC_PWM_CTL2);
-		} else if (val == 0) {
-			val = dev_priv->regfile.saveBLC_PWM_CTL;
-			I915_WRITE(BLC_PWM_CTL, val);
+		/* Aspects match, Let hw scale both directions */
+		*pfit_control |= (PFIT_ENABLE |
+				  VERT_AUTO_SCALE | HORIZ_AUTO_SCALE |
+				  VERT_INTERP_BILINEAR |
+				  HORIZ_INTERP_BILINEAR);
+	}
+}
+
+void intel_gmch_panel_fitting(struct intel_crtc *intel_crtc,
+			      struct intel_crtc_state *pipe_config,
+			      int fitting_mode)
+{
+	struct drm_device *dev = intel_crtc->base.dev;
+	u32 pfit_control = 0, pfit_pgm_ratios = 0, border = 0;
+	struct drm_display_mode *adjusted_mode = &pipe_config->base.adjusted_mode;
+
+	/* Native modes don't need fitting */
+	if (adjusted_mode->crtc_hdisplay == pipe_config->pipe_src_w &&
+	    adjusted_mode->crtc_vdisplay == pipe_config->pipe_src_h)
+		goto out;
+
+	switch (fitting_mode) {
+	case DRM_MODE_SCALE_CENTER:
+		/*
+		 * For centered modes, we have to calculate border widths &
+		 * heights and modify the values programmed into the CRTC.
+		 */
+		centre_horizontally(adjusted_mode, pipe_config->pipe_src_w);
+		centre_vertically(adjusted_mode, pipe_config->pipe_src_h);
+		border = LVDS_BORDER_ENABLE;
+		break;
+	case DRM_MODE_SCALE_ASPECT:
+		/* Scale but preserve the aspect ratio */
+		if (INTEL_INFO(dev)->gen >= 4)
+			i965_scale_aspect(pipe_config, &pfit_control);
+		else
+			i9xx_scale_aspect(pipe_config, &pfit_control,
+					  &pfit_pgm_ratios, &border);
+		break;
+	case DRM_MODE_SCALE_FULLSCREEN:
+		/*
+		 * Full scaling, even if it changes the aspect ratio.
+		 * Fortunately this is all done for us in hw.
+		 */
+		if (pipe_config->pipe_src_h != adjusted_mode->crtc_vdisplay ||
+		    pipe_config->pipe_src_w != adjusted_mode->crtc_hdisplay) {
+			pfit_control |= PFIT_ENABLE;
 			if (INTEL_INFO(dev)->gen >= 4)
-				I915_WRITE(BLC_PWM_CTL2,
-					   dev_priv->regfile.saveBLC_PWM_CTL2);
+				pfit_control |= PFIT_SCALING_AUTO;
+			else
+				pfit_control |= (VERT_AUTO_SCALE |
+						 VERT_INTERP_BILINEAR |
+						 HORIZ_AUTO_SCALE |
+						 HORIZ_INTERP_BILINEAR);
 		}
+		break;
+	default:
+		WARN(1, "bad panel fit mode: %d\n", fitting_mode);
+		return;
 	}
 
-	return val;
+	/* 965+ wants fuzzy fitting */
+	/* FIXME: handle multiple panels by failing gracefully */
+	if (INTEL_INFO(dev)->gen >= 4)
+		pfit_control |= ((intel_crtc->pipe << PFIT_PIPE_SHIFT) |
+				 PFIT_FILTER_FUZZY);
+
+out:
+	if ((pfit_control & PFIT_ENABLE) == 0) {
+		pfit_control = 0;
+		pfit_pgm_ratios = 0;
+	}
+
+	/* Make sure pre-965 set dither correctly for 18bpp panels. */
+	if (INTEL_INFO(dev)->gen < 4 && pipe_config->pipe_bpp == 18)
+		pfit_control |= PANEL_8TO6_DITHER_ENABLE;
+
+	pipe_config->gmch_pfit.control = pfit_control;
+	pipe_config->gmch_pfit.pgm_ratios = pfit_pgm_ratios;
+	pipe_config->gmch_pfit.lvds_border_bits = border;
 }
 
-static u32 _intel_panel_get_max_backlight(struct drm_device *dev)
+enum drm_connector_status
+intel_panel_detect(struct drm_device *dev)
 {
-	u32 max;
-
-	max = i915_read_blc_pwm_ctl(dev);
+	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	if (HAS_PCH_SPLIT(dev)) {
-		max >>= 16;
-	} else {
-		if (INTEL_INFO(dev)->gen < 4)
-			max >>= 17;
-		else
-			max >>= 16;
+	/* Assume that the BIOS does not lie through the OpRegion... */
+	if (!i915.panel_ignore_lid && dev_priv->opregion.lid_state) {
+		return *dev_priv->opregion.lid_state & 0x1 ?
+			connector_status_connected :
+			connector_status_disconnected;
+	}
 
-		if (is_backlight_combination_mode(dev))
-			max *= 0xff;
+	switch (i915.panel_ignore_lid) {
+	case -2:
+		return connector_status_connected;
+	case -1:
+		return connector_status_disconnected;
+	default:
+		return connector_status_unknown;
 	}
+}
+
+/**
+ * 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);
 
-	return max;
+	/* avoid overflows */
+	target_val = DIV_ROUND_CLOSEST_ULL((uint64_t)(source_val - source_min) *
+			(target_max - target_min), source_max - source_min);
+	target_val += target_min;
+
+	return target_val;
 }
 
-u32 intel_panel_get_max_backlight(struct drm_device *dev)
+/* 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)
 {
-	u32 max;
+	struct intel_panel *panel = &connector->panel;
 
-	max = _intel_panel_get_max_backlight(dev);
-	if (max == 0) {
-		/* XXX add code here to query mode clock or hardware clock
-		 * and program max PWM appropriately.
-		 */
-		pr_warn_once("fixme: max PWM is zero\n");
-		return 1;
-	}
+	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;
 
-	DRM_DEBUG_DRIVER("max backlight PWM = %d\n", max);
-	return max;
+	return scale(hw_level, panel->backlight.min, panel->backlight.max,
+		     0, user_max);
 }
 
-static int i915_panel_invert_brightness;
-MODULE_PARM_DESC(invert_brightness, "Invert backlight brightness "
-	"(-1 force normal, 0 machine defaults, 1 force inversion), please "
-	"report PCI device ID, subsystem vendor and subsystem device ID "
-	"to dri-devel@lists.freedesktop.org, if your machine needs it. "
-	"It will then be included in an upcoming module version.");
-module_param_named(invert_brightness, i915_panel_invert_brightness, int, 0600);
-static u32 intel_panel_compute_brightness(struct drm_device *dev, u32 val)
+static u32 intel_panel_compute_brightness(struct intel_connector *connector,
+					  u32 val)
 {
+	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);
 
-	if (i915_panel_invert_brightness < 0)
+	if (i915.invert_brightness < 0)
 		return val;
 
-	if (i915_panel_invert_brightness > 0 ||
-	    dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS)
-		return intel_panel_get_max_backlight(dev) - val;
+	if (i915.invert_brightness > 0 ||
+	    dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS) {
+		return panel->backlight.max - val;
+	}
 
 	return val;
 }
 
-static u32 intel_panel_get_backlight(struct drm_device *dev)
+static u32 lpt_get_backlight(struct intel_connector *connector)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	return I915_READ(BLC_PWM_PCH_CTL2) & BACKLIGHT_DUTY_CYCLE_MASK;
+}
+
+static u32 pch_get_backlight(struct intel_connector *connector)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	return I915_READ(BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
+}
+
+static u32 i9xx_get_backlight(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;
 	u32 val;
 
