2 * message.c - synchronous message handling
5 #include <linux/pci.h> /* for scatterlist macros */
7 #include <linux/module.h>
8 #include <linux/slab.h>
9 #include <linux/init.h>
11 #include <linux/timer.h>
12 #include <linux/ctype.h>
13 #include <linux/nls.h>
14 #include <linux/device.h>
15 #include <linux/scatterlist.h>
16 #include <linux/usb/quirks.h>
17 #include <linux/usb/hcd.h> /* for usbcore internals */
18 #include <asm/byteorder.h>
22 static void cancel_async_set_config(struct usb_device
*udev
);
25 struct completion done
;
29 static void usb_api_blocking_completion(struct urb
*urb
)
31 struct api_context
*ctx
= urb
->context
;
33 ctx
->status
= urb
->status
;
39 * Starts urb and waits for completion or timeout. Note that this call
40 * is NOT interruptible. Many device driver i/o requests should be
41 * interruptible and therefore these drivers should implement their
42 * own interruptible routines.
44 static int usb_start_wait_urb(struct urb
*urb
, int timeout
, int *actual_length
)
46 struct api_context ctx
;
50 init_completion(&ctx
.done
);
52 urb
->actual_length
= 0;
53 retval
= usb_submit_urb(urb
, GFP_NOIO
);
57 expire
= timeout
? msecs_to_jiffies(timeout
) : MAX_SCHEDULE_TIMEOUT
;
58 if (!wait_for_completion_timeout(&ctx
.done
, expire
)) {
60 retval
= (ctx
.status
== -ENOENT
? -ETIMEDOUT
: ctx
.status
);
62 dev_dbg(&urb
->dev
->dev
,
63 "%s timed out on ep%d%s len=%u/%u\n",
65 usb_endpoint_num(&urb
->ep
->desc
),
66 usb_urb_dir_in(urb
) ? "in" : "out",
68 urb
->transfer_buffer_length
);
73 *actual_length
= urb
->actual_length
;
79 /*-------------------------------------------------------------------*/
80 /* returns status (negative) or length (positive) */
81 static int usb_internal_control_msg(struct usb_device
*usb_dev
,
83 struct usb_ctrlrequest
*cmd
,
84 void *data
, int len
, int timeout
)
90 urb
= usb_alloc_urb(0, GFP_NOIO
);
94 usb_fill_control_urb(urb
, usb_dev
, pipe
, (unsigned char *)cmd
, data
,
95 len
, usb_api_blocking_completion
, NULL
);
97 retv
= usb_start_wait_urb(urb
, timeout
, &length
);
105 * usb_control_msg - Builds a control urb, sends it off and waits for completion
106 * @dev: pointer to the usb device to send the message to
107 * @pipe: endpoint "pipe" to send the message to
108 * @request: USB message request value
109 * @requesttype: USB message request type value
110 * @value: USB message value
111 * @index: USB message index value
112 * @data: pointer to the data to send
113 * @size: length in bytes of the data to send
114 * @timeout: time in msecs to wait for the message to complete before timing
115 * out (if 0 the wait is forever)
117 * Context: !in_interrupt ()
119 * This function sends a simple control message to a specified endpoint and
120 * waits for the message to complete, or timeout.
122 * If successful, it returns the number of bytes transferred, otherwise a
123 * negative error number.
125 * Don't use this function from within an interrupt context, like a bottom half
126 * handler. If you need an asynchronous message, or need to send a message
127 * from within interrupt context, use usb_submit_urb().
128 * If a thread in your driver uses this call, make sure your disconnect()
129 * method can wait for it to complete. Since you don't have a handle on the
130 * URB used, you can't cancel the request.
132 int usb_control_msg(struct usb_device
*dev
, unsigned int pipe
, __u8 request
,
133 __u8 requesttype
, __u16 value
, __u16 index
, void *data
,
134 __u16 size
, int timeout
)
136 struct usb_ctrlrequest
*dr
;
139 dr
= kmalloc(sizeof(struct usb_ctrlrequest
), GFP_NOIO
);
143 dr
->bRequestType
= requesttype
;
144 dr
->bRequest
= request
;
145 dr
->wValue
= cpu_to_le16(value
);
146 dr
->wIndex
= cpu_to_le16(index
);
147 dr
->wLength
= cpu_to_le16(size
);
149 /* dbg("usb_control_msg"); */
151 ret
= usb_internal_control_msg(dev
, pipe
, dr
, data
, size
, timeout
);
157 EXPORT_SYMBOL_GPL(usb_control_msg
);
160 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
161 * @usb_dev: pointer to the usb device to send the message to
162 * @pipe: endpoint "pipe" to send the message to
163 * @data: pointer to the data to send
164 * @len: length in bytes of the data to send
165 * @actual_length: pointer to a location to put the actual length transferred
167 * @timeout: time in msecs to wait for the message to complete before
168 * timing out (if 0 the wait is forever)
170 * Context: !in_interrupt ()
172 * This function sends a simple interrupt message to a specified endpoint and
173 * waits for the message to complete, or timeout.
175 * If successful, it returns 0, otherwise a negative error number. The number
176 * of actual bytes transferred will be stored in the actual_length paramater.
178 * Don't use this function from within an interrupt context, like a bottom half
179 * handler. If you need an asynchronous message, or need to send a message
180 * from within interrupt context, use usb_submit_urb() If a thread in your
181 * driver uses this call, make sure your disconnect() method can wait for it to
182 * complete. Since you don't have a handle on the URB used, you can't cancel
185 int usb_interrupt_msg(struct usb_device
*usb_dev
, unsigned int pipe
,
186 void *data
, int len
, int *actual_length
, int timeout
)
188 return usb_bulk_msg(usb_dev
, pipe
, data
, len
, actual_length
, timeout
);
190 EXPORT_SYMBOL_GPL(usb_interrupt_msg
);
193 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
194 * @usb_dev: pointer to the usb device to send the message to
195 * @pipe: endpoint "pipe" to send the message to
196 * @data: pointer to the data to send
197 * @len: length in bytes of the data to send
198 * @actual_length: pointer to a location to put the actual length transferred
200 * @timeout: time in msecs to wait for the message to complete before
201 * timing out (if 0 the wait is forever)
203 * Context: !in_interrupt ()
205 * This function sends a simple bulk message to a specified endpoint
206 * and waits for the message to complete, or timeout.
208 * If successful, it returns 0, otherwise a negative error number. The number
209 * of actual bytes transferred will be stored in the actual_length paramater.
211 * Don't use this function from within an interrupt context, like a bottom half
212 * handler. If you need an asynchronous message, or need to send a message
213 * from within interrupt context, use usb_submit_urb() If a thread in your
214 * driver uses this call, make sure your disconnect() method can wait for it to
215 * complete. Since you don't have a handle on the URB used, you can't cancel
218 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
219 * users are forced to abuse this routine by using it to submit URBs for
220 * interrupt endpoints. We will take the liberty of creating an interrupt URB
221 * (with the default interval) if the target is an interrupt endpoint.
