MTK USB 子系统

一、USB 子系统初始化

1. kernel/drivers/usb/core/usb.c

1 subsys_initcall(usb_init);

 1 static int __init usb_init(void)
 2 {
 3     int retval;
 4     if (nousb) {
 5         pr_info("%s: USB support disabled
", usbcore_name);
 6         return 0;
 7     }
 8     
 9     usb_init_pool_max();
10 
11     retval = usb_debugfs_init();
12     if (retval)
13         goto out;
14 
15     usb_acpi_register();
16     retval = bus_register(&usb_bus_type);
17     if (retval)
18         goto bus_register_failed;
19     retval = bus_register_notifier(&usb_bus_type, &usb_bus_nb);
20     if (retval)
21         goto bus_notifier_failed;
22     retval = usb_major_init();
23     if (retval)
24         goto major_init_failed;
25     retval = usb_register(&usbfs_driver);
26     if (retval)
27         goto driver_register_failed;
28     retval = usb_devio_init();
29     if (retval)
30         goto usb_devio_init_failed;
31     retval = usb_hub_init();
32     if (retval)
33         goto hub_init_failed;
34     retval = usb_register_device_driver(&usb_generic_driver, THIS_MODULE);
35     if (!retval)
36         goto out;
37 
38     usb_hub_cleanup();
39 hub_init_failed:
40     usb_devio_cleanup();
41 usb_devio_init_failed:
42     usb_deregister(&usbfs_driver);
43 driver_register_failed:
44     usb_major_cleanup();
45 major_init_failed:
46     bus_unregister_notifier(&usb_bus_type, &usb_bus_nb);
47 bus_notifier_failed:
48     bus_unregister(&usb_bus_type);
49 bus_register_failed:
50     usb_acpi_unregister();
51     usb_debugfs_cleanup();
52 out:
53     return retval;
54 }