diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 4a012d9..584ed9f 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -159,6 +159,15 @@
 	  This driver can also be built as a module.  If so, the module
 	  will be called at25.
 
+config SPI_SPIDEV
+	tristate "User mode SPI device driver support"
+	depends on SPI_MASTER && EXPERIMENTAL
+	help
+	  This supports user mode SPI protocol drivers.
+
+	  Note that this application programming interface is EXPERIMENTAL
+	  and hence SUBJECT TO CHANGE WITHOUT NOTICE while it stabilizes.
+
 #
 # Add new SPI protocol masters in alphabetical order above this line
 #
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index a95ade8..4cc5e99 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -25,6 +25,7 @@
 
 # SPI protocol drivers (device/link on bus)
 obj-$(CONFIG_SPI_AT25)		+= at25.o
+obj-$(CONFIG_SPI_SPIDEV)	+= spidev.o
 # 	... add above this line ...
 
 # SPI slave controller drivers (upstream link)
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
new file mode 100644
index 0000000..c0a6dce
--- /dev/null
+++ b/drivers/spi/spidev.c
@@ -0,0 +1,584 @@
+/*
+ * spidev.c -- simple synchronous userspace interface to SPI devices
+ *
+ * Copyright (C) 2006 SWAPP
+ *	Andrea Paterniani <a.paterniani@swapp-eng.it>
+ * Copyright (C) 2007 David Brownell (simplification, cleanup)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/ioctl.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spidev.h>
+
+#include <asm/uaccess.h>
+
+
+/*
+ * This supports acccess to SPI devices using normal userspace I/O calls.
+ * Note that while traditional UNIX/POSIX I/O semantics are half duplex,
+ * and often mask message boundaries, full SPI support requires full duplex
+ * transfers.  There are several kinds of of internal message boundaries to
+ * handle chipselect management and other protocol options.
+ *
+ * SPI has a character major number assigned.  We allocate minor numbers
+ * dynamically using a bitmask.  You must use hotplug tools, such as udev
+ * (or mdev with busybox) to create and destroy the /dev/spidevB.C device
+ * nodes, since there is no fixed association of minor numbers with any
+ * particular SPI bus or device.
+ */
+#define SPIDEV_MAJOR			153	/* assigned */
+#define N_SPI_MINORS			32	/* ... up to 256 */
+
+static unsigned long	minors[N_SPI_MINORS / BITS_PER_LONG];
+
+
+/* Bit masks for spi_device.mode management */
+#define SPI_MODE_MASK			(SPI_CPHA | SPI_CPOL)
+
+
+struct spidev_data {
+	struct device		dev;
+	struct spi_device	*spi;
+	struct list_head	device_entry;
+
+	struct mutex		buf_lock;
+	unsigned		users;
+	u8			*buffer;
+};
+
+static LIST_HEAD(device_list);
+static DEFINE_MUTEX(device_list_lock);
+
+static unsigned bufsiz = 4096;
+module_param(bufsiz, uint, S_IRUGO);
+MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message");
+
+/*-------------------------------------------------------------------------*/
+
+/* Read-only message with current device setup */
+static ssize_t
+spidev_read(struct file *filp, char __user *buf, size_t count, loff_t *f_pos)
+{
+	struct spidev_data	*spidev;
+	struct spi_device	*spi;
+	ssize_t			status = 0;
+
+	/* chipselect only toggles at start or end of operation */
+	if (count > bufsiz)
+		return -EMSGSIZE;
+
+	spidev = filp->private_data;
+	spi = spidev->spi;
+
+	mutex_lock(&spidev->buf_lock);
+	status = spi_read(spi, spidev->buffer, count);
+	if (status == 0) {
+		unsigned long	missing;
+
+		missing = copy_to_user(buf, spidev->buffer, count);
+		if (count && missing == count)
+			status = -EFAULT;
