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 static int usb_serial_device_probe (struct device *dev) 41 { 42 struct usb_serial_driver *driver; 43 struct usb_serial_port *port; 44 int retval = 0; 45 int minor; 46 47 port = to_usb_serial_port(dev); 48 if (!port) { 49 retval = -ENODEV; 50 goto exit; 51 } 52 53 driver = port->serial->type; 54 if (driver->port_probe) { 55 if (!try_module_get(driver->driver.owner)) { 56 dev_err(dev, "module get failed, exiting\n"); 57 retval = -EIO; 58 goto exit; 59 } 60 retval = driver->port_probe (port); 61 module_put(driver->driver.owner); 62 if (retval) 63 goto exit; 64 } 65 66 minor = port->number; 67 tty_register_device (usb_serial_tty_driver, minor, dev); 68 dev_info(&port->serial->dev->dev, 69 "%s converter now attached to ttyUSB%d\n", 70 driver->description, minor); 71 72 exit: 73 return retval; 74 } 75 76 static int usb_serial_device_remove (struct device *dev) 77 { 78 struct usb_serial_driver *driver; 79 struct usb_serial_port *port; 80 int retval = 0; 81 int minor; 82 83 port = to_usb_serial_port(dev); 84 if (!port) { 85 return -ENODEV; 86 } 87 88 driver = port->serial->type; 89 if (driver->port_remove) { 90 if (!try_module_get(driver->driver.owner)) { 91 dev_err(dev, "module get failed, exiting\n"); 92 retval = -EIO; 93 goto exit; 94 } 95 retval = driver->port_remove (port); 96 module_put(driver->driver.owner); 97 } 98 exit: 99 minor = port->number; 100 tty_unregister_device (usb_serial_tty_driver, minor); 101 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n", 102 driver->description, minor); 103 104 return retval; 105 } 106 107 struct bus_type usb_serial_bus_type = { 108 .name = "usb-serial", 109 .match = usb_serial_device_match, 110 .probe = usb_serial_device_probe, 111 .remove = usb_serial_device_remove, 112 }; 113 114 int usb_serial_bus_register(struct usb_serial_driver *driver) 115 { 116 int retval; 117 118 driver->driver.bus = &usb_serial_bus_type; 119 retval = driver_register(&driver->driver); 120 121 return retval; 122 } 123 124 void usb_serial_bus_deregister(struct usb_serial_driver *driver) 125 { 126 driver_unregister(&driver->driver); 127 } 128 129