1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * USB Serial Converter Bus specific functions 4 * 5 * Copyright (C) 2002 Greg Kroah-Hartman (greg@kroah.com) 6 * 7 * This program is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU General Public License version 9 * 2 as published by the Free Software Foundation. 10 */ 11 12 #include <linux/kernel.h> 13 #include <linux/errno.h> 14 #include <linux/tty.h> 15 #include <linux/slab.h> 16 #include <linux/module.h> 17 #include <linux/usb.h> 18 #include <linux/usb/serial.h> 19 20 static int usb_serial_device_match(struct device *dev, 21 struct device_driver *drv) 22 { 23 struct usb_serial_driver *driver; 24 const struct usb_serial_port *port; 25 26 /* 27 * drivers are already assigned to ports in serial_probe so it's 28 * a simple check here. 29 */ 30 port = to_usb_serial_port(dev); 31 if (!port) 32 return 0; 33 34 driver = to_usb_serial_driver(drv); 35 36 if (driver == port->serial->type) 37 return 1; 38 39 return 0; 40 } 41 42 static int usb_serial_device_probe(struct device *dev) 43 { 44 struct usb_serial_driver *driver; 45 struct usb_serial_port *port; 46 struct device *tty_dev; 47 int retval = 0; 48 int minor; 49 50 port = to_usb_serial_port(dev); 51 if (!port) 52 return -ENODEV; 53 54 /* make sure suspend/resume doesn't race against port_probe */ 55 retval = usb_autopm_get_interface(port->serial->interface); 56 if (retval) 57 return retval; 58 59 driver = port->serial->type; 60 if (driver->port_probe) { 61 retval = driver->port_probe(port); 62 if (retval) 63 goto err_autopm_put; 64 } 65 66 minor = port->minor; 67 tty_dev = tty_register_device(usb_serial_tty_driver, minor, dev); 68 if (IS_ERR(tty_dev)) { 69 retval = PTR_ERR(tty_dev); 70 goto err_port_remove; 71 } 72 73 usb_autopm_put_interface(port->serial->interface); 74 75 dev_info(&port->serial->dev->dev, 76 "%s converter now attached to ttyUSB%d\n", 77 driver->description, minor); 78 79 return 0; 80 81 err_port_remove: 82 if (driver->port_remove) 83 driver->port_remove(port); 84 err_autopm_put: 85 usb_autopm_put_interface(port->serial->interface); 86 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 int autopm_err; 97 98 port = to_usb_serial_port(dev); 99 if (!port) 100 return -ENODEV; 101 102 /* 103 * Make sure suspend/resume doesn't race against port_remove. 104 * 105 * Note that no further runtime PM callbacks will be made if 106 * autopm_get fails. 107 */ 108 autopm_err = usb_autopm_get_interface(port->serial->interface); 109 110 minor = port->minor; 111 tty_unregister_device(usb_serial_tty_driver, minor); 112 113 driver = port->serial->type; 114 if (driver->port_remove) 115 retval = driver->port_remove(port); 116 117 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n", 118 driver->description, minor); 119 120 if (!autopm_err) 121 usb_autopm_put_interface(port->serial->interface); 122 123 return retval; 124 } 125 126 static ssize_t new_id_store(struct device_driver *driver, 127 const char *buf, size_t count) 128 { 129 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); 130 ssize_t retval = usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, 131 driver, buf, count); 132 133 if (retval >= 0 && usb_drv->usb_driver != NULL) 134 retval = usb_store_new_id(&usb_drv->usb_driver->dynids, 135 usb_drv->usb_driver->id_table, 136 &usb_drv->usb_driver->drvwrap.driver, 137 buf, count); 138 return retval; 139 } 140 141 static ssize_t new_id_show(struct device_driver *driver, char *buf) 142 { 143 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); 144 145 return usb_show_dynids(&usb_drv->dynids, buf); 146 } 147 static DRIVER_ATTR_RW(new_id); 148 149 static struct attribute *usb_serial_drv_attrs[] = { 150 &driver_attr_new_id.attr, 151 NULL, 152 }; 153 ATTRIBUTE_GROUPS(usb_serial_drv); 154 155 static void free_dynids(struct usb_serial_driver *drv) 156 { 157 struct usb_dynid *dynid, *n; 158 159 spin_lock(&drv->dynids.lock); 160 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { 161 list_del(&dynid->node); 162 kfree(dynid); 163 } 164 spin_unlock(&drv->dynids.lock); 165 } 166 167 struct bus_type usb_serial_bus_type = { 168 .name = "usb-serial", 169 .match = usb_serial_device_match, 170 .probe = usb_serial_device_probe, 171 .remove = usb_serial_device_remove, 172 .drv_groups = usb_serial_drv_groups, 173 }; 174 175 int usb_serial_bus_register(struct usb_serial_driver *driver) 176 { 177 int retval; 178 179 driver->driver.bus = &usb_serial_bus_type; 180 spin_lock_init(&driver->dynids.lock); 181 INIT_LIST_HEAD(&driver->dynids.list); 182 183 retval = driver_register(&driver->driver); 184 185 return retval; 186 } 187 188 void usb_serial_bus_deregister(struct usb_serial_driver *driver) 189 { 190 free_dynids(driver); 191 driver_unregister(&driver->driver); 192 } 193 194