[RFC,v5,08/11] media: uapi: Add audio rate controls support

Audio rate controls is used for user to configure
the audio sample rate to driver.

Add V4L2_CID_ASRC_SOURCE_RATE and V4L2_CID_ASRC_DEST_RATE
new ID for ASRC rate control.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
---
 .../userspace-api/media/v4l/common.rst        |  1 +
 .../media/v4l/ext-ctrls-asrc-rate.rst         | 36 +++++++++++++++++++
 .../media/v4l/vidioc-g-ext-ctrls.rst          |  4 +++
 .../media/v4l/vidioc-queryctrl.rst            |  7 ++++
 .../media/videodev2.h.rst.exceptions          |  1 +
 drivers/media/v4l2-core/v4l2-ctrls-core.c     |  5 +++
 drivers/media/v4l2-core/v4l2-ctrls-defs.c     |  4 +++
 include/media/v4l2-ctrls.h                    |  1 +
 include/uapi/linux/v4l2-controls.h            | 13 +++++++
 include/uapi/linux/videodev2.h                |  1 +
 10 files changed, 73 insertions(+)
 create mode 100644 Documentation/userspace-api/media/v4l/ext-ctrls-asrc-rate.rst

On 28/09/2023 11:00, Shengjiu Wang wrote:
> Audio rate controls is used for user to configure

is -> are
for -> by the

> the audio sample rate to driver.
> 
> Add V4L2_CID_ASRC_SOURCE_RATE and V4L2_CID_ASRC_DEST_RATE
> new ID for ASRC rate control.

ID -> IDs

> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> ---
>  .../userspace-api/media/v4l/common.rst        |  1 +
>  .../media/v4l/ext-ctrls-asrc-rate.rst         | 36 +++++++++++++++++++
>  .../media/v4l/vidioc-g-ext-ctrls.rst          |  4 +++
>  .../media/v4l/vidioc-queryctrl.rst            |  7 ++++
>  .../media/videodev2.h.rst.exceptions          |  1 +
>  drivers/media/v4l2-core/v4l2-ctrls-core.c     |  5 +++
>  drivers/media/v4l2-core/v4l2-ctrls-defs.c     |  4 +++
>  include/media/v4l2-ctrls.h                    |  1 +
>  include/uapi/linux/v4l2-controls.h            | 13 +++++++
>  include/uapi/linux/videodev2.h                |  1 +
>  10 files changed, 73 insertions(+)
>  create mode 100644 Documentation/userspace-api/media/v4l/ext-ctrls-asrc-rate.rst
> 
> diff --git a/Documentation/userspace-api/media/v4l/common.rst b/Documentation/userspace-api/media/v4l/common.rst
> index ea0435182e44..fe6cd7ae60e4 100644
> --- a/Documentation/userspace-api/media/v4l/common.rst
> +++ b/Documentation/userspace-api/media/v4l/common.rst
> @@ -52,6 +52,7 @@ applicable to all devices.
>      ext-ctrls-fm-rx
>      ext-ctrls-detect
>      ext-ctrls-colorimetry
> +    ext-ctrls-asrc-rate
>      fourcc
>      format
>      planar-apis
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-asrc-rate.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-asrc-rate.rst
> new file mode 100644
> index 000000000000..28bf9e1628e1
> --- /dev/null
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-asrc-rate.rst
> @@ -0,0 +1,36 @@
> +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
> +
> +.. _asrc-rate-controls:
> +
> +***************************
> +ASRC RATE Control Reference

RATE -> Rate

> +***************************
> +
> +These controls is intended to support asynchronous sample

is -> are
support -> support an

> +rate converter.
> +
> +.. _v4l2-audio-asrc:
> +
> +``V4L2_CID_ASRC_SOURCE_RATE``
> +    sets the rasampler source rate.

You mean 'resampler'?

> +
> +``V4L2_CID_ASRC_DEST_RATE``
> +    sets the rasampler destination rate.

