include: replace linux/module.h with "struct module" wherever possible
[linux-2.6/next.git] / drivers / usb / core / hcd.c
blob8669ba3fe79486ffe487e6b6b266ff4767afe670
1 /*
2 * (C) Copyright Linus Torvalds 1999
3 * (C) Copyright Johannes Erdfelt 1999-2001
4 * (C) Copyright Andreas Gal 1999
5 * (C) Copyright Gregory P. Smith 1999
6 * (C) Copyright Deti Fliegl 1999
7 * (C) Copyright Randy Dunlap 2000
8 * (C) Copyright David Brownell 2000-2002
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
17 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 * for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software Foundation,
22 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #include <linux/module.h>
26 #include <linux/version.h>
27 #include <linux/kernel.h>
28 #include <linux/slab.h>
29 #include <linux/completion.h>
30 #include <linux/utsname.h>
31 #include <linux/mm.h>
32 #include <asm/io.h>
33 #include <linux/device.h>
34 #include <linux/dma-mapping.h>
35 #include <linux/mutex.h>
36 #include <asm/irq.h>
37 #include <asm/byteorder.h>
38 #include <asm/unaligned.h>
39 #include <linux/platform_device.h>
40 #include <linux/workqueue.h>
42 #include <linux/usb.h>
43 #include <linux/usb/hcd.h>
45 #include "usb.h"
48 /*-------------------------------------------------------------------------*/
51 * USB Host Controller Driver framework
53 * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
54 * HCD-specific behaviors/bugs.
56 * This does error checks, tracks devices and urbs, and delegates to a
57 * "hc_driver" only for code (and data) that really needs to know about
58 * hardware differences. That includes root hub registers, i/o queues,
59 * and so on ... but as little else as possible.
61 * Shared code includes most of the "root hub" code (these are emulated,
62 * though each HC's hardware works differently) and PCI glue, plus request
63 * tracking overhead. The HCD code should only block on spinlocks or on
64 * hardware handshaking; blocking on software events (such as other kernel
65 * threads releasing resources, or completing actions) is all generic.
67 * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
68 * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
69 * only by the hub driver ... and that neither should be seen or used by
70 * usb client device drivers.
72 * Contributors of ideas or unattributed patches include: David Brownell,
73 * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
75 * HISTORY:
76 * 2002-02-21 Pull in most of the usb_bus support from usb.c; some
77 * associated cleanup. "usb_hcd" still != "usb_bus".
78 * 2001-12-12 Initial patch version for Linux 2.5.1 kernel.
81 /*-------------------------------------------------------------------------*/
83 /* Keep track of which host controller drivers are loaded */
84 unsigned long usb_hcds_loaded;
85 EXPORT_SYMBOL_GPL(usb_hcds_loaded);
87 /* host controllers we manage */
88 LIST_HEAD (usb_bus_list);
89 EXPORT_SYMBOL_GPL (usb_bus_list);
91 /* used when allocating bus numbers */
92 #define USB_MAXBUS 64
93 struct usb_busmap {
94 unsigned long busmap [USB_MAXBUS / (8*sizeof (unsigned long))];
96 static struct usb_busmap busmap;
98 /* used when updating list of hcds */
99 DEFINE_MUTEX(usb_bus_list_lock); /* exported only for usbfs */
100 EXPORT_SYMBOL_GPL (usb_bus_list_lock);
102 /* used for controlling access to virtual root hubs */
103 static DEFINE_SPINLOCK(hcd_root_hub_lock);
105 /* used when updating an endpoint's URB list */
106 static DEFINE_SPINLOCK(hcd_urb_list_lock);
108 /* used to protect against unlinking URBs after the device is gone */
109 static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
111 /* wait queue for synchronous unlinks */
112 DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
114 static inline int is_root_hub(struct usb_device *udev)
116 return (udev->parent == NULL);
119 /*-------------------------------------------------------------------------*/
122 * Sharable chunks of root hub code.
125 /*-------------------------------------------------------------------------*/
127 #define KERNEL_REL ((LINUX_VERSION_CODE >> 16) & 0x0ff)
128 #define KERNEL_VER ((LINUX_VERSION_CODE >> 8) & 0x0ff)
130 /* usb 3.0 root hub device descriptor */
131 static const u8 usb3_rh_dev_descriptor[18] = {
132 0x12, /* __u8 bLength; */
133 0x01, /* __u8 bDescriptorType; Device */
134 0x00, 0x03, /* __le16 bcdUSB; v3.0 */
136 0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */
137 0x00, /* __u8 bDeviceSubClass; */
138 0x03, /* __u8 bDeviceProtocol; USB 3.0 hub */
139 0x09, /* __u8 bMaxPacketSize0; 2^9 = 512 Bytes */
141 0x6b, 0x1d, /* __le16 idVendor; Linux Foundation */
142 0x03, 0x00, /* __le16 idProduct; device 0x0003 */
143 KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */
145 0x03, /* __u8 iManufacturer; */
146 0x02, /* __u8 iProduct; */
147 0x01, /* __u8 iSerialNumber; */
148 0x01 /* __u8 bNumConfigurations; */
151 /* usb 2.0 root hub device descriptor */
152 static const u8 usb2_rh_dev_descriptor [18] = {
153 0x12, /* __u8 bLength; */
154 0x01, /* __u8 bDescriptorType; Device */
155 0x00, 0x02, /* __le16 bcdUSB; v2.0 */
157 0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */
158 0x00, /* __u8 bDeviceSubClass; */
159 0x00, /* __u8 bDeviceProtocol; [ usb 2.0 no TT ] */
160 0x40, /* __u8 bMaxPacketSize0; 64 Bytes */
162 0x6b, 0x1d, /* __le16 idVendor; Linux Foundation */
163 0x02, 0x00, /* __le16 idProduct; device 0x0002 */
164 KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */
166 0x03, /* __u8 iManufacturer; */
167 0x02, /* __u8 iProduct; */
168 0x01, /* __u8 iSerialNumber; */
169 0x01 /* __u8 bNumConfigurations; */
172 /* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
174 /* usb 1.1 root hub device descriptor */
175 static const u8 usb11_rh_dev_descriptor [18] = {
176 0x12, /* __u8 bLength; */
177 0x01, /* __u8 bDescriptorType; Device */
178 0x10, 0x01, /* __le16 bcdUSB; v1.1 */
180 0x09, /* __u8 bDeviceClass; HUB_CLASSCODE */
181 0x00, /* __u8 bDeviceSubClass; */
182 0x00, /* __u8 bDeviceProtocol; [ low/full speeds only ] */
183 0x40, /* __u8 bMaxPacketSize0; 64 Bytes */
185 0x6b, 0x1d, /* __le16 idVendor; Linux Foundation */
186 0x01, 0x00, /* __le16 idProduct; device 0x0001 */
187 KERNEL_VER, KERNEL_REL, /* __le16 bcdDevice */
189 0x03, /* __u8 iManufacturer; */
190 0x02, /* __u8 iProduct; */
191 0x01, /* __u8 iSerialNumber; */
192 0x01 /* __u8 bNumConfigurations; */
196 /*-------------------------------------------------------------------------*/
198 /* Configuration descriptors for our root hubs */
200 static const u8 fs_rh_config_descriptor [] = {
202 /* one configuration */
203 0x09, /* __u8 bLength; */
204 0x02, /* __u8 bDescriptorType; Configuration */
205 0x19, 0x00, /* __le16 wTotalLength; */
206 0x01, /* __u8 bNumInterfaces; (1) */
207 0x01, /* __u8 bConfigurationValue; */
208 0x00, /* __u8 iConfiguration; */
209 0xc0, /* __u8 bmAttributes;
210 Bit 7: must be set,
211 6: Self-powered,
212 5: Remote wakeup,
213 4..0: resvd */
214 0x00, /* __u8 MaxPower; */
216 /* USB 1.1:
217 * USB 2.0, single TT organization (mandatory):
218 * one interface, protocol 0
220 * USB 2.0, multiple TT organization (optional):
221 * two interfaces, protocols 1 (like single TT)
222 * and 2 (multiple TT mode) ... config is
223 * sometimes settable
224 * NOT IMPLEMENTED
227 /* one interface */
228 0x09, /* __u8 if_bLength; */
229 0x04, /* __u8 if_bDescriptorType; Interface */
230 0x00, /* __u8 if_bInterfaceNumber; */
231 0x00, /* __u8 if_bAlternateSetting; */
232 0x01, /* __u8 if_bNumEndpoints; */
233 0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */
234 0x00, /* __u8 if_bInterfaceSubClass; */
235 0x00, /* __u8 if_bInterfaceProtocol; [usb1.1 or single tt] */
236 0x00, /* __u8 if_iInterface; */
238 /* one endpoint (status change endpoint) */
239 0x07, /* __u8 ep_bLength; */
240 0x05, /* __u8 ep_bDescriptorType; Endpoint */
241 0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */
242 0x03, /* __u8 ep_bmAttributes; Interrupt */
243 0x02, 0x00, /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
244 0xff /* __u8 ep_bInterval; (255ms -- usb 2.0 spec) */
247 static const u8 hs_rh_config_descriptor [] = {
249 /* one configuration */
250 0x09, /* __u8 bLength; */
251 0x02, /* __u8 bDescriptorType; Configuration */
252 0x19, 0x00, /* __le16 wTotalLength; */
253 0x01, /* __u8 bNumInterfaces; (1) */
254 0x01, /* __u8 bConfigurationValue; */
255 0x00, /* __u8 iConfiguration; */
256 0xc0, /* __u8 bmAttributes;
257 Bit 7: must be set,
258 6: Self-powered,
259 5: Remote wakeup,
260 4..0: resvd */
261 0x00, /* __u8 MaxPower; */
263 /* USB 1.1:
264 * USB 2.0, single TT organization (mandatory):
265 * one interface, protocol 0
267 * USB 2.0, multiple TT organization (optional):
268 * two interfaces, protocols 1 (like single TT)
269 * and 2 (multiple TT mode) ... config is
270 * sometimes settable
271 * NOT IMPLEMENTED
274 /* one interface */
275 0x09, /* __u8 if_bLength; */
276 0x04, /* __u8 if_bDescriptorType; Interface */
277 0x00, /* __u8 if_bInterfaceNumber; */
278 0x00, /* __u8 if_bAlternateSetting; */
279 0x01, /* __u8 if_bNumEndpoints; */
280 0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */
281 0x00, /* __u8 if_bInterfaceSubClass; */
282 0x00, /* __u8 if_bInterfaceProtocol; [usb1.1 or single tt] */
283 0x00, /* __u8 if_iInterface; */
285 /* one endpoint (status change endpoint) */
286 0x07, /* __u8 ep_bLength; */
287 0x05, /* __u8 ep_bDescriptorType; Endpoint */
288 0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */
289 0x03, /* __u8 ep_bmAttributes; Interrupt */
290 /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
291 * see hub.c:hub_configure() for details. */
292 (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
293 0x0c /* __u8 ep_bInterval; (256ms -- usb 2.0 spec) */
296 static const u8 ss_rh_config_descriptor[] = {
297 /* one configuration */
298 0x09, /* __u8 bLength; */
299 0x02, /* __u8 bDescriptorType; Configuration */
300 0x1f, 0x00, /* __le16 wTotalLength; */
301 0x01, /* __u8 bNumInterfaces; (1) */
302 0x01, /* __u8 bConfigurationValue; */
303 0x00, /* __u8 iConfiguration; */
304 0xc0, /* __u8 bmAttributes;
305 Bit 7: must be set,
306 6: Self-powered,
307 5: Remote wakeup,
308 4..0: resvd */
309 0x00, /* __u8 MaxPower; */
311 /* one interface */
312 0x09, /* __u8 if_bLength; */
313 0x04, /* __u8 if_bDescriptorType; Interface */
314 0x00, /* __u8 if_bInterfaceNumber; */
315 0x00, /* __u8 if_bAlternateSetting; */
316 0x01, /* __u8 if_bNumEndpoints; */
317 0x09, /* __u8 if_bInterfaceClass; HUB_CLASSCODE */
318 0x00, /* __u8 if_bInterfaceSubClass; */
319 0x00, /* __u8 if_bInterfaceProtocol; */
320 0x00, /* __u8 if_iInterface; */
322 /* one endpoint (status change endpoint) */
323 0x07, /* __u8 ep_bLength; */
324 0x05, /* __u8 ep_bDescriptorType; Endpoint */
325 0x81, /* __u8 ep_bEndpointAddress; IN Endpoint 1 */
326 0x03, /* __u8 ep_bmAttributes; Interrupt */
327 /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
328 * see hub.c:hub_configure() for details. */
329 (USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
330 0x0c, /* __u8 ep_bInterval; (256ms -- usb 2.0 spec) */
332 /* one SuperSpeed endpoint companion descriptor */
333 0x06, /* __u8 ss_bLength */
334 0x30, /* __u8 ss_bDescriptorType; SuperSpeed EP Companion */
335 0x00, /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
336 0x00, /* __u8 ss_bmAttributes; 1 packet per service interval */
337 0x02, 0x00 /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
340 /* authorized_default behaviour:
341 * -1 is authorized for all devices except wireless (old behaviour)
342 * 0 is unauthorized for all devices
343 * 1 is authorized for all devices
345 static int authorized_default = -1;
346 module_param(authorized_default, int, S_IRUGO|S_IWUSR);
347 MODULE_PARM_DESC(authorized_default,
348 "Default USB device authorization: 0 is not authorized, 1 is "
349 "authorized, -1 is authorized except for wireless USB (default, "
350 "old behaviour");
351 /*-------------------------------------------------------------------------*/
354 * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
355 * @s: Null-terminated ASCII (actually ISO-8859-1) string
356 * @buf: Buffer for USB string descriptor (header + UTF-16LE)
357 * @len: Length (in bytes; may be odd) of descriptor buffer.
359 * The return value is the number of bytes filled in: 2 + 2*strlen(s) or
360 * buflen, whichever is less.
362 * USB String descriptors can contain at most 126 characters; input
363 * strings longer than that are truncated.
365 static unsigned
366 ascii2desc(char const *s, u8 *buf, unsigned len)
368 unsigned n, t = 2 + 2*strlen(s);
370 if (t > 254)
371 t = 254; /* Longest possible UTF string descriptor */
372 if (len > t)
373 len = t;
375 t += USB_DT_STRING << 8; /* Now t is first 16 bits to store */
377 n = len;
378 while (n--) {
379 *buf++ = t;
380 if (!n--)
381 break;
382 *buf++ = t >> 8;
383 t = (unsigned char)*s++;
385 return len;
389 * rh_string() - provides string descriptors for root hub
390 * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
391 * @hcd: the host controller for this root hub
392 * @data: buffer for output packet
393 * @len: length of the provided buffer
395 * Produces either a manufacturer, product or serial number string for the
396 * virtual root hub device.
397 * Returns the number of bytes filled in: the length of the descriptor or
398 * of the provided buffer, whichever is less.
400 static unsigned
401 rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
403 char buf[100];
404 char const *s;
405 static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
407 // language ids
408 switch (id) {
409 case 0:
410 /* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
411 /* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
412 if (len > 4)
413 len = 4;
414 memcpy(data, langids, len);
415 return len;
416 case 1:
417 /* Serial number */
418 s = hcd->self.bus_name;
419 break;
420 case 2:
421 /* Product name */
422 s = hcd->product_desc;
423 break;
424 case 3:
425 /* Manufacturer */
426 snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
427 init_utsname()->release, hcd->driver->description);
428 s = buf;
429 break;
430 default:
431 /* Can't happen; caller guarantees it */
432 return 0;
435 return ascii2desc(s, data, len);
439 /* Root hub control transfers execute synchronously */
440 static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
442 struct usb_ctrlrequest *cmd;
443 u16 typeReq, wValue, wIndex, wLength;
444 u8 *ubuf = urb->transfer_buffer;
445 u8 tbuf [sizeof (struct usb_hub_descriptor)]
446 __attribute__((aligned(4)));
447 const u8 *bufp = tbuf;
448 unsigned len = 0;
449 int status;
450 u8 patch_wakeup = 0;
451 u8 patch_protocol = 0;
453 might_sleep();
455 spin_lock_irq(&hcd_root_hub_lock);
456 status = usb_hcd_link_urb_to_ep(hcd, urb);
457 spin_unlock_irq(&hcd_root_hub_lock);
458 if (status)
459 return status;
460 urb->hcpriv = hcd; /* Indicate it's queued */
462 cmd = (struct usb_ctrlrequest *) urb->setup_packet;
463 typeReq = (cmd->bRequestType << 8) | cmd->bRequest;
464 wValue = le16_to_cpu (cmd->wValue);
465 wIndex = le16_to_cpu (cmd->wIndex);
466 wLength = le16_to_cpu (cmd->wLength);
468 if (wLength > urb->transfer_buffer_length)
469 goto error;
471 urb->actual_length = 0;
472 switch (typeReq) {
474 /* DEVICE REQUESTS */
476 /* The root hub's remote wakeup enable bit is implemented using
477 * driver model wakeup flags. If this system supports wakeup
478 * through USB, userspace may change the default "allow wakeup"
479 * policy through sysfs or these calls.
481 * Most root hubs support wakeup from downstream devices, for
482 * runtime power management (disabling USB clocks and reducing
483 * VBUS power usage). However, not all of them do so; silicon,
484 * board, and BIOS bugs here are not uncommon, so these can't
485 * be treated quite like external hubs.
487 * Likewise, not all root hubs will pass wakeup events upstream,
488 * to wake up the whole system. So don't assume root hub and
489 * controller capabilities are identical.
492 case DeviceRequest | USB_REQ_GET_STATUS:
493 tbuf [0] = (device_may_wakeup(&hcd->self.root_hub->dev)
494 << USB_DEVICE_REMOTE_WAKEUP)
495 | (1 << USB_DEVICE_SELF_POWERED);
496 tbuf [1] = 0;
497 len = 2;
498 break;
499 case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
500 if (wValue == USB_DEVICE_REMOTE_WAKEUP)
501 device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
502 else
503 goto error;
504 break;
505 case DeviceOutRequest | USB_REQ_SET_FEATURE:
506 if (device_can_wakeup(&hcd->self.root_hub->dev)
507 && wValue == USB_DEVICE_REMOTE_WAKEUP)
508 device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
509 else
510 goto error;
511 break;
512 case DeviceRequest | USB_REQ_GET_CONFIGURATION:
513 tbuf [0] = 1;
514 len = 1;
515 /* FALLTHROUGH */
516 case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
517 break;
518 case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
519 switch (wValue & 0xff00) {
520 case USB_DT_DEVICE << 8:
521 switch (hcd->speed) {
522 case HCD_USB3:
523 bufp = usb3_rh_dev_descriptor;
524 break;
525 case HCD_USB2:
526 bufp = usb2_rh_dev_descriptor;
527 break;
528 case HCD_USB11:
529 bufp = usb11_rh_dev_descriptor;
530 break;
531 default:
532 goto error;
534 len = 18;
535 if (hcd->has_tt)
536 patch_protocol = 1;
537 break;
538 case USB_DT_CONFIG << 8:
539 switch (hcd->speed) {
540 case HCD_USB3:
541 bufp = ss_rh_config_descriptor;
542 len = sizeof ss_rh_config_descriptor;
543 break;
544 case HCD_USB2:
545 bufp = hs_rh_config_descriptor;
546 len = sizeof hs_rh_config_descriptor;
547 break;
548 case HCD_USB11:
549 bufp = fs_rh_config_descriptor;
550 len = sizeof fs_rh_config_descriptor;
551 break;
552 default:
553 goto error;
555 if (device_can_wakeup(&hcd->self.root_hub->dev))
556 patch_wakeup = 1;
557 break;
558 case USB_DT_STRING << 8:
559 if ((wValue & 0xff) < 4)
560 urb->actual_length = rh_string(wValue & 0xff,
561 hcd, ubuf, wLength);
562 else /* unsupported IDs --> "protocol stall" */
563 goto error;
564 break;
565 default:
566 goto error;
568 break;
569 case DeviceRequest | USB_REQ_GET_INTERFACE:
570 tbuf [0] = 0;
571 len = 1;
572 /* FALLTHROUGH */
573 case DeviceOutRequest | USB_REQ_SET_INTERFACE:
574 break;
575 case DeviceOutRequest | USB_REQ_SET_ADDRESS:
576 // wValue == urb->dev->devaddr
577 dev_dbg (hcd->self.controller, "root hub device address %d\n",
578 wValue);
579 break;
581 /* INTERFACE REQUESTS (no defined feature/status flags) */
583 /* ENDPOINT REQUESTS */
585 case EndpointRequest | USB_REQ_GET_STATUS:
586 // ENDPOINT_HALT flag
587 tbuf [0] = 0;
588 tbuf [1] = 0;
589 len = 2;
590 /* FALLTHROUGH */
591 case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
592 case EndpointOutRequest | USB_REQ_SET_FEATURE:
593 dev_dbg (hcd->self.controller, "no endpoint features yet\n");
594 break;
596 /* CLASS REQUESTS (and errors) */
598 default:
599 /* non-generic request */
600 switch (typeReq) {
601 case GetHubStatus:
602 case GetPortStatus:
603 len = 4;
604 break;
605 case GetHubDescriptor:
606 len = sizeof (struct usb_hub_descriptor);
607 break;
609 status = hcd->driver->hub_control (hcd,
610 typeReq, wValue, wIndex,
611 tbuf, wLength);
612 break;
613 error:
614 /* "protocol stall" on error */
615 status = -EPIPE;
618 if (status) {
619 len = 0;
620 if (status != -EPIPE) {
621 dev_dbg (hcd->self.controller,
622 "CTRL: TypeReq=0x%x val=0x%x "
623 "idx=0x%x len=%d ==> %d\n",
624 typeReq, wValue, wIndex,
625 wLength, status);
628 if (len) {
629 if (urb->transfer_buffer_length < len)
630 len = urb->transfer_buffer_length;
631 urb->actual_length = len;
632 // always USB_DIR_IN, toward host
633 memcpy (ubuf, bufp, len);
635 /* report whether RH hardware supports remote wakeup */
636 if (patch_wakeup &&
637 len > offsetof (struct usb_config_descriptor,
638 bmAttributes))
639 ((struct usb_config_descriptor *)ubuf)->bmAttributes
640 |= USB_CONFIG_ATT_WAKEUP;
642 /* report whether RH hardware has an integrated TT */
643 if (patch_protocol &&
644 len > offsetof(struct usb_device_descriptor,
645 bDeviceProtocol))
646 ((struct usb_device_descriptor *) ubuf)->
647 bDeviceProtocol = 1;
650 /* any errors get returned through the urb completion */
651 spin_lock_irq(&hcd_root_hub_lock);
652 usb_hcd_unlink_urb_from_ep(hcd, urb);
654 /* This peculiar use of spinlocks echoes what real HC drivers do.
655 * Avoiding calls to local_irq_disable/enable makes the code
656 * RT-friendly.
658 spin_unlock(&hcd_root_hub_lock);
659 usb_hcd_giveback_urb(hcd, urb, status);
660 spin_lock(&hcd_root_hub_lock);
662 spin_unlock_irq(&hcd_root_hub_lock);
663 return 0;
666 /*-------------------------------------------------------------------------*/
669 * Root Hub interrupt transfers are polled using a timer if the
670 * driver requests it; otherwise the driver is responsible for
671 * calling usb_hcd_poll_rh_status() when an event occurs.
673 * Completions are called in_interrupt(), but they may or may not
674 * be in_irq().
676 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
678 struct urb *urb;
679 int length;
680 unsigned long flags;
681 char buffer[6]; /* Any root hubs with > 31 ports? */
683 if (unlikely(!hcd->rh_pollable))
684 return;
685 if (!hcd->uses_new_polling && !hcd->status_urb)
686 return;
688 length = hcd->driver->hub_status_data(hcd, buffer);
689 if (length > 0) {
691 /* try to complete the status urb */
692 spin_lock_irqsave(&hcd_root_hub_lock, flags);
693 urb = hcd->status_urb;
694 if (urb) {
695 clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
696 hcd->status_urb = NULL;
697 urb->actual_length = length;
698 memcpy(urb->transfer_buffer, buffer, length);
700 usb_hcd_unlink_urb_from_ep(hcd, urb);
701 spin_unlock(&hcd_root_hub_lock);
702 usb_hcd_giveback_urb(hcd, urb, 0);
703 spin_lock(&hcd_root_hub_lock);
704 } else {
705 length = 0;
706 set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
708 spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
711 /* The USB 2.0 spec says 256 ms. This is close enough and won't
712 * exceed that limit if HZ is 100. The math is more clunky than
713 * maybe expected, this is to make sure that all timers for USB devices
714 * fire at the same time to give the CPU a break in between */
715 if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
716 (length == 0 && hcd->status_urb != NULL))
717 mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
719 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
721 /* timer callback */
722 static void rh_timer_func (unsigned long _hcd)
724 usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
727 /*-------------------------------------------------------------------------*/
729 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
731 int retval;
732 unsigned long flags;
733 unsigned len = 1 + (urb->dev->maxchild / 8);
735 spin_lock_irqsave (&hcd_root_hub_lock, flags);
736 if (hcd->status_urb || urb->transfer_buffer_length < len) {
737 dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
738 retval = -EINVAL;
739 goto done;
742 retval = usb_hcd_link_urb_to_ep(hcd, urb);
743 if (retval)
744 goto done;
746 hcd->status_urb = urb;
747 urb->hcpriv = hcd; /* indicate it's queued */
748 if (!hcd->uses_new_polling)
749 mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
751 /* If a status change has already occurred, report it ASAP */
752 else if (HCD_POLL_PENDING(hcd))
753 mod_timer(&hcd->rh_timer, jiffies);
754 retval = 0;
755 done:
756 spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
757 return retval;
760 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
762 if (usb_endpoint_xfer_int(&urb->ep->desc))
763 return rh_queue_status (hcd, urb);
764 if (usb_endpoint_xfer_control(&urb->ep->desc))
765 return rh_call_control (hcd, urb);
766 return -EINVAL;
769 /*-------------------------------------------------------------------------*/
771 /* Unlinks of root-hub control URBs are legal, but they don't do anything
772 * since these URBs always execute synchronously.
774 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
776 unsigned long flags;
777 int rc;
779 spin_lock_irqsave(&hcd_root_hub_lock, flags);
780 rc = usb_hcd_check_unlink_urb(hcd, urb, status);
781 if (rc)
782 goto done;
784 if (usb_endpoint_num(&urb->ep->desc) == 0) { /* Control URB */
785 ; /* Do nothing */
787 } else { /* Status URB */
788 if (!hcd->uses_new_polling)
789 del_timer (&hcd->rh_timer);
790 if (urb == hcd->status_urb) {
791 hcd->status_urb = NULL;
792 usb_hcd_unlink_urb_from_ep(hcd, urb);
794 spin_unlock(&hcd_root_hub_lock);
795 usb_hcd_giveback_urb(hcd, urb, status);
796 spin_lock(&hcd_root_hub_lock);
799 done:
800 spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
801 return rc;
807 * Show & store the current value of authorized_default
809 static ssize_t usb_host_authorized_default_show(struct device *dev,
810 struct device_attribute *attr,
811 char *buf)
813 struct usb_device *rh_usb_dev = to_usb_device(dev);
814 struct usb_bus *usb_bus = rh_usb_dev->bus;
815 struct usb_hcd *usb_hcd;
817 if (usb_bus == NULL) /* FIXME: not sure if this case is possible */
818 return -ENODEV;
819 usb_hcd = bus_to_hcd(usb_bus);
820 return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
823 static ssize_t usb_host_authorized_default_store(struct device *dev,
824 struct device_attribute *attr,
825 const char *buf, size_t size)
827 ssize_t result;
828 unsigned val;
829 struct usb_device *rh_usb_dev = to_usb_device(dev);
830 struct usb_bus *usb_bus = rh_usb_dev->bus;
831 struct usb_hcd *usb_hcd;
833 if (usb_bus == NULL) /* FIXME: not sure if this case is possible */
834 return -ENODEV;
835 usb_hcd = bus_to_hcd(usb_bus);
836 result = sscanf(buf, "%u\n", &val);
837 if (result == 1) {
838 usb_hcd->authorized_default = val? 1 : 0;
839 result = size;
841 else
842 result = -EINVAL;
843 return result;
846 static DEVICE_ATTR(authorized_default, 0644,
847 usb_host_authorized_default_show,
848 usb_host_authorized_default_store);
851 /* Group all the USB bus attributes */
852 static struct attribute *usb_bus_attrs[] = {
853 &dev_attr_authorized_default.attr,
854 NULL,
857 static struct attribute_group usb_bus_attr_group = {
858 .name = NULL, /* we want them in the same directory */
859 .attrs = usb_bus_attrs,
864 /*-------------------------------------------------------------------------*/
867 * usb_bus_init - shared initialization code
868 * @bus: the bus structure being initialized
870 * This code is used to initialize a usb_bus structure, memory for which is
871 * separately managed.
873 static void usb_bus_init (struct usb_bus *bus)
875 memset (&bus->devmap, 0, sizeof(struct usb_devmap));
877 bus->devnum_next = 1;
879 bus->root_hub = NULL;
880 bus->busnum = -1;
881 bus->bandwidth_allocated = 0;
882 bus->bandwidth_int_reqs = 0;
883 bus->bandwidth_isoc_reqs = 0;
885 INIT_LIST_HEAD (&bus->bus_list);
888 /*-------------------------------------------------------------------------*/
891 * usb_register_bus - registers the USB host controller with the usb core
892 * @bus: pointer to the bus to register
893 * Context: !in_interrupt()
895 * Assigns a bus number, and links the controller into usbcore data
896 * structures so that it can be seen by scanning the bus list.
898 static int usb_register_bus(struct usb_bus *bus)
900 int result = -E2BIG;
901 int busnum;
903 mutex_lock(&usb_bus_list_lock);
904 busnum = find_next_zero_bit (busmap.busmap, USB_MAXBUS, 1);
905 if (busnum >= USB_MAXBUS) {
906 printk (KERN_ERR "%s: too many buses\n", usbcore_name);
907 goto error_find_busnum;
909 set_bit (busnum, busmap.busmap);
910 bus->busnum = busnum;
912 /* Add it to the local list of buses */
913 list_add (&bus->bus_list, &usb_bus_list);
914 mutex_unlock(&usb_bus_list_lock);
916 usb_notify_add_bus(bus);
918 dev_info (bus->controller, "new USB bus registered, assigned bus "
919 "number %d\n", bus->busnum);
920 return 0;
922 error_find_busnum:
923 mutex_unlock(&usb_bus_list_lock);
924 return result;
928 * usb_deregister_bus - deregisters the USB host controller
929 * @bus: pointer to the bus to deregister
930 * Context: !in_interrupt()
932 * Recycles the bus number, and unlinks the controller from usbcore data
933 * structures so that it won't be seen by scanning the bus list.
935 static void usb_deregister_bus (struct usb_bus *bus)
937 dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
940 * NOTE: make sure that all the devices are removed by the
941 * controller code, as well as having it call this when cleaning
942 * itself up
944 mutex_lock(&usb_bus_list_lock);
945 list_del (&bus->bus_list);
946 mutex_unlock(&usb_bus_list_lock);
948 usb_notify_remove_bus(bus);
950 clear_bit (bus->busnum, busmap.busmap);
954 * register_root_hub - called by usb_add_hcd() to register a root hub
955 * @hcd: host controller for this root hub
957 * This function registers the root hub with the USB subsystem. It sets up
958 * the device properly in the device tree and then calls usb_new_device()
959 * to register the usb device. It also assigns the root hub's USB address
960 * (always 1).
962 static int register_root_hub(struct usb_hcd *hcd)
964 struct device *parent_dev = hcd->self.controller;
965 struct usb_device *usb_dev = hcd->self.root_hub;
966 const int devnum = 1;
967 int retval;
969 usb_dev->devnum = devnum;
970 usb_dev->bus->devnum_next = devnum + 1;
971 memset (&usb_dev->bus->devmap.devicemap, 0,
972 sizeof usb_dev->bus->devmap.devicemap);
973 set_bit (devnum, usb_dev->bus->devmap.devicemap);
974 usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
976 mutex_lock(&usb_bus_list_lock);
978 usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
979 retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
980 if (retval != sizeof usb_dev->descriptor) {
981 mutex_unlock(&usb_bus_list_lock);
982 dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
983 dev_name(&usb_dev->dev), retval);
984 return (retval < 0) ? retval : -EMSGSIZE;
987 retval = usb_new_device (usb_dev);
988 if (retval) {
989 dev_err (parent_dev, "can't register root hub for %s, %d\n",
990 dev_name(&usb_dev->dev), retval);
992 mutex_unlock(&usb_bus_list_lock);
994 if (retval == 0) {
995 spin_lock_irq (&hcd_root_hub_lock);
996 hcd->rh_registered = 1;
997 spin_unlock_irq (&hcd_root_hub_lock);
999 /* Did the HC die before the root hub was registered? */
1000 if (HCD_DEAD(hcd))
1001 usb_hc_died (hcd); /* This time clean up */
1004 return retval;
1008 /*-------------------------------------------------------------------------*/
1011 * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1012 * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1013 * @is_input: true iff the transaction sends data to the host
1014 * @isoc: true for isochronous transactions, false for interrupt ones
1015 * @bytecount: how many bytes in the transaction.
1017 * Returns approximate bus time in nanoseconds for a periodic transaction.
1018 * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1019 * scheduled in software, this function is only used for such scheduling.
1021 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1023 unsigned long tmp;
1025 switch (speed) {
1026 case USB_SPEED_LOW: /* INTR only */
1027 if (is_input) {
1028 tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1029 return (64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
1030 } else {
1031 tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1032 return (64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
1034 case USB_SPEED_FULL: /* ISOC or INTR */
1035 if (isoc) {
1036 tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1037 return (((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp);
1038 } else {
1039 tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1040 return (9107L + BW_HOST_DELAY + tmp);
1042 case USB_SPEED_HIGH: /* ISOC or INTR */
1043 // FIXME adjust for input vs output
1044 if (isoc)
1045 tmp = HS_NSECS_ISO (bytecount);
1046 else
1047 tmp = HS_NSECS (bytecount);
1048 return tmp;
1049 default:
1050 pr_debug ("%s: bogus device speed!\n", usbcore_name);
1051 return -1;
1054 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1057 /*-------------------------------------------------------------------------*/
1060 * Generic HC operations.
1063 /*-------------------------------------------------------------------------*/
1066 * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1067 * @hcd: host controller to which @urb was submitted
1068 * @urb: URB being submitted
1070 * Host controller drivers should call this routine in their enqueue()
1071 * method. The HCD's private spinlock must be held and interrupts must
1072 * be disabled. The actions carried out here are required for URB
1073 * submission, as well as for endpoint shutdown and for usb_kill_urb.
1075 * Returns 0 for no error, otherwise a negative error code (in which case
1076 * the enqueue() method must fail). If no error occurs but enqueue() fails
1077 * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1078 * the private spinlock and returning.
1080 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1082 int rc = 0;
1084 spin_lock(&hcd_urb_list_lock);
1086 /* Check that the URB isn't being killed */
1087 if (unlikely(atomic_read(&urb->reject))) {
1088 rc = -EPERM;
1089 goto done;
1092 if (unlikely(!urb->ep->enabled)) {
1093 rc = -ENOENT;
1094 goto done;
1097 if (unlikely(!urb->dev->can_submit)) {
1098 rc = -EHOSTUNREACH;
1099 goto done;
1103 * Check the host controller's state and add the URB to the
1104 * endpoint's queue.
1106 if (HCD_RH_RUNNING(hcd)) {
1107 urb->unlinked = 0;
1108 list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1109 } else {
1110 rc = -ESHUTDOWN;
1111 goto done;
1113 done:
1114 spin_unlock(&hcd_urb_list_lock);
1115 return rc;
1117 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1120 * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1121 * @hcd: host controller to which @urb was submitted
1122 * @urb: URB being checked for unlinkability
1123 * @status: error code to store in @urb if the unlink succeeds
1125 * Host controller drivers should call this routine in their dequeue()
1126 * method. The HCD's private spinlock must be held and interrupts must
1127 * be disabled. The actions carried out here are required for making
1128 * sure than an unlink is valid.
1130 * Returns 0 for no error, otherwise a negative error code (in which case
1131 * the dequeue() method must fail). The possible error codes are:
1133 * -EIDRM: @urb was not submitted or has already completed.
1134 * The completion function may not have been called yet.
1136 * -EBUSY: @urb has already been unlinked.
1138 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1139 int status)
1141 struct list_head *tmp;
1143 /* insist the urb is still queued */
1144 list_for_each(tmp, &urb->ep->urb_list) {
1145 if (tmp == &urb->urb_list)
1146 break;
1148 if (tmp != &urb->urb_list)
1149 return -EIDRM;
1151 /* Any status except -EINPROGRESS means something already started to
1152 * unlink this URB from the hardware. So there's no more work to do.
1154 if (urb->unlinked)
1155 return -EBUSY;
1156 urb->unlinked = status;
1158 /* IRQ setup can easily be broken so that USB controllers
1159 * never get completion IRQs ... maybe even the ones we need to
1160 * finish unlinking the initial failed usb_set_address()
1161 * or device descriptor fetch.
1163 if (!HCD_SAW_IRQ(hcd) && !is_root_hub(urb->dev)) {
1164 dev_warn(hcd->self.controller, "Unlink after no-IRQ? "
1165 "Controller is probably using the wrong IRQ.\n");
1166 set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
1167 if (hcd->shared_hcd)
1168 set_bit(HCD_FLAG_SAW_IRQ, &hcd->shared_hcd->flags);
1171 return 0;
1173 EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
1176 * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
1177 * @hcd: host controller to which @urb was submitted
1178 * @urb: URB being unlinked
1180 * Host controller drivers should call this routine before calling
1181 * usb_hcd_giveback_urb(). The HCD's private spinlock must be held and
1182 * interrupts must be disabled. The actions carried out here are required
1183 * for URB completion.
1185 void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
1187 /* clear all state linking urb to this dev (and hcd) */
1188 spin_lock(&hcd_urb_list_lock);
1189 list_del_init(&urb->urb_list);
1190 spin_unlock(&hcd_urb_list_lock);
1192 EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
1195 * Some usb host controllers can only perform dma using a small SRAM area.
1196 * The usb core itself is however optimized for host controllers that can dma
1197 * using regular system memory - like pci devices doing bus mastering.
1199 * To support host controllers with limited dma capabilites we provide dma
1200 * bounce buffers. This feature can be enabled using the HCD_LOCAL_MEM flag.
1201 * For this to work properly the host controller code must first use the
1202 * function dma_declare_coherent_memory() to point out which memory area
1203 * that should be used for dma allocations.
1205 * The HCD_LOCAL_MEM flag then tells the usb code to allocate all data for
1206 * dma using dma_alloc_coherent() which in turn allocates from the memory
1207 * area pointed out with dma_declare_coherent_memory().
1209 * So, to summarize...
1211 * - We need "local" memory, canonical example being
1212 * a small SRAM on a discrete controller being the
1213 * only memory that the controller can read ...
1214 * (a) "normal" kernel memory is no good, and
1215 * (b) there's not enough to share
1217 * - The only *portable* hook for such stuff in the
1218 * DMA framework is dma_declare_coherent_memory()
1220 * - So we use that, even though the primary requirement
1221 * is that the memory be "local" (hence addressible
1222 * by that device), not "coherent".
1226 static int hcd_alloc_coherent(struct usb_bus *bus,
1227 gfp_t mem_flags, dma_addr_t *dma_handle,
1228 void **vaddr_handle, size_t size,
1229 enum dma_data_direction dir)
1231 unsigned char *vaddr;
1233 if (*vaddr_handle == NULL) {
1234 WARN_ON_ONCE(1);
1235 return -EFAULT;
1238 vaddr = hcd_buffer_alloc(bus, size + sizeof(vaddr),
1239 mem_flags, dma_handle);
1240 if (!vaddr)
1241 return -ENOMEM;
1244 * Store the virtual address of the buffer at the end
1245 * of the allocated dma buffer. The size of the buffer
1246 * may be uneven so use unaligned functions instead
1247 * of just rounding up. It makes sense to optimize for
1248 * memory footprint over access speed since the amount
1249 * of memory available for dma may be limited.
1251 put_unaligned((unsigned long)*vaddr_handle,
1252 (unsigned long *)(vaddr + size));
1254 if (dir == DMA_TO_DEVICE)
1255 memcpy(vaddr, *vaddr_handle, size);
1257 *vaddr_handle = vaddr;
1258 return 0;
1261 static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
1262 void **vaddr_handle, size_t size,
1263 enum dma_data_direction dir)
1265 unsigned char *vaddr = *vaddr_handle;
1267 vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
1269 if (dir == DMA_FROM_DEVICE)
1270 memcpy(vaddr, *vaddr_handle, size);
1272 hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
1274 *vaddr_handle = vaddr;
1275 *dma_handle = 0;
1278 void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
1280 if (urb->transfer_flags & URB_SETUP_MAP_SINGLE)
1281 dma_unmap_single(hcd->self.controller,
1282 urb->setup_dma,
1283 sizeof(struct usb_ctrlrequest),
1284 DMA_TO_DEVICE);
1285 else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
1286 hcd_free_coherent(urb->dev->bus,
1287 &urb->setup_dma,
1288 (void **) &urb->setup_packet,
1289 sizeof(struct usb_ctrlrequest),
1290 DMA_TO_DEVICE);
1292 /* Make it safe to call this routine more than once */
1293 urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
1295 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
1297 static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1299 if (hcd->driver->unmap_urb_for_dma)
1300 hcd->driver->unmap_urb_for_dma(hcd, urb);
1301 else
1302 usb_hcd_unmap_urb_for_dma(hcd, urb);
1305 void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
1307 enum dma_data_direction dir;
1309 usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
1311 dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1312 if (urb->transfer_flags & URB_DMA_MAP_SG)
1313 dma_unmap_sg(hcd->self.controller,
1314 urb->sg,
1315 urb->num_sgs,
1316 dir);
1317 else if (urb->transfer_flags & URB_DMA_MAP_PAGE)
1318 dma_unmap_page(hcd->self.controller,
1319 urb->transfer_dma,
1320 urb->transfer_buffer_length,
1321 dir);
1322 else if (urb->transfer_flags & URB_DMA_MAP_SINGLE)
1323 dma_unmap_single(hcd->self.controller,
1324 urb->transfer_dma,
1325 urb->transfer_buffer_length,
1326 dir);
1327 else if (urb->transfer_flags & URB_MAP_LOCAL)
1328 hcd_free_coherent(urb->dev->bus,
1329 &urb->transfer_dma,
1330 &urb->transfer_buffer,
1331 urb->transfer_buffer_length,
1332 dir);
1334 /* Make it safe to call this routine more than once */
1335 urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
1336 URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
1338 EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
1340 static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1341 gfp_t mem_flags)
1343 if (hcd->driver->map_urb_for_dma)
1344 return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
1345 else
1346 return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
1349 int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
1350 gfp_t mem_flags)
1352 enum dma_data_direction dir;
1353 int ret = 0;
1355 /* Map the URB's buffers for DMA access.
