drm/i915/chv: Trigger phy common lane reset

During cold boot, the display controller needs to deassert the common
lane reset.  Only do it once during intel_init_dpio for both PHYx2 and
PHYx1.

Besides, assert the common lane reset when disable pll.  This still
to be determined whether need to do it by driver.
Signed-off-by: Chon Ming Lee <chon.ming.lee@intel.com>
[vsyrjala: Don't disable DPIO PLL when using DSI]
[vsyrjala: Don't call vlv_disable_pll() by accident on CHV]
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
[danvet: Move part of a moved comment back as suggested by Imre since
it's valid for both byt and chv.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -1423,6 +1423,14 @@ enum punit_power_well {
 /* Additional CHV pll/phy registers */
 #define DPIO_PHY_STATUS			(VLV_DISPLAY_BASE + 0x6240)
 #define   DPLL_PORTD_READY_MASK		(0xf)
+#define DISPLAY_PHY_CONTROL (VLV_DISPLAY_BASE + 0x60100)
+#define   PHY_COM_LANE_RESET_DEASSERT(phy, val) \
+				((phy == DPIO_PHY0) ? (val | 1) : (val | 2))
+#define   PHY_COM_LANE_RESET_ASSERT(phy, val) \
+				((phy == DPIO_PHY0) ? (val & ~1) : (val & ~2))
+#define DISPLAY_PHY_STATUS (VLV_DISPLAY_BASE + 0x60104)
+#define   PHY_POWERGOOD(phy)	((phy == DPIO_PHY0) ? (1<<31) : (1<<30))
+
 /*
  * The i830 generation, in LVDS mode, defines P1 as the bit number set within
  * this field (only one bit may be set).

drivers/gpu/drm/i915/intel_display.c

@@ -1395,17 +1395,42 @@ static void intel_reset_dpio(struct drm_device *dev)
 		   DPLL_REFA_CLK_ENABLE_VLV |
 		   DPLL_INTEGRATED_CRI_CLK_VLV);
 
+	if (IS_CHERRYVIEW(dev)) {
+		enum dpio_phy phy;
+		u32 val;
+
+		for (phy = DPIO_PHY0; phy < I915_NUM_PHYS_VLV; phy++) {
+			/* Poll for phypwrgood signal */
+			if (wait_for(I915_READ(DISPLAY_PHY_STATUS) &
+						PHY_POWERGOOD(phy), 1))
+				DRM_ERROR("Display PHY %d is not power up\n", phy);
+
+			/*
+			 * Deassert common lane reset for PHY.
+			 *
+			 * This should only be done on init and resume from S3
+			 * with both PLLs disabled, or we risk losing DPIO and
+			 * PLL synchronization.
+			 */
+			val = I915_READ(DISPLAY_PHY_CONTROL);
+			I915_WRITE(DISPLAY_PHY_CONTROL,
+				PHY_COM_LANE_RESET_DEASSERT(phy, val));
+		}
+
+	} else {
 		/*
 		 * From VLV2A0_DP_eDP_DPIO_driver_vbios_notes_10.docx -
 		 *  6.	De-assert cmn_reset/side_reset. Same as VLV X0.
 		 *   a.	GUnit 0x2110 bit[0] set to 1 (def 0)
-	 *   b.	The other bits such as sfr settings / modesel may all be set
-	 *      to 0.
+		 *   b.	The other bits such as sfr settings / modesel may all
+		 *	be set to 0.
 		 *
-	 * This should only be done on init and resume from S3 with both
-	 * PLLs disabled, or we risk losing DPIO and PLL synchronization.
+		 * This should only be done on init and resume from S3 with
+		 * both PLLs disabled, or we risk losing DPIO and PLL
+		 * synchronization.
 		 */
 		I915_WRITE(DPIO_CTL, I915_READ(DPIO_CTL) | DPIO_CMNRST);
+	}
 }
 
 static void vlv_enable_pll(struct intel_crtc *crtc)
@@ -1529,6 +1554,19 @@ static void vlv_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
 		val = DPLL_INTEGRATED_CRI_CLK_VLV | DPLL_REFA_CLK_ENABLE_VLV;
 	I915_WRITE(DPLL(pipe), val);
 	POSTING_READ(DPLL(pipe));
+
+}
+
+static void chv_disable_pll(struct drm_i915_private *dev_priv, enum pipe pipe)
+{
+	int dpll = DPLL(pipe);
+	u32 val;
+
+	/* Set PLL en = 0 */
+	val = I915_READ(dpll);
+	val &= ~DPLL_VCO_ENABLE;
+	I915_WRITE(dpll, val);
+
 }
 
 void vlv_wait_port_ready(struct drm_i915_private *dev_priv,
@@ -4446,10 +4484,14 @@ static void i9xx_crtc_disable(struct drm_crtc *crtc)
 		if (encoder->post_disable)
 			encoder->post_disable(encoder);
 
-	if (IS_VALLEYVIEW(dev) && !intel_pipe_has_type(crtc, INTEL_OUTPUT_DSI))
+	if (!intel_pipe_has_type(crtc, INTEL_OUTPUT_DSI)) {
+		if (IS_CHERRYVIEW(dev))
+			chv_disable_pll(dev_priv, pipe);
+		else if (IS_VALLEYVIEW(dev))
 			vlv_disable_pll(dev_priv, pipe);
-	else if (!IS_VALLEYVIEW(dev))
+		else
 			i9xx_disable_pll(dev_priv, pipe);
+	}
 
 	intel_crtc->active = false;
 	intel_update_watermarks(crtc);