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[RFC,v7,00/13] Add audio support in v4l2 framework

Message ID 1697794232-2607-1-git-send-email-shengjiu.wang@nxp.com
Headers show
Series Add audio support in v4l2 framework | expand

Message

Shengjiu Wang Oct. 20, 2023, 9:30 a.m. UTC
Audio signal processing also has the requirement for memory to
memory similar as Video.

This asrc memory to memory (memory ->asrc->memory) case is a non
real time use case.

User fills the input buffer to the asrc module, after conversion, then asrc
sends back the output buffer to user. So it is not a traditional ALSA playback
and capture case.

It is a specific use case,  there is no reference in current kernel.
v4l2 memory to memory is the closed implementation,  v4l2 current
support video, image, radio, tuner, touch devices, so it is not
complicated to add support for this specific audio case.

Because we had implemented the "memory -> asrc ->i2s device-> codec"
use case in ALSA.  Now the "memory->asrc->memory" needs
to reuse the code in asrc driver, so the first 3 patches is for refining
the code to make it can be shared by the "memory->asrc->memory"
driver.

The main change is in the v4l2 side, A /dev/vl4-audioX will be created,
user applications only use the ioctl of v4l2 framework.

Other change is to add memory to memory support for two kinds of i.MX ASRC
module.

changes in v7:
- add acked-by from Mark
- separate commit for fixed point, m2m audio class, audio rate controls
- use INTEGER_MENU for rate,  FIXED_POINT for rate offset
- remove used fmts
- address other comments for Hans

changes in v6:
- use m2m_prepare/m2m_unprepare/m2m_start/m2m_stop to replace
  m2m_start_part_one/m2m_stop_part_one, m2m_start_part_two/m2m_stop_part_two.
- change V4L2_CTRL_TYPE_ASRC_RATE to V4L2_CTRL_TYPE_FIXED_POINT
- fix warning by kernel test rebot
- remove some unused format V4L2_AUDIO_FMT_XX
- Get SNDRV_PCM_FORMAT from V4L2_AUDIO_FMT in driver.
- rename audm2m to viaudm2m.

changes in v5:
- remove V4L2_AUDIO_FMT_LPCM
- define audio pixel format like V4L2_AUDIO_FMT_S8...
- remove rate and format in struct v4l2_audio_format.
- Add V4L2_CID_ASRC_SOURCE_RATE and V4L2_CID_ASRC_DEST_RATE controls
- updata document accordingly.

changes in v4:
- update document style
- separate V4L2_AUDIO_FMT_LPCM and V4L2_CAP_AUDIO_M2M in separate commit

changes in v3:
- Modify documents for adding audio m2m support
- Add audio virtual m2m driver
- Defined V4L2_AUDIO_FMT_LPCM format type for audio.
- Defined V4L2_CAP_AUDIO_M2M capability type for audio m2m case.
- with modification in v4l-utils, pass v4l2-compliance test.

changes in v2:
- decouple the implementation in v4l2 and ALSA
- implement the memory to memory driver as a platfrom driver
  and move it to driver/media
- move fsl_asrc_common.h to include/sound folder

Shengjiu Wang (13):
  ASoC: fsl_asrc: define functions for memory to memory usage
  ASoC: fsl_easrc: define functions for memory to memory usage
  ASoC: fsl_asrc: move fsl_asrc_common.h to include/sound
  ASoC: fsl_asrc: register m2m platform device
  ASoC: fsl_easrc: register m2m platform device
  media: uapi: Add V4L2_CAP_AUDIO_M2M capability flag
  media: v4l2: Add audio capture and output support
  media: uapi: define audio sample format fourcc type
  media: uapi: Add V4L2_CTRL_CLASS_M2M_AUDIO
  media: uapi: Add V4L2_CTRL_TYPE_FIXED_POINT
  media: uapi: Add audio rate controls support
  media: imx-asrc: Add memory to memory driver
  media: vim2m_audio: add virtual driver for audio memory to memory

 .../userspace-api/media/v4l/buffer.rst        |    6 +
 .../userspace-api/media/v4l/common.rst        |    1 +
 .../media/v4l/dev-audio-mem2mem.rst           |   71 +
 .../userspace-api/media/v4l/devices.rst       |    1 +
 .../media/v4l/ext-ctrls-audio-m2m.rst         |   39 +
 .../userspace-api/media/v4l/pixfmt-audio.rst  |   87 ++
 .../userspace-api/media/v4l/pixfmt.rst        |    1 +
 .../media/v4l/vidioc-enum-fmt.rst             |    2 +
 .../media/v4l/vidioc-g-ext-ctrls.rst          |    4 +
 .../userspace-api/media/v4l/vidioc-g-fmt.rst  |    4 +
 .../media/v4l/vidioc-querycap.rst             |    3 +
 .../media/v4l/vidioc-queryctrl.rst            |    6 +
 .../media/videodev2.h.rst.exceptions          |    4 +
 .../media/common/videobuf2/videobuf2-v4l2.c   |    4 +
 drivers/media/platform/nxp/Kconfig            |   12 +
 drivers/media/platform/nxp/Makefile           |    1 +
 drivers/media/platform/nxp/imx-asrc.c         | 1207 +++++++++++++++++
 drivers/media/test-drivers/Kconfig            |    9 +
 drivers/media/test-drivers/Makefile           |    1 +
 drivers/media/test-drivers/vim2m_audio.c      |  680 ++++++++++
 drivers/media/v4l2-core/v4l2-ctrls-api.c      |    5 +-
 drivers/media/v4l2-core/v4l2-ctrls-core.c     |    2 +
 drivers/media/v4l2-core/v4l2-ctrls-defs.c     |   16 +
 drivers/media/v4l2-core/v4l2-dev.c            |   17 +
 drivers/media/v4l2-core/v4l2-ioctl.c          |   66 +
 include/media/v4l2-dev.h                      |    2 +
 include/media/v4l2-ioctl.h                    |   34 +
 .../fsl => include/sound}/fsl_asrc_common.h   |   60 +
 include/uapi/linux/v4l2-controls.h            |    9 +
 include/uapi/linux/videodev2.h                |   42 +
 sound/soc/fsl/fsl_asrc.c                      |  144 ++
 sound/soc/fsl/fsl_asrc.h                      |    4 +-
 sound/soc/fsl/fsl_asrc_dma.c                  |    2 +-
 sound/soc/fsl/fsl_easrc.c                     |  233 ++++
 sound/soc/fsl/fsl_easrc.h                     |    6 +-
 35 files changed, 2781 insertions(+), 4 deletions(-)
 create mode 100644 Documentation/userspace-api/media/v4l/dev-audio-mem2mem.rst
 create mode 100644 Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
 create mode 100644 Documentation/userspace-api/media/v4l/pixfmt-audio.rst
 create mode 100644 drivers/media/platform/nxp/imx-asrc.c
 create mode 100644 drivers/media/test-drivers/vim2m_audio.c
 rename {sound/soc/fsl => include/sound}/fsl_asrc_common.h (60%)

Comments

Hans Verkuil Oct. 25, 2023, 10:47 a.m. UTC | #1
On 20/10/2023 11:30, Shengjiu Wang wrote:
> Add V4L2_CID_M2M_AUDIO_SOURCE_RATE and V4L2_CID_M2M_AUDIO_DEST_RATE
> new IDs for rate control.
> 
> Add V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET and
> V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET for clock drift.
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> ---
>  .../media/v4l/ext-ctrls-audio-m2m.rst          | 18 ++++++++++++++++++
>  drivers/media/v4l2-core/v4l2-ctrls-defs.c      | 12 ++++++++++++
>  include/uapi/linux/v4l2-controls.h             |  5 +++++
>  3 files changed, 35 insertions(+)
> 
> diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
> index 82d2ecedbfee..e6972a2d3b17 100644
> --- a/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
> +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
> @@ -19,3 +19,21 @@ Audio M2M Control IDs
>      The Audio M2M class descriptor. Calling
>      :ref:`VIDIOC_QUERYCTRL` for this control will
>      return a description of this control class.
> +
> +.. _v4l2-audio-asrc:
> +
> +``V4L2_CID_M2M_AUDIO_SOURCE_RATE``

Add ' (integer menu)' after the name.

> +    Sets the audio source rate, unit is (Hz)

(Hz) -> Hz.

General question: is 'rate' good enough or should it be 'sample rate'?

> +
> +``V4L2_CID_M2M_AUDIO_DEST_RATE``
> +    Sets the audio destination rate, unit is (Hz)

Ditto here.

> +
> +``V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET``

Add ' (fixed point)' after the name.

> +    Sets the offset for audio source rate, unit is (Hz).

for -> from the

(Hz) -> Hz

> +    Offset expresses the drift of clock if there is. It is
> +    equal to real rate minus ideal rate.

How about:

The offset compensates for any clock drift. The actual source audio
rate is the ideal source audio rate from ``V4L2_CID_M2M_AUDIO_SOURCE_RATE``
plus this fixed point offset.

