[PATCH 08/19] drm/i915: manual FDI training for Ivy Bridge

[Jesse Barnes <jbarnes@virtuousgeek.org>]

A0 stepping chips need to use manual training, but the bits have all
moved.  So fix things up so we can at least train FDI for VGA links.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
---
 drivers/gpu/drm/i915/i915_reg.h      |   10 +++
 drivers/gpu/drm/i915/intel_display.c |  128 +++++++++++++++++++++++++++++++++-
 2 files changed, 135 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 8848411..aba3fe5 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3105,7 +3105,15 @@
 #define  FDI_TX_ENHANCE_FRAME_ENABLE    (1<<18)
 /* Ironlake: hardwired to 1 */
 #define  FDI_TX_PLL_ENABLE              (1<<14)
+
+/* Ivybridge has different bits for lolz */
+#define  FDI_LINK_TRAIN_PATTERN_1_IVB       (0<<8)
+#define  FDI_LINK_TRAIN_PATTERN_2_IVB       (1<<8)
+#define  FDI_LINK_TRAIN_PATTERN_IDLE_IVB    (2<<8)
+#define  FDI_LINK_TRAIN_NONE_IVB            (3<<8)
+
 /* both Tx and Rx */
+#define  FDI_LINK_TRAIN_AUTO		(1<<10)
 #define  FDI_SCRAMBLING_ENABLE          (0<<7)
 #define  FDI_SCRAMBLING_DISABLE         (1<<7)
 
@@ -3115,6 +3123,8 @@
 #define FDI_RX_CTL(pipe) _PIPE(pipe, _FDI_RXA_CTL, _FDI_RXB_CTL)
 #define  FDI_RX_ENABLE          (1<<31)
 /* train, dp width same as FDI_TX */
+#define  FDI_FS_ERRC_ENABLE		(1<<27)
+#define  FDI_FE_ERRC_ENABLE		(1<<26)
 #define  FDI_DP_PORT_WIDTH_X8           (7<<19)
 #define  FDI_8BPC                       (0<<16)
 #define  FDI_10BPC                      (1<<16)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0dadc8e..ab840a6 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2047,8 +2047,13 @@ static void intel_fdi_normal_train(struct drm_crtc *crtc)
 	/* enable normal train */
 	reg = FDI_TX_CTL(pipe);
 	temp = I915_READ(reg);
-	temp &= ~FDI_LINK_TRAIN_NONE;
-	temp |= FDI_LINK_TRAIN_NONE | FDI_TX_ENHANCE_FRAME_ENABLE;
+	if (IS_GEN6(dev)) {
+		temp &= ~FDI_LINK_TRAIN_NONE;
+		temp |= FDI_LINK_TRAIN_NONE | FDI_TX_ENHANCE_FRAME_ENABLE;
+	} else if (IS_IVYBRIDGE(dev)) {
+		temp &= ~FDI_LINK_TRAIN_NONE_IVB;
+		temp |= FDI_LINK_TRAIN_NONE_IVB | FDI_TX_ENHANCE_FRAME_ENABLE;
+	}
 	I915_WRITE(reg, temp);
 
 	reg = FDI_RX_CTL(pipe);
@@ -2065,6 +2070,11 @@ static void intel_fdi_normal_train(struct drm_crtc *crtc)
 	/* wait one idle pattern time */
 	POSTING_READ(reg);
 	udelay(1000);
+
+	/* IVB wants error correction enabled */
+	if (IS_IVYBRIDGE(dev))
+		I915_WRITE(reg, I915_READ(reg) | FDI_FS_ERRC_ENABLE |
+			   FDI_FE_ERRC_ENABLE);
 }
 
 /* The FDI link training functions for ILK/Ibexpeak. */
@@ -2292,7 +2302,116 @@ static void gen6_fdi_link_train(struct drm_crtc *crtc)
 	DRM_DEBUG_KMS("FDI train done.\n");
 }
 
