[PATCH v2] drm/rockchip: cdn-dp: Convert to drm bridge
Chaoyi Chen
chaoyi.chen at rock-chips.com
Mon May 26 01:30:30 UTC 2025
Hi Dmitry,
On 2025/5/24 6:17, Dmitry Baryshkov wrote:
> On Fri, May 23, 2025 at 09:13:10AM +0800, Chaoyi Chen wrote:
>> From: Chaoyi Chen <chaoyi.chen at rock-chips.com>
>>
>> Convert it to drm bridge driver, it will be convenient for us to
>> migrate the connector part to the display driver later.
>>
>> Considering that some code depend on the connector, the following
>> changes have been made:
>> - Do not get edid in cdn_dp_get_sink_capability() when connector is
>> not present.
>> - Update bpc info in cdn_dp_bridge_atomic_enable() instead of
>> cdn_dp_encoder_mode_set(). Actually, the bpc data will be used in
>> cdn_dp_bridge_atomic_enable().
>>
>> This patch also convert to use devm_drm_bridge_alloc() API.
>>
>> Tested with RK3399 EVB IND board.
>>
>> Signed-off-by: Chaoyi Chen <chaoyi.chen at rock-chips.com>
>> ---
>>
>> Changes in v2:
>> - Link to V1: https://lore.kernel.org/all/20250507035148.415-1-kernel@airkyi.com/
>> - Use drm_atomic_get_new_connector_for_encoder() to get connector
>> - Convert to use devm_drm_bridge_alloc() API
>> - Fix typo: cdn_dp_connector_edid_read -> cdn_dp_bridge_edid_read
>>
>> drivers/gpu/drm/rockchip/cdn-dp-core.c | 204 +++++++++++++------------
>> drivers/gpu/drm/rockchip/cdn-dp-core.h | 5 +-
>> 2 files changed, 112 insertions(+), 97 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c b/drivers/gpu/drm/rockchip/cdn-dp-core.c
>> index 292c31de18f1..848f47d41111 100644
>> --- a/drivers/gpu/drm/rockchip/cdn-dp-core.c
>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c
>> @@ -25,9 +25,9 @@
>> #include "cdn-dp-core.h"
>> #include "cdn-dp-reg.h"
>>
>> -static inline struct cdn_dp_device *connector_to_dp(struct drm_connector *connector)
>> +static inline struct cdn_dp_device *bridge_to_dp(struct drm_bridge *bridge)
>> {
>> - return container_of(connector, struct cdn_dp_device, connector);
>> + return container_of(bridge, struct cdn_dp_device, bridge);
>> }
>>
>> static inline struct cdn_dp_device *encoder_to_dp(struct drm_encoder *encoder)
>> @@ -231,9 +231,9 @@ static bool cdn_dp_check_sink_connection(struct cdn_dp_device *dp)
>> }
>>
>> static enum drm_connector_status
>> -cdn_dp_connector_detect(struct drm_connector *connector, bool force)
>> +cdn_dp_bridge_detect(struct drm_bridge *bridge)
>> {
>> - struct cdn_dp_device *dp = connector_to_dp(connector);
>> + struct cdn_dp_device *dp = bridge_to_dp(bridge);
>> enum drm_connector_status status = connector_status_disconnected;
>>
>> mutex_lock(&dp->lock);
>> @@ -244,41 +244,25 @@ cdn_dp_connector_detect(struct drm_connector *connector, bool force)
>> return status;
>> }
>>
>> -static void cdn_dp_connector_destroy(struct drm_connector *connector)
>> +static const struct drm_edid *
>> +cdn_dp_bridge_edid_read(struct drm_bridge *bridge, struct drm_connector *connector)
>> {
>> - drm_connector_unregister(connector);
>> - drm_connector_cleanup(connector);
>> -}
>> -
>> -static const struct drm_connector_funcs cdn_dp_atomic_connector_funcs = {
>> - .detect = cdn_dp_connector_detect,
>> - .destroy = cdn_dp_connector_destroy,
>> - .fill_modes = drm_helper_probe_single_connector_modes,
>> - .reset = drm_atomic_helper_connector_reset,
>> - .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
>> - .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
>> -};
>> -
>> -static int cdn_dp_connector_get_modes(struct drm_connector *connector)
>> -{
>> - struct cdn_dp_device *dp = connector_to_dp(connector);
>> - int ret = 0;
>> + struct cdn_dp_device *dp = bridge_to_dp(bridge);
>> + const struct drm_edid *drm_edid;
>>
>> mutex_lock(&dp->lock);
>> -
>> - ret = drm_edid_connector_add_modes(connector);
>> -
>> + drm_edid = drm_edid_read_custom(connector, cdn_dp_get_edid_block, dp);
>> mutex_unlock(&dp->lock);
> I know that the lock has been here. What does it protect here?
