Re: [PATCH] media: rcar-vin: add support for GREY format

From: "Niklas Söderlund" <niklas.soderlund@ragnatech.se>
To: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
	linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Subject: Re: [PATCH] media: rcar-vin: add support for GREY format
Date: Fri, 24 Sep 2021 12:00:20 +0200	[thread overview]
Message-ID: <YU2htCDCbedXi4ai@oden.dyn.berto.se> (raw)
In-Reply-To: <20210924081938.30230-1-nikita.yoush@cogentembedded.com>

Hi Nikita and Vladimir,

Thanks for your work.

On 2021-09-24 11:19:39 +0300, Nikita Yushchenko wrote:
> From: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
> 
> This adds support for MEDIA_BUS_FMT_Y8_1X8 input and V4L2_PIX_FMT_GREY
> output format.

Thanks for this, I'm happy to see this code!

I been wrestling a while with this as I have no sensor where I could 
test it with I always put it off. May I ask what sensor and platform was 
used to test this?

The code looks good and I truest that it's tested and produce a good 
image, one small nit below.

> 
> Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
> Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
> ---
>  drivers/media/platform/rcar-vin/rcar-dma.c  | 14 ++++++++++++++
>  drivers/media/platform/rcar-vin/rcar-v4l2.c |  4 ++++
>  2 files changed, 18 insertions(+)
> 
> diff --git a/drivers/media/platform/rcar-vin/rcar-dma.c b/drivers/media/platform/rcar-vin/rcar-dma.c
> index f5f722ab1d4e..d2bfd3e575fa 100644
> --- a/drivers/media/platform/rcar-vin/rcar-dma.c
> +++ b/drivers/media/platform/rcar-vin/rcar-dma.c
> @@ -114,6 +114,7 @@
>  /* Video n Data Mode Register bits */
>  #define VNDMR_A8BIT(n)		(((n) & 0xff) << 24)
>  #define VNDMR_A8BIT_MASK	(0xff << 24)
> +#define VNDMR_YMODE_Y8		(1 << 12)
>  #define VNDMR_EXRGB		(1 << 8)
>  #define VNDMR_BPSM		(1 << 4)
>  #define VNDMR_ABIT		(1 << 2)
> @@ -603,6 +604,7 @@ void rvin_crop_scale_comp(struct rvin_dev *vin)
>  	case V4L2_PIX_FMT_SGBRG8:
>  	case V4L2_PIX_FMT_SGRBG8:
>  	case V4L2_PIX_FMT_SRGGB8:
> +	case V4L2_PIX_FMT_GREY:
>  		stride /= 2;
>  		break;
>  	default:
> @@ -695,6 +697,7 @@ static int rvin_setup(struct rvin_dev *vin)
>  	case MEDIA_BUS_FMT_SGBRG8_1X8:
>  	case MEDIA_BUS_FMT_SGRBG8_1X8:
>  	case MEDIA_BUS_FMT_SRGGB8_1X8:
> +	case MEDIA_BUS_FMT_Y8_1X8:
>  		vnmc |= VNMC_INF_RAW8;
>  		break;
>  	default:
> @@ -774,6 +777,13 @@ static int rvin_setup(struct rvin_dev *vin)
>  	case V4L2_PIX_FMT_SRGGB8:
>  		dmr = 0;
>  		break;
> +	case V4L2_PIX_FMT_GREY:
> +		if (input_is_yuv) {
> +			dmr = VNDMR_DTMD_YCSEP | VNDMR_YMODE_Y8;
> +			output_is_yuv = true;
> +		} else
> +			dmr = 0;

Please encapsulate the else clause in { } if the corresponding if clause 
body uses { }.

> +		break;
>  	default:
>  		vin_err(vin, "Invalid pixelformat (0x%x)\n",
>  			vin->format.pixelformat);
> @@ -1145,6 +1155,10 @@ static int rvin_mc_validate_format(struct rvin_dev *vin, struct v4l2_subdev *sd,
>  		if (vin->format.pixelformat != V4L2_PIX_FMT_SRGGB8)
>  			return -EPIPE;
>  		break;
> +	case MEDIA_BUS_FMT_Y8_1X8:
> +		if (vin->format.pixelformat != V4L2_PIX_FMT_GREY)
> +			return -EPIPE;
> +		break;
>  	default:
>  		return -EPIPE;
>  	}
> diff --git a/drivers/media/platform/rcar-vin/rcar-v4l2.c b/drivers/media/platform/rcar-vin/rcar-v4l2.c
> index 0d141155f0e3..bdeff51bf768 100644
> --- a/drivers/media/platform/rcar-vin/rcar-v4l2.c
> +++ b/drivers/media/platform/rcar-vin/rcar-v4l2.c
> @@ -82,6 +82,10 @@ static const struct rvin_video_format rvin_formats[] = {
>  		.fourcc			= V4L2_PIX_FMT_SRGGB8,
>  		.bpp			= 1,
>  	},
> +	{
> +		.fourcc			= V4L2_PIX_FMT_GREY,
> +		.bpp			= 1,
> +	},
>  };
>  
>  const struct rvin_video_format *rvin_format_from_pixel(struct rvin_dev *vin,
> -- 
> 2.30.2
> 

-- 
Regards,
Niklas Söderlund