Branch data Line data Source code
1 : : // SPDX-License-Identifier: GPL-2.0
2 : : /*
3 : : * drivers/usb/generic.c - generic driver for USB devices (not interfaces)
4 : : *
5 : : * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
6 : : *
7 : : * based on drivers/usb/usb.c which had the following copyrights:
8 : : * (C) Copyright Linus Torvalds 1999
9 : : * (C) Copyright Johannes Erdfelt 1999-2001
10 : : * (C) Copyright Andreas Gal 1999
11 : : * (C) Copyright Gregory P. Smith 1999
12 : : * (C) Copyright Deti Fliegl 1999 (new USB architecture)
13 : : * (C) Copyright Randy Dunlap 2000
14 : : * (C) Copyright David Brownell 2000-2004
15 : : * (C) Copyright Yggdrasil Computing, Inc. 2000
16 : : * (usb_device_id matching changes by Adam J. Richter)
17 : : * (C) Copyright Greg Kroah-Hartman 2002-2003
18 : : *
19 : : * Released under the GPLv2 only.
20 : : */
21 : :
22 : : #include <linux/usb.h>
23 : : #include <linux/usb/hcd.h>
24 : : #include <uapi/linux/usb/audio.h>
25 : : #include "usb.h"
26 : :
27 : 0 : static inline const char *plural(int n)
28 : : {
29 : 0 : return (n == 1 ? "" : "s");
30 : : }
31 : :
32 : 0 : static int is_rndis(struct usb_interface_descriptor *desc)
33 : : {
34 : 0 : return desc->bInterfaceClass == USB_CLASS_COMM
35 [ # # ]: 0 : && desc->bInterfaceSubClass == 2
36 [ # # # # ]: 0 : && desc->bInterfaceProtocol == 0xff;
37 : : }
38 : :
39 : 0 : static int is_activesync(struct usb_interface_descriptor *desc)
40 : : {
41 : 0 : return desc->bInterfaceClass == USB_CLASS_MISC
42 [ # # ]: 0 : && desc->bInterfaceSubClass == 1
43 [ # # # # ]: 0 : && desc->bInterfaceProtocol == 1;
44 : : }
45 : :
46 : 0 : static bool is_audio(struct usb_interface_descriptor *desc)
47 : : {
48 : 0 : return desc->bInterfaceClass == USB_CLASS_AUDIO;
49 : : }
50 : :
51 : 0 : static bool is_uac3_config(struct usb_interface_descriptor *desc)
52 : : {
53 : 0 : return desc->bInterfaceProtocol == UAC_VERSION_3;
54 : : }
55 : :
56 : 0 : int usb_choose_configuration(struct usb_device *udev)
57 : : {
58 : 0 : int i;
59 : 0 : int num_configs;
60 : 0 : int insufficient_power = 0;
61 : 0 : struct usb_host_config *c, *best;
62 : :
63 [ # # ]: 0 : if (usb_device_is_owned(udev))
64 : : return 0;
65 : :
66 : 0 : best = NULL;
67 : 0 : c = udev->config;
68 : 0 : num_configs = udev->descriptor.bNumConfigurations;
69 [ # # ]: 0 : for (i = 0; i < num_configs; (i++, c++)) {
70 : 0 : struct usb_interface_descriptor *desc = NULL;
71 : :
72 : : /* It's possible that a config has no interfaces! */
73 [ # # ]: 0 : if (c->desc.bNumInterfaces > 0)
74 : 0 : desc = &c->intf_cache[0]->altsetting->desc;
75 : :
76 : : /*
77 : : * HP's USB bus-powered keyboard has only one configuration
78 : : * and it claims to be self-powered; other devices may have
79 : : * similar errors in their descriptors. If the next test
80 : : * were allowed to execute, such configurations would always
81 : : * be rejected and the devices would not work as expected.
82 : : * In the meantime, we run the risk of selecting a config
83 : : * that requires external power at a time when that power
84 : : * isn't available. It seems to be the lesser of two evils.
85 : : *
86 : : * Bugzilla #6448 reports a device that appears to crash
87 : : * when it receives a GET_DEVICE_STATUS request! We don't
88 : : * have any other way to tell whether a device is self-powered,
89 : : * but since we don't use that information anywhere but here,
90 : : * the call has been removed.
91 : : *
92 : : * Maybe the GET_DEVICE_STATUS call and the test below can
93 : : * be reinstated when device firmwares become more reliable.
94 : : * Don't hold your breath.
95 : : */
96 : : #if 0
97 : : /* Rule out self-powered configs for a bus-powered device */
98 : : if (bus_powered && (c->desc.bmAttributes &
99 : : USB_CONFIG_ATT_SELFPOWER))
100 : : continue;
101 : : #endif
102 : :
103 : : /*
104 : : * The next test may not be as effective as it should be.
105 : : * Some hubs have errors in their descriptor, claiming
106 : : * to be self-powered when they are really bus-powered.
107 : : * We will overestimate the amount of current such hubs
108 : : * make available for each port.
109 : : *
110 : : * This is a fairly benign sort of failure. It won't
111 : : * cause us to reject configurations that we should have
112 : : * accepted.
113 : : */
114 : :
115 : : /* Rule out configs that draw too much bus current */
116 [ # # # # ]: 0 : if (usb_get_max_power(udev, c) > udev->bus_mA) {
117 : 0 : insufficient_power++;
118 : 0 : continue;
119 : : }
120 : :
121 : : /*
122 : : * Select first configuration as default for audio so that
123 : : * devices that don't comply with UAC3 protocol are supported.
124 : : * But, still iterate through other configurations and
125 : : * select UAC3 compliant config if present.
126 : : */
127 [ # # # # ]: 0 : if (desc && is_audio(desc)) {
128 : : /* Always prefer the first found UAC3 config */
129 [ # # ]: 0 : if (is_uac3_config(desc)) {
130 : : best = c;
131 : : break;
132 : : }
133 : :
134 : : /* If there is no UAC3 config, prefer the first config */
135 [ # # ]: 0 : else if (i == 0)
136 : 0 : best = c;
137 : :
138 : : /* Unconditional continue, because the rest of the code
139 : : * in the loop is irrelevant for audio devices, and
140 : : * because it can reassign best, which for audio devices
141 : : * we don't want.
142 : : */
143 : 0 : continue;
144 : : }
145 : :
146 : : /* When the first config's first interface is one of Microsoft's
147 : : * pet nonstandard Ethernet-over-USB protocols, ignore it unless
148 : : * this kernel has enabled the necessary host side driver.
149 : : * But: Don't ignore it if it's the only config.
150 : : */
151 [ # # # # ]: 0 : if (i == 0 && num_configs > 1 && desc &&
152 : : (is_rndis(desc) || is_activesync(desc))) {
153 : : #if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE)
154 : 0 : continue;
155 : : #else
156 : : best = c;
157 : : #endif
158 : : }
159 : :
160 : : /* From the remaining configs, choose the first one whose
161 : : * first interface is for a non-vendor-specific class.
162 : : * Reason: Linux is more likely to have a class driver
163 : : * than a vendor-specific driver. */
164 [ # # ]: 0 : else if (udev->descriptor.bDeviceClass !=
165 [ # # ]: 0 : USB_CLASS_VENDOR_SPEC &&
166 [ # # ]: 0 : (desc && desc->bInterfaceClass !=
167 : : USB_CLASS_VENDOR_SPEC)) {
168 : : best = c;
169 : : break;
170 : : }
171 : :
172 : : /* If all the remaining configs are vendor-specific,
173 : : * choose the first one. */
174 [ # # ]: 0 : else if (!best)
175 : 0 : best = c;
176 : : }
177 : :
178 [ # # ]: 0 : if (insufficient_power > 0)
179 [ # # ]: 0 : dev_info(&udev->dev, "rejected %d configuration%s "
180 : : "due to insufficient available bus power\n",
181 : : insufficient_power, plural(insufficient_power));
182 : :
183 [ # # ]: 0 : if (best) {
184 : 0 : i = best->desc.bConfigurationValue;
185 : 0 : dev_dbg(&udev->dev,
186 : : "configuration #%d chosen from %d choice%s\n",
187 : : i, num_configs, plural(num_configs));
188 : : } else {
189 : 0 : i = -1;
190 [ # # ]: 0 : dev_warn(&udev->dev,
191 : : "no configuration chosen from %d choice%s\n",
192 : : num_configs, plural(num_configs));
193 : : }
194 : : return i;
195 : : }
196 : : EXPORT_SYMBOL_GPL(usb_choose_configuration);
197 : :
198 : 0 : static int generic_probe(struct usb_device *udev)
199 : : {
200 : 0 : int err, c;
201 : :
202 : : /* Choose and set the configuration. This registers the interfaces
203 : : * with the driver core and lets interface drivers bind to them.
204 : : */
205 [ # # ]: 0 : if (udev->authorized == 0)
206 : 0 : dev_err(&udev->dev, "Device is not authorized for usage\n");
207 : : else {
208 : 0 : c = usb_choose_configuration(udev);
209 [ # # ]: 0 : if (c >= 0) {
210 : 0 : err = usb_set_configuration(udev, c);
211 [ # # ]: 0 : if (err && err != -ENODEV) {
212 : 0 : dev_err(&udev->dev, "can't set config #%d, error %d\n",
213 : : c, err);
214 : : /* This need not be fatal. The user can try to
215 : : * set other configurations. */
216 : : }
217 : : }
218 : : }
219 : : /* USB device state == configured ... usable */
220 : 0 : usb_notify_add_device(udev);
221 : :
222 : 0 : return 0;
223 : : }
224 : :
225 : 0 : static void generic_disconnect(struct usb_device *udev)
226 : : {
227 : 0 : usb_notify_remove_device(udev);
228 : :
229 : : /* if this is only an unbind, not a physical disconnect, then
230 : : * unconfigure the device */
231 [ # # ]: 0 : if (udev->actconfig)
232 : 0 : usb_set_configuration(udev, -1);
233 : 0 : }
234 : :
235 : : #ifdef CONFIG_PM
236 : :
237 : 0 : static int generic_suspend(struct usb_device *udev, pm_message_t msg)
238 : : {
239 : 0 : int rc;
240 : :
241 : : /* Normal USB devices suspend through their upstream port.
242 : : * Root hubs don't have upstream ports to suspend,
243 : : * so we have to shut down their downstream HC-to-USB
244 : : * interfaces manually by doing a bus (or "global") suspend.
245 : : */
246 [ # # ]: 0 : if (!udev->parent)
247 : 0 : rc = hcd_bus_suspend(udev, msg);
248 : :
249 : : /*
250 : : * Non-root USB2 devices don't need to do anything for FREEZE
251 : : * or PRETHAW. USB3 devices don't support global suspend and
252 : : * needs to be selectively suspended.
253 : : */
254 [ # # ]: 0 : else if ((msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW)
255 [ # # ]: 0 : && (udev->speed < USB_SPEED_SUPER))
256 : : rc = 0;
257 : : else
258 : 0 : rc = usb_port_suspend(udev, msg);
259 : :
260 [ # # ]: 0 : if (rc == 0)
261 : 0 : usbfs_notify_suspend(udev);
262 : 0 : return rc;
263 : : }
264 : :
265 : 0 : static int generic_resume(struct usb_device *udev, pm_message_t msg)
266 : : {
267 : 0 : int rc;
268 : :
269 : : /* Normal USB devices resume/reset through their upstream port.
270 : : * Root hubs don't have upstream ports to resume or reset,
271 : : * so we have to start up their downstream HC-to-USB
272 : : * interfaces manually by doing a bus (or "global") resume.
273 : : */
274 [ # # ]: 0 : if (!udev->parent)
275 : 0 : rc = hcd_bus_resume(udev, msg);
276 : : else
277 : 0 : rc = usb_port_resume(udev, msg);
278 : :
279 [ # # ]: 0 : if (rc == 0)
280 : 0 : usbfs_notify_resume(udev);
281 : 0 : return rc;
282 : : }
283 : :
284 : : #endif /* CONFIG_PM */
285 : :
286 : : struct usb_device_driver usb_generic_driver = {
287 : : .name = "usb",
288 : : .probe = generic_probe,
289 : : .disconnect = generic_disconnect,
290 : : #ifdef CONFIG_PM
291 : : .suspend = generic_suspend,
292 : : .resume = generic_resume,
293 : : #endif
294 : : .supports_autosuspend = 1,
295 : : };
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