> +
> +``V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET``
> +    Sets the offset for audio destination rate, unit is (Hz)
> +    Offset expresses the drift of clock if there is. It is
> +    equal to real rate minus ideal rate.

Same changes as for V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET.

> diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> index 2a85ea3dc92f..b695cbdd1f6e 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> @@ -1245,6 +1245,10 @@ const char *v4l2_ctrl_get_name(u32 id)
>  
>  	/* Audio M2M controls */
>  	case V4L2_CID_M2M_AUDIO_CLASS:  return "Audio M2M Controls";
> +	case V4L2_CID_M2M_AUDIO_SOURCE_RATE:	return "Audio Source Sample Rate";
> +	case V4L2_CID_M2M_AUDIO_DEST_RATE:	return "Audio Dest Sample Rate";
> +	case V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET:	return "Audio Source Sample Rate Offset";
> +	case V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET:	return "Audio Dest Sample Rate Offset";

Related to my question above: "Sample Rate" or just "Rate"? Whatever we pick, it should
be consistent.

>  	default:
>  		return NULL;
>  	}
> @@ -1606,6 +1610,14 @@ 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_M2M_AUDIO_SOURCE_RATE:
> +	case V4L2_CID_M2M_AUDIO_DEST_RATE:
> +		*type = V4L2_CTRL_TYPE_INTEGER_MENU;
> +		break;
> +	case V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET:
> +	case V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET:
> +		*type = V4L2_CTRL_TYPE_FIXED_POINT;
> +		break;
>  	default:
>  		*type = V4L2_CTRL_TYPE_INTEGER;
>  		break;
> diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> index eb0f0a76f867..d433c6f0b533 100644
> --- a/include/uapi/linux/v4l2-controls.h
> +++ b/include/uapi/linux/v4l2-controls.h
> @@ -3498,4 +3498,9 @@ struct v4l2_ctrl_av1_film_grain {
>  #define V4L2_CID_M2M_AUDIO_CLASS_BASE  (V4L2_CTRL_CLASS_M2M_AUDIO | 0x900)
>  #define V4L2_CID_M2M_AUDIO_CLASS       (V4L2_CTRL_CLASS_M2M_AUDIO | 1)
>  
> +#define V4L2_CID_M2M_AUDIO_SOURCE_RATE	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 0)
> +#define V4L2_CID_M2M_AUDIO_DEST_RATE	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 1)
> +#define V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 2)
> +#define V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET	(V4L2_CID_M2M_AUDIO_CLASS_BASE + 3)
> +
>  #endif

Regards,

	Hans
Hans Verkuil Oct. 25, 2023, 11:01 a.m. UTC | #2
On 20/10/2023 11:30, Shengjiu Wang wrote:
> Implement the ASRC memory to memory function using
> the v4l2 framework, user can use this function with
> v4l2 ioctl interface.
> 
> User send the output and capture buffer to driver and
> driver store the converted data to the capture buffer.
> 
> This feature can be shared by ASRC and EASRC drivers
> 
> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> ---
>  drivers/media/platform/nxp/Kconfig    |   12 +
>  drivers/media/platform/nxp/Makefile   |    1 +
>  drivers/media/platform/nxp/imx-asrc.c | 1207 +++++++++++++++++++++++++
>  3 files changed, 1220 insertions(+)
>  create mode 100644 drivers/media/platform/nxp/imx-asrc.c
> 
> diff --git a/drivers/media/platform/nxp/Kconfig b/drivers/media/platform/nxp/Kconfig
> index 40e3436669e2..8234644ee341 100644
> --- a/drivers/media/platform/nxp/Kconfig
> +++ b/drivers/media/platform/nxp/Kconfig
> @@ -67,3 +67,15 @@ config VIDEO_MX2_EMMAPRP
>  
>  source "drivers/media/platform/nxp/dw100/Kconfig"
>  source "drivers/media/platform/nxp/imx-jpeg/Kconfig"
> +
> +config VIDEO_IMX_ASRC
> +	tristate "NXP i.MX ASRC M2M support"
> +	depends on V4L_MEM2MEM_DRIVERS
> +	depends on MEDIA_SUPPORT
> +	select VIDEOBUF2_DMA_CONTIG
> +	select V4L2_MEM2MEM_DEV
> +	help
> +	    Say Y if you want to add ASRC M2M support for NXP CPUs.
> +	    It is a complement for ASRC M2P and ASRC P2M features.
> +	    This option is only useful for out-of-tree drivers since
> +	    in-tree drivers select it automatically.
> diff --git a/drivers/media/platform/nxp/Makefile b/drivers/media/platform/nxp/Makefile
> index 4d90eb713652..1325675e34f5 100644
> --- a/drivers/media/platform/nxp/Makefile
> +++ b/drivers/media/platform/nxp/Makefile
> @@ -9,3 +9,4 @@ obj-$(CONFIG_VIDEO_IMX8MQ_MIPI_CSI2) += imx8mq-mipi-csi2.o
>  obj-$(CONFIG_VIDEO_IMX_MIPI_CSIS) += imx-mipi-csis.o
>  obj-$(CONFIG_VIDEO_IMX_PXP) += imx-pxp.o
>  obj-$(CONFIG_VIDEO_MX2_EMMAPRP) += mx2_emmaprp.o
> +obj-$(CONFIG_VIDEO_IMX_ASRC) += imx-asrc.o
> diff --git a/drivers/media/platform/nxp/imx-asrc.c b/drivers/media/platform/nxp/imx-asrc.c
> new file mode 100644
> index 000000000000..b1b5f1bbdf19
> --- /dev/null
> +++ b/drivers/media/platform/nxp/imx-asrc.c
> @@ -0,0 +1,1207 @@
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (C) 2014-2016 Freescale Semiconductor, Inc.
> +// Copyright (C) 2019-2023 NXP
> +//
> +// Freescale ASRC Memory to Memory (M2M) driver
> +
> +#include <linux/dma/imx-dma.h>
> +#include <linux/pm_runtime.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-device.h>
> +#include <media/v4l2-event.h>
> +#include <media/v4l2-fh.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/v4l2-mem2mem.h>
> +#include <media/videobuf2-dma-contig.h>
> +#include <sound/dmaengine_pcm.h>
> +#include <sound/fsl_asrc_common.h>
> +
> +#define V4L_CAP OUT
> +#define V4L_OUT IN
> +
> +#define ASRC_xPUT_DMA_CALLBACK(dir) \
> +	(((dir) == V4L_OUT) ? asrc_input_dma_callback \
> +	: asrc_output_dma_callback)
> +
> +#define DIR_STR(dir) (dir) == V4L_OUT ? "out" : "cap"
> +
> +/* Maximum output and capture buffer size */
> +#define ASRC_M2M_BUFFER_SIZE (512 * 1024)
> +
> +/* Maximum output and capture period size */
> +#define ASRC_M2M_PERIOD_SIZE (48 * 1024)
> +
> +struct asrc_pair_m2m {
> +	struct fsl_asrc_pair *pair;
> +	struct asrc_m2m *m2m;
> +	struct v4l2_fh fh;
> +	struct v4l2_ctrl_handler ctrl_handler;
> +	int channels[2];
> +	s64 src_rate_off_prev;		/* Q31.32 */
> +	s64 dst_rate_off_prev;		/* Q31.32 */
> +	s64 src_rate_off_cur;		/* Q31.32 */
> +	s64 dst_rate_off_cur;		/* Q31.32 */
> +};
> +
> +struct asrc_m2m {
> +	struct fsl_asrc_m2m_pdata pdata;
> +	struct v4l2_device v4l2_dev;
> +	struct v4l2_m2m_dev *m2m_dev;
> +	struct video_device *dec_vdev;
> +	struct mutex mlock; /* v4l2 ioctls serialization */
> +	struct platform_device *pdev;
> +};
> +
> +static u32 formats[] = {
> +	V4L2_AUDIO_FMT_S8,
> +	V4L2_AUDIO_FMT_S16_LE,
> +	V4L2_AUDIO_FMT_U16_LE,
> +	V4L2_AUDIO_FMT_S24_LE,
> +	V4L2_AUDIO_FMT_S24_3LE,
> +	V4L2_AUDIO_FMT_U24_LE,
> +	V4L2_AUDIO_FMT_U24_3LE,
> +	V4L2_AUDIO_FMT_S32_LE,
> +	V4L2_AUDIO_FMT_U32_LE,
> +	V4L2_AUDIO_FMT_S20_3LE,
> +	V4L2_AUDIO_FMT_U20_3LE,
> +	V4L2_AUDIO_FMT_FLOAT_LE,
> +	V4L2_AUDIO_FMT_IEC958_SUBFRAME_LE,
> +};
> +
> +#define NUM_FORMATS ARRAY_SIZE(formats)
> +
> +static const s64 asrc_v1_m2m_rates[] = {
> +	5512, 8000, 11025, 12000, 16000,
> +	22050, 24000, 32000, 44100,
> +	48000, 64000, 88200, 96000,
> +	128000, 176400, 192000,
> +};
> +
> +static const s64 asrc_v2_m2m_rates[] = {
> +	8000, 11025, 12000, 16000,
> +	22050, 24000, 32000, 44100,
> +	48000, 64000, 88200, 96000,
> +	128000, 176400, 192000, 256000,
> +	352800, 384000, 705600, 768000,
> +};
> +
> +static u32 find_fourcc(snd_pcm_format_t format)
> +{
> +	snd_pcm_format_t fmt;
> +	unsigned int k;
> +
> +	for (k = 0; k < NUM_FORMATS; k++) {
> +		fmt = v4l2_fourcc_to_audfmt(formats[k]);
> +		if (fmt == format)
> +			break;

Just do 'return formats[k];' here.

> +	}

and return 0 here.
> +
> +	if (k == NUM_FORMATS)
> +		return 0;
> +
> +	return formats[k];
> +}
> +
> +static snd_pcm_format_t find_format(u32 fourcc)
> +{
> +	snd_pcm_format_t fmt;
> +	unsigned int k;
> +
> +	for (k = 0; k < NUM_FORMATS; k++) {
> +		if (formats[k] == fourcc)
> +			break;
> +	}
> +
> +	if (k == NUM_FORMATS)
> +		return 0;
> +
> +	fmt = v4l2_fourcc_to_audfmt(formats[k]);
> +
> +	return fmt;

Make a similar change here.

> +}
> +
> +static int asrc_check_format(struct asrc_pair_m2m *pair_m2m, u8 dir, u32 format)
> +{
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +	struct fsl_asrc_m2m_pdata *pdata = &m2m->pdata;
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +	snd_pcm_format_t fmt;
> +	u64 format_bit = 0;
> +	int i;
> +
> +	for (i = 0; i < NUM_FORMATS; ++i) {
> +		if (formats[i] == format) {
> +			fmt = v4l2_fourcc_to_audfmt(formats[i]);
> +			format_bit = pcm_format_to_bits(fmt);
> +			break;
> +		}
> +	}
> +
> +	if (dir == IN && !(format_bit & pdata->fmt_in))
> +		return find_fourcc(pair->sample_format[V4L_OUT]);
> +	else if (dir == OUT && !(format_bit & pdata->fmt_out))

Drop 'else'.

> +		return find_fourcc(pair->sample_format[V4L_CAP]);
> +	else

Ditto.

> +		return format;
> +}
> +
> +static int asrc_check_channel(struct asrc_pair_m2m *pair_m2m, u8 dir, u32 channels)
> +{
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +	struct fsl_asrc_m2m_pdata *pdata = &m2m->pdata;
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +
> +	if (channels < pdata->chan_min || channels > pdata->chan_max)
> +		return pair->channels;
> +	else

Ditto.

> +		return channels;
> +}
> +
> +static inline struct asrc_pair_m2m *asrc_m2m_fh_to_ctx(struct v4l2_fh *fh)
> +{
> +	return container_of(fh, struct asrc_pair_m2m, fh);
> +}
> +
> +/**
> + * asrc_read_last_fifo: read all the remaining data from FIFO
> + *	@pair: Structure pointer of fsl_asrc_pair
> + *	@dma_vaddr: virtual address of capture buffer
> + *	@length: payload length of capture buffer
> + */
> +static void asrc_read_last_fifo(struct fsl_asrc_pair *pair, void *dma_vaddr, u32 *length)
> +{
> +	struct fsl_asrc *asrc = pair->asrc;
> +	enum asrc_pair_index index = pair->index;
> +	u32 i, reg, size, t_size = 0, width;
> +	u32 *reg32 = NULL;
> +	u16 *reg16 = NULL;
> +	u8  *reg24 = NULL;
> +
> +	width = snd_pcm_format_physical_width(pair->sample_format[V4L_CAP]);
> +	if (width == 32)
> +		reg32 = dma_vaddr + *length;
> +	else if (width == 16)
> +		reg16 = dma_vaddr + *length;
> +	else
> +		reg24 = dma_vaddr + *length;
> +retry:
> +	size = asrc->get_output_fifo_size(pair);
> +	if (size + *length > ASRC_M2M_BUFFER_SIZE)
> +		goto end;
> +
> +	for (i = 0; i < size * pair->channels; i++) {
> +		regmap_read(asrc->regmap, asrc->get_fifo_addr(OUT, index), &reg);
> +		if (reg32) {
> +			*(reg32) = reg;
> +			reg32++;

Easier is:

*reg32++ = reg;

> +		} else if (reg16) {
> +			*(reg16) = (u16)reg;
> +			reg16++;

Ditto.

