[PATCH 1/3] mtd: m25p80: utilize dedicated 4-byte addressing commands

[Peter Korsgaard]

>>>>> "B" == Brian Norris <computersforpeace at gmail.com> writes:

Hi,

 B> This patch provides support for the new stateless command set, so that
 B> we can avoid the problems that come with a stateful addressing mode
 B> change. The flash can be left in "3-byte mode" while still accessing the
 B> entire flash.

Patch looks good (besides the build issue ;)

 B> diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
 B> index e80db9e..5ff14ee 100644
 B> --- a/drivers/mtd/devices/m25p80.c
 B> +++ b/drivers/mtd/devices/m25p80.c
 B> @@ -48,6 +48,12 @@
 B>  #define	OPCODE_SE		0xd8	/* Sector erase (usually 64KiB) */
 B>  #define	OPCODE_RDID		0x9f	/* Read JEDEC ID */
 
 B> +/* 4-byte address opcodes - used on Spansion and some Macronix flashes. */
 B> +#define	OPCODE_NORM_READ_4B	0x13	/* Read data bytes (low frequency) */
 B> +#define	OPCODE_FAST_READ_4B	0x0c	/* Read data bytes (high frequency) */
 B> +#define	OPCODE_PP_4B		0x12	/* Page program (up to 256 bytes) */
 B> +#define	OPCODE_SE_4B		0xdc	/* Sector erase (usually 64KiB) */

FYI, looking at a Micron N25Q datasheet, they support the same 4B
read/fast read commands, but NOT the 4B PP/SE ones - So for those you
need the enter-4B / exit-4B dance :/

-- 
Bye, Peter Korsgaard