[PATCH 04/21] drm/i915: Haswell specific code for the DP Link Training

Eugeni Dodonov
2012-06-28T18:54:13Z

From: Shobhit Kumar <shobhit.kumar@intel.com>

In Haswell the DDIs have moved on to CPU. The AUX control is on LPT. Had
to split the code in such a way so as to be able to do source training
using DDI_BUF_CTL and DP_TP_CTL and sink side using AUX on LPT.

Also added new routine to get the Volatge and pre-emphashis values. This
is now done for DDI_BUF_CTL which now has common bits indicating a
combination of voltage and pre-emphasis values

Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
---
drivers/gpu/drm/i915/i915_reg.h | 4 ++
drivers/gpu/drm/i915/intel_ddi.c | 23 +++++++++
drivers/gpu/drm/i915/intel_dp.c | 100 ++++++++++++++++++++++++++++++++++++---
drivers/gpu/drm/i915/intel_drv.h | 3 ++
4 files changed, 123 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 51398a8..5b0c5f6 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -4308,7 +4308,10 @@
#define DP_TP_CTL_LINK_TRAIN_MASK (7<<8)
#define DP_TP_CTL_LINK_TRAIN_PAT1 (0<<8)
#define DP_TP_CTL_LINK_TRAIN_PAT2 (1<<8)
+#define DP_TP_CTL_LINK_TRAIN_IDLE (2<<8)
#define DP_TP_CTL_LINK_TRAIN_NORMAL (3<<8)
+#define DP_TP_CTL_LINK_TRAIN_PAT3 (4<<8)
+#define DP_TP_CTL_SCRAMBLE_DISABLE (1<<7)

/* DisplayPort Transport Status */
#define DP_TP_STATUS_A 0x64044
@@ -4317,6 +4320,7 @@
DP_TP_STATUS_A, \
DP_TP_STATUS_B)
#define DP_TP_STATUS_AUTOTRAIN_DONE (1<<12)
+#define DP_TP_STATUS_IDLE_DONE (1<<25)

/* DDI Buffer Control */
#define DDI_BUF_CTL_A 0x64000
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 91ed708..f08ce6c 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -907,3 +907,26 @@ void intel_ddi_dpms(struct drm_encoder *encoder, int mode)
temp);
}
}
+
+void intel_ddi_dp_set_link_train_src(struct intel_dp *intel_dp, u32 dp_reg_value)
+{
+ struct drm_device *dev = intel_dp->base.base.dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ int port = intel_dp->ddi_port;
+
+ /* Configure DP_TP_CTL with training pattern
+ * TBD: Only SST now; Enable MST later
+ * */
+
+ I915_WRITE(DP_TP_CTL(port),
+ intel_dp->TP | DP_TP_CTL_SCRAMBLE_DISABLE |
+ DP_TP_CTL_MODE_SST |
+ DP_TP_CTL_ENABLE);
+
+ /* Configure and enable DDI_BUF_CTL for DDI with next voltage */
+ I915_WRITE(DDI_BUF_CTL(port),
+ DDI_BUF_CTL_ENABLE |
+ dp_reg_value);
+
+ udelay(600);
+}
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index f4c6e98..38a1d3b 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1437,6 +1437,18 @@ intel_dp_pre_emphasis_max(struct intel_dp *intel_dp, uint8_t voltage_swing)
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;
+ 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 {
switch (voltage_swing & DP_TRAIN_VOLTAGE_SWING_MASK) {
case DP_TRAIN_VOLTAGE_SWING_400:
@@ -1581,6 +1593,40 @@ intel_gen7_edp_signal_levels(uint8_t train_set)
}
}

