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author | Marin Mitov <mitov@issp.bas.bg> | 2010-04-30 18:36:09 +0300 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-05-11 11:35:59 -0700 |
commit | d42bffb8990ca9e74cc1ba625ce23dda2bd8c8c5 (patch) | |
tree | fe9d46dd4c0e3ee1eb39547ad74784ac917553d4 /drivers/staging/dt3155v4l/Makefile | |
parent | 6608224c9e5c8aacf88914697be2d5f1fc7a0be6 (diff) | |
download | op-kernel-dev-d42bffb8990ca9e74cc1ba625ce23dda2bd8c8c5.zip op-kernel-dev-d42bffb8990ca9e74cc1ba625ce23dda2bd8c8c5.tar.gz |
Staging: Yet another (third) dt3155 driver PCI/video4linux compliant
Kernel module (device driver) for dt3155 frame grabber
video4linux2 compliant (finally). Works with "xawtv -f".
======================================================
This driver is written (almost) from scratch, using the
allocator developed for dt3155pci see bellow). The driver
uses videobuf-dma-contig interface modified to use the above
mentioned allocator instead of dma_alloc_coheren().
The first thing to do was to design a new allocator based
on allocating a configurable number of 4MB chunks of memory,
that latter are broken into frame buffers of 768x576 bytes
kept in different FIFOs (queues). As far as the driver autoloads
as a kernel module during kernel boot, the allocation of 4MB
chunks succeeds.
The driver keeps three FIFOs: one for 4MB chunks, one for free
buffers (available for allocations) and one for buffers already
allocated. Allocation/deallocation is done automatically though
the video4linux videobuf subsystem (some pointers to functions
are replaced by driver supplied functions).
Sure, there are problems:
1. The device tested to work with "xawtv -f" either via read()
method (DT3155_STREAMING not selected), or via mmap() method
(DT3155_STREAMING is selected) only. This coresponds to either
cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_READWRITE;
or
cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
but not when
cap->capabilities = V4L2_CAP_VIDEO_CAPTURE |
V4L2_CAP_STREAMING |
V4L2_CAP_READWRITE;
This is because xawtv calls poll() before starting streaming,
but videobuf_poll_stream() automatically starts reading if streaming
is not started.
This selection is made during kernel configuration (for now).
2. Works for CCIR, but should work for RS-170 (not tested)
This is made also during kernel configuration.
3. Could work for multiple dt3155 frame grabbers in a PC,
(private data is allocated during PCI probe() method), but
is not tested due to lack of a second board.
4. Not tested on a BIG ENDIAN architecture.
5. Many others you could find .... :-)
All critics, comments, suggestions are wellcome.
Signed-off-by: Marin Mitov <mitov@issp.bas.bg>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/staging/dt3155v4l/Makefile')
-rw-r--r-- | drivers/staging/dt3155v4l/Makefile | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/staging/dt3155v4l/Makefile b/drivers/staging/dt3155v4l/Makefile new file mode 100644 index 0000000..3a207cc --- /dev/null +++ b/drivers/staging/dt3155v4l/Makefile @@ -0,0 +1,4 @@ +obj-$(CONFIG_VIDEO_DT3155) += dt3155_v4l.o +dt3155_v4l-objs := \ + dt3155-bufs.o \ + dt3155v4l.o |