summaryrefslogtreecommitdiff
path: root/drivers/usb/serial/bus.c
blob: b8364a8de7df485bdabfbeb6d1978feb3ca5f483 (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
/*
 * USB Serial Converter Bus specific functions
 *
 * Copyright (C) 2002 Greg Kroah-Hartman (greg@kroah.com)
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License version
 *	2 as published by the Free Software Foundation.
 */

#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/module.h>
#include <linux/usb.h>
#include "usb-serial.h"

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

	/*
	 * drivers are already assigned to ports in serial_probe so it's
	 * a simple check here.
	 */
	port = to_usb_serial_port(dev);
	if (!port)
		return 0;

	driver = to_usb_serial_driver(drv);

	if (driver == port->serial->type)
		return 1;

	return 0;
}

struct bus_type usb_serial_bus_type = {
	.name =		"usb-serial",
	.match =	usb_serial_device_match,
};

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

	port = to_usb_serial_port(dev);
	if (!port) {
		retval = -ENODEV;
		goto exit;
	}

	driver = port->serial->type;
	if (driver->port_probe) {
		if (!try_module_get(driver->driver.owner)) {
			dev_err(dev, "module get failed, exiting\n");
			retval = -EIO;
			goto exit;
		}
		retval = driver->port_probe (port);
		module_put(driver->driver.owner);
		if (retval)
			goto exit;
	}

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

exit:
	return retval;
}

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

	port = to_usb_serial_port(dev);
	if (!port) {
		return -ENODEV;
	}

	driver = port->serial->type;
	if (driver->port_remove) {
		if (!try_module_get(driver->driver.owner)) {
			dev_err(dev, "module get failed, exiting\n");
			retval = -EIO;
			goto exit;
		}
		retval = driver->port_remove (port);
		module_put(driver->driver.owner);
	}
exit:
	minor = port->number;
	tty_unregister_device (usb_serial_tty_driver, minor);
	dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
		 driver->name, minor);

	return retval;
}

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

	if (driver->short_name)
		driver->driver.name = (char *)driver->short_name;
	else
		driver->driver.name = (char *)driver->name;
	driver->driver.bus = &usb_serial_bus_type;
	driver->driver.probe = usb_serial_device_probe;
	driver->driver.remove = usb_serial_device_remove;

	retval = driver_register(&driver->driver);

	return retval;
}

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