+/* Gen7.5's (HSW) DP voltage swing and pre-emphasis control */
+static uint32_t
+intel_dp_signal_levels_hsw(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_HSW;
+ case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_3_5:
+ return DDI_BUF_EMP_400MV_3_5DB_HSW;
+ case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_6:
+ return DDI_BUF_EMP_400MV_6DB_HSW;
+ case DP_TRAIN_VOLTAGE_SWING_400 | DP_TRAIN_PRE_EMPHASIS_9_5:
+ return DDI_BUF_EMP_400MV_9_5DB_HSW;
+
+ case DP_TRAIN_VOLTAGE_SWING_600 | DP_TRAIN_PRE_EMPHASIS_0:
+ return DDI_BUF_EMP_600MV_0DB_HSW;
+ case DP_TRAIN_VOLTAGE_SWING_600 | DP_TRAIN_PRE_EMPHASIS_3_5:
+ return DDI_BUF_EMP_600MV_3_5DB_HSW;
+ case DP_TRAIN_VOLTAGE_SWING_600 | DP_TRAIN_PRE_EMPHASIS_6:
+ return DDI_BUF_EMP_600MV_6DB_HSW;
+
+ case DP_TRAIN_VOLTAGE_SWING_800 | DP_TRAIN_PRE_EMPHASIS_0:
+ return DDI_BUF_EMP_800MV_0DB_HSW;
+ case DP_TRAIN_VOLTAGE_SWING_800 | DP_TRAIN_PRE_EMPHASIS_3_5:
+ return DDI_BUF_EMP_800MV_3_5DB_HSW;
+ default:
+ DRM_DEBUG_KMS("Unsupported voltage swing/pre-emphasis level:"
+ "0x%x\n", signal_levels);
+ return DDI_BUF_EMP_400MV_0DB_HSW;
+ }
+}
+
static uint8_t
intel_get_lane_status(uint8_t link_status[DP_LINK_STATUS_SIZE],
int lane)
@@ -1638,8 +1684,12 @@ intel_dp_set_link_train(struct intel_dp *intel_dp,
struct drm_i915_private *dev_priv = dev->dev_private;
int ret;

- I915_WRITE(intel_dp->output_reg, dp_reg_value);
- POSTING_READ(intel_dp->output_reg);
+ if (IS_HASWELL(dev))
+ intel_ddi_dp_set_link_train_src(intel_dp, dp_reg_value);
+ else {
+ I915_WRITE(intel_dp->output_reg, dp_reg_value);
+ POSTING_READ(intel_dp->output_reg);
+ }

intel_dp_aux_native_write_1(intel_dp,
DP_TRAINING_PATTERN_SET,
@@ -1674,7 +1724,7 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
* will happen below in intel_dp_set_link_train. Otherwise, enable
* the port and wait for it to become active.
*/
- if (!HAS_PCH_CPT(dev)) {
+ if (!HAS_PCH_CPT(dev) && !IS_HASWELL(dev)) {
I915_WRITE(intel_dp->output_reg, intel_dp->DP);
POSTING_READ(intel_dp->output_reg);
intel_wait_for_vblank(dev, intel_crtc->pipe);
@@ -1689,8 +1739,9 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)

if (HAS_PCH_CPT(dev) && (IS_GEN7(dev) || !is_cpu_edp(intel_dp)))
DP &= ~DP_LINK_TRAIN_MASK_CPT;
- else
+ else if (!IS_HASWELL(dev))
DP &= ~DP_LINK_TRAIN_MASK;
+
memset(intel_dp->train_set, 0, 4);
voltage = 0xff;
voltage_tries = 0;
@@ -1708,6 +1759,10 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
} else if (IS_GEN6(dev) && is_cpu_edp(intel_dp)) {
signal_levels = intel_gen6_edp_signal_levels(intel_dp->train_set[0]);
DP = (DP & ~EDP_LINK_TRAIN_VOL_EMP_MASK_SNB) | signal_levels;
+ } else if (IS_HASWELL(dev)) {
+ signal_levels = intel_dp_signal_levels_hsw(intel_dp->train_set[0]);
+ DRM_DEBUG_KMS("training pattern 1 signal levels hsw %08x\n", signal_levels);
+ DP = (DP & ~DDI_BUF_EMP_MASK) | signal_levels;
} else {
signal_levels = intel_dp_signal_levels(intel_dp->train_set[0]);
DRM_DEBUG_KMS("training pattern 1 signal levels %08x\n", signal_levels);
@@ -1716,6 +1771,10 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)

if (HAS_PCH_CPT(dev) && (IS_GEN7(dev) || !is_cpu_edp(intel_dp)))
reg = DP | DP_LINK_TRAIN_PAT_1_CPT;
+ else if (IS_HASWELL(dev)) {
+ reg = DP;
+ intel_dp->TP = (intel_dp->TP & ~DP_TP_CTL_LINK_TRAIN_MASK) | DP_TP_CTL_LINK_TRAIN_PAT1;
+ }
else
reg = DP | DP_LINK_TRAIN_PAT_1;

@@ -1779,6 +1838,7 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp)
int tries, cr_tries;
u32 reg;
uint32_t DP = intel_dp->DP;
+ uint32_t TP = intel_dp->TP;

/* channel equalization */
tries = 0;
@@ -1801,6 +1861,9 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp)
} else if (IS_GEN6(dev) && is_cpu_edp(intel_dp)) {
signal_levels = intel_gen6_edp_signal_levels(intel_dp->train_set[0]);
DP = (DP & ~EDP_LINK_TRAIN_VOL_EMP_MASK_SNB) | signal_levels;
+ } else if (IS_HASWELL(dev)) {
+ signal_levels = intel_dp_signal_levels_hsw(intel_dp->train_set[0]);
+ DP = (DP & ~DDI_BUF_EMP_MASK) | signal_levels;
} else {
signal_levels = intel_dp_signal_levels(intel_dp->train_set[0]);
DP = (DP & ~(DP_VOLTAGE_MASK|DP_PRE_EMPHASIS_MASK)) | signal_levels;
@@ -1808,6 +1871,10 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp)

if (HAS_PCH_CPT(dev) && (IS_GEN7(dev) || !is_cpu_edp(intel_dp)))
reg = DP | DP_LINK_TRAIN_PAT_2_CPT;
+ else if (IS_HASWELL(dev)) {
+ reg = DP;
+ intel_dp->TP = (intel_dp->TP & ~DP_TP_CTL_LINK_TRAIN_MASK) | DP_TP_CTL_LINK_TRAIN_PAT2;
+ }
else
reg = DP | DP_LINK_TRAIN_PAT_2;

@@ -1847,15 +1914,34 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp)
++tries;
}

+ if (channel_eq)
+ DRM_DEBUG_KMS("Channel EQ done. DP Training successfull\n");
+
if (HAS_PCH_CPT(dev) && (IS_GEN7(dev) || !is_cpu_edp(intel_dp)))
reg = DP | DP_LINK_TRAIN_OFF_CPT;
+ else if (IS_HASWELL(dev)) {
+ TP &= ~DP_TP_CTL_LINK_TRAIN_MASK;
+ reg = TP | DP_TP_CTL_LINK_TRAIN_IDLE;
+ I915_WRITE(DP_TP_CTL(intel_dp->ddi_port), reg);
+ if (wait_for((I915_READ(DP_TP_STATUS(intel_dp->ddi_port)) & DP_TP_STATUS_IDLE_DONE) == 0,
+ 800))
+ DRM_ERROR("Timed out waiting for DP min idle patterns\n");
+
+ TP &= ~DP_TP_CTL_LINK_TRAIN_MASK;
+ reg = TP | DP_TP_CTL_LINK_TRAIN_NORMAL;
+ I915_WRITE(DP_TP_CTL(intel_dp->ddi_port), reg);
+ }
else
reg = DP | DP_LINK_TRAIN_OFF;

- I915_WRITE(intel_dp->output_reg, reg);
- POSTING_READ(intel_dp->output_reg);
+ if (!IS_HASWELL(dev)) {
+ I915_WRITE(intel_dp->output_reg, reg);
+ POSTING_READ(intel_dp->output_reg);
+ }
+
intel_dp_aux_native_write_1(intel_dp,
- DP_TRAINING_PATTERN_SET, DP_TRAINING_PATTERN_DISABLE);
+ DP_TRAINING_PATTERN_SET,
+ DP_TRAINING_PATTERN_DISABLE);
}

static void
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 65b5b7c..5ca133d 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -543,4 +543,7 @@ intel_ddi_mode_set_dp(struct drm_encoder *encoder,
struct drm_display_mode *adjusted_mode);

+extern void intel_ddi_dp_set_link_train_src(struct intel_dp *intel_dp,
+ u32 dp_reg_value);
+
#endif /* __INTEL_DRV_H__ */
--
1.7.11.1