// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver for onboard USB devices
 *
 * Copyright (c) 2022, Google LLC
 */

#include <linux/clk.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/suspend.h>
#include <linux/sysfs.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/usb/onboard_dev.h>
#include <linux/workqueue.h>

#include "onboard_usb_dev.h"

/* USB5744 register offset and mask */
#define USB5744_CMD_ATTACH                      0xAA
#define USB5744_CMD_ATTACH_LSB                  0x56
#define USB5744_CMD_CREG_ACCESS                 0x99
#define USB5744_CMD_CREG_ACCESS_LSB             0x37
#define USB5744_CREG_MEM_ADDR                   0x00
#define USB5744_CREG_MEM_RD_ADDR                0x04
#define USB5744_CREG_WRITE                      0x00
#define USB5744_CREG_READ                       0x01
#define USB5744_CREG_RUNTIMEFLAGS2              0x411D
#define USB5744_CREG_BYPASS_UDC_SUSPEND         BIT(3)

static void onboard_dev_attach_usb_driver(struct work_struct *work);

static struct usb_device_driver onboard_dev_usbdev_driver;
static DECLARE_WORK(attach_usb_driver_work, onboard_dev_attach_usb_driver);

/************************** Platform driver **************************/

struct usbdev_node {
        struct usb_device *udev;
        struct list_head list;
};

struct onboard_dev {
        struct regulator_bulk_data supplies[MAX_SUPPLIES];
        struct device *dev;
        const struct onboard_dev_pdata *pdata;
        struct gpio_desc *reset_gpio;
        bool always_powered_in_suspend;
        bool is_powered_on;
        bool going_away;
        struct list_head udev_list;
        struct mutex lock;
        struct clk *clk;
};

static int onboard_dev_get_regulators(struct onboard_dev *onboard_dev)
{
        const char * const *supply_names = onboard_dev->pdata->supply_names;
        unsigned int num_supplies = onboard_dev->pdata->num_supplies;
        struct device *dev = onboard_dev->dev;
        unsigned int i;
        int err;

        if (num_supplies > MAX_SUPPLIES)
                return dev_err_probe(dev, -EINVAL, "max %d supplies supported!\n",
                                     MAX_SUPPLIES);

        for (i = 0; i < num_supplies; i++)
                onboard_dev->supplies[i].supply = supply_names[i];

        err = devm_regulator_bulk_get(dev, num_supplies, onboard_dev->supplies);
        if (err)
                dev_err(dev, "Failed to get regulator supplies: %pe\n",
                        ERR_PTR(err));

        return err;
}

static int onboard_dev_power_on(struct onboard_dev *onboard_dev)
{
        int err;

        err = clk_prepare_enable(onboard_dev->clk);
        if (err) {
                dev_err(onboard_dev->dev, "failed to enable clock: %pe\n",
                        ERR_PTR(err));
                return err;
        }

        err = regulator_bulk_enable(onboard_dev->pdata->num_supplies,
                                    onboard_dev->supplies);
        if (err) {
                dev_err(onboard_dev->dev, "failed to enable supplies: %pe\n",
                        ERR_PTR(err));
                goto disable_clk;
        }

        fsleep(onboard_dev->pdata->reset_us);
        gpiod_set_value_cansleep(onboard_dev->reset_gpio, 0);
        fsleep(onboard_dev->pdata->power_on_delay_us);

        onboard_dev->is_powered_on = true;

        return 0;

disable_clk:
        clk_disable_unprepare(onboard_dev->clk);
        return err;
}

static int onboard_dev_power_off(struct onboard_dev *onboard_dev)
{
        int err;

        gpiod_set_value_cansleep(onboard_dev->reset_gpio, 1);

        err = regulator_bulk_disable(onboard_dev->pdata->num_supplies,
                                     onboard_dev->supplies);
        if (err) {
                dev_err(onboard_dev->dev, "failed to disable supplies: %pe\n",
                        ERR_PTR(err));
                return err;
        }

