/*
 * 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 through 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>
#include <console.h>

#include <asm/blackfin.h>
#include <asm/clock.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")

static int check_voltage(void)
{
        /* Make sure voltage limits are within datasheet spec */
        uint16_t vr_ctl = bfin_read_VR_CTL();

#ifdef __ADSPBF54x__
        /* 0.9V <= VDDINT <= 1.1V */
        if ((vr_ctl & 0xc) && (vr_ctl & 0xc0) == 0xc0)
                return 1;
#else
        /* for the parts w/out qualification yet */
        (void)vr_ctl;
#endif

        return 0;
}

static void set_otp_timing(bool write)
{
        static uint32_t timing;
        if (!timing) {
                uint32_t tp1, tp2, tp3;
                /* OTP_TP1 = 1000 / sclk_period (in nanoseconds)
                 * OTP_TP1 = 1000 / (1 / get_sclk() * 10^9)
                 * OTP_TP1 = (1000 * get_sclk()) / 10^9
                 * OTP_TP1 = get_sclk() / 10^6
                 */
                tp1 = get_sclk() / 1000000;
                /* OTP_TP2 = 400 / (2 * sclk_period)
                 * OTP_TP2 = 400 / (2 * 1 / get_sclk() * 10^9)
                 * OTP_TP2 = (400 * get_sclk()) / (2 * 10^9)
                 * OTP_TP2 = (2 * get_sclk()) / 10^7
                 */
                tp2 = (2 * get_sclk() / 10000000) << 8;
                /* OTP_TP3 = magic constant */
                tp3 = (0x1401) << 15;
                timing = tp1 | tp2 | tp3;
        }

        bfrom_OtpCommand(OTP_INIT, write ? timing : timing & ~(-1 << 15));
}

int do_otp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
        char *cmd;
        uint32_t ret, base_flags;
        bool prompt_user, force_read;
        uint32_t (*otp_func)(uint32_t page, uint32_t flags, uint64_t *page_content);

        if (argc < 4) {
 usage:
                return CMD_RET_USAGE;
        }

        prompt_user = false;
        base_flags = 0;
        cmd = argv[1];
        if (!strcmp(cmd, "read"))
                otp_func = bfrom_OtpRead;
        else if (!strcmp(cmd, "dump")) {
                otp_func = bfrom_OtpRead;
                force_read = true;
        } else if (!strcmp(cmd, "write")) {
                otp_func = bfrom_OtpWrite;
                base_flags = OTP_CHECK_FOR_PREV_WRITE;
                if (!strcmp(argv[2], "--force")) {
                        argv++;
                        --argc;
                } else
                        prompt_user = false;
        } else if (!strcmp(cmd, "lock")) {
                if (argc != 4)
                        goto usage;
                otp_func = bfrom_OtpWrite;
                base_flags = OTP_LOCK;
        } else
                goto usage;

        uint64_t *addr = (uint64_t *)simple_strtoul(argv[2], NULL, 16);
        uint32_t page = simple_strtoul(argv[3], NULL, 16);
        uint32_t flags;
        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;

        /* "otp lock" has slightly different semantics */
        if (base_flags & OTP_LOCK) {
                count = page;
                page = (uint32_t)addr;
                addr = NULL;
        }

        /* do to the nature of OTP, make sure users are sure */
        if (prompt_user) {
                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%03lX\n"
                        "   number to write: %lu halfpages\n"
                        " type \"YES\" (no quotes) to confirm: ",
                        addr,
                        lowup(half), page,
                        lowup(half + count - 1), page + (half + count - 1) / 2,
                        half + count
                );
                if (!confirm_yesno()) {
                        printf(" Aborting\n");
                        return 1;
                }
        }

        printf("OTP memory %s: addr 0x%p  page 0x%03X  count %zu ... ",
                cmd, addr, page, count);

        set_otp_timing(otp_func == bfrom_OtpWrite);
        if (otp_func == bfrom_OtpWrite && check_voltage()) {
                puts("ERROR: VDDINT voltage is out of spec for writing\n");
                return -1;
        }

        /* Do the actual reading/writing stuff */
        ret = 0;
        for (i = half; i < count + half; ++i) {
                flags = base_flags | (i % 2 ? OTP_UPPER_HALF : OTP_LOWER_HALF);
 try_again:
                ret = otp_func(page, flags, addr);
                if (ret & OTP_MASTER_ERROR) {
                        if (force_read) {
                                if (flags & OTP_NO_ECC)
                                        break;
                                else
                                        flags |= OTP_NO_ECC;
                                puts("E");
                                goto try_again;
                        } else
                                break;
                } else if (ret)
                        puts("W");
                else
                        puts(".");
                if (!(base_flags & OTP_LOCK)) {
                        ++addr;
                        if (i % 2)
                                ++page;
                } else
                        ++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");

        /* Make sure we disable writing */
        set_otp_timing(false);
        bfrom_OtpCommand(OTP_CLOSE, 0);

        return ret;
}

U_BOOT_CMD(
        otp, 7, 0, do_otp,
        "One-Time-Programmable sub-system",
        "read <addr> <page> [count] [half]\n"
        " - read 'count' half-pages starting at 'page' (offset 'half') to 'addr'\n"
        "otp dump <addr> <page> [count] [half]\n"
        " - like 'otp read', but skip read errors\n"
        "otp write [--force] <addr> <page> [count] [half]\n"
        " - write 'count' half-pages starting at 'page' (offset 'half') from 'addr'\n"
        "otp lock <page> <count>\n"
        " - lock 'count' pages starting at 'page'"
);