[PATCH v2 2/3] drm/i915: Get CZ clock for VLV

[Vandana Kannan <vandana.kannan@intel.com>]

CZ clock is related to data flow from memory to display plane. This is
required for comparison with CD clock before programming PFI credits.

v2: Ville's review comments
	- Re-ordered CCK_CZ_CONTROL
	- Refactored get_clock_speed

Signed-off-by: Vandana Kannan <vandana.kannan@intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h      |  2 ++
 drivers/gpu/drm/i915/i915_reg.h      |  1 +
 drivers/gpu/drm/i915/intel_display.c | 43 ++++++++++++++++++++++++++++++------
 3 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index dccd0a2..881e0a6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2784,6 +2784,8 @@ void vlv_flisdsi_write(struct drm_i915_private *dev_priv, u32 reg, u32 val);
 int vlv_gpu_freq(struct drm_i915_private *dev_priv, int val);
 int vlv_freq_opcode(struct drm_i915_private *dev_priv, int val);
 
+int valleyview_get_cz_clock_speed(struct drm_device *dev);
+
 #define FORCEWAKE_RENDER	(1 << 0)
 #define FORCEWAKE_MEDIA		(1 << 1)
 #define FORCEWAKE_ALL		(FORCEWAKE_RENDER | FORCEWAKE_MEDIA)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index a8275b7..fb111cd 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -616,6 +616,7 @@ enum punit_power_well {
 #define  DSI_PLL_N1_DIV_MASK			(3 << 16)
 #define  DSI_PLL_M1_DIV_SHIFT			0
 #define  DSI_PLL_M1_DIV_MASK			(0x1ff << 0)
+#define CCK_CZ_CONTROL				0x62
 #define CCK_DISPLAY_CLOCK_CONTROL		0x6b
 #define  CCK_TRUNK_FORCE_ON			(1 << 17)
 #define  CCK_TRUNK_FORCE_OFF			(1 << 16)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index f1f1b54..2089319 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -5316,30 +5316,59 @@ static int intel_crtc_compute_config(struct intel_crtc *crtc,
 	return 0;
 }
 
-static int valleyview_get_display_clock_speed(struct drm_device *dev)
+enum disp_clk {
+	CDCLK,
+	CZCLK
+};
+
+static int valleyview_get_cck_clock_speed(struct drm_device *dev,
+					  enum disp_clk clk)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	int vco = valleyview_get_vco(dev_priv);
-	u32 val;
+	u32 val, reg;
 	int divider;
 
-	/* FIXME: Punit isn't quite ready yet */
-	if (IS_CHERRYVIEW(dev))
-		return 400000;
+	switch(clk) {
+	case CDCLK:
+	default:
+		reg = CCK_DISPLAY_CLOCK_CONTROL;
+		break;
+	case CZCLK:
+		reg = CCK_CZ_CONTROL;
+		break;
+	}
+
 	mutex_lock(&dev_priv->dpio_lock);
-	val = vlv_cck_read(dev_priv, CCK_DISPLAY_CLOCK_CONTROL);
+	val = vlv_cck_read(dev_priv, reg);
 	mutex_unlock(&dev_priv->dpio_lock);
 
 	divider = val & CCK_FREQUENCY_VALUES;
 
 	WARN((val & CCK_FREQUENCY_STATUS) !=
 	     (divider << CCK_FREQUENCY_STATUS_SHIFT),
-	     "cdclk change in progress\n");
+	     "%sclk change in progress\n", (clk == CDCLK) ? "cd" : "cz");
 
 	return DIV_ROUND_CLOSEST(vco << 1, divider + 1);
 }
 
+static int valleyview_get_display_clock_speed(struct drm_device *dev)
+{
+	/* FIXME: Punit isn't quite ready yet */
+	if (IS_CHERRYVIEW(dev))
+		return 400000;
+	else
+		return valleyview_get_cck_clock_speed(dev, CDCLK);
+}
+
+int valleyview_get_cz_clock_speed(struct drm_device *dev)
+{
+	return valleyview_get_cck_clock_speed(dev, CZCLK);
+}
+
 static int i945_get_display_clock_speed(struct drm_device *dev)
 {
 	return 400000;
-- 
2.0.1