> +		} else {
> +			*reg24++ = (u8)reg;
> +			*reg24++ = (u8)(reg >> 8);
> +			*reg24++ = (u8)(reg >> 16);
> +		}
> +	}
> +	t_size += size;
> +
> +	/* In case there is data left in FIFO */
> +	if (size)
> +		goto retry;
> +end:
> +	/* Update payload length */
> +	if (reg32)
> +		*length += t_size * pair->channels * 4;
> +	else if (reg16)
> +		*length += t_size * pair->channels * 2;
> +	else
> +		*length += t_size * pair->channels * 3;
> +}
> +
> +static int asrc_m2m_start_streaming(struct vb2_queue *q, unsigned int count)
> +{
> +	struct asrc_pair_m2m *pair_m2m = vb2_get_drv_priv(q);
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +	struct fsl_asrc *asrc = pair->asrc;
> +	struct device *dev = &m2m->pdev->dev;
> +	struct vb2_v4l2_buffer *buf;
> +	bool request_flag = false;
> +	int ret;
> +
> +	dev_dbg(dev, "Start streaming pair=%p, %d\n", pair, q->type);
> +
> +	ret = pm_runtime_get_sync(dev);
> +	if (ret < 0) {
> +		dev_err(dev, "Failed to power up asrc\n");
> +		goto err_pm_runtime;
> +	}
> +
> +	/* Request asrc pair/context */
> +	if (!pair->req_pair) {
> +		/* flag for error handler of this function */
> +		request_flag = true;
> +
> +		ret = asrc->request_pair(pair->channels, pair);
> +		if (ret) {
> +			dev_err(dev, "failed to request pair: %d\n", ret);
> +			goto err_request_pair;
> +		}
> +
> +		ret = asrc->m2m_prepare(pair);
> +		if (ret) {
> +			dev_err(dev, "failed to start pair part one: %d\n", ret);
> +			goto err_start_part_one;
> +		}
> +
> +		pair->req_pair = true;
> +	}
> +
> +	/* Request dma channels */
> +	if (V4L2_TYPE_IS_OUTPUT(q->type)) {
> +		pair->dma_chan[V4L_OUT] = asrc->get_dma_channel(pair, IN);
> +		if (!pair->dma_chan[V4L_OUT]) {
> +			dev_err(dev, "[ctx%d] failed to get input DMA channel\n", pair->index);
> +			ret = -EBUSY;
> +			goto err_dma_channel;
> +		}
> +	} else {
> +		pair->dma_chan[V4L_CAP] = asrc->get_dma_channel(pair, OUT);
> +		if (!pair->dma_chan[V4L_CAP]) {
> +			dev_err(dev, "[ctx%d] failed to get output DMA channel\n", pair->index);
> +			ret = -EBUSY;
> +			goto err_dma_channel;
> +		}
> +	}
> +
> +	v4l2_m2m_update_start_streaming_state(pair_m2m->fh.m2m_ctx, q);
> +
> +	return 0;
> +
> +err_dma_channel:
> +	if (request_flag && asrc->m2m_unprepare)
> +		asrc->m2m_unprepare(pair);
> +err_start_part_one:
> +	if (request_flag)
> +		asrc->release_pair(pair);
> +err_request_pair:
> +	pm_runtime_put_sync(dev);
> +err_pm_runtime:
> +	/* Release buffers */
> +	if (V4L2_TYPE_IS_OUTPUT(q->type)) {
> +		while ((buf = v4l2_m2m_src_buf_remove(pair_m2m->fh.m2m_ctx)))
> +			v4l2_m2m_buf_done(buf, VB2_BUF_STATE_QUEUED);
> +	} else {
> +		while ((buf = v4l2_m2m_dst_buf_remove(pair_m2m->fh.m2m_ctx)))
> +			v4l2_m2m_buf_done(buf, VB2_BUF_STATE_QUEUED);
> +	}
> +	return ret;
> +}
> +
> +static void asrc_m2m_stop_streaming(struct vb2_queue *q)
> +{
> +	struct asrc_pair_m2m *pair_m2m = vb2_get_drv_priv(q);
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +	struct fsl_asrc *asrc = pair->asrc;
> +	struct device *dev = &m2m->pdev->dev;
> +
> +	dev_dbg(dev, "Stop streaming pair=%p, %d\n", pair, q->type);
> +
> +	v4l2_m2m_update_stop_streaming_state(pair_m2m->fh.m2m_ctx, q);
> +
> +	/* Stop & release pair/context */
> +	if (asrc->m2m_stop)
> +		asrc->m2m_stop(pair);
> +
> +	if (pair->req_pair) {
> +		if (asrc->m2m_unprepare)
> +			asrc->m2m_unprepare(pair);
> +		asrc->release_pair(pair);
> +		pair->req_pair = false;
> +	}
> +
> +	/* Release dma channel */
> +	if (V4L2_TYPE_IS_OUTPUT(q->type)) {
> +		if (pair->dma_chan[V4L_OUT])
> +			dma_release_channel(pair->dma_chan[V4L_OUT]);
> +	} else {
> +		if (pair->dma_chan[V4L_CAP])
> +			dma_release_channel(pair->dma_chan[V4L_CAP]);
> +	}
> +
> +	pm_runtime_put_sync(dev);
> +}
> +
> +static int asrc_m2m_queue_setup(struct vb2_queue *q,
> +				unsigned int *num_buffers, unsigned int *num_planes,
> +				unsigned int sizes[], struct device *alloc_devs[])
> +{
> +	struct asrc_pair_m2m *pair_m2m = vb2_get_drv_priv(q);
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +	u32 size;
> +
> +	/*
> +	 * The capture buffer size depends on output buffer size
> +	 * and the convert ratio.
> +	 *
> +	 * Here just use a fix length for capture and output buffer.
> +	 * User need to care about it.
> +	 */
> +	if (V4L2_TYPE_IS_OUTPUT(q->type))
> +		size = pair->buf_len[V4L_OUT];
> +	else
> +		size = pair->buf_len[V4L_CAP];
> +
> +	if (*num_planes)
> +		return sizes[0] < size ? -EINVAL : 0;
> +
> +	*num_planes = 1;
> +	sizes[0] = size;
> +
> +	return 0;
> +}
> +
> +static void asrc_m2m_buf_queue(struct vb2_buffer *vb)
> +{
> +	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
> +	struct asrc_pair_m2m *pair_m2m = vb2_get_drv_priv(vb->vb2_queue);
> +
> +	/* queue buffer */
> +	v4l2_m2m_buf_queue(pair_m2m->fh.m2m_ctx, vbuf);
> +}
> +
> +static const struct vb2_ops asrc_m2m_qops = {
> +	.wait_prepare		= vb2_ops_wait_prepare,
> +	.wait_finish		= vb2_ops_wait_finish,
> +	.start_streaming	= asrc_m2m_start_streaming,
> +	.stop_streaming		= asrc_m2m_stop_streaming,
> +	.queue_setup		= asrc_m2m_queue_setup,
> +	.buf_queue		= asrc_m2m_buf_queue,
> +};
> +
> +/* Init video buffer queue for src and dst. */
> +static int asrc_m2m_queue_init(void *priv, struct vb2_queue *src_vq,
> +			       struct vb2_queue *dst_vq)
> +{
> +	struct asrc_pair_m2m *pair_m2m = priv;
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +	int ret;
> +
> +	src_vq->type = V4L2_BUF_TYPE_AUDIO_OUTPUT;
> +	src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
> +	src_vq->drv_priv = pair_m2m;
> +	src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
> +	src_vq->ops = &asrc_m2m_qops;
> +	src_vq->mem_ops = &vb2_dma_contig_memops;
> +	src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> +	src_vq->lock = &m2m->mlock;
> +	src_vq->dev = &m2m->pdev->dev;
> +	src_vq->min_buffers_needed = 1;
> +
> +	ret = vb2_queue_init(src_vq);
> +	if (ret)
> +		return ret;
> +
> +	dst_vq->type = V4L2_BUF_TYPE_AUDIO_CAPTURE;
> +	dst_vq->io_modes = VB2_MMAP | VB2_DMABUF;
> +	dst_vq->drv_priv = pair_m2m;
> +	dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
> +	dst_vq->ops = &asrc_m2m_qops;
> +	dst_vq->mem_ops = &vb2_dma_contig_memops;
> +	dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
> +	dst_vq->lock = &m2m->mlock;
> +	dst_vq->dev = &m2m->pdev->dev;
> +	dst_vq->min_buffers_needed = 1;
> +
> +	ret = vb2_queue_init(dst_vq);
> +	return ret;
> +}
> +
> +static int asrc_m2m_op_s_ctrl(struct v4l2_ctrl *ctrl)
> +{
> +	struct asrc_pair_m2m *pair_m2m =
> +		container_of(ctrl->handler, struct asrc_pair_m2m, ctrl_handler);
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +	struct fsl_asrc_m2m_pdata *pdata = &m2m->pdata;
> +	int new_rate;
> +	int ret = 0;
> +
> +	switch (ctrl->id) {
> +	case V4L2_CID_M2M_AUDIO_SOURCE_RATE:
> +		if (pdata->rate_min == 5512)
> +			new_rate = asrc_v1_m2m_rates[ctrl->val];
> +		else
> +			new_rate = asrc_v2_m2m_rates[ctrl->val];

You can just do:

		new_rate = ctrl->qmenu_int[ctrl->val];

> +		pair->rate[V4L_OUT] = new_rate;
> +		break;
> +	case V4L2_CID_M2M_AUDIO_DEST_RATE:
> +		if (pdata->rate_min == 5512)
> +			new_rate = asrc_v1_m2m_rates[ctrl->val];
> +		else
> +			new_rate = asrc_v2_m2m_rates[ctrl->val];

Ditto.

> +		pair->rate[V4L_CAP] = new_rate;
> +		break;
> +	case V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET:
> +		pair_m2m->src_rate_off_cur = *ctrl->p_new.p_s64;
> +		break;
> +	case V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET:
> +		pair_m2m->dst_rate_off_cur = *ctrl->p_new.p_s64;
> +		break;
> +	default:
> +		ret = -EINVAL;
> +		break;
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct v4l2_ctrl_ops asrc_m2m_ctrl_ops = {
> +	.s_ctrl = asrc_m2m_op_s_ctrl,
> +};
> +
> +/* system callback for open() */
> +static int asrc_m2m_open(struct file *file)
> +{
> +	struct asrc_m2m *m2m = video_drvdata(file);
> +	struct fsl_asrc *asrc = m2m->pdata.asrc;
> +	struct video_device *vdev = video_devdata(file);
> +	struct fsl_asrc_pair *pair;
> +	struct asrc_pair_m2m *pair_m2m;
> +	int ret = 0;
> +
> +	if (mutex_lock_interruptible(&m2m->mlock))
> +		return -ERESTARTSYS;
> +
> +	pair = kzalloc(sizeof(*pair) + asrc->pair_priv_size, GFP_KERNEL);
> +	if (!pair) {
> +		ret = -ENOMEM;
> +		goto err_alloc_pair;
> +	}
> +
> +	pair_m2m = kzalloc(sizeof(*pair_m2m), GFP_KERNEL);
> +	if (!pair_m2m) {
> +		ret = -ENOMEM;
> +		goto err_alloc_pair_m2m;
> +	}
> +
> +	pair->private = (void *)pair + sizeof(struct fsl_asrc_pair);
> +	pair->asrc = asrc;
> +
> +	pair->buf_len[V4L_OUT] = ASRC_M2M_BUFFER_SIZE;
> +	pair->buf_len[V4L_CAP] = ASRC_M2M_BUFFER_SIZE;
> +
> +	pair->channels = 2;
> +	pair->rate[V4L_OUT] = 8000;
> +	pair->rate[V4L_CAP] = 8000;
> +	pair->sample_format[V4L_OUT] = SNDRV_PCM_FORMAT_S16_LE;
> +	pair->sample_format[V4L_CAP] = SNDRV_PCM_FORMAT_S16_LE;
> +
> +	init_completion(&pair->complete[V4L_OUT]);
> +	init_completion(&pair->complete[V4L_CAP]);
> +
> +	v4l2_fh_init(&pair_m2m->fh, vdev);
> +	v4l2_fh_add(&pair_m2m->fh);
> +	file->private_data = &pair_m2m->fh;
> +
> +	pair_m2m->pair = pair;
> +	pair_m2m->m2m = m2m;
> +	/* m2m context init */
> +	pair_m2m->fh.m2m_ctx = v4l2_m2m_ctx_init(m2m->m2m_dev, pair_m2m,
> +						 asrc_m2m_queue_init);
> +	if (IS_ERR(pair_m2m->fh.m2m_ctx)) {
> +		ret = PTR_ERR(pair_m2m->fh.m2m_ctx);
> +		goto err_ctx_init;
> +	}
> +
> +	v4l2_ctrl_handler_init(&pair_m2m->ctrl_handler, 4);
> +
> +	if (m2m->pdata.rate_min == 5512) {
> +		v4l2_ctrl_new_int_menu(&pair_m2m->ctrl_handler, &asrc_m2m_ctrl_ops,
> +				       V4L2_CID_M2M_AUDIO_SOURCE_RATE,
> +				       ARRAY_SIZE(asrc_v1_m2m_rates) - 1, 1, asrc_v1_m2m_rates);
> +		v4l2_ctrl_new_int_menu(&pair_m2m->ctrl_handler, &asrc_m2m_ctrl_ops,
> +				       V4L2_CID_M2M_AUDIO_DEST_RATE,
> +				       ARRAY_SIZE(asrc_v1_m2m_rates) - 1, 1, asrc_v1_m2m_rates);
> +	} else {
> +		v4l2_ctrl_new_int_menu(&pair_m2m->ctrl_handler, &asrc_m2m_ctrl_ops,
> +				       V4L2_CID_M2M_AUDIO_SOURCE_RATE,
> +				       ARRAY_SIZE(asrc_v2_m2m_rates) - 1, 0, asrc_v2_m2m_rates);
> +		v4l2_ctrl_new_int_menu(&pair_m2m->ctrl_handler, &asrc_m2m_ctrl_ops,
> +				       V4L2_CID_M2M_AUDIO_DEST_RATE,
> +				       ARRAY_SIZE(asrc_v2_m2m_rates) - 1, 0, asrc_v2_m2m_rates);
> +	}
> +
> +	v4l2_ctrl_new_std(&pair_m2m->ctrl_handler, &asrc_m2m_ctrl_ops,
> +			  V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET,
> +			  0xFFFFFF0000000000, 0x7fffffffff, 1, 0);
> +	v4l2_ctrl_new_std(&pair_m2m->ctrl_handler, &asrc_m2m_ctrl_ops,
> +			  V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET,
> +			  0xFFFFFF0000000000, 0x7fffffffff, 1, 0);
> +
> +	if (pair_m2m->ctrl_handler.error) {
> +		ret = pair_m2m->ctrl_handler.error;
> +		v4l2_ctrl_handler_free(&pair_m2m->ctrl_handler);
> +		goto err_ctrl_handler;
> +	}
> +
> +	pair_m2m->fh.ctrl_handler = &pair_m2m->ctrl_handler;
> +
> +	mutex_unlock(&m2m->mlock);
> +
> +	return 0;
> +
> +err_ctrl_handler:
> +	v4l2_m2m_ctx_release(pair_m2m->fh.m2m_ctx);
> +err_ctx_init:
> +	v4l2_fh_del(&pair_m2m->fh);
> +	v4l2_fh_exit(&pair_m2m->fh);
> +	kfree(pair_m2m);
> +err_alloc_pair_m2m:
> +	kfree(pair);
> +err_alloc_pair:
> +	mutex_unlock(&m2m->mlock);
> +	return ret;
> +}
> +
> +static int asrc_m2m_release(struct file *file)
> +{
> +	struct asrc_m2m *m2m = video_drvdata(file);
> +	struct asrc_pair_m2m *pair_m2m = asrc_m2m_fh_to_ctx(file->private_data);
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +
> +	mutex_lock(&m2m->mlock);
> +	v4l2_ctrl_handler_free(&pair_m2m->ctrl_handler);
> +	v4l2_m2m_ctx_release(pair_m2m->fh.m2m_ctx);
> +	v4l2_fh_del(&pair_m2m->fh);
> +	v4l2_fh_exit(&pair_m2m->fh);
> +	kfree(pair_m2m);
> +	kfree(pair);
> +	mutex_unlock(&m2m->mlock);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_file_operations asrc_m2m_fops = {
> +	.owner          = THIS_MODULE,
> +	.open           = asrc_m2m_open,
> +	.release        = asrc_m2m_release,
> +	.poll           = v4l2_m2m_fop_poll,
> +	.unlocked_ioctl = video_ioctl2,
> +	.mmap           = v4l2_m2m_fop_mmap,
> +};
> +
> +static int asrc_m2m_querycap(struct file *file, void *priv,
> +			     struct v4l2_capability *cap)
> +{
> +	strscpy(cap->driver, "imx asrc m2m", sizeof(cap->driver));
> +	strscpy(cap->card, "imx asrc m2m", sizeof(cap->card));
> +	cap->device_caps = V4L2_CAP_STREAMING | V4L2_CAP_AUDIO_M2M;
> +
> +	return 0;
> +}
> +
> +static int enum_fmt(struct v4l2_fmtdesc *f, u64 fmtbit)
> +{
> +	snd_pcm_format_t fmt;
> +	int i, num;
> +
> +	num = 0;
> +
> +	for (i = 0; i < NUM_FORMATS; ++i) {
> +		fmt = v4l2_fourcc_to_audfmt(formats[i]);
> +		if (pcm_format_to_bits(fmt) & fmtbit) {
> +			if (num == f->index)
> +				break;
> +			/*
> +			 * Correct type but haven't reached our index yet,
> +			 * just increment per-type index
> +			 */
> +			++num;
> +		}
> +	}
> +
> +	if (i < NUM_FORMATS) {
> +		/* Format found */
> +		f->pixelformat = formats[i];
> +		return 0;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int asrc_m2m_enum_fmt_aud_cap(struct file *file, void *fh,
> +				     struct v4l2_fmtdesc *f)
> +{
> +	struct asrc_pair_m2m *pair_m2m = asrc_m2m_fh_to_ctx(fh);
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +
> +	return enum_fmt(f, m2m->pdata.fmt_out);
> +}
> +
> +static int asrc_m2m_enum_fmt_aud_out(struct file *file, void *fh,
> +				     struct v4l2_fmtdesc *f)
> +{
> +	struct asrc_pair_m2m *pair_m2m = asrc_m2m_fh_to_ctx(fh);
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +
> +	return enum_fmt(f, m2m->pdata.fmt_in);
> +}
> +
> +static int asrc_m2m_g_fmt_aud_cap(struct file *file, void *fh,
> +				  struct v4l2_format *f)
> +{
> +	struct asrc_pair_m2m *pair_m2m = asrc_m2m_fh_to_ctx(fh);
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +
> +	f->fmt.audio.channels = pair->channels;
> +	f->fmt.audio.buffersize = pair->buf_len[V4L_CAP];
> +	f->fmt.audio.audioformat = find_fourcc(pair->sample_format[V4L_CAP]);
> +
> +	return 0;
> +}
> +
> +static int asrc_m2m_g_fmt_aud_out(struct file *file, void *fh,
> +				  struct v4l2_format *f)
> +{
> +	struct asrc_pair_m2m *pair_m2m = asrc_m2m_fh_to_ctx(fh);
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +
> +	f->fmt.audio.channels = pair->channels;
> +	f->fmt.audio.buffersize = pair->buf_len[V4L_OUT];
> +	f->fmt.audio.audioformat = find_fourcc(pair->sample_format[V4L_OUT]);
> +
> +	return 0;
> +}
> +
> +/* output for asrc */
> +static int asrc_m2m_s_fmt_aud_cap(struct file *file, void *fh,
> +				  struct v4l2_format *f)
> +{
> +	struct asrc_pair_m2m *pair_m2m = asrc_m2m_fh_to_ctx(fh);
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +	struct device *dev = &m2m->pdev->dev;
> +
> +	f->fmt.audio.audioformat = asrc_check_format(pair_m2m, OUT, f->fmt.audio.audioformat);
> +	f->fmt.audio.channels = asrc_check_channel(pair_m2m, OUT, f->fmt.audio.channels);
> +
> +	if (pair_m2m->channels[V4L_CAP] > 0 &&
> +	    pair_m2m->channels[V4L_CAP] != f->fmt.audio.channels) {
> +		dev_err(dev, "channels don't match for cap and out\n");
> +		return -EINVAL;
> +	}
> +
> +	pair_m2m->channels[V4L_CAP] = f->fmt.audio.channels;
> +	pair->channels = f->fmt.audio.channels;
> +	pair->sample_format[V4L_CAP] = find_format(f->fmt.audio.audioformat);
> +
> +	return 0;
> +}
> +
> +/* input for asrc */
> +static int asrc_m2m_s_fmt_aud_out(struct file *file, void *fh,
> +				  struct v4l2_format *f)
> +{
> +	struct asrc_pair_m2m *pair_m2m = asrc_m2m_fh_to_ctx(fh);
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +	struct device *dev = &m2m->pdev->dev;
> +
> +	f->fmt.audio.audioformat = asrc_check_format(pair_m2m, IN, f->fmt.audio.audioformat);
> +	f->fmt.audio.channels = asrc_check_channel(pair_m2m, IN, f->fmt.audio.channels);
> +	if (pair_m2m->channels[V4L_OUT] > 0 &&
> +	    pair_m2m->channels[V4L_OUT] != f->fmt.audio.channels) {
> +		dev_err(dev, "channels don't match for cap and out\n");
> +		return -EINVAL;
> +	}
> +
> +	pair_m2m->channels[V4L_OUT] = f->fmt.audio.channels;
> +	pair->channels = f->fmt.audio.channels;
> +	pair->sample_format[V4L_OUT] = find_format(f->fmt.audio.audioformat);
> +
> +	return 0;
> +}
> +
> +static int asrc_m2m_try_fmt_audio_cap(struct file *file, void *fh,
> +				      struct v4l2_format *f)
> +{
> +	struct asrc_pair_m2m *pair_m2m = asrc_m2m_fh_to_ctx(fh);
> +
> +	f->fmt.audio.audioformat = asrc_check_format(pair_m2m, OUT, f->fmt.audio.audioformat);
> +	f->fmt.audio.channels = asrc_check_channel(pair_m2m, OUT, f->fmt.audio.channels);
> +
> +	return 0;
> +}
> +
> +static int asrc_m2m_try_fmt_audio_out(struct file *file, void *fh,
> +				      struct v4l2_format *f)
> +{
> +	struct asrc_pair_m2m *pair_m2m = asrc_m2m_fh_to_ctx(fh);
> +
> +	f->fmt.audio.audioformat = asrc_check_format(pair_m2m, IN, f->fmt.audio.audioformat);
> +	f->fmt.audio.channels = asrc_check_channel(pair_m2m, IN, f->fmt.audio.channels);
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_ioctl_ops asrc_m2m_ioctl_ops = {
> +	.vidioc_querycap		= asrc_m2m_querycap,
> +
> +	.vidioc_enum_fmt_audio_cap	= asrc_m2m_enum_fmt_aud_cap,
> +	.vidioc_enum_fmt_audio_out	= asrc_m2m_enum_fmt_aud_out,
> +
> +	.vidioc_g_fmt_audio_cap		= asrc_m2m_g_fmt_aud_cap,
> +	.vidioc_g_fmt_audio_out		= asrc_m2m_g_fmt_aud_out,
> +
> +	.vidioc_s_fmt_audio_cap		= asrc_m2m_s_fmt_aud_cap,
> +	.vidioc_s_fmt_audio_out		= asrc_m2m_s_fmt_aud_out,
> +
> +	.vidioc_try_fmt_audio_cap	= asrc_m2m_try_fmt_audio_cap,
> +	.vidioc_try_fmt_audio_out	= asrc_m2m_try_fmt_audio_out,
> +
> +	.vidioc_qbuf			= v4l2_m2m_ioctl_qbuf,
> +	.vidioc_dqbuf			= v4l2_m2m_ioctl_dqbuf,
> +
> +	.vidioc_create_bufs		= v4l2_m2m_ioctl_create_bufs,
> +	.vidioc_prepare_buf		= v4l2_m2m_ioctl_prepare_buf,
> +	.vidioc_reqbufs			= v4l2_m2m_ioctl_reqbufs,
> +	.vidioc_querybuf		= v4l2_m2m_ioctl_querybuf,
> +	.vidioc_streamon		= v4l2_m2m_ioctl_streamon,
> +	.vidioc_streamoff		= v4l2_m2m_ioctl_streamoff,
> +	.vidioc_subscribe_event		= v4l2_ctrl_subscribe_event,
> +	.vidioc_unsubscribe_event	= v4l2_event_unsubscribe,
> +};
> +
> +/* dma complete callback */
> +static void asrc_input_dma_callback(void *data)
> +{
> +	struct fsl_asrc_pair *pair = (struct fsl_asrc_pair *)data;
> +
> +	complete(&pair->complete[V4L_OUT]);
> +}
> +
> +/* dma complete callback */
> +static void asrc_output_dma_callback(void *data)
> +{
> +	struct fsl_asrc_pair *pair = (struct fsl_asrc_pair *)data;
> +
> +	complete(&pair->complete[V4L_CAP]);
> +}
> +
> +/* config dma channel */
> +static int asrc_dmaconfig(struct asrc_pair_m2m *pair_m2m,
> +			  struct dma_chan *chan,
> +			  u32 dma_addr, dma_addr_t buf_addr, u32 buf_len,
> +			  int dir, int width)
> +{
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +	struct fsl_asrc *asrc = pair->asrc;
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +	struct device *dev = &m2m->pdev->dev;
> +	struct dma_slave_config slave_config;
> +	enum dma_slave_buswidth buswidth;
> +	unsigned int sg_len, max_period_size;
> +	struct scatterlist *sg;
> +	int ret, i;
> +
> +	switch (width) {
> +	case 8:
> +		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
> +		break;
> +	case 16:
> +		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
> +		break;
> +	case 24:
> +		buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
> +		break;
> +	case 32:
> +		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
> +		break;
> +	default:
> +		dev_err(dev, "invalid word width\n");
> +		return -EINVAL;
> +	}
> +
> +	memset(&slave_config, 0, sizeof(slave_config));
> +	if (dir == V4L_OUT) {
> +		slave_config.direction = DMA_MEM_TO_DEV;
> +		slave_config.dst_addr = dma_addr;
> +		slave_config.dst_addr_width = buswidth;
> +		slave_config.dst_maxburst = asrc->m2m_get_maxburst(IN, pair);
> +	} else {
> +		slave_config.direction = DMA_DEV_TO_MEM;
> +		slave_config.src_addr = dma_addr;
> +		slave_config.src_addr_width = buswidth;
> +		slave_config.src_maxburst = asrc->m2m_get_maxburst(OUT, pair);
> +	}
> +
> +	ret = dmaengine_slave_config(chan, &slave_config);
> +	if (ret) {
> +		dev_err(dev, "failed to config dmaengine for %s task: %d\n",
> +			DIR_STR(dir), ret);
> +		return -EINVAL;
> +	}
> +
> +	max_period_size = rounddown(ASRC_M2M_PERIOD_SIZE, width * pair->channels / 8);
> +	/* scatter gather mode */
> +	sg_len = buf_len / max_period_size;
> +	if (buf_len % max_period_size)
> +		sg_len += 1;
> +
> +	sg = kmalloc_array(sg_len, sizeof(*sg), GFP_KERNEL);
> +	if (!sg)
> +		return -ENOMEM;
> +
> +	sg_init_table(sg, sg_len);
> +	for (i = 0; i < (sg_len - 1); i++) {
> +		sg_dma_address(&sg[i]) = buf_addr + i * max_period_size;
> +		sg_dma_len(&sg[i]) = max_period_size;
> +	}
> +	sg_dma_address(&sg[i]) = buf_addr + i * max_period_size;
> +	sg_dma_len(&sg[i]) = buf_len - i * max_period_size;
> +
> +	pair->desc[dir] = dmaengine_prep_slave_sg(chan, sg, sg_len,
> +						  slave_config.direction,
> +						  DMA_PREP_INTERRUPT);
> +	kfree(sg);
> +	if (!pair->desc[dir]) {
> +		dev_err(dev, "failed to prepare dmaengine for %s task\n", DIR_STR(dir));
> +		return -EINVAL;
> +	}
> +
> +	pair->desc[dir]->callback = ASRC_xPUT_DMA_CALLBACK(dir);
> +	pair->desc[dir]->callback_param = pair;
> +
> +	return 0;
> +}
> +
> +static void asrc_m2m_set_ratio_mod(struct asrc_pair_m2m *pair_m2m)
> +{
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +	struct fsl_asrc *asrc = pair->asrc;
> +	s32 src_rate_int, dst_rate_int;
> +	s64 src_rate_frac;
> +	s64 dst_rate_frac;
> +	u64 src_rate, dst_rate;
> +	u64 ratio_pre, ratio_cur;
> +	s64 ratio_diff;
> +
> +	if (!asrc->m2m_set_ratio_mod)
> +		return;
> +
> +	if (pair_m2m->src_rate_off_cur == pair_m2m->src_rate_off_prev &&
> +	    pair_m2m->dst_rate_off_cur == pair_m2m->dst_rate_off_prev)
> +		return;
> +
> +	/*
> +	 * use maximum rate 768kHz as limitation, then we can shift right 21 bit for
> +	 * division
> +	 */
> +	src_rate_int = pair->rate[V4L_OUT];
> +	src_rate_frac = pair_m2m->src_rate_off_prev;
> +
> +	src_rate = ((s64)src_rate_int << 32) + src_rate_frac;
> +
> +	dst_rate_int = pair->rate[V4L_CAP];
> +	dst_rate_frac = pair_m2m->dst_rate_off_prev;
> +
> +	dst_rate = ((s64)dst_rate_int << 32) + dst_rate_frac;
> +	dst_rate >>= 21;
> +	do_div(src_rate, dst_rate);
> +	ratio_pre = src_rate;
> +
> +	src_rate_frac = pair_m2m->src_rate_off_cur;
> +	src_rate = ((s64)src_rate_int << 32) + src_rate_frac;
> +
> +	dst_rate_frac = pair_m2m->dst_rate_off_cur;
> +	dst_rate = ((s64)dst_rate_int << 32) + dst_rate_frac;
> +	dst_rate >>= 21;
> +	do_div(src_rate, dst_rate);
> +	ratio_cur = src_rate;
> +
> +	ratio_diff = ratio_cur - ratio_pre;
> +	asrc->m2m_set_ratio_mod(pair, ratio_diff << 10);
> +
> +	pair_m2m->src_rate_off_prev = pair_m2m->src_rate_off_cur;
> +	pair_m2m->dst_rate_off_prev = pair_m2m->dst_rate_off_cur;
> +}
> +
> +/* main function of converter */
> +static void asrc_m2m_device_run(void *priv)
> +{
> +	struct asrc_pair_m2m *pair_m2m = priv;
> +	struct fsl_asrc_pair *pair = pair_m2m->pair;
> +	struct asrc_m2m *m2m = pair_m2m->m2m;
> +	struct fsl_asrc *asrc = pair->asrc;
> +	struct device *dev = &m2m->pdev->dev;
> +	enum asrc_pair_index index = pair->index;
> +	struct vb2_v4l2_buffer *src_buf, *dst_buf;
> +	unsigned int out_buf_len;
> +	unsigned int cap_dma_len;
> +	unsigned int width;
> +	u32 fifo_addr;
> +	int ret;
> +
> +	/* set ratio mod */
> +	asrc_m2m_set_ratio_mod(pair_m2m);
> +
> +	src_buf = v4l2_m2m_next_src_buf(pair_m2m->fh.m2m_ctx);
> +	dst_buf = v4l2_m2m_next_dst_buf(pair_m2m->fh.m2m_ctx);
> +
> +	width = snd_pcm_format_physical_width(pair->sample_format[V4L_OUT]);
> +	fifo_addr = asrc->paddr + asrc->get_fifo_addr(IN, index);
> +	out_buf_len = vb2_get_plane_payload(&src_buf->vb2_buf, 0);
> +	if (out_buf_len < width * pair->channels / 8 ||
> +	    out_buf_len > ASRC_M2M_BUFFER_SIZE ||
> +	    out_buf_len % (width * pair->channels / 8)) {
> +		dev_err(dev, "out buffer size is error: [%d]\n", out_buf_len);
> +		goto end;
> +	}
> +
> +	/* dma config for output dma channel */
> +	ret = asrc_dmaconfig(pair_m2m,
> +			     pair->dma_chan[V4L_OUT],
> +			     fifo_addr,
> +			     vb2_dma_contig_plane_dma_addr(&src_buf->vb2_buf, 0),
> +			     out_buf_len, V4L_OUT, width);
> +	if (ret) {
> +		dev_err(dev, "out dma config error\n");
> +		goto end;
> +	}
> +
> +	width = snd_pcm_format_physical_width(pair->sample_format[V4L_CAP]);
> +	fifo_addr = asrc->paddr + asrc->get_fifo_addr(OUT, index);
> +	cap_dma_len = asrc->m2m_calc_out_len(pair, out_buf_len);
> +	if (cap_dma_len > 0 && cap_dma_len <= ASRC_M2M_BUFFER_SIZE) {
> +		/* dma config for capture dma channel */
> +		ret = asrc_dmaconfig(pair_m2m,
> +				     pair->dma_chan[V4L_CAP],
> +				     fifo_addr,
> +				     vb2_dma_contig_plane_dma_addr(&dst_buf->vb2_buf, 0),
> +				     cap_dma_len, V4L_CAP, width);
> +		if (ret) {
> +			dev_err(dev, "cap dma config error\n");
> +			goto end;
> +		}
> +	} else if (cap_dma_len > ASRC_M2M_BUFFER_SIZE) {
> +		dev_err(dev, "cap buffer size error\n");
> +		goto end;
> +	}
> +
> +	reinit_completion(&pair->complete[V4L_OUT]);
> +	reinit_completion(&pair->complete[V4L_CAP]);
> +
> +	/* Submit DMA request */
> +	dmaengine_submit(pair->desc[V4L_OUT]);
> +	dma_async_issue_pending(pair->desc[V4L_OUT]->chan);
> +	if (cap_dma_len > 0) {
> +		dmaengine_submit(pair->desc[V4L_CAP]);
> +		dma_async_issue_pending(pair->desc[V4L_CAP]->chan);
> +	}
> +
> +	asrc->m2m_start(pair);
> +
> +	if (!wait_for_completion_interruptible_timeout(&pair->complete[V4L_OUT], 10 * HZ)) {
> +		dev_err(dev, "out DMA task timeout\n");
> +		goto end;
> +	}
> +
> +	if (cap_dma_len > 0) {
> +		if (!wait_for_completion_interruptible_timeout(&pair->complete[V4L_CAP], 10 * HZ)) {
> +			dev_err(dev, "cap DMA task timeout\n");
> +			goto end;
> +		}
> +	}
> +
> +	/* read the last words from FIFO */
> +	asrc_read_last_fifo(pair, vb2_plane_vaddr(&dst_buf->vb2_buf, 0), &cap_dma_len);
> +	/* update payload length for capture */
> +	vb2_set_plane_payload(&dst_buf->vb2_buf, 0, cap_dma_len);
> +
> +end:
> +	src_buf = v4l2_m2m_src_buf_remove(pair_m2m->fh.m2m_ctx);
> +	dst_buf = v4l2_m2m_dst_buf_remove(pair_m2m->fh.m2m_ctx);
> +
> +	v4l2_m2m_buf_done(src_buf, VB2_BUF_STATE_DONE);
> +	v4l2_m2m_buf_done(dst_buf, VB2_BUF_STATE_DONE);
> +
> +	v4l2_m2m_job_finish(m2m->m2m_dev, pair_m2m->fh.m2m_ctx);
> +}
> +
> +static int asrc_m2m_job_ready(void *priv)
> +{
> +	struct asrc_pair_m2m *pair_m2m = priv;
> +
> +	if (v4l2_m2m_num_src_bufs_ready(pair_m2m->fh.m2m_ctx) > 0 &&
> +	    v4l2_m2m_num_dst_bufs_ready(pair_m2m->fh.m2m_ctx) > 0) {
> +		return 1;
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct v4l2_m2m_ops asrc_m2m_ops = {
> +	.job_ready = asrc_m2m_job_ready,
> +	.device_run = asrc_m2m_device_run,
> +};
> +
> +static int asrc_m2m_probe(struct platform_device *pdev)
> +{
> +	struct fsl_asrc_m2m_pdata *data = pdev->dev.platform_data;
> +	struct device *dev = &pdev->dev;
> +	struct asrc_m2m *m2m;
> +	int ret;
> +
> +	m2m = devm_kzalloc(dev, sizeof(struct asrc_m2m), GFP_KERNEL);
> +	if (!m2m)
> +		return -ENOMEM;
> +
> +	m2m->pdata = *data;
> +	m2m->pdev = pdev;
> +
> +	ret = v4l2_device_register(dev, &m2m->v4l2_dev);
> +	if (ret) {
> +		dev_err(dev, "failed to register v4l2 device\n");
> +		goto err_register;
> +	}
> +
> +	m2m->m2m_dev = v4l2_m2m_init(&asrc_m2m_ops);
> +	if (IS_ERR(m2m->m2m_dev)) {
> +		dev_err(dev, "failed to register v4l2 device\n");
> +		ret = PTR_ERR(m2m->m2m_dev);
> +		goto err_m2m;
> +	}
> +
> +	m2m->dec_vdev = video_device_alloc();
> +	if (!m2m->dec_vdev) {
> +		dev_err(dev, "failed to register v4l2 device\n");
> +		ret = -ENOMEM;
> +		goto err_vdev_alloc;
> +	}
> +
> +	mutex_init(&m2m->mlock);
> +
> +	m2m->dec_vdev->fops = &asrc_m2m_fops;
> +	m2m->dec_vdev->ioctl_ops = &asrc_m2m_ioctl_ops;
> +	m2m->dec_vdev->minor = -1;
> +	m2m->dec_vdev->release = video_device_release;
> +	m2m->dec_vdev->lock = &m2m->mlock; /* lock for ioctl serialization */
> +	m2m->dec_vdev->v4l2_dev = &m2m->v4l2_dev;
> +	m2m->dec_vdev->vfl_dir = VFL_DIR_M2M;
> +	m2m->dec_vdev->device_caps = V4L2_CAP_STREAMING | V4L2_CAP_AUDIO_M2M;
> +
> +	ret = video_register_device(m2m->dec_vdev, VFL_TYPE_AUDIO, -1);
> +	if (ret) {
> +		dev_err(dev, "failed to register video device\n");
> +		goto err_vdev_register;
> +	}
> +
> +	video_set_drvdata(m2m->dec_vdev, m2m);
> +	platform_set_drvdata(pdev, m2m);
> +	pm_runtime_enable(&pdev->dev);
> +
> +	return 0;
> +
> +err_vdev_register:
> +	video_device_release(m2m->dec_vdev);
> +err_vdev_alloc:
> +	v4l2_m2m_release(m2m->m2m_dev);
> +err_m2m:
> +	v4l2_device_unregister(&m2m->v4l2_dev);
> +err_register:
> +	return ret;
> +}
> +
> +static void asrc_m2m_remove(struct platform_device *pdev)
> +{
> +	struct asrc_m2m *m2m = platform_get_drvdata(pdev);
> +
> +	pm_runtime_disable(&pdev->dev);
> +	video_unregister_device(m2m->dec_vdev);
> +	video_device_release(m2m->dec_vdev);
> +	v4l2_m2m_release(m2m->m2m_dev);
> +	v4l2_device_unregister(&m2m->v4l2_dev);
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +/* suspend callback for m2m */
> +static int asrc_m2m_suspend(struct device *dev)
> +{
> +	struct asrc_m2m *m2m = dev_get_drvdata(dev);
> +	struct fsl_asrc *asrc = m2m->pdata.asrc;
> +	struct fsl_asrc_pair *pair;
> +	unsigned long lock_flags;
> +	int i;
> +
> +	for (i = 0; i < PAIR_CTX_NUM; i++) {
> +		spin_lock_irqsave(&asrc->lock, lock_flags);
> +		pair = asrc->pair[i];
> +		if (!pair || !pair->req_pair) {
> +			spin_unlock_irqrestore(&asrc->lock, lock_flags);
> +			continue;
> +		}
> +		if (!completion_done(&pair->complete[V4L_OUT])) {
> +			if (pair->dma_chan[V4L_OUT])
> +				dmaengine_terminate_all(pair->dma_chan[V4L_OUT]);
> +			asrc_input_dma_callback((void *)pair);
> +		}
> +		if (!completion_done(&pair->complete[V4L_CAP])) {
> +			if (pair->dma_chan[V4L_CAP])
> +				dmaengine_terminate_all(pair->dma_chan[V4L_CAP]);
> +			asrc_output_dma_callback((void *)pair);
> +		}
> +
> +		if (asrc->m2m_pair_suspend)
> +			asrc->m2m_pair_suspend(pair);
> +
> +		spin_unlock_irqrestore(&asrc->lock, lock_flags);
> +	}
> +
> +	return 0;
> +}
> +
> +static int asrc_m2m_resume(struct device *dev)
> +{
> +	struct asrc_m2m *m2m = dev_get_drvdata(dev);
> +	struct fsl_asrc *asrc = m2m->pdata.asrc;
> +	struct fsl_asrc_pair *pair;
> +	unsigned long lock_flags;
> +	int i;
> +
> +	for (i = 0; i < PAIR_CTX_NUM; i++) {
> +		spin_lock_irqsave(&asrc->lock, lock_flags);
> +		pair = asrc->pair[i];
> +		if (!pair || !pair->req_pair) {
> +			spin_unlock_irqrestore(&asrc->lock, lock_flags);
> +			continue;
> +		}
> +		if (asrc->m2m_pair_resume)
> +			asrc->m2m_pair_resume(pair);
> +
> +		spin_unlock_irqrestore(&asrc->lock, lock_flags);
> +	}
> +
> +	return 0;
> +}
> +#endif
> +
> +static const struct dev_pm_ops asrc_m2m_pm_ops = {
> +	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(asrc_m2m_suspend,
> +				      asrc_m2m_resume)
> +};
> +
> +static struct platform_driver asrc_m2m_driver = {
> +	.probe  = asrc_m2m_probe,
> +	.remove_new = asrc_m2m_remove,
> +	.driver = {
> +		.name = "fsl_asrc_m2m",
> +		.pm = &asrc_m2m_pm_ops,
> +	},
> +};
> +module_platform_driver(asrc_m2m_driver);
> +
> +MODULE_DESCRIPTION("Freescale ASRC M2M driver");
> +MODULE_LICENSE("GPL");

