drm/i915: update BDW DDI buffer translations

Two BSpec updates changed the recommended values for BDW eDP and DP
DDI buffer translations. Now the signal levels also match the HSW signal
levels, which simplify things a little bit.

It seems some DP sinks don't work properly without voltage level 0 and
pre-emphasis level 3, so this patch may fix some bugs on
panels/monitors that happen on BDW but not on HSW.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -5821,7 +5821,6 @@ enum punit_power_well {
 #define DDI_BUF_CTL_B				0x64100
 #define DDI_BUF_CTL(port) _PORT(port, DDI_BUF_CTL_A, DDI_BUF_CTL_B)
 #define  DDI_BUF_CTL_ENABLE			(1<<31)
-/* Haswell */
 #define  DDI_BUF_EMP_400MV_0DB_HSW		(0<<24)   /* Sel0 */
 #define  DDI_BUF_EMP_400MV_3_5DB_HSW		(1<<24)   /* Sel1 */
 #define  DDI_BUF_EMP_400MV_6DB_HSW		(2<<24)   /* Sel2 */
@@ -5831,16 +5830,6 @@ enum punit_power_well {
 #define  DDI_BUF_EMP_600MV_6DB_HSW		(6<<24)   /* Sel6 */
 #define  DDI_BUF_EMP_800MV_0DB_HSW		(7<<24)   /* Sel7 */
 #define  DDI_BUF_EMP_800MV_3_5DB_HSW		(8<<24)   /* Sel8 */
-/* Broadwell */
-#define  DDI_BUF_EMP_400MV_0DB_BDW		(0<<24)   /* Sel0 */
-#define  DDI_BUF_EMP_400MV_3_5DB_BDW		(1<<24)   /* Sel1 */
-#define  DDI_BUF_EMP_400MV_6DB_BDW		(2<<24)   /* Sel2 */
-#define  DDI_BUF_EMP_600MV_0DB_BDW		(3<<24)   /* Sel3 */
-#define  DDI_BUF_EMP_600MV_3_5DB_BDW		(4<<24)   /* Sel4 */
-#define  DDI_BUF_EMP_600MV_6DB_BDW		(5<<24)   /* Sel5 */
-#define  DDI_BUF_EMP_800MV_0DB_BDW		(6<<24)   /* Sel6 */
-#define  DDI_BUF_EMP_800MV_3_5DB_BDW		(7<<24)   /* Sel7 */
-#define  DDI_BUF_EMP_1200MV_0DB_BDW		(8<<24)   /* Sel8 */
 #define  DDI_BUF_EMP_MASK			(0xf<<24)
 #define  DDI_BUF_PORT_REVERSAL			(1<<16)
 #define  DDI_BUF_IS_IDLE			(1<<7)

drivers/gpu/drm/i915/intel_ddi.c

@@ -76,12 +76,12 @@ static const u32 bdw_ddi_translations_edp[] = {
 	0x00FFFFFF, 0x00000012,		/* eDP parameters */
 	0x00EBAFFF, 0x00020011,
 	0x00C71FFF, 0x0006000F,
+	0x00AAAFFF, 0x000E000A,
 	0x00FFFFFF, 0x00020011,
 	0x00DB6FFF, 0x0005000F,
 	0x00BEEFFF, 0x000A000C,
 	0x00FFFFFF, 0x0005000F,
 	0x00DB6FFF, 0x000A000C,
-	0x00FFFFFF, 0x000A000C,
 	0x00FFFFFF, 0x00140006		/* HDMI parameters 800mV 0dB*/
 };
 
@@ -89,12 +89,12 @@ static const u32 bdw_ddi_translations_dp[] = {
 	0x00FFFFFF, 0x0007000E,		/* DP parameters */
 	0x00D75FFF, 0x000E000A,
 	0x00BEFFFF, 0x00140006,
+	0x80B2CFFF, 0x001B0002,
 	0x00FFFFFF, 0x000E000A,
 	0x00D75FFF, 0x00180004,
 	0x80CB2FFF, 0x001B0002,
 	0x00F7DFFF, 0x00180004,
 	0x80D75FFF, 0x001B0002,
-	0x80FFFFFF, 0x001B0002,
 	0x00FFFFFF, 0x00140006		/* HDMI parameters 800mV 0dB*/
 };
 

drivers/gpu/drm/i915/intel_dp.c

@@ -2330,7 +2330,7 @@ intel_dp_voltage_max(struct intel_dp *intel_dp)
 	struct drm_device *dev = intel_dp_to_dev(intel_dp);
 	enum port port = dp_to_dig_port(intel_dp)->port;
 
