[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: NLennert Buytenhek <buytenh@wantstofly.org> Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Showing
想要评论请 注册 或 登录