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 8 #include <linux/kernel.h> 9 #include <linux/errno.h> 10 #include <linux/tty.h> 11 #include <linux/slab.h> 12 #include <linux/module.h> 13 #include <linux/usb.h> 14 #include <linux/usb/serial.h> 15 16 static int usb_serial_device_match(struct device *dev, 17 struct device_driver *drv) 18 { 19 struct usb_serial_driver *driver; 20 const struct usb_serial_port *port; 21 22 /* 23 * drivers are already assigned to ports in serial_probe so it's 24 * a simple check here. 25 */ 26 port = to_usb_serial_port(dev); 27 if (!port) 28 return 0; 29 30 driver = to_usb_serial_driver(drv); 31 32 if (driver == port->serial->type) 33 return 1; 34 35 return 0; 36 } 37 38 static int usb_serial_device_probe(struct device *dev) 39 { 40 struct usb_serial_driver *driver; 41 struct usb_serial_port *port; 42 struct device *tty_dev; 43 int retval = 0; 44 int minor; 45 46 port = to_usb_serial_port(dev); 47 if (!port) 48 return -ENODEV; 49 50 /* make sure suspend/resume doesn't race against port_probe */ 51 retval = usb_autopm_get_interface(port->serial->interface); 52 if (retval) 53 return retval; 54 55 driver = port->serial->type; 56 if (driver->port_probe) { 57 retval = driver->port_probe(port); 58 if (retval) 59 goto err_autopm_put; 60 } 61 62 minor = port->minor; 63 tty_dev = tty_register_device(usb_serial_tty_driver, minor, dev); 64 if (IS_ERR(tty_dev)) { 65 retval = PTR_ERR(tty_dev); 66 goto err_port_remove; 67 } 68 69 usb_autopm_put_interface(port->serial->interface); 70 71 dev_info(&port->serial->dev->dev, 72 "%s converter now attached to ttyUSB%d\n", 73 driver->description, minor); 74 75 return 0; 76 77 err_port_remove: 78 if (driver->port_remove) 79 driver->port_remove(port); 80 err_autopm_put: 81 usb_autopm_put_interface(port->serial->interface); 82 83 return retval; 84 } 85 86 static int usb_serial_device_remove(struct device *dev) 87 { 88 struct usb_serial_driver *driver; 89 struct usb_serial_port *port; 90 int retval = 0; 91 int minor; 92 int autopm_err; 93 94 port = to_usb_serial_port(dev); 95 if (!port) 96 return -ENODEV; 97 98 /* 99 * Make sure suspend/resume doesn't race against port_remove. 100 * 101 * Note that no further runtime PM callbacks will be made if 102 * autopm_get fails. 103 */ 104 autopm_err = usb_autopm_get_interface(port->serial->interface); 105 106 minor = port->minor; 107 tty_unregister_device(usb_serial_tty_driver, minor); 108 109 driver = port->serial->type; 110 if (driver->port_remove) 111 retval = driver->port_remove(port); 112 113 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n", 114 driver->description, minor); 115 116 if (!autopm_err) 117 usb_autopm_put_interface(port->serial->interface); 118 119 return retval; 120 } 121 122 static ssize_t new_id_store(struct device_driver *driver, 123 const char *buf, size_t count) 124 { 125 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); 126 ssize_t retval = usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, 127 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->id_table, 132 &usb_drv->usb_driver->drvwrap.driver, 133 buf, count); 134 return retval; 135 } 136 137 static ssize_t new_id_show(struct device_driver *driver, char *buf) 138 { 139 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); 140 141 return usb_show_dynids(&usb_drv->dynids, buf); 142 } 143 static DRIVER_ATTR_RW(new_id); 144 145 static struct attribute *usb_serial_drv_attrs[] = { 146 &driver_attr_new_id.attr, 147 NULL, 148 }; 149 ATTRIBUTE_GROUPS(usb_serial_drv); 150 151 static void free_dynids(struct usb_serial_driver *drv) 152 { 153 struct usb_dynid *dynid, *n; 154 155 spin_lock(&drv->dynids.lock); 156 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { 157 list_del(&dynid->node); 158 kfree(dynid); 159 } 160 spin_unlock(&drv->dynids.lock); 161 } 162 163 struct bus_type usb_serial_bus_type = { 164 .name = "usb-serial", 165 .match = usb_serial_device_match, 166 .probe = usb_serial_device_probe, 167 .remove = usb_serial_device_remove, 168 .drv_groups = usb_serial_drv_groups, 169 }; 170 171 int usb_serial_bus_register(struct usb_serial_driver *driver) 172 { 173 int retval; 174 175 driver->driver.bus = &usb_serial_bus_type; 176 spin_lock_init(&driver->dynids.lock); 177 INIT_LIST_HEAD(&driver->dynids.list); 178 179 retval = driver_register(&driver->driver); 180 181 return retval; 182 } 183 184 void usb_serial_bus_deregister(struct usb_serial_driver *driver) 185 { 186 free_dynids(driver); 187 driver_unregister(&driver->driver); 188 } 189 190