The cdn worker may read the edid at the same time.
>
>>
>> - return ret;
>> + return drm_edid;
>> }
>>
>> static enum drm_mode_status
>> -cdn_dp_connector_mode_valid(struct drm_connector *connector,
>> - const struct drm_display_mode *mode)
>> +cdn_dp_bridge_mode_valid(struct drm_bridge *bridge,
>> + const struct drm_display_info *display_info,
>> + const struct drm_display_mode *mode)
>> {
>> - struct cdn_dp_device *dp = connector_to_dp(connector);
>> - struct drm_display_info *display_info = &dp->connector.display_info;
>> + struct cdn_dp_device *dp = bridge_to_dp(bridge);
>> u32 requested, actual, rate, sink_max, source_max = 0;
>> u8 lanes, bpc;
>>
>> @@ -323,11 +307,6 @@ cdn_dp_connector_mode_valid(struct drm_connector *connector,
>> return MODE_OK;
>> }
>>
>> -static struct drm_connector_helper_funcs cdn_dp_connector_helper_funcs = {
>> - .get_modes = cdn_dp_connector_get_modes,
>> - .mode_valid = cdn_dp_connector_mode_valid,
>> -};
>> -
>> static int cdn_dp_firmware_init(struct cdn_dp_device *dp)
>> {
>> int ret;
>> @@ -360,7 +339,8 @@ static int cdn_dp_firmware_init(struct cdn_dp_device *dp)
>>
>> static int cdn_dp_get_sink_capability(struct cdn_dp_device *dp)
>> {
>> - const struct drm_display_info *info = &dp->connector.display_info;
>> + struct drm_connector *connector = dp->connector;
>> + const struct drm_display_info *info;
>> int ret;
>>
>> if (!cdn_dp_check_sink_connection(dp))
>> @@ -373,10 +353,15 @@ static int cdn_dp_get_sink_capability(struct cdn_dp_device *dp)
>> return ret;
>> }
>>
>> + if (!connector)
>> + return 0;
> Just pass connector directly as an argument.
Ok, will fix in v3.
>
>> +
>> + info = &connector->display_info;
>> +
>> drm_edid_free(dp->drm_edid);
>> - dp->drm_edid = drm_edid_read_custom(&dp->connector,
>> + dp->drm_edid = drm_edid_read_custom(dp->connector,
>> cdn_dp_get_edid_block, dp);
>> - drm_edid_connector_update(&dp->connector, dp->drm_edid);
>> + drm_edid_connector_update(dp->connector, dp->drm_edid);
>>
>> dp->sink_has_audio = info->has_audio;
>>
>> @@ -416,11 +401,11 @@ static int cdn_dp_enable_phy(struct cdn_dp_device *dp, struct cdn_dp_port *port)
>> goto err_power_on;
>> }
>>
>> - ret = extcon_get_property(port->extcon, EXTCON_DISP_DP,
>> - EXTCON_PROP_USB_TYPEC_POLARITY, &property);
>> - if (ret) {
>> - DRM_DEV_ERROR(dp->dev, "get property failed\n");
>> - goto err_power_on;
>> + ret = extcon_get_property(port->extcon, EXTCON_DISP_DP,
>> + EXTCON_PROP_USB_TYPEC_POLARITY, &property);
> The indentation here is strange. Could you please doubltcheck it?
Oh sorry, I forgot to remove them. Will remove them in v3.
>
>> + if (ret) {
>> + DRM_DEV_ERROR(dp->dev, "get property failed\n");
>> + goto err_power_on;
>> }
>>
>> port->lanes = cdn_dp_get_port_lanes(port);
>> @@ -551,21 +536,8 @@ static void cdn_dp_encoder_mode_set(struct drm_encoder *encoder,
>> struct drm_display_mode *adjusted)
>> {
>> struct cdn_dp_device *dp = encoder_to_dp(encoder);
>> - struct drm_display_info *display_info = &dp->connector.display_info;
>> struct video_info *video = &dp->video_info;
>>
>> - switch (display_info->bpc) {
>> - case 10:
>> - video->color_depth = 10;
>> - break;
>> - case 6:
>> - video->color_depth = 6;
>> - break;
>> - default:
>> - video->color_depth = 8;
>> - break;
>> - }
>> -
> I'd suggest to perform this part in additional step, especially if you
> keep an always-assigned dp->connector for a few commits.
