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/kernel.h>
12#include <linux/errno.h>
13#include <linux/tty.h>
14#include <linux/module.h>
15#include <linux/usb.h>
16#include <linux/usb/serial.h>
17
18static int usb_serial_device_match(struct device *dev,
19 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
40static ssize_t show_port_number(struct device *dev,
41 struct device_attribute *attr, char *buf)
42{
43 struct usb_serial_port *port = to_usb_serial_port(dev);
44
45 return sprintf(buf, "%d\n", port->number - port->serial->minor);
46}
47
48static DEVICE_ATTR(port_number, S_IRUGO, show_port_number, NULL);
49
50static int usb_serial_device_probe(struct device *dev)
51{
52 struct usb_serial_driver *driver;
53 struct usb_serial_port *port;
54 int retval = 0;
55 int minor;
56
57 port = to_usb_serial_port(dev);
58 if (!port) {
59 retval = -ENODEV;
60 goto exit;
61 }
62
63 driver = port->serial->type;
64 if (driver->port_probe) {
65 if (!try_module_get(driver->driver.owner)) {
66 dev_err(dev, "module get failed, exiting\n");
67 retval = -EIO;
68 goto exit;
69 }
70 retval = driver->port_probe(port);
71 module_put(driver->driver.owner);
72 if (retval)
73 goto exit;
74 }
75
76 retval = device_create_file(dev, &dev_attr_port_number);
77 if (retval)
78 goto exit;
79
80 minor = port->number;
81 tty_register_device(usb_serial_tty_driver, minor, dev);
82 dev_info(&port->serial->dev->dev,
83 "%s converter now attached to ttyUSB%d\n",
84 driver->description, minor);
85
86exit:
87 return retval;
88}
89
90static int usb_serial_device_remove(struct device *dev)
91{
92 struct usb_serial_driver *driver;
93 struct usb_serial_port *port;
94 int retval = 0;
95 int minor;
96
97 port = to_usb_serial_port(dev);
98 if (!port)
99 return -ENODEV;
100
101 device_remove_file(&port->dev, &dev_attr_port_number);
102
103 driver = port->serial->type;
104 if (driver->port_remove) {
105 if (!try_module_get(driver->driver.owner)) {
106 dev_err(dev, "module get failed, exiting\n");
107 retval = -EIO;
108 goto exit;
109 }
110 retval = driver->port_remove(port);
111 module_put(driver->driver.owner);
112 }
113exit:
114 minor = port->number;
115 tty_unregister_device(usb_serial_tty_driver, minor);
116 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
117 driver->description, minor);
118
119 return retval;
120}
121
122#ifdef CONFIG_HOTPLUG
123static ssize_t store_new_id(struct device_driver *driver,
124 const char *buf, size_t count)
125{
126 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
127 ssize_t retval = usb_store_new_id(&usb_drv->dynids, driver, buf, count);
128
129 if (retval >= 0 && usb_drv->usb_driver != NULL)
130 retval = usb_store_new_id(&usb_drv->usb_driver->dynids,
131 &usb_drv->usb_driver->drvwrap.driver,
132 buf, count);
133 return retval;
134}
135
136static struct driver_attribute drv_attrs[] = {
137 __ATTR(new_id, S_IWUSR, NULL, store_new_id),
138 __ATTR_NULL,
139};
140
141static void free_dynids(struct usb_serial_driver *drv)
142{
143 struct usb_dynid *dynid, *n;
144
145 spin_lock(&drv->dynids.lock);
146 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
147 list_del(&dynid->node);
148 kfree(dynid);
149 }
150 spin_unlock(&drv->dynids.lock);
151}
152
153#else
154static struct driver_attribute drv_attrs[] = {
155 __ATTR_NULL,
156};
157static inline void free_dynids(struct usb_serial_driver *drv)
158{
159}
160#endif
161
162struct bus_type usb_serial_bus_type = {
163 .name = "usb-serial",
164 .match = usb_serial_device_match,
165 .probe = usb_serial_device_probe,
166 .remove = usb_serial_device_remove,
167 .drv_attrs = drv_attrs,
168};
169
170int usb_serial_bus_register(struct usb_serial_driver *driver)
171{
172 int retval;
173
174 driver->driver.bus = &usb_serial_bus_type;
175 spin_lock_init(&driver->dynids.lock);
176 INIT_LIST_HEAD(&driver->dynids.list);
177
178 retval = driver_register(&driver->driver);
179
180 return retval;
181}
182
183void usb_serial_bus_deregister(struct usb_serial_driver *driver)
184{
185 free_dynids(driver);
186 driver_unregister(&driver->driver);
187}
188