Add a RKISP1_CID_SUPPORTED_PARAMS_BLOCKS V4L2 control to be able to
query the parameters blocks supported by the current kernel on the
current hardware from user space.

As a drive-by fix handle an (very unlikely) error in
rkisp1_params_init_vb2_queue().

Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>

---

Changes in v2:
- Added docs improvements from review
- Moved ctrl_config declaration to top
- Moved rkisp1_params_init_vb2_queue() return check into this patch as
  the previous patch got dropped
- Call rkisp1_ctrl_init() after media_entity_pads_init() for easier
  error handling
---
 .../media/platform/rockchip/rkisp1/rkisp1-common.h |  2 +
 .../media/platform/rockchip/rkisp1/rkisp1-params.c | 57 ++++++++++++++++++++--
 include/uapi/linux/rkisp1-config.h                 |  9 ++++
 include/uapi/linux/v4l2-controls.h                 |  6 +++
 4 files changed, 70 insertions(+), 4 deletions(-)

diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
index ca952fd0829b..5f187f9efc7b 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
@@ -415,6 +415,8 @@ struct rkisp1_params {
 	spinlock_t config_lock; /* locks the buffers list 'params' */
 	struct list_head params;
 
+	struct v4l2_ctrl_handler ctrls;
+
 	const struct v4l2_meta_format *metafmt;
 
 	enum v4l2_quantization quantization;
diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
index b28f4140c8a3..b276926beb3c 100644
--- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
+++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
@@ -2736,6 +2736,44 @@ static int rkisp1_params_init_vb2_queue(struct vb2_queue *q,
 	return vb2_queue_init(q);
 }
 
+static int rkisp1_ctrl_init(struct rkisp1_params *params)
+{
+	struct v4l2_ctrl_config ctrl_config = {
+		.id = RKISP1_CID_SUPPORTED_PARAMS_BLOCKS,
+		.name = "Supported Params Blocks",
+		.type = V4L2_CTRL_TYPE_BITMASK,
+		.flags = V4L2_CTRL_FLAG_READ_ONLY,
+	};
+	int ret;
+
+	v4l2_ctrl_handler_init(&params->ctrls, 1);
+
+	for (unsigned int i = 0; i < ARRAY_SIZE(rkisp1_ext_params_handlers); i++) {
+		const struct rkisp1_ext_params_handler *block_handler;
+
+		block_handler = &rkisp1_ext_params_handlers[i];
+		ctrl_config.max |= BIT(i);
+
+		if ((params->rkisp1->info->features & block_handler->features) !=
+		    block_handler->features)
+			continue;
+
+		ctrl_config.def |= BIT(i);
+	}
+
+	v4l2_ctrl_new_custom(&params->ctrls, &ctrl_config, NULL);
+
+	params->vnode.vdev.ctrl_handler = &params->ctrls;
+
+	if (params->ctrls.error) {
+		ret = params->ctrls.error;
+		v4l2_ctrl_handler_free(&params->ctrls);
+		return ret;
+	}
+
+	return 0;
+}
+
 int rkisp1_params_register(struct rkisp1_device *rkisp1)
 {
 	struct rkisp1_params *params = &rkisp1->params;
@@ -2763,7 +2801,9 @@ int rkisp1_params_register(struct rkisp1_device *rkisp1)
 	vdev->queue = &node->buf_queue;
 	vdev->device_caps = V4L2_CAP_STREAMING | V4L2_CAP_META_OUTPUT;
 	vdev->vfl_dir = VFL_DIR_TX;
-	rkisp1_params_init_vb2_queue(vdev->queue, params);
+	ret = rkisp1_params_init_vb2_queue(vdev->queue, params);
+	if (ret)
+		goto err_media;
 
 	params->metafmt = &rkisp1_params_formats[RKISP1_PARAMS_FIXED];
 
@@ -2777,18 +2817,26 @@ int rkisp1_params_register(struct rkisp1_device *rkisp1)
 	node->pad.flags = MEDIA_PAD_FL_SOURCE;
 	ret = media_entity_pads_init(&vdev->entity, 1, &node->pad);
 	if (ret)
-		goto error;
+		goto err_media;
+
+	ret = rkisp1_ctrl_init(params);
+	if (ret) {
+		dev_err(rkisp1->dev, "Control initialization error %d\n", ret);
+		goto err_media;
+	}
 
