[RFC PATCH v6 09/11] media: uapi: Add audio rate controls support

From: Shengjiu Wang
Date: Fri Oct 13 2023 - 05:10:00 EST


Fixed point controls are used by the user to configure
the audio sample rate to driver.

Add V4L2_CID_ASRC_SOURCE_RATE and V4L2_CID_ASRC_DEST_RATE
new IDs for ASRC rate control.

Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
---
.../userspace-api/media/v4l/common.rst | 1 +
.../media/v4l/ext-ctrls-fixed-point.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 | 2 ++
include/uapi/linux/v4l2-controls.h | 13 +++++++
include/uapi/linux/videodev2.h | 3 ++
10 files changed, 76 insertions(+)
create mode 100644 Documentation/userspace-api/media/v4l/ext-ctrls-fixed-point.rst

diff --git a/Documentation/userspace-api/media/v4l/common.rst b/Documentation/userspace-api/media/v4l/common.rst
index ea0435182e44..35707edffb13 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-fixed-point
fourcc
format
planar-apis
diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-fixed-point.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-fixed-point.rst
new file mode 100644
index 000000000000..2ef6e250580c
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/ext-ctrls-fixed-point.rst
@@ -0,0 +1,36 @@
+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+
+.. _fixed-point-controls:
+
+***************************
+Fixed Point Control Reference
+***************************
+
+These controls are intended to support an asynchronous sample
+rate converter.
+
+.. _v4l2-audio-asrc:
+
+``V4L2_CID_ASRC_SOURCE_RATE``
+ sets the resampler source rate.
+
+``V4L2_CID_ASRC_DEST_RATE``
+ sets the resampler destination rate.
+
+.. c:type:: v4l2_ctrl_fixed_point
+
+.. cssclass:: longtable
+
+.. tabularcolumns:: |p{1.5cm}|p{5.8cm}|p{10.0cm}|
+
+.. flat-table:: struct v4l2_ctrl_fixed_point
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 1 1 2
+
+ * - __u32
+ - ``integer``
+ - integer part of fixed point value.
+ * - __s32
+ - ``fractional``
+ - fractional part of fixed point value, 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..1811dabf5c74 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_fixed_point` *
+ - ``p_fixed_point``
+ - A pointer to a struct :c:type:`v4l2_ctrl_fixed_point`. Valid if this control is
+ of type ``V4L2_CTRL_TYPE_FIXED_POINT``.
* - 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..9285f4f39eed 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_FIXED_POINT``
+ - n/a
+ - n/a
+ - n/a
+ - A struct :c:type:`v4l2_ctrl_fixed_point`, containing parameter which has
+ integer part and fractional part, i.e. audio sample rate.
+

.. raw:: latex

diff --git a/Documentation/userspace-api/media/videodev2.h.rst.exceptions b/Documentation/userspace-api/media/videodev2.h.rst.exceptions
index e61152bb80d1..2faa5a2015eb 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_FIXED_POINT :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..7a616ac91059 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_FIXED_POINT:
+ 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_FIXED_POINT:
+ elem_size = sizeof(struct v4l2_ctrl_fixed_point);
+ 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..d8f232df6b6a 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_FIXED_POINT;
+ break;
default:
*type = V4L2_CTRL_TYPE_INTEGER;
break;
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 59679a42b3e7..645e4cccafc7 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -56,6 +56,7 @@ struct video_device;
* @p_av1_tile_group_entry: Pointer to an AV1 tile group entry structure.
* @p_av1_frame: Pointer to an AV1 frame structure.
* @p_av1_film_grain: Pointer to an AV1 film grain structure.
+ * @p_fixed_point: Pointer to a struct v4l2_ctrl_fixed_point.
* @p: Pointer to a compound value.
* @p_const: Pointer to a constant compound value.
*/
@@ -89,6 +90,7 @@ 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_fixed_point *p_fixed_point;
void *p;
const void *p_const;
};
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index c3604a0a3e30..91096259e3ea 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_fixed_point - fixed point parameter.
+ *
+ * @rate_integer: integer part of fixed point value.
+ * @rate_fractional: fractional part of fixed point value
+ */
+struct v4l2_ctrl_fixed_point {
+ __u32 integer;
+ __u32 fractional;
+};
+
#endif
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 2ac7b989394c..3ef32c09c2fa 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -1888,6 +1888,7 @@ 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_fixed_point __user *p_fixed_point;
void __user *ptr;
};
} __attribute__ ((packed));
@@ -1966,6 +1967,8 @@ enum v4l2_ctrl_type {
V4L2_CTRL_TYPE_AV1_TILE_GROUP_ENTRY = 0x281,
V4L2_CTRL_TYPE_AV1_FRAME = 0x282,
V4L2_CTRL_TYPE_AV1_FILM_GRAIN = 0x283,
+
+ V4L2_CTRL_TYPE_FIXED_POINT = 0x290,
};

/* Used in the VIDIOC_QUERYCTRL ioctl for querying controls */
--
2.34.1