Adds the basic API bits for Software Digital Radio (SDR) at the V4L2 API.
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxx>
---
Documentation/DocBook/media/v4l/common.xml | 35 ++++++++++++++++++
Documentation/DocBook/media/v4l/pixfmt.xml | 41 ++++++++++++++++++++++
Documentation/DocBook/media/v4l/v4l2.xml | 1 +
.../DocBook/media/v4l/vidioc-querycap.xml | 7 ++++
drivers/media/v4l2-core/v4l2-dev.c | 3 ++
include/media/v4l2-dev.h | 3 +-
include/uapi/linux/videodev2.h | 11 ++++++
7 files changed, 100 insertions(+), 1 deletion(-)
diff --git a/Documentation/DocBook/media/v4l/common.xml b/Documentation/DocBook/media/v4l/common.xml
index 1ddf354..f59c67d 100644
--- a/Documentation/DocBook/media/v4l/common.xml
+++ b/Documentation/DocBook/media/v4l/common.xml
@@ -513,6 +513,41 @@ the &v4l2-capability; returned by the &VIDIOC-QUERYCAP; ioctl when the
device has one or more modulators.</para>
</section>
+ <section id="sdr_tuner">
+ <title>Software Digital Radio (SDR) Tuners and Modulators</title>
+
+ <para>Those devices are special types of Radio devices that don't
+have any analog demodulator. Instead, it samples the radio IF or baseband
+and sends the samples for userspace to demodulate.</para>
+ <section>
+ <title>Tuners</title>
+
+ <para>SDR receivers can have one or more tuners sampling RF signals.
+Each tuner is associated with one or more inputs, depending on the number
+of RF connectors on the tuner. The <structfield>type</structfield> field of
+the respective &v4l2-input; returned by the &VIDIOC-ENUMINPUT; ioctl is set to
+<constant>V4L2_INPUT_TYPE_TUNER</constant> and its
+<structfield>tuner</structfield> field contains the index number of
+the tuner input.</para>
+
+<para>To query and change tuner properties applications use the
+&VIDIOC-G-TUNER; and &VIDIOC-S-TUNER; ioctl, respectively. The
+&v4l2-tuner; returned by <constant>VIDIOC_G_TUNER</constant> also
+contains signal status information applicable when the tuner of the
+current SDR input is queried. In order to change the SDR input,
+<constant>VIDIOC_S_TUNER</constant> with a new SDR index should be called.
+Drivers must support both ioctls and set the
+<constant>V4L2_CAP_SDR</constant> and <constant>V4L2_CAP_TUNER</constant>
+flags in the &v4l2-capability; returned by the &VIDIOC-QUERYCAP; ioctl.</para>
+ </section>
+
+ <section>
+ <title>Modulators</title>
+ <para>To be defined.</para>
+ </section>
+ </section>
+
+
<section>
<title>Radio Frequency</title>
diff --git a/Documentation/DocBook/media/v4l/pixfmt.xml b/Documentation/DocBook/media/v4l/pixfmt.xml
index 99b8d2a..e30075e 100644
--- a/Documentation/DocBook/media/v4l/pixfmt.xml
+++ b/Documentation/DocBook/media/v4l/pixfmt.xml
@@ -203,6 +203,47 @@ codes can be used.</entry>
</table>
</section>
+<section>
+ <title>SDR format struture</title>
+ <table pgwide="1" frame="none" id="v4l2-sdr-format">
+ <title>struct <structname>v4l2_sdr_format</structname></title>
+ <tgroup cols="3">
+ &cs-str;
+ <tbody valign="top">
+ <row>
+ <entry>__u32</entry>
+ <entry><structfield>sampleformat</structfield></entry>
+ <entry>The format of the samples used by the SDR device.
+ This is a little endian
+ <link linkend="v4l2-sdr-fourcc">
+ four character code</link>.</entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+ <table pgwide="1" frame="none" id="v4l2-sdr-fourcc">
+ <title>SDR formats</title>
+ <tgroup cols="2">
+ &cs-str;
+ <tbody valign="top">
+ <row>
+ <entry><constant>V4L2_SDR_FMT_I8Q8</constant></entry>
+ <entry>Samples are given by a sequence of 8 bits in-phase(I) and
+ 8 bits quadrature (Q) samples taken from a
+ <emphasis>signal(t)</emphasis> represented by the following
+ expression:
+ <informalequation>
+ <alt>signal(t) = I cos(2π f t) - Q sin(2π f t)</alt>
+ <mathphrase><emphasis>signal(t) = I * cos(2π f<subscript>c</subscript> t) - Q * sin(2π f<subscript>c</subscript> t)</emphasis></mathphrase>
+ </informalequation>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </table>
+
+</section>
+
<section>
<title>Standard Image Formats</title>
diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml
index bfc93cd..b53a5cf 100644
--- a/Documentation/DocBook/media/v4l/v4l2.xml
+++ b/Documentation/DocBook/media/v4l/v4l2.xml
@@ -521,6 +521,7 @@ and discussions on the V4L mailing list.</revremark>
<section id="ttx"> &sub-dev-teletext; </section>
<section id="radio"> &sub-dev-radio; </section>
<section id="rds"> &sub-dev-rds; </section>
+ <section id="sdr"> &sub-dev-sdr; </section>
<section id="event"> &sub-dev-event; </section>
<section id="subdev"> &sub-dev-subdev; </section>
</chapter>
diff --git a/Documentation/DocBook/media/v4l/vidioc-querycap.xml b/Documentation/DocBook/media/v4l/vidioc-querycap.xml
index d5a3c97..97bb25a 100644
--- a/Documentation/DocBook/media/v4l/vidioc-querycap.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-querycap.xml
@@ -296,6 +296,13 @@ modulator programming see
<xref linkend="tuner" />.</entry>
</row>
<row>
+ <entry><constant>V4L2_CAP_SDR</constant></entry>
+ <entry>0x00100000</entry>
+ <entry>The device is a Software Digital Radio.
+ For more information about SDR programming see
+<xref linkend="sdr_tuner" />.</entry>
+ </row>
+ <row>
<entry><constant>V4L2_CAP_READWRITE</constant></entry>
<entry>0x01000000</entry>
<entry>The device supports the <link
diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index 5923c5d..a48e070 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -796,6 +796,9 @@ int __video_register_device(struct video_device *vdev, int type, int nr,
case VFL_TYPE_SUBDEV:
name_base = "v4l-subdev";
break;
+ case VFL_TYPE_SDR:
+ name_base = "sdr";
+ break;
default:
printk(KERN_ERR "%s called with unknown type: %d\n",
__func__, type);
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index 95d1c91..95863bb 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -24,7 +24,8 @@
#define VFL_TYPE_VBI 1
#define VFL_TYPE_RADIO 2
#define VFL_TYPE_SUBDEV 3
-#define VFL_TYPE_MAX 4
+#define VFL_TYPE_SDR 4
+#define VFL_TYPE_MAX 5
/* Is this a receiver, transmitter or mem-to-mem? */
/* Ignored for VFL_TYPE_SUBDEV. */
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 97fb392..4aa24c3 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -284,6 +284,7 @@ struct v4l2_capability {
#define V4L2_CAP_AUDIO 0x00020000 /* has audio support */
#define V4L2_CAP_RADIO 0x00040000 /* is a radio device */
#define V4L2_CAP_MODULATOR 0x00080000 /* has a modulator */
+#define V4L2_CAP_SDR 0x00100000 /* is a SDR device */
#define V4L2_CAP_READWRITE 0x01000000 /* read/write systemcalls */
#define V4L2_CAP_ASYNCIO 0x02000000 /* async I/O */
@@ -1700,6 +1701,15 @@ struct v4l2_pix_format_mplane {
__u8 reserved[11];
} __attribute__ ((packed));
+
+struct v4l2_sdr_format {
+ __u32 sampleformat;
+};
+
+/* Sample format Description */
+
+#define V4L2_SDR_FMT_I8Q8 v4l2_fourcc('I', '8', 'Q', '8') /* I 8bits, Q 8bits */
+
/**
* struct v4l2_format - stream data format
* @type: enum v4l2_buf_type; type of the data stream
@@ -1718,6 +1728,7 @@ struct v4l2_format {
struct v4l2_window win; /* V4L2_BUF_TYPE_VIDEO_OVERLAY */
struct v4l2_vbi_format vbi; /* V4L2_BUF_TYPE_VBI_CAPTURE */
struct v4l2_sliced_vbi_format sliced; /* V4L2_BUF_TYPE_SLICED_VBI_CAPTURE */
+ struct v4l2_sdr_format fmt; /* V4L2_BUF_TYPE_SDR_CAPTURE */
__u8 raw_data[200]; /* user-defined */
} fmt;
};
--
1.8.1.4
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