drm/i915/chv: Force clock buffer enables

Try to force the PHY clock buffer enables to make the clock routing
work.

v2: Fix the pipe B case to actually enable CH0 clock buffers

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -881,6 +881,16 @@ enum punit_power_well {
 #define   DPIO_CHV_PROP_COEFF_SHIFT	0
 #define CHV_PLL_DW6(ch) _PIPE(ch, _CHV_PLL_DW6_CH0, _CHV_PLL_DW6_CH1)
 
+#define _CHV_CMN_DW5_CH0               0x8114
+#define   CHV_BUFRIGHTENA1_DISABLE	(0 << 20)
+#define   CHV_BUFRIGHTENA1_NORMAL	(1 << 20)
+#define   CHV_BUFRIGHTENA1_FORCE	(3 << 20)
+#define   CHV_BUFRIGHTENA1_MASK		(3 << 20)
+#define   CHV_BUFLEFTENA1_DISABLE	(0 << 22)
+#define   CHV_BUFLEFTENA1_NORMAL	(1 << 22)
+#define   CHV_BUFLEFTENA1_FORCE		(3 << 22)
+#define   CHV_BUFLEFTENA1_MASK		(3 << 22)
+
 #define _CHV_CMN_DW13_CH0		0x8134
 #define _CHV_CMN_DW0_CH1		0x8080
 #define   DPIO_CHV_S1_DIV_SHIFT		21
@@ -895,6 +905,14 @@ enum punit_power_well {
 #define _CHV_CMN_DW1_CH1		0x8084
 #define   DPIO_AFC_RECAL		(1 << 14)
 #define   DPIO_DCLKP_EN			(1 << 13)
+#define   CHV_BUFLEFTENA2_DISABLE	(0 << 17) /* CL2 DW1 only */
+#define   CHV_BUFLEFTENA2_NORMAL	(1 << 17) /* CL2 DW1 only */
+#define   CHV_BUFLEFTENA2_FORCE		(3 << 17) /* CL2 DW1 only */
+#define   CHV_BUFLEFTENA2_MASK		(3 << 17) /* CL2 DW1 only */
+#define   CHV_BUFRIGHTENA2_DISABLE	(0 << 19) /* CL2 DW1 only */
+#define   CHV_BUFRIGHTENA2_NORMAL	(1 << 19) /* CL2 DW1 only */
+#define   CHV_BUFRIGHTENA2_FORCE	(3 << 19) /* CL2 DW1 only */
+#define   CHV_BUFRIGHTENA2_MASK		(3 << 19) /* CL2 DW1 only */
 #define CHV_CMN_DW14(ch) _PIPE(ch, _CHV_CMN_DW14_CH0, _CHV_CMN_DW1_CH1)
 
 #define _CHV_CMN_DW19_CH0		0x814c

drivers/gpu/drm/i915/intel_dp.c

@@ -2132,6 +2132,25 @@ static void chv_dp_pre_pll_enable(struct intel_encoder *encoder)
 
 	mutex_lock(&dev_priv->dpio_lock);
 
+	/* program left/right clock distribution */
+	if (pipe != PIPE_B) {
+		val = vlv_dpio_read(dev_priv, pipe, _CHV_CMN_DW5_CH0);
+		val &= ~(CHV_BUFLEFTENA1_MASK | CHV_BUFRIGHTENA1_MASK);
+		if (ch == DPIO_CH0)
+			val |= CHV_BUFLEFTENA1_FORCE;
+		if (ch == DPIO_CH1)
+			val |= CHV_BUFRIGHTENA1_FORCE;
+		vlv_dpio_write(dev_priv, pipe, _CHV_CMN_DW5_CH0, val);
+	} else {
+		val = vlv_dpio_read(dev_priv, pipe, _CHV_CMN_DW1_CH1);
+		val &= ~(CHV_BUFLEFTENA2_MASK | CHV_BUFRIGHTENA2_MASK);
+		if (ch == DPIO_CH0)
+			val |= CHV_BUFLEFTENA2_FORCE;
+		if (ch == DPIO_CH1)
+			val |= CHV_BUFRIGHTENA2_FORCE;
+		vlv_dpio_write(dev_priv, pipe, _CHV_CMN_DW1_CH1, val);
+	}
+
 	/* program clock channel usage */
 	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW8(ch));
 	val |= CHV_PCS_USEDCLKCHANNEL_OVRRIDE;

drivers/gpu/drm/i915/intel_hdmi.c

@@ -1242,6 +1242,25 @@ static void chv_hdmi_pre_pll_enable(struct intel_encoder *encoder)
 
 	mutex_lock(&dev_priv->dpio_lock);
 
+	/* program left/right clock distribution */
+	if (pipe != PIPE_B) {
+		val = vlv_dpio_read(dev_priv, pipe, _CHV_CMN_DW5_CH0);
+		val &= ~(CHV_BUFLEFTENA1_MASK | CHV_BUFRIGHTENA1_MASK);
+		if (ch == DPIO_CH0)
+			val |= CHV_BUFLEFTENA1_FORCE;
+		if (ch == DPIO_CH1)
+			val |= CHV_BUFRIGHTENA1_FORCE;
+		vlv_dpio_write(dev_priv, pipe, _CHV_CMN_DW5_CH0, val);
+	} else {
+		val = vlv_dpio_read(dev_priv, pipe, _CHV_CMN_DW1_CH1);
+		val &= ~(CHV_BUFLEFTENA2_MASK | CHV_BUFRIGHTENA2_MASK);
+		if (ch == DPIO_CH0)
+			val |= CHV_BUFLEFTENA2_FORCE;
+		if (ch == DPIO_CH1)
+			val |= CHV_BUFRIGHTENA2_FORCE;
+		vlv_dpio_write(dev_priv, pipe, _CHV_CMN_DW1_CH1, val);
+	}
+
 	/* program clock channel usage */
 	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW8(ch));
 	val |= CHV_PCS_USEDCLKCHANNEL_OVRRIDE;