 	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
 	if (ret) {
 		dev_err(rkisp1->dev,
 			"failed to register %s, ret=%d\n", vdev->name, ret);
-		goto error;
+		goto err_ctrl;
 	}
 
 	return 0;
 
-error:
+err_ctrl:
+	v4l2_ctrl_handler_free(&params->ctrls);
+err_media:
 	media_entity_cleanup(&vdev->entity);
 	mutex_destroy(&node->vlock);
 	return ret;
@@ -2804,6 +2852,7 @@ void rkisp1_params_unregister(struct rkisp1_device *rkisp1)
 		return;
 
 	vb2_video_unregister_device(vdev);
+	v4l2_ctrl_handler_free(&params->ctrls);
 	media_entity_cleanup(&vdev->entity);
 	mutex_destroy(&node->vlock);
 }
diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
index 2d995f3c1ca3..85c1b02f3f78 100644
--- a/include/uapi/linux/rkisp1-config.h
+++ b/include/uapi/linux/rkisp1-config.h
@@ -1086,6 +1086,9 @@ enum rkisp1_ext_params_block_type {
 #define RKISP1_EXT_PARAMS_FL_BLOCK_DISABLE	(1U << 0)
 #define RKISP1_EXT_PARAMS_FL_BLOCK_ENABLE	(1U << 1)
 
+/* A bitmask of parameters blocks supported on the current hardware. */
+#define RKISP1_CID_SUPPORTED_PARAMS_BLOCKS	(V4L2_CID_USER_RKISP1_BASE + 0x01)
+
 /**
  * struct rkisp1_ext_params_block_header - RkISP1 extensible parameters block
  *					   header
@@ -1520,6 +1523,12 @@ enum rksip1_ext_param_buffer_version {
  * V4L2 control. If such control is not available, userspace should assume only
  * RKISP1_EXT_PARAM_BUFFER_V1 is supported by the driver.
  *
+ * The read-only V4L2 control ``RKISP1_CID_SUPPORTED_PARAMS_BLOCKS`` can be used
+ * to query the blocks supported by the device. It contains a bitmask where each
+ * bit represents the availability of the corresponding entry from the
+ * :c:type:`rkisp1_ext_params_block_type` enum. The max value of the control
+ * represents the blocks supported by the kernel (independent of the device).
+ *
  * For each ISP block that userspace wants to configure, a block-specific
  * structure is appended to the @data buffer, one after the other without gaps
  * in between nor overlaps. Userspace shall populate the @data_size field with
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index 72e32814ea83..f836512e9deb 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -222,6 +222,12 @@ enum v4l2_colorfx {
  */
 #define V4L2_CID_USER_UVC_BASE			(V4L2_CID_USER_BASE + 0x11e0)
 
+/*
+ * The base for Rockchip ISP1 driver controls.
+ * We reserve 16 controls for this driver.
+ */
+#define V4L2_CID_USER_RKISP1_BASE		(V4L2_CID_USER_BASE + 0x1220)
+
 /* MPEG-class control IDs */
 /* The MPEG controls are applicable to all codec controls
  * and the 'MPEG' part of the define is historical */

-- 
2.43.0

Hi Stefan,

Thank you for the patch.

On Fri, May 23, 2025 at 12:07:31PM +0200, Stefan Klug wrote:
> Add a RKISP1_CID_SUPPORTED_PARAMS_BLOCKS V4L2 control to be able to
> query the parameters blocks supported by the current kernel on the
> current hardware from user space.
> 
> As a drive-by fix handle an (very unlikely) error in
> rkisp1_params_init_vb2_queue().

"While at it" changes are fine for very minor changes, but this is a fix
(even if it fixes a minor issue), so it should be a separate patch.

> Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
> Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> 
> ---
> 
> Changes in v2:
> - Added docs improvements from review
> - Moved ctrl_config declaration to top
> - Moved rkisp1_params_init_vb2_queue() return check into this patch as
>   the previous patch got dropped
> - Call rkisp1_ctrl_init() after media_entity_pads_init() for easier
>   error handling
> ---
>  .../media/platform/rockchip/rkisp1/rkisp1-common.h |  2 +
>  .../media/platform/rockchip/rkisp1/rkisp1-params.c | 57 ++++++++++++++++++++--
>  include/uapi/linux/rkisp1-config.h                 |  9 ++++
>  include/uapi/linux/v4l2-controls.h                 |  6 +++
>  4 files changed, 70 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
> index ca952fd0829b..5f187f9efc7b 100644
> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
> @@ -415,6 +415,8 @@ struct rkisp1_params {
>  	spinlock_t config_lock; /* locks the buffers list 'params' */
>  	struct list_head params;
>  
> +	struct v4l2_ctrl_handler ctrls;
> +
>  	const struct v4l2_meta_format *metafmt;
>  
>  	enum v4l2_quantization quantization;
> diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
> index b28f4140c8a3..b276926beb3c 100644
> --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
> +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
> @@ -2736,6 +2736,44 @@ static int rkisp1_params_init_vb2_queue(struct vb2_queue *q,
>  	return vb2_queue_init(q);
>  }
>  
> +static int rkisp1_ctrl_init(struct rkisp1_params *params)

s/rkisp1_ctrl_init/rkisp1_params_ctrl_init/

> +{
> +	struct v4l2_ctrl_config ctrl_config = {
> +		.id = RKISP1_CID_SUPPORTED_PARAMS_BLOCKS,
> +		.name = "Supported Params Blocks",
> +		.type = V4L2_CTRL_TYPE_BITMASK,
> +		.flags = V4L2_CTRL_FLAG_READ_ONLY,
> +	};
> +	int ret;
> +
> +	v4l2_ctrl_handler_init(&params->ctrls, 1);
> +
> +	for (unsigned int i = 0; i < ARRAY_SIZE(rkisp1_ext_params_handlers); i++) {
> +		const struct rkisp1_ext_params_handler *block_handler;
> +
> +		block_handler = &rkisp1_ext_params_handlers[i];
> +		ctrl_config.max |= BIT(i);
> +
> +		if ((params->rkisp1->info->features & block_handler->features) !=
> +		    block_handler->features)
> +			continue;
> +
> +		ctrl_config.def |= BIT(i);
> +	}
> +
> +	v4l2_ctrl_new_custom(&params->ctrls, &ctrl_config, NULL);
> +
> +	params->vnode.vdev.ctrl_handler = &params->ctrls;
> +
> +	if (params->ctrls.error) {
> +		ret = params->ctrls.error;
> +		v4l2_ctrl_handler_free(&params->ctrls);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>  int rkisp1_params_register(struct rkisp1_device *rkisp1)
>  {
>  	struct rkisp1_params *params = &rkisp1->params;
> @@ -2763,7 +2801,9 @@ int rkisp1_params_register(struct rkisp1_device *rkisp1)
>  	vdev->queue = &node->buf_queue;
>  	vdev->device_caps = V4L2_CAP_STREAMING | V4L2_CAP_META_OUTPUT;
>  	vdev->vfl_dir = VFL_DIR_TX;
> -	rkisp1_params_init_vb2_queue(vdev->queue, params);
> +	ret = rkisp1_params_init_vb2_queue(vdev->queue, params);
> +	if (ret)
> +		goto err_media;
>  
>  	params->metafmt = &rkisp1_params_formats[RKISP1_PARAMS_FIXED];
>  
> @@ -2777,18 +2817,26 @@ int rkisp1_params_register(struct rkisp1_device *rkisp1)
>  	node->pad.flags = MEDIA_PAD_FL_SOURCE;
>  	ret = media_entity_pads_init(&vdev->entity, 1, &node->pad);
>  	if (ret)
> -		goto error;
> +		goto err_media;
> +
> +	ret = rkisp1_ctrl_init(params);
> +	if (ret) {
> +		dev_err(rkisp1->dev, "Control initialization error %d\n", ret);
> +		goto err_media;
> +	}
>  
>  	ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
>  	if (ret) {
>  		dev_err(rkisp1->dev,
>  			"failed to register %s, ret=%d\n", vdev->name, ret);
> -		goto error;
> +		goto err_ctrl;
>  	}
>  
>  	return 0;
>  
> -error:
> +err_ctrl:
> +	v4l2_ctrl_handler_free(&params->ctrls);
> +err_media:
>  	media_entity_cleanup(&vdev->entity);
>  	mutex_destroy(&node->vlock);
>  	return ret;
> @@ -2804,6 +2852,7 @@ void rkisp1_params_unregister(struct rkisp1_device *rkisp1)
>  		return;
>  
>  	vb2_video_unregister_device(vdev);
> +	v4l2_ctrl_handler_free(&params->ctrls);
>  	media_entity_cleanup(&vdev->entity);
>  	mutex_destroy(&node->vlock);
>  }
> diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> index 2d995f3c1ca3..85c1b02f3f78 100644
> --- a/include/uapi/linux/rkisp1-config.h
> +++ b/include/uapi/linux/rkisp1-config.h
> @@ -1086,6 +1086,9 @@ enum rkisp1_ext_params_block_type {
>  #define RKISP1_EXT_PARAMS_FL_BLOCK_DISABLE	(1U << 0)
>  #define RKISP1_EXT_PARAMS_FL_BLOCK_ENABLE	(1U << 1)
>  
> +/* A bitmask of parameters blocks supported on the current hardware. */
> +#define RKISP1_CID_SUPPORTED_PARAMS_BLOCKS	(V4L2_CID_USER_RKISP1_BASE + 0x01)
> +
>  /**
>   * struct rkisp1_ext_params_block_header - RkISP1 extensible parameters block
>   *					   header
> @@ -1520,6 +1523,12 @@ enum rksip1_ext_param_buffer_version {
>   * V4L2 control. If such control is not available, userspace should assume only
>   * RKISP1_EXT_PARAM_BUFFER_V1 is supported by the driver.
>   *
> + * The read-only V4L2 control ``RKISP1_CID_SUPPORTED_PARAMS_BLOCKS`` can be used
> + * to query the blocks supported by the device. It contains a bitmask where each
> + * bit represents the availability of the corresponding entry from the
> + * :c:type:`rkisp1_ext_params_block_type` enum. The max value of the control
> + * represents the blocks supported by the kernel (independent of the device).

Have you seen my comment in v1 ?

 * from the :c:type:`rkisp1_ext_params_block_type` enum. The current and default
 * values of the control represents the blocks supported by the device instance,
 * while the maximum value represents the blocks supported by the kernel driver,
 * independently of the device instance.

> + *
>   * For each ISP block that userspace wants to configure, a block-specific
>   * structure is appended to the @data buffer, one after the other without gaps
>   * in between nor overlaps. Userspace shall populate the @data_size field with
> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> index 72e32814ea83..f836512e9deb 100644
> --- a/include/uapi/linux/v4l2-controls.h
> +++ b/include/uapi/linux/v4l2-controls.h
> @@ -222,6 +222,12 @@ enum v4l2_colorfx {
>   */
>  #define V4L2_CID_USER_UVC_BASE			(V4L2_CID_USER_BASE + 0x11e0)
>  
> +/*
> + * The base for Rockchip ISP1 driver controls.
> + * We reserve 16 controls for this driver.
> + */
> +#define V4L2_CID_USER_RKISP1_BASE		(V4L2_CID_USER_BASE + 0x1220)
> +
>  /* MPEG-class control IDs */
>  /* The MPEG controls are applicable to all codec controls
>   * and the 'MPEG' part of the define is historical */

-- 
Regards,

Laurent Pinchart

Hi Laurent,

Thank you for the review.

Quoting Laurent Pinchart (2025-05-23 12:33:46)
> Hi Stefan,
> 
> Thank you for the patch.
> 
> On Fri, May 23, 2025 at 12:07:31PM +0200, Stefan Klug wrote:
> > Add a RKISP1_CID_SUPPORTED_PARAMS_BLOCKS V4L2 control to be able to
> > query the parameters blocks supported by the current kernel on the
> > current hardware from user space.
> > 
> > As a drive-by fix handle an (very unlikely) error in
> > rkisp1_params_init_vb2_queue().
> 
> "While at it" changes are fine for very minor changes, but this is a fix
> (even if it fixes a minor issue), so it should be a separate patch.

Dang. It was so small that I even considered completely dropping it.
I'll wait a bit for further feedback and then post a v3 with the patch
split out again.

> 
> > Signed-off-by: Stefan Klug <stefan.klug@ideasonboard.com>
> > Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
> > 
> > ---
> > 
> > Changes in v2:
> > - Added docs improvements from review
> > - Moved ctrl_config declaration to top
> > - Moved rkisp1_params_init_vb2_queue() return check into this patch as
> >   the previous patch got dropped
> > - Call rkisp1_ctrl_init() after media_entity_pads_init() for easier
> >   error handling
> > ---
> >  .../media/platform/rockchip/rkisp1/rkisp1-common.h |  2 +
> >  .../media/platform/rockchip/rkisp1/rkisp1-params.c | 57 ++++++++++++++++++++--
> >  include/uapi/linux/rkisp1-config.h                 |  9 ++++
> >  include/uapi/linux/v4l2-controls.h                 |  6 +++
> >  4 files changed, 70 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
> > index ca952fd0829b..5f187f9efc7b 100644
> > --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
> > +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-common.h
> > @@ -415,6 +415,8 @@ struct rkisp1_params {
> >       spinlock_t config_lock; /* locks the buffers list 'params' */
> >       struct list_head params;
> >  
> > +     struct v4l2_ctrl_handler ctrls;
> > +
> >       const struct v4l2_meta_format *metafmt;
> >  
> >       enum v4l2_quantization quantization;
> > diff --git a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
> > index b28f4140c8a3..b276926beb3c 100644
> > --- a/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
> > +++ b/drivers/media/platform/rockchip/rkisp1/rkisp1-params.c
> > @@ -2736,6 +2736,44 @@ static int rkisp1_params_init_vb2_queue(struct vb2_queue *q,
> >       return vb2_queue_init(q);
> >  }
> >  
> > +static int rkisp1_ctrl_init(struct rkisp1_params *params)
> 
> s/rkisp1_ctrl_init/rkisp1_params_ctrl_init/
> 
> > +{
> > +     struct v4l2_ctrl_config ctrl_config = {
> > +             .id = RKISP1_CID_SUPPORTED_PARAMS_BLOCKS,
> > +             .name = "Supported Params Blocks",
> > +             .type = V4L2_CTRL_TYPE_BITMASK,
> > +             .flags = V4L2_CTRL_FLAG_READ_ONLY,
> > +     };
> > +     int ret;
> > +
> > +     v4l2_ctrl_handler_init(&params->ctrls, 1);
> > +
> > +     for (unsigned int i = 0; i < ARRAY_SIZE(rkisp1_ext_params_handlers); i++) {
> > +             const struct rkisp1_ext_params_handler *block_handler;
> > +
> > +             block_handler = &rkisp1_ext_params_handlers[i];
> > +             ctrl_config.max |= BIT(i);
> > +
> > +             if ((params->rkisp1->info->features & block_handler->features) !=
> > +                 block_handler->features)
> > +                     continue;
> > +
> > +             ctrl_config.def |= BIT(i);
> > +     }
> > +
> > +     v4l2_ctrl_new_custom(&params->ctrls, &ctrl_config, NULL);
> > +
> > +     params->vnode.vdev.ctrl_handler = &params->ctrls;
> > +
> > +     if (params->ctrls.error) {
> > +             ret = params->ctrls.error;
> > +             v4l2_ctrl_handler_free(&params->ctrls);
> > +             return ret;
> > +     }
> > +
> > +     return 0;
> > +}
> > +
> >  int rkisp1_params_register(struct rkisp1_device *rkisp1)
> >  {
> >       struct rkisp1_params *params = &rkisp1->params;
> > @@ -2763,7 +2801,9 @@ int rkisp1_params_register(struct rkisp1_device *rkisp1)
> >       vdev->queue = &node->buf_queue;
> >       vdev->device_caps = V4L2_CAP_STREAMING | V4L2_CAP_META_OUTPUT;
> >       vdev->vfl_dir = VFL_DIR_TX;
> > -     rkisp1_params_init_vb2_queue(vdev->queue, params);
> > +     ret = rkisp1_params_init_vb2_queue(vdev->queue, params);
> > +     if (ret)
> > +             goto err_media;
> >  
> >       params->metafmt = &rkisp1_params_formats[RKISP1_PARAMS_FIXED];
> >  
> > @@ -2777,18 +2817,26 @@ int rkisp1_params_register(struct rkisp1_device *rkisp1)
> >       node->pad.flags = MEDIA_PAD_FL_SOURCE;
> >       ret = media_entity_pads_init(&vdev->entity, 1, &node->pad);
> >       if (ret)
> > -             goto error;
> > +             goto err_media;
> > +
> > +     ret = rkisp1_ctrl_init(params);
> > +     if (ret) {
> > +             dev_err(rkisp1->dev, "Control initialization error %d\n", ret);
> > +             goto err_media;
> > +     }
> >  
> >       ret = video_register_device(vdev, VFL_TYPE_VIDEO, -1);
> >       if (ret) {
> >               dev_err(rkisp1->dev,
> >                       "failed to register %s, ret=%d\n", vdev->name, ret);
> > -             goto error;
> > +             goto err_ctrl;
> >       }
> >  
> >       return 0;
> >  
> > -error:
> > +err_ctrl:
> > +     v4l2_ctrl_handler_free(&params->ctrls);
> > +err_media:
> >       media_entity_cleanup(&vdev->entity);
> >       mutex_destroy(&node->vlock);
> >       return ret;
> > @@ -2804,6 +2852,7 @@ void rkisp1_params_unregister(struct rkisp1_device *rkisp1)
> >               return;
> >  
> >       vb2_video_unregister_device(vdev);
> > +     v4l2_ctrl_handler_free(&params->ctrls);
> >       media_entity_cleanup(&vdev->entity);
> >       mutex_destroy(&node->vlock);
> >  }
> > diff --git a/include/uapi/linux/rkisp1-config.h b/include/uapi/linux/rkisp1-config.h
> > index 2d995f3c1ca3..85c1b02f3f78 100644
> > --- a/include/uapi/linux/rkisp1-config.h
> > +++ b/include/uapi/linux/rkisp1-config.h
> > @@ -1086,6 +1086,9 @@ enum rkisp1_ext_params_block_type {
> >  #define RKISP1_EXT_PARAMS_FL_BLOCK_DISABLE   (1U << 0)
> >  #define RKISP1_EXT_PARAMS_FL_BLOCK_ENABLE    (1U << 1)
> >  
> > +/* A bitmask of parameters blocks supported on the current hardware. */
> > +#define RKISP1_CID_SUPPORTED_PARAMS_BLOCKS   (V4L2_CID_USER_RKISP1_BASE + 0x01)
> > +
> >  /**
> >   * struct rkisp1_ext_params_block_header - RkISP1 extensible parameters block
> >   *                                      header
> > @@ -1520,6 +1523,12 @@ enum rksip1_ext_param_buffer_version {
> >   * V4L2 control. If such control is not available, userspace should assume only
> >   * RKISP1_EXT_PARAM_BUFFER_V1 is supported by the driver.
> >   *
> > + * The read-only V4L2 control ``RKISP1_CID_SUPPORTED_PARAMS_BLOCKS`` can be used
> > + * to query the blocks supported by the device. It contains a bitmask where each
> > + * bit represents the availability of the corresponding entry from the
> > + * :c:type:`rkisp1_ext_params_block_type` enum. The max value of the control
> > + * represents the blocks supported by the kernel (independent of the device).
> 
> Have you seen my comment in v1 ?
> 
>  * from the :c:type:`rkisp1_ext_params_block_type` enum. The current and default
>  * values of the control represents the blocks supported by the device instance,
>  * while the maximum value represents the blocks supported by the kernel driver,
>  * independently of the device instance.

Oh sorry, I missed those lines. I'll add them in v3.

Best regards,
Stefan

> 
> > + *
> >   * For each ISP block that userspace wants to configure, a block-specific
> >   * structure is appended to the @data buffer, one after the other without gaps
> >   * in between nor overlaps. Userspace shall populate the @data_size field with
> > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> > index 72e32814ea83..f836512e9deb 100644
> > --- a/include/uapi/linux/v4l2-controls.h
> > +++ b/include/uapi/linux/v4l2-controls.h
> > @@ -222,6 +222,12 @@ enum v4l2_colorfx {
> >   */
> >  #define V4L2_CID_USER_UVC_BASE                       (V4L2_CID_USER_BASE + 0x11e0)
> >  
> > +/*
> > + * The base for Rockchip ISP1 driver controls.
> > + * We reserve 16 controls for this driver.
> > + */
> > +#define V4L2_CID_USER_RKISP1_BASE            (V4L2_CID_USER_BASE + 0x1220)
> > +
> >  /* MPEG-class control IDs */
> >  /* The MPEG controls are applicable to all codec controls
> >   * and the 'MPEG' part of the define is historical */
> 
> -- 
> Regards,
> 
> Laurent Pinchart