[PATCH v1 drm-dp 2/4] drm/hisilicon/hibmc: Getting connector info and edid by using aux channel

Yongbang Shi posted 4 patches 3 days, 15 hours ago
[PATCH v1 drm-dp 2/4] drm/hisilicon/hibmc: Getting connector info and edid by using aux channel
Posted by Yongbang Shi 3 days, 15 hours ago
From: Baihan Li <libaihan@huawei.com>

Registering drm_aux and using it to get connector edid with drm functions.
Refactoring some structs to fit aux's register framework.

Signed-off-by: Baihan Li <libaihan@huawei.com>
Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
---
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c   | 16 +++++---
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h  |  7 +++-
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c    |  5 ++-
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h    |  2 +
 drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c  | 22 +++++-----
 .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c    | 40 +++++++++++++++++--
 .../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h   |  5 +++
 7 files changed, 72 insertions(+), 25 deletions(-)

diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
index 0a903cce1fa9..c07c970d2e50 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
@@ -8,6 +8,7 @@
 #include <drm/drm_print.h>
 #include "dp_comm.h"
 #include "dp_reg.h"
+#include "dp_hw.h"
 
 #define HIBMC_AUX_CMD_REQ_LEN		GENMASK(7, 4)
 #define HIBMC_AUX_CMD_ADDR		GENMASK(27, 8)
@@ -124,7 +125,8 @@ static int hibmc_dp_aux_parse_xfer(struct hibmc_dp_dev *dp, struct drm_dp_aux_ms
 /* ret >= 0 ,ret is size; ret < 0, ret is err code */
 static ssize_t hibmc_dp_aux_xfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
 {
-	struct hibmc_dp_dev *dp = container_of(aux, struct hibmc_dp_dev, aux);
+	struct hibmc_dp_dev *dp = ((struct hibmc_dp *)container_of(aux, struct hibmc_dp,
+								   aux))->dp_dev;
 	u32 aux_cmd;
 	int ret;
 	u32 val; /* val will be assigned at the beginning of readl_poll_timeout function */
@@ -151,14 +153,16 @@ static ssize_t hibmc_dp_aux_xfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *
 	return hibmc_dp_aux_parse_xfer(dp, msg);
 }
 
-void hibmc_dp_aux_init(struct hibmc_dp_dev *dp)
+void hibmc_dp_aux_init(struct hibmc_dp *dp)
 {
-	hibmc_dp_reg_write_field(dp, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_SYNC_LEN_SEL, 0x0);
-	hibmc_dp_reg_write_field(dp, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_TIMER_TIMEOUT, 0x1);
-	hibmc_dp_reg_write_field(dp, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_MIN_PULSE_NUM,
+	hibmc_dp_reg_write_field(dp->dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_SYNC_LEN_SEL, 0x0);
+	hibmc_dp_reg_write_field(dp->dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_TIMER_TIMEOUT, 0x1);
+	hibmc_dp_reg_write_field(dp->dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_MIN_PULSE_NUM,
 				 HIBMC_DP_MIN_PULSE_NUM);
 
 	dp->aux.transfer = hibmc_dp_aux_xfer;
-	dp->aux.is_remote = 0;
+	dp->aux.name = kasprintf(GFP_KERNEL, "HIBMC DRM dp aux");
+	dp->aux.drm_dev = dp->drm_dev;
 	drm_dp_aux_init(&dp->aux);
+	dp->dp_dev->aux = &dp->aux;
 }
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
index 00b23301d26e..7edcecd5a5f0 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
@@ -11,8 +11,11 @@
 #include <linux/kernel.h>
 #include <linux/bitfield.h>
 #include <linux/io.h>
+
 #include <drm/display/drm_dp_helper.h>
 
