Add driver to read OTP data

Signed-off-by: Avinash Tahakik <[email protected]>
Signed-off-by: Francois Berder <[email protected]>

Author: Avinash95

drivers/mtd/spi/Makefile

@@ -16,6 +16,7 @@ endif
 obj-$(CONFIG_SPI_FLASH) += sf_probe.o
 #endif
 obj-$(CONFIG_CMD_SF) += sf.o
+obj-$(CONFIG_WINBOND_OTP) += winbond-otp.o
 obj-$(CONFIG_SPI_FLASH) += sf_ops.o sf_params.o
 obj-$(CONFIG_SPI_FLASH_DATAFLASH) += sf_dataflash.o
 obj-$(CONFIG_SPI_FLASH_MTD) += sf_mtd.o

drivers/mtd/spi/winbond-otp.c

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Avinash Tahakik <[email protected]>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <spi.h>
+#include <spi_flash.h>
+#include <winbond-otp.h>
+
+#include "sf_internal.h"
+
+/* SPI FLASH opcodes */
+
+#define SPINOR_OP_RD_SECURITY_REG	0x48 /* Read security register */
+#define SECURITY_REG_SIZE		256 /* bytes per security register */
+
+#define REG1_START_ADDRESS		0X1000
+#define REG2_START_ADDRESS		0X2000
+#define REG3_START_ADDRESS		0X3000
+
+#define REG1_END_ADDRESS		0X10FF
+#define REG2_END_ADDRESS		0X20FF
+#define REG3_END_ADDRESS		0X30FF
+
+static struct spi_flash *flash;
+
+static int check_addr_validity(loff_t from, size_t len)
+{
+	if ((REG1_START_ADDRESS <= from && from + len <= REG1_END_ADDRESS)
+	|| (REG2_START_ADDRESS <= from && from + len <= REG2_END_ADDRESS)
+	|| (REG3_START_ADDRESS <= from && from + len <= REG3_END_ADDRESS))
+		return 0;
+
+	return -1;
+}
+
+int read_otp_data(loff_t from, size_t len, char *data)
+{
+	if (check_addr_validity(from, len))
+		return -1;
+
+	if (!flash)
+		flash = spi_flash_probe(1, 0, CONFIG_SF_DEFAULT_SPEED,
+					CONFIG_SF_DEFAULT_MODE);
+
+	if (!flash) {
+		printf("Failed to initialize SPI flash at 1:0\n");
+		return -1;
+	}
+
+	flash->read_cmd = SPINOR_OP_RD_SECURITY_REG;
+	return spi_flash_cmd_read_ops(flash, from, len, data);
+}

include/winbond-otp.h

@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) 2015 Imagination Technologies
+ * Author: Avinash Tahakik <[email protected]>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef WINBOND_OTP_H
+#define WINBOND_OTP_H
+
+#define MAC_ADDR_LEN 6
+
+int read_otp_data(loff_t from, size_t len, char *data);
+
+#endif