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percpu, x86: don't use PMD_SIZE as embedded atom_size on 32bit
[zen-stable.git] / drivers / usb / gadget / inode.c
blob4f18a0e46070b13ceaeaab12209453b66527f1b3
1 /*
2 * inode.c -- user mode filesystem api for usb gadget controllers
3 *
4 * Copyright (C) 2003-2004 David Brownell
5 * Copyright (C) 2003 Agilent Technologies
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 */
12
13
14 /* #define VERBOSE_DEBUG */
15
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/fs.h>
19 #include <linux/pagemap.h>
20 #include <linux/uts.h>
21 #include <linux/wait.h>
22 #include <linux/compiler.h>
23 #include <asm/uaccess.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/poll.h>
27
28 #include <linux/device.h>
29 #include <linux/moduleparam.h>
30
31 #include <linux/usb/gadgetfs.h>
32 #include <linux/usb/gadget.h>
33
34
35 /*
36 * The gadgetfs API maps each endpoint to a file descriptor so that you
37 * can use standard synchronous read/write calls for I/O. There's some
38 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
39 * drivers show how this works in practice. You can also use AIO to
40 * eliminate I/O gaps between requests, to help when streaming data.
41 *
42 * Key parts that must be USB-specific are protocols defining how the
43 * read/write operations relate to the hardware state machines. There
44 * are two types of files. One type is for the device, implementing ep0.
45 * The other type is for each IN or OUT endpoint. In both cases, the
46 * user mode driver must configure the hardware before using it.
47 *
48 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
49 * (by writing configuration and device descriptors). Afterwards it
50 * may serve as a source of device events, used to handle all control
51 * requests other than basic enumeration.
52 *
53 * - Then, after a SET_CONFIGURATION control request, ep_config() is
54 * called when each /dev/gadget/ep* file is configured (by writing
55 * endpoint descriptors). Afterwards these files are used to write()
56 * IN data or to read() OUT data. To halt the endpoint, a "wrong
57 * direction" request is issued (like reading an IN endpoint).
58 *
59 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
60 * not possible on all hardware. For example, precise fault handling with
61 * respect to data left in endpoint fifos after aborted operations; or
62 * selective clearing of endpoint halts, to implement SET_INTERFACE.
63 */
64
65 #define DRIVER_DESC "USB Gadget filesystem"
66 #define DRIVER_VERSION "24 Aug 2004"
67
68 static const char driver_desc [] = DRIVER_DESC;
69 static const char shortname [] = "gadgetfs";
70
71 MODULE_DESCRIPTION (DRIVER_DESC);
72 MODULE_AUTHOR ("David Brownell");
73 MODULE_LICENSE ("GPL");
74
75
76 /*----------------------------------------------------------------------*/
77
78 #define GADGETFS_MAGIC 0xaee71ee7
79 #define DMA_ADDR_INVALID (~(dma_addr_t)0)
80
81 /* /dev/gadget/$CHIP represents ep0 and the whole device */
82 enum ep0_state {
83 /* DISBLED is the initial state.
84 */
85 STATE_DEV_DISABLED = 0,
86
87 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
88 * ep0/device i/o modes and binding to the controller. Driver
89 * must always write descriptors to initialize the device, then
90 * the device becomes UNCONNECTED until enumeration.
91 */
92 STATE_DEV_OPENED,
93
94 /* From then on, ep0 fd is in either of two basic modes:
95 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
96 * - SETUP: read/write will transfer control data and succeed;
97 * or if "wrong direction", performs protocol stall
98 */
99 STATE_DEV_UNCONNECTED,
100 STATE_DEV_CONNECTED,
101 STATE_DEV_SETUP,
102
103 /* UNBOUND means the driver closed ep0, so the device won't be
104 * accessible again (DEV_DISABLED) until all fds are closed.
105 */
106 STATE_DEV_UNBOUND,
107 };
108
109 /* enough for the whole queue: most events invalidate others */
110 #define N_EVENT 5
111
112 struct dev_data {
113 spinlock_t lock;
114 atomic_t count;
115 enum ep0_state state; /* P: lock */
116 struct usb_gadgetfs_event event [N_EVENT];
117 unsigned ev_next;
118 struct fasync_struct *fasync;
119 u8 current_config;
120
121 /* drivers reading ep0 MUST handle control requests (SETUP)
122 * reported that way; else the host will time out.
123 */
124 unsigned usermode_setup : 1,
125 setup_in : 1,
126 setup_can_stall : 1,
127 setup_out_ready : 1,
128 setup_out_error : 1,
129 setup_abort : 1;
130 unsigned setup_wLength;
131
132 /* the rest is basically write-once */
133 struct usb_config_descriptor *config, *hs_config;
134 struct usb_device_descriptor *dev;
135 struct usb_request *req;
136 struct usb_gadget *gadget;
137 struct list_head epfiles;
138 void *buf;
139 wait_queue_head_t wait;
140 struct super_block *sb;
141 struct dentry *dentry;
142
143 /* except this scratch i/o buffer for ep0 */
144 u8 rbuf [256];
145 };
146
147 static inline void get_dev (struct dev_data *data)
148 {
149 atomic_inc (&data->count);
150 }
151
152 static void put_dev (struct dev_data *data)
153 {
154 if (likely (!atomic_dec_and_test (&data->count)))
155 return;
156 /* needs no more cleanup */
157 BUG_ON (waitqueue_active (&data->wait));
158 kfree (data);
159 }
160
161 static struct dev_data *dev_new (void)
162 {
163 struct dev_data *dev;
164
165 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
166 if (!dev)
167 return NULL;
168 dev->state = STATE_DEV_DISABLED;
169 atomic_set (&dev->count, 1);
170 spin_lock_init (&dev->lock);
171 INIT_LIST_HEAD (&dev->epfiles);
172 init_waitqueue_head (&dev->wait);
173 return dev;
174 }
175
176 /*----------------------------------------------------------------------*/
177
178 /* other /dev/gadget/$ENDPOINT files represent endpoints */
179 enum ep_state {
180 STATE_EP_DISABLED = 0,
181 STATE_EP_READY,
182 STATE_EP_ENABLED,
183 STATE_EP_UNBOUND,
184 };
185
186 struct ep_data {
187 struct mutex lock;
188 enum ep_state state;
189 atomic_t count;
190 struct dev_data *dev;
191 /* must hold dev->lock before accessing ep or req */
192 struct usb_ep *ep;
193 struct usb_request *req;
194 ssize_t status;
195 char name [16];
196 struct usb_endpoint_descriptor desc, hs_desc;
197 struct list_head epfiles;
198 wait_queue_head_t wait;
199 struct dentry *dentry;
200 struct inode *inode;
201 };
202
203 static inline void get_ep (struct ep_data *data)
204 {
205 atomic_inc (&data->count);
206 }
207
208 static void put_ep (struct ep_data *data)
209 {
210 if (likely (!atomic_dec_and_test (&data->count)))
211 return;
212 put_dev (data->dev);
213 /* needs no more cleanup */
214 BUG_ON (!list_empty (&data->epfiles));
215 BUG_ON (waitqueue_active (&data->wait));
216 kfree (data);
217 }
218
219 /*----------------------------------------------------------------------*/
220
221 /* most "how to use the hardware" policy choices are in userspace:
222 * mapping endpoint roles (which the driver needs) to the capabilities
223 * which the usb controller has. most of those capabilities are exposed
224 * implicitly, starting with the driver name and then endpoint names.
225 */
226
227 static const char *CHIP;
228
229 /*----------------------------------------------------------------------*/
230
231 /* NOTE: don't use dev_printk calls before binding to the gadget
232 * at the end of ep0 configuration, or after unbind.
233 */
234
235 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
236 #define xprintk(d,level,fmt,args...) \
237 printk(level "%s: " fmt , shortname , ## args)
238
239 #ifdef DEBUG
240 #define DBG(dev,fmt,args...) \
241 xprintk(dev , KERN_DEBUG , fmt , ## args)
242 #else
243 #define DBG(dev,fmt,args...) \
244 do { } while (0)
245 #endif /* DEBUG */
246
247 #ifdef VERBOSE_DEBUG
248 #define VDEBUG DBG
249 #else
250 #define VDEBUG(dev,fmt,args...) \
251 do { } while (0)
252 #endif /* DEBUG */
253
254 #define ERROR(dev,fmt,args...) \
255 xprintk(dev , KERN_ERR , fmt , ## args)
256 #define INFO(dev,fmt,args...) \
257 xprintk(dev , KERN_INFO , fmt , ## args)
258
259
260 /*----------------------------------------------------------------------*/
261
262 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
263 *
264 * After opening, configure non-control endpoints. Then use normal
265 * stream read() and write() requests; and maybe ioctl() to get more
266 * precise FIFO status when recovering from cancellation.
