diff mbox series

[v8,2/9] media: v4l: Support obtaining link frequency via get_mbus_config

Message ID 20241217215445.901459-3-sakari.ailus@linux.intel.com (mailing list archive)
State New
Headers show
Series Use V4L2 mbus config for conveying link frequency | expand

Commit Message

Sakari Ailus Dec. 17, 2024, 9:54 p.m. UTC
Add link_freq field to struct v4l2_mbus_config in order to pass the link
frequency to the receiving sub-device.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 drivers/media/v4l2-core/v4l2-common.c | 15 +++++++++++++--
 include/media/v4l2-mediabus.h         |  2 ++
 2 files changed, 15 insertions(+), 2 deletions(-)

Comments

Tomi Valkeinen Dec. 20, 2024, 12:59 p.m. UTC | #1
Hi,

On 17/12/2024 23:54, Sakari Ailus wrote:
> Add link_freq field to struct v4l2_mbus_config in order to pass the link
> frequency to the receiving sub-device.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> ---
>   drivers/media/v4l2-core/v4l2-common.c | 15 +++++++++++++--
>   include/media/v4l2-mediabus.h         |  2 ++
>   2 files changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> index 9fe74c7e064f..e4b2de3833ee 100644
> --- a/drivers/media/v4l2-core/v4l2-common.c
> +++ b/drivers/media/v4l2-core/v4l2-common.c
> @@ -508,12 +508,23 @@ EXPORT_SYMBOL_GPL(__v4l2_get_link_freq_ctrl);
>   s64 __v4l2_get_link_freq_pad(struct media_pad *pad, unsigned int mul,
>   			     unsigned int div)
>   {
> +	struct v4l2_mbus_config mbus_config = {};
>   	struct v4l2_subdev *sd;
> +	int ret;
>   
>   	sd = media_entity_to_v4l2_subdev(pad->entity);
> -	if (!sd)
> -		return -ENODEV;
> +	ret = v4l2_subdev_call(sd, pad, get_mbus_config, pad->index,
> +			       &mbus_config);
> +	if (ret < 0 && ret != -ENOIOCTLCMD)
> +		return ret;
> +
> +	if (mbus_config.link_freq)
> +		return mbus_config.link_freq;
>   
> +	/*
> +	 * Fall back to using the link frequency control if the media bus config
> +	 * doesn't provide a link frequency.
> +	 */
>   	return __v4l2_get_link_freq_ctrl(sd->ctrl_handler, mul, div);
>   }
>   EXPORT_SYMBOL_GPL(__v4l2_get_link_freq_pad);
> diff --git a/include/media/v4l2-mediabus.h b/include/media/v4l2-mediabus.h
> index e7f019f68c8d..24c738cd7894 100644
> --- a/include/media/v4l2-mediabus.h
> +++ b/include/media/v4l2-mediabus.h
> @@ -169,6 +169,7 @@ enum v4l2_mbus_type {
>   /**
>    * struct v4l2_mbus_config - media bus configuration
>    * @type: interface type
> + * @link_freq: The link frequency. See also V4L2_CID_LINK_FREQ control.
>    * @bus: bus configuration data structure
>    * @bus.parallel: embedded &struct v4l2_mbus_config_parallel.
>    *		  Used if the bus is parallel or BT.656.
> @@ -183,6 +184,7 @@ enum v4l2_mbus_type {
>    */
>   struct v4l2_mbus_config {
>   	enum v4l2_mbus_type type;
> +	u64 link_freq;
>   	union {
>   		struct v4l2_mbus_config_parallel parallel;
>   		struct v4l2_mbus_config_mipi_csi1 mipi_csi1;

Maybe the docs (V4L2_CID_LINK_FREQ and/or struct v4l2_mbus_config?) 
should mention that only if v4l2_mbus_config.link_freq is == 0, 
V4L2_CID_LINK_FREQ is used. Or, in other words, the driver must only use 
one of those methods.

  Tomi
diff mbox series

Patch

diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
index 9fe74c7e064f..e4b2de3833ee 100644
--- a/drivers/media/v4l2-core/v4l2-common.c
+++ b/drivers/media/v4l2-core/v4l2-common.c
@@ -508,12 +508,23 @@  EXPORT_SYMBOL_GPL(__v4l2_get_link_freq_ctrl);
 s64 __v4l2_get_link_freq_pad(struct media_pad *pad, unsigned int mul,
 			     unsigned int div)
 {
+	struct v4l2_mbus_config mbus_config = {};
 	struct v4l2_subdev *sd;
+	int ret;
 
 	sd = media_entity_to_v4l2_subdev(pad->entity);
-	if (!sd)
-		return -ENODEV;
+	ret = v4l2_subdev_call(sd, pad, get_mbus_config, pad->index,
+			       &mbus_config);
+	if (ret < 0 && ret != -ENOIOCTLCMD)
+		return ret;
+
+	if (mbus_config.link_freq)
+		return mbus_config.link_freq;
 
+	/*
+	 * Fall back to using the link frequency control if the media bus config
+	 * doesn't provide a link frequency.
+	 */
 	return __v4l2_get_link_freq_ctrl(sd->ctrl_handler, mul, div);
 }
 EXPORT_SYMBOL_GPL(__v4l2_get_link_freq_pad);
diff --git a/include/media/v4l2-mediabus.h b/include/media/v4l2-mediabus.h
index e7f019f68c8d..24c738cd7894 100644
--- a/include/media/v4l2-mediabus.h
+++ b/include/media/v4l2-mediabus.h
@@ -169,6 +169,7 @@  enum v4l2_mbus_type {
 /**
  * struct v4l2_mbus_config - media bus configuration
  * @type: interface type
+ * @link_freq: The link frequency. See also V4L2_CID_LINK_FREQ control.
  * @bus: bus configuration data structure
  * @bus.parallel: embedded &struct v4l2_mbus_config_parallel.
  *		  Used if the bus is parallel or BT.656.
@@ -183,6 +184,7 @@  enum v4l2_mbus_type {
  */
 struct v4l2_mbus_config {
 	enum v4l2_mbus_type type;
+	u64 link_freq;
 	union {
 		struct v4l2_mbus_config_parallel parallel;
 		struct v4l2_mbus_config_mipi_csi1 mipi_csi1;