Re: [PATCH] rcar-csi2: Allow configuring of video standard

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Niklas,

Thank you for the patch.

On Sat, Feb 16, 2019 at 11:57:58PM +0100, Niklas Söderlund wrote:
> Allow the hardware to to do proper field detection for interlaced field
> formats by implementing s_std() and g_std(). Depending on which video
> standard is selected the driver needs to setup the hardware to correctly
> identify fields.

I don't think this belongs to the CSI-2 receiver. Standards are really
an analog concept, and should be handled by the analog front-end. At the
CSI-2 level there's no concept of analog standard anymore.

> Later versions of the datasheet have also been updated to make it clear
> that FLD register should be set to 0 when dealing with none interlaced
> field formats.
> 
> Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
> ---
>  drivers/media/platform/rcar-vin/rcar-csi2.c | 33 +++++++++++++++++++--
>  1 file changed, 30 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/media/platform/rcar-vin/rcar-csi2.c b/drivers/media/platform/rcar-vin/rcar-csi2.c
> index f3099f3e536d808a..664d3784be2b9db9 100644
> --- a/drivers/media/platform/rcar-vin/rcar-csi2.c
> +++ b/drivers/media/platform/rcar-vin/rcar-csi2.c
> @@ -361,6 +361,7 @@ struct rcar_csi2 {
>  	struct v4l2_subdev *remote;
>  
>  	struct v4l2_mbus_framefmt mf;
> +	v4l2_std_id std;
>  
>  	struct mutex lock;
>  	int stream_count;
> @@ -389,6 +390,22 @@ static void rcsi2_write(struct rcar_csi2 *priv, unsigned int reg, u32 data)
>  	iowrite32(data, priv->base + reg);
>  }
>  
> +static int rcsi2_s_std(struct v4l2_subdev *sd, v4l2_std_id std)
> +{
> +	struct rcar_csi2 *priv = sd_to_csi2(sd);
> +
> +	priv->std = std;
> +	return 0;
> +}
> +
> +static int rcsi2_g_std(struct v4l2_subdev *sd, v4l2_std_id *std)
> +{
> +	struct rcar_csi2 *priv = sd_to_csi2(sd);
> +
> +	*std = priv->std;
> +	return 0;
> +}
> +
>  static void rcsi2_standby_mode(struct rcar_csi2 *priv, int on)
>  {
>  	if (!on) {
> @@ -475,7 +492,7 @@ static int rcsi2_calc_mbps(struct rcar_csi2 *priv, unsigned int bpp)
>  static int rcsi2_start_receiver(struct rcar_csi2 *priv)
>  {
>  	const struct rcar_csi2_format *format;
> -	u32 phycnt, vcdt = 0, vcdt2 = 0;
> +	u32 phycnt, vcdt = 0, vcdt2 = 0, fld = 0;
>  	unsigned int i;
>  	int mbps, ret;
>  
> @@ -507,6 +524,15 @@ static int rcsi2_start_receiver(struct rcar_csi2 *priv)
>  			vcdt2 |= vcdt_part << ((i % 2) * 16);
>  	}
>  
> +	if (priv->mf.field != V4L2_FIELD_NONE) {
> +		fld =  FLD_FLD_EN4 | FLD_FLD_EN3 | FLD_FLD_EN2 | FLD_FLD_EN;
> +
> +		if (priv->std & V4L2_STD_525_60)
> +			fld |= FLD_FLD_NUM(2);
> +		else
> +			fld |= FLD_FLD_NUM(1);
> +	}
> +
>  	phycnt = PHYCNT_ENABLECLK;
>  	phycnt |= (1 << priv->lanes) - 1;
>  
> @@ -519,8 +545,7 @@ static int rcsi2_start_receiver(struct rcar_csi2 *priv)
>  	rcsi2_write(priv, PHTC_REG, 0);
>  
>  	/* Configure */
> -	rcsi2_write(priv, FLD_REG, FLD_FLD_NUM(2) | FLD_FLD_EN4 |
> -		    FLD_FLD_EN3 | FLD_FLD_EN2 | FLD_FLD_EN);
> +	rcsi2_write(priv, FLD_REG, fld);
>  	rcsi2_write(priv, VCDT_REG, vcdt);
>  	if (vcdt2)
>  		rcsi2_write(priv, VCDT2_REG, vcdt2);
> @@ -662,6 +687,8 @@ static int rcsi2_get_pad_format(struct v4l2_subdev *sd,
>  }
>  
>  static const struct v4l2_subdev_video_ops rcar_csi2_video_ops = {
> +	.s_std = rcsi2_s_std,
> +	.g_std = rcsi2_g_std,
>  	.s_stream = rcsi2_s_stream,
>  };
>  

-- 
Regards,

Laurent Pinchart