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-rw-r--r--Documentation/DocBook/v4l/io.xml3
-rw-r--r--Documentation/DocBook/v4l/vidioc-qbuf.xml40
-rw-r--r--Documentation/DocBook/v4l/vidioc-querybuf.xml7
-rw-r--r--Documentation/DocBook/v4l/vidioc-reqbufs.xml36
-rw-r--r--Documentation/dvb/get_dvb_firmware23
-rw-r--r--Documentation/video4linux/CARDLIST.cx238851
-rw-r--r--Documentation/video4linux/CARDLIST.saa71341
-rw-r--r--Documentation/video4linux/CARDLIST.tuner1
-rw-r--r--Documentation/video4linux/README.tlg230047
-rw-r--r--Documentation/video4linux/gspca.txt25
-rw-r--r--Documentation/video4linux/v4l2-framework.txt106
-rw-r--r--Documentation/video4linux/videobuf360
12 files changed, 501 insertions, 149 deletions
diff --git a/Documentation/DocBook/v4l/io.xml b/Documentation/DocBook/v4l/io.xml
index f92f24323b2..e870330cbf7 100644
--- a/Documentation/DocBook/v4l/io.xml
+++ b/Documentation/DocBook/v4l/io.xml
@@ -589,7 +589,8 @@ number of a video input as in &v4l2-input; field
<entry></entry>
<entry>A place holder for future extensions and custom
(driver defined) buffer types
-<constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher.</entry>
+<constant>V4L2_BUF_TYPE_PRIVATE</constant> and higher. Applications
+should set this to 0.</entry>
</row>
</tbody>
</tgroup>
diff --git a/Documentation/DocBook/v4l/vidioc-qbuf.xml b/Documentation/DocBook/v4l/vidioc-qbuf.xml
index 18708177815..b843bd7b389 100644
--- a/Documentation/DocBook/v4l/vidioc-qbuf.xml
+++ b/Documentation/DocBook/v4l/vidioc-qbuf.xml
@@ -54,12 +54,10 @@ to enqueue an empty (capturing) or filled (output) buffer in the
driver's incoming queue. The semantics depend on the selected I/O
method.</para>
- <para>To enqueue a <link linkend="mmap">memory mapped</link>
-buffer applications set the <structfield>type</structfield> field of a
-&v4l2-buffer; to the same buffer type as previously &v4l2-format;
-<structfield>type</structfield> and &v4l2-requestbuffers;
-<structfield>type</structfield>, the <structfield>memory</structfield>
-field to <constant>V4L2_MEMORY_MMAP</constant> and the
+ <para>To enqueue a buffer applications set the <structfield>type</structfield>
+field of a &v4l2-buffer; to the same buffer type as was previously used
+with &v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers;
+<structfield>type</structfield>. Applications must also set the
<structfield>index</structfield> field. Valid index numbers range from
zero to the number of buffers allocated with &VIDIOC-REQBUFS;
(&v4l2-requestbuffers; <structfield>count</structfield>) minus one. The
@@ -70,8 +68,19 @@ intended for output (<structfield>type</structfield> is
<constant>V4L2_BUF_TYPE_VBI_OUTPUT</constant>) applications must also
initialize the <structfield>bytesused</structfield>,
<structfield>field</structfield> and
-<structfield>timestamp</structfield> fields. See <xref
- linkend="buffer" /> for details. When
+<structfield>timestamp</structfield> fields, see <xref
+linkend="buffer" /> for details.
+Applications must also set <structfield>flags</structfield> to 0. If a driver
+supports capturing from specific video inputs and you want to specify a video
+input, then <structfield>flags</structfield> should be set to
+<constant>V4L2_BUF_FLAG_INPUT</constant> and the field
+<structfield>input</structfield> must be initialized to the desired input.
+The <structfield>reserved</structfield> field must be set to 0.
+</para>
+
+ <para>To enqueue a <link linkend="mmap">memory mapped</link>
+buffer applications set the <structfield>memory</structfield>
+field to <constant>V4L2_MEMORY_MMAP</constant>. When
<constant>VIDIOC_QBUF</constant> is called with a pointer to this
structure the driver sets the
<constant>V4L2_BUF_FLAG_MAPPED</constant> and
@@ -81,14 +90,10 @@ structure the driver sets the
&EINVAL;.</para>
<para>To enqueue a <link linkend="userp">user pointer</link>
-buffer applications set the <structfield>type</structfield> field of a
-&v4l2-buffer; to the same buffer type as previously &v4l2-format;
-<structfield>type</structfield> and &v4l2-requestbuffers;
-<structfield>type</structfield>, the <structfield>memory</structfield>
-field to <constant>V4L2_MEMORY_USERPTR</constant> and the
+buffer applications set the <structfield>memory</structfield>
+field to <constant>V4L2_MEMORY_USERPTR</constant>, the
<structfield>m.userptr</structfield> field to the address of the
-buffer and <structfield>length</structfield> to its size. When the
-buffer is intended for output additional fields must be set as above.
+buffer and <structfield>length</structfield> to its size.
When <constant>VIDIOC_QBUF</constant> is called with a pointer to this
structure the driver sets the <constant>V4L2_BUF_FLAG_QUEUED</constant>
flag and clears the <constant>V4L2_BUF_FLAG_MAPPED</constant> and
@@ -96,13 +101,14 @@ flag and clears the <constant>V4L2_BUF_FLAG_MAPPED</constant> and
<structfield>flags</structfield> field, or it returns an error code.
This ioctl locks the memory pages of the buffer in physical memory,
they cannot be swapped out to disk. Buffers remain locked until
-dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl are
+dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl is
called, or until the device is closed.</para>
<para>Applications call the <constant>VIDIOC_DQBUF</constant>
ioctl to dequeue a filled (capturing) or displayed (output) buffer
from the driver's outgoing queue. They just set the
-<structfield>type</structfield> and <structfield>memory</structfield>
+<structfield>type</structfield>, <structfield>memory</structfield>
+and <structfield>reserved</structfield>
fields of a &v4l2-buffer; as above, when <constant>VIDIOC_DQBUF</constant>
is called with a pointer to this structure the driver fills the
remaining fields or returns an error code.</para>
diff --git a/Documentation/DocBook/v4l/vidioc-querybuf.xml b/Documentation/DocBook/v4l/vidioc-querybuf.xml
index d834993e619..e649805a490 100644
--- a/Documentation/DocBook/v4l/vidioc-querybuf.xml
+++ b/Documentation/DocBook/v4l/vidioc-querybuf.xml
@@ -54,12 +54,13 @@ buffer at any time after buffers have been allocated with the
&VIDIOC-REQBUFS; ioctl.</para>
<para>Applications set the <structfield>type</structfield> field
- of a &v4l2-buffer; to the same buffer type as previously
+ of a &v4l2-buffer; to the same buffer type as was previously used with
&v4l2-format; <structfield>type</structfield> and &v4l2-requestbuffers;
<structfield>type</structfield>, and the <structfield>index</structfield>
field. Valid index numbers range from zero
to the number of buffers allocated with &VIDIOC-REQBUFS;
(&v4l2-requestbuffers; <structfield>count</structfield>) minus one.
+The <structfield>reserved</structfield> field should to set to 0.
After calling <constant>VIDIOC_QUERYBUF</constant> with a pointer to
this structure drivers return an error code or fill the rest of
the structure.</para>
@@ -68,8 +69,8 @@ the structure.</para>
<constant>V4L2_BUF_FLAG_MAPPED</constant>,
<constant>V4L2_BUF_FLAG_QUEUED</constant> and
<constant>V4L2_BUF_FLAG_DONE</constant> flags will be valid. The
-<structfield>memory</structfield> field will be set to
-<constant>V4L2_MEMORY_MMAP</constant>, the <structfield>m.offset</structfield>
+<structfield>memory</structfield> field will be set to the current
+I/O method, the <structfield>m.offset</structfield>
contains the offset of the buffer from the start of the device memory,
the <structfield>length</structfield> field its size. The driver may
or may not set the remaining fields and flags, they are meaningless in
diff --git a/Documentation/DocBook/v4l/vidioc-reqbufs.xml b/Documentation/DocBook/v4l/vidioc-reqbufs.xml
index bab38084454..1c081637207 100644
--- a/Documentation/DocBook/v4l/vidioc-reqbufs.xml
+++ b/Documentation/DocBook/v4l/vidioc-reqbufs.xml
@@ -54,23 +54,23 @@ I/O. Memory mapped buffers are located in device memory and must be
allocated with this ioctl before they can be mapped into the
application's address space. User buffers are allocated by
applications themselves, and this ioctl is merely used to switch the
-driver into user pointer I/O mode.</para>
+driver into user pointer I/O mode and to setup some internal structures.</para>
- <para>To allocate device buffers applications initialize three
-fields of a <structname>v4l2_requestbuffers</structname> structure.
+ <para>To allocate device buffers applications initialize all
+fields of the <structname>v4l2_requestbuffers</structname> structure.
They set the <structfield>type</structfield> field to the respective
stream or buffer type, the <structfield>count</structfield> field to
-the desired number of buffers, and <structfield>memory</structfield>
-must be set to <constant>V4L2_MEMORY_MMAP</constant>. When the ioctl
-is called with a pointer to this structure the driver attempts to
-allocate the requested number of buffers and stores the actual number
+the desired number of buffers, <structfield>memory</structfield>
+must be set to the requested I/O method and the reserved array
+must be zeroed. When the ioctl
+is called with a pointer to this structure the driver will attempt to allocate
+the requested number of buffers and it stores the actual number
allocated in the <structfield>count</structfield> field. It can be
smaller than the number requested, even zero, when the driver runs out
-of free memory. A larger number is possible when the driver requires
-more buffers to function correctly.<footnote>
- <para>For example video output requires at least two buffers,
+of free memory. A larger number is also possible when the driver requires
+more buffers to function correctly. For example video output requires at least two buffers,
one displayed and one filled by the application.</para>
- </footnote> When memory mapping I/O is not supported the ioctl
+ <para>When the I/O method is not supported the ioctl
returns an &EINVAL;.</para>
<para>Applications can call <constant>VIDIOC_REQBUFS</constant>
