/*
 * Command for accessing SPI flash.
 *
 * Copyright (C) 2008 Atmel Corporation
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <div64.h>
#include <dm.h>
#include <malloc.h>
#include <spi.h>
#include <spi_flash.h>

#include <asm/io.h>
#include <dm/device-internal.h>

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;
}

/**
 * This function takes a byte length and a delta unit of time to compute the
 * approximate bytes per second
 *
 * @param len           amount of bytes currently processed
 * @param start_ms      start time of processing in ms
 * @return bytes per second if OK, 0 on error
 */
static ulong bytes_per_second(unsigned int len, ulong start_ms)
{
        /* less accurate but avoids overflow */
        if (len >= ((unsigned int) -1) / 1024)
                return len / (max(get_timer(start_ms) / 1024, 1UL));
        else
                return 1024 * len / max(get_timer(start_ms), 1UL);
}

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;
#ifdef CONFIG_DM_SPI_FLASH
        struct udevice *new, *bus_dev;
        int ret;
#else
        struct spi_flash *new;
#endif

        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;
        }

#ifdef CONFIG_DM_SPI_FLASH
        /* Remove the old device, otherwise probe will just be a nop */
        ret = spi_find_bus_and_cs(bus, cs, &bus_dev, &new);
        if (!ret) {
                device_remove(new);
                device_unbind(new);
        }
        flash = NULL;
        ret = spi_flash_probe_bus_cs(bus, cs, speed, mode, &new);
        if (ret) {
                printf("Failed to initialize SPI flash at %u:%u (error %d)\n",
                       bus, cs, ret);
                return 1;
        }

        flash = new->uclass_priv;
#else
        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;
#endif

        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);
        /* Read the entire sector so to allow for rewriting */
        if (spi_flash_read(flash, offset, flash->sector_size, cmp_buf))
                return "read";
        /* Compare only what is meaningful (len) */
        if (memcmp(cmp_buf, buf, len) == 0) {
                debug("Skip region %x size %zx: no change\n",
                      offset, len);
                *skipped += len;
                return NULL;
        }
        /* Erase the entire sector */
        if (spi_flash_erase(flash, offset, flash->sector_size))
                return "erase";
        /* Write the initial part of the block from the source */
        if (spi_flash_write(flash, offset, len, buf))
                return "write";
        /* If it's a partial sector, rewrite the existing part */
        if (len != flash->sector_size) {
                /* Rewrite the original data to the end of the sector */
                if (spi_flash_write(flash, offset + len,
                                    flash->sector_size - len, &cmp_buf[len]))
                        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 */
        const ulong start_time = get_timer(0);
        size_t scale = 1;
        const char *start_buf = buf;
        ulong delta;

        if (end - buf >= 200)
                scale = (end - buf) / 100;
        cmp_buf = malloc(flash->sector_size);
        if (cmp_buf) {
                ulong last_update = get_timer(0);

                for (; buf < end && !err_oper; buf += todo, offset += todo) {
                        todo = min_t(size_t, end - buf, flash->sector_size);
                        if (get_timer(last_update) > 100) {
                                printf("   \rUpdating, %zu%% %lu B/s",
                                       100 - (end - buf) / scale,
                                        bytes_per_second(buf - start_buf,
                                                         start_time));
                                last_update = get_timer(0);
                        }
                        err_oper = spi_flash_update_block(flash, offset, todo,
                                        buf, cmp_buf, &skipped);
                }
        } else {
                err_oper = "malloc";
        }
        free(cmp_buf);
        putc('\r');
        if (err_oper) {
                printf("SPI flash failed in %s step\n", err_oper);
                return 1;
        }

        delta = get_timer(start_time);
        printf("%zu bytes written, %zu bytes skipped", len - skipped,
               skipped);
        printf(" in %ld.%lds, speed %ld B/s\n",
               delta / 1000, delta % 1000, bytes_per_second(len, start_time));

        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 = 1;

        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;

        /* Consistency checking */
        if (offset + len > flash->size) {
                printf("ERROR: attempting %s past flash size (%#x)\n",
                       argv[0], flash->size);
                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 (strncmp(argv[0], "read", 4) == 0 ||
                        strncmp(argv[0], "write", 5) == 0) {
                int read;

                read = strncmp(argv[0], "read", 4) == 0;
                if (read)
                        ret = spi_flash_read(flash, offset, len, buf);
                else
                        ret = spi_flash_write(flash, offset, len, buf);

                printf("SF: %zu bytes @ %#x %s: %s\n", (size_t)len, (u32)offset,
                       read ? "Read" : "Written", ret ? "ERROR" : "OK");
        }

        unmap_physmem(buf, len);

        return ret == 0 ? 0 : 1;
}

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;