267 */
268
269 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
270 {
271 struct ep_data *epdata = ep->driver_data;
272
273 if (!req->context)
274 return;
275 if (req->status)
276 epdata->status = req->status;
277 else
278 epdata->status = req->actual;
279 complete ((struct completion *)req->context);
280 }
281
282 /* tasklock endpoint, returning when it's connected.
283 * still need dev->lock to use epdata->ep.
284 */
285 static int
286 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
287 {
288 int val;
289
290 if (f_flags & O_NONBLOCK) {
291 if (!mutex_trylock(&epdata->lock))
292 goto nonblock;
293 if (epdata->state != STATE_EP_ENABLED) {
294 mutex_unlock(&epdata->lock);
295 nonblock:
296 val = -EAGAIN;
297 } else
298 val = 0;
299 return val;
300 }
301
302 val = mutex_lock_interruptible(&epdata->lock);
303 if (val < 0)
304 return val;
305
306 switch (epdata->state) {
307 case STATE_EP_ENABLED:
308 break;
309 // case STATE_EP_DISABLED: /* "can't happen" */
310 // case STATE_EP_READY: /* "can't happen" */
311 default: /* error! */
312 pr_debug ("%s: ep %p not available, state %d\n",
313 shortname, epdata, epdata->state);
314 // FALLTHROUGH
315 case STATE_EP_UNBOUND: /* clean disconnect */
316 val = -ENODEV;
317 mutex_unlock(&epdata->lock);
318 }
319 return val;
320 }
321
322 static ssize_t
323 ep_io (struct ep_data *epdata, void *buf, unsigned len)
324 {
325 DECLARE_COMPLETION_ONSTACK (done);
326 int value;
327
328 spin_lock_irq (&epdata->dev->lock);
329 if (likely (epdata->ep != NULL)) {
330 struct usb_request *req = epdata->req;
331
332 req->context = &done;
333 req->complete = epio_complete;
334 req->buf = buf;
335 req->length = len;
336 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
337 } else
338 value = -ENODEV;
339 spin_unlock_irq (&epdata->dev->lock);
340
341 if (likely (value == 0)) {
342 value = wait_event_interruptible (done.wait, done.done);
343 if (value != 0) {
344 spin_lock_irq (&epdata->dev->lock);
345 if (likely (epdata->ep != NULL)) {
346 DBG (epdata->dev, "%s i/o interrupted\n",
347 epdata->name);
348 usb_ep_dequeue (epdata->ep, epdata->req);
349 spin_unlock_irq (&epdata->dev->lock);
350
351 wait_event (done.wait, done.done);
352 if (epdata->status == -ECONNRESET)
353 epdata->status = -EINTR;
354 } else {
355 spin_unlock_irq (&epdata->dev->lock);
356
357 DBG (epdata->dev, "endpoint gone\n");
358 epdata->status = -ENODEV;
359 }
360 }
361 return epdata->status;
362 }
363 return value;
364 }
365
366
367 /* handle a synchronous OUT bulk/intr/iso transfer */
368 static ssize_t
369 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
370 {
371 struct ep_data *data = fd->private_data;
372 void *kbuf;
373 ssize_t value;
374
375 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
376 return value;
377
378 /* halt any endpoint by doing a "wrong direction" i/o call */
379 if (usb_endpoint_dir_in(&data->desc)) {
380 if (usb_endpoint_xfer_isoc(&data->desc)) {
381 mutex_unlock(&data->lock);
382 return -EINVAL;
383 }
384 DBG (data->dev, "%s halt\n", data->name);
385 spin_lock_irq (&data->dev->lock);
386 if (likely (data->ep != NULL))
387 usb_ep_set_halt (data->ep);
388 spin_unlock_irq (&data->dev->lock);
389 mutex_unlock(&data->lock);
390 return -EBADMSG;
391 }
392
393 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
394
395 value = -ENOMEM;
396 kbuf = kmalloc (len, GFP_KERNEL);
397 if (unlikely (!kbuf))
398 goto free1;
399
400 value = ep_io (data, kbuf, len);
401 VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
402 data->name, len, (int) value);
403 if (value >= 0 && copy_to_user (buf, kbuf, value))
404 value = -EFAULT;
405
406 free1:
407 mutex_unlock(&data->lock);
408 kfree (kbuf);
409 return value;
410 }
411
412 /* handle a synchronous IN bulk/intr/iso transfer */
413 static ssize_t
414 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
415 {
416 struct ep_data *data = fd->private_data;
417 void *kbuf;
418 ssize_t value;
419
420 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
421 return value;
422
423 /* halt any endpoint by doing a "wrong direction" i/o call */
424 if (!usb_endpoint_dir_in(&data->desc)) {
425 if (usb_endpoint_xfer_isoc(&data->desc)) {
426 mutex_unlock(&data->lock);
427 return -EINVAL;
428 }
429 DBG (data->dev, "%s halt\n", data->name);
430 spin_lock_irq (&data->dev->lock);
431 if (likely (data->ep != NULL))
432 usb_ep_set_halt (data->ep);
433 spin_unlock_irq (&data->dev->lock);
434 mutex_unlock(&data->lock);
435 return -EBADMSG;
436 }
437
438 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
439
440 value = -ENOMEM;
441 kbuf = kmalloc (len, GFP_KERNEL);
442 if (!kbuf)
443 goto free1;
444 if (copy_from_user (kbuf, buf, len)) {
445 value = -EFAULT;
446 goto free1;
447 }
448
449 value = ep_io (data, kbuf, len);
450 VDEBUG (data->dev, "%s write %zu IN, status %d\n",
451 data->name, len, (int) value);
452 free1:
453 mutex_unlock(&data->lock);
454 kfree (kbuf);
455 return value;
456 }
457
458 static int
459 ep_release (struct inode *inode, struct file *fd)
460 {
461 struct ep_data *data = fd->private_data;
462 int value;
463
464 value = mutex_lock_interruptible(&data->lock);
465 if (value < 0)
466 return value;
467
468 /* clean up if this can be reopened */
469 if (data->state != STATE_EP_UNBOUND) {
470 data->state = STATE_EP_DISABLED;
471 data->desc.bDescriptorType = 0;
472 data->hs_desc.bDescriptorType = 0;
473 usb_ep_disable(data->ep);
474 }
475 mutex_unlock(&data->lock);
476 put_ep (data);
477 return 0;
478 }
479
480 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
481 {
482 struct ep_data *data = fd->private_data;
483 int status;
484
485 if ((status = get_ready_ep (fd->f_flags, data)) < 0)
486 return status;
487
488 spin_lock_irq (&data->dev->lock);
489 if (likely (data->ep != NULL)) {
490 switch (code) {
491 case GADGETFS_FIFO_STATUS:
492 status = usb_ep_fifo_status (data->ep);
493 break;
494 case GADGETFS_FIFO_FLUSH:
495 usb_ep_fifo_flush (data->ep);
496 break;
497 case GADGETFS_CLEAR_HALT:
498 status = usb_ep_clear_halt (data->ep);
499 break;
500 default:
501 status = -ENOTTY;
502 }
503 } else
504 status = -ENODEV;
505 spin_unlock_irq (&data->dev->lock);
506 mutex_unlock(&data->lock);
507 return status;
508 }
509
510 /*----------------------------------------------------------------------*/
511
512 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
513
514 struct kiocb_priv {
515 struct usb_request *req;
516 struct ep_data *epdata;
517 void *buf;
518 const struct iovec *iv;
519 unsigned long nr_segs;
520 unsigned actual;
521 };
522
523 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
524 {
525 struct kiocb_priv *priv = iocb->private;
526 struct ep_data *epdata;
527 int value;
528
529 local_irq_disable();
530 epdata = priv->epdata;
531 // spin_lock(&epdata->dev->lock);
532 kiocbSetCancelled(iocb);
533 if (likely(epdata && epdata->ep && priv->req))
534 value = usb_ep_dequeue (epdata->ep, priv->req);
535 else
536 value = -EINVAL;
537 // spin_unlock(&epdata->dev->lock);
538 local_irq_enable();
539
540 aio_put_req(iocb);
541 return value;
542 }
543
544 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
545 {
546 struct kiocb_priv *priv = iocb->private;
547 ssize_t len, total;
548 void *to_copy;
549 int i;
550
551 /* we "retry" to get the right mm context for this: */
552
553 /* copy stuff into user buffers */
554 total = priv->actual;
555 len = 0;
556 to_copy = priv->buf;
557 for (i=0; i < priv->nr_segs; i++) {
558 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
559
560 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
561 if (len == 0)
562 len = -EFAULT;
563 break;
564 }
565
566 total -= this;
567 len += this;
568 to_copy += this;
569 if (total == 0)
570 break;
571 }
572 kfree(priv->buf);
573 kfree(priv);
574 return len;
575 }
576
577 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
578 {
579 struct kiocb *iocb = req->context;
580 struct kiocb_priv *priv = iocb->private;
581 struct ep_data *epdata = priv->epdata;
582
583 /* lock against disconnect (and ideally, cancel) */
584 spin_lock(&epdata->dev->lock);
585 priv->req = NULL;
586 priv->epdata = NULL;
587
588 /* if this was a write or a read returning no data then we
589 * don't need to copy anything to userspace, so we can
590 * complete the aio request immediately.
591 */
592 if (priv->iv == NULL || unlikely(req->actual == 0)) {
593 kfree(req->buf);
594 kfree(priv);
595 iocb->private = NULL;
596 /* aio_complete() reports bytes-transferred _and_ faults */
597 aio_complete(iocb, req->actual ? req->actual : req->status,
598 req->status);
599 } else {
600 /* retry() won't report both; so we hide some faults */
601 if (unlikely(0 != req->status))
602 DBG(epdata->dev, "%s fault %d len %d\n",
603 ep->name, req->status, req->actual);
604
605 priv->buf = req->buf;
606 priv->actual = req->actual;
607 kick_iocb(iocb);
608 }
609 spin_unlock(&epdata->dev->lock);
610
611 usb_ep_free_request(ep, req);
612 put_ep(epdata);
613 }
614
615 static ssize_t
616 ep_aio_rwtail(
617 struct kiocb *iocb,
618 char *buf,
619 size_t len,
620 struct ep_data *epdata,
621 const struct iovec *iv,
622 unsigned long nr_segs
623 )
624 {
625 struct kiocb_priv *priv;
626 struct usb_request *req;
627 ssize_t value;
628
629 priv = kmalloc(sizeof *priv, GFP_KERNEL);
630 if (!priv) {
631 value = -ENOMEM;
632 fail:
633 kfree(buf);
634 return value;
635 }
636 iocb->private = priv;
637 priv->iv = iv;
638 priv->nr_segs = nr_segs;
639
640 value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
641 if (unlikely(value < 0)) {
642 kfree(priv);
643 goto fail;
644 }
645
646 iocb->ki_cancel = ep_aio_cancel;
647 get_ep(epdata);
648 priv->epdata = epdata;
649 priv->actual = 0;
650
651 /* each kiocb is coupled to one usb_request, but we can't
652 * allocate or submit those if the host disconnected.
653 */
654 spin_lock_irq(&epdata->dev->lock);
655 if (likely(epdata->ep)) {
656 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
657 if (likely(req)) {
658 priv->req = req;
659 req->buf = buf;
660 req->length = len;
661 req->complete = ep_aio_complete;
662 req->context = iocb;
663 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
664 if (unlikely(0 != value))
665 usb_ep_free_request(epdata->ep, req);
666 } else
667 value = -EAGAIN;
668 } else
669 value = -ENODEV;
670 spin_unlock_irq(&epdata->dev->lock);
671
672 mutex_unlock(&epdata->lock);
673
674 if (unlikely(value)) {
675 kfree(priv);
676 put_ep(epdata);
677 } else
678 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
679 return value;
680 }
681
682 static ssize_t
683 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
684 unsigned long nr_segs, loff_t o)
685 {
686 struct ep_data *epdata = iocb->ki_filp->private_data;
687 char *buf;
688
689 if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
690 return -EINVAL;
691
692 buf = kmalloc(iocb->ki_left, GFP_KERNEL);
693 if (unlikely(!buf))
694 return -ENOMEM;
695
696 iocb->ki_retry = ep_aio_read_retry;
697 return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
698 }
699
700 static ssize_t
701 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
702 unsigned long nr_segs, loff_t o)
703 {
704 struct ep_data *epdata = iocb->ki_filp->private_data;
705 char *buf;
706 size_t len = 0;
707 int i = 0;
708
709 if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
710 return -EINVAL;
711
712 buf = kmalloc(iocb->ki_left, GFP_KERNEL);
713 if (unlikely(!buf))
714 return -ENOMEM;
715
716 for (i=0; i < nr_segs; i++) {
717 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
718 iov[i].iov_len) != 0)) {
719 kfree(buf);
720 return -EFAULT;
721 }
722 len += iov[i].iov_len;
723 }
724 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
725 }
726
727 /*----------------------------------------------------------------------*/
728
729 /* used after endpoint configuration */
730 static const struct file_operations ep_io_operations = {
731 .owner = THIS_MODULE,
732 .llseek = no_llseek,
733
734 .read = ep_read,
735 .write = ep_write,
736 .unlocked_ioctl = ep_ioctl,
737 .release = ep_release,
738
739 .aio_read = ep_aio_read,
740 .aio_write = ep_aio_write,
741 };
742
743 /* ENDPOINT INITIALIZATION
744 *
745 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
746 * status = write (fd, descriptors, sizeof descriptors)
747 *
748 * That write establishes the endpoint configuration, configuring
749 * the controller to process bulk, interrupt, or isochronous transfers
750 * at the right maxpacket size, and so on.
751 *
752 * The descriptors are message type 1, identified by a host order u32
753 * at the beginning of what's written. Descriptor order is: full/low
754 * speed descriptor, then optional high speed descriptor.
755 */
756 static ssize_t
757 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
758 {
759 struct ep_data *data = fd->private_data;
760 struct usb_ep *ep;
761 u32 tag;
762 int value, length = len;
763
764 value = mutex_lock_interruptible(&data->lock);
765 if (value < 0)
766 return value;
767
768 if (data->state != STATE_EP_READY) {
769 value = -EL2HLT;
770 goto fail;
771 }
772
773 value = len;
774 if (len < USB_DT_ENDPOINT_SIZE + 4)
775 goto fail0;
776
777 /* we might need to change message format someday */
778 if (copy_from_user (&tag, buf, 4)) {
779 goto fail1;
780 }
781 if (tag != 1) {
782 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
783 goto fail0;
784 }
785 buf += 4;
786 len -= 4;
787
788 /* NOTE: audio endpoint extensions not accepted here;
789 * just don't include the extra bytes.
790 */
791
792 /* full/low speed descriptor, then high speed */
793 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
794 goto fail1;
795 }
796 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
797 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
798 goto fail0;
799 if (len != USB_DT_ENDPOINT_SIZE) {
800 if (len != 2 * USB_DT_ENDPOINT_SIZE)
801 goto fail0;
802 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
803 USB_DT_ENDPOINT_SIZE)) {
804 goto fail1;
805 }
806 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
807 || data->hs_desc.bDescriptorType
808 != USB_DT_ENDPOINT) {
809 DBG(data->dev, "config %s, bad hs length or type\n",
810 data->name);
811 goto fail0;
812 }
813 }
814
815 spin_lock_irq (&data->dev->lock);
816 if (data->dev->state == STATE_DEV_UNBOUND) {
817 value = -ENOENT;
818 goto gone;
819 } else if ((ep = data->ep) == NULL) {
820 value = -ENODEV;
821 goto gone;
822 }
823 switch (data->dev->gadget->speed) {
824 case USB_SPEED_LOW:
825 case USB_SPEED_FULL:
826 ep->desc = &data->desc;
827 value = usb_ep_enable(ep);
828 if (value == 0)
829 data->state = STATE_EP_ENABLED;
830 break;
831 #ifdef CONFIG_USB_GADGET_DUALSPEED
832 case USB_SPEED_HIGH:
833 /* fails if caller didn't provide that descriptor... */
834 ep->desc = &data->hs_desc;
835 value = usb_ep_enable(ep);
836 if (value == 0)
837 data->state = STATE_EP_ENABLED;
838 break;
839 #endif
840 default:
841 DBG(data->dev, "unconnected, %s init abandoned\n",
842 data->name);
843 value = -EINVAL;
844 }
845 if (value == 0) {
846 fd->f_op = &ep_io_operations;
847 value = length;
848 }
849 gone:
850 spin_unlock_irq (&data->dev->lock);
851 if (value < 0) {
852 fail:
853 data->desc.bDescriptorType = 0;
854 data->hs_desc.bDescriptorType = 0;
855 }
856 mutex_unlock(&data->lock);
857 return value;
858 fail0:
859 value = -EINVAL;
860 goto fail;
861 fail1:
862 value = -EFAULT;
863 goto fail;
864 }
865
866 static int
867 ep_open (struct inode *inode, struct file *fd)
868 {
869 struct ep_data *data = inode->i_private;
870 int value = -EBUSY;
871
872 if (mutex_lock_interruptible(&data->lock) != 0)
873 return -EINTR;
874 spin_lock_irq (&data->dev->lock);
875 if (data->dev->state == STATE_DEV_UNBOUND)
876 value = -ENOENT;
877 else if (data->state == STATE_EP_DISABLED) {
878 value = 0;
879 data->state = STATE_EP_READY;
880 get_ep (data);
881 fd->private_data = data;
882 VDEBUG (data->dev, "%s ready\n", data->name);
883 } else
884 DBG (data->dev, "%s state %d\n",
885 data->name, data->state);
886 spin_unlock_irq (&data->dev->lock);
887 mutex_unlock(&data->lock);
888 return value;
889 }
890
891 /* used before endpoint configuration */
892 static const struct file_operations ep_config_operations = {
893 .owner = THIS_MODULE,
894 .llseek = no_llseek,
895
896 .open = ep_open,
897 .write = ep_config,
898 .release = ep_release,
899 };
900
901 /*----------------------------------------------------------------------*/
902
903 /* EP0 IMPLEMENTATION can be partly in userspace.
