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
16static 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
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	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
147const 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
155int 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
168void usb_serial_bus_deregister(struct usb_serial_driver *driver)
169{
170	free_dynids(driver);
171	driver_unregister(&driver->driver);
172}
173
174