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authorAlan Cox <alan@redhat.com>2006-02-27 00:09:05 -0300
committerMauro Carvalho Chehab <mchehab@infradead.org>2006-02-27 00:09:05 -0300
commitab33d5071de7a33616842882c11b5eb52a6c26a1 (patch)
tree5484a1a0d671e7191a47a1b51d5e1ae67fc8916f /Documentation/video4linux/cpia2_overview.txt
parentf05cce863fa399dd79c5aa3896d608b8b86d8030 (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>
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+ Programmer's View of Cpia2
+
+Cpia2 is the second generation video coprocessor from VLSI Vision Ltd (now a
+division of ST Microelectronics). There are two versions. The first is the
+STV0672, which is capable of up to 30 frames per second (fps) in frame sizes
+up to CIF, and 15 fps for VGA frames. The STV0676 is an improved version,
+which can handle up to 30 fps VGA. Both coprocessors can be attached to two
+CMOS sensors - the vvl6410 CIF sensor and the vvl6500 VGA sensor. These will
+be referred to as the 410 and the 500 sensors, or the CIF and VGA sensors.
+
+The two chipsets operate almost identically. The core is an 8051 processor,
+running two different versions of firmware. The 672 runs the VP4 video
+processor code, the 676 runs VP5. There are a few differences in register
+mappings for the two chips. In these cases, the symbols defined in the
+header files are marked with VP4 or VP5 as part of the symbol name.
+
+The cameras appear externally as three sets of registers. Setting register
+values is the only way to control the camera. Some settings are
+interdependant, such as the sequence required to power up the camera. I will
+try to make note of all of these cases.
+
+The register sets are called blocks. Block 0 is the system block. This
+section is always powered on when the camera is plugged in. It contains
+registers that control housekeeping functions such as powering up the video
+processor. The video processor is the VP block. These registers control
+how the video from the sensor is processed. Examples are timing registers,
+user mode (vga, qvga), scaling, cropping, framerates, and so on. The last
+block is the video compressor (VC). The video stream sent from the camera is
+compressed as Motion JPEG (JPEGA). The VC controls all of the compression
+parameters. Looking at the file cpia2_registers.h, you can get a full view
+of these registers and the possible values for most of them.
+
+One or more registers can be set or read by sending a usb control message to
+the camera. There are three modes for this. Block mode requests a number
+of contiguous registers. Random mode reads or writes random registers with
+a tuple structure containing address/value pairs. The repeat mode is only
+used by VP4 to load a firmware patch. It contains a starting address and
+a sequence of bytes to be written into a gpio port. \ No newline at end of file