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/device.h>
14 #include <linux/scatterlist.h>
15 #include <linux/usb/quirks.h>
16 #include <asm/byteorder.h>
18 #include "hcd.h" /* for usbcore internals */
22 struct completion done
;
26 static void usb_api_blocking_completion(struct urb
*urb
)
28 struct api_context
*ctx
= urb
->context
;
30 ctx
->status
= urb
->status
;
36 * Starts urb and waits for completion or timeout. Note that this call
37 * is NOT interruptible. Many device driver i/o requests should be
38 * interruptible and therefore these drivers should implement their
39 * own interruptible routines.
41 static int usb_start_wait_urb(struct urb
*urb
, int timeout
, int *actual_length
)
43 struct api_context ctx
;
47 init_completion(&ctx
.done
);
49 urb
->actual_length
= 0;
50 retval
= usb_submit_urb(urb
, GFP_NOIO
);
54 expire
= timeout
? msecs_to_jiffies(timeout
) : MAX_SCHEDULE_TIMEOUT
;
55 if (!wait_for_completion_timeout(&ctx
.done
, expire
)) {
57 retval
= (ctx
.status
== -ENOENT
? -ETIMEDOUT
: ctx
.status
);
59 dev_dbg(&urb
->dev
->dev
,
60 "%s timed out on ep%d%s len=%d/%d\n",
62 usb_endpoint_num(&urb
->ep
->desc
),
63 usb_urb_dir_in(urb
) ? "in" : "out",
65 urb
->transfer_buffer_length
);
70 *actual_length
= urb
->actual_length
;
76 /*-------------------------------------------------------------------*/
77 /* returns status (negative) or length (positive) */
78 static int usb_internal_control_msg(struct usb_device
*usb_dev
,
80 struct usb_ctrlrequest
*cmd
,
81 void *data
, int len
, int timeout
)
87 urb
= usb_alloc_urb(0, GFP_NOIO
);
91 usb_fill_control_urb(urb
, usb_dev
, pipe
, (unsigned char *)cmd
, data
,
92 len
, usb_api_blocking_completion
, NULL
);
94 retv
= usb_start_wait_urb(urb
, timeout
, &length
);
102 * usb_control_msg - Builds a control urb, sends it off and waits for completion
103 * @dev: pointer to the usb device to send the message to
104 * @pipe: endpoint "pipe" to send the message to
105 * @request: USB message request value
106 * @requesttype: USB message request type value
107 * @value: USB message value
108 * @index: USB message index value
109 * @data: pointer to the data to send
110 * @size: length in bytes of the data to send
111 * @timeout: time in msecs to wait for the message to complete before timing
112 * out (if 0 the wait is forever)
114 * Context: !in_interrupt ()
116 * This function sends a simple control message to a specified endpoint and
117 * waits for the message to complete, or timeout.
119 * If successful, it returns the number of bytes transferred, otherwise a
120 * negative error number.
122 * Don't use this function from within an interrupt context, like a bottom half
123 * handler. If you need an asynchronous message, or need to send a message
124 * from within interrupt context, use usb_submit_urb().
125 * If a thread in your driver uses this call, make sure your disconnect()
126 * method can wait for it to complete. Since you don't have a handle on the
127 * URB used, you can't cancel the request.
129 int usb_control_msg(struct usb_device
*dev
, unsigned int pipe
, __u8 request
,
130 __u8 requesttype
, __u16 value
, __u16 index
, void *data
,
131 __u16 size
, int timeout
)
133 struct usb_ctrlrequest
*dr
;
136 dr
= kmalloc(sizeof(struct usb_ctrlrequest
), GFP_NOIO
);
140 dr
->bRequestType
= requesttype
;
141 dr
->bRequest
= request
;
142 dr
->wValue
= cpu_to_le16p(&value
);
143 dr
->wIndex
= cpu_to_le16p(&index
);
144 dr
->wLength
= cpu_to_le16p(&size
);
146 /* dbg("usb_control_msg"); */
148 ret
= usb_internal_control_msg(dev
, pipe
, dr
, data
, size
, timeout
);
154 EXPORT_SYMBOL_GPL(usb_control_msg
);
157 * usb_interrupt_msg - Builds an interrupt urb, sends it off and waits for completion
158 * @usb_dev: pointer to the usb device to send the message to
159 * @pipe: endpoint "pipe" to send the message to
160 * @data: pointer to the data to send
161 * @len: length in bytes of the data to send
162 * @actual_length: pointer to a location to put the actual length transferred
164 * @timeout: time in msecs to wait for the message to complete before
165 * timing out (if 0 the wait is forever)
167 * Context: !in_interrupt ()
169 * This function sends a simple interrupt message to a specified endpoint and
170 * waits for the message to complete, or timeout.
172 * If successful, it returns 0, otherwise a negative error number. The number
173 * of actual bytes transferred will be stored in the actual_length paramater.
175 * Don't use this function from within an interrupt context, like a bottom half
176 * handler. If you need an asynchronous message, or need to send a message
177 * from within interrupt context, use usb_submit_urb() If a thread in your
178 * driver uses this call, make sure your disconnect() method can wait for it to
179 * complete. Since you don't have a handle on the URB used, you can't cancel
182 int usb_interrupt_msg(struct usb_device
*usb_dev
, unsigned int pipe
,
183 void *data
, int len
, int *actual_length
, int timeout
)
185 return usb_bulk_msg(usb_dev
, pipe
, data
, len
, actual_length
, timeout
);
187 EXPORT_SYMBOL_GPL(usb_interrupt_msg
);
190 * usb_bulk_msg - Builds a bulk urb, sends it off and waits for completion
191 * @usb_dev: pointer to the usb device to send the message to
192 * @pipe: endpoint "pipe" to send the message to
193 * @data: pointer to the data to send
194 * @len: length in bytes of the data to send
195 * @actual_length: pointer to a location to put the actual length transferred
197 * @timeout: time in msecs to wait for the message to complete before
198 * timing out (if 0 the wait is forever)
200 * Context: !in_interrupt ()
202 * This function sends a simple bulk message to a specified endpoint
203 * and waits for the message to complete, or timeout.
205 * If successful, it returns 0, otherwise a negative error number. The number
206 * of actual bytes transferred will be stored in the actual_length paramater.
208 * Don't use this function from within an interrupt context, like a bottom half
209 * handler. If you need an asynchronous message, or need to send a message
210 * from within interrupt context, use usb_submit_urb() If a thread in your
211 * driver uses this call, make sure your disconnect() method can wait for it to
212 * complete. Since you don't have a handle on the URB used, you can't cancel
215 * Because there is no usb_interrupt_msg() and no USBDEVFS_INTERRUPT ioctl,
216 * users are forced to abuse this routine by using it to submit URBs for
217 * interrupt endpoints. We will take the liberty of creating an interrupt URB
218 * (with the default interval) if the target is an interrupt endpoint.
