[PATCH 45/62] drm/i915/bdw: add support for BDW DP voltage swings and pre-emphasis

Ben Widawsky
2013-11-03T04:08:24Z

From: Paulo Zanoni <paulo.r.zanoni@intel.com>

They're not the same as the Haswell ones.

Reviewed-by: Art Runyan <arthur.j.runyan@intel.com>
Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 11 +++++++++
drivers/gpu/drm/i915/intel_dp.c | 55 ++++++++++++++++++++++++++++++++++++++---
2 files changed, 63 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 4131223..6f834b3 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -5176,6 +5176,7 @@
#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 */
@@ -5185,6 +5186,16 @@
#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)
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index b3cc333..7725f81 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1950,7 +1950,7 @@ 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))
+ if (IS_VALLEYVIEW(dev) || IS_BROADWELL(dev))
return DP_TRAIN_VOLTAGE_SWING_1200;
else if (IS_GEN7(dev) && port == PORT_A)
return DP_TRAIN_VOLTAGE_SWING_800;
@@ -1966,7 +1966,18 @@ 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 (HAS_DDI(dev)) {
+ 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)) {
switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
case DP_TRAIN_VOLTAGE_SWING_400:
return DP_TRAIN_PRE_EMPHASIS_9_5;
@@ -2278,6 +2289,41 @@ 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)
@@ -2288,7 +2334,10 @@ 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 (HAS_DDI(dev)) {
+ if (IS_BROADWELL(dev)) {
+ signal_levels = intel_bdw_signal_levels(train_set);
+ mask = DDI_BUF_EMP_MASK;
+ } else if (IS_HASWELL(dev)) {
signal_levels = intel_hsw_signal_levels(train_set);
mask = DDI_BUF_EMP_MASK;
} else if (IS_VALLEYVIEW(dev)) {
--
1.8.4.2