Re: [PATCH v2 07/11] media: i2c: max9286: Support 12-bit raw bayer formats

From: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To: Jacopo Mondi <jacopo@jmondi.org>
Cc: linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
	"Kieran Bingham" <kieran.bingham@ideasonboard.com>,
	"Niklas Söderlund" <niklas.soderlund@ragnatech.se>,
	"Thomas Nizan" <tnizan@witekio.com>
Subject: Re: [PATCH v2 07/11] media: i2c: max9286: Support 12-bit raw bayer formats
Date: Mon, 10 Jan 2022 01:19:01 +0200	[thread overview]
Message-ID: <YdttZRlTlTRJNmCP@pendragon.ideasonboard.com> (raw)
In-Reply-To: <20220109103409.dedytvxvchnar7m2@uno.localdomain>

Hi Jacopo,

On Sun, Jan 09, 2022 at 11:34:09AM +0100, Jacopo Mondi wrote:
> On Sat, Jan 01, 2022 at 08:28:02PM +0200, Laurent Pinchart wrote:
> > Add support for 12-bit raw bayer formats to the driver, configuring the
> > GMSL format accordingly.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
> > ---
> >  drivers/media/i2c/max9286.c | 128 ++++++++++++++++++++++++++----------
> >  1 file changed, 95 insertions(+), 33 deletions(-)
> >
> > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> > index 576d9c6fac14..24c2bf4fda53 100644
> > --- a/drivers/media/i2c/max9286.c
> > +++ b/drivers/media/i2c/max9286.c
> > @@ -135,6 +135,11 @@
> >  #define MAX9286_N_PADS			5
> >  #define MAX9286_SRC_PAD			4
> >
> > +struct max9286_format_info {
> > +	u32 code;
> > +	u8 datatype;
> > +};
> > +
> >  struct max9286_source {
> >  	struct v4l2_subdev *sd;
> >  	struct fwnode_handle *fwnode;
> > @@ -214,6 +219,34 @@ static inline struct max9286_priv *sd_to_max9286(struct v4l2_subdev *sd)
> >  	return container_of(sd, struct max9286_priv, sd);
> >  }
> >
> > +static const struct max9286_format_info max9286_formats[] = {
> > +	{
> > +		.code = MEDIA_BUS_FMT_UYVY8_1X16,
> > +		.datatype = MAX9286_DATATYPE_YUV422_8BIT,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_VYUY8_1X16,
> > +		.datatype = MAX9286_DATATYPE_YUV422_8BIT,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_YUYV8_1X16,
> > +		.datatype = MAX9286_DATATYPE_YUV422_8BIT,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_YVYU8_1X16,
> > +		.datatype = MAX9286_DATATYPE_YUV422_8BIT,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_SBGGR12_1X12,
> > +		.datatype = MAX9286_DATATYPE_RAW12,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_SGBRG12_1X12,
> > +		.datatype = MAX9286_DATATYPE_RAW12,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_SGRBG12_1X12,
> > +		.datatype = MAX9286_DATATYPE_RAW12,
> > +	}, {
> > +		.code = MEDIA_BUS_FMT_SRGGB12_1X12,
> > +		.datatype = MAX9286_DATATYPE_RAW12,
> > +	},
> > +};
> > +
> >  /* -----------------------------------------------------------------------------
> >   * I2C IO
> >   */
> > @@ -475,6 +508,38 @@ static int max9286_check_config_link(struct max9286_priv *priv,
> >  	return 0;
> >  }
> >
> > +static void max9286_set_video_format(struct max9286_priv *priv,
> > +				     const struct v4l2_mbus_framefmt *format)
> > +{
> > +	const struct max9286_format_info *info = NULL;
> > +	unsigned int i;
> > +
> > +	for (i = 0; i < ARRAY_SIZE(max9286_formats); ++i) {
> > +		if (max9286_formats[i].code == format->code) {
> > +			info = &max9286_formats[i];
> > +			break;
> > +		}
> > +	}
> > +
> > +	if (WARN_ON(!info))
> > +		return;
> > +
> > +	/*
> > +	 * Video format setup:
> > +	 * Disable CSI output, VC is set according to Link number.
> > +	 */
> > +	max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
> 
> I'm a bit scared about the fact settnig the video format disables the
> CSI-2 output. But for the current usage pattern, it seems ok

I'd like to further reorganize this (on top of this series) by avoiding
the max9286_set_video_format() call from max9286_setup(), as that
shouldn't be needed at probe time.