-	if (IS_VALLEYVIEW(dev) || IS_BROADWELL(dev))
+	if (IS_VALLEYVIEW(dev))
 		return DP_TRAIN_VOLTAGE_SWING_1200;
 	else if (IS_GEN7(dev) && port == PORT_A)
 		return DP_TRAIN_VOLTAGE_SWING_800;
@@ -2346,18 +2346,7 @@ intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing)
 	struct drm_device *dev = intel_dp_to_dev(intel_dp);
 	enum port port = dp_to_dig_port(intel_dp)->port;
 
-	if (IS_BROADWELL(dev)) {
-		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
-		case DP_TRAIN_VOLTAGE_SWING_400:
-		case DP_TRAIN_VOLTAGE_SWING_600:
-			return DP_TRAIN_PRE_EMPHASIS_6;
-		case DP_TRAIN_VOLTAGE_SWING_800:
-			return DP_TRAIN_PRE_EMPHASIS_3_5;
-		case DP_TRAIN_VOLTAGE_SWING_1200:
-		default:
-			return DP_TRAIN_PRE_EMPHASIS_0;
-		}
-	} else if (IS_HASWELL(dev)) {
+	if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
 		switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
 		case DP_TRAIN_VOLTAGE_SWING_400:
 			return DP_TRAIN_PRE_EMPHASIS_9_5;
@@ -2829,41 +2818,6 @@ intel_hsw_signal_levels(uint8_t train_set)
 	}
 }
 
-static uint32_t
-intel_bdw_signal_levels(uint8_t train_set)
-{
-	int signal_levels = train_set & (DP_TRAIN_VOLTAGE_SWING_MASK |
-					 DP_TRAIN_PRE_EMPHASIS_MASK);
-	switch (signal_levels) {
-	case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_0:
-		return DDI_BUF_EMP_400MV_0DB_BDW;	/* Sel0 */
-	case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_3_5:
-		return DDI_BUF_EMP_400MV_3_5DB_BDW;	/* Sel1 */
-	case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_6:
-		return DDI_BUF_EMP_400MV_6DB_BDW;	/* Sel2 */
-
-	case DP_TRAIN_VOLTAGE_SWING_600 | DP_TRAIN_PRE_EMPHASIS_0:
-		return DDI_BUF_EMP_600MV_0DB_BDW;	/* Sel3 */
-	case DP_TRAIN_VOLTAGE_SWING_600 | DP_TRAIN_PRE_EMPHASIS_3_5:
-		return DDI_BUF_EMP_600MV_3_5DB_BDW;	/* Sel4 */
-	case DP_TRAIN_VOLTAGE_SWING_600 | DP_TRAIN_PRE_EMPHASIS_6:
-		return DDI_BUF_EMP_600MV_6DB_BDW;	/* Sel5 */
-
-	case DP_TRAIN_VOLTAGE_SWING_800 | DP_TRAIN_PRE_EMPHASIS_0:
-		return DDI_BUF_EMP_800MV_0DB_BDW;	/* Sel6 */
-	case DP_TRAIN_VOLTAGE_SWING_800 | DP_TRAIN_PRE_EMPHASIS_3_5:
-		return DDI_BUF_EMP_800MV_3_5DB_BDW;	/* Sel7 */
-
-	case DP_TRAIN_VOLTAGE_SWING_1200 | DP_TRAIN_PRE_EMPHASIS_0:
-		return DDI_BUF_EMP_1200MV_0DB_BDW;	/* Sel8 */
-
-	default:
-		DRM_DEBUG_KMS("Unsupported voltage swing/pre-emphasis level:"
-			      "0x%x\n", signal_levels);
-		return DDI_BUF_EMP_400MV_0DB_BDW;	/* Sel0 */
-	}
-}
-
 /* Properly updates "DP" with the correct signal levels. */
 static void
 intel_dp_set_signal_levels(struct intel_dp *intel_dp, uint32_t *DP)
@@ -2874,10 +2828,7 @@ intel_dp_set_signal_levels(struct intel_dp *intel_dp, uint32_t *DP)
 	uint32_t signal_levels, mask;
 	uint8_t train_set = intel_dp->train_set[0];
 
-	if (IS_BROADWELL(dev)) {
-		signal_levels = intel_bdw_signal_levels(train_set);
-		mask = DDI_BUF_EMP_MASK;
-	} else if (IS_HASWELL(dev)) {
+	if (IS_HASWELL(dev) || IS_BROADWELL(dev)) {
 		signal_levels = intel_hsw_signal_levels(train_set);
 		mask = DDI_BUF_EMP_MASK;
 	} else if (IS_CHERRYVIEW(dev)) {