drivers: add support for the TI VLYNQ bus

Add support for the TI VLYNQ high-speed, serial and packetized bus.

This bus allows external devices to be connected to the System-on-Chip and
appear in the main system memory just like any memory mapped peripheral.
It is widely used in TI's networking and multimedia SoC, including the AR7
SoC.

Signed-off-by: Eugene Konev <ejka@imfi.kspu.ru>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

3 files changed, 839 insertions, 0 deletions

diff --git a/drivers/vlynq/Kconfig b/drivers/vlynq/Kconfig
new file mode 100644
index 00000000000..f6542211db4
--- /dev/null
+++ b/drivers/vlynq/Kconfig
@@ -0,0 +1,20 @@
+menu "TI VLYNQ"
+
+config VLYNQ
+	bool "TI VLYNQ bus support"
+	depends on AR7 && EXPERIMENTAL
+	help
+	  Support for Texas Instruments(R) VLYNQ bus.
+	  The VLYNQ bus is a high-speed, serial and packetized
+	  data bus which allows external peripherals of a SoC
+	  to appear into the system's main memory.
+
+	  If unsure, say N
+
+config VLYNQ_DEBUG
+	bool "VLYNQ bus debug"
+	depends on VLYNQ && KERNEL_DEBUG
+	help
+	  Turn on VLYNQ bus debugging.
+
+endmenu
diff --git a/drivers/vlynq/Makefile b/drivers/vlynq/Makefile
new file mode 100644
index 00000000000..b3f61149b59
--- /dev/null
+++ b/drivers/vlynq/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for kernel vlynq drivers
+#
+
+obj-$(CONFIG_VLYNQ) += vlynq.o
diff --git a/drivers/vlynq/vlynq.c b/drivers/vlynq/vlynq.c
new file mode 100644
index 00000000000..7335433b067
--- /dev/null
+++ b/drivers/vlynq/vlynq.c
@@ -0,0 +1,814 @@
+/*
+ * Copyright (C) 2006, 2007 Eugene Konev <ejka@openwrt.org>
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Parts of the VLYNQ specification can be found here:
+ * http://www.ti.com/litv/pdf/sprue36a
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+
+#include <linux/vlynq.h>
+
+#define VLYNQ_CTRL_PM_ENABLE		0x80000000
+#define VLYNQ_CTRL_CLOCK_INT		0x00008000
+#define VLYNQ_CTRL_CLOCK_DIV(x)		(((x) & 7) << 16)
+#define VLYNQ_CTRL_INT_LOCAL		0x00004000
+#define VLYNQ_CTRL_INT_ENABLE		0x00002000
+#define VLYNQ_CTRL_INT_VECTOR(x)	(((x) & 0x1f) << 8)
+#define VLYNQ_CTRL_INT2CFG		0x00000080
+#define VLYNQ_CTRL_RESET		0x00000001
+
+#define VLYNQ_CTRL_CLOCK_MASK          (0x7 << 16)
+
+#define VLYNQ_INT_OFFSET		0x00000014
+#define VLYNQ_REMOTE_OFFSET		0x00000080
+
+#define VLYNQ_STATUS_LINK		0x00000001
+#define VLYNQ_STATUS_LERROR		0x00000080
+#define VLYNQ_STATUS_RERROR		0x00000100
+
+#define VINT_ENABLE			0x00000100
+#define VINT_TYPE_EDGE			0x00000080
+#define VINT_LEVEL_LOW			0x00000040
+#define VINT_VECTOR(x)			((x) & 0x1f)
+#define VINT_OFFSET(irq)		(8 * ((irq) % 4))
+
+#define VLYNQ_AUTONEGO_V2		0x00010000
+
+struct vlynq_regs {
+	u32 revision;
+	u32 control;
+	u32 status;
+	u32 int_prio;
+	u32 int_status;
+	u32 int_pending;
+	u32 int_ptr;
+	u32 tx_offset;
+	struct vlynq_mapping rx_mapping[4];
+	u32 chip;
+	u32 autonego;
+	u32 unused[6];
+	u32 int_device[8];
+};
+
+#ifdef VLYNQ_DEBUG
