mxc: ocotp fix hole in shadow registers

There is a hole in shadow registers address map of size 0x100
between bank 5 and bank 6 on iMX6QP, iMX6DQ, iMX6SDL, iMX6SX and iMX6UL.
Bank 5 ends at 0x6F0 and Bank 6 starts at 0x800. When reading the fuses,
we should account for this hole in address space.

Similar hole exists between bank 14 and bank 15 of size
0x80 on iMX6QP, iMX6DQ, iMX6SDL and iMX6SX.
Note: iMX6SL has only 0-7 banks and there is no hole.
Note: iMX6UL doesn't have this one.

When reading, we use register offset, so need to account for holes
to get the correct address.
When writing, we use bank/word index, there is no need to account
for holes, always use bank/word index from fuse map.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>

2 files changed, 75 insertions, 6 deletions

diff --git a/arch/arm/include/asm/arch-mx6/imx-regs.h b/arch/arm/include/asm/arch-mx6/imx-regs.h
index 4d84a9b753f..a685ed2c3b4 100644
--- a/arch/arm/include/asm/arch-mx6/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx6/imx-regs.h
@@ -630,9 +630,10 @@ struct ocotp_regs {
 	u32     version;
 	u32     rsvd7[0xdb];
 
+	/* fuse banks */
 	struct fuse_bank {
 		u32	fuse_regs[0x20];
-	} bank[16];
+	} bank[0];
 };
 
 struct fuse_bank0_regs {
diff --git a/drivers/misc/mxc_ocotp.c b/drivers/misc/mxc_ocotp.c
index d9b02c78e2c..65ff8158e59 100644
--- a/drivers/misc/mxc_ocotp.c
+++ b/drivers/misc/mxc_ocotp.c
@@ -57,6 +57,68 @@
 
 #define WRITE_POSTAMBLE_US		2
 
+#if defined(CONFIG_MX6) || defined(CONFIG_VF610)
+#define FUSE_BANK_SIZE	0x80
+#ifdef CONFIG_MX6SL
+#define FUSE_BANKS	8
+#else
+#define FUSE_BANKS	16
+#endif
+#elif defined CONFIG_MX7
+#define FUSE_BANK_SIZE	0x40
+#define FUSE_BANKS	16
+#else
+#error "Unsupported architecture\n"
+#endif
+
+#if defined(CONFIG_MX6)
+#include <asm/arch/sys_proto.h>
+
+/*
+ * There is a hole in shadow registers address map of size 0x100
+ * between bank 5 and bank 6 on iMX6QP, iMX6DQ, iMX6SDL, iMX6SX and iMX6UL.
+ * Bank 5 ends at 0x6F0 and Bank 6 starts at 0x800. When reading the fuses,
+ * we should account for this hole in address space.
+ *
+ * Similar hole exists between bank 14 and bank 15 of size
+ * 0x80 on iMX6QP, iMX6DQ, iMX6SDL and iMX6SX.
+ * Note: iMX6SL has only 0-7 banks and there is no hole.
+ * Note: iMX6UL doesn't have this one.
+ *
+ * This function is to covert user input to physical bank index.
+ * Only needed when read fuse, because we use register offset, so
+ * need to calculate real register offset.
+ * When write, no need to consider hole, always use the bank/word
+ * index from fuse map.
+ */
+u32 fuse_bank_physical(int index)
+{
+	u32 phy_index;
+
+	if (is_cpu_type(MXC_CPU_MX6SL)) {
+		phy_index = index;
+	} else if (is_cpu_type(MXC_CPU_MX6UL)) {
+		if (index >= 6)
+			phy_index = fuse_bank_physical(5) + (index - 6) + 3;
+		else
+			phy_index = index;
+	} else {
+		if (index >= 15)
+			phy_index = fuse_bank_physical(14) + (index - 15) + 2;
+		else if (index >= 6)
+			phy_index = fuse_bank_physical(5) + (index - 6) + 3;
+		else
+			phy_index = index;
+	}
+	return phy_index;
+}
+#else
+u32 fuse_bank_physical(int index)
+{
+	return index;
+}
+#endif
+
 static void wait_busy(struct ocotp_regs *regs, unsigned int delay_us)
 {
 	while (readl(&regs->ctrl) & BM_CTRL_BUSY)
@@ -73,9 +135,9 @@ static int prepare_access(struct ocotp_regs **regs, u32 bank, u32 word,
 {
 	*regs = (struct ocotp_regs *)OCOTP_BASE_ADDR;
 
-	if (bank >= ARRAY_SIZE((*regs)->bank) ||
-			word >= ARRAY_SIZE((*regs)->bank[0].fuse_regs) >> 2 ||
-			!assert) {
+	if (bank >= FUSE_BANKS ||
+	    word >= ARRAY_SIZE((*regs)->bank[0].fuse_regs) >> 2 ||
+	    !assert) {
 		printf("mxc_ocotp %s(): Invalid argument\n", caller);
 		return -EINVAL;
 	}
@@ -113,12 +175,15 @@ int fuse_read(u32 bank, u32 word, u32 *val)
 {
 	struct ocotp_regs *regs;
 	int ret;
+	u32 phy_bank;
 
 	ret = prepare_read(&regs, bank, word, val, __func__);
 	if (ret)
 		return ret;
 
-	*val = readl(&regs->bank[bank].fuse_regs[word << 2]);
+	phy_bank = fuse_bank_physical(bank);
+
+	*val = readl(&regs->bank[phy_bank].fuse_regs[word << 2]);
 
 	return finish_access(regs, __func__);
 }
@@ -259,12 +324,15 @@ int fuse_override(u32 bank, u32 word, u32 val)
 {
 	struct ocotp_regs *regs;
 	int ret;
+	u32 phy_bank;
 
 	ret = prepare_write(&regs, bank, word, __func__);
 	if (ret)
 		return ret;
 
-	writel(val, &regs->bank[bank].fuse_regs[word << 2]);
+	phy_bank = fuse_bank_physical(bank);
+
+	writel(val, &regs->bank[phy_bank].fuse_regs[word << 2]);
 
 	return finish_access(regs, __func__);
 }