drm/i915: Kill duplicated cdclk readout code from i2c

We have a slightly different way of readoing out the cdclk in
gmbus_set_freq(). Kill that and just call .get_display_clock_speed().

Also need to remove the GMBUSFREQ update from intel_i2c_reset() since
that gets called way too early. Let's do it in intel_modeset_init_hw()
instead, and also pull the initial vlv_cdclk_freq update there from
init_clock gating.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/intel_display.c

@@ -4466,7 +4466,7 @@ static void modeset_update_crtc_power_domains(struct drm_device *dev)
 }
 
 /* returns HPLL frequency in kHz */
-int valleyview_get_vco(struct drm_i915_private *dev_priv)
+static int valleyview_get_vco(struct drm_i915_private *dev_priv)
 {
 	int hpll_freq, vco_freq[] = { 800, 1600, 2000, 2400 };
 
@@ -4479,14 +4479,29 @@ int valleyview_get_vco(struct drm_i915_private *dev_priv)
 	return vco_freq[hpll_freq] * 1000;
 }
 
+static void vlv_update_cdclk(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+
+	dev_priv->vlv_cdclk_freq = dev_priv->display.get_display_clock_speed(dev);
+	DRM_DEBUG_DRIVER("Current CD clock rate: %d kHz",
+			 dev_priv->vlv_cdclk_freq);
+
+	/*
+	 * Program the gmbus_freq based on the cdclk frequency.
+	 * BSpec erroneously claims we should aim for 4MHz, but
+	 * in fact 1MHz is the correct frequency.
+	 */
+	I915_WRITE(GMBUSFREQ_VLV, dev_priv->vlv_cdclk_freq);
+}
+
 /* Adjust CDclk dividers to allow high res or save power if possible */
 static void valleyview_set_cdclk(struct drm_device *dev, int cdclk)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	u32 val, cmd;
 
 	WARN_ON(dev_priv->display.get_display_clock_speed(dev) != dev_priv->vlv_cdclk_freq);
-	dev_priv->vlv_cdclk_freq = cdclk;
 
 	if (cdclk >= 320000) /* jump to highest voltage for 400MHz too */
 		cmd = 2;
@@ -4543,8 +4558,7 @@ static void valleyview_set_cdclk(struct drm_device *dev, int cdclk)
 	vlv_bunit_write(dev_priv, BUNIT_REG_BISOC, val);
 	mutex_unlock(&dev_priv->dpio_lock);
 
-	/* Since we changed the CDclk, we need to update the GMBUSFREQ too */
-	intel_i2c_reset(dev);
+	vlv_update_cdclk(dev);
 }
 
 static int valleyview_calc_cdclk(struct drm_i915_private *dev_priv,
@@ -12440,6 +12454,9 @@ void intel_modeset_init_hw(struct drm_device *dev)
 {
 	intel_prepare_ddi(dev);
 
+	if (IS_VALLEYVIEW(dev))
+		vlv_update_cdclk(dev);
+
 	intel_init_clock_gating(dev);
 
 	intel_reset_dpio(dev);

drivers/gpu/drm/i915/intel_drv.h

@@ -830,7 +830,6 @@ void hsw_disable_ips(struct intel_crtc *crtc);
 void intel_display_set_init_power(struct drm_i915_private *dev, bool enable);
 enum intel_display_power_domain
 intel_display_port_power_domain(struct intel_encoder *intel_encoder);
-int valleyview_get_vco(struct drm_i915_private *dev_priv);
 void intel_mode_from_pipe_config(struct drm_display_mode *mode,
 				 struct intel_crtc_config *pipe_config);
 int intel_format_to_fourcc(int format);

drivers/gpu/drm/i915/intel_i2c.c

@@ -34,11 +34,6 @@
 #include <drm/i915_drm.h>
 #include "i915_drv.h"
 
-enum disp_clk {
-	CDCLK,
-	CZCLK
-};
-
 struct gmbus_port {
 	const char *name;
 	int reg;
@@ -63,60 +58,11 @@ to_intel_gmbus(struct i2c_adapter *i2c)
 	return container_of(i2c, struct intel_gmbus, adapter);
 }
 
-static int get_disp_clk_div(struct drm_i915_private *dev_priv,
-			    enum disp_clk clk)
-{
-	u32 reg_val;
-	int clk_ratio;
-
-	reg_val = I915_READ(CZCLK_CDCLK_FREQ_RATIO);
-
-	if (clk == CDCLK)
-		clk_ratio =
-			((reg_val & CDCLK_FREQ_MASK) >> CDCLK_FREQ_SHIFT) + 1;
-	else
-		clk_ratio = (reg_val & CZCLK_FREQ_MASK) + 1;
-
-	return clk_ratio;
-}
-
-static void gmbus_set_freq(struct drm_i915_private *dev_priv)
-{
-	int vco, gmbus_freq = 0, cdclk_div;
-
-	BUG_ON(!IS_VALLEYVIEW(dev_priv->dev));
-
-	vco = valleyview_get_vco(dev_priv) / 1000;
-
-	/* Get the CDCLK divide ratio */
-	cdclk_div = get_disp_clk_div(dev_priv, CDCLK);
-
-	/*
-	 * Program the gmbus_freq based on the cdclk frequency.
-	 * BSpec erroneously claims we should aim for 4MHz, but
-	 * in fact 1MHz is the correct frequency.
-	 */
-	if (cdclk_div)
-		gmbus_freq = (vco << 1) / cdclk_div;
-
-	if (WARN_ON(gmbus_freq == 0))
-		return;
-
-	I915_WRITE(GMBUSFREQ_VLV, gmbus_freq);
-}
-
 void
 intel_i2c_reset(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 
-	/*
-	 * In BIOS-less system, program the correct gmbus frequency
-	 * before reading edid.
-	 */
-	if (IS_VALLEYVIEW(dev))
-		gmbus_set_freq(dev_priv);
-
 	I915_WRITE(dev_priv->gpio_mmio_base + GMBUS0, 0);
 	I915_WRITE(dev_priv->gpio_mmio_base + GMBUS4, 0);
 }

drivers/gpu/drm/i915/intel_pm.c

@@ -5595,10 +5595,6 @@ static void valleyview_init_clock_gating(struct drm_device *dev)
 	}
 	DRM_DEBUG_DRIVER("DDR speed: %d MHz", dev_priv->mem_freq);
 
-	dev_priv->vlv_cdclk_freq = dev_priv->display.get_display_clock_speed(dev);
-	DRM_DEBUG_DRIVER("Current CD clock rate: %d kHz",
-			 dev_priv->vlv_cdclk_freq);
-
 	I915_WRITE(DSPCLK_GATE_D, VRHUNIT_CLOCK_GATE_DISABLE);
 
 	/* WaDisableEarlyCull:vlv */