i2c-eg20t: change timeout value 50msec to 1000msec
[zen-stable.git] / drivers / usb / core / hcd.c
blobe1282328fc27f1ef17228ff4ad57747c79e2c927
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;
446 * tbuf should be as big as the BOS descriptor and
447 * the USB hub descriptor.
449 u8 tbuf[USB_DT_BOS_SIZE + USB_DT_USB_SS_CAP_SIZE]
450 __attribute__((aligned(4)));
451 const u8 *bufp = tbuf;
452 unsigned len = 0;
453 int status;
454 u8 patch_wakeup = 0;
455 u8 patch_protocol = 0;
457 might_sleep();
459 spin_lock_irq(&hcd_root_hub_lock);
460 status = usb_hcd_link_urb_to_ep(hcd, urb);
461 spin_unlock_irq(&hcd_root_hub_lock);
462 if (status)
463 return status;
464 urb->hcpriv = hcd; /* Indicate it's queued */
466 cmd = (struct usb_ctrlrequest *) urb->setup_packet;
467 typeReq = (cmd->bRequestType << 8) | cmd->bRequest;
468 wValue = le16_to_cpu (cmd->wValue);
469 wIndex = le16_to_cpu (cmd->wIndex);
470 wLength = le16_to_cpu (cmd->wLength);
472 if (wLength > urb->transfer_buffer_length)
473 goto error;
475 urb->actual_length = 0;
476 switch (typeReq) {
478 /* DEVICE REQUESTS */
480 /* The root hub's remote wakeup enable bit is implemented using
481 * driver model wakeup flags. If this system supports wakeup
482 * through USB, userspace may change the default "allow wakeup"
483 * policy through sysfs or these calls.
485 * Most root hubs support wakeup from downstream devices, for
486 * runtime power management (disabling USB clocks and reducing
487 * VBUS power usage). However, not all of them do so; silicon,
488 * board, and BIOS bugs here are not uncommon, so these can't
489 * be treated quite like external hubs.
491 * Likewise, not all root hubs will pass wakeup events upstream,
492 * to wake up the whole system. So don't assume root hub and
493 * controller capabilities are identical.
496 case DeviceRequest | USB_REQ_GET_STATUS:
497 tbuf [0] = (device_may_wakeup(&hcd->self.root_hub->dev)
498 << USB_DEVICE_REMOTE_WAKEUP)
499 | (1 << USB_DEVICE_SELF_POWERED);
500 tbuf [1] = 0;
501 len = 2;
502 break;
503 case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
504 if (wValue == USB_DEVICE_REMOTE_WAKEUP)
505 device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
506 else
507 goto error;
508 break;
509 case DeviceOutRequest | USB_REQ_SET_FEATURE:
510 if (device_can_wakeup(&hcd->self.root_hub->dev)
511 && wValue == USB_DEVICE_REMOTE_WAKEUP)
512 device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
513 else
514 goto error;
515 break;
516 case DeviceRequest | USB_REQ_GET_CONFIGURATION:
517 tbuf [0] = 1;
518 len = 1;
519 /* FALLTHROUGH */
520 case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
521 break;
522 case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
523 switch (wValue & 0xff00) {
524 case USB_DT_DEVICE << 8:
525 switch (hcd->speed) {
526 case HCD_USB3:
527 bufp = usb3_rh_dev_descriptor;
528 break;
529 case HCD_USB2:
530 bufp = usb2_rh_dev_descriptor;
531 break;
532 case HCD_USB11:
533 bufp = usb11_rh_dev_descriptor;
534 break;
535 default:
536 goto error;
538 len = 18;
539 if (hcd->has_tt)
540 patch_protocol = 1;
541 break;
542 case USB_DT_CONFIG << 8:
543 switch (hcd->speed) {
544 case HCD_USB3:
545 bufp = ss_rh_config_descriptor;
546 len = sizeof ss_rh_config_descriptor;
547 break;
548 case HCD_USB2:
549 bufp = hs_rh_config_descriptor;
550 len = sizeof hs_rh_config_descriptor;
551 break;
552 case HCD_USB11:
553 bufp = fs_rh_config_descriptor;
554 len = sizeof fs_rh_config_descriptor;
555 break;
556 default:
557 goto error;
559 if (device_can_wakeup(&hcd->self.root_hub->dev))
560 patch_wakeup = 1;
561 break;
562 case USB_DT_STRING << 8:
563 if ((wValue & 0xff) < 4)
564 urb->actual_length = rh_string(wValue & 0xff,
565 hcd, ubuf, wLength);
566 else /* unsupported IDs --> "protocol stall" */
567 goto error;
568 break;
569 case USB_DT_BOS << 8:
570 goto nongeneric;
571 default:
572 goto error;
574 break;
575 case DeviceRequest | USB_REQ_GET_INTERFACE:
576 tbuf [0] = 0;
577 len = 1;
578 /* FALLTHROUGH */
579 case DeviceOutRequest | USB_REQ_SET_INTERFACE:
580 break;
581 case DeviceOutRequest | USB_REQ_SET_ADDRESS:
582 // wValue == urb->dev->devaddr
583 dev_dbg (hcd->self.controller, "root hub device address %d\n",
584 wValue);
585 break;
587 /* INTERFACE REQUESTS (no defined feature/status flags) */
589 /* ENDPOINT REQUESTS */
591 case EndpointRequest | USB_REQ_GET_STATUS:
592 // ENDPOINT_HALT flag
593 tbuf [0] = 0;
594 tbuf [1] = 0;
595 len = 2;
596 /* FALLTHROUGH */
597 case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
598 case EndpointOutRequest | USB_REQ_SET_FEATURE:
599 dev_dbg (hcd->self.controller, "no endpoint features yet\n");
600 break;
602 /* CLASS REQUESTS (and errors) */
604 default:
605 nongeneric:
606 /* non-generic request */
607 switch (typeReq) {
608 case GetHubStatus:
609 case GetPortStatus:
610 len = 4;
611 break;
612 case GetHubDescriptor:
613 len = sizeof (struct usb_hub_descriptor);
614 break;
615 case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
616 /* len is returned by hub_control */
617 break;
619 status = hcd->driver->hub_control (hcd,
620 typeReq, wValue, wIndex,
621 tbuf, wLength);
622 break;
623 error:
624 /* "protocol stall" on error */
625 status = -EPIPE;
628 if (status < 0) {
629 len = 0;
630 if (status != -EPIPE) {
631 dev_dbg (hcd->self.controller,
632 "CTRL: TypeReq=0x%x val=0x%x "
633 "idx=0x%x len=%d ==> %d\n",
634 typeReq, wValue, wIndex,
635 wLength, status);
637 } else if (status > 0) {
638 /* hub_control may return the length of data copied. */
639 len = status;
640 status = 0;
642 if (len) {
643 if (urb->transfer_buffer_length < len)
644 len = urb->transfer_buffer_length;
645 urb->actual_length = len;
646 // always USB_DIR_IN, toward host
647 memcpy (ubuf, bufp, len);
649 /* report whether RH hardware supports remote wakeup */
650 if (patch_wakeup &&
651 len > offsetof (struct usb_config_descriptor,
652 bmAttributes))
653 ((struct usb_config_descriptor *)ubuf)->bmAttributes
654 |= USB_CONFIG_ATT_WAKEUP;
656 /* report whether RH hardware has an integrated TT */
657 if (patch_protocol &&
658 len > offsetof(struct usb_device_descriptor,
659 bDeviceProtocol))
660 ((struct usb_device_descriptor *) ubuf)->
661 bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
664 /* any errors get returned through the urb completion */
665 spin_lock_irq(&hcd_root_hub_lock);
666 usb_hcd_unlink_urb_from_ep(hcd, urb);
668 /* This peculiar use of spinlocks echoes what real HC drivers do.
669 * Avoiding calls to local_irq_disable/enable makes the code
670 * RT-friendly.
