/*
 * Command for accessing SPI flash.
 *
 * Copyright (C) 2008 Atmel Corporation
 * Licensed under the GPL-2 or later.
 */

#include <common.h>
#include <malloc.h>
#include <spi_flash.h>

#include <asm/io.h>

#ifndef CONFIG_SF_DEFAULT_SPEED
# define CONFIG_SF_DEFAULT_SPEED        1000000
#endif
#ifndef CONFIG_SF_DEFAULT_MODE
# define CONFIG_SF_DEFAULT_MODE         SPI_MODE_3
#endif
#ifndef CONFIG_SF_DEFAULT_CS
# define CONFIG_SF_DEFAULT_CS           0
#endif
#ifndef CONFIG_SF_DEFAULT_BUS
# define CONFIG_SF_DEFAULT_BUS          0
#endif

static struct spi_flash *flash;


/*
 * This function computes the length argument for the erase command.
 * The length on which the command is to operate can be given in two forms:
 * 1. <cmd> offset len  - operate on <'offset',  'len')
 * 2. <cmd> offset +len - operate on <'offset',  'round_up(len)')
 * If the second form is used and the length doesn't fall on the
 * sector boundary, than it will be adjusted to the next sector boundary.
 * If it isn't in the flash, the function will fail (return -1).
 * Input:
 *    arg: length specification (i.e. both command arguments)
 * Output:
 *    len: computed length for operation
 * Return:
 *    1: success
 *   -1: failure (bad format, bad address).
 */
static int sf_parse_len_arg(char *arg, ulong *len)
{
        char *ep;
        char round_up_len; /* indicates if the "+length" form used */
        ulong len_arg;

        round_up_len = 0;
        if (*arg == '+') {
                round_up_len = 1;
                ++arg;
        }

        len_arg = simple_strtoul(arg, &ep, 16);
        if (ep == arg || *ep != '\0')
                return -1;

        if (round_up_len && flash->sector_size > 0)
                *len = ROUND(len_arg, flash->sector_size);
        else
                *len = len_arg;

        return 1;
}

static int do_spi_flash_probe(int argc, char * const argv[])
{
        unsigned int bus = CONFIG_SF_DEFAULT_BUS;
        unsigned int cs = CONFIG_SF_DEFAULT_CS;
        unsigned int speed = CONFIG_SF_DEFAULT_SPEED;
        unsigned int mode = CONFIG_SF_DEFAULT_MODE;
        char *endp;
        struct spi_flash *new;

        if (argc >= 2) {
                cs = simple_strtoul(argv[1], &endp, 0);
                if (*argv[1] == 0 || (*endp != 0 && *endp != ':'))
                        return -1;
                if (*endp == ':') {
                        if (endp[1] == 0)
                                return -1;

                        bus = cs;
                        cs = simple_strtoul(endp + 1, &endp, 0);
                        if (*endp != 0)
                                return -1;
                }
        }

        if (argc >= 3) {
                speed = simple_strtoul(argv[2], &endp, 0);
                if (*argv[2] == 0 || *endp != 0)
                        return -1;
        }
        if (argc >= 4) {
                mode = simple_strtoul(argv[3], &endp, 16);
                if (*argv[3] == 0 || *endp != 0)
                        return -1;
        }

        new = spi_flash_probe(bus, cs, speed, mode);
        if (!new) {
                printf("Failed to initialize SPI flash at %u:%u\n", bus, cs);
                return 1;
        }

        if (flash)
                spi_flash_free(flash);
        flash = new;

        return 0;
}

/**
 * Write a block of data to SPI flash, first checking if it is different from
 * what is already there.
 *
 * If the data being written is the same, then *skipped is incremented by len.
 *
 * @param flash         flash context pointer
 * @param offset        flash offset to write
 * @param len           number of bytes to write
 * @param buf           buffer to write from
 * @param cmp_buf       read buffer to use to compare data
 * @param skipped       Count of skipped data (incremented by this function)
 * @return NULL if OK, else a string containing the stage which failed
 */
static const char *spi_flash_update_block(struct spi_flash *flash, u32 offset,
                size_t len, const char *buf, char *cmp_buf, size_t *skipped)
{
        debug("offset=%#x, sector_size=%#x, len=%#zx\n",
                offset, flash->sector_size, len);
        if (spi_flash_read(flash, offset, len, cmp_buf))
                return "read";
        if (memcmp(cmp_buf, buf, len) == 0) {
                debug("Skip region %x size %zx: no change\n",
                        offset, len);
                *skipped += len;
                return NULL;
        }
        if (spi_flash_erase(flash, offset, len))
                return "erase";
        if (spi_flash_write(flash, offset, len, buf))
                return "write";
        return NULL;
}

