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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 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22
23/* #define VERBOSE_DEBUG */
24
25#include <linux/init.h>
26#include <linux/module.h>
27#include <linux/fs.h>
28#include <linux/pagemap.h>
29#include <linux/uts.h>
30#include <linux/wait.h>
31#include <linux/compiler.h>
32#include <asm/uaccess.h>
33#include <linux/sched.h>
34#include <linux/slab.h>
35#include <linux/poll.h>
36
37#include <linux/device.h>
38#include <linux/moduleparam.h>
39
40#include <linux/usb/gadgetfs.h>
41#include <linux/usb/gadget.h>
42
43
44/*
45 * The gadgetfs API maps each endpoint to a file descriptor so that you
46 * can use standard synchronous read/write calls for I/O. There's some
47 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
48 * drivers show how this works in practice. You can also use AIO to
49 * eliminate I/O gaps between requests, to help when streaming data.
50 *
51 * Key parts that must be USB-specific are protocols defining how the
52 * read/write operations relate to the hardware state machines. There
53 * are two types of files. One type is for the device, implementing ep0.
54 * The other type is for each IN or OUT endpoint. In both cases, the
55 * user mode driver must configure the hardware before using it.
56 *
57 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
58 * (by writing configuration and device descriptors). Afterwards it
59 * may serve as a source of device events, used to handle all control
60 * requests other than basic enumeration.
61 *
62 * - Then, after a SET_CONFIGURATION control request, ep_config() is
63 * called when each /dev/gadget/ep* file is configured (by writing
64 * endpoint descriptors). Afterwards these files are used to write()
65 * IN data or to read() OUT data. To halt the endpoint, a "wrong
66 * direction" request is issued (like reading an IN endpoint).
67 *
68 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
69 * not possible on all hardware. For example, precise fault handling with
70 * respect to data left in endpoint fifos after aborted operations; or
71 * selective clearing of endpoint halts, to implement SET_INTERFACE.
72 */
73
74#define DRIVER_DESC "USB Gadget filesystem"
75#define DRIVER_VERSION "24 Aug 2004"
76
77static const char driver_desc [] = DRIVER_DESC;
78static const char shortname [] = "gadgetfs";
79
80MODULE_DESCRIPTION (DRIVER_DESC);
81MODULE_AUTHOR ("David Brownell");
82MODULE_LICENSE ("GPL");
83
84
85/*----------------------------------------------------------------------*/
86
87#define GADGETFS_MAGIC 0xaee71ee7
88#define DMA_ADDR_INVALID (~(dma_addr_t)0)
89
90/* /dev/gadget/$CHIP represents ep0 and the whole device */
91enum ep0_state {
92 /* DISBLED is the initial state.
93 */
94 STATE_DEV_DISABLED = 0,
95
96 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
97 * ep0/device i/o modes and binding to the controller. Driver
98 * must always write descriptors to initialize the device, then
99 * the device becomes UNCONNECTED until enumeration.
100 */
101 STATE_DEV_OPENED,
102
103 /* From then on, ep0 fd is in either of two basic modes:
104 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
105 * - SETUP: read/write will transfer control data and succeed;
106 * or if "wrong direction", performs protocol stall
107 */
108 STATE_DEV_UNCONNECTED,
109 STATE_DEV_CONNECTED,
110 STATE_DEV_SETUP,
111
112 /* UNBOUND means the driver closed ep0, so the device won't be
113 * accessible again (DEV_DISABLED) until all fds are closed.
114 */
115 STATE_DEV_UNBOUND,
116};
117
118/* enough for the whole queue: most events invalidate others */
119#define N_EVENT 5
120
121struct dev_data {
122 spinlock_t lock;
123 atomic_t count;
124 enum ep0_state state; /* P: lock */
125 struct usb_gadgetfs_event event [N_EVENT];
126 unsigned ev_next;
127 struct fasync_struct *fasync;
128 u8 current_config;
129
130 /* drivers reading ep0 MUST handle control requests (SETUP)
131 * reported that way; else the host will time out.