672 spin_unlock(&hcd_root_hub_lock);
673 usb_hcd_giveback_urb(hcd, urb, status);
674 spin_lock(&hcd_root_hub_lock);
676 spin_unlock_irq(&hcd_root_hub_lock);
677 return 0;
680 /*-------------------------------------------------------------------------*/
683 * Root Hub interrupt transfers are polled using a timer if the
684 * driver requests it; otherwise the driver is responsible for
685 * calling usb_hcd_poll_rh_status() when an event occurs.
687 * Completions are called in_interrupt(), but they may or may not
688 * be in_irq().
690 void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
692 struct urb *urb;
693 int length;
694 unsigned long flags;
695 char buffer[6]; /* Any root hubs with > 31 ports? */
697 if (unlikely(!hcd->rh_pollable))
698 return;
699 if (!hcd->uses_new_polling && !hcd->status_urb)
700 return;
702 length = hcd->driver->hub_status_data(hcd, buffer);
703 if (length > 0) {
705 /* try to complete the status urb */
706 spin_lock_irqsave(&hcd_root_hub_lock, flags);
707 urb = hcd->status_urb;
708 if (urb) {
709 clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
710 hcd->status_urb = NULL;
711 urb->actual_length = length;
712 memcpy(urb->transfer_buffer, buffer, length);
714 usb_hcd_unlink_urb_from_ep(hcd, urb);
715 spin_unlock(&hcd_root_hub_lock);
716 usb_hcd_giveback_urb(hcd, urb, 0);
717 spin_lock(&hcd_root_hub_lock);
718 } else {
719 length = 0;
720 set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
722 spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
725 /* The USB 2.0 spec says 256 ms. This is close enough and won't
726 * exceed that limit if HZ is 100. The math is more clunky than
727 * maybe expected, this is to make sure that all timers for USB devices
728 * fire at the same time to give the CPU a break in between */
729 if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
730 (length == 0 && hcd->status_urb != NULL))
731 mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
733 EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
735 /* timer callback */
736 static void rh_timer_func (unsigned long _hcd)
738 usb_hcd_poll_rh_status((struct usb_hcd *) _hcd);
741 /*-------------------------------------------------------------------------*/
743 static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
745 int retval;
746 unsigned long flags;
747 unsigned len = 1 + (urb->dev->maxchild / 8);
749 spin_lock_irqsave (&hcd_root_hub_lock, flags);
750 if (hcd->status_urb || urb->transfer_buffer_length < len) {
751 dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
752 retval = -EINVAL;
753 goto done;
756 retval = usb_hcd_link_urb_to_ep(hcd, urb);
757 if (retval)
758 goto done;
760 hcd->status_urb = urb;
761 urb->hcpriv = hcd; /* indicate it's queued */
762 if (!hcd->uses_new_polling)
763 mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
765 /* If a status change has already occurred, report it ASAP */
766 else if (HCD_POLL_PENDING(hcd))
767 mod_timer(&hcd->rh_timer, jiffies);
768 retval = 0;
769 done:
770 spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
771 return retval;
774 static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
776 if (usb_endpoint_xfer_int(&urb->ep->desc))
777 return rh_queue_status (hcd, urb);
778 if (usb_endpoint_xfer_control(&urb->ep->desc))
779 return rh_call_control (hcd, urb);
780 return -EINVAL;
783 /*-------------------------------------------------------------------------*/
785 /* Unlinks of root-hub control URBs are legal, but they don't do anything
786 * since these URBs always execute synchronously.
788 static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
790 unsigned long flags;
791 int rc;
793 spin_lock_irqsave(&hcd_root_hub_lock, flags);
794 rc = usb_hcd_check_unlink_urb(hcd, urb, status);
795 if (rc)
796 goto done;
798 if (usb_endpoint_num(&urb->ep->desc) == 0) { /* Control URB */
799 ; /* Do nothing */
801 } else { /* Status URB */
802 if (!hcd->uses_new_polling)
803 del_timer (&hcd->rh_timer);
804 if (urb == hcd->status_urb) {
805 hcd->status_urb = NULL;
806 usb_hcd_unlink_urb_from_ep(hcd, urb);
808 spin_unlock(&hcd_root_hub_lock);
809 usb_hcd_giveback_urb(hcd, urb, status);
810 spin_lock(&hcd_root_hub_lock);
813 done:
814 spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
815 return rc;
821 * Show & store the current value of authorized_default
823 static ssize_t usb_host_authorized_default_show(struct device *dev,
824 struct device_attribute *attr,
825 char *buf)
827 struct usb_device *rh_usb_dev = to_usb_device(dev);
828 struct usb_bus *usb_bus = rh_usb_dev->bus;
829 struct usb_hcd *usb_hcd;
831 if (usb_bus == NULL) /* FIXME: not sure if this case is possible */
832 return -ENODEV;
833 usb_hcd = bus_to_hcd(usb_bus);
834 return snprintf(buf, PAGE_SIZE, "%u\n", usb_hcd->authorized_default);
837 static ssize_t usb_host_authorized_default_store(struct device *dev,
838 struct device_attribute *attr,
839 const char *buf, size_t size)
841 ssize_t result;
842 unsigned val;
843 struct usb_device *rh_usb_dev = to_usb_device(dev);
844 struct usb_bus *usb_bus = rh_usb_dev->bus;
845 struct usb_hcd *usb_hcd;
847 if (usb_bus == NULL) /* FIXME: not sure if this case is possible */
848 return -ENODEV;
849 usb_hcd = bus_to_hcd(usb_bus);
850 result = sscanf(buf, "%u\n", &val);
851 if (result == 1) {
852 usb_hcd->authorized_default = val? 1 : 0;
853 result = size;
855 else
856 result = -EINVAL;
857 return result;
860 static DEVICE_ATTR(authorized_default, 0644,
861 usb_host_authorized_default_show,
862 usb_host_authorized_default_store);
865 /* Group all the USB bus attributes */
866 static struct attribute *usb_bus_attrs[] = {
867 &dev_attr_authorized_default.attr,
868 NULL,
871 static struct attribute_group usb_bus_attr_group = {
872 .name = NULL, /* we want them in the same directory */
873 .attrs = usb_bus_attrs,
878 /*-------------------------------------------------------------------------*/
881 * usb_bus_init - shared initialization code
882 * @bus: the bus structure being initialized
884 * This code is used to initialize a usb_bus structure, memory for which is
885 * separately managed.
887 static void usb_bus_init (struct usb_bus *bus)
889 memset (&bus->devmap, 0, sizeof(struct usb_devmap));
891 bus->devnum_next = 1;
893 bus->root_hub = NULL;
894 bus->busnum = -1;
895 bus->bandwidth_allocated = 0;
896 bus->bandwidth_int_reqs = 0;
897 bus->bandwidth_isoc_reqs = 0;
899 INIT_LIST_HEAD (&bus->bus_list);
902 /*-------------------------------------------------------------------------*/
905 * usb_register_bus - registers the USB host controller with the usb core
906 * @bus: pointer to the bus to register
907 * Context: !in_interrupt()
909 * Assigns a bus number, and links the controller into usbcore data
910 * structures so that it can be seen by scanning the bus list.
912 static int usb_register_bus(struct usb_bus *bus)
914 int result = -E2BIG;
915 int busnum;
917 mutex_lock(&usb_bus_list_lock);
918 busnum = find_next_zero_bit (busmap.busmap, USB_MAXBUS, 1);
919 if (busnum >= USB_MAXBUS) {
920 printk (KERN_ERR "%s: too many buses\n", usbcore_name);
921 goto error_find_busnum;
923 set_bit (busnum, busmap.busmap);
924 bus->busnum = busnum;
926 /* Add it to the local list of buses */
927 list_add (&bus->bus_list, &usb_bus_list);
928 mutex_unlock(&usb_bus_list_lock);
930 usb_notify_add_bus(bus);
932 dev_info (bus->controller, "new USB bus registered, assigned bus "
933 "number %d\n", bus->busnum);
934 return 0;
936 error_find_busnum:
937 mutex_unlock(&usb_bus_list_lock);
938 return result;
942 * usb_deregister_bus - deregisters the USB host controller
943 * @bus: pointer to the bus to deregister
944 * Context: !in_interrupt()
946 * Recycles the bus number, and unlinks the controller from usbcore data
947 * structures so that it won't be seen by scanning the bus list.
