Re: [PATCH v1 3/4] drm/rockchip: dw_hdmi: Apply DRM_BRIDGE_ATTACH_NO_CONNECTOR and the bridge-connector

[Jonas Karlman <jonas@kwiboo.se>]

Hi Damon,

On 4/3/2026 9:00 AM, Damon Ding wrote:
> Convert this driver to DRM_BRIDGE_ATTACH_NO_CONNECTOR and to the
> drm_bridge_connector framework which is the current DRM bridge best
> practice.

Changing to use the bridge connector at this stage will cause the
Rockchip platform to drop features the dw-hdmi connector currently only
can provide, e.g. a CEC notifier, some connector properties and more.

I am also currently working on a multi series effort to:
- phy: rockchip: inno-hdmi: Change TMDS rate handling to configure() ops [v2]
- drm/rockchip: dw_hdmi: Misc cleanup and propagate bus format [v1]
- drm: bridge: dw_hdmi: Misc enable/disable, CEC and EDID cleanup [v5]
- drm/bridge: dw-hdmi: Improve input/output bus format handling
- drm/bridge: dw-hdmi: Convert to a HDMI bridge and use of bridge connector
- drm/bridge: dw-hdmi: Add and use tmds_char_rate_valid() plat data ops
- drm/meson: hdmi: Misc cleanup and use CEC notifier helpers
- drm/rockchip: dw_hdmi: Enable YCbCr and Deep Color modes
Link to snapshot: https://github.com/Kwiboo/linux-rockchip/commits/next-20260508-rk-hdmi-v3/

Part of that effort include to fully convert the dw-hdmi bridge into a
HDMI bridge, something that is required to fully be able to replace all
features currently provided by the use of the dw-hdmi connector.

In that effort I have also taken a different approach and instead
replace the dw-hdmi connector with the bridge connector directly from
inside the dw-hdmi bridge driver.

Regards,
Jonas

> Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
> ---
>  drivers/gpu/drm/rockchip/Kconfig            |  1 +
>  drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 19 +++++++++++++++----
>  2 files changed, 16 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/rockchip/Kconfig b/drivers/gpu/drm/rockchip/Kconfig
> index e7f49fe845ea..69b832d0c8c4 100644
> --- a/drivers/gpu/drm/rockchip/Kconfig
> +++ b/drivers/gpu/drm/rockchip/Kconfig
> @@ -76,6 +76,7 @@ config ROCKCHIP_DW_DP
>  
>  config ROCKCHIP_DW_HDMI
>  	bool "Rockchip specific extensions for Synopsys DW HDMI"
> +	select DRM_BRIDGE_CONNECTOR
>  	help
>  	  This selects support for Rockchip SoC specific extensions
>  	  for the Synopsys DesignWare HDMI driver. If you want to
> diff --git a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
> index 21b141b7cb9c..b5cfcb936078 100644
> --- a/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
> +++ b/drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c
> @@ -13,6 +13,7 @@
>  #include <linux/regulator/consumer.h>
>  
>  #include <drm/bridge/dw_hdmi.h>
> +#include <drm/drm_bridge_connector.h>
>  #include <drm/drm_edid.h>
>  #include <drm/drm_of.h>
>  #include <drm/drm_probe_helper.h>
> @@ -542,6 +543,7 @@ static int dw_hdmi_rockchip_bind(struct device *dev, struct device *master,
>  	struct drm_device *drm = data;
>  	struct drm_encoder *encoder;
>  	struct rockchip_hdmi *hdmi;
> +	struct drm_connector *connector;
>  	int ret;
>  
>  	if (!pdev->dev.of_node)
> @@ -608,7 +610,7 @@ static int dw_hdmi_rockchip_bind(struct device *dev, struct device *master,
>  
>  	platform_set_drvdata(pdev, hdmi);
>  
> -	hdmi->hdmi = dw_hdmi_bind(pdev, encoder, plat_data, 0);
> +	hdmi->hdmi = dw_hdmi_bind(pdev, encoder, plat_data, DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>  
>  	/*
>  	 * If dw_hdmi_bind() fails we'll never call dw_hdmi_unbind(),
> @@ -616,12 +618,21 @@ static int dw_hdmi_rockchip_bind(struct device *dev, struct device *master,
>  	 */
>  	if (IS_ERR(hdmi->hdmi)) {
>  		ret = PTR_ERR(hdmi->hdmi);
> -		goto err_bind;
> +		goto err_cleanup_encoder;
>  	}
>  
> -	return 0;
> +	connector = drm_bridge_connector_init(drm, encoder);
> +	if (IS_ERR(connector)) {
> +		ret = PTR_ERR(connector);
> +		dev_err(hdmi->dev, "Failed to initialize bridge_connector\n");
> +		goto err_unbind_bridge;
> +	}
>  
> -err_bind:
> +	return drm_connector_attach_encoder(connector, encoder);
> +
> +err_unbind_bridge:
> +	dw_hdmi_unbind(hdmi->hdmi);
> +err_cleanup_encoder:
>  	drm_encoder_cleanup(encoder);
>  
>  	return ret;