Linux Kernel设备驱动模型之驱动注册

设备模型之驱动注册：
/**
 * driver_register - register driver with bus
 * @drv: driver to register
 *
 * We pass off most of the work to the bus_add_driver() call,
 * since most of the things we have to do deal with the bus
 * structures.
 */
int driver_register(struct device_driver *drv)
{
 int ret;
 struct device_driver *other;
 
 BUG_ON(!drv->bus->p);
 if ((drv->bus->probe && drv->probe) ||
     (drv->bus->remove && drv->remove) ||
     (drv->bus->shutdown && drv->shutdown))
  printk(KERN_WARNING "Driver '%s' needs updating - please use "
   "bus_type methods\n", drv->name);
 other = driver_find(drv->name, drv->bus);
 if (other) {
  printk(KERN_ERR "Error: Driver '%s' is already registered, "
   "aborting...\n", drv->name);
  return -EBUSY;
 }
 ret = bus_add_driver(drv);
 if (ret)
  return ret;
 ret = driver_add_groups(drv, drv->groups);
 if (ret) {
  bus_remove_driver(drv);
  return ret;
 }
 kobject_uevent(&drv->p->kobj, KOBJ_ADD);
 return ret;
}