tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * USB Serial Converter Bus specific functions
3 *
4 * Copyright (C) 2002 Greg Kroah-Hartman (greg@kroah.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License version
8 * 2 as published by the Free Software Foundation.
9 */
10
11#include <linux/config.h>
12#include <linux/kernel.h>
13#include <linux/errno.h>
14#include <linux/tty.h>
15#include <linux/module.h>
16#include <linux/usb.h>
17#include "usb-serial.h"
18
19static int usb_serial_device_match (struct device *dev, struct device_driver *drv)
20{
21 struct usb_serial_driver *driver;
22 const struct usb_serial_port *port;
23
24 /*
25 * drivers are already assigned to ports in serial_probe so it's
26 * a simple check here.
27 */
28 port = to_usb_serial_port(dev);
29 if (!port)
30 return 0;
31
32 driver = to_usb_serial_driver(drv);
33
34 if (driver == port->serial->type)
35 return 1;
36
37 return 0;
38}
39
40struct bus_type usb_serial_bus_type = {
41 .name = "usb-serial",
42 .match = usb_serial_device_match,
43};
44
45static int usb_serial_device_probe (struct device *dev)
46{
47 struct usb_serial_driver *driver;
48 struct usb_serial_port *port;
49 int retval = 0;
50 int minor;
51
52 port = to_usb_serial_port(dev);
53 if (!port) {
54 retval = -ENODEV;
55 goto exit;
56 }
57
58 driver = port->serial->type;
59 if (driver->port_probe) {
60 if (!try_module_get(driver->driver.owner)) {
61 dev_err(dev, "module get failed, exiting\n");
62 retval = -EIO;
63 goto exit;
64 }
65 retval = driver->port_probe (port);
66 module_put(driver->driver.owner);
67 if (retval)
68 goto exit;
69 }
70
71 minor = port->number;
72 tty_register_device (usb_serial_tty_driver, minor, dev);
73 dev_info(&port->serial->dev->dev,
74 "%s converter now attached to ttyUSB%d\n",
75 driver->description, minor);
76
77exit:
78 return retval;
79}
80
81static int usb_serial_device_remove (struct device *dev)
82{
83 struct usb_serial_driver *driver;
84 struct usb_serial_port *port;
85 int retval = 0;
86 int minor;
87
88 port = to_usb_serial_port(dev);
89 if (!port) {
90 return -ENODEV;
91 }
92
93 driver = port->serial->type;
94 if (driver->port_remove) {
95 if (!try_module_get(driver->driver.owner)) {
96 dev_err(dev, "module get failed, exiting\n");
97 retval = -EIO;
98 goto exit;
99 }
100 retval = driver->port_remove (port);
101 module_put(driver->driver.owner);
102 }
103exit:
104 minor = port->number;
105 tty_unregister_device (usb_serial_tty_driver, minor);
106 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
107 driver->description, minor);
108
109 return retval;
110}
111
112int usb_serial_bus_register(struct usb_serial_driver *driver)
113{
114 int retval;
115
116 driver->driver.bus = &usb_serial_bus_type;
117 driver->driver.probe = usb_serial_device_probe;
118 driver->driver.remove = usb_serial_device_remove;
119
120 retval = driver_register(&driver->driver);
121
122 return retval;
123}
124
125void usb_serial_bus_deregister(struct usb_serial_driver *driver)
126{
127 driver_unregister(&driver->driver);
128}
129