mtd: cfi_flash: Fix CFI flash driver for 8-bit bus support

This commit is based on that patch from aaron.williams@caviumnetworks.com
with same commit title. pulled the same code changes into current u-boot tree.

http://patchwork.ozlabs.org/patch/140863/
http://lists.denx.de/pipermail/u-boot/2011-April/089606.html

This patch corrects the addresses used when working with Spansion/AMD FLASH chips.
Addressing for 8 and 16 bits is almost identical except in the 16-bit case the
LSB of the address is always 0.  The confusion arose because the addresses
in the datasheet for 16-bit mode are word addresses but this code assumed it was
byte addresses.

I have only been able to test this on our Octeon boards which use either an 8-bit
or 16-bit bus.  I have not tested the case where there's an 8-bit part on a 16-bit
bus.

This patch also adds some delays as suggested by Spansion.

If a part can be both 8 and 16-bits, it forces it to work in 8-bit mode if an
8-bit bus is detected.

Apart from the pulled changes, fixed few minor code cleanups and tested
on 256M29EW, 512M29EW flashes.

Before this fix:
---------------
Bank # 1: CFI conformant flash (8 x 8)  Size: 64 MB in 512 Sectors
  AMD Standard command set, Manufacturer ID: 0xFF, Device ID: 0xFF
  Erase timeout: 4096 ms, write timeout: 2 ms
  Buffer write timeout: 5 ms, buffer size: 1024 bytes

After this fix:
--------------
Bank # 1: CFI conformant flash (8 x 8)  Size: 64 MB in 512 Sectors
  AMD Standard command set, Manufacturer ID: 0x89, Device ID: 0x7E2301
  Erase timeout: 4096 ms, write timeout: 2 ms
  Buffer write timeout: 5 ms, buffer size: 1024 bytes

Signed-off-by: Aaron Williams <aaron.williams@caviumnetworks.com>
Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Tested-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
mtd: cfi_flash: Write buffer size adjustment for M29EW Numonyx devices

This patch addjusted the write buffer size for M29EW devices those
are operated in 8-bit mode.

The M29EW devices seem to report the CFI information wrong when
it's in 8 bit mode.

There's an app note from Numonyx on this issue and there's a patch
in the open source as well for Linux, but it doesn't seem to be in mainline.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
Tested-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>
cfi_flash: Use uintptr_t for casts from u32 to void *

This fixes this build warning:

Configuring for qemu_mips64 - Board: qemu-mips64, Options: SYS_BIG_ENDIAN
   text    data     bss     dec     hex filename
 215344   13082  218720  447146   6d2aa qemu_mips64/u-boot
cfi_flash.c: In function 'flash_map':
cfi_flash.c:217:9: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Tom Rini <trini@ti.com>
Merge branch 'master' of git://www.denx.de/git/u-boot-cfi-flash