drm/i915: add intel_dp_set_signal_levels

So we can de-duplicate code that's inside intel_dp_start_link_train
and intel_dp_complete_link_train.

V2: Rebase since patch 3/5 was discarded.

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

1 files changed, 33 insertions, 36 deletions

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 185bf4e7614e..2d3b26832397 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1587,7 +1587,7 @@ intel_get_adjust_train(struct intel_dp *intel_dp, uint8_t link_status[DP_LINK_ST
 }
 
 static uint32_t
-intel_dp_signal_levels(uint8_t train_set)
+intel_gen4_signal_levels(uint8_t train_set)
 {
         uint32_t        signal_levels = 0;
 
@@ -1685,7 +1685,7 @@ 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)
+intel_hsw_signal_levels(uint8_t train_set)
 {
         int signal_levels = train_set & (DP_TRAIN_VOLTAGE_SWING_MASK |
                                          DP_TRAIN_PRE_EMPHASIS_MASK);
@@ -1717,6 +1717,34 @@ intel_dp_signal_levels_hsw(uint8_t train_set)
         }
 }
 
+/* Properly updates "DP" with the correct signal levels. */
+static void
+intel_dp_set_signal_levels(struct intel_dp *intel_dp, uint32_t *DP)
+{
+        struct intel_digital_port *intel_dig_port = dp_to_dig_port(intel_dp);
+        struct drm_device *dev = intel_dig_port->base.base.dev;
+        uint32_t signal_levels, mask;
+        uint8_t train_set = intel_dp->train_set[0];
+
+        if (IS_HASWELL(dev)) {
+                signal_levels = intel_hsw_signal_levels(train_set);
+                mask = DDI_BUF_EMP_MASK;
+        } else if (IS_GEN7(dev) && is_cpu_edp(intel_dp) && !IS_VALLEYVIEW(dev)) {
+                signal_levels = intel_gen7_edp_signal_levels(train_set);
+                mask = EDP_LINK_TRAIN_VOL_EMP_MASK_IVB;
+        } else if (IS_GEN6(dev) && is_cpu_edp(intel_dp)) {
+                signal_levels = intel_gen6_edp_signal_levels(train_set);
+                mask = EDP_LINK_TRAIN_VOL_EMP_MASK_SNB;
+        } else {
+                signal_levels = intel_gen4_signal_levels(train_set);
+                mask = DP_VOLTAGE_MASK | DP_PRE_EMPHASIS_MASK;
+        }
+
+        DRM_DEBUG_KMS("Using signal levels %08x\n", signal_levels);
+
+        *DP = (*DP & ~mask) | signal_levels;
+}
+
 static bool
 intel_dp_set_link_train(struct intel_dp *intel_dp,
                         uint32_t dp_reg_value,
@@ -1853,24 +1881,8 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
         for (;;) {
                 /* Use intel_dp->train_set[0] to set the voltage and pre emphasis values */
                 uint8_t     link_status[DP_LINK_STATUS_SIZE];
-                uint32_t    signal_levels;
-
-                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 if (IS_GEN7(dev) && is_cpu_edp(intel_dp) && !IS_VALLEYVIEW(dev)) {
-                        signal_levels = intel_gen7_edp_signal_levels(intel_dp->train_set[0]);
-                        DP = (DP & ~EDP_LINK_TRAIN_VOL_EMP_MASK_IVB) | signal_levels;
-                } 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 {
-                        signal_levels = intel_dp_signal_levels(intel_dp->train_set[0]);
-                        DP = (DP & ~(DP_VOLTAGE_MASK|DP_PRE_EMPHASIS_MASK)) | signal_levels;
-                }
-                DRM_DEBUG_KMS("training pattern 1 signal levels %08x\n",
-                              signal_levels);
+
+                intel_dp_set_signal_levels(intel_dp, &DP);
 
                 /* Set training pattern 1 */
                 if (!intel_dp_set_link_train(intel_dp, DP,
@@ -1926,7 +1938,6 @@ intel_dp_start_link_train(struct intel_dp *intel_dp)
 void
 intel_dp_complete_link_train(struct intel_dp *intel_dp)
 {
-        struct drm_device *dev = intel_dp_to_dev(intel_dp);
         bool channel_eq = false;
         int tries, cr_tries;
         uint32_t DP = intel_dp->DP;
@@ -1936,8 +1947,6 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp)
         cr_tries = 0;
         channel_eq = false;
         for (;;) {
-                /* Use intel_dp->train_set[0] to set the voltage and pre emphasis values */
-                uint32_t    signal_levels;
                 uint8_t     link_status[DP_LINK_STATUS_SIZE];
 
                 if (cr_tries > 5) {
@@ -1946,19 +1955,7 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp)
                         break;
                 }
 
-                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 if (IS_GEN7(dev) && is_cpu_edp(intel_dp) && !IS_VALLEYVIEW(dev)) {
-                        signal_levels = intel_gen7_edp_signal_levels(intel_dp->train_set[0]);
-                        DP = (DP & ~EDP_LINK_TRAIN_VOL_EMP_MASK_IVB) | signal_levels;
-                } 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 {
-                        signal_levels = intel_dp_signal_levels(intel_dp->train_set[0]);
-                        DP = (DP & ~(DP_VOLTAGE_MASK|DP_PRE_EMPHASIS_MASK)) | signal_levels;
-                }
+                intel_dp_set_signal_levels(intel_dp, &DP);
 
                 /* channel eq pattern */
                 if (!intel_dp_set_link_train(intel_dp, DP,