Merge branch 'nfs-server-stable' of git://linux-nfs.org/~bfields/linux
[linux-2.6] / drivers / usb / serial / bus.c
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
18 static int usb_serial_device_match (struct device *dev, struct device_driver *drv)
19 {
20         struct usb_serial_driver *driver;
21         const struct usb_serial_port *port;
22
23         /*
24          * drivers are already assigned to ports in serial_probe so it's
25          * a simple check here.
26          */
27         port = to_usb_serial_port(dev);
28         if (!port)
29                 return 0;
30
31         driver = to_usb_serial_driver(drv);
32
33         if (driver == port->serial->type)
34                 return 1;
35
36         return 0;
37 }
38
39 static ssize_t show_port_number(struct device *dev,
40                                 struct device_attribute *attr, char *buf)
41 {
42         struct usb_serial_port *port = to_usb_serial_port(dev);
43
44         return sprintf(buf, "%d\n", port->number - port->serial->minor);
45 }
46
47 static DEVICE_ATTR(port_number, S_IRUGO, show_port_number, NULL);
48
49 static int usb_serial_device_probe (struct device *dev)
50 {
51         struct usb_serial_driver *driver;
52         struct usb_serial_port *port;
53         int retval = 0;
54         int minor;
55
56         port = to_usb_serial_port(dev);
57         if (!port) {
58                 retval = -ENODEV;
59                 goto exit;
60         }
61
62         driver = port->serial->type;
63         if (driver->port_probe) {
64                 if (!try_module_get(driver->driver.owner)) {
65                         dev_err(dev, "module get failed, exiting\n");
66                         retval = -EIO;
67                         goto exit;
68                 }
69                 retval = driver->port_probe (port);
70                 module_put(driver->driver.owner);
71                 if (retval)
72                         goto exit;
73         }
74
75         retval = device_create_file(dev, &dev_attr_port_number);
76         if (retval)
77                 goto exit;
78
79         minor = port->number;
80         tty_register_device (usb_serial_tty_driver, minor, dev);
81         dev_info(&port->serial->dev->dev, 
82                  "%s converter now attached to ttyUSB%d\n",
83                  driver->description, minor);
84
85 exit:
86         return retval;
87 }
88
89 static int usb_serial_device_remove (struct device *dev)
90 {
91         struct usb_serial_driver *driver;
92         struct usb_serial_port *port;
93         int retval = 0;
94         int minor;
95
96         port = to_usb_serial_port(dev);
97         if (!port) {
98                 return -ENODEV;
99         }
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         }
113 exit:
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
123 static 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
136 static struct driver_attribute drv_attrs[] = {
137         __ATTR(new_id, S_IWUSR, NULL, store_new_id),
138         __ATTR_NULL,
139 };
140
141 static 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
154 static struct driver_attribute drv_attrs[] = {
155         __ATTR_NULL,
156 };
157 static inline void free_dynids(struct usb_serial_driver *drv)
158 {
159 }
160 #endif
161
162 struct 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
170 int 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
183 void usb_serial_bus_deregister(struct usb_serial_driver *driver)
184 {
185         free_dynids(driver);
186         driver_unregister(&driver->driver);
187 }
188