223 int usb_bulk_msg(struct usb_device
*usb_dev
, unsigned int pipe
,
224 void *data
, int len
, int *actual_length
, int timeout
)
227 struct usb_host_endpoint
*ep
;
229 ep
= usb_pipe_endpoint(usb_dev
, pipe
);
233 urb
= usb_alloc_urb(0, GFP_KERNEL
);
237 if ((ep
->desc
.bmAttributes
& USB_ENDPOINT_XFERTYPE_MASK
) ==
238 USB_ENDPOINT_XFER_INT
) {
239 pipe
= (pipe
& ~(3 << 30)) | (PIPE_INTERRUPT
<< 30);
240 usb_fill_int_urb(urb
, usb_dev
, pipe
, data
, len
,
241 usb_api_blocking_completion
, NULL
,
244 usb_fill_bulk_urb(urb
, usb_dev
, pipe
, data
, len
,
245 usb_api_blocking_completion
, NULL
);
247 return usb_start_wait_urb(urb
, timeout
, actual_length
);
249 EXPORT_SYMBOL_GPL(usb_bulk_msg
);
251 /*-------------------------------------------------------------------*/
253 static void sg_clean(struct usb_sg_request
*io
)
256 while (io
->entries
--)
257 usb_free_urb(io
->urbs
[io
->entries
]);
264 static void sg_complete(struct urb
*urb
)
266 struct usb_sg_request
*io
= urb
->context
;
267 int status
= urb
->status
;
269 spin_lock(&io
->lock
);
271 /* In 2.5 we require hcds' endpoint queues not to progress after fault
272 * reports, until the completion callback (this!) returns. That lets
273 * device driver code (like this routine) unlink queued urbs first,
274 * if it needs to, since the HC won't work on them at all. So it's
275 * not possible for page N+1 to overwrite page N, and so on.
277 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
278 * complete before the HCD can get requests away from hardware,
279 * though never during cleanup after a hard fault.
282 && (io
->status
!= -ECONNRESET
283 || status
!= -ECONNRESET
)
284 && urb
->actual_length
) {
285 dev_err(io
->dev
->bus
->controller
,
286 "dev %s ep%d%s scatterlist error %d/%d\n",
288 usb_endpoint_num(&urb
->ep
->desc
),
289 usb_urb_dir_in(urb
) ? "in" : "out",
294 if (io
->status
== 0 && status
&& status
!= -ECONNRESET
) {
295 int i
, found
, retval
;
299 /* the previous urbs, and this one, completed already.
300 * unlink pending urbs so they won't rx/tx bad data.
301 * careful: unlink can sometimes be synchronous...
303 spin_unlock(&io
->lock
);
304 for (i
= 0, found
= 0; i
< io
->entries
; i
++) {
305 if (!io
->urbs
[i
] || !io
->urbs
[i
]->dev
)
308 retval
= usb_unlink_urb(io
->urbs
[i
]);
309 if (retval
!= -EINPROGRESS
&&
312 dev_err(&io
->dev
->dev
,
313 "%s, unlink --> %d\n",
315 } else if (urb
== io
->urbs
[i
])
318 spin_lock(&io
->lock
);
322 /* on the last completion, signal usb_sg_wait() */
323 io
->bytes
+= urb
->actual_length
;
326 complete(&io
->complete
);
328 spin_unlock(&io
->lock
);
333 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
334 * @io: request block being initialized. until usb_sg_wait() returns,
335 * treat this as a pointer to an opaque block of memory,
336 * @dev: the usb device that will send or receive the data
337 * @pipe: endpoint "pipe" used to transfer the data
338 * @period: polling rate for interrupt endpoints, in frames or
339 * (for high speed endpoints) microframes; ignored for bulk
340 * @sg: scatterlist entries
341 * @nents: how many entries in the scatterlist
342 * @length: how many bytes to send from the scatterlist, or zero to
343 * send every byte identified in the list.
344 * @mem_flags: SLAB_* flags affecting memory allocations in this call
346 * Returns zero for success, else a negative errno value. This initializes a
347 * scatter/gather request, allocating resources such as I/O mappings and urb
348 * memory (except maybe memory used by USB controller drivers).
350 * The request must be issued using usb_sg_wait(), which waits for the I/O to
351 * complete (or to be canceled) and then cleans up all resources allocated by
354 * The request may be canceled with usb_sg_cancel(), either before or after
355 * usb_sg_wait() is called.
357 int usb_sg_init(struct usb_sg_request
*io
, struct usb_device
*dev
,
358 unsigned pipe
, unsigned period
, struct scatterlist
*sg
,
359 int nents
, size_t length
, gfp_t mem_flags
)
365 if (!io
|| !dev
|| !sg
366 || usb_pipecontrol(pipe
)
367 || usb_pipeisoc(pipe
)
371 spin_lock_init(&io
->lock
);
375 if (dev
->bus
->sg_tablesize
> 0) {
383 /* initialize all the urbs we'll use */
384 io
->urbs
= kmalloc(io
->entries
* sizeof *io
->urbs
, mem_flags
);
388 urb_flags
= URB_NO_INTERRUPT
;
389 if (usb_pipein(pipe
))
390 urb_flags
|= URB_SHORT_NOT_OK
;
392 for_each_sg(sg
, sg
, io
->entries
, i
) {
396 urb
= usb_alloc_urb(0, mem_flags
);
405 urb
->interval
= period
;
406 urb
->transfer_flags
= urb_flags
;
407 urb
->complete
= sg_complete
;
412 /* There is no single transfer buffer */
413 urb
->transfer_buffer
= NULL
;
414 urb
->num_sgs
= nents
;
416 /* A length of zero means transfer the whole sg list */
419 struct scatterlist
*sg2
;
422 for_each_sg(sg
, sg2
, nents
, j
)
427 * Some systems can't use DMA; they use PIO instead.
428 * For their sakes, transfer_buffer is set whenever
431 if (!PageHighMem(sg_page(sg
)))
432 urb
->transfer_buffer
= sg_virt(sg
);
434 urb
->transfer_buffer
= NULL
;
438 len
= min_t(unsigned, len
, length
);
444 urb
->transfer_buffer_length
= len
;
446 io
->urbs
[--i
]->transfer_flags
&= ~URB_NO_INTERRUPT
;
448 /* transaction state */
449 io
->count
= io
->entries
;
452 init_completion(&io
->complete
);
459 EXPORT_SYMBOL_GPL(usb_sg_init
);
462 * usb_sg_wait - synchronously execute scatter/gather request
463 * @io: request block handle, as initialized with usb_sg_init().
464 * some fields become accessible when this call returns.
465 * Context: !in_interrupt ()
467 * This function blocks until the specified I/O operation completes. It
468 * leverages the grouping of the related I/O requests to get good transfer
469 * rates, by queueing the requests. At higher speeds, such queuing can
470 * significantly improve USB throughput.
472 * There are three kinds of completion for this function.
473 * (1) success, where io->status is zero. The number of io->bytes
474 * transferred is as requested.
475 * (2) error, where io->status is a negative errno value. The number
476 * of io->bytes transferred before the error is usually less
477 * than requested, and can be nonzero.
478 * (3) cancellation, a type of error with status -ECONNRESET that
479 * is initiated by usb_sg_cancel().
481 * When this function returns, all memory allocated through usb_sg_init() or
482 * this call will have been freed. The request block parameter may still be
483 * passed to usb_sg_cancel(), or it may be freed. It could also be
484 * reinitialized and then reused.
486 * Data Transfer Rates:
488 * Bulk transfers are valid for full or high speed endpoints.
489 * The best full speed data rate is 19 packets of 64 bytes each
490 * per frame, or 1216 bytes per millisecond.
491 * The best high speed data rate is 13 packets of 512 bytes each
492 * per microframe, or 52 KBytes per millisecond.
494 * The reason to use interrupt transfers through this API would most likely
495 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
496 * could be transferred. That capability is less useful for low or full
497 * speed interrupt endpoints, which allow at most one packet per millisecond,
498 * of at most 8 or 64 bytes (respectively).
500 * It is not necessary to call this function to reserve bandwidth for devices
501 * under an xHCI host controller, as the bandwidth is reserved when the
502 * configuration or interface alt setting is selected.
504 void usb_sg_wait(struct usb_sg_request
*io
)
507 int entries
= io
->entries
;
509 /* queue the urbs. */
510 spin_lock_irq(&io
->lock
);
512 while (i
< entries
&& !io
->status
) {
515 io
->urbs
[i
]->dev
= io
->dev
;
516 retval
= usb_submit_urb(io
->urbs
[i
], GFP_ATOMIC
);
518 /* after we submit, let completions or cancelations fire;
519 * we handshake using io->status.
