Re: [PATCH v4 2/9] drm/bridge: simple-bridge: Use fwnode API to acquire device properties

Dmitry Baryshkov
2024-04-22T19:56:25Z

On Tue, Apr 23, 2024 at 03:18:56AM +0800, Sui Jingfeng wrote:
> Make this driver less DT-dependent by calling the freshly created helpers,
> should be no functional changes for DT based systems. But open the door for
> otherwise use cases. Even though there is no user emerged yet, this still
> do no harms.
>
> Signed-off-by: Sui Jingfeng <sui.jingfeng@linux.dev>
> ---
> drivers/gpu/drm/bridge/simple-bridge.c | 22 ++++++++++------------
> 1 file changed, 10 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/simple-bridge.c b/drivers/gpu/drm/bridge/simple-bridge.c
> index 5813a2c4fc5e..3b09bdd5ad4d 100644
> --- a/drivers/gpu/drm/bridge/simple-bridge.c
> +++ b/drivers/gpu/drm/bridge/simple-bridge.c
> @@ -9,7 +9,6 @@
> #include <linux/gpio/consumer.h>
> #include <linux/module.h>
> #include <linux/of.h>
> -#include <linux/of_graph.h>
> #include <linux/platform_device.h>
> #include <linux/regulator/consumer.h>
>
> @@ -169,33 +168,32 @@ static const struct drm_bridge_funcs simple_bridge_bridge_funcs = {
>
> static int simple_bridge_probe(struct platform_device *pdev)
> {
> + struct fwnode_handle *fwnode = dev_fwnode(&pdev->dev);
> struct simple_bridge *sbridge;
> - struct device_node *remote;
> + int ret;
>
> sbridge = devm_kzalloc(&pdev->dev, sizeof(*sbridge), GFP_KERNEL);
> if (!sbridge)
> return -ENOMEM;
> platform_set_drvdata(pdev, sbridge);
>
> - sbridge->info = of_device_get_match_data(&pdev->dev);
> + sbridge->info = device_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);
> -
> + sbridge->next_bridge = drm_bridge_find_next_bridge_by_fwnode(fwnode, 1);

Can we please stick to the interface of drm_of_find_panel_or_bridge()?

Also note, the driver isn't looking for the next_bridge. It is looking
for the bridge at the fwnode remote endpoint.

> if (!sbridge->next_bridge) {
> dev_dbg(&pdev->dev, "Next bridge not found, deferring probe\n");
> return -EPROBE_DEFER;
> + } else if (IS_ERR(sbridge->next_bridge)) {
> + ret = PTR_ERR(sbridge->next_bridge);
> + dev_err(&pdev->dev, "Error on finding the next bridge: %d\n", ret);
> + return ret;
> }
>
> /* Get the regulator and GPIO resources. */
> sbridge->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
> if (IS_ERR(sbridge->vdd)) {
> - int ret = PTR_ERR(sbridge->vdd);
> + ret = PTR_ERR(sbridge->vdd);
> if (ret == -EPROBE_DEFER)
> return -EPROBE_DEFER;
> sbridge->vdd = NULL;
> @@ -210,9 +208,9 @@ 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.timings = sbridge->info->timings;
>
> + drm_bridge_set_node(&sbridge->bridge, fwnode);

Please don't move the code. Having it in place of of_node setter
simplifies the review.

LGTM otherwise.

> drm_bridge_add(&sbridge->bridge);
>
> return 0;
> --
> 2.34.1
>

--
With best wishes
Dmitry