I will try to do it in v3.
>
>> video->color_fmt = PXL_RGB;
>> video->v_sync_polarity = !!(mode->flags & DRM_MODE_FLAG_NVSYNC);
>> video->h_sync_polarity = !!(mode->flags & DRM_MODE_FLAG_NHSYNC);
>> @@ -599,12 +571,31 @@ static void cdn_dp_audio_handle_plugged_change(struct cdn_dp_device *dp,
>> dp->plugged_cb(dp->codec_dev, plugged);
>> }
>>
>> -static void cdn_dp_encoder_enable(struct drm_encoder *encoder)
>> +static void cdn_dp_bridge_atomic_enable(struct drm_bridge *bridge, struct drm_atomic_state *state)
>> {
>> - struct cdn_dp_device *dp = encoder_to_dp(encoder);
>> + struct cdn_dp_device *dp = bridge_to_dp(bridge);
>> + struct video_info *video = &dp->video_info;
>> + struct drm_display_info *display_info;
>> int ret, val;
>>
>> - ret = drm_of_encoder_active_endpoint_id(dp->dev->of_node, encoder);
>> + dp->connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
>> + if (!dp->connector)
>> + return;
>> +
>> + display_info = &dp->connector->display_info;
>> + switch (display_info->bpc) {
>> + case 10:
>> + video->color_depth = 10;
>> + break;
>> + case 6:
>> + video->color_depth = 6;
>> + break;
>> + default:
>> + video->color_depth = 8;
>> + break;
>> + }
>> +
>> + ret = drm_of_encoder_active_endpoint_id(dp->dev->of_node, &dp->encoder.encoder);
>> if (ret < 0) {
>> DRM_DEV_ERROR(dp->dev, "Could not get vop id, %d", ret);
>> return;
>> @@ -625,7 +616,7 @@ static void cdn_dp_encoder_enable(struct drm_encoder *encoder)
>>
>> ret = cdn_dp_enable(dp);
>> if (ret) {
>> - DRM_DEV_ERROR(dp->dev, "Failed to enable encoder %d\n",
>> + DRM_DEV_ERROR(dp->dev, "Failed to enable bridge %d\n",
>> ret);
>> goto out;
>> }
>> @@ -661,9 +652,9 @@ static void cdn_dp_encoder_enable(struct drm_encoder *encoder)
>> mutex_unlock(&dp->lock);
>> }
>>
>> -static void cdn_dp_encoder_disable(struct drm_encoder *encoder)
>> +static void cdn_dp_bridge_atomic_disable(struct drm_bridge *bridge, struct drm_atomic_state *state)
>> {
>> - struct cdn_dp_device *dp = encoder_to_dp(encoder);
>> + struct cdn_dp_device *dp = bridge_to_dp(bridge);
>> int ret;
>>
>> mutex_lock(&dp->lock);
>> @@ -672,7 +663,7 @@ static void cdn_dp_encoder_disable(struct drm_encoder *encoder)
>> if (dp->active) {
>> ret = cdn_dp_disable(dp);
>> if (ret) {
>> - DRM_DEV_ERROR(dp->dev, "Failed to disable encoder %d\n",
>> + DRM_DEV_ERROR(dp->dev, "Failed to disable bridge %d\n",
>> ret);
>> }
>> }
>> @@ -703,13 +694,31 @@ static int cdn_dp_encoder_atomic_check(struct drm_encoder *encoder,
>> return 0;
>> }
>>
>> +static void cdn_dp_hpd_notify(struct drm_bridge *bridge,
>> + enum drm_connector_status status)
>> +{
>> + struct cdn_dp_device *dp = bridge_to_dp(bridge);
>> +
>> + schedule_work(&dp->event_work);
>> +}
>> +
>> static const struct drm_encoder_helper_funcs cdn_dp_encoder_helper_funcs = {
>> .mode_set = cdn_dp_encoder_mode_set,
>> - .enable = cdn_dp_encoder_enable,
>> - .disable = cdn_dp_encoder_disable,
>> .atomic_check = cdn_dp_encoder_atomic_check,
>> };
>>
>> +static const struct drm_bridge_funcs cdn_dp_bridge_funcs = {
>> + .atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
>> + .atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
>> + .atomic_reset = drm_atomic_helper_bridge_reset,
>> + .detect = cdn_dp_bridge_detect,
>> + .edid_read = cdn_dp_bridge_edid_read,
>> + .atomic_enable = cdn_dp_bridge_atomic_enable,
>> + .atomic_disable = cdn_dp_bridge_atomic_disable,
>> + .mode_valid = cdn_dp_bridge_mode_valid,
>> + .hpd_notify = cdn_dp_hpd_notify,
>> +};
>> +
>> static int cdn_dp_parse_dt(struct cdn_dp_device *dp)
>> {
>> struct device *dev = dp->dev;
>> @@ -859,7 +868,7 @@ static int cdn_dp_audio_get_eld(struct device *dev, void *data,
>> {
>> struct cdn_dp_device *dp = dev_get_drvdata(dev);
>>
>> - memcpy(buf, dp->connector.eld, min(sizeof(dp->connector.eld), len));
>> + memcpy(buf, dp->connector->eld, min(sizeof(dp->connector->eld), len));
> get_eld() might be called before .atomic_enable(). I'd suggest to switch
> to DP_AUDIO helpers, which would remove a need to store dp->connector
> here. You can do converstion graciously: store connector in the probe
> path (as you create it anyway), switch to DRM_BRIDGE_OP_DP_AUDIO (should
> be relatively easy), then drop dp->connector completely.
That make sense. I will try to do it in v3.
>
>>
>> return 0;
>> }
>> @@ -1006,7 +1015,6 @@ static void cdn_dp_pd_event_work(struct work_struct *work)
>>
>> out:
>> mutex_unlock(&dp->lock);
>> - drm_connector_helper_hpd_irq_event(&dp->connector);
> Don't you need to call drm_bridge_hpd_notify() here?
No, this could get into an infinite call loop. Also, the
drm_bridge_hpd_notify() related changes have nothing to do with this
patch, I forgot to remove them. I'll remove them in v3.
>
>> }
>>
>> static int cdn_dp_pd_event(struct notifier_block *nb,
>> @@ -1030,9 +1038,9 @@ static int cdn_dp_bind(struct device *dev, struct device *master, void *data)
>> {
>> struct cdn_dp_device *dp = dev_get_drvdata(dev);
>> struct drm_encoder *encoder;
>> - struct drm_connector *connector;
>> struct cdn_dp_port *port;
>> struct drm_device *drm_dev = data;
>> + struct drm_connector *connector;
> Kind of useless move. Please move it back.
Will fix in v3.
>
>> int ret, i;
>>
>> ret = cdn_dp_parse_dt(dp);
>> @@ -1053,6 +1061,15 @@ static int cdn_dp_bind(struct device *dev, struct device *master, void *data)
>> dev->of_node);
>> DRM_DEBUG_KMS("possible_crtcs = 0x%x\n", encoder->possible_crtcs);
>>
>> + /*
>> + * If we failed to find the CRTC(s) which this encoder is
>> + * supposed to be connected to, it's because the CRTC has
>> + * not been registered yet. Defer probing, and hope that
>> + * the required CRTC is added later.
>> + */
>> + if (encoder->possible_crtcs == 0)
>> + return -EPROBE_DEFER;
> I don't see this check beforehand. If this is a fix, please move it to a
> separate commit.
Okay, will fix in v3.
>
>> +
>> ret = drm_simple_encoder_init(drm_dev, encoder,
>> DRM_MODE_ENCODER_TMDS);
>> if (ret) {
>> @@ -1062,26 +1079,29 @@ static int cdn_dp_bind(struct device *dev, struct device *master, void *data)
>>
>> drm_encoder_helper_add(encoder, &cdn_dp_encoder_helper_funcs);
>>
>> - connector = &dp->connector;
>> - connector->polled = DRM_CONNECTOR_POLL_HPD;
>> - connector->dpms = DRM_MODE_DPMS_OFF;
>> + dp->bridge.ops = DRM_BRIDGE_OP_DETECT |
>> + DRM_BRIDGE_OP_EDID |
>> + DRM_BRIDGE_OP_HPD;
>> + dp->bridge.of_node = dp->dev->of_node;
>> + dp->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
>>
>> - ret = drm_connector_init(drm_dev, connector,
>> - &cdn_dp_atomic_connector_funcs,
>> - DRM_MODE_CONNECTOR_DisplayPort);
>> - if (ret) {
>> - DRM_ERROR("failed to initialize connector with drm\n");
>> - goto err_free_encoder;
>> - }
>> + ret = devm_drm_bridge_add(dev, &dp->bridge);
>> + if (ret)
>> + return ret;
>>
>> - drm_connector_helper_add(connector, &cdn_dp_connector_helper_funcs);
>> + ret = drm_bridge_attach(encoder, &dp->bridge, NULL, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>> + if (ret)
>> + return ret;
>>
>> - ret = drm_connector_attach_encoder(connector, encoder);
>> - if (ret) {
>> - DRM_ERROR("failed to attach connector and encoder\n");
>> - goto err_free_connector;
>> + connector = drm_bridge_connector_init(drm_dev, encoder);
>> + if (IS_ERR(connector)) {
>> + ret = PTR_ERR(connector);
>> + dev_err(dp->dev, "failed to init bridge connector: %d\n", ret);
>> + return ret;
>> }
>>
>> + drm_connector_attach_encoder(connector, encoder);
>> +
>> for (i = 0; i < dp->ports; i++) {
>> port = dp->port[i];
>>
>> @@ -1092,7 +1112,7 @@ static int cdn_dp_bind(struct device *dev, struct device *master, void *data)
>> if (ret) {
>> DRM_DEV_ERROR(dev,
>> "register EXTCON_DISP_DP notifier err\n");
>> - goto err_free_connector;
>> + return ret;
>> }
>> }
>>
>> @@ -1101,24 +1121,15 @@ static int cdn_dp_bind(struct device *dev, struct device *master, void *data)
>> schedule_work(&dp->event_work);
>>
>> return 0;
>> -
>> -err_free_connector:
>> - drm_connector_cleanup(connector);
>> -err_free_encoder:
>> - drm_encoder_cleanup(encoder);
>> - return ret;
>> }
>>
>> static void cdn_dp_unbind(struct device *dev, struct device *master, void *data)
>> {
>> struct cdn_dp_device *dp = dev_get_drvdata(dev);
>> struct drm_encoder *encoder = &dp->encoder.encoder;
>> - struct drm_connector *connector = &dp->connector;
>>
>> cancel_work_sync(&dp->event_work);
>> - cdn_dp_encoder_disable(encoder);
>> encoder->funcs->destroy(encoder);
> You've dropped drm_encoder_cleanup() from the bind path. Should it be
> dropped here too? DRM subsystem will do it for you, if I'm not mistaken.
Will fix in v3.
>
>> - connector->funcs->destroy(connector);
>>
>> pm_runtime_disable(dev);
>> if (dp->fw_loaded)
>> @@ -1171,9 +1182,10 @@ static int cdn_dp_probe(struct platform_device *pdev)
>> int ret;
>> int i;
>>
>> - dp = devm_kzalloc(dev, sizeof(*dp), GFP_KERNEL);
>> - if (!dp)
>> - return -ENOMEM;
>> + dp = devm_drm_bridge_alloc(dev, struct cdn_dp_device, bridge,
>> + &cdn_dp_bridge_funcs);
>> + if (IS_ERR(dp))
>> + return PTR_ERR(dp);
>> dp->dev = dev;
>>
>> match = of_match_node(cdn_dp_dt_ids, pdev->dev.of_node);
>> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.h b/drivers/gpu/drm/rockchip/cdn-dp-core.h
>> index 17498f576ce7..d2778f7a5b31 100644
>> --- a/drivers/gpu/drm/rockchip/cdn-dp-core.h
>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-core.h
>> @@ -8,6 +8,8 @@
>> #define _CDN_DP_CORE_H
>>
>> #include <drm/display/drm_dp_helper.h>
>> +#include <drm/drm_bridge.h>
>> +#include <drm/drm_bridge_connector.h>
>> #include <drm/drm_panel.h>
>> #include <drm/drm_probe_helper.h>
>> #include <sound/hdmi-codec.h>
>> @@ -65,7 +67,8 @@ struct cdn_dp_port {
>> struct cdn_dp_device {
>> struct device *dev;
>> struct drm_device *drm_dev;
>> - struct drm_connector connector;
>> + struct drm_bridge bridge;
>> + struct drm_connector *connector;
>> struct rockchip_encoder encoder;
>> struct drm_display_mode mode;
>> struct platform_device *audio_pdev;
>> --
>> 2.49.0
>>
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