/*
 * dfu.c -- DFU back-end routines
 *
 * Copyright (C) 2012 Samsung Electronics
 * author: Lukasz Majewski <l.majewski@samsung.com>
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include <common.h>
#include <errno.h>
#include <malloc.h>
#include <mmc.h>
#include <fat.h>
#include <dfu.h>
#include <hash.h>
#include <linux/list.h>
#include <linux/compiler.h>

static LIST_HEAD(dfu_list);
static int dfu_alt_num;
static int alt_num_cnt;
static struct hash_algo *dfu_hash_algo;

/*
 * The purpose of the dfu_usb_get_reset() function is to
 * provide information if after USB_DETACH request
 * being sent the dfu-util performed reset of USB
 * bus.
 *
 * Described behaviour is the only way to distinct if
 * user has typed -e (detach) or -R (reset) when invoking
 * dfu-util command.
 *
 */
__weak bool dfu_usb_get_reset(void)
{
        return true;
}

static int dfu_find_alt_num(const char *s)
{
        int i = 0;

        for (; *s; s++)
                if (*s == ';')
                        i++;

        return ++i;
}

int dfu_init_env_entities(char *interface, char *devstr)
{
        const char *str_env;
        char *env_bkp;
        int ret;

#ifdef CONFIG_SET_DFU_ALT_INFO
        set_dfu_alt_info(interface, devstr);
#endif
        str_env = getenv("dfu_alt_info");
        if (!str_env) {
                error("\"dfu_alt_info\" env variable not defined!\n");
                return -EINVAL;
        }

        env_bkp = strdup(str_env);
        ret = dfu_config_entities(env_bkp, interface, devstr);
        if (ret) {
                error("DFU entities configuration failed!\n");
                return ret;
        }

        free(env_bkp);
        return 0;
}

static unsigned char *dfu_buf;
static unsigned long dfu_buf_size;

unsigned char *dfu_free_buf(void)
{
        free(dfu_buf);
        dfu_buf = NULL;
        return dfu_buf;
}

unsigned long dfu_get_buf_size(void)
{
        return dfu_buf_size;
}

unsigned char *dfu_get_buf(struct dfu_entity *dfu)
{
        char *s;

        if (dfu_buf != NULL)
                return dfu_buf;

        s = getenv("dfu_bufsiz");
        if (s)
                dfu_buf_size = (unsigned long)simple_strtol(s, NULL, 0);

        if (!s || !dfu_buf_size)
                dfu_buf_size = CONFIG_SYS_DFU_DATA_BUF_SIZE;

        if (dfu->max_buf_size && dfu_buf_size > dfu->max_buf_size)
                dfu_buf_size = dfu->max_buf_size;

        dfu_buf = memalign(CONFIG_SYS_CACHELINE_SIZE, dfu_buf_size);
        if (dfu_buf == NULL)
                printf("%s: Could not memalign 0x%lx bytes\n",
                       __func__, dfu_buf_size);

        return dfu_buf;
}

static char *dfu_get_hash_algo(void)
{
        char *s;

        s = getenv("dfu_hash_algo");
        if (!s)
                return NULL;

        if (!strcmp(s, "crc32")) {
                debug("%s: DFU hash method: %s\n", __func__, s);
                return s;
        }

        error("DFU hash method: %s not supported!\n", s);
        return NULL;
}

static int dfu_write_buffer_drain(struct dfu_entity *dfu)
{
        long w_size;
        int ret;

        /* flush size? */
        w_size = dfu->i_buf - dfu->i_buf_start;
        if (w_size == 0)
                return 0;

        if (dfu_hash_algo)
                dfu_hash_algo->hash_update(dfu_hash_algo, &dfu->crc,
                                           dfu->i_buf_start, w_size, 0);

        ret = dfu->write_medium(dfu, dfu->offset, dfu->i_buf_start, &w_size);
        if (ret)
                debug("%s: Write error!\n", __func__);

        /* point back */
        dfu->i_buf = dfu->i_buf_start;