+#include "dp_hw.h"
+
 #define HIBMC_DP_LANE_NUM_MAX 2
 
 struct hibmc_link_status {
@@ -32,7 +35,7 @@ struct hibmc_dp_link {
 };
 
 struct hibmc_dp_dev {
-	struct drm_dp_aux aux;
+	struct drm_dp_aux *aux;
 	struct drm_device *dev;
 	void __iomem *base;
 	struct mutex lock; /* protects concurrent RW in hibmc_dp_reg_write_field() */
@@ -58,7 +61,7 @@ struct hibmc_dp_dev {
 		mutex_unlock(&_dp->lock);				\
 	} while (0)
 
-void hibmc_dp_aux_init(struct hibmc_dp_dev *dp);
+void hibmc_dp_aux_init(struct hibmc_dp *dp);
 int hibmc_dp_link_training(struct hibmc_dp_dev *dp);
 
 #endif
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
index 0dac4cfdde7c..50050908606f 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
@@ -3,6 +3,7 @@
 
 #include <linux/io.h>
 #include <linux/delay.h>
+#include <drm/drm_managed.h>
 #include "dp_config.h"
 #include "dp_comm.h"
 #include "dp_reg.h"
@@ -156,7 +157,7 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
 	struct drm_device *drm_dev = dp->drm_dev;
 	struct hibmc_dp_dev *dp_dev;
 
-	dp_dev = devm_kzalloc(drm_dev->dev, sizeof(struct hibmc_dp_dev), GFP_KERNEL);
+	dp_dev = drmm_kcalloc(drm_dev, 1, sizeof(struct hibmc_dp_dev), GFP_KERNEL);
 	if (!dp_dev)
 		return -ENOMEM;
 
@@ -167,7 +168,7 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
 	dp_dev->dev = drm_dev;
 	dp_dev->base = dp->mmio + HIBMC_DP_OFFSET;
 
-	hibmc_dp_aux_init(dp_dev);
+	hibmc_dp_aux_init(dp);
 
 	if (hibmc_dp_phy_init(dp_dev))
 		return -EAGAIN;
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
index 4dc13b3d9875..53b6d0beecea 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
@@ -10,6 +10,7 @@
 #include <drm/drm_encoder.h>
 #include <drm/drm_connector.h>
 #include <drm/drm_print.h>
+#include <drm/display/drm_dp_helper.h>
 
 struct hibmc_dp_dev;
 
@@ -19,6 +20,7 @@ struct hibmc_dp {
 	struct drm_encoder encoder;
 	struct drm_connector connector;
 	void __iomem *mmio;
+	struct drm_dp_aux aux;
 };
 
 int hibmc_dp_hw_init(struct hibmc_dp *dp);
diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
index 1124cd70c320..695cb9c0b643 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
@@ -27,7 +27,7 @@ static int hibmc_dp_link_training_configure(struct hibmc_dp_dev *dp)
 	/* set rate and lane count */
 	buf[0] = dp->link.cap.link_rate;
 	buf[1] = DP_LANE_COUNT_ENHANCED_FRAME_EN | dp->link.cap.lanes;
-	ret = drm_dp_dpcd_write(&dp->aux, DP_LINK_BW_SET, buf, sizeof(buf));
+	ret = drm_dp_dpcd_write(dp->aux, DP_LINK_BW_SET, buf, sizeof(buf));
 	if (ret != sizeof(buf)) {
 		drm_dbg_dp(dp->dev, "dp aux write link rate and lanes failed, ret: %d\n", ret);
 		return ret >= 0 ? -EIO : ret;
@@ -36,13 +36,13 @@ static int hibmc_dp_link_training_configure(struct hibmc_dp_dev *dp)
 	/* set 8b/10b and downspread */
 	buf[0] = DP_SPREAD_AMP_0_5;
 	buf[1] = DP_SET_ANSI_8B10B;
-	ret = drm_dp_dpcd_write(&dp->aux, DP_DOWNSPREAD_CTRL, buf, sizeof(buf));
+	ret = drm_dp_dpcd_write(dp->aux, DP_DOWNSPREAD_CTRL, buf, sizeof(buf));
 	if (ret != sizeof(buf)) {
 		drm_dbg_dp(dp->dev, "dp aux write 8b/10b and downspread failed, ret: %d\n", ret);
 		return ret >= 0 ? -EIO : ret;
 	}
 
