Subject: Re: [PATCH v15 2/9] drm/bridge: aux: Add drm_aux_bridge_register_from_node()

From: Nicolas Frattaroli <[email-masked]>
Date: Thu, 28 May 2026 17:46:15 +0200

On Wednesday, 4 March 2026 10:41:45 Central European Summer Time Chaoyi Chen wrote:
> From: Chaoyi Chen <[email-masked]>
> 
> The drm_aux_bridge_register() uses the device->of_node as the
> bridge->of_node.
> 
> This patch adds drm_aux_bridge_register_from_node() to allow
> specifying the of_node corresponding to the bridge.
> 
> Signed-off-by: Chaoyi Chen <[email-masked]>
> Reviewed-by: Neil Armstrong <[email-masked]>
> ---
> 
> (no changes since v11)
> ---
> 
>  drivers/gpu/drm/bridge/aux-bridge.c | 24 ++++++++++++++++++++++--
>  include/drm/bridge/aux-bridge.h     |  6 ++++++
>  2 files changed, 28 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/bridge/aux-bridge.c b/drivers/gpu/drm/bridge/aux-bridge.c
> index b3e4cdff61d6..52dff4601c2d 100644
> --- a/drivers/gpu/drm/bridge/aux-bridge.c
> +++ b/drivers/gpu/drm/bridge/aux-bridge.c
> @@ -35,6 +35,7 @@ static void drm_aux_bridge_unregister_adev(void *_adev)
>  /**
>   * drm_aux_bridge_register - Create a simple bridge device to link the chain

Function name needs to be changed here as well. You can validate
kernel doc strings for a single file with:

  ./tools/docs/kernel-doc -v -none drivers/gpu/drm/bridge/aux-bridge.c

With that fixed:

Reviewed-by: Nicolas Frattaroli <[email-masked]>

Kind regards,
Nicolas Frattaroli

>   * @parent: device instance providing this bridge
> + * @np: device node pointer corresponding to this bridge instance
>   *
>   * Creates a simple DRM bridge that doesn't implement any drm_bridge
>   * operations. Such bridges merely fill a place in the bridge chain linking
> @@ -42,7 +43,7 @@ static void drm_aux_bridge_unregister_adev(void *_adev)
>   *
>   * Return: zero on success, negative error code on failure
>   */
> -int drm_aux_bridge_register(struct device *parent)
> +int drm_aux_bridge_register_from_node(struct device *parent, struct device_node *np)
>  {
>  	struct auxiliary_device *adev;
>  	int ret;
> @@ -62,7 +63,10 @@ int drm_aux_bridge_register(struct device *parent)
>  	adev->dev.parent = parent;
>  	adev->dev.release = drm_aux_bridge_release;
>  
> -	device_set_of_node_from_dev(&adev->dev, parent);
> +	if (np)
> +		device_set_node(&adev->dev, of_fwnode_handle(np));
> +	else
> +		device_set_of_node_from_dev(&adev->dev, parent);
>  
>  	ret = auxiliary_device_init(adev);
>  	if (ret) {
> @@ -80,6 +84,22 @@ int drm_aux_bridge_register(struct device *parent)
>  
>  	return devm_add_action_or_reset(parent, drm_aux_bridge_unregister_adev, adev);
>  }
> +EXPORT_SYMBOL_GPL(drm_aux_bridge_register_from_node);
> +
> +/**
> + * drm_aux_bridge_register - Create a simple bridge device to link the chain
> + * @parent: device instance providing this bridge
> + *
> + * Creates a simple DRM bridge that doesn't implement any drm_bridge
> + * operations. Such bridges merely fill a place in the bridge chain linking
> + * surrounding DRM bridges.
> + *
> + * Return: zero on success, negative error code on failure
> + */
> +int drm_aux_bridge_register(struct device *parent)
> +{
> +	return drm_aux_bridge_register_from_node(parent, NULL);
> +}
>  EXPORT_SYMBOL_GPL(drm_aux_bridge_register);
>  
>  struct drm_aux_bridge_data {
> diff --git a/include/drm/bridge/aux-bridge.h b/include/drm/bridge/aux-bridge.h
> index c2f5a855512f..7dd1f17a1354 100644
> --- a/include/drm/bridge/aux-bridge.h
> +++ b/include/drm/bridge/aux-bridge.h
> @@ -13,11 +13,17 @@ struct auxiliary_device;
>  
>  #if IS_ENABLED(CONFIG_DRM_AUX_BRIDGE)
>  int drm_aux_bridge_register(struct device *parent);
> +int drm_aux_bridge_register_from_node(struct device *parent, struct device_node *np);
>  #else
>  static inline int drm_aux_bridge_register(struct device *parent)
>  {
>  	return 0;
>  }
> +
> +static inline int drm_aux_bridge_register_from_node(struct device *parent, struct device_node *np)
> +{
> +	return 0;
> +}
>  #endif
>  
>  #if IS_ENABLED(CONFIG_DRM_AUX_HPD_BRIDGE)
>