Branch data Line data Source code
1 : : /*
2 : : * drivers/usb/generic.c - generic driver for USB devices (not interfaces)
3 : : *
4 : : * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
5 : : *
6 : : * based on drivers/usb/usb.c which had the following copyrights:
7 : : * (C) Copyright Linus Torvalds 1999
8 : : * (C) Copyright Johannes Erdfelt 1999-2001
9 : : * (C) Copyright Andreas Gal 1999
10 : : * (C) Copyright Gregory P. Smith 1999
11 : : * (C) Copyright Deti Fliegl 1999 (new USB architecture)
12 : : * (C) Copyright Randy Dunlap 2000
13 : : * (C) Copyright David Brownell 2000-2004
14 : : * (C) Copyright Yggdrasil Computing, Inc. 2000
15 : : * (usb_device_id matching changes by Adam J. Richter)
16 : : * (C) Copyright Greg Kroah-Hartman 2002-2003
17 : : *
18 : : */
19 : :
20 : : #include <linux/usb.h>
21 : : #include <linux/usb/hcd.h>
22 : : #include "usb.h"
23 : :
24 : : static inline const char *plural(int n)
25 : : {
26 [ # # ][ # # ]: 0 : return (n == 1 ? "" : "s");
27 : : }
28 : :
29 : : static int is_rndis(struct usb_interface_descriptor *desc)
30 : : {
31 : 0 : return desc->bInterfaceClass == USB_CLASS_COMM
32 [ # # ]: 0 : && desc->bInterfaceSubClass == 2
33 [ # # ][ # # ]: 0 : && desc->bInterfaceProtocol == 0xff;
34 : : }
35 : :
36 : : static int is_activesync(struct usb_interface_descriptor *desc)
37 : : {
38 : : return desc->bInterfaceClass == USB_CLASS_MISC
39 [ # # ]: 0 : && desc->bInterfaceSubClass == 1
40 [ # # ][ # # ]: 0 : && desc->bInterfaceProtocol == 1;
41 : : }
42 : :
43 : 0 : int usb_choose_configuration(struct usb_device *udev)
44 : : {
45 : : int i;
46 : : int num_configs;
47 : : int insufficient_power = 0;
48 : 2 : struct usb_host_config *c, *best;
49 : :
50 [ + - ]: 2 : if (usb_device_is_owned(udev))
51 : : return 0;
52 : :
53 : : best = NULL;
54 : 2 : c = udev->config;
55 : 2 : num_configs = udev->descriptor.bNumConfigurations;
56 [ + - ]: 2 : for (i = 0; i < num_configs; (i++, c++)) {
57 : : struct usb_interface_descriptor *desc = NULL;
58 : :
59 : : /* It's possible that a config has no interfaces! */
60 [ + - ]: 2 : if (c->desc.bNumInterfaces > 0)
61 : 2 : desc = &c->intf_cache[0]->altsetting->desc;
62 : :
63 : : /*
64 : : * HP's USB bus-powered keyboard has only one configuration
65 : : * and it claims to be self-powered; other devices may have
66 : : * similar errors in their descriptors. If the next test
67 : : * were allowed to execute, such configurations would always
68 : : * be rejected and the devices would not work as expected.
69 : : * In the meantime, we run the risk of selecting a config
70 : : * that requires external power at a time when that power
71 : : * isn't available. It seems to be the lesser of two evils.
72 : : *
73 : : * Bugzilla #6448 reports a device that appears to crash
74 : : * when it receives a GET_DEVICE_STATUS request! We don't
75 : : * have any other way to tell whether a device is self-powered,
76 : : * but since we don't use that information anywhere but here,
77 : : * the call has been removed.
78 : : *
79 : : * Maybe the GET_DEVICE_STATUS call and the test below can
80 : : * be reinstated when device firmwares become more reliable.
81 : : * Don't hold your breath.
82 : : */
83 : : #if 0
84 : : /* Rule out self-powered configs for a bus-powered device */
85 : : if (bus_powered && (c->desc.bmAttributes &
86 : : USB_CONFIG_ATT_SELFPOWER))
87 : : continue;
88 : : #endif
89 : :
90 : : /*
91 : : * The next test may not be as effective as it should be.
92 : : * Some hubs have errors in their descriptor, claiming
93 : : * to be self-powered when they are really bus-powered.
94 : : * We will overestimate the amount of current such hubs
95 : : * make available for each port.
96 : : *
97 : : * This is a fairly benign sort of failure. It won't
98 : : * cause us to reject configurations that we should have
99 : : * accepted.
100 : : */
101 : :
102 : : /* Rule out configs that draw too much bus current */
103 [ - + ]: 2 : if (usb_get_max_power(udev, c) > udev->bus_mA) {
104 : 0 : insufficient_power++;
105 : 0 : continue;
106 : : }
107 : :
108 : : /* When the first config's first interface is one of Microsoft's
109 : : * pet nonstandard Ethernet-over-USB protocols, ignore it unless
110 : : * this kernel has enabled the necessary host side driver.
111 : : * But: Don't ignore it if it's the only config.