-	ret = drm_dp_read_dpcd_caps(&dp->aux, dp->dpcd);
+	ret = drm_dp_read_dpcd_caps(dp->aux, dp->dpcd);
 	if (ret)
 		drm_err(dp->dev, "dp aux read dpcd failed, ret: %d\n", ret);
 
@@ -85,7 +85,7 @@ static int hibmc_dp_link_set_pattern(struct hibmc_dp_dev *dp, int pattern)
 
 	hibmc_dp_reg_write_field(dp, HIBMC_DP_PHYIF_CTRL0, HIBMC_DP_CFG_PAT_SEL, val);
 
-	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_PATTERN_SET, &buf, sizeof(buf));
+	ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_PATTERN_SET, &buf, sizeof(buf));
 	if (ret != sizeof(buf)) {
 		drm_dbg_dp(dp->dev, "dp aux write training pattern set failed\n");
 		return ret >= 0 ? -EIO : ret;
@@ -115,7 +115,7 @@ static int hibmc_dp_link_training_cr_pre(struct hibmc_dp_dev *dp)
 	if (ret)
 		return ret;
 
-	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, train_set, dp->link.cap.lanes);
+	ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_LANE0_SET, train_set, dp->link.cap.lanes);
 	if (ret != dp->link.cap.lanes) {
 		drm_dbg_dp(dp->dev, "dp aux write training lane set failed\n");
 		return ret >= 0 ? -EIO : ret;
@@ -198,9 +198,9 @@ static int hibmc_dp_link_training_cr(struct hibmc_dp_dev *dp)
 
 	voltage_tries = 1;
 	for (cr_tries = 0; cr_tries < 80; cr_tries++) {
-		drm_dp_link_train_clock_recovery_delay(&dp->aux, dp->dpcd);
+		drm_dp_link_train_clock_recovery_delay(dp->aux, dp->dpcd);
 
-		ret = drm_dp_dpcd_read_link_status(&dp->aux, lane_status);
+		ret = drm_dp_dpcd_read_link_status(dp->aux, lane_status);
 		if (ret != DP_LINK_STATUS_SIZE) {
 			drm_err(dp->dev, "Get lane status failed\n");
 			return ret;
@@ -224,7 +224,7 @@ static int hibmc_dp_link_training_cr(struct hibmc_dp_dev *dp)
 		if (ret)
 			return ret;
 
-		ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, dp->link.train_set,
+		ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_LANE0_SET, dp->link.train_set,
 					dp->link.cap.lanes);
 		if (ret != dp->link.cap.lanes) {
 			drm_dbg_dp(dp->dev, "Update link training failed\n");
@@ -251,9 +251,9 @@ static int hibmc_dp_link_training_channel_eq(struct hibmc_dp_dev *dp)
 		return ret;
 
 	for (eq_tries = 0; eq_tries < HIBMC_EQ_MAX_RETRY; eq_tries++) {
-		drm_dp_link_train_channel_eq_delay(&dp->aux, dp->dpcd);
+		drm_dp_link_train_channel_eq_delay(dp->aux, dp->dpcd);
 
-		ret = drm_dp_dpcd_read_link_status(&dp->aux, lane_status);
+		ret = drm_dp_dpcd_read_link_status(dp->aux, lane_status);
 		if (ret != DP_LINK_STATUS_SIZE) {
 			drm_err(dp->dev, "get lane status failed\n");
 			break;
@@ -278,7 +278,7 @@ static int hibmc_dp_link_training_channel_eq(struct hibmc_dp_dev *dp)
 		if (ret)
 			return ret;
 
-		ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET,
+		ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_LANE0_SET,
 					dp->link.train_set, dp->link.cap.lanes);
 		if (ret != dp->link.cap.lanes) {
 			drm_dbg_dp(dp->dev, "Update link training failed\n");
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
index 603d6b198a54..fac8485a69d9 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
@@ -15,11 +15,27 @@
 
 static int hibmc_dp_connector_get_modes(struct drm_connector *connector)
 {
+	struct hibmc_dp *dp = to_hibmc_dp(connector);
+	const struct drm_edid *drm_edid;
 	int count;
 
