diff options
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml')
| -rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml | 64 |
1 files changed, 12 insertions, 52 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml b/Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml index d13bac9e2445..3d038e75d12b 100644 --- a/Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml +++ b/Documentation/DocBook/media/v4l/vidioc-dbg-g-register.xml @@ -76,7 +76,7 @@ compiled with the <constant>CONFIG_VIDEO_ADV_DEBUG</constant> option to enable these ioctls.</para> <para>To write a register applications must initialize all fields -of a &v4l2-dbg-register; and call +of a &v4l2-dbg-register; except for <structfield>size</structfield> and call <constant>VIDIOC_DBG_S_REGISTER</constant> with a pointer to this structure. The <structfield>match.type</structfield> and <structfield>match.addr</structfield> or <structfield>match.name</structfield> @@ -91,8 +91,8 @@ written into the register.</para> <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 -<structfield>val</structfield> field. On failure the structure remains -unchanged.</para> +<structfield>val</structfield> field and the size (in bytes) of the +value in <structfield>size</structfield>.</para> <para>When <structfield>match.type</structfield> is <constant>V4L2_CHIP_MATCH_BRIDGE</constant>, @@ -102,39 +102,9 @@ chip connected to the PCI or USB bus. You can find out which chips are present with the &VIDIOC-DBG-G-CHIP-INFO; ioctl.</para> <para>When <structfield>match.type</structfield> is -<constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant>, -<structfield>match.name</structfield> contains the I2C driver name. -For instance -<constant>"saa7127"</constant> will match any chip -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-INFO; ioctl you can find out which &i2c; chips are -present.</para> - - <para>When <structfield>match.type</structfield> is -<constant>V4L2_CHIP_MATCH_I2C_ADDR</constant>, -<structfield>match.addr</structfield> selects a chip by its 7 bit &i2c; -bus address.</para> - - <para>When <structfield>match.type</structfield> is -<constant>V4L2_CHIP_MATCH_AC97</constant>, -<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</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-INFO; -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-INFO;. Conversely it may support @@ -150,7 +120,7 @@ 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-chip-ident.sgml + <!-- Note for convenience vidioc-dbg-g-chip-info.sgml contains a duplicate of this table. --> <table pgwide="1" frame="none" id="v4l2-dbg-match"> <title>struct <structname>v4l2_dbg_match</structname></title> @@ -160,7 +130,7 @@ access instructions.</para> <row> <entry>__u32</entry> <entry><structfield>type</structfield></entry> - <entry>See <xref linkend="ident-chip-match-types" /> for a list of + <entry>See <xref linkend="chip-match-types" /> for a list of possible types.</entry> </row> <row> @@ -179,7 +149,7 @@ to the <structfield>type</structfield> field.</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> +to the <structfield>type</structfield> field. Currently unused.</entry> </row> </tbody> </tgroup> @@ -199,6 +169,11 @@ to the <structfield>type</structfield> field.</entry> <entry>How to match the chip, see <xref linkend="v4l2-dbg-match" />.</entry> </row> <row> + <entry>__u32</entry> + <entry><structfield>size</structfield></entry> + <entry>The register size in bytes.</entry> + </row> + <row> <entry>__u64</entry> <entry><structfield>reg</structfield></entry> <entry>A register number.</entry> @@ -213,7 +188,7 @@ register.</entry> </tgroup> </table> - <!-- Note for convenience vidioc-dbg-g-chip-ident.sgml + <!-- Note for convenience vidioc-dbg-g-chip-info.sgml contains a duplicate of this table. --> <table pgwide="1" frame="none" id="chip-match-types"> <title>Chip Match Types</title> @@ -227,21 +202,6 @@ register.</entry> 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.</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.</entry> - </row> - <row> - <entry><constant>V4L2_CHIP_MATCH_AC97</constant></entry> - <entry>3</entry> - <entry>Match the nth anciliary AC97 chip.</entry> - </row> - <row> <entry><constant>V4L2_CHIP_MATCH_SUBDEV</constant></entry> <entry>4</entry> <entry>Match the nth sub-device.</entry> |