[PATCH] ARM: mx6: Add function to read UNIQUE_ID

[Sean Anderson]

This is almost identical to the imx7 version, except that the register
names are different.

Signed-off-by: Sean Anderson <sean.anderson at seco.com>
---

 arch/arm/mach-imx/mx6/soc.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/arch/arm/mach-imx/mx6/soc.c b/arch/arm/mach-imx/mx6/soc.c
index bf6dddfdc9..cb729be46f 100644
--- a/arch/arm/mach-imx/mx6/soc.c
+++ b/arch/arm/mach-imx/mx6/soc.c
@@ -11,6 +11,7 @@
 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <asm/io.h>
+#include <asm/setup.h>
 #include <asm/arch/imx-regs.h>
 #include <asm/arch/clock.h>
 #include <asm/arch/sys_proto.h>
@@ -705,6 +706,38 @@ int arch_misc_init(void)
 }
 #endif
 
+#ifdef CONFIG_SERIAL_TAG
+/*
+ * UNIQUE_ID describes a unique ID based on silicon wafer
+ * and die X/Y position
+ *
+ * UNIQUE_ID offset 0x410
+ * 31:0 fuse 0
+ * FSL-wide unique, encoded LOT ID STD II/SJC CHALLENGE/ Unique ID
+ *
+ * UNIQUE_ID offset 0x420
+ * 31:24 fuse 1
+ * The X-coordinate of the die location on the wafer/SJC CHALLENGE/ Unique ID
+ * 23:16 fuse 1
+ * The Y-coordinate of the die location on the wafer/SJC CHALLENGE/ Unique ID
+ * 15:11 fuse 1
+ * The wafer number of the wafer on which the device was fabricated/SJC
+ * CHALLENGE/ Unique ID
+ * 10:0 fuse 1
+ * FSL-wide unique, encoded LOT ID STD II/SJC CHALLENGE/ Unique ID
+ */
+void get_board_serial(struct tag_serialnr *serialnr)
+{
+	struct ocotp_regs *ocotp = (struct ocotp_regs *)OCOTP_BASE_ADDR;
+	struct fuse_bank *bank = &ocotp->bank[0];
+	struct fuse_bank0_regs *fuse =
+		(struct fuse_bank0_regs *)bank->fuse_regs;
+
+	serialnr->low = fuse->uid_low;
+	serialnr->high = fuse->uid_high;
+}
+#endif
+
 /*
  * gpr_init() function is common for boards using MX6S, MX6DL, MX6D,
  * MX6Q and MX6QP processors
-- 
2.25.1