Hi Laurent,
Thanks for the review comments.
> On Tuesday 07 Feb 2017 15:02:35 Ramesh Shanmugasundaram wrote:
> > This patch adds documentation for the three new SDR formats
> >
> > V4L2_SDR_FMT_PCU16BE
> > V4L2_SDR_FMT_PCU18BE
> > V4L2_SDR_FMT_PCU20BE
> >
> > Signed-off-by: Ramesh Shanmugasundaram
> > <ramesh.shanmugasundaram@xxxxxxxxxxxxxx> ---
> > .../media/uapi/v4l/pixfmt-sdr-pcu16be.rst | 55
> +++++++++++++++++++
> > .../media/uapi/v4l/pixfmt-sdr-pcu18be.rst | 55
> +++++++++++++++++++
> > .../media/uapi/v4l/pixfmt-sdr-pcu20be.rst | 54
> +++++++++++++++++++
> > Documentation/media/uapi/v4l/sdr-formats.rst | 3 ++
> > 4 files changed, 167 insertions(+)
> > create mode 100644
> > Documentation/media/uapi/v4l/pixfmt-sdr-pcu16be.rst
> > create mode 100644
> > Documentation/media/uapi/v4l/pixfmt-sdr-pcu18be.rst
> > create mode 100644
> > Documentation/media/uapi/v4l/pixfmt-sdr-pcu20be.rst
> >
> > diff --git a/Documentation/media/uapi/v4l/pixfmt-sdr-pcu16be.rst
> > b/Documentation/media/uapi/v4l/pixfmt-sdr-pcu16be.rst new file mode
> > 100644 index 0000000..2de1b1a
> > --- /dev/null
> > +++ b/Documentation/media/uapi/v4l/pixfmt-sdr-pcu16be.rst
> > @@ -0,0 +1,55 @@
> > +.. -*- coding: utf-8; mode: rst -*-
> > +
> > +.. _V4L2-SDR-FMT-PCU16BE:
> > +
> > +******************************
> > +V4L2_SDR_FMT_PCU16BE ('PC16')
> > +******************************
> > +
> > +Planar complex unsigned 16-bit big endian IQ sample
> > +
> > +Description
> > +===========
> > +
> > +This format contains a sequence of complex number samples. Each
> > +complex number consist of two parts called In-phase and Quadrature
> > +(IQ). Both I and Q are represented as a 16 bit unsigned big endian
> > +number stored in
> > +32 bit space. The remaining unused bits within the 32 bit space will
> > +be padded with 0. I value starts first and Q value starts at an
> > +offset equalling half of the buffer size (i.e.) offset =
> > +buffersize/2. Out of the 16 bits, bit 15:2 (14 bit) is data and bit
> > +1:0 (2 bit) can be any value.
>
> This sounds very strange to me. Are the two lower bits always random ?
> What is that used for ?
It could be zeros or it could be status bits in case of MAX2175 (if enabled). I mentioned any value because the user app does not have any assumptions on these bits value.
>
> > +**Byte Order.**
> > +Each cell is one byte.
> > +
> > +.. flat-table::
> > + :header-rows: 1
> > + :stub-columns: 0
> > +
> > + * - Offset:
> > + - Byte B0
> > + - Byte B1
> > + - Byte B2
> > + - Byte B3
> > + * - start + 0:
> > + - I'\ :sub:`0[13:6]`
> > + - I'\ :sub:`0[5:0]; B1[1:0]=pad`
> > + - pad
> > + - pad
> > + * - start + 4:
> > + - I'\ :sub:`1[13:6]`
> > + - I'\ :sub:`1[5:0]; B1[1:0]=pad`
> > + - pad
> > + - pad
> > + * - ...
> > + * - start + offset:
> > + - Q'\ :sub:`0[13:6]`
> > + - Q'\ :sub:`0[5:0]; B1[1:0]=pad`
> > + - pad
> > + - pad
> > + * - start + offset + 4:
> > + - Q'\ :sub:`1[13:6]`
> > + - Q'\ :sub:`1[5:0]; B1[1:0]=pad`
> > + - pad
> > + - pad
> > diff --git a/Documentation/media/uapi/v4l/pixfmt-sdr-pcu18be.rst
> > b/Documentation/media/uapi/v4l/pixfmt-sdr-pcu18be.rst new file mode
> > 100644 index 0000000..da8b26b
> > --- /dev/null
> > +++ b/Documentation/media/uapi/v4l/pixfmt-sdr-pcu18be.rst
> > @@ -0,0 +1,55 @@
> > +.. -*- coding: utf-8; mode: rst -*-
> > +
> > +.. _V4L2-SDR-FMT-PCU18BE:
> > +
> > +******************************
> > +V4L2_SDR_FMT_PCU18BE ('PC18')
> > +******************************
> > +
> > +Planar complex unsigned 18-bit big endian IQ sample
> > +
> > +Description
> > +===========
> > +
> > +This format contains a sequence of complex number samples. Each
> > +complex number consist of two parts called In-phase and Quadrature
> > +(IQ). Both I and Q are represented as a 18 bit unsigned big endian
> > +number stored in
> > +32 bit space. The remaining unused bits within the 32 bit space will
> > +be padded with 0. I value starts first and Q value starts at an
> > +offset equalling half of the buffer size (i.e.) offset =
> > +buffersize/2. Out of the 18 bits, bit 17:2 (16 bit) is data and bit
> > +1:0 (2 bit) can be any value.
> > +
> > +**Byte Order.**
> > +Each cell is one byte.
> > +
> > +.. flat-table::
> > + :header-rows: 1
> > + :stub-columns: 0
> > +
> > + * - Offset:
> > + - Byte B0
> > + - Byte B1
> > + - Byte B2
> > + - Byte B3
> > + * - start + 0:
> > + - I'\ :sub:`0[17:10]`
> > + - I'\ :sub:`0[9:2]`
> > + - I'\ :sub:`0[1:0]; B2[5:0]=pad`
> > + - pad
> > + * - start + 4:
> > + - I'\ :sub:`1[17:10]`
> > + - I'\ :sub:`1[9:2]`
> > + - I'\ :sub:`1[1:0]; B2[5:0]=pad`
> > + - pad
> > + * - ...
> > + * - start + offset:
> > + - Q'\ :sub:`0[17:10]`
> > + - Q'\ :sub:`0[9:2]`
> > + - Q'\ :sub:`0[1:0]; B2[5:0]=pad`
> > + - pad
> > + * - start + offset + 4:
> > + - Q'\ :sub:`1[17:10]`
> > + - Q'\ :sub:`1[9:2]`
> > + - Q'\ :sub:`1[1:0]; B2[5:0]=pad`
> > + - pad
> > diff --git a/Documentation/media/uapi/v4l/pixfmt-sdr-pcu20be.rst
> > b/Documentation/media/uapi/v4l/pixfmt-sdr-pcu20be.rst new file mode
> > 100644 index 0000000..5499eed
> > --- /dev/null
> > +++ b/Documentation/media/uapi/v4l/pixfmt-sdr-pcu20be.rst
> > @@ -0,0 +1,54 @@
> > +.. -*- coding: utf-8; mode: rst -*-
> > +.. _V4L2-SDR-FMT-PCU20BE:
> > +
> > +******************************
> > +V4L2_SDR_FMT_PCU20BE ('PC20')
> > +******************************
> > +
> > +Planar complex unsigned 20-bit big endian IQ sample
> > +
> > +Description
> > +===========
> > +
> > +This format contains a sequence of complex number samples. Each
> > +complex number consist of two parts called In-phase and Quadrature
> > +(IQ). Both I and Q are represented as a 20 bit unsigned big endian
> > +number stored in
> > +32 bit space. The remaining unused bits within the 32 bit space will
> > +be padded with 0. I value starts first and Q value starts at an
> > +offset equalling half of the buffer size (i.e.) offset =
> > +buffersize/2. Out of the 20 bits, bit 19:2 (18 bit) is data and bit
> > +1:0 (2 bit) can be any value.
> > +
> > +**Byte Order.**
> > +Each cell is one byte.
> > +
> > +.. flat-table::
> > + :header-rows: 1
> > + :stub-columns: 0
> > +
> > + * - Offset:
> > + - Byte B0
> > + - Byte B1
> > + - Byte B2
> > + - Byte B3
> > + * - start + 0:
> > + - I'\ :sub:`0[19:12]`
> > + - I'\ :sub:`0[11:4]`
> > + - I'\ :sub:`0[3:0]; B2[3:0]=pad`
> > + - pad
> > + * - start + 4:
> > + - I'\ :sub:`1[19:12]`
> > + - I'\ :sub:`1[11:4]`
> > + - I'\ :sub:`1[3:0]; B2[3:0]=pad`
> > + - pad
> > + * - ...
> > + * - start + offset:
> > + - Q'\ :sub:`0[19:12]`
> > + - Q'\ :sub:`0[11:4]`
> > + - Q'\ :sub:`0[3:0]; B2[3:0]=pad`
> > + - pad
> > + * - start + offset + 4:
> > + - Q'\ :sub:`1[19:12]`
> > + - Q'\ :sub:`1[11:4]`
> > + - Q'\ :sub:`1[3:0]; B2[3:0]=pad`
> > + - pad
> > diff --git a/Documentation/media/uapi/v4l/sdr-formats.rst
> > b/Documentation/media/uapi/v4l/sdr-formats.rst index f863c08..2037f5b
> > 100644
> > --- a/Documentation/media/uapi/v4l/sdr-formats.rst
> > +++ b/Documentation/media/uapi/v4l/sdr-formats.rst
> > @@ -17,3 +17,6 @@ These formats are used for :ref:`SDR <sdr>`
> > interface only. pixfmt-sdr-cs08
> > pixfmt-sdr-cs14le
> > pixfmt-sdr-ru12le
> > + pixfmt-sdr-pcu16be
> > + pixfmt-sdr-pcu18be
> > + pixfmt-sdr-pcu20be
Thanks,
Ramesh