-	if (HAS_PCH_SPLIT(dev)) {
-		val = I915_READ(BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
-	} else {
-		val = I915_READ(BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
-		if (INTEL_INFO(dev)->gen < 4)
-			val >>= 1;
+	val = I915_READ(BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
+	if (INTEL_INFO(dev)->gen < 4)
+		val >>= 1;
 
-		if (is_backlight_combination_mode(dev)) {
-			u8 lbpc;
+	if (panel->backlight.combination_mode) {
+		u8 lbpc;
 
-			pci_read_config_byte(dev->pdev, PCI_LBPC, &lbpc);
-			val *= lbpc;
-		}
+		pci_read_config_byte(dev->pdev, PCI_LBPC, &lbpc);
+		val *= lbpc;
+	}
+
+	return val;
+}
+
+static u32 _vlv_get_backlight(struct drm_device *dev, enum pipe pipe)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+		return 0;
+
+	return I915_READ(VLV_BLC_PWM_CTL(pipe)) & BACKLIGHT_DUTY_CYCLE_MASK;
+}
+
+static u32 vlv_get_backlight(struct intel_connector *connector)
+{
+	struct drm_device *dev = connector->base.dev;
+	enum pipe pipe = intel_get_pipe_from_connector(connector);
+
+	return _vlv_get_backlight(dev, pipe);
+}
+
+static u32 bxt_get_backlight(struct intel_connector *connector)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct intel_panel *panel = &connector->panel;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	return I915_READ(BXT_BLC_PWM_DUTY(panel->backlight.controller));
+}
+
+static u32 pwm_get_backlight(struct intel_connector *connector)
+{
+	struct intel_panel *panel = &connector->panel;
+	int duty_ns;
+
+	duty_ns = pwm_get_duty_cycle(panel->backlight.pwm);
+	return DIV_ROUND_UP(duty_ns * 100, CRC_PMIC_PWM_PERIOD_NS);
+}
+
+static u32 intel_panel_get_backlight(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;
+	u32 val = 0;
+
+	mutex_lock(&dev_priv->backlight_lock);
+
+	if (panel->backlight.enabled) {
+		val = panel->backlight.get(connector);
+		val = intel_panel_compute_brightness(connector, val);
 	}
 
-	val = intel_panel_compute_brightness(dev, val);
+	mutex_unlock(&dev_priv->backlight_lock);
+
 	DRM_DEBUG_DRIVER("get backlight PWM = %d\n", val);
 	return val;
 }
 
-static void intel_pch_panel_set_backlight(struct drm_device *dev, u32 level)
+static void lpt_set_backlight(struct intel_connector *connector, u32 level)
 {
+	struct drm_device *dev = connector->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	u32 val = I915_READ(BLC_PWM_CPU_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
-	I915_WRITE(BLC_PWM_CPU_CTL, val | level);
+	u32 val = I915_READ(BLC_PWM_PCH_CTL2) & ~BACKLIGHT_DUTY_CYCLE_MASK;
+	I915_WRITE(BLC_PWM_PCH_CTL2, val | level);
 }
 
-static void intel_panel_actually_set_backlight(struct drm_device *dev, u32 level)
+static void pch_set_backlight(struct intel_connector *connector, u32 level)
 {
+	struct drm_device *dev = connector->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	u32 tmp;
 
-	DRM_DEBUG_DRIVER("set backlight PWM = %d\n", level);
-	level = intel_panel_compute_brightness(dev, level);
+	tmp = I915_READ(BLC_PWM_CPU_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
+	I915_WRITE(BLC_PWM_CPU_CTL, tmp | level);
+}
+
+static void i9xx_set_backlight(struct intel_connector *connector, u32 level)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_panel *panel = &connector->panel;
+	u32 tmp, mask;
 
-	if (HAS_PCH_SPLIT(dev))
-		return intel_pch_panel_set_backlight(dev, level);
+	WARN_ON(panel->backlight.max == 0);
 
-	if (is_backlight_combination_mode(dev)) {
-		u32 max = intel_panel_get_max_backlight(dev);
+	if (panel->backlight.combination_mode) {
 		u8 lbpc;
 
-		lbpc = level * 0xfe / max + 1;
+		lbpc = level * 0xfe / panel->backlight.max + 1;
 		level /= lbpc;
 		pci_write_config_byte(dev->pdev, PCI_LBPC, lbpc);
 	}
 
-	tmp = I915_READ(BLC_PWM_CTL);
-	if (INTEL_INFO(dev)->gen < 4)
+	if (IS_GEN4(dev)) {
+		mask = BACKLIGHT_DUTY_CYCLE_MASK;
+	} else {
 		level <<= 1;
-	tmp &= ~BACKLIGHT_DUTY_CYCLE_MASK;
+		mask = BACKLIGHT_DUTY_CYCLE_MASK_PNV;
+	}
+
+	tmp = I915_READ(BLC_PWM_CTL) & ~mask;
 	I915_WRITE(BLC_PWM_CTL, tmp | level);
 }
 
-void intel_panel_set_backlight(struct drm_device *dev, u32 level)
+static void vlv_set_backlight(struct intel_connector *connector, u32 level)
 {
+	struct drm_device *dev = connector->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum pipe pipe = intel_get_pipe_from_connector(connector);
+	u32 tmp;
 
-	dev_priv->backlight.level = level;
-	if (dev_priv->backlight.device)
-		dev_priv->backlight.device->props.brightness = level;
+	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+		return;
 
-	if (dev_priv->backlight.enabled)
-		intel_panel_actually_set_backlight(dev, level);
+	tmp = I915_READ(VLV_BLC_PWM_CTL(pipe)) & ~BACKLIGHT_DUTY_CYCLE_MASK;
+	I915_WRITE(VLV_BLC_PWM_CTL(pipe), tmp | level);
 }
 
-void intel_panel_disable_backlight(struct drm_device *dev)
+static void bxt_set_backlight(struct intel_connector *connector, u32 level)
 {
+	struct drm_device *dev = connector->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_panel *panel = &connector->panel;
 
-	dev_priv->backlight.enabled = false;
-	intel_panel_actually_set_backlight(dev, 0);
+	I915_WRITE(BXT_BLC_PWM_DUTY(panel->backlight.controller), level);
+}
 
-	if (INTEL_INFO(dev)->gen >= 4) {
-		uint32_t reg, tmp;
+static void pwm_set_backlight(struct intel_connector *connector, u32 level)
+{
+	struct intel_panel *panel = &connector->panel;
+	int duty_ns = DIV_ROUND_UP(level * CRC_PMIC_PWM_PERIOD_NS, 100);
 
-		reg = HAS_PCH_SPLIT(dev) ? BLC_PWM_CPU_CTL2 : BLC_PWM_CTL2;
+	pwm_config(panel->backlight.pwm, duty_ns, CRC_PMIC_PWM_PERIOD_NS);
+}
 
-		I915_WRITE(reg, I915_READ(reg) & ~BLM_PWM_ENABLE);
+static void
+intel_panel_actually_set_backlight(struct intel_connector *connector, u32 level)
+{
+	struct intel_panel *panel = &connector->panel;
 