132 */
133 unsigned usermode_setup : 1,
134 setup_in : 1,
135 setup_can_stall : 1,
136 setup_out_ready : 1,
137 setup_out_error : 1,
138 setup_abort : 1;
139 unsigned setup_wLength;
140
141 /* the rest is basically write-once */
142 struct usb_config_descriptor *config, *hs_config;
143 struct usb_device_descriptor *dev;
144 struct usb_request *req;
145 struct usb_gadget *gadget;
146 struct list_head epfiles;
147 void *buf;
148 wait_queue_head_t wait;
149 struct super_block *sb;
150 struct dentry *dentry;
151
152 /* except this scratch i/o buffer for ep0 */
153 u8 rbuf [256];
154};
155
156static inline void get_dev (struct dev_data *data)
157{
158 atomic_inc (&data->count);
159}
160
161static void put_dev (struct dev_data *data)
162{
163 if (likely (!atomic_dec_and_test (&data->count)))
164 return;
165 /* needs no more cleanup */
166 BUG_ON (waitqueue_active (&data->wait));
167 kfree (data);
168}
169
170static struct dev_data *dev_new (void)
171{
172 struct dev_data *dev;
173
174 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
175 if (!dev)
176 return NULL;
177 dev->state = STATE_DEV_DISABLED;
178 atomic_set (&dev->count, 1);
179 spin_lock_init (&dev->lock);
180 INIT_LIST_HEAD (&dev->epfiles);
181 init_waitqueue_head (&dev->wait);
182 return dev;
183}
184
185/*----------------------------------------------------------------------*/
186
187/* other /dev/gadget/$ENDPOINT files represent endpoints */
188enum ep_state {
189 STATE_EP_DISABLED = 0,
190 STATE_EP_READY,
191 STATE_EP_ENABLED,
192 STATE_EP_UNBOUND,
193};
194
195struct ep_data {
196 struct mutex lock;
197 enum ep_state state;
198 atomic_t count;
199 struct dev_data *dev;
200 /* must hold dev->lock before accessing ep or req */
201 struct usb_ep *ep;
202 struct usb_request *req;
203 ssize_t status;
204 char name [16];
205 struct usb_endpoint_descriptor desc, hs_desc;
206 struct list_head epfiles;
207 wait_queue_head_t wait;
208 struct dentry *dentry;
209 struct inode *inode;
210};
211
212static inline void get_ep (struct ep_data *data)
213{
214 atomic_inc (&data->count);
215}
216
217static void put_ep (struct ep_data *data)
218{
219 if (likely (!atomic_dec_and_test (&data->count)))
220 return;
221 put_dev (data->dev);
222 /* needs no more cleanup */
223 BUG_ON (!list_empty (&data->epfiles));
224 BUG_ON (waitqueue_active (&data->wait));
225 kfree (data);
226}
227
228/*----------------------------------------------------------------------*/
229
230/* most "how to use the hardware" policy choices are in userspace:
231 * mapping endpoint roles (which the driver needs) to the capabilities
232 * which the usb controller has. most of those capabilities are exposed
233 * implicitly, starting with the driver name and then endpoint names.
234 */
235
236static const char *CHIP;
237
238/*----------------------------------------------------------------------*/
239
240/* NOTE: don't use dev_printk calls before binding to the gadget
241 * at the end of ep0 configuration, or after unbind.
242 */
243
244/* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
245#define xprintk(d,level,fmt,args...) \
246 printk(level "%s: " fmt , shortname , ## args)
247
248#ifdef DEBUG
249#define DBG(dev,fmt,args...) \
250 xprintk(dev , KERN_DEBUG , fmt , ## args)
251#else
252#define DBG(dev,fmt,args...) \
253 do { } while (0)
254#endif /* DEBUG */
255
256#ifdef VERBOSE_DEBUG
257#define VDEBUG DBG
258#else
259#define VDEBUG(dev,fmt,args...) \
260 do { } while (0)
261#endif /* DEBUG */
262
263#define ERROR(dev,fmt,args...) \
264 xprintk(dev , KERN_ERR , fmt , ## args)
265#define INFO(dev,fmt,args...) \
266 xprintk(dev , KERN_INFO , fmt , ## args)
267
268
269/*----------------------------------------------------------------------*/
270
271/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
272 *
273 * After opening, configure non-control endpoints. Then use normal
274 * stream read() and write() requests; and maybe ioctl() to get more
275 * precise FIFO status when recovering from cancellation.
276 */
277
278static void epio_complete (struct usb_ep *ep, struct usb_request *req)
279{
280 struct ep_data *epdata = ep->driver_data;
281
282 if (!req->context)
283 return;
284 if (req->status)
285 epdata->status = req->status;
286 else
287 epdata->status = req->actual;
288 complete ((struct completion *)req->context);
289}
290
291/* tasklock endpoint, returning when it's connected.
