forked from torvalds/linux
-
Notifications
You must be signed in to change notification settings - Fork 132
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
mtd: spi-nor: aspeed-smc: Use io string accessors to fifo
Make and use new routines to access the fifo when in user mode. Instead of using memcpy_fromio, base the new routines on the io port string accessors. When the smc controllers are configured to transfer in user mode, the exact address within the chip select region is ignored and all valid data bytes are sent to the device fifo. It has been determined the reason _memcpy_fromio, an arm specific byte-by-byte variant of memcpy_fromio was required in read_reg, is that the later will stutter when coping from memory, discarding some bytes read, when switching from words to bytes for the final unaligned length. This change includes a hack to make inw/outw work. The default generic IO_SPACE_LIMIT is 0, and twenty bits when PCI is selected. While there is a PCMCIA SOC config to select the full 4GB space it would bring in the PCMCIA core for no use to the ast2400. We want to be part of the generic multi-platform arm kernel and therefore mach/io.h is not going to work. However, the limit is under an ifndef, so define it in this file an check it was not redefine at probe time. To avoid redefinition errors or warnings, guard the setting with CONFIG_ARM for cross-arch compile testing and with a Kconfig dependency for arm cross-compile tests. While some other architecture may not accept unsigned long addresses as ioport cookies, that can be addressed when, if ever, the hardware appears on another arch. While the change to use the designed-for-memory optimised copy template, even reusing the bytes of memcpy, was a recent change and only for little endian arm, designing and proposing a patch will take some time and there could be debate if the routine needs to work on changing memory. Signed-off-by: Milton Miller <miltonm@us.ibm.com> Reviewed-by: Andrew Jeffery <andrew@aj.id.au> Signed-off-by: Joel Stanley <joel@jms.id.au>
- Loading branch information
1 parent
794044d
commit 908a999
Showing
2 changed files
with
113 additions
and
9 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters