drm/i915/lvds: Restore initial HW state during encoder enabling

Atm the LVDS encoder depends on the PPS HW context being saved/restored
from generic suspend/resume code. Since the PPS is specific to the LVDS
and eDP encoders a cleaner way is to reinitialize it during encoder
enabling, so do this here for LVDS. Follow-up patches will init the PPS
for the eDP encoder similarly and remove the suspend/resume time save /
restore.

v2:
- Apply BSpec +1 offset and use DIV_ROUND_UP() when programming the
power cycle delay. (Ville)
v3: (Ville)
- Fix +1 vs. round-up order.
- s/reset_on_powerdown/powerdown_on_reset/

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470827254-21954-3-git-send-email-imre.deak@intel.com

drivers/gpu/drm/i915/i915_reg.h

@@ -3710,6 +3710,7 @@ enum {
 
 #define _PP_ON_DELAYS			0x61208
 #define PP_ON_DELAYS(pps_idx)		_MMIO_PPS(pps_idx, _PP_ON_DELAYS)
+#define  PANEL_PORT_SELECT_SHIFT	30
 #define  PANEL_PORT_SELECT_MASK		(3 << 30)
 #define  PANEL_PORT_SELECT_LVDS		(0 << 30)
 #define  PANEL_PORT_SELECT_DPA		(1 << 30)

drivers/gpu/drm/i915/intel_lvds.c

@@ -48,6 +48,20 @@ struct intel_lvds_connector {
 	struct notifier_block lid_notifier;
 };
 
+struct intel_lvds_pps {
+	/* 100us units */
+	int t1_t2;
+	int t3;
+	int t4;
+	int t5;
+	int tx;
+
+	int divider;
+
+	int port;
+	bool powerdown_on_reset;
+};
+
 struct intel_lvds_encoder {
 	struct intel_encoder base;
 
@@ -55,6 +69,9 @@ struct intel_lvds_encoder {
 	i915_reg_t reg;
 	u32 a3_power;
 
+	struct intel_lvds_pps init_pps;
+	u32 init_lvds_val;
+
 	struct intel_lvds_connector *attached_connector;
 };
 
@@ -136,6 +153,83 @@ static void intel_lvds_get_config(struct intel_encoder *encoder,
 	pipe_config->base.adjusted_mode.crtc_clock = pipe_config->port_clock;
 }
 
+static void intel_lvds_pps_get_hw_state(struct drm_i915_private *dev_priv,
+					struct intel_lvds_pps *pps)
+{
+	u32 val;
+
+	pps->powerdown_on_reset = I915_READ(PP_CONTROL(0)) & PANEL_POWER_RESET;
+
+	val = I915_READ(PP_ON_DELAYS(0));
+	pps->port = (val & PANEL_PORT_SELECT_MASK) >>
+		    PANEL_PORT_SELECT_SHIFT;
+	pps->t1_t2 = (val & PANEL_POWER_UP_DELAY_MASK) >>
+		     PANEL_POWER_UP_DELAY_SHIFT;
+	pps->t5 = (val & PANEL_LIGHT_ON_DELAY_MASK) >>
+		  PANEL_LIGHT_ON_DELAY_SHIFT;
+
+	val = I915_READ(PP_OFF_DELAYS(0));
+	pps->t3 = (val & PANEL_POWER_DOWN_DELAY_MASK) >>
+		  PANEL_POWER_DOWN_DELAY_SHIFT;
+	pps->tx = (val & PANEL_LIGHT_OFF_DELAY_MASK) >>
+		  PANEL_LIGHT_OFF_DELAY_SHIFT;
+
+	val = I915_READ(PP_DIVISOR(0));
+	pps->divider = (val & PP_REFERENCE_DIVIDER_MASK) >>
+		       PP_REFERENCE_DIVIDER_SHIFT;
+	val = (val & PANEL_POWER_CYCLE_DELAY_MASK) >>
+	      PANEL_POWER_CYCLE_DELAY_SHIFT;
+	/*
+	 * Remove the BSpec specified +1 (100ms) offset that accounts for a
+	 * too short power-cycle delay due to the asynchronous programming of
+	 * the register.
+	 */
+	if (val)
+		val--;
+	/* Convert from 100ms to 100us units */
+	pps->t4 = val * 1000;
+
+	if (INTEL_INFO(dev_priv)->gen <= 4 &&
+	    pps->t1_t2 == 0 && pps->t5 == 0 && pps->t3 == 0 && pps->tx == 0) {
+		DRM_DEBUG_KMS("Panel power timings uninitialized, "
+			      "setting defaults\n");
+		/* Set T2 to 40ms and T5 to 200ms in 100 usec units */
+		pps->t1_t2 = 40 * 10;
+		pps->t5 = 200 * 10;
+		/* Set T3 to 35ms and Tx to 200ms in 100 usec units */
+		pps->t3 = 35 * 10;
+		pps->tx = 200 * 10;
+	}
+
+	DRM_DEBUG_DRIVER("LVDS PPS:t1+t2 %d t3 %d t4 %d t5 %d tx %d "
+			 "divider %d port %d powerdown_on_reset %d\n",
+			 pps->t1_t2, pps->t3, pps->t4, pps->t5, pps->tx,
+			 pps->divider, pps->port, pps->powerdown_on_reset);
+}
+
+static void intel_lvds_pps_init_hw(struct drm_i915_private *dev_priv,
+				   struct intel_lvds_pps *pps)
+{
+	u32 val;
+
+	val = I915_READ(PP_CONTROL(0));
+	WARN_ON((val & PANEL_UNLOCK_MASK) != PANEL_UNLOCK_REGS);
+	if (pps->powerdown_on_reset)
+		val |= PANEL_POWER_RESET;
+	I915_WRITE(PP_CONTROL(0), val);
+
+	I915_WRITE(PP_ON_DELAYS(0), (pps->port << PANEL_PORT_SELECT_SHIFT) |
+				    (pps->t1_t2 << PANEL_POWER_UP_DELAY_SHIFT) |
+				    (pps->t5 << PANEL_LIGHT_ON_DELAY_SHIFT));
+	I915_WRITE(PP_OFF_DELAYS(0), (pps->t3 << PANEL_POWER_DOWN_DELAY_SHIFT) |
+				     (pps->tx << PANEL_LIGHT_OFF_DELAY_SHIFT));
+
+	val = pps->divider << PP_REFERENCE_DIVIDER_SHIFT;
+	val |= (DIV_ROUND_UP(pps->t4, 1000) + 1) <<
+	       PANEL_POWER_CYCLE_DELAY_SHIFT;
+	I915_WRITE(PP_DIVISOR(0), val);
+}
+
 static void intel_pre_enable_lvds(struct intel_encoder *encoder)
 {
 	struct intel_lvds_encoder *lvds_encoder = to_lvds_encoder(&encoder->base);
@@ -154,7 +248,9 @@ static void intel_pre_enable_lvds(struct intel_encoder *encoder)
 		assert_pll_disabled(dev_priv, pipe);
 	}
 
-	temp = I915_READ(lvds_encoder->reg);
+	intel_lvds_pps_init_hw(dev_priv, &lvds_encoder->init_pps);
+
+	temp = lvds_encoder->init_lvds_val;
 	temp |= LVDS_PORT_EN | LVDS_A0A2_CLKA_POWER_UP;
 
 	if (HAS_PCH_CPT(dev)) {
@@ -922,18 +1018,6 @@ void intel_lvds_init(struct drm_device *dev)
 		DRM_DEBUG_KMS("LVDS is not present in VBT, but enabled anyway\n");
 	}
 
-	 /* Set the Panel Power On/Off timings if uninitialized. */
-	if (INTEL_INFO(dev_priv)->gen < 5 &&
-	    I915_READ(PP_ON_DELAYS(0)) == 0 && I915_READ(PP_OFF_DELAYS(0)) == 0) {
-		/* Set T2 to 40ms and T5 to 200ms */
-		I915_WRITE(PP_ON_DELAYS(0), 0x019007d0);
-
-		/* Set T3 to 35ms and Tx to 200ms */
-		I915_WRITE(PP_OFF_DELAYS(0), 0x015e07d0);
-
-		DRM_DEBUG_KMS("Panel power timings uninitialized, setting defaults\n");
-	}
-
 	lvds_encoder = kzalloc(sizeof(*lvds_encoder), GFP_KERNEL);
 	if (!lvds_encoder)
 		return;
@@ -999,6 +1083,10 @@ void intel_lvds_init(struct drm_device *dev)
 				      dev->mode_config.scaling_mode_property,
 				      DRM_MODE_SCALE_ASPECT);
 	intel_connector->panel.fitting_mode = DRM_MODE_SCALE_ASPECT;
+
+	intel_lvds_pps_get_hw_state(dev_priv, &lvds_encoder->init_pps);
+	lvds_encoder->init_lvds_val = lvds;
+
 	/*
 	 * LVDS discovery:
 	 * 1) check for EDID on DDC