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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
24static inline const char *plural(int n)
25{
26 return (n == 1 ? "" : "s");
27}
28
29static int is_rndis(struct usb_interface_descriptor *desc)
30{
31 return desc->bInterfaceClass == USB_CLASS_COMM
32 && desc->bInterfaceSubClass == 2
33 && desc->bInterfaceProtocol == 0xff;
34}
35
36static int is_activesync(struct usb_interface_descriptor *desc)
37{
38 return desc->bInterfaceClass == USB_CLASS_MISC
39 && desc->bInterfaceSubClass == 1
40 && desc->bInterfaceProtocol == 1;
41}
42
43int usb_choose_configuration(struct usb_device *udev)
44{
45 int i;
46 int num_configs;
47 int insufficient_power = 0;
48 struct usb_host_config *c, *best;
49
50 if (usb_device_is_owned(udev))
51 return 0;
52
53 best = NULL;
54 c = udev->config;
55 num_configs = udev->descriptor.bNumConfigurations;
56 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 if (c->desc.bNumInterfaces > 0)
61 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 if (usb_get_max_power(udev, c) > udev->bus_mA) {
104 insufficient_power++;
105 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 if (i == 0 && num_configs > 1 && desc &&
114 (is_rndis(desc) || is_activesync(desc))) {
115#if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE)
116 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 else if (udev->descriptor.bDeviceClass !=
127 USB_CLASS_VENDOR_SPEC &&
128 (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 else if (!best)
137 best = c;
138 }
139
140 if (insufficient_power > 0)
141 dev_info(&udev->dev, "rejected %d configuration%s "
142 "due to insufficient available bus power\n",
143 insufficient_power, plural(insufficient_power));
144
145 if (best) {
146 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 dev_warn(&udev->dev,
153 "no configuration chosen from %d choice%s\n",
154 num_configs, plural(num_configs));
155 }
156 return i;
157}
158EXPORT_SYMBOL_GPL(usb_choose_configuration);
159
160static int generic_probe(struct usb_device *udev)
161{
162 int err, c;
163
164 /* Choose and set the configuration. This registers the interfaces
165 * with the driver core and lets interface drivers bind to them.
166 */
167 if (udev->authorized == 0)
168 dev_err(&udev->dev, "Device is not authorized for usage\n");
169 else {
170 c = usb_choose_configuration(udev);
171 if (c >= 0) {
172 err = usb_set_configuration(udev, c);
173 if (err && err != -ENODEV) {
174 dev_err(&udev->dev, "can't set config #%d, error %d\n",
175 c, err);
176 /* This need not be fatal. The user can try to
177 * set other configurations. */
178 }
179 }
180 }
181 /* USB device state == configured ... usable */
182 usb_notify_add_device(udev);
183
184 return 0;
185}
186
187static void generic_disconnect(struct usb_device *udev)
188{
189 usb_notify_remove_device(udev);
190
191 /* if this is only an unbind, not a physical disconnect, then
192 * unconfigure the device */
193 if (udev->actconfig)
194 usb_set_configuration(udev, -1);
195}
196
197#ifdef CONFIG_PM
198
199static int generic_suspend(struct usb_device *udev, pm_message_t msg)
200{
201 int rc;
202
203 /* Normal USB devices suspend through their upstream port.
204 * Root hubs don't have upstream ports to suspend,
205 * so we have to shut down their downstream HC-to-USB
206 * interfaces manually by doing a bus (or "global") suspend.
207 */
208 if (!udev->parent)
209 rc = hcd_bus_suspend(udev, msg);
210
211 /* Non-root devices don't need to do anything for FREEZE or PRETHAW */
212 else if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW)
213 rc = 0;
214 else
215 rc = usb_port_suspend(udev, msg);
216
217 return rc;
218}
219
220static int generic_resume(struct usb_device *udev, pm_message_t msg)
221{
222 int rc;
223
224 /* Normal USB devices resume/reset through their upstream port.
225 * Root hubs don't have upstream ports to resume or reset,
226 * so we have to start up their downstream HC-to-USB
227 * interfaces manually by doing a bus (or "global") resume.
228 */
229 if (!udev->parent)
230 rc = hcd_bus_resume(udev, msg);
231 else
232 rc = usb_port_resume(udev, msg);
233 return rc;
234}
235
236#endif /* CONFIG_PM */
237
238struct usb_device_driver usb_generic_driver = {
239 .name = "usb",
240 .probe = generic_probe,
241 .disconnect = generic_disconnect,
242#ifdef CONFIG_PM
243 .suspend = generic_suspend,
244 .resume = generic_resume,
245#endif
246 .supports_autosuspend = 1,
247};
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 * Released under the GPLv2 only.
19 * SPDX-License-Identifier: GPL-2.0
20 */
21
22#include <linux/usb.h>
23#include <linux/usb/hcd.h>
24#include "usb.h"
25
26static inline const char *plural(int n)
27{
28 return (n == 1 ? "" : "s");
29}
30
31static int is_rndis(struct usb_interface_descriptor *desc)
32{
33 return desc->bInterfaceClass == USB_CLASS_COMM
34 && desc->bInterfaceSubClass == 2
35 && desc->bInterfaceProtocol == 0xff;
36}
37
38static int is_activesync(struct usb_interface_descriptor *desc)
39{
40 return desc->bInterfaceClass == USB_CLASS_MISC
41 && desc->bInterfaceSubClass == 1
42 && desc->bInterfaceProtocol == 1;
43}
44
45int usb_choose_configuration(struct usb_device *udev)
46{
47 int i;
48 int num_configs;
49 int insufficient_power = 0;
50 struct usb_host_config *c, *best;
51
52 if (usb_device_is_owned(udev))
53 return 0;
54
55 best = NULL;
56 c = udev->config;
57 num_configs = udev->descriptor.bNumConfigurations;
58 for (i = 0; i < num_configs; (i++, c++)) {
59 struct usb_interface_descriptor *desc = NULL;
60
61 /* It's possible that a config has no interfaces! */
62 if (c->desc.bNumInterfaces > 0)
63 desc = &c->intf_cache[0]->altsetting->desc;
64
65 /*
66 * HP's USB bus-powered keyboard has only one configuration
67 * and it claims to be self-powered; other devices may have
68 * similar errors in their descriptors. If the next test
69 * were allowed to execute, such configurations would always
70 * be rejected and the devices would not work as expected.
71 * In the meantime, we run the risk of selecting a config
72 * that requires external power at a time when that power
73 * isn't available. It seems to be the lesser of two evils.
74 *
75 * Bugzilla #6448 reports a device that appears to crash
76 * when it receives a GET_DEVICE_STATUS request! We don't
77 * have any other way to tell whether a device is self-powered,
78 * but since we don't use that information anywhere but here,
79 * the call has been removed.
80 *
81 * Maybe the GET_DEVICE_STATUS call and the test below can
82 * be reinstated when device firmwares become more reliable.
83 * Don't hold your breath.
84 */
85#if 0
86 /* Rule out self-powered configs for a bus-powered device */
87 if (bus_powered && (c->desc.bmAttributes &
88 USB_CONFIG_ATT_SELFPOWER))
89 continue;
90#endif
91
92 /*
93 * The next test may not be as effective as it should be.
94 * Some hubs have errors in their descriptor, claiming
95 * to be self-powered when they are really bus-powered.
96 * We will overestimate the amount of current such hubs
97 * make available for each port.
98 *
99 * This is a fairly benign sort of failure. It won't
100 * cause us to reject configurations that we should have
101 * accepted.
102 */
103
104 /* Rule out configs that draw too much bus current */
105 if (usb_get_max_power(udev, c) > udev->bus_mA) {
106 insufficient_power++;
107 continue;
108 }
109
110 /* When the first config's first interface is one of Microsoft's
111 * pet nonstandard Ethernet-over-USB protocols, ignore it unless
112 * this kernel has enabled the necessary host side driver.
113 * But: Don't ignore it if it's the only config.
