1 /* 2 * USB Serial Converter Bus specific functions 3 * 4 * Copyright (C) 2002 Greg Kroah-Hartman (greg@kroah.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License version 8 * 2 as published by the Free Software Foundation. 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/errno.h> 13 #include <linux/tty.h> 14 #include <linux/module.h> 15 #include <linux/usb.h> 16 #include <linux/usb/serial.h> 17 18 static int usb_serial_device_match (struct device *dev, struct device_driver *drv) 19 { 20 struct usb_serial_driver *driver; 21 const struct usb_serial_port *port; 22 23 /* 24 * drivers are already assigned to ports in serial_probe so it's 25 * a simple check here. 26 */ 27 port = to_usb_serial_port(dev); 28 if (!port) 29 return 0; 30 31 driver = to_usb_serial_driver(drv); 32 33 if (driver == port->serial->type) 34 return 1; 35 36 return 0; 37 } 38 39 static int usb_serial_device_probe (struct device *dev) 40 { 41 struct usb_serial_driver *driver; 42 struct usb_serial_port *port; 43 int retval = 0; 44 int minor; 45 46 port = to_usb_serial_port(dev); 47 if (!port) { 48 retval = -ENODEV; 49 goto exit; 50 } 51 52 driver = port->serial->type; 53 if (driver->port_probe) { 54 if (!try_module_get(driver->driver.owner)) { 55 dev_err(dev, "module get failed, exiting\n"); 56 retval = -EIO; 57 goto exit; 58 } 59 retval = driver->port_probe (port); 60 module_put(driver->driver.owner); 61 if (retval) 62 goto exit; 63 } 64 65 minor = port->number; 66 tty_register_device (usb_serial_tty_driver, minor, dev); 67 dev_info(&port->serial->dev->dev, 68 "%s converter now attached to ttyUSB%d\n", 69 driver->description, minor); 70 71 exit: 72 return retval; 73 } 74 75 static int usb_serial_device_remove (struct device *dev) 76 { 77 struct usb_serial_driver *driver; 78 struct usb_serial_port *port; 79 int retval = 0; 80 int minor; 81 82 port = to_usb_serial_port(dev); 83 if (!port) { 84 return -ENODEV; 85 } 86 87 driver = port->serial->type; 88 if (driver->port_remove) { 89 if (!try_module_get(driver->driver.owner)) { 90 dev_err(dev, "module get failed, exiting\n"); 91 retval = -EIO; 92 goto exit; 93 } 94 retval = driver->port_remove (port); 95 module_put(driver->driver.owner); 96 } 97 exit: 98 minor = port->number; 99 tty_unregister_device (usb_serial_tty_driver, minor); 100 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n", 101 driver->description, minor); 102 103 return retval; 104 } 105 106 struct bus_type usb_serial_bus_type = { 107 .name = "usb-serial", 108 .match = usb_serial_device_match, 109 .probe = usb_serial_device_probe, 110 .remove = usb_serial_device_remove, 111 }; 112 113 int usb_serial_bus_register(struct usb_serial_driver *driver) 114 { 115 int retval; 116 117 driver->driver.bus = &usb_serial_bus_type; 118 retval = driver_register(&driver->driver); 119 120 return retval; 121 } 122 123 void usb_serial_bus_deregister(struct usb_serial_driver *driver) 124 { 125 driver_unregister(&driver->driver); 126 } 127 128