Re: [PATCH v11 15/15] media: vim2m-audio: add virtual driver for audio memory to memory

On Wed, Jan 17, 2024 at 6:32 PM Hans Verkuil hverkuil@xs4all.nl wrote:

On 22/11/2023 08:23, Shengjiu Wang wrote:

...

Audio memory to memory virtual driver use video memory to memory virtual driver vim2m.c as example. The main difference is device type is VFL_TYPE_AUDIO and device cap type is V4L2_CAP_AUDIO_M2M.

The device_run function is a dummy function, which is simply copy the data from input buffer to output buffer.

Signed-off-by: Shengjiu Wang shengjiu.wang@nxp.com

drivers/media/test-drivers/Kconfig | 11 + drivers/media/test-drivers/Makefile | 1 + drivers/media/test-drivers/vim2m-audio.c | 799 +++++++++++++++++++++++ 3 files changed, 811 insertions(+) create mode 100644 drivers/media/test-drivers/vim2m-audio.c

diff --git a/drivers/media/test-drivers/Kconfig b/drivers/media/test-drivers/Kconfig index 459b433e9fae..55f8af6ee4e2 100644 --- a/drivers/media/test-drivers/Kconfig +++ b/drivers/media/test-drivers/Kconfig @@ -17,6 +17,17 @@ config VIDEO_VIM2M This is a virtual test device for the memory-to-memory driver framework.

+config VIDEO_VIM2M_AUDIO

• tristate "Virtual Memory-to-Memory Driver For Audio"
  

• depends on VIDEO_DEV
  

• select VIDEOBUF2_VMALLOC
  

• select V4L2_MEM2MEM_DEV
  

• select MEDIA_CONTROLLER
  

• select MEDIA_CONTROLLER_REQUEST_API
  

Drop this. This option has been removed.

...

• help
  

•   This is a virtual audio test device for the memory-to-memory driver
  

•   framework.
  

source "drivers/media/test-drivers/vicodec/Kconfig" source "drivers/media/test-drivers/vimc/Kconfig" source "drivers/media/test-drivers/vivid/Kconfig" diff --git a/drivers/media/test-drivers/Makefile b/drivers/media/test-drivers/Makefile index 740714a4584d..0c61c9ada3e1 100644 --- a/drivers/media/test-drivers/Makefile +++ b/drivers/media/test-drivers/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_DVB_VIDTV) += vidtv/

obj-$(CONFIG_VIDEO_VICODEC) += vicodec/ obj-$(CONFIG_VIDEO_VIM2M) += vim2m.o +obj-$(CONFIG_VIDEO_VIM2M_AUDIO) += vim2m-audio.o obj-$(CONFIG_VIDEO_VIMC) += vimc/ obj-$(CONFIG_VIDEO_VIVID) += vivid/ obj-$(CONFIG_VIDEO_VISL) += visl/ diff --git a/drivers/media/test-drivers/vim2m-audio.c b/drivers/media/test-drivers/vim2m-audio.c new file mode 100644 index 000000000000..72806ada8628 --- /dev/null +++ b/drivers/media/test-drivers/vim2m-audio.c @@ -0,0 +1,799 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*

• • A virtual v4l2-mem2mem example for audio device.
• */

+#include <linux/module.h> +#include <linux/delay.h> +#include <linux/fs.h> +#include <linux/sched.h> +#include <linux/slab.h>

+#include <linux/platform_device.h> +#include <media/v4l2-mem2mem.h> +#include <media/v4l2-device.h> +#include <media/v4l2-ioctl.h> +#include <media/v4l2-ctrls.h> +#include <media/v4l2-event.h> +#include <media/videobuf2-vmalloc.h> +#include <sound/dmaengine_pcm.h>

+MODULE_DESCRIPTION("Virtual device for audio mem2mem testing"); +MODULE_LICENSE("GPL");

+static unsigned int debug; +module_param(debug, uint, 0644); +MODULE_PARM_DESC(debug, "debug level");

+#define MEM2MEM_NAME "vim2m-audio"

+#define dprintk(dev, lvl, fmt, arg...) \

• v4l2_dbg(lvl, debug, &(dev)->v4l2_dev, "%s: " fmt, __func__, ## arg)
  

+#define SAMPLE_NUM 4096

+static void audm2m_dev_release(struct device *dev) +{}

+static struct platform_device audm2m_pdev = {

• .name           = MEM2MEM_NAME,
  

• .dev.release    = audm2m_dev_release,
  

+};

+static u32 formats[] = {

• V4L2_AUDIO_FMT_S16_LE,
  

+};

+#define NUM_FORMATS ARRAY_SIZE(formats)

+/* Per-queue, driver-specific private data */ +struct audm2m_q_data {

• unsigned int            rate;
  

• unsigned int            channels;
  

• unsigned int            buffersize;
  

• unsigned int            sequence;
  

• u32                     fourcc;
  

+};

+enum {

• V4L2_M2M_SRC = 0,
  

• V4L2_M2M_DST = 1,
  

+};

+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;
  

+}

+struct audm2m_dev {

• struct v4l2_device      v4l2_dev;
  

• struct video_device     vfd;
  

• struct mutex            dev_mutex;
  

• struct v4l2_m2m_dev     *m2m_dev;
  

+#ifdef CONFIG_MEDIA_CONTROLLER

• struct media_device     mdev;
  

+#endif +};

+struct audm2m_ctx {

• struct v4l2_fh          fh;
  

• struct v4l2_ctrl_handler        ctrl_handler;
  

• struct audm2m_dev       *dev;
  

• struct mutex            vb_mutex;
  

• /* Source and destination queue data */
  

• struct audm2m_q_data   q_data[2];
  

+};

+static inline struct audm2m_ctx *file2ctx(struct file *file) +{

• return container_of(file->private_data, struct audm2m_ctx, fh);
  

+}

+static struct audm2m_q_data *get_q_data(struct audm2m_ctx *ctx,

•                                 enum v4l2_buf_type type)
  

+{

• if (type == V4L2_BUF_TYPE_AUDIO_OUTPUT)
  

•         return &ctx->q_data[V4L2_M2M_SRC];
  

• return &ctx->q_data[V4L2_M2M_DST];
  

+}

+static const char *type_name(enum v4l2_buf_type type) +{

• if (type == V4L2_BUF_TYPE_AUDIO_OUTPUT)
  

•         return "Output";
  

• return "Capture";
  

+}

+/*

• • mem2mem callbacks
• */

+/*

• • device_run() - prepares and starts the device
• */

+static void device_run(void *priv) +{

• struct audm2m_ctx *ctx = priv;
  

• struct audm2m_dev *audm2m_dev;
  

• struct vb2_v4l2_buffer *src_buf, *dst_buf;
  

• struct audm2m_q_data *q_data_src, *q_data_dst;
  

• int src_size, dst_size = 0;
  

• short *src_addr, *dst_addr;
  

• int i;
  

• audm2m_dev = ctx->dev;
  

• q_data_src = get_q_data(ctx, V4L2_BUF_TYPE_AUDIO_OUTPUT);
  

• if (!q_data_src)
  

•         return;
  

• q_data_dst = get_q_data(ctx, V4L2_BUF_TYPE_AUDIO_CAPTURE);
  

• if (!q_data_dst)
  

•         return;
  

• src_buf = v4l2_m2m_next_src_buf(ctx->fh.m2m_ctx);
  

• dst_buf = v4l2_m2m_next_dst_buf(ctx->fh.m2m_ctx);
  

• src_buf->sequence = q_data_src->sequence++;
  

• dst_buf->sequence = q_data_dst->sequence++;
  

• v4l2_m2m_buf_copy_metadata(src_buf, dst_buf, false);
  

• /* Process the conversion */
  

• src_size = vb2_get_plane_payload(&src_buf->vb2_buf, 0);
  

• src_addr = vb2_plane_vaddr(&src_buf->vb2_buf, 0);
  

• dst_addr = vb2_plane_vaddr(&dst_buf->vb2_buf, 0);
  

• if (q_data_src->rate == q_data_dst->rate) {
  

•         memcpy(dst_addr, src_addr, src_size);
  

•         dst_size = src_size;
  

• } else if (q_data_src->rate == 2 * q_data_dst->rate) {
  

•         /* 8k to 16k */
  

•         for (i = 0; i < src_size / 2; i++) {
  

•                 *dst_addr++ = *src_addr++;
  

•                 src_addr++;
  

•         }
  

•         dst_size = src_size / 2;
  

• } else if (q_data_src->rate * 2 == q_data_dst->rate) {
  

•         /* 16k to 8k */
  

•         for (i = 0; i < src_size / 2; i++) {
  

•                 *dst_addr++ = *src_addr;
  

•                 *dst_addr++ = *src_addr++;
  

•         }
  

•         dst_size = src_size * 2;
  

• }
  

• vb2_set_plane_payload(&dst_buf->vb2_buf, 0, dst_size);
  

• src_buf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
  

• dst_buf = v4l2_m2m_dst_buf_remove(ctx->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(audm2m_dev->m2m_dev, ctx->fh.m2m_ctx);
  

+}

+static int audm2m_querycap(struct file *file, void *priv,

•                    struct v4l2_capability *cap)
  

+{

• strscpy(cap->driver, MEM2MEM_NAME, sizeof(cap->driver));
  

• strscpy(cap->card, MEM2MEM_NAME, sizeof(cap->card));
  

• snprintf(cap->bus_info, sizeof(cap->bus_info),
  

•          "platform:%s", MEM2MEM_NAME);
  

You can drop this bus_info line, it's filled in for you.

I see there is a warning from v4l2-compliance test if this line is removed.

warn: v4l2-compliance.cpp(676): media bus_info 'platform:vim2m-audio' differs from V4L2 bus_info 'platform:vim2m-audio.0'

Best regards Shengjiu Wang

...

• return 0;
  

+}

+static int enum_fmt(struct v4l2_fmtdesc *f) +{

• int i, num;
  

• num = 0;
  

• for (i = 0; i < NUM_FORMATS; ++i) {
  

•         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;
  

• }
  

• /* Format not found */
  

• return -EINVAL;
  

+}

+static int audm2m_enum_fmt_audio_cap(struct file *file, void *priv,

•                              struct v4l2_fmtdesc *f)
  

+{

• return enum_fmt(f);
  

+}

+static int audm2m_enum_fmt_audio_out(struct file *file, void *priv,

•                              struct v4l2_fmtdesc *f)
  

+{

• return enum_fmt(f);
  

+}

+static int audm2m_g_fmt(struct audm2m_ctx *ctx, struct v4l2_format *f) +{

• struct vb2_queue *vq;
  

• struct audm2m_q_data *q_data;
  

• vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
  

• if (!vq)
  

•         return -EINVAL;
  

• q_data = get_q_data(ctx, f->type);
  

• if (!q_data)
  

•         return -EINVAL;
  

• f->fmt.audio.audioformat = q_data->fourcc;
  

• f->fmt.audio.channels   = q_data->channels;
  

• f->fmt.audio.buffersize = q_data->buffersize;
  

• return 0;
  

+}

+static int audm2m_g_fmt_audio_out(struct file *file, void *priv,

•                           struct v4l2_format *f)
  

+{

• return audm2m_g_fmt(file2ctx(file), f);
  

+}

+static int audm2m_g_fmt_audio_cap(struct file *file, void *priv,

•                           struct v4l2_format *f)
  

+{

• return audm2m_g_fmt(file2ctx(file), f);
  

+}

+static int audm2m_try_fmt(struct v4l2_format *f, snd_pcm_format_t fmt) +{

• f->fmt.audio.channels = 1;
  

• f->fmt.audio.buffersize = f->fmt.audio.channels *
  

•                           snd_pcm_format_physical_width(fmt) *
  

•                           SAMPLE_NUM;
  

• return 0;
  

+}

+static int audm2m_try_fmt_audio_cap(struct file *file, void *priv,

•                             struct v4l2_format *f)
  

+{

• snd_pcm_format_t fmt;
  

• fmt = find_format(f->fmt.audio.audioformat);
  

• if (!fmt) {
  

•         f->fmt.audio.audioformat = formats[0];
  

•         fmt = find_format(f->fmt.audio.audioformat);
  

• }
  

• return audm2m_try_fmt(f, fmt);
  

+}

+static int audm2m_try_fmt_audio_out(struct file *file, void *priv,

•                             struct v4l2_format *f)
  

+{

• snd_pcm_format_t fmt;
  

• fmt = find_format(f->fmt.audio.audioformat);
  

• if (!fmt) {
  

•         f->fmt.audio.audioformat = formats[0];
  

•         fmt = find_format(f->fmt.audio.audioformat);
  

• }
  

• return audm2m_try_fmt(f, fmt);
  

+}

+static int audm2m_s_fmt(struct audm2m_ctx *ctx, struct v4l2_format *f) +{

• struct audm2m_q_data *q_data;
  

• struct vb2_queue *vq;
  

• snd_pcm_format_t fmt;
  

• vq = v4l2_m2m_get_vq(ctx->fh.m2m_ctx, f->type);
  

• if (!vq)
  

•         return -EINVAL;
  

• q_data = get_q_data(ctx, f->type);
  

• if (!q_data)
  

•         return -EINVAL;
  

• if (vb2_is_busy(vq)) {
  

•         v4l2_err(&ctx->dev->v4l2_dev, "%s queue busy\n", __func__);
  

•         return -EBUSY;
  

• }
  

• q_data->fourcc  = f->fmt.audio.audioformat;
  

• q_data->channels = f->fmt.audio.channels;
  

• fmt = find_format(f->fmt.audio.audioformat);
  

• q_data->buffersize = q_data->channels *
  

•                      snd_pcm_format_physical_width(fmt) *
  

•                      SAMPLE_NUM;
  

• dprintk(ctx->dev, 1,
  

•         "Format for type %s: %d/%d, fmt: %c%c%c%c\n",
  

•         type_name(f->type), q_data->rate,
  

•         q_data->channels,
  

•         (q_data->fourcc & 0xff),
  

•         (q_data->fourcc >>  8) & 0xff,
  

•         (q_data->fourcc >> 16) & 0xff,
  

•         (q_data->fourcc >> 24) & 0xff);
  

• return 0;
  

+}

+static int audm2m_s_fmt_audio_cap(struct file *file, void *priv,

•                           struct v4l2_format *f)
  

+{

• int ret;
  

• ret = audm2m_try_fmt_audio_cap(file, priv, f);
  

• if (ret)
  

•         return ret;
  

• return audm2m_s_fmt(file2ctx(file), f);
  

+}

+static int audm2m_s_fmt_audio_out(struct file *file, void *priv,

•                           struct v4l2_format *f)
  

+{

• int ret;
  

• ret = audm2m_try_fmt_audio_out(file, priv, f);
  

• if (ret)
  

•         return ret;
  

• return audm2m_s_fmt(file2ctx(file), f);
  

+}

+static const struct v4l2_ioctl_ops audm2m_ioctl_ops = {

• .vidioc_querycap                = audm2m_querycap,
  

• .vidioc_enum_fmt_audio_cap      = audm2m_enum_fmt_audio_cap,
  

• .vidioc_g_fmt_audio_cap         = audm2m_g_fmt_audio_cap,
  

• .vidioc_try_fmt_audio_cap       = audm2m_try_fmt_audio_cap,
  

• .vidioc_s_fmt_audio_cap         = audm2m_s_fmt_audio_cap,
  

• .vidioc_enum_fmt_audio_out      = audm2m_enum_fmt_audio_out,
  

• .vidioc_g_fmt_audio_out         = audm2m_g_fmt_audio_out,
  

• .vidioc_try_fmt_audio_out       = audm2m_try_fmt_audio_out,
  

• .vidioc_s_fmt_audio_out         = audm2m_s_fmt_audio_out,
  

• .vidioc_reqbufs                 = v4l2_m2m_ioctl_reqbufs,
  

• .vidioc_querybuf                = v4l2_m2m_ioctl_querybuf,
  

• .vidioc_qbuf                    = v4l2_m2m_ioctl_qbuf,
  

• .vidioc_dqbuf                   = v4l2_m2m_ioctl_dqbuf,
  

• .vidioc_prepare_buf             = v4l2_m2m_ioctl_prepare_buf,
  

• .vidioc_create_bufs             = v4l2_m2m_ioctl_create_bufs,
  

• .vidioc_expbuf                  = v4l2_m2m_ioctl_expbuf,
  

• .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,
  

+};

+/*

• • Queue operations
• */

+static int audm2m_queue_setup(struct vb2_queue *vq,

•                       unsigned int *nbuffers,
  

•                       unsigned int *nplanes,
  

•                       unsigned int sizes[],
  

•                       struct device *alloc_devs[])
  

+{

• struct audm2m_ctx *ctx = vb2_get_drv_priv(vq);
  

• struct audm2m_q_data *q_data;
  

• q_data = get_q_data(ctx, vq->type);
  

• if (*nplanes)
  

•         return sizes[0] < q_data->buffersize ? -EINVAL : 0;
  

• *nplanes = 1;
  

• sizes[0] = q_data->buffersize;
  

• dprintk(ctx->dev, 1, "%s: get %d buffer(s) of size %d each.\n",
  

•         type_name(vq->type), *nplanes, sizes[0]);
  

• return 0;
  

+}

+static void audm2m_buf_queue(struct vb2_buffer *vb) +{

• struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
  

• struct audm2m_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
  

• v4l2_m2m_buf_queue(ctx->fh.m2m_ctx, vbuf);
  

+}

+static int audm2m_start_streaming(struct vb2_queue *q, unsigned int count) +{

• struct audm2m_ctx *ctx = vb2_get_drv_priv(q);
  

• struct audm2m_q_data *q_data = get_q_data(ctx, q->type);
  

• q_data->sequence = 0;
  

• return 0;
  

+}

+static void audm2m_stop_streaming(struct vb2_queue *q) +{

• struct audm2m_ctx *ctx = vb2_get_drv_priv(q);
  

• struct vb2_v4l2_buffer *vbuf;
  

• for (;;) {
  

•         if (V4L2_TYPE_IS_OUTPUT(q->type))
  

•                 vbuf = v4l2_m2m_src_buf_remove(ctx->fh.m2m_ctx);
  

•         else
  

•                 vbuf = v4l2_m2m_dst_buf_remove(ctx->fh.m2m_ctx);
  

•         if (!vbuf)
  

•                 return;
  

•         v4l2_m2m_buf_done(vbuf, VB2_BUF_STATE_ERROR);
  

• }
  

+}

+static const struct vb2_ops audm2m_qops = {

• .queue_setup     = audm2m_queue_setup,
  

• .buf_queue       = audm2m_buf_queue,
  

• .start_streaming = audm2m_start_streaming,
  

• .stop_streaming  = audm2m_stop_streaming,
  

• .wait_prepare    = vb2_ops_wait_prepare,
  

• .wait_finish     = vb2_ops_wait_finish,
  

+};

+static int queue_init(void *priv, struct vb2_queue *src_vq,

•               struct vb2_queue *dst_vq)
  

+{

• struct audm2m_ctx *ctx = priv;
  

• int ret;
  

• src_vq->type = V4L2_BUF_TYPE_AUDIO_OUTPUT;
  

• src_vq->io_modes = VB2_MMAP | VB2_DMABUF;
  

• src_vq->drv_priv = ctx;
  

• src_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
  

• src_vq->ops = &audm2m_qops;
  

• src_vq->mem_ops = &vb2_vmalloc_memops;
  

• src_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
  

• src_vq->lock = &ctx->vb_mutex;
  

• src_vq->min_buffers_needed = 1;
  

Drop this, it's not needed.

...

• 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 = ctx;
  

• dst_vq->buf_struct_size = sizeof(struct v4l2_m2m_buffer);
  

• dst_vq->ops = &audm2m_qops;
  

• dst_vq->mem_ops = &vb2_vmalloc_memops;
  

• dst_vq->timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_COPY;
  

• dst_vq->lock = &ctx->vb_mutex;
  

• dst_vq->min_buffers_needed = 1;
  

Ditto.

...

• return vb2_queue_init(dst_vq);
  

+}

+static const s64 audm2m_rates[] = {

• 8000, 16000,
  

+};

+static int audm2m_op_s_ctrl(struct v4l2_ctrl *ctrl) +{

• struct audm2m_ctx *ctx =
  

•         container_of(ctrl->handler, struct audm2m_ctx, ctrl_handler);
  

• int ret = 0;
  

• switch (ctrl->id) {
  

• case V4L2_CID_M2M_AUDIO_SOURCE_RATE:
  

•         ctx->q_data[V4L2_M2M_SRC].rate = ctrl->qmenu_int[ctrl->val];
  

•         break;
  

• case V4L2_CID_M2M_AUDIO_DEST_RATE:
  

•         ctx->q_data[V4L2_M2M_DST].rate = ctrl->qmenu_int[ctrl->val];
  

•         break;
  

• default:
  

•         ret = -EINVAL;
  

•         break;
  

• }
  

• return ret;
  

+}

+static const struct v4l2_ctrl_ops audm2m_ctrl_ops = {

• .s_ctrl = audm2m_op_s_ctrl,
  

+};

+/*

• • File operations
• */

+static int audm2m_open(struct file *file) +{

• struct audm2m_dev *dev = video_drvdata(file);
  

• struct audm2m_ctx *ctx = NULL;
  

• snd_pcm_format_t fmt;
  

• int width;
  

• int rc = 0;
  

• if (mutex_lock_interruptible(&dev->dev_mutex))
  

•         return -ERESTARTSYS;
  

• ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
  

• if (!ctx) {
  

•         rc = -ENOMEM;
  

•         goto open_unlock;
  

• }
  

• v4l2_fh_init(&ctx->fh, video_devdata(file));
  

• file->private_data = &ctx->fh;
  

• ctx->dev = dev;
  

• ctx->q_data[V4L2_M2M_SRC].fourcc = formats[0];
  

• ctx->q_data[V4L2_M2M_SRC].rate = 8000;
  

• ctx->q_data[V4L2_M2M_SRC].channels = 1;
  

• /* Fix to 4096 samples */
  

• fmt = find_format(formats[0]);
  

• width = snd_pcm_format_physical_width(fmt);
  

• ctx->q_data[V4L2_M2M_SRC].buffersize = SAMPLE_NUM * width;
  

• ctx->q_data[V4L2_M2M_DST] = ctx->q_data[V4L2_M2M_SRC];
  

• ctx->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, ctx, &queue_init);
  

• mutex_init(&ctx->vb_mutex);
  

• if (IS_ERR(ctx->fh.m2m_ctx)) {
  

•         rc = PTR_ERR(ctx->fh.m2m_ctx);
  

•         v4l2_fh_exit(&ctx->fh);
  

•         kfree(ctx);
  

•         goto open_unlock;
  

• }
  

• v4l2_fh_add(&ctx->fh);
  

• dprintk(dev, 1, "Created instance: %p, m2m_ctx: %p\n",
  

•         ctx, ctx->fh.m2m_ctx);
  

• v4l2_ctrl_handler_init(&ctx->ctrl_handler, 2);
  

• v4l2_ctrl_new_int_menu(&ctx->ctrl_handler, &audm2m_ctrl_ops,
  

•                        V4L2_CID_M2M_AUDIO_SOURCE_RATE,
  

•                        ARRAY_SIZE(audm2m_rates) - 1, 0, audm2m_rates);
  

• v4l2_ctrl_new_int_menu(&ctx->ctrl_handler, &audm2m_ctrl_ops,
  

•                        V4L2_CID_M2M_AUDIO_DEST_RATE,
  

•                        ARRAY_SIZE(audm2m_rates) - 1, 0, audm2m_rates);
  

• if (ctx->ctrl_handler.error) {
  

•         rc = ctx->ctrl_handler.error;
  

•         v4l2_ctrl_handler_free(&ctx->ctrl_handler);
  

•         goto err_ctrl_handler;
  

• }
  

• ctx->fh.ctrl_handler = &ctx->ctrl_handler;
  

• mutex_unlock(&dev->dev_mutex);
  

• return 0;
  

+err_ctrl_handler:

• v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
  

+open_unlock:

• mutex_unlock(&dev->dev_mutex);
  

• return rc;
  

+}

+static int audm2m_release(struct file *file) +{

• struct audm2m_dev *dev = video_drvdata(file);
  

• struct audm2m_ctx *ctx = file2ctx(file);
  

• dprintk(dev, 1, "Releasing instance %p\n", ctx);
  

• v4l2_ctrl_handler_free(&ctx->ctrl_handler);
  

• v4l2_fh_del(&ctx->fh);
  

• v4l2_fh_exit(&ctx->fh);
  

• mutex_lock(&dev->dev_mutex);
  

• v4l2_m2m_ctx_release(ctx->fh.m2m_ctx);
  

• mutex_unlock(&dev->dev_mutex);
  

• kfree(ctx);
  

• return 0;
  

+}

+static void audm2m_device_release(struct video_device *vdev) +{

• struct audm2m_dev *dev = container_of(vdev, struct audm2m_dev, vfd);
  

• v4l2_device_unregister(&dev->v4l2_dev);
  

• v4l2_m2m_release(dev->m2m_dev);
  

+#ifdef CONFIG_MEDIA_CONTROLLER

• media_device_cleanup(&dev->mdev);
  

+#endif

• kfree(dev);
  

+}

+static const struct v4l2_file_operations audm2m_fops = {

• .owner          = THIS_MODULE,
  

• .open           = audm2m_open,
  

• .release        = audm2m_release,
  

• .poll           = v4l2_m2m_fop_poll,
  

• .unlocked_ioctl = video_ioctl2,
  

• .mmap           = v4l2_m2m_fop_mmap,
  

+};

+static const struct video_device audm2m_videodev = {

• .name           = MEM2MEM_NAME,
  

• .vfl_dir        = VFL_DIR_M2M,
  

• .fops           = &audm2m_fops,
  

• .ioctl_ops      = &audm2m_ioctl_ops,
  

• .minor          = -1,
  

• .release        = audm2m_device_release,
  

• .device_caps    = V4L2_CAP_AUDIO_M2M | V4L2_CAP_STREAMING,
  

+};

+static const struct v4l2_m2m_ops m2m_ops = {

• .device_run     = device_run,
  

+};

+static const struct media_device_ops audm2m_media_ops = {

• .req_validate = vb2_request_validate,
  

• .req_queue = v4l2_m2m_request_queue,
  

+};

+static int audm2m_probe(struct platform_device *pdev) +{

• struct audm2m_dev *dev;
  

• struct video_device *vfd;
  

• int ret;
  

• dev = kzalloc(sizeof(*dev), GFP_KERNEL);
  

• if (!dev)
  

•         return -ENOMEM;
  

• ret = v4l2_device_register(&pdev->dev, &dev->v4l2_dev);
  

• if (ret)
  

•         goto error_free;
  

• mutex_init(&dev->dev_mutex);
  

• dev->vfd = audm2m_videodev;
  

• vfd = &dev->vfd;
  

• vfd->lock = &dev->dev_mutex;
  

• vfd->v4l2_dev = &dev->v4l2_dev;
  

• video_set_drvdata(vfd, dev);
  

• platform_set_drvdata(pdev, dev);
  

• dev->m2m_dev = v4l2_m2m_init(&m2m_ops);
  

• if (IS_ERR(dev->m2m_dev)) {
  

•         v4l2_err(&dev->v4l2_dev, "Failed to init mem2mem device\n");
  

•         ret = PTR_ERR(dev->m2m_dev);
  

•         dev->m2m_dev = NULL;
  

•         goto error_dev;
  

• }
  

+#ifdef CONFIG_MEDIA_CONTROLLER

• dev->mdev.dev = &pdev->dev;
  

• strscpy(dev->mdev.model, MEM2MEM_NAME, sizeof(dev->mdev.model));
  

• snprintf(dev->mdev.bus_info, sizeof(dev->mdev.bus_info),
  

•          "platform:%s", MEM2MEM_NAME);
  

• media_device_init(&dev->mdev);
  

• dev->mdev.ops = &audm2m_media_ops;
  

• dev->v4l2_dev.mdev = &dev->mdev;
  

+#endif

• ret = video_register_device(vfd, VFL_TYPE_AUDIO, 0);
  

• if (ret) {
  

•         v4l2_err(&dev->v4l2_dev, "Failed to register video device\n");
  

•         goto error_m2m;
  

• }
  

+#ifdef CONFIG_MEDIA_CONTROLLER

• ret = v4l2_m2m_register_media_controller(dev->m2m_dev, vfd,
  

•                                          MEDIA_ENT_F_PROC_AUDIO_RESAMPLER);
  

• if (ret) {
  

•         v4l2_err(&dev->v4l2_dev, "Failed to init mem2mem media controller\n");
  

•         goto error_v4l2;
  

• }
  

• ret = media_device_register(&dev->mdev);
  

• if (ret) {
  

•         v4l2_err(&dev->v4l2_dev, "Failed to register mem2mem media device\n");
  

•         goto error_m2m_mc;
  

• }
  

+#endif

• v4l2_info(&dev->v4l2_dev,
  

•           "Device registered as /dev/v4l-audio%d\n", vfd->num);
  

• return 0;
  

+#ifdef CONFIG_MEDIA_CONTROLLER +error_m2m_mc:

• v4l2_m2m_unregister_media_controller(dev->m2m_dev);
  

+#endif +error_v4l2:

• video_unregister_device(&dev->vfd);
  

• /* audm2m_device_release called by video_unregister_device to release various objects */
  

• return ret;
  

+error_m2m:

• v4l2_m2m_release(dev->m2m_dev);
  

+error_dev:

• v4l2_device_unregister(&dev->v4l2_dev);
  

+error_free:

• kfree(dev);
  

• return ret;
  

+}

+static void audm2m_remove(struct platform_device *pdev) +{

• struct audm2m_dev *dev = platform_get_drvdata(pdev);
  

• v4l2_info(&dev->v4l2_dev, "Removing " MEM2MEM_NAME);
  

+#ifdef CONFIG_MEDIA_CONTROLLER

• media_device_unregister(&dev->mdev);
  

• v4l2_m2m_unregister_media_controller(dev->m2m_dev);
  

+#endif

• video_unregister_device(&dev->vfd);
  

+}

+static struct platform_driver audm2m_pdrv = {

• .probe          = audm2m_probe,
  

• .remove_new     = audm2m_remove,
  

• .driver         = {
  

•         .name   = MEM2MEM_NAME,
  

• },
  

+};

+static void __exit audm2m_exit(void) +{

• platform_driver_unregister(&audm2m_pdrv);
  

• platform_device_unregister(&audm2m_pdev);
  

+}

+static int __init audm2m_init(void) +{

• int ret;
  

• ret = platform_device_register(&audm2m_pdev);
  

• if (ret)
  

•         return ret;
  

• ret = platform_driver_register(&audm2m_pdrv);
  

• if (ret)
  

•         platform_device_unregister(&audm2m_pdev);
  

• return ret;
  

+}

+module_init(audm2m_init); +module_exit(audm2m_exit);

Regards,

    Hans