blob: 271e761f563ee42e54f59eb175e23e06e4d19c5b [file] [log] [blame]
Alan Stern36e56a32006-07-01 22:08:06 -04001/*
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
Alan Stern36e56a32006-07-01 22:08:06 -040020#include <linux/usb.h>
Eric Lescouet27729aa2010-04-24 23:21:52 +020021#include <linux/usb/hcd.h>
Alan Stern36e56a32006-07-01 22:08:06 -040022#include "usb.h"
23
Alan Stern782da722006-07-01 22:09:35 -040024static inline const char *plural(int n)
25{
26 return (n == 1 ? "" : "s");
27}
28
Ole Andre Vadla Ravnasad55d712006-12-14 16:01:28 -080029static 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
Greg Kroah-Hartmanb5ea0602007-08-02 22:44:27 -060043int usb_choose_configuration(struct usb_device *udev)
Alan Stern782da722006-07-01 22:09:35 -040044{
45 int i;
46 int num_configs;
47 int insufficient_power = 0;
48 struct usb_host_config *c, *best;
49
Hindin Josephc13b86a2012-11-04 22:50:08 +020050 if (usb_device_is_owned(udev))
51 return 0;
52
Alan Stern782da722006-07-01 22:09:35 -040053 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 */
Sebastian Andrzej Siewior8d8479d2012-12-18 15:25:46 +0100103 if (usb_get_max_power(udev, c) > udev->bus_mA) {
Alan Stern782da722006-07-01 22:09:35 -0400104 insufficient_power++;
105 continue;
106 }
107
Ole Andre Vadla Ravnasad55d712006-12-14 16:01:28 -0800108 /* 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.
Alan Sternc4e0b502010-07-27 11:28:42 -0400111 * But: Don't ignore it if it's the only config.
Ole Andre Vadla Ravnasad55d712006-12-14 16:01:28 -0800112 */
Alan Sternc4e0b502010-07-27 11:28:42 -0400113 if (i == 0 && num_configs > 1 && desc &&
114 (is_rndis(desc) || is_activesync(desc))) {
Ole Andre Vadla Ravnasad55d712006-12-14 16:01:28 -0800115#if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE)
Alan Stern782da722006-07-01 22:09:35 -0400116 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 &&
Alan Stern62f9cfa2010-04-20 10:40:59 -0400128 (desc && desc->bInterfaceClass !=
Alan Stern782da722006-07-01 22:09:35 -0400129 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;
Matthew Wilcoxb1f0a342009-09-24 16:18:27 -0600147 dev_dbg(&udev->dev,
Alan Stern782da722006-07-01 22:09:35 -0400148 "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}
158
Alan Stern8bb54ab2006-07-01 22:08:49 -0400159static int generic_probe(struct usb_device *udev)
Alan Stern36e56a32006-07-01 22:08:06 -0400160{
Alan Stern782da722006-07-01 22:09:35 -0400161 int err, c;
162
Alan Stern782da722006-07-01 22:09:35 -0400163 /* Choose and set the configuration. This registers the interfaces
164 * with the driver core and lets interface drivers bind to them.