        clk_disable_unprepare(onboard_dev->clk);

        onboard_dev->is_powered_on = false;

        return 0;
}

static int __maybe_unused onboard_dev_suspend(struct device *dev)
{
        struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
        struct usbdev_node *node;
        bool power_off = true;

        if (onboard_dev->always_powered_in_suspend)
                return 0;

        mutex_lock(&onboard_dev->lock);

        list_for_each_entry(node, &onboard_dev->udev_list, list) {
                if (!device_may_wakeup(node->udev->bus->controller))
                        continue;

                if (usb_wakeup_enabled_descendants(node->udev)) {
                        power_off = false;
                        break;
                }
        }

        mutex_unlock(&onboard_dev->lock);

        if (!power_off)
                return 0;

        return onboard_dev_power_off(onboard_dev);
}

static int __maybe_unused onboard_dev_resume(struct device *dev)
{
        struct onboard_dev *onboard_dev = dev_get_drvdata(dev);

        if (onboard_dev->is_powered_on)
                return 0;

        return onboard_dev_power_on(onboard_dev);
}

static inline void get_udev_link_name(const struct usb_device *udev, char *buf,
                                      size_t size)
{
        snprintf(buf, size, "usb_dev.%s", dev_name(&udev->dev));
}

static int onboard_dev_add_usbdev(struct onboard_dev *onboard_dev,
                                  struct usb_device *udev)
{
        struct usbdev_node *node;
        char link_name[64];
        int err;

        mutex_lock(&onboard_dev->lock);

        if (onboard_dev->going_away) {
                err = -EINVAL;
                goto error;
        }

        node = kzalloc_obj(*node);
        if (!node) {
                err = -ENOMEM;
                goto error;
        }

        node->udev = udev;

        list_add(&node->list, &onboard_dev->udev_list);

        mutex_unlock(&onboard_dev->lock);

        get_udev_link_name(udev, link_name, sizeof(link_name));
        WARN_ON(sysfs_create_link(&onboard_dev->dev->kobj, &udev->dev.kobj,
                                  link_name));

        return 0;

error:
        mutex_unlock(&onboard_dev->lock);

        return err;
}

static void onboard_dev_remove_usbdev(struct onboard_dev *onboard_dev,
                                      const struct usb_device *udev)
{
        struct usbdev_node *node;
        char link_name[64];

        get_udev_link_name(udev, link_name, sizeof(link_name));
        sysfs_remove_link(&onboard_dev->dev->kobj, link_name);

        mutex_lock(&onboard_dev->lock);

        list_for_each_entry(node, &onboard_dev->udev_list, list) {
                if (node->udev == udev) {
                        list_del(&node->list);
                        kfree(node);
                        break;
                }
        }

        mutex_unlock(&onboard_dev->lock);
}

static ssize_t always_powered_in_suspend_show(struct device *dev,
                                              struct device_attribute *attr,
                                              char *buf)
{
        const struct onboard_dev *onboard_dev = dev_get_drvdata(dev);

        return sysfs_emit(buf, "%d\n", onboard_dev->always_powered_in_suspend);
}

static ssize_t always_powered_in_suspend_store(struct device *dev,
                                               struct device_attribute *attr,
                                               const char *buf, size_t count)
{
        struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
        bool val;
        int ret;

        ret = kstrtobool(buf, &val);
        if (ret < 0)
                return ret;

        onboard_dev->always_powered_in_suspend = val;

        return count;
}
static DEVICE_ATTR_RW(always_powered_in_suspend);

static struct attribute *onboard_dev_attrs[] = {
        &dev_attr_always_powered_in_suspend.attr,
        NULL,
};

static umode_t onboard_dev_attrs_are_visible(struct kobject *kobj,
                                             struct attribute *attr,
                                             int n)
{
        struct device *dev = kobj_to_dev(kobj);
        struct onboard_dev *onboard_dev = dev_get_drvdata(dev);

        if (attr == &dev_attr_always_powered_in_suspend.attr &&
            !onboard_dev->pdata->is_hub)
                return 0;

        return attr->mode;
}

static const struct attribute_group onboard_dev_group = {
        .is_visible = onboard_dev_attrs_are_visible,
        .attrs = onboard_dev_attrs,
};
__ATTRIBUTE_GROUPS(onboard_dev);


static void onboard_dev_attach_usb_driver(struct work_struct *work)
{
        int err;

        err = driver_attach(&onboard_dev_usbdev_driver.driver);
        if (err)
                pr_err("Failed to attach USB driver: %pe\n", ERR_PTR(err));
}

#if IS_ENABLED(CONFIG_USB_ONBOARD_DEV_USB5744)
static int onboard_dev_5744_i2c_read_byte(struct i2c_client *client, u16 addr, u8 *data)
{
        struct i2c_msg msg[2];
        u8 rd_buf[3];
        int ret;

        u8 wr_buf[7] = {0, USB5744_CREG_MEM_ADDR, 4,
                        USB5744_CREG_READ, 1,
                        addr >> 8 & 0xff,
                        addr & 0xff};
        msg[0].addr = client->addr;
        msg[0].flags = 0;
        msg[0].len = sizeof(wr_buf);
        msg[0].buf = wr_buf;

        ret = i2c_transfer(client->adapter, msg, 1);
        if (ret < 0)
                return ret;

        wr_buf[0] = USB5744_CMD_CREG_ACCESS;
        wr_buf[1] = USB5744_CMD_CREG_ACCESS_LSB;
        wr_buf[2] = 0;
        msg[0].len = 3;

        ret = i2c_transfer(client->adapter, msg, 1);
        if (ret < 0)
                return ret;

        wr_buf[0] = 0;
        wr_buf[1] = USB5744_CREG_MEM_RD_ADDR;
        msg[0].len = 2;

        msg[1].addr = client->addr;
        msg[1].flags = I2C_M_RD;
        msg[1].len = 2;
        msg[1].buf = rd_buf;

        ret = i2c_transfer(client->adapter, msg, 2);
        if (ret < 0)
                return ret;
        *data = rd_buf[1];

        return 0;
}

static int onboard_dev_5744_i2c_write_byte(struct i2c_client *client, u16 addr, u8 data)
{
        struct i2c_msg msg[2];
        int ret;

        u8 wr_buf[8] = {0, USB5744_CREG_MEM_ADDR, 5,
                        USB5744_CREG_WRITE, 1,
                        addr >> 8 & 0xff,
                        addr & 0xff,
                        data};
        msg[0].addr = client->addr;
        msg[0].flags = 0;
        msg[0].len = sizeof(wr_buf);
        msg[0].buf = wr_buf;

        ret = i2c_transfer(client->adapter, msg, 1);
        if (ret < 0)
                return ret;

        msg[0].len = 3;
        wr_buf[0] = USB5744_CMD_CREG_ACCESS;
        wr_buf[1] = USB5744_CMD_CREG_ACCESS_LSB;
        wr_buf[2] = 0;

        ret = i2c_transfer(client->adapter, msg, 1);
        if (ret < 0)
                return ret;

        return 0;
}

static int onboard_dev_5744_i2c_init(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        int ret;
        u8 reg;

        /*
         * Set BYPASS_UDC_SUSPEND bit to ensure MCU is always enabled
         * and ready to respond to SMBus runtime commands.
         * The command writes 5 bytes to memory and single data byte in
         * configuration register.
         */
        ret = onboard_dev_5744_i2c_read_byte(client,
                                             USB5744_CREG_RUNTIMEFLAGS2, &reg);
        if (ret)
                return dev_err_probe(dev, ret, "CREG_RUNTIMEFLAGS2 read failed\n");

        reg |= USB5744_CREG_BYPASS_UDC_SUSPEND;
        ret = onboard_dev_5744_i2c_write_byte(client,
                                              USB5744_CREG_RUNTIMEFLAGS2, reg);
        if (ret)
                return dev_err_probe(dev, ret, "BYPASS_UDC_SUSPEND bit configuration failed\n");

        /* Send SMBus command to boot hub. */
        ret = i2c_smbus_write_word_data(client, USB5744_CMD_ATTACH,
                                        USB5744_CMD_ATTACH_LSB);
        if (ret < 0)
                return dev_err_probe(dev, ret, "USB Attach with SMBus command failed\n");

        return ret;
}
#else
static int onboard_dev_5744_i2c_init(struct i2c_client *client)
{
        return -ENODEV;
}
#endif

static int onboard_dev_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct onboard_dev *onboard_dev;
        struct device_node *i2c_node;
        int err;

        onboard_dev = devm_kzalloc(dev, sizeof(*onboard_dev), GFP_KERNEL);
        if (!onboard_dev)
                return -ENOMEM;

        onboard_dev->pdata = device_get_match_data(dev);
        if (!onboard_dev->pdata)
                return -EINVAL;

        if (!onboard_dev->pdata->is_hub)
                onboard_dev->always_powered_in_suspend = true;

        onboard_dev->dev = dev;

        err = onboard_dev_get_regulators(onboard_dev);
        if (err)
                return err;

        onboard_dev->clk = devm_clk_get_optional(dev, NULL);
        if (IS_ERR(onboard_dev->clk))
                return dev_err_probe(dev, PTR_ERR(onboard_dev->clk),
                                     "failed to get clock\n");

        onboard_dev->reset_gpio = devm_gpiod_get_optional(dev, "reset",
                                                          GPIOD_OUT_HIGH);
        if (IS_ERR(onboard_dev->reset_gpio))
                return dev_err_probe(dev, PTR_ERR(onboard_dev->reset_gpio),
                                     "failed to get reset GPIO\n");

        mutex_init(&onboard_dev->lock);
        INIT_LIST_HEAD(&onboard_dev->udev_list);

        dev_set_drvdata(dev, onboard_dev);

        err = onboard_dev_power_on(onboard_dev);
        if (err)
                return err;

        i2c_node = of_parse_phandle(pdev->dev.of_node, "i2c-bus", 0);
        if (i2c_node) {
                struct i2c_client *client = NULL;

#if IS_ENABLED(CONFIG_USB_ONBOARD_DEV_USB5744)
                client = of_find_i2c_device_by_node(i2c_node);
#endif
                of_node_put(i2c_node);

                if (!client) {
                        err = -EPROBE_DEFER;
                        goto err_power_off;
                }

                if (of_device_is_compatible(pdev->dev.of_node, "usb424,2744") ||
                    of_device_is_compatible(pdev->dev.of_node, "usb424,5744")) {
                        err = onboard_dev_5744_i2c_init(client);
                        onboard_dev->always_powered_in_suspend = true;
                }

                put_device(&client->dev);
                if (err < 0)
                        goto err_power_off;
        }

        /*
         * The USB driver might have been detached from the USB devices by
         * onboard_dev_remove() (e.g. through an 'unbind' by userspace),
         * make sure to re-attach it if needed.
         *
         * This needs to be done deferred to avoid self-deadlocks on systems
         * with nested onboard hubs.
         */
        schedule_work(&attach_usb_driver_work);

        return 0;

err_power_off:
        onboard_dev_power_off(onboard_dev);
        return err;
}

static void onboard_dev_remove(struct platform_device *pdev)
{
        struct onboard_dev *onboard_dev = dev_get_drvdata(&pdev->dev);
        struct usbdev_node *node;
        struct usb_device *udev;

        onboard_dev->going_away = true;

        mutex_lock(&onboard_dev->lock);

        /* unbind the USB devices to avoid dangling references to this device */
        while (!list_empty(&onboard_dev->udev_list)) {
                node = list_first_entry(&onboard_dev->udev_list,
                                        struct usbdev_node, list);
                udev = node->udev;

                /*
                 * Unbinding the driver will call onboard_dev_remove_usbdev(),
                 * which acquires onboard_dev->lock. We must release the lock
                 * first.
                 */
                get_device(&udev->dev);
                mutex_unlock(&onboard_dev->lock);
                device_release_driver(&udev->dev);
                put_device(&udev->dev);
                mutex_lock(&onboard_dev->lock);
        }

        mutex_unlock(&onboard_dev->lock);

        onboard_dev_power_off(onboard_dev);
}

MODULE_DEVICE_TABLE(of, onboard_dev_match);

static const struct dev_pm_ops __maybe_unused onboard_dev_pm_ops = {
        SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_dev_suspend, onboard_dev_resume)
};

static struct platform_driver onboard_dev_driver = {
        .probe = onboard_dev_probe,
        .remove = onboard_dev_remove,

        .driver = {
                .name = "onboard-usb-dev",
                .of_match_table = onboard_dev_match,
                .pm = pm_ptr(&onboard_dev_pm_ops),
                .dev_groups = onboard_dev_groups,
        },
};

/************************** USB driver **************************/

#define VENDOR_ID_BISON         0x5986
#define VENDOR_ID_CYPRESS       0x04b4
#define VENDOR_ID_GENESYS       0x05e3
#define VENDOR_ID_MICROCHIP     0x0424
#define VENDOR_ID_PARADE        0x1da0
#define VENDOR_ID_REALTEK       0x0bda
#define VENDOR_ID_TI            0x0451
#define VENDOR_ID_VIA           0x2109
#define VENDOR_ID_XMOS          0x20B1

/*
 * Returns the onboard_dev platform device that is associated with the USB
 * device passed as parameter.
 */
static struct onboard_dev *_find_onboard_dev(struct device *dev)
{
        struct platform_device *pdev;
        struct device_node *np;
        struct onboard_dev *onboard_dev;

        pdev = of_find_device_by_node(dev->of_node);
        if (!pdev) {
                np = of_parse_phandle(dev->of_node, "peer-hub", 0);
                if (!np) {
                        dev_err(dev, "failed to find device node for peer hub\n");
                        return ERR_PTR(-EINVAL);
                }

                pdev = of_find_device_by_node(np);
                of_node_put(np);

                if (!pdev)
                        return ERR_PTR(-ENODEV);
        }

        onboard_dev = dev_get_drvdata(&pdev->dev);
        put_device(&pdev->dev);

        /*
         * The presence of drvdata indicates that the platform driver finished
         * probing. This handles the case where (conceivably) we could be
         * running at the exact same time as the platform driver's probe. If
         * we detect the race we request probe deferral and we'll come back and
         * try again.
         */
        if (!onboard_dev)
                return ERR_PTR(-EPROBE_DEFER);

        return onboard_dev;
}

static bool onboard_dev_usbdev_match(struct usb_device *udev)
{
        /* Onboard devices using this driver must have a device tree node */
        return !!udev->dev.of_node;
}

static int onboard_dev_usbdev_probe(struct usb_device *udev)
{
        struct device *dev = &udev->dev;
        struct onboard_dev *onboard_dev;
        int err;

        onboard_dev = _find_onboard_dev(dev);
        if (IS_ERR(onboard_dev))
                return PTR_ERR(onboard_dev);

        dev_set_drvdata(dev, onboard_dev);

        err = onboard_dev_add_usbdev(onboard_dev, udev);
        if (err)
                return err;

        return 0;
}

static void onboard_dev_usbdev_disconnect(struct usb_device *udev)
{
        struct onboard_dev *onboard_dev = dev_get_drvdata(&udev->dev);

        onboard_dev_remove_usbdev(onboard_dev, udev);
}

static const struct usb_device_id onboard_dev_id_table[] = {
        { USB_DEVICE(VENDOR_ID_BISON, 0x1198) }, /* Bison Electronics Inc. Integrated Camera */
        { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6500) }, /* CYUSB330x 3.0 HUB */
        { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6502) }, /* CYUSB330x 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6503) }, /* CYUSB33{0,1}x 2.0 HUB, Vendor Mode */
        { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6504) }, /* CYUSB331x 3.0 HUB */
        { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6506) }, /* CYUSB331x 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6507) }, /* CYUSB332x 2.0 HUB, Vendor Mode */
        { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6508) }, /* CYUSB332x 3.0 HUB */
        { USB_DEVICE(VENDOR_ID_CYPRESS, 0x650a) }, /* CYUSB332x 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_CYPRESS, 0x6570) }, /* CY7C6563x 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_GENESYS, 0x0608) }, /* Genesys Logic GL850G USB 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_GENESYS, 0x0610) }, /* Genesys Logic GL852G USB 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_GENESYS, 0x0620) }, /* Genesys Logic GL3523 USB 3.1 HUB */
        { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2412) }, /* USB2412 USB 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2514) }, /* USB2514B USB 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2517) }, /* USB2517 USB 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2744) }, /* USB5744 USB 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_MICROCHIP, 0x5744) }, /* USB5744 USB 3.0 HUB */
        { USB_DEVICE(VENDOR_ID_PARADE, 0x5511) }, /* PS5511 USB 3.2 */
        { USB_DEVICE(VENDOR_ID_PARADE, 0x55a1) }, /* PS5511 USB 2.0 */
        { USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.1 HUB */
        { USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.1 HUB */
        { USB_DEVICE(VENDOR_ID_REALTEK, 0x0414) }, /* RTS5414 USB 3.2 HUB */
        { USB_DEVICE(VENDOR_ID_REALTEK, 0x5414) }, /* RTS5414 USB 2.1 HUB */
        { USB_DEVICE(VENDOR_ID_REALTEK, 0x0179) }, /* RTL8188ETV 2.4GHz WiFi */
        { USB_DEVICE(VENDOR_ID_TI, 0x8025) }, /* TI USB8020B 3.0 HUB */
        { USB_DEVICE(VENDOR_ID_TI, 0x8027) }, /* TI USB8020B 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_TI, 0x8140) }, /* TI USB8041 3.0 HUB */
        { USB_DEVICE(VENDOR_ID_TI, 0x8142) }, /* TI USB8041 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_TI, 0x8440) }, /* TI USB8044 3.0 HUB */
        { USB_DEVICE(VENDOR_ID_TI, 0x8442) }, /* TI USB8044 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_VIA, 0x0817) }, /* VIA VL817 3.1 HUB */
        { USB_DEVICE(VENDOR_ID_VIA, 0x2817) }, /* VIA VL817 2.0 HUB */
        { USB_DEVICE(VENDOR_ID_XMOS, 0x0013) }, /* XMOS XVF3500 Voice Processor */
        {}
};
MODULE_DEVICE_TABLE(usb, onboard_dev_id_table);

static struct usb_device_driver onboard_dev_usbdev_driver = {
        .name = "onboard-usb-dev",
        .match = onboard_dev_usbdev_match,
        .probe = onboard_dev_usbdev_probe,
        .disconnect = onboard_dev_usbdev_disconnect,
        .generic_subclass = 1,
        .supports_autosuspend = 1,
        .id_table = onboard_dev_id_table,
};

static int __init onboard_dev_init(void)
{
        int ret;

        ret = usb_register_device_driver(&onboard_dev_usbdev_driver, THIS_MODULE);
        if (ret)
                return ret;

        ret = platform_driver_register(&onboard_dev_driver);
        if (ret)
                usb_deregister_device_driver(&onboard_dev_usbdev_driver);

        return ret;
}
module_init(onboard_dev_init);

static void __exit onboard_dev_exit(void)
{
        usb_deregister_device_driver(&onboard_dev_usbdev_driver);
        platform_driver_unregister(&onboard_dev_driver);

        cancel_work_sync(&attach_usb_driver_work);
}
module_exit(onboard_dev_exit);

MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>");
MODULE_DESCRIPTION("Driver for discrete onboard USB devices");
MODULE_LICENSE("GPL v2");