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/config.h> 12 #include <linux/kernel.h> 13 #include <linux/errno.h> 14 #include <linux/tty.h> 15 #include <linux/module.h> 16 #include <linux/usb.h> 17 #include "usb-serial.h" 18 19 static int usb_serial_device_match (struct device *dev, struct device_driver *drv) 20 { 21 struct usb_serial_driver *driver; 22 const struct usb_serial_port *port; 23 24 /* 25 * drivers are already assigned to ports in serial_probe so it's 26 * a simple check here. 27 */ 28 port = to_usb_serial_port(dev); 29 if (!port) 30 return 0; 31 32 driver = to_usb_serial_driver(drv); 33 34 if (driver == port->serial->type) 35 return 1; 36 37 return 0; 38 } 39 40 struct bus_type usb_serial_bus_type = { 41 .name = "usb-serial", 42 .match = usb_serial_device_match, 43 }; 44 45 static int usb_serial_device_probe (struct device *dev) 46 { 47 struct usb_serial_driver *driver; 48 struct usb_serial_port *port; 49 int retval = 0; 50 int minor; 51 52 port = to_usb_serial_port(dev); 53 if (!port) { 54 retval = -ENODEV; 55 goto exit; 56 } 57 58 driver = port->serial->type; 59 if (driver->port_probe) { 60 if (!try_module_get(driver->driver.owner)) { 61 dev_err(dev, "module get failed, exiting\n"); 62 retval = -EIO; 63 goto exit; 64 } 65 retval = driver->port_probe (port); 66 module_put(driver->driver.owner); 67 if (retval) 68 goto exit; 69 } 70 71 minor = port->number; 72 tty_register_device (usb_serial_tty_driver, minor, dev); 73 dev_info(&port->serial->dev->dev, 74 "%s converter now attached to ttyUSB%d\n", 75 driver->description, minor); 76 77 exit: 78 return retval; 79 } 80 81 static int usb_serial_device_remove (struct device *dev) 82 { 83 struct usb_serial_driver *driver; 84 struct usb_serial_port *port; 85 int retval = 0; 86 int minor; 87 88 port = to_usb_serial_port(dev); 89 if (!port) { 90 return -ENODEV; 91 } 92 93 driver = port->serial->type; 94 if (driver->port_remove) { 95 if (!try_module_get(driver->driver.owner)) { 96 dev_err(dev, "module get failed, exiting\n"); 97 retval = -EIO; 98 goto exit; 99 } 100 retval = driver->port_remove (port); 101 module_put(driver->driver.owner); 102 } 103 exit: 104 minor = port->number; 105 tty_unregister_device (usb_serial_tty_driver, minor); 106 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n", 107 driver->description, minor); 108 109 return retval; 110 } 111 112 int usb_serial_bus_register(struct usb_serial_driver *driver) 113 { 114 int retval; 115 116 driver->driver.bus = &usb_serial_bus_type; 117 driver->driver.probe = usb_serial_device_probe; 118 driver->driver.remove = usb_serial_device_remove; 119 120 retval = driver_register(&driver->driver); 121 122 return retval; 123 } 124 125 void usb_serial_bus_deregister(struct usb_serial_driver *driver) 126 { 127 driver_unregister(&driver->driver); 128 } 129 130