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