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, 19 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 ssize_t show_port_number(struct device *dev, 41 struct device_attribute *attr, char *buf) 42 { 43 struct usb_serial_port *port = to_usb_serial_port(dev); 44 45 return sprintf(buf, "%d\n", port->number - port->serial->minor); 46 } 47 48 static DEVICE_ATTR(port_number, S_IRUGO, show_port_number, NULL); 49 50 static int usb_serial_device_probe(struct device *dev) 51 { 52 struct usb_serial_driver *driver; 53 struct usb_serial_port *port; 54 int retval = 0; 55 int minor; 56 57 port = to_usb_serial_port(dev); 58 if (!port) { 59 retval = -ENODEV; 60 goto exit; 61 } 62 63 driver = port->serial->type; 64 if (driver->port_probe) { 65 if (!try_module_get(driver->driver.owner)) { 66 dev_err(dev, "module get failed, exiting\n"); 67 retval = -EIO; 68 goto exit; 69 } 70 retval = driver->port_probe(port); 71 module_put(driver->driver.owner); 72 if (retval) 73 goto exit; 74 } 75 76 retval = device_create_file(dev, &dev_attr_port_number); 77 if (retval) 78 goto exit; 79 80 minor = port->number; 81 tty_register_device(usb_serial_tty_driver, minor, dev); 82 dev_info(&port->serial->dev->dev, 83 "%s converter now attached to ttyUSB%d\n", 84 driver->description, minor); 85 86 exit: 87 return retval; 88 } 89 90 static int usb_serial_device_remove(struct device *dev) 91 { 92 struct usb_serial_driver *driver; 93 struct usb_serial_port *port; 94 int retval = 0; 95 int minor; 96 97 port = to_usb_serial_port(dev); 98 if (!port) 99 return -ENODEV; 100 101 device_remove_file(&port->dev, &dev_attr_port_number); 102 103 driver = port->serial->type; 104 if (driver->port_remove) { 105 if (!try_module_get(driver->driver.owner)) { 106 dev_err(dev, "module get failed, exiting\n"); 107 retval = -EIO; 108 goto exit; 109 } 110 retval = driver->port_remove(port); 111 module_put(driver->driver.owner); 112 } 113 exit: 114 minor = port->number; 115 tty_unregister_device(usb_serial_tty_driver, minor); 116 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n", 117 driver->description, minor); 118 119 return retval; 120 } 121 122 #ifdef CONFIG_HOTPLUG 123 static ssize_t store_new_id(struct device_driver *driver, 124 const char *buf, size_t count) 125 { 126 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); 127 ssize_t retval = usb_store_new_id(&usb_drv->dynids, driver, buf, count); 128 129 if (retval >= 0 && usb_drv->usb_driver != NULL) 130 retval = usb_store_new_id(&usb_drv->usb_driver->dynids, 131 &usb_drv->usb_driver->drvwrap.driver, 132 buf, count); 133 return retval; 134 } 135 136 static struct driver_attribute drv_attrs[] = { 137 __ATTR(new_id, S_IWUSR, NULL, store_new_id), 138 __ATTR_NULL, 139 }; 140 141 static void free_dynids(struct usb_serial_driver *drv) 142 { 143 struct usb_dynid *dynid, *n; 144 145 spin_lock(&drv->dynids.lock); 146 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { 147 list_del(&dynid->node); 148 kfree(dynid); 149 } 150 spin_unlock(&drv->dynids.lock); 151 } 152 153 #else 154 static struct driver_attribute drv_attrs[] = { 155 __ATTR_NULL, 156 }; 157 static inline void free_dynids(struct usb_serial_driver *drv) 158 { 159 } 160 #endif 161 162 struct bus_type usb_serial_bus_type = { 163 .name = "usb-serial", 164 .match = usb_serial_device_match, 165 .probe = usb_serial_device_probe, 166 .remove = usb_serial_device_remove, 167 .drv_attrs = drv_attrs, 168 }; 169 170 int usb_serial_bus_register(struct usb_serial_driver *driver) 171 { 172 int retval; 173 174 driver->driver.bus = &usb_serial_bus_type; 175 spin_lock_init(&driver->dynids.lock); 176 INIT_LIST_HEAD(&driver->dynids.list); 177 178 retval = driver_register(&driver->driver); 179 180 return retval; 181 } 182 183 void usb_serial_bus_deregister(struct usb_serial_driver *driver) 184 { 185 free_dynids(driver); 186 driver_unregister(&driver->driver); 187 } 188 189