-	count = drm_add_modes_noedid(connector, connector->dev->mode_config.max_width,
+	drm_edid = drm_edid_read_ddc(connector, &dp->aux.ddc);
+
+	drm_edid_connector_update(connector, drm_edid);
+
+	if (drm_edid) {
+		count = drm_edid_connector_add_modes(connector);
+		if (count)
+			goto out;
+	}
+
+	count = drm_add_modes_noedid(connector,
+				     connector->dev->mode_config.max_width,
 				     connector->dev->mode_config.max_height);
-	drm_set_preferred_mode(connector, 1024, 768); // temporary implementation
+	drm_set_preferred_mode(connector, 1024, 768);
+
+out:
+	drm_edid_free(drm_edid);
 
 	return count;
 }
@@ -28,12 +44,28 @@ static const struct drm_connector_helper_funcs hibmc_dp_conn_helper_funcs = {
 	.get_modes = hibmc_dp_connector_get_modes,
 };
 
+static int hibmc_dp_late_register(struct drm_connector *connector)
+{
+	struct hibmc_dp *dp = to_hibmc_dp(connector);
+
+	return drm_dp_aux_register(&dp->aux);
+}
+
+static void hibmc_dp_early_unregister(struct drm_connector *connector)
+{
+	struct hibmc_dp *dp = to_hibmc_dp(connector);
+
+	drm_dp_aux_unregister(&dp->aux);
+}
+
 static const struct drm_connector_funcs hibmc_dp_conn_funcs = {
 	.reset = drm_atomic_helper_connector_reset,
 	.fill_modes = drm_helper_probe_single_connector_modes,
 	.destroy = drm_connector_cleanup,
 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
+	.late_register = hibmc_dp_late_register,
+	.early_unregister = hibmc_dp_early_unregister,
 };
 
 static inline int hibmc_dp_prepare(struct hibmc_dp *dp, struct drm_display_mode *mode)
@@ -103,8 +135,8 @@ int hibmc_dp_init(struct hibmc_drm_private *priv)
 
 	drm_encoder_helper_add(encoder, &hibmc_dp_encoder_helper_funcs);
 
-	ret = drm_connector_init(dev, connector, &hibmc_dp_conn_funcs,
-				 DRM_MODE_CONNECTOR_DisplayPort);
+	ret = drm_connector_init_with_ddc(dev, connector, &hibmc_dp_conn_funcs,
+					  DRM_MODE_CONNECTOR_DisplayPort, &dp->aux.ddc);
 	if (ret) {
 		drm_err(dev, "init dp connector failed: %d\n", ret);
 		return ret;
diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
index d982f1e4b958..3ddd71aada66 100644
--- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
+++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
@@ -47,6 +47,11 @@ static inline struct hibmc_vdac *to_hibmc_vdac(struct drm_connector *connector)
 	return container_of(connector, struct hibmc_vdac, connector);
 }
 
