diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/video4linux/cafe_ccic | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/video4linux/cafe_ccic')
-rw-r--r-- | kernel/Documentation/video4linux/cafe_ccic | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/kernel/Documentation/video4linux/cafe_ccic b/kernel/Documentation/video4linux/cafe_ccic new file mode 100644 index 000000000..88821022a --- /dev/null +++ b/kernel/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 |