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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * USB Serial Converter Bus specific functions
4 *
5 * Copyright (C) 2002 Greg Kroah-Hartman ([email protected])
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
16static int usb_serial_device_match(struct device *dev,
17 const struct device_driver *drv)
18{
19 const struct usb_serial_port *port = to_usb_serial_port(dev);
20 const 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
32static 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
68err_port_remove:
69 if (driver->port_remove)
70 driver->port_remove(port);
71err_autopm_put:
72 usb_autopm_put_interface(port->serial->interface);
73
74 return retval;
75}
76
77static 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
106static 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->driver,
117 buf, count);
118 return retval;
119}
120
121static 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}
127static DRIVER_ATTR_RW(new_id);
128
129static struct attribute *usb_serial_drv_attrs[] = {
130 &driver_attr_new_id.attr,
131 NULL,
132};
133ATTRIBUTE_GROUPS(usb_serial_drv);
134
135static void free_dynids(struct usb_serial_driver *drv)
136{
137 struct usb_dynid *dynid, *n;
138
139 guard(mutex)(&usb_dynids_lock);
140 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
141 list_del(&dynid->node);
142 kfree(dynid);
143 }
144}
145
146const struct bus_type usb_serial_bus_type = {
147 .name = "usb-serial",
148 .match = usb_serial_device_match,
149 .probe = usb_serial_device_probe,
150 .remove = usb_serial_device_remove,
151 .drv_groups = usb_serial_drv_groups,
152};
153
154int usb_serial_bus_register(struct usb_serial_driver *driver)
155{
156 int retval;
157
158 driver->driver.bus = &usb_serial_bus_type;
159 INIT_LIST_HEAD(&driver->dynids.list);
160
161 retval = driver_register(&driver->driver);
162
163 return retval;
164}
165
166void usb_serial_bus_deregister(struct usb_serial_driver *driver)
167{
168 driver_unregister(&driver->driver);
169 free_dynids(driver);
170}
171
172void usb_serial_bus_remove_new_id(struct usb_serial_driver *driver)
173{
174 driver_remove_file(&driver->driver, &driver_attr_new_id);
175}