114 */
115 if (i == 0 && num_configs > 1 && desc &&
116 (is_rndis(desc) || is_activesync(desc))) {
117#if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE)
118 continue;
119#else
120 best = c;
121#endif
122 }
123
124 /* From the remaining configs, choose the first one whose
125 * first interface is for a non-vendor-specific class.
126 * Reason: Linux is more likely to have a class driver
127 * than a vendor-specific driver. */
128 else if (udev->descriptor.bDeviceClass !=
129 USB_CLASS_VENDOR_SPEC &&
130 (desc && desc->bInterfaceClass !=
131 USB_CLASS_VENDOR_SPEC)) {
132 best = c;
133 break;
134 }
135
136 /* If all the remaining configs are vendor-specific,
137 * choose the first one. */
138 else if (!best)
139 best = c;
140 }
141
142 if (insufficient_power > 0)
143 dev_info(&udev->dev, "rejected %d configuration%s "
144 "due to insufficient available bus power\n",
145 insufficient_power, plural(insufficient_power));
146
147 if (best) {
148 i = best->desc.bConfigurationValue;
149 dev_dbg(&udev->dev,
150 "configuration #%d chosen from %d choice%s\n",
151 i, num_configs, plural(num_configs));
152 } else {
153 i = -1;
154 dev_warn(&udev->dev,
155 "no configuration chosen from %d choice%s\n",
156 num_configs, plural(num_configs));
157 }
158 return i;
159}
160EXPORT_SYMBOL_GPL(usb_choose_configuration);
161
162static int generic_probe(struct usb_device *udev)
163{
164 int err, c;
165
166 /* Choose and set the configuration. This registers the interfaces
167 * with the driver core and lets interface drivers bind to them.
168 */
169 if (udev->authorized == 0)
170 dev_err(&udev->dev, "Device is not authorized for usage\n");
171 else {
172 c = usb_choose_configuration(udev);
173 if (c >= 0) {
174 err = usb_set_configuration(udev, c);
175 if (err && err != -ENODEV) {
176 dev_err(&udev->dev, "can't set config #%d, error %d\n",
177 c, err);
178 /* This need not be fatal. The user can try to
179 * set other configurations. */
180 }
181 }
182 }
183 /* USB device state == configured ... usable */
184 usb_notify_add_device(udev);
185
186 return 0;
187}
188
189static void generic_disconnect(struct usb_device *udev)
190{
191 usb_notify_remove_device(udev);
192
193 /* if this is only an unbind, not a physical disconnect, then
194 * unconfigure the device */
195 if (udev->actconfig)
196 usb_set_configuration(udev, -1);
197}
198
199#ifdef CONFIG_PM
200
201static int generic_suspend(struct usb_device *udev, pm_message_t msg)
202{
203 int rc;
204
205 /* Normal USB devices suspend through their upstream port.
206 * Root hubs don't have upstream ports to suspend,
207 * so we have to shut down their downstream HC-to-USB
208 * interfaces manually by doing a bus (or "global") suspend.
209 */
210 if (!udev->parent)
211 rc = hcd_bus_suspend(udev, msg);
212
213 /* Non-root devices don't need to do anything for FREEZE or PRETHAW */
214 else if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW)
215 rc = 0;
216 else
217 rc = usb_port_suspend(udev, msg);
218
219 return rc;
220}
221
222static int generic_resume(struct usb_device *udev, pm_message_t msg)
223{
224 int rc;
225
226 /* Normal USB devices resume/reset through their upstream port.
227 * Root hubs don't have upstream ports to resume or reset,
228 * so we have to start up their downstream HC-to-USB
229 * interfaces manually by doing a bus (or "global") resume.
230 */
231 if (!udev->parent)
232 rc = hcd_bus_resume(udev, msg);
233 else
234 rc = usb_port_resume(udev, msg);
235 return rc;
236}
237
238#endif /* CONFIG_PM */
239
240struct usb_device_driver usb_generic_driver = {
241 .name = "usb",
242 .probe = generic_probe,
243 .disconnect = generic_disconnect,
244#ifdef CONFIG_PM
245 .suspend = generic_suspend,
246 .resume = generic_resume,
247#endif
248 .supports_autosuspend = 1,
249};