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author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-10-11 05:55:04 -0400 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-10-11 05:55:04 -0400 |
commit | a0f0dd57f4a85310d9936f1770a0424b49fef876 (patch) | |
tree | 2f85b8b67dda13d19b02ca39e0fbef921cb1cf8b /Documentation/DocBook/media/v4l/vidioc-subdev-g-edid.xml | |
parent | 2a552d5e63d7fa602c9a9a0717008737f55625a6 (diff) | |
parent | 846a136881b8f73c1f74250bf6acfaa309cab1f2 (diff) |
Merge branch 'fixes' into for-linus
Conflicts:
arch/arm/kernel/smp.c
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-subdev-g-edid.xml')
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-subdev-g-edid.xml | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-subdev-g-edid.xml b/Documentation/DocBook/media/v4l/vidioc-subdev-g-edid.xml new file mode 100644 index 000000000000..bbd18f0e6ede --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-subdev-g-edid.xml | |||
@@ -0,0 +1,152 @@ | |||
1 | <refentry id="vidioc-subdev-g-edid"> | ||
2 | <refmeta> | ||
3 | <refentrytitle>ioctl VIDIOC_SUBDEV_G_EDID, VIDIOC_SUBDEV_S_EDID</refentrytitle> | ||
4 | &manvol; | ||
5 | </refmeta> | ||
6 | |||
7 | <refnamediv> | ||
8 | <refname>VIDIOC_SUBDEV_G_EDID</refname> | ||
9 | <refname>VIDIOC_SUBDEV_S_EDID</refname> | ||
10 | <refpurpose>Get or set the EDID of a video receiver/transmitter</refpurpose> | ||
11 | </refnamediv> | ||
12 | |||
13 | <refsynopsisdiv> | ||
14 | <funcsynopsis> | ||
15 | <funcprototype> | ||
16 | <funcdef>int <function>ioctl</function></funcdef> | ||
17 | <paramdef>int <parameter>fd</parameter></paramdef> | ||
18 | <paramdef>int <parameter>request</parameter></paramdef> | ||
19 | <paramdef>struct v4l2_subdev_edid *<parameter>argp</parameter></paramdef> | ||
20 | </funcprototype> | ||
21 | </funcsynopsis> | ||
22 | <funcsynopsis> | ||
23 | <funcprototype> | ||
24 | <funcdef>int <function>ioctl</function></funcdef> | ||
25 | <paramdef>int <parameter>fd</parameter></paramdef> | ||
26 | <paramdef>int <parameter>request</parameter></paramdef> | ||
27 | <paramdef>const struct v4l2_subdev_edid *<parameter>argp</parameter></paramdef> | ||
28 | </funcprototype> | ||
29 | </funcsynopsis> | ||
30 | </refsynopsisdiv> | ||
31 | |||
32 | <refsect1> | ||
33 | <title>Arguments</title> | ||
34 | |||
35 | <variablelist> | ||
36 | <varlistentry> | ||
37 | <term><parameter>fd</parameter></term> | ||
38 | <listitem> | ||
39 | <para>&fd;</para> | ||
40 | </listitem> | ||
41 | </varlistentry> | ||
42 | <varlistentry> | ||
43 | <term><parameter>request</parameter></term> | ||
44 | <listitem> | ||
45 | <para>VIDIOC_SUBDEV_G_EDID, VIDIOC_SUBDEV_S_EDID</para> | ||
46 | </listitem> | ||
47 | </varlistentry> | ||
48 | <varlistentry> | ||
49 | <term><parameter>argp</parameter></term> | ||
50 | <listitem> | ||
51 | <para></para> | ||
52 | </listitem> | ||
53 | </varlistentry> | ||
54 | </variablelist> | ||
55 | </refsect1> | ||
56 | |||
57 | <refsect1> | ||
58 | <title>Description</title> | ||
59 | <para>These ioctls can be used to get or set an EDID associated with an input pad | ||
60 | from a receiver or an output pad of a transmitter subdevice.</para> | ||
61 | |||
62 | <para>To get the EDID data the application has to fill in the <structfield>pad</structfield>, | ||
63 | <structfield>start_block</structfield>, <structfield>blocks</structfield> and <structfield>edid</structfield> | ||
64 | fields and call <constant>VIDIOC_SUBDEV_G_EDID</constant>. The current EDID from block | ||
65 | <structfield>start_block</structfield> and of size <structfield>blocks</structfield> | ||
66 | will be placed in the memory <structfield>edid</structfield> points to. The <structfield>edid</structfield> | ||
67 | pointer must point to memory at least <structfield>blocks</structfield> * 128 bytes | ||
68 | large (the size of one block is 128 bytes).</para> | ||
69 | |||
