spi_flash: support old STMicro parts with RES

Some old STMicro parts do not support JEDEC ID (0x9f). This patch
uses RES (0xab) to get Electronic ID and translates it to JEDEC ID.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Mike Frysinger <vapier@gentoo.org>

drivers/mtd/spi/spi_flash.c

@@ -147,6 +147,7 @@ struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
 #endif
 #ifdef CONFIG_SPI_FLASH_STMICRO
 	case 0x20:
+	case 0xff: /* Let the stmicro func handle non-JEDEC ids */
 		flash = spi_flash_probe_stmicro(spi, idcode);
 		break;
 #endif

drivers/mtd/spi/stmicro.c

@@ -46,6 +46,7 @@
 #define CMD_M25PXX_DP		0xb9	/* Deep Power-down */
 #define CMD_M25PXX_RES		0xab	/* Release from DP, and Read Signature */
 
+#define STM_ID_M25P10		0x11
 #define STM_ID_M25P16		0x15
 #define STM_ID_M25P20		0x12
 #define STM_ID_M25P32		0x16
@@ -77,6 +78,13 @@ static inline struct stmicro_spi_flash *to_stmicro_spi_flash(struct spi_flash
 }
 
 static const struct stmicro_spi_flash_params stmicro_spi_flash_table[] = {
+	{
+		.idcode1 = STM_ID_M25P10,
+		.page_size = 256,
+		.pages_per_sector = 128,
+		.nr_sectors = 4,
+		.name = "M25P10",
+	},
 	{
 		.idcode1 = STM_ID_M25P16,
 		.page_size = 256,
@@ -316,6 +324,19 @@ struct spi_flash *spi_flash_probe_stmicro(struct spi_slave *spi, u8 * idcode)
 	struct stmicro_spi_flash *stm;
 	unsigned int i;
 
+	if (idcode[0] == 0xff) {
+		i = spi_flash_cmd(spi, CMD_M25PXX_RES,
+				  idcode, 4);
+		if (i)
+			return NULL;
+		if ((idcode[3] & 0xf0) == 0x10) {
+			idcode[0] = 0x20;
+			idcode[1] = 0x20;
+			idcode[2] = idcode[3] + 1;
+		} else
+			return NULL;
+	}
+
 	for (i = 0; i < ARRAY_SIZE(stmicro_spi_flash_table); i++) {
 		params = &stmicro_spi_flash_table[i];
 		if (params->idcode1 == idcode[2]) {