+static inline struct hibmc_dp *to_hibmc_dp(struct drm_connector *connector)
+{
+	return container_of(connector, struct hibmc_dp, connector);
+}
+
 static inline struct hibmc_drm_private *to_hibmc_drm_private(struct drm_device *dev)
 {
 	return container_of(dev, struct hibmc_drm_private, dev);
-- 
2.33.0
Re: [PATCH v1 drm-dp 2/4] drm/hisilicon/hibmc: Getting connector info and edid by using aux channel
Posted by Dmitry Baryshkov 2 days, 4 hours ago
On Mon, Jan 27, 2025 at 11:20:22AM +0800, Yongbang Shi wrote:
> From: Baihan Li <libaihan@huawei.com>
> 
> Registering drm_aux and using it to get connector edid with drm functions.
> Refactoring some structs to fit aux's register framework.
> 
> Signed-off-by: Baihan Li <libaihan@huawei.com>
> Signed-off-by: Yongbang Shi <shiyongbang@huawei.com>
> ---
>  drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c   | 16 +++++---
>  drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h  |  7 +++-
>  drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c    |  5 ++-
>  drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h    |  2 +
>  drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c  | 22 +++++-----
>  .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c    | 40 +++++++++++++++++--
>  .../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h   |  5 +++
>  7 files changed, 72 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
> index 0a903cce1fa9..c07c970d2e50 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
> @@ -8,6 +8,7 @@
>  #include <drm/drm_print.h>
>  #include "dp_comm.h"
>  #include "dp_reg.h"
> +#include "dp_hw.h"
>  
>  #define HIBMC_AUX_CMD_REQ_LEN		GENMASK(7, 4)
>  #define HIBMC_AUX_CMD_ADDR		GENMASK(27, 8)
> @@ -124,7 +125,8 @@ static int hibmc_dp_aux_parse_xfer(struct hibmc_dp_dev *dp, struct drm_dp_aux_ms
>  /* ret >= 0 ,ret is size; ret < 0, ret is err code */
>  static ssize_t hibmc_dp_aux_xfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg)
>  {
> -	struct hibmc_dp_dev *dp = container_of(aux, struct hibmc_dp_dev, aux);
> +	struct hibmc_dp_dev *dp = ((struct hibmc_dp *)container_of(aux, struct hibmc_dp,
> +								   aux))->dp_dev;

You should not need type conversion here.

>  	u32 aux_cmd;
>  	int ret;
>  	u32 val; /* val will be assigned at the beginning of readl_poll_timeout function */
> @@ -151,14 +153,16 @@ static ssize_t hibmc_dp_aux_xfer(struct drm_dp_aux *aux, struct drm_dp_aux_msg *
>  	return hibmc_dp_aux_parse_xfer(dp, msg);
>  }
>  
> -void hibmc_dp_aux_init(struct hibmc_dp_dev *dp)
> +void hibmc_dp_aux_init(struct hibmc_dp *dp)
>  {
> -	hibmc_dp_reg_write_field(dp, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_SYNC_LEN_SEL, 0x0);
> -	hibmc_dp_reg_write_field(dp, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_TIMER_TIMEOUT, 0x1);
> -	hibmc_dp_reg_write_field(dp, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_MIN_PULSE_NUM,
> +	hibmc_dp_reg_write_field(dp->dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_SYNC_LEN_SEL, 0x0);
> +	hibmc_dp_reg_write_field(dp->dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_TIMER_TIMEOUT, 0x1);
> +	hibmc_dp_reg_write_field(dp->dp_dev, HIBMC_DP_AUX_REQ, HIBMC_DP_CFG_AUX_MIN_PULSE_NUM,
>  				 HIBMC_DP_MIN_PULSE_NUM);
>  
>  	dp->aux.transfer = hibmc_dp_aux_xfer;
> -	dp->aux.is_remote = 0;
> +	dp->aux.name = kasprintf(GFP_KERNEL, "HIBMC DRM dp aux");
> +	dp->aux.drm_dev = dp->drm_dev;
>  	drm_dp_aux_init(&dp->aux);
> +	dp->dp_dev->aux = &dp->aux;
>  }
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
> index 00b23301d26e..7edcecd5a5f0 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_comm.h
> @@ -11,8 +11,11 @@
>  #include <linux/kernel.h>
>  #include <linux/bitfield.h>
>  #include <linux/io.h>
> +
>  #include <drm/display/drm_dp_helper.h>
>  
> +#include "dp_hw.h"
> +
>  #define HIBMC_DP_LANE_NUM_MAX 2
>  
>  struct hibmc_link_status {
> @@ -32,7 +35,7 @@ struct hibmc_dp_link {
>  };
>  
>  struct hibmc_dp_dev {
> -	struct drm_dp_aux aux;
> +	struct drm_dp_aux *aux;
>  	struct drm_device *dev;
>  	void __iomem *base;
>  	struct mutex lock; /* protects concurrent RW in hibmc_dp_reg_write_field() */
> @@ -58,7 +61,7 @@ struct hibmc_dp_dev {
>  		mutex_unlock(&_dp->lock);				\
>  	} while (0)
>  
> -void hibmc_dp_aux_init(struct hibmc_dp_dev *dp);
> +void hibmc_dp_aux_init(struct hibmc_dp *dp);
>  int hibmc_dp_link_training(struct hibmc_dp_dev *dp);
>  
>  #endif
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> index 0dac4cfdde7c..50050908606f 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> @@ -3,6 +3,7 @@
>  
>  #include <linux/io.h>
>  #include <linux/delay.h>
> +#include <drm/drm_managed.h>
>  #include "dp_config.h"
>  #include "dp_comm.h"
>  #include "dp_reg.h"
> @@ -156,7 +157,7 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
>  	struct drm_device *drm_dev = dp->drm_dev;
>  	struct hibmc_dp_dev *dp_dev;
>  
> -	dp_dev = devm_kzalloc(drm_dev->dev, sizeof(struct hibmc_dp_dev), GFP_KERNEL);
> +	dp_dev = drmm_kcalloc(drm_dev, 1, sizeof(struct hibmc_dp_dev), GFP_KERNEL);

Too many unrelated changes at the same time. How is devm -> drmm
connected to the DP AUX? Please split it away.

>  	if (!dp_dev)
>  		return -ENOMEM;
>  
> @@ -167,7 +168,7 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
>  	dp_dev->dev = drm_dev;
>  	dp_dev->base = dp->mmio + HIBMC_DP_OFFSET;
>  
> -	hibmc_dp_aux_init(dp_dev);
> +	hibmc_dp_aux_init(dp);
>  
>  	if (hibmc_dp_phy_init(dp_dev))
>  		return -EAGAIN;
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> index 4dc13b3d9875..53b6d0beecea 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> @@ -10,6 +10,7 @@
>  #include <drm/drm_encoder.h>
>  #include <drm/drm_connector.h>
>  #include <drm/drm_print.h>
> +#include <drm/display/drm_dp_helper.h>
>  
>  struct hibmc_dp_dev;
>  
> @@ -19,6 +20,7 @@ struct hibmc_dp {
>  	struct drm_encoder encoder;
>  	struct drm_connector connector;
>  	void __iomem *mmio;
> +	struct drm_dp_aux aux;
>  };
>  
>  int hibmc_dp_hw_init(struct hibmc_dp *dp);
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
> index 1124cd70c320..695cb9c0b643 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
> @@ -27,7 +27,7 @@ static int hibmc_dp_link_training_configure(struct hibmc_dp_dev *dp)
>  	/* set rate and lane count */
>  	buf[0] = dp->link.cap.link_rate;
>  	buf[1] = DP_LANE_COUNT_ENHANCED_FRAME_EN | dp->link.cap.lanes;
> -	ret = drm_dp_dpcd_write(&dp->aux, DP_LINK_BW_SET, buf, sizeof(buf));
> +	ret = drm_dp_dpcd_write(dp->aux, DP_LINK_BW_SET, buf, sizeof(buf));
>  	if (ret != sizeof(buf)) {
>  		drm_dbg_dp(dp->dev, "dp aux write link rate and lanes failed, ret: %d\n", ret);
>  		return ret >= 0 ? -EIO : ret;
> @@ -36,13 +36,13 @@ static int hibmc_dp_link_training_configure(struct hibmc_dp_dev *dp)
>  	/* set 8b/10b and downspread */
>  	buf[0] = DP_SPREAD_AMP_0_5;
>  	buf[1] = DP_SET_ANSI_8B10B;
> -	ret = drm_dp_dpcd_write(&dp->aux, DP_DOWNSPREAD_CTRL, buf, sizeof(buf));
> +	ret = drm_dp_dpcd_write(dp->aux, DP_DOWNSPREAD_CTRL, buf, sizeof(buf));
>  	if (ret != sizeof(buf)) {
>  		drm_dbg_dp(dp->dev, "dp aux write 8b/10b and downspread failed, ret: %d\n", ret);
>  		return ret >= 0 ? -EIO : ret;
>  	}
>  
> -	ret = drm_dp_read_dpcd_caps(&dp->aux, dp->dpcd);
> +	ret = drm_dp_read_dpcd_caps(dp->aux, dp->dpcd);
>  	if (ret)
>  		drm_err(dp->dev, "dp aux read dpcd failed, ret: %d\n", ret);
>  
> @@ -85,7 +85,7 @@ static int hibmc_dp_link_set_pattern(struct hibmc_dp_dev *dp, int pattern)
>  
>  	hibmc_dp_reg_write_field(dp, HIBMC_DP_PHYIF_CTRL0, HIBMC_DP_CFG_PAT_SEL, val);
>  
> -	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_PATTERN_SET, &buf, sizeof(buf));
> +	ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_PATTERN_SET, &buf, sizeof(buf));
>  	if (ret != sizeof(buf)) {
>  		drm_dbg_dp(dp->dev, "dp aux write training pattern set failed\n");
>  		return ret >= 0 ? -EIO : ret;
> @@ -115,7 +115,7 @@ static int hibmc_dp_link_training_cr_pre(struct hibmc_dp_dev *dp)
>  	if (ret)
>  		return ret;
>  
> -	ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, train_set, dp->link.cap.lanes);
> +	ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_LANE0_SET, train_set, dp->link.cap.lanes);
>  	if (ret != dp->link.cap.lanes) {
>  		drm_dbg_dp(dp->dev, "dp aux write training lane set failed\n");
>  		return ret >= 0 ? -EIO : ret;
> @@ -198,9 +198,9 @@ static int hibmc_dp_link_training_cr(struct hibmc_dp_dev *dp)
>  
>  	voltage_tries = 1;
>  	for (cr_tries = 0; cr_tries < 80; cr_tries++) {
> -		drm_dp_link_train_clock_recovery_delay(&dp->aux, dp->dpcd);
> +		drm_dp_link_train_clock_recovery_delay(dp->aux, dp->dpcd);
>  
> -		ret = drm_dp_dpcd_read_link_status(&dp->aux, lane_status);
> +		ret = drm_dp_dpcd_read_link_status(dp->aux, lane_status);
>  		if (ret != DP_LINK_STATUS_SIZE) {
>  			drm_err(dp->dev, "Get lane status failed\n");
>  			return ret;
> @@ -224,7 +224,7 @@ static int hibmc_dp_link_training_cr(struct hibmc_dp_dev *dp)
>  		if (ret)
>  			return ret;
>  
> -		ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, dp->link.train_set,
> +		ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_LANE0_SET, dp->link.train_set,
>  					dp->link.cap.lanes);
>  		if (ret != dp->link.cap.lanes) {
>  			drm_dbg_dp(dp->dev, "Update link training failed\n");
> @@ -251,9 +251,9 @@ static int hibmc_dp_link_training_channel_eq(struct hibmc_dp_dev *dp)
>  		return ret;
>  
>  	for (eq_tries = 0; eq_tries < HIBMC_EQ_MAX_RETRY; eq_tries++) {
> -		drm_dp_link_train_channel_eq_delay(&dp->aux, dp->dpcd);
> +		drm_dp_link_train_channel_eq_delay(dp->aux, dp->dpcd);
>  
> -		ret = drm_dp_dpcd_read_link_status(&dp->aux, lane_status);
> +		ret = drm_dp_dpcd_read_link_status(dp->aux, lane_status);
>  		if (ret != DP_LINK_STATUS_SIZE) {
>  			drm_err(dp->dev, "get lane status failed\n");
>  			break;
> @@ -278,7 +278,7 @@ static int hibmc_dp_link_training_channel_eq(struct hibmc_dp_dev *dp)
>  		if (ret)
>  			return ret;
>  
> -		ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET,
> +		ret = drm_dp_dpcd_write(dp->aux, DP_TRAINING_LANE0_SET,
>  					dp->link.train_set, dp->link.cap.lanes);
>  		if (ret != dp->link.cap.lanes) {
>  			drm_dbg_dp(dp->dev, "Update link training failed\n");
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> index 603d6b198a54..fac8485a69d9 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> @@ -15,11 +15,27 @@
>  
>  static int hibmc_dp_connector_get_modes(struct drm_connector *connector)
>  {
> +	struct hibmc_dp *dp = to_hibmc_dp(connector);
> +	const struct drm_edid *drm_edid;
>  	int count;
>  
> -	count = drm_add_modes_noedid(connector, connector->dev->mode_config.max_width,
> +	drm_edid = drm_edid_read_ddc(connector, &dp->aux.ddc);
> +
> +	drm_edid_connector_update(connector, drm_edid);
> +
> +	if (drm_edid) {

