Quelle  onboard_usb_dev.c   Sprache: unbekannt

// 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(sizeof(*node), GFP_KERNEL);
 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, ®);
 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 ");
MODULE_DESCRIPTION("Driver for discrete onboard USB devices");
MODULE_LICENSE("GPL v2");