Re: [PATCH v6 12/14] media: mtk-vcodec: vdec: add media device if using stateless api

[Dafna Hirschfeld <dafna.hirschfeld@collabora.com>]

On 05.07.21 07:32, Alexandre Courbot wrote:
> From: Yunfei Dong <yunfei.dong@mediatek.com>
> 
> The stateless API requires a media device for issuing requests. Add one
> if we are being instantiated as a stateless decoder.
> 
> Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
> [acourbot: refactor, cleanup and split]
> Co-developed-by: Alexandre Courbot <acourbot@chromium.org>
> Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
> Reviewed-by: Tzung-Bi Shih <tzungbi@google.com>
> ---
>   drivers/media/platform/Kconfig                |  2 +
>   .../platform/mtk-vcodec/mtk_vcodec_dec_drv.c  | 38 +++++++++++++++++++
>   .../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..aa277a19e275 100644
> --- a/drivers/media/platform/Kconfig
> +++ b/drivers/media/platform/Kconfig
> @@ -315,6 +315,8 @@ 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
> +	select MEDIA_CONTROLLER_REQUEST_API
>   	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 1460951f302c..c8a84fa11e4a 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"
> @@ -316,6 +317,30 @@ 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);

the media's node minor is not vfd_dec->num

> +	}
>   	ret = video_register_device(vfd_dec, VFL_TYPE_VIDEO, 0);
>   	if (ret) {
>   		mtk_v4l2_err("Failed to register video device");
> @@ -328,6 +353,12 @@ 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);
> @@ -360,6 +391,13 @@ 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 8fb333a99a40..d4f840a7bbcb 100644
> --- a/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
> +++ b/drivers/media/platform/mtk-vcodec/mtk_vcodec_drv.h
> @@ -389,6 +389,7 @@ 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
> @@ -426,6 +427,7 @@ struct mtk_vcodec_enc_pdata {
>   struct mtk_vcodec_dev {

This structs has a lot of duplicated fields for enc/dec
Since the device represents either a decoder or an encoder,
I think all those dupliactes can be removed, so for example
instead of having both 'dec_irq' and 'enc_irq' we can have just 'irq'

Thanks,
Dafna

>   	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;
>