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| author | Eric Miao <eric.miao@marvell.com> | 2008-12-16 11:54:34 +0800 |
|---|---|---|
| committer | Eric Miao <eric.miao@marvell.com> | 2008-12-29 17:59:16 +0800 |
| commit | 77e196752bdd76a0c58ab082658d28c6a90fa40e (patch) | |
| tree | 935fbe8b897d8770fff05254c6c91dc0a8058984 /Documentation | |
| parent | 5bfb4093be6ac7b6c06c8e6461d85241654acc61 (diff) | |
| download | lwn-77e196752bdd76a0c58ab082658d28c6a90fa40e.tar.gz lwn-77e196752bdd76a0c58ab082658d28c6a90fa40e.zip | |
[ARM] pxafb: allow video memory size to be configurable
The amount of video memory size is decided according to the following
order:
1. <xres> x <yres> x <bits_per_pixel> by default, which is the backward
compatible way
2. size specified in platform data
3. size specified in module parameter 'options' string or specified in
kernel boot command line (see updated Documentation/fb/pxafb.txt)
And now since the memory is allocated from system memory, the pxafb_mmap
can be removed and the default fb_mmap() should be working all right.
Also, since we now have introduced the 'struct pxafb_dma_buff' for DMA
descriptors and palettes, the allocation can be separated cleanly.
NOTE: the LCD DMA actually supports chained transfer (i.e. page-based
transfers), to simplify the logic and keep the performance (with less
TLB misses when accessing from memory mapped user space), the memory
is allocated by alloc_pages_*() to ensures it's physical contiguous.
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Eric Miao <ycmiao@ycmiao-hp520.(none)>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/fb/pxafb.txt | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/Documentation/fb/pxafb.txt b/Documentation/fb/pxafb.txt index db9b8500b43b..ad94b5ca0095 100644 --- a/Documentation/fb/pxafb.txt +++ b/Documentation/fb/pxafb.txt @@ -5,9 +5,13 @@ The driver supports the following options, either via options=<OPTIONS> when modular or video=pxafb:<OPTIONS> when built in. For example: - modprobe pxafb options=mode:640x480-8,passive + modprobe pxafb options=vmem:2M,mode:640x480-8,passive or on the kernel command line - video=pxafb:mode:640x480-8,passive + video=pxafb:vmem:2M,mode:640x480-8,passive + +vmem: VIDEO_MEM_SIZE + Amount of video memory to allocate (can be suffixed with K or M + for kilobytes or megabytes) mode:XRESxYRES[-BPP] XRES == LCCR1_PPL + 1 |