        /* Consistency checking */
        if (offset + len > flash->size) {
                printf("ERROR: attempting %s past flash size (%#x)\n",
                       argv[0], flash->size);
                return 1;
        }

        ret = spi_flash_erase(flash, offset, len);
        printf("SF: %zu bytes @ %#x Erased: %s\n", (size_t)len, (u32)offset,
               ret ? "ERROR" : "OK");

        return ret == 0 ? 0 : 1;
}

#ifdef CONFIG_CMD_SF_TEST
enum {
        STAGE_ERASE,
        STAGE_CHECK,
        STAGE_WRITE,
        STAGE_READ,

        STAGE_COUNT,
};

static char *stage_name[STAGE_COUNT] = {
        "erase",
        "check",
        "write",
        "read",
};

struct test_info {
        int stage;
        int bytes;
        unsigned base_ms;
        unsigned time_ms[STAGE_COUNT];
};

static void show_time(struct test_info *test, int stage)
{
        uint64_t speed; /* KiB/s */
        int bps;        /* Bits per second */

        speed = (long long)test->bytes * 1000;
        if (test->time_ms[stage])
                do_div(speed, test->time_ms[stage] * 1024);
        bps = speed * 8;

        printf("%d %s: %d ticks, %d KiB/s %d.%03d Mbps\n", stage,
               stage_name[stage], test->time_ms[stage],
               (int)speed, bps / 1000, bps % 1000);
}

static void spi_test_next_stage(struct test_info *test)
{
        test->time_ms[test->stage] = get_timer(test->base_ms);
        show_time(test, test->stage);
        test->base_ms = get_timer(0);
        test->stage++;
}

/**
 * Run a test on the SPI flash
 *
 * @param flash         SPI flash to use
 * @param buf           Source buffer for data to write
 * @param len           Size of data to read/write
 * @param offset        Offset within flash to check
 * @param vbuf          Verification buffer
 * @return 0 if ok, -1 on error
 */
static int spi_flash_test(struct spi_flash *flash, uint8_t *buf, ulong len,
                           ulong offset, uint8_t *vbuf)
{
        struct test_info test;
        int i;

        printf("SPI flash test:\n");
        memset(&test, '\0', sizeof(test));
        test.base_ms = get_timer(0);
        test.bytes = len;
        if (spi_flash_erase(flash, offset, len)) {
                printf("Erase failed\n");
                return -1;
        }
        spi_test_next_stage(&test);

        if (spi_flash_read(flash, offset, len, vbuf)) {
                printf("Check read failed\n");
                return -1;
        }
        for (i = 0; i < len; i++) {
                if (vbuf[i] != 0xff) {
                        printf("Check failed at %d\n", i);
                        print_buffer(i, vbuf + i, 1,
                                     min_t(uint, len - i, 0x40), 0);
                        return -1;
                }
        }
        spi_test_next_stage(&test);

        if (spi_flash_write(flash, offset, len, buf)) {
                printf("Write failed\n");
                return -1;
        }
        memset(vbuf, '\0', len);
        spi_test_next_stage(&test);

        if (spi_flash_read(flash, offset, len, vbuf)) {
                printf("Read failed\n");
                return -1;
        }
        spi_test_next_stage(&test);

        for (i = 0; i < len; i++) {
                if (buf[i] != vbuf[i]) {
                        printf("Verify failed at %d, good data:\n", i);
                        print_buffer(i, buf + i, 1,
                                     min_t(uint, len - i, 0x40), 0);
                        printf("Bad data:\n");
                        print_buffer(i, vbuf + i, 1,
                                     min_t(uint, len - i, 0x40), 0);
                        return -1;
                }
        }
        printf("Test passed\n");
        for (i = 0; i < STAGE_COUNT; i++)
                show_time(&test, i);

        return 0;
}

static int do_spi_flash_test(int argc, char * const argv[])
{
        unsigned long offset;
        unsigned long len;
        uint8_t *buf, *from;
        char *endp;
        uint8_t *vbuf;
        int ret;

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

        vbuf = malloc(len);
        if (!vbuf) {
                printf("Cannot allocate memory (%lu bytes)\n", len);
                return 1;
        }
        buf = malloc(len);
        if (!buf) {
                free(vbuf);
                printf("Cannot allocate memory (%lu bytes)\n", len);
                return 1;
        }

        from = map_sysmem(CONFIG_SYS_TEXT_BASE, 0);
        memcpy(buf, from, len);
        ret = spi_flash_test(flash, buf, len, offset, vbuf);
        free(vbuf);
        free(buf);
        if (ret) {
                printf("Test failed\n");
                return 1;
        }

        return 0;
}
#endif /* CONFIG_CMD_SF_TEST */

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);
#ifdef CONFIG_CMD_SF_TEST
        else if (!strcmp(cmd, "test"))
                ret = do_spi_flash_test(argc, argv);
#endif
        else
                ret = -1;

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

usage:
        return CMD_RET_USAGE;
}

#ifdef CONFIG_CMD_SF_TEST
#define SF_TEST_HELP "\nsf test offset len              " \
                "- run a very basic destructive test"
#else
#define SF_TEST_HELP
#endif

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'"
        SF_TEST_HELP
);