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authorEric Miao <eric.miao@marvell.com>2008-12-15 22:54:34 -0500
committerEric Miao <eric.miao@marvell.com>2008-12-29 04:59:16 -0500
commit77e196752bdd76a0c58ab082658d28c6a90fa40e (patch)
tree935fbe8b897d8770fff05254c6c91dc0a8058984 /Documentation/fb/pxafb.txt
parent5bfb4093be6ac7b6c06c8e6461d85241654acc61 (diff)
[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/fb/pxafb.txt')
-rw-r--r--Documentation/fb/pxafb.txt8
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
5options=<OPTIONS> when modular or video=pxafb:<OPTIONS> when built in. 5options=<OPTIONS> when modular or video=pxafb:<OPTIONS> when built in.
6 6
7For example: 7For example:
8 modprobe pxafb options=mode:640x480-8,passive 8 modprobe pxafb options=vmem:2M,mode:640x480-8,passive
9or on the kernel command line 9or on the kernel command line
10 video=pxafb:mode:640x480-8,passive 10 video=pxafb:vmem:2M,mode:640x480-8,passive
11
12vmem: VIDEO_MEM_SIZE
13 Amount of video memory to allocate (can be suffixed with K or M
14 for kilobytes or megabytes)
11 15
12mode:XRESxYRES[-BPP] 16mode:XRESxYRES[-BPP]
13 XRES == LCCR1_PPL + 1 17 XRES == LCCR1_PPL + 1