Re: [PATCH] media: i2c: tvp7002: enable TVP7002 decoder for media controller based usage

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

Hi Prabhakar,

Thank you for the patch.

On Friday 26 April 2013 13:35:35 Prabhakar Lad wrote:
> From: Lad, Prabhakar <prabhakar.csengg@gmail.com>
> 
> This patch enables tvp7002 decoder driver for media controller
> based usage by adding v4l2_subdev_pad_ops  operations support
> for enum_mbus_code, set_pad_format, get_pad_format and media_entity_init()
> on probe and media_entity_cleanup() on remove.
> 
> The device supports 1 output pad and no input pads.

We should actually define input pads, connected to connector entities, but 
that's out of scope for this patch.

> Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
> ---
>  drivers/media/i2c/tvp7002.c |  125 ++++++++++++++++++++++++++++++++++++++--
>  include/media/tvp7002.h     |    2 +
>  2 files changed, 122 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/media/i2c/tvp7002.c b/drivers/media/i2c/tvp7002.c
> index 027809c..b212d41 100644
> --- a/drivers/media/i2c/tvp7002.c
> +++ b/drivers/media/i2c/tvp7002.c
> @@ -424,6 +424,8 @@ struct tvp7002 {
>  	int streaming;
> 
>  	const struct tvp7002_timings_definition *current_timings;
> +	struct media_pad pad;
> +	struct v4l2_mbus_framefmt format;
>  };
> 
>  /*
> @@ -880,6 +882,93 @@ static const struct v4l2_ctrl_ops tvp7002_ctrl_ops = {
>  	.s_ctrl = tvp7002_s_ctrl,
>  };
> 
> +/*
> + * tvp7002_enum_mbus_code() - Enum supported digital video format on pad
> + * @sd: pointer to standard V4L2 sub-device structure
> + * @fh: file handle for the subdev
> + * @code: pointer to subdev enum mbus code struct
> + *
> + * Enumerate supported digital video formats for pad.
> + */
> +static int
> +tvp7002_enum_mbus_code(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
> +		       struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	/* Check pad index is valid */
> +	if (code->pad != 0)
> +		return -EINVAL;

That check is already performed in the subdev core, there's no need to 
duplicate it here.

> +
> +	/* Check requested format index is within range */
> +	if (code->index != 0)
> +		return -EINVAL;
> +
> +	code->code = V4L2_MBUS_FMT_YUYV10_1X20;
> +
> +	return 0;
> +}
> +
> +/*
> + * tvp7002_set_pad_format() - set video format on pad
> + * @sd: pointer to standard V4L2 sub-device structure
> + * @fh: file handle for the subdev
> + * @fmt: pointer to subdev format struct
> + *
> + * set video format for pad.
> +*/
> +static int
> +tvp7002_set_pad_format(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
> +		       struct v4l2_subdev_format *fmt)
> +{
> +	struct tvp7002 *tvp7002 = to_tvp7002(sd);
> +
> +	/* Check pad index is valid */
> +	if (fmt->pad != 0)
> +		return -EINVAL;

Redundant check as well.

> +	if (fmt->format.field != tvp7002->current_timings->scanmode ||
> +	    fmt->format.code != V4L2_MBUS_FMT_YUYV10_1X20 ||
> +	    fmt->format.colorspace != tvp7002->current_timings->color_space ||
> +	    fmt->format.width != tvp7002->current_timings->timings.bt.width ||
> +	    fmt->format.height != tvp7002->current_timings->timings.bt.height)
> +		return -EINVAL;

You shouldn't return an error, but fix the input parameters according to what 
the device supports. As the format is fixed for a giving set of timings, the 
.set_pad_format() handler should just perform the same operations as 
.get_pad_format(). You could even define tvp7002_get_pad_format() only and use 
it as a handler for both .get_pad_format() and .set_pad_format().

> +	tvp7002->format = fmt->format;
> +
> +	return 0;
> +}
> +
> +/*
> + * tvp7002_get_pad_format() - get video format on pad
> + * @sd: pointer to standard V4L2 sub-device structure
> + * @fh: file handle for the subdev
> + * @fmt: pointer to subdev format struct
> + *
> + * get video format for pad.
> + */
> +static int
> +tvp7002_get_pad_format(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh,
> +		       struct v4l2_subdev_format *fmt)
> +{
> +	struct tvp7002 *tvp7002 = to_tvp7002(sd);
> +
> +	/* Check pad index is valid */
> +	if (fmt->pad != 0)
> +		return -EINVAL;

Redundant check.

