Merge tag 'drm-intel-next-2017-07-17' of git://anongit.freedesktop.org/git/drm-intel into drm-next

2nd round of 4.14 features:

- prep for deferred fbdev setup
- refactor fixed 16.16 computations and skl+ wm code (Mahesh Kumar)
- more cnl paches (Rodrigo, Imre et al)
- tighten context cleanup and handling (Chris Wilson)
- fix interlaced handling on skl+ (Mahesh Kumar)
- small bits as usual

* tag 'drm-intel-next-2017-07-17' of git://anongit.freedesktop.org/git/drm-intel: (84 commits)
  drm/i915: Update DRIVER_DATE to 20170717
  drm/i915: Protect against deferred fbdev setup
  drm/i915/fbdev: Always forward hotplug events
  drm/i915/skl+: unify cpp value in WM calculation
  drm/i915/skl+: WM calculation don't require height
  drm/i915: Addition wrapper for fixed16.16 operation
  drm/i915: cleanup fixed-point wrappers naming
  drm/i915: Always perform internal fixed16 division in 64 bits
  drm/i915: take-out common clamping code of fixed16 wrappers
  drm/i915/cnl: Add missing type case.
  drm/i915/cnl: Add max allowed Cannonlake DC.
  drm/i915: Make DP-MST connector info work
  drm/i915/cnl: Get DDI clock based on PLLs.
  drm/i915/cnl: Inherit RPS stuff from previous platforms.
  drm/i915/cnl: Gen10 render context size.
  drm/i915/cnl: Don't trust VBT's alternate pin for port D for now.
  drm/i915: Fix the kernel panic when using aliasing ppgtt
  drm/i915/cnl: Cannonlake color init.
  drm/i915/cnl: Add force wake for gen10+.
  x86/gpu: CNL uses the same GMS values as SKL
  ...

1 files changed, 174 insertions, 11 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
index 228ca06..b25cd88 100644
--- a/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
+++ b/drivers/gpu/drm/i915/intel_dp_aux_backlight.c
@@ -98,13 +98,105 @@ intel_dp_aux_set_backlight(const struct drm_connector_state *conn_state, u32 lev
 	}
 }
 
+/*
+ * Set PWM Frequency divider to match desired frequency in vbt.
+ * The PWM Frequency is calculated as 27Mhz / (F x P).
+ * - Where F = PWM Frequency Pre-Divider value programmed by field 7:0 of the
+ *             EDP_BACKLIGHT_FREQ_SET register (DPCD Address 00728h)
+ * - Where P = 2^Pn, where Pn is the value programmed by field 4:0 of the
+ *             EDP_PWMGEN_BIT_COUNT register (DPCD Address 00724h)
+ */
+static bool intel_dp_aux_set_pwm_freq(struct intel_connector *connector)
+{
+	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+	struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base);
+	int freq, fxp, fxp_min, fxp_max, fxp_actual, f = 1;
+	u8 pn, pn_min, pn_max;
+
+	/* Find desired value of (F x P)
+	 * Note that, if F x P is out of supported range, the maximum value or
+	 * minimum value will applied automatically. So no need to check that.
+	 */
+	freq = dev_priv->vbt.backlight.pwm_freq_hz;
+	DRM_DEBUG_KMS("VBT defined backlight frequency %u Hz\n", freq);
+	if (!freq) {
+		DRM_DEBUG_KMS("Use panel default backlight frequency\n");
+		return false;
+	}
+
+	fxp = DIV_ROUND_CLOSEST(KHz(DP_EDP_BACKLIGHT_FREQ_BASE_KHZ), freq);
+
+	/* Use highest possible value of Pn for more granularity of brightness
+	 * adjustment while satifying the conditions below.
+	 * - Pn is in the range of Pn_min and Pn_max
+	 * - F is in the range of 1 and 255
+	 * - FxP is within 25% of desired value.
+	 *   Note: 25% is arbitrary value and may need some tweak.
+	 */
+	if (drm_dp_dpcd_readb(&intel_dp->aux,
+			       DP_EDP_PWMGEN_BIT_COUNT_CAP_MIN, &pn_min) != 1) {
+		DRM_DEBUG_KMS("Failed to read pwmgen bit count cap min\n");
+		return false;
+	}
+	if (drm_dp_dpcd_readb(&intel_dp->aux,
+			       DP_EDP_PWMGEN_BIT_COUNT_CAP_MAX, &pn_max) != 1) {
+		DRM_DEBUG_KMS("Failed to read pwmgen bit count cap max\n");
+		return false;
+	}
+	pn_min &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
+	pn_max &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
+
+	fxp_min = DIV_ROUND_CLOSEST(fxp * 3, 4);
+	fxp_max = DIV_ROUND_CLOSEST(fxp * 5, 4);
+	if (fxp_min < (1 << pn_min) || (255 << pn_max) < fxp_max) {
+		DRM_DEBUG_KMS("VBT defined backlight frequency out of range\n");
+		return false;
+	}
+
+	for (pn = pn_max; pn >= pn_min; pn--) {
+		f = clamp(DIV_ROUND_CLOSEST(fxp, 1 << pn), 1, 255);
+		fxp_actual = f << pn;
+		if (fxp_min <= fxp_actual && fxp_actual <= fxp_max)
+			break;
+	}
+
+	if (drm_dp_dpcd_writeb(&intel_dp->aux,
+			       DP_EDP_PWMGEN_BIT_COUNT, pn) < 0) {
+		DRM_DEBUG_KMS("Failed to write aux pwmgen bit count\n");
+		return false;
+	}
+	if (drm_dp_dpcd_writeb(&intel_dp->aux,
+			       DP_EDP_BACKLIGHT_FREQ_SET, (u8) f) < 0) {
+		DRM_DEBUG_KMS("Failed to write aux backlight freq\n");
+		return false;
+	}
+	return true;
+}
+
+/*
+* Set minimum / maximum dynamic brightness percentage. This value is expressed
+* as the percentage of normal brightness in 5% increments.
+*/
+static bool
+intel_dp_aux_set_dynamic_backlight_percent(struct intel_dp *intel_dp,
+					   u32 min, u32 max)
+{
+	u8 dbc[] = { DIV_ROUND_CLOSEST(min, 5), DIV_ROUND_CLOSEST(max, 5) };
+
+	if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_DBC_MINIMUM_BRIGHTNESS_SET,
+			  dbc, sizeof(dbc)) < 0) {
+		DRM_DEBUG_KMS("Failed to write aux DBC brightness level\n");
+		return false;
+	}
+	return true;
+}
+
 static void intel_dp_aux_enable_backlight(const struct intel_crtc_state *crtc_state,
 					  const struct drm_connector_state *conn_state)
 {
 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
 	struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base);
-	uint8_t dpcd_buf = 0;
-	uint8_t edp_backlight_mode = 0;
+	uint8_t dpcd_buf, new_dpcd_buf, edp_backlight_mode;
 
 	if (drm_dp_dpcd_readb(&intel_dp->aux,
 			DP_EDP_BACKLIGHT_MODE_SET_REGISTER, &dpcd_buf) != 1) {
@@ -113,18 +205,15 @@ static void intel_dp_aux_enable_backlight(const struct intel_crtc_state *crtc_st
 		return;
 	}
 
+	new_dpcd_buf = dpcd_buf;
 	edp_backlight_mode = dpcd_buf & DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
 
 	switch (edp_backlight_mode) {
 	case DP_EDP_BACKLIGHT_CONTROL_MODE_PWM:
 	case DP_EDP_BACKLIGHT_CONTROL_MODE_PRESET:
 	case DP_EDP_BACKLIGHT_CONTROL_MODE_PRODUCT:
-		dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
-		dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD;
-		if (drm_dp_dpcd_writeb(&intel_dp->aux,
-			DP_EDP_BACKLIGHT_MODE_SET_REGISTER, dpcd_buf) < 0) {
-			DRM_DEBUG_KMS("Failed to write aux backlight mode\n");
-		}
+		new_dpcd_buf &= ~DP_EDP_BACKLIGHT_CONTROL_MODE_MASK;
+		new_dpcd_buf |= DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD;
 		break;
 
 	/* Do nothing when it is already DPCD mode */
@@ -133,6 +222,25 @@ static void intel_dp_aux_enable_backlight(const struct intel_crtc_state *crtc_st
 		break;
 	}
 
+	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP)
+		if (intel_dp_aux_set_pwm_freq(connector))
+			new_dpcd_buf |= DP_EDP_BACKLIGHT_FREQ_AUX_SET_ENABLE;
+
+	if (i915.enable_dbc &&
+	    (intel_dp->edp_dpcd[2] & DP_EDP_DYNAMIC_BACKLIGHT_CAP)) {
+		if(intel_dp_aux_set_dynamic_backlight_percent(intel_dp, 0, 100)) {
+			new_dpcd_buf |= DP_EDP_DYNAMIC_BACKLIGHT_ENABLE;
+			DRM_DEBUG_KMS("Enable dynamic brightness.\n");
+		}
+	}
+
+	if (new_dpcd_buf != dpcd_buf) {
+		if (drm_dp_dpcd_writeb(&intel_dp->aux,
+			DP_EDP_BACKLIGHT_MODE_SET_REGISTER, new_dpcd_buf) < 0) {
+			DRM_DEBUG_KMS("Failed to write aux backlight mode\n");
+		}
+	}
+
 	set_aux_backlight_enable(intel_dp, true);
 	intel_dp_aux_set_backlight(conn_state, connector->panel.backlight.level);
 }
@@ -169,15 +277,66 @@ intel_dp_aux_display_control_capable(struct intel_connector *connector)
 	/* Check the eDP Display control capabilities registers to determine if
 	 * the panel can support backlight control over the aux channel
 	 */
-	if (intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP &&
-	    (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP) &&
-	    !(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP)) {
+	if ((intel_dp->edp_dpcd[1] & DP_EDP_TCON_BACKLIGHT_ADJUSTMENT_CAP) &&
+	    (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_AUX_SET_CAP)) {
 		DRM_DEBUG_KMS("AUX Backlight Control Supported!\n");
 		return true;
 	}
 	return false;
 }
 
+/*
+ * Heuristic function whether we should use AUX for backlight adjustment or not.
+ *
+ * We should use AUX for backlight brightness adjustment if panel doesn't this
+ * via PWM pin or using AUX is better than using PWM pin.
+ *
+ * The heuristic to determine that using AUX pin is better than using PWM pin is
+ * that the panel support any of the feature list here.
+ * - Regional backlight brightness adjustment
+ * - Backlight PWM frequency set
+ * - More than 8 bits resolution of brightness level
+ * - Backlight enablement via AUX and not by BL_ENABLE pin
+ *
+ * If all above are not true, assume that using PWM pin is better.
+ */
+static bool
+intel_dp_aux_display_control_heuristic(struct intel_connector *connector)
+{
+	struct intel_dp *intel_dp = enc_to_intel_dp(&connector->encoder->base);
+	uint8_t reg_val;
+
+	/* Panel doesn't support adjusting backlight brightness via PWN pin */
+	if (!(intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_PWM_PIN_CAP))
+		return true;
+
+	/* Panel supports regional backlight brightness adjustment */
+	if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_GENERAL_CAP_3,
+			      &reg_val) != 1) {
+		DRM_DEBUG_KMS("Failed to read DPCD register 0x%x\n",
+			       DP_EDP_GENERAL_CAP_3);
+		return false;
+	}
+	if (reg_val > 0)
+		return true;
+
+	/* Panel supports backlight PWM frequency set */
+	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_FREQ_AUX_SET_CAP)
+		return true;
+
+	/* Panel supports more than 8 bits resolution of brightness level */
+	if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT)
+		return true;
+
+	/* Panel supports enabling backlight via AUX but not by BL_ENABLE pin */
+	if ((intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP) &&
+	    !(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_PIN_ENABLE_CAP))
+		return true;
+
+	return false;
+
+}
+
 int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
 {
 	struct intel_panel *panel = &intel_connector->panel;
@@ -188,6 +347,10 @@ int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector)
 	if (!intel_dp_aux_display_control_capable(intel_connector))
 		return -ENODEV;
 
+	if (i915.enable_dpcd_backlight == -1 &&
+	    !intel_dp_aux_display_control_heuristic(intel_connector))
+		return -ENODEV;
+
 	panel->backlight.setup = intel_dp_aux_setup_backlight;
 	panel->backlight.enable = intel_dp_aux_enable_backlight;
 	panel->backlight.disable = intel_dp_aux_disable_backlight;