/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009 Oleksandr Tymoshenko.  All rights reserved.
 * Copyright (c) 2018 Ian Lepore.  All rights reserved.
 * Copyright (c) 2006 M. Warner Losh <imp@FreeBSD.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#include "opt_platform.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <geom/geom_disk.h>

#ifdef FDT
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/ofw/openfirm.h>
#endif

#include <dev/spibus/spi.h>
#include "spibus_if.h"

#include <dev/flash/mx25lreg.h>

#define FL_NONE                 0x00
#define FL_ERASE_4K             0x01
#define FL_ERASE_32K            0x02
#define FL_ENABLE_4B_ADDR       0x04
#define FL_DISABLE_4B_ADDR      0x08

/*
 * Define the sectorsize to be a smaller size rather than the flash
 * sector size. Trying to run FFS off of a 64k flash sector size
 * results in a completely un-usable system.
 */
#define MX25L_SECTORSIZE        512

struct mx25l_flash_ident
{
        const char      *name;
        uint8_t         manufacturer_id;
        uint16_t        device_id;
        unsigned int    sectorsize;
        unsigned int    sectorcount;
        unsigned int    flags;
};

struct mx25l_softc 
{
        device_t        sc_dev;
        device_t        sc_parent;
        uint8_t         sc_manufacturer_id;
        uint16_t        sc_device_id;
        unsigned int    sc_erasesize;
        struct mtx      sc_mtx;
        struct disk     *sc_disk;
        struct proc     *sc_p;
        struct bio_queue_head sc_bio_queue;
        unsigned int    sc_flags;
        unsigned int    sc_taskstate;
        uint8_t         sc_dummybuf[FLASH_PAGE_SIZE];
};

#define TSTATE_STOPPED  0
#define TSTATE_STOPPING 1
#define TSTATE_RUNNING  2

#define M25PXX_LOCK(_sc)                mtx_lock(&(_sc)->sc_mtx)
#define M25PXX_UNLOCK(_sc)              mtx_unlock(&(_sc)->sc_mtx)
#define M25PXX_LOCK_INIT(_sc) \
        mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->sc_dev), \
            "mx25l", MTX_DEF)
#define M25PXX_LOCK_DESTROY(_sc)        mtx_destroy(&_sc->sc_mtx);
#define M25PXX_ASSERT_LOCKED(_sc)       mtx_assert(&_sc->sc_mtx, MA_OWNED);
#define M25PXX_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_NOTOWNED);

/* disk routines */
static int mx25l_open(struct disk *dp);
static int mx25l_close(struct disk *dp);
static int mx25l_ioctl(struct disk *, u_long, void *, int, struct thread *);
static void mx25l_strategy(struct bio *bp);
static int mx25l_getattr(struct bio *bp);
static void mx25l_task(void *arg);

static struct mx25l_flash_ident flash_devices[] = {
        { "en25f32",    0x1c, 0x3116, 64 * 1024, 64, FL_NONE },
        { "en25p32",    0x1c, 0x2016, 64 * 1024, 64, FL_NONE },
        { "en25p64",    0x1c, 0x2017, 64 * 1024, 128, FL_NONE },
        { "en25q32",    0x1c, 0x3016, 64 * 1024, 64, FL_NONE },
        { "en25q64",    0x1c, 0x3017, 64 * 1024, 128, FL_ERASE_4K },
        { "m25p32",     0x20, 0x2016, 64 * 1024, 64, FL_NONE },
        { "m25p64",     0x20, 0x2017, 64 * 1024, 128, FL_NONE },
        { "mx25l1606e", 0xc2, 0x2015, 64 * 1024, 32, FL_ERASE_4K},
        { "mx25ll32",   0xc2, 0x2016, 64 * 1024, 64, FL_NONE },
        { "mx25ll64",   0xc2, 0x2017, 64 * 1024, 128, FL_NONE },
        { "mx25ll128",  0xc2, 0x2018, 64 * 1024, 256, FL_ERASE_4K | FL_ERASE_32K },
        { "mx25ll256",  0xc2, 0x2019, 64 * 1024, 512, FL_ERASE_4K | FL_ERASE_32K | FL_ENABLE_4B_ADDR },
        { "n25q64",     0x20, 0xba17, 64 * 1024, 128, FL_ERASE_4K },
        { "s25fl032",   0x01, 0x0215, 64 * 1024, 64, FL_NONE },
        { "s25fl064",   0x01, 0x0216, 64 * 1024, 128, FL_NONE },
        { "s25fl128",   0x01, 0x2018, 64 * 1024, 256, FL_NONE },
        { "s25fl256s",  0x01, 0x0219, 64 * 1024, 512, FL_NONE },
        { "s25fl512s",  0x01, 0x0220, 64 * 1024, 1024, FL_NONE },
        { "SST25VF010A", 0xbf, 0x2549, 4 * 1024, 32, FL_ERASE_4K | FL_ERASE_32K },
        { "SST25VF032B", 0xbf, 0x254a, 64 * 1024, 64, FL_ERASE_4K | FL_ERASE_32K },

