Commit b5958dc3 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
Browse files

[media] DocBook media: add VIDIOC_DBG_G_CHIP_NAME documentation 



And update the other debug ioctls accordingly.

Signed-off-by: default avatarHans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent 3b2d17b4

Documentation/DocBook/media/v4l/v4l2.xml

+2 −2
Original line number Diff line number Diff line
@@ -156,8 +156,7 @@ applications. --> 
	<date>2012-12-03</date>

	<authorinitials>sa, sn</authorinitials>

	<revremark>Added timestamp types to v4l2_buffer.

	Added <constant>V4L2_EVENT_CTRL_CH_RANGE</constant> control

	event changes flag, see <xref linkend="changes-flags"/>.

	Added V4L2_EVENT_CTRL_CH_RANGE control event changes flag.

	</revremark>

      </revision>
@@ -549,6 +548,7 @@ and discussions on the V4L mailing list.</revremark> 
    &sub-create-bufs;

    &sub-cropcap;

    &sub-dbg-g-chip-ident;

    &sub-dbg-g-chip-name;

    &sub-dbg-g-register;

    &sub-decoder-cmd;

    &sub-dqevent;

Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-ident.xml

+12 −2
Original line number Diff line number Diff line
@@ -200,10 +200,10 @@ the values from <xref linkend="chip-ids" />.</entry> 
	&cs-def;

	<tbody valign="top">

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_HOST</constant></entry>

	    <entry><constant>V4L2_CHIP_MATCH_BRIDGE</constant></entry>

	    <entry>0</entry>

	    <entry>Match the nth chip on the card, zero for the

	    host chip. Does not match &i2c; chips.</entry>

	    bridge chip. Does not match sub-devices.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant></entry>
@@ -220,6 +220,16 @@ the values from <xref linkend="chip-ids" />.</entry> 
	    <entry>3</entry>

	    <entry>Match the nth anciliary AC97 chip.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_SUBDEV_NAME</constant></entry>

	    <entry>4</entry>

	    <entry>Match the sub-device by name. Can't be used with this ioctl.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_SUBDEV_IDX</constant></entry>

	    <entry>5</entry>

	    <entry>Match the nth sub-device. Can't be used with this ioctl.</entry>

	  </row>

	</tbody>

      </tgroup>

    </table>

Documentation/DocBook/media/v4l/vidioc-dbg-g-chip-name.xml

0 → 100644
+234 −0
Original line number Diff line number Diff line 
<refentry id="vidioc-dbg-g-chip-name">

  <refmeta>

    <refentrytitle>ioctl VIDIOC_DBG_G_CHIP_NAME</refentrytitle>

    &manvol;

  </refmeta>



  <refnamediv>

    <refname>VIDIOC_DBG_G_CHIP_NAME</refname>

    <refpurpose>Identify the chips on a TV card</refpurpose>

  </refnamediv>



  <refsynopsisdiv>

    <funcsynopsis>

      <funcprototype>

	<funcdef>int <function>ioctl</function></funcdef>

	<paramdef>int <parameter>fd</parameter></paramdef>

	<paramdef>int <parameter>request</parameter></paramdef>

	<paramdef>struct v4l2_dbg_chip_name

*<parameter>argp</parameter></paramdef>

      </funcprototype>

    </funcsynopsis>

  </refsynopsisdiv>



  <refsect1>

    <title>Arguments</title>



    <variablelist>

      <varlistentry>

	<term><parameter>fd</parameter></term>

	<listitem>

	  <para>&fd;</para>

	</listitem>

      </varlistentry>

      <varlistentry>

	<term><parameter>request</parameter></term>

	<listitem>

	  <para>VIDIOC_DBG_G_CHIP_NAME</para>

	</listitem>

      </varlistentry>

      <varlistentry>

	<term><parameter>argp</parameter></term>

	<listitem>

	  <para></para>

	</listitem>

      </varlistentry>

    </variablelist>

  </refsect1>



  <refsect1>

    <title>Description</title>



    <note>

      <title>Experimental</title>



      <para>This is an <link

linkend="experimental">experimental</link> interface and may change in

the future.</para>

    </note>



    <para>For driver debugging purposes this ioctl allows test

applications to query the driver about the chips present on the TV

card. Regular applications must not use it. When you found a chip

specific bug, please contact the linux-media mailing list (&v4l-ml;)

so it can be fixed.</para>



    <para>To query the driver applications must initialize the

<structfield>match.type</structfield> and

<structfield>match.addr</structfield> or <structfield>match.name</structfield>

fields of a &v4l2-dbg-chip-name;

and call <constant>VIDIOC_DBG_G_CHIP_NAME</constant> with a pointer to

this structure. On success the driver stores information about the

selected chip in the <structfield>name</structfield> and

<structfield>flags</structfield> fields. On failure the structure

remains unchanged.</para>



    <para>When <structfield>match.type</structfield> is

<constant>V4L2_CHIP_MATCH_BRIDGE</constant>,

<structfield>match.addr</structfield> selects the nth bridge 'chip'

on the TV card. You can enumerate all chips by starting at zero and

incrementing <structfield>match.addr</structfield> by one until

<constant>VIDIOC_DBG_G_CHIP_NAME</constant> fails with an &EINVAL;.