112 : : */
113 [ - + ][ # # ]: 2 : if (i == 0 && num_configs > 1 && desc &&
[ # # ]
114 [ # # ]: 0 : (is_rndis(desc) || is_activesync(desc))) {
115 : : #if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE)
116 : 0 : continue;
117 : : #else
118 : : best = c;
119 : : #endif
120 : : }
121 : :
122 : : /* From the remaining configs, choose the first one whose
123 : : * first interface is for a non-vendor-specific class.
124 : : * Reason: Linux is more likely to have a class driver
125 : : * than a vendor-specific driver. */
126 [ # # ]: 2 : else if (udev->descriptor.bDeviceClass !=
127 [ + - ]: 2 : USB_CLASS_VENDOR_SPEC &&
128 [ + - ]: 2 : (desc && desc->bInterfaceClass !=
129 : : USB_CLASS_VENDOR_SPEC)) {
130 : : best = c;
131 : : break;
132 : : }
133 : :
134 : : /* If all the remaining configs are vendor-specific,
135 : : * choose the first one. */
136 [ # # ]: 0 : else if (!best)
137 : : best = c;
138 : : }
139 : :
140 [ # # ]: 0 : if (insufficient_power > 0)
141 : 0 : dev_info(&udev->dev, "rejected %d configuration%s "
142 : : "due to insufficient available bus power\n",
143 : : insufficient_power, plural(insufficient_power));
144 : :
145 [ + - ]: 2 : if (best) {
146 : 2 : i = best->desc.bConfigurationValue;
147 : : dev_dbg(&udev->dev,
148 : : "configuration #%d chosen from %d choice%s\n",
149 : : i, num_configs, plural(num_configs));
150 : : } else {
151 : : i = -1;
152 : 0 : dev_warn(&udev->dev,
153 : : "no configuration chosen from %d choice%s\n",
154 : : num_configs, plural(num_configs));
155 : : }
156 : 2 : return i;
157 : : }
158 : :
159 : 0 : static int generic_probe(struct usb_device *udev)
160 : : {
161 : : int err, c;
162 : :
163 : : /* Choose and set the configuration. This registers the interfaces
164 : : * with the driver core and lets interface drivers bind to them.
165 : : */
166 [ - + ]: 2 : if (udev->authorized == 0)
167 : 0 : dev_err(&udev->dev, "Device is not authorized for usage\n");
168 : : else {
169 : 2 : c = usb_choose_configuration(udev);
170 [ + - ]: 2 : if (c >= 0) {
171 : 2 : err = usb_set_configuration(udev, c);
172 [ - + ]: 2 : if (err && err != -ENODEV) {
173 : 0 : dev_err(&udev->dev, "can't set config #%d, error %d\n",
174 : : c, err);
175 : : /* This need not be fatal. The user can try to
176 : : * set other configurations. */
177 : : }
178 : : }
179 : : }
180 : : /* USB device state == configured ... usable */
181 : 2 : usb_notify_add_device(udev);
182 : :
183 : 2 : return 0;
184 : : }
185 : :
186 : 0 : static void generic_disconnect(struct usb_device *udev)
187 : : {
188 : 2 : usb_notify_remove_device(udev);
189 : :
190 : : /* if this is only an unbind, not a physical disconnect, then
191 : : * unconfigure the device */
192 [ - + ]: 2 : if (udev->actconfig)
193 : 0 : usb_set_configuration(udev, -1);
194 : 0 : }
195 : :
196 : : #ifdef CONFIG_PM
197 : :
198 : 0 : static int generic_suspend(struct usb_device *udev, pm_message_t msg)
199 : : {
200 : : int rc;
201 : :
202 : : /* Normal USB devices suspend through their upstream port.
203 : : * Root hubs don't have upstream ports to suspend,
204 : : * so we have to shut down their downstream HC-to-USB
205 : : * interfaces manually by doing a bus (or "global") suspend.
206 : : */
207 [ # # ]: 0 : if (!udev->parent)
208 : 0 : rc = hcd_bus_suspend(udev, msg);
209 : :
210 : : /* Non-root devices don't need to do anything for FREEZE or PRETHAW */
211 [ # # ]: 0 : else if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW)
212 : : rc = 0;
213 : : else
214 : 0 : rc = usb_port_suspend(udev, msg);
215 : :
216 : 0 : return rc;
217 : : }
218 : :
219 : 0 : static int generic_resume(struct usb_device *udev, pm_message_t msg)
220 : : {
221 : : int rc;
222 : :
223 : : /* Normal USB devices resume/reset through their upstream port.
224 : : * Root hubs don't have upstream ports to resume or reset,
225 : : * so we have to start up their downstream HC-to-USB
226 : : * interfaces manually by doing a bus (or "global") resume.
227 : : */
228 [ # # ]: 0 : if (!udev->parent)
229 : 0 : rc = hcd_bus_resume(udev, msg);
230 : : else
231 : 0 : rc = usb_port_resume(udev, msg);
232 : 0 : return rc;
233 : : }
234 : :
235 : : #endif /* CONFIG_PM */
236 : :
237 : : struct usb_device_driver usb_generic_driver = {
238 : : .name = "usb",
239 : : .probe = generic_probe,
240 : : .disconnect = generic_disconnect,
241 : : #ifdef CONFIG_PM
242 : : .suspend = generic_suspend,
243 : : .resume = generic_resume,
244 : : #endif
245 : : .supports_autosuspend = 1,
246 : : };
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