        /* Winbond -- w25x "blocks" are 64K, "sectors" are 4KiB */
        { "w25x32",     0xef, 0x3016, 64 * 1024, 64, FL_ERASE_4K },
        { "w25x64",     0xef, 0x3017, 64 * 1024, 128, FL_ERASE_4K },
        { "w25q32",     0xef, 0x4016, 64 * 1024, 64, FL_ERASE_4K },
        { "w25q64",     0xef, 0x4017, 64 * 1024, 128, FL_ERASE_4K },
        { "w25q64bv",   0xef, 0x4017, 64 * 1024, 128, FL_ERASE_4K },
        { "w25q128",    0xef, 0x4018, 64 * 1024, 256, FL_ERASE_4K },
        { "w25q256",    0xef, 0x4019, 64 * 1024, 512, FL_ERASE_4K },

         /* Atmel */
        { "at25df641",  0x1f, 0x4800, 64 * 1024, 128, FL_ERASE_4K },

        /* GigaDevice */
        { "gd25q64",    0xc8, 0x4017, 64 * 1024, 128, FL_ERASE_4K },
        { "gd25q128",   0xc8, 0x4018, 64 * 1024, 256, FL_ERASE_4K },

        /* Integrated Silicon Solution */
        { "is25wp256",  0x9d, 0x7019, 64 * 1024, 512, FL_ERASE_4K | FL_ENABLE_4B_ADDR},
};

static int
mx25l_wait_for_device_ready(struct mx25l_softc *sc)
{
        uint8_t txBuf[2], rxBuf[2];
        struct spi_command cmd;
        int err;

        memset(&cmd, 0, sizeof(cmd));

        do {
                txBuf[0] = CMD_READ_STATUS;
                cmd.tx_cmd = txBuf;
                cmd.rx_cmd = rxBuf;
                cmd.rx_cmd_sz = 2;
                cmd.tx_cmd_sz = 2;
                err = SPIBUS_TRANSFER(sc->sc_parent, sc->sc_dev, &cmd);
        } while (err == 0 && (rxBuf[1] & STATUS_WIP));

        return (err);
}

static struct mx25l_flash_ident*
mx25l_get_device_ident(struct mx25l_softc *sc)
{
        uint8_t txBuf[8], rxBuf[8];
        struct spi_command cmd;
        uint8_t manufacturer_id;
        uint16_t dev_id;
        int err, i;

        memset(&cmd, 0, sizeof(cmd));
        memset(txBuf, 0, sizeof(txBuf));
        memset(rxBuf, 0, sizeof(rxBuf));

        txBuf[0] = CMD_READ_IDENT;
        cmd.tx_cmd = &txBuf;
        cmd.rx_cmd = &rxBuf;
        /*
         * Some compatible devices has extended two-bytes ID
         * We'll use only manufacturer/deviceid atm
         */
        cmd.tx_cmd_sz = 4;
        cmd.rx_cmd_sz = 4;
        err = SPIBUS_TRANSFER(sc->sc_parent, sc->sc_dev, &cmd);
        if (err)
                return (NULL);

        manufacturer_id = rxBuf[1];
        dev_id = (rxBuf[2] << 8) | (rxBuf[3]);

