Re: [PATCH v4 1/2] media: add new mediabus format enums for dm365

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Manjunath,

On Tuesday 17 July 2012 12:22:42 Hadli, Manjunath wrote:
> On Tue, Jul 17, 2012 at 17:25:42, Laurent Pinchart wrote:
> > On Tuesday 17 July 2012 11:41:11 Hadli, Manjunath wrote:
> > > On Tue, Jul 17, 2012 at 16:26:24, Laurent Pinchart wrote:
> > > > On Friday 30 March 2012 10:09:13 Hadli, Manjunath wrote:
> > > > > add new enum entries for supporting the media-bus formats on dm365.
> > > > > These include some bayer and some non-bayer formats.
> > > > > V4L2_MBUS_FMT_YDYC8_1X16 and V4L2_MBUS_FMT_UV8_1X8 are used
> > > > > internal to the hardware by the resizer.
> > > > > V4L2_MBUS_FMT_SBGGR10_ALAW8_1X8 represents the bayer ALAW format
> > > > > that is supported by dm365 hardware.
> > > > > 
> > > > > Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
> > > > > Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > > > > Cc: Sakari Ailus <sakari.ailus@iki.fi>
> > > > > Cc: Hans Verkuil <hans.verkuil@cisco.com>
> > > > > ---
> > > > > 
> > > > >  Documentation/DocBook/media/v4l/subdev-formats.xml |  171 
> > > > >  ++++++++++++
> > > > >  include/linux/v4l2-mediabus.h                      |   10 +-
> > > > >  2 files changed, 179 insertions(+), 2 deletions(-)
> > > > > 
> > > > > diff --git a/Documentation/DocBook/media/v4l/subdev-formats.xml
> > > > > b/Documentation/DocBook/media/v4l/subdev-formats.xml index
> > > > > 49c532e..48d92bb
> > > > > 100644
> > > > > --- a/Documentation/DocBook/media/v4l/subdev-formats.xml
> > > > > +++ b/Documentation/DocBook/media/v4l/subdev-formats.xml
> > 
> > [snip]
> > 
> > > > > @@ -965,6 +1036,56 @@
> > > > > 
> > > > >  	      <entry>y<subscript>1</subscript></entry>
> > > > >  	      <entry>y<subscript>0</subscript></entry>
> > > > >  	    
> > > > >  	    </row>
> > > > > 
> > > > > +	    <row id="V4L2-MBUS-FMT-UV8-1X8">
> > > > 
> > > > That's a weird one. Just out of curiosity, what's the point of
> > > > transferring chroma information without luma ?
> > > 
> > > DM365 supports this format.
> > 
> > Right, but what is it used for ?
> 
> Sorry about that. The Resizer in Dm365 can take only chroma and resize the
> buffer. It can also take luma of course. In general it can take UV8, Y8 and
> also UYVY.

So UV8 is used to resize an NV buffer in two passes (first Y8 then UV8) ?

> > [snip]
> > 
> > > > > @@ -2415,6 +2536,56 @@
> > > > > 
> > > > >  	      <entry>u<subscript>1</subscript></entry>
> > > > >  	      <entry>u<subscript>0</subscript></entry>
> > > > >  	    
> > > > >  	    </row>
> > > > > 
> > > > > +	    <row id="V4L2-MBUS-FMT-YDYC8-1X16">
> > > > 
> > > > What is this beast ? We at least need a textual description, as I have
> > > > no
> > > > idea what the format corresponds to.
> > > 
> > > This was discussed earlier over here
> > > http://patchwork.linuxtv.org/patch/8843/
> > 
> > My bad, I should have remembered that. Please add a textual description of
> > the format, it's not clear from the name what D and C are.
> 
> I see no description for individual MBUS formats but a collective para on
> everything together. Would you like me to add in the same or otherwise can
> you point to me where I can add this description?

What about the following patch ? Note that I've renamed YDYC to YDYU, as we
might later need a YDYV format.

(Hans, Sakari, any opinion ?)

diff --git a/Documentation/DocBook/media/v4l/subdev-formats.xml b/Documentation/DocBook/media/v4l/subdev-formats.xml
index 49c532e..47a485e 100644
--- a/Documentation/DocBook/media/v4l/subdev-formats.xml
+++ b/Documentation/DocBook/media/v4l/subdev-formats.xml
@@ -853,10 +853,15 @@
       <title>Packed YUV Formats</title>
 
       <para>Those data formats transfer pixel data as (possibly downsampled) Y, U
-      and V components. The format code is made of the following information.
+      and V components. Some formats include dummy bits in some of their samples
+      and are collectively referred to as "YDYC" (Y-Dummy-Y-Chroma) formats.
+      </para>
+
+      <para>The format code is made of the following information.
       <itemizedlist>
 	<listitem><para>The Y, U and V components order code, as transferred on the
-	bus. Possible values are YUYV, UYVY, YVYU and VYUY.</para></listitem>
+	bus. Possible values are YUYV, UYVY, YVYU and VYUY for formats with no
+	dummy bit, and YDYU, YDYV, YUYD and YVYD for YDYC formats.</para></listitem>
 	<listitem><para>The number of bits per pixel component. All components are
 	transferred on the same number of bits. Common values are 8, 10 and 12.</para>
 	</listitem>
@@ -877,7 +882,21 @@
       U, Y, V, Y order will be named <constant>V4L2_MBUS_FMT_UYVY8_2X8</constant>.
       </para>
 
