+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 */
+ }
+}
+