        for (i = 0; i < nitems(flash_devices); i++) {
                if ((flash_devices[i].manufacturer_id == manufacturer_id) &&
                    (flash_devices[i].device_id == dev_id))
                        return &flash_devices[i];
        }

        device_printf(sc->sc_dev,
            "Unknown SPI flash device. Vendor: %02x, device id: %04x\n",
            manufacturer_id, dev_id);
        return (NULL);
}

static int
mx25l_set_writable(struct mx25l_softc *sc, int writable)
{
        uint8_t txBuf[1], rxBuf[1];
        struct spi_command cmd;
        int err;

        memset(&cmd, 0, sizeof(cmd));
        memset(txBuf, 0, sizeof(txBuf));
        memset(rxBuf, 0, sizeof(rxBuf));

        txBuf[0] = writable ? CMD_WRITE_ENABLE : CMD_WRITE_DISABLE;
        cmd.tx_cmd = txBuf;
        cmd.rx_cmd = rxBuf;
        cmd.rx_cmd_sz = 1;
        cmd.tx_cmd_sz = 1;
        err = SPIBUS_TRANSFER(sc->sc_parent, sc->sc_dev, &cmd);
        return (err);
}

static int
mx25l_erase_cmd(struct mx25l_softc *sc, off_t sector)
{
        uint8_t txBuf[5], rxBuf[5];
        struct spi_command cmd;
        int err;

        if ((err = mx25l_set_writable(sc, 1)) != 0)
                return (err);

        memset(&cmd, 0, sizeof(cmd));
        memset(txBuf, 0, sizeof(txBuf));
        memset(rxBuf, 0, sizeof(rxBuf));

        cmd.tx_cmd = txBuf;
        cmd.rx_cmd = rxBuf;

        if (sc->sc_flags & FL_ERASE_4K)
                txBuf[0] = CMD_BLOCK_4K_ERASE;
        else if (sc->sc_flags & FL_ERASE_32K)
                txBuf[0] = CMD_BLOCK_32K_ERASE;
        else
                txBuf[0] = CMD_SECTOR_ERASE;

        if (sc->sc_flags & FL_ENABLE_4B_ADDR) {
                cmd.rx_cmd_sz = 5;
                cmd.tx_cmd_sz = 5;
                txBuf[1] = ((sector >> 24) & 0xff);
                txBuf[2] = ((sector >> 16) & 0xff);
                txBuf[3] = ((sector >> 8) & 0xff);
                txBuf[4] = (sector & 0xff);
        } else {
                cmd.rx_cmd_sz = 4;
                cmd.tx_cmd_sz = 4;
                txBuf[1] = ((sector >> 16) & 0xff);
                txBuf[2] = ((sector >> 8) & 0xff);
                txBuf[3] = (sector & 0xff);
        }
        if ((err = SPIBUS_TRANSFER(sc->sc_parent, sc->sc_dev, &cmd)) != 0)
                return (err);
        err = mx25l_wait_for_device_ready(sc);
        return (err);
}

static int
mx25l_write(struct mx25l_softc *sc, off_t offset, caddr_t data, off_t count)
{
        uint8_t txBuf[8], rxBuf[8];
        struct spi_command cmd;
        off_t bytes_to_write;
        int err = 0;

        if (sc->sc_flags & FL_ENABLE_4B_ADDR) {
                cmd.tx_cmd_sz = 5;
                cmd.rx_cmd_sz = 5;
        } else {
                cmd.tx_cmd_sz = 4;
                cmd.rx_cmd_sz = 4;
        }

        /*
         * Writes must be aligned to the erase sectorsize, since blocks are
         * fully erased before they're written to.
         */
        if (count % sc->sc_erasesize != 0 || offset % sc->sc_erasesize != 0)
                return (EIO);

        /*
         * Maximum write size for CMD_PAGE_PROGRAM is FLASH_PAGE_SIZE, so loop
         * to write chunks of FLASH_PAGE_SIZE bytes each.
         */
        while (count != 0) {
                /* If we crossed a sector boundary, erase the next sector. */
                if (((offset) % sc->sc_erasesize) == 0) {
                        err = mx25l_erase_cmd(sc, offset);
                        if (err)
                                break;
                }

                txBuf[0] = CMD_PAGE_PROGRAM;
                if (sc->sc_flags & FL_ENABLE_4B_ADDR) {
                        txBuf[1] = (offset >> 24) & 0xff;
                        txBuf[2] = (offset >> 16) & 0xff;
                        txBuf[3] = (offset >> 8) & 0xff;
                        txBuf[4] = offset & 0xff;
                } else {
                        txBuf[1] = (offset >> 16) & 0xff;
                        txBuf[2] = (offset >> 8) & 0xff;
                        txBuf[3] = offset & 0xff;
                }

                bytes_to_write = MIN(FLASH_PAGE_SIZE, count);
                cmd.tx_cmd = txBuf;
                cmd.rx_cmd = rxBuf;
                cmd.tx_data = data;
                cmd.rx_data = sc->sc_dummybuf;
                cmd.tx_data_sz = (uint32_t)bytes_to_write;
                cmd.rx_data_sz = (uint32_t)bytes_to_write;

                /*
                 * Each completed write operation resets WEL (write enable
                 * latch) to disabled state, so we re-enable it here.
                 */
                if ((err = mx25l_wait_for_device_ready(sc)) != 0)
                        break;
                if ((err = mx25l_set_writable(sc, 1)) != 0)
                        break;

                err = SPIBUS_TRANSFER(sc->sc_parent, sc->sc_dev, &cmd);
                if (err != 0)
                        break;
                err = mx25l_wait_for_device_ready(sc);
                if (err)
                        break;

                data   += bytes_to_write;
                offset += bytes_to_write;
                count  -= bytes_to_write;
        }

        return (err);
}

static int
mx25l_read(struct mx25l_softc *sc, off_t offset, caddr_t data, off_t count)
{
        uint8_t txBuf[8], rxBuf[8];
        struct spi_command cmd;
        int err = 0;

        /*
         * Enforce that reads are aligned to the disk sectorsize, not the
         * erase sectorsize.  In this way, smaller read IO is possible,
         * dramatically speeding up filesystem/geom_compress access.
         */
        if (count % sc->sc_disk->d_sectorsize != 0 ||
            offset % sc->sc_disk->d_sectorsize != 0)
                return (EIO);

        txBuf[0] = CMD_FAST_READ;
        if (sc->sc_flags & FL_ENABLE_4B_ADDR) {
                cmd.tx_cmd_sz = 6;
                cmd.rx_cmd_sz = 6;

                txBuf[1] = (offset >> 24) & 0xff;
                txBuf[2] = (offset >> 16) & 0xff;
                txBuf[3] = (offset >> 8) & 0xff;
                txBuf[4] = offset & 0xff;
                /* Dummy byte */
                txBuf[5] = 0;
        } else {
                cmd.tx_cmd_sz = 5;
                cmd.rx_cmd_sz = 5;

                txBuf[1] = (offset >> 16) & 0xff;
                txBuf[2] = (offset >> 8) & 0xff;
                txBuf[3] = offset & 0xff;
                /* Dummy byte */
                txBuf[4] = 0;
        }

        cmd.tx_cmd = txBuf;
        cmd.rx_cmd = rxBuf;
        cmd.tx_data = data;
        cmd.rx_data = data;
        cmd.tx_data_sz = count;
        cmd.rx_data_sz = count;

        err = SPIBUS_TRANSFER(sc->sc_parent, sc->sc_dev, &cmd);
        return (err);
}

static int
mx25l_set_4b_mode(struct mx25l_softc *sc, uint8_t command)
{
        uint8_t txBuf[1], rxBuf[1];
        struct spi_command cmd;
        int err;

        memset(&cmd, 0, sizeof(cmd));
        memset(txBuf, 0, sizeof(txBuf));
        memset(rxBuf, 0, sizeof(rxBuf));

        cmd.tx_cmd_sz = cmd.rx_cmd_sz = 1;

        cmd.tx_cmd = txBuf;
        cmd.rx_cmd = rxBuf;

        txBuf[0] = command;

        if ((err = SPIBUS_TRANSFER(sc->sc_parent, sc->sc_dev, &cmd)) == 0)
                err = mx25l_wait_for_device_ready(sc);

        return (err);
}

#ifdef  FDT
static struct ofw_compat_data compat_data[] = {
        { "st,m25p",            1 },
        { "jedec,spi-nor",      1 },
        { NULL,                 0 },
};
#endif

static int
mx25l_probe(device_t dev)
{
#ifdef FDT
        int i;

        if (!ofw_bus_status_okay(dev))
                return (ENXIO);

        /* First try to match the compatible property to the compat_data */
        if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 1)
                goto found;

        /*
         * Next, try to find a compatible device using the names in the
         * flash_devices structure
         */
        for (i = 0; i < nitems(flash_devices); i++)
                if (ofw_bus_is_compatible(dev, flash_devices[i].name))
                        goto found;

        return (ENXIO);
found:
#endif
        device_set_desc(dev, "M25Pxx Flash Family");

        return (0);
}

static int
mx25l_attach(device_t dev)
{
        struct mx25l_softc *sc;
        struct mx25l_flash_ident *ident;
        int err;

        sc = device_get_softc(dev);
        sc->sc_dev = dev;
        sc->sc_parent = device_get_parent(sc->sc_dev);

        M25PXX_LOCK_INIT(sc);

        ident = mx25l_get_device_ident(sc);
        if (ident == NULL)
                return (ENXIO);

        if ((err = mx25l_wait_for_device_ready(sc)) != 0)
                return (err);

        sc->sc_flags = ident->flags;

        if (sc->sc_flags & FL_ERASE_4K)
                sc->sc_erasesize = 4 * 1024;
        else if (sc->sc_flags & FL_ERASE_32K)
                sc->sc_erasesize = 32 * 1024;
        else
                sc->sc_erasesize = ident->sectorsize;

        if (sc->sc_flags & FL_ENABLE_4B_ADDR) {
                if ((err = mx25l_set_4b_mode(sc, CMD_ENTER_4B_MODE)) != 0)
                        return (err);
        } else if (sc->sc_flags & FL_DISABLE_4B_ADDR) {
                if ((err = mx25l_set_4b_mode(sc, CMD_EXIT_4B_MODE)) != 0)
                        return (err);
        }

        sc->sc_disk = disk_alloc();
        sc->sc_disk->d_open = mx25l_open;
        sc->sc_disk->d_close = mx25l_close;
        sc->sc_disk->d_strategy = mx25l_strategy;
        sc->sc_disk->d_getattr = mx25l_getattr;
        sc->sc_disk->d_ioctl = mx25l_ioctl;
        sc->sc_disk->d_name = "flash/spi";
        sc->sc_disk->d_drv1 = sc;
        sc->sc_disk->d_maxsize = DFLTPHYS;
        sc->sc_disk->d_sectorsize = MX25L_SECTORSIZE;
        sc->sc_disk->d_mediasize = ident->sectorsize * ident->sectorcount;
        sc->sc_disk->d_stripesize = sc->sc_erasesize;
        sc->sc_disk->d_unit = device_get_unit(sc->sc_dev);
        sc->sc_disk->d_dump = NULL;             /* NB: no dumps */
        strlcpy(sc->sc_disk->d_descr, ident->name,
            sizeof(sc->sc_disk->d_descr));

        disk_create(sc->sc_disk, DISK_VERSION);
        bioq_init(&sc->sc_bio_queue);

        kproc_create(&mx25l_task, sc, &sc->sc_p, 0, 0, "task: mx25l flash");
        sc->sc_taskstate = TSTATE_RUNNING;

        device_printf(sc->sc_dev, 
            "device type %s, size %dK in %d sectors of %dK, erase size %dK\n",
            ident->name,
            ident->sectorcount * ident->sectorsize / 1024,
            ident->sectorcount, ident->sectorsize / 1024,
            sc->sc_erasesize / 1024);

        return (0);
}

static int
mx25l_detach(device_t dev)
{
        struct mx25l_softc *sc;
        int err;

        sc = device_get_softc(dev);
        err = 0;

        M25PXX_LOCK(sc);
        if (sc->sc_taskstate == TSTATE_RUNNING) {
                sc->sc_taskstate = TSTATE_STOPPING;
                wakeup(sc);
                while (err == 0 && sc->sc_taskstate != TSTATE_STOPPED) {
                        err = msleep(sc, &sc->sc_mtx, 0, "mx25dt", hz * 3);
                        if (err != 0) {
                                sc->sc_taskstate = TSTATE_RUNNING;
                                device_printf(sc->sc_dev,
                                    "Failed to stop queue task\n");
                        }
                }
        }
        M25PXX_UNLOCK(sc);

        if (err == 0 && sc->sc_taskstate == TSTATE_STOPPED) {
                disk_destroy(sc->sc_disk);
                bioq_flush(&sc->sc_bio_queue, NULL, ENXIO);
                M25PXX_LOCK_DESTROY(sc);
        }
        return (err);
}

static int
mx25l_open(struct disk *dp)
{
        return (0);
}

static int
mx25l_close(struct disk *dp)
{

        return (0);
}

static int
mx25l_ioctl(struct disk *dp, u_long cmd, void *data, int fflag,
        struct thread *td)
{

        return (EINVAL);
}

static void
mx25l_strategy(struct bio *bp)
{
        struct mx25l_softc *sc;

        sc = (struct mx25l_softc *)bp->bio_disk->d_drv1;
        M25PXX_LOCK(sc);
        bioq_disksort(&sc->sc_bio_queue, bp);
        wakeup(sc);
        M25PXX_UNLOCK(sc);
}

static int
mx25l_getattr(struct bio *bp)
{
        struct mx25l_softc *sc;
        device_t dev;

        if (bp->bio_disk == NULL || bp->bio_disk->d_drv1 == NULL)
                return (ENXIO);

        sc = bp->bio_disk->d_drv1;
        dev = sc->sc_dev;

        if (strcmp(bp->bio_attribute, "SPI::device") == 0) {
                if (bp->bio_length != sizeof(dev))
                        return (EFAULT);
                bcopy(&dev, bp->bio_data, sizeof(dev));
        } else
                return (-1);
        return (0);
}

static void
mx25l_task(void *arg)
{
        struct mx25l_softc *sc = (struct mx25l_softc*)arg;
        struct bio *bp;

        for (;;) {
                M25PXX_LOCK(sc);
                do {
                        if (sc->sc_taskstate == TSTATE_STOPPING) {
                                sc->sc_taskstate = TSTATE_STOPPED;
                                M25PXX_UNLOCK(sc);
                                wakeup(sc);
                                kproc_exit(0);
                        }
                        bp = bioq_first(&sc->sc_bio_queue);
                        if (bp == NULL)
                                msleep(sc, &sc->sc_mtx, PRIBIO, "mx25jq", 0);
                } while (bp == NULL);
                bioq_remove(&sc->sc_bio_queue, bp);
                M25PXX_UNLOCK(sc);

                switch (bp->bio_cmd) {
                case BIO_READ:
                        bp->bio_error = mx25l_read(sc, bp->bio_offset, 
                            bp->bio_data, bp->bio_bcount);
                        break;
                case BIO_WRITE:
                        bp->bio_error = mx25l_write(sc, bp->bio_offset, 
                            bp->bio_data, bp->bio_bcount);
                        break;
                default:
                        bp->bio_error = EOPNOTSUPP;
                }


                biodone(bp);
        }
}

static device_method_t mx25l_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         mx25l_probe),
        DEVMETHOD(device_attach,        mx25l_attach),
        DEVMETHOD(device_detach,        mx25l_detach),

        DEVMETHOD_END
};

static driver_t mx25l_driver = {
        "mx25l",
        mx25l_methods,
        sizeof(struct mx25l_softc),
};

DRIVER_MODULE(mx25l, spibus, mx25l_driver, 0, 0);
MODULE_DEPEND(mx25l, spibus, 1, 1, 1);
#ifdef  FDT
MODULE_DEPEND(mx25l, fdt_slicer, 1, 1, 1);
SPIBUS_FDT_PNP_INFO(compat_data);
#endif