904 *
905 * Drivers that use this facility receive various events, including
906 * control requests the kernel doesn't handle. Drivers that don't
907 * use this facility may be too simple-minded for real applications.
908 */
909
910 static inline void ep0_readable (struct dev_data *dev)
911 {
912 wake_up (&dev->wait);
913 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
914 }
915
916 static void clean_req (struct usb_ep *ep, struct usb_request *req)
917 {
918 struct dev_data *dev = ep->driver_data;
919
920 if (req->buf != dev->rbuf) {
921 kfree(req->buf);
922 req->buf = dev->rbuf;
923 req->dma = DMA_ADDR_INVALID;
924 }
925 req->complete = epio_complete;
926 dev->setup_out_ready = 0;
927 }
928
929 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
930 {
931 struct dev_data *dev = ep->driver_data;
932 unsigned long flags;
933 int free = 1;
934
935 /* for control OUT, data must still get to userspace */
936 spin_lock_irqsave(&dev->lock, flags);
937 if (!dev->setup_in) {
938 dev->setup_out_error = (req->status != 0);
939 if (!dev->setup_out_error)
940 free = 0;
941 dev->setup_out_ready = 1;
942 ep0_readable (dev);
943 }
944
945 /* clean up as appropriate */
946 if (free && req->buf != &dev->rbuf)
947 clean_req (ep, req);
948 req->complete = epio_complete;
949 spin_unlock_irqrestore(&dev->lock, flags);
950 }
951
952 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
953 {
954 struct dev_data *dev = ep->driver_data;
955
956 if (dev->setup_out_ready) {
957 DBG (dev, "ep0 request busy!\n");
958 return -EBUSY;
959 }
960 if (len > sizeof (dev->rbuf))
961 req->buf = kmalloc(len, GFP_ATOMIC);
962 if (req->buf == NULL) {
963 req->buf = dev->rbuf;
964 return -ENOMEM;
965 }
966 req->complete = ep0_complete;
967 req->length = len;
968 req->zero = 0;
969 return 0;
970 }
971
972 static ssize_t
973 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
974 {
975 struct dev_data *dev = fd->private_data;
976 ssize_t retval;
977 enum ep0_state state;
978
979 spin_lock_irq (&dev->lock);
980
981 /* report fd mode change before acting on it */
982 if (dev->setup_abort) {
983 dev->setup_abort = 0;
984 retval = -EIDRM;
985 goto done;
986 }
987
988 /* control DATA stage */
989 if ((state = dev->state) == STATE_DEV_SETUP) {
990
991 if (dev->setup_in) { /* stall IN */
992 VDEBUG(dev, "ep0in stall\n");
993 (void) usb_ep_set_halt (dev->gadget->ep0);
994 retval = -EL2HLT;
995 dev->state = STATE_DEV_CONNECTED;
996
997 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
998 struct usb_ep *ep = dev->gadget->ep0;
999 struct usb_request *req = dev->req;
1000
1001 if ((retval = setup_req (ep, req, 0)) == 0)
1002 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1003 dev->state = STATE_DEV_CONNECTED;
1004
1005 /* assume that was SET_CONFIGURATION */
1006 if (dev->current_config) {
1007 unsigned power;
1008
1009 if (gadget_is_dualspeed(dev->gadget)
1010 && (dev->gadget->speed
1011 == USB_SPEED_HIGH))
1012 power = dev->hs_config->bMaxPower;
1013 else
1014 power = dev->config->bMaxPower;
1015 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1016 }
1017
1018 } else { /* collect OUT data */
1019 if ((fd->f_flags & O_NONBLOCK) != 0
1020 && !dev->setup_out_ready) {
1021 retval = -EAGAIN;
1022 goto done;
1023 }
1024 spin_unlock_irq (&dev->lock);
1025 retval = wait_event_interruptible (dev->wait,
1026 dev->setup_out_ready != 0);
1027
1028 /* FIXME state could change from under us */
1029 spin_lock_irq (&dev->lock);
1030 if (retval)
1031 goto done;
1032
1033 if (dev->state != STATE_DEV_SETUP) {
1034 retval = -ECANCELED;
1035 goto done;
1036 }
1037 dev->state = STATE_DEV_CONNECTED;
1038
1039 if (dev->setup_out_error)
1040 retval = -EIO;
1041 else {
1042 len = min (len, (size_t)dev->req->actual);
1043 // FIXME don't call this with the spinlock held ...
1044 if (copy_to_user (buf, dev->req->buf, len))
1045 retval = -EFAULT;
1046 else
1047 retval = len;
1048 clean_req (dev->gadget->ep0, dev->req);
1049 /* NOTE userspace can't yet choose to stall */
1050 }
1051 }
1052 goto done;
1053 }
1054
1055 /* else normal: return event data */
1056 if (len < sizeof dev->event [0]) {
1057 retval = -EINVAL;
1058 goto done;
1059 }
1060 len -= len % sizeof (struct usb_gadgetfs_event);
1061 dev->usermode_setup = 1;
1062
1063 scan:
1064 /* return queued events right away */
1065 if (dev->ev_next != 0) {
1066 unsigned i, n;
1067
1068 n = len / sizeof (struct usb_gadgetfs_event);
1069 if (dev->ev_next < n)
1070 n = dev->ev_next;
1071
1072 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1073 for (i = 0; i < n; i++) {
1074 if (dev->event [i].type == GADGETFS_SETUP) {
1075 dev->state = STATE_DEV_SETUP;
1076 n = i + 1;
1077 break;
1078 }
1079 }
1080 spin_unlock_irq (&dev->lock);
1081 len = n * sizeof (struct usb_gadgetfs_event);
1082 if (copy_to_user (buf, &dev->event, len))
1083 retval = -EFAULT;
1084 else
1085 retval = len;
1086 if (len > 0) {
1087 /* NOTE this doesn't guard against broken drivers;
1088 * concurrent ep0 readers may lose events.