+		else
+			status = count - missing;
+	}
+	mutex_unlock(&spidev->buf_lock);
+
+	return status;
+}
+
+/* Write-only message with current device setup */
+static ssize_t
+spidev_write(struct file *filp, const char __user *buf,
+		size_t count, loff_t *f_pos)
+{
+	struct spidev_data	*spidev;
+	struct spi_device	*spi;
+	ssize_t			status = 0;
+	unsigned long		missing;
+
+	/* chipselect only toggles at start or end of operation */
+	if (count > bufsiz)
+		return -EMSGSIZE;
+
+	spidev = filp->private_data;
+	spi = spidev->spi;
+
+	mutex_lock(&spidev->buf_lock);
+	missing = copy_from_user(spidev->buffer, buf, count);
+	if (missing == 0) {
+		status = spi_write(spi, spidev->buffer, count);
+		if (status == 0)
+			status = count;
+	} else
+		status = -EFAULT;
+	mutex_unlock(&spidev->buf_lock);
+
+	return status;
+}
+
+static int spidev_message(struct spidev_data *spidev,
+		struct spi_ioc_transfer *u_xfers, unsigned n_xfers)
+{
+	struct spi_message	msg;
+	struct spi_transfer	*k_xfers;
+	struct spi_transfer	*k_tmp;
+	struct spi_ioc_transfer *u_tmp;
+	struct spi_device	*spi = spidev->spi;
+	unsigned		n, total;
+	u8			*buf;
+	int			status = -EFAULT;
+
+	spi_message_init(&msg);
+	k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL);
+	if (k_xfers == NULL)
+		return -ENOMEM;
+
+	/* Construct spi_message, copying any tx data to bounce buffer.
+	 * We walk the array of user-provided transfers, using each one
+	 * to initialize a kernel version of the same transfer.
+	 */
+	mutex_lock(&spidev->buf_lock);
+	buf = spidev->buffer;
+	total = 0;
+	for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers;
+			n;
+			n--, k_tmp++, u_tmp++) {
+		k_tmp->len = u_tmp->len;
+
+		if (u_tmp->rx_buf) {
+			k_tmp->rx_buf = buf;
+			if (!access_ok(VERIFY_WRITE, u_tmp->rx_buf, u_tmp->len))
+				goto done;
+		}
+		if (u_tmp->tx_buf) {
+			k_tmp->tx_buf = buf;
+			if (copy_from_user(buf, (const u8 __user *)u_tmp->tx_buf,
+					u_tmp->len))
+				goto done;
+		}
+
+		total += k_tmp->len;
+		if (total > bufsiz) {
+			status = -EMSGSIZE;
+			goto done;
+		}
+		buf += k_tmp->len;
+
+		k_tmp->cs_change = !!u_tmp->cs_change;
+		k_tmp->bits_per_word = u_tmp->bits_per_word;
+		k_tmp->delay_usecs = u_tmp->delay_usecs;
+		k_tmp->speed_hz = u_tmp->speed_hz;
+#ifdef VERBOSE
+		dev_dbg(&spi->dev,
+			"  xfer len %zd %s%s%s%dbits %u usec %uHz\n",
+			u_tmp->len,
+			u_tmp->rx_buf ? "rx " : "",
+			u_tmp->tx_buf ? "tx " : "",
+			u_tmp->cs_change ? "cs " : "",
+			u_tmp->bits_per_word ? : spi->bits_per_word,
+			u_tmp->delay_usecs,
+			u_tmp->speed_hz ? : spi->max_speed_hz);
+#endif
+		spi_message_add_tail(k_tmp, &msg);
+	}
+
+	status = spi_sync(spi, &msg);
+	if (status < 0)
+		goto done;
+
+	/* copy any rx data out of bounce buffer */
+	buf = spidev->buffer;
+	for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) {
+		if (u_tmp->rx_buf) {
+			if (__copy_to_user((u8 __user *)u_tmp->rx_buf, buf,
+					u_tmp->len)) {
+				status = -EFAULT;
+				goto done;
+			}
+		}
+		buf += u_tmp->len;
+	}
+	status = total;
+
+done:
+	mutex_unlock(&spidev->buf_lock);
+	kfree(k_xfers);
+	return status;
+}
+
+static int
+spidev_ioctl(struct inode *inode, struct file *filp,
+		unsigned int cmd, unsigned long arg)
+{
+	int			err = 0;
+	int			retval = 0;
+	struct spidev_data	*spidev;
+	struct spi_device	*spi;
+	u32			tmp;
+	unsigned		n_ioc;
+	struct spi_ioc_transfer	*ioc;
+
+	/* Check type and command number */
+	if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC)
+		return -ENOTTY;
+
+	/* Check access direction once here; don't repeat below.
