drm/i915: Implement chv display PHY lane stagger setup

Set up the chv display PHY lane stagger registers according to
"Programming Guide for 1273 CHV eDP/DP/HDMI Display PHY" v1.04

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by:  Deepak S <deepak.s@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 590d46b..86355f1 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1487,7 +1487,7 @@
 		&intel_crtc->config->base.adjusted_mode;
 	enum dpio_channel ch = vlv_dport_to_channel(dport);
 	int pipe = intel_crtc->pipe;
-	int data, i;
+	int data, i, stagger;
 	u32 val;
 
 	mutex_lock(&dev_priv->dpio_lock);
@@ -1527,7 +1527,38 @@
 	}
 
 	/* Data lane stagger programming */
-	/* FIXME: Fix up value only after power analysis */
+	if (intel_crtc->config->port_clock > 270000)
+		stagger = 0x18;
+	else if (intel_crtc->config->port_clock > 135000)
+		stagger = 0xd;
+	else if (intel_crtc->config->port_clock > 67500)
+		stagger = 0x7;
+	else if (intel_crtc->config->port_clock > 33750)
+		stagger = 0x4;
+	else
+		stagger = 0x2;
+
+	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW11(ch));
+	val |= DPIO_TX2_STAGGER_MASK(0x1f);
+	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW11(ch), val);
+
+	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW11(ch));
+	val |= DPIO_TX2_STAGGER_MASK(0x1f);
+	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW11(ch), val);
+
+	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW12(ch),
+		       DPIO_LANESTAGGER_STRAP(stagger) |
+		       DPIO_LANESTAGGER_STRAP_OVRD |
+		       DPIO_TX1_STAGGER_MASK(0x1f) |
+		       DPIO_TX1_STAGGER_MULT(6) |
+		       DPIO_TX2_STAGGER_MULT(0));
+
+	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW12(ch),
+		       DPIO_LANESTAGGER_STRAP(stagger) |
+		       DPIO_LANESTAGGER_STRAP_OVRD |
+		       DPIO_TX1_STAGGER_MASK(0x1f) |
+		       DPIO_TX1_STAGGER_MULT(7) |
+		       DPIO_TX2_STAGGER_MULT(5));
 
 	/* Clear calc init */
 	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW10(ch));