+static void vlynq_dump_regs(struct vlynq_device *dev)
+{
+	int i;
+
+	printk(KERN_DEBUG "VLYNQ local=%p remote=%p\n",
+			dev->local, dev->remote);
+	for (i = 0; i < 32; i++) {
+		printk(KERN_DEBUG "VLYNQ: local %d: %08x\n",
+			i + 1, ((u32 *)dev->local)[i]);
+		printk(KERN_DEBUG "VLYNQ: remote %d: %08x\n",
+			i + 1, ((u32 *)dev->remote)[i]);
+	}
+}
+
+static void vlynq_dump_mem(u32 *base, int count)
+{
+	int i;
+
+	for (i = 0; i < (count + 3) / 4; i++) {
+		if (i % 4 == 0)
+			printk(KERN_DEBUG "\nMEM[0x%04x]:", i * 4);
+		printk(KERN_DEBUG " 0x%08x", *(base + i));
+	}
+	printk(KERN_DEBUG "\n");
+}
+#endif
+
+/* Check the VLYNQ link status with a given device */
+static int vlynq_linked(struct vlynq_device *dev)
+{
+	int i;
+
+	for (i = 0; i < 100; i++)
+		if (readl(&dev->local->status) & VLYNQ_STATUS_LINK)
+			return 1;
+		else
+			cpu_relax();
+
+	return 0;
+}
+
+static void vlynq_reset(struct vlynq_device *dev)
+{
+	writel(readl(&dev->local->control) | VLYNQ_CTRL_RESET,
+			&dev->local->control);
+
+	/* Wait for the devices to finish resetting */
+	msleep(5);
+
+	/* Remove reset bit */
+	writel(readl(&dev->local->control) & ~VLYNQ_CTRL_RESET,
+			&dev->local->control);
+
+	/* Give some time for the devices to settle */
+	msleep(5);
+}
+
+static void vlynq_irq_unmask(unsigned int irq)
+{
+	u32 val;
+	struct vlynq_device *dev = get_irq_chip_data(irq);
+	int virq;
+
+	BUG_ON(!dev);
+	virq = irq - dev->irq_start;
+	val = readl(&dev->remote->int_device[virq >> 2]);
+	val |= (VINT_ENABLE | virq) << VINT_OFFSET(virq);
+	writel(val, &dev->remote->int_device[virq >> 2]);
+}
+
+static void vlynq_irq_mask(unsigned int irq)
+{
+	u32 val;
+	struct vlynq_device *dev = get_irq_chip_data(irq);
+	int virq;
+
+	BUG_ON(!dev);
+	virq = irq - dev->irq_start;
+	val = readl(&dev->remote->int_device[virq >> 2]);
+	val &= ~(VINT_ENABLE << VINT_OFFSET(virq));
+	writel(val, &dev->remote->int_device[virq >> 2]);
+}
+
+static int vlynq_irq_type(unsigned int irq, unsigned int flow_type)
+{
+	u32 val;
+	struct vlynq_device *dev = get_irq_chip_data(irq);
+	int virq;
+
+	BUG_ON(!dev);
+	virq = irq - dev->irq_start;
+	val = readl(&dev->remote->int_device[virq >> 2]);
+	switch (flow_type & IRQ_TYPE_SENSE_MASK) {
+	case IRQ_TYPE_EDGE_RISING:
+	case IRQ_TYPE_EDGE_FALLING:
+	case IRQ_TYPE_EDGE_BOTH:
+		val |= VINT_TYPE_EDGE << VINT_OFFSET(virq);
+		val &= ~(VINT_LEVEL_LOW << VINT_OFFSET(virq));
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		val &= ~(VINT_TYPE_EDGE << VINT_OFFSET(virq));
+		val &= ~(VINT_LEVEL_LOW << VINT_OFFSET(virq));
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		val &= ~(VINT_TYPE_EDGE << VINT_OFFSET(virq));
+		val |= VINT_LEVEL_LOW << VINT_OFFSET(virq);
+		break;
+	default:
+		return -EINVAL;
+	}
+	writel(val, &dev->remote->int_device[virq >> 2]);
+	return 0;
+}
+
+static void vlynq_local_ack(unsigned int irq)
+{
+	struct vlynq_device *dev = get_irq_chip_data(irq);
+
+	u32 status = readl(&dev->local->status);
+
+	pr_debug("%s: local status: 0x%08x\n",