1089 */
1090 spin_lock_irq (&dev->lock);
1091 if (dev->ev_next > n) {
1092 memmove(&dev->event[0], &dev->event[n],
1093 sizeof (struct usb_gadgetfs_event)
1094 * (dev->ev_next - n));
1095 }
1096 dev->ev_next -= n;
1097 spin_unlock_irq (&dev->lock);
1098 }
1099 return retval;
1100 }
1101 if (fd->f_flags & O_NONBLOCK) {
1102 retval = -EAGAIN;
1103 goto done;
1104 }
1105
1106 switch (state) {
1107 default:
1108 DBG (dev, "fail %s, state %d\n", __func__, state);
1109 retval = -ESRCH;
1110 break;
1111 case STATE_DEV_UNCONNECTED:
1112 case STATE_DEV_CONNECTED:
1113 spin_unlock_irq (&dev->lock);
1114 DBG (dev, "%s wait\n", __func__);
1115
1116 /* wait for events */
1117 retval = wait_event_interruptible (dev->wait,
1118 dev->ev_next != 0);
1119 if (retval < 0)
1120 return retval;
1121 spin_lock_irq (&dev->lock);
1122 goto scan;
1123 }
1124
1125 done:
1126 spin_unlock_irq (&dev->lock);
1127 return retval;
1128 }
1129
1130 static struct usb_gadgetfs_event *
1131 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1132 {
1133 struct usb_gadgetfs_event *event;
1134 unsigned i;
1135
1136 switch (type) {
1137 /* these events purge the queue */
1138 case GADGETFS_DISCONNECT:
1139 if (dev->state == STATE_DEV_SETUP)
1140 dev->setup_abort = 1;
1141 // FALL THROUGH
1142 case GADGETFS_CONNECT:
1143 dev->ev_next = 0;
1144 break;
1145 case GADGETFS_SETUP: /* previous request timed out */
1146 case GADGETFS_SUSPEND: /* same effect */
1147 /* these events can't be repeated */
1148 for (i = 0; i != dev->ev_next; i++) {
1149 if (dev->event [i].type != type)
1150 continue;
1151 DBG(dev, "discard old event[%d] %d\n", i, type);
1152 dev->ev_next--;
1153 if (i == dev->ev_next)
1154 break;
1155 /* indices start at zero, for simplicity */
1156 memmove (&dev->event [i], &dev->event [i + 1],
1157 sizeof (struct usb_gadgetfs_event)
1158 * (dev->ev_next - i));
1159 }
1160 break;
1161 default:
1162 BUG ();
1163 }
1164 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1165 event = &dev->event [dev->ev_next++];
1166 BUG_ON (dev->ev_next > N_EVENT);
1167 memset (event, 0, sizeof *event);
1168 event->type = type;
1169 return event;
1170 }
1171
1172 static ssize_t
1173 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1174 {
1175 struct dev_data *dev = fd->private_data;
1176 ssize_t retval = -ESRCH;
1177
1178 spin_lock_irq (&dev->lock);
1179
1180 /* report fd mode change before acting on it */
1181 if (dev->setup_abort) {
1182 dev->setup_abort = 0;
1183 retval = -EIDRM;
1184
1185 /* data and/or status stage for control request */
1186 } else if (dev->state == STATE_DEV_SETUP) {
1187
1188 /* IN DATA+STATUS caller makes len <= wLength */
1189 if (dev->setup_in) {
1190 retval = setup_req (dev->gadget->ep0, dev->req, len);
1191 if (retval == 0) {
1192 dev->state = STATE_DEV_CONNECTED;
1193 spin_unlock_irq (&dev->lock);
1194 if (copy_from_user (dev->req->buf, buf, len))
1195 retval = -EFAULT;
1196 else {
1197 if (len < dev->setup_wLength)
1198 dev->req->zero = 1;
1199 retval = usb_ep_queue (
1200 dev->gadget->ep0, dev->req,
1201 GFP_KERNEL);
1202 }
1203 if (retval < 0) {
1204 spin_lock_irq (&dev->lock);
1205 clean_req (dev->gadget->ep0, dev->req);
1206 spin_unlock_irq (&dev->lock);
1207 } else
1208 retval = len;
1209
1210 return retval;
1211 }
1212
1213 /* can stall some OUT transfers */
1214 } else if (dev->setup_can_stall) {
1215 VDEBUG(dev, "ep0out stall\n");
1216 (void) usb_ep_set_halt (dev->gadget->ep0);
1217 retval = -EL2HLT;
1218 dev->state = STATE_DEV_CONNECTED;
1219 } else {
1220 DBG(dev, "bogus ep0out stall!\n");
1221 }
1222 } else
1223 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1224
1225 spin_unlock_irq (&dev->lock);
1226 return retval;
1227 }
1228
1229 static int
1230 ep0_fasync (int f, struct file *fd, int on)
1231 {
1232 struct dev_data *dev = fd->private_data;
1233 // caller must F_SETOWN before signal delivery happens
1234 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1235 return fasync_helper (f, fd, on, &dev->fasync);
1236 }
1237
1238 static struct usb_gadget_driver gadgetfs_driver;
1239
1240 static int
1241 dev_release (struct inode *inode, struct file *fd)
1242 {
1243 struct dev_data *dev = fd->private_data;
1244
1245 /* closing ep0 === shutdown all */
1246
1247 usb_gadget_unregister_driver (&gadgetfs_driver);
1248
1249 /* at this point "good" hardware has disconnected the
1250 * device from USB; the host won't see it any more.
1251 * alternatively, all host requests will time out.
1252 */
1253
1254 kfree (dev->buf);
1255 dev->buf = NULL;
1256 put_dev (dev);
1257
1258 /* other endpoints were all decoupled from this device */
1259 spin_lock_irq(&dev->lock);
1260 dev->state = STATE_DEV_DISABLED;
1261 spin_unlock_irq(&dev->lock);
1262 return 0;
1263 }
1264
1265 static unsigned int
1266 ep0_poll (struct file *fd, poll_table *wait)
1267 {
1268 struct dev_data *dev = fd->private_data;
1269 int mask = 0;
1270
1271 poll_wait(fd, &dev->wait, wait);
1272
1273 spin_lock_irq (&dev->lock);
1274
1275 /* report fd mode change before acting on it */
1276 if (dev->setup_abort) {
1277 dev->setup_abort = 0;
1278 mask = POLLHUP;
1279 goto out;
1280 }
1281
1282 if (dev->state == STATE_DEV_SETUP) {
1283 if (dev->setup_in || dev->setup_can_stall)
1284 mask = POLLOUT;
1285 } else {
1286 if (dev->ev_next != 0)
1287 mask = POLLIN;
1288 }
1289 out:
1290 spin_unlock_irq(&dev->lock);
1291 return mask;
1292 }
1293
1294 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1295 {
1296 struct dev_data *dev = fd->private_data;
1297 struct usb_gadget *gadget = dev->gadget;
1298 long ret = -ENOTTY;
1299
1300 if (gadget->ops->ioctl)
1301 ret = gadget->ops->ioctl (gadget, code, value);
1302
1303 return ret;
1304 }
1305
1306 /* used after device configuration */
1307 static const struct file_operations ep0_io_operations = {
1308 .owner = THIS_MODULE,
1309 .llseek = no_llseek,
1310
1311 .read = ep0_read,
1312 .write = ep0_write,
1313 .fasync = ep0_fasync,
1314 .poll = ep0_poll,
1315 .unlocked_ioctl = dev_ioctl,
1316 .release = dev_release,
1317 };
1318
1319 /*----------------------------------------------------------------------*/
1320
1321 /* The in-kernel gadget driver handles most ep0 issues, in particular
1322 * enumerating the single configuration (as provided from user space).
1323 *
1324 * Unrecognized ep0 requests may be handled in user space.
1325 */
1326
1327 #ifdef CONFIG_USB_GADGET_DUALSPEED
1328 static void make_qualifier (struct dev_data *dev)
1329 {
1330 struct usb_qualifier_descriptor qual;
1331 struct usb_device_descriptor *desc;
1332
1333 qual.bLength = sizeof qual;
1334 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1335 qual.bcdUSB = cpu_to_le16 (0x0200);
1336
1337 desc = dev->dev;
1338 qual.bDeviceClass = desc->bDeviceClass;
1339 qual.bDeviceSubClass = desc->bDeviceSubClass;
1340 qual.bDeviceProtocol = desc->bDeviceProtocol;
1341
1342 /* assumes ep0 uses the same value for both speeds ... */
1343 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1344
1345 qual.bNumConfigurations = 1;
1346 qual.bRESERVED = 0;
1347
1348 memcpy (dev->rbuf, &qual, sizeof qual);
1349 }
1350 #endif
1351
1352 static int
1353 config_buf (struct dev_data *dev, u8 type, unsigned index)
1354 {
1355 int len;
1356 int hs = 0;
1357
1358 /* only one configuration */
1359 if (index > 0)
1360 return -EINVAL;
1361
1362 if (gadget_is_dualspeed(dev->gadget)) {
1363 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1364 if (type == USB_DT_OTHER_SPEED_CONFIG)
1365 hs = !hs;
1366 }
1367 if (hs) {
1368 dev->req->buf = dev->hs_config;
1369 len = le16_to_cpu(dev->hs_config->wTotalLength);
1370 } else {
1371 dev->req->buf = dev->config;
1372 len = le16_to_cpu(dev->config->wTotalLength);
1373 }
1374 ((u8 *)dev->req->buf) [1] = type;
1375 return len;
1376 }
1377
1378 static int
1379 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1380 {
1381 struct dev_data *dev = get_gadget_data (gadget);
1382 struct usb_request *req = dev->req;
1383 int value = -EOPNOTSUPP;
1384 struct usb_gadgetfs_event *event;
1385 u16 w_value = le16_to_cpu(ctrl->wValue);
1386 u16 w_length = le16_to_cpu(ctrl->wLength);
1387
1388 spin_lock (&dev->lock);
1389 dev->setup_abort = 0;
1390 if (dev->state == STATE_DEV_UNCONNECTED) {
1391 if (gadget_is_dualspeed(gadget)
1392 && gadget->speed == USB_SPEED_HIGH
1393 && dev->hs_config == NULL) {
1394 spin_unlock(&dev->lock);
1395 ERROR (dev, "no high speed config??\n");
1396 return -EINVAL;
1397 }
1398
1399 dev->state = STATE_DEV_CONNECTED;
1400
1401 INFO (dev, "connected\n");
1402 event = next_event (dev, GADGETFS_CONNECT);
1403 event->u.speed = gadget->speed;
1404 ep0_readable (dev);
1405
1406 /* host may have given up waiting for response. we can miss control
1407 * requests handled lower down (device/endpoint status and features);
1408 * then ep0_{read,write} will report the wrong status. controller
1409 * driver will have aborted pending i/o.
1410 */
1411 } else if (dev->state == STATE_DEV_SETUP)
1412 dev->setup_abort = 1;
1413
1414 req->buf = dev->rbuf;
1415 req->dma = DMA_ADDR_INVALID;
1416 req->context = NULL;
1417 value = -EOPNOTSUPP;
1418 switch (ctrl->bRequest) {
1419
1420 case USB_REQ_GET_DESCRIPTOR:
1421 if (ctrl->bRequestType != USB_DIR_IN)
1422 goto unrecognized;
1423 switch (w_value >> 8) {
1424
1425 case USB_DT_DEVICE:
1426 value = min (w_length, (u16) sizeof *dev->dev);
1427 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1428 req->buf = dev->dev;
1429 break;
1430 #ifdef CONFIG_USB_GADGET_DUALSPEED
1431 case USB_DT_DEVICE_QUALIFIER:
1432 if (!dev->hs_config)
1433 break;
1434 value = min (w_length, (u16)
1435 sizeof (struct usb_qualifier_descriptor));
1436 make_qualifier (dev);
1437 break;
1438 case USB_DT_OTHER_SPEED_CONFIG:
1439 // FALLTHROUGH
1440 #endif
1441 case USB_DT_CONFIG:
1442 value = config_buf (dev,
1443 w_value >> 8,
1444 w_value & 0xff);
1445 if (value >= 0)
1446 value = min (w_length, (u16) value);
1447 break;
1448 case USB_DT_STRING:
1449 goto unrecognized;
1450
1451 default: // all others are errors
1452 break;
1453 }
1454 break;
1455
1456 /* currently one config, two speeds */
1457 case USB_REQ_SET_CONFIGURATION:
1458 if (ctrl->bRequestType != 0)
1459 goto unrecognized;
1460 if (0 == (u8) w_value) {
1461 value = 0;
1462 dev->current_config = 0;
1463 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1464 // user mode expected to disable endpoints
1465 } else {
1466 u8 config, power;
1467
1468 if (gadget_is_dualspeed(gadget)
1469 && gadget->speed == USB_SPEED_HIGH) {
1470 config = dev->hs_config->bConfigurationValue;
1471 power = dev->hs_config->bMaxPower;
1472 } else {
1473 config = dev->config->bConfigurationValue;
1474 power = dev->config->bMaxPower;
1475 }
1476
1477 if (config == (u8) w_value) {
1478 value = 0;
1479 dev->current_config = config;
1480 usb_gadget_vbus_draw(gadget, 2 * power);
1481 }
1482 }
1483
1484 /* report SET_CONFIGURATION like any other control request,
1485 * except that usermode may not stall this. the next
1486 * request mustn't be allowed start until this finishes:
1487 * endpoints and threads set up, etc.
1488 *
1489 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1490 * has bad/racey automagic that prevents synchronizing here.
1491 * even kernel mode drivers often miss them.
1492 */
1493 if (value == 0) {
1494 INFO (dev, "configuration #%d\n", dev->current_config);
1495 if (dev->usermode_setup) {
1496 dev->setup_can_stall = 0;
1497 goto delegate;
1498 }
1499 }
1500 break;
1501
1502 #ifndef CONFIG_USB_GADGET_PXA25X
1503 /* PXA automagically handles this request too */
1504 case USB_REQ_GET_CONFIGURATION:
1505 if (ctrl->bRequestType != 0x80)
1506 goto unrecognized;
1507 *(u8 *)req->buf = dev->current_config;
1508 value = min (w_length, (u16) 1);
1509 break;
1510 #endif
1511
1512 default:
1513 unrecognized:
1514 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1515 dev->usermode_setup ? "delegate" : "fail",
1516 ctrl->bRequestType, ctrl->bRequest,
1517 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1518
1519 /* if there's an ep0 reader, don't stall */
1520 if (dev->usermode_setup) {
1521 dev->setup_can_stall = 1;
1522 delegate:
1523 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1524 ? 1 : 0;
1525 dev->setup_wLength = w_length;
1526 dev->setup_out_ready = 0;
1527 dev->setup_out_error = 0;
1528 value = 0;
1529
1530 /* read DATA stage for OUT right away */
1531 if (unlikely (!dev->setup_in && w_length)) {
1532 value = setup_req (gadget->ep0, dev->req,
1533 w_length);
1534 if (value < 0)
1535 break;
1536 value = usb_ep_queue (gadget->ep0, dev->req,
1537 GFP_ATOMIC);
1538 if (value < 0) {
1539 clean_req (gadget->ep0, dev->req);
1540 break;
1541 }
1542
1543 /* we can't currently stall these */
1544 dev->setup_can_stall = 0;
1545 }
1546
1547 /* state changes when reader collects event */
1548 event = next_event (dev, GADGETFS_SETUP);
1549 event->u.setup = *ctrl;
1550 ep0_readable (dev);
1551 spin_unlock (&dev->lock);
1552 return 0;
1553 }
1554 }
1555
1556 /* proceed with data transfer and status phases? */
1557 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1558 req->length = value;
1559 req->zero = value < w_length;
1560 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1561 if (value < 0) {
1562 DBG (dev, "ep_queue --> %d\n", value);
1563 req->status = 0;
1564 }
1565 }
1566
1567 /* device stalls when value < 0 */
1568 spin_unlock (&dev->lock);
1569 return value;
1570 }
1571
1572 static void destroy_ep_files (struct dev_data *dev)
1573 {
1574 struct list_head *entry, *tmp;
1575
1576 DBG (dev, "%s %d\n", __func__, dev->state);
1577
1578 /* dev->state must prevent interference */
1579 restart:
1580 spin_lock_irq (&dev->lock);
1581 list_for_each_safe (entry, tmp, &dev->epfiles) {
1582 struct ep_data *ep;
1583 struct inode *parent;
1584 struct dentry *dentry;
1585
1586 /* break link to FS */
1587 ep = list_entry (entry, struct ep_data, epfiles);
1588 list_del_init (&ep->epfiles);
1589 dentry = ep->dentry;
1590 ep->dentry = NULL;
1591 parent = dentry->d_parent->d_inode;
1592
1593 /* break link to controller */
1594 if (ep->state == STATE_EP_ENABLED)
1595 (void) usb_ep_disable (ep->ep);
1596 ep->state = STATE_EP_UNBOUND;
1597 usb_ep_free_request (ep->ep, ep->req);
1598 ep->ep = NULL;
1599 wake_up (&ep->wait);
1600 put_ep (ep);
1601
1602 spin_unlock_irq (&dev->lock);
1603
1604 /* break link to dcache */
1605 mutex_lock (&parent->i_mutex);
1606 d_delete (dentry);
1607 dput (dentry);
1608 mutex_unlock (&parent->i_mutex);
1609
1610 /* fds may still be open */
1611 goto restart;
1612 }
1613 spin_unlock_irq (&dev->lock);
1614 }
1615
1616
1617 static struct inode *
1618 gadgetfs_create_file (struct super_block *sb, char const *name,
1619 void *data, const struct file_operations *fops,
1620 struct dentry **dentry_p);
1621
1622 static int activate_ep_files (struct dev_data *dev)
1623 {
1624 struct usb_ep *ep;
1625 struct ep_data *data;
1626
1627 gadget_for_each_ep (ep, dev->gadget) {
1628
1629 data = kzalloc(sizeof(*data), GFP_KERNEL);
1630 if (!data)
1631 goto enomem0;
1632 data->state = STATE_EP_DISABLED;
1633 mutex_init(&data->lock);
1634 init_waitqueue_head (&data->wait);
1635
1636 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1637 atomic_set (&data->count, 1);
1638 data->dev = dev;
1639 get_dev (dev);
1640
1641 data->ep = ep;
1642 ep->driver_data = data;
1643
1644 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1645 if (!data->req)
1646 goto enomem1;
1647
1648 data->inode = gadgetfs_create_file (dev->sb, data->name,
1649 data, &ep_config_operations,
1650 &data->dentry);
1651 if (!data->inode)
1652 goto enomem2;
1653 list_add_tail (&data->epfiles, &dev->epfiles);
1654 }
1655 return 0;
1656
1657 enomem2:
1658 usb_ep_free_request (ep, data->req);
1659 enomem1:
1660 put_dev (dev);
1661 kfree (data);
1662 enomem0:
1663 DBG (dev, "%s enomem\n", __func__);
1664 destroy_ep_files (dev);
1665 return -ENOMEM;
1666 }
1667
1668 static void
1669 gadgetfs_unbind (struct usb_gadget *gadget)
1670 {
1671 struct dev_data *dev = get_gadget_data (gadget);
1672
1673 DBG (dev, "%s\n", __func__);
1674
1675 spin_lock_irq (&dev->lock);
1676 dev->state = STATE_DEV_UNBOUND;
1677 spin_unlock_irq (&dev->lock);
1678
1679 destroy_ep_files (dev);
1680 gadget->ep0->driver_data = NULL;
1681 set_gadget_data (gadget, NULL);
1682
1683 /* we've already been disconnected ... no i/o is active */
1684 if (dev->req)
1685 usb_ep_free_request (gadget->ep0, dev->req);
1686 DBG (dev, "%s done\n", __func__);
1687 put_dev (dev);
1688 }
1689
1690 static struct dev_data *the_device;
1691
1692 static int
1693 gadgetfs_bind (struct usb_gadget *gadget)
1694 {
1695 struct dev_data *dev = the_device;
1696
1697 if (!dev)
1698 return -ESRCH;
1699 if (0 != strcmp (CHIP, gadget->name)) {
1700 pr_err("%s expected %s controller not %s\n",
1701 shortname, CHIP, gadget->name);
1702 return -ENODEV;
1703 }
1704
1705 set_gadget_data (gadget, dev);
1706 dev->gadget = gadget;
1707 gadget->ep0->driver_data = dev;
1708
1709 /* preallocate control response and buffer */
1710 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1711 if (!dev->req)
1712 goto enomem;
1713 dev->req->context = NULL;
1714 dev->req->complete = epio_complete;
1715
1716 if (activate_ep_files (dev) < 0)
1717 goto enomem;
1718
1719 INFO (dev, "bound to %s driver\n", gadget->name);
1720 spin_lock_irq(&dev->lock);
1721 dev->state = STATE_DEV_UNCONNECTED;
1722 spin_unlock_irq(&dev->lock);
1723 get_dev (dev);
1724 return 0;
1725
1726 enomem:
1727 gadgetfs_unbind (gadget);
1728 return -ENOMEM;
1729 }
1730
1731 static void
1732 gadgetfs_disconnect (struct usb_gadget *gadget)
1733 {
1734 struct dev_data *dev = get_gadget_data (gadget);
1735 unsigned long flags;
1736
1737 spin_lock_irqsave (&dev->lock, flags);
1738 if (dev->state == STATE_DEV_UNCONNECTED)
1739 goto exit;
1740 dev->state = STATE_DEV_UNCONNECTED;
1741
1742 INFO (dev, "disconnected\n");
1743 next_event (dev, GADGETFS_DISCONNECT);
1744 ep0_readable (dev);
1745 exit:
1746 spin_unlock_irqrestore (&dev->lock, flags);
1747 }
1748
1749 static void
1750 gadgetfs_suspend (struct usb_gadget *gadget)
1751 {
1752 struct dev_data *dev = get_gadget_data (gadget);
1753
1754 INFO (dev, "suspended from state %d\n", dev->state);
1755 spin_lock (&dev->lock);
1756 switch (dev->state) {
1757 case STATE_DEV_SETUP: // VERY odd... host died??
1758 case STATE_DEV_CONNECTED:
1759 case STATE_DEV_UNCONNECTED:
1760 next_event (dev, GADGETFS_SUSPEND);
1761 ep0_readable (dev);
1762 /* FALLTHROUGH */
1763 default:
1764 break;
1765 }
1766 spin_unlock (&dev->lock);
1767 }
1768
1769 static struct usb_gadget_driver gadgetfs_driver = {
1770 #ifdef CONFIG_USB_GADGET_DUALSPEED
1771 .max_speed = USB_SPEED_HIGH,
1772 #else
1773 .max_speed = USB_SPEED_FULL,
1774 #endif
1775 .function = (char *) driver_desc,
1776 .unbind = gadgetfs_unbind,
1777 .setup = gadgetfs_setup,
1778 .disconnect = gadgetfs_disconnect,
1779 .suspend = gadgetfs_suspend,
1780
1781 .driver = {
1782 .name = (char *) shortname,
1783 },
1784 };
1785
1786 /*----------------------------------------------------------------------*/
1787
1788 static void gadgetfs_nop(struct usb_gadget *arg) { }
1789
1790 static int gadgetfs_probe (struct usb_gadget *gadget)
1791 {
1792 CHIP = gadget->name;
1793 return -EISNAM;
1794 }
1795
1796 static struct usb_gadget_driver probe_driver = {
1797 .max_speed = USB_SPEED_HIGH,
1798 .unbind = gadgetfs_nop,
1799 .setup = (void *)gadgetfs_nop,
1800 .disconnect = gadgetfs_nop,
1801 .driver = {
1802 .name = "nop",
1803 },
1804 };
1805
1806
1807 /* DEVICE INITIALIZATION
1808 *
1809 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1810 * status = write (fd, descriptors, sizeof descriptors)
1811 *
1812 * That write establishes the device configuration, so the kernel can
1813 * bind to the controller ... guaranteeing it can handle enumeration
1814 * at all necessary speeds. Descriptor order is:
1815 *
1816 * . message tag (u32, host order) ... for now, must be zero; it
1817 * would change to support features like multi-config devices
1818 * . full/low speed config ... all wTotalLength bytes (with interface,
1819 * class, altsetting, endpoint, and other descriptors)
1820 * . high speed config ... all descriptors, for high speed operation;
1821 * this one's optional except for high-speed hardware
1822 * . device descriptor
1823 *
1824 * Endpoints are not yet enabled. Drivers must wait until device
1825 * configuration and interface altsetting changes create
1826 * the need to configure (or unconfigure) them.
1827 *
1828 * After initialization, the device stays active for as long as that
1829 * $CHIP file is open. Events must then be read from that descriptor,
1830 * such as configuration notifications.
1831 */
1832
1833 static int is_valid_config (struct usb_config_descriptor *config)
1834 {
1835 return config->bDescriptorType == USB_DT_CONFIG
1836 && config->bLength == USB_DT_CONFIG_SIZE
1837 && config->bConfigurationValue != 0
1838 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1839 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1840 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1841 /* FIXME check lengths: walk to end */
1842 }
1843
1844 static ssize_t
1845 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1846 {
1847 struct dev_data *dev = fd->private_data;
1848 ssize_t value = len, length = len;
1849 unsigned total;
1850 u32 tag;
1851 char *kbuf;
1852
1853 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1854 return -EINVAL;
1855
1856 /* we might need to change message format someday */
1857 if (copy_from_user (&tag, buf, 4))
1858 return -EFAULT;
1859 if (tag != 0)
1860 return -EINVAL;
1861 buf += 4;
1862 length -= 4;
1863
1864 kbuf = memdup_user(buf, length);
1865 if (IS_ERR(kbuf))
1866 return PTR_ERR(kbuf);
1867
1868 spin_lock_irq (&dev->lock);
1869 value = -EINVAL;
1870 if (dev->buf)
1871 goto fail;
1872 dev->buf = kbuf;
1873
1874 /* full or low speed config */
1875 dev->config = (void *) kbuf;
1876 total = le16_to_cpu(dev->config->wTotalLength);
1877 if (!is_valid_config (dev->config) || total >= length)
1878 goto fail;
1879 kbuf += total;
1880 length -= total;
1881
1882 /* optional high speed config */
1883 if (kbuf [1] == USB_DT_CONFIG) {
1884 dev->hs_config = (void *) kbuf;
1885 total = le16_to_cpu(dev->hs_config->wTotalLength);
1886 if (!is_valid_config (dev->hs_config) || total >= length)
1887 goto fail;
1888 kbuf += total;
1889 length -= total;
1890 }
1891
1892 /* could support multiple configs, using another encoding! */
1893
1894 /* device descriptor (tweaked for paranoia) */
1895 if (length != USB_DT_DEVICE_SIZE)
1896 goto fail;
1897 dev->dev = (void *)kbuf;
1898 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1899 || dev->dev->bDescriptorType != USB_DT_DEVICE
1900 || dev->dev->bNumConfigurations != 1)
1901 goto fail;
1902 dev->dev->bNumConfigurations = 1;
1903 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1904
1905 /* triggers gadgetfs_bind(); then we can enumerate. */
1906 spin_unlock_irq (&dev->lock);
1907 value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1908 if (value != 0) {
1909 kfree (dev->buf);
1910 dev->buf = NULL;
1911 } else {
1912 /* at this point "good" hardware has for the first time
1913 * let the USB the host see us. alternatively, if users
1914 * unplug/replug that will clear all the error state.
1915 *
1916 * note: everything running before here was guaranteed
1917 * to choke driver model style diagnostics. from here
1918 * on, they can work ... except in cleanup paths that
1919 * kick in after the ep0 descriptor is closed.
1920 */
1921 fd->f_op = &ep0_io_operations;
1922 value = len;
1923 }
1924 return value;
1925
1926 fail:
1927 spin_unlock_irq (&dev->lock);
1928 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1929 kfree (dev->buf);
1930 dev->buf = NULL;
1931 return value;
1932 }
1933
1934 static int
1935 dev_open (struct inode *inode, struct file *fd)
1936 {
1937 struct dev_data *dev = inode->i_private;
1938 int value = -EBUSY;
1939
1940 spin_lock_irq(&dev->lock);
1941 if (dev->state == STATE_DEV_DISABLED) {
1942 dev->ev_next = 0;
1943 dev->state = STATE_DEV_OPENED;
1944 fd->private_data = dev;
1945 get_dev (dev);
1946 value = 0;
1947 }
1948 spin_unlock_irq(&dev->lock);
1949 return value;
1950 }
1951
1952 static const struct file_operations dev_init_operations = {
1953 .owner = THIS_MODULE,
1954 .llseek = no_llseek,
1955
1956 .open = dev_open,
1957 .write = dev_config,
1958 .fasync = ep0_fasync,
1959 .unlocked_ioctl = dev_ioctl,
1960 .release = dev_release,
1961 };
1962
1963 /*----------------------------------------------------------------------*/
1964
1965 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1966 *
1967 * Mounting the filesystem creates a controller file, used first for
1968 * device configuration then later for event monitoring.
1969 */
1970
1971
1972 /* FIXME PAM etc could set this security policy without mount options
1973 * if epfiles inherited ownership and permissons from ep0 ...
1974 */
1975
1976 static unsigned default_uid;
1977 static unsigned default_gid;
1978 static unsigned default_perm = S_IRUSR | S_IWUSR;
1979
1980 module_param (default_uid, uint, 0644);
1981 module_param (default_gid, uint, 0644);
1982 module_param (default_perm, uint, 0644);
1983
1984
1985 static struct inode *
1986 gadgetfs_make_inode (struct super_block *sb,
1987 void *data, const struct file_operations *fops,
1988 int mode)
1989 {
1990 struct inode *inode = new_inode (sb);
1991
1992 if (inode) {
1993 inode->i_ino = get_next_ino();
1994 inode->i_mode = mode;
1995 inode->i_uid = default_uid;
1996 inode->i_gid = default_gid;
1997 inode->i_atime = inode->i_mtime = inode->i_ctime
1998 = CURRENT_TIME;
1999 inode->i_private = data;
2000 inode->i_fop = fops;
2001 }
2002 return inode;
2003 }
2004
2005 /* creates in fs root directory, so non-renamable and non-linkable.
2006 * so inode and dentry are paired, until device reconfig.
2007 */
2008 static struct inode *
2009 gadgetfs_create_file (struct super_block *sb, char const *name,
2010 void *data, const struct file_operations *fops,
2011 struct dentry **dentry_p)
2012 {
2013 struct dentry *dentry;
2014 struct inode *inode;
2015
2016 dentry = d_alloc_name(sb->s_root, name);
2017 if (!dentry)
2018 return NULL;
2019
2020 inode = gadgetfs_make_inode (sb, data, fops,
2021 S_IFREG | (default_perm & S_IRWXUGO));
2022 if (!inode) {
2023 dput(dentry);
2024 return NULL;
2025 }
2026 d_add (dentry, inode);
2027 *dentry_p = dentry;
2028 return inode;
2029 }
2030
2031 static const struct super_operations gadget_fs_operations = {
2032 .statfs = simple_statfs,
2033 .drop_inode = generic_delete_inode,
2034 };
2035
2036 static int
2037 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2038 {
2039 struct inode *inode;
2040 struct dev_data *dev;
2041
2042 if (the_device)
2043 return -ESRCH;
2044
2045 /* fake probe to determine $CHIP */
2046 (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2047 if (!CHIP)
2048 return -ENODEV;
2049
2050 /* superblock */
2051 sb->s_blocksize = PAGE_CACHE_SIZE;
2052 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2053 sb->s_magic = GADGETFS_MAGIC;
2054 sb->s_op = &gadget_fs_operations;
2055 sb->s_time_gran = 1;
2056
2057 /* root inode */
2058 inode = gadgetfs_make_inode (sb,
2059 NULL, &simple_dir_operations,
2060 S_IFDIR | S_IRUGO | S_IXUGO);
2061 if (!inode)
2062 goto Enomem;
2063 inode->i_op = &simple_dir_inode_operations;
2064 if (!(sb->s_root = d_alloc_root (inode))) {
2065 iput(inode);
2066 goto Enomem;
2067 }
2068
2069 /* the ep0 file is named after the controller we expect;
2070 * user mode code can use it for sanity checks, like we do.
2071 */
2072 dev = dev_new ();
2073 if (!dev)
2074 goto Enomem;
2075
2076 dev->sb = sb;
2077 if (!gadgetfs_create_file (sb, CHIP,
2078 dev, &dev_init_operations,
2079 &dev->dentry)) {
2080 put_dev(dev);
2081 goto Enomem;
2082 }
2083
2084 /* other endpoint files are available after hardware setup,
2085 * from binding to a controller.
2086 */
2087 the_device = dev;
2088 return 0;
2089
2090 Enomem:
2091 return -ENOMEM;
2092 }
2093
2094 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2095 static struct dentry *
2096 gadgetfs_mount (struct file_system_type *t, int flags,
2097 const char *path, void *opts)
2098 {
2099 return mount_single (t, flags, opts, gadgetfs_fill_super);
2100 }
2101
2102 static void
2103 gadgetfs_kill_sb (struct super_block *sb)
2104 {
2105 kill_litter_super (sb);
2106 if (the_device) {
2107 put_dev (the_device);
2108 the_device = NULL;
2109 }
2110 }
2111
2112 /*----------------------------------------------------------------------*/
2113
2114 static struct file_system_type gadgetfs_type = {
2115 .owner = THIS_MODULE,
2116 .name = shortname,
2117 .mount = gadgetfs_mount,
2118 .kill_sb = gadgetfs_kill_sb,
2119 };
2120
2121 /*----------------------------------------------------------------------*/
2122
2123 static int __init init (void)
2124 {
2125 int status;
2126
2127 status = register_filesystem (&gadgetfs_type);
2128 if (status == 0)
2129 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2130 shortname, driver_desc);
2131 return status;
2132 }
2133 module_init (init);
2134
2135 static void __exit cleanup (void)
2136 {
2137 pr_debug ("unregister %s\n", shortname);
2138 unregister_filesystem (&gadgetfs_type);
2139 }
2140 module_exit (cleanup);
2141