-static void ironlake_fdi_enable(struct drm_crtc *crtc)
+/* Manual link training for Ivy Bridge A0 parts */
+static void ivb_manual_fdi_link_train(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	int pipe = intel_crtc->pipe;
+	u32 reg, temp, i;
+
+	/* Train 1: umask FDI RX Interrupt symbol_lock and bit_lock bit
+	   for train result */
+	reg = FDI_RX_IMR(pipe);
+	temp = I915_READ(reg);
+	temp &= ~FDI_RX_SYMBOL_LOCK;
+	temp &= ~FDI_RX_BIT_LOCK;
+	I915_WRITE(reg, temp);
+
+	POSTING_READ(reg);
+	udelay(150);
+
+	/* enable CPU FDI TX and PCH FDI RX */
+	reg = FDI_TX_CTL(pipe);
+	temp = I915_READ(reg);
+	temp &= ~(7 << 19);
+	temp |= (intel_crtc->fdi_lanes - 1) << 19;
+	temp &= ~(FDI_LINK_TRAIN_AUTO | FDI_LINK_TRAIN_NONE_IVB);
+	temp |= FDI_LINK_TRAIN_PATTERN_1_IVB;
+	temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
+	temp |= FDI_LINK_TRAIN_400MV_0DB_SNB_B;
+	I915_WRITE(reg, temp | FDI_TX_ENABLE);
+
+	reg = FDI_RX_CTL(pipe);
+	temp = I915_READ(reg);
+	temp &= ~FDI_LINK_TRAIN_AUTO;
+	temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
+	temp |= FDI_LINK_TRAIN_PATTERN_1_CPT;
+	I915_WRITE(reg, temp | FDI_RX_ENABLE);
+
+	POSTING_READ(reg);
+	udelay(150);
+
+	for (i = 0; i < 4; i++ ) {
+		reg = FDI_TX_CTL(pipe);
+		temp = I915_READ(reg);
+		temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
+		temp |= snb_b_fdi_train_param[i];
+		I915_WRITE(reg, temp);
+
+		POSTING_READ(reg);
+		udelay(500);
+
+		reg = FDI_RX_IIR(pipe);
+		temp = I915_READ(reg);
+		DRM_DEBUG_KMS("FDI_RX_IIR 0x%x\n", temp);
+
+		if (temp & FDI_RX_BIT_LOCK ||
+		    (I915_READ(reg) & FDI_RX_BIT_LOCK)) {
+			I915_WRITE(reg, temp | FDI_RX_BIT_LOCK);
+			DRM_DEBUG_KMS("FDI train 1 done.\n");
+			break;
+		}
+	}
+	if (i == 4)
+		DRM_ERROR("FDI train 1 fail!\n");
+
+	/* Train 2 */
+	reg = FDI_TX_CTL(pipe);
+	temp = I915_READ(reg);
+	temp &= ~FDI_LINK_TRAIN_NONE_IVB;
+	temp |= FDI_LINK_TRAIN_PATTERN_2_IVB;
+	temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
+	temp |= FDI_LINK_TRAIN_400MV_0DB_SNB_B;
+	I915_WRITE(reg, temp);
+
+	reg = FDI_RX_CTL(pipe);
+	temp = I915_READ(reg);
+	temp &= ~FDI_LINK_TRAIN_PATTERN_MASK_CPT;
+	temp |= FDI_LINK_TRAIN_PATTERN_2_CPT;
+	I915_WRITE(reg, temp);
+
+	POSTING_READ(reg);
+	udelay(150);
+
+	for (i = 0; i < 4; i++ ) {
+		reg = FDI_TX_CTL(pipe);
+		temp = I915_READ(reg);
+		temp &= ~FDI_LINK_TRAIN_VOL_EMP_MASK;
+		temp |= snb_b_fdi_train_param[i];
+		I915_WRITE(reg, temp);
+
+		POSTING_READ(reg);
+		udelay(500);
+
+		reg = FDI_RX_IIR(pipe);
+		temp = I915_READ(reg);
+		DRM_DEBUG_KMS("FDI_RX_IIR 0x%x\n", temp);
+
+		if (temp & FDI_RX_SYMBOL_LOCK) {
+			I915_WRITE(reg, temp | FDI_RX_SYMBOL_LOCK);
+			DRM_DEBUG_KMS("FDI train 2 done.\n");
+			break;
+		}
+	}
+	if (i == 4)
+		DRM_ERROR("FDI train 2 fail!\n");
+
+	DRM_DEBUG_KMS("FDI train done.\n");
+}
+
+static void ironlake_fdi_pll_enable(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -7297,6 +7416,9 @@ static void intel_init_display(struct drm_device *dev)
 				dev_priv->display.update_wm = NULL;
 			}
 			dev_priv->display.fdi_link_train = gen6_fdi_link_train;
+		} else if (IS_IVYBRIDGE(dev)) {
+			/* FIXME: detect B0+ stepping and use auto training */
+			dev_priv->display.fdi_link_train = ivb_manual_fdi_link_train;
 		} else
 			dev_priv->display.update_wm = NULL;
 	} else if (IS_PINEVIEW(dev)) {
-- 
1.7.4.1