Regards,

	Hans
Shengjiu Wang Oct. 27, 2023, 5:27 a.m. UTC | #3
On Wed, Oct 25, 2023 at 6:47 PM Hans Verkuil <hverkuil@xs4all.nl> wrote:
>
> On 20/10/2023 11:30, Shengjiu Wang wrote:
> > Add V4L2_CID_M2M_AUDIO_SOURCE_RATE and V4L2_CID_M2M_AUDIO_DEST_RATE
> > new IDs for rate control.
> >
> > Add V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET and
> > V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET for clock drift.
> >
> > Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
> > ---
> >  .../media/v4l/ext-ctrls-audio-m2m.rst          | 18 ++++++++++++++++++
> >  drivers/media/v4l2-core/v4l2-ctrls-defs.c      | 12 ++++++++++++
> >  include/uapi/linux/v4l2-controls.h             |  5 +++++
> >  3 files changed, 35 insertions(+)
> >
> > diff --git a/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst b/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
> > index 82d2ecedbfee..e6972a2d3b17 100644
> > --- a/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
> > +++ b/Documentation/userspace-api/media/v4l/ext-ctrls-audio-m2m.rst
> > @@ -19,3 +19,21 @@ Audio M2M Control IDs
> >      The Audio M2M class descriptor. Calling
> >      :ref:`VIDIOC_QUERYCTRL` for this control will
> >      return a description of this control class.
> > +
> > +.. _v4l2-audio-asrc:
> > +
> > +``V4L2_CID_M2M_AUDIO_SOURCE_RATE``
>
> Add ' (integer menu)' after the name.
>
> > +    Sets the audio source rate, unit is (Hz)
>
> (Hz) -> Hz.
>
> General question: is 'rate' good enough or should it be 'sample rate'?

Ok, will use 'sample rate'.

Best regards
Wang shengjiu
>
> > +
> > +``V4L2_CID_M2M_AUDIO_DEST_RATE``
> > +    Sets the audio destination rate, unit is (Hz)
>
> Ditto here.
>
> > +
> > +``V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET``
>
> Add ' (fixed point)' after the name.
>
> > +    Sets the offset for audio source rate, unit is (Hz).
>
> for -> from the
>
> (Hz) -> Hz
>
> > +    Offset expresses the drift of clock if there is. It is
> > +    equal to real rate minus ideal rate.
>
> How about:
>
> The offset compensates for any clock drift. The actual source audio
> rate is the ideal source audio rate from ``V4L2_CID_M2M_AUDIO_SOURCE_RATE``
> plus this fixed point offset.
>
> > +
> > +``V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET``
> > +    Sets the offset for audio destination rate, unit is (Hz)
> > +    Offset expresses the drift of clock if there is. It is
> > +    equal to real rate minus ideal rate.
>
> Same changes as for V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET.
>
> > diff --git a/drivers/media/v4l2-core/v4l2-ctrls-defs.c b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > index 2a85ea3dc92f..b695cbdd1f6e 100644
> > --- a/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > +++ b/drivers/media/v4l2-core/v4l2-ctrls-defs.c
> > @@ -1245,6 +1245,10 @@ const char *v4l2_ctrl_get_name(u32 id)
> >
> >       /* Audio M2M controls */
> >       case V4L2_CID_M2M_AUDIO_CLASS:  return "Audio M2M Controls";
> > +     case V4L2_CID_M2M_AUDIO_SOURCE_RATE:    return "Audio Source Sample Rate";
> > +     case V4L2_CID_M2M_AUDIO_DEST_RATE:      return "Audio Dest Sample Rate";
> > +     case V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET:     return "Audio Source Sample Rate Offset";
> > +     case V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET:       return "Audio Dest Sample Rate Offset";
>
> Related to my question above: "Sample Rate" or just "Rate"? Whatever we pick, it should
> be consistent.
>
> >       default:
> >               return NULL;
> >       }
> > @@ -1606,6 +1610,14 @@ 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_M2M_AUDIO_SOURCE_RATE:
> > +     case V4L2_CID_M2M_AUDIO_DEST_RATE:
> > +             *type = V4L2_CTRL_TYPE_INTEGER_MENU;
> > +             break;
> > +     case V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET:
> > +     case V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET:
> > +             *type = V4L2_CTRL_TYPE_FIXED_POINT;
> > +             break;
> >       default:
> >               *type = V4L2_CTRL_TYPE_INTEGER;
> >               break;
> > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
> > index eb0f0a76f867..d433c6f0b533 100644
> > --- a/include/uapi/linux/v4l2-controls.h
> > +++ b/include/uapi/linux/v4l2-controls.h
> > @@ -3498,4 +3498,9 @@ struct v4l2_ctrl_av1_film_grain {
> >  #define V4L2_CID_M2M_AUDIO_CLASS_BASE  (V4L2_CTRL_CLASS_M2M_AUDIO | 0x900)
> >  #define V4L2_CID_M2M_AUDIO_CLASS       (V4L2_CTRL_CLASS_M2M_AUDIO | 1)
> >
> > +#define V4L2_CID_M2M_AUDIO_SOURCE_RATE       (V4L2_CID_M2M_AUDIO_CLASS_BASE + 0)
> > +#define V4L2_CID_M2M_AUDIO_DEST_RATE (V4L2_CID_M2M_AUDIO_CLASS_BASE + 1)
> > +#define V4L2_CID_M2M_AUDIO_SOURCE_RATE_OFFSET        (V4L2_CID_M2M_AUDIO_CLASS_BASE + 2)
> > +#define V4L2_CID_M2M_AUDIO_DEST_RATE_OFFSET  (V4L2_CID_M2M_AUDIO_CLASS_BASE + 3)
> > +
> >  #endif
>
> Regards,
>
>         Hans