1356 * Lower level HCD code should use *_dma exclusively,
1357 * unless it uses pio or talks to another transport,
1358 * or uses the provided scatter gather list for bulk.
1361 if (usb_endpoint_xfer_control(&urb->ep->desc)) {
1362 if (hcd->self.uses_pio_for_control)
1363 return ret;
1364 if (hcd->self.uses_dma) {
1365 urb->setup_dma = dma_map_single(
1366 hcd->self.controller,
1367 urb->setup_packet,
1368 sizeof(struct usb_ctrlrequest),
1369 DMA_TO_DEVICE);
1370 if (dma_mapping_error(hcd->self.controller,
1371 urb->setup_dma))
1372 return -EAGAIN;
1373 urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
1374 } else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1375 ret = hcd_alloc_coherent(
1376 urb->dev->bus, mem_flags,
1377 &urb->setup_dma,
1378 (void **)&urb->setup_packet,
1379 sizeof(struct usb_ctrlrequest),
1380 DMA_TO_DEVICE);
1381 if (ret)
1382 return ret;
1383 urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
1387 dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
1388 if (urb->transfer_buffer_length != 0
1389 && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
1390 if (hcd->self.uses_dma) {
1391 if (urb->num_sgs) {
1392 int n = dma_map_sg(
1393 hcd->self.controller,
1394 urb->sg,
1395 urb->num_sgs,
1396 dir);
1397 if (n <= 0)
1398 ret = -EAGAIN;
1399 else
1400 urb->transfer_flags |= URB_DMA_MAP_SG;
1401 if (n != urb->num_sgs) {
1402 urb->num_sgs = n;
1403 urb->transfer_flags |=
1404 URB_DMA_SG_COMBINED;
1406 } else if (urb->sg) {
1407 struct scatterlist *sg = urb->sg;
1408 urb->transfer_dma = dma_map_page(
1409 hcd->self.controller,
1410 sg_page(sg),
1411 sg->offset,
1412 urb->transfer_buffer_length,
1413 dir);
1414 if (dma_mapping_error(hcd->self.controller,
1415 urb->transfer_dma))
1416 ret = -EAGAIN;
1417 else
1418 urb->transfer_flags |= URB_DMA_MAP_PAGE;
1419 } else {
1420 urb->transfer_dma = dma_map_single(
1421 hcd->self.controller,
1422 urb->transfer_buffer,
1423 urb->transfer_buffer_length,
1424 dir);
1425 if (dma_mapping_error(hcd->self.controller,
1426 urb->transfer_dma))
1427 ret = -EAGAIN;
1428 else
1429 urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1431 } else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1432 ret = hcd_alloc_coherent(
1433 urb->dev->bus, mem_flags,
1434 &urb->transfer_dma,
1435 &urb->transfer_buffer,
1436 urb->transfer_buffer_length,
1437 dir);
1438 if (ret == 0)
1439 urb->transfer_flags |= URB_MAP_LOCAL;
1441 if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1442 URB_SETUP_MAP_LOCAL)))
1443 usb_hcd_unmap_urb_for_dma(hcd, urb);
1445 return ret;
1447 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1449 /*-------------------------------------------------------------------------*/
1451 /* may be called in any context with a valid urb->dev usecount
1452 * caller surrenders "ownership" of urb
1453 * expects usb_submit_urb() to have sanity checked and conditioned all
1454 * inputs in the urb
1456 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1458 int status;
1459 struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1461 /* increment urb's reference count as part of giving it to the HCD
1462 * (which will control it). HCD guarantees that it either returns
1463 * an error or calls giveback(), but not both.
1465 usb_get_urb(urb);
1466 atomic_inc(&urb->use_count);
1467 atomic_inc(&urb->dev->urbnum);
1468 usbmon_urb_submit(&hcd->self, urb);
1470 /* NOTE requirements on root-hub callers (usbfs and the hub
1471 * driver, for now): URBs' urb->transfer_buffer must be
1472 * valid and usb_buffer_{sync,unmap}() not be needed, since
1473 * they could clobber root hub response data. Also, control
1474 * URBs must be submitted in process context with interrupts
1475 * enabled.
1478 if (is_root_hub(urb->dev)) {
1479 status = rh_urb_enqueue(hcd, urb);
1480 } else {
1481 status = map_urb_for_dma(hcd, urb, mem_flags);
1482 if (likely(status == 0)) {
1483 status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1484 if (unlikely(status))
1485 unmap_urb_for_dma(hcd, urb);
1489 if (unlikely(status)) {
1490 usbmon_urb_submit_error(&hcd->self, urb, status);
1491 urb->hcpriv = NULL;
1492 INIT_LIST_HEAD(&urb->urb_list);
1493 atomic_dec(&urb->use_count);
1494 atomic_dec(&urb->dev->urbnum);
1495 if (atomic_read(&urb->reject))
1496 wake_up(&usb_kill_urb_queue);
1497 usb_put_urb(urb);
1499 return status;
1502 /*-------------------------------------------------------------------------*/
1504 /* this makes the hcd giveback() the urb more quickly, by kicking it
1505 * off hardware queues (which may take a while) and returning it as
1506 * soon as practical. we've already set up the urb's return status,
1507 * but we can't know if the callback completed already.
1509 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1511 int value;
1513 if (is_root_hub(urb->dev))
1514 value = usb_rh_urb_dequeue(hcd, urb, status);
1515 else {
1517 /* The only reason an HCD might fail this call is if
1518 * it has not yet fully queued the urb to begin with.
1519 * Such failures should be harmless. */
1520 value = hcd->driver->urb_dequeue(hcd, urb, status);
1522 return value;
1526 * called in any context
1528 * caller guarantees urb won't be recycled till both unlink()
1529 * and the urb's completion function return
1531 int usb_hcd_unlink_urb (struct urb *urb, int status)
1533 struct usb_hcd *hcd;
1534 int retval = -EIDRM;
1535 unsigned long flags;
1537 /* Prevent the device and bus from going away while
1538 * the unlink is carried out. If they are already gone
1539 * then urb->use_count must be 0, since disconnected
1540 * devices can't have any active URBs.
1542 spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1543 if (atomic_read(&urb->use_count) > 0) {
1544 retval = 0;
1545 usb_get_dev(urb->dev);
1547 spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1548 if (retval == 0) {
1549 hcd = bus_to_hcd(urb->dev->bus);
1550 retval = unlink1(hcd, urb, status);
1551 usb_put_dev(urb->dev);
1554 if (retval == 0)
1555 retval = -EINPROGRESS;
1556 else if (retval != -EIDRM && retval != -EBUSY)
1557 dev_dbg(&urb->dev->dev, "hcd_unlink_urb %p fail %d\n",
1558 urb, retval);
1559 return retval;
1562 /*-------------------------------------------------------------------------*/
1565 * usb_hcd_giveback_urb - return URB from HCD to device driver
1566 * @hcd: host controller returning the URB
1567 * @urb: urb being returned to the USB device driver.
1568 * @status: completion status code for the URB.
1569 * Context: in_interrupt()
1571 * This hands the URB from HCD to its USB device driver, using its
1572 * completion function. The HCD has freed all per-urb resources
1573 * (and is done using urb->hcpriv). It also released all HCD locks;
1574 * the device driver won't cause problems if it frees, modifies,
1575 * or resubmits this URB.
1577 * If @urb was unlinked, the value of @status will be overridden by
1578 * @urb->unlinked. Erroneous short transfers are detected in case
1579 * the HCD hasn't checked for them.
1581 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1583 urb->hcpriv = NULL;
1584 if (unlikely(urb->unlinked))
1585 status = urb->unlinked;
1586 else if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1587 urb->actual_length < urb->transfer_buffer_length &&
1588 !status))
1589 status = -EREMOTEIO;
1591 unmap_urb_for_dma(hcd, urb);
1592 usbmon_urb_complete(&hcd->self, urb, status);
1593 usb_unanchor_urb(urb);
1595 /* pass ownership to the completion handler */
1596 urb->status = status;
1597 urb->complete (urb);
1598 atomic_dec (&urb->use_count);
1599 if (unlikely(atomic_read(&urb->reject)))
1600 wake_up (&usb_kill_urb_queue);
1601 usb_put_urb (urb);
1603 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1605 /*-------------------------------------------------------------------------*/
1607 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1608 * queue to drain completely. The caller must first insure that no more
1609 * URBs can be submitted for this endpoint.
