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
usb_serial_device_match(struct device * dev,struct device_driver * drv)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
usb_serial_device_probe(struct device * dev)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_port_register_device(&port->port, usb_serial_tty_driver,
64 minor, dev);
65 if (IS_ERR(tty_dev)) {
66 retval = PTR_ERR(tty_dev);
67 goto err_port_remove;
68 }
69
70 usb_autopm_put_interface(port->serial->interface);
71
72 dev_info(&port->serial->dev->dev,
73 "%s converter now attached to ttyUSB%d\n",
74 driver->description, minor);
75
76 return 0;
77
78 err_port_remove:
79 if (driver->port_remove)
80 driver->port_remove(port);
81 err_autopm_put:
82 usb_autopm_put_interface(port->serial->interface);
83
84 return retval;
85 }
86
usb_serial_device_remove(struct device * dev)87 static int usb_serial_device_remove(struct device *dev)
88 {
89 struct usb_serial_driver *driver;
90 struct usb_serial_port *port;
91 int retval = 0;
92 int minor;
93 int autopm_err;
94
95 port = to_usb_serial_port(dev);
96 if (!port)
97 return -ENODEV;
98
99 /*
100 * Make sure suspend/resume doesn't race against port_remove.
101 *
102 * Note that no further runtime PM callbacks will be made if
103 * autopm_get fails.
104 */
105 autopm_err = usb_autopm_get_interface(port->serial->interface);
106
107 minor = port->minor;
108 tty_unregister_device(usb_serial_tty_driver, minor);
109
110 driver = port->serial->type;
111 if (driver->port_remove)
112 retval = driver->port_remove(port);
113
114 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
115 driver->description, minor);
116
117 if (!autopm_err)
118 usb_autopm_put_interface(port->serial->interface);
119
120 return retval;
121 }
122
new_id_store(struct device_driver * driver,const char * buf,size_t count)123 static ssize_t new_id_store(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, usb_drv->id_table,
128 driver, buf, count);
129
130 if (retval >= 0 && usb_drv->usb_driver != NULL)
131 retval = usb_store_new_id(&usb_drv->usb_driver->dynids,
132 usb_drv->usb_driver->id_table,
133 &usb_drv->usb_driver->drvwrap.driver,
134 buf, count);
135 return retval;
136 }
137
new_id_show(struct device_driver * driver,char * buf)138 static ssize_t new_id_show(struct device_driver *driver, char *buf)
139 {
140 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
141
142 return usb_show_dynids(&usb_drv->dynids, buf);
143 }
144 static DRIVER_ATTR_RW(new_id);
145
146 static struct attribute *usb_serial_drv_attrs[] = {
147 &driver_attr_new_id.attr,
148 NULL,
149 };
150 ATTRIBUTE_GROUPS(usb_serial_drv);
151
free_dynids(struct usb_serial_driver * drv)152 static void free_dynids(struct usb_serial_driver *drv)
153 {
154 struct usb_dynid *dynid, *n;
155
156 spin_lock(&drv->dynids.lock);
157 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
158 list_del(&dynid->node);
159 kfree(dynid);
160 }
161 spin_unlock(&drv->dynids.lock);
162 }
163
164 struct bus_type usb_serial_bus_type = {
165 .name = "usb-serial",
166 .match = usb_serial_device_match,
167 .probe = usb_serial_device_probe,
168 .remove = usb_serial_device_remove,
169 .drv_groups = usb_serial_drv_groups,
170 };
171
usb_serial_bus_register(struct usb_serial_driver * driver)172 int usb_serial_bus_register(struct usb_serial_driver *driver)
173 {
174 int retval;
175
176 driver->driver.bus = &usb_serial_bus_type;
177 spin_lock_init(&driver->dynids.lock);
178 INIT_LIST_HEAD(&driver->dynids.list);
179
180 retval = driver_register(&driver->driver);
181
182 return retval;
183 }
184
usb_serial_bus_deregister(struct usb_serial_driver * driver)185 void usb_serial_bus_deregister(struct usb_serial_driver *driver)
186 {
187 free_dynids(driver);
188 driver_unregister(&driver->driver);
189 }
190
191
