Patch from Alessandro Zummo
This patch fixes AHB/PCI endianness problems when the
processor is in little-endian mode.
The patch configures the CSR register closely following the directives
in [1], paragraph 4.1, page 19.
According to the considerations in [1], page 11, while the AHB bus
supports both endian modes, on the IXP4XX it always uses big-endian.
The PCI bus is connected to the South AHB. A wrong setting in the CSR
register will thus cause a malfunctional PCI bus.
A schematic diagram of the bus interconnections on the IXP4XX
can be found in [1], page 18.
The patch has been verified to work on the NSLU2 in
both LE and BE modes.
The author is Peter Korsgaard.
[1] Intel® IXP4XX Product Line of Network Processors and IXC1100
Control Plane Processor:
Understanding Big Endian and Little Endian Modes
http://www.intel.com/design/network/applnots/25423701.pdf
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
84613387cb