bcm2708 framebuffer driver

Signed-off-by: popcornmix <popcornmix@gmail.com>

bcm2708_fb : Implement blanking support using the mailbox property interface

bcm2708_fb: Add pan and vsync controls

bcm2708_fb: DMA acceleration for fb_copyarea

Based on http://www.raspberrypi.org/phpBB3/viewtopic.php?p=62425#p62425


Also used Simon's dmaer_master module as a reference for tweaking DMA
settings for better performance.

For now busylooping only. IRQ support might be added later.
With non-overclocked Raspberry Pi, the performance is ~360 MB/s
for simple copy or ~260 MB/s for two-pass copy (used when dragging
windows to the right).

In the case of using DMA channel 0, the performance improves
to ~440 MB/s.

For comparison, VFP optimized CPU copy can only do ~114 MB/s in
the same conditions (hindered by reading uncached source buffer).

Signed-off-by: Siarhei Siamashka <siarhei.siamashka@gmail.com>

bcm2708_fb: report number of dma copies

Add a counter (exported via debugfs) reporting the
number of dma copies that the framebuffer driver
has done, in order to help evaluate different
optimization strategies.

Signed-off-by: Luke Diamand <luked@broadcom.com>

bcm2708_fb: use IRQ for DMA copies

The copyarea ioctl() uses DMA to speed things along. This
was busy-waiting for completion. This change supports using
an interrupt instead for larger transfers. For small
transfers, busy-waiting is still likely to be faster.

Signed-off-by: Luke Diamand <luke@diamand.org>

bcm2708: Make ioctl logging quieter

video: fbdev: bcm2708_fb: Don't panic on error

No need to panic the kernel if the video driver fails.
Just print a message and return an error.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

fbdev: bcm2708_fb: Add ARCH_BCM2835 support

Add Device Tree support.
Pass the device to dma_alloc_coherent() in order to get the
correct bus address on ARCH_BCM2835.
Use the new DMA legacy API header file.
Including <mach/platform.h> is not necessary.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>

BCM270x_DT: Add bcm2708-fb device

Add bcm2708-fb to Device Tree and don't add the
platform device when booting in DT mode.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>