source: SVN/rincon/u-boot/common/cmd_otp.c @ 55

/*
 * 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