Revert "spi: add config option to enable the WP pin function on st micron flashes"

This reverts commit 562f8df1.

Note: Even un-reverting this patch couldn't works as expected, based
on the latest testing from Heiko Schocher.
Signed-off-by: NJagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
Cc: Heiko Schocher <hs@denx.de>

README

@@ -3086,17 +3086,6 @@ CBFS (Coreboot Filesystem) support
 		memories can be connected with a given cs line.
 		Currently Xilinx Zynq qspi supports these type of connections.
 
-		CONFIG_SYS_SPI_ST_ENABLE_WP_PIN
-		enable the W#/Vpp signal to disable writing to the status
-		register on ST MICRON flashes like the N25Q128.
-		The status register write enable/disable bit, combined with
-		the W#/VPP signal provides hardware data protection for the
-		device as follows: When the enable/disable bit is set to 1,
-		and the W#/VPP signal is driven LOW, the status register
-		nonvolatile bits become read-only and the WRITE STATUS REGISTER
-		operation will not execute. The only way to exit this
-		hardware-protected mode is to drive W#/VPP HIGH.
-
 - SystemACE Support:
 		CONFIG_SYSTEMACE
 

drivers/mtd/spi/sf_internal.h

@@ -97,10 +97,6 @@ enum {
 #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)

drivers/mtd/spi/sf_probe.c

@@ -288,34 +288,6 @@ int spi_flash_decode_fdt(const void *blob, struct spi_flash *flash)
 }
 #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
-
 /**
  * spi_flash_probe_slave() - Probe for a SPI flash device on a bus
  *
@@ -394,8 +366,6 @@ int spi_flash_probe_slave(struct spi_slave *spi, struct spi_flash *flash)
 		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);