+		       dev_name(&dev->dev), status);
+	writel(status, &dev->local->status);
+}
+
+static void vlynq_remote_ack(unsigned int irq)
+{
+	struct vlynq_device *dev = get_irq_chip_data(irq);
+
+	u32 status = readl(&dev->remote->status);
+
+	pr_debug("%s: remote status: 0x%08x\n",
+		       dev_name(&dev->dev), status);
+	writel(status, &dev->remote->status);
+}
+
+static irqreturn_t vlynq_irq(int irq, void *dev_id)
+{
+	struct vlynq_device *dev = dev_id;
+	u32 status;
+	int virq = 0;
+
+	status = readl(&dev->local->int_status);
+	writel(status, &dev->local->int_status);
+
+	if (unlikely(!status))
+		spurious_interrupt();
+
+	while (status) {
+		if (status & 1)
+			do_IRQ(dev->irq_start + virq);
+		status >>= 1;
+		virq++;
+	}
+
+	return IRQ_HANDLED;
+}
+
+static struct irq_chip vlynq_irq_chip = {
+	.name = "vlynq",
+	.unmask = vlynq_irq_unmask,
+	.mask = vlynq_irq_mask,
+	.set_type = vlynq_irq_type,
+};
+
+static struct irq_chip vlynq_local_chip = {
+	.name = "vlynq local error",
+	.unmask = vlynq_irq_unmask,
+	.mask = vlynq_irq_mask,
+	.ack = vlynq_local_ack,
+};
+
+static struct irq_chip vlynq_remote_chip = {
+	.name = "vlynq local error",
+	.unmask = vlynq_irq_unmask,
+	.mask = vlynq_irq_mask,
+	.ack = vlynq_remote_ack,
+};
+
+static int vlynq_setup_irq(struct vlynq_device *dev)
+{
+	u32 val;
+	int i, virq;
+
+	if (dev->local_irq == dev->remote_irq) {
+		printk(KERN_ERR
+		       "%s: local vlynq irq should be different from remote\n",
+		       dev_name(&dev->dev));
+		return -EINVAL;
+	}
+
+	/* Clear local and remote error bits */
+	writel(readl(&dev->local->status), &dev->local->status);
+	writel(readl(&dev->remote->status), &dev->remote->status);
+
+	/* Now setup interrupts */
+	val = VLYNQ_CTRL_INT_VECTOR(dev->local_irq);
+	val |= VLYNQ_CTRL_INT_ENABLE | VLYNQ_CTRL_INT_LOCAL |
+		VLYNQ_CTRL_INT2CFG;
+	val |= readl(&dev->local->control);
+	writel(VLYNQ_INT_OFFSET, &dev->local->int_ptr);
+	writel(val, &dev->local->control);
+
+	val = VLYNQ_CTRL_INT_VECTOR(dev->remote_irq);
+	val |= VLYNQ_CTRL_INT_ENABLE;
+	val |= readl(&dev->remote->control);
+	writel(VLYNQ_INT_OFFSET, &dev->remote->int_ptr);
+	writel(val, &dev->remote->int_ptr);
+	writel(val, &dev->remote->control);
+
+	for (i = dev->irq_start; i <= dev->irq_end; i++) {
+		virq = i - dev->irq_start;
+		if (virq == dev->local_irq) {
+			set_irq_chip_and_handler(i, &vlynq_local_chip,
+						 handle_level_irq);
+			set_irq_chip_data(i, dev);
+		} else if (virq == dev->remote_irq) {
+			set_irq_chip_and_handler(i, &vlynq_remote_chip,
+						 handle_level_irq);
+			set_irq_chip_data(i, dev);
+		} else {
+			set_irq_chip_and_handler(i, &vlynq_irq_chip,
+						 handle_simple_irq);
+			set_irq_chip_data(i, dev);
+			writel(0, &dev->remote->int_device[virq >> 2]);
+		}
+	}
+
+	if (request_irq(dev->irq, vlynq_irq, IRQF_SHARED, "vlynq", dev)) {
+		printk(KERN_ERR "%s: request_irq failed\n",
+					dev_name(&dev->dev));
+		return -EAGAIN;
+	}
+
+	return 0;
+}
+
+static void vlynq_device_release(struct device *dev)
+{
+	struct vlynq_device *vdev = to_vlynq_device(dev);
+	kfree(vdev);
+}
+
+static int vlynq_device_match(struct device *dev,
+			      struct device_driver *drv)
+{
+	struct vlynq_device *vdev = to_vlynq_device(dev);
+	struct vlynq_driver *vdrv = to_vlynq_driver(drv);
+	struct vlynq_device_id *ids = vdrv->id_table;
+
+	while (ids->id) {
+		if (ids->id == vdev->dev_id) {
+			vdev->divisor = ids->divisor;
+			vlynq_set_drvdata(vdev, ids);
+			printk(KERN_INFO "Driver found for VLYNQ "
+				"device: %08x\n", vdev->dev_id);
+			return 1;
+		}
+		printk(KERN_DEBUG "Not using the %08x VLYNQ device's driver"
+			" for VLYNQ device: %08x\n", ids->id, vdev->dev_id);
+		ids++;
+	}
+	return 0;
+}
+
+static int vlynq_device_probe(struct device *dev)
+{
+	struct vlynq_device *vdev = to_vlynq_device(dev);
+	struct vlynq_driver *drv = to_vlynq_driver(dev->driver);
+	struct vlynq_device_id *id = vlynq_get_drvdata(vdev);
+	int result = -ENODEV;
+
+	if (drv->probe)
+		result = drv->probe(vdev, id);
+	if (result)
+		put_device(dev);
+	return result;
+}
+
+static int vlynq_device_remove(struct device *dev)
+{
+	struct vlynq_driver *drv = to_vlynq_driver(dev->driver);
+
+	if (drv->remove)
+		drv->remove(to_vlynq_device(dev));
+
+	return 0;
+}
+
+int __vlynq_register_driver(struct vlynq_driver *driver, struct module *owner)
+{
+	driver->driver.name = driver->name;
+	driver->driver.bus = &vlynq_bus_type;
+	return driver_register(&driver->driver);
+}
+EXPORT_SYMBOL(__vlynq_register_driver);
+
+void vlynq_unregister_driver(struct vlynq_driver *driver)
+{
+	driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL(vlynq_unregister_driver);
+
+/*
+ * A VLYNQ remote device can clock the VLYNQ bus master
+ * using a dedicated clock line. In that case, both the
+ * remove device and the bus master should have the same
+ * serial clock dividers configured. Iterate through the
+ * 8 possible dividers until we actually link with the
+ * device.
+ */
+static int __vlynq_try_remote(struct vlynq_device *dev)
+{
+	int i;
+
+	vlynq_reset(dev);
+	for (i = dev->dev_id ? vlynq_rdiv2 : vlynq_rdiv8; dev->dev_id ?
+			i <= vlynq_rdiv8 : i >= vlynq_rdiv2;
+		dev->dev_id ? i++ : i--) {
+
+		if (!vlynq_linked(dev))
+			break;
+
+		writel((readl(&dev->remote->control) &
+				~VLYNQ_CTRL_CLOCK_MASK) |
+				VLYNQ_CTRL_CLOCK_INT |
+				VLYNQ_CTRL_CLOCK_DIV(i - vlynq_rdiv1),
+				&dev->remote->control);
+		writel((readl(&dev->local->control)
+				& ~(VLYNQ_CTRL_CLOCK_INT |
+				VLYNQ_CTRL_CLOCK_MASK)) |
+				VLYNQ_CTRL_CLOCK_DIV(i - vlynq_rdiv1),
+				&dev->local->control);
+
+		if (vlynq_linked(dev)) {
+			printk(KERN_DEBUG
+				"%s: using remote clock divisor %d\n",
+				dev_name(&dev->dev), i - vlynq_rdiv1 + 1);
+			dev->divisor = i;
+			return 0;
+		} else {
+			vlynq_reset(dev);
+		}
+	}
+
+	return -ENODEV;
+}
+
+/*
+ * A VLYNQ remote device can be clocked by the VLYNQ bus
+ * master using a dedicated clock line. In that case, only
+ * the bus master configures the serial clock divider.
+ * Iterate through the 8 possible dividers until we
+ * actually get a link with the device.
+ */
+static int __vlynq_try_local(struct vlynq_device *dev)
+{
+	int i;
+
+	vlynq_reset(dev);
+
+	for (i = dev->dev_id ? vlynq_ldiv2 : vlynq_ldiv8; dev->dev_id ?
+			i <= vlynq_ldiv8 : i >= vlynq_ldiv2;
+		dev->dev_id ? i++ : i--) {
+
+		writel((readl(&dev->local->control) &
+				~VLYNQ_CTRL_CLOCK_MASK) |
+				VLYNQ_CTRL_CLOCK_INT |
+				VLYNQ_CTRL_CLOCK_DIV(i - vlynq_ldiv1),
+				&dev->local->control);
+
+		if (vlynq_linked(dev)) {
+			printk(KERN_DEBUG
+				"%s: using local clock divisor %d\n",
+				dev_name(&dev->dev), i - vlynq_ldiv1 + 1);
+			dev->divisor = i;
+			return 0;
+		} else {
+			vlynq_reset(dev);
+		}
+	}
+
+	return -ENODEV;
+}
+
+/*
+ * When using external clocking method, serial clock
+ * is supplied by an external oscillator, therefore we
+ * should mask the local clock bit in the clock control
+ * register for both the bus master and the remote device.
+ */
+static int __vlynq_try_external(struct vlynq_device *dev)
+{
+	vlynq_reset(dev);
+	if (!vlynq_linked(dev))
+		return -ENODEV;
+
+	writel((readl(&dev->remote->control) &
+			~VLYNQ_CTRL_CLOCK_INT),
+			&dev->remote->control);
+
+	writel((readl(&dev->local->control) &
+			~VLYNQ_CTRL_CLOCK_INT),
+			&dev->local->control);
+
+	if (vlynq_linked(dev)) {
+		printk(KERN_DEBUG "%s: using external clock\n",
+			dev_name(&dev->dev));
+			dev->divisor = vlynq_div_external;
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
+static int __vlynq_enable_device(struct vlynq_device *dev)
+{
+	int result;
+	struct plat_vlynq_ops *ops = dev->dev.platform_data;
+
+	result = ops->on(dev);
+	if (result)
+		return result;
+
+	switch (dev->divisor) {
+	case vlynq_div_external:
+	case vlynq_div_auto:
+		/* When the device is brought from reset it should have clock
+		 * generation negotiated by hardware.
+		 * Check which device is generating clocks and perform setup
+		 * accordingly */
+		if (vlynq_linked(dev) && readl(&dev->remote->control) &
+		   VLYNQ_CTRL_CLOCK_INT) {
+			if (!__vlynq_try_remote(dev) ||
+				!__vlynq_try_local(dev)  ||
+				!__vlynq_try_external(dev))
+				return 0;
+		} else {
+			if (!__vlynq_try_external(dev) ||
+				!__vlynq_try_local(dev)    ||
+				!__vlynq_try_remote(dev))
+				return 0;
+		}
+		break;
+	case vlynq_ldiv1:
+	case vlynq_ldiv2:
+	case vlynq_ldiv3:
+	case vlynq_ldiv4:
+	case vlynq_ldiv5:
+	case vlynq_ldiv6:
+	case vlynq_ldiv7:
+	case vlynq_ldiv8:
+		writel(VLYNQ_CTRL_CLOCK_INT |
+			VLYNQ_CTRL_CLOCK_DIV(dev->divisor -
+			vlynq_ldiv1), &dev->local->control);
+		writel(0, &dev->remote->control);
+		if (vlynq_linked(dev)) {
+			printk(KERN_DEBUG
+				"%s: using local clock divisor %d\n",
+				dev_name(&dev->dev),
+				dev->divisor - vlynq_ldiv1 + 1);
+			return 0;
+		}
+		break;
+	case vlynq_rdiv1:
+	case vlynq_rdiv2:
+	case vlynq_rdiv3:
+	case vlynq_rdiv4:
+	case vlynq_rdiv5:
+	case vlynq_rdiv6:
+	case vlynq_rdiv7:
+	case vlynq_rdiv8:
+		writel(0, &dev->local->control);
+		writel(VLYNQ_CTRL_CLOCK_INT |