The number zero always selects the bridge chip itself, &eg; the chip

connected to the PCI or USB bus. Non-zero numbers identify specific

parts of the bridge chip such as an AC97 register block.</para>



    <para>When <structfield>match.type</structfield> is

<constant>V4L2_CHIP_MATCH_SUBDEV_NAME</constant>,

<structfield>match.name</structfield> contains the name of a sub-device.

For instance

<constant>"saa7127 6-0044"</constant> will match the saa7127 sub-device

at the given i2c bus. This match type is not very useful for this ioctl

and is here only for consistency.

</para>



    <para>When <structfield>match.type</structfield> is

<constant>V4L2_CHIP_MATCH_SUBDEV_IDX</constant>,

<structfield>match.addr</structfield> selects the nth sub-device. This

allows you to enumerate over all sub-devices.</para>



    <para>On success, the <structfield>name</structfield> field will

contain a chip name and the <structfield>flags</structfield> field will

contain <constant>V4L2_CHIP_FL_READABLE</constant> if the driver supports

reading registers from the device or <constant>V4L2_CHIP_FL_WRITABLE</constant>

if the driver supports writing registers to the device.</para>



    <para>We recommended the <application>v4l2-dbg</application>

utility over calling this ioctl directly. It is available from the

LinuxTV v4l-dvb repository; see <ulink

url="http://linuxtv.org/repo/">http://linuxtv.org/repo/</ulink> for

access instructions.</para>



    <!-- Note for convenience vidioc-dbg-g-register.sgml

	 contains a duplicate of this table. -->

    <table pgwide="1" frame="none" id="name-v4l2-dbg-match">

      <title>struct <structname>v4l2_dbg_match</structname></title>

      <tgroup cols="4">

	&cs-ustr;

	<tbody valign="top">

	  <row>

	    <entry>__u32</entry>

	    <entry><structfield>type</structfield></entry>

	    <entry>See <xref linkend="name-chip-match-types" /> for a list of

possible types.</entry>

	  </row>

	  <row>

	    <entry>union</entry>

	    <entry>(anonymous)</entry>

	  </row>

	  <row>

	    <entry></entry>

	    <entry>__u32</entry>

	    <entry><structfield>addr</structfield></entry>

	    <entry>Match a chip by this number, interpreted according

to the <structfield>type</structfield> field.</entry>

	  </row>

	  <row>

	    <entry></entry>

	    <entry>char</entry>

	    <entry><structfield>name[32]</structfield></entry>

	    <entry>Match a chip by this name, interpreted according

to the <structfield>type</structfield> field.</entry>

	  </row>

	</tbody>

      </tgroup>

    </table>



    <table pgwide="1" frame="none" id="v4l2-dbg-chip-name">

      <title>struct <structname>v4l2_dbg_chip_name</structname></title>

      <tgroup cols="3">

	&cs-str;

	<tbody valign="top">

	  <row>

	    <entry>struct v4l2_dbg_match</entry>

	    <entry><structfield>match</structfield></entry>

	    <entry>How to match the chip, see <xref linkend="name-v4l2-dbg-match" />.</entry>

	  </row>

	  <row>

	    <entry>char</entry>

	    <entry><structfield>name[32]</structfield></entry>

	    <entry>The name of the chip.</entry>

	  </row>

	  <row>

	    <entry>__u32</entry>

	    <entry><structfield>flags</structfield></entry>

	    <entry>Set by the driver. If <constant>V4L2_CHIP_FL_READABLE</constant>

is set, then the driver supports reading registers from the device. If

<constant>V4L2_CHIP_FL_WRITABLE</constant> is set, then it supports writing registers.</entry>

	  </row>

	  <row>

	    <entry>__u32</entry>

	    <entry><structfield>reserved[8]</structfield></entry>

	    <entry>Reserved fields, both application and driver must set these to 0.</entry>

	  </row>

	</tbody>

      </tgroup>

    </table>



    <!-- Note for convenience vidioc-dbg-g-register.sgml

	 contains a duplicate of this table. -->

    <table pgwide="1" frame="none" id="name-chip-match-types">

      <title>Chip Match Types</title>

      <tgroup cols="3">

	&cs-def;

	<tbody valign="top">

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_BRIDGE</constant></entry>

	    <entry>0</entry>

	    <entry>Match the nth chip on the card, zero for the

	    bridge chip. Does not match sub-devices.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant></entry>

	    <entry>1</entry>

	    <entry>Match an &i2c; chip by its driver name. Can't be used with this ioctl.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_I2C_ADDR</constant></entry>

	    <entry>2</entry>

	    <entry>Match a chip by its 7 bit &i2c; bus address. Can't be used with this ioctl.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_AC97</constant></entry>

	    <entry>3</entry>

	    <entry>Match the nth anciliary AC97 chip. Can't be used with this ioctl.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_SUBDEV_NAME</constant></entry>

	    <entry>4</entry>

	    <entry>Match the sub-device by name.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_SUBDEV_IDX</constant></entry>

