sf: Disable 4-KB erase command for SPANSION S25FS-S family

The S25FS-S family physical sectors may be configured as a hybrid
combination of eight 4-kB parameter sectors at the top or bottom
of the address space with all but one of the remaining sectors
being uniform size.
The default status of the flash is in this hybrid architecture.
The parameter sectors and the uniform sectors have different erase
commands.
This patch disable the hybrid sector architecture then the flash will
has uniform sector size and uniform erase command.
This configuration is temporary, the flash will revert to hybrid
architecture after power on reset.

Signed-off-by: Yuan Yao <yao.yuan@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>

drivers/mtd/spi/spi_flash.c

@@ -971,6 +971,43 @@ int spi_flash_decode_fdt(const void *blob, struct spi_flash *flash)
 }
 #endif /* CONFIG_IS_ENABLED(OF_CONTROL) */
 
+#ifdef CONFIG_SPI_FLASH_SPANSION
+static int spansion_s25fss_disable_4KB_erase(struct spi_slave *spi)
+{
+	u8 cmd[4];
+	u32 offset = 0x800004; /* CR3V register offset */
+	u8 cr3v;
+	int ret;
+
+	cmd[0] = CMD_SPANSION_RDAR;
+	cmd[1] = offset >> 16;
+	cmd[2] = offset >> 8;
+	cmd[3] = offset >> 0;
+
+	ret = spi_flash_cmd_read(spi, cmd, 4, &cr3v, 1);
+	if (ret)
+		return -EIO;
+	/* CR3V bit3: 4-KB Erase */
+	if (cr3v & 0x8)
+		return 0;
+
+	cmd[0] = CMD_SPANSION_WRAR;
+	cr3v |= 0x8;
+	ret = spi_flash_cmd_write(spi, cmd, 4, &cr3v, 1);
+	if (ret)
+		return -EIO;
+
+	cmd[0] = CMD_SPANSION_RDAR;
+	ret = spi_flash_cmd_read(spi, cmd, 4, &cr3v, 1);
+	if (ret)
+		return -EIO;
+	if (!(cr3v & 0x8))
+		return -EFAULT;
+
+	return 0;
+}
+#endif
+
 int spi_flash_scan(struct spi_flash *flash)
 {
 	struct spi_slave *spi = flash->spi;
@@ -1021,6 +1058,41 @@ int spi_flash_scan(struct spi_flash *flash)
 		return -EPROTONOSUPPORT;
 	}
 
+#ifdef CONFIG_SPI_FLASH_SPANSION
+	/*
+	 * The S25FS-S family physical sectors may be configured as a
+	 * hybrid combination of eight 4-kB parameter sectors
+	 * at the top or bottom of the address space with all
+	 * but one of the remaining sectors being uniform size.
+	 * The Parameter Sector Erase commands (20h or 21h) must
+	 * be used to erase the 4-kB parameter sectors individually.
+	 * The Sector (uniform sector) Erase commands (D8h or DCh)
+	 * must be used to erase any of the remaining
+	 * sectors, including the portion of highest or lowest address
+	 * sector that is not overlaid by the parameter sectors.
+	 * The uniform sector erase command has no effect on parameter sectors.
+	 */
+	if (jedec == 0x0219 && (ext_jedec & 0xff00) == 0x4d00) {
+		int ret;
+		u8 id[6];
+
+		/* Read the ID codes again, 6 bytes */
+		ret = spi_flash_cmd(flash->spi, CMD_READ_ID, id, sizeof(id));
+		if (ret)
+			return -EIO;
+
+		ret = memcmp(id, idcode, 5);
+		if (ret)
+			return -EIO;
+
+		/* 0x81: S25FS-S family 0x80: S25FL-S family */
+		if (id[5] == 0x81) {
+			ret = spansion_s25fss_disable_4KB_erase(spi);
+			if (ret)
+				return ret;
+		}
+	}
+#endif
 	/* Flash powers up read-only, so clear BP# bits */
 	if (idcode[0] == SPI_FLASH_CFI_MFR_ATMEL ||
 	    idcode[0] == SPI_FLASH_CFI_MFR_MACRONIX ||