70 | <para>If there are fewer blocks than specified, then the driver will set <structfield>blocks</structfield> | ||
71 | to the actual number of blocks. If there are no EDID blocks available at all, then the error code | ||
72 | ENODATA is set.</para> | ||
73 | |||
74 | <para>If blocks have to be retrieved from the sink, then this call will block until they | ||
75 | have been read.</para> | ||
76 | |||
77 | <para>To set the EDID blocks of a receiver the application has to fill in the <structfield>pad</structfield>, | ||
78 | <structfield>blocks</structfield> and <structfield>edid</structfield> fields and set | ||
79 | <structfield>start_block</structfield> to 0. It is not possible to set part of an EDID, | ||
80 | it is always all or nothing. Setting the EDID data is only valid for receivers as it makes | ||
81 | no sense for a transmitter.</para> | ||
82 | |||
83 | <para>The driver assumes that the full EDID is passed in. If there are more EDID blocks than | ||
84 | the hardware can handle then the EDID is not written, but instead the error code E2BIG is set | ||
85 | and <structfield>blocks</structfield> is set to the maximum that the hardware supports. | ||
86 | If <structfield>start_block</structfield> is any | ||
87 | value other than 0 then the error code EINVAL is set.</para> | ||
88 | |||
89 | <para>To disable an EDID you set <structfield>blocks</structfield> to 0. Depending on the | ||
90 | hardware this will drive the hotplug pin low and/or block the source from reading the EDID | ||
91 | data in some way. In any case, the end result is the same: the EDID is no longer available. | ||
92 | </para> | ||
93 | |||
94 | <table pgwide="1" frame="none" id="v4l2-subdev-edid"> | ||
95 | <title>struct <structname>v4l2_subdev_edid</structname></title> | ||
96 | <tgroup cols="3"> | ||
97 | &cs-str; | ||
98 | <tbody valign="top"> | ||
99 | <row> | ||
100 | <entry>__u32</entry> | ||
101 | <entry><structfield>pad</structfield></entry> | ||
102 | <entry>Pad for which to get/set the EDID blocks.</entry> | ||
103 | </row> | ||
104 | <row> | ||
105 | <entry>__u32</entry> | ||
106 | <entry><structfield>start_block</structfield></entry> | ||
107 | <entry>Read the EDID from starting with this block. Must be 0 when setting | ||
108 | the EDID.</entry> | ||
109 | </row> | ||
110 | <row> | ||
111 | <entry>__u32</entry> | ||
112 | <entry><structfield>blocks</structfield></entry> | ||
113 | <entry>The number of blocks to get or set. Must be less or equal to 256 (the | ||
114 | maximum number of blocks as defined by the standard). When you set the EDID and | ||
115 | <structfield>blocks</structfield> is 0, then the EDID is disabled or erased.</entry> | ||
116 | </row> | ||
117 | <row> | ||
118 | <entry>__u8 *</entry> | ||
119 | <entry><structfield>edid</structfield></entry> | ||
120 | <entry>Pointer to memory that contains the EDID. The minimum size is | ||
121 | <structfield>blocks</structfield> * 128.</entry> | ||
122 | </row> | ||
123 | <row> | ||
124 | <entry>__u32</entry> | ||
125 | <entry><structfield>reserved</structfield>[5]</entry> | ||
126 | <entry>Reserved for future extensions. Applications and drivers must | ||
127 | set the array to zero.</entry> | ||
128 | </row> | ||
129 | </tbody> | ||
130 | </tgroup> | ||
131 | </table> | ||
132 | </refsect1> | ||
133 | |||
134 | <refsect1> | ||
135 | &return-value; | ||
136 | |||
137 | <variablelist> | ||
138 | <varlistentry> | ||
139 | <term><errorcode>ENODATA</errorcode></term> | ||
140 | <listitem> | ||
141 | <para>The EDID data is not available.</para> | ||
142 | </listitem> | ||
143 | </varlistentry> | ||
144 | <varlistentry> | ||
145 | <term><errorcode>E2BIG</errorcode></term> | ||
146 | <listitem> | ||
147 | <para>The EDID data you provided is more than the hardware can handle.</para> | ||
148 | </listitem> | ||
149 | </varlistentry> | ||
150 | </variablelist> | ||
151 | </refsect1> | ||
152 | </refentry> | ||