vlynq.c

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/*
 * Copyright (C) 2006, 2007 Eugene Konev <[email protected]>
 *
 * 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/delay.h>
#include <linux/io.h>
#include <linux/slab.h>
#include <linux/irq.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 CONFIG_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(struct irq_data *d)
{
    struct vlynq_device *dev = irq_data_get_irq_chip_data(d);
    int virq;
    u32 val;

    BUG_ON(!dev);
    virq = d->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(struct irq_data *d)
{
    struct vlynq_device *dev = irq_data_get_irq_chip_data(d);
    int virq;
    u32 val;

    BUG_ON(!dev);
    virq = d->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(struct irq_data *d, unsigned int flow_type)
{
    struct vlynq_device *dev = irq_data_get_irq_chip_data(d);
    int virq;
    u32 val;

    BUG_ON(!dev);
    virq = d->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(struct irq_data *d)
{
    struct vlynq_device *dev = irq_data_get_irq_chip_data(d);
    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(struct irq_data *d)
{
    struct vlynq_device *dev = irq_data_get_irq_chip_data(d);
    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",
    .irq_unmask = vlynq_irq_unmask,
    .irq_mask = vlynq_irq_mask,
    .irq_set_type = vlynq_irq_type,
};

static struct irq_chip vlynq_local_chip = {
    .name = "vlynq local error",
    .irq_unmask = vlynq_irq_unmask,
    .irq_mask = vlynq_irq_mask,
    .irq_ack = vlynq_local_ack,
};

static struct irq_chip vlynq_remote_chip = {
    .name = "vlynq local error",
    .irq_unmask = vlynq_irq_unmask,
    .irq_mask = vlynq_irq_mask,
    .irq_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) {
            irq_set_chip_and_handler(i, &vlynq_local_chip,
                         handle_level_irq);
            irq_set_chip_data(i, dev);
        } else if (virq == dev->remote_irq) {
            irq_set_chip_and_handler(i, &vlynq_remote_chip,
                         handle_level_irq);
            irq_set_chip_data(i, dev);
        } else {
            irq_set_chip_and_handler(i, &vlynq_irq_chip,
                         handle_simple_irq);
            irq_set_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 = resource_size(regs_res);
    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);