1611 void usb_hcd_flush_endpoint(struct usb_device *udev,
1612 struct usb_host_endpoint *ep)
1614 struct usb_hcd *hcd;
1615 struct urb *urb;
1617 if (!ep)
1618 return;
1619 might_sleep();
1620 hcd = bus_to_hcd(udev->bus);
1622 /* No more submits can occur */
1623 spin_lock_irq(&hcd_urb_list_lock);
1624 rescan:
1625 list_for_each_entry (urb, &ep->urb_list, urb_list) {
1626 int is_in;
1628 if (urb->unlinked)
1629 continue;
1630 usb_get_urb (urb);
1631 is_in = usb_urb_dir_in(urb);
1632 spin_unlock(&hcd_urb_list_lock);
1634 /* kick hcd */
1635 unlink1(hcd, urb, -ESHUTDOWN);
1636 dev_dbg (hcd->self.controller,
1637 "shutdown urb %p ep%d%s%s\n",
1638 urb, usb_endpoint_num(&ep->desc),
1639 is_in ? "in" : "out",
1640 ({ char *s;
1642 switch (usb_endpoint_type(&ep->desc)) {
1643 case USB_ENDPOINT_XFER_CONTROL:
1644 s = ""; break;
1645 case USB_ENDPOINT_XFER_BULK:
1646 s = "-bulk"; break;
1647 case USB_ENDPOINT_XFER_INT:
1648 s = "-intr"; break;
1649 default:
1650 s = "-iso"; break;
1653 }));
1654 usb_put_urb (urb);
1656 /* list contents may have changed */
1657 spin_lock(&hcd_urb_list_lock);
1658 goto rescan;
1660 spin_unlock_irq(&hcd_urb_list_lock);
1662 /* Wait until the endpoint queue is completely empty */
1663 while (!list_empty (&ep->urb_list)) {
1664 spin_lock_irq(&hcd_urb_list_lock);
1666 /* The list may have changed while we acquired the spinlock */
1667 urb = NULL;
1668 if (!list_empty (&ep->urb_list)) {
1669 urb = list_entry (ep->urb_list.prev, struct urb,
1670 urb_list);
1671 usb_get_urb (urb);
1673 spin_unlock_irq(&hcd_urb_list_lock);
1675 if (urb) {
1676 usb_kill_urb (urb);
1677 usb_put_urb (urb);
1683 * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1684 * the bus bandwidth
1685 * @udev: target &usb_device
1686 * @new_config: new configuration to install
1687 * @cur_alt: the current alternate interface setting
1688 * @new_alt: alternate interface setting that is being installed
1690 * To change configurations, pass in the new configuration in new_config,
1691 * and pass NULL for cur_alt and new_alt.
1693 * To reset a device's configuration (put the device in the ADDRESSED state),
1694 * pass in NULL for new_config, cur_alt, and new_alt.
1696 * To change alternate interface settings, pass in NULL for new_config,
1697 * pass in the current alternate interface setting in cur_alt,
1698 * and pass in the new alternate interface setting in new_alt.
1700 * Returns an error if the requested bandwidth change exceeds the
1701 * bus bandwidth or host controller internal resources.
1703 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1704 struct usb_host_config *new_config,
1705 struct usb_host_interface *cur_alt,
1706 struct usb_host_interface *new_alt)
1708 int num_intfs, i, j;
1709 struct usb_host_interface *alt = NULL;
1710 int ret = 0;
1711 struct usb_hcd *hcd;
1712 struct usb_host_endpoint *ep;
1714 hcd = bus_to_hcd(udev->bus);
1715 if (!hcd->driver->check_bandwidth)
1716 return 0;
1718 /* Configuration is being removed - set configuration 0 */
1719 if (!new_config && !cur_alt) {
1720 for (i = 1; i < 16; ++i) {
1721 ep = udev->ep_out[i];
1722 if (ep)
1723 hcd->driver->drop_endpoint(hcd, udev, ep);
1724 ep = udev->ep_in[i];
1725 if (ep)
1726 hcd->driver->drop_endpoint(hcd, udev, ep);
1728 hcd->driver->check_bandwidth(hcd, udev);
1729 return 0;
1731 /* Check if the HCD says there's enough bandwidth. Enable all endpoints
1732 * each interface's alt setting 0 and ask the HCD to check the bandwidth
1733 * of the bus. There will always be bandwidth for endpoint 0, so it's
1734 * ok to exclude it.
1736 if (new_config) {
1737 num_intfs = new_config->desc.bNumInterfaces;
1738 /* Remove endpoints (except endpoint 0, which is always on the
1739 * schedule) from the old config from the schedule
1741 for (i = 1; i < 16; ++i) {
1742 ep = udev->ep_out[i];
1743 if (ep) {
1744 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1745 if (ret < 0)
1746 goto reset;
1748 ep = udev->ep_in[i];
1749 if (ep) {
1750 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1751 if (ret < 0)
1752 goto reset;
1755 for (i = 0; i < num_intfs; ++i) {
1756 struct usb_host_interface *first_alt;
1757 int iface_num;
1759 first_alt = &new_config->intf_cache[i]->altsetting[0];
1760 iface_num = first_alt->desc.bInterfaceNumber;
1761 /* Set up endpoints for alternate interface setting 0 */
1762 alt = usb_find_alt_setting(new_config, iface_num, 0);
1763 if (!alt)
1764 /* No alt setting 0? Pick the first setting. */
1765 alt = first_alt;
1767 for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1768 ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1769 if (ret < 0)
1770 goto reset;
1774 if (cur_alt && new_alt) {
1775 struct usb_interface *iface = usb_ifnum_to_if(udev,
1776 cur_alt->desc.bInterfaceNumber);
1778 if (iface->resetting_device) {
1780 * The USB core just reset the device, so the xHCI host
1781 * and the device will think alt setting 0 is installed.
1782 * However, the USB core will pass in the alternate
1783 * setting installed before the reset as cur_alt. Dig
1784 * out the alternate setting 0 structure, or the first
1785 * alternate setting if a broken device doesn't have alt
1786 * setting 0.
1788 cur_alt = usb_altnum_to_altsetting(iface, 0);
1789 if (!cur_alt)
1790 cur_alt = &iface->altsetting[0];
1793 /* Drop all the endpoints in the current alt setting */
1794 for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1795 ret = hcd->driver->drop_endpoint(hcd, udev,
1796 &cur_alt->endpoint[i]);
1797 if (ret < 0)
1798 goto reset;
1800 /* Add all the endpoints in the new alt setting */
1801 for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1802 ret = hcd->driver->add_endpoint(hcd, udev,
1803 &new_alt->endpoint[i]);
1804 if (ret < 0)
1805 goto reset;
1808 ret = hcd->driver->check_bandwidth(hcd, udev);
1809 reset:
1810 if (ret < 0)
1811 hcd->driver->reset_bandwidth(hcd, udev);
1812 return ret;
1815 /* Disables the endpoint: synchronizes with the hcd to make sure all
1816 * endpoint state is gone from hardware. usb_hcd_flush_endpoint() must
1817 * have been called previously. Use for set_configuration, set_interface,
1818 * driver removal, physical disconnect.
1820 * example: a qh stored in ep->hcpriv, holding state related to endpoint
1821 * type, maxpacket size, toggle, halt status, and scheduling.
1823 void usb_hcd_disable_endpoint(struct usb_device *udev,
1824 struct usb_host_endpoint *ep)
1826 struct usb_hcd *hcd;
1828 might_sleep();
1829 hcd = bus_to_hcd(udev->bus);
1830 if (hcd->driver->endpoint_disable)
1831 hcd->driver->endpoint_disable(hcd, ep);
1835 * usb_hcd_reset_endpoint - reset host endpoint state
1836 * @udev: USB device.
1837 * @ep: the endpoint to reset.
1839 * Resets any host endpoint state such as the toggle bit, sequence
1840 * number and current window.
1842 void usb_hcd_reset_endpoint(struct usb_device *udev,
1843 struct usb_host_endpoint *ep)
1845 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1847 if (hcd->driver->endpoint_reset)
1848 hcd->driver->endpoint_reset(hcd, ep);
1849 else {
1850 int epnum = usb_endpoint_num(&ep->desc);
1851 int is_out = usb_endpoint_dir_out(&ep->desc);
1852 int is_control = usb_endpoint_xfer_control(&ep->desc);
1854 usb_settoggle(udev, epnum, is_out, 0);
1855 if (is_control)
1856 usb_settoggle(udev, epnum, !is_out, 0);
1861 * usb_alloc_streams - allocate bulk endpoint stream IDs.
1862 * @interface: alternate setting that includes all endpoints.
1863 * @eps: array of endpoints that need streams.
1864 * @num_eps: number of endpoints in the array.
1865 * @num_streams: number of streams to allocate.
1866 * @mem_flags: flags hcd should use to allocate memory.
1868 * Sets up a group of bulk endpoints to have num_streams stream IDs available.
1869 * Drivers may queue multiple transfers to different stream IDs, which may
1870 * complete in a different order than they were queued.
1872 int usb_alloc_streams(struct usb_interface *interface,
1873 struct usb_host_endpoint **eps, unsigned int num_eps,
1874 unsigned int num_streams, gfp_t mem_flags)
1876 struct usb_hcd *hcd;
1877 struct usb_device *dev;
1878 int i;
1880 dev = interface_to_usbdev(interface);
1881 hcd = bus_to_hcd(dev->bus);
1882 if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
1883 return -EINVAL;
1884 if (dev->speed != USB_SPEED_SUPER)
1885 return -EINVAL;
1887 /* Streams only apply to bulk endpoints. */
1888 for (i = 0; i < num_eps; i++)
1889 if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
1890 return -EINVAL;
1892 return hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
1893 num_streams, mem_flags);
1895 EXPORT_SYMBOL_GPL(usb_alloc_streams);
1898 * usb_free_streams - free bulk endpoint stream IDs.
1899 * @interface: alternate setting that includes all endpoints.
1900 * @eps: array of endpoints to remove streams from.
1901 * @num_eps: number of endpoints in the array.
1902 * @mem_flags: flags hcd should use to allocate memory.
1904 * Reverts a group of bulk endpoints back to not using stream IDs.
1905 * Can fail if we are given bad arguments, or HCD is broken.
1907 void usb_free_streams(struct usb_interface *interface,
1908 struct usb_host_endpoint **eps, unsigned int num_eps,
1909 gfp_t mem_flags)
1911 struct usb_hcd *hcd;
1912 struct usb_device *dev;
1913 int i;
1915 dev = interface_to_usbdev(interface);
1916 hcd = bus_to_hcd(dev->bus);
1917 if (dev->speed != USB_SPEED_SUPER)
1918 return;
1920 /* Streams only apply to bulk endpoints. */
1921 for (i = 0; i < num_eps; i++)
1922 if (!eps[i] || !usb_endpoint_xfer_bulk(&eps[i]->desc))
1923 return;
1925 hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
1927 EXPORT_SYMBOL_GPL(usb_free_streams);
1929 /* Protect against drivers that try to unlink URBs after the device
1930 * is gone, by waiting until all unlinks for @udev are finished.
1931 * Since we don't currently track URBs by device, simply wait until
1932 * nothing is running in the locked region of usb_hcd_unlink_urb().
