Re: [PATCH RFC v3 1/7] v4l: add new tuner types for SDR

[Hans Verkuil <hverkuil@xs4all.nl>]

On 12/16/2013 11:08 PM, Antti Palosaari wrote:
> Define tuner types V4L2_TUNER_ADC and V4L2_TUNER_RF for SDR usage.
> 
> ADC is used for setting sampling rate (sampling frequency) to SDR
> device.
> 
> Another tuner type, named as V4L2_TUNER_RF, is possible RF tuner.
> Is is used to down-convert RF frequency to range ADC could sample.
> Having RF tuner is optional, whilst in practice it is almost always
> there.
> 
> Also add checks to VIDIOC_G_FREQUENCY, VIDIOC_S_FREQUENCY and
> VIDIOC_ENUM_FREQ_BANDS only allow these two tuner types when device
> type is SDR (VFL_TYPE_SDR). For VIDIOC_G_FREQUENCY we do not check
> tuner type, instead override type with V4L2_TUNER_ADC in every
> case (requested by Hans in order to keep functionality in line with
> existing tuners and existing API does not specify it).
> 
> Prohibit VIDIOC_S_HW_FREQ_SEEK explicitly when device type is SDR,
> as device cannot do hardware seek without a hardware demodulator.
> 
> Cc: Hans Verkuil <hverkuil@xs4all.nl>
> Signed-off-by: Antti Palosaari <crope@iki.fi>
> ---
>  drivers/media/v4l2-core/v4l2-ioctl.c | 39 ++++++++++++++++++++++++++----------
>  include/uapi/linux/videodev2.h       |  2 ++
>  2 files changed, 30 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
> index 68e6b5e..04ec9f9 100644
> --- a/drivers/media/v4l2-core/v4l2-ioctl.c
> +++ b/drivers/media/v4l2-core/v4l2-ioctl.c
> @@ -1288,8 +1288,11 @@ static int v4l_g_frequency(const struct v4l2_ioctl_ops *ops,
>  	struct video_device *vfd = video_devdata(file);
>  	struct v4l2_frequency *p = arg;
>  
> -	p->type = (vfd->vfl_type == VFL_TYPE_RADIO) ?
> -			V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV;
> +	if (vfd->vfl_type == VFL_TYPE_SDR)
> +		p->type = V4L2_TUNER_ADC;
> +	else
> +		p->type = (vfd->vfl_type == VFL_TYPE_RADIO) ?
> +				V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV;
>  	return ops->vidioc_g_frequency(file, fh, p);
>  }
>  
> @@ -1300,10 +1303,15 @@ static int v4l_s_frequency(const struct v4l2_ioctl_ops *ops,
>  	const struct v4l2_frequency *p = arg;
>  	enum v4l2_tuner_type type;
>  
> -	type = (vfd->vfl_type == VFL_TYPE_RADIO) ?
> -			V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV;
> -	if (p->type != type)
> -		return -EINVAL;
> +	if (vfd->vfl_type == VFL_TYPE_SDR) {
> +		if (p->type != V4L2_TUNER_ADC && p->type != V4L2_TUNER_RF)
> +			return -EINVAL;
> +	} else {
> +		type = (vfd->vfl_type == VFL_TYPE_RADIO) ?
> +				V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV;
> +		if (type != p->type)
> +			return -EINVAL;
> +	}
>  	return ops->vidioc_s_frequency(file, fh, p);
>  }
>  
> @@ -1383,6 +1391,10 @@ static int v4l_s_hw_freq_seek(const struct v4l2_ioctl_ops *ops,
>  	struct v4l2_hw_freq_seek *p = arg;
>  	enum v4l2_tuner_type type;
>  
> +	/* s_hw_freq_seek is not supported for SDR for now */
> +	if (vfd->vfl_type == VFL_TYPE_SDR)
> +		return -EINVAL;
> +
>  	type = (vfd->vfl_type == VFL_TYPE_RADIO) ?
>  		V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV;
>  	if (p->type != type)
> @@ -1882,11 +1894,16 @@ static int v4l_enum_freq_bands(const struct v4l2_ioctl_ops *ops,
>  	enum v4l2_tuner_type type;
>  	int err;
>  
> -	type = (vfd->vfl_type == VFL_TYPE_RADIO) ?
> -			V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV;
> -
> -	if (type != p->type)
> -		return -EINVAL;
> +	if (vfd->vfl_type == VFL_TYPE_SDR) {
> +		if (p->type != V4L2_TUNER_ADC && p->type != V4L2_TUNER_RF)
> +			return -EINVAL;
> +		type = p->type; /* silence compiler warning */

No need for the comment. 'type' is used later, so the compiler warning
makes sense.

After dropping this comment you can add my:

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

for this patch.

Regards,

	Hans

> +	} else {
> +		type = (vfd->vfl_type == VFL_TYPE_RADIO) ?
> +				V4L2_TUNER_RADIO : V4L2_TUNER_ANALOG_TV;
> +		if (type != p->type)
> +			return -EINVAL;
> +	}
>  	if (ops->vidioc_enum_freq_bands)
>  		return ops->vidioc_enum_freq_bands(file, fh, p);
>  	if (is_valid_ioctl(vfd, VIDIOC_G_TUNER)) {
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 437f1b0..3fff116 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -159,6 +159,8 @@ enum v4l2_tuner_type {
>  	V4L2_TUNER_RADIO	     = 1,
>  	V4L2_TUNER_ANALOG_TV	     = 2,
>  	V4L2_TUNER_DIGITAL_TV	     = 3,
> +	V4L2_TUNER_ADC               = 4,
> +	V4L2_TUNER_RF                = 5,
>  };
>  
>  enum v4l2_memory {
>