No need for a conditional, please drop.

> +		count = drm_edid_connector_add_modes(connector);
> +		if (count)
> +			goto out;
> +	}
> +
> +	count = drm_add_modes_noedid(connector,
> +				     connector->dev->mode_config.max_width,
>  				     connector->dev->mode_config.max_height);
> -	drm_set_preferred_mode(connector, 1024, 768); // temporary implementation
> +	drm_set_preferred_mode(connector, 1024, 768);

You don't need this anymore, please drop it.
drm_helper_probe_single_connector_modes() will add a default 640x480 per
the standard.

> +
> +out:
> +	drm_edid_free(drm_edid);
>  
>  	return count;
>  }
> @@ -28,12 +44,28 @@ static const struct drm_connector_helper_funcs hibmc_dp_conn_helper_funcs = {
>  	.get_modes = hibmc_dp_connector_get_modes,
>  };
>  
> +static int hibmc_dp_late_register(struct drm_connector *connector)
> +{
> +	struct hibmc_dp *dp = to_hibmc_dp(connector);
> +
> +	return drm_dp_aux_register(&dp->aux);
> +}
> +
> +static void hibmc_dp_early_unregister(struct drm_connector *connector)
> +{
> +	struct hibmc_dp *dp = to_hibmc_dp(connector);
> +
> +	drm_dp_aux_unregister(&dp->aux);
> +}
> +
>  static const struct drm_connector_funcs hibmc_dp_conn_funcs = {
>  	.reset = drm_atomic_helper_connector_reset,
>  	.fill_modes = drm_helper_probe_single_connector_modes,
>  	.destroy = drm_connector_cleanup,
>  	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
>  	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
> +	.late_register = hibmc_dp_late_register,
> +	.early_unregister = hibmc_dp_early_unregister,
>  };
>  
>  static inline int hibmc_dp_prepare(struct hibmc_dp *dp, struct drm_display_mode *mode)
> @@ -103,8 +135,8 @@ int hibmc_dp_init(struct hibmc_drm_private *priv)
>  
>  	drm_encoder_helper_add(encoder, &hibmc_dp_encoder_helper_funcs);
>  
> -	ret = drm_connector_init(dev, connector, &hibmc_dp_conn_funcs,
> -				 DRM_MODE_CONNECTOR_DisplayPort);
> +	ret = drm_connector_init_with_ddc(dev, connector, &hibmc_dp_conn_funcs,
> +					  DRM_MODE_CONNECTOR_DisplayPort, &dp->aux.ddc);
>  	if (ret) {
>  		drm_err(dev, "init dp connector failed: %d\n", ret);
>  		return ret;
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> index d982f1e4b958..3ddd71aada66 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> @@ -47,6 +47,11 @@ static inline struct hibmc_vdac *to_hibmc_vdac(struct drm_connector *connector)
>  	return container_of(connector, struct hibmc_vdac, connector);
>  }
>  
> +static inline struct hibmc_dp *to_hibmc_dp(struct drm_connector *connector)
> +{
> +	return container_of(connector, struct hibmc_dp, connector);
> +}
> +
>  static inline struct hibmc_drm_private *to_hibmc_drm_private(struct drm_device *dev)
>  {
>  	return container_of(dev, struct hibmc_drm_private, dev);
> -- 
> 2.33.0
> 

-- 
With best wishes
Dmitry