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 void 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 } 105 106 static ssize_t new_id_store(struct device_driver *driver, 107 const char *buf, size_t count) 108 { 109 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); 110 ssize_t retval = usb_store_new_id(&usb_drv->dynids, usb_drv->id_table, 111 driver, buf, count); 112 113 if (retval >= 0 && usb_drv->usb_driver != NULL) 114 retval = usb_store_new_id(&usb_drv->usb_driver->dynids, 115 usb_drv->usb_driver->id_table, 116 &usb_drv->usb_driver->drvwrap.driver, 117 buf, count); 118 return retval; 119 } 120 121 static ssize_t new_id_show(struct device_driver *driver, char *buf) 122 { 123 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver); 124 125 return usb_show_dynids(&usb_drv->dynids, buf); 126 } 127 static DRIVER_ATTR_RW(new_id); 128 129 static struct attribute *usb_serial_drv_attrs[] = { 130 &driver_attr_new_id.attr, 131 NULL, 132 }; 133 ATTRIBUTE_GROUPS(usb_serial_drv); 134 135 static void free_dynids(struct usb_serial_driver *drv) 136 { 137 struct usb_dynid *dynid, *n; 138 139 spin_lock(&drv->dynids.lock); 140 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) { 141 list_del(&dynid->node); 142 kfree(dynid); 143 } 144 spin_unlock(&drv->dynids.lock); 145 } 146 147 const struct bus_type usb_serial_bus_type = { 148 .name = "usb-serial", 149 .match = usb_serial_device_match, 150 .probe = usb_serial_device_probe, 151 .remove = usb_serial_device_remove, 152 .drv_groups = usb_serial_drv_groups, 153 }; 154 155 int usb_serial_bus_register(struct usb_serial_driver *driver) 156 { 157 int retval; 158 159 driver->driver.bus = &usb_serial_bus_type; 160 spin_lock_init(&driver->dynids.lock); 161 INIT_LIST_HEAD(&driver->dynids.list); 162 163 retval = driver_register(&driver->driver); 164 165 return retval; 166 } 167 168 void usb_serial_bus_deregister(struct usb_serial_driver *driver) 169 { 170 free_dynids(driver); 171 driver_unregister(&driver->driver); 172 } 173 174