Commit | Line | Data |
---|---|---|
b5958dc3 HV |
1 | <refentry id="vidioc-dbg-g-chip-name"> |
2 | <refmeta> | |
3 | <refentrytitle>ioctl VIDIOC_DBG_G_CHIP_NAME</refentrytitle> | |
4 | &manvol; | |
5 | </refmeta> | |
6 | ||
7 | <refnamediv> | |
8 | <refname>VIDIOC_DBG_G_CHIP_NAME</refname> | |
9 | <refpurpose>Identify the chips on a TV card</refpurpose> | |
10 | </refnamediv> | |
11 | ||
12 | <refsynopsisdiv> | |
13 | <funcsynopsis> | |
14 | <funcprototype> | |
15 | <funcdef>int <function>ioctl</function></funcdef> | |
16 | <paramdef>int <parameter>fd</parameter></paramdef> | |
17 | <paramdef>int <parameter>request</parameter></paramdef> | |
18 | <paramdef>struct v4l2_dbg_chip_name | |
19 | *<parameter>argp</parameter></paramdef> | |
20 | </funcprototype> | |
21 | </funcsynopsis> | |
22 | </refsynopsisdiv> | |
23 | ||
24 | <refsect1> | |
25 | <title>Arguments</title> | |
26 | ||
27 | <variablelist> | |
28 | <varlistentry> | |
29 | <term><parameter>fd</parameter></term> | |
30 | <listitem> | |
31 | <para>&fd;</para> | |
32 | </listitem> | |
33 | </varlistentry> | |
34 | <varlistentry> | |
35 | <term><parameter>request</parameter></term> | |
36 | <listitem> | |
37 | <para>VIDIOC_DBG_G_CHIP_NAME</para> | |
38 | </listitem> | |
39 | </varlistentry> | |
40 | <varlistentry> | |
41 | <term><parameter>argp</parameter></term> | |
42 | <listitem> | |
43 | <para></para> | |
44 | </listitem> | |
45 | </varlistentry> | |
46 | </variablelist> | |
47 | </refsect1> | |
48 | ||
49 | <refsect1> | |
50 | <title>Description</title> | |
51 | ||
52 | <note> | |
53 | <title>Experimental</title> | |
54 | ||
55 | <para>This is an <link | |
56 | linkend="experimental">experimental</link> interface and may change in | |
57 | the future.</para> | |
58 | </note> | |
59 | ||
60 | <para>For driver debugging purposes this ioctl allows test | |
61 | applications to query the driver about the chips present on the TV | |
62 | card. Regular applications must not use it. When you found a chip | |
63 | specific bug, please contact the linux-media mailing list (&v4l-ml;) | |
64 | so it can be fixed.</para> | |
65 | ||
cd634f1b HV |
66 | <para>Additionally the Linux kernel must be compiled with the |
67 | <constant>CONFIG_VIDEO_ADV_DEBUG</constant> option to enable this ioctl.</para> | |
68 | ||
b5958dc3 HV |
69 | <para>To query the driver applications must initialize the |
70 | <structfield>match.type</structfield> and | |
71 | <structfield>match.addr</structfield> or <structfield>match.name</structfield> | |
72 | fields of a &v4l2-dbg-chip-name; | |
73 | and call <constant>VIDIOC_DBG_G_CHIP_NAME</constant> with a pointer to | |
74 | this structure. On success the driver stores information about the | |
75 | selected chip in the <structfield>name</structfield> and | |
76 | <structfield>flags</structfield> fields. On failure the structure | |
77 | remains unchanged.</para> | |
78 | ||
79 | <para>When <structfield>match.type</structfield> is | |
80 | <constant>V4L2_CHIP_MATCH_BRIDGE</constant>, | |
81 | <structfield>match.addr</structfield> selects the nth bridge 'chip' | |
82 | on the TV card. You can enumerate all chips by starting at zero and | |
83 | incrementing <structfield>match.addr</structfield> by one until | |
84 | <constant>VIDIOC_DBG_G_CHIP_NAME</constant> fails with an &EINVAL;. | |
85 | The number zero always selects the bridge chip itself, ⪚ the chip | |
86 | connected to the PCI or USB bus. Non-zero numbers identify specific | |
87 | parts of the bridge chip such as an AC97 register block.</para> | |
88 | ||
89 | <para>When <structfield>match.type</structfield> is | |
3eef2510 | 90 | <constant>V4L2_CHIP_MATCH_SUBDEV</constant>, |
b5958dc3 HV |
91 | <structfield>match.addr</structfield> selects the nth sub-device. This |
92 | allows you to enumerate over all sub-devices.</para> | |
93 | ||
94 | <para>On success, the <structfield>name</structfield> field will | |
95 | contain a chip name and the <structfield>flags</structfield> field will | |
96 | contain <constant>V4L2_CHIP_FL_READABLE</constant> if the driver supports | |
97 | reading registers from the device or <constant>V4L2_CHIP_FL_WRITABLE</constant> | |
98 | if the driver supports writing registers to the device.</para> | |
99 | ||
100 | <para>We recommended the <application>v4l2-dbg</application> | |
101 | utility over calling this ioctl directly. It is available from the | |
102 | LinuxTV v4l-dvb repository; see <ulink | |
103 | url="http://linuxtv.org/repo/">http://linuxtv.org/repo/</ulink> for | |
104 | access instructions.</para> | |
