Re: [PATCH v3 07/15] drm/bridge: analogix_dp: Add support for phy configuration.

Add support to configurate link rate, lane count, voltage swing and
pre-emphasis with phy_configure(). It is helpful in application scenarios
where analogix controller is mixed with the phy of other vendors.

Signed-off-by: Damon Ding <redacted>

---

Changes in v2:
- remove needless assignments for phy_configure()
- remove unnecessary changes for phy_power_on()/phy_power_off()
---
 .../drm/bridge/analogix/analogix_dp_core.c    |  1 +
 .../gpu/drm/bridge/analogix/analogix_dp_reg.c | 56 +++++++++++++++++++
 2 files changed, 57 insertions(+)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 6f10d88a34c5..9429c50cc1bc 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c

@@ -1696,6 +1696,7 @@ int analogix_dp_resume(struct analogix_dp_device *dp)
 	if (dp->plat_data->power_on)
 		dp->plat_data->power_on(dp->plat_data);
 
+	phy_set_mode(dp->phy, PHY_MODE_DP);
 	phy_power_on(dp->phy);
 
 	analogix_dp_init_dp(dp);

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
index 3afc73c858c4..613ce504bea6 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_reg.c

@@ -11,6 +11,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
+#include <linux/phy/phy.h>
 
 #include <drm/bridge/analogix_dp.h>
 

@@ -513,10 +514,25 @@ void analogix_dp_enable_sw_function(struct analogix_dp_device *dp)
 void analogix_dp_set_link_bandwidth(struct analogix_dp_device *dp, u32 bwtype)
 {
 	u32 reg;
+	int ret;
 
 	reg = bwtype;
 	if ((bwtype == DP_LINK_BW_2_7) || (bwtype == DP_LINK_BW_1_62))
 		writel(reg, dp->reg_base + ANALOGIX_DP_LINK_BW_SET);
+
+	if (dp->phy) {
+		union phy_configure_opts phy_cfg = {0};
+
+		phy_cfg.dp.lanes = dp->link_train.lane_count;

+		phy_cfg.dp.link_rate =
+			drm_dp_bw_code_to_link_rate(dp->link_train.link_rate) / 100;
+		phy_cfg.dp.set_rate = true;
+		ret = phy_configure(dp->phy, &phy_cfg);
+		if (ret && ret != -EOPNOTSUPP) {
+			dev_err(dp->dev, "%s: phy_configure() failed: %d\n", __func__, ret);
+			return;
+		}
+	}
 }
 
 void analogix_dp_get_link_bandwidth(struct analogix_dp_device *dp, u32 *bwtype)

@@ -530,9 +546,22 @@ void analogix_dp_get_link_bandwidth(struct analogix_dp_device *dp, u32 *bwtype)
 void analogix_dp_set_lane_count(struct analogix_dp_device *dp, u32 count)
 {
 	u32 reg;
+	int ret;
 
 	reg = count;
 	writel(reg, dp->reg_base + ANALOGIX_DP_LANE_COUNT_SET);
+
+	if (dp->phy) {
+		union phy_configure_opts phy_cfg = {0};
+
+		phy_cfg.dp.lanes = dp->link_train.lane_count;
+		phy_cfg.dp.set_lanes = true;
+		ret = phy_configure(dp->phy, &phy_cfg);
+		if (ret && ret != -EOPNOTSUPP) {
+			dev_err(dp->dev, "%s: phy_configure() failed: %d\n", __func__, ret);
+			return;
+		}
+	}
 }
 
 void analogix_dp_get_lane_count(struct analogix_dp_device *dp, u32 *count)

@@ -546,10 +575,37 @@ void analogix_dp_get_lane_count(struct analogix_dp_device *dp, u32 *count)
 void analogix_dp_set_lane_link_training(struct analogix_dp_device *dp)
 {
 	u8 lane;
+	int ret;
 
 	for (lane = 0; lane < dp->link_train.lane_count; lane++)
 		writel(dp->link_train.training_lane[lane],
 		       dp->reg_base + ANALOGIX_DP_LN0_LINK_TRAINING_CTL + 4 * lane);
+
+	if (dp->phy) {
+		union phy_configure_opts phy_cfg = {0};
+
+		for (lane = 0; lane < dp->link_train.lane_count; lane++) {
+			u8 training_lane = dp->link_train.training_lane[lane];
+			u8 vs, pe;
+
+			vs = (training_lane & DP_TRAIN_VOLTAGE_SWING_MASK) >>
+			     DP_TRAIN_VOLTAGE_SWING_SHIFT;
+			pe = (training_lane & DP_TRAIN_PRE_EMPHASIS_MASK) >>
+			     DP_TRAIN_PRE_EMPHASIS_SHIFT;
+			phy_cfg.dp.voltage[lane] = vs;
+			phy_cfg.dp.pre[lane] = pe;
+		}
+
+		phy_cfg.dp.lanes = dp->link_train.lane_count;
+		phy_cfg.dp.link_rate =
+			drm_dp_bw_code_to_link_rate(dp->link_train.link_rate) / 100;