949 static void usb_deregister_bus (struct usb_bus *bus)
951 dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
954 * NOTE: make sure that all the devices are removed by the
955 * controller code, as well as having it call this when cleaning
956 * itself up
958 mutex_lock(&usb_bus_list_lock);
959 list_del (&bus->bus_list);
960 mutex_unlock(&usb_bus_list_lock);
962 usb_notify_remove_bus(bus);
964 clear_bit (bus->busnum, busmap.busmap);
968 * register_root_hub - called by usb_add_hcd() to register a root hub
969 * @hcd: host controller for this root hub
971 * This function registers the root hub with the USB subsystem. It sets up
972 * the device properly in the device tree and then calls usb_new_device()
973 * to register the usb device. It also assigns the root hub's USB address
974 * (always 1).
976 static int register_root_hub(struct usb_hcd *hcd)
978 struct device *parent_dev = hcd->self.controller;
979 struct usb_device *usb_dev = hcd->self.root_hub;
980 const int devnum = 1;
981 int retval;
983 usb_dev->devnum = devnum;
984 usb_dev->bus->devnum_next = devnum + 1;
985 memset (&usb_dev->bus->devmap.devicemap, 0,
986 sizeof usb_dev->bus->devmap.devicemap);
987 set_bit (devnum, usb_dev->bus->devmap.devicemap);
988 usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
990 mutex_lock(&usb_bus_list_lock);
992 usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
993 retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
994 if (retval != sizeof usb_dev->descriptor) {
995 mutex_unlock(&usb_bus_list_lock);
996 dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
997 dev_name(&usb_dev->dev), retval);
998 return (retval < 0) ? retval : -EMSGSIZE;
1001 retval = usb_new_device (usb_dev);
1002 if (retval) {
1003 dev_err (parent_dev, "can't register root hub for %s, %d\n",
1004 dev_name(&usb_dev->dev), retval);
1006 mutex_unlock(&usb_bus_list_lock);
1008 if (retval == 0) {
1009 spin_lock_irq (&hcd_root_hub_lock);
1010 hcd->rh_registered = 1;
1011 spin_unlock_irq (&hcd_root_hub_lock);
1013 /* Did the HC die before the root hub was registered? */
1014 if (HCD_DEAD(hcd))
1015 usb_hc_died (hcd); /* This time clean up */
1018 return retval;
1022 /*-------------------------------------------------------------------------*/
1025 * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
1026 * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
1027 * @is_input: true iff the transaction sends data to the host
1028 * @isoc: true for isochronous transactions, false for interrupt ones
1029 * @bytecount: how many bytes in the transaction.
1031 * Returns approximate bus time in nanoseconds for a periodic transaction.
1032 * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
1033 * scheduled in software, this function is only used for such scheduling.
1035 long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
1037 unsigned long tmp;
1039 switch (speed) {
1040 case USB_SPEED_LOW: /* INTR only */
1041 if (is_input) {
1042 tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
1043 return (64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
1044 } else {
1045 tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
1046 return (64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp);
1048 case USB_SPEED_FULL: /* ISOC or INTR */
1049 if (isoc) {
1050 tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1051 return (((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp);
1052 } else {
1053 tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
1054 return (9107L + BW_HOST_DELAY + tmp);
1056 case USB_SPEED_HIGH: /* ISOC or INTR */
1057 // FIXME adjust for input vs output
1058 if (isoc)
1059 tmp = HS_NSECS_ISO (bytecount);
1060 else
1061 tmp = HS_NSECS (bytecount);
1062 return tmp;
1063 default:
1064 pr_debug ("%s: bogus device speed!\n", usbcore_name);
1065 return -1;
1068 EXPORT_SYMBOL_GPL(usb_calc_bus_time);
1071 /*-------------------------------------------------------------------------*/
1074 * Generic HC operations.
1077 /*-------------------------------------------------------------------------*/
1080 * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
1081 * @hcd: host controller to which @urb was submitted
1082 * @urb: URB being submitted
1084 * Host controller drivers should call this routine in their enqueue()
1085 * method. The HCD's private spinlock must be held and interrupts must
1086 * be disabled. The actions carried out here are required for URB
1087 * submission, as well as for endpoint shutdown and for usb_kill_urb.
1089 * Returns 0 for no error, otherwise a negative error code (in which case
1090 * the enqueue() method must fail). If no error occurs but enqueue() fails
1091 * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
1092 * the private spinlock and returning.
1094 int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
1096 int rc = 0;
1098 spin_lock(&hcd_urb_list_lock);
1100 /* Check that the URB isn't being killed */
1101 if (unlikely(atomic_read(&urb->reject))) {
1102 rc = -EPERM;
1103 goto done;
1106 if (unlikely(!urb->ep->enabled)) {
1107 rc = -ENOENT;
1108 goto done;
1111 if (unlikely(!urb->dev->can_submit)) {
1112 rc = -EHOSTUNREACH;
1113 goto done;
1117 * Check the host controller's state and add the URB to the
1118 * endpoint's queue.
1120 if (HCD_RH_RUNNING(hcd)) {
1121 urb->unlinked = 0;
1122 list_add_tail(&urb->urb_list, &urb->ep->urb_list);
1123 } else {
1124 rc = -ESHUTDOWN;
1125 goto done;
1127 done:
1128 spin_unlock(&hcd_urb_list_lock);
1129 return rc;
1131 EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
1134 * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
1135 * @hcd: host controller to which @urb was submitted
1136 * @urb: URB being checked for unlinkability
1137 * @status: error code to store in @urb if the unlink succeeds
1139 * Host controller drivers should call this routine in their dequeue()
1140 * method. The HCD's private spinlock must be held and interrupts must
1141 * be disabled. The actions carried out here are required for making
1142 * sure than an unlink is valid.
1144 * Returns 0 for no error, otherwise a negative error code (in which case
1145 * the dequeue() method must fail). The possible error codes are:
1147 * -EIDRM: @urb was not submitted or has already completed.
1148 * The completion function may not have been called yet.
1150 * -EBUSY: @urb has already been unlinked.
1152 int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
1153 int status)
1155 struct list_head *tmp;
1157 /* insist the urb is still queued */
1158 list_for_each(tmp, &urb->ep->urb_list) {
1159 if (tmp == &urb->urb_list)
1160 break;
1162 if (tmp != &urb->urb_list)
1163 return -EIDRM;
1165 /* Any status except -EINPROGRESS means something already started to
1166 * unlink this URB from the hardware. So there's no more work to do.
