spi: add config option to enable the WP pin function on st micron flashes
enable the W#/Vpp signal to disable writing to the status
register on ST MICRON flashes like the N25Q128 thorugh
the new config option CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
diff --git a/drivers/mtd/spi/sf_internal.h b/drivers/mtd/spi/sf_internal.h
index 6bcd522..19d4914 100644
--- a/drivers/mtd/spi/sf_internal.h
+++ b/drivers/mtd/spi/sf_internal.h
@@ -60,6 +60,10 @@
#define STATUS_QEB_MXIC (1 << 6)
#define STATUS_PEC (1 << 7)
+#ifdef CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
+#define STATUS_SRWD (1 << 7) /* SR write protect */
+#endif
+
/* Flash timeout values */
#define SPI_FLASH_PROG_TIMEOUT (2 * CONFIG_SYS_HZ)
#define SPI_FLASH_PAGE_ERASE_TIMEOUT (5 * CONFIG_SYS_HZ)
diff --git a/drivers/mtd/spi/sf_probe.c b/drivers/mtd/spi/sf_probe.c
index 36ae5e0..4d148d1 100644
--- a/drivers/mtd/spi/sf_probe.c
+++ b/drivers/mtd/spi/sf_probe.c
@@ -281,6 +281,34 @@
}
#endif /* CONFIG_OF_CONTROL */
+#ifdef CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
+/* enable the W#/Vpp signal to disable writing to the status register */
+static int spi_enable_wp_pin(struct spi_flash *flash)
+{
+ u8 status;
+ int ret;
+
+ ret = spi_flash_cmd_read_status(flash, &status);
+ if (ret < 0)
+ return ret;
+
+ ret = spi_flash_cmd_write_status(flash, STATUS_SRWD);
+ if (ret < 0)
+ return ret;
+
+ ret = spi_flash_cmd_write_disable(flash);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+#else
+static int spi_enable_wp_pin(struct spi_flash *flash)
+{
+ return 0;
+}
+#endif
+
static struct spi_flash *spi_flash_probe_slave(struct spi_slave *spi)
{
struct spi_flash *flash = NULL;
@@ -351,6 +379,8 @@
puts(" Full access #define CONFIG_SPI_FLASH_BAR\n");
}
#endif
+ if (spi_enable_wp_pin(flash))
+ puts("Enable WP pin failed\n");
/* Release spi bus */
spi_release_bus(spi);