[PATCH v1 03/14] drm/msm/dp: add configure mainlink_levels base on lane number

[Kuogee Hsieh]

Mainlink_levels determined when two actions to take place by hardware,
a new BS sequence due to start of video and a static HW MVID is sent
to panel. This patch add function to configure mainlink level properly
base on lane number.

Signed-off-by: Kuogee Hsieh <quic_khsieh at quicinc.com>
---
 drivers/gpu/drm/msm/dp/dp_catalog.c | 37 ++++++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/msm/dp/dp_catalog.h |  4 +++-
 drivers/gpu/drm/msm/dp/dp_ctrl.c    |  4 ++++
 3 files changed, 43 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.c b/drivers/gpu/drm/msm/dp/dp_catalog.c
index 676279d..7ac37d8 100644
--- a/drivers/gpu/drm/msm/dp/dp_catalog.c
+++ b/drivers/gpu/drm/msm/dp/dp_catalog.c
@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017-2023, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2021. Qualcomm Innovation Center, Inc. All rights reserved
  */
 
 #define pr_fmt(fmt)	"[drm-dp] %s: " fmt, __func__
@@ -359,6 +360,40 @@ void dp_catalog_ctrl_lane_mapping(struct dp_catalog *dp_catalog)
 			ln_mapping);
 }
 
+void dp_catalog_ctrl_mainlink_levels(struct dp_catalog *dp_catalog,
+					u8 lane_cnt)
+{
+	struct dp_catalog_private *catalog = container_of(dp_catalog,
+				struct dp_catalog_private, dp_catalog);
+
+	u32 mainlink_levels, safe_to_exit_level = 14;
+
+	switch (lane_cnt) {
+	case 1:
+		safe_to_exit_level = 14;
+		break;
+	case 2:
+		safe_to_exit_level = 8;
+		break;
+	case 4:
+		safe_to_exit_level = 5;
+		break;
+	default:
+		drm_dbg_dp(catalog->drm_dev, "setting the default safe_to_exit_level=%u\n",
+				safe_to_exit_level);
+		break;
+	}
+
+	mainlink_levels = dp_read_link(catalog, REG_DP_MAINLINK_LEVELS);
+	mainlink_levels &= 0xFE0;
+	mainlink_levels |= safe_to_exit_level;
+
+	drm_dbg_dp(catalog->drm_dev, "mainlink_level=0x%x, safe_to_exit_level=0x%x\n",
+		mainlink_levels, safe_to_exit_level);
+
+	dp_write_link(catalog, REG_DP_MAINLINK_LEVELS, mainlink_levels);
+}
+
 void dp_catalog_ctrl_mainlink_ctrl(struct dp_catalog *dp_catalog,
 						bool enable)
 {
diff --git a/drivers/gpu/drm/msm/dp/dp_catalog.h b/drivers/gpu/drm/msm/dp/dp_catalog.h
index 1f717f4..990c162 100644
--- a/drivers/gpu/drm/msm/dp/dp_catalog.h
+++ b/drivers/gpu/drm/msm/dp/dp_catalog.h
@@ -1,6 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /*
- * Copyright (c) 2017-2020, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2017-2023, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2021. Qualcomm Innovation Center, Inc. All rights reserved
  */
 
 #ifndef _DP_CATALOG_H_
@@ -92,6 +93,7 @@ u32 dp_catalog_aux_get_irq(struct dp_catalog *dp_catalog);
 void dp_catalog_ctrl_state_ctrl(struct dp_catalog *dp_catalog, u32 state);
 void dp_catalog_ctrl_config_ctrl(struct dp_catalog *dp_catalog, u32 config);
 void dp_catalog_ctrl_lane_mapping(struct dp_catalog *dp_catalog);
+void dp_catalog_ctrl_mainlink_levels(struct dp_catalog *dp_catalog, u8 lane_cnt);
 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,
diff --git a/drivers/gpu/drm/msm/dp/dp_ctrl.c b/drivers/gpu/drm/msm/dp/dp_ctrl.c
index dd26ca6..959a78c 100644
--- a/drivers/gpu/drm/msm/dp/dp_ctrl.c
+++ b/drivers/gpu/drm/msm/dp/dp_ctrl.c
@@ -161,6 +161,8 @@ static void dp_ctrl_configure_source_params(struct dp_ctrl_private *ctrl)
 	u32 cc, tb;
 
 	dp_catalog_ctrl_lane_mapping(ctrl->catalog);
+	dp_catalog_ctrl_mainlink_levels(ctrl->catalog,
+				ctrl->link->link_params.num_lanes);
 	dp_catalog_ctrl_mainlink_ctrl(ctrl->catalog, true);
 
 	dp_ctrl_config_ctrl(ctrl);
@@ -1296,6 +1298,8 @@ static int dp_ctrl_setup_main_link(struct dp_ctrl_private *ctrl,
 {
 	int ret = 0;
 
+	dp_catalog_ctrl_mainlink_levels(ctrl->catalog,
+				ctrl->link->link_params.num_lanes);
 	dp_catalog_ctrl_mainlink_ctrl(ctrl->catalog, true);
 
 	if (ctrl->link->sink_request & DP_TEST_LINK_PHY_TEST_PATTERN)
-- 
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