Re: [PATCH v7 drm-dp 5/9] drm/hisilicon/hibmc: Getting connector info and EDID by using AUX channel
From: Jani Nikula
Date: Thu Mar 20 2025 - 05:51:06 EST
On Wed, 19 Mar 2025, Yongbang Shi <shiyongbang@xxxxxxxxxx> wrote:
> From: Baihan Li <libaihan@xxxxxxxxxx>
>
> Add registering drm_aux and use it to get connector edid with drm
> functions. Add ddc channel in connector initialization to put drm_aux
> in drm_connector.
>
> Signed-off-by: Baihan Li <libaihan@xxxxxxxxxx>
> Signed-off-by: Yongbang Shi <shiyongbang@xxxxxxxxxx>
> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> ---
> ChangeLog:
> v6 -> v7:
> - add if statement about drm aux in hibmc_dp_connector_get_modes(), suggested by Jani Nikula
I don't understand this, and I did not suggest such a thing.
BR,
Jani.
> v5 -> v6:
> - move the detect_ctx() to the patch 7/9.
> v2 -> v3:
> - Capitalized EDID and AUX, suggested by Dmitry Baryshkov.
> v1 -> v2:
> - deleting type conversion, suggested by Dmitry Baryshkov.
> - deleting hibmc_dp_connector_get_modes() and using drm_connector_helper_get_modes(), suggested by Dmitry Baryshkov.
> ---
> drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c | 3 +-
> .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c | 35 ++++++++++++++++---
> .../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h | 5 +++
> 3 files changed, 37 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
> index ded9e7ce887a..e0bb9b14d9d8 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_aux.c
> @@ -161,7 +161,8 @@ void hibmc_dp_aux_init(struct hibmc_dp *dp)
> 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/hibmc_drm_dp.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> index 603d6b198a54..0256724d8b9b 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> @@ -15,11 +15,20 @@
>
> 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,
> - connector->dev->mode_config.max_height);
> - drm_set_preferred_mode(connector, 1024, 768); // temporary implementation
> + if (!dp->aux.name)
> + return 0;
> +
> + drm_edid = drm_edid_read_ddc(connector, &dp->aux.ddc);
> +
> + drm_edid_connector_update(connector, drm_edid);
> +
> + count = drm_edid_connector_add_modes(connector);
> +
> + drm_edid_free(drm_edid);
>
> return count;
> }
> @@ -28,12 +37,28 @@ 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 +128,8 @@ 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);
--
Jani Nikula, Intel