Commit Graph

3 Commits

Author SHA1 Message Date
Eric Miao 198fc108ee [ARM] pxafb: add support for overlay1 and overlay2 as framebuffer devices
PXA27x and later processors support overlay1 and overlay2 on-top of the
base framebuffer (although under-neath the base is also possible). They
support palette and no-palette RGB formats, as well as YUV formats (only
available on overlay2). These overlays have dedicated DMA channels and
behave in a similar way as a framebuffer.

This heavily simplified and re-structured work is based on the original
pxafb_overlay.c (which is pending for mainline merge for a long time).

The major problems with this pxafb_overlay.c are (if you are interested
in the history):

  1. heavily redundant (the control logics for overlay1 and overlay2 are
     actually identical except for some small operations,  which are now
     abstracted into a 'pxafb_layer_ops' structure)

  2. a lot of useless and un-tested code (two workarounds which are now
     fixed on mature silicons)

  3. cursorfb is actually useless, hardware cursor should not be used
     this way, and the code was actually un-tested for a long time.

The code in this patch should be self-explanatory, I tried to add minimum
comments. As said, this is basically simplified, there are several things
still on the pending list:

  1. palette mode is un-supported and un-tested (although re-using the
     palette code of the base framebuffer is actually very easy now with
     previous clean-up patches)

  2. fb_pan_display for overlay(s) is un-supported

  3. the base framebuffer can actually be abstracted by 'pxafb_layer' as
     well, which will help further re-use of the code and keep a better
     and consistent structure. (This is the reason I named it 'pxafb_layer'
     instead of 'pxafb_overlay' or something alike)

See Documentation/fb/pxafb.txt for additional usage information.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Cc: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Eric Miao <ycmiao@ycmiao-hp520.(none)>
2008-12-29 18:00:04 +08:00
Eric Miao 77e196752b [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)>
2008-12-29 17:59:16 +08:00
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00