-      <para>The following table lisst existing packet YUV formats.</para>
+      <para><xref linkend="v4l2-mbus-pixelcode-yuv8"/> list existing packet YUV
+      formats and describes the organization of each pixel data in each sample.
+      When a format pattern is split across multiple samples each of the samples
+      in the pattern is described.</para>
+
+      <para>The role of each bit transferred over the bus is identified by one
+      of the following codes.</para>
+
+      <itemizedlist>
+        <listitem><para>y<subscript>x</subscript> for luma component bit number x</para></listitem>
+        <listitem><para>u<subscript>x</subscript> for blue chroma component bit number x</para></listitem>
+        <listitem><para>v<subscript>x</subscript> for red chroma component bit number x</para></listitem>
+        <listitem><para>- for non-available bits (for positions higher than the bus width)</para></listitem>
+        <listitem><para>/ for dummy bits</para></listitem>
+      </itemizedlist>
 
       <table pgwide="0" frame="none" id="v4l2-mbus-pixelcode-yuv8">
 	<title>YUV Formats</title>
@@ -2415,6 +2434,106 @@
 	      <entry>u<subscript>1</subscript></entry>
 	      <entry>u<subscript>0</subscript></entry>
 	    </row>
+	    <row id="V4L2-MBUS-FMT-YDYU8-1X16">
+	      <entry>V4L2_MBUS_FMT_YDYU8_1X16</entry>
+	      <entry>0x2014</entry>
+	      <entry></entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>y<subscript>7</subscript></entry>
+	      <entry>y<subscript>6</subscript></entry>
+	      <entry>y<subscript>5</subscript></entry>
+	      <entry>y<subscript>4</subscript></entry>
+	      <entry>y<subscript>3</subscript></entry>
+	      <entry>y<subscript>2</subscript></entry>
+	      <entry>y<subscript>1</subscript></entry>
+	      <entry>y<subscript>0</subscript></entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	    </row>
+	    <row>
+	      <entry></entry>
+	      <entry></entry>
+	      <entry></entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>y<subscript>7</subscript></entry>
+	      <entry>y<subscript>6</subscript></entry>
+	      <entry>y<subscript>5</subscript></entry>
+	      <entry>y<subscript>4</subscript></entry>
+	      <entry>y<subscript>3</subscript></entry>
+	      <entry>y<subscript>2</subscript></entry>
+	      <entry>y<subscript>1</subscript></entry>
+	      <entry>y<subscript>0</subscript></entry>
+	      <entry>u<subscript>7</subscript></entry>
+	      <entry>u<subscript>6</subscript></entry>
+	      <entry>u<subscript>5</subscript></entry>
+	      <entry>u<subscript>4</subscript></entry>
+	      <entry>u<subscript>3</subscript></entry>
+	      <entry>u<subscript>2</subscript></entry>
+	      <entry>u<subscript>1</subscript></entry>
+	      <entry>u<subscript>0</subscript></entry>
+	    </row>
+	    <row>
+	      <entry></entry>
+	      <entry></entry>
+	      <entry></entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>y<subscript>7</subscript></entry>
+	      <entry>y<subscript>6</subscript></entry>
+	      <entry>y<subscript>5</subscript></entry>
+	      <entry>y<subscript>4</subscript></entry>
+	      <entry>y<subscript>3</subscript></entry>
+	      <entry>y<subscript>2</subscript></entry>
+	      <entry>y<subscript>1</subscript></entry>
+	      <entry>y<subscript>0</subscript></entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	      <entry>/</entry>
+	    </row>
+	    <row>
+	      <entry></entry>
+	      <entry></entry>
+	      <entry></entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>-</entry>
+	      <entry>y<subscript>7</subscript></entry>
+	      <entry>y<subscript>6</subscript></entry>
+	      <entry>y<subscript>5</subscript></entry>
+	      <entry>y<subscript>4</subscript></entry>
+	      <entry>y<subscript>3</subscript></entry>
+	      <entry>y<subscript>2</subscript></entry>
+	      <entry>y<subscript>1</subscript></entry>
+	      <entry>y<subscript>0</subscript></entry>
+	      <entry>v<subscript>7</subscript></entry>
+	      <entry>v<subscript>6</subscript></entry>
+	      <entry>v<subscript>5</subscript></entry>
+	      <entry>v<subscript>4</subscript></entry>
+	      <entry>v<subscript>3</subscript></entry>
+	      <entry>v<subscript>2</subscript></entry>
+	      <entry>v<subscript>1</subscript></entry>
+	      <entry>v<subscript>0</subscript></entry>
+	    </row>
 	    <row id="V4L2-MBUS-FMT-YUYV10-1X20">
 	      <entry>V4L2_MBUS_FMT_YUYV10_1X20</entry>
 	      <entry>0x200d</entry>

-- 
Regards,

Laurent Pinchart