drm/i915: Clean up CHV lane soft reset programming

Currently we release the lane soft reset before lane stagger settings
have been programmed. I believe that means we don't actually do lane
staggering. So move the soft reset deassert to happen after lane
staggering has been programmed.

The one confusing thing in this is that when we remove the power down
override from the lanes, they power up with defaul register values,
which do not have the soft reset overrides enabled. And according to
some docs by default the data lane resets are tied to cmnreset. So that
would mean that lanes would come out of reset without staggering as
soon as the power down overrides are removed. But since we can't access
either the lane stagger register nor the soft reset override registers
until the lanes are powered on, we can't really do anything about it.
So let's just set the soft reset overrides as soon as the lane is
powered on and hope for the best.

v2: Fix typos in commit message (Daniel)

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>

1 files changed, 52 insertions, 39 deletions

diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
index 7c56053..4da737c 100644
--- a/drivers/gpu/drm/i915/intel_hdmi.c
+++ b/drivers/gpu/drm/i915/intel_hdmi.c
@@ -1615,6 +1615,50 @@ static void vlv_hdmi_pre_pll_enable(struct intel_encoder *encoder)
 	mutex_unlock(&dev_priv->sb_lock);
 }
 
+static void chv_data_lane_soft_reset(struct intel_encoder *encoder,
+				     bool reset)
+{
+	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
+	enum dpio_channel ch = vlv_dport_to_channel(enc_to_dig_port(&encoder->base));
+	struct intel_crtc *crtc = to_intel_crtc(encoder->base.crtc);
+	enum pipe pipe = crtc->pipe;
+	uint32_t val;
+
+	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW0(ch));
+	if (reset)
+		val &= ~(DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET);
+	else
+		val |= DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET;
+	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW0(ch), val);
+
+	if (crtc->config->lane_count > 2) {
+		val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW0(ch));
+		if (reset)
+			val &= ~(DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET);
+		else
+			val |= DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET;
+		vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW0(ch), val);
+	}
+
+	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW1(ch));
+	val |= CHV_PCS_REQ_SOFTRESET_EN;
+	if (reset)
+		val &= ~DPIO_PCS_CLK_SOFT_RESET;
+	else
+		val |= DPIO_PCS_CLK_SOFT_RESET;
+	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW1(ch), val);
+
+	if (crtc->config->lane_count > 2) {
+		val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW1(ch));
+		val |= CHV_PCS_REQ_SOFTRESET_EN;
+		if (reset)
+			val &= ~DPIO_PCS_CLK_SOFT_RESET;
+		else
+			val |= DPIO_PCS_CLK_SOFT_RESET;
+		vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW1(ch), val);
+	}
+}
+
 static void chv_hdmi_pre_pll_enable(struct intel_encoder *encoder)
 {
 	struct intel_digital_port *dport = enc_to_dig_port(&encoder->base);
@@ -1640,6 +1684,9 @@ static void chv_hdmi_pre_pll_enable(struct intel_encoder *encoder)
 
 	mutex_lock(&dev_priv->sb_lock);
 
+	/* Assert data lane reset */
+	chv_data_lane_soft_reset(encoder, true);
+
 	/* program left/right clock distribution */
 	if (pipe != PIPE_B) {
 		val = vlv_dpio_read(dev_priv, pipe, _CHV_CMN_DW5_CH0);
@@ -1742,33 +1789,13 @@ static void vlv_hdmi_post_disable(struct intel_encoder *encoder)
 
 static void chv_hdmi_post_disable(struct intel_encoder *encoder)
 {
-	struct intel_digital_port *dport = enc_to_dig_port(&encoder->base);
 	struct drm_device *dev = encoder->base.dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
-	struct intel_crtc *intel_crtc =
-		to_intel_crtc(encoder->base.crtc);
-	enum dpio_channel ch = vlv_dport_to_channel(dport);
-	enum pipe pipe = intel_crtc->pipe;
-	u32 val;
 
 	mutex_lock(&dev_priv->sb_lock);
 
-	/* Propagate soft reset to data lane reset */
-	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW1(ch));
-	val |= CHV_PCS_REQ_SOFTRESET_EN;
-	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW1(ch), val);
-
-	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW1(ch));
-	val |= CHV_PCS_REQ_SOFTRESET_EN;
-	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW1(ch), val);
-
-	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW0(ch));
-	val &= ~(DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET);
-	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW0(ch), val);
-
-	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW0(ch));
-	val &= ~(DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET);
-	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW0(ch), val);
+	/* Assert data lane reset */
+	chv_data_lane_soft_reset(encoder, true);
 
 	mutex_unlock(&dev_priv->sb_lock);
 }
@@ -1799,23 +1826,6 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder)
 	val &= ~DPIO_LANEDESKEW_STRAP_OVRD;
 	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW11(ch), val);
 
-	/* Deassert soft data lane reset*/
-	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW1(ch));
-	val |= CHV_PCS_REQ_SOFTRESET_EN;
-	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW1(ch), val);
-
-	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW1(ch));
-	val |= CHV_PCS_REQ_SOFTRESET_EN;
-	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW1(ch), val);
-
-	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW0(ch));
-	val |= (DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET);
-	vlv_dpio_write(dev_priv, pipe, VLV_PCS01_DW0(ch), val);
-
-	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS23_DW0(ch));
-	val |= (DPIO_PCS_TX_LANE2_RESET | DPIO_PCS_TX_LANE1_RESET);
-	vlv_dpio_write(dev_priv, pipe, VLV_PCS23_DW0(ch), val);
-
 	/* Program Tx latency optimal setting */
 	for (i = 0; i < 4; i++) {
 		/* Set the upar bit */
@@ -1858,6 +1868,9 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder)
 		       DPIO_TX1_STAGGER_MULT(7) |
 		       DPIO_TX2_STAGGER_MULT(5));
 
+	/* Deassert data lane reset */
+	chv_data_lane_soft_reset(encoder, false);
+
 	/* Clear calc init */
 	val = vlv_dpio_read(dev_priv, pipe, VLV_PCS01_DW10(ch));
 	val &= ~(DPIO_PCS_SWING_CALC_TX0_TX2 | DPIO_PCS_SWING_CALC_TX1_TX3);