On Sat, Feb 23, 2013 at 5:08 PM, Jagannadha Sutradharudu Teki jagannadha.sutradharudu-teki@xilinx.com wrote:
The current implementation in spi_flash supports 3-byte address mode due to this up to 16MB amount of flash is able to access for those flashes which has an actual size of > 16MB.
List of flashes: S25FL256S N25Q256 N25Q256A W25Q256(not yet mainlined)
extended/bank address register contains an information to access the 4th byte addressing hence the flashes which has > 16MB can be accessible.
extended/bank address read/write commands in spansion & winbond/stmicro are different, currently I have added support for spansion.
if the user is giving an offset > 0x1000000 for read/write/erase commands the implementation will subtract the offset from 0x1000000 and then enable the extended/bank address register.
[pseudo] if (offset > 0x1000000) { offset -= 0x1000000; enable the ext/bank addr register } else disable the ext/bank addr register
Thanks, Jagan.
Jagannadha Sutradharudu Teki (4): sf: Add extended address register writing support sf: Add extended address register reading support sf: Add extended address access support sf: winbond: Add support for W25Q256
drivers/mtd/spi/spi_flash.c | 145 ++++++++++++++++++++++++++++++++++ drivers/mtd/spi/spi_flash_internal.h | 18 ++++ drivers/mtd/spi/winbond.c | 5 + 3 files changed, 168 insertions(+), 0 deletions(-)
-- 1.7.4
Thanks for your contribution for new feature setup. Could you please send the v2 for these > 16MB flash support patch set.
-- Thanks, Jagan.