+			VLYNQ_CTRL_CLOCK_DIV(dev->divisor -
+			vlynq_rdiv1), &dev->remote->control);
+		if (vlynq_linked(dev)) {
+			printk(KERN_DEBUG
+				"%s: using remote clock divisor %d\n",
+				dev_name(&dev->dev),
+				dev->divisor - vlynq_rdiv1 + 1);
+			return 0;
+		}
+		break;
+	}
+
+	ops->off(dev);
+	return -ENODEV;
+}
+
+int vlynq_enable_device(struct vlynq_device *dev)
+{
+	struct plat_vlynq_ops *ops = dev->dev.platform_data;
+	int result = -ENODEV;
+
+	result = __vlynq_enable_device(dev);
+	if (result)
+		return result;
+
+	result = vlynq_setup_irq(dev);
+	if (result)
+		ops->off(dev);
+
+	dev->enabled = !result;
+	return result;
+}
+EXPORT_SYMBOL(vlynq_enable_device);
+
+
+void vlynq_disable_device(struct vlynq_device *dev)
+{
+	struct plat_vlynq_ops *ops = dev->dev.platform_data;
+
+	dev->enabled = 0;
+	free_irq(dev->irq, dev);
+	ops->off(dev);
+}
+EXPORT_SYMBOL(vlynq_disable_device);
+
+int vlynq_set_local_mapping(struct vlynq_device *dev, u32 tx_offset,
+			    struct vlynq_mapping *mapping)
+{
+	int i;
+
+	if (!dev->enabled)
+		return -ENXIO;
+
+	writel(tx_offset, &dev->local->tx_offset);
+	for (i = 0; i < 4; i++) {
+		writel(mapping[i].offset, &dev->local->rx_mapping[i].offset);
+		writel(mapping[i].size, &dev->local->rx_mapping[i].size);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(vlynq_set_local_mapping);
+
+int vlynq_set_remote_mapping(struct vlynq_device *dev, u32 tx_offset,
+			     struct vlynq_mapping *mapping)
+{
+	int i;
+
+	if (!dev->enabled)
+		return -ENXIO;
+
+	writel(tx_offset, &dev->remote->tx_offset);
+	for (i = 0; i < 4; i++) {
+		writel(mapping[i].offset, &dev->remote->rx_mapping[i].offset);
+		writel(mapping[i].size, &dev->remote->rx_mapping[i].size);
+	}
+	return 0;
+}
+EXPORT_SYMBOL(vlynq_set_remote_mapping);
+
+int vlynq_set_local_irq(struct vlynq_device *dev, int virq)
+{
+	int irq = dev->irq_start + virq;
+	if (dev->enabled)
+		return -EBUSY;
+
+	if ((irq < dev->irq_start) || (irq > dev->irq_end))
+		return -EINVAL;
+
+	if (virq == dev->remote_irq)
+		return -EINVAL;
+
+	dev->local_irq = virq;
+
+	return 0;
+}
+EXPORT_SYMBOL(vlynq_set_local_irq);
+
+int vlynq_set_remote_irq(struct vlynq_device *dev, int virq)
+{
+	int irq = dev->irq_start + virq;
+	if (dev->enabled)
+		return -EBUSY;
+
+	if ((irq < dev->irq_start) || (irq > dev->irq_end))
+		return -EINVAL;
+
+	if (virq == dev->local_irq)
+		return -EINVAL;
+
+	dev->remote_irq = virq;
+
+	return 0;
+}
+EXPORT_SYMBOL(vlynq_set_remote_irq);
+
+static int vlynq_probe(struct platform_device *pdev)
+{
+	struct vlynq_device *dev;
+	struct resource *regs_res, *mem_res, *irq_res;
+	int len, result;
+
+	regs_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "regs");
+	if (!regs_res)
+		return -ENODEV;
+
+	mem_res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "mem");
+	if (!mem_res)
+		return -ENODEV;
+
+	irq_res = platform_get_resource_byname(pdev, IORESOURCE_IRQ, "devirq");
+	if (!irq_res)
+		return -ENODEV;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev) {
+		printk(KERN_ERR
+		       "vlynq: failed to allocate device structure\n");
+		return -ENOMEM;
+	}
+
+	dev->id = pdev->id;
+	dev->dev.bus = &vlynq_bus_type;
+	dev->dev.parent = &pdev->dev;
+	dev_set_name(&dev->dev, "vlynq%d", dev->id);
+	dev->dev.platform_data = pdev->dev.platform_data;
+	dev->dev.release = vlynq_device_release;
+
+	dev->regs_start = regs_res->start;
+	dev->regs_end = regs_res->end;
+	dev->mem_start = mem_res->start;
+	dev->mem_end = mem_res->end;
+
+	len = regs_res->end - regs_res->start;
+	if (!request_mem_region(regs_res->start, len, dev_name(&dev->dev))) {
+		printk(KERN_ERR "%s: Can't request vlynq registers\n",
+		       dev_name(&dev->dev));
+		result = -ENXIO;
+		goto fail_request;
+	}
+
+	dev->local = ioremap(regs_res->start, len);
+	if (!dev->local) {
+		printk(KERN_ERR "%s: Can't remap vlynq registers\n",
+		       dev_name(&dev->dev));
+		result = -ENXIO;
+		goto fail_remap;
+	}
+
+	dev->remote = (struct vlynq_regs *)((void *)dev->local +
+					    VLYNQ_REMOTE_OFFSET);
+
+	dev->irq = platform_get_irq_byname(pdev, "irq");
+	dev->irq_start = irq_res->start;
+	dev->irq_end = irq_res->end;
+	dev->local_irq = dev->irq_end - dev->irq_start;
+	dev->remote_irq = dev->local_irq - 1;
+
+	if (device_register(&dev->dev))
+		goto fail_register;
+	platform_set_drvdata(pdev, dev);
+
+	printk(KERN_INFO "%s: regs 0x%p, irq %d, mem 0x%p\n",
+	       dev_name(&dev->dev), (void *)dev->regs_start, dev->irq,
+	       (void *)dev->mem_start);
+
+	dev->dev_id = 0;
+	dev->divisor = vlynq_div_auto;
+	result = __vlynq_enable_device(dev);
+	if (result == 0) {
+		dev->dev_id = readl(&dev->remote->chip);
+		((struct plat_vlynq_ops *)(dev->dev.platform_data))->off(dev);
+	}
+	if (dev->dev_id)
+		printk(KERN_INFO "Found a VLYNQ device: %08x\n", dev->dev_id);
+
+	return 0;
+
+fail_register:
+	iounmap(dev->local);
+fail_remap:
+fail_request:
+	release_mem_region(regs_res->start, len);
+	kfree(dev);
+	return result;
+}
+
+static int vlynq_remove(struct platform_device *pdev)
+{
+	struct vlynq_device *dev = platform_get_drvdata(pdev);
+
+	device_unregister(&dev->dev);
+	iounmap(dev->local);
+	release_mem_region(dev->regs_start, dev->regs_end - dev->regs_start);
+
+	kfree(dev);
+
+	return 0;
+}
+
+static struct platform_driver vlynq_platform_driver = {
+	.driver.name = "vlynq",
+	.probe = vlynq_probe,
+	.remove = __devexit_p(vlynq_remove),
+};
+
+struct bus_type vlynq_bus_type = {
+	.name = "vlynq",
+	.match = vlynq_device_match,
+	.probe = vlynq_device_probe,
+	.remove = vlynq_device_remove,
+};
+EXPORT_SYMBOL(vlynq_bus_type);
+
+static int __devinit vlynq_init(void)
+{
+	int res = 0;
+
+	res = bus_register(&vlynq_bus_type);
+	if (res)
+		goto fail_bus;
+
+	res = platform_driver_register(&vlynq_platform_driver);
+	if (res)
+		goto fail_platform;
+
+	return 0;
+
+fail_platform:
+	bus_unregister(&vlynq_bus_type);
+fail_bus:
+	return res;
+}
+
+static void __devexit vlynq_exit(void)
+{
+	platform_driver_unregister(&vlynq_platform_driver);
+	bus_unregister(&vlynq_bus_type);
+}
+
+module_init(vlynq_init);
+module_exit(vlynq_exit);