-		if (HAS_PCH_SPLIT(dev)) {
-			tmp = I915_READ(BLC_PWM_PCH_CTL1);
-			tmp &= ~BLM_PCH_PWM_ENABLE;
-			I915_WRITE(BLC_PWM_PCH_CTL1, tmp);
-		}
+	DRM_DEBUG_DRIVER("set backlight PWM = %d\n", level);
+
+	level = intel_panel_compute_brightness(connector, level);
+	panel->backlight.set(connector, level);
+}
+
+/* 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;
+	u32 hw_level;
+
+	if (!panel->backlight.present)
+		return;
+
+	mutex_lock(&dev_priv->backlight_lock);
+
+	WARN_ON(panel->backlight.max == 0);
+
+	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);
+
+	mutex_unlock(&dev_priv->backlight_lock);
+}
+
+/* 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;
+
+	/*
+	 * INVALID_PIPE may occur during driver init because
+	 * connection_mutex isn't held across the entire backlight
+	 * setup + modeset readout, and the BIOS can issue the
+	 * requests at any time.
+	 */
+	if (!panel->backlight.present || pipe == INVALID_PIPE)
+		return;
+
+	mutex_lock(&dev_priv->backlight_lock);
+
+	WARN_ON(panel->backlight.max == 0);
+
+	hw_level = clamp_user_to_hw(connector, user_level, user_max);
+	panel->backlight.level = hw_level;
+
+	if (panel->backlight.device)
+		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, hw_level);
+
+	mutex_unlock(&dev_priv->backlight_lock);
+}
+
+static void lpt_disable_backlight(struct intel_connector *connector)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 tmp;
+
+	intel_panel_actually_set_backlight(connector, 0);
+
+	/*
+	 * Although we don't support or enable CPU PWM with LPT/SPT based
+	 * systems, it may have been enabled prior to loading the
+	 * driver. Disable to avoid warnings on LCPLL disable.
+	 *
+	 * This needs rework if we need to add support for CPU PWM on PCH split
+	 * platforms.
+	 */
+	tmp = I915_READ(BLC_PWM_CPU_CTL2);
+	if (tmp & BLM_PWM_ENABLE) {
+		DRM_DEBUG_KMS("cpu backlight was enabled, disabling\n");
+		I915_WRITE(BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE);
+	}
+
+	tmp = I915_READ(BLC_PWM_PCH_CTL1);
+	I915_WRITE(BLC_PWM_PCH_CTL1, tmp & ~BLM_PCH_PWM_ENABLE);
+}
+
+static void pch_disable_backlight(struct intel_connector *connector)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 tmp;
+
+	intel_panel_actually_set_backlight(connector, 0);
+
+	tmp = I915_READ(BLC_PWM_CPU_CTL2);
+	I915_WRITE(BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE);
+
+	tmp = I915_READ(BLC_PWM_PCH_CTL1);
+	I915_WRITE(BLC_PWM_PCH_CTL1, tmp & ~BLM_PCH_PWM_ENABLE);
+}
+
+static void i9xx_disable_backlight(struct intel_connector *connector)
+{
+	intel_panel_actually_set_backlight(connector, 0);
+}
+
+static void i965_disable_backlight(struct intel_connector *connector)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 tmp;
+
+	intel_panel_actually_set_backlight(connector, 0);
+
+	tmp = I915_READ(BLC_PWM_CTL2);
+	I915_WRITE(BLC_PWM_CTL2, tmp & ~BLM_PWM_ENABLE);
+}
+
+static void vlv_disable_backlight(struct intel_connector *connector)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	enum pipe pipe = intel_get_pipe_from_connector(connector);
+	u32 tmp;
+
+	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+		return;
+
+	intel_panel_actually_set_backlight(connector, 0);
+
+	tmp = I915_READ(VLV_BLC_PWM_CTL2(pipe));
+	I915_WRITE(VLV_BLC_PWM_CTL2(pipe), tmp & ~BLM_PWM_ENABLE);
+}
+
+static void bxt_disable_backlight(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;
+	u32 tmp, val;
+
+	intel_panel_actually_set_backlight(connector, 0);
+
+	tmp = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
+	I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller),
+			tmp & ~BXT_BLC_PWM_ENABLE);
+
+	if (panel->backlight.controller == 1) {
+		val = I915_READ(UTIL_PIN_CTL);
+		val &= ~UTIL_PIN_ENABLE;
+		I915_WRITE(UTIL_PIN_CTL, val);
 	}
 }
 
-void intel_panel_enable_backlight(struct drm_device *dev,
-				  enum pipe pipe)
+static void pwm_disable_backlight(struct intel_connector *connector)
+{
+	struct intel_panel *panel = &connector->panel;
+
+	/* Disable the backlight */
+	pwm_config(panel->backlight.pwm, 0, CRC_PMIC_PWM_PERIOD_NS);
+	usleep_range(2000, 3000);
+	pwm_disable(panel->backlight.pwm);
+}
+
+void intel_panel_disable_backlight(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;
 
-	if (dev_priv->backlight.level == 0) {
-		dev_priv->backlight.level = intel_panel_get_max_backlight(dev);
-		if (dev_priv->backlight.device)
-			dev_priv->backlight.device->props.brightness =
-				dev_priv->backlight.level;
+	if (!panel->backlight.present)
+		return;
+
+	/*
+	 * Do not disable backlight on the vga_switcheroo path. When switching
+	 * away from i915, the other client may depend on i915 to handle the
+	 * backlight. This will leave the backlight on unnecessarily when
+	 * another client is not activated.
+	 */
+	if (dev->switch_power_state == DRM_SWITCH_POWER_CHANGING) {
+		DRM_DEBUG_DRIVER("Skipping backlight disable on vga switch\n");
+		return;
 	}
 
-	if (INTEL_INFO(dev)->gen >= 4) {
-		uint32_t reg, tmp;
+	mutex_lock(&dev_priv->backlight_lock);
 
-		reg = HAS_PCH_SPLIT(dev) ? BLC_PWM_CPU_CTL2 : BLC_PWM_CTL2;
+	if (panel->backlight.device)
+		panel->backlight.device->props.power = FB_BLANK_POWERDOWN;
+	panel->backlight.enabled = false;
+	panel->backlight.disable(connector);
 
+	mutex_unlock(&dev_priv->backlight_lock);
+}
+
+static void lpt_enable_backlight(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;
+	u32 pch_ctl1, pch_ctl2;
 
-		tmp = I915_READ(reg);
+	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
+	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
+		DRM_DEBUG_KMS("pch backlight already enabled\n");
+		pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
+		I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
+	}
 
-		/* Note that this can also get called through dpms changes. And
-		 * we don't track the backlight dpms state, hence check whether
-		 * we have to do anything first. */
-		if (tmp & BLM_PWM_ENABLE)
-			goto set_level;
+	pch_ctl2 = panel->backlight.max << 16;
+	I915_WRITE(BLC_PWM_PCH_CTL2, pch_ctl2);
 
-		if (INTEL_INFO(dev)->num_pipes == 3)
-			tmp &= ~BLM_PIPE_SELECT_IVB;
-		else
-			tmp &= ~BLM_PIPE_SELECT;
+	pch_ctl1 = 0;
+	if (panel->backlight.active_low_pwm)
+		pch_ctl1 |= BLM_PCH_POLARITY;
 
-		tmp |= BLM_PIPE(pipe);
-		tmp &= ~BLM_PWM_ENABLE;
+	/* After LPT, override is the default. */
+	if (HAS_PCH_LPT(dev_priv))
+		pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;
 
-		I915_WRITE(reg, tmp);
-		POSTING_READ(reg);
-		I915_WRITE(reg, tmp | BLM_PWM_ENABLE);
-
-		if (HAS_PCH_SPLIT(dev) &&
-		    !(dev_priv->quirks & QUIRK_NO_PCH_PWM_ENABLE)) {
-			tmp = I915_READ(BLC_PWM_PCH_CTL1);
-			tmp |= BLM_PCH_PWM_ENABLE;
-			tmp &= ~BLM_PCH_OVERRIDE_ENABLE;
-			I915_WRITE(BLC_PWM_PCH_CTL1, tmp);
-		}
+	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
+	POSTING_READ(BLC_PWM_PCH_CTL1);
+	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);
+
+	/* This won't stick until the above enable. */
+	intel_panel_actually_set_backlight(connector, panel->backlight.level);
+}
+
+static void pch_enable_backlight(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;
+	enum pipe pipe = intel_get_pipe_from_connector(connector);
+	enum transcoder cpu_transcoder =
+		intel_pipe_to_cpu_transcoder(dev_priv, pipe);
+	u32 cpu_ctl2, pch_ctl1, pch_ctl2;
+
+	cpu_ctl2 = I915_READ(BLC_PWM_CPU_CTL2);
+	if (cpu_ctl2 & BLM_PWM_ENABLE) {
+		DRM_DEBUG_KMS("cpu backlight already enabled\n");
+		cpu_ctl2 &= ~BLM_PWM_ENABLE;
+		I915_WRITE(BLC_PWM_CPU_CTL2, cpu_ctl2);
 	}
 
-set_level:
-	/* Call below after setting BLC_PWM_CPU_CTL2 and BLC_PWM_PCH_CTL1.
-	 * BLC_PWM_CPU_CTL may be cleared to zero automatically when these
-	 * registers are set.
+	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
+	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
+		DRM_DEBUG_KMS("pch backlight already enabled\n");
+		pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
+		I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
+	}
+
+	if (cpu_transcoder == TRANSCODER_EDP)
+		cpu_ctl2 = BLM_TRANSCODER_EDP;
+	else
+		cpu_ctl2 = BLM_PIPE(cpu_transcoder);
+	I915_WRITE(BLC_PWM_CPU_CTL2, cpu_ctl2);
+	POSTING_READ(BLC_PWM_CPU_CTL2);
+	I915_WRITE(BLC_PWM_CPU_CTL2, cpu_ctl2 | BLM_PWM_ENABLE);
+
+	/* This won't stick until the above enable. */
+	intel_panel_actually_set_backlight(connector, panel->backlight.level);
+
+	pch_ctl2 = panel->backlight.max << 16;
+	I915_WRITE(BLC_PWM_PCH_CTL2, pch_ctl2);
+
+	pch_ctl1 = 0;
+	if (panel->backlight.active_low_pwm)
+		pch_ctl1 |= BLM_PCH_POLARITY;
+
+	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1);
+	POSTING_READ(BLC_PWM_PCH_CTL1);
+	I915_WRITE(BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);
+}
+
+static void i9xx_enable_backlight(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;
+	u32 ctl, freq;
+
+	ctl = I915_READ(BLC_PWM_CTL);
+	if (ctl & BACKLIGHT_DUTY_CYCLE_MASK_PNV) {
+		DRM_DEBUG_KMS("backlight already enabled\n");
+		I915_WRITE(BLC_PWM_CTL, 0);
+	}
+
+	freq = panel->backlight.max;
+	if (panel->backlight.combination_mode)
+		freq /= 0xff;
+
+	ctl = freq << 17;
+	if (panel->backlight.combination_mode)
+		ctl |= BLM_LEGACY_MODE;
+	if (IS_PINEVIEW(dev) && panel->backlight.active_low_pwm)
+		ctl |= BLM_POLARITY_PNV;
+
+	I915_WRITE(BLC_PWM_CTL, ctl);
+	POSTING_READ(BLC_PWM_CTL);
+
+	/* XXX: combine this into above write? */
+	intel_panel_actually_set_backlight(connector, panel->backlight.level);
+
+	/*
+	 * Needed to enable backlight on some 855gm models. BLC_HIST_CTL is
+	 * 855gm only, but checking for gen2 is safe, as 855gm is the only gen2
+	 * that has backlight.
 	 */
-	dev_priv->backlight.enabled = true;
-	intel_panel_actually_set_backlight(dev, dev_priv->backlight.level);
+	if (IS_GEN2(dev))
+		I915_WRITE(BLC_HIST_CTL, BLM_HISTOGRAM_ENABLE);
 }
 
-static void intel_panel_init_backlight(struct drm_device *dev)
+static void i965_enable_backlight(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;
+	enum pipe pipe = intel_get_pipe_from_connector(connector);
+	u32 ctl, ctl2, freq;
+
+	ctl2 = I915_READ(BLC_PWM_CTL2);
+	if (ctl2 & BLM_PWM_ENABLE) {
+		DRM_DEBUG_KMS("backlight already enabled\n");
+		ctl2 &= ~BLM_PWM_ENABLE;
+		I915_WRITE(BLC_PWM_CTL2, ctl2);
+	}
+
+	freq = panel->backlight.max;
+	if (panel->backlight.combination_mode)
+		freq /= 0xff;
 
-	dev_priv->backlight.level = intel_panel_get_backlight(dev);
-	dev_priv->backlight.enabled = dev_priv->backlight.level != 0;
+	ctl = freq << 16;
+	I915_WRITE(BLC_PWM_CTL, ctl);
+
+	ctl2 = BLM_PIPE(pipe);
+	if (panel->backlight.combination_mode)
+		ctl2 |= BLM_COMBINATION_MODE;
+	if (panel->backlight.active_low_pwm)
+		ctl2 |= BLM_POLARITY_I965;
+	I915_WRITE(BLC_PWM_CTL2, ctl2);
+	POSTING_READ(BLC_PWM_CTL2);
+	I915_WRITE(BLC_PWM_CTL2, ctl2 | BLM_PWM_ENABLE);
+
+	intel_panel_actually_set_backlight(connector, panel->backlight.level);
 }
 
-enum drm_connector_status
-intel_panel_detect(struct drm_device *dev)
+static void vlv_enable_backlight(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;
+	enum pipe pipe = intel_get_pipe_from_connector(connector);
+	u32 ctl, ctl2;
+
+	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+		return;
+
+	ctl2 = I915_READ(VLV_BLC_PWM_CTL2(pipe));
+	if (ctl2 & BLM_PWM_ENABLE) {
+		DRM_DEBUG_KMS("backlight already enabled\n");
+		ctl2 &= ~BLM_PWM_ENABLE;
+		I915_WRITE(VLV_BLC_PWM_CTL2(pipe), ctl2);
+	}
 
-	/* Assume that the BIOS does not lie through the OpRegion... */
-	if (!i915_panel_ignore_lid && dev_priv->opregion.lid_state) {
-		return ioread32(dev_priv->opregion.lid_state) & 0x1 ?
-			connector_status_connected :
-			connector_status_disconnected;
+	ctl = panel->backlight.max << 16;
+	I915_WRITE(VLV_BLC_PWM_CTL(pipe), ctl);
+
+	/* XXX: combine this into above write? */
+	intel_panel_actually_set_backlight(connector, panel->backlight.level);
+
+	ctl2 = 0;
+	if (panel->backlight.active_low_pwm)
+		ctl2 |= BLM_POLARITY_I965;
+	I915_WRITE(VLV_BLC_PWM_CTL2(pipe), ctl2);
+	POSTING_READ(VLV_BLC_PWM_CTL2(pipe));
+	I915_WRITE(VLV_BLC_PWM_CTL2(pipe), ctl2 | BLM_PWM_ENABLE);
+}
+
+static void bxt_enable_backlight(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;
+	enum pipe pipe = intel_get_pipe_from_connector(connector);
+	u32 pwm_ctl, val;
+
+	/* To use 2nd set of backlight registers, utility pin has to be
+	 * enabled with PWM mode.
+	 * The field should only be changed when the utility pin is disabled
+	 */
+	if (panel->backlight.controller == 1) {
+		val = I915_READ(UTIL_PIN_CTL);
+		if (val & UTIL_PIN_ENABLE) {
+			DRM_DEBUG_KMS("util pin already enabled\n");
+			val &= ~UTIL_PIN_ENABLE;
+			I915_WRITE(UTIL_PIN_CTL, val);
+		}
+
+		val = 0;
+		if (panel->backlight.util_pin_active_low)
+			val |= UTIL_PIN_POLARITY;
+		I915_WRITE(UTIL_PIN_CTL, val | UTIL_PIN_PIPE(pipe) |
+				UTIL_PIN_MODE_PWM | UTIL_PIN_ENABLE);
 	}
 
-	switch (i915_panel_ignore_lid) {
-	case -2:
-		return connector_status_connected;
-	case -1:
-		return connector_status_disconnected;
-	default:
-		return connector_status_unknown;
+	pwm_ctl = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
+	if (pwm_ctl & BXT_BLC_PWM_ENABLE) {
+		DRM_DEBUG_KMS("backlight already enabled\n");
+		pwm_ctl &= ~BXT_BLC_PWM_ENABLE;
+		I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller),
+				pwm_ctl);
 	}
+
+	I915_WRITE(BXT_BLC_PWM_FREQ(panel->backlight.controller),
+			panel->backlight.max);
+
+	intel_panel_actually_set_backlight(connector, panel->backlight.level);
+
+	pwm_ctl = 0;
+	if (panel->backlight.active_low_pwm)
+		pwm_ctl |= BXT_BLC_PWM_POLARITY;
+
+	I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller), pwm_ctl);
+	POSTING_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
+	I915_WRITE(BXT_BLC_PWM_CTL(panel->backlight.controller),
+			pwm_ctl | BXT_BLC_PWM_ENABLE);
 }
 
-#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
-static int intel_panel_update_status(struct backlight_device *bd)
+static void pwm_enable_backlight(struct intel_connector *connector)
 {
-	struct drm_device *dev = bl_get_data(bd);
-	intel_panel_set_backlight(dev, bd->props.brightness);
+	struct intel_panel *panel = &connector->panel;
+
+	pwm_enable(panel->backlight.pwm);
+	intel_panel_actually_set_backlight(connector, panel->backlight.level);
+}
+
+void intel_panel_enable_backlight(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;
+	enum pipe pipe = intel_get_pipe_from_connector(connector);
+
+	if (!panel->backlight.present)
+		return;
+
+	DRM_DEBUG_KMS("pipe %c\n", pipe_name(pipe));
+
+	mutex_lock(&dev_priv->backlight_lock);
+
+	WARN_ON(panel->backlight.max == 0);
+
+	if (panel->backlight.level <= panel->backlight.min) {
+		panel->backlight.level = panel->backlight.max;
+		if (panel->backlight.device)
+			panel->backlight.device->props.brightness =
+				scale_hw_to_user(connector,
+						 panel->backlight.level,
+						 panel->backlight.device->props.max_brightness);
+	}
+
+	panel->backlight.enable(connector);
+	panel->backlight.enabled = true;
+	if (panel->backlight.device)
+		panel->backlight.device->props.power = FB_BLANK_UNBLANK;
+
+	mutex_unlock(&dev_priv->backlight_lock);
+}
+
+#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
+static int intel_backlight_device_update_status(struct backlight_device *bd)
+{
+	struct intel_connector *connector = bl_get_data(bd);
+	struct intel_panel *panel = &connector->panel;
+	struct drm_device *dev = connector->base.dev;
+
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+	DRM_DEBUG_KMS("updating intel_backlight, brightness=%d/%d\n",
+		      bd->props.brightness, bd->props.max_brightness);
+	intel_panel_set_backlight(connector, bd->props.brightness,
+				  bd->props.max_brightness);
+
+	/*
+	 * Allow flipping bl_power as a sub-state of enabled. Sadly the
+	 * backlight class device does not make it easy to to differentiate
+	 * between callbacks for brightness and bl_power, so our backlight_power
+	 * callback needs to take this into account.
+	 */
+	if (panel->backlight.enabled) {
+		if (panel->backlight.power) {
+			bool enable = bd->props.power == FB_BLANK_UNBLANK &&
+				bd->props.brightness != 0;
+			panel->backlight.power(connector, enable);
+		}
+	} else {
+		bd->props.power = FB_BLANK_POWERDOWN;
+	}
+
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
 	return 0;
 }
 
-static int intel_panel_get_brightness(struct backlight_device *bd)
+static int intel_backlight_device_get_brightness(struct backlight_device *bd)
 {
-	struct drm_device *dev = bl_get_data(bd);
-	return intel_panel_get_backlight(dev);
+	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);
+
+	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);
+
+	return ret;
 }
 
-static const struct backlight_ops intel_panel_bl_ops = {
-	.update_status = intel_panel_update_status,
-	.get_brightness = intel_panel_get_brightness,
+static const struct backlight_ops intel_backlight_device_ops = {
+	.update_status = intel_backlight_device_update_status,
+	.get_brightness = intel_backlight_device_get_brightness,
 };
 
-int intel_panel_setup_backlight(struct drm_connector *connector)
+static int intel_backlight_device_register(struct intel_connector *connector)
 {
-	struct drm_device *dev = connector->dev;
-	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_panel *panel = &connector->panel;
 	struct backlight_properties props;
 
-	intel_panel_init_backlight(dev);
-
-	if (WARN_ON(dev_priv->backlight.device))
+	if (WARN_ON(panel->backlight.device))
 		return -ENODEV;
 
+	if (!panel->backlight.present)
+		return 0;
+
+	WARN_ON(panel->backlight.max == 0);
+
 	memset(&props, 0, sizeof(props));
 	props.type = BACKLIGHT_RAW;
-	props.brightness = dev_priv->backlight.level;
-	props.max_brightness = _intel_panel_get_max_backlight(dev);
-	if (props.max_brightness == 0) {
-		DRM_DEBUG_DRIVER("Failed to get maximum backlight value\n");
-		return -ENODEV;
-	}
-	dev_priv->backlight.device =
+
+	/*
+	 * 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);
+
+	if (panel->backlight.enabled)
+		props.power = FB_BLANK_UNBLANK;
+	else
+		props.power = FB_BLANK_POWERDOWN;
+
+	/*
+	 * Note: using the same name independent of the connector prevents
+	 * registration of multiple backlight devices in the driver.
+	 */
+	panel->backlight.device =
 		backlight_device_register("intel_backlight",
-					  &connector->kdev, dev,
-					  &intel_panel_bl_ops, &props);
+					  connector->base.kdev,
+					  connector,
+					  &intel_backlight_device_ops, &props);
 
