mtd: cfi_cmdset_0002: Add support for polling status register
HyperFlash devices are compliant with CFI AMD/Fujitsu Extended Command Set (0x0002) for flash operations, therefore drivers/mtd/chips/cfi_cmdset_0002.c can be used as is. But these devices do not support DQ polling method of determining chip ready/good status. These flashes provide Status Register whose bits can be polled to know status of flash operation. Cypress HyperFlash datasheet here[1], talks about CFI Amd/Fujitsu Extended Query version 1.5. Bit 0 of "Software Features supported" field of CFI Primary Vendor-Specific Extended Query table indicates presence/absence of status register and Bit 1 indicates whether or not DQ polling is supported. Using these bits, its possible to determine whether flash supports DQ polling or need to use Status Register. Add support for polling Status Register to know device ready/status of erase/write operations when DQ polling is not supported. Print error messages on erase/program failure by looking at related Status Register bits. [1] https://www.cypress.com/file/213346/download Signed-off-by:Vignesh Raghavendra <vigneshr@ti.com> Reviewed-by: