Re: [PATCH v4 07/15] media: mtk-vcodec: vdec: add media device if using stateless api

[Hans Verkuil]

On 27/04/2021 13:15, Alexandre Courbot wrote:
> From: Yunfei Dong <yunfei.dong@xxxxxxxxxxxx>
> 
> The stateless API requires a media device for issuing requests. Add one
> if we are being instantiated as a stateless decoder.

Why for the stateless decoder only? Why not create one for all?

It's not a blocker, but I would recommend looking at this.

Regards,

	Hans

> 
> Signed-off-by: Yunfei Dong <yunfei.dong@xxxxxxxxxxxx>
> [acourbot: refactor, cleanup and split]
> Co-developed-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
> Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
> ---
>  drivers/media/platform/Kconfig                |  1 +
>  .../platform/mtk-vcodec/mtk_vcodec_dec_drv.c  | 39 +++++++++++++++++++
>  .../platform/mtk-vcodec/mtk_vcodec_drv.h      |  2 +
>  3 files changed, 42 insertions(+)
> 
> diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> index ae1468aa1b4e..4154fdec2efb 100644
> --- a/drivers/media/platform/Kconfig
> +++ b/drivers/media/platform/Kconfig
> @@ -315,6 +315,7 @@ config VIDEO_MEDIATEK_VCODEC
>  	select VIDEO_MEDIATEK_VCODEC_VPU if VIDEO_MEDIATEK_VPU
>  	select VIDEO_MEDIATEK_VCODEC_SCP if MTK_SCP
>  	select V4L2_H264
> +	select MEDIA_CONTROLLER
>  	help
>  	  Mediatek video codec driver provides HW capability to
>  	  encode and decode in a range of video formats on MT8173
> diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c
> index 533781d4680a..e942e28f96fe 100644
> --- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c
> +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_dec_drv.c
> @@ -14,6 +14,7 @@
>  #include <media/v4l2-event.h>
>  #include <media/v4l2-mem2mem.h>
>  #include <media/videobuf2-dma-contig.h>
> +#include <media/v4l2-device.h>
>  
>  #include "mtk_vcodec_drv.h"
>  #include "mtk_vcodec_dec.h"
> @@ -324,6 +325,31 @@ static int mtk_vcodec_probe(struct platform_device *pdev)
>  		goto err_event_workq;
>  	}
>  
> +	if (dev->vdec_pdata->uses_stateless_api) {
> +		dev->mdev_dec.dev = &pdev->dev;
> +		strscpy(dev->mdev_dec.model, MTK_VCODEC_DEC_NAME,
> +				sizeof(dev->mdev_dec.model));
> +
> +		media_device_init(&dev->mdev_dec);
> +		dev->mdev_dec.ops = &mtk_vcodec_media_ops;
> +		dev->v4l2_dev.mdev = &dev->mdev_dec;
> +
> +		ret = v4l2_m2m_register_media_controller(dev->m2m_dev_dec,
> +			dev->vfd_dec, MEDIA_ENT_F_PROC_VIDEO_DECODER);
> +		if (ret) {
> +			mtk_v4l2_err("Failed to register media controller");
> +			goto err_reg_cont;
> +		}
> +
> +		ret = media_device_register(&dev->mdev_dec);
> +		if (ret) {
> +			mtk_v4l2_err("Failed to register media device");
> +			goto err_media_reg;
> +		}
> +
> +		mtk_v4l2_debug(0, "media registered as /dev/media%d",
> +			vfd_dec->num);
> +	}
>  	ret = video_register_device(vfd_dec, VFL_TYPE_VIDEO, 0);
>  	if (ret) {
>  		mtk_v4l2_err("Failed to register video device");
> @@ -336,6 +362,12 @@ static int mtk_vcodec_probe(struct platform_device *pdev)
>  	return 0;
>  
>  err_dec_reg:
> +	if (dev->vdec_pdata->uses_stateless_api)
> +		media_device_unregister(&dev->mdev_dec);
> +err_media_reg:
> +	if (dev->vdec_pdata->uses_stateless_api)
> +		v4l2_m2m_unregister_media_controller(dev->m2m_dev_dec);
> +err_reg_cont:
>  	destroy_workqueue(dev->decode_workqueue);
>  err_event_workq:
>  	v4l2_m2m_release(dev->m2m_dev_dec);
> @@ -368,6 +400,13 @@ static int mtk_vcodec_dec_remove(struct platform_device *pdev)
>  
>  	flush_workqueue(dev->decode_workqueue);
>  	destroy_workqueue(dev->decode_workqueue);
> +
> +	if (media_devnode_is_registered(dev->mdev_dec.devnode)) {
> +		media_device_unregister(&dev->mdev_dec);
> +		v4l2_m2m_unregister_media_controller(dev->m2m_dev_dec);
> +		media_device_cleanup(&dev->mdev_dec);
> +	}
> +
>  	if (dev->m2m_dev_dec)
>  		v4l2_m2m_release(dev->m2m_dev_dec);
>  
> diff --git a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
> index 78d4a7728ddf..10edd238c939 100644
> --- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
> +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
> @@ -383,6 +383,7 @@ struct mtk_vcodec_enc_pdata {
>   * struct mtk_vcodec_dev - driver data
>   * @v4l2_dev: V4L2 device to register video devices for.
>   * @vfd_dec: Video device for decoder
> + * @mdev_dec: Media device for decoder
>   * @vfd_enc: Video device for encoder.
>   *
>   * @m2m_dev_dec: m2m device for decoder
> @@ -418,6 +419,7 @@ struct mtk_vcodec_enc_pdata {
>  struct mtk_vcodec_dev {
>  	struct v4l2_device v4l2_dev;
>  	struct video_device *vfd_dec;
> +	struct media_device mdev_dec;
>  	struct video_device *vfd_enc;
>  
>  	struct v4l2_m2m_dev *m2m_dev_dec;
>