Re: [PATCH 3/5] drm/bridge: simple-bridge: Allow acquiring the next bridge with fwnode API

Laurent Pinchart
2024-01-23T01:18:57Z

On Tue, Jan 23, 2024 at 12:32:18AM +0800, Sui Jingfeng wrote:
> Which make it possible to use this driver on non-DT based systems,
> meanwhile, made no functional changes for DT based systems.
>
> Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>
> ---
> drivers/gpu/drm/bridge/simple-bridge.c | 51 ++++++++++++++++++++++----
> 1 file changed, 44 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/simple-bridge.c b/drivers/gpu/drm/bridge/simple-bridge.c
> index 595f672745b9..cfea5a67cc5b 100644
> --- a/drivers/gpu/drm/bridge/simple-bridge.c
> +++ b/drivers/gpu/drm/bridge/simple-bridge.c
> @@ -184,6 +184,39 @@ static const void *simple_bridge_get_match_data(const struct device *dev)
> return NULL;
> }
>
> +static int simple_bridge_get_next_bridge_by_fwnode(struct device *dev,
> + struct drm_bridge **next_bridge)
> +{
> + struct drm_bridge *bridge;
> + struct fwnode_handle *ep;
> + struct fwnode_handle *remote;
> +
> + ep = fwnode_graph_get_endpoint_by_id(dev->fwnode, 1, 0, 0);
> + if (!ep) {
> + dev_err(dev, "The endpoint is unconnected\n");
> + return -EINVAL;
> + }
> +
> + remote = fwnode_graph_get_remote_port_parent(ep);
> + fwnode_handle_put(ep);
> + if (!remote) {
> + dev_err(dev, "No valid remote node\n");
> + return -ENODEV;
> + }
> +
> + bridge = drm_bridge_find_by_fwnode(remote);
> + fwnode_handle_put(remote);
> +
> + if (!bridge) {
> + dev_warn(dev, "Next bridge not found, deferring probe\n");
> + return -EPROBE_DEFER;
> + }
> +
> + *next_bridge = bridge;
> +
> + return 0;
> +}
> +

Hmmmm yes, this convinces me further that we should switch to fwnode,
not implement fwnode and OF side-by-side.

> static int simple_bridge_probe(struct platform_device *pdev)
> {
> struct simple_bridge *sbridge;
> @@ -199,14 +232,17 @@ static int simple_bridge_probe(struct platform_device *pdev)
> else
> sbridge->info = simple_bridge_get_match_data(&pdev->dev);
>
> - /* Get the next bridge in the pipeline. */
> - remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
> - if (!remote)
> - return -EINVAL;
> -
> - sbridge->next_bridge = of_drm_find_bridge(remote);
> - of_node_put(remote);
> + if (pdev->dev.of_node) {
> + /* Get the next bridge in the pipeline. */
> + remote = of_graph_get_remote_node(pdev->dev.of_node, 1, -1);
> + if (!remote)
> + return -EINVAL;
>
> + sbridge->next_bridge = of_drm_find_bridge(remote);
> + of_node_put(remote);
> + } else {
> + simple_bridge_get_next_bridge_by_fwnode(&pdev->dev, &sbridge->next_bridge);
> + }
> if (!sbridge->next_bridge) {
> dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");
> return -EPROBE_DEFER;
> @@ -231,6 +267,7 @@ static int simple_bridge_probe(struct platform_device *pdev)
> /* Register the bridge. */
> sbridge->bridge.funcs = &simple_bridge_bridge_funcs;
> sbridge->bridge.of_node = pdev->dev.of_node;
> + sbridge->bridge.fwnode = pdev->dev.fwnode;
> sbridge->bridge.timings = sbridge->info->timings;
>
> drm_bridge_add(&sbridge->bridge);
> --
> 2.25.1
>

--
Regards,

Laurent Pinchart