521 spin_unlock_irq(&io
->lock
);
523 /* maybe we retrying will recover */
524 case -ENXIO
: /* hc didn't queue this one */
527 io
->urbs
[i
]->dev
= NULL
;
532 /* no error? continue immediately.
534 * NOTE: to work better with UHCI (4K I/O buffer may
535 * need 3K of TDs) it may be good to limit how many
536 * URBs are queued at once; N milliseconds?
543 /* fail any uncompleted urbs */
545 io
->urbs
[i
]->dev
= NULL
;
546 io
->urbs
[i
]->status
= retval
;
547 dev_dbg(&io
->dev
->dev
, "%s, submit --> %d\n",
551 spin_lock_irq(&io
->lock
);
552 if (retval
&& (io
->status
== 0 || io
->status
== -ECONNRESET
))
555 io
->count
-= entries
- i
;
557 complete(&io
->complete
);
558 spin_unlock_irq(&io
->lock
);
560 /* OK, yes, this could be packaged as non-blocking.
561 * So could the submit loop above ... but it's easier to
562 * solve neither problem than to solve both!
564 wait_for_completion(&io
->complete
);
568 EXPORT_SYMBOL_GPL(usb_sg_wait
);
571 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
572 * @io: request block, initialized with usb_sg_init()
574 * This stops a request after it has been started by usb_sg_wait().
575 * It can also prevents one initialized by usb_sg_init() from starting,
576 * so that call just frees resources allocated to the request.
578 void usb_sg_cancel(struct usb_sg_request
*io
)
582 spin_lock_irqsave(&io
->lock
, flags
);
584 /* shut everything down, if it didn't already */
588 io
->status
= -ECONNRESET
;
589 spin_unlock(&io
->lock
);
590 for (i
= 0; i
< io
->entries
; i
++) {
593 if (!io
->urbs
[i
]->dev
)
595 retval
= usb_unlink_urb(io
->urbs
[i
]);
596 if (retval
!= -EINPROGRESS
&& retval
!= -EBUSY
)
597 dev_warn(&io
->dev
->dev
, "%s, unlink --> %d\n",
600 spin_lock(&io
->lock
);
602 spin_unlock_irqrestore(&io
->lock
, flags
);
604 EXPORT_SYMBOL_GPL(usb_sg_cancel
);
606 /*-------------------------------------------------------------------*/
609 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
610 * @dev: the device whose descriptor is being retrieved
611 * @type: the descriptor type (USB_DT_*)
612 * @index: the number of the descriptor
613 * @buf: where to put the descriptor
614 * @size: how big is "buf"?
615 * Context: !in_interrupt ()
617 * Gets a USB descriptor. Convenience functions exist to simplify
618 * getting some types of descriptors. Use
619 * usb_get_string() or usb_string() for USB_DT_STRING.
620 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
621 * are part of the device structure.
622 * In addition to a number of USB-standard descriptors, some
623 * devices also use class-specific or vendor-specific descriptors.
625 * This call is synchronous, and may not be used in an interrupt context.
627 * Returns the number of bytes received on success, or else the status code
628 * returned by the underlying usb_control_msg() call.
630 int usb_get_descriptor(struct usb_device
*dev
, unsigned char type
,
631 unsigned char index
, void *buf
, int size
)
636 memset(buf
, 0, size
); /* Make sure we parse really received data */
638 for (i
= 0; i
< 3; ++i
) {
639 /* retry on length 0 or error; some devices are flakey */
640 result
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
641 USB_REQ_GET_DESCRIPTOR
, USB_DIR_IN
,
642 (type
<< 8) + index
, 0, buf
, size
,
643 USB_CTRL_GET_TIMEOUT
);
644 if (result
<= 0 && result
!= -ETIMEDOUT
)
646 if (result
> 1 && ((u8
*)buf
)[1] != type
) {
654 EXPORT_SYMBOL_GPL(usb_get_descriptor
);
657 * usb_get_string - gets a string descriptor
658 * @dev: the device whose string descriptor is being retrieved
659 * @langid: code for language chosen (from string descriptor zero)
660 * @index: the number of the descriptor
661 * @buf: where to put the string
662 * @size: how big is "buf"?
663 * Context: !in_interrupt ()
665 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
666 * in little-endian byte order).
667 * The usb_string() function will often be a convenient way to turn
668 * these strings into kernel-printable form.
670 * Strings may be referenced in device, configuration, interface, or other
671 * descriptors, and could also be used in vendor-specific ways.
673 * This call is synchronous, and may not be used in an interrupt context.
675 * Returns the number of bytes received on success, or else the status code
676 * returned by the underlying usb_control_msg() call.
678 static int usb_get_string(struct usb_device
*dev
, unsigned short langid
,
679 unsigned char index
, void *buf
, int size
)
684 for (i
= 0; i
< 3; ++i
) {
685 /* retry on length 0 or stall; some devices are flakey */
686 result
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
687 USB_REQ_GET_DESCRIPTOR
, USB_DIR_IN
,
688 (USB_DT_STRING
<< 8) + index
, langid
, buf
, size
,
689 USB_CTRL_GET_TIMEOUT
);
690 if (result
== 0 || result
== -EPIPE
)
692 if (result
> 1 && ((u8
*) buf
)[1] != USB_DT_STRING
) {
701 static void usb_try_string_workarounds(unsigned char *buf
, int *length
)
703 int newlength
, oldlength
= *length
;
705 for (newlength
= 2; newlength
+ 1 < oldlength
; newlength
+= 2)
706 if (!isprint(buf
[newlength
]) || buf
[newlength
+ 1])
715 static int usb_string_sub(struct usb_device
*dev
, unsigned int langid
,
716 unsigned int index
, unsigned char *buf
)
720 /* Try to read the string descriptor by asking for the maximum
721 * possible number of bytes */
722 if (dev
->quirks
& USB_QUIRK_STRING_FETCH_255
)
725 rc
= usb_get_string(dev
, langid
, index
, buf
, 255);
727 /* If that failed try to read the descriptor length, then
728 * ask for just that many bytes */
730 rc
= usb_get_string(dev
, langid
, index
, buf
, 2);
732 rc
= usb_get_string(dev
, langid
, index
, buf
, buf
[0]);
736 if (!buf
[0] && !buf
[1])
737 usb_try_string_workarounds(buf
, &rc
);
739 /* There might be extra junk at the end of the descriptor */
743 rc
= rc
- (rc
& 1); /* force a multiple of two */
747 rc
= (rc
< 0 ? rc
: -EINVAL
);
752 static int usb_get_langid(struct usb_device
*dev
, unsigned char *tbuf
)
756 if (dev
->have_langid
)
759 if (dev
->string_langid
< 0)
762 err
= usb_string_sub(dev
, 0, 0, tbuf
);
764 /* If the string was reported but is malformed, default to english
766 if (err
== -ENODATA
|| (err
> 0 && err
< 4)) {
767 dev
->string_langid
= 0x0409;
768 dev
->have_langid
= 1;
770 "string descriptor 0 malformed (err = %d), "
771 "defaulting to 0x%04x\n",
772 err
, dev
->string_langid
);
776 /* In case of all other errors, we assume the device is not able to
777 * deal with strings at all. Set string_langid to -1 in order to
778 * prevent any string to be retrieved from the device */
780 dev_err(&dev
->dev
, "string descriptor 0 read error: %d\n",
782 dev
->string_langid
= -1;
786 /* always use the first langid listed */
787 dev
->string_langid
= tbuf
[2] | (tbuf
[3] << 8);
788 dev
->have_langid
= 1;
789 dev_dbg(&dev
->dev
, "default language 0x%04x\n",
795 * usb_string - returns UTF-8 version of a string descriptor
796 * @dev: the device whose string descriptor is being retrieved
797 * @index: the number of the descriptor
798 * @buf: where to put the string
799 * @size: how big is "buf"?
