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 const struct usb_serial_port *port = to_usb_serial_port(dev); 20 struct usb_serial_driver *driver = to_usb_serial_driver(drv); 21 22 /* 23 * drivers are already assigned to ports in serial_probe so it's 24 * a simple check here. 25 */ 26 if (driver == port->serial->type) 27 return 1; 28 29 return 0; 30 } 31 32 static int usb_serial_device_probe(struct device *dev) 33 { 34 struct usb_serial_port *port = to_usb_serial_port(dev); 35 struct usb_serial_driver *driver; 36 struct device *tty_dev; 37 int retval = 0; 38 int minor; 39 40 /* make sure suspend/resume doesn't race against port_probe */ 41 retval = usb_autopm_get_interface(port->serial->interface); 42 if (retval) 43 return retval; 44 45 driver = port->serial->type; 46 if (driver->port_probe) { 47 retval = driver->port_probe(port); 48 if (retval) 49 goto err_autopm_put; 50 } 51 52 minor = port->minor; 53 tty_dev = tty_port_register_device(&port->port, usb_serial_tty_driver, 54 minor, dev); 55 if (IS_ERR(tty_dev)) { 56 retval = PTR_ERR(tty_dev); 57 goto err_port_remove; 58 } 59 60 usb_autopm_put_interface(port->serial->interface); 61 62 dev_info(&port->serial->dev->dev, 63 "%s converter now attached to ttyUSB%d\n", 64 driver->description, minor); 65 66 return 0; 67 68 err_port_remove: 69 if (driver->port_remove) 70 driver->port_remove(port); 71 err_autopm_put: 72 usb_autopm_put_interface(port->serial->interface); 73 74 return retval; 75 } 76 77 static int usb_serial_device_remove(struct device *dev) 78 { 79 struct usb_serial_port *port = to_usb_serial_port(dev); 80 struct usb_serial_driver *driver; 81 int minor; 82 int autopm_err; 83 84 /* 85 * Make sure suspend/resume doesn't race against port_remove. 86 * 87 * Note that no further runtime PM callbacks will be made if 88 * autopm_get fails. 89 */ 90 autopm_err = usb_autopm_get_interface(port->serial->interface); 91 92 minor = port->minor; 93 tty_unregister_device(usb_serial_tty_driver, minor); 94 95 driver = port->serial->type; 96 if (driver->port_remove) 97 driver->port_remove(port); 98 99 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n", 100 driver->description, minor); 101 102 if (!autopm_err) 103 usb_autopm_put_interface(port->serial->interface); 104 105 return 0; 106 } 107 108 static ssize_t new_id_store(struct device_driver *driver, 109 const char *buf, size_t count) 110 { 111 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); 112 ssize_t retval = usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, 113 driver, buf, count); 114 115 if (retval >= 0 && usb_drv->usb_driver != NULL) 116 retval = usb_store_new_id(&usb_drv->usb_driver->dynids, 117 usb_drv->usb_driver->id_table, 118 &usb_drv->usb_driver->drvwrap.driver, 119 buf, count); 120 return retval; 121 } 122 123 static ssize_t new_id_show(struct device_driver *driver, char *buf) 124 { 125 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); 126 127 return usb_show_dynids(&usb_drv->dynids, buf); 128 } 129 static DRIVER_ATTR_RW(new_id); 130 131 static struct attribute *usb_serial_drv_attrs[] = { 132 &driver_attr_new_id.attr, 133 NULL, 134 }; 135 ATTRIBUTE_GROUPS(usb_serial_drv); 136 137 static void free_dynids(struct usb_serial_driver *drv) 138 { 139 struct usb_dynid *dynid, *n; 140 141 spin_lock(&drv->dynids.lock); 142 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { 143 list_del(&dynid->node); 144 kfree(dynid); 145 } 146 spin_unlock(&drv->dynids.lock); 147 } 148 149 struct bus_type usb_serial_bus_type = { 150 .name = "usb-serial", 151 .match = usb_serial_device_match, 152 .probe = usb_serial_device_probe, 153 .remove = usb_serial_device_remove, 154 .drv_groups = usb_serial_drv_groups, 155 }; 156 157 int usb_serial_bus_register(struct usb_serial_driver *driver) 158 { 159 int retval; 160 161 driver->driver.bus = &usb_serial_bus_type; 162 spin_lock_init(&driver->dynids.lock); 163 INIT_LIST_HEAD(&driver->dynids.list); 164 165 retval = driver_register(&driver->driver); 166 167 return retval; 168 } 169 170 void usb_serial_bus_deregister(struct usb_serial_driver *driver) 171 { 172 free_dynids(driver); 173 driver_unregister(&driver->driver); 174 } 175 176