Re: [PATCH 1/5] drm/bridge: Add drm_bridge_find_by_fwnode() helper

Laurent Pinchart
2024-01-23T01:17:10Z

Hi Sui,

Thank you for the patch.

On Tue, Jan 23, 2024 at 12:32:16AM +0800, Sui Jingfeng wrote:
> Because ACPI based systems only has the fwnode associated, the of_node
> member of struct device is NULL. To order to move things forward, we add
> drm_bridge_find_by_fwnode() to extend the support.
>
> Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>

Could we switch completely to fwnode, instead of maintaining the fwnode
and OF options side-by-side ?

> ---
> drivers/gpu/drm/drm_bridge.c | 33 +++++++++++++++++++++++++++++++++
> include/drm/drm_bridge.h | 4 ++++
> 2 files changed, 37 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
> index cee3188adf3d..ffd969adc2fb 100644
> --- a/drivers/gpu/drm/drm_bridge.c
> +++ b/drivers/gpu/drm/drm_bridge.c
> @@ -1347,6 +1347,39 @@ struct drm_bridge *of_drm_find_bridge(struct device_node *np)
> EXPORT_SYMBOL(of_drm_find_bridge);
> #endif
>
> +/**
> + * drm_bridge_find_by_fwnode - Find the bridge corresponding to the associated fwnode
> + *
> + * @fwnode: fwnode for which to find the matching drm_bridge
> + *
> + * This function looks up a drm_bridge based on its associated fwnode.
> + *
> + * RETURNS:
> + * A reference to the drm_bridge control structure if found, NULL on failure.
> + */
> +struct drm_bridge *drm_bridge_find_by_fwnode(struct fwnode_handle *fwnode)
> +{
> + struct drm_bridge *ret = NULL;
> + struct drm_bridge *bridge;
> +
> + if (!fwnode)
> + return NULL;
> +
> + mutex_lock(&bridge_lock);
> +
> + list_for_each_entry(bridge, &bridge_list, list) {
> + if (bridge->fwnode == fwnode) {
> + ret = bridge;
> + break;
> + }
> + }
> +
> + mutex_unlock(&bridge_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_bridge_find_by_fwnode);
> +
> MODULE_AUTHOR("Ajay Kumar <ajaykumar.rs@samsung.com>");
> MODULE_DESCRIPTION("DRM bridge infrastructure");
> MODULE_LICENSE("GPL and additional rights");
> diff --git a/include/drm/drm_bridge.h b/include/drm/drm_bridge.h
> index e39da5807ba7..fe3d5f4bf37f 100644
> --- a/include/drm/drm_bridge.h
> +++ b/include/drm/drm_bridge.h
> @@ -720,6 +720,8 @@ struct drm_bridge {
> struct list_head chain_node;
> /** @of_node: device node pointer to the bridge */
> struct device_node *of_node;
> + /** @fwnode: associated fwnode supplied by platform firmware */
> + struct fwnode_handle *fwnode;
> /** @list: to keep track of all added bridges */
> struct list_head list;
> /**
> @@ -796,6 +798,8 @@ static inline struct drm_bridge *of_drm_find_bridge(struct device_node *np)
> }
> #endif
>
> +struct drm_bridge *drm_bridge_find_by_fwnode(struct fwnode_handle *fwnode);
> +
> /**
> * drm_bridge_get_next_bridge() - Get the next bridge in the chain
> * @bridge: bridge object

--
Regards,

Laurent Pinchart