@@ -81,14 +81,6 @@ in progress, an implicit &VIDIOC-STREAMOFF;. <!-- mhs: I see no
reason why munmap()ping one or even all buffers must imply
streamoff.--></para>
- <para>To negotiate user pointer I/O, applications initialize only
-the <structfield>type</structfield> field and set
-<structfield>memory</structfield> to
-<constant>V4L2_MEMORY_USERPTR</constant>. When the ioctl is called
-with a pointer to this structure the driver prepares for user pointer
-I/O, when this I/O method is not supported the ioctl returns an
-&EINVAL;.</para>
-
<table pgwide="1" frame="none" id="v4l2-requestbuffers">
<title>struct <structname>v4l2_requestbuffers</structname></title>
<tgroup cols="3">
@@ -97,9 +89,7 @@ I/O, when this I/O method is not supported the ioctl returns an
<row>
<entry>__u32</entry>
<entry><structfield>count</structfield></entry>
- <entry>The number of buffers requested or granted. This
-field is only used when <structfield>memory</structfield> is set to
-<constant>V4L2_MEMORY_MMAP</constant>.</entry>
+ <entry>The number of buffers requested or granted.</entry>
</row>
<row>
<entry>&v4l2-buf-type;</entry>
@@ -120,7 +110,7 @@ as the &v4l2-format; <structfield>type</structfield> field. See <xref
<entry><structfield>reserved</structfield>[2]</entry>
<entry>A place holder for future extensions and custom
(driver defined) buffer types <constant>V4L2_BUF_TYPE_PRIVATE</constant> and
-higher.</entry>
+higher. This array should be zeroed by applications.</entry>
</row>
</tbody>
</tgroup>
diff --git a/Documentation/dvb/get_dvb_firmware b/Documentation/dvb/get_dvb_firmware
index 14b7b5a3bcb..239cbdbf4d1 100644
--- a/Documentation/dvb/get_dvb_firmware
+++ b/Documentation/dvb/get_dvb_firmware
@@ -26,7 +26,7 @@ use IO::Handle;
"dec3000s", "vp7041", "dibusb", "nxt2002", "nxt2004",
"or51211", "or51132_qam", "or51132_vsb", "bluebird",
"opera1", "cx231xx", "cx18", "cx23885", "pvrusb2", "mpc718",
- "af9015");
+ "af9015", "ngene");
# Check args
syntax() if (scalar(@ARGV) != 1);
@@ -39,7 +39,7 @@ for ($i=0; $i < scalar(@components); $i++) {
die $@ if $@;
print STDERR <<EOF;
Firmware(s) $outfile extracted successfully.
-Now copy it(they) to either /usr/lib/hotplug/firmware or /lib/firmware
+Now copy it(them) to either /usr/lib/hotplug/firmware or /lib/firmware
(depending on configuration of firmware hotplug).
EOF
exit(0);
@@ -549,6 +549,24 @@ sub af9015 {
close INFILE;
}
+sub ngene {
+ my $url = "http://www.digitaldevices.de/download/";
+ my $file1 = "ngene_15.fw";
+ my $hash1 = "d798d5a757121174f0dbc5f2833c0c85";
+ my $file2 = "ngene_17.fw";
+ my $hash2 = "26b687136e127b8ac24b81e0eeafc20b";
+
+ checkstandard();
+
+ wgetfile($file1, $url . $file1);
+ verify($file1, $hash1);
+
+ wgetfile($file2, $url . $file2);
+ verify($file2, $hash2);
+
+ "$file1, $file2";
+}
+
# ---------------------------------------------------------------
# Utilities
@@ -667,6 +685,7 @@ sub delzero{
sub syntax() {
print STDERR "syntax: get_dvb_firmware <component>\n";
print STDERR "Supported components:\n";
+ @components = sort @components;
for($i=0; $i < scalar(@components); $i++) {
print STDERR "\t" . $components[$i] . "\n";
}
diff --git a/Documentation/video4linux/CARDLIST.cx23885 b/Documentation/video4linux/CARDLIST.cx23885
index 7539e8fa1ff..16ca030e118 100644
--- a/Documentation/video4linux/CARDLIST.cx23885
+++ b/Documentation/video4linux/CARDLIST.cx23885
@@ -26,3 +26,4 @@
25 -> Compro VideoMate E800 [1858:e800]
26 -> Hauppauge WinTV-HVR1290 [0070:8551]
27 -> Mygica X8558 PRO DMB-TH [14f1:8578]
+ 28 -> LEADTEK WinFast PxTV1200 [107d:6f22]
diff --git a/Documentation/video4linux/CARDLIST.saa7134 b/Documentation/video4linux/CARDLIST.saa7134
index fce1e7eb047..b4a767060ed 100644
--- a/Documentation/video4linux/CARDLIST.saa7134
+++ b/Documentation/video4linux/CARDLIST.saa7134
@@ -174,3 +174,4 @@
173 -> Zolid Hybrid TV Tuner PCI [1131:2004]
174 -> Asus Europa Hybrid OEM [1043:4847]
175 -> Leadtek Winfast DTV1000S [107d:6655]
+176 -> Beholder BeholdTV 505 RDS [0000:5051]
diff --git a/Documentation/video4linux/CARDLIST.tuner b/Documentation/video4linux/CARDLIST.tuner
index e0d298fe883..9b2e0dd6017 100644
--- a/Documentation/video4linux/CARDLIST.tuner
+++ b/Documentation/video4linux/CARDLIST.tuner
@@ -81,3 +81,4 @@ tuner=80 - Philips FQ1216LME MK3 PAL/SECAM w/active loopthrough
tuner=81 - Partsnic (Daewoo) PTI-5NF05
tuner=82 - Philips CU1216L
tuner=83 - NXP TDA18271
+tuner=84 - Sony BTF-Pxn01Z
diff --git a/Documentation/video4linux/README.tlg2300 b/Documentation/video4linux/README.tlg2300
new file mode 100644
index 00000000000..416ccb93d8c
--- /dev/null
+++ b/Documentation/video4linux/README.tlg2300
@@ -0,0 +1,47 @@
+tlg2300 release notes
+====================
+
+This is a v4l2/dvb device driver for the tlg2300 chip.
+
+
+current status
+==============
+
+video
+ - support mmap and read().(no overlay)
+
+audio
+ - The driver will register a ALSA card for the audio input.
+
+vbi
+ - Works for almost TV norms.
+
+dvb-t
+ - works for DVB-T
+
+FM
+ - Works for radio.
+
+---------------------------------------------------------------------------
+TESTED APPLICATIONS:
+
+-VLC1.0.4 test the video and dvb. The GUI is friendly to use.
+
+-Mplayer test the video.
+
+-Mplayer test the FM. The mplayer should be compiled with --enable-radio and
+ --enable-radio-capture.
+ The command runs as this(The alsa audio registers to card 1):
+ #mplayer radio://103.7/capture/ -radio adevice=hw=1,0:arate=48000 \
+ -rawaudio rate=48000:channels=2
+
+---------------------------------------------------------------------------
+KNOWN PROBLEMS:
+about preemphasis:
+ You can set the preemphasis for radio by the following command:
+ #v4l2-ctl -d /dev/radio0 --set-ctrl=pre_emphasis_settings=1
+
+ "pre_emphasis_settings=1" means that you select the 50us. If you want
+ to select the 75us, please use "pre_emphasis_settings=2"
+
+
diff --git a/Documentation/video4linux/gspca.txt b/Documentation/video4linux/gspca.txt
index 1800a62cf13..181b9e6fd98 100644
--- a/Documentation/video4linux/gspca.txt
+++ b/Documentation/video4linux/gspca.txt
@@ -42,6 +42,7 @@ ov519 041e:4064 Creative Live! VISTA VF0420
ov519 041e:4067 Creative Live! Cam Video IM (VF0350)
ov519 041e:4068 Creative Live! VISTA VF0470
spca561 0458:7004 Genius VideoCAM Express V2
+sn9c2028 0458:7005 Genius Smart 300, version 2
sunplus 0458:7006 Genius Dsc 1.3 Smart
zc3xx 0458:7007 Genius VideoCam V2
zc3xx 0458:700c Genius VideoCam V3
@@ -109,6 +110,7 @@ sunplus 04a5:3003 Benq DC 1300
sunplus 04a5:3008 Benq DC 1500
sunplus 04a5:300a Benq DC 3410
spca500 04a5:300c Benq DC 1016
+benq 04a5:3035 Benq DC E300
finepix 04cb:0104 Fujifilm FinePix 4800
finepix 04cb:0109 Fujifilm FinePix A202
finepix 04cb:010b Fujifilm FinePix A203
@@ -142,6 +144,7 @@ sunplus 04fc:5360 Sunplus Generic
spca500 04fc:7333 PalmPixDC85
sunplus 04fc:ffff Pure DigitalDakota
spca501 0506:00df 3Com HomeConnect Lite
+sunplus 052b:1507 Megapixel 5 Pretec DC-1007
sunplus 052b:1513 Megapix V4
sunplus 052b:1803 MegaImage VI
tv8532 0545:808b Veo Stingray
@@ -151,6 +154,7 @@ sunplus 0546:3191 Polaroid Ion 80
sunplus 0546:3273 Polaroid PDC2030
ov519 054c:0154 Sonny toy4
ov519 054c:0155 Sonny toy5
+cpia1 0553:0002 CPIA CPiA (version1) based cameras
zc3xx 055f:c005 Mustek Wcam300A
spca500 055f:c200 Mustek Gsmart 300
sunplus 055f:c211 Kowa Bs888e Microcamera
@@ -188,8 +192,7 @@ spca500 06bd:0404 Agfa CL20
spca500 06be:0800 Optimedia
sunplus 06d6:0031 Trust 610 LCD PowerC@m Zoom
spca506 06e1:a190 ADS Instant VCD
-ov534 06f8:3002 Hercules Blog Webcam
-ov534 06f8:3003 Hercules Dualpix HD Weblog
+ov534_9 06f8:3003 Hercules Dualpix HD Weblog
sonixj 06f8:3004 Hercules Classic Silver
sonixj 06f8:3008 Hercules Deluxe Optical Glass
pac7302 06f8:3009 Hercules Classic Link
@@ -204,6 +207,7 @@ sunplus 0733:2221 Mercury Digital Pro 3.1p
sunplus 0733:3261 Concord 3045 spca536a
sunplus 0733:3281 Cyberpix S550V
spca506 0734:043b 3DeMon USB Capture aka
+cpia1 0813:0001 QX3 camera
ov519 0813:0002 Dual Mode USB Camera Plus
spca500 084d:0003 D-Link DSC-350
spca500 08ca:0103 Aiptek PocketDV
@@ -225,7 +229,8 @@ sunplus 08ca:2050 Medion MD 41437
sunplus 08ca:2060 Aiptek PocketDV5300
tv8532 0923:010f ICM532 cams
mars 093a:050f Mars-Semi Pc-Camera
-mr97310a 093a:010f Sakar Digital no. 77379
+mr97310a 093a:010e All known CIF cams with this ID
+mr97310a 093a:010f All known VGA cams with this ID
pac207 093a:2460 Qtec Webcam 100
pac207 093a:2461 HP Webcam
pac207 093a:2463 Philips SPC 220 NC
@@ -302,6 +307,7 @@ sonixj 0c45:613b Surfer SN-206
sonixj 0c45:613c Sonix Pccam168
sonixj 0c45:6143 Sonix Pccam168
sonixj 0c45:6148 Digitus DA-70811/ZSMC USB PC Camera ZS211/Microdia
+sonixj 0c45:614a Frontech E-Ccam (JIL-2225)
sn9c20x 0c45:6240 PC Camera (SN9C201 + MT9M001)
sn9c20x 0c45:6242 PC Camera (SN9C201 + MT9M111)
sn9c20x 0c45:6248 PC Camera (SN9C201 + OV9655)
@@ -324,6 +330,10 @@ sn9c20x 0c45:62b0 PC Camera (SN9C202 + MT9V011/MT9V111/MT9V112)
sn9c20x 0c45:62b3 PC Camera (SN9C202 + OV9655)
sn9c20x 0c45:62bb PC Camera (SN9C202 + OV7660)
sn9c20x 0c45:62bc PC Camera (SN9C202 + HV7131R)
+sn9c2028 0c45:8001 Wild Planet Digital Spy Camera
+sn9c2028 0c45:8003 Sakar #11199, #6637x, #67480 keychain cams
+sn9c2028 0c45:8008 Mini-Shotz ms-350
+sn9c2028 0c45:800a Vivitar Vivicam 3350B
sunplus 0d64:0303 Sunplus FashionCam DXG
ov519 0e96:c001 TRUST 380 USB2 SPACEC@M
etoms 102c:6151 Qcam Sangha CIF
@@ -341,10 +351,11 @@ spca501 1776:501c Arowana 300K CMOS Camera
t613 17a1:0128 TASCORP JPEG Webcam, NGS Cyclops
vc032x 17ef:4802 Lenovo Vc0323+MI1310_SOC
pac207 2001:f115 D-Link DSB-C120
-sq905c 2770:9050 sq905c
-sq905c 2770:905c DualCamera
-sq905 2770:9120 Argus Digital Camera DC1512
-sq905c 2770:913d sq905c
+sq905c 2770:9050 Disney pix micro (CIF)
+sq905c 2770:9052 Disney pix micro 2 (VGA)
+sq905c 2770:905c All 11 known cameras with this ID
+sq905 2770:9120 All 24 known cameras with this ID
+sq905c 2770:913d All 4 known cameras with this ID
spca500 2899:012c Toptro Industrial
ov519 8020:ef04 ov519
spca508 8086:0110 Intel Easy PC Camera
diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt
index 74d677c8b03..5155700c206 100644
--- a/Documentation/video4linux/v4l2-framework.txt
+++ b/Documentation/video4linux/v4l2-framework.txt
@@ -599,99 +599,13 @@ video_device::minor fields.
video buffer helper functions
-----------------------------
-The v4l2 core API provides a standard method for dealing with video
-buffers. Those methods allow a driver to implement read(), mmap() and
-overlay() on a consistent way.
-
-There are currently methods for using video buffers on devices that
-supports DMA with scatter/gather method (videobuf-dma-sg), DMA with
-linear access (videobuf-dma-contig), and vmalloced buffers, mostly
-used on USB drivers (videobuf-vmalloc).
-
-Any driver using videobuf should provide operations (callbacks) for
-four handlers:
-
-ops->buf_setup - calculates the size of the video buffers and avoid they
- to waste more than some maximum limit of RAM;
-ops->buf_prepare - fills the video buffer structs and calls
- videobuf_iolock() to alloc and prepare mmaped memory;
-ops->buf_queue - advices the driver that another buffer were
- requested (by read() or by QBUF);
-ops->buf_release - frees any buffer that were allocated.
-
-In order to use it, the driver need to have a code (generally called at
-interrupt context) that will properly handle the buffer request lists,
-announcing that a new buffer were filled.
-
-The irq handling code should handle the videobuf task lists, in order
-to advice videobuf that a new frame were filled, in order to honor to a
-request. The code is generally like this one:
- if (list_empty(&dma_q->active))
- return;
-
- buf = list_entry(dma_q->active.next, struct vbuffer, vb.queue);
-
- if (!waitqueue_active(&buf->vb.done))
- return;
-
- /* Some logic to handle the buf may be needed here */
-
- list_del(&buf->vb.queue);
- do_gettimeofday(&buf->vb.ts);
- wake_up(&buf->vb.done);
-
-Those are the videobuffer functions used on drivers, implemented on
-videobuf-core:
-
-- Videobuf init functions
- videobuf_queue_sg_init()
- Initializes the videobuf infrastructure. This function should be
- called before any other videobuf function on drivers that uses DMA
- Scatter/Gather buffers.
-
- videobuf_queue_dma_contig_init
- Initializes the videobuf infrastructure. This function should be
- called before any other videobuf function on drivers that need DMA
- contiguous buffers.
-
- videobuf_queue_vmalloc_init()
- Initializes the videobuf infrastructure. This function should be
- called before any other videobuf function on USB (and other drivers)
- that need a vmalloced type of videobuf.
-
-- videobuf_iolock()
- Prepares the videobuf memory for the proper method (read, mmap, overlay).
-
-- videobuf_queue_is_busy()
- Checks if a videobuf is streaming.
-
-- videobuf_queue_cancel()
- Stops video handling.
-
-- videobuf_mmap_free()
- frees mmap buffers.
-
-- videobuf_stop()
- Stops video handling, ends mmap and frees mmap and other buffers.
-
-- V4L2 api functions. Those functions correspond to VIDIOC_foo ioctls:
- videobuf_reqbufs(), videobuf_querybuf(), videobuf_qbuf(),
- videobuf_dqbuf(), videobuf_streamon(), videobuf_streamoff().
-
-- V4L1 api function (corresponds to VIDIOCMBUF ioctl):
- videobuf_cgmbuf()
- This function is used to provide backward compatibility with V4L1
- API.
-
-- Some help functions for read()/poll() operations:
- videobuf_read_stream()
- For continuous stream read()
- videobuf_read_one()
- For snapshot read()
- videobuf_poll_stream()
- polling help function
-
-The better way to understand it is to take a look at vivi driver. One
-of the main reasons for vivi is to be a videobuf usage example. the
-vivi_thread_tick() does the task that the IRQ callback would do on PCI
-drivers (or the irq callback on USB).
+The v4l2 core API provides a set of standard methods (called "videobuf")
+for dealing with video buffers. Those methods allow a driver to implement
+read(), mmap() and overlay() in a consistent way. There are currently
+methods for using video buffers on devices that supports DMA with
+scatter/gather method (videobuf-dma-sg), DMA with linear access
+(videobuf-dma-contig), and vmalloced buffers, mostly used on USB drivers
+(videobuf-vmalloc).
+
+Please see Documentation/video4linux/videobuf for more information on how
+to use the videobuf layer.
diff --git a/Documentation/video4linux/videobuf b/Documentation/video4linux/videobuf
new file mode 100644
index 00000000000..17a1f9abf26
--- /dev/null
+++ b/Documentation/video4linux/videobuf
@@ -0,0 +1,360 @@
+An introduction to the videobuf layer
+Jonathan Corbet <corbet@lwn.net>
+Current as of 2.6.33
+
+The videobuf layer functions as a sort of glue layer between a V4L2 driver
+and user space. It handles the allocation and management of buffers for
+the storage of video frames. There is a set of functions which can be used
+to implement many of the standard POSIX I/O system calls, including read(),
+poll(), and, happily, mmap(). Another set of functions can be used to
+implement the bulk of the V4L2 ioctl() calls related to streaming I/O,
+including buffer allocation, queueing and dequeueing, and streaming
+control. Using videobuf imposes a few design decisions on the driver
+author, but the payback comes in the form of reduced code in the driver and
+a consistent implementation of the V4L2 user-space API.
+
+Buffer types
+
+Not all video devices use the same kind of buffers. In fact, there are (at
+least) three common variations:
+
+ - Buffers which are scattered in both the physical and (kernel) virtual
+ address spaces. (Almost) all user-space buffers are like this, but it
+ makes great sense to allocate kernel-space buffers this way as well when
+ it is possible. Unfortunately, it is not always possible; working with
+ this kind of buffer normally requires hardware which can do
+ scatter/gather DMA operations.
+
+ - Buffers which are physically scattered, but which are virtually
+ contiguous; buffers allocated with vmalloc(), in other words. These
+ buffers are just as hard to use for DMA operations, but they can be
+ useful in situations where DMA is not available but virtually-contiguous
+ buffers are convenient.
+
+ - Buffers which are physically contiguous. Allocation of this kind of
+ buffer can be unreliable on fragmented systems, but simpler DMA
+ controllers cannot deal with anything else.
+
+Videobuf can work with all three types of buffers, but the driver author
+must pick one at the outset and design the driver around that decision.
+
+[It's worth noting that there's a fourth kind of buffer: "overlay" buffers
+which are located within the system's video memory. The overlay
+functionality is considered to be deprecated for most use, but it still
+shows up occasionally in system-on-chip drivers where the performance
+benefits merit the use of this technique. Overlay buffers can be handled
+as a form of scattered buffer, but there are very few implementations in
+the kernel and a description of this technique is currently beyond the
+scope of this document.]
+
+Data structures, callbacks, and initialization
+
+Depending on which type of buffers are being used, the driver should
+include one of the following files:
+
+ <media/videobuf-dma-sg.h> /* Physically scattered */
+ <media/videobuf-vmalloc.h> /* vmalloc() buffers */
+ <media/videobuf-dma-contig.h> /* Physically contiguous */
+
+The driver's data structure describing a V4L2 device should include a
+struct videobuf_queue instance for the management of the buffer queue,
+along with a list_head for the queue of available buffers. There will also
+need to be an interrupt-safe spinlock which is used to protect (at least)
+the queue.
+
+The next step is to write four simple callbacks to help videobuf deal with
+the management of buffers:
+
+ struct videobuf_queue_ops {
+ int (*buf_setup)(struct videobuf_queue *q,
+ unsigned int *count, unsigned int *size);
+ int (*buf_prepare)(struct videobuf_queue *q,
+ struct videobuf_buffer *vb,
+ enum v4l2_field field);
+ void (*buf_queue)(struct videobuf_queue *q,
+ struct videobuf_buffer *vb);
+ void (*buf_release)(struct videobuf_queue *q,
+ struct videobuf_buffer *vb);
+ };
+
+buf_setup() is called early in the I/O process, when streaming is being
+initiated; its purpose is to tell videobuf about the I/O stream. The count
+parameter will be a suggested number of buffers to use; the driver should
+check it for rationality and adjust it if need be. As a practical rule, a
+minimum of two buffers are needed for proper streaming, and there is
+usually a maximum (which cannot exceed 32) which makes sense for each
+device. The size parameter should be set to the expected (maximum) size
+for each frame of data.
+
+Each buffer (in the form of a struct videobuf_buffer pointer) will be
+passed to buf_prepare(), which should set the buffer's size, width, height,
+and field fields properly. If the buffer's state field is
+VIDEOBUF_NEEDS_INIT, the driver should pass it to:
+
+ int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
+ struct v4l2_framebuffer *fbuf);
+
+Among other things, this call will usually allocate memory for the buffer.
+Finally, the buf_prepare() function should set the buffer's state to
+VIDEOBUF_PREPARED.
