Commit | Line | Data |
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36e56a34 AS |
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 | ||
36e56a34 AS |
20 | #include <linux/usb.h> |
21 | #include "usb.h" | |
22 | ||
782da727 AS |
23 | static inline const char *plural(int n) |
24 | { | |
25 | return (n == 1 ? "" : "s"); | |
26 | } | |
27 | ||
ad55d71a OAVR |
28 | static int is_rndis(struct usb_interface_descriptor *desc) |
29 | { | |
30 | return desc->bInterfaceClass == USB_CLASS_COMM | |
31 | && desc->bInterfaceSubClass == 2 | |
32 | && desc->bInterfaceProtocol == 0xff; | |
33 | } | |
34 | ||
35 | static int is_activesync(struct usb_interface_descriptor *desc) | |
36 | { | |
37 | return desc->bInterfaceClass == USB_CLASS_MISC | |
38 | && desc->bInterfaceSubClass == 1 | |
39 | && desc->bInterfaceProtocol == 1; | |
40 | } | |
41 | ||
782da727 AS |
42 | static int choose_configuration(struct usb_device *udev) |
43 | { | |
44 | int i; | |
45 | int num_configs; | |
46 | int insufficient_power = 0; | |
47 | struct usb_host_config *c, *best; | |
48 | ||
49 | best = NULL; | |
50 | c = udev->config; | |
51 | num_configs = udev->descriptor.bNumConfigurations; | |
52 | for (i = 0; i < num_configs; (i++, c++)) { | |
53 | struct usb_interface_descriptor *desc = NULL; | |
54 | ||
55 | /* It's possible that a config has no interfaces! */ | |
56 | if (c->desc.bNumInterfaces > 0) | |
57 | desc = &c->intf_cache[0]->altsetting->desc; | |
58 | ||
59 | /* | |
60 | * HP's USB bus-powered keyboard has only one configuration | |
61 | * and it claims to be self-powered; other devices may have | |
62 | * similar errors in their descriptors. If the next test | |
63 | * were allowed to execute, such configurations would always | |
64 | * be rejected and the devices would not work as expected. | |
65 | * In the meantime, we run the risk of selecting a config | |
66 | * that requires external power at a time when that power | |
67 | * isn't available. It seems to be the lesser of two evils. | |
68 | * | |
69 | * Bugzilla #6448 reports a device that appears to crash | |
70 | * when it receives a GET_DEVICE_STATUS request! We don't | |
71 | * have any other way to tell whether a device is self-powered, | |
72 | * but since we don't use that information anywhere but here, | |
73 | * the call has been removed. | |
74 | * | |
75 | * Maybe the GET_DEVICE_STATUS call and the test below can | |
76 | * be reinstated when device firmwares become more reliable. | |
77 | * Don't hold your breath. | |
78 | */ | |
79 | #if 0 | |
80 | /* Rule out self-powered configs for a bus-powered device */ | |
81 | if (bus_powered && (c->desc.bmAttributes & | |
82 | USB_CONFIG_ATT_SELFPOWER)) | |
83 | continue; | |
84 | #endif | |
85 | ||
86 | /* | |
87 | * The next test may not be as effective as it should be. | |
88 | * Some hubs have errors in their descriptor, claiming | |
89 | * to be self-powered when they are really bus-powered. | |
90 | * We will overestimate the amount of current such hubs | |
91 | * make available for each port. | |
92 | * | |
93 | * This is a fairly benign sort of failure. It won't | |
94 | * cause us to reject configurations that we should have | |
95 | * accepted. | |
96 | */ | |
97 | ||
98 | /* Rule out configs that draw too much bus current */ | |
99 | if (c->desc.bMaxPower * 2 > udev->bus_mA) { | |
100 | insufficient_power++; | |
101 | continue; | |
102 | } | |
103 | ||
ad55d71a OAVR |
104 | /* When the first config's first interface is one of Microsoft's |
105 | * pet nonstandard Ethernet-over-USB protocols, ignore it unless | |
106 | * this kernel has enabled the necessary host side driver. | |
107 | */ | |
108 | if (i == 0 && desc && (is_rndis(desc) || is_activesync(desc))) { | |
109 | #if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE) | |
782da727 AS |
110 | continue; |
111 | #else | |
112 | best = c; | |
113 | #endif | |
114 | } | |
115 | ||
116 | /* From the remaining configs, choose the first one whose | |
117 | * first interface is for a non-vendor-specific class. | |
118 | * Reason: Linux is more likely to have a class driver | |
119 | * than a vendor-specific driver. */ | |
120 | else if (udev->descriptor.bDeviceClass != | |
121 | USB_CLASS_VENDOR_SPEC && | |
122 | (!desc || desc->bInterfaceClass != | |
123 | USB_CLASS_VENDOR_SPEC)) { | |
124 | best = c; | |
125 | break; | |
126 | } | |
127 | ||
128 | /* If all the remaining configs are vendor-specific, | |
129 | * choose the first one. */ | |
130 | else if (!best) | |
131 | best = c; | |
132 | } | |
133 | ||
134 | if (insufficient_power > 0) | |
135 | dev_info(&udev->dev, "rejected %d configuration%s " | |
136 | "due to insufficient available bus power\n", | |
137 | insufficient_power, plural(insufficient_power)); | |
138 | ||
139 | if (best) { | |
140 | i = best->desc.bConfigurationValue; | |
141 | dev_info(&udev->dev, | |
142 | "configuration #%d chosen from %d choice%s\n", | |
143 | i, num_configs, plural(num_configs)); | |
144 | } else { | |
145 | i = -1; | |
146 | dev_warn(&udev->dev, | |
147 | "no configuration chosen from %d choice%s\n", | |
148 | num_configs, plural(num_configs)); | |
149 | } | |
150 | return i; | |
151 | } | |
152 | ||
8bb54ab5 | 153 | static int generic_probe(struct usb_device *udev) |
36e56a34 | 154 | { |
782da727 AS |
155 | int err, c; |
156 | ||
157 | /* put device-specific files into sysfs */ | |
158 | usb_create_sysfs_dev_files(udev); | |
159 | ||
160 | /* Choose and set the configuration. This registers the interfaces | |
161 | * with the driver core and lets interface drivers bind to them. | |
162 | */ | |
163 | c = choose_configuration(udev); | |
164 | if (c >= 0) { | |
165 | err = usb_set_configuration(udev, c); | |
166 | if (err) { | |
167 | dev_err(&udev->dev, "can't set config #%d, error %d\n", | |
168 | c, err); | |
169 | /* This need not be fatal. The user can try to | |
170 | * set other configurations. */ | |
171 | } | |
172 | } | |
173 | ||
174 | /* USB device state == configured ... usable */ | |
175 | usb_notify_add_device(udev); | |
176 | ||
36e56a34 AS |
177 | return 0; |
178 | } | |
782da727 | 179 | |
8bb54ab5 | 180 | static void generic_disconnect(struct usb_device *udev) |
36e56a34 | 181 | { |
782da727 AS |
182 | usb_notify_remove_device(udev); |
183 | ||
36e56a34 AS |
184 | /* if this is only an unbind, not a physical disconnect, then |
185 | * unconfigure the device */ | |
01d883d4 | 186 | if (udev->actconfig) |
3f141e2a | 187 | usb_set_configuration(udev, -1); |
36e56a34 | 188 | |
782da727 | 189 | usb_remove_sysfs_dev_files(udev); |
36e56a34 AS |
190 | } |
191 | ||
782da727 AS |
192 | #ifdef CONFIG_PM |
193 | ||
782da727 AS |
194 | static int generic_suspend(struct usb_device *udev, pm_message_t msg) |
195 | { | |
782da727 AS |
196 | /* USB devices enter SUSPEND state through their hubs, but can be |
197 | * marked for FREEZE as soon as their children are already idled. | |
198 | * But those semantics are useless, so we equate the two (sigh). | |
199 | */ | |
200 | return usb_port_suspend(udev); | |
201 | } | |
202 | ||
203 | static int generic_resume(struct usb_device *udev) | |
204 | { | |
782da727 AS |
205 | return usb_port_resume(udev); |
206 | } | |
207 | ||
208 | #endif /* CONFIG_PM */ | |
209 | ||
8bb54ab5 | 210 | struct usb_device_driver usb_generic_driver = { |
36e56a34 | 211 | .name = "usb", |
36e56a34 | 212 | .probe = generic_probe, |
8bb54ab5 | 213 | .disconnect = generic_disconnect, |
782da727 AS |
214 | #ifdef CONFIG_PM |
215 | .suspend = generic_suspend, | |
216 | .resume = generic_resume, | |
217 | #endif | |
01d883d4 | 218 | .supports_autosuspend = 1, |
36e56a34 | 219 | }; |