diff options
author | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-10 09:59:18 -0800 |
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committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-10 09:59:18 -0800 |
commit | bb7320d1d96dc2e479180ae8e7a112caf0726ace (patch) | |
tree | 65a81fefd82d188f5496b70439db73ca911b3f76 /Documentation/video4linux/cafe_ccic | |
parent | 6aa8b732ca01c3d7a54e93f4d701b8aabbe60fb7 (diff) | |
parent | 1de1bf06330920802d3b7646a088965bdd918356 (diff) |
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb
* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (132 commits)
V4L/DVB 4949b: Fix container_of pointer retreival
V4L/DVB (4949a): Fix INIT_WORK
V4L/DVB (4949): Cxusb: codingstyle cleanups
V4L/DVB (4948): Cxusb: Convert tuner functions to use dvb_pll_attach
V4L/DVB (4947): Cx88: trivial cleanups
V4L/DVB (4946): Cx88: Move cx88_dvb_bus_ctrl out of the card-specific area
V4L/DVB (4945): Cx88: consolidate cx22702_config structs
V4L/DVB (4944): Cx88: Convert DViCO FusionHDTV Hybrid to use dvb_pll_attach
V4L/DVB (4943): Cx88: cleanup dvb_pll_attach for lgdt3302 tuners
V4L/DVB (4953): Usbvision minor fixes
V4L/DVB (4951): Add version.h, since it is required for VIDIOC_QUERYCAP
V4L/DVB (4940): Or51211: Changed SNR and signal strength calculations
V4L/DVB (4939): Or51132: Changed SNR and signal strength reporting
V4L/DVB (4938): Cx88: Convert lgdt3302 tuning function to use dvb_pll_attach
V4L/DVB (4941): Remove LINUX_VERSION_CODE and fix identations
V4L/DVB (4942): Whitespace cleanups
V4L/DVB (4937): Usbvision cleanup and code reorganization
V4L/DVB (4936): Make MT4049FM5 tuner to set FM Gain to Normal
V4L/DVB (4935): Added the capability of selecting fm gain by tuner
V4L/DVB (4934): Usbvision radio requires GainNormal at e register
...
Diffstat (limited to 'Documentation/video4linux/cafe_ccic')
-rw-r--r-- | Documentation/video4linux/cafe_ccic | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/Documentation/video4linux/cafe_ccic b/Documentation/video4linux/cafe_ccic new file mode 100644 index 00000000000..88821022a5d --- /dev/null +++ b/Documentation/video4linux/cafe_ccic @@ -0,0 +1,54 @@ +"cafe_ccic" is a driver for the Marvell 88ALP01 "cafe" CMOS camera +controller. This is the controller found in first-generation OLPC systems, +and this driver was written with support from the OLPC project. + +Current status: the core driver works. It can generate data in YUV422, +RGB565, and RGB444 formats. (Anybody looking at the code will see RGB32 as +well, but that is a debugging aid which will be removed shortly). VGA and +QVGA modes work; CIF is there but the colors remain funky. Only the OV7670 +sensor is known to work with this controller at this time. + +To try it out: either of these commands will work: + + mplayer tv:// -tv driver=v4l2:width=640:height=480 -nosound + mplayer tv:// -tv driver=v4l2:width=640:height=480:outfmt=bgr16 -nosound + +The "xawtv" utility also works; gqcam does not, for unknown reasons. + +There are a few load-time options, most of which can be changed after +loading via sysfs as well: + + - alloc_bufs_at_load: Normally, the driver will not allocate any DMA + buffers until the time comes to transfer data. If this option is set, + then worst-case-sized buffers will be allocated at module load time. + This option nails down the memory for the life of the module, but + perhaps decreases the chances of an allocation failure later on. + + - dma_buf_size: The size of DMA buffers to allocate. Note that this + option is only consulted for load-time allocation; when buffers are + allocated at run time, they will be sized appropriately for the current + camera settings. + + - n_dma_bufs: The controller can cycle through either two or three DMA + buffers. Normally, the driver tries to use three buffers; on faster + systems, however, it will work well with only two. + + - min_buffers: The minimum number of streaming I/O buffers that the driver + will consent to work with. Default is one, but, on slower systems, + better behavior with mplayer can be achieved by setting to a higher + value (like six). + + - max_buffers: The maximum number of streaming I/O buffers; default is + ten. That number was carefully picked out of a hat and should not be + assumed to actually mean much of anything. + + - flip: If this boolean parameter is set, the sensor will be instructed to + invert the video image. Whether it makes sense is determined by how + your particular camera is mounted. + +Work is ongoing with this driver, stay tuned. + +jon + +Jonathan Corbet +corbet@lwn.net |