1934 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
1936 spin_lock_irq(&hcd_urb_unlink_lock);
1937 spin_unlock_irq(&hcd_urb_unlink_lock);
1940 /*-------------------------------------------------------------------------*/
1942 /* called in any context */
1943 int usb_hcd_get_frame_number (struct usb_device *udev)
1945 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1947 if (!HCD_RH_RUNNING(hcd))
1948 return -ESHUTDOWN;
1949 return hcd->driver->get_frame_number (hcd);
1952 /*-------------------------------------------------------------------------*/
1954 #ifdef CONFIG_PM
1956 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
1958 struct usb_hcd *hcd = container_of(rhdev->bus, struct usb_hcd, self);
1959 int status;
1960 int old_state = hcd->state;
1962 dev_dbg(&rhdev->dev, "bus %s%s\n",
1963 (msg.event & PM_EVENT_AUTO ? "auto-" : ""), "suspend");
1964 if (HCD_DEAD(hcd)) {
1965 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
1966 return 0;
1969 if (!hcd->driver->bus_suspend) {
1970 status = -ENOENT;
1971 } else {
1972 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
1973 hcd->state = HC_STATE_QUIESCING;
1974 status = hcd->driver->bus_suspend(hcd);
1976 if (status == 0) {
1977 usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
1978 hcd->state = HC_STATE_SUSPENDED;
1979 } else {
1980 spin_lock_irq(&hcd_root_hub_lock);
1981 if (!HCD_DEAD(hcd)) {
1982 set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
1983 hcd->state = old_state;
1985 spin_unlock_irq(&hcd_root_hub_lock);
1986 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
1987 "suspend", status);
1989 return status;
1992 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
1994 struct usb_hcd *hcd = container_of(rhdev->bus, struct usb_hcd, self);
1995 int status;
1996 int old_state = hcd->state;
1998 dev_dbg(&rhdev->dev, "usb %s%s\n",
1999 (msg.event & PM_EVENT_AUTO ? "auto-" : ""), "resume");
2000 if (HCD_DEAD(hcd)) {
2001 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2002 return 0;
2004 if (!hcd->driver->bus_resume)
2005 return -ENOENT;
2006 if (HCD_RH_RUNNING(hcd))
2007 return 0;
2009 hcd->state = HC_STATE_RESUMING;
2010 status = hcd->driver->bus_resume(hcd);
2011 clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2012 if (status == 0) {
2013 /* TRSMRCY = 10 msec */
2014 msleep(10);
2015 spin_lock_irq(&hcd_root_hub_lock);
2016 if (!HCD_DEAD(hcd)) {
2017 usb_set_device_state(rhdev, rhdev->actconfig
2018 ? USB_STATE_CONFIGURED
2019 : USB_STATE_ADDRESS);
2020 set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2021 hcd->state = HC_STATE_RUNNING;
2023 spin_unlock_irq(&hcd_root_hub_lock);
2024 } else {
2025 hcd->state = old_state;
2026 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2027 "resume", status);
2028 if (status != -ESHUTDOWN)
2029 usb_hc_died(hcd);
2031 return status;
2034 #endif /* CONFIG_PM */
2036 #ifdef CONFIG_USB_SUSPEND
2038 /* Workqueue routine for root-hub remote wakeup */
2039 static void hcd_resume_work(struct work_struct *work)
2041 struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2042 struct usb_device *udev = hcd->self.root_hub;
2044 usb_lock_device(udev);
2045 usb_remote_wakeup(udev);
2046 usb_unlock_device(udev);
2050 * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2051 * @hcd: host controller for this root hub
2053 * The USB host controller calls this function when its root hub is
2054 * suspended (with the remote wakeup feature enabled) and a remote
2055 * wakeup request is received. The routine submits a workqueue request
2056 * to resume the root hub (that is, manage its downstream ports again).
2058 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2060 unsigned long flags;
2062 spin_lock_irqsave (&hcd_root_hub_lock, flags);
2063 if (hcd->rh_registered) {
2064 set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2065 queue_work(pm_wq, &hcd->wakeup_work);
2067 spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2069 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2071 #endif /* CONFIG_USB_SUSPEND */
2073 /*-------------------------------------------------------------------------*/
2075 #ifdef CONFIG_USB_OTG
2078 * usb_bus_start_enum - start immediate enumeration (for OTG)
2079 * @bus: the bus (must use hcd framework)
2080 * @port_num: 1-based number of port; usually bus->otg_port
2081 * Context: in_interrupt()
2083 * Starts enumeration, with an immediate reset followed later by
2084 * khubd identifying and possibly configuring the device.
2085 * This is needed by OTG controller drivers, where it helps meet
2086 * HNP protocol timing requirements for starting a port reset.
2088 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2090 struct usb_hcd *hcd;
2091 int status = -EOPNOTSUPP;
2093 /* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2094 * boards with root hubs hooked up to internal devices (instead of
2095 * just the OTG port) may need more attention to resetting...
2097 hcd = container_of (bus, struct usb_hcd, self);
2098 if (port_num && hcd->driver->start_port_reset)
2099 status = hcd->driver->start_port_reset(hcd, port_num);
2101 /* run khubd shortly after (first) root port reset finishes;
2102 * it may issue others, until at least 50 msecs have passed.
2104 if (status == 0)
2105 mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2106 return status;
2108 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2110 #endif
2112 /*-------------------------------------------------------------------------*/
2115 * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2116 * @irq: the IRQ being raised
2117 * @__hcd: pointer to the HCD whose IRQ is being signaled
2119 * If the controller isn't HALTed, calls the driver's irq handler.
2120 * Checks whether the controller is now dead.
2122 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2124 struct usb_hcd *hcd = __hcd;
2125 unsigned long flags;
2126 irqreturn_t rc;
2128 /* IRQF_DISABLED doesn't work correctly with shared IRQs
2129 * when the first handler doesn't use it. So let's just
2130 * assume it's never used.
2132 local_irq_save(flags);
2134 if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd))) {
2135 rc = IRQ_NONE;
2136 } else if (hcd->driver->irq(hcd) == IRQ_NONE) {
2137 rc = IRQ_NONE;
2138 } else {
2139 set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
2140 if (hcd->shared_hcd)
2141 set_bit(HCD_FLAG_SAW_IRQ, &hcd->shared_hcd->flags);
2142 rc = IRQ_HANDLED;
2145 local_irq_restore(flags);
2146 return rc;
2148 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2150 /*-------------------------------------------------------------------------*/
2153 * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2154 * @hcd: pointer to the HCD representing the controller
2156 * This is called by bus glue to report a USB host controller that died
2157 * while operations may still have been pending. It's called automatically
2158 * by the PCI glue, so only glue for non-PCI busses should need to call it.
2160 * Only call this function with the primary HCD.
2162 void usb_hc_died (struct usb_hcd *hcd)
2164 unsigned long flags;
2166 dev_err (hcd->self.controller, "HC died; cleaning up\n");
2168 spin_lock_irqsave (&hcd_root_hub_lock, flags);
2169 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2170 set_bit(HCD_FLAG_DEAD, &hcd->flags);
2171 if (hcd->rh_registered) {
2172 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2174 /* make khubd clean up old urbs and devices */
2175 usb_set_device_state (hcd->self.root_hub,
2176 USB_STATE_NOTATTACHED);
2177 usb_kick_khubd (hcd->self.root_hub);
2179 if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2180 hcd = hcd->shared_hcd;
2181 if (hcd->rh_registered) {
2182 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2184 /* make khubd clean up old urbs and devices */
2185 usb_set_device_state(hcd->self.root_hub,
2186 USB_STATE_NOTATTACHED);
2187 usb_kick_khubd(hcd->self.root_hub);
2190 spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2191 /* Make sure that the other roothub is also deallocated. */
2193 EXPORT_SYMBOL_GPL (usb_hc_died);
2195 /*-------------------------------------------------------------------------*/
2198 * usb_create_shared_hcd - create and initialize an HCD structure
2199 * @driver: HC driver that will use this hcd
2200 * @dev: device for this HC, stored in hcd->self.controller
2201 * @bus_name: value to store in hcd->self.bus_name
2202 * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2203 * PCI device. Only allocate certain resources for the primary HCD
2204 * Context: !in_interrupt()
2206 * Allocate a struct usb_hcd, with extra space at the end for the
2207 * HC driver's private data. Initialize the generic members of the
2208 * hcd structure.
2210 * If memory is unavailable, returns NULL.
2212 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2213 struct device *dev, const char *bus_name,
2214 struct usb_hcd *primary_hcd)
2216 struct usb_hcd *hcd;
2218 hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2219 if (!hcd) {
2220 dev_dbg (dev, "hcd alloc failed\n");
2221 return NULL;
2223 if (primary_hcd == NULL) {
2224 hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2225 GFP_KERNEL);
2226 if (!hcd->bandwidth_mutex) {
2227 kfree(hcd);
2228 dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2229 return NULL;
2231 mutex_init(hcd->bandwidth_mutex);
2232 dev_set_drvdata(dev, hcd);
2233 } else {
2234 hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2235 hcd->primary_hcd = primary_hcd;
2236 primary_hcd->primary_hcd = primary_hcd;
2237 hcd->shared_hcd = primary_hcd;
2238 primary_hcd->shared_hcd = hcd;
2241 kref_init(&hcd->kref);
2243 usb_bus_init(&hcd->self);
2244 hcd->self.controller = dev;
2245 hcd->self.bus_name = bus_name;
2246 hcd->self.uses_dma = (dev->dma_mask != NULL);
2248 init_timer(&hcd->rh_timer);
2249 hcd->rh_timer.function = rh_timer_func;
2250 hcd->rh_timer.data = (unsigned long) hcd;
2251 #ifdef CONFIG_USB_SUSPEND
2252 INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2253 #endif
2255 hcd->driver = driver;
2256 hcd->speed = driver->flags & HCD_MASK;
2257 hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2258 "USB Host Controller";
2259 return hcd;
2261 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2264 * usb_create_hcd - create and initialize an HCD structure
2265 * @driver: HC driver that will use this hcd
2266 * @dev: device for this HC, stored in hcd->self.controller
2267 * @bus_name: value to store in hcd->self.bus_name
2268 * Context: !in_interrupt()
2270 * Allocate a struct usb_hcd, with extra space at the end for the
2271 * HC driver's private data. Initialize the generic members of the
2272 * hcd structure.
2274 * If memory is unavailable, returns NULL.
2276 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2277 struct device *dev, const char *bus_name)
2279 return usb_create_shared_hcd(driver, dev, bus_name, NULL);
2281 EXPORT_SYMBOL_GPL(usb_create_hcd);
2284 * Roothubs that share one PCI device must also share the bandwidth mutex.
2285 * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2286 * deallocated.
2288 * Make sure to only deallocate the bandwidth_mutex when the primary HCD is
2289 * freed. When hcd_release() is called for the non-primary HCD, set the
2290 * primary_hcd's shared_hcd pointer to null (since the non-primary HCD will be
2291 * freed shortly).
