freebsd-dev/sys/dev/flash/mx25l.c

/*-
 * 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),

	{ 0, 0 }
};

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