Re: [PATCH v11 15/15] media: vim2m-audio: add virtual driver for audio memory to memory
From: Hans Verkuil
Date: Thu Jan 18 2024 - 02:56:25 EST
On 18/01/2024 07:13, Shengjiu Wang wrote:
> On Wed, Jan 17, 2024 at 6:32 PM Hans Verkuil <hverkuil@xxxxxxxxx> 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@xxxxxxx>
>>> ---
>>> 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'
You should also drop the line filling in the bus_info in the media device:
<snip>
>>> +static int audm2m_probe(struct platform_device *pdev)
>>> +{
<snip>
>>> +#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);
Drop this line.
>>> + media_device_init(&dev->mdev);
This function will fill it in automatically as well, and with the same
name as querycap.
Regards,
Hans
>>> + 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