1168 if (urb->unlinked)
1169 return -EBUSY;
1170 urb->unlinked = status;
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 urb->num_mapped_sgs = n;
1402 if (n != urb->num_sgs)
1403 urb->transfer_flags |=
1404 URB_DMA_SG_COMBINED;
1405 } else if (urb->sg) {
1406 struct scatterlist *sg = urb->sg;
1407 urb->transfer_dma = dma_map_page(
1408 hcd->self.controller,
1409 sg_page(sg),
1410 sg->offset,
1411 urb->transfer_buffer_length,
1412 dir);
1413 if (dma_mapping_error(hcd->self.controller,
1414 urb->transfer_dma))
1415 ret = -EAGAIN;
1416 else
1417 urb->transfer_flags |= URB_DMA_MAP_PAGE;
1418 } else {
1419 urb->transfer_dma = dma_map_single(
1420 hcd->self.controller,
1421 urb->transfer_buffer,
1422 urb->transfer_buffer_length,
1423 dir);
1424 if (dma_mapping_error(hcd->self.controller,
1425 urb->transfer_dma))
1426 ret = -EAGAIN;
1427 else
1428 urb->transfer_flags |= URB_DMA_MAP_SINGLE;
1430 } else if (hcd->driver->flags & HCD_LOCAL_MEM) {
1431 ret = hcd_alloc_coherent(
1432 urb->dev->bus, mem_flags,
1433 &urb->transfer_dma,
1434 &urb->transfer_buffer,
1435 urb->transfer_buffer_length,
1436 dir);
1437 if (ret == 0)
1438 urb->transfer_flags |= URB_MAP_LOCAL;
1440 if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
1441 URB_SETUP_MAP_LOCAL)))
1442 usb_hcd_unmap_urb_for_dma(hcd, urb);
1444 return ret;
1446 EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
1448 /*-------------------------------------------------------------------------*/
1450 /* may be called in any context with a valid urb->dev usecount
1451 * caller surrenders "ownership" of urb
1452 * expects usb_submit_urb() to have sanity checked and conditioned all
1453 * inputs in the urb
1455 int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
1457 int status;
1458 struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
1460 /* increment urb's reference count as part of giving it to the HCD
1461 * (which will control it). HCD guarantees that it either returns
1462 * an error or calls giveback(), but not both.
1464 usb_get_urb(urb);
1465 atomic_inc(&urb->use_count);
1466 atomic_inc(&urb->dev->urbnum);
1467 usbmon_urb_submit(&hcd->self, urb);
1469 /* NOTE requirements on root-hub callers (usbfs and the hub
1470 * driver, for now): URBs' urb->transfer_buffer must be
1471 * valid and usb_buffer_{sync,unmap}() not be needed, since
1472 * they could clobber root hub response data. Also, control
1473 * URBs must be submitted in process context with interrupts
1474 * enabled.
1477 if (is_root_hub(urb->dev)) {
1478 status = rh_urb_enqueue(hcd, urb);
1479 } else {
1480 status = map_urb_for_dma(hcd, urb, mem_flags);
1481 if (likely(status == 0)) {
1482 status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
1483 if (unlikely(status))
1484 unmap_urb_for_dma(hcd, urb);
1488 if (unlikely(status)) {
1489 usbmon_urb_submit_error(&hcd->self, urb, status);
1490 urb->hcpriv = NULL;
1491 INIT_LIST_HEAD(&urb->urb_list);
1492 atomic_dec(&urb->use_count);
1493 atomic_dec(&urb->dev->urbnum);
1494 if (atomic_read(&urb->reject))
1495 wake_up(&usb_kill_urb_queue);
1496 usb_put_urb(urb);
1498 return status;
1501 /*-------------------------------------------------------------------------*/
1503 /* this makes the hcd giveback() the urb more quickly, by kicking it
1504 * off hardware queues (which may take a while) and returning it as
1505 * soon as practical. we've already set up the urb's return status,
1506 * but we can't know if the callback completed already.
1508 static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
1510 int value;
1512 if (is_root_hub(urb->dev))
1513 value = usb_rh_urb_dequeue(hcd, urb, status);
1514 else {
1516 /* The only reason an HCD might fail this call is if
1517 * it has not yet fully queued the urb to begin with.
1518 * Such failures should be harmless. */
1519 value = hcd->driver->urb_dequeue(hcd, urb, status);
1521 return value;
1525 * called in any context
1527 * caller guarantees urb won't be recycled till both unlink()
1528 * and the urb's completion function return
1530 int usb_hcd_unlink_urb (struct urb *urb, int status)
1532 struct usb_hcd *hcd;
1533 int retval = -EIDRM;
1534 unsigned long flags;
1536 /* Prevent the device and bus from going away while
1537 * the unlink is carried out. If they are already gone
1538 * then urb->use_count must be 0, since disconnected
1539 * devices can't have any active URBs.
1541 spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
1542 if (atomic_read(&urb->use_count) > 0) {
1543 retval = 0;
1544 usb_get_dev(urb->dev);
1546 spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
1547 if (retval == 0) {
1548 hcd = bus_to_hcd(urb->dev->bus);
1549 retval = unlink1(hcd, urb, status);
1550 usb_put_dev(urb->dev);
1553 if (retval == 0)
1554 retval = -EINPROGRESS;
1555 else if (retval != -EIDRM && retval != -EBUSY)
1556 dev_dbg(&urb->dev->dev, "hcd_unlink_urb %p fail %d\n",
1557 urb, retval);
1558 return retval;
1561 /*-------------------------------------------------------------------------*/
1564 * usb_hcd_giveback_urb - return URB from HCD to device driver
1565 * @hcd: host controller returning the URB
1566 * @urb: urb being returned to the USB device driver.
1567 * @status: completion status code for the URB.
1568 * Context: in_interrupt()
1570 * This hands the URB from HCD to its USB device driver, using its
1571 * completion function. The HCD has freed all per-urb resources
1572 * (and is done using urb->hcpriv). It also released all HCD locks;
1573 * the device driver won't cause problems if it frees, modifies,
1574 * or resubmits this URB.
1576 * If @urb was unlinked, the value of @status will be overridden by
1577 * @urb->unlinked. Erroneous short transfers are detected in case
1578 * the HCD hasn't checked for them.
1580 void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
1582 urb->hcpriv = NULL;
1583 if (unlikely(urb->unlinked))
1584 status = urb->unlinked;
1585 else if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
1586 urb->actual_length < urb->transfer_buffer_length &&
1587 !status))
1588 status = -EREMOTEIO;
1590 unmap_urb_for_dma(hcd, urb);
1591 usbmon_urb_complete(&hcd->self, urb, status);
1592 usb_unanchor_urb(urb);
1594 /* pass ownership to the completion handler */
1595 urb->status = status;
1596 urb->complete (urb);
1597 atomic_dec (&urb->use_count);
1598 if (unlikely(atomic_read(&urb->reject)))
1599 wake_up (&usb_kill_urb_queue);
1600 usb_put_urb (urb);
1602 EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
1604 /*-------------------------------------------------------------------------*/
1606 /* Cancel all URBs pending on this endpoint and wait for the endpoint's
1607 * queue to drain completely. The caller must first insure that no more
1608 * URBs can be submitted for this endpoint.
1610 void usb_hcd_flush_endpoint(struct usb_device *udev,
1611 struct usb_host_endpoint *ep)
1613 struct usb_hcd *hcd;
1614 struct urb *urb;
1616 if (!ep)
1617 return;
1618 might_sleep();
1619 hcd = bus_to_hcd(udev->bus);
1621 /* No more submits can occur */
1622 spin_lock_irq(&hcd_urb_list_lock);
1623 rescan:
1624 list_for_each_entry (urb, &ep->urb_list, urb_list) {
1625 int is_in;
1627 if (urb->unlinked)
1628 continue;
1629 usb_get_urb (urb);
1630 is_in = usb_urb_dir_in(urb);
1631 spin_unlock(&hcd_urb_list_lock);
1633 /* kick hcd */
1634 unlink1(hcd, urb, -ESHUTDOWN);
1635 dev_dbg (hcd->self.controller,
1636 "shutdown urb %p ep%d%s%s\n",
1637 urb, usb_endpoint_num(&ep->desc),
1638 is_in ? "in" : "out",
1639 ({ char *s;
1641 switch (usb_endpoint_type(&ep->desc)) {
1642 case USB_ENDPOINT_XFER_CONTROL:
1643 s = ""; break;
1644 case USB_ENDPOINT_XFER_BULK:
1645 s = "-bulk"; break;
1646 case USB_ENDPOINT_XFER_INT:
1647 s = "-intr"; break;
1648 default:
1649 s = "-iso"; break;
1652 }));
1653 usb_put_urb (urb);
1655 /* list contents may have changed */
1656 spin_lock(&hcd_urb_list_lock);
1657 goto rescan;
1659 spin_unlock_irq(&hcd_urb_list_lock);
1661 /* Wait until the endpoint queue is completely empty */
1662 while (!list_empty (&ep->urb_list)) {
1663 spin_lock_irq(&hcd_urb_list_lock);
1665 /* The list may have changed while we acquired the spinlock */
1666 urb = NULL;
1667 if (!list_empty (&ep->urb_list)) {
1668 urb = list_entry (ep->urb_list.prev, struct urb,
1669 urb_list);
1670 usb_get_urb (urb);
1672 spin_unlock_irq(&hcd_urb_list_lock);
1674 if (urb) {
1675 usb_kill_urb (urb);
1676 usb_put_urb (urb);
1682 * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
1683 * the bus bandwidth
1684 * @udev: target &usb_device
1685 * @new_config: new configuration to install
1686 * @cur_alt: the current alternate interface setting
1687 * @new_alt: alternate interface setting that is being installed
1689 * To change configurations, pass in the new configuration in new_config,
1690 * and pass NULL for cur_alt and new_alt.
1692 * To reset a device's configuration (put the device in the ADDRESSED state),
1693 * pass in NULL for new_config, cur_alt, and new_alt.
1695 * To change alternate interface settings, pass in NULL for new_config,
1696 * pass in the current alternate interface setting in cur_alt,
1697 * and pass in the new alternate interface setting in new_alt.
1699 * Returns an error if the requested bandwidth change exceeds the
1700 * bus bandwidth or host controller internal resources.
1702 int usb_hcd_alloc_bandwidth(struct usb_device *udev,
1703 struct usb_host_config *new_config,
1704 struct usb_host_interface *cur_alt,
1705 struct usb_host_interface *new_alt)
1707 int num_intfs, i, j;
1708 struct usb_host_interface *alt = NULL;
1709 int ret = 0;
1710 struct usb_hcd *hcd;
1711 struct usb_host_endpoint *ep;
1713 hcd = bus_to_hcd(udev->bus);
1714 if (!hcd->driver->check_bandwidth)
1715 return 0;
1717 /* Configuration is being removed - set configuration 0 */
1718 if (!new_config && !cur_alt) {
1719 for (i = 1; i < 16; ++i) {
1720 ep = udev->ep_out[i];
1721 if (ep)
1722 hcd->driver->drop_endpoint(hcd, udev, ep);
1723 ep = udev->ep_in[i];
1724 if (ep)
1725 hcd->driver->drop_endpoint(hcd, udev, ep);
1727 hcd->driver->check_bandwidth(hcd, udev);
1728 return 0;
1730 /* Check if the HCD says there's enough bandwidth. Enable all endpoints
1731 * each interface's alt setting 0 and ask the HCD to check the bandwidth
1732 * of the bus. There will always be bandwidth for endpoint 0, so it's
1733 * ok to exclude it.
1735 if (new_config) {
1736 num_intfs = new_config->desc.bNumInterfaces;
1737 /* Remove endpoints (except endpoint 0, which is always on the
1738 * schedule) from the old config from the schedule
1740 for (i = 1; i < 16; ++i) {
1741 ep = udev->ep_out[i];
1742 if (ep) {
1743 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1744 if (ret < 0)
1745 goto reset;
1747 ep = udev->ep_in[i];
1748 if (ep) {
1749 ret = hcd->driver->drop_endpoint(hcd, udev, ep);
1750 if (ret < 0)
1751 goto reset;
1754 for (i = 0; i < num_intfs; ++i) {
1755 struct usb_host_interface *first_alt;
1756 int iface_num;
1758 first_alt = &new_config->intf_cache[i]->altsetting[0];
1759 iface_num = first_alt->desc.bInterfaceNumber;
1760 /* Set up endpoints for alternate interface setting 0 */
1761 alt = usb_find_alt_setting(new_config, iface_num, 0);
1762 if (!alt)
1763 /* No alt setting 0? Pick the first setting. */
1764 alt = first_alt;
1766 for (j = 0; j < alt->desc.bNumEndpoints; j++) {
1767 ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
1768 if (ret < 0)
1769 goto reset;
1773 if (cur_alt && new_alt) {
1774 struct usb_interface *iface = usb_ifnum_to_if(udev,
1775 cur_alt->desc.bInterfaceNumber);
1777 if (!iface)
1778 return -EINVAL;
1779 if (iface->resetting_device) {
1781 * The USB core just reset the device, so the xHCI host
1782 * and the device will think alt setting 0 is installed.
1783 * However, the USB core will pass in the alternate
1784 * setting installed before the reset as cur_alt. Dig
1785 * out the alternate setting 0 structure, or the first
1786 * alternate setting if a broken device doesn't have alt
1787 * setting 0.
1789 cur_alt = usb_altnum_to_altsetting(iface, 0);
1790 if (!cur_alt)
1791 cur_alt = &iface->altsetting[0];
1794 /* Drop all the endpoints in the current alt setting */
1795 for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
1796 ret = hcd->driver->drop_endpoint(hcd, udev,
1797 &cur_alt->endpoint[i]);
1798 if (ret < 0)
1799 goto reset;
1801 /* Add all the endpoints in the new alt setting */
1802 for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
1803 ret = hcd->driver->add_endpoint(hcd, udev,
1804 &new_alt->endpoint[i]);
1805 if (ret < 0)
1806 goto reset;
1809 ret = hcd->driver->check_bandwidth(hcd, udev);
1810 reset:
1811 if (ret < 0)
1812 hcd->driver->reset_bandwidth(hcd, udev);
1813 return ret;
1816 /* Disables the endpoint: synchronizes with the hcd to make sure all
1817 * endpoint state is gone from hardware. usb_hcd_flush_endpoint() must
1818 * have been called previously. Use for set_configuration, set_interface,
1819 * driver removal, physical disconnect.
1821 * example: a qh stored in ep->hcpriv, holding state related to endpoint
1822 * type, maxpacket size, toggle, halt status, and scheduling.
1824 void usb_hcd_disable_endpoint(struct usb_device *udev,
1825 struct usb_host_endpoint *ep)
1827 struct usb_hcd *hcd;
1829 might_sleep();
1830 hcd = bus_to_hcd(udev->bus);
1831 if (hcd->driver->endpoint_disable)
1832 hcd->driver->endpoint_disable(hcd, ep);
1836 * usb_hcd_reset_endpoint - reset host endpoint state
1837 * @udev: USB device.
1838 * @ep: the endpoint to reset.
1840 * Resets any host endpoint state such as the toggle bit, sequence
1841 * number and current window.
1843 void usb_hcd_reset_endpoint(struct usb_device *udev,
1844 struct usb_host_endpoint *ep)
1846 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1848 if (hcd->driver->endpoint_reset)
1849 hcd->driver->endpoint_reset(hcd, ep);
1850 else {
1851 int epnum = usb_endpoint_num(&ep->desc);
1852 int is_out = usb_endpoint_dir_out(&ep->desc);
1853 int is_control = usb_endpoint_xfer_control(&ep->desc);
1855 usb_settoggle(udev, epnum, is_out, 0);
1856 if (is_control)
1857 usb_settoggle(udev, epnum, !is_out, 0);
1862 * usb_alloc_streams - allocate bulk endpoint stream IDs.
1863 * @interface: alternate setting that includes all endpoints.
1864 * @eps: array of endpoints that need streams.
1865 * @num_eps: number of endpoints in the array.
1866 * @num_streams: number of streams to allocate.
1867 * @mem_flags: flags hcd should use to allocate memory.
1869 * Sets up a group of bulk endpoints to have num_streams stream IDs available.
1870 * Drivers may queue multiple transfers to different stream IDs, which may
1871 * complete in a different order than they were queued.
1873 int usb_alloc_streams(struct usb_interface *interface,
1874 struct usb_host_endpoint **eps, unsigned int num_eps,
1875 unsigned int num_streams, gfp_t mem_flags)
1877 struct usb_hcd *hcd;
1878 struct usb_device *dev;
1879 int i;
1881 dev = interface_to_usbdev(interface);
1882 hcd = bus_to_hcd(dev->bus);
1883 if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
1884 return -EINVAL;
1885 if (dev->speed != USB_SPEED_SUPER)
1886 return -EINVAL;
1888 /* Streams only apply to bulk endpoints. */
1889 for (i = 0; i < num_eps; i++)
1890 if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
1891 return -EINVAL;
1893 return hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
1894 num_streams, mem_flags);
1896 EXPORT_SYMBOL_GPL(usb_alloc_streams);
1899 * usb_free_streams - free bulk endpoint stream IDs.
1900 * @interface: alternate setting that includes all endpoints.
1901 * @eps: array of endpoints to remove streams from.
1902 * @num_eps: number of endpoints in the array.
1903 * @mem_flags: flags hcd should use to allocate memory.
1905 * Reverts a group of bulk endpoints back to not using stream IDs.
1906 * Can fail if we are given bad arguments, or HCD is broken.
1908 void usb_free_streams(struct usb_interface *interface,
1909 struct usb_host_endpoint **eps, unsigned int num_eps,
1910 gfp_t mem_flags)
1912 struct usb_hcd *hcd;
1913 struct usb_device *dev;
1914 int i;
1916 dev = interface_to_usbdev(interface);
1917 hcd = bus_to_hcd(dev->bus);
1918 if (dev->speed != USB_SPEED_SUPER)
1919 return;
1921 /* Streams only apply to bulk endpoints. */
1922 for (i = 0; i < num_eps; i++)
1923 if (!eps[i] || !usb_endpoint_xfer_bulk(&eps[i]->desc))
1924 return;
1926 hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
1928 EXPORT_SYMBOL_GPL(usb_free_streams);
1930 /* Protect against drivers that try to unlink URBs after the device
1931 * is gone, by waiting until all unlinks for @udev are finished.
1932 * Since we don't currently track URBs by device, simply wait until
1933 * nothing is running in the locked region of usb_hcd_unlink_urb().
1935 void usb_hcd_synchronize_unlinks(struct usb_device *udev)
1937 spin_lock_irq(&hcd_urb_unlink_lock);
1938 spin_unlock_irq(&hcd_urb_unlink_lock);
1941 /*-------------------------------------------------------------------------*/
1943 /* called in any context */
1944 int usb_hcd_get_frame_number (struct usb_device *udev)
1946 struct usb_hcd *hcd = bus_to_hcd(udev->bus);
1948 if (!HCD_RH_RUNNING(hcd))
1949 return -ESHUTDOWN;
1950 return hcd->driver->get_frame_number (hcd);
1953 /*-------------------------------------------------------------------------*/
1955 #ifdef CONFIG_PM
1957 int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
1959 struct usb_hcd *hcd = container_of(rhdev->bus, struct usb_hcd, self);
1960 int status;
1961 int old_state = hcd->state;
1963 dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
1964 (PMSG_IS_AUTO(msg) ? "auto-" : ""),
1965 rhdev->do_remote_wakeup);
1966 if (HCD_DEAD(hcd)) {
1967 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
1968 return 0;
1971 if (!hcd->driver->bus_suspend) {
1972 status = -ENOENT;
1973 } else {
1974 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
1975 hcd->state = HC_STATE_QUIESCING;
1976 status = hcd->driver->bus_suspend(hcd);
1978 if (status == 0) {
1979 usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
1980 hcd->state = HC_STATE_SUSPENDED;
1981 } else {
1982 spin_lock_irq(&hcd_root_hub_lock);
1983 if (!HCD_DEAD(hcd)) {
1984 set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
1985 hcd->state = old_state;
1987 spin_unlock_irq(&hcd_root_hub_lock);
1988 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
1989 "suspend", status);
1991 return status;
1994 int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
1996 struct usb_hcd *hcd = container_of(rhdev->bus, struct usb_hcd, self);
1997 int status;
1998 int old_state = hcd->state;
2000 dev_dbg(&rhdev->dev, "usb %sresume\n",
2001 (PMSG_IS_AUTO(msg) ? "auto-" : ""));
2002 if (HCD_DEAD(hcd)) {
2003 dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
2004 return 0;
2006 if (!hcd->driver->bus_resume)
2007 return -ENOENT;
2008 if (HCD_RH_RUNNING(hcd))
2009 return 0;
2011 hcd->state = HC_STATE_RESUMING;
2012 status = hcd->driver->bus_resume(hcd);
2013 clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2014 if (status == 0) {
2015 /* TRSMRCY = 10 msec */
2016 msleep(10);
2017 spin_lock_irq(&hcd_root_hub_lock);
2018 if (!HCD_DEAD(hcd)) {
2019 usb_set_device_state(rhdev, rhdev->actconfig
2020 ? USB_STATE_CONFIGURED
2021 : USB_STATE_ADDRESS);
2022 set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2023 hcd->state = HC_STATE_RUNNING;
2025 spin_unlock_irq(&hcd_root_hub_lock);
2026 } else {
2027 hcd->state = old_state;
2028 dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
2029 "resume", status);
2030 if (status != -ESHUTDOWN)
2031 usb_hc_died(hcd);
2033 return status;
2036 #endif /* CONFIG_PM */
2038 #ifdef CONFIG_USB_SUSPEND
2040 /* Workqueue routine for root-hub remote wakeup */
2041 static void hcd_resume_work(struct work_struct *work)
2043 struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
2044 struct usb_device *udev = hcd->self.root_hub;
2046 usb_lock_device(udev);
2047 usb_remote_wakeup(udev);
2048 usb_unlock_device(udev);
2052 * usb_hcd_resume_root_hub - called by HCD to resume its root hub
2053 * @hcd: host controller for this root hub
2055 * The USB host controller calls this function when its root hub is
2056 * suspended (with the remote wakeup feature enabled) and a remote
2057 * wakeup request is received. The routine submits a workqueue request
2058 * to resume the root hub (that is, manage its downstream ports again).
2060 void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
2062 unsigned long flags;
2064 spin_lock_irqsave (&hcd_root_hub_lock, flags);
2065 if (hcd->rh_registered) {
2066 set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
2067 queue_work(pm_wq, &hcd->wakeup_work);
2069 spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2071 EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
2073 #endif /* CONFIG_USB_SUSPEND */
2075 /*-------------------------------------------------------------------------*/
2077 #ifdef CONFIG_USB_OTG
2080 * usb_bus_start_enum - start immediate enumeration (for OTG)
2081 * @bus: the bus (must use hcd framework)
2082 * @port_num: 1-based number of port; usually bus->otg_port
2083 * Context: in_interrupt()
2085 * Starts enumeration, with an immediate reset followed later by
2086 * khubd identifying and possibly configuring the device.
2087 * This is needed by OTG controller drivers, where it helps meet
2088 * HNP protocol timing requirements for starting a port reset.
2090 int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
2092 struct usb_hcd *hcd;
2093 int status = -EOPNOTSUPP;
2095 /* NOTE: since HNP can't start by grabbing the bus's address0_sem,
2096 * boards with root hubs hooked up to internal devices (instead of
2097 * just the OTG port) may need more attention to resetting...
2099 hcd = container_of (bus, struct usb_hcd, self);
2100 if (port_num && hcd->driver->start_port_reset)
2101 status = hcd->driver->start_port_reset(hcd, port_num);
2103 /* run khubd shortly after (first) root port reset finishes;
2104 * it may issue others, until at least 50 msecs have passed.
2106 if (status == 0)
2107 mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
2108 return status;
2110 EXPORT_SYMBOL_GPL(usb_bus_start_enum);
2112 #endif
2114 /*-------------------------------------------------------------------------*/
2117 * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
2118 * @irq: the IRQ being raised
2119 * @__hcd: pointer to the HCD whose IRQ is being signaled
2121 * If the controller isn't HALTed, calls the driver's irq handler.
2122 * Checks whether the controller is now dead.
2124 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
2126 struct usb_hcd *hcd = __hcd;
2127 unsigned long flags;
2128 irqreturn_t rc;
2130 /* IRQF_DISABLED doesn't work correctly with shared IRQs
2131 * when the first handler doesn't use it. So let's just
2132 * assume it's never used.
2134 local_irq_save(flags);
2136 if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
2137 rc = IRQ_NONE;
2138 else if (hcd->driver->irq(hcd) == IRQ_NONE)
2139 rc = IRQ_NONE;
2140 else
2141 rc = IRQ_HANDLED;
2143 local_irq_restore(flags);
2144 return rc;
2146 EXPORT_SYMBOL_GPL(usb_hcd_irq);
2148 /*-------------------------------------------------------------------------*/
2151 * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
2152 * @hcd: pointer to the HCD representing the controller
2154 * This is called by bus glue to report a USB host controller that died
2155 * while operations may still have been pending. It's called automatically
2156 * by the PCI glue, so only glue for non-PCI busses should need to call it.
2158 * Only call this function with the primary HCD.
2160 void usb_hc_died (struct usb_hcd *hcd)
2162 unsigned long flags;
2164 dev_err (hcd->self.controller, "HC died; cleaning up\n");
2166 spin_lock_irqsave (&hcd_root_hub_lock, flags);
2167 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2168 set_bit(HCD_FLAG_DEAD, &hcd->flags);
2169 if (hcd->rh_registered) {
2170 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2172 /* make khubd clean up old urbs and devices */
2173 usb_set_device_state (hcd->self.root_hub,
2174 USB_STATE_NOTATTACHED);
2175 usb_kick_khubd (hcd->self.root_hub);
2177 if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
2178 hcd = hcd->shared_hcd;
2179 if (hcd->rh_registered) {
2180 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2182 /* make khubd clean up old urbs and devices */
2183 usb_set_device_state(hcd->self.root_hub,
2184 USB_STATE_NOTATTACHED);
2185 usb_kick_khubd(hcd->self.root_hub);
2188 spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
2189 /* Make sure that the other roothub is also deallocated. */
2191 EXPORT_SYMBOL_GPL (usb_hc_died);
2193 /*-------------------------------------------------------------------------*/
2196 * usb_create_shared_hcd - create and initialize an HCD structure
2197 * @driver: HC driver that will use this hcd
2198 * @dev: device for this HC, stored in hcd->self.controller
2199 * @bus_name: value to store in hcd->self.bus_name
2200 * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
2201 * PCI device. Only allocate certain resources for the primary HCD
2202 * Context: !in_interrupt()
2204 * Allocate a struct usb_hcd, with extra space at the end for the
2205 * HC driver's private data. Initialize the generic members of the
2206 * hcd structure.
2208 * If memory is unavailable, returns NULL.
2210 struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
2211 struct device *dev, const char *bus_name,
2212 struct usb_hcd *primary_hcd)
2214 struct usb_hcd *hcd;
2216 hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
2217 if (!hcd) {
2218 dev_dbg (dev, "hcd alloc failed\n");
2219 return NULL;
2221 if (primary_hcd == NULL) {
2222 hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
2223 GFP_KERNEL);
2224 if (!hcd->bandwidth_mutex) {
2225 kfree(hcd);
2226 dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
2227 return NULL;
2229 mutex_init(hcd->bandwidth_mutex);
2230 dev_set_drvdata(dev, hcd);
2231 } else {
2232 hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
2233 hcd->primary_hcd = primary_hcd;
2234 primary_hcd->primary_hcd = primary_hcd;
2235 hcd->shared_hcd = primary_hcd;
2236 primary_hcd->shared_hcd = hcd;
2239 kref_init(&hcd->kref);
2241 usb_bus_init(&hcd->self);
2242 hcd->self.controller = dev;
2243 hcd->self.bus_name = bus_name;
2244 hcd->self.uses_dma = (dev->dma_mask != NULL);
2246 init_timer(&hcd->rh_timer);
2247 hcd->rh_timer.function = rh_timer_func;
2248 hcd->rh_timer.data = (unsigned long) hcd;
2249 #ifdef CONFIG_USB_SUSPEND
2250 INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
2251 #endif
2253 hcd->driver = driver;
2254 hcd->speed = driver->flags & HCD_MASK;
2255 hcd->product_desc = (driver->product_desc) ? driver->product_desc :
2256 "USB Host Controller";
2257 return hcd;
2259 EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
2262 * usb_create_hcd - create and initialize an HCD structure
2263 * @driver: HC driver that will use this hcd
2264 * @dev: device for this HC, stored in hcd->self.controller
2265 * @bus_name: value to store in hcd->self.bus_name
2266 * Context: !in_interrupt()
2268 * Allocate a struct usb_hcd, with extra space at the end for the
2269 * HC driver's private data. Initialize the generic members of the
2270 * hcd structure.
2272 * If memory is unavailable, returns NULL.
2274 struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
2275 struct device *dev, const char *bus_name)
2277 return usb_create_shared_hcd(driver, dev, bus_name, NULL);
2279 EXPORT_SYMBOL_GPL(usb_create_hcd);
2282 * Roothubs that share one PCI device must also share the bandwidth mutex.
2283 * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
2284 * deallocated.
2286 * Make sure to only deallocate the bandwidth_mutex when the primary HCD is
2287 * freed. When hcd_release() is called for the non-primary HCD, set the
2288 * primary_hcd's shared_hcd pointer to null (since the non-primary HCD will be
2289 * freed shortly).
2291 static void hcd_release (struct kref *kref)
2293 struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
2295 if (usb_hcd_is_primary_hcd(hcd))
2296 kfree(hcd->bandwidth_mutex);
2297 else
2298 hcd->shared_hcd->shared_hcd = NULL;
2299 kfree(hcd);
2302 struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
2304 if (hcd)
2305 kref_get (&hcd->kref);
2306 return hcd;
2308 EXPORT_SYMBOL_GPL(usb_get_hcd);
2310 void usb_put_hcd (struct usb_hcd *hcd)
2312 if (hcd)
2313 kref_put (&hcd->kref, hcd_release);
2315 EXPORT_SYMBOL_GPL(usb_put_hcd);
2317 int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
2319 if (!hcd->primary_hcd)
2320 return 1;
2321 return hcd == hcd->primary_hcd;
2323 EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
2325 static int usb_hcd_request_irqs(struct usb_hcd *hcd,
2326 unsigned int irqnum, unsigned long irqflags)
2328 int retval;
2330 if (hcd->driver->irq) {
2332 /* IRQF_DISABLED doesn't work as advertised when used together
2333 * with IRQF_SHARED. As usb_hcd_irq() will always disable
2334 * interrupts we can remove it here.
2336 if (irqflags & IRQF_SHARED)
2337 irqflags &= ~IRQF_DISABLED;
2339 snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
2340 hcd->driver->description, hcd->self.busnum);
2341 retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
2342 hcd->irq_descr, hcd);
2343 if (retval != 0) {
2344 dev_err(hcd->self.controller,
2345 "request interrupt %d failed\n",
2346 irqnum);
2347 return retval;
2349 hcd->irq = irqnum;
2350 dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
2351 (hcd->driver->flags & HCD_MEMORY) ?
2352 "io mem" : "io base",
2353 (unsigned long long)hcd->rsrc_start);
2354 } else {
2355 hcd->irq = -1;
2356 if (hcd->rsrc_start)
2357 dev_info(hcd->self.controller, "%s 0x%08llx\n",
2358 (hcd->driver->flags & HCD_MEMORY) ?
2359 "io mem" : "io base",
2360 (unsigned long long)hcd->rsrc_start);
2362 return 0;
2366 * usb_add_hcd - finish generic HCD structure initialization and register
2367 * @hcd: the usb_hcd structure to initialize
2368 * @irqnum: Interrupt line to allocate
2369 * @irqflags: Interrupt type flags
2371 * Finish the remaining parts of generic HCD initialization: allocate the
2372 * buffers of consistent memory, register the bus, request the IRQ line,
2373 * and call the driver's reset() and start() routines.
2375 int usb_add_hcd(struct usb_hcd *hcd,
2376 unsigned int irqnum, unsigned long irqflags)
2378 int retval;
2379 struct usb_device *rhdev;
2381 dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
2383 /* Keep old behaviour if authorized_default is not in [0, 1]. */
2384 if (authorized_default < 0 || authorized_default > 1)
2385 hcd->authorized_default = hcd->wireless? 0 : 1;
2386 else
2387 hcd->authorized_default = authorized_default;
2388 set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
2390 /* HC is in reset state, but accessible. Now do the one-time init,
2391 * bottom up so that hcds can customize the root hubs before khubd
2392 * starts talking to them. (Note, bus id is assigned early too.)
2394 if ((retval = hcd_buffer_create(hcd)) != 0) {
2395 dev_dbg(hcd->self.controller, "pool alloc failed\n");
2396 return retval;
2399 if ((retval = usb_register_bus(&hcd->self)) < 0)
2400 goto err_register_bus;
2402 if ((rhdev = usb_alloc_dev(NULL, &hcd->self, 0)) == NULL) {
2403 dev_err(hcd->self.controller, "unable to allocate root hub\n");
2404 retval = -ENOMEM;
2405 goto err_allocate_root_hub;
2407 hcd->self.root_hub = rhdev;
2409 switch (hcd->speed) {
2410 case HCD_USB11:
2411 rhdev->speed = USB_SPEED_FULL;
2412 break;
2413 case HCD_USB2:
2414 rhdev->speed = USB_SPEED_HIGH;
2415 break;
2416 case HCD_USB3:
2417 rhdev->speed = USB_SPEED_SUPER;
2418 break;
2419 default:
2420 retval = -EINVAL;
2421 goto err_set_rh_speed;
2424 /* wakeup flag init defaults to "everything works" for root hubs,
2425 * but drivers can override it in reset() if needed, along with
2426 * recording the overall controller's system wakeup capability.
2428 device_set_wakeup_capable(&rhdev->dev, 1);
2430 /* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
2431 * registered. But since the controller can die at any time,
2432 * let's initialize the flag before touching the hardware.
2434 set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2436 /* "reset" is misnamed; its role is now one-time init. the controller
2437 * should already have been reset (and boot firmware kicked off etc).
2439 if (hcd->driver->reset && (retval = hcd->driver->reset(hcd)) < 0) {
2440 dev_err(hcd->self.controller, "can't setup\n");
2441 goto err_hcd_driver_setup;
2443 hcd->rh_pollable = 1;
2445 /* NOTE: root hub and controller capabilities may not be the same */
2446 if (device_can_wakeup(hcd->self.controller)
2447 && device_can_wakeup(&hcd->self.root_hub->dev))
2448 dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
2450 /* enable irqs just before we start the controller,
2451 * if the BIOS provides legacy PCI irqs.
2453 if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
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);
2481 * Host controllers don't generate their own wakeup requests;
2482 * they only forward requests from the root hub. Therefore
2483 * controllers should always be enabled for remote wakeup.
2485 device_wakeup_enable(hcd->self.controller);
2486 return retval;
2488 error_create_attr_group:
2489 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2490 if (HC_IS_RUNNING(hcd->state))
2491 hcd->state = HC_STATE_QUIESCING;
2492 spin_lock_irq(&hcd_root_hub_lock);
2493 hcd->rh_registered = 0;
2494 spin_unlock_irq(&hcd_root_hub_lock);
2496 #ifdef CONFIG_USB_SUSPEND
2497 cancel_work_sync(&hcd->wakeup_work);
2498 #endif
2499 mutex_lock(&usb_bus_list_lock);
2500 usb_disconnect(&rhdev); /* Sets rhdev to NULL */
2501 mutex_unlock(&usb_bus_list_lock);
2502 err_register_root_hub:
2503 hcd->rh_pollable = 0;
2504 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2505 del_timer_sync(&hcd->rh_timer);
2506 hcd->driver->stop(hcd);
2507 hcd->state = HC_STATE_HALT;
2508 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2509 del_timer_sync(&hcd->rh_timer);
2510 err_hcd_driver_start:
2511 if (usb_hcd_is_primary_hcd(hcd) && hcd->irq >= 0)
2512 free_irq(irqnum, hcd);
2513 err_request_irq:
2514 err_hcd_driver_setup:
2515 err_set_rh_speed:
2516 usb_put_dev(hcd->self.root_hub);
2517 err_allocate_root_hub:
2518 usb_deregister_bus(&hcd->self);
2519 err_register_bus:
2520 hcd_buffer_destroy(hcd);
2521 return retval;
2523 EXPORT_SYMBOL_GPL(usb_add_hcd);
2526 * usb_remove_hcd - shutdown processing for generic HCDs
2527 * @hcd: the usb_hcd structure to remove
2528 * Context: !in_interrupt()
2530 * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
2531 * invoking the HCD's stop() method.
2533 void usb_remove_hcd(struct usb_hcd *hcd)
2535 struct usb_device *rhdev = hcd->self.root_hub;
2537 dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
2539 usb_get_dev(rhdev);
2540 sysfs_remove_group(&rhdev->dev.kobj, &usb_bus_attr_group);
2542 clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
2543 if (HC_IS_RUNNING (hcd->state))
2544 hcd->state = HC_STATE_QUIESCING;
2546 dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
2547 spin_lock_irq (&hcd_root_hub_lock);
2548 hcd->rh_registered = 0;
2549 spin_unlock_irq (&hcd_root_hub_lock);
2551 #ifdef CONFIG_USB_SUSPEND
2552 cancel_work_sync(&hcd->wakeup_work);
2553 #endif
2555 mutex_lock(&usb_bus_list_lock);
2556 usb_disconnect(&rhdev); /* Sets rhdev to NULL */
2557 mutex_unlock(&usb_bus_list_lock);
2559 /* Prevent any more root-hub status calls from the timer.
2560 * The HCD might still restart the timer (if a port status change
2561 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
2562 * the hub_status_data() callback.
2564 hcd->rh_pollable = 0;
2565 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2566 del_timer_sync(&hcd->rh_timer);
2568 hcd->driver->stop(hcd);
2569 hcd->state = HC_STATE_HALT;
2571 /* In case the HCD restarted the timer, stop it again. */
2572 clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
2573 del_timer_sync(&hcd->rh_timer);
2575 if (usb_hcd_is_primary_hcd(hcd)) {
2576 if (hcd->irq >= 0)
2577 free_irq(hcd->irq, hcd);
2580 usb_put_dev(hcd->self.root_hub);
2581 usb_deregister_bus(&hcd->self);
2582 hcd_buffer_destroy(hcd);
2584 EXPORT_SYMBOL_GPL(usb_remove_hcd);
2586 void
2587 usb_hcd_platform_shutdown(struct platform_device* dev)
2589 struct usb_hcd *hcd = platform_get_drvdata(dev);
2591 if (hcd->driver->shutdown)
2592 hcd->driver->shutdown(hcd);
2594 EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
2596 /*-------------------------------------------------------------------------*/
2598 #if defined(CONFIG_USB_MON) || defined(CONFIG_USB_MON_MODULE)
2600 struct usb_mon_operations *mon_ops;
2603 * The registration is unlocked.
2604 * We do it this way because we do not want to lock in hot paths.
2606 * Notice that the code is minimally error-proof. Because usbmon needs
2607 * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
2610 int usb_mon_register (struct usb_mon_operations *ops)
2613 if (mon_ops)
2614 return -EBUSY;
2616 mon_ops = ops;
2617 mb();
2618 return 0;
2620 EXPORT_SYMBOL_GPL (usb_mon_register);
2622 void usb_mon_deregister (void)
2625 if (mon_ops == NULL) {
2626 printk(KERN_ERR "USB: monitor was not registered\n");
2627 return;
2629 mon_ops = NULL;
2630 mb();
2632 EXPORT_SYMBOL_GPL (usb_mon_deregister);
2634 #endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */