Re: [RFC PATCH v6 11/11] media: viaudm2m: add virtual driver for audio memory to memory

On 13/10/2023 10:31, 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 | 9 + drivers/media/test-drivers/Makefile | 1 + drivers/media/test-drivers/viaudm2m.c | 707 ++++++++++++++++++++++++++ 3 files changed, 717 insertions(+) create mode 100644 drivers/media/test-drivers/viaudm2m.c

diff --git a/drivers/media/test-drivers/Kconfig b/drivers/media/test-drivers/Kconfig index 459b433e9fae..143d829e1b67 100644 --- a/drivers/media/test-drivers/Kconfig +++ b/drivers/media/test-drivers/Kconfig @@ -17,6 +17,15 @@ config VIDEO_VIM2M This is a virtual test device for the memory-to-memory driver framework.

+config VIDEO_VIAUDM2M

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

I think this is better:

VIDEO_VIM2M_AUDIO

and name the source: vim2m_audio.c.

• depends on VIDEO_DEV
• select VIDEOBUF2_VMALLOC
• select V4L2_MEM2MEM_DEV
• 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..a39d27eb53fa 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-$(CONFIG_VIDEO_VIAUDM2M) += viaudm2m.o obj-$(CONFIG_VIDEO_VIMC) += vimc/ obj-$(CONFIG_VIDEO_VIVID) += vivid/ obj-$(CONFIG_VIDEO_VISL) += visl/ diff --git a/drivers/media/test-drivers/viaudm2m.c b/drivers/media/test-drivers/viaudm2m.c new file mode 100644 index 000000000000..5fefd616b6c8 --- /dev/null +++ b/drivers/media/test-drivers/viaudm2m.c @@ -0,0 +1,707 @@ +// 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"); +MODULE_VERSION("0.1");

Drop this, rarely needed.

+MODULE_ALIAS("audio_mem2mem_testdev");

Drop this as well. I'm not sure why it is in the original vim2m.c source.

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

+#define MEM2MEM_NAME "viaudm2m"

"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,

+};

+struct audm2m_fmt {

• u32 fourcc;
• snd_pcm_format_t format;

Same as for the previous driver: I think you can just drop this field and thus the whole struct.

+};

+static struct audm2m_fmt formats[] = {

And this is just a u32 array.

• {

• .fourcc = V4L2_AUDIO_FMT_S8,
  

• },
• {

• .fourcc = V4L2_AUDIO_FMT_S16_LE,
  

• },
• {

• .fourcc = V4L2_AUDIO_FMT_U16_LE,
  

• },
• {

• .fourcc = V4L2_AUDIO_FMT_S24_LE,
  

• },
• {

• .fourcc = V4L2_AUDIO_FMT_S24_3LE,
  

• },
• {

• .fourcc = V4L2_AUDIO_FMT_U24_LE,
  

• },
• {

• .fourcc = V4L2_AUDIO_FMT_U24_3LE,
  

• },
• {

• .fourcc = V4L2_AUDIO_FMT_S32_LE,
  

• },
• {

• .fourcc = V4L2_AUDIO_FMT_U32_LE,
  

• },
• {

• .fourcc = V4L2_AUDIO_FMT_S20_3LE,
  

• },
• {

• .fourcc = V4L2_AUDIO_FMT_U20_3LE,
  

• },

+};

+#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;
• struct audm2m_fmt *fmt;

+};

+enum {

• V4L2_M2M_SRC = 0,
• V4L2_M2M_DST = 1,

+};

+static struct audm2m_fmt *find_format(u32 fourcc) +{

• struct audm2m_fmt *fmt;
• unsigned int k;
• for (k = 0; k < NUM_FORMATS; k++) {

• fmt = &formats[k];
  

• if (fmt->fourcc == fourcc)
  

• 	break;
  

• }
• if (k == NUM_FORMATS)

• return NULL;
  

• formats[k].format = (__force snd_pcm_format_t)v4l2_fourcc_to_audfmt(formats[k].fourcc);
• return &formats[k];

+}

+struct audm2m_dev {

• struct v4l2_device v4l2_dev;
• struct video_device vfd;
• struct mutex dev_mutex;
• struct v4l2_m2m_dev *m2m_dev;

+};

+struct audm2m_ctx {

• struct v4l2_fh fh;
• 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;
• 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);
• /* Process the conversion */
• src_size = vb2_get_plane_payload(&src_buf->vb2_buf, 0);
• if (src_size > q_data_dst->buffersize)

• dst_size = q_data_dst->buffersize;
  

• else

• dst_size = src_size;
  

• memcpy(vb2_plane_vaddr(&dst_buf->vb2_buf, 0),

•       vb2_plane_vaddr(&src_buf->vb2_buf, 0),
  

•       dst_size);
  

• 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);
  

• return 0;

+}

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

• int i, num;
• struct audm2m_fmt *fmt;
• 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 */
  

• fmt = &formats[i];
  

• f->pixelformat = fmt->fourcc;
  

• 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->fmt->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, struct audm2m_fmt *fmt) +{

• if (f->fmt.audio.channels < 1)

• f->fmt.audio.channels = 1;
  

• else if (f->fmt.audio.channels > 8)

• f->fmt.audio.channels = 8;
  

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

• 		  snd_pcm_format_physical_width(fmt->format) *
  

• 		  SAMPLE_NUM;
  

• return 0;

+}

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

• 		    struct v4l2_format *f)
  

+{

• struct audm2m_fmt *fmt;
• fmt = find_format(f->fmt.audio.audioformat);
• if (!fmt) {

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

• 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)
  

+{

• struct audm2m_fmt *fmt;
• fmt = find_format(f->fmt.audio.audioformat);
• if (!fmt) {

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

• 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;
• 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->fmt = find_format(f->fmt.audio.audioformat);
• q_data->channels = f->fmt.audio.channels;
• q_data->buffersize = q_data->channels *

• 	     snd_pcm_format_physical_width(q_data->fmt->format) *
  

• 	     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->fmt->fourcc & 0xff),
  

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

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

• (q_data->fmt->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 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,
• .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;
• 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;
• return vb2_queue_init(dst_vq);

+}

+/*

• • File operations
• */

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

• struct audm2m_dev *dev = video_drvdata(file);
• struct audm2m_ctx *ctx = NULL;
• 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].fmt = &formats[0];
• ctx->q_data[V4L2_M2M_SRC].rate = 8000;
• ctx->q_data[V4L2_M2M_SRC].channels = 2;
• /* Fix to 4096 samples */
• width = snd_pcm_format_physical_width(formats[0].format);
• ctx->q_data[V4L2_M2M_SRC].buffersize = SAMPLE_NUM * 2 * 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);
  

+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_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);
• 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 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);
• v4l2_info(&dev->v4l2_dev,

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

• 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;
  

• }
• 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;
  

• }
• return 0;

+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);
• 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