-	if (IS_ERR(dev_priv->backlight.device)) {
+	if (IS_ERR(panel->backlight.device)) {
 		DRM_ERROR("Failed to register backlight: %ld\n",
-			  PTR_ERR(dev_priv->backlight.device));
-		dev_priv->backlight.device = NULL;
+			  PTR_ERR(panel->backlight.device));
+		panel->backlight.device = NULL;
+		return -ENODEV;
+	}
+
+	DRM_DEBUG_KMS("Connector %s backlight sysfs interface registered\n",
+		      connector->base.name);
+
+	return 0;
+}
+
+static void intel_backlight_device_unregister(struct intel_connector *connector)
+{
+	struct intel_panel *panel = &connector->panel;
+
+	if (panel->backlight.device) {
+		backlight_device_unregister(panel->backlight.device);
+		panel->backlight.device = NULL;
+	}
+}
+#else /* CONFIG_BACKLIGHT_CLASS_DEVICE */
+static int intel_backlight_device_register(struct intel_connector *connector)
+{
+	return 0;
+}
+static void intel_backlight_device_unregister(struct intel_connector *connector)
+{
+}
+#endif /* CONFIG_BACKLIGHT_CLASS_DEVICE */
+
+/*
+ * SPT: This value represents the period of the PWM stream in clock periods
+ * multiplied by 16 (default increment) or 128 (alternate increment selected in
+ * SCHICKEN_1 bit 0). PWM clock is 24 MHz.
+ */
+static u32 spt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 mul, clock;
+
+	if (I915_READ(SOUTH_CHICKEN1) & SPT_PWM_GRANULARITY)
+		mul = 128;
+	else
+		mul = 16;
+
+	clock = MHz(24);
+
+	return clock / (pwm_freq_hz * mul);
+}
+
+/*
+ * LPT: This value represents the period of the PWM stream in clock periods
+ * multiplied by 128 (default increment) or 16 (alternate increment, selected in
+ * LPT SOUTH_CHICKEN2 register bit 5).
+ */
+static u32 lpt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	u32 mul, clock;
+
+	if (I915_READ(SOUTH_CHICKEN2) & LPT_PWM_GRANULARITY)
+		mul = 16;
+	else
+		mul = 128;
+
+	if (dev_priv->pch_id == INTEL_PCH_LPT_DEVICE_ID_TYPE)
+		clock = MHz(135); /* LPT:H */
+	else
+		clock = MHz(24); /* LPT:LP */
+
+	return clock / (pwm_freq_hz * mul);
+}
+
+/*
+ * ILK/SNB/IVB: This value represents the period of the PWM stream in PCH
+ * display raw clocks multiplied by 128.
+ */
+static u32 pch_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
+{
+	struct drm_device *dev = connector->base.dev;
+	int clock = MHz(intel_pch_rawclk(dev));
+
+	return clock / (pwm_freq_hz * 128);
+}
+
+/*
+ * Gen2: This field determines the number of time base events (display core
+ * clock frequency/32) in total for a complete cycle of modulated backlight
+ * control.
+ *
+ * Gen3: A time base event equals the display core clock ([DevPNV] HRAW clock)
+ * divided by 32.
+ */
+static u32 i9xx_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int clock;
+
+	if (IS_PINEVIEW(dev))
+		clock = intel_hrawclk(dev);
+	else
+		clock = 1000 * dev_priv->display.get_display_clock_speed(dev);
+
+	return clock / (pwm_freq_hz * 32);
+}
+
+/*
+ * Gen4: This value represents the period of the PWM stream in display core
+ * clocks multiplied by 128.
+ */
+static u32 i965_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int clock = 1000 * dev_priv->display.get_display_clock_speed(dev);
+
+	return clock / (pwm_freq_hz * 128);
+}
+
+/*
+ * VLV: This value represents the period of the PWM stream in display core
+ * clocks ([DevCTG] 200MHz HRAW clocks) multiplied by 128 or 25MHz S0IX clocks
+ * multiplied by 16. CHV uses a 19.2MHz S0IX clock.
+ */
+static u32 vlv_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	int clock;
+
+	if ((I915_READ(CBR1_VLV) & CBR_PWM_CLOCK_MUX_SELECT) == 0) {
+		if (IS_CHERRYVIEW(dev))
+			return KHz(19200) / (pwm_freq_hz * 16);
+		else
+			return MHz(25) / (pwm_freq_hz * 16);
+	} else {
+		clock = intel_hrawclk(dev);
+		return MHz(clock) / (pwm_freq_hz * 128);
+	}
+}
+
+static u32 get_backlight_max_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;
+	u16 pwm_freq_hz = dev_priv->vbt.backlight.pwm_freq_hz;
+	u32 pwm;
+
+	if (!pwm_freq_hz) {
+		DRM_DEBUG_KMS("backlight frequency not specified in VBT\n");
+		return 0;
+	}
+
+	if (!panel->backlight.hz_to_pwm) {
+		DRM_DEBUG_KMS("backlight frequency setting from VBT currently not supported on this platform\n");
+		return 0;
+	}
+
+	pwm = panel->backlight.hz_to_pwm(connector, pwm_freq_hz);
+	if (!pwm) {
+		DRM_DEBUG_KMS("backlight frequency conversion failed\n");
+		return 0;
+	}
+
+	DRM_DEBUG_KMS("backlight frequency %u Hz from VBT\n", pwm_freq_hz);
+
+	return pwm;
+}
+
+/*
+ * Note: The setup hooks can't assume pipe is set!
+ */
+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;
+	int min;
+
+	WARN_ON(panel->backlight.max == 0);
+
+	/*
+	 * XXX: If the vbt value is 255, it makes min equal to max, which leads
+	 * to problems. There are such machines out there. Either our
+	 * interpretation is wrong or the vbt has bogus data. Or both. Safeguard
+	 * against this by letting the minimum be at most (arbitrarily chosen)
+	 * 25% of the max.
+	 */
+	min = clamp_t(int, dev_priv->vbt.backlight.min_brightness, 0, 64);
+	if (min != dev_priv->vbt.backlight.min_brightness) {
+		DRM_DEBUG_KMS("clamping VBT min backlight %d/255 to %d/255\n",
+			      dev_priv->vbt.backlight.min_brightness, min);
+	}
+
+	/* vbt value is a coefficient in range [0..255] */
+	return scale(min, 0, 255, 0, panel->backlight.max);
+}
+
+static int lpt_setup_backlight(struct intel_connector *connector, enum pipe unused)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_panel *panel = &connector->panel;
+	u32 pch_ctl1, pch_ctl2, val;
+
+	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
+	panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
+
+	pch_ctl2 = I915_READ(BLC_PWM_PCH_CTL2);
+	panel->backlight.max = pch_ctl2 >> 16;
+
+	if (!panel->backlight.max)
+		panel->backlight.max = get_backlight_max_vbt(connector);
+
+	if (!panel->backlight.max)
+		return -ENODEV;
+
+	panel->backlight.min = get_backlight_min_vbt(connector);
+
+	val = lpt_get_backlight(connector);
+	panel->backlight.level = intel_panel_compute_brightness(connector, val);
+
+	panel->backlight.enabled = (pch_ctl1 & BLM_PCH_PWM_ENABLE) &&
+		panel->backlight.level != 0;
+
+	return 0;
+}
+
+static int pch_setup_backlight(struct intel_connector *connector, enum pipe unused)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_panel *panel = &connector->panel;
+	u32 cpu_ctl2, pch_ctl1, pch_ctl2, val;
+
+	pch_ctl1 = I915_READ(BLC_PWM_PCH_CTL1);
+	panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
+
+	pch_ctl2 = I915_READ(BLC_PWM_PCH_CTL2);
+	panel->backlight.max = pch_ctl2 >> 16;
+
+	if (!panel->backlight.max)
+		panel->backlight.max = get_backlight_max_vbt(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);
+
+	cpu_ctl2 = I915_READ(BLC_PWM_CPU_CTL2);
+	panel->backlight.enabled = (cpu_ctl2 & BLM_PWM_ENABLE) &&
+		(pch_ctl1 & BLM_PCH_PWM_ENABLE) && panel->backlight.level != 0;
+
+	return 0;
+}
+
+static int i9xx_setup_backlight(struct intel_connector *connector, enum pipe unused)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_panel *panel = &connector->panel;
+	u32 ctl, val;
+
+	ctl = I915_READ(BLC_PWM_CTL);
+
+	if (IS_GEN2(dev) || IS_I915GM(dev) || IS_I945GM(dev))
+		panel->backlight.combination_mode = ctl & BLM_LEGACY_MODE;
+
+	if (IS_PINEVIEW(dev))
+		panel->backlight.active_low_pwm = ctl & BLM_POLARITY_PNV;
+
+	panel->backlight.max = ctl >> 17;
+
+	if (!panel->backlight.max) {
+		panel->backlight.max = get_backlight_max_vbt(connector);
+		panel->backlight.max >>= 1;
 	}
+
+	if (!panel->backlight.max)
+		return -ENODEV;
+
+	if (panel->backlight.combination_mode)
+		panel->backlight.max *= 0xff;
+
+	panel->backlight.min = get_backlight_min_vbt(connector);
+
+	val = i9xx_get_backlight(connector);
+	panel->backlight.level = intel_panel_compute_brightness(connector, val);
+
+	panel->backlight.enabled = panel->backlight.level != 0;
+
+	return 0;
+}
+
+static int i965_setup_backlight(struct intel_connector *connector, enum pipe unused)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_panel *panel = &connector->panel;
+	u32 ctl, ctl2, val;
+
+	ctl2 = I915_READ(BLC_PWM_CTL2);
+	panel->backlight.combination_mode = ctl2 & BLM_COMBINATION_MODE;
+	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
+
+	ctl = I915_READ(BLC_PWM_CTL);
+	panel->backlight.max = ctl >> 16;
+
+	if (!panel->backlight.max)
+		panel->backlight.max = get_backlight_max_vbt(connector);
+
+	if (!panel->backlight.max)
+		return -ENODEV;
+
+	if (panel->backlight.combination_mode)
+		panel->backlight.max *= 0xff;
+
+	panel->backlight.min = get_backlight_min_vbt(connector);
+
+	val = i9xx_get_backlight(connector);
+	panel->backlight.level = intel_panel_compute_brightness(connector, val);
+
+	panel->backlight.enabled = (ctl2 & BLM_PWM_ENABLE) &&
+		panel->backlight.level != 0;
+
+	return 0;
+}
+
+static int vlv_setup_backlight(struct intel_connector *connector, enum pipe pipe)
+{
+	struct drm_device *dev = connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_panel *panel = &connector->panel;
+	u32 ctl, ctl2, val;
+
+	if (WARN_ON(pipe != PIPE_A && pipe != PIPE_B))
+		return -ENODEV;
+
+	ctl2 = I915_READ(VLV_BLC_PWM_CTL2(pipe));
+	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
+
+	ctl = I915_READ(VLV_BLC_PWM_CTL(pipe));
+	panel->backlight.max = ctl >> 16;
+
+	if (!panel->backlight.max)
+		panel->backlight.max = get_backlight_max_vbt(connector);
+
+	if (!panel->backlight.max)
+		return -ENODEV;
+
+	panel->backlight.min = get_backlight_min_vbt(connector);
+
+	val = _vlv_get_backlight(dev, pipe);
+	panel->backlight.level = intel_panel_compute_brightness(connector, val);
+
+	panel->backlight.enabled = (ctl2 & BLM_PWM_ENABLE) &&
+		panel->backlight.level != 0;
+
 	return 0;
 }
 
