summaryrefslogtreecommitdiff
path: root/drivers/usb/serial/bus.c
blob: 9e38142acd38cc24f4de9eb7e8928c39a850b130 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
// SPDX-License-Identifier: GPL-2.0
/*
 * USB Serial Converter Bus specific functions
 *
 * Copyright (C) 2002 Greg Kroah-Hartman (greg@kroah.com)
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>

static int usb_serial_device_match(struct device *dev,
						struct device_driver *drv)
{
	const struct usb_serial_port *port = to_usb_serial_port(dev);
	struct usb_serial_driver *driver = to_usb_serial_driver(drv);

	/*
	 * drivers are already assigned to ports in serial_probe so it's
	 * a simple check here.
	 */
	if (driver == port->serial->type)
		return 1;

	return 0;
}

static int usb_serial_device_probe(struct device *dev)
{
	struct usb_serial_port *port = to_usb_serial_port(dev);
	struct usb_serial_driver *driver;
	struct device *tty_dev;
	int retval = 0;
	int minor;

	/* make sure suspend/resume doesn't race against port_probe */
	retval = usb_autopm_get_interface(port->serial->interface);
	if (retval)
		return retval;

	driver = port->serial->type;
	if (driver->port_probe) {
		retval = driver->port_probe(port);
		if (retval)
			goto err_autopm_put;
	}

	minor = port->minor;
	tty_dev = tty_port_register_device(&port->port, usb_serial_tty_driver,
					   minor, dev);
	if (IS_ERR(tty_dev)) {
		retval = PTR_ERR(tty_dev);
		goto err_port_remove;
	}

	usb_autopm_put_interface(port->serial->interface);

	dev_info(&port->serial->dev->dev,
		 "%s converter now attached to ttyUSB%d\n",
		 driver->description, minor);

	return 0;

err_port_remove:
	if (driver->port_remove)
		driver->port_remove(port);
err_autopm_put:
	usb_autopm_put_interface(port->serial->interface);

	return retval;
}

static void usb_serial_device_remove(struct device *dev)
{
	struct usb_serial_port *port = to_usb_serial_port(dev);
	struct usb_serial_driver *driver;
	int minor;
	int autopm_err;

	/*
	 * Make sure suspend/resume doesn't race against port_remove.
	 *
	 * Note that no further runtime PM callbacks will be made if
	 * autopm_get fails.
	 */
	autopm_err = usb_autopm_get_interface(port->serial->interface);

	minor = port->minor;
	tty_unregister_device(usb_serial_tty_driver, minor);

	driver = port->serial->type;
	if (driver->port_remove)
		driver->port_remove(port);

	dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
		 driver->description, minor);

	if (!autopm_err)
		usb_autopm_put_interface(port->serial->interface);
}

static ssize_t new_id_store(struct device_driver *driver,
			    const char *buf, size_t count)
{
	struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
	ssize_t retval = usb_store_new_id(&usb_drv->dynids, usb_drv->id_table,
					 driver, buf, count);

	if (retval >= 0 && usb_drv->usb_driver != NULL)
		retval = usb_store_new_id(&usb_drv->usb_driver->dynids,
					  usb_drv->usb_driver->id_table,
					  &usb_drv->usb_driver->drvwrap.driver,
					  buf, count);
	return retval;
}

static ssize_t new_id_show(struct device_driver *driver, char *buf)
{
	struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);

	return usb_show_dynids(&usb_drv->dynids, buf);
}
static DRIVER_ATTR_RW(new_id);

static struct attribute *usb_serial_drv_attrs[] = {
	&driver_attr_new_id.attr,
	NULL,
};
ATTRIBUTE_GROUPS(usb_serial_drv);

static void free_dynids(struct usb_serial_driver *drv)
{
	struct usb_dynid *dynid, *n;

	spin_lock(&drv->dynids.lock);
	list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
		list_del(&dynid->node);
		kfree(dynid);
	}
	spin_unlock(&drv->dynids.lock);
}

struct bus_type usb_serial_bus_type = {
	.name =		"usb-serial",
	.match =	usb_serial_device_match,
	.probe =	usb_serial_device_probe,
	.remove =	usb_serial_device_remove,
	.drv_groups = 	usb_serial_drv_groups,
};

int usb_serial_bus_register(struct usb_serial_driver *driver)
{
	int retval;

	driver->driver.bus = &usb_serial_bus_type;
	spin_lock_init(&driver->dynids.lock);
	INIT_LIST_HEAD(&driver->dynids.list);

	retval = driver_register(&driver->driver);

	return retval;
}

void usb_serial_bus_deregister(struct usb_serial_driver *driver)
{
	free_dynids(driver);
	driver_unregister(&driver->driver);
}