Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux

Pull DRM updates from Dave Airlie:
 "Like all good pull reqs this ends with a revert, so it must mean we
  tested it,

[ Ed. That's _one_ way of looking at it ]

  This pull is missing nouveau, Ben has been stuck trying to track down
  a very longstanding bug that revealed itself due to some other
  changes.  I've asked him to send you a direct pull request for nouveau
  once he cleans things up.  I'm away until Monday so don't want to
  delay things, you can make a decision on that when he sends it, I have
  my phone so I can ack things just not really merge much.

  It has one trivial conflict with your tree in armada_drv.c, and also
  the pull request contains some component changes that are already in
  your tree, the base tree from Russell went via Greg's tree already,
  but some stuff still shows up in here that doesn't when I merge my
  tree into yours.

  Otherwise all pretty standard graphics fare, one new driver and
  changes all over the place.

  New drivers:
   - sti kms driver for STMicroelectronics chipsets stih416 and stih407.

  core:
   - lots of cleanups to the drm core
   - DP MST helper code merged
   - universal cursor planes.
   - render nodes enabled by default

  panel:
   - better panel interfaces
   - new panel support
   - non-continuous cock advertising ability

  ttm:
   - shrinker fixes

  i915:
   - hopefully ditched UMS support
   - runtime pm fixes
   - psr tracking and locking - now enabled by default
   - userptr fixes
   - backlight brightness fixes
   - MST support merged
   - runtime PM for dpms
   - primary planes locking fixes
   - gen8 hw semaphore support
   - fbc fixes
   - runtime PM on SOix sleep state hw.
   - mmio base page flipping
   - lots of vlv/chv fixes.
   - universal cursor planes

  radeon:
   - Hawaii fixes
   - display scalar support for non-fixed mode displays
   - new firmware format support
   - dpm on more asics by default
   - GPUVM improvements
   - uncached and wc GTT buffers
   - BOs > visible VRAM

  exynos:
   - i80 interface support
   - module auto-loading
   - ipp driver consolidated.

  armada:
   - irq handling in crtc layer only
   - crtc renumbering
   - add component support
   - DT interaction changes.

  tegra:
   - load as module fixes
   - eDP bpp and sync polarity fixed
   - DSI non-continuous clock mode support
   - better support for importing buffers from nouveau

  msm:
   - mdp5/adq8084 v1.3 hw enablement
   - devicetree clk changse
   - ifc6410 board working

  tda998x:
   - component support
   - DT documentation update

  vmwgfx:
   - fix compat shader namespace"

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (551 commits)
  Revert "drm: drop redundant drm_file->is_master"
  drm/panel: simple: Use devm_gpiod_get_optional()
  drm/dsi: Replace upcasting macro by function
  drm/panel: ld9040: Replace upcasting macro by function
  drm/exynos: dp: Modify driver to support drm_panel
  drm/exynos: Move DP setup into commit()
  drm/panel: simple: Add AUO B133HTN01 panel support
  drm/panel: simple: Support delays in panel functions
  drm/panel: simple: Add proper definition for prepare and unprepare
  drm/panel: s6e8aa0: Add proper definition for prepare and unprepare
  drm/panel: ld9040: Add proper definition for prepare and unprepare
  drm/tegra: Add support for panel prepare and unprepare routines
  drm/exynos: dsi: Add support for panel prepare and unprepare routines
  drm/exynos: dpi: Add support for panel prepare and unprepare routines
  drm/panel: simple: Add dummy prepare and unprepare routines
  drm/panel: s6e8aa0: Add dummy prepare and unprepare routines
  drm/panel: ld9040: Add dummy prepare and unprepare routines
  drm/panel: Provide convenience wrapper for .get_modes()
  drm/panel: add .prepare() and .unprepare() functions
  drm/panel: simple: Remove simple-panel compatible
  ...

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 12b02fe1d0a..59b028f0b1e 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);