-void intel_panel_destroy_backlight(struct drm_device *dev)
+static int
+bxt_setup_backlight(struct intel_connector *connector, enum pipe unused)
 {
+	struct drm_device *dev = connector->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	if (dev_priv->backlight.device) {
-		backlight_device_unregister(dev_priv->backlight.device);
-		dev_priv->backlight.device = NULL;
+	struct intel_panel *panel = &connector->panel;
+	u32 pwm_ctl, val;
+
+	/*
+	 * For BXT hard coding the Backlight controller to 0.
+	 * TODO : Read the controller value from VBT and generalize
+	 */
+	panel->backlight.controller = 0;
+
+	pwm_ctl = I915_READ(BXT_BLC_PWM_CTL(panel->backlight.controller));
+
+	/* Keeping the check if controller 1 is to be programmed.
+	 * This will come into affect once the VBT parsing
+	 * is fixed for controller selection, and controller 1 is used
+	 * for a prticular display configuration.
+	 */
+	if (panel->backlight.controller == 1) {
+		val = I915_READ(UTIL_PIN_CTL);
+		panel->backlight.util_pin_active_low =
+					val & UTIL_PIN_POLARITY;
 	}
+
+	panel->backlight.active_low_pwm = pwm_ctl & BXT_BLC_PWM_POLARITY;
+	panel->backlight.max =
+		I915_READ(BXT_BLC_PWM_FREQ(panel->backlight.controller));
+
+	if (!panel->backlight.max)
+		panel->backlight.max = get_backlight_max_vbt(connector);
+
+	if (!panel->backlight.max)
+		return -ENODEV;
+
+	val = bxt_get_backlight(connector);
+	panel->backlight.level = intel_panel_compute_brightness(connector, val);
+
+	panel->backlight.enabled = (pwm_ctl & BXT_BLC_PWM_ENABLE) &&
+		panel->backlight.level != 0;
+
+	return 0;
 }
-#else
-int intel_panel_setup_backlight(struct drm_connector *connector)
+
+static int pwm_setup_backlight(struct intel_connector *connector,
+			       enum pipe pipe)
 {
-	intel_panel_init_backlight(connector->dev);
+	struct drm_device *dev = connector->base.dev;
+	struct intel_panel *panel = &connector->panel;
+	int retval;
+
+	/* Get the PWM chip for backlight control */
+	panel->backlight.pwm = pwm_get(dev->dev, "pwm_backlight");
+	if (IS_ERR(panel->backlight.pwm)) {
+		DRM_ERROR("Failed to own the pwm chip\n");
+		panel->backlight.pwm = NULL;
+		return -ENODEV;
+	}
+
+	retval = pwm_config(panel->backlight.pwm, CRC_PMIC_PWM_PERIOD_NS,
+			    CRC_PMIC_PWM_PERIOD_NS);
+	if (retval < 0) {
+		DRM_ERROR("Failed to configure the pwm chip\n");
+		pwm_put(panel->backlight.pwm);
+		panel->backlight.pwm = NULL;
+		return retval;
+	}
+
+	panel->backlight.min = 0; /* 0% */
+	panel->backlight.max = 100; /* 100% */
+	panel->backlight.level = DIV_ROUND_UP(
+				 pwm_get_duty_cycle(panel->backlight.pwm) * 100,
+				 CRC_PMIC_PWM_PERIOD_NS);
+	panel->backlight.enabled = panel->backlight.level != 0;
+
 	return 0;
 }
 
-void intel_panel_destroy_backlight(struct drm_device *dev)
+int intel_panel_setup_backlight(struct drm_connector *connector, enum pipe pipe)
 {
-	return;
+	struct drm_device *dev = connector->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct intel_panel *panel = &intel_connector->panel;
+	int ret;
+
+	if (!dev_priv->vbt.backlight.present) {
+		if (dev_priv->quirks & QUIRK_BACKLIGHT_PRESENT) {
+			DRM_DEBUG_KMS("no backlight present per VBT, but present per quirk\n");
+		} else {
+			DRM_DEBUG_KMS("no backlight present per VBT\n");
+			return 0;
+		}
+	}
+
+	/* ensure intel_panel has been initialized first */
+	if (WARN_ON(!panel->backlight.setup))
+		return -ENODEV;
+
+	/* set level and max in panel struct */
+	mutex_lock(&dev_priv->backlight_lock);
+	ret = panel->backlight.setup(intel_connector, pipe);
+	mutex_unlock(&dev_priv->backlight_lock);
+
+	if (ret) {
+		DRM_DEBUG_KMS("failed to setup backlight for connector %s\n",
+			      connector->name);
+		return ret;
+	}
+
+	panel->backlight.present = true;
+
+	DRM_DEBUG_KMS("Connector %s backlight initialized, %s, brightness %u/%u\n",
+		      connector->name,
+		      panel->backlight.enabled ? "enabled" : "disabled",
+		      panel->backlight.level, panel->backlight.max);
+
+	return 0;
+}
+
+void intel_panel_destroy_backlight(struct drm_connector *connector)
+{
+	struct intel_connector *intel_connector = to_intel_connector(connector);
+	struct intel_panel *panel = &intel_connector->panel;
+
+	/* dispose of the pwm */
+	if (panel->backlight.pwm)
+		pwm_put(panel->backlight.pwm);
+
+	panel->backlight.present = false;
+}
+
+/* Set up chip specific backlight functions */
+static void
+intel_panel_init_backlight_funcs(struct intel_panel *panel)
+{
+	struct intel_connector *intel_connector =
+		container_of(panel, struct intel_connector, panel);
+	struct drm_device *dev = intel_connector->base.dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	if (IS_BROXTON(dev)) {
+		panel->backlight.setup = bxt_setup_backlight;
+		panel->backlight.enable = bxt_enable_backlight;
+		panel->backlight.disable = bxt_disable_backlight;
+		panel->backlight.set = bxt_set_backlight;
+		panel->backlight.get = bxt_get_backlight;
+	} else if (HAS_PCH_LPT(dev) || HAS_PCH_SPT(dev)) {
+		panel->backlight.setup = lpt_setup_backlight;
+		panel->backlight.enable = lpt_enable_backlight;
+		panel->backlight.disable = lpt_disable_backlight;
+		panel->backlight.set = lpt_set_backlight;
+		panel->backlight.get = lpt_get_backlight;
+		if (HAS_PCH_LPT(dev))
+			panel->backlight.hz_to_pwm = lpt_hz_to_pwm;
+		else
+			panel->backlight.hz_to_pwm = spt_hz_to_pwm;
+	} else if (HAS_PCH_SPLIT(dev)) {
+		panel->backlight.setup = pch_setup_backlight;
+		panel->backlight.enable = pch_enable_backlight;
+		panel->backlight.disable = pch_disable_backlight;
+		panel->backlight.set = pch_set_backlight;
+		panel->backlight.get = pch_get_backlight;
+		panel->backlight.hz_to_pwm = pch_hz_to_pwm;
+	} else if (IS_VALLEYVIEW(dev)) {
+		if (dev_priv->vbt.has_mipi) {
+			panel->backlight.setup = pwm_setup_backlight;
+			panel->backlight.enable = pwm_enable_backlight;
+			panel->backlight.disable = pwm_disable_backlight;
+			panel->backlight.set = pwm_set_backlight;
+			panel->backlight.get = pwm_get_backlight;
+		} else {
+			panel->backlight.setup = vlv_setup_backlight;
+			panel->backlight.enable = vlv_enable_backlight;
+			panel->backlight.disable = vlv_disable_backlight;
+			panel->backlight.set = vlv_set_backlight;
+			panel->backlight.get = vlv_get_backlight;
+			panel->backlight.hz_to_pwm = vlv_hz_to_pwm;
+		}
+	} else if (IS_GEN4(dev)) {
+		panel->backlight.setup = i965_setup_backlight;
+		panel->backlight.enable = i965_enable_backlight;
+		panel->backlight.disable = i965_disable_backlight;
+		panel->backlight.set = i9xx_set_backlight;
+		panel->backlight.get = i9xx_get_backlight;
+		panel->backlight.hz_to_pwm = i965_hz_to_pwm;
+	} else {
+		panel->backlight.setup = i9xx_setup_backlight;
+		panel->backlight.enable = i9xx_enable_backlight;
+		panel->backlight.disable = i9xx_disable_backlight;
+		panel->backlight.set = i9xx_set_backlight;
+		panel->backlight.get = i9xx_get_backlight;
+		panel->backlight.hz_to_pwm = i9xx_hz_to_pwm;
+	}
 }
-#endif
 
 int intel_panel_init(struct intel_panel *panel,
-		     struct drm_display_mode *fixed_mode)
+		     struct drm_display_mode *fixed_mode,
+		     struct drm_display_mode *downclock_mode)
 {
+	intel_panel_init_backlight_funcs(panel);
+
 	panel->fixed_mode = fixed_mode;
+	panel->downclock_mode = downclock_mode;
 
 	return 0;
 }
@@ -490,4 +1818,24 @@
 
 	if (panel->fixed_mode)
 		drm_mode_destroy(intel_connector->base.dev, panel->fixed_mode);
+
+	if (panel->downclock_mode)
+		drm_mode_destroy(intel_connector->base.dev,
+				panel->downclock_mode);
+}
+
+void intel_backlight_register(struct drm_device *dev)
+{
+	struct intel_connector *connector;
+
+	list_for_each_entry(connector, &dev->mode_config.connector_list, base.head)
+		intel_backlight_device_register(connector);
+}
+
+void intel_backlight_unregister(struct drm_device *dev)
+{
+	struct intel_connector *connector;
+
+	list_for_each_entry(connector, &dev->mode_config.connector_list, base.head)
+		intel_backlight_device_unregister(connector);
 }