> > +
> > +	/* Enable CSI-2 Lane D0-D3 only, DBL mode. */
> > +	max9286_write(priv, 0x12, MAX9286_CSIDBL | MAX9286_DBL |
> > +		      MAX9286_CSILANECNT(priv->csi2_data_lanes) |
> > +		      info->datatype);
> > +
> > +	/* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
> > +	max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
> > +		      MAX9286_HVSRC_D14);
> > +}
> > +
> >  static void max9286_set_fsync_period(struct max9286_priv *priv)
> >  {
> >  	u32 fsync;
> > @@ -693,6 +758,15 @@ static int max9286_s_stream(struct v4l2_subdev *sd, int enable)
> >  	int ret;
> >
> >  	if (enable) {
> > +		const struct v4l2_mbus_framefmt *format;
> > +
> > +		/*
> > +		 * Get the format from the first used sink pad, as all sink
> > +		 * formats must be identical.
> > +		 */
> > +		format = &priv->fmt[__ffs(priv->bound_sources)];
> > +
> > +		max9286_set_video_format(priv, format);
> >  		max9286_set_fsync_period(priv);
> >
> >  		/*
> > @@ -813,22 +887,20 @@ static int max9286_set_fmt(struct v4l2_subdev *sd,
> >  {
> >  	struct max9286_priv *priv = sd_to_max9286(sd);
> >  	struct v4l2_mbus_framefmt *cfg_fmt;
> > +	unsigned int i;
> >
> >  	if (format->pad == MAX9286_SRC_PAD)
> >  		return -EINVAL;
> >
> > -	/* Refuse non YUV422 formats as we hardcode DT to 8 bit YUV422 */
> > -	switch (format->format.code) {
> > -	case MEDIA_BUS_FMT_UYVY8_1X16:
> > -	case MEDIA_BUS_FMT_VYUY8_1X16:
> > -	case MEDIA_BUS_FMT_YUYV8_1X16:
> > -	case MEDIA_BUS_FMT_YVYU8_1X16:
> > -		break;
> > -	default:
> > -		format->format.code = MEDIA_BUS_FMT_UYVY8_1X16;
> > -		break;
> > +	/* Validate the format. */
> > +	for (i = 0; i < ARRAY_SIZE(max9286_formats); ++i) {
> > +		if (max9286_formats[i].code == format->format.code)
> > +			break;
> >  	}
> >
> > +	if (i == ARRAY_SIZE(max9286_formats))
> > +		format->format.code = max9286_formats[i].code;
> 
> Isn't i past the end of the array now ?

Oops, it should be [0]. I'll fix it.

> > +
> >  	cfg_fmt = max9286_get_pad_format(priv, sd_state, format->pad,
> >  					 format->which);
> >  	if (!cfg_fmt)
> > @@ -886,16 +958,20 @@ static const struct v4l2_subdev_ops max9286_subdev_ops = {
> >  	.pad		= &max9286_pad_ops,
> >  };
> >
> > +static const struct v4l2_mbus_framefmt max9286_default_format = {
> > +	.width		= 1280,
> > +	.height		= 800,
> > +	.code		= MEDIA_BUS_FMT_UYVY8_1X16,
> > +	.colorspace	= V4L2_COLORSPACE_SRGB,
> > +	.field		= V4L2_FIELD_NONE,
> > +	.ycbcr_enc	= V4L2_YCBCR_ENC_DEFAULT,
> > +	.quantization	= V4L2_QUANTIZATION_DEFAULT,
> > +	.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
> > +};
> > +
> >  static void max9286_init_format(struct v4l2_mbus_framefmt *fmt)
> >  {
> > -	fmt->width		= 1280;
> > -	fmt->height		= 800;
> > -	fmt->code		= MEDIA_BUS_FMT_UYVY8_1X16;
> > -	fmt->colorspace		= V4L2_COLORSPACE_SRGB;
> > -	fmt->field		= V4L2_FIELD_NONE;
> > -	fmt->ycbcr_enc		= V4L2_YCBCR_ENC_DEFAULT;
> > -	fmt->quantization	= V4L2_QUANTIZATION_DEFAULT;
> > -	fmt->xfer_func		= V4L2_XFER_FUNC_DEFAULT;
> > +	*fmt = max9286_default_format;
> >  }
> >
> >  static int max9286_open(struct v4l2_subdev *subdev, struct v4l2_subdev_fh *fh)
> > @@ -1054,23 +1130,9 @@ static int max9286_setup(struct max9286_priv *priv)
> >  	max9286_write(priv, 0x0b, link_order[priv->route_mask]);
> >  	max9286_write(priv, 0x69, (0xf & ~priv->route_mask));
> >
> > -	/*
> > -	 * Video format setup:
> > -	 * Disable CSI output, VC is set according to Link number.
> > -	 */
> > -	max9286_write(priv, 0x15, MAX9286_VCTYPE | MAX9286_0X15_RESV);
> > -
> > -	/* Enable CSI-2 Lane D0-D3 only, DBL mode, YUV422 8-bit. */
> > -	max9286_write(priv, 0x12, MAX9286_CSIDBL | MAX9286_DBL |
> > -		      MAX9286_CSILANECNT(priv->csi2_data_lanes) |
> > -		      MAX9286_DATATYPE_YUV422_8BIT);
> > -
> > +	max9286_set_video_format(priv, &max9286_default_format);
> >  	max9286_set_fsync_period(priv);
> >
> > -	/* Enable HS/VS encoding, use D14/15 for HS/VS, invert VS. */
> > -	max9286_write(priv, 0x0c, MAX9286_HVEN | MAX9286_INVVS |
> > -		      MAX9286_HVSRC_D14);
> > -
> >  	/*
> >  	 * The overlap window seems to provide additional validation by tracking
> >  	 * the delay between vsync and frame sync, generating an error if the

-- 
Regards,

Laurent Pinchart