drm/msm/dp: add support of tps4 (training pattern 4) for HBR3

Some DP sinkers prefer to use tps4 instead of tps3 during training #2.
This patch will use tps4 to perform link training #2 if sinker's DPCD
supports it.

Changes in V2:
-- replace  dp_catalog_ctrl_set_pattern() with  dp_catalog_ctrl_set_pattern_state_bit()

Changes in V3:
-- change state_ctrl_bits type to u32 and pattern type to u8

Changes in V4:
-- align } else if { and } else {

Changes in v10:
--  group into one series

Changes in v11:
-- drop drm/msm/dp: dp_link_parse_sink_count() return immediately if aux read
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1642531648-8448-4-git-send-email-quic_khsieh@quicinc.comSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

drivers/gpu/drm/msm/dp/dp_catalog.c

@@ -456,19 +456,19 @@ void dp_catalog_ctrl_config_msa(struct dp_catalog *dp_catalog,
 	dp_write_p0(catalog, MMSS_DP_DSC_DTO, 0x0);
 }
 
-int dp_catalog_ctrl_set_pattern(struct dp_catalog *dp_catalog,
-					u32 pattern)
+int dp_catalog_ctrl_set_pattern_state_bit(struct dp_catalog *dp_catalog,
+					u32 state_bit)
 {
 	int bit, ret;
 	u32 data;
 	struct dp_catalog_private *catalog = container_of(dp_catalog,
 				struct dp_catalog_private, dp_catalog);
 
-	bit = BIT(pattern - 1);
-	DRM_DEBUG_DP("hw: bit=%d train=%d\n", bit, pattern);
+	bit = BIT(state_bit - 1);
+	DRM_DEBUG_DP("hw: bit=%d train=%d\n", bit, state_bit);
 	dp_catalog_ctrl_state_ctrl(dp_catalog, bit);
 
-	bit = BIT(pattern - 1) << DP_MAINLINK_READY_LINK_TRAINING_SHIFT;
+	bit = BIT(state_bit - 1) << DP_MAINLINK_READY_LINK_TRAINING_SHIFT;
 
 	/* Poll for mainlink ready status */
 	ret = readx_poll_timeout(readl, catalog->io->dp_controller.link.base +
@@ -476,7 +476,7 @@ int dp_catalog_ctrl_set_pattern(struct dp_catalog *dp_catalog,
 					data, data & bit,
 					POLLING_SLEEP_US, POLLING_TIMEOUT_US);
 	if (ret < 0) {
-		DRM_ERROR("set pattern for link_train=%d failed\n", pattern);
+		DRM_ERROR("set state_bit for link_train=%d failed\n", state_bit);
 		return ret;
 	}
 	return 0;

drivers/gpu/drm/msm/dp/dp_catalog.h

@@ -94,7 +94,7 @@ void dp_catalog_ctrl_mainlink_ctrl(struct dp_catalog *dp_catalog, bool enable);
 void dp_catalog_ctrl_config_misc(struct dp_catalog *dp_catalog, u32 cc, u32 tb);
 void dp_catalog_ctrl_config_msa(struct dp_catalog *dp_catalog, u32 rate,
 				u32 stream_rate_khz, bool fixed_nvid);
-int dp_catalog_ctrl_set_pattern(struct dp_catalog *dp_catalog, u32 pattern);
+int dp_catalog_ctrl_set_pattern_state_bit(struct dp_catalog *dp_catalog, u32 pattern);
 void dp_catalog_ctrl_reset(struct dp_catalog *dp_catalog);
 bool dp_catalog_ctrl_mainlink_ready(struct dp_catalog *dp_catalog);
 void dp_catalog_ctrl_enable_irq(struct dp_catalog *dp_catalog, bool enable);

drivers/gpu/drm/msm/dp/dp_ctrl.c

@@ -1083,7 +1083,7 @@ static int dp_ctrl_link_train_1(struct dp_ctrl_private *ctrl,
 
 	*training_step = DP_TRAINING_1;
 
-	ret = dp_catalog_ctrl_set_pattern(ctrl->catalog, DP_TRAINING_PATTERN_1);
+	ret = dp_catalog_ctrl_set_pattern_state_bit(ctrl->catalog, 1);
 	if (ret)
 		return ret;
 	dp_ctrl_train_pattern_set(ctrl, DP_TRAINING_PATTERN_1 |
@@ -1181,7 +1181,8 @@ static int dp_ctrl_link_train_2(struct dp_ctrl_private *ctrl,
 			int *training_step)
 {
 	int tries = 0, ret = 0;
-	char pattern;
+	u8 pattern;
+	u32 state_ctrl_bit;
 	int const maximum_retries = 5;
 	u8 link_status[DP_LINK_STATUS_SIZE];
 
@@ -1189,12 +1190,18 @@ static int dp_ctrl_link_train_2(struct dp_ctrl_private *ctrl,
 
 	*training_step = DP_TRAINING_2;
 
-	if (drm_dp_tps3_supported(ctrl->panel->dpcd))
+	if (drm_dp_tps4_supported(ctrl->panel->dpcd)) {
+		pattern = DP_TRAINING_PATTERN_4;
+		state_ctrl_bit = 4;
+	} else if (drm_dp_tps3_supported(ctrl->panel->dpcd)) {
 		pattern = DP_TRAINING_PATTERN_3;
-	else
+		state_ctrl_bit = 3;
+	} else {
 		pattern = DP_TRAINING_PATTERN_2;
+		state_ctrl_bit = 2;
+	}
 
-	ret = dp_catalog_ctrl_set_pattern(ctrl->catalog, pattern);
+	ret = dp_catalog_ctrl_set_pattern_state_bit(ctrl->catalog, state_ctrl_bit);
 	if (ret)
 		return ret;