800 * Context: !in_interrupt ()
802 * This converts the UTF-16LE encoded strings returned by devices, from
803 * usb_get_string_descriptor(), to null-terminated UTF-8 encoded ones
804 * that are more usable in most kernel contexts. Note that this function
805 * chooses strings in the first language supported by the device.
807 * This call is synchronous, and may not be used in an interrupt context.
809 * Returns length of the string (>= 0) or usb_control_msg status (< 0).
811 int usb_string(struct usb_device
*dev
, int index
, char *buf
, size_t size
)
816 if (dev
->state
== USB_STATE_SUSPENDED
)
817 return -EHOSTUNREACH
;
818 if (size
<= 0 || !buf
|| !index
)
821 tbuf
= kmalloc(256, GFP_NOIO
);
825 err
= usb_get_langid(dev
, tbuf
);
829 err
= usb_string_sub(dev
, dev
->string_langid
, index
, tbuf
);
833 size
--; /* leave room for trailing NULL char in output buffer */
834 err
= utf16s_to_utf8s((wchar_t *) &tbuf
[2], (err
- 2) / 2,
835 UTF16_LITTLE_ENDIAN
, buf
, size
);
838 if (tbuf
[1] != USB_DT_STRING
)
840 "wrong descriptor type %02x for string %d (\"%s\")\n",
841 tbuf
[1], index
, buf
);
847 EXPORT_SYMBOL_GPL(usb_string
);
849 /* one UTF-8-encoded 16-bit character has at most three bytes */
850 #define MAX_USB_STRING_SIZE (127 * 3 + 1)
853 * usb_cache_string - read a string descriptor and cache it for later use
854 * @udev: the device whose string descriptor is being read
855 * @index: the descriptor index
857 * Returns a pointer to a kmalloc'ed buffer containing the descriptor string,
858 * or NULL if the index is 0 or the string could not be read.
860 char *usb_cache_string(struct usb_device
*udev
, int index
)
863 char *smallbuf
= NULL
;
869 buf
= kmalloc(MAX_USB_STRING_SIZE
, GFP_NOIO
);
871 len
= usb_string(udev
, index
, buf
, MAX_USB_STRING_SIZE
);
873 smallbuf
= kmalloc(++len
, GFP_NOIO
);
876 memcpy(smallbuf
, buf
, len
);
884 * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
885 * @dev: the device whose device descriptor is being updated
886 * @size: how much of the descriptor to read
887 * Context: !in_interrupt ()
889 * Updates the copy of the device descriptor stored in the device structure,
890 * which dedicates space for this purpose.
892 * Not exported, only for use by the core. If drivers really want to read
893 * the device descriptor directly, they can call usb_get_descriptor() with
894 * type = USB_DT_DEVICE and index = 0.
896 * This call is synchronous, and may not be used in an interrupt context.
898 * Returns the number of bytes received on success, or else the status code
899 * returned by the underlying usb_control_msg() call.
901 int usb_get_device_descriptor(struct usb_device
*dev
, unsigned int size
)
903 struct usb_device_descriptor
*desc
;
906 if (size
> sizeof(*desc
))
908 desc
= kmalloc(sizeof(*desc
), GFP_NOIO
);
912 ret
= usb_get_descriptor(dev
, USB_DT_DEVICE
, 0, desc
, size
);
914 memcpy(&dev
->descriptor
, desc
, size
);
920 * usb_get_status - issues a GET_STATUS call
921 * @dev: the device whose status is being checked
922 * @type: USB_RECIP_*; for device, interface, or endpoint
923 * @target: zero (for device), else interface or endpoint number
924 * @data: pointer to two bytes of bitmap data
925 * Context: !in_interrupt ()
927 * Returns device, interface, or endpoint status. Normally only of
928 * interest to see if the device is self powered, or has enabled the
929 * remote wakeup facility; or whether a bulk or interrupt endpoint
930 * is halted ("stalled").
932 * Bits in these status bitmaps are set using the SET_FEATURE request,
933 * and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
934 * function should be used to clear halt ("stall") status.
936 * This call is synchronous, and may not be used in an interrupt context.
938 * Returns the number of bytes received on success, or else the status code
939 * returned by the underlying usb_control_msg() call.
941 int usb_get_status(struct usb_device
*dev
, int type
, int target
, void *data
)
944 u16
*status
= kmalloc(sizeof(*status
), GFP_KERNEL
);
949 ret
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
950 USB_REQ_GET_STATUS
, USB_DIR_IN
| type
, 0, target
, status
,
951 sizeof(*status
), USB_CTRL_GET_TIMEOUT
);
953 *(u16
*)data
= *status
;
957 EXPORT_SYMBOL_GPL(usb_get_status
);
960 * usb_clear_halt - tells device to clear endpoint halt/stall condition
961 * @dev: device whose endpoint is halted
962 * @pipe: endpoint "pipe" being cleared
963 * Context: !in_interrupt ()
965 * This is used to clear halt conditions for bulk and interrupt endpoints,
966 * as reported by URB completion status. Endpoints that are halted are
967 * sometimes referred to as being "stalled". Such endpoints are unable
968 * to transmit or receive data until the halt status is cleared. Any URBs
969 * queued for such an endpoint should normally be unlinked by the driver
970 * before clearing the halt condition, as described in sections 5.7.5
971 * and 5.8.5 of the USB 2.0 spec.
973 * Note that control and isochronous endpoints don't halt, although control
974 * endpoints report "protocol stall" (for unsupported requests) using the
975 * same status code used to report a true stall.
977 * This call is synchronous, and may not be used in an interrupt context.
979 * Returns zero on success, or else the status code returned by the
980 * underlying usb_control_msg() call.
982 int usb_clear_halt(struct usb_device
*dev
, int pipe
)
985 int endp
= usb_pipeendpoint(pipe
);
987 if (usb_pipein(pipe
))
990 /* we don't care if it wasn't halted first. in fact some devices
991 * (like some ibmcam model 1 units) seem to expect hosts to make
992 * this request for iso endpoints, which can't halt!
994 result
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
995 USB_REQ_CLEAR_FEATURE
, USB_RECIP_ENDPOINT
,
996 USB_ENDPOINT_HALT
, endp
, NULL
, 0,
997 USB_CTRL_SET_TIMEOUT
);
999 /* don't un-halt or force to DATA0 except on success */
1003 /* NOTE: seems like Microsoft and Apple don't bother verifying
1004 * the clear "took", so some devices could lock up if you check...
1005 * such as the Hagiwara FlashGate DUAL. So we won't bother.
1007 * NOTE: make sure the logic here doesn't diverge much from
1008 * the copy in usb-storage, for as long as we need two copies.
1011 usb_reset_endpoint(dev
, endp
);
1015 EXPORT_SYMBOL_GPL(usb_clear_halt
);
1017 static int create_intf_ep_devs(struct usb_interface
*intf
)
1019 struct usb_device
*udev
= interface_to_usbdev(intf
);
1020 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1023 if (intf
->ep_devs_created
|| intf
->unregistering
)
1026 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
)
1027 (void) usb_create_ep_devs(&intf
->dev
, &alt
->endpoint
[i
], udev
);
1028 intf
->ep_devs_created
= 1;
1032 static void remove_intf_ep_devs(struct usb_interface
*intf
)
1034 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1037 if (!intf
->ep_devs_created
)
1040 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
)
1041 usb_remove_ep_devs(&alt
->endpoint
[i
]);
1042 intf
->ep_devs_created
= 0;
1046 * usb_disable_endpoint -- Disable an endpoint by address
1047 * @dev: the device whose endpoint is being disabled
1048 * @epaddr: the endpoint's address. Endpoint number for output,
1049 * endpoint number + USB_DIR_IN for input
1050 * @reset_hardware: flag to erase any endpoint state stored in the
1051 * controller hardware
1053 * Disables the endpoint for URB submission and nukes all pending URBs.
1054 * If @reset_hardware is set then also deallocates hcd/hardware state
1057 void usb_disable_endpoint(struct usb_device
*dev
, unsigned int epaddr
,
1058 bool reset_hardware
)
1060 unsigned int epnum
= epaddr
& USB_ENDPOINT_NUMBER_MASK
;
1061 struct usb_host_endpoint
*ep
;
1066 if (usb_endpoint_out(epaddr
)) {
1067 ep
= dev
->ep_out
[epnum
];
1069 dev
->ep_out
[epnum
] = NULL
;
1071 ep
= dev
->ep_in
[epnum
];
1073 dev
->ep_in
[epnum
] = NULL
;
1077 usb_hcd_flush_endpoint(dev
, ep
);
1079 usb_hcd_disable_endpoint(dev
, ep
);
1084 * usb_reset_endpoint - Reset an endpoint's state.
1085 * @dev: the device whose endpoint is to be reset
1086 * @epaddr: the endpoint's address. Endpoint number for output,
1087 * endpoint number + USB_DIR_IN for input
1089 * Resets any host-side endpoint state such as the toggle bit,
1090 * sequence number or current window.
1092 void usb_reset_endpoint(struct usb_device
*dev
, unsigned int epaddr
)
1094 unsigned int epnum
= epaddr
& USB_ENDPOINT_NUMBER_MASK
;
1095 struct usb_host_endpoint
*ep
;
1097 if (usb_endpoint_out(epaddr
))
1098 ep
= dev
->ep_out
[epnum
];
1100 ep
= dev
->ep_in
[epnum
];
1102 usb_hcd_reset_endpoint(dev
, ep
);
1104 EXPORT_SYMBOL_GPL(usb_reset_endpoint
);
1108 * usb_disable_interface -- Disable all endpoints for an interface
1109 * @dev: the device whose interface is being disabled
1110 * @intf: pointer to the interface descriptor
1111 * @reset_hardware: flag to erase any endpoint state stored in the
1112 * controller hardware
1114 * Disables all the endpoints for the interface's current altsetting.
1116 void usb_disable_interface(struct usb_device
*dev
, struct usb_interface
*intf
,
1117 bool reset_hardware
)
1119 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1122 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
) {
1123 usb_disable_endpoint(dev
,
1124 alt
->endpoint
[i
].desc
.bEndpointAddress
,
1130 * usb_disable_device - Disable all the endpoints for a USB device
1131 * @dev: the device whose endpoints are being disabled
1132 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1134 * Disables all the device's endpoints, potentially including endpoint 0.
1135 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1136 * pending urbs) and usbcore state for the interfaces, so that usbcore
1137 * must usb_set_configuration() before any interfaces could be used.
1139 * Must be called with hcd->bandwidth_mutex held.
1141 void usb_disable_device(struct usb_device
*dev
, int skip_ep0
)
1144 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1146 /* getting rid of interfaces will disconnect
1147 * any drivers bound to them (a key side effect)
1149 if (dev
->actconfig
) {
1150 for (i
= 0; i
< dev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1151 struct usb_interface
*interface
;
1153 /* remove this interface if it has been registered */
1154 interface
= dev
->actconfig
->interface
[i
];
1155 if (!device_is_registered(&interface
->dev
))
1157 dev_dbg(&dev
->dev
, "unregistering interface %s\n",
1158 dev_name(&interface
->dev
));
1159 interface
->unregistering
= 1;
1160 remove_intf_ep_devs(interface
);
1161 device_del(&interface
->dev
);
1164 /* Now that the interfaces are unbound, nobody should
1165 * try to access them.
1167 for (i
= 0; i
< dev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1168 put_device(&dev
->actconfig
->interface
[i
]->dev
);
1169 dev
->actconfig
->interface
[i
] = NULL
;
1171 dev
->actconfig
= NULL
;
1172 if (dev
->state
== USB_STATE_CONFIGURED
)
1173 usb_set_device_state(dev
, USB_STATE_ADDRESS
);
1176 dev_dbg(&dev
->dev
, "%s nuking %s URBs\n", __func__
,
1177 skip_ep0
? "non-ep0" : "all");
1178 if (hcd
->driver
->check_bandwidth
) {
1179 /* First pass: Cancel URBs, leave endpoint pointers intact. */
1180 for (i
= skip_ep0
; i
< 16; ++i
) {
1181 usb_disable_endpoint(dev
, i
, false);
1182 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
, false);
1184 /* Remove endpoints from the host controller internal state */
1185 usb_hcd_alloc_bandwidth(dev
, NULL
, NULL
, NULL
);
1186 /* Second pass: remove endpoint pointers */
1188 for (i
= skip_ep0
; i
< 16; ++i
) {
1189 usb_disable_endpoint(dev
, i
, true);
1190 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
, true);
1195 * usb_enable_endpoint - Enable an endpoint for USB communications
1196 * @dev: the device whose interface is being enabled
1198 * @reset_ep: flag to reset the endpoint state
1200 * Resets the endpoint state if asked, and sets dev->ep_{in,out} pointers.
1201 * For control endpoints, both the input and output sides are handled.
1203 void usb_enable_endpoint(struct usb_device
*dev
, struct usb_host_endpoint
*ep
,
1206 int epnum
= usb_endpoint_num(&ep
->desc
);
1207 int is_out
= usb_endpoint_dir_out(&ep
->desc
);
1208 int is_control
= usb_endpoint_xfer_control(&ep
->desc
);
1211 usb_hcd_reset_endpoint(dev
, ep
);
1212 if (is_out
|| is_control
)
1213 dev
->ep_out
[epnum
] = ep
;
1214 if (!is_out
|| is_control
)
1215 dev
->ep_in
[epnum
] = ep
;
1220 * usb_enable_interface - Enable all the endpoints for an interface
1221 * @dev: the device whose interface is being enabled
1222 * @intf: pointer to the interface descriptor
1223 * @reset_eps: flag to reset the endpoints' state
1225 * Enables all the endpoints for the interface's current altsetting.
1227 void usb_enable_interface(struct usb_device
*dev
,
1228 struct usb_interface
*intf
, bool reset_eps
)
1230 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1233 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
)
1234 usb_enable_endpoint(dev
, &alt
->endpoint
[i
], reset_eps
);
1238 * usb_set_interface - Makes a particular alternate setting be current
1239 * @dev: the device whose interface is being updated
1240 * @interface: the interface being updated
1241 * @alternate: the setting being chosen.
1242 * Context: !in_interrupt ()
1244 * This is used to enable data transfers on interfaces that may not
1245 * be enabled by default. Not all devices support such configurability.
1246 * Only the driver bound to an interface may change its setting.
1248 * Within any given configuration, each interface may have several
1249 * alternative settings. These are often used to control levels of
1250 * bandwidth consumption. For example, the default setting for a high
1251 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1252 * while interrupt transfers of up to 3KBytes per microframe are legal.
1253 * Also, isochronous endpoints may never be part of an
1254 * interface's default setting. To access such bandwidth, alternate
1255 * interface settings must be made current.
1257 * Note that in the Linux USB subsystem, bandwidth associated with
1258 * an endpoint in a given alternate setting is not reserved until an URB
1259 * is submitted that needs that bandwidth. Some other operating systems
1260 * allocate bandwidth early, when a configuration is chosen.
1262 * This call is synchronous, and may not be used in an interrupt context.
1263 * Also, drivers must not change altsettings while urbs are scheduled for
1264 * endpoints in that interface; all such urbs must first be completed
1265 * (perhaps forced by unlinking).
1267 * Returns zero on success, or else the status code returned by the
1268 * underlying usb_control_msg() call.
