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

[Yongbang Shi <shiyongbang@huawei.com>]

> 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.

Hi Dmitry,

Thanks! I will split them to make them seem more reasonable, and drop some unecessary parts.


>> +
>> +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
>>