// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2007-2008 Semihalf
 *
 * Written by: Rafal Jaworowski <raj@semihalf.com>
 */

#include <config.h>
#include <api_public.h>
#include <part.h>
#include <scsi.h>
#include <linux/types.h>

#if defined(CONFIG_CMD_USB) && defined(CONFIG_USB_STORAGE)
#include <usb.h>
#endif

#define DEBUG
#undef DEBUG

#ifdef DEBUG
#define debugf(fmt, args...) do { printf("%s(): ", __func__); printf(fmt, ##args); } while (0)
#else
#define debugf(fmt, args...)
#endif

#define errf(fmt, args...) do { printf("ERROR @ %s(): ", __func__); printf(fmt, ##args); } while (0)

#define ENUM_IDE        0
#define ENUM_USB        1
#define ENUM_SCSI       2
#define ENUM_MMC        3
#define ENUM_SATA       4
#define ENUM_MAX        5

struct stor_spec {
        int             max_dev;
        int             enum_started;
        int             enum_ended;
        int             type;   /* "external" type: DT_STOR_{IDE,USB,etc} */
        char            *name;
};

static struct stor_spec specs[ENUM_MAX] = { { 0, 0, 0, 0, NULL }, };

void dev_stor_init(void)
{
#if defined(CONFIG_IDE)
        specs[ENUM_IDE].max_dev = CONFIG_SYS_IDE_MAXDEVICE;
        specs[ENUM_IDE].enum_started = 0;
        specs[ENUM_IDE].enum_ended = 0;
        specs[ENUM_IDE].type = DEV_TYP_STOR | DT_STOR_IDE;
        specs[ENUM_IDE].name = "ide";
#endif
#if defined(CONFIG_CMD_MMC)
        specs[ENUM_MMC].max_dev = CONFIG_SYS_MMC_MAX_DEVICE;
        specs[ENUM_MMC].enum_started = 0;
        specs[ENUM_MMC].enum_ended = 0;
        specs[ENUM_MMC].type = DEV_TYP_STOR | DT_STOR_MMC;
        specs[ENUM_MMC].name = "mmc";
#endif
#if defined(CONFIG_SATA)
        specs[ENUM_SATA].max_dev = CONFIG_SYS_SATA_MAX_DEVICE;
        specs[ENUM_SATA].enum_started = 0;
        specs[ENUM_SATA].enum_ended = 0;
        specs[ENUM_SATA].type = DEV_TYP_STOR | DT_STOR_SATA;
        specs[ENUM_SATA].name = "sata";
#endif
#if defined(CONFIG_CMD_USB) && defined(CONFIG_USB_STORAGE)
        specs[ENUM_USB].max_dev = USB_MAX_STOR_DEV;
        specs[ENUM_USB].enum_started = 0;
        specs[ENUM_USB].enum_ended = 0;
        specs[ENUM_USB].type = DEV_TYP_STOR | DT_STOR_USB;
        specs[ENUM_USB].name = "usb";
#endif
}

/*
 * Finds next available device in the storage group
 *
 * type:        storage group type - ENUM_IDE, ENUM_SCSI etc.
 *
 * more:        returns 0/1 depending if there are more devices in this group
 *              available (for future iterations)
 *
 * returns:     0/1 depending if device found in this iteration
 */
static int dev_stor_get(int type, int *more, struct device_info *di)
{
        struct blk_desc *dd;
        int found = 0;
        int found_last = 0;
        int i = 0;

        /* Wasn't configured for this type, return 0 directly */
        if (specs[type].name == NULL)
                return 0;

        if (di->cookie != NULL) {
                /* Find the last device we've returned  */
                for (i = 0; i < specs[type].max_dev; i++) {
                        if (di->cookie ==
                            (void *)blk_get_dev(specs[type].name, i)) {
                                i += 1;
                                found_last = 1;
                                break;
                        }
                }

                if (!found_last)
                        i = 0;
        }

        for (; i < specs[type].max_dev; i++) {
                di->cookie = (void *)blk_get_dev(specs[type].name, i);

                if (di->cookie != NULL) {
                        found = 1;
                        break;
                }
        }

        if (i == specs[type].max_dev)
                *more = 0;
        else
                *more = 1;

        if (found) {
                di->type = specs[type].type;

                dd = (struct blk_desc *)di->cookie;
                if (dd->type == DEV_TYPE_UNKNOWN) {
                        debugf("device instance exists, but is not active..");
                        found = 0;
                } else {
                        di->di_stor.block_count = dd->lba;
                        di->di_stor.block_size = dd->blksz;
                }
        } else {
                di->cookie = NULL;
        }

        return found;
}

/* returns: ENUM_IDE, ENUM_USB etc. based on struct blk_desc */

static int dev_stor_type(struct blk_desc *dd)
{
        int i, j;

        for (i = ENUM_IDE; i < ENUM_MAX; i++)
                for (j = 0; j < specs[i].max_dev; j++)
                        if (dd == blk_get_dev(specs[i].name, j))
                                return i;

        return ENUM_MAX;
}

/* returns: 0/1 whether cookie points to some device in this group */

static int dev_is_stor(int type, struct device_info *di)
{
        return (dev_stor_type(di->cookie) == type) ? 1 : 0;
}

static int dev_enum_stor(int type, struct device_info *di)
{
        int found = 0, more = 0;

        debugf("called, type %d\n", type);

        /*
         * Formulae for enumerating storage devices:
         * 1. if cookie (hint from previous enum call) is NULL we start again
         *    with enumeration, so return the first available device, done.
         *
         * 2. if cookie is not NULL, check if it identifies some device in
         *    this group:
         *
         * 2a. if cookie is a storage device from our group (IDE, USB etc.),
         *     return next available (if exists) in this group
         *
         * 2b. if it isn't device from our group, check if such devices were
         *     ever enumerated before:
         *     - if not, return the first available device from this group
         *     - else return 0
         */

        if (di->cookie == NULL) {
                debugf("group%d - enum restart\n", type);

                /*
                 * 1. Enumeration (re-)started: take the first available
                 * device, if exists
                 */
                found = dev_stor_get(type, &more, di);
                specs[type].enum_started = 1;

        } else if (dev_is_stor(type, di)) {
                debugf("group%d - enum continued for the next device\n", type);

                if (specs[type].enum_ended) {
                        debugf("group%d - nothing more to enum!\n", type);
                        return 0;
                }

                /* 2a. Attempt to take a next available device in the group */
                found = dev_stor_get(type, &more, di);

        } else {
                if (specs[type].enum_ended) {
                        debugf("group %d - already enumerated, skipping\n", type);
                        return 0;
                }

                debugf("group%d - first time enum\n", type);

                if (specs[type].enum_started == 0) {
                        /*
                         * 2b.  If enumerating devices in this group did not
                         * happen before, it means the cookie pointed to a
                         * device from some other group (another storage
                         * group, or network); in this case try to take the
                         * first available device from our group
                         */
                        specs[type].enum_started = 1;

                        /*
                         * Attempt to take the first device in this group:
                         *'first element' flag is set
                         */
                        found = dev_stor_get(type, &more, di);

                } else {
                        errf("group%d - out of order iteration\n", type);
                        found = 0;
                        more = 0;
                }
        }

        /*
         * If there are no more devices in this group, consider its
         * enumeration finished
         */
        specs[type].enum_ended = (!more) ? 1 : 0;

        if (found)
                debugf("device found, returning cookie 0x%08x\n",
                       (u_int32_t)di->cookie);
        else
                debugf("no device found\n");

        return found;
}

void dev_enum_reset(void)
{
        int i;

        for (i = 0; i < ENUM_MAX; i ++) {
                specs[i].enum_started = 0;
                specs[i].enum_ended = 0;
        }
}

int dev_enum_storage(struct device_info *di)
{
        int i;

        /* check: ide, usb, scsi, mmc */
        for (i = ENUM_IDE; i < ENUM_MAX; i ++) {
                if (dev_enum_stor(i, di))
                        return 1;
        }

        return 0;
}

static int dev_stor_is_valid(int type, struct blk_desc *dd)
{
        int i;

        for (i = 0; i < specs[type].max_dev; i++)
                if (dd == blk_get_dev(specs[type].name, i))
                        if (dd->type != DEV_TYPE_UNKNOWN)
                                return 1;

        return 0;
}

int dev_open_stor(void *cookie)
{
        int type = dev_stor_type(cookie);

        if (type == ENUM_MAX)
                return API_ENODEV;

        if (dev_stor_is_valid(type, (struct blk_desc *)cookie))
                return 0;

        return API_ENODEV;
}

int dev_close_stor(void *cookie)
{
        /*
         * Not much to do as we actually do not alter storage devices upon
         * close
         */
        return 0;
}

lbasize_t dev_read_stor(void *cookie, void *buf, lbasize_t len, lbastart_t start)
{
        int type;
        struct blk_desc *dd = (struct blk_desc *)cookie;

        if ((type = dev_stor_type(dd)) == ENUM_MAX)
                return 0;

        if (!dev_stor_is_valid(type, dd))
                return 0;

#ifdef CONFIG_BLK
        return blk_dread(dd, start, len, buf);
#else
        if ((dd->block_read) == NULL) {
                debugf("no block_read() for device 0x%08x\n", cookie);
                return 0;
        }

        return dd->block_read(dd, start, len, buf);
#endif  /* defined(CONFIG_BLK) */
}

lbasize_t dev_write_stor(void *cookie, void *buf, lbasize_t len, lbastart_t start)
{
        struct blk_desc *dd = (struct blk_desc *)cookie;
        int type = dev_stor_type(dd);

        if (type == ENUM_MAX)
                return 0;

        if (!dev_stor_is_valid(type, dd))
                return 0;

#ifdef CONFIG_BLK
        return blk_dwrite(dd, start, len, buf);
#else
        if (dd->block_write == NULL) {
                debugf("no block_write() for device 0x%08x\n", cookie);
                return 0;
        }

        return dd->block_write(dd, start, len, buf);
#endif  /* defined(CONFIG_BLK) */
}