> +	if (fmt->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
> +		fmt->format = tvp7002->format;
> +		return 0;
> +	}
> +
> +	fmt->format.code = V4L2_MBUS_FMT_YUYV10_1X20;
> +	fmt->format.width = tvp7002->current_timings->timings.bt.width;
> +	fmt->format.height = tvp7002->current_timings->timings.bt.height;
> +	fmt->format.field = tvp7002->current_timings->scanmode;
> +	fmt->format.colorspace = tvp7002->current_timings->color_space;
> +
> +	return 0;
> +}
> +
>  /* V4L2 core operation handlers */
>  static const struct v4l2_subdev_core_ops tvp7002_core_ops = {
>  	.g_chip_ident = tvp7002_g_chip_ident,
> @@ -910,10 +999,18 @@ static const struct v4l2_subdev_video_ops
> tvp7002_video_ops = { .enum_mbus_fmt = tvp7002_enum_mbus_fmt,
>  };
> 
> +/* media pad related operation handlers */
> +static const struct v4l2_subdev_pad_ops tvp7002_pad_ops = {
> +	.enum_mbus_code = tvp7002_enum_mbus_code,
> +	.get_fmt = tvp7002_get_pad_format,
> +	.set_fmt = tvp7002_set_pad_format,

We will need to define pad-aware DV timings operations.

> +};
> +
>  /* V4L2 top level operation handlers */
>  static const struct v4l2_subdev_ops tvp7002_ops = {
>  	.core = &tvp7002_core_ops,
>  	.video = &tvp7002_video_ops,
> +	.pad = &tvp7002_pad_ops,
>  };
> 
>  /*
> @@ -993,19 +1090,35 @@ static int tvp7002_probe(struct i2c_client *c, const
> struct i2c_device_id *id) timings = device->current_timings->timings;
>  	error = tvp7002_s_dv_timings(sd, &timings);
> 
> +#if defined(CONFIG_MEDIA_CONTROLLER)
> +	strlcpy(sd->name, TVP7002_MODULE_NAME, sizeof(sd->name));
> +	device->pad.flags = MEDIA_PAD_FL_SOURCE;
> +	device->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	device->sd.entity.flags |= MEDIA_ENT_T_V4L2_SUBDEV_DECODER;
> +
> +	error = media_entity_init(&device->sd.entity, 1, &device->pad, 0);
> +	if (error < 0)
> +		return error;
> +#endif
> +
>  	v4l2_ctrl_handler_init(&device->hdl, 1);
>  	v4l2_ctrl_new_std(&device->hdl, &tvp7002_ctrl_ops,
>  			V4L2_CID_GAIN, 0, 255, 1, 0);
>  	sd->ctrl_handler = &device->hdl;
>  	if (device->hdl.error) {
> -		int err = device->hdl.error;
> -
> -		v4l2_ctrl_handler_free(&device->hdl);
> -		return err;
> +		error = device->hdl.error;
> +		goto done;
>  	}
>  	v4l2_ctrl_handler_setup(&device->hdl);
> 
>  	return 0;
> +
> +done:
> +	v4l2_ctrl_handler_free(&device->hdl);
> +#if defined(CONFIG_MEDIA_CONTROLLER)
> +	media_entity_cleanup(&device->sd.entity);
> +#endif
> +	return error;
>  }
> 
>  /*
> @@ -1022,7 +1135,9 @@ static int tvp7002_remove(struct i2c_client *c)
> 
>  	v4l2_dbg(1, debug, sd, "Removing tvp7002 adapter"
>  				"on address 0x%x\n", c->addr);
> -
> +#if defined(CONFIG_MEDIA_CONTROLLER)
> +	media_entity_cleanup(&device->sd.entity);
> +#endif
>  	v4l2_device_unregister_subdev(sd);
>  	v4l2_ctrl_handler_free(&device->hdl);
>  	return 0;
> diff --git a/include/media/tvp7002.h b/include/media/tvp7002.h
> index ee43534..7123048 100644
> --- a/include/media/tvp7002.h
> +++ b/include/media/tvp7002.h
> @@ -26,6 +26,8 @@
>  #ifndef _TVP7002_H_
>  #define _TVP7002_H_
> 
> +#define TVP7002_MODULE_NAME "tvp7002"
> +
>  /* Platform-dependent data
>   *
>   * clk_polarity:
-- 
Regards,

Laurent Pinchart