        /* update offset */
        dfu->offset += w_size;

        puts("#");

        return ret;
}

void dfu_write_transaction_cleanup(struct dfu_entity *dfu)
{
        /* clear everything */
        dfu->crc = 0;
        dfu->offset = 0;
        dfu->i_blk_seq_num = 0;
        dfu->i_buf_start = dfu_buf;
        dfu->i_buf_end = dfu_buf;
        dfu->i_buf = dfu->i_buf_start;
        dfu->inited = 0;
}

int dfu_flush(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
{
        int ret = 0;

        ret = dfu_write_buffer_drain(dfu);
        if (ret)
                return ret;

        if (dfu->flush_medium)
                ret = dfu->flush_medium(dfu);

        if (dfu_hash_algo)
                printf("\nDFU complete %s: 0x%08x\n", dfu_hash_algo->name,
                       dfu->crc);

        dfu_write_transaction_cleanup(dfu);

        return ret;
}

int dfu_write(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
{
        int ret;

        debug("%s: name: %s buf: 0x%p size: 0x%x p_num: 0x%x offset: 0x%llx bufoffset: 0x%lx\n",
              __func__, dfu->name, buf, size, blk_seq_num, dfu->offset,
              (unsigned long)(dfu->i_buf - dfu->i_buf_start));

        if (!dfu->inited) {
                /* initial state */
                dfu->crc = 0;
                dfu->offset = 0;
                dfu->bad_skip = 0;
                dfu->i_blk_seq_num = 0;
                dfu->i_buf_start = dfu_get_buf(dfu);
                if (dfu->i_buf_start == NULL)
                        return -ENOMEM;
                dfu->i_buf_end = dfu_get_buf(dfu) + dfu_buf_size;
                dfu->i_buf = dfu->i_buf_start;

                dfu->inited = 1;
        }

        if (dfu->i_blk_seq_num != blk_seq_num) {
                printf("%s: Wrong sequence number! [%d] [%d]\n",
                       __func__, dfu->i_blk_seq_num, blk_seq_num);
                dfu_write_transaction_cleanup(dfu);
                return -1;
        }

        /* DFU 1.1 standard says:
         * The wBlockNum field is a block sequence number. It increments each
         * time a block is transferred, wrapping to zero from 65,535. It is used
         * to provide useful context to the DFU loader in the device."
         *
         * This means that it's a 16 bit counter that roll-overs at
         * 0xffff -> 0x0000. By having a typical 4K transfer block
         * we roll-over at exactly 256MB. Not very fun to debug.
         *
         * Handling rollover, and having an inited variable,
         * makes things work.
         */

        /* handle rollover */
        dfu->i_blk_seq_num = (dfu->i_blk_seq_num + 1) & 0xffff;

        /* flush buffer if overflow */
        if ((dfu->i_buf + size) > dfu->i_buf_end) {
                ret = dfu_write_buffer_drain(dfu);
                if (ret) {
                        dfu_write_transaction_cleanup(dfu);
                        return ret;
                }
        }

        /* we should be in buffer now (if not then size too large) */
        if ((dfu->i_buf + size) > dfu->i_buf_end) {
                error("Buffer overflow! (0x%p + 0x%x > 0x%p)\n", dfu->i_buf,
                      size, dfu->i_buf_end);
                dfu_write_transaction_cleanup(dfu);
                return -1;
        }

        memcpy(dfu->i_buf, buf, size);
        dfu->i_buf += size;

        /* if end or if buffer full flush */
        if (size == 0 || (dfu->i_buf + size) > dfu->i_buf_end) {
                ret = dfu_write_buffer_drain(dfu);
                if (ret) {
                        dfu_write_transaction_cleanup(dfu);
                        return ret;
                }
        }

        return 0;
}

static int dfu_read_buffer_fill(struct dfu_entity *dfu, void *buf, int size)
{
        long chunk;
        int ret, readn;

        readn = 0;
        while (size > 0) {
                /* get chunk that can be read */
                chunk = min((long)size, dfu->b_left);
                /* consume */
                if (chunk > 0) {
                        memcpy(buf, dfu->i_buf, chunk);
                        if (dfu_hash_algo)
                                dfu_hash_algo->hash_update(dfu_hash_algo,
                                                           &dfu->crc, buf,
                                                           chunk, 0);

                        dfu->i_buf += chunk;
                        dfu->b_left -= chunk;
                        size -= chunk;
                        buf += chunk;
                        readn += chunk;
                }

                /* all done */
                if (size > 0) {
                        /* no more to read */
                        if (dfu->r_left == 0)
                                break;

                        dfu->i_buf = dfu->i_buf_start;
                        dfu->b_left = dfu->i_buf_end - dfu->i_buf_start;

                        /* got to read, but buffer is empty */
                        if (dfu->b_left > dfu->r_left)
                                dfu->b_left = dfu->r_left;
                        ret = dfu->read_medium(dfu, dfu->offset, dfu->i_buf,
                                        &dfu->b_left);
                        if (ret != 0) {
                                debug("%s: Read error!\n", __func__);
                                return ret;
                        }
                        dfu->offset += dfu->b_left;
                        dfu->r_left -= dfu->b_left;

                        puts("#");
                }
        }

        return readn;
}

int dfu_read(struct dfu_entity *dfu, void *buf, int size, int blk_seq_num)
{
        int ret = 0;

        debug("%s: name: %s buf: 0x%p size: 0x%x p_num: 0x%x i_buf: 0x%p\n",
               __func__, dfu->name, buf, size, blk_seq_num, dfu->i_buf);

        if (!dfu->inited) {
                dfu->i_buf_start = dfu_get_buf(dfu);
                if (dfu->i_buf_start == NULL)
                        return -ENOMEM;

                dfu->r_left = dfu->get_medium_size(dfu);
                if (dfu->r_left < 0)
                        return dfu->r_left;

                debug("%s: %s %ld [B]\n", __func__, dfu->name, dfu->r_left);

                dfu->i_blk_seq_num = 0;
                dfu->crc = 0;
                dfu->offset = 0;
                dfu->i_buf_end = dfu_get_buf(dfu) + dfu_buf_size;
                dfu->i_buf = dfu->i_buf_start;
                dfu->b_left = 0;

                dfu->bad_skip = 0;

                dfu->inited = 1;
        }

        if (dfu->i_blk_seq_num != blk_seq_num) {
                printf("%s: Wrong sequence number! [%d] [%d]\n",
                       __func__, dfu->i_blk_seq_num, blk_seq_num);
                return -1;
        }
        /* handle rollover */
        dfu->i_blk_seq_num = (dfu->i_blk_seq_num + 1) & 0xffff;

        ret = dfu_read_buffer_fill(dfu, buf, size);
        if (ret < 0) {
                printf("%s: Failed to fill buffer\n", __func__);
                return -1;
        }

        if (ret < size) {
                if (dfu_hash_algo)
                        debug("%s: %s %s: 0x%x\n", __func__, dfu->name,
                              dfu_hash_algo->name, dfu->crc);
                puts("\nUPLOAD ... done\nCtrl+C to exit ...\n");

                dfu->i_blk_seq_num = 0;
                dfu->crc = 0;
                dfu->offset = 0;
                dfu->i_buf_start = dfu_buf;
                dfu->i_buf_end = dfu_buf;
                dfu->i_buf = dfu->i_buf_start;
                dfu->b_left = 0;

                dfu->bad_skip = 0;

                dfu->inited = 0;
        }

        return ret;
}

static int dfu_fill_entity(struct dfu_entity *dfu, char *s, int alt,
                           char *interface, char *devstr)
{
        char *st;

        debug("%s: %s interface: %s dev: %s\n", __func__, s, interface, devstr);
        st = strsep(&s, " ");
        strcpy(dfu->name, st);

        dfu->alt = alt;
        dfu->max_buf_size = 0;
        dfu->free_entity = NULL;

        /* Specific for mmc device */
        if (strcmp(interface, "mmc") == 0) {
                if (dfu_fill_entity_mmc(dfu, devstr, s))
                        return -1;
        } else if (strcmp(interface, "nand") == 0) {
                if (dfu_fill_entity_nand(dfu, devstr, s))
                        return -1;
        } else if (strcmp(interface, "ram") == 0) {
                if (dfu_fill_entity_ram(dfu, devstr, s))
                        return -1;
        } else if (strcmp(interface, "sf") == 0) {
                if (dfu_fill_entity_sf(dfu, devstr, s))
                        return -1;
        } else {
                printf("%s: Device %s not (yet) supported!\n",
                       __func__,  interface);
                return -1;
        }
        dfu_get_buf(dfu);

        return 0;
}

void dfu_free_entities(void)
{
        struct dfu_entity *dfu, *p, *t = NULL;

        dfu_free_buf();
        list_for_each_entry_safe_reverse(dfu, p, &dfu_list, list) {
                list_del(&dfu->list);
                if (dfu->free_entity)
                        dfu->free_entity(dfu);
                t = dfu;
        }
        if (t)
                free(t);
        INIT_LIST_HEAD(&dfu_list);

        alt_num_cnt = 0;
}

int dfu_config_entities(char *env, char *interface, char *devstr)
{
        struct dfu_entity *dfu;
        int i, ret;
        char *s;

        dfu_alt_num = dfu_find_alt_num(env);
        debug("%s: dfu_alt_num=%d\n", __func__, dfu_alt_num);

        dfu_hash_algo = NULL;
        s = dfu_get_hash_algo();
        if (s) {
                ret = hash_lookup_algo(s, &dfu_hash_algo);
                if (ret)
                        error("Hash algorithm %s not supported\n", s);
        }

        dfu = calloc(sizeof(*dfu), dfu_alt_num);
        if (!dfu)
                return -1;
        for (i = 0; i < dfu_alt_num; i++) {

                s = strsep(&env, ";");
                ret = dfu_fill_entity(&dfu[i], s, alt_num_cnt, interface,
                                      devstr);
                if (ret) {
                        free(dfu);
                        return -1;
                }

                list_add_tail(&dfu[i].list, &dfu_list);
                alt_num_cnt++;
        }

        return 0;
}

const char *dfu_get_dev_type(enum dfu_device_type t)
{
        const char *dev_t[] = {NULL, "eMMC", "OneNAND", "NAND", "RAM" };
        return dev_t[t];
}

const char *dfu_get_layout(enum dfu_layout l)
{
        const char *dfu_layout[] = {NULL, "RAW_ADDR", "FAT", "EXT2",
                                           "EXT3", "EXT4", "RAM_ADDR" };
        return dfu_layout[l];
}

void dfu_show_entities(void)
{
        struct dfu_entity *dfu;

        puts("DFU alt settings list:\n");

        list_for_each_entry(dfu, &dfu_list, list) {
                printf("dev: %s alt: %d name: %s layout: %s\n",
                       dfu_get_dev_type(dfu->dev_type), dfu->alt,
                       dfu->name, dfu_get_layout(dfu->layout));
        }
}

int dfu_get_alt_number(void)
{
        return dfu_alt_num;
}

struct dfu_entity *dfu_get_entity(int alt)
{
        struct dfu_entity *dfu;

        list_for_each_entry(dfu, &dfu_list, list) {
                if (dfu->alt == alt)
                        return dfu;
        }

        return NULL;
}

int dfu_get_alt(char *name)
{
        struct dfu_entity *dfu;
        char *str;

        list_for_each_entry(dfu, &dfu_list, list) {
                if (dfu->name[0] != '/') {
                        if (!strncmp(dfu->name, name, strlen(dfu->name)))
                                return dfu->alt;
                } else {
                        /*
                         * One must also consider absolute path
                         * (/boot/bin/uImage) available at dfu->name when
                         * compared "plain" file name (uImage)
                         *
                         * It is the case for e.g. thor gadget where lthor SW
                         * sends only the file name, so only the very last part
                         * of path must be checked for equality
                         */

                        str = strstr(dfu->name, name);
                        if (!str)
                                continue;

                        /*
                         * Check if matching substring is the last element of
                         * dfu->name (uImage)
                         */
                        if (strlen(dfu->name) ==
                            ((str - dfu->name) + strlen(name)))
                                return dfu->alt;
                }
        }

        return -ENODEV;
}

int dfu_write_from_mem_addr(struct dfu_entity *dfu, void *buf, int size)
{
        unsigned long dfu_buf_size, write, left = size;
        int i, ret = 0;
        void *dp = buf;

        /*
         * Here we must call dfu_get_buf(dfu) first to be sure that dfu_buf_size
         * has been properly initialized - e.g. if "dfu_bufsiz" has been taken
         * into account.
         */
        dfu_get_buf(dfu);
        dfu_buf_size = dfu_get_buf_size();
        debug("%s: dfu buf size: %lu\n", __func__, dfu_buf_size);

        for (i = 0; left > 0; i++) {
                write = min(dfu_buf_size, left);

                debug("%s: dp: 0x%p left: %lu write: %lu\n", __func__,
                      dp, left, write);
                ret = dfu_write(dfu, dp, write, i);
                if (ret) {
                        error("DFU write failed\n");
                        return ret;
                }

                dp += write;
                left -= write;
        }

        ret = dfu_flush(dfu, NULL, 0, i);
        if (ret)
                error("DFU flush failed!");

        return ret;
}