diff options
author | Alan Cox <alan@redhat.com> | 2006-02-26 22:09:05 -0500 |
---|---|---|
committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2006-02-26 22:09:05 -0500 |
commit | ab33d5071de7a33616842882c11b5eb52a6c26a1 (patch) | |
tree | 5484a1a0d671e7191a47a1b51d5e1ae67fc8916f /Documentation/video4linux/cpia2_overview.txt | |
parent | f05cce863fa399dd79c5aa3896d608b8b86d8030 (diff) |
V4L/DVB (3376): Add cpia2 camera support
There has been a CPIA2 driver out of kernel for a long time and it has
been pretty clean for some time too. This is an import of the
sourceforge driver which has been stripped of
- 2.4 back compatibility
- 2.4 old style MJPEG ioctls
A couple of functions have been made static and the docs have been
repackaged into Documentation/video4linux. The rvmalloc/free functions now
match the cpia driver again. Other than that this is the code as is.
Tested on x86-64 with a QX5 microscope.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'Documentation/video4linux/cpia2_overview.txt')
-rw-r--r-- | Documentation/video4linux/cpia2_overview.txt | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/Documentation/video4linux/cpia2_overview.txt b/Documentation/video4linux/cpia2_overview.txt new file mode 100644 index 000000000000..a6e53665216b --- /dev/null +++ b/Documentation/video4linux/cpia2_overview.txt | |||
@@ -0,0 +1,38 @@ | |||
1 | Programmer's View of Cpia2 | ||
2 | |||
3 | Cpia2 is the second generation video coprocessor from VLSI Vision Ltd (now a | ||
4 | division of ST Microelectronics). There are two versions. The first is the | ||
5 | STV0672, which is capable of up to 30 frames per second (fps) in frame sizes | ||
6 | up to CIF, and 15 fps for VGA frames. The STV0676 is an improved version, | ||
7 | which can handle up to 30 fps VGA. Both coprocessors can be attached to two | ||
8 | CMOS sensors - the vvl6410 CIF sensor and the vvl6500 VGA sensor. These will | ||
9 | be referred to as the 410 and the 500 sensors, or the CIF and VGA sensors. | ||
10 | |||
11 | The two chipsets operate almost identically. The core is an 8051 processor, | ||
12 | running two different versions of firmware. The 672 runs the VP4 video | ||
13 | processor code, the 676 runs VP5. There are a few differences in register | ||
14 | mappings for the two chips. In these cases, the symbols defined in the | ||
15 | header files are marked with VP4 or VP5 as part of the symbol name. | ||
16 | |||
17 | The cameras appear externally as three sets of registers. Setting register | ||
18 | values is the only way to control the camera. Some settings are | ||
19 | interdependant, such as the sequence required to power up the camera. I will | ||
20 | try to make note of all of these cases. | ||
21 | |||
22 | The register sets are called blocks. Block 0 is the system block. This | ||
23 | section is always powered on when the camera is plugged in. It contains | ||
24 | registers that control housekeeping functions such as powering up the video | ||
25 | processor. The video processor is the VP block. These registers control | ||
26 | how the video from the sensor is processed. Examples are timing registers, | ||
27 | user mode (vga, qvga), scaling, cropping, framerates, and so on. The last | ||
28 | block is the video compressor (VC). The video stream sent from the camera is | ||
29 | compressed as Motion JPEG (JPEGA). The VC controls all of the compression | ||
30 | parameters. Looking at the file cpia2_registers.h, you can get a full view | ||
31 | of these registers and the possible values for most of them. | ||
32 | |||
33 | One or more registers can be set or read by sending a usb control message to | ||
34 | the camera. There are three modes for this. Block mode requests a number | ||
35 | of contiguous registers. Random mode reads or writes random registers with | ||
36 | a tuple structure containing address/value pairs. The repeat mode is only | ||
37 | used by VP4 to load a firmware patch. It contains a starting address and | ||
38 | a sequence of bytes to be written into a gpio port. \ No newline at end of file | ||