	    <entry>5</entry>

	    <entry>Match the nth sub-device.</entry>

	  </row>

	</tbody>

      </tgroup>

    </table>

  </refsect1>



  <refsect1>

    &return-value;



    <variablelist>

      <varlistentry>

	<term><errorcode>EINVAL</errorcode></term>

	<listitem>

	  <para>The <structfield>match_type</structfield> is invalid or

no device could be matched.</para>

	</listitem>

      </varlistentry>

     </variablelist>

  </refsect1>

</refentry>

Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml

+32 −10
Original line number Diff line number Diff line
@@ -87,7 +87,7 @@ written into the register.</para> 


    <para>To read a register applications must initialize the

<structfield>match.type</structfield>,

<structfield>match.chip</structfield> or <structfield>match.name</structfield> and

<structfield>match.addr</structfield> or <structfield>match.name</structfield> and

<structfield>reg</structfield> fields, and call

<constant>VIDIOC_DBG_G_REGISTER</constant> with a pointer to this

structure. On success the driver stores the register value in the
@@ -95,11 +95,11 @@ structure. On success the driver stores the register value in the 
unchanged.</para>



    <para>When <structfield>match.type</structfield> is

<constant>V4L2_CHIP_MATCH_HOST</constant>,

<structfield>match.addr</structfield> selects the nth non-&i2c; chip

<constant>V4L2_CHIP_MATCH_BRIDGE</constant>,

<structfield>match.addr</structfield> selects the nth non-sub-device chip

on the TV card.  The number zero always selects the host chip, &eg; the

chip connected to the PCI or USB bus. You can find out which chips are

present with the &VIDIOC-DBG-G-CHIP-IDENT; ioctl.</para>

present with the &VIDIOC-DBG-G-CHIP-NAME; ioctl.</para>



    <para>When <structfield>match.type</structfield> is

<constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant>,
@@ -109,7 +109,7 @@ For instance 
supported by the saa7127 driver, regardless of its &i2c; bus address.

When multiple chips supported by the same driver are present, the

effect of these ioctls is undefined. Again with the

&VIDIOC-DBG-G-CHIP-IDENT; ioctl you can find out which &i2c; chips are

&VIDIOC-DBG-G-CHIP-NAME; ioctl you can find out which &i2c; chips are

present.</para>



    <para>When <structfield>match.type</structfield> is
@@ -122,19 +122,31 @@ bus address.</para> 
<structfield>match.addr</structfield> selects the nth AC97 chip

on the TV card.</para>



    <para>When <structfield>match.type</structfield> is

<constant>V4L2_CHIP_MATCH_SUBDEV_NAME</constant>,

<structfield>match.name</structfield> contains the sub-device name.

For instance

<constant>"saa7127 6-0044"</constant> will match this specific saa7127

sub-device. Again with the &VIDIOC-DBG-G-CHIP-NAME; ioctl you can find

out which sub-devices are present.</para>



    <para>When <structfield>match.type</structfield> is

<constant>V4L2_CHIP_MATCH_SUBDEV_IDX</constant>,

<structfield>match.addr</structfield> selects the nth sub-device.</para>



    <note>

      <title>Success not guaranteed</title>



      <para>Due to a flaw in the Linux &i2c; bus driver these ioctls may

return successfully without actually reading or writing a register. To

catch the most likely failure we recommend a &VIDIOC-DBG-G-CHIP-IDENT;

catch the most likely failure we recommend a &VIDIOC-DBG-G-CHIP-NAME;

call confirming the presence of the selected &i2c; chip.</para>

    </note>



    <para>These ioctls are optional, not all drivers may support them.

However when a driver supports these ioctls it must also support

&VIDIOC-DBG-G-CHIP-IDENT;. Conversely it may support

<constant>VIDIOC_DBG_G_CHIP_IDENT</constant> but not these ioctls.</para>

&VIDIOC-DBG-G-CHIP-NAME;. Conversely it may support

<constant>VIDIOC_DBG_G_CHIP_NAME</constant> but not these ioctls.</para>



    <para><constant>VIDIOC_DBG_G_REGISTER</constant> and

<constant>VIDIOC_DBG_S_REGISTER</constant> were introduced in Linux
@@ -217,10 +229,10 @@ register.</entry> 
	&cs-def;

	<tbody valign="top">

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_HOST</constant></entry>

	    <entry><constant>V4L2_CHIP_MATCH_BRIDGE</constant></entry>

	    <entry>0</entry>

	    <entry>Match the nth chip on the card, zero for the

	    host chip. Does not match &i2c; chips.</entry>

	    bridge chip. Does not match sub-devices.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant></entry>
@@ -237,6 +249,16 @@ register.</entry> 
	    <entry>3</entry>

	    <entry>Match the nth anciliary AC97 chip.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_SUBDEV_NAME</constant></entry>

	    <entry>4</entry>

	    <entry>Match the sub-device by name.</entry>

	  </row>

	  <row>

	    <entry><constant>V4L2_CHIP_MATCH_SUBDEV_IDX</constant></entry>

	    <entry>5</entry>

	    <entry>Match the nth sub-device.</entry>

	  </row>

	</tbody>

      </tgroup>

    </table>

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