2293 static void hcd_release (struct kref *kref)
2295 struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2297 if (usb_hcd_is_primary_hcd(hcd))
2298 kfree(hcd->bandwidth_mutex);
2299 else
2300 hcd->shared_hcd->shared_hcd = NULL;
2301 kfree(hcd);
2304 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2306 if (hcd)
2307 kref_get (&hcd->kref);
2308 return hcd;
2310 EXPORT_SYMBOL_GPL(usb_get_hcd);
2312 void usb_put_hcd (struct usb_hcd *hcd)
2314 if (hcd)
2315 kref_put (&hcd->kref, hcd_release);
2317 EXPORT_SYMBOL_GPL(usb_put_hcd);
2319 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2321 if (!hcd->primary_hcd)
2322 return 1;
2323 return hcd == hcd->primary_hcd;
2325 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2327 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2328 unsigned int irqnum, unsigned long irqflags)
2330 int retval;
2332 if (hcd->driver->irq) {
2334 /* IRQF_DISABLED doesn't work as advertised when used together
2335 * with IRQF_SHARED. As usb_hcd_irq() will always disable
2336 * interrupts we can remove it here.
2338 if (irqflags & IRQF_SHARED)
2339 irqflags &= ~IRQF_DISABLED;
2341 snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2342 hcd->driver->description, hcd->self.busnum);
2343 retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2344 hcd->irq_descr, hcd);
2345 if (retval != 0) {
2346 dev_err(hcd->self.controller,
2347 "request interrupt %d failed\n",
2348 irqnum);
2349 return retval;
2351 hcd->irq = irqnum;
2352 dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2353 (hcd->driver->flags & HCD_MEMORY) ?
2354 "io mem" : "io base",
2355 (unsigned long long)hcd->rsrc_start);
2356 } else {
2357 hcd->irq = -1;
2358 if (hcd->rsrc_start)
2359 dev_info(hcd->self.controller, "%s 0x%08llx\n",
2360 (hcd->driver->flags & HCD_MEMORY) ?
2361 "io mem" : "io base",
2362 (unsigned long long)hcd->rsrc_start);
2364 return 0;
2368 * usb_add_hcd - finish generic HCD structure initialization and register
2369 * @hcd: the usb_hcd structure to initialize
2370 * @irqnum: Interrupt line to allocate
2371 * @irqflags: Interrupt type flags
2373 * Finish the remaining parts of generic HCD initialization: allocate the
2374 * buffers of consistent memory, register the bus, request the IRQ line,
2375 * and call the driver's reset() and start() routines.
2377 int usb_add_hcd(struct usb_hcd *hcd,
2378 unsigned int irqnum, unsigned long irqflags)
2380 int retval;
2381 struct usb_device *rhdev;
2383 dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2385 /* Keep old behaviour if authorized_default is not in [0, 1]. */
2386 if (authorized_default < 0 || authorized_default > 1)
2387 hcd->authorized_default = hcd->wireless? 0 : 1;
2388 else
2389 hcd->authorized_default = authorized_default;
2390 set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2392 /* HC is in reset state, but accessible. Now do the one-time init,
2393 * bottom up so that hcds can customize the root hubs before khubd
2394 * starts talking to them. (Note, bus id is assigned early too.)
2396 if ((retval = hcd_buffer_create(hcd)) != 0) {
2397 dev_dbg(hcd->self.controller, "pool alloc failed\n");
2398 return retval;
2401 if ((retval = usb_register_bus(&hcd->self)) < 0)
2402 goto err_register_bus;
2404 if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
2405 dev_err(hcd->self.controller, "unable to allocate root hub\n");
2406 retval = -ENOMEM;
2407 goto err_allocate_root_hub;
2409 hcd->self.root_hub = rhdev;
2411 switch (hcd->speed) {
2412 case HCD_USB11:
2413 rhdev->speed = USB_SPEED_FULL;
2414 break;
2415 case HCD_USB2:
2416 rhdev->speed = USB_SPEED_HIGH;
2417 break;
2418 case HCD_USB3:
2419 rhdev->speed = USB_SPEED_SUPER;
2420 break;
2421 default:
2422 retval = -EINVAL;
2423 goto err_set_rh_speed;
2426 /* wakeup flag init defaults to "everything works" for root hubs,
2427 * but drivers can override it in reset() if needed, along with
2428 * recording the overall controller's system wakeup capability.
2430 device_init_wakeup(&rhdev->dev, 1);
2432 /* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2433 * registered. But since the controller can die at any time,
2434 * let's initialize the flag before touching the hardware.
2436 set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2438 /* "reset" is misnamed; its role is now one-time init. the controller
2439 * should already have been reset (and boot firmware kicked off etc).
2441 if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
2442 dev_err(hcd->self.controller, "can't setup\n");
2443 goto err_hcd_driver_setup;
2445 hcd->rh_pollable = 1;
2447 /* NOTE: root hub and controller capabilities may not be the same */
2448 if (device_can_wakeup(hcd->self.controller)
2449 && device_can_wakeup(&hcd->self.root_hub->dev))
2450 dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2452 /* enable irqs just before we start the controller */
2453 if (usb_hcd_is_primary_hcd(hcd)) {
2454 retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
2455 if (retval)
2456 goto err_request_irq;
2459 hcd->state = HC_STATE_RUNNING;
2460 retval = hcd->driver->start(hcd);
2461 if (retval < 0) {
2462 dev_err(hcd->self.controller, "startup error %d\n", retval);
2463 goto err_hcd_driver_start;
2466 /* starting here, usbcore will pay attention to this root hub */
2467 rhdev->bus_mA = min(500u, hcd->power_budget);
2468 if ((retval = register_root_hub(hcd)) != 0)
2469 goto err_register_root_hub;
2471 retval = sysfs_create_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2472 if (retval < 0) {
2473 printk(KERN_ERR "Cannot register USB bus sysfs attributes: %d\n",
2474 retval);
2475 goto error_create_attr_group;
2477 if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
2478 usb_hcd_poll_rh_status(hcd);
2479 return retval;
2481 error_create_attr_group:
2482 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2483 if (HC_IS_RUNNING(hcd->state))
2484 hcd->state = HC_STATE_QUIESCING;
2485 spin_lock_irq(&hcd_root_hub_lock);
2486 hcd->rh_registered = 0;
2487 spin_unlock_irq(&hcd_root_hub_lock);
2489 #ifdef CONFIG_USB_SUSPEND
2490 cancel_work_sync(&hcd->wakeup_work);
2491 #endif
2492 mutex_lock(&usb_bus_list_lock);
2493 usb_disconnect(&rhdev); /* Sets rhdev to NULL */
2494 mutex_unlock(&usb_bus_list_lock);
2495 err_register_root_hub:
2496 hcd->rh_pollable = 0;
2497 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2498 del_timer_sync(&hcd->rh_timer);
2499 hcd->driver->stop(hcd);
2500 hcd->state = HC_STATE_HALT;
2501 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2502 del_timer_sync(&hcd->rh_timer);
2503 err_hcd_driver_start:
2504 if (usb_hcd_is_primary_hcd(hcd) && hcd->irq >= 0)
2505 free_irq(irqnum, hcd);
2506 err_request_irq:
2507 err_hcd_driver_setup:
2508 err_set_rh_speed:
2509 usb_put_dev(hcd->self.root_hub);
2510 err_allocate_root_hub:
2511 usb_deregister_bus(&hcd->self);
2512 err_register_bus:
2513 hcd_buffer_destroy(hcd);
2514 return retval;
2516 EXPORT_SYMBOL_GPL(usb_add_hcd);
2519 * usb_remove_hcd - shutdown processing for generic HCDs
2520 * @hcd: the usb_hcd structure to remove
2521 * Context: !in_interrupt()
2523 * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2524 * invoking the HCD's stop() method.
2526 void usb_remove_hcd(struct usb_hcd *hcd)
2528 struct usb_device *rhdev = hcd->self.root_hub;
2530 dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2532 usb_get_dev(rhdev);
2533 sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2535 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2536 if (HC_IS_RUNNING (hcd->state))
2537 hcd->state = HC_STATE_QUIESCING;
2539 dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2540 spin_lock_irq (&hcd_root_hub_lock);
2541 hcd->rh_registered = 0;
2542 spin_unlock_irq (&hcd_root_hub_lock);
2544 #ifdef CONFIG_USB_SUSPEND
2545 cancel_work_sync(&hcd->wakeup_work);
2546 #endif
2548 mutex_lock(&usb_bus_list_lock);
2549 usb_disconnect(&rhdev); /* Sets rhdev to NULL */
2550 mutex_unlock(&usb_bus_list_lock);
2552 /* Prevent any more root-hub status calls from the timer.
2553 * The HCD might still restart the timer (if a port status change
2554 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2555 * the hub_status_data() callback.
2557 hcd->rh_pollable = 0;
2558 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2559 del_timer_sync(&hcd->rh_timer);
2561 hcd->driver->stop(hcd);
2562 hcd->state = HC_STATE_HALT;
2564 /* In case the HCD restarted the timer, stop it again. */
2565 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2566 del_timer_sync(&hcd->rh_timer);
2568 if (usb_hcd_is_primary_hcd(hcd)) {
2569 if (hcd->irq >= 0)
2570 free_irq(hcd->irq, hcd);
2573 usb_put_dev(hcd->self.root_hub);
2574 usb_deregister_bus(&hcd->self);
2575 hcd_buffer_destroy(hcd);
2577 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2579 void
2580 usb_hcd_platform_shutdown(struct platform_device* dev)
2582 struct usb_hcd *hcd = platform_get_drvdata(dev);
2584 if (hcd->driver->shutdown)
2585 hcd->driver->shutdown(hcd);
2587 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2589 /*-------------------------------------------------------------------------*/
2591 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
2593 struct usb_mon_operations *mon_ops;
2596 * The registration is unlocked.
2597 * We do it this way because we do not want to lock in hot paths.
2599 * Notice that the code is minimally error-proof. Because usbmon needs
2600 * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2603 int usb_mon_register (struct usb_mon_operations *ops)
2606 if (mon_ops)
2607 return -EBUSY;
2609 mon_ops = ops;
2610 mb();
2611 return 0;
2613 EXPORT_SYMBOL_GPL (usb_mon_register);
2615 void usb_mon_deregister (void)
2618 if (mon_ops == NULL) {
2619 printk(KERN_ERR "USB: monitor was not registered\n");
2620 return;
2622 mon_ops = NULL;
2623 mb();
2625 EXPORT_SYMBOL_GPL (usb_mon_deregister);
2627 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */