// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2000, 2001
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 */

/*
 * Support for read and write access to EEPROM like memory devices. This
 * includes regular EEPROM as well as  FRAM (ferroelectic nonvolaile RAM).
 * FRAM devices read and write data at bus speed. In particular, there is no
 * write delay. Also, there is no limit imposed on the number of bytes that can
 * be transferred with a single read or write.
 *
 * Use the following configuration options to ensure no unneeded performance
 * degradation (typical for EEPROM) is incured for FRAM memory:
 *
 * #define CONFIG_SYS_I2C_FRAM
 * #undef CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS
 *
 */

#include <common.h>
#include <config.h>
#include <command.h>
#include <eeprom.h>
#include <i2c.h>
#include <eeprom_layout.h>
#include <linux/delay.h>

#ifndef CONFIG_SYS_I2C_SPEED
#define CONFIG_SYS_I2C_SPEED    50000
#endif

#ifndef CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS
#define CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS   0
#endif

#ifndef CONFIG_SYS_EEPROM_PAGE_WRITE_BITS
#define CONFIG_SYS_EEPROM_PAGE_WRITE_BITS       8
#endif

#ifndef I2C_RXTX_LEN
#define I2C_RXTX_LEN    128
#endif

#define EEPROM_PAGE_SIZE        (1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)
#define EEPROM_PAGE_OFFSET(x)   ((x) & (EEPROM_PAGE_SIZE - 1))

/*
 * for CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 2 (16-bit EEPROM address) offset is
 *   0x000nxxxx for EEPROM address selectors at n, offset xxxx in EEPROM.
 *
 * for CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 1 (8-bit EEPROM page address) offset is
 *   0x00000nxx for EEPROM address selectors and page number at n.
 */
#if !defined(CONFIG_SPI) || defined(CONFIG_ENV_EEPROM_IS_ON_I2C)
#if !defined(CONFIG_SYS_I2C_EEPROM_ADDR_LEN) || \
        (CONFIG_SYS_I2C_EEPROM_ADDR_LEN < 1) || \
        (CONFIG_SYS_I2C_EEPROM_ADDR_LEN > 2)
#error CONFIG_SYS_I2C_EEPROM_ADDR_LEN must be 1 or 2
#endif
#endif

#if CONFIG_IS_ENABLED(DM_I2C)
static int eeprom_i2c_bus;
#endif

__weak int eeprom_write_enable(unsigned dev_addr, int state)
{
        return 0;
}

void eeprom_init(int bus)
{
        /* I2C EEPROM */
#if CONFIG_IS_ENABLED(DM_I2C)
        eeprom_i2c_bus = bus;
#elif defined(CONFIG_SYS_I2C_LEGACY)
        if (bus >= 0)
                i2c_set_bus_num(bus);
        i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
#endif
}

static int eeprom_addr(unsigned dev_addr, unsigned offset, uchar *addr)
{
        unsigned blk_off;
        int alen;

        blk_off = offset & 0xff;        /* block offset */
#if CONFIG_SYS_I2C_EEPROM_ADDR_LEN == 1
        addr[0] = offset >> 8;          /* block number */
        addr[1] = blk_off;              /* block offset */
        alen = 2;
#else
        addr[0] = offset >> 16;         /* block number */
        addr[1] = offset >>  8;         /* upper address octet */
        addr[2] = blk_off;              /* lower address octet */
        alen = 3;
#endif  /* CONFIG_SYS_I2C_EEPROM_ADDR_LEN */

        addr[0] |= dev_addr;            /* insert device address */

        return alen;
}

static int eeprom_len(unsigned offset, unsigned end)
{
        unsigned len = end - offset;

        /*
         * For a FRAM device there is no limit on the number of the
         * bytes that can be accessed with the single read or write
         * operation.
         */
#if !defined(CONFIG_SYS_I2C_FRAM)
        unsigned blk_off = offset & 0xff;
        unsigned maxlen = EEPROM_PAGE_SIZE - EEPROM_PAGE_OFFSET(blk_off);

        if (maxlen > I2C_RXTX_LEN)
                maxlen = I2C_RXTX_LEN;

        if (len > maxlen)
                len = maxlen;
#endif

        return len;
}

static int eeprom_rw_block(unsigned offset, uchar *addr, unsigned alen,
                           uchar *buffer, unsigned len, bool read)
{
        int ret = 0;

#if CONFIG_IS_ENABLED(DM_I2C)
        struct udevice *dev;

        ret = i2c_get_chip_for_busnum(eeprom_i2c_bus, addr[0],
                                      alen - 1, &dev);
        if (ret) {
                printf("%s: Cannot find udev for a bus %d\n", __func__,
                       eeprom_i2c_bus);
                return CMD_RET_FAILURE;
        }

        if (read)
                ret = dm_i2c_read(dev, offset, buffer, len);
        else
                ret = dm_i2c_write(dev, offset, buffer, len);

#else /* Non DM I2C support - will be removed */

        if (read)
                ret = i2c_read(addr[0], offset, alen - 1, buffer, len);
        else
                ret = i2c_write(addr[0], offset, alen - 1, buffer, len);
#endif /* CONFIG_DM_I2C */
        if (ret)
                ret = CMD_RET_FAILURE;

        return ret;
}

static int eeprom_rw(unsigned dev_addr, unsigned offset, uchar *buffer,
                     unsigned cnt, bool read)
{
        unsigned end = offset + cnt;
        unsigned alen, len;
        int rcode = 0;
        uchar addr[3];

#if defined(CONFIG_SYS_I2C_EEPROM_BUS)
        eeprom_init(CONFIG_SYS_I2C_EEPROM_BUS);
#endif

        while (offset < end) {
                alen = eeprom_addr(dev_addr, offset, addr);

                len = eeprom_len(offset, end);

                rcode = eeprom_rw_block(offset, addr, alen, buffer, len, read);

                buffer += len;
                offset += len;

                if (!read)
                        udelay(CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS * 1000);
        }

        return rcode;
}

int eeprom_read(unsigned dev_addr, unsigned offset, uchar *buffer, unsigned cnt)
{
        /*
         * Read data until done or would cross a page boundary.
         * We must write the address again when changing pages
         * because the next page may be in a different device.
         */
        return eeprom_rw(dev_addr, offset, buffer, cnt, 1);
}

int eeprom_write(unsigned dev_addr, unsigned offset,
                 uchar *buffer, unsigned cnt)
{
        int ret;

        eeprom_write_enable(dev_addr, 1);

        /*
         * Write data until done or would cross a write page boundary.
         * We must write the address again when changing pages
         * because the address counter only increments within a page.
         */
        ret = eeprom_rw(dev_addr, offset, buffer, cnt, 0);

        eeprom_write_enable(dev_addr, 0);
        return ret;
}

static int parse_numeric_param(char *str)
{
        char *endptr;
        int value = simple_strtol(str, &endptr, 16);

        return (*endptr != '\0') ? -1 : value;
}

/**
 * parse_i2c_bus_addr - parse the i2c bus and i2c devaddr parameters
 *
 * @i2c_bus:    address to store the i2c bus
 * @i2c_addr:   address to store the device i2c address
 * @argc:       count of command line arguments left to parse
 * @argv:       command line arguments left to parse
 * @argc_no_bus_addr:   argc value we expect to see when bus & addr aren't given
 *
 * @returns:    number of arguments parsed or CMD_RET_USAGE if error
 */
static int parse_i2c_bus_addr(int *i2c_bus, ulong *i2c_addr, int argc,
                              char *const argv[], int argc_no_bus_addr)
{
        int argc_no_bus = argc_no_bus_addr + 1;
        int argc_bus_addr = argc_no_bus_addr + 2;

#ifdef CONFIG_SYS_DEF_EEPROM_ADDR
        if (argc == argc_no_bus_addr) {
                *i2c_bus = -1;
                *i2c_addr = CONFIG_SYS_DEF_EEPROM_ADDR;

                return 0;
        }
#endif
        if (argc == argc_no_bus) {
                *i2c_bus = -1;
                *i2c_addr = parse_numeric_param(argv[0]);

                return 1;
        }

        if (argc == argc_bus_addr) {
                *i2c_bus = parse_numeric_param(argv[0]);
                *i2c_addr = parse_numeric_param(argv[1]);

                return 2;
        }

        return CMD_RET_USAGE;
}

#ifdef CONFIG_CMD_EEPROM_LAYOUT

__weak int eeprom_parse_layout_version(char *str)
{
        return LAYOUT_VERSION_UNRECOGNIZED;
}

static unsigned char eeprom_buf[CONFIG_SYS_EEPROM_SIZE];

#endif

enum eeprom_action {
        EEPROM_READ,
        EEPROM_WRITE,
        EEPROM_PRINT,
        EEPROM_UPDATE,
        EEPROM_ACTION_INVALID,
};

static enum eeprom_action parse_action(char *cmd)
{
        if (!strncmp(cmd, "read", 4))
                return EEPROM_READ;
        if (!strncmp(cmd, "write", 5))
                return EEPROM_WRITE;
#ifdef CONFIG_CMD_EEPROM_LAYOUT
        if (!strncmp(cmd, "print", 5))
                return EEPROM_PRINT;
        if (!strncmp(cmd, "update", 6))
                return EEPROM_UPDATE;
#endif

        return EEPROM_ACTION_INVALID;
}

static int eeprom_execute_command(enum eeprom_action action, int i2c_bus,
                                  ulong i2c_addr, int layout_ver, char *key,
                                  char *value, ulong addr, ulong off, ulong cnt)
{
        int rcode = 0;
        const char *const fmt =
                "\nEEPROM @0x%lX %s: addr 0x%08lx  off 0x%04lx  count %ld ... ";
#ifdef CONFIG_CMD_EEPROM_LAYOUT
        struct eeprom_layout layout;
#endif

        if (action == EEPROM_ACTION_INVALID)
                return CMD_RET_USAGE;

        eeprom_init(i2c_bus);
        if (action == EEPROM_READ) {
                printf(fmt, i2c_addr, "read", addr, off, cnt);

                rcode = eeprom_read(i2c_addr, off, (uchar *)addr, cnt);

                puts("done\n");
                return rcode;
        } else if (action == EEPROM_WRITE) {
                printf(fmt, i2c_addr, "write", addr, off, cnt);

                rcode = eeprom_write(i2c_addr, off, (uchar *)addr, cnt);

                puts("done\n");
                return rcode;
        }

#ifdef CONFIG_CMD_EEPROM_LAYOUT
        rcode = eeprom_read(i2c_addr, 0, eeprom_buf, CONFIG_SYS_EEPROM_SIZE);
        if (rcode < 0)
                return rcode;

        eeprom_layout_setup(&layout, eeprom_buf, CONFIG_SYS_EEPROM_SIZE,
                            layout_ver);

        if (action == EEPROM_PRINT) {
                layout.print(&layout);
                return 0;
        }

        layout.update(&layout, key, value);

        rcode = eeprom_write(i2c_addr, 0, layout.data, CONFIG_SYS_EEPROM_SIZE);
#endif

        return rcode;
}

#define NEXT_PARAM(argc, index) { (argc)--; (index)++; }
int do_eeprom(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
        int layout_ver = LAYOUT_VERSION_AUTODETECT;
        enum eeprom_action action = EEPROM_ACTION_INVALID;
        int i2c_bus = -1, index = 0;
        ulong i2c_addr = -1, addr = 0, cnt = 0, off = 0;
        int ret;
        char *field_name = "";
        char *field_value = "";

        if (argc <= 1)
                return CMD_RET_USAGE;

        NEXT_PARAM(argc, index); /* Skip program name */

        action = parse_action(argv[index]);
        NEXT_PARAM(argc, index);

        if (action == EEPROM_ACTION_INVALID)
                return CMD_RET_USAGE;

#ifdef CONFIG_CMD_EEPROM_LAYOUT
        if (action == EEPROM_PRINT || action == EEPROM_UPDATE) {
                if (!strcmp(argv[index], "-l")) {
                        NEXT_PARAM(argc, index);
                        layout_ver = eeprom_parse_layout_version(argv[index]);
                        NEXT_PARAM(argc, index);
                }
        }
#endif

        switch (action) {
        case EEPROM_READ:
        case EEPROM_WRITE:
                ret = parse_i2c_bus_addr(&i2c_bus, &i2c_addr, argc,
                                         argv + index, 3);
                break;
        case EEPROM_PRINT:
                ret = parse_i2c_bus_addr(&i2c_bus, &i2c_addr, argc,
                                         argv + index, 0);
                break;
        case EEPROM_UPDATE:
                ret = parse_i2c_bus_addr(&i2c_bus, &i2c_addr, argc,
                                         argv + index, 2);
                break;
        default:
                /* Get compiler to stop whining */
                return CMD_RET_USAGE;
        }

        if (ret == CMD_RET_USAGE)
                return ret;

        while (ret--)
                NEXT_PARAM(argc, index);

        if (action == EEPROM_READ || action == EEPROM_WRITE) {
                addr = parse_numeric_param(argv[index]);
                NEXT_PARAM(argc, index);
                off = parse_numeric_param(argv[index]);
                NEXT_PARAM(argc, index);
                cnt = parse_numeric_param(argv[index]);
        }

#ifdef CONFIG_CMD_EEPROM_LAYOUT
        if (action == EEPROM_UPDATE) {
                field_name = argv[index];
                NEXT_PARAM(argc, index);
                field_value = argv[index];
                NEXT_PARAM(argc, index);
        }
#endif

        return eeprom_execute_command(action, i2c_bus, i2c_addr, layout_ver,
                                      field_name, field_value, addr, off, cnt);
}

U_BOOT_CMD(
        eeprom, 8,      1,      do_eeprom,
        "EEPROM sub-system",
        "read  <bus> <devaddr> addr off cnt\n"
        "eeprom write <bus> <devaddr> addr off cnt\n"
        "       - read/write `cnt' bytes from `devaddr` EEPROM at offset `off'"
#ifdef CONFIG_CMD_EEPROM_LAYOUT
        "\n"
        "eeprom print [-l <layout_version>] <bus> <devaddr>\n"
        "       - Print layout fields and their data in human readable format\n"
        "eeprom update [-l <layout_version>] <bus> <devaddr> field_name field_value\n"
        "       - Update a specific eeprom field with new data.\n"
        "         The new data must be written in the same human readable format as shown by the print command.\n"
        "\n"
        "LAYOUT VERSIONS\n"
        "The -l option can be used to force the command to interpret the EEPROM data using the chosen layout.\n"
        "If the -l option is omitted, the command will auto detect the layout based on the data in the EEPROM.\n"
        "The values which can be provided with the -l option are:\n"
        CONFIG_EEPROM_LAYOUT_HELP_STRING"\n"
#endif
)