Re: [PATCH v3 01/14] media: ov7670: split register setting from set_fmt() logic

From: jacopo mondi <jacopo@jmondi.org>
To: Lubomir Rintel <lkundrak@v3.sk>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>,
	Jonathan Corbet <corbet@lwn.net>,
	linux-media@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	James Cameron <quozl@laptop.org>, Pavel Machek <pavel@ucw.cz>,
	Libin Yang <lbyang@marvell.com>,
	Albert Wang <twang13@marvell.com>
Subject: Re: [PATCH v3 01/14] media: ov7670: split register setting from set_fmt() logic
Date: Thu, 22 Nov 2018 19:37:30 +0100	[thread overview]
Message-ID: <20181122183730.GE3808@w540> (raw)
In-Reply-To: <20181120100318.367987-2-lkundrak@v3.sk>

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Hi Lubomir,

On Tue, Nov 20, 2018 at 11:03:06AM +0100, Lubomir Rintel wrote:
> This will allow us to restore the last set format after the device returns
> from a power off.
>
> Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
>
> ---
> Changes since v2:
> - This patch was added to the series
>
>  drivers/media/i2c/ov7670.c | 80 ++++++++++++++++++++++----------------
>  1 file changed, 46 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/media/i2c/ov7670.c b/drivers/media/i2c/ov7670.c
> index bc68a3a5b4ec..ee2302fbdeee 100644
> --- a/drivers/media/i2c/ov7670.c
> +++ b/drivers/media/i2c/ov7670.c
> @@ -240,6 +240,7 @@ struct ov7670_info {
>  	};
>  	struct v4l2_mbus_framefmt format;
>  	struct ov7670_format_struct *fmt;  /* Current format */
> +	struct ov7670_win_size *wsize;
>  	struct clk *clk;
>  	struct gpio_desc *resetb_gpio;
>  	struct gpio_desc *pwdn_gpio;
> @@ -1003,48 +1004,20 @@ static int ov7670_try_fmt_internal(struct v4l2_subdev *sd,
>  	return 0;
>  }
>
> -/*
> - * Set a format.
> - */
> -static int ov7670_set_fmt(struct v4l2_subdev *sd,
> -		struct v4l2_subdev_pad_config *cfg,
> -		struct v4l2_subdev_format *format)
> +static int ov7670_apply_fmt(struct v4l2_subdev *sd)
>  {
> -	struct ov7670_format_struct *ovfmt;
> -	struct ov7670_win_size *wsize;
>  	struct ov7670_info *info = to_state(sd);
> -#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
> -	struct v4l2_mbus_framefmt *mbus_fmt;
> -#endif
> +	struct ov7670_win_size *wsize = info->wsize;
>  	unsigned char com7, com10 = 0;
>  	int ret;
>
> -	if (format->pad)
> -		return -EINVAL;
> -
> -	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
> -		ret = ov7670_try_fmt_internal(sd, &format->format, NULL, NULL);
> -		if (ret)
> -			return ret;
> -#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
> -		mbus_fmt = v4l2_subdev_get_try_format(sd, cfg, format->pad);
> -		*mbus_fmt = format->format;
> -		return 0;
> -#else
> -		return -ENOTTY;
> -#endif
> -	}
> -
> -	ret = ov7670_try_fmt_internal(sd, &format->format, &ovfmt, &wsize);
> -	if (ret)
> -		return ret;
>  	/*
>  	 * COM7 is a pain in the ass, it doesn't like to be read then
>  	 * quickly written afterward.  But we have everything we need
>  	 * to set it absolutely here, as long as the format-specific
>  	 * register sets list it first.
>  	 */
> -	com7 = ovfmt->regs[0].value;
> +	com7 = info->fmt->regs[0].value;
>  	com7 |= wsize->com7_bit;
>  	ret = ov7670_write(sd, REG_COM7, com7);
>  	if (ret)
> @@ -1066,7 +1039,7 @@ static int ov7670_set_fmt(struct v4l2_subdev *sd,
>  	/*
>  	 * Now write the rest of the array.  Also store start/stops
>  	 */
> -	ret = ov7670_write_array(sd, ovfmt->regs + 1);
> +	ret = ov7670_write_array(sd, info->fmt->regs + 1);
>  	if (ret)
>  		return ret;
>
> @@ -1081,8 +1054,6 @@ static int ov7670_set_fmt(struct v4l2_subdev *sd,
>  			return ret;
>  	}
>
> -	info->fmt = ovfmt;
> -
>  	/*
>  	 * If we're running RGB565, we must rewrite clkrc after setting
>  	 * the other parameters or the image looks poor.  If we're *not*
> @@ -1100,6 +1071,46 @@ static int ov7670_set_fmt(struct v4l2_subdev *sd,
>  	return 0;
>  }
>
> +/*
> + * Set a format.
> + */
> +static int ov7670_set_fmt(struct v4l2_subdev *sd,
> +		struct v4l2_subdev_pad_config *cfg,
> +		struct v4l2_subdev_format *format)
> +{
> +	struct ov7670_info *info = to_state(sd);
> +#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
> +	struct v4l2_mbus_framefmt *mbus_fmt;
> +#endif
> +	int ret;
> +
> +	if (format->pad)
> +		return -EINVAL;
> +
> +	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
> +		ret = ov7670_try_fmt_internal(sd, &format->format, NULL, NULL);
> +		if (ret)
> +			return ret;
> +#ifdef CONFIG_VIDEO_V4L2_SUBDEV_API
> +		mbus_fmt = v4l2_subdev_get_try_format(sd, cfg, format->pad);

This #ifdef CONFIG_VIDEO_V4L2_SUBDEV_API seems to be quite in some
drivers... Maybe stubs should be defined in v4l2-subdev.h.

Anway, that's unrealted, the patch seems fine to me:
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

Thanks
  j

> +		*mbus_fmt = format->format;
> +		return 0;
> +#else
> +		return -ENOTTY;
> +#endif
> +	}
> +
> +	ret = ov7670_try_fmt_internal(sd, &format->format, &info->fmt, &info->wsize);
> +	if (ret)
> +		return ret;
> +
> +	ret = ov7670_apply_fmt(sd);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
>  static int ov7670_get_fmt(struct v4l2_subdev *sd,
>  			  struct v4l2_subdev_pad_config *cfg,
>  			  struct v4l2_subdev_format *format)
> @@ -1847,6 +1858,7 @@ static int ov7670_probe(struct i2c_client *client,
>
>  	info->devtype = &ov7670_devdata[id->driver_data];
>  	info->fmt = &ov7670_formats[0];
> +	info->wsize = &info->devtype->win_sizes[0];
>
>  	ov7670_get_default_format(sd, &info->format);
>
> --
> 2.19.1
>

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