105 | ||
106 | <!-- Note for convenience vidioc-dbg-g-register.sgml | |
107 | contains a duplicate of this table. --> | |
108 | <table pgwide="1" frame="none" id="name-v4l2-dbg-match"> | |
109 | <title>struct <structname>v4l2_dbg_match</structname></title> | |
110 | <tgroup cols="4"> | |
111 | &cs-ustr; | |
112 | <tbody valign="top"> | |
113 | <row> | |
114 | <entry>__u32</entry> | |
115 | <entry><structfield>type</structfield></entry> | |
116 | <entry>See <xref linkend="name-chip-match-types" /> for a list of | |
117 | possible types.</entry> | |
118 | </row> | |
119 | <row> | |
120 | <entry>union</entry> | |
121 | <entry>(anonymous)</entry> | |
122 | </row> | |
123 | <row> | |
124 | <entry></entry> | |
125 | <entry>__u32</entry> | |
126 | <entry><structfield>addr</structfield></entry> | |
127 | <entry>Match a chip by this number, interpreted according | |
128 | to the <structfield>type</structfield> field.</entry> | |
129 | </row> | |
130 | <row> | |
131 | <entry></entry> | |
132 | <entry>char</entry> | |
133 | <entry><structfield>name[32]</structfield></entry> | |
134 | <entry>Match a chip by this name, interpreted according | |
135 | to the <structfield>type</structfield> field.</entry> | |
136 | </row> | |
137 | </tbody> | |
138 | </tgroup> | |
139 | </table> | |
140 | ||
141 | <table pgwide="1" frame="none" id="v4l2-dbg-chip-name"> | |
142 | <title>struct <structname>v4l2_dbg_chip_name</structname></title> | |
143 | <tgroup cols="3"> | |
144 | &cs-str; | |
145 | <tbody valign="top"> | |
146 | <row> | |
147 | <entry>struct v4l2_dbg_match</entry> | |
148 | <entry><structfield>match</structfield></entry> | |
149 | <entry>How to match the chip, see <xref linkend="name-v4l2-dbg-match" />.</entry> | |
150 | </row> | |
151 | <row> | |
152 | <entry>char</entry> | |
153 | <entry><structfield>name[32]</structfield></entry> | |
154 | <entry>The name of the chip.</entry> | |
155 | </row> | |
156 | <row> | |
157 | <entry>__u32</entry> | |
158 | <entry><structfield>flags</structfield></entry> | |
159 | <entry>Set by the driver. If <constant>V4L2_CHIP_FL_READABLE</constant> | |
160 | is set, then the driver supports reading registers from the device. If | |
161 | <constant>V4L2_CHIP_FL_WRITABLE</constant> is set, then it supports writing registers.</entry> | |
162 | </row> | |
163 | <row> | |
164 | <entry>__u32</entry> | |
165 | <entry><structfield>reserved[8]</structfield></entry> | |
166 | <entry>Reserved fields, both application and driver must set these to 0.</entry> | |
167 | </row> | |
168 | </tbody> | |
169 | </tgroup> | |
170 | </table> | |
171 | ||
172 | <!-- Note for convenience vidioc-dbg-g-register.sgml | |
173 | contains a duplicate of this table. --> | |
174 | <table pgwide="1" frame="none" id="name-chip-match-types"> | |
175 | <title>Chip Match Types</title> | |
176 | <tgroup cols="3"> | |
177 | &cs-def; | |
178 | <tbody valign="top"> | |
179 | <row> | |
180 | <entry><constant>V4L2_CHIP_MATCH_BRIDGE</constant></entry> | |
181 | <entry>0</entry> | |
182 | <entry>Match the nth chip on the card, zero for the | |
183 | bridge chip. Does not match sub-devices.</entry> | |
184 | </row> | |
185 | <row> | |
186 | <entry><constant>V4L2_CHIP_MATCH_I2C_DRIVER</constant></entry> | |
187 | <entry>1</entry> | |
188 | <entry>Match an &i2c; chip by its driver name. Can't be used with this ioctl.</entry> | |
189 | </row> | |
190 | <row> | |
191 | <entry><constant>V4L2_CHIP_MATCH_I2C_ADDR</constant></entry> | |
192 | <entry>2</entry> | |
193 | <entry>Match a chip by its 7 bit &i2c; bus address. Can't be used with this ioctl.</entry> | |
194 | </row> | |
195 | <row> | |
196 | <entry><constant>V4L2_CHIP_MATCH_AC97</constant></entry> | |
197 | <entry>3</entry> | |
198 | <entry>Match the nth anciliary AC97 chip. Can't be used with this ioctl.</entry> | |
199 | </row> | |
200 | <row> | |
3eef2510 | 201 | <entry><constant>V4L2_CHIP_MATCH_SUBDEV</constant></entry> |
b5958dc3 | 202 | <entry>4</entry> |
b5958dc3 HV |
203 | <entry>Match the nth sub-device.</entry> |
204 | </row> | |
205 | </tbody> | |
206 | </tgroup> | |
207 | </table> | |
208 | </refsect1> | |
209 | ||
210 | <refsect1> | |
211 | &return-value; | |
212 | ||
213 | <variablelist> | |
214 | <varlistentry> | |
215 | <term><errorcode>EINVAL</errorcode></term> | |
216 | <listitem> | |
217 | <para>The <structfield>match_type</structfield> is invalid or | |
218 | no device could be matched.</para> | |
219 | </listitem> | |
220 | </varlistentry> | |
221 | </variablelist> | |
222 | </refsect1> | |
223 | </refentry> |