1270 int usb_set_interface(struct usb_device
*dev
, int interface
, int alternate
)
1272 struct usb_interface
*iface
;
1273 struct usb_host_interface
*alt
;
1274 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1277 unsigned int epaddr
;
1280 if (dev
->state
== USB_STATE_SUSPENDED
)
1281 return -EHOSTUNREACH
;
1283 iface
= usb_ifnum_to_if(dev
, interface
);
1285 dev_dbg(&dev
->dev
, "selecting invalid interface %d\n",
1290 alt
= usb_altnum_to_altsetting(iface
, alternate
);
1292 dev_warn(&dev
->dev
, "selecting invalid altsetting %d\n",
1297 /* Make sure we have enough bandwidth for this alternate interface.
1298 * Remove the current alt setting and add the new alt setting.
1300 mutex_lock(hcd
->bandwidth_mutex
);
1301 ret
= usb_hcd_alloc_bandwidth(dev
, NULL
, iface
->cur_altsetting
, alt
);
1303 dev_info(&dev
->dev
, "Not enough bandwidth for altsetting %d\n",
1305 mutex_unlock(hcd
->bandwidth_mutex
);
1309 if (dev
->quirks
& USB_QUIRK_NO_SET_INTF
)
1312 ret
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1313 USB_REQ_SET_INTERFACE
, USB_RECIP_INTERFACE
,
1314 alternate
, interface
, NULL
, 0, 5000);
1316 /* 9.4.10 says devices don't need this and are free to STALL the
1317 * request if the interface only has one alternate setting.
1319 if (ret
== -EPIPE
&& iface
->num_altsetting
== 1) {
1321 "manual set_interface for iface %d, alt %d\n",
1322 interface
, alternate
);
1324 } else if (ret
< 0) {
1325 /* Re-instate the old alt setting */
1326 usb_hcd_alloc_bandwidth(dev
, NULL
, alt
, iface
->cur_altsetting
);
1327 mutex_unlock(hcd
->bandwidth_mutex
);
1330 mutex_unlock(hcd
->bandwidth_mutex
);
1332 /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1333 * when they implement async or easily-killable versions of this or
1334 * other "should-be-internal" functions (like clear_halt).
1335 * should hcd+usbcore postprocess control requests?
1338 /* prevent submissions using previous endpoint settings */
1339 if (iface
->cur_altsetting
!= alt
) {
1340 remove_intf_ep_devs(iface
);
1341 usb_remove_sysfs_intf_files(iface
);
1343 usb_disable_interface(dev
, iface
, true);
1345 iface
->cur_altsetting
= alt
;
1347 /* If the interface only has one altsetting and the device didn't
1348 * accept the request, we attempt to carry out the equivalent action
1349 * by manually clearing the HALT feature for each endpoint in the
1355 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; i
++) {
1356 epaddr
= alt
->endpoint
[i
].desc
.bEndpointAddress
;
1357 pipe
= __create_pipe(dev
,
1358 USB_ENDPOINT_NUMBER_MASK
& epaddr
) |
1359 (usb_endpoint_out(epaddr
) ?
1360 USB_DIR_OUT
: USB_DIR_IN
);
1362 usb_clear_halt(dev
, pipe
);
1366 /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1369 * Despite EP0 is always present in all interfaces/AS, the list of
1370 * endpoints from the descriptor does not contain EP0. Due to its
1371 * omnipresence one might expect EP0 being considered "affected" by
1372 * any SetInterface request and hence assume toggles need to be reset.
1373 * However, EP0 toggles are re-synced for every individual transfer
1374 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1375 * (Likewise, EP0 never "halts" on well designed devices.)
1377 usb_enable_interface(dev
, iface
, true);
1378 if (device_is_registered(&iface
->dev
)) {
1379 usb_create_sysfs_intf_files(iface
);
1380 create_intf_ep_devs(iface
);
1384 EXPORT_SYMBOL_GPL(usb_set_interface
);
1387 * usb_reset_configuration - lightweight device reset
1388 * @dev: the device whose configuration is being reset
1390 * This issues a standard SET_CONFIGURATION request to the device using
1391 * the current configuration. The effect is to reset most USB-related
1392 * state in the device, including interface altsettings (reset to zero),
1393 * endpoint halts (cleared), and endpoint state (only for bulk and interrupt
1394 * endpoints). Other usbcore state is unchanged, including bindings of
1395 * usb device drivers to interfaces.
1397 * Because this affects multiple interfaces, avoid using this with composite
1398 * (multi-interface) devices. Instead, the driver for each interface may
1399 * use usb_set_interface() on the interfaces it claims. Be careful though;
1400 * some devices don't support the SET_INTERFACE request, and others won't
1401 * reset all the interface state (notably endpoint state). Resetting the whole
1402 * configuration would affect other drivers' interfaces.
1404 * The caller must own the device lock.
1406 * Returns zero on success, else a negative error code.
1408 int usb_reset_configuration(struct usb_device
*dev
)
1411 struct usb_host_config
*config
;
1412 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1414 if (dev
->state
== USB_STATE_SUSPENDED
)
1415 return -EHOSTUNREACH
;
1417 /* caller must have locked the device and must own
1418 * the usb bus readlock (so driver bindings are stable);
1419 * calls during probe() are fine
1422 for (i
= 1; i
< 16; ++i
) {
1423 usb_disable_endpoint(dev
, i
, true);
1424 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
, true);
1427 config
= dev
->actconfig
;
1429 mutex_lock(hcd
->bandwidth_mutex
);
1430 /* Make sure we have enough bandwidth for each alternate setting 0 */
1431 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++) {
1432 struct usb_interface
*intf
= config
->interface
[i
];
1433 struct usb_host_interface
*alt
;
1435 alt
= usb_altnum_to_altsetting(intf
, 0);
1437 alt
= &intf
->altsetting
[0];
1438 if (alt
!= intf
->cur_altsetting
)
1439 retval
= usb_hcd_alloc_bandwidth(dev
, NULL
,
1440 intf
->cur_altsetting
, alt
);
1444 /* If not, reinstate the old alternate settings */
1447 for (i
--; i
>= 0; i
--) {
1448 struct usb_interface
*intf
= config
->interface
[i
];
1449 struct usb_host_interface
*alt
;
1451 alt
= usb_altnum_to_altsetting(intf
, 0);
1453 alt
= &intf
->altsetting
[0];
1454 if (alt
!= intf
->cur_altsetting
)
1455 usb_hcd_alloc_bandwidth(dev
, NULL
,
1456 alt
, intf
->cur_altsetting
);
1458 mutex_unlock(hcd
->bandwidth_mutex
);
1461 retval
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1462 USB_REQ_SET_CONFIGURATION
, 0,
1463 config
->desc
.bConfigurationValue
, 0,
1464 NULL
, 0, USB_CTRL_SET_TIMEOUT
);
1466 goto reset_old_alts
;
1467 mutex_unlock(hcd
->bandwidth_mutex
);
1469 /* re-init hc/hcd interface/endpoint state */
1470 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++) {
1471 struct usb_interface
*intf
= config
->interface
[i
];
1472 struct usb_host_interface
*alt
;
1474 alt
= usb_altnum_to_altsetting(intf
, 0);
1476 /* No altsetting 0? We'll assume the first altsetting.
1477 * We could use a GetInterface call, but if a device is
1478 * so non-compliant that it doesn't have altsetting 0
1479 * then I wouldn't trust its reply anyway.
1482 alt
= &intf
->altsetting
[0];
1484 if (alt
!= intf
->cur_altsetting
) {
1485 remove_intf_ep_devs(intf
);
1486 usb_remove_sysfs_intf_files(intf
);
1488 intf
->cur_altsetting
= alt
;
1489 usb_enable_interface(dev
, intf
, true);
1490 if (device_is_registered(&intf
->dev
)) {
1491 usb_create_sysfs_intf_files(intf
);
1492 create_intf_ep_devs(intf
);
1497 EXPORT_SYMBOL_GPL(usb_reset_configuration
);
1499 static void usb_release_interface(struct device
*dev
)
1501 struct usb_interface
*intf
= to_usb_interface(dev
);
1502 struct usb_interface_cache
*intfc
=
1503 altsetting_to_usb_interface_cache(intf
->altsetting
);
1505 kref_put(&intfc
->ref
, usb_release_interface_cache
);
1509 #ifdef CONFIG_HOTPLUG
1510 static int usb_if_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1512 struct usb_device
*usb_dev
;
1513 struct usb_interface
*intf
;
1514 struct usb_host_interface
*alt
;
1516 intf
= to_usb_interface(dev
);
1517 usb_dev
= interface_to_usbdev(intf
);
1518 alt
= intf
->cur_altsetting
;
1520 if (add_uevent_var(env
, "INTERFACE=%d/%d/%d",
1521 alt
->desc
.bInterfaceClass
,
1522 alt
->desc
.bInterfaceSubClass
,
1523 alt
->desc
.bInterfaceProtocol
))
1526 if (add_uevent_var(env
,
1528 "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X",
1529 le16_to_cpu(usb_dev
->descriptor
.idVendor
),
1530 le16_to_cpu(usb_dev
->descriptor
.idProduct
),
1531 le16_to_cpu(usb_dev
->descriptor
.bcdDevice
),
1532 usb_dev
->descriptor
.bDeviceClass
,
1533 usb_dev
->descriptor
.bDeviceSubClass
,
1534 usb_dev
->descriptor
.bDeviceProtocol
,
1535 alt
->desc
.bInterfaceClass
,
1536 alt
->desc
.bInterfaceSubClass
,
1537 alt
->desc
.bInterfaceProtocol
))
1545 static int usb_if_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1549 #endif /* CONFIG_HOTPLUG */
1551 struct device_type usb_if_device_type
= {
1552 .name
= "usb_interface",
1553 .release
= usb_release_interface
,
1554 .uevent
= usb_if_uevent
,
1557 static struct usb_interface_assoc_descriptor
*find_iad(struct usb_device
*dev
,
1558 struct usb_host_config
*config
,
1561 struct usb_interface_assoc_descriptor
*retval
= NULL
;
1562 struct usb_interface_assoc_descriptor
*intf_assoc
;
1567 for (i
= 0; (i
< USB_MAXIADS
&& config
->intf_assoc
[i
]); i
++) {
1568 intf_assoc
= config
->intf_assoc
[i
];
1569 if (intf_assoc
->bInterfaceCount
== 0)
1572 first_intf
= intf_assoc
->bFirstInterface
;
1573 last_intf
= first_intf
+ (intf_assoc
->bInterfaceCount
- 1);
1574 if (inum
>= first_intf
&& inum
<= last_intf
) {
1576 retval
= intf_assoc
;
1578 dev_err(&dev
->dev
, "Interface #%d referenced"
1579 " by multiple IADs\n", inum
);
1588 * Internal function to queue a device reset
1590 * This is initialized into the workstruct in 'struct
1591 * usb_device->reset_ws' that is launched by
1592 * message.c:usb_set_configuration() when initializing each 'struct
1595 * It is safe to get the USB device without reference counts because
1596 * the life cycle of @iface is bound to the life cycle of @udev. Then,
1597 * this function will be ran only if @iface is alive (and before
1598 * freeing it any scheduled instances of it will have been cancelled).
1600 * We need to set a flag (usb_dev->reset_running) because when we call
1601 * the reset, the interfaces might be unbound. The current interface
1602 * cannot try to remove the queued work as it would cause a deadlock
1603 * (you cannot remove your work from within your executing
1604 * workqueue). This flag lets it know, so that
1605 * usb_cancel_queued_reset() doesn't try to do it.
1607 * See usb_queue_reset_device() for more details
1609 static void __usb_queue_reset_device(struct work_struct
*ws
)
1612 struct usb_interface
*iface
=
1613 container_of(ws
, struct usb_interface
, reset_ws
);
1614 struct usb_device
*udev
= interface_to_usbdev(iface
);
1616 rc
= usb_lock_device_for_reset(udev
, iface
);
1618 iface
->reset_running
= 1;
1619 usb_reset_device(udev
);
1620 iface
->reset_running
= 0;
1621 usb_unlock_device(udev
);
1627 * usb_set_configuration - Makes a particular device setting be current
1628 * @dev: the device whose configuration is being updated
1629 * @configuration: the configuration being chosen.
1630 * Context: !in_interrupt(), caller owns the device lock
1632 * This is used to enable non-default device modes. Not all devices
1633 * use this kind of configurability; many devices only have one
1636 * @configuration is the value of the configuration to be installed.
1637 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1638 * must be non-zero; a value of zero indicates that the device in
1639 * unconfigured. However some devices erroneously use 0 as one of their
1640 * configuration values. To help manage such devices, this routine will
1641 * accept @configuration = -1 as indicating the device should be put in
1642 * an unconfigured state.
1644 * USB device configurations may affect Linux interoperability,
1645 * power consumption and the functionality available. For example,
1646 * the default configuration is limited to using 100mA of bus power,
1647 * so that when certain device functionality requires more power,
1648 * and the device is bus powered, that functionality should be in some
1649 * non-default device configuration. Other device modes may also be
1650 * reflected as configuration options, such as whether two ISDN
1651 * channels are available independently; and choosing between open
1652 * standard device protocols (like CDC) or proprietary ones.
1654 * Note that a non-authorized device (dev->authorized == 0) will only
1655 * be put in unconfigured mode.
1657 * Note that USB has an additional level of device configurability,
1658 * associated with interfaces. That configurability is accessed using
1659 * usb_set_interface().
1661 * This call is synchronous. The calling context must be able to sleep,
1662 * must own the device lock, and must not hold the driver model's USB
1663 * bus mutex; usb interface driver probe() methods cannot use this routine.
1665 * Returns zero on success, or else the status code returned by the
1666 * underlying call that failed. On successful completion, each interface
1667 * in the original device configuration has been destroyed, and each one
1668 * in the new configuration has been probed by all relevant usb device
1669 * drivers currently known to the kernel.
1671 int usb_set_configuration(struct usb_device
*dev
, int configuration
)
1674 struct usb_host_config
*cp
= NULL
;
1675 struct usb_interface
**new_interfaces
= NULL
;
1676 struct usb_hcd
*hcd
= bus_to_hcd(dev
->bus
);
1679 if (dev
->authorized
== 0 || configuration
== -1)
1682 for (i
= 0; i
< dev
->descriptor
.bNumConfigurations
; i
++) {
1683 if (dev
->config
[i
].desc
.bConfigurationValue
==
1685 cp
= &dev
->config
[i
];
1690 if ((!cp
&& configuration
!= 0))
1693 /* The USB spec says configuration 0 means unconfigured.
1694 * But if a device includes a configuration numbered 0,
1695 * we will accept it as a correctly configured state.
1696 * Use -1 if you really want to unconfigure the device.
1698 if (cp
&& configuration
== 0)
1699 dev_warn(&dev
->dev
, "config 0 descriptor??\n");
1701 /* Allocate memory for new interfaces before doing anything else,
1702 * so that if we run out then nothing will have changed. */
1705 nintf
= cp
->desc
.bNumInterfaces
;
1706 new_interfaces
= kmalloc(nintf
* sizeof(*new_interfaces
),
1708 if (!new_interfaces
) {
1709 dev_err(&dev
->dev
, "Out of memory\n");
1713 for (; n
< nintf
; ++n
) {
1714 new_interfaces
[n
] = kzalloc(
1715 sizeof(struct usb_interface
),
1717 if (!new_interfaces
[n
]) {
1718 dev_err(&dev
->dev
, "Out of memory\n");
1722 kfree(new_interfaces
[n
]);
1723 kfree(new_interfaces
);
1728 i
= dev
->bus_mA
- cp
->desc
.bMaxPower
* 2;
1730 dev_warn(&dev
->dev
, "new config #%d exceeds power "
1735 /* Wake up the device so we can send it the Set-Config request */
1736 ret
= usb_autoresume_device(dev
);
1738 goto free_interfaces
;
1740 /* if it's already configured, clear out old state first.
1741 * getting rid of old interfaces means unbinding their drivers.
1743 mutex_lock(hcd
->bandwidth_mutex
);
1744 if (dev
->state
!= USB_STATE_ADDRESS
)
1745 usb_disable_device(dev
, 1); /* Skip ep0 */
1747 /* Get rid of pending async Set-Config requests for this device */
1748 cancel_async_set_config(dev
);
1750 /* Make sure we have bandwidth (and available HCD resources) for this
1751 * configuration. Remove endpoints from the schedule if we're dropping
1752 * this configuration to set configuration 0. After this point, the
1753 * host controller will not allow submissions to dropped endpoints. If
1754 * this call fails, the device state is unchanged.
1756 ret
= usb_hcd_alloc_bandwidth(dev
, cp
, NULL
, NULL
);
1758 mutex_unlock(hcd
->bandwidth_mutex
);
1759 usb_autosuspend_device(dev
);
1760 goto free_interfaces
;
1763 ret
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1764 USB_REQ_SET_CONFIGURATION
, 0, configuration
, 0,
1765 NULL
, 0, USB_CTRL_SET_TIMEOUT
);
1767 /* All the old state is gone, so what else can we do?
1768 * The device is probably useless now anyway.
1773 dev
->actconfig
= cp
;
1775 usb_set_device_state(dev
, USB_STATE_ADDRESS
);
1776 usb_hcd_alloc_bandwidth(dev
, NULL
, NULL
, NULL
);
1777 mutex_unlock(hcd
->bandwidth_mutex
);
1778 usb_autosuspend_device(dev
);
1779 goto free_interfaces
;
1781 mutex_unlock(hcd
->bandwidth_mutex
);
1782 usb_set_device_state(dev
, USB_STATE_CONFIGURED
);
1784 /* Initialize the new interface structures and the
1785 * hc/hcd/usbcore interface/endpoint state.
1787 for (i
= 0; i
< nintf
; ++i
) {
1788 struct usb_interface_cache
*intfc
;
1789 struct usb_interface
*intf
;
1790 struct usb_host_interface
*alt
;
1792 cp
->interface
[i
] = intf
= new_interfaces
[i
];
1793 intfc
= cp
->intf_cache
[i
];
1794 intf
->altsetting
= intfc
->altsetting
;
1795 intf
->num_altsetting
= intfc
->num_altsetting
;
1796 intf
->intf_assoc
= find_iad(dev
, cp
, i
);
1797 kref_get(&intfc
->ref
);
1799 alt
= usb_altnum_to_altsetting(intf
, 0);
1801 /* No altsetting 0? We'll assume the first altsetting.
1802 * We could use a GetInterface call, but if a device is
1803 * so non-compliant that it doesn't have altsetting 0
1804 * then I wouldn't trust its reply anyway.
1807 alt
= &intf
->altsetting
[0];
1809 intf
->cur_altsetting
= alt
;
1810 usb_enable_interface(dev
, intf
, true);
1811 intf
->dev
.parent
= &dev
->dev
;
1812 intf
->dev
.driver
= NULL
;
1813 intf
->dev
.bus
= &usb_bus_type
;
1814 intf
->dev
.type
= &usb_if_device_type
;
1815 intf
->dev
.groups
= usb_interface_groups
;
1816 intf
->dev
.dma_mask
= dev
->dev
.dma_mask
;
1817 INIT_WORK(&intf
->reset_ws
, __usb_queue_reset_device
);
1819 device_initialize(&intf
->dev
);
1820 pm_runtime_no_callbacks(&intf
->dev
);
1821 dev_set_name(&intf
->dev
, "%d-%s:%d.%d",
1822 dev
->bus
->busnum
, dev
->devpath
,
1823 configuration
, alt
->desc
.bInterfaceNumber
);
1825 kfree(new_interfaces
);
1827 if (cp
->string
== NULL
&&
1828 !(dev
->quirks
& USB_QUIRK_CONFIG_INTF_STRINGS
))
1829 cp
->string
= usb_cache_string(dev
, cp
->desc
.iConfiguration
);
1831 /* Now that all the interfaces are set up, register them
1832 * to trigger binding of drivers to interfaces. probe()
1833 * routines may install different altsettings and may
1834 * claim() any interfaces not yet bound. Many class drivers
1835 * need that: CDC, audio, video, etc.
1837 for (i
= 0; i
< nintf
; ++i
) {
1838 struct usb_interface
*intf
= cp
->interface
[i
];
1841 "adding %s (config #%d, interface %d)\n",
1842 dev_name(&intf
->dev
), configuration
,
1843 intf
->cur_altsetting
->desc
.bInterfaceNumber
);
1844 device_enable_async_suspend(&intf
->dev
);
1845 ret
= device_add(&intf
->dev
);
1847 dev_err(&dev
->dev
, "device_add(%s) --> %d\n",
1848 dev_name(&intf
->dev
), ret
);
1851 create_intf_ep_devs(intf
);
1854 usb_autosuspend_device(dev
);
1858 static LIST_HEAD(set_config_list
);
1859 static DEFINE_SPINLOCK(set_config_lock
);
1861 struct set_config_request
{
1862 struct usb_device
*udev
;
1864 struct work_struct work
;
1865 struct list_head node
;
1868 /* Worker routine for usb_driver_set_configuration() */
1869 static void driver_set_config_work(struct work_struct
*work
)
1871 struct set_config_request
*req
=
1872 container_of(work
, struct set_config_request
, work
);
1873 struct usb_device
*udev
= req
->udev
;
1875 usb_lock_device(udev
);
1876 spin_lock(&set_config_lock
);
1877 list_del(&req
->node
);
1878 spin_unlock(&set_config_lock
);
1880 if (req
->config
>= -1) /* Is req still valid? */
1881 usb_set_configuration(udev
, req
->config
);
1882 usb_unlock_device(udev
);
1887 /* Cancel pending Set-Config requests for a device whose configuration
1890 static void cancel_async_set_config(struct usb_device
*udev
)
1892 struct set_config_request
*req
;
1894 spin_lock(&set_config_lock
);
1895 list_for_each_entry(req
, &set_config_list
, node
) {
1896 if (req
->udev
== udev
)
1897 req
->config
= -999; /* Mark as cancelled */
1899 spin_unlock(&set_config_lock
);
1903 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
1904 * @udev: the device whose configuration is being updated
1905 * @config: the configuration being chosen.
1906 * Context: In process context, must be able to sleep
1908 * Device interface drivers are not allowed to change device configurations.
1909 * This is because changing configurations will destroy the interface the
1910 * driver is bound to and create new ones; it would be like a floppy-disk
1911 * driver telling the computer to replace the floppy-disk drive with a
1914 * Still, in certain specialized circumstances the need may arise. This
1915 * routine gets around the normal restrictions by using a work thread to
1916 * submit the change-config request.
1918 * Returns 0 if the request was successfully queued, error code otherwise.
1919 * The caller has no way to know whether the queued request will eventually
1922 int usb_driver_set_configuration(struct usb_device
*udev
, int config
)
1924 struct set_config_request
*req
;
1926 req
= kmalloc(sizeof(*req
), GFP_KERNEL
);
1930 req
->config
= config
;
1931 INIT_WORK(&req
->work
, driver_set_config_work
);
1933 spin_lock(&set_config_lock
);
1934 list_add(&req
->node
, &set_config_list
);
1935 spin_unlock(&set_config_lock
);
1938 schedule_work(&req
->work
);
1941 EXPORT_SYMBOL_GPL(usb_driver_set_configuration
);