+
+When a buffer is queued for I/O, it is passed to buf_queue(), which should
+put it onto the driver's list of available buffers and set its state to
+VIDEOBUF_QUEUED. Note that this function is called with the queue spinlock
+held; if it tries to acquire it as well things will come to a screeching
+halt. Yes, this is the voice of experience. Note also that videobuf may
+wait on the first buffer in the queue; placing other buffers in front of it
+could again gum up the works. So use list_add_tail() to enqueue buffers.
+
+Finally, buf_release() is called when a buffer is no longer intended to be
+used. The driver should ensure that there is no I/O active on the buffer,
+then pass it to the appropriate free routine(s):
+
+ /* Scatter/gather drivers */
+ int videobuf_dma_unmap(struct videobuf_queue *q,
+ struct videobuf_dmabuf *dma);
+ int videobuf_dma_free(struct videobuf_dmabuf *dma);
+
+ /* vmalloc drivers */
+ void videobuf_vmalloc_free (struct videobuf_buffer *buf);
+
+ /* Contiguous drivers */
+ void videobuf_dma_contig_free(struct videobuf_queue *q,
+ struct videobuf_buffer *buf);
+
+One way to ensure that a buffer is no longer under I/O is to pass it to:
+
+ int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr);
+
+Here, vb is the buffer, non_blocking indicates whether non-blocking I/O
+should be used (it should be zero in the buf_release() case), and intr
+controls whether an interruptible wait is used.
+
+File operations
+
+At this point, much of the work is done; much of the rest is slipping
+videobuf calls into the implementation of the other driver callbacks. The
+first step is in the open() function, which must initialize the
+videobuf queue. The function to use depends on the type of buffer used:
+
+ void videobuf_queue_sg_init(struct videobuf_queue *q,
+ struct videobuf_queue_ops *ops,
+ struct device *dev,
+ spinlock_t *irqlock,
+ enum v4l2_buf_type type,
+ enum v4l2_field field,
+ unsigned int msize,
+ void *priv);
+
+ void videobuf_queue_vmalloc_init(struct videobuf_queue *q,
+ struct videobuf_queue_ops *ops,
+ struct device *dev,
+ spinlock_t *irqlock,
+ enum v4l2_buf_type type,
+ enum v4l2_field field,
+ unsigned int msize,
+ void *priv);
+
+ void videobuf_queue_dma_contig_init(struct videobuf_queue *q,
+ struct videobuf_queue_ops *ops,
+ struct device *dev,
+ spinlock_t *irqlock,
+ enum v4l2_buf_type type,
+ enum v4l2_field field,
+ unsigned int msize,
+ void *priv);
+
+In each case, the parameters are the same: q is the queue structure for the
+device, ops is the set of callbacks as described above, dev is the device
+structure for this video device, irqlock is an interrupt-safe spinlock to
+protect access to the data structures, type is the buffer type used by the
+device (cameras will use V4L2_BUF_TYPE_VIDEO_CAPTURE, for example), field
+describes which field is being captured (often V4L2_FIELD_NONE for
+progressive devices), msize is the size of any containing structure used
+around struct videobuf_buffer, and priv is a private data pointer which
+shows up in the priv_data field of struct videobuf_queue. Note that these
+are void functions which, evidently, are immune to failure.
+
+V4L2 capture drivers can be written to support either of two APIs: the
+read() system call and the rather more complicated streaming mechanism. As
+a general rule, it is necessary to support both to ensure that all
+applications have a chance of working with the device. Videobuf makes it
+easy to do that with the same code. To implement read(), the driver need
+only make a call to one of:
+
+ ssize_t videobuf_read_one(struct videobuf_queue *q,
+ char __user *data, size_t count,
+ loff_t *ppos, int nonblocking);
+
+ ssize_t videobuf_read_stream(struct videobuf_queue *q,
+ char __user *data, size_t count,
+ loff_t *ppos, int vbihack, int nonblocking);
+
+Either one of these functions will read frame data into data, returning the
+amount actually read; the difference is that videobuf_read_one() will only
+read a single frame, while videobuf_read_stream() will read multiple frames
+if they are needed to satisfy the count requested by the application. A
+typical driver read() implementation will start the capture engine, call
+one of the above functions, then stop the engine before returning (though a
+smarter implementation might leave the engine running for a little while in
+anticipation of another read() call happening in the near future).
+
+The poll() function can usually be implemented with a direct call to:
+
+ unsigned int videobuf_poll_stream(struct file *file,
+ struct videobuf_queue *q,
+ poll_table *wait);
+
+Note that the actual wait queue eventually used will be the one associated
+with the first available buffer.
+
+When streaming I/O is done to kernel-space buffers, the driver must support
+the mmap() system call to enable user space to access the data. In many
+V4L2 drivers, the often-complex mmap() implementation simplifies to a
+single call to:
+
+ int videobuf_mmap_mapper(struct videobuf_queue *q,
+ struct vm_area_struct *vma);
+
+Everything else is handled by the videobuf code.
+
+The release() function requires two separate videobuf calls:
+
+ void videobuf_stop(struct videobuf_queue *q);
+ int videobuf_mmap_free(struct videobuf_queue *q);
+
+The call to videobuf_stop() terminates any I/O in progress - though it is
+still up to the driver to stop the capture engine. The call to
+videobuf_mmap_free() will ensure that all buffers have been unmapped; if
+so, they will all be passed to the buf_release() callback. If buffers
+remain mapped, videobuf_mmap_free() returns an error code instead. The
+purpose is clearly to cause the closing of the file descriptor to fail if
+buffers are still mapped, but every driver in the 2.6.32 kernel cheerfully
+ignores its return value.
+
+ioctl() operations
+
+The V4L2 API includes a very long list of driver callbacks to respond to
+the many ioctl() commands made available to user space. A number of these
+- those associated with streaming I/O - turn almost directly into videobuf
+calls. The relevant helper functions are:
+
+ int videobuf_reqbufs(struct videobuf_queue *q,
+ struct v4l2_requestbuffers *req);
+ int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
+ int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b);
+ int videobuf_dqbuf(struct videobuf_queue *q, struct v4l2_buffer *b,
+ int nonblocking);
+ int videobuf_streamon(struct videobuf_queue *q);
+ int videobuf_streamoff(struct videobuf_queue *q);
+ int videobuf_cgmbuf(struct videobuf_queue *q, struct video_mbuf *mbuf,
+ int count);
+
+So, for example, a VIDIOC_REQBUFS call turns into a call to the driver's
+vidioc_reqbufs() callback which, in turn, usually only needs to locate the
+proper struct videobuf_queue pointer and pass it to videobuf_reqbufs().
+These support functions can replace a great deal of buffer management
+boilerplate in a lot of V4L2 drivers.
+
+The vidioc_streamon() and vidioc_streamoff() functions will be a bit more
+complex, of course, since they will also need to deal with starting and
+stopping the capture engine. videobuf_cgmbuf(), called from the driver's
+vidiocgmbuf() function, only exists if the V4L1 compatibility module has
+been selected with CONFIG_VIDEO_V4L1_COMPAT, so its use must be surrounded
+with #ifdef directives.
+
+Buffer allocation
+
+Thus far, we have talked about buffers, but have not looked at how they are
+allocated. The scatter/gather case is the most complex on this front. For
+allocation, the driver can leave buffer allocation entirely up to the
+videobuf layer; in this case, buffers will be allocated as anonymous
+user-space pages and will be very scattered indeed. If the application is
+using user-space buffers, no allocation is needed; the videobuf layer will
+take care of calling get_user_pages() and filling in the scatterlist array.
+
+If the driver needs to do its own memory allocation, it should be done in
+the vidioc_reqbufs() function, *after* calling videobuf_reqbufs(). The
+first step is a call to:
+
+ struct videobuf_dmabuf *videobuf_to_dma(struct videobuf_buffer *buf);
+
+The returned videobuf_dmabuf structure (defined in
+<media/videobuf-dma-sg.h>) includes a couple of relevant fields:
+
+ struct scatterlist *sglist;
+ int sglen;
+
+The driver must allocate an appropriately-sized scatterlist array and
+populate it with pointers to the pieces of the allocated buffer; sglen
+should be set to the length of the array.
+
+Drivers using the vmalloc() method need not (and cannot) concern themselves
+with buffer allocation at all; videobuf will handle those details. The
+same is normally true of contiguous-DMA drivers as well; videobuf will
+allocate the buffers (with dma_alloc_coherent()) when it sees fit. That
+means that these drivers may be trying to do high-order allocations at any
+time, an operation which is not always guaranteed to work. Some drivers
+play tricks by allocating DMA space at system boot time; videobuf does not
+currently play well with those drivers.
+
+As of 2.6.31, contiguous-DMA drivers can work with a user-supplied buffer,
+as long as that buffer is physically contiguous. Normal user-space
+allocations will not meet that criterion, but buffers obtained from other
+kernel drivers, or those contained within huge pages, will work with these
+drivers.
+
+Filling the buffers
+
+The final part of a videobuf implementation has no direct callback - it's
+the portion of the code which actually puts frame data into the buffers,
+usually in response to interrupts from the device. For all types of
+drivers, this process works approximately as follows:
+
+ - Obtain the next available buffer and make sure that somebody is actually
+ waiting for it.
+
+ - Get a pointer to the memory and put video data there.
+
+ - Mark the buffer as done and wake up the process waiting for it.
+
+Step (1) above is done by looking at the driver-managed list_head structure
+- the one which is filled in the buf_queue() callback. Because starting
+the engine and enqueueing buffers are done in separate steps, it's possible
+for the engine to be running without any buffers available - in the
+vmalloc() case especially. So the driver should be prepared for the list
+to be empty. It is equally possible that nobody is yet interested in the
+buffer; the driver should not remove it from the list or fill it until a
+process is waiting on it. That test can be done by examining the buffer's
+done field (a wait_queue_head_t structure) with waitqueue_active().
+
+A buffer's state should be set to VIDEOBUF_ACTIVE before being mapped for
+DMA; that ensures that the videobuf layer will not try to do anything with
+it while the device is transferring data.
+
+For scatter/gather drivers, the needed memory pointers will be found in the
+scatterlist structure described above. Drivers using the vmalloc() method
+can get a memory pointer with:
+
+ void *videobuf_to_vmalloc(struct videobuf_buffer *buf);
+
+For contiguous DMA drivers, the function to use is:
+
+ dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf);
+
+The contiguous DMA API goes out of its way to hide the kernel-space address
+of the DMA buffer from drivers.
+
+The final step is to set the size field of the relevant videobuf_buffer
+structure to the actual size of the captured image, set state to
+VIDEOBUF_DONE, then call wake_up() on the done queue. At this point, the
+buffer is owned by the videobuf layer and the driver should not touch it
+again.
+
+Developers who are interested in more information can go into the relevant
+header files; there are a few low-level functions declared there which have
+not been talked about here. Also worthwhile is the vivi driver
+(drivers/media/video/vivi.c), which is maintained as an example of how V4L2
+drivers should be written. Vivi only uses the vmalloc() API, but it's good
+enough to get started with. Note also that all of these calls are exported
+GPL-only, so they will not be available to non-GPL kernel modules.
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-30 16:12:53 +0000