220 int usb_bulk_msg(struct usb_device
*usb_dev
, unsigned int pipe
,
221 void *data
, int len
, int *actual_length
, int timeout
)
224 struct usb_host_endpoint
*ep
;
226 ep
= (usb_pipein(pipe
) ? usb_dev
->ep_in
: usb_dev
->ep_out
)
227 [usb_pipeendpoint(pipe
)];
231 urb
= usb_alloc_urb(0, GFP_KERNEL
);
235 if ((ep
->desc
.bmAttributes
& USB_ENDPOINT_XFERTYPE_MASK
) ==
236 USB_ENDPOINT_XFER_INT
) {
237 pipe
= (pipe
& ~(3 << 30)) | (PIPE_INTERRUPT
<< 30);
238 usb_fill_int_urb(urb
, usb_dev
, pipe
, data
, len
,
239 usb_api_blocking_completion
, NULL
,
242 usb_fill_bulk_urb(urb
, usb_dev
, pipe
, data
, len
,
243 usb_api_blocking_completion
, NULL
);
245 return usb_start_wait_urb(urb
, timeout
, actual_length
);
247 EXPORT_SYMBOL_GPL(usb_bulk_msg
);
249 /*-------------------------------------------------------------------*/
251 static void sg_clean(struct usb_sg_request
*io
)
254 while (io
->entries
--)
255 usb_free_urb(io
->urbs
[io
->entries
]);
259 if (io
->dev
->dev
.dma_mask
!= NULL
)
260 usb_buffer_unmap_sg(io
->dev
, usb_pipein(io
->pipe
),
265 static void sg_complete(struct urb
*urb
)
267 struct usb_sg_request
*io
= urb
->context
;
268 int status
= urb
->status
;
270 spin_lock(&io
->lock
);
272 /* In 2.5 we require hcds' endpoint queues not to progress after fault
273 * reports, until the completion callback (this!) returns. That lets
274 * device driver code (like this routine) unlink queued urbs first,
275 * if it needs to, since the HC won't work on them at all. So it's
276 * not possible for page N+1 to overwrite page N, and so on.
278 * That's only for "hard" faults; "soft" faults (unlinks) sometimes
279 * complete before the HCD can get requests away from hardware,
280 * though never during cleanup after a hard fault.
283 && (io
->status
!= -ECONNRESET
284 || status
!= -ECONNRESET
)
285 && urb
->actual_length
) {
286 dev_err(io
->dev
->bus
->controller
,
287 "dev %s ep%d%s scatterlist error %d/%d\n",
289 usb_endpoint_num(&urb
->ep
->desc
),
290 usb_urb_dir_in(urb
) ? "in" : "out",
295 if (io
->status
== 0 && status
&& status
!= -ECONNRESET
) {
296 int i
, found
, retval
;
300 /* the previous urbs, and this one, completed already.
301 * unlink pending urbs so they won't rx/tx bad data.
302 * careful: unlink can sometimes be synchronous...
304 spin_unlock(&io
->lock
);
305 for (i
= 0, found
= 0; i
< io
->entries
; i
++) {
306 if (!io
->urbs
[i
] || !io
->urbs
[i
]->dev
)
309 retval
= usb_unlink_urb(io
->urbs
[i
]);
310 if (retval
!= -EINPROGRESS
&&
313 dev_err(&io
->dev
->dev
,
314 "%s, unlink --> %d\n",
316 } else if (urb
== io
->urbs
[i
])
319 spin_lock(&io
->lock
);
323 /* on the last completion, signal usb_sg_wait() */
324 io
->bytes
+= urb
->actual_length
;
327 complete(&io
->complete
);
329 spin_unlock(&io
->lock
);
334 * usb_sg_init - initializes scatterlist-based bulk/interrupt I/O request
335 * @io: request block being initialized. until usb_sg_wait() returns,
336 * treat this as a pointer to an opaque block of memory,
337 * @dev: the usb device that will send or receive the data
338 * @pipe: endpoint "pipe" used to transfer the data
339 * @period: polling rate for interrupt endpoints, in frames or
340 * (for high speed endpoints) microframes; ignored for bulk
341 * @sg: scatterlist entries
342 * @nents: how many entries in the scatterlist
343 * @length: how many bytes to send from the scatterlist, or zero to
344 * send every byte identified in the list.
345 * @mem_flags: SLAB_* flags affecting memory allocations in this call
347 * Returns zero for success, else a negative errno value. This initializes a
348 * scatter/gather request, allocating resources such as I/O mappings and urb
349 * memory (except maybe memory used by USB controller drivers).
351 * The request must be issued using usb_sg_wait(), which waits for the I/O to
352 * complete (or to be canceled) and then cleans up all resources allocated by
355 * The request may be canceled with usb_sg_cancel(), either before or after
356 * usb_sg_wait() is called.
358 int usb_sg_init(struct usb_sg_request
*io
, struct usb_device
*dev
,
359 unsigned pipe
, unsigned period
, struct scatterlist
*sg
,
360 int nents
, size_t length
, gfp_t mem_flags
)
366 if (!io
|| !dev
|| !sg
367 || usb_pipecontrol(pipe
)
368 || usb_pipeisoc(pipe
)
372 spin_lock_init(&io
->lock
);
378 /* not all host controllers use DMA (like the mainstream pci ones);
379 * they can use PIO (sl811) or be software over another transport.
381 dma
= (dev
->dev
.dma_mask
!= NULL
);
383 io
->entries
= usb_buffer_map_sg(dev
, usb_pipein(pipe
),
388 /* initialize all the urbs we'll use */
389 if (io
->entries
<= 0)
392 io
->count
= io
->entries
;
393 io
->urbs
= kmalloc(io
->entries
* sizeof *io
->urbs
, mem_flags
);
397 urb_flags
= URB_NO_INTERRUPT
;
399 urb_flags
|= URB_NO_TRANSFER_DMA_MAP
;
400 if (usb_pipein(pipe
))
401 urb_flags
|= URB_SHORT_NOT_OK
;
403 for_each_sg(sg
, sg
, io
->entries
, i
) {
406 io
->urbs
[i
] = usb_alloc_urb(0, mem_flags
);
412 io
->urbs
[i
]->dev
= NULL
;
413 io
->urbs
[i
]->pipe
= pipe
;
414 io
->urbs
[i
]->interval
= period
;
415 io
->urbs
[i
]->transfer_flags
= urb_flags
;
417 io
->urbs
[i
]->complete
= sg_complete
;
418 io
->urbs
[i
]->context
= io
;
421 * Some systems need to revert to PIO when DMA is temporarily
422 * unavailable. For their sakes, both transfer_buffer and
423 * transfer_dma are set when possible. However this can only
424 * work on systems without:
426 * - HIGHMEM, since DMA buffers located in high memory are
427 * not directly addressable by the CPU for PIO;
429 * - IOMMU, since dma_map_sg() is allowed to use an IOMMU to
430 * make virtually discontiguous buffers be "dma-contiguous"
431 * so that PIO and DMA need diferent numbers of URBs.
433 * So when HIGHMEM or IOMMU are in use, transfer_buffer is NULL
434 * to prevent stale pointers and to help spot bugs.
