interface to Blackfin on-chip One-Time-Programmable memory

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 163 insertions, 0 deletions

diff --git a/common/cmd_otp.c b/common/cmd_otp.c
new file mode 100644
index 0000000..825fa34
--- /dev/null
+++ b/common/cmd_otp.c
@@ -0,0 +1,163 @@
+/*
+ * cmd_otp.c - interface to Blackfin on-chip One-Time-Programmable memory
+ *
+ * Copyright (c) 2007-2008 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+/* There are 512 128-bit "pages" (0x000 to 0x1FF).
+ * The pages are accessable as 64-bit "halfpages" (an upper and lower half).
+ * The pages are not part of the memory map.  There is an OTP controller which
+ * handles scanning in/out of bits.  While access is done through OTP MMRs,
+ * the bootrom provides C-callable helper functions to handle the interaction.
+ */
+
+#include <config.h>
+#include <common.h>
+#include <command.h>
+
+#ifdef CONFIG_CMD_OTP
+
+#include <asm/blackfin.h>
+#include <asm/mach-common/bits/otp.h>
+
+static const char *otp_strerror(uint32_t err)
+{
+	switch (err) {
+	case 0:                   return "no error";
+	case OTP_WRITE_ERROR:     return "OTP fuse write error";
+	case OTP_READ_ERROR:      return "OTP fuse read error";
+	case OTP_ACC_VIO_ERROR:   return "invalid OTP address";
+	case OTP_DATA_MULT_ERROR: return "multiple bad bits detected";
+	case OTP_ECC_MULT_ERROR:  return "error in ECC bits";
+	case OTP_PREV_WR_ERROR:   return "space already written";
+	case OTP_DATA_SB_WARN:    return "single bad bit in half page";
+	case OTP_ECC_SB_WARN:     return "single bad bit in ECC";
+	default:                  return "unknown error";
+	}
+}
+
+#define lowup(x) ((x) % 2 ? "upper" : "lower")
+
+int do_otp(cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
+{
+	bool force = false;
+	if (!strcmp(argv[1], "--force")) {
+		force = true;
+		argv[1] = argv[0];
+		argv++;
+		--argc;
+	}
+
+	uint32_t (*otp_func)(uint32_t page, uint32_t flags, uint64_t *page_content);
+	if (!strcmp(argv[1], "read"))
+		otp_func = otp_read;
+	else if (!strcmp(argv[1], "write"))
+		otp_func = otp_write;
+	else {
+ usage:
+		printf("Usage:\n%s\n", cmdtp->usage);
+		return 1;
+	}
+
+	uint64_t *addr = (uint64_t *)simple_strtoul(argv[2], NULL, 16);
+	uint32_t page = simple_strtoul(argv[3], NULL, 16);
+	uint32_t flags, ret;
+	size_t i, count;
+	ulong half;
+
+	if (argc > 4)
+		count = simple_strtoul(argv[4], NULL, 16);
+	else
+		count = 2;
+
+	if (argc > 5) {
+		half = simple_strtoul(argv[5], NULL, 16);
+		if (half != 0 && half != 1) {
+			puts("Error: 'half' can only be '0' or '1'\n");
+			goto usage;
+		}
+	} else
+		half = 0;
+
+	/* do to the nature of OTP, make sure users are sure */
+	if (!force && otp_func == otp_write) {
+		printf(
+			"Writing one time programmable memory\n"
+			"Make sure your operating voltages and temperature are within spec\n"
+			"   source address:  0x%p\n"
+			"   OTP destination: %s page 0x%03X - %s page 0x%03X\n"
+			"   number to write: %ld halfpages\n"
+			" type \"YES\" (no quotes) to confirm: ",
+			addr,
+			lowup(half), page,
+			lowup(half + count - 1), page + (half + count - 1) / 2,
+			half + count
+		);
+
+		i = 0;
+		while (1) {
+			if (tstc()) {
+				const char exp_ans[] = "YES\r";
+				char c;
+				putc(c = getc());
+				if (exp_ans[i++] != c) {
+					printf(" Aborting\n");
+					return 1;
+				} else if (!exp_ans[i]) {
+					puts("\n");
+					break;
+				}
+			}
+		}
+
+		/* Only supported in newer silicon ... enable writing */
+#if (0)
+		otp_command(OTP_INIT, ...);
+#else
+		*pOTP_TIMING = 0x32149485;
+#endif
+	}
+
+	printf("OTP memory %s: addr 0x%08lx  page 0x%03X  count %ld ... ",
+		argv[1], addr, page, count);
+
+	ret = 0;
+	for (i = half; i < count + half; ++i) {
+		flags = (i % 2) ? OTP_UPPER_HALF : OTP_LOWER_HALF;
+		ret = otp_func(page, flags, addr);
+		if (ret & 0x1)
+			break;
+		else if (ret)
+			puts("W");
+		else
+			puts(".");
+		++addr;
+		if (i % 2)
+			++page;
+	}
+	if (ret & 0x1)
+		printf("\nERROR at page 0x%03X (%s-halfpage): 0x%03X: %s\n",
+			page, lowup(i), ret, otp_strerror(ret));
+	else
+		puts(" done\n");
+
+	if (otp_func == otp_write)
+		/* Only supported in newer silicon ... disable writing */
+#if (0)
+		otp_command(OTP_INIT, ...);
+#else
+		*pOTP_TIMING = 0x1485;
+#endif
+
+	return ret;
+}
+
+U_BOOT_CMD(otp, 6, 0, do_otp,
+	"otp - One-Time-Programmable sub-system\n",
+	"read <addr> <page> [count] [half]\n"
+	"otp write [--force] <addr> <page> [count] [half]\n"
+	"    - read/write 'count' half-pages starting at page 'page' (offset 'half')\n");
+
+#endif