165 */
Hindin Josephc13b86a2012-11-04 22:50:08 +0200166 if (udev->authorized == 0)
Inaky Perez-Gonzalezf8a37462007-07-31 20:34:04 -0700167 dev_err(&udev->dev, "Device is not authorized for usage\n");
168 else {
Greg Kroah-Hartmanb5ea0602007-08-02 22:44:27 -0600169 c = usb_choose_configuration(udev);
Inaky Perez-Gonzalezf8a37462007-07-31 20:34:04 -0700170 if (c >= 0) {
171 err = usb_set_configuration(udev, c);
172 if (err) {
173 dev_err(&udev->dev, "can't set config #%d, error %d\n",
Alan Stern782da722006-07-01 22:09:35 -0400174 c, err);
Inaky Perez-Gonzalezf8a37462007-07-31 20:34:04 -0700175 /* This need not be fatal. The user can try to
176 * set other configurations. */
177 }
Alan Stern782da722006-07-01 22:09:35 -0400178 }
179 }
Alan Stern782da722006-07-01 22:09:35 -0400180 /* USB device state == configured ... usable */
181 usb_notify_add_device(udev);
182
Alan Stern36e56a32006-07-01 22:08:06 -0400183 return 0;
184}
Alan Stern782da722006-07-01 22:09:35 -0400185
Alan Stern8bb54ab2006-07-01 22:08:49 -0400186static void generic_disconnect(struct usb_device *udev)
Alan Stern36e56a32006-07-01 22:08:06 -0400187{
Alan Stern782da722006-07-01 22:09:35 -0400188 usb_notify_remove_device(udev);
189
Alan Stern36e56a32006-07-01 22:08:06 -0400190 /* if this is only an unbind, not a physical disconnect, then
191 * unconfigure the device */
Alan Stern01d883d2006-08-30 15:47:18 -0400192 if (udev->actconfig)
Alan Stern3f141e22007-02-08 16:40:43 -0500193 usb_set_configuration(udev, -1);
Alan Stern36e56a32006-07-01 22:08:06 -0400194}
195
Alan Stern782da722006-07-01 22:09:35 -0400196#ifdef CONFIG_PM
197
Alan Stern782da722006-07-01 22:09:35 -0400198static int generic_suspend(struct usb_device *udev, pm_message_t msg)
199{
Alan Sternb6f64362007-05-04 11:51:54 -0400200 int rc;
201
Alan Stern686314c2007-05-30 15:34:36 -0400202 /* 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.
Alan Sternb6f64362007-05-04 11:51:54 -0400206 */
Alan Stern686314c2007-05-30 15:34:36 -0400207 if (!udev->parent)
Alan Stern65bfd292008-11-25 16:39:18 -0500208 rc = hcd_bus_suspend(udev, msg);
Alan Stern5ad4f712007-09-10 11:31:43 -0400209
210 /* Non-root devices don't need to do anything for FREEZE or PRETHAW */
211 else if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW)
212 rc = 0;
Alan Stern686314c2007-05-30 15:34:36 -0400213 else
Alan Stern65bfd292008-11-25 16:39:18 -0500214 rc = usb_port_suspend(udev, msg);
Alan Stern5ad4f712007-09-10 11:31:43 -0400215
Alan Sternb6f64362007-05-04 11:51:54 -0400216 return rc;
Alan Stern782da722006-07-01 22:09:35 -0400217}
218
Alan Stern65bfd292008-11-25 16:39:18 -0500219static int generic_resume(struct usb_device *udev, pm_message_t msg)
Alan Stern782da722006-07-01 22:09:35 -0400220{
Alan Sternb6f64362007-05-04 11:51:54 -0400221 int rc;
222
Alan Stern686314c2007-05-30 15:34:36 -0400223 /* 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 if (!udev->parent)
Alan Stern65bfd292008-11-25 16:39:18 -0500229 rc = hcd_bus_resume(udev, msg);
Alan Stern0458d5b2007-05-04 11:52:20 -0400230 else
Alan Stern65bfd292008-11-25 16:39:18 -0500231 rc = usb_port_resume(udev, msg);
Alan Sternb6f64362007-05-04 11:51:54 -0400232 return rc;
Alan Stern782da722006-07-01 22:09:35 -0400233}
234
235#endif /* CONFIG_PM */
236
Alan Stern8bb54ab2006-07-01 22:08:49 -0400237struct usb_device_driver usb_generic_driver = {
Alan Stern36e56a32006-07-01 22:08:06 -0400238 .name = "usb",
Alan Stern36e56a32006-07-01 22:08:06 -0400239 .probe = generic_probe,
Alan Stern8bb54ab2006-07-01 22:08:49 -0400240 .disconnect = generic_disconnect,
Alan Stern782da722006-07-01 22:09:35 -0400241#ifdef CONFIG_PM
242 .suspend = generic_suspend,
243 .resume = generic_resume,
244#endif
Alan Stern01d883d2006-08-30 15:47:18 -0400245 .supports_autosuspend = 1,
Alan Stern36e56a32006-07-01 22:08:06 -0400246};