Ditto

> +
> +.. c:type:: v4l2_ctrl_asrc_rate
> +
> +.. cssclass:: longtable
> +
> +.. tabularcolumns:: |p{1.5cm}|p{5.8cm}|p{10.0cm}|
> +
> +.. flat-table:: struct v4l2_ctrl_asrc_rate
> +    :header-rows:  0
> +    :stub-columns: 0
> +    :widths:       1 1 2
> +
> +    * - __u32
> +      - ``rate_integer``
> +      - integer part of sample rate.
> +    * - __s32
> +      - ``rate_fractional``
> +      - fractional part of sample rate, which is Q31.
> diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst
> index f9f73530a6be..93ce15330490 100644
> --- a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst
> +++ b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst
> @@ -295,6 +295,10 @@ still cause this situation.
>        - ``p_av1_film_grain``
>        - A pointer to a struct :c:type:`v4l2_ctrl_av1_film_grain`. Valid if this control is
>          of type ``V4L2_CTRL_TYPE_AV1_FILM_GRAIN``.
> +    * - struct :c:type:`v4l2_ctrl_asrc_rate` *
> +      - ``p_asrc_rate``
> +      - A pointer to a struct :c:type:`v4l2_ctrl_asrc_rate`. Valid if this control is
> +        of type ``V4L2_CTRL_TYPE_ASRC_RATE``.
>      * - void *
>        - ``ptr``
>        - A pointer to a compound type which can be an N-dimensional array
> diff --git a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> index 4d38acafe8e1..8c15a0bb0fbc 100644
> --- a/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> +++ b/Documentation/userspace-api/media/v4l/vidioc-queryctrl.rst
> @@ -549,6 +549,13 @@ See also the examples in :ref:`control`.
>        - n/a
>        - A struct :c:type:`v4l2_ctrl_av1_film_grain`, containing AV1 Film Grain
>          parameters for stateless video decoders.
> +    * - ``V4L2_CTRL_TYPE_ASRC_RATE``
> +      - n/a
> +      - n/a
> +      - n/a
> +      - A struct :c:type:`v4l2_ctrl_asrc_rate`, containing audio
> +        parameters for asrc component.
> +

You relate the name of the type to the controls that use it, but I think
the type should be about the actual value it carries. So:

V4L2_CTRL_TYPE_FRACTIONAL

I.e. it is the type for a fractional value and it can be used by any
control that would need a fractional value.

Note: I'm not sure if 'fractional' is the best name. Perhaps 'FIXED_POINT'
would be better? Suggestions welcome.

>  
>  .. raw:: latex
>  
> diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> index e61152bb80d1..769e333a2b75 100644
> --- a/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> +++ b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
> @@ -167,6 +167,7 @@ replace symbol V4L2_CTRL_TYPE_AV1_SEQUENCE :c:type:`v4l2_ctrl_type`
>  replace symbol V4L2_CTRL_TYPE_AV1_TILE_GROUP_ENTRY :c:type:`v4l2_ctrl_type`
>  replace symbol V4L2_CTRL_TYPE_AV1_FRAME :c:type:`v4l2_ctrl_type`
>  replace symbol V4L2_CTRL_TYPE_AV1_FILM_GRAIN :c:type:`v4l2_ctrl_type`
> +replace symbol V4L2_CTRL_TYPE_ASRC_RATE :c:type:`v4l2_ctrl_type`
>  
>  # V4L2 capability defines
>  replace define V4L2_CAP_VIDEO_CAPTURE device-capabilities
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-core.c b/drivers/media/v4l2-core/v4l2-ctrls-core.c
> index a662fb60f73f..2a72779f3508 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-core.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-core.c
> @@ -1168,6 +1168,8 @@ static int std_validate_compound(const struct v4l2_ctrl *ctrl, u32 idx,
>  		if (!area->width || !area->height)
>  			return -EINVAL;
>  		break;
> +	case V4L2_CTRL_TYPE_ASRC_RATE:
> +		break;
>  
>  	default:
>  		return -EINVAL;
> @@ -1868,6 +1870,9 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>  	case V4L2_CTRL_TYPE_AREA:
>  		elem_size = sizeof(struct v4l2_area);
>  		break;
> +	case V4L2_CTRL_TYPE_ASRC_RATE:
> +		elem_size = sizeof(struct v4l2_ctrl_asrc_rate);
> +		break;
>  	default:
>  		if (type < V4L2_CTRL_COMPOUND_TYPES)
>  			elem_size = sizeof(s32);
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> index 8696eb1cdd61..84766037db80 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> @@ -1602,6 +1602,10 @@ void v4l2_ctrl_fill(u32 id, const char **name, enum v4l2_ctrl_type *type,
>  	case V4L2_CID_COLORIMETRY_HDR10_MASTERING_DISPLAY:
>  		*type = V4L2_CTRL_TYPE_HDR10_MASTERING_DISPLAY;
>  		break;
> +	case V4L2_CID_ASRC_SOURCE_RATE:
> +	case V4L2_CID_ASRC_DEST_RATE:
> +		*type = V4L2_CTRL_TYPE_ASRC_RATE;
> +		break;
>  	default:
>  		*type = V4L2_CTRL_TYPE_INTEGER;
>  		break;
> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> index 59679a42b3e7..40475965f8e4 100644
> --- a/include/media/v4l2-ctrls.h
> +++ b/include/media/v4l2-ctrls.h
> @@ -89,6 +89,7 @@ union v4l2_ctrl_ptr {
>  	struct v4l2_ctrl_av1_tile_group_entry *p_av1_tile_group_entry;
>  	struct v4l2_ctrl_av1_frame *p_av1_frame;
>  	struct v4l2_ctrl_av1_film_grain *p_av1_film_grain;
> +	struct v4l2_ctrl_asrc_rate *p_asrc_rate;
>  	void *p;
>  	const void *p_const;
>  };
> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> index c3604a0a3e30..a08be3bd5977 100644
> --- a/include/uapi/linux/v4l2-controls.h
> +++ b/include/uapi/linux/v4l2-controls.h
> @@ -112,6 +112,8 @@ enum v4l2_colorfx {
>  
>  /* last CID + 1 */
>  #define V4L2_CID_LASTP1                         (V4L2_CID_BASE+44)
> +#define V4L2_CID_ASRC_SOURCE_RATE		(V4L2_CID_BASE + 45)
> +#define V4L2_CID_ASRC_DEST_RATE			(V4L2_CID_BASE + 46)
>  
>  /* USER-class private control IDs */
>  
> @@ -3488,4 +3490,15 @@ struct v4l2_ctrl_av1_film_grain {
>  #define V4L2_CID_MPEG_MFC51_BASE        V4L2_CID_CODEC_MFC51_BASE
>  #endif
>  
> +/**
> + * struct v4l2_ctrl_asrc_rate - ASRC sample rate.
> + *
> + * @rate_integer: integer part of rate.
> + * @rate_fractional: fractional part of rate, most time may be zero
> + */
> +struct v4l2_ctrl_asrc_rate {
> +	__u32 rate_integer;
> +	__u32 rate_fractional;
> +};
> +
>  #endif
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 3630f50eedb1..166c51f537cc 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -1840,6 +1840,7 @@ struct v4l2_ext_control {
>  		struct v4l2_ctrl_av1_tile_group_entry __user *p_av1_tile_group_entry;
>  		struct v4l2_ctrl_av1_frame __user *p_av1_frame;
>  		struct v4l2_ctrl_av1_film_grain __user *p_av1_film_grain;
> +		struct v4l2_ctrl_asrc_rate __user *p_asrc_rate;
>  		void __user *ptr;
>  	};
>  } __attribute__ ((packed));

Regards,

	Hans