mtd: m25p80: introduce SST_WRITE flag for SST byte programming

Not all SST devices implement the SST byte programming command.
Some devices (like SST25VF064C) implement only standard m25p80 page
write command.

Now SPI flash devices that need sst_write() are explicitly marked
with new SST_WRITE flag and the decision to use sst_write() is based
on this flag instead of manufacturer id.

Signed-off-by: Krzysztof Mazur <krzysiek@podlesie.net>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

drivers/mtd/devices/m25p80.c

@@ -681,6 +681,7 @@ struct flash_info {
 	u16		flags;
 #define	SECT_4K		0x01		/* OPCODE_BE_4K works uniformly */
 #define	M25P_NO_ERASE	0x02		/* No erase command needed */
+#define	SST_WRITE	0x04		/* use SST byte programming */
 };
 
 #define INFO(_jedec_id, _ext_id, _sector_size, _n_sectors, _flags)	\
@@ -783,14 +784,14 @@ static const struct spi_device_id m25p_ids[] = {
 	{ "s25fl064k",  INFO(0xef4017,      0,  64 * 1024, 128, SECT_4K) },
 
 	/* SST -- large erase sizes are "overlays", "sectors" are 4K */
-	{ "sst25vf040b", INFO(0xbf258d, 0, 64 * 1024,  8, SECT_4K) },
-	{ "sst25vf080b", INFO(0xbf258e, 0, 64 * 1024, 16, SECT_4K) },
-	{ "sst25vf016b", INFO(0xbf2541, 0, 64 * 1024, 32, SECT_4K) },
-	{ "sst25vf032b", INFO(0xbf254a, 0, 64 * 1024, 64, SECT_4K) },
-	{ "sst25wf512",  INFO(0xbf2501, 0, 64 * 1024,  1, SECT_4K) },
-	{ "sst25wf010",  INFO(0xbf2502, 0, 64 * 1024,  2, SECT_4K) },
-	{ "sst25wf020",  INFO(0xbf2503, 0, 64 * 1024,  4, SECT_4K) },
-	{ "sst25wf040",  INFO(0xbf2504, 0, 64 * 1024,  8, SECT_4K) },
+	{ "sst25vf040b", INFO(0xbf258d, 0, 64 * 1024,  8, SECT_4K | SST_WRITE) },
+	{ "sst25vf080b", INFO(0xbf258e, 0, 64 * 1024, 16, SECT_4K | SST_WRITE) },
+	{ "sst25vf016b", INFO(0xbf2541, 0, 64 * 1024, 32, SECT_4K | SST_WRITE) },
+	{ "sst25vf032b", INFO(0xbf254a, 0, 64 * 1024, 64, SECT_4K | SST_WRITE) },
+	{ "sst25wf512",  INFO(0xbf2501, 0, 64 * 1024,  1, SECT_4K | SST_WRITE) },
+	{ "sst25wf010",  INFO(0xbf2502, 0, 64 * 1024,  2, SECT_4K | SST_WRITE) },
+	{ "sst25wf020",  INFO(0xbf2503, 0, 64 * 1024,  4, SECT_4K | SST_WRITE) },
+	{ "sst25wf040",  INFO(0xbf2504, 0, 64 * 1024,  8, SECT_4K | SST_WRITE) },
 
 	/* ST Microelectronics -- newer production may have feature updates */
 	{ "m25p05",  INFO(0x202010,  0,  32 * 1024,   2, 0) },
@@ -1002,7 +1003,7 @@ static int m25p_probe(struct spi_device *spi)
 	}
 
 	/* sst flash chips use AAI word program */
-	if (JEDEC_MFR(info->jedec_id) == CFI_MFR_SST)
+	if (info->flags & SST_WRITE)
 		flash->mtd._write = sst_write;
 	else
 		flash->mtd._write = m25p80_write;