437 io
->urbs
[i
]->transfer_dma
= sg_dma_address(sg
);
438 len
= sg_dma_len(sg
);
439 #if defined(CONFIG_HIGHMEM) || defined(CONFIG_GART_IOMMU)
440 io
->urbs
[i
]->transfer_buffer
= NULL
;
442 io
->urbs
[i
]->transfer_buffer
= sg_virt(sg
);
445 /* hc may use _only_ transfer_buffer */
446 io
->urbs
[i
]->transfer_buffer
= sg_virt(sg
);
451 len
= min_t(unsigned, len
, length
);
456 io
->urbs
[i
]->transfer_buffer_length
= len
;
458 io
->urbs
[--i
]->transfer_flags
&= ~URB_NO_INTERRUPT
;
460 /* transaction state */
463 init_completion(&io
->complete
);
470 EXPORT_SYMBOL_GPL(usb_sg_init
);
473 * usb_sg_wait - synchronously execute scatter/gather request
474 * @io: request block handle, as initialized with usb_sg_init().
475 * some fields become accessible when this call returns.
476 * Context: !in_interrupt ()
478 * This function blocks until the specified I/O operation completes. It
479 * leverages the grouping of the related I/O requests to get good transfer
480 * rates, by queueing the requests. At higher speeds, such queuing can
481 * significantly improve USB throughput.
483 * There are three kinds of completion for this function.
484 * (1) success, where io->status is zero. The number of io->bytes
485 * transferred is as requested.
486 * (2) error, where io->status is a negative errno value. The number
487 * of io->bytes transferred before the error is usually less
488 * than requested, and can be nonzero.
489 * (3) cancellation, a type of error with status -ECONNRESET that
490 * is initiated by usb_sg_cancel().
492 * When this function returns, all memory allocated through usb_sg_init() or
493 * this call will have been freed. The request block parameter may still be
494 * passed to usb_sg_cancel(), or it may be freed. It could also be
495 * reinitialized and then reused.
497 * Data Transfer Rates:
499 * Bulk transfers are valid for full or high speed endpoints.
500 * The best full speed data rate is 19 packets of 64 bytes each
501 * per frame, or 1216 bytes per millisecond.
502 * The best high speed data rate is 13 packets of 512 bytes each
503 * per microframe, or 52 KBytes per millisecond.
505 * The reason to use interrupt transfers through this API would most likely
506 * be to reserve high speed bandwidth, where up to 24 KBytes per millisecond
507 * could be transferred. That capability is less useful for low or full
508 * speed interrupt endpoints, which allow at most one packet per millisecond,
509 * of at most 8 or 64 bytes (respectively).
511 void usb_sg_wait(struct usb_sg_request
*io
)
514 int entries
= io
->entries
;
516 /* queue the urbs. */
517 spin_lock_irq(&io
->lock
);
519 while (i
< entries
&& !io
->status
) {
522 io
->urbs
[i
]->dev
= io
->dev
;
523 retval
= usb_submit_urb(io
->urbs
[i
], GFP_ATOMIC
);
525 /* after we submit, let completions or cancelations fire;
526 * we handshake using io->status.
528 spin_unlock_irq(&io
->lock
);
530 /* maybe we retrying will recover */
531 case -ENXIO
: /* hc didn't queue this one */
534 io
->urbs
[i
]->dev
= NULL
;
539 /* no error? continue immediately.
541 * NOTE: to work better with UHCI (4K I/O buffer may
542 * need 3K of TDs) it may be good to limit how many
543 * URBs are queued at once; N milliseconds?
550 /* fail any uncompleted urbs */
552 io
->urbs
[i
]->dev
= NULL
;
553 io
->urbs
[i
]->status
= retval
;
554 dev_dbg(&io
->dev
->dev
, "%s, submit --> %d\n",
558 spin_lock_irq(&io
->lock
);
559 if (retval
&& (io
->status
== 0 || io
->status
== -ECONNRESET
))
562 io
->count
-= entries
- i
;
564 complete(&io
->complete
);
565 spin_unlock_irq(&io
->lock
);
567 /* OK, yes, this could be packaged as non-blocking.
568 * So could the submit loop above ... but it's easier to
569 * solve neither problem than to solve both!
571 wait_for_completion(&io
->complete
);
575 EXPORT_SYMBOL_GPL(usb_sg_wait
);
578 * usb_sg_cancel - stop scatter/gather i/o issued by usb_sg_wait()
579 * @io: request block, initialized with usb_sg_init()
581 * This stops a request after it has been started by usb_sg_wait().
582 * It can also prevents one initialized by usb_sg_init() from starting,
583 * so that call just frees resources allocated to the request.
585 void usb_sg_cancel(struct usb_sg_request
*io
)
589 spin_lock_irqsave(&io
->lock
, flags
);
591 /* shut everything down, if it didn't already */
595 io
->status
= -ECONNRESET
;
596 spin_unlock(&io
->lock
);
597 for (i
= 0; i
< io
->entries
; i
++) {
600 if (!io
->urbs
[i
]->dev
)
602 retval
= usb_unlink_urb(io
->urbs
[i
]);
603 if (retval
!= -EINPROGRESS
&& retval
!= -EBUSY
)
604 dev_warn(&io
->dev
->dev
, "%s, unlink --> %d\n",
607 spin_lock(&io
->lock
);
609 spin_unlock_irqrestore(&io
->lock
, flags
);
611 EXPORT_SYMBOL_GPL(usb_sg_cancel
);
613 /*-------------------------------------------------------------------*/
616 * usb_get_descriptor - issues a generic GET_DESCRIPTOR request
617 * @dev: the device whose descriptor is being retrieved
618 * @type: the descriptor type (USB_DT_*)
619 * @index: the number of the descriptor
620 * @buf: where to put the descriptor
621 * @size: how big is "buf"?
622 * Context: !in_interrupt ()
624 * Gets a USB descriptor. Convenience functions exist to simplify
625 * getting some types of descriptors. Use
626 * usb_get_string() or usb_string() for USB_DT_STRING.
627 * Device (USB_DT_DEVICE) and configuration descriptors (USB_DT_CONFIG)
628 * are part of the device structure.
629 * In addition to a number of USB-standard descriptors, some
630 * devices also use class-specific or vendor-specific descriptors.
632 * This call is synchronous, and may not be used in an interrupt context.
634 * Returns the number of bytes received on success, or else the status code
635 * returned by the underlying usb_control_msg() call.
637 int usb_get_descriptor(struct usb_device
*dev
, unsigned char type
,
638 unsigned char index
, void *buf
, int size
)
643 memset(buf
, 0, size
); /* Make sure we parse really received data */
645 for (i
= 0; i
< 3; ++i
) {
646 /* retry on length 0 or error; some devices are flakey */
647 result
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
648 USB_REQ_GET_DESCRIPTOR
, USB_DIR_IN
,
649 (type
<< 8) + index
, 0, buf
, size
,
650 USB_CTRL_GET_TIMEOUT
);
651 if (result
<= 0 && result
!= -ETIMEDOUT
)
653 if (result
> 1 && ((u8
*)buf
)[1] != type
) {
661 EXPORT_SYMBOL_GPL(usb_get_descriptor
);
664 * usb_get_string - gets a string descriptor
665 * @dev: the device whose string descriptor is being retrieved
666 * @langid: code for language chosen (from string descriptor zero)
667 * @index: the number of the descriptor
668 * @buf: where to put the string
669 * @size: how big is "buf"?
670 * Context: !in_interrupt ()
672 * Retrieves a string, encoded using UTF-16LE (Unicode, 16 bits per character,
673 * in little-endian byte order).
674 * The usb_string() function will often be a convenient way to turn
675 * these strings into kernel-printable form.
677 * Strings may be referenced in device, configuration, interface, or other
678 * descriptors, and could also be used in vendor-specific ways.
680 * This call is synchronous, and may not be used in an interrupt context.
682 * Returns the number of bytes received on success, or else the status code
683 * returned by the underlying usb_control_msg() call.
685 static int usb_get_string(struct usb_device
*dev
, unsigned short langid
,
686 unsigned char index
, void *buf
, int size
)
691 for (i
= 0; i
< 3; ++i
) {
692 /* retry on length 0 or stall; some devices are flakey */
693 result
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
694 USB_REQ_GET_DESCRIPTOR
, USB_DIR_IN
,
695 (USB_DT_STRING
<< 8) + index
, langid
, buf
, size
,
696 USB_CTRL_GET_TIMEOUT
);
697 if (!(result
== 0 || result
== -EPIPE
))
703 static void usb_try_string_workarounds(unsigned char *buf
, int *length
)
705 int newlength
, oldlength
= *length
;
707 for (newlength
= 2; newlength
+ 1 < oldlength
; newlength
+= 2)
708 if (!isprint(buf
[newlength
]) || buf
[newlength
+ 1])
717 static int usb_string_sub(struct usb_device
*dev
, unsigned int langid
,
718 unsigned int index
, unsigned char *buf
)
722 /* Try to read the string descriptor by asking for the maximum
723 * possible number of bytes */
724 if (dev
->quirks
& USB_QUIRK_STRING_FETCH_255
)
727 rc
= usb_get_string(dev
, langid
, index
, buf
, 255);
729 /* If that failed try to read the descriptor length, then
730 * ask for just that many bytes */
732 rc
= usb_get_string(dev
, langid
, index
, buf
, 2);
734 rc
= usb_get_string(dev
, langid
, index
, buf
, buf
[0]);
738 if (!buf
[0] && !buf
[1])
739 usb_try_string_workarounds(buf
, &rc
);
741 /* There might be extra junk at the end of the descriptor */
745 rc
= rc
- (rc
& 1); /* force a multiple of two */
749 rc
= (rc
< 0 ? rc
: -EINVAL
);
755 * usb_string - returns ISO 8859-1 version of a string descriptor
756 * @dev: the device whose string descriptor is being retrieved
757 * @index: the number of the descriptor
758 * @buf: where to put the string
759 * @size: how big is "buf"?
760 * Context: !in_interrupt ()
762 * This converts the UTF-16LE encoded strings returned by devices, from
763 * usb_get_string_descriptor(), to null-terminated ISO-8859-1 encoded ones
764 * that are more usable in most kernel contexts. Note that all characters
765 * in the chosen descriptor that can't be encoded using ISO-8859-1
766 * are converted to the question mark ("?") character, and this function
767 * chooses strings in the first language supported by the device.
769 * The ASCII (or, redundantly, "US-ASCII") character set is the seven-bit
770 * subset of ISO 8859-1. ISO-8859-1 is the eight-bit subset of Unicode,
771 * and is appropriate for use many uses of English and several other
772 * Western European languages. (But it doesn't include the "Euro" symbol.)
774 * This call is synchronous, and may not be used in an interrupt context.
776 * Returns length of the string (>= 0) or usb_control_msg status (< 0).
778 int usb_string(struct usb_device
*dev
, int index
, char *buf
, size_t size
)
784 if (dev
->state
== USB_STATE_SUSPENDED
)
785 return -EHOSTUNREACH
;
786 if (size
<= 0 || !buf
|| !index
)
789 tbuf
= kmalloc(256, GFP_NOIO
);
793 /* get langid for strings if it's not yet known */
794 if (!dev
->have_langid
) {
795 err
= usb_string_sub(dev
, 0, 0, tbuf
);
798 "string descriptor 0 read error: %d\n",
801 } else if (err
< 4) {
802 dev_err(&dev
->dev
, "string descriptor 0 too short\n");
806 dev
->have_langid
= 1;
807 dev
->string_langid
= tbuf
[2] | (tbuf
[3] << 8);
808 /* always use the first langid listed */
809 dev_dbg(&dev
->dev
, "default language 0x%04x\n",
814 err
= usb_string_sub(dev
, dev
->string_langid
, index
, tbuf
);
818 size
--; /* leave room for trailing NULL char in output buffer */
819 for (idx
= 0, u
= 2; u
< err
; u
+= 2) {
822 if (tbuf
[u
+1]) /* high byte */
823 buf
[idx
++] = '?'; /* non ISO-8859-1 character */
825 buf
[idx
++] = tbuf
[u
];
830 if (tbuf
[1] != USB_DT_STRING
)
832 "wrong descriptor type %02x for string %d (\"%s\")\n",
833 tbuf
[1], index
, buf
);
839 EXPORT_SYMBOL_GPL(usb_string
);
842 * usb_cache_string - read a string descriptor and cache it for later use
843 * @udev: the device whose string descriptor is being read
844 * @index: the descriptor index
846 * Returns a pointer to a kmalloc'ed buffer containing the descriptor string,
847 * or NULL if the index is 0 or the string could not be read.
849 char *usb_cache_string(struct usb_device
*udev
, int index
)
852 char *smallbuf
= NULL
;
858 buf
= kmalloc(256, GFP_KERNEL
);
860 len
= usb_string(udev
, index
, buf
, 256);
862 smallbuf
= kmalloc(++len
, GFP_KERNEL
);
865 memcpy(smallbuf
, buf
, len
);
873 * usb_get_device_descriptor - (re)reads the device descriptor (usbcore)
874 * @dev: the device whose device descriptor is being updated
875 * @size: how much of the descriptor to read
876 * Context: !in_interrupt ()
878 * Updates the copy of the device descriptor stored in the device structure,
879 * which dedicates space for this purpose.
881 * Not exported, only for use by the core. If drivers really want to read
882 * the device descriptor directly, they can call usb_get_descriptor() with
883 * type = USB_DT_DEVICE and index = 0.
885 * This call is synchronous, and may not be used in an interrupt context.
887 * Returns the number of bytes received on success, or else the status code
888 * returned by the underlying usb_control_msg() call.
890 int usb_get_device_descriptor(struct usb_device
*dev
, unsigned int size
)
892 struct usb_device_descriptor
*desc
;
895 if (size
> sizeof(*desc
))
897 desc
= kmalloc(sizeof(*desc
), GFP_NOIO
);
901 ret
= usb_get_descriptor(dev
, USB_DT_DEVICE
, 0, desc
, size
);
903 memcpy(&dev
->descriptor
, desc
, size
);
909 * usb_get_status - issues a GET_STATUS call
910 * @dev: the device whose status is being checked
911 * @type: USB_RECIP_*; for device, interface, or endpoint
912 * @target: zero (for device), else interface or endpoint number
913 * @data: pointer to two bytes of bitmap data
914 * Context: !in_interrupt ()
916 * Returns device, interface, or endpoint status. Normally only of
917 * interest to see if the device is self powered, or has enabled the
918 * remote wakeup facility; or whether a bulk or interrupt endpoint
919 * is halted ("stalled").
921 * Bits in these status bitmaps are set using the SET_FEATURE request,
922 * and cleared using the CLEAR_FEATURE request. The usb_clear_halt()
923 * function should be used to clear halt ("stall") status.
925 * This call is synchronous, and may not be used in an interrupt context.
927 * Returns the number of bytes received on success, or else the status code
928 * returned by the underlying usb_control_msg() call.
930 int usb_get_status(struct usb_device
*dev
, int type
, int target
, void *data
)
933 u16
*status
= kmalloc(sizeof(*status
), GFP_KERNEL
);
938 ret
= usb_control_msg(dev
, usb_rcvctrlpipe(dev
, 0),
939 USB_REQ_GET_STATUS
, USB_DIR_IN
| type
, 0, target
, status
,
940 sizeof(*status
), USB_CTRL_GET_TIMEOUT
);
942 *(u16
*)data
= *status
;
946 EXPORT_SYMBOL_GPL(usb_get_status
);
949 * usb_clear_halt - tells device to clear endpoint halt/stall condition
950 * @dev: device whose endpoint is halted
951 * @pipe: endpoint "pipe" being cleared
952 * Context: !in_interrupt ()
954 * This is used to clear halt conditions for bulk and interrupt endpoints,
955 * as reported by URB completion status. Endpoints that are halted are
956 * sometimes referred to as being "stalled". Such endpoints are unable
957 * to transmit or receive data until the halt status is cleared. Any URBs
958 * queued for such an endpoint should normally be unlinked by the driver
959 * before clearing the halt condition, as described in sections 5.7.5
960 * and 5.8.5 of the USB 2.0 spec.
962 * Note that control and isochronous endpoints don't halt, although control
963 * endpoints report "protocol stall" (for unsupported requests) using the
964 * same status code used to report a true stall.
966 * This call is synchronous, and may not be used in an interrupt context.
968 * Returns zero on success, or else the status code returned by the
969 * underlying usb_control_msg() call.
971 int usb_clear_halt(struct usb_device
*dev
, int pipe
)
974 int endp
= usb_pipeendpoint(pipe
);
976 if (usb_pipein(pipe
))
979 /* we don't care if it wasn't halted first. in fact some devices
980 * (like some ibmcam model 1 units) seem to expect hosts to make
981 * this request for iso endpoints, which can't halt!
983 result
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
984 USB_REQ_CLEAR_FEATURE
, USB_RECIP_ENDPOINT
,
985 USB_ENDPOINT_HALT
, endp
, NULL
, 0,
986 USB_CTRL_SET_TIMEOUT
);
988 /* don't un-halt or force to DATA0 except on success */
992 /* NOTE: seems like Microsoft and Apple don't bother verifying
993 * the clear "took", so some devices could lock up if you check...
994 * such as the Hagiwara FlashGate DUAL. So we won't bother.
996 * NOTE: make sure the logic here doesn't diverge much from
997 * the copy in usb-storage, for as long as we need two copies.
1000 /* toggle was reset by the clear */
1001 usb_settoggle(dev
, usb_pipeendpoint(pipe
), usb_pipeout(pipe
), 0);
1005 EXPORT_SYMBOL_GPL(usb_clear_halt
);
1008 * usb_disable_endpoint -- Disable an endpoint by address
1009 * @dev: the device whose endpoint is being disabled
1010 * @epaddr: the endpoint's address. Endpoint number for output,
1011 * endpoint number + USB_DIR_IN for input
1013 * Deallocates hcd/hardware state for this endpoint ... and nukes all
1016 * If the HCD hasn't registered a disable() function, this sets the
1017 * endpoint's maxpacket size to 0 to prevent further submissions.
1019 void usb_disable_endpoint(struct usb_device
*dev
, unsigned int epaddr
)
1021 unsigned int epnum
= epaddr
& USB_ENDPOINT_NUMBER_MASK
;
1022 struct usb_host_endpoint
*ep
;
1027 if (usb_endpoint_out(epaddr
)) {
1028 ep
= dev
->ep_out
[epnum
];
1029 dev
->ep_out
[epnum
] = NULL
;
1031 ep
= dev
->ep_in
[epnum
];
1032 dev
->ep_in
[epnum
] = NULL
;
1036 usb_hcd_flush_endpoint(dev
, ep
);
1037 usb_hcd_disable_endpoint(dev
, ep
);
1042 * usb_disable_interface -- Disable all endpoints for an interface
1043 * @dev: the device whose interface is being disabled
1044 * @intf: pointer to the interface descriptor
1046 * Disables all the endpoints for the interface's current altsetting.
1048 void usb_disable_interface(struct usb_device
*dev
, struct usb_interface
*intf
)
1050 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1053 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
) {
1054 usb_disable_endpoint(dev
,
1055 alt
->endpoint
[i
].desc
.bEndpointAddress
);
1060 * usb_disable_device - Disable all the endpoints for a USB device
1061 * @dev: the device whose endpoints are being disabled
1062 * @skip_ep0: 0 to disable endpoint 0, 1 to skip it.
1064 * Disables all the device's endpoints, potentially including endpoint 0.
1065 * Deallocates hcd/hardware state for the endpoints (nuking all or most
1066 * pending urbs) and usbcore state for the interfaces, so that usbcore
1067 * must usb_set_configuration() before any interfaces could be used.
1069 void usb_disable_device(struct usb_device
*dev
, int skip_ep0
)
1073 dev_dbg(&dev
->dev
, "%s nuking %s URBs\n", __func__
,
1074 skip_ep0
? "non-ep0" : "all");
1075 for (i
= skip_ep0
; i
< 16; ++i
) {
1076 usb_disable_endpoint(dev
, i
);
1077 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
);
1079 dev
->toggle
[0] = dev
->toggle
[1] = 0;
1081 /* getting rid of interfaces will disconnect
1082 * any drivers bound to them (a key side effect)
1084 if (dev
->actconfig
) {
1085 for (i
= 0; i
< dev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1086 struct usb_interface
*interface
;
1088 /* remove this interface if it has been registered */
1089 interface
= dev
->actconfig
->interface
[i
];
1090 if (!device_is_registered(&interface
->dev
))
1092 dev_dbg(&dev
->dev
, "unregistering interface %s\n",
1093 dev_name(&interface
->dev
));
1094 device_del(&interface
->dev
);
1095 usb_remove_sysfs_intf_files(interface
);
1098 /* Now that the interfaces are unbound, nobody should
1099 * try to access them.
1101 for (i
= 0; i
< dev
->actconfig
->desc
.bNumInterfaces
; i
++) {
1102 put_device(&dev
->actconfig
->interface
[i
]->dev
);
1103 dev
->actconfig
->interface
[i
] = NULL
;
1105 dev
->actconfig
= NULL
;
1106 if (dev
->state
== USB_STATE_CONFIGURED
)
1107 usb_set_device_state(dev
, USB_STATE_ADDRESS
);
1112 * usb_enable_endpoint - Enable an endpoint for USB communications
1113 * @dev: the device whose interface is being enabled
1116 * Resets the endpoint toggle, and sets dev->ep_{in,out} pointers.
1117 * For control endpoints, both the input and output sides are handled.
1119 void usb_enable_endpoint(struct usb_device
*dev
, struct usb_host_endpoint
*ep
)
1121 int epnum
= usb_endpoint_num(&ep
->desc
);
1122 int is_out
= usb_endpoint_dir_out(&ep
->desc
);
1123 int is_control
= usb_endpoint_xfer_control(&ep
->desc
);
1125 if (is_out
|| is_control
) {
1126 usb_settoggle(dev
, epnum
, 1, 0);
1127 dev
->ep_out
[epnum
] = ep
;
1129 if (!is_out
|| is_control
) {
1130 usb_settoggle(dev
, epnum
, 0, 0);
1131 dev
->ep_in
[epnum
] = ep
;
1137 * usb_enable_interface - Enable all the endpoints for an interface
1138 * @dev: the device whose interface is being enabled
1139 * @intf: pointer to the interface descriptor
1141 * Enables all the endpoints for the interface's current altsetting.
1143 static void usb_enable_interface(struct usb_device
*dev
,
1144 struct usb_interface
*intf
)
1146 struct usb_host_interface
*alt
= intf
->cur_altsetting
;
1149 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; ++i
)
1150 usb_enable_endpoint(dev
, &alt
->endpoint
[i
]);
1154 * usb_set_interface - Makes a particular alternate setting be current
1155 * @dev: the device whose interface is being updated
1156 * @interface: the interface being updated
1157 * @alternate: the setting being chosen.
1158 * Context: !in_interrupt ()
1160 * This is used to enable data transfers on interfaces that may not
1161 * be enabled by default. Not all devices support such configurability.
1162 * Only the driver bound to an interface may change its setting.
1164 * Within any given configuration, each interface may have several
1165 * alternative settings. These are often used to control levels of
1166 * bandwidth consumption. For example, the default setting for a high
1167 * speed interrupt endpoint may not send more than 64 bytes per microframe,
1168 * while interrupt transfers of up to 3KBytes per microframe are legal.
1169 * Also, isochronous endpoints may never be part of an
1170 * interface's default setting. To access such bandwidth, alternate
1171 * interface settings must be made current.
1173 * Note that in the Linux USB subsystem, bandwidth associated with
1174 * an endpoint in a given alternate setting is not reserved until an URB
1175 * is submitted that needs that bandwidth. Some other operating systems
1176 * allocate bandwidth early, when a configuration is chosen.
1178 * This call is synchronous, and may not be used in an interrupt context.
1179 * Also, drivers must not change altsettings while urbs are scheduled for
1180 * endpoints in that interface; all such urbs must first be completed
1181 * (perhaps forced by unlinking).
1183 * Returns zero on success, or else the status code returned by the
1184 * underlying usb_control_msg() call.
1186 int usb_set_interface(struct usb_device
*dev
, int interface
, int alternate
)
1188 struct usb_interface
*iface
;
1189 struct usb_host_interface
*alt
;
1192 unsigned int epaddr
;
1195 if (dev
->state
== USB_STATE_SUSPENDED
)
1196 return -EHOSTUNREACH
;
1198 iface
= usb_ifnum_to_if(dev
, interface
);
1200 dev_dbg(&dev
->dev
, "selecting invalid interface %d\n",
1205 alt
= usb_altnum_to_altsetting(iface
, alternate
);
1207 warn("selecting invalid altsetting %d", alternate
);
1211 if (dev
->quirks
& USB_QUIRK_NO_SET_INTF
)
1214 ret
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1215 USB_REQ_SET_INTERFACE
, USB_RECIP_INTERFACE
,
1216 alternate
, interface
, NULL
, 0, 5000);
1218 /* 9.4.10 says devices don't need this and are free to STALL the
1219 * request if the interface only has one alternate setting.
1221 if (ret
== -EPIPE
&& iface
->num_altsetting
== 1) {
1223 "manual set_interface for iface %d, alt %d\n",
1224 interface
, alternate
);
1229 /* FIXME drivers shouldn't need to replicate/bugfix the logic here
1230 * when they implement async or easily-killable versions of this or
1231 * other "should-be-internal" functions (like clear_halt).
1232 * should hcd+usbcore postprocess control requests?
1235 /* prevent submissions using previous endpoint settings */
1236 if (iface
->cur_altsetting
!= alt
)
1237 usb_remove_sysfs_intf_files(iface
);
1238 usb_disable_interface(dev
, iface
);
1240 iface
->cur_altsetting
= alt
;
1242 /* If the interface only has one altsetting and the device didn't
1243 * accept the request, we attempt to carry out the equivalent action
1244 * by manually clearing the HALT feature for each endpoint in the
1250 for (i
= 0; i
< alt
->desc
.bNumEndpoints
; i
++) {
1251 epaddr
= alt
->endpoint
[i
].desc
.bEndpointAddress
;
1252 pipe
= __create_pipe(dev
,
1253 USB_ENDPOINT_NUMBER_MASK
& epaddr
) |
1254 (usb_endpoint_out(epaddr
) ?
1255 USB_DIR_OUT
: USB_DIR_IN
);
1257 usb_clear_halt(dev
, pipe
);
1261 /* 9.1.1.5: reset toggles for all endpoints in the new altsetting
1264 * Despite EP0 is always present in all interfaces/AS, the list of
1265 * endpoints from the descriptor does not contain EP0. Due to its
1266 * omnipresence one might expect EP0 being considered "affected" by
1267 * any SetInterface request and hence assume toggles need to be reset.
1268 * However, EP0 toggles are re-synced for every individual transfer
1269 * during the SETUP stage - hence EP0 toggles are "don't care" here.
1270 * (Likewise, EP0 never "halts" on well designed devices.)
1272 usb_enable_interface(dev
, iface
);
1273 if (device_is_registered(&iface
->dev
))
1274 usb_create_sysfs_intf_files(iface
);
1278 EXPORT_SYMBOL_GPL(usb_set_interface
);
1281 * usb_reset_configuration - lightweight device reset
1282 * @dev: the device whose configuration is being reset
1284 * This issues a standard SET_CONFIGURATION request to the device using
1285 * the current configuration. The effect is to reset most USB-related
1286 * state in the device, including interface altsettings (reset to zero),
1287 * endpoint halts (cleared), and data toggle (only for bulk and interrupt
1288 * endpoints). Other usbcore state is unchanged, including bindings of
1289 * usb device drivers to interfaces.
1291 * Because this affects multiple interfaces, avoid using this with composite
1292 * (multi-interface) devices. Instead, the driver for each interface may
1293 * use usb_set_interface() on the interfaces it claims. Be careful though;
1294 * some devices don't support the SET_INTERFACE request, and others won't
1295 * reset all the interface state (notably data toggles). Resetting the whole
1296 * configuration would affect other drivers' interfaces.
1298 * The caller must own the device lock.
1300 * Returns zero on success, else a negative error code.
1302 int usb_reset_configuration(struct usb_device
*dev
)
1305 struct usb_host_config
*config
;
1307 if (dev
->state
== USB_STATE_SUSPENDED
)
1308 return -EHOSTUNREACH
;
1310 /* caller must have locked the device and must own
1311 * the usb bus readlock (so driver bindings are stable);
1312 * calls during probe() are fine
1315 for (i
= 1; i
< 16; ++i
) {
1316 usb_disable_endpoint(dev
, i
);
1317 usb_disable_endpoint(dev
, i
+ USB_DIR_IN
);
1320 config
= dev
->actconfig
;
1321 retval
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1322 USB_REQ_SET_CONFIGURATION
, 0,
1323 config
->desc
.bConfigurationValue
, 0,
1324 NULL
, 0, USB_CTRL_SET_TIMEOUT
);
1328 dev
->toggle
[0] = dev
->toggle
[1] = 0;
1330 /* re-init hc/hcd interface/endpoint state */
1331 for (i
= 0; i
< config
->desc
.bNumInterfaces
; i
++) {
1332 struct usb_interface
*intf
= config
->interface
[i
];
1333 struct usb_host_interface
*alt
;
1335 usb_remove_sysfs_intf_files(intf
);
1336 alt
= usb_altnum_to_altsetting(intf
, 0);
1338 /* No altsetting 0? We'll assume the first altsetting.
1339 * We could use a GetInterface call, but if a device is
1340 * so non-compliant that it doesn't have altsetting 0
1341 * then I wouldn't trust its reply anyway.
1344 alt
= &intf
->altsetting
[0];
1346 intf
->cur_altsetting
= alt
;
1347 usb_enable_interface(dev
, intf
);
1348 if (device_is_registered(&intf
->dev
))
1349 usb_create_sysfs_intf_files(intf
);
1353 EXPORT_SYMBOL_GPL(usb_reset_configuration
);
1355 static void usb_release_interface(struct device
*dev
)
1357 struct usb_interface
*intf
= to_usb_interface(dev
);
1358 struct usb_interface_cache
*intfc
=
1359 altsetting_to_usb_interface_cache(intf
->altsetting
);
1361 kref_put(&intfc
->ref
, usb_release_interface_cache
);
1365 #ifdef CONFIG_HOTPLUG
1366 static int usb_if_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1368 struct usb_device
*usb_dev
;
1369 struct usb_interface
*intf
;
1370 struct usb_host_interface
*alt
;
1372 intf
= to_usb_interface(dev
);
1373 usb_dev
= interface_to_usbdev(intf
);
1374 alt
= intf
->cur_altsetting
;
1376 if (add_uevent_var(env
, "INTERFACE=%d/%d/%d",
1377 alt
->desc
.bInterfaceClass
,
1378 alt
->desc
.bInterfaceSubClass
,
1379 alt
->desc
.bInterfaceProtocol
))
1382 if (add_uevent_var(env
,
1384 "v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X",
1385 le16_to_cpu(usb_dev
->descriptor
.idVendor
),
1386 le16_to_cpu(usb_dev
->descriptor
.idProduct
),
1387 le16_to_cpu(usb_dev
->descriptor
.bcdDevice
),
1388 usb_dev
->descriptor
.bDeviceClass
,
1389 usb_dev
->descriptor
.bDeviceSubClass
,
1390 usb_dev
->descriptor
.bDeviceProtocol
,
1391 alt
->desc
.bInterfaceClass
,
1392 alt
->desc
.bInterfaceSubClass
,
1393 alt
->desc
.bInterfaceProtocol
))
1401 static int usb_if_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
1405 #endif /* CONFIG_HOTPLUG */
1407 struct device_type usb_if_device_type
= {
1408 .name
= "usb_interface",
1409 .release
= usb_release_interface
,
1410 .uevent
= usb_if_uevent
,
1413 static struct usb_interface_assoc_descriptor
*find_iad(struct usb_device
*dev
,
1414 struct usb_host_config
*config
,
1417 struct usb_interface_assoc_descriptor
*retval
= NULL
;
1418 struct usb_interface_assoc_descriptor
*intf_assoc
;
1423 for (i
= 0; (i
< USB_MAXIADS
&& config
->intf_assoc
[i
]); i
++) {
1424 intf_assoc
= config
->intf_assoc
[i
];
1425 if (intf_assoc
->bInterfaceCount
== 0)
1428 first_intf
= intf_assoc
->bFirstInterface
;
1429 last_intf
= first_intf
+ (intf_assoc
->bInterfaceCount
- 1);
1430 if (inum
>= first_intf
&& inum
<= last_intf
) {
1432 retval
= intf_assoc
;
1434 dev_err(&dev
->dev
, "Interface #%d referenced"
1435 " by multiple IADs\n", inum
);
1443 * usb_set_configuration - Makes a particular device setting be current
1444 * @dev: the device whose configuration is being updated
1445 * @configuration: the configuration being chosen.
1446 * Context: !in_interrupt(), caller owns the device lock
1448 * This is used to enable non-default device modes. Not all devices
1449 * use this kind of configurability; many devices only have one
1452 * @configuration is the value of the configuration to be installed.
1453 * According to the USB spec (e.g. section 9.1.1.5), configuration values
1454 * must be non-zero; a value of zero indicates that the device in
1455 * unconfigured. However some devices erroneously use 0 as one of their
1456 * configuration values. To help manage such devices, this routine will
1457 * accept @configuration = -1 as indicating the device should be put in
1458 * an unconfigured state.
1460 * USB device configurations may affect Linux interoperability,
1461 * power consumption and the functionality available. For example,
1462 * the default configuration is limited to using 100mA of bus power,
1463 * so that when certain device functionality requires more power,
1464 * and the device is bus powered, that functionality should be in some
1465 * non-default device configuration. Other device modes may also be
1466 * reflected as configuration options, such as whether two ISDN
1467 * channels are available independently; and choosing between open
1468 * standard device protocols (like CDC) or proprietary ones.
1470 * Note that a non-authorized device (dev->authorized == 0) will only
1471 * be put in unconfigured mode.
1473 * Note that USB has an additional level of device configurability,
1474 * associated with interfaces. That configurability is accessed using
1475 * usb_set_interface().
1477 * This call is synchronous. The calling context must be able to sleep,
1478 * must own the device lock, and must not hold the driver model's USB
1479 * bus mutex; usb interface driver probe() methods cannot use this routine.
1481 * Returns zero on success, or else the status code returned by the
1482 * underlying call that failed. On successful completion, each interface
1483 * in the original device configuration has been destroyed, and each one
1484 * in the new configuration has been probed by all relevant usb device
1485 * drivers currently known to the kernel.
1487 int usb_set_configuration(struct usb_device
*dev
, int configuration
)
1490 struct usb_host_config
*cp
= NULL
;
1491 struct usb_interface
**new_interfaces
= NULL
;
1494 if (dev
->authorized
== 0 || configuration
== -1)
1497 for (i
= 0; i
< dev
->descriptor
.bNumConfigurations
; i
++) {
1498 if (dev
->config
[i
].desc
.bConfigurationValue
==
1500 cp
= &dev
->config
[i
];
1505 if ((!cp
&& configuration
!= 0))
1508 /* The USB spec says configuration 0 means unconfigured.
1509 * But if a device includes a configuration numbered 0,
1510 * we will accept it as a correctly configured state.
1511 * Use -1 if you really want to unconfigure the device.
1513 if (cp
&& configuration
== 0)
1514 dev_warn(&dev
->dev
, "config 0 descriptor??\n");
1516 /* Allocate memory for new interfaces before doing anything else,
1517 * so that if we run out then nothing will have changed. */
1520 nintf
= cp
->desc
.bNumInterfaces
;
1521 new_interfaces
= kmalloc(nintf
* sizeof(*new_interfaces
),
1523 if (!new_interfaces
) {
1524 dev_err(&dev
->dev
, "Out of memory\n");
1528 for (; n
< nintf
; ++n
) {
1529 new_interfaces
[n
] = kzalloc(
1530 sizeof(struct usb_interface
),
1532 if (!new_interfaces
[n
]) {
1533 dev_err(&dev
->dev
, "Out of memory\n");
1537 kfree(new_interfaces
[n
]);
1538 kfree(new_interfaces
);
1543 i
= dev
->bus_mA
- cp
->desc
.bMaxPower
* 2;
1545 dev_warn(&dev
->dev
, "new config #%d exceeds power "
1550 /* Wake up the device so we can send it the Set-Config request */
1551 ret
= usb_autoresume_device(dev
);
1553 goto free_interfaces
;
1555 /* if it's already configured, clear out old state first.
1556 * getting rid of old interfaces means unbinding their drivers.
1558 if (dev
->state
!= USB_STATE_ADDRESS
)
1559 usb_disable_device(dev
, 1); /* Skip ep0 */
1561 ret
= usb_control_msg(dev
, usb_sndctrlpipe(dev
, 0),
1562 USB_REQ_SET_CONFIGURATION
, 0, configuration
, 0,
1563 NULL
, 0, USB_CTRL_SET_TIMEOUT
);
1565 /* All the old state is gone, so what else can we do?
1566 * The device is probably useless now anyway.
1571 dev
->actconfig
= cp
;
1573 usb_set_device_state(dev
, USB_STATE_ADDRESS
);
1574 usb_autosuspend_device(dev
);
1575 goto free_interfaces
;
1577 usb_set_device_state(dev
, USB_STATE_CONFIGURED
);
1579 /* Initialize the new interface structures and the
1580 * hc/hcd/usbcore interface/endpoint state.
1582 for (i
= 0; i
< nintf
; ++i
) {
1583 struct usb_interface_cache
*intfc
;
1584 struct usb_interface
*intf
;
1585 struct usb_host_interface
*alt
;
1587 cp
->interface
[i
] = intf
= new_interfaces
[i
];
1588 intfc
= cp
->intf_cache
[i
];
1589 intf
->altsetting
= intfc
->altsetting
;
1590 intf
->num_altsetting
= intfc
->num_altsetting
;
1591 intf
->intf_assoc
= find_iad(dev
, cp
, i
);
1592 kref_get(&intfc
->ref
);
1594 alt
= usb_altnum_to_altsetting(intf
, 0);
1596 /* No altsetting 0? We'll assume the first altsetting.
1597 * We could use a GetInterface call, but if a device is
1598 * so non-compliant that it doesn't have altsetting 0
1599 * then I wouldn't trust its reply anyway.
1602 alt
= &intf
->altsetting
[0];
1604 intf
->cur_altsetting
= alt
;
1605 usb_enable_interface(dev
, intf
);
1606 intf
->dev
.parent
= &dev
->dev
;
1607 intf
->dev
.driver
= NULL
;
1608 intf
->dev
.bus
= &usb_bus_type
;
1609 intf
->dev
.type
= &usb_if_device_type
;
1610 intf
->dev
.groups
= usb_interface_groups
;
1611 intf
->dev
.dma_mask
= dev
->dev
.dma_mask
;
1612 device_initialize(&intf
->dev
);
1613 mark_quiesced(intf
);
1614 dev_set_name(&intf
->dev
, "%d-%s:%d.%d",
1615 dev
->bus
->busnum
, dev
->devpath
,
1616 configuration
, alt
->desc
.bInterfaceNumber
);
1618 kfree(new_interfaces
);
1620 if (cp
->string
== NULL
)
1621 cp
->string
= usb_cache_string(dev
, cp
->desc
.iConfiguration
);
1623 /* Now that all the interfaces are set up, register them
1624 * to trigger binding of drivers to interfaces. probe()
1625 * routines may install different altsettings and may
1626 * claim() any interfaces not yet bound. Many class drivers
1627 * need that: CDC, audio, video, etc.
1629 for (i
= 0; i
< nintf
; ++i
) {
1630 struct usb_interface
*intf
= cp
->interface
[i
];
1633 "adding %s (config #%d, interface %d)\n",
1634 dev_name(&intf
->dev
), configuration
,
1635 intf
->cur_altsetting
->desc
.bInterfaceNumber
);
1636 ret
= device_add(&intf
->dev
);
1638 dev_err(&dev
->dev
, "device_add(%s) --> %d\n",
1639 dev_name(&intf
->dev
), ret
);
1642 usb_create_sysfs_intf_files(intf
);
1645 usb_autosuspend_device(dev
);
1649 struct set_config_request
{
1650 struct usb_device
*udev
;
1652 struct work_struct work
;
1655 /* Worker routine for usb_driver_set_configuration() */
1656 static void driver_set_config_work(struct work_struct
*work
)
1658 struct set_config_request
*req
=
1659 container_of(work
, struct set_config_request
, work
);
1661 usb_lock_device(req
->udev
);
1662 usb_set_configuration(req
->udev
, req
->config
);
1663 usb_unlock_device(req
->udev
);
1664 usb_put_dev(req
->udev
);
1669 * usb_driver_set_configuration - Provide a way for drivers to change device configurations
1670 * @udev: the device whose configuration is being updated
1671 * @config: the configuration being chosen.
1672 * Context: In process context, must be able to sleep
1674 * Device interface drivers are not allowed to change device configurations.
1675 * This is because changing configurations will destroy the interface the
1676 * driver is bound to and create new ones; it would be like a floppy-disk
1677 * driver telling the computer to replace the floppy-disk drive with a
1680 * Still, in certain specialized circumstances the need may arise. This
1681 * routine gets around the normal restrictions by using a work thread to
1682 * submit the change-config request.
1684 * Returns 0 if the request was succesfully queued, error code otherwise.
1685 * The caller has no way to know whether the queued request will eventually
1688 int usb_driver_set_configuration(struct usb_device
*udev
, int config
)
1690 struct set_config_request
*req
;
1692 req
= kmalloc(sizeof(*req
), GFP_KERNEL
);
1696 req
->config
= config
;
1697 INIT_WORK(&req
->work
, driver_set_config_work
);
1700 schedule_work(&req
->work
);
1703 EXPORT_SYMBOL_GPL(usb_driver_set_configuration
);