+	 * IOC_DIR is from the user perspective, while access_ok is
+	 * from the kernel perspective; so they look reversed.
+	 */
+	if (_IOC_DIR(cmd) & _IOC_READ)
+		err = !access_ok(VERIFY_WRITE,
+				(void __user *)arg, _IOC_SIZE(cmd));
+	if (err == 0 && _IOC_DIR(cmd) & _IOC_WRITE)
+		err = !access_ok(VERIFY_READ,
+				(void __user *)arg, _IOC_SIZE(cmd));
+	if (err)
+		return -EFAULT;
+
+	spidev = filp->private_data;
+	spi = spidev->spi;
+
+	switch (cmd) {
+	/* read requests */
+	case SPI_IOC_RD_MODE:
+		retval = __put_user(spi->mode & SPI_MODE_MASK,
+					(__u8 __user *)arg);
+		break;
+	case SPI_IOC_RD_LSB_FIRST:
+		retval = __put_user((spi->mode & SPI_LSB_FIRST) ?  1 : 0,
+					(__u8 __user *)arg);
+		break;
+	case SPI_IOC_RD_BITS_PER_WORD:
+		retval = __put_user(spi->bits_per_word, (__u8 __user *)arg);
+		break;
+	case SPI_IOC_RD_MAX_SPEED_HZ:
+		retval = __put_user(spi->max_speed_hz, (__u32 __user *)arg);
+		break;
+
+	/* write requests */
+	case SPI_IOC_WR_MODE:
+		retval = __get_user(tmp, (u8 __user *)arg);
+		if (retval == 0) {
+			u8	save = spi->mode;
+
+			if (tmp & ~SPI_MODE_MASK) {
+				retval = -EINVAL;
+				break;
+			}
+
+			tmp |= spi->mode & ~SPI_MODE_MASK;
+			spi->mode = (u8)tmp;
+			retval = spi_setup(spi);
+			if (retval < 0)
+				spi->mode = save;
+			else
+				dev_dbg(&spi->dev, "spi mode %02x\n", tmp);
+		}
+		break;
+	case SPI_IOC_WR_LSB_FIRST:
+		retval = __get_user(tmp, (__u8 __user *)arg);
+		if (retval == 0) {
+			u8	save = spi->mode;
+
+			if (tmp)
+				spi->mode |= SPI_LSB_FIRST;
+			else
+				spi->mode &= ~SPI_LSB_FIRST;
+			retval = spi_setup(spi);
+			if (retval < 0)
+				spi->mode = save;
+			else
+				dev_dbg(&spi->dev, "%csb first\n",
+						tmp ? 'l' : 'm');
+		}
+		break;
+	case SPI_IOC_WR_BITS_PER_WORD:
+		retval = __get_user(tmp, (__u8 __user *)arg);
+		if (retval == 0) {
+			u8	save = spi->bits_per_word;
+
+			spi->bits_per_word = tmp;
+			retval = spi_setup(spi);
+			if (retval < 0)
+				spi->bits_per_word = save;
+			else
+				dev_dbg(&spi->dev, "%d bits per word\n", tmp);
+		}
+		break;
+	case SPI_IOC_WR_MAX_SPEED_HZ:
+		retval = __get_user(tmp, (__u32 __user *)arg);
+		if (retval == 0) {
+			u32	save = spi->max_speed_hz;
+
+			spi->max_speed_hz = tmp;
+			retval = spi_setup(spi);
+			if (retval < 0)
+				spi->max_speed_hz = save;
+			else
+				dev_dbg(&spi->dev, "%d Hz (max)\n", tmp);
+		}
+		break;
+
+	default:
+		/* segmented and/or full-duplex I/O request */
+		if (_IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0))
+				|| _IOC_DIR(cmd) != _IOC_WRITE)
+			return -ENOTTY;
+
+		tmp = _IOC_SIZE(cmd);
+		if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) {
+			retval = -EINVAL;
+			break;
+		}
+		n_ioc = tmp / sizeof(struct spi_ioc_transfer);
+		if (n_ioc == 0)
+			break;
+
+		/* copy into scratch area */
+		ioc = kmalloc(tmp, GFP_KERNEL);
+		if (!ioc) {
+			retval = -ENOMEM;
+			break;
+		}
+		if (__copy_from_user(ioc, (void __user *)arg, tmp)) {
+			retval = -EFAULT;
+			break;
+		}
+
+		/* translate to spi_message, execute */
+		retval = spidev_message(spidev, ioc, n_ioc);
+		kfree(ioc);
+		break;
+	}
+	return retval;
+}
+
+static int spidev_open(struct inode *inode, struct file *filp)
+{
+	struct spidev_data	*spidev;
+	int			status = -ENXIO;
+
+	mutex_lock(&device_list_lock);
+
+	list_for_each_entry(spidev, &device_list, device_entry) {
+		if (spidev->dev.devt == inode->i_rdev) {
+			status = 0;
+			break;
+		}
+	}
+	if (status == 0) {
+		if (!spidev->buffer) {
+			spidev->buffer = kmalloc(bufsiz, GFP_KERNEL);
+			if (!spidev->buffer) {
+				dev_dbg(&spidev->spi->dev, "open/ENOMEM\n");
+				status = -ENOMEM;
+			}
+		}
+		if (status == 0) {
+			spidev->users++;
+			filp->private_data = spidev;
+			nonseekable_open(inode, filp);
+		}
+	} else
+		pr_debug("spidev: nothing for minor %d\n", iminor(inode));
+
+	mutex_unlock(&device_list_lock);
+	return status;
+}
+
+static int spidev_release(struct inode *inode, struct file *filp)
+{
+	struct spidev_data	*spidev;
+	int			status = 0;
+
+	mutex_lock(&device_list_lock);
+	spidev = filp->private_data;
+	filp->private_data = NULL;
+	spidev->users--;
+	if (!spidev->users) {
+		kfree(spidev->buffer);
+		spidev->buffer = NULL;
+	}
+	mutex_unlock(&device_list_lock);
+
+	return status;
+}
+
+static struct file_operations spidev_fops = {
+	.owner =	THIS_MODULE,
+	/* REVISIT switch to aio primitives, so that userspace
+	 * gets more complete API coverage.  It'll simplify things
+	 * too, except for the locking.
+	 */
+	.write =	spidev_write,
+	.read =		spidev_read,
+	.ioctl =	spidev_ioctl,
+	.open =		spidev_open,
+	.release =	spidev_release,
+};
+
+/*-------------------------------------------------------------------------*/
+
+/* The main reason to have this class is to make mdev/udev create the
+ * /dev/spidevB.C character device nodes exposing our userspace API.
+ * It also simplifies memory management.
+ */
+
+static void spidev_classdev_release(struct device *dev)
+{
+	struct spidev_data	*spidev;
+
+	spidev = container_of(dev, struct spidev_data, dev);
+	kfree(spidev);
+}
+
+static struct class spidev_class = {
+	.name		= "spidev",
+	.owner		= THIS_MODULE,
+	.dev_release	= spidev_classdev_release,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int spidev_probe(struct spi_device *spi)
+{
+	struct spidev_data	*spidev;
+	int			status;
+	unsigned long		minor;
+
+	/* Allocate driver data */
+	spidev = kzalloc(sizeof(*spidev), GFP_KERNEL);
+	if (!spidev)
+		return -ENOMEM;
+
+	/* Initialize the driver data */
+	spidev->spi = spi;
+	mutex_init(&spidev->buf_lock);
+
+	INIT_LIST_HEAD(&spidev->device_entry);
+
+	/* If we can allocate a minor number, hook up this device.
+	 * Reusing minors is fine so long as udev or mdev is working.
+	 */
+	mutex_lock(&device_list_lock);
+	minor = find_first_zero_bit(minors, ARRAY_SIZE(minors));
+	if (minor < N_SPI_MINORS) {
+		spidev->dev.parent = &spi->dev;
+		spidev->dev.class = &spidev_class;
+		spidev->dev.devt = MKDEV(SPIDEV_MAJOR, minor);
+		snprintf(spidev->dev.bus_id, sizeof spidev->dev.bus_id,
+				"spidev%d.%d",
+				spi->master->bus_num, spi->chip_select);
+		status = device_register(&spidev->dev);
+	} else {
+		dev_dbg(&spi->dev, "no minor number available!\n");
+		status = -ENODEV;
+	}
+	if (status == 0) {
+		set_bit(minor, minors);
+		dev_set_drvdata(&spi->dev, spidev);
+		list_add(&spidev->device_entry, &device_list);
+	}
+	mutex_unlock(&device_list_lock);
+
+	if (status != 0)
+		kfree(spidev);
+
+	return status;
+}
+
+static int spidev_remove(struct spi_device *spi)
+{
+	struct spidev_data	*spidev = dev_get_drvdata(&spi->dev);
+
+	mutex_lock(&device_list_lock);
+
+	list_del(&spidev->device_entry);
+	dev_set_drvdata(&spi->dev, NULL);
+	clear_bit(MINOR(spidev->dev.devt), minors);
+	device_unregister(&spidev->dev);
+
+	mutex_unlock(&device_list_lock);
+
+	return 0;
+}
+
+static struct spi_driver spidev_spi = {
+	.driver = {
+		.name =		"spidev",
+		.owner =	THIS_MODULE,
+	},
+	.probe =	spidev_probe,
+	.remove =	__devexit_p(spidev_remove),
+
+	/* NOTE:  suspend/resume methods are not necessary here.
+	 * We don't do anything except pass the requests to/from
+	 * the underlying controller.  The refrigerator handles
+	 * most issues; the controller driver handles the rest.
+	 */
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int __init spidev_init(void)
+{
+	int status;
+
+	/* Claim our 256 reserved device numbers.  Then register a class
+	 * that will key udev/mdev to add/remove /dev nodes.  Last, register
+	 * the driver which manages those device numbers.
+	 */
+	BUILD_BUG_ON(N_SPI_MINORS > 256);
+	status = register_chrdev(SPIDEV_MAJOR, "spi", &spidev_fops);
+	if (status < 0)
+		return status;
+
+	status = class_register(&spidev_class);
+	if (status < 0) {
+		unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name);
+		return status;
+	}
+
+	status = spi_register_driver(&spidev_spi);
+	if (status < 0) {
+		class_unregister(&spidev_class);
+		unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name);
+	}
+	return status;
+}
+module_init(spidev_init);
+
+static void __exit spidev_exit(void)
+{
+	spi_unregister_driver(&spidev_spi);
+	class_unregister(&spidev_class);
+	unregister_chrdev(SPIDEV_MAJOR, spidev_spi.driver.name);
+}
+module_exit(spidev_exit);
+
+MODULE_AUTHOR("Andrea Paterniani, <a.paterniani@swapp-eng.it>");
+MODULE_DESCRIPTION("User mode SPI device interface");
+MODULE_LICENSE("GPL");