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/slab.h>
15 #include <linux/module.h>
16 #include <linux/usb.h>
17 #include <linux/usb/serial.h>
18
usb_serial_device_match(struct device * dev,struct device_driver * drv)19 static int usb_serial_device_match(struct device *dev,
20 struct device_driver *drv)
21 {
22 struct usb_serial_driver *driver;
23 const struct usb_serial_port *port;
24
25 /*
26 * drivers are already assigned to ports in serial_probe so it's
27 * a simple check here.
28 */
29 port = to_usb_serial_port(dev);
30 if (!port)
31 return 0;
32
33 driver = to_usb_serial_driver(drv);
34
35 if (driver == port->serial->type)
36 return 1;
37
38 return 0;
39 }
40
show_port_number(struct device * dev,struct device_attribute * attr,char * buf)41 static ssize_t show_port_number(struct device *dev,
42 struct device_attribute *attr, char *buf)
43 {
44 struct usb_serial_port *port = to_usb_serial_port(dev);
45
46 return sprintf(buf, "%d\n", port->number - port->serial->minor);
47 }
48
49 static DEVICE_ATTR(port_number, S_IRUGO, show_port_number, NULL);
50
usb_serial_device_probe(struct device * dev)51 static int usb_serial_device_probe(struct device *dev)
52 {
53 struct usb_serial_driver *driver;
54 struct usb_serial_port *port;
55 int retval = 0;
56 int minor;
57
58 port = to_usb_serial_port(dev);
59 if (!port) {
60 retval = -ENODEV;
61 goto exit;
62 }
63
64 driver = port->serial->type;
65 if (driver->port_probe) {
66 retval = driver->port_probe(port);
67 if (retval)
68 goto exit;
69 }
70
71 retval = device_create_file(dev, &dev_attr_port_number);
72 if (retval) {
73 if (driver->port_remove)
74 retval = driver->port_remove(port);
75 goto exit;
76 }
77
78 minor = port->number;
79 tty_register_device(usb_serial_tty_driver, minor, dev);
80 dev_info(&port->serial->dev->dev,
81 "%s converter now attached to ttyUSB%d\n",
82 driver->description, minor);
83
84 exit:
85 return retval;
86 }
87
usb_serial_device_remove(struct device * dev)88 static int usb_serial_device_remove(struct device *dev)
89 {
90 struct usb_serial_driver *driver;
91 struct usb_serial_port *port;
92 int retval = 0;
93 int minor;
94
95 port = to_usb_serial_port(dev);
96 if (!port)
97 return -ENODEV;
98
99 device_remove_file(&port->dev, &dev_attr_port_number);
100
101 driver = port->serial->type;
102 if (driver->port_remove)
103 retval = driver->port_remove(port);
104
105 minor = port->number;
106 tty_unregister_device(usb_serial_tty_driver, minor);
107 dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",
108 driver->description, minor);
109
110 return retval;
111 }
112
113 #ifdef CONFIG_HOTPLUG
store_new_id(struct device_driver * driver,const char * buf,size_t count)114 static ssize_t store_new_id(struct device_driver *driver,
115 const char *buf, size_t count)
116 {
117 struct usb_serial_driver *usb_drv = to_usb_serial_driver(driver);
118 ssize_t retval = usb_store_new_id(&usb_drv->dynids, driver, buf, count);
119
120 if (retval >= 0 && usb_drv->usb_driver != NULL)
121 retval = usb_store_new_id(&usb_drv->usb_driver->dynids,
122 &usb_drv->usb_driver->drvwrap.driver,
123 buf, count);
124 return retval;
125 }
126
127 static struct driver_attribute drv_attrs[] = {
128 __ATTR(new_id, S_IWUSR, NULL, store_new_id),
129 __ATTR_NULL,
130 };
131
free_dynids(struct usb_serial_driver * drv)132 static void free_dynids(struct usb_serial_driver *drv)
133 {
134 struct usb_dynid *dynid, *n;
135
136 spin_lock(&drv->dynids.lock);
137 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
138 list_del(&dynid->node);
139 kfree(dynid);
140 }
141 spin_unlock(&drv->dynids.lock);
142 }
143
144 #else
145 static struct driver_attribute drv_attrs[] = {
146 __ATTR_NULL,
147 };
free_dynids(struct usb_serial_driver * drv)148 static inline void free_dynids(struct usb_serial_driver *drv)
149 {
150 }
151 #endif
152
153 struct bus_type usb_serial_bus_type = {
154 .name = "usb-serial",
155 .match = usb_serial_device_match,
156 .probe = usb_serial_device_probe,
157 .remove = usb_serial_device_remove,
158 .drv_attrs = drv_attrs,
159 };
160
usb_serial_bus_register(struct usb_serial_driver * driver)161 int usb_serial_bus_register(struct usb_serial_driver *driver)
162 {
163 int retval;
164
165 driver->driver.bus = &usb_serial_bus_type;
166 spin_lock_init(&driver->dynids.lock);
167 INIT_LIST_HEAD(&driver->dynids.list);
168
169 retval = driver_register(&driver->driver);
170
171 return retval;
172 }
173
usb_serial_bus_deregister(struct usb_serial_driver * driver)174 void usb_serial_bus_deregister(struct usb_serial_driver *driver)
175 {
176 free_dynids(driver);
177 driver_unregister(&driver->driver);
178 }
179
180