drm/i915: split PCH clock gating init

Ibex Peak and CougarPoint already require a different setting (added
here), and future chips will likely follow that precedent.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>

drivers/gpu/drm/i915/i915_drv.h

@@ -210,6 +210,7 @@ struct drm_i915_display_funcs {
 			     struct drm_framebuffer *old_fb);
 	void (*fdi_link_train)(struct drm_crtc *crtc);
 	void (*init_clock_gating)(struct drm_device *dev);
+	void (*init_pch_clock_gating)(struct drm_device *dev);
 	/* clock updates for mode set */
 	/* cursor updates */
 	/* render clock increase/decrease */

drivers/gpu/drm/i915/i915_reg.h

@@ -3074,6 +3074,9 @@
 #define  TRANS_6BPC             (2<<5)
 #define  TRANS_12BPC            (3<<5)
 
+#define SOUTH_CHICKEN2		0xc2004
+#define  DPLS_EDP_PPS_FIX_DIS	(1<<0)
+
 #define _FDI_RXA_CHICKEN         0xc200c
 #define _FDI_RXB_CHICKEN         0xc2010
 #define  FDI_RX_PHASE_SYNC_POINTER_OVR	(1<<1)

drivers/gpu/drm/i915/i915_suspend.c

@@ -863,8 +863,7 @@ int i915_restore_state(struct drm_device *dev)
 		I915_WRITE(IMR, dev_priv->saveIMR);
 	}
 
-	/* Clock gating state */
-	dev_priv->display.init_clock_gating(dev);
+	intel_init_clock_gating(dev);
 
 	if (IS_IRONLAKE_M(dev)) {
 		ironlake_enable_drps(dev);

drivers/gpu/drm/i915/intel_display.c

@@ -7231,13 +7231,6 @@ static void ironlake_init_clock_gating(struct drm_device *dev)
 
 	I915_WRITE(PCH_DSPCLK_GATE_D, dspclk_gate);
 
-	/*
-	 * On Ibex Peak and Cougar Point, we need to disable clock
-	 * gating for the panel power sequencer or it will fail to
-	 * start up when no ports are active.
-	 */
-	I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
-
 	/*
 	 * According to the spec the following bits should be set in
 	 * order to enable memory self-refresh
@@ -7295,13 +7288,6 @@ static void gen6_init_clock_gating(struct drm_device *dev)
 
 	I915_WRITE(PCH_DSPCLK_GATE_D, dspclk_gate);
 
-	/*
-	 * On Ibex Peak and Cougar Point, we need to disable clock
-	 * gating for the panel power sequencer or it will fail to
-	 * start up when no ports are active.
-	 */
-	I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
-
 	I915_WRITE(ILK_DISPLAY_CHICKEN2,
 		   I915_READ(ILK_DISPLAY_CHICKEN2) |
 		   ILK_ELPIN_409_SELECT);
@@ -7344,13 +7330,6 @@ static void ivybridge_init_clock_gating(struct drm_device *dev)
 
 	I915_WRITE(PCH_DSPCLK_GATE_D, dspclk_gate);
 
-	/*
-	 * On Ibex Peak and Cougar Point, we need to disable clock
-	 * gating for the panel power sequencer or it will fail to
-	 * start up when no ports are active.
-	 */
-	I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
-
 	I915_WRITE(WM3_LP_ILK, 0);
 	I915_WRITE(WM2_LP_ILK, 0);
 	I915_WRITE(WM1_LP_ILK, 0);
@@ -7428,6 +7407,32 @@ static void i830_init_clock_gating(struct drm_device *dev)
 	I915_WRITE(DSPCLK_GATE_D, OVRUNIT_CLOCK_GATE_DISABLE);
 }
 
+static void ibx_init_clock_gating(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	/*
+	 * On Ibex Peak and Cougar Point, we need to disable clock
+	 * gating for the panel power sequencer or it will fail to
+	 * start up when no ports are active.
+	 */
+	I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
+}
+
+static void cpt_init_clock_gating(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	/*
+	 * On Ibex Peak and Cougar Point, we need to disable clock
+	 * gating for the panel power sequencer or it will fail to
+	 * start up when no ports are active.
+	 */
+	I915_WRITE(SOUTH_DSPCLK_GATE_D, PCH_DPLSUNIT_CLOCK_GATE_DISABLE);
+	I915_WRITE(SOUTH_CHICKEN2, I915_READ(SOUTH_CHICKEN2) |
+		   DPLS_EDP_PPS_FIX_DIS);
+}
+
 static void ironlake_teardown_rc6(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -7543,6 +7548,15 @@ void ironlake_enable_rc6(struct drm_device *dev)
 	mutex_unlock(&dev->struct_mutex);
 }
 
+void intel_init_clock_gating(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	dev_priv->display.init_clock_gating(dev);
+
+	if (dev_priv->display.init_pch_clock_gating)
+		dev_priv->display.init_pch_clock_gating(dev);
+}
 
 /* Set up chip specific display functions */
 static void intel_init_display(struct drm_device *dev)
@@ -7600,6 +7614,11 @@ static void intel_init_display(struct drm_device *dev)
 
 	/* For FIFO watermark updates */
 	if (HAS_PCH_SPLIT(dev)) {
+		if (HAS_PCH_IBX(dev))
+			dev_priv->display.init_pch_clock_gating = ibx_init_clock_gating;
+		else if (HAS_PCH_CPT(dev))
+			dev_priv->display.init_pch_clock_gating = cpt_init_clock_gating;
+
 		if (IS_GEN5(dev)) {
 			if (I915_READ(MLTR_ILK) & ILK_SRLT_MASK)
 				dev_priv->display.update_wm = ironlake_update_wm;
@@ -7802,7 +7821,7 @@ void intel_modeset_init(struct drm_device *dev)
 	i915_disable_vga(dev);
 	intel_setup_outputs(dev);
 
-	dev_priv->display.init_clock_gating(dev);
+	intel_init_clock_gating(dev);
 
 	if (IS_IRONLAKE_M(dev)) {
 		ironlake_enable_drps(dev);

drivers/gpu/drm/i915/intel_drv.h

@@ -344,4 +344,6 @@ extern int intel_overlay_attrs(struct drm_device *dev, void *data,
 
 extern void intel_fb_output_poll_changed(struct drm_device *dev);
 extern void intel_fb_restore_mode(struct drm_device *dev);
+
+extern void intel_init_clock_gating(struct drm_device *dev);
 #endif /* __INTEL_DRV_H__ */