[PATCH RFC v4 2/7] v4l: add new tuner types for SDR

Antti Palosaari
2013-12-19T04:00:23Z

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>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
---
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..0397fc6 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;
+ } 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 {
--
1.8.4.2