diff options
| author | Lennert Buytenhek <buytenh@wantstofly.org> | 2005-09-15 13:00:25 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2005-09-15 13:00:25 +0100 |
| commit | 917afce1000d978dfd3f07da5da9d864bc49c77e (patch) | |
| tree | fd8487f4cf64dc5be9559820a1f4c3e6c759aad2 | |
| parent | fea2efe3bba15f0aa8f840fbe052699808187cb6 (diff) | |
| download | linux-917afce1000d978dfd3f07da5da9d864bc49c77e.tar.gz | |
[ARM] 2911/1: ixp2000_reg_{read,write} accessors
Patch from Lennert Buytenhek This patch: - changes the ixp2000_reg_write accessor to take a 'volatile void *' instead of a 'volatile unsigned long *', which then allows passing in a u32 * as first argument without being greeted with a warning; and - adds an ixp2000_reg_read accessor. We can then use these accessors in ixp2000 code to access on-chip peripherals, instead of directly dereferencing pointers. This is for use by the ixp2000 microengine driver which was recently announced on netdev. We can't use readl/writel on the ixp2000 since it is usually run in big-endian mode, and on big-endian platforms, readl/writel perform byteswapping. A future patch will remove the readback from ixp2000_reg_write, since it's not needed to prevent erratum #66, and add manual readbacks to the places that need them (writes are not synchronous since we map in device space using XCB=101 nowadays), such as interrupt disabling and GPIO manipulation. See also: http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2005-February/027084.html Patch has been ACKed by Jeff Garzik. Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | include/asm-arm/arch-ixp2000/platform.h | 14 |
1 files changed, 9 insertions, 5 deletions
diff --git a/include/asm-arm/arch-ixp2000/platform.h b/include/asm-arm/arch-ixp2000/platform.h index c0caf3e3e6fd..6519498dbe25 100644 --- a/include/asm-arm/arch-ixp2000/platform.h +++ b/include/asm-arm/arch-ixp2000/platform.h @@ -31,20 +31,24 @@ #include <asm/system.h> /* Pickup local_irq_ functions */ -static inline void ixp2000_reg_write(volatile unsigned long *reg, unsigned long val) +static inline void ixp2000_reg_write(volatile void *reg, unsigned long val) { - volatile unsigned long dummy; + unsigned long dummy; unsigned long flags; local_irq_save(flags); - *reg = val; + *((volatile unsigned long *)reg) = val; barrier(); - dummy = *reg; + dummy = *((volatile unsigned long *)reg); local_irq_restore(flags); } #else -#define ixp2000_reg_write(reg, val) (*reg = val) +static inline void ixp2000_reg_write(volatile void *reg, unsigned long val) +{ + *((volatile unsigned long *)reg) = val; +} #endif /* IXDP2400 || IXDP2401 */ +#define ixp2000_reg_read(reg) (*((volatile unsigned long *)reg)) /* * Boards may multiplex different devices on the 2nd channel of |