/**
 * Update an area of SPI flash by erasing and writing any blocks which need
 * to change. Existing blocks with the correct data are left unchanged.
 *
 * @param flash         flash context pointer
 * @param offset        flash offset to write
 * @param len           number of bytes to write
 * @param buf           buffer to write from
 * @return 0 if ok, 1 on error
 */
static int spi_flash_update(struct spi_flash *flash, u32 offset,
                size_t len, const char *buf)
{
        const char *err_oper = NULL;
        char *cmp_buf;
        const char *end = buf + len;
        size_t todo;            /* number of bytes to do in this pass */
        size_t skipped = 0;     /* statistics */

        cmp_buf = malloc(flash->sector_size);
        if (cmp_buf) {
                for (; buf < end && !err_oper; buf += todo, offset += todo) {
                        todo = min(end - buf, flash->sector_size);
                        err_oper = spi_flash_update_block(flash, offset, todo,
                                        buf, cmp_buf, &skipped);
                }
        } else {
                err_oper = "malloc";
        }
        free(cmp_buf);
        if (err_oper) {
                printf("SPI flash failed in %s step\n", err_oper);
                return 1;
        }
        printf("%zu bytes written, %zu bytes skipped\n", len - skipped,
               skipped);

        return 0;
}

static int do_spi_flash_read_write(int argc, char * const argv[])
{
        unsigned long addr;
        unsigned long offset;
        unsigned long len;
        void *buf;
        char *endp;
        int ret;

        if (argc < 4)
                return -1;

        addr = simple_strtoul(argv[1], &endp, 16);
        if (*argv[1] == 0 || *endp != 0)
                return -1;
        offset = simple_strtoul(argv[2], &endp, 16);
        if (*argv[2] == 0 || *endp != 0)
                return -1;
        len = simple_strtoul(argv[3], &endp, 16);
        if (*argv[3] == 0 || *endp != 0)
                return -1;

        buf = map_physmem(addr, len, MAP_WRBACK);
        if (!buf) {
                puts("Failed to map physical memory\n");
                return 1;
        }

        if (strcmp(argv[0], "update") == 0)
                ret = spi_flash_update(flash, offset, len, buf);
        else if (strcmp(argv[0], "read") == 0)
                ret = spi_flash_read(flash, offset, len, buf);
        else
                ret = spi_flash_write(flash, offset, len, buf);

        unmap_physmem(buf, len);

        if (ret) {
                printf("SPI flash %s failed\n", argv[0]);
                return 1;
        }

        return 0;
}

static int do_spi_flash_erase(int argc, char * const argv[])
{
        unsigned long offset;
        unsigned long len;
        char *endp;
        int ret;

        if (argc < 3)
                return -1;

        offset = simple_strtoul(argv[1], &endp, 16);
        if (*argv[1] == 0 || *endp != 0)
                return -1;

        ret = sf_parse_len_arg(argv[2], &len);
        if (ret != 1)
                return -1;

        ret = spi_flash_erase(flash, offset, len);
        if (ret) {
                printf("SPI flash %s failed\n", argv[0]);
                return 1;
        }

        return 0;
}

static int do_spi_flash(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
        const char *cmd;
        int ret;

        /* need at least two arguments */
        if (argc < 2)
                goto usage;

        cmd = argv[1];
        --argc;
        ++argv;

        if (strcmp(cmd, "probe") == 0) {
                ret = do_spi_flash_probe(argc, argv);
                goto done;
        }

        /* The remaining commands require a selected device */
        if (!flash) {
                puts("No SPI flash selected. Please run `sf probe'\n");
                return 1;
        }

        if (strcmp(cmd, "read") == 0 || strcmp(cmd, "write") == 0 ||
            strcmp(cmd, "update") == 0)
                ret = do_spi_flash_read_write(argc, argv);
        else if (strcmp(cmd, "erase") == 0)
                ret = do_spi_flash_erase(argc, argv);
        else
                ret = -1;

done:
        if (ret != -1)
                return ret;

usage:
        return CMD_RET_USAGE;
}

U_BOOT_CMD(
        sf,     5,      1,      do_spi_flash,
        "SPI flash sub-system",
        "probe [[bus:]cs] [hz] [mode]   - init flash device on given SPI bus\n"
        "                                 and chip select\n"
        "sf read addr offset len        - read `len' bytes starting at\n"
        "                                 `offset' to memory at `addr'\n"
        "sf write addr offset len       - write `len' bytes from memory\n"
        "                                 at `addr' to flash at `offset'\n"
        "sf erase offset [+]len         - erase `len' bytes from `offset'\n"
        "                                 `+len' round up `len' to block size\n"
        "sf update addr offset len      - erase and write `len' bytes from memory\n"
        "                                 at `addr' to flash at `offset'"
);