From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp-vbr12.xs4all.nl ([194.109.24.32]:4616 "EHLO smtp-vbr12.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750992AbaAEMLy (ORCPT ); Sun, 5 Jan 2014 07:11:54 -0500 Message-ID: <52C94BF5.4030905@xs4all.nl> Date: Sun, 05 Jan 2014 13:11:33 +0100 From: Hans Verkuil MIME-Version: 1.0 To: Antti Palosaari CC: linux-media@vger.kernel.org, Mauro Carvalho Chehab Subject: Re: [PATCH RFC v6 11/12] DocBook: Software Defined Radio Interface References: <1388289844-2766-1-git-send-email-crope@iki.fi> <1388289844-2766-12-git-send-email-crope@iki.fi> In-Reply-To: <1388289844-2766-12-git-send-email-crope@iki.fi> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: More small fixes: On 12/29/2013 05:04 AM, Antti Palosaari wrote: > Document V4L2 SDR interface. > > Cc: Hans Verkuil > Signed-off-by: Antti Palosaari > --- > Documentation/DocBook/media/v4l/compat.xml | 10 ++ > Documentation/DocBook/media/v4l/dev-sdr.xml | 107 +++++++++++++++++++++ > Documentation/DocBook/media/v4l/io.xml | 6 ++ > Documentation/DocBook/media/v4l/v4l2.xml | 1 + > Documentation/DocBook/media/v4l/vidioc-g-fmt.xml | 7 ++ > .../DocBook/media/v4l/vidioc-querycap.xml | 6 ++ > 6 files changed, 137 insertions(+) > create mode 100644 Documentation/DocBook/media/v4l/dev-sdr.xml > > diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml > index 0c7195e..85fb864 100644 > --- a/Documentation/DocBook/media/v4l/compat.xml > +++ b/Documentation/DocBook/media/v4l/compat.xml > @@ -2523,6 +2523,16 @@ that used it. It was originally scheduled for removal in 2.6.35. > > > > +
> + V4L2 in Linux 3.14 > + > + > + Added Software Defined Radio (SDR) Interface. > + > + > + > +
> + >
> Relation of V4L2 to other Linux multimedia APIs > > diff --git a/Documentation/DocBook/media/v4l/dev-sdr.xml b/Documentation/DocBook/media/v4l/dev-sdr.xml > new file mode 100644 > index 0000000..db4859f > --- /dev/null > +++ b/Documentation/DocBook/media/v4l/dev-sdr.xml > @@ -0,0 +1,107 @@ > + Software Defined Radio Interface (SDR) > + > + > +SDR is an abbreviation of Software Defined Radio, the radio device > +which uses application software for modulation or demodulation. This interface > +is intended for controlling and data streaming of such devices. > + > + > + > +SDR devices are accessed through character device special files named > +/dev/swradio0 to /dev/swradio255 > +with major number 81 and dynamically allocated minor numbers 0 to 255. > + > + > +
> + Querying Capabilities > + > + > +Devices supporting the SDR receiver interface set the > +V4L2_CAP_SDR_CAPTURE and > +V4L2_CAP_TUNER flag in the > +capabilities field of &v4l2-capability; > +returned by the &VIDIOC-QUERYCAP; ioctl. That flag means the device has an > +Analog to Digital Converter (ADC), which is a mandatory element for the SDR receiver. > +At least one of the read/write, streaming or asynchronous I/O methods must > +be supported. > + > +
> + > +
> + Supplemental Functions > + > + > +SDR devices can support controls, and must > +support the tuner ioctls. Tuner ioctls are used > +for setting the ADC sampling rate (sampling frequency) and the possible RF tuner > +frequency. > + > + > + > +The V4L2_TUNER_ADC tuner type is used for ADC tuners, and > +the V4L2_TUNER_RF is used for RF tuners. The tuner index s/is used/tuner type is used/ > +of the RF tuner (if any) must always follow the ADC tuner index. Normally the > +ADC tuner is #0 and the RF tuner is #1. > + > + > + > +The &VIDIOC-S-HW-FREQ-SEEK; ioctl is not supported. > + > +
> + > +
> + Data Format Negotiation > + > + > +The SDR capture device uses the format ioctls to > +select the capture format. Both the sampling resolution and the data streaming > +format are bound to that selectable format. In addition to basic s/to basic/to the basic/ > +format ioctls, the &VIDIOC-ENUM-FMT; ioctl > +must be supported too. s/too/as well/ > + > + > + > +To use the format ioctls applications set the > +type field of a &v4l2-format; to > +V4L2_BUF_TYPE_SDR_CAPTURE and use the &v4l2-format-sdr; > +sdr member of the fmt > +union as needed per the desired operation. > +Currently only the pixelformat field of > +&v4l2-format-sdr; is used. The content of that field is the V4L2 fourcc code > +of the data format. > + > + > + > + struct <structname>v4l2_format_sdr</structname> > + > + &cs-str; > + > + > + __u32 > + pixelformat > + > +The pixel format or type of compression, set by the > +application. This is a little endian > +four character code. V4L2 defines > +standard RGB formats in , YUV formats in > +, and reserved codes in > + Instead of pointing to the RGB/YUV/Reserved codes (which makes no sense for SDR) you need to point to a new section where the SDR fourcc formats are described. > + > + > + > + __u8 > + reserved[28] > + This array is reserved for future extensions. > +Drivers and applications must set it to zero. > + > + > + > +
> + > + > +An SDR device may support read/write > +and/or streaming (memory mapping > +or user pointer) I/O. > + > + > +
> diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml > index 2c4c068..1fb11e8 100644 > --- a/Documentation/DocBook/media/v4l/io.xml > +++ b/Documentation/DocBook/media/v4l/io.xml > @@ -1005,6 +1005,12 @@ should set this to 0. > Buffer for video output overlay (OSD), see linkend="osd" />. > > + > + V4L2_BUF_TYPE_SDR_CAPTURE > + 11 > + Buffer for Software Defined Radio (SDR), see + linkend="sdr" />. > + > > > > diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml > index 8469fe1..a27fcae 100644 > --- a/Documentation/DocBook/media/v4l/v4l2.xml > +++ b/Documentation/DocBook/media/v4l/v4l2.xml > @@ -529,6 +529,7 @@ and discussions on the V4L mailing list. >
&sub-dev-teletext;
>
&sub-dev-radio;
>
&sub-dev-rds;
> +
&sub-dev-sdr;
>
&sub-dev-event;
>
&sub-dev-subdev;
> > diff --git a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml > index ee8f56e..ffed137 100644 > --- a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml > +++ b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml > @@ -172,6 +172,13 @@ capture and output devices. > > > > + &v4l2-format-sdr; > + sdr > + Definition of an data format, see > +, used by SDR capture devices. > + > + > + > __u8 > raw_data[200] > Place holder for future extensions. > diff --git a/Documentation/DocBook/media/v4l/vidioc-querycap.xml b/Documentation/DocBook/media/v4l/vidioc-querycap.xml > index d5a3c97..370d49d 100644 > --- a/Documentation/DocBook/media/v4l/vidioc-querycap.xml > +++ b/Documentation/DocBook/media/v4l/vidioc-querycap.xml > @@ -296,6 +296,12 @@ modulator programming see > . > > > + V4L2_CAP_SDR_CAPTURE > + 0x00100000 > + The device supports the > +SDR Capture interface. > + > + > V4L2_CAP_READWRITE > 0x01000000 > The device supports the Regards, Hans