Check version register of the OTP

The version of register 0 and 1 must be greater or equal to 1,
otherwise do not attempt to read any data from the OTP.

Signed-off-by: Francois Berder <francois.berder@imgtec.com>

board/imgtec/pistachio_bub/Makefile

@@ -21,4 +21,5 @@ obj-y				+= cmd_scratchpad.o
 endif
 ifdef CONFIG_WINBOND_OTP
 obj-y				+= fdt.o
+obj-y				+= otp.o
 endif

board/imgtec/pistachio_bub/fdt.c

@@ -10,10 +10,7 @@
 #if defined(CONFIG_OF_LIBFDT) && defined(CONFIG_OF_BOARD_SETUP)
 
 #include <winbond-otp.h>
-
-#define WIFI_STA_MAC_ADDRESS_OFFSET	0x1003
-#define WIFI_AP_MAC_ADDRESS_OFFSET	0x1009
-#define DCXO_OFFSET			0x2003
+#include "otp.h"
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -24,13 +21,15 @@ static void fixup_wifi_mac(void *blob, int node)
 	memset(wifi_sta_mac_addr, 0, sizeof(wifi_sta_mac_addr));
 	memset(wifi_ap_mac_addr, 0, sizeof(wifi_ap_mac_addr));
 
-	/* Read MAC addresses from OTP */
-	if (read_otp_data(WIFI_STA_MAC_ADDRESS_OFFSET, MAC_ADDR_LEN,
-			  (char *)wifi_sta_mac_addr)
-	||  read_otp_data(WIFI_AP_MAC_ADDRESS_OFFSET, MAC_ADDR_LEN,
-			  (char *)wifi_ap_mac_addr)) {
-		printf("WARNING: Could not read Wifi MAC addresses from OTP\n");
-		return;
+	if (read_otp_version(VERSION_REG0_OFFSET) >= 1) {
+		/* Read MAC addresses from OTP */
+		if (read_otp_data(WIFI_STA_MAC_ADDRESS_OFFSET, MAC_ADDR_LEN,
+				  (char *)wifi_sta_mac_addr)
+		||  read_otp_data(WIFI_AP_MAC_ADDRESS_OFFSET, MAC_ADDR_LEN,
+				  (char *)wifi_ap_mac_addr)) {
+			printf("WARNING: Could not read Wifi MAC addresses from OTP\n");
+			return;
+		}
 	}
 
 	/* Set Wifi STA and AP MAC address in device tree */
@@ -52,11 +51,14 @@ static void fixup_wifi_calibration(void *blob, int node)
 	int len;
 	char dcxo;
 	char *rf_params_prop;
-
-	/* Read calibration data from OTP */
-	if (read_otp_data(DCXO_OFFSET, sizeof(dcxo), &dcxo)) {
-		printf("WARNING: Could not read dcxo from OTP\n");
-		return;
+	int version_reg1 = read_otp_version(VERSION_REG1_OFFSET);
+
+	if (version_reg1 >= 1) {
+		/* Read calibration data from OTP */
+		if (read_otp_data(DCXO_OFFSET, sizeof(dcxo), &dcxo)) {
+			printf("WARNING: Could not read dcxo from OTP\n");
+			return;
+		}
 	}
 
 	/* Overwrite first byte of rf-params property with DXCO */
@@ -66,7 +68,9 @@ static void fixup_wifi_calibration(void *blob, int node)
 		return;
 	}
 
-	rf_params_prop[0] = dcxo;
+	if (version_reg1 >= 1)
+		rf_params_prop[0] = dcxo;
+
 	fdt_setprop(blob, node, "rf-params", rf_params_prop, len);
 }
 

board/imgtec/pistachio_bub/otp.c

@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Francois Berder <francois.berder@imgtec.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <winbond-otp.h>
+#include "otp.h"
+
+int read_otp_version(loff_t offset)
+{
+	u_char version;
+
+	if (read_otp_data(offset, sizeof(version), (char *)&version)) {
+		printf("WARNING: Could not read register version from OTP.\n");
+		return -1;
+	}
+
+	return version;
+}

board/imgtec/pistachio_bub/otp.h

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2016 Imagination Technologies
+ * Author: Francois Berder <francois.berder@imgtec.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _OTP_H
+#define _OTP_H
+
+#define MAC_ADDR_LEN 6
+
+#ifdef CONFIG_WINBOND_OTP
+
+#include <linux/types.h>
+
+#define VERSION_REG0_OFFSET		0x1002
+#define VERSION_REG1_OFFSET		0x2002
+#define WIFI_STA_MAC_ADDRESS_OFFSET	0x1003
+#define WIFI_AP_MAC_ADDRESS_OFFSET	0x1009
+#define ETH_MAC_ADDRESS_OFFSET		0x1015
+#define DCXO_OFFSET			0x2003
+
+int read_otp_version(loff_t offset);
+
+#endif
+
+#endif

board/imgtec/pistachio_bub/pistachio.c

@@ -23,8 +23,8 @@
 #include <tpm.h>
 #include <winbond-otp.h>
 #include "mfio.h"
+#include "otp.h"
 
-#define ETH_MAC_ADDRESS_OFFSET          0x1015 /* Ethernet MAC address offset */
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -130,12 +130,14 @@ int board_eth_init(bd_t *bs)
 
 #ifdef CONFIG_WINBOND_OTP
 	if (!is_valid_ethaddr(mac_addr)) {
-		if (!read_otp_data(ETH_MAC_ADDRESS_OFFSET, MAC_ADDR_LEN,
-				   (char *)mac_addr)
-		&&  is_valid_ethaddr(mac_addr))
-			eth_setenv_enetaddr("ethaddr", (u8 *)mac_addr);
-		else
-			printf("Could not read MAC address from OTP\n");
+		if (read_otp_version(VERSION_REG0_OFFSET) >= 1) {
+			if (!read_otp_data(ETH_MAC_ADDRESS_OFFSET, MAC_ADDR_LEN,
+					   (char *)mac_addr)
+			&&  is_valid_ethaddr(mac_addr))
+				eth_setenv_enetaddr("ethaddr", (u8 *)mac_addr);
+			else
+				printf("Could not read MAC address from OTP\n");
+		}
 	}
 #endif
 #ifdef CONFIG_OF_CONTROL

include/winbond-otp.h

@@ -8,8 +8,6 @@
 #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