292 * still need dev->lock to use epdata->ep.
293 */
294static int
295get_ready_ep (unsigned f_flags, struct ep_data *epdata)
296{
297 int val;
298
299 if (f_flags & O_NONBLOCK) {
300 if (!mutex_trylock(&epdata->lock))
301 goto nonblock;
302 if (epdata->state != STATE_EP_ENABLED) {
303 mutex_unlock(&epdata->lock);
304nonblock:
305 val = -EAGAIN;
306 } else
307 val = 0;
308 return val;
309 }
310
311 val = mutex_lock_interruptible(&epdata->lock);
312 if (val < 0)
313 return val;
314
315 switch (epdata->state) {
316 case STATE_EP_ENABLED:
317 break;
318 // case STATE_EP_DISABLED: /* "can't happen" */
319 // case STATE_EP_READY: /* "can't happen" */
320 default: /* error! */
321 pr_debug ("%s: ep %p not available, state %d\n",
322 shortname, epdata, epdata->state);
323 // FALLTHROUGH
324 case STATE_EP_UNBOUND: /* clean disconnect */
325 val = -ENODEV;
326 mutex_unlock(&epdata->lock);
327 }
328 return val;
329}
330
331static ssize_t
332ep_io (struct ep_data *epdata, void *buf, unsigned len)
333{
334 DECLARE_COMPLETION_ONSTACK (done);
335 int value;
336
337 spin_lock_irq (&epdata->dev->lock);
338 if (likely (epdata->ep != NULL)) {
339 struct usb_request *req = epdata->req;
340
341 req->context = &done;
342 req->complete = epio_complete;
343 req->buf = buf;
344 req->length = len;
345 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
346 } else
347 value = -ENODEV;
348 spin_unlock_irq (&epdata->dev->lock);
349
350 if (likely (value == 0)) {
351 value = wait_event_interruptible (done.wait, done.done);
352 if (value != 0) {
353 spin_lock_irq (&epdata->dev->lock);
354 if (likely (epdata->ep != NULL)) {
355 DBG (epdata->dev, "%s i/o interrupted\n",
356 epdata->name);
357 usb_ep_dequeue (epdata->ep, epdata->req);
358 spin_unlock_irq (&epdata->dev->lock);
359
360 wait_event (done.wait, done.done);
361 if (epdata->status == -ECONNRESET)
362 epdata->status = -EINTR;
363 } else {
364 spin_unlock_irq (&epdata->dev->lock);
365
366 DBG (epdata->dev, "endpoint gone\n");
367 epdata->status = -ENODEV;
368 }
369 }
370 return epdata->status;
371 }
372 return value;
373}
374
375
376/* handle a synchronous OUT bulk/intr/iso transfer */
377static ssize_t
378ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
379{
380 struct ep_data *data = fd->private_data;
381 void *kbuf;
382 ssize_t value;
383
384 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
385 return value;
386
387 /* halt any endpoint by doing a "wrong direction" i/o call */
388 if (usb_endpoint_dir_in(&data->desc)) {
389 if (usb_endpoint_xfer_isoc(&data->desc)) {
390 mutex_unlock(&data->lock);
391 return -EINVAL;
392 }
393 DBG (data->dev, "%s halt\n", data->name);
394 spin_lock_irq (&data->dev->lock);
395 if (likely (data->ep != NULL))
396 usb_ep_set_halt (data->ep);
397 spin_unlock_irq (&data->dev->lock);
398 mutex_unlock(&data->lock);
399 return -EBADMSG;
400 }
401
402 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
403
404 value = -ENOMEM;
405 kbuf = kmalloc (len, GFP_KERNEL);
406 if (unlikely (!kbuf))
407 goto free1;
408
409 value = ep_io (data, kbuf, len);
410 VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
411 data->name, len, (int) value);
412 if (value >= 0 && copy_to_user (buf, kbuf, value))
413 value = -EFAULT;
414
415free1:
416 mutex_unlock(&data->lock);
417 kfree (kbuf);
418 return value;
419}
420
421/* handle a synchronous IN bulk/intr/iso transfer */
422static ssize_t
423ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
424{
425 struct ep_data *data = fd->private_data;
426 void *kbuf;
427 ssize_t value;
428
429 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
430 return value;
431
432 /* halt any endpoint by doing a "wrong direction" i/o call */
433 if (!usb_endpoint_dir_in(&data->desc)) {
434 if (usb_endpoint_xfer_isoc(&data->desc)) {
435 mutex_unlock(&data->lock);
436 return -EINVAL;
437 }
438 DBG (data->dev, "%s halt\n", data->name);
439 spin_lock_irq (&data->dev->lock);
440 if (likely (data->ep != NULL))
441 usb_ep_set_halt (data->ep);
442 spin_unlock_irq (&data->dev->lock);
443 mutex_unlock(&data->lock);
444 return -EBADMSG;
445 }
446
447 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
448
449 value = -ENOMEM;
450 kbuf = kmalloc (len, GFP_KERNEL);
451 if (!kbuf)
452 goto free1;
453 if (copy_from_user (kbuf, buf, len)) {
454 value = -EFAULT;
455 goto free1;
456 }
457
458 value = ep_io (data, kbuf, len);
459 VDEBUG (data->dev, "%s write %zu IN, status %d\n",
460 data->name, len, (int) value);
461free1:
462 mutex_unlock(&data->lock);
463 kfree (kbuf);
464 return value;
465}
466
467static int
468ep_release (struct inode *inode, struct file *fd)
469{
470 struct ep_data *data = fd->private_data;
471 int value;
472
473 value = mutex_lock_interruptible(&data->lock);
474 if (value < 0)
475 return value;
476
477 /* clean up if this can be reopened */
478 if (data->state != STATE_EP_UNBOUND) {
479 data->state = STATE_EP_DISABLED;
480 data->desc.bDescriptorType = 0;
481 data->hs_desc.bDescriptorType = 0;
482 usb_ep_disable(data->ep);
483 }
484 mutex_unlock(&data->lock);
485 put_ep (data);
486 return 0;
487}
488
489static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
490{
491 struct ep_data *data = fd->private_data;
492 int status;
493
494 if ((status = get_ready_ep (fd->f_flags, data)) < 0)
495 return status;
496
497 spin_lock_irq (&data->dev->lock);
498 if (likely (data->ep != NULL)) {
499 switch (code) {
500 case GADGETFS_FIFO_STATUS:
501 status = usb_ep_fifo_status (data->ep);
502 break;
503 case GADGETFS_FIFO_FLUSH:
504 usb_ep_fifo_flush (data->ep);
505 break;
506 case GADGETFS_CLEAR_HALT:
507 status = usb_ep_clear_halt (data->ep);
508 break;
509 default:
510 status = -ENOTTY;
511 }
512 } else
513 status = -ENODEV;
514 spin_unlock_irq (&data->dev->lock);
515 mutex_unlock(&data->lock);
516 return status;
517}
518
519/*----------------------------------------------------------------------*/
520
521/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
522
523struct kiocb_priv {
524 struct usb_request *req;
525 struct ep_data *epdata;
526 void *buf;
527 const struct iovec *iv;
528 unsigned long nr_segs;
529 unsigned actual;
530};
531
532static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
533{
534 struct kiocb_priv *priv = iocb->private;
535 struct ep_data *epdata;
536 int value;
537
538 local_irq_disable();
539 epdata = priv->epdata;
540 // spin_lock(&epdata->dev->lock);
541 kiocbSetCancelled(iocb);
542 if (likely(epdata && epdata->ep && priv->req))
543 value = usb_ep_dequeue (epdata->ep, priv->req);
544 else
545 value = -EINVAL;
546 // spin_unlock(&epdata->dev->lock);
547 local_irq_enable();
548
549 aio_put_req(iocb);
550 return value;
551}
552
553static ssize_t ep_aio_read_retry(struct kiocb *iocb)
554{
555 struct kiocb_priv *priv = iocb->private;
556 ssize_t len, total;
557 void *to_copy;
558 int i;
559
560 /* we "retry" to get the right mm context for this: */
561
562 /* copy stuff into user buffers */
563 total = priv->actual;
564 len = 0;
565 to_copy = priv->buf;
566 for (i=0; i < priv->nr_segs; i++) {
567 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
568
569 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
570 if (len == 0)
571 len = -EFAULT;
572 break;
573 }
574
575 total -= this;
576 len += this;
577 to_copy += this;
578 if (total == 0)
579 break;
580 }
581 kfree(priv->buf);
582 kfree(priv);
583 return len;
584}
585
586static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
587{
588 struct kiocb *iocb = req->context;
589 struct kiocb_priv *priv = iocb->private;
590 struct ep_data *epdata = priv->epdata;
591
592 /* lock against disconnect (and ideally, cancel) */
593 spin_lock(&epdata->dev->lock);
594 priv->req = NULL;
595 priv->epdata = NULL;
596
597 /* if this was a write or a read returning no data then we
598 * don't need to copy anything to userspace, so we can
599 * complete the aio request immediately.
600 */
601 if (priv->iv == NULL || unlikely(req->actual == 0)) {
602 kfree(req->buf);
603 kfree(priv);
604 iocb->private = NULL;
605 /* aio_complete() reports bytes-transferred _and_ faults */
606 aio_complete(iocb, req->actual ? req->actual : req->status,
607 req->status);
608 } else {
609 /* retry() won't report both; so we hide some faults */
610 if (unlikely(0 != req->status))
611 DBG(epdata->dev, "%s fault %d len %d\n",
612 ep->name, req->status, req->actual);
613
614 priv->buf = req->buf;
615 priv->actual = req->actual;
616 kick_iocb(iocb);
617 }
618 spin_unlock(&epdata->dev->lock);
619
620 usb_ep_free_request(ep, req);
621 put_ep(epdata);
622}
623
624static ssize_t
625ep_aio_rwtail(
626 struct kiocb *iocb,
627 char *buf,
628 size_t len,
629 struct ep_data *epdata,
630 const struct iovec *iv,
631 unsigned long nr_segs
632)
633{
634 struct kiocb_priv *priv;
635 struct usb_request *req;
636 ssize_t value;
637
638 priv = kmalloc(sizeof *priv, GFP_KERNEL);
639 if (!priv) {
640 value = -ENOMEM;
641fail:
642 kfree(buf);
643 return value;
644 }
645 iocb->private = priv;
646 priv->iv = iv;
647 priv->nr_segs = nr_segs;
648
649 value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
650 if (unlikely(value < 0)) {
651 kfree(priv);
652 goto fail;
653 }
654
655 iocb->ki_cancel = ep_aio_cancel;
656 get_ep(epdata);
657 priv->epdata = epdata;
658 priv->actual = 0;
659
660 /* each kiocb is coupled to one usb_request, but we can't
661 * allocate or submit those if the host disconnected.
662 */
663 spin_lock_irq(&epdata->dev->lock);
664 if (likely(epdata->ep)) {
665 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
666 if (likely(req)) {
667 priv->req = req;
668 req->buf = buf;
669 req->length = len;
670 req->complete = ep_aio_complete;
671 req->context = iocb;
672 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
673 if (unlikely(0 != value))
674 usb_ep_free_request(epdata->ep, req);
675 } else
676 value = -EAGAIN;
677 } else
678 value = -ENODEV;
679 spin_unlock_irq(&epdata->dev->lock);
680
681 mutex_unlock(&epdata->lock);
682
683 if (unlikely(value)) {
684 kfree(priv);
685 put_ep(epdata);
686 } else
687 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
688 return value;
689}
690
691static ssize_t
692ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
693 unsigned long nr_segs, loff_t o)
694{
695 struct ep_data *epdata = iocb->ki_filp->private_data;
696 char *buf;
697
698 if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
699 return -EINVAL;
700
701 buf = kmalloc(iocb->ki_left, GFP_KERNEL);
702 if (unlikely(!buf))
703 return -ENOMEM;
704
705 iocb->ki_retry = ep_aio_read_retry;
706 return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
707}
708
709static ssize_t
710ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
711 unsigned long nr_segs, loff_t o)
712{
713 struct ep_data *epdata = iocb->ki_filp->private_data;
714 char *buf;
715 size_t len = 0;
716 int i = 0;
717
718 if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
719 return -EINVAL;
720
721 buf = kmalloc(iocb->ki_left, GFP_KERNEL);
722 if (unlikely(!buf))
723 return -ENOMEM;
724
725 for (i=0; i < nr_segs; i++) {
726 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
727 iov[i].iov_len) != 0)) {
728 kfree(buf);
729 return -EFAULT;
730 }
731 len += iov[i].iov_len;
732 }
733 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
734}
735
736/*----------------------------------------------------------------------*/
737
738/* used after endpoint configuration */
739static const struct file_operations ep_io_operations = {
740 .owner = THIS_MODULE,
741 .llseek = no_llseek,
742
743 .read = ep_read,
744 .write = ep_write,
745 .unlocked_ioctl = ep_ioctl,
746 .release = ep_release,
747
748 .aio_read = ep_aio_read,
749 .aio_write = ep_aio_write,
750};
751
752/* ENDPOINT INITIALIZATION
753 *
754 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
755 * status = write (fd, descriptors, sizeof descriptors)
756 *
757 * That write establishes the endpoint configuration, configuring
758 * the controller to process bulk, interrupt, or isochronous transfers
759 * at the right maxpacket size, and so on.
760 *
761 * The descriptors are message type 1, identified by a host order u32
762 * at the beginning of what's written. Descriptor order is: full/low
763 * speed descriptor, then optional high speed descriptor.
764 */
765static ssize_t
766ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
767{
768 struct ep_data *data = fd->private_data;
769 struct usb_ep *ep;
770 u32 tag;
771 int value, length = len;
772
773 value = mutex_lock_interruptible(&data->lock);
774 if (value < 0)
775 return value;
776
777 if (data->state != STATE_EP_READY) {
778 value = -EL2HLT;
779 goto fail;
780 }
781
782 value = len;
783 if (len < USB_DT_ENDPOINT_SIZE + 4)
784 goto fail0;
785
786 /* we might need to change message format someday */
787 if (copy_from_user (&tag, buf, 4)) {
788 goto fail1;
789 }
790 if (tag != 1) {
791 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
792 goto fail0;
793 }
794 buf += 4;
795 len -= 4;
796
797 /* NOTE: audio endpoint extensions not accepted here;
798 * just don't include the extra bytes.
799 */
800
801 /* full/low speed descriptor, then high speed */
802 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
803 goto fail1;
804 }
805 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
806 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
807 goto fail0;
808 if (len != USB_DT_ENDPOINT_SIZE) {
809 if (len != 2 * USB_DT_ENDPOINT_SIZE)
810 goto fail0;
811 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
812 USB_DT_ENDPOINT_SIZE)) {
813 goto fail1;
814 }
815 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
816 || data->hs_desc.bDescriptorType
817 != USB_DT_ENDPOINT) {
818 DBG(data->dev, "config %s, bad hs length or type\n",
819 data->name);
820 goto fail0;
821 }
822 }
823
824 spin_lock_irq (&data->dev->lock);
825 if (data->dev->state == STATE_DEV_UNBOUND) {
826 value = -ENOENT;
827 goto gone;
828 } else if ((ep = data->ep) == NULL) {
829 value = -ENODEV;
830 goto gone;
831 }
832 switch (data->dev->gadget->speed) {
833 case USB_SPEED_LOW:
834 case USB_SPEED_FULL:
835 ep->desc = &data->desc;
836 value = usb_ep_enable(ep);
837 if (value == 0)
838 data->state = STATE_EP_ENABLED;
839 break;
840#ifdef CONFIG_USB_GADGET_DUALSPEED
841 case USB_SPEED_HIGH:
842 /* fails if caller didn't provide that descriptor... */
843 ep->desc = &data->hs_desc;
844 value = usb_ep_enable(ep);
845 if (value == 0)
846 data->state = STATE_EP_ENABLED;
847 break;
848#endif
849 default:
850 DBG(data->dev, "unconnected, %s init abandoned\n",
851 data->name);
852 value = -EINVAL;
853 }
854 if (value == 0) {
855 fd->f_op = &ep_io_operations;
856 value = length;
857 }
858gone:
859 spin_unlock_irq (&data->dev->lock);
860 if (value < 0) {
861fail:
862 data->desc.bDescriptorType = 0;
863 data->hs_desc.bDescriptorType = 0;
864 }
865 mutex_unlock(&data->lock);
866 return value;
867fail0:
868 value = -EINVAL;
869 goto fail;
870fail1:
871 value = -EFAULT;
872 goto fail;
873}
874
875static int
876ep_open (struct inode *inode, struct file *fd)
877{
878 struct ep_data *data = inode->i_private;
879 int value = -EBUSY;
880
881 if (mutex_lock_interruptible(&data->lock) != 0)
882 return -EINTR;
883 spin_lock_irq (&data->dev->lock);
884 if (data->dev->state == STATE_DEV_UNBOUND)
885 value = -ENOENT;
886 else if (data->state == STATE_EP_DISABLED) {
887 value = 0;
888 data->state = STATE_EP_READY;
889 get_ep (data);
890 fd->private_data = data;
891 VDEBUG (data->dev, "%s ready\n", data->name);
892 } else
893 DBG (data->dev, "%s state %d\n",
894 data->name, data->state);
895 spin_unlock_irq (&data->dev->lock);
896 mutex_unlock(&data->lock);
897 return value;
898}
899
900/* used before endpoint configuration */
901static const struct file_operations ep_config_operations = {
902 .owner = THIS_MODULE,
903 .llseek = no_llseek,
904
905 .open = ep_open,
906 .write = ep_config,
907 .release = ep_release,
908};
909
910/*----------------------------------------------------------------------*/
911
912/* EP0 IMPLEMENTATION can be partly in userspace.
913 *
914 * Drivers that use this facility receive various events, including
915 * control requests the kernel doesn't handle. Drivers that don't
916 * use this facility may be too simple-minded for real applications.
917 */
918
919static inline void ep0_readable (struct dev_data *dev)
920{
921 wake_up (&dev->wait);
922 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
923}
924
925static void clean_req (struct usb_ep *ep, struct usb_request *req)
926{
927 struct dev_data *dev = ep->driver_data;
928
929 if (req->buf != dev->rbuf) {
930 kfree(req->buf);
931 req->buf = dev->rbuf;
932 req->dma = DMA_ADDR_INVALID;
933 }
934 req->complete = epio_complete;
935 dev->setup_out_ready = 0;
936}
937
938static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
939{
940 struct dev_data *dev = ep->driver_data;
941 unsigned long flags;
942 int free = 1;
943
944 /* for control OUT, data must still get to userspace */
945 spin_lock_irqsave(&dev->lock, flags);
946 if (!dev->setup_in) {
947 dev->setup_out_error = (req->status != 0);
948 if (!dev->setup_out_error)
949 free = 0;
950 dev->setup_out_ready = 1;
951 ep0_readable (dev);
952 }
953
954 /* clean up as appropriate */
955 if (free && req->buf != &dev->rbuf)
956 clean_req (ep, req);
957 req->complete = epio_complete;
958 spin_unlock_irqrestore(&dev->lock, flags);
959}
960
961static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
962{
963 struct dev_data *dev = ep->driver_data;
964
965 if (dev->setup_out_ready) {
966 DBG (dev, "ep0 request busy!\n");
967 return -EBUSY;
968 }
969 if (len > sizeof (dev->rbuf))
970 req->buf = kmalloc(len, GFP_ATOMIC);
971 if (req->buf == NULL) {
972 req->buf = dev->rbuf;
973 return -ENOMEM;
974 }
975 req->complete = ep0_complete;
976 req->length = len;
977 req->zero = 0;
978 return 0;
979}
980
981static ssize_t
982ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
983{
984 struct dev_data *dev = fd->private_data;
985 ssize_t retval;
986 enum ep0_state state;
987
988 spin_lock_irq (&dev->lock);
989
990 /* report fd mode change before acting on it */
991 if (dev->setup_abort) {
992 dev->setup_abort = 0;
993 retval = -EIDRM;
994 goto done;
995 }
996
997 /* control DATA stage */
998 if ((state = dev->state) == STATE_DEV_SETUP) {
999
1000 if (dev->setup_in) { /* stall IN */
1001 VDEBUG(dev, "ep0in stall\n");
1002 (void) usb_ep_set_halt (dev->gadget->ep0);
1003 retval = -EL2HLT;
1004 dev->state = STATE_DEV_CONNECTED;
1005
1006 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
1007 struct usb_ep *ep = dev->gadget->ep0;
1008 struct usb_request *req = dev->req;
1009
1010 if ((retval = setup_req (ep, req, 0)) == 0)
1011 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1012 dev->state = STATE_DEV_CONNECTED;
1013
1014 /* assume that was SET_CONFIGURATION */
1015 if (dev->current_config) {
1016 unsigned power;
1017
1018 if (gadget_is_dualspeed(dev->gadget)
1019 && (dev->gadget->speed
1020 == USB_SPEED_HIGH))
1021 power = dev->hs_config->bMaxPower;
1022 else
1023 power = dev->config->bMaxPower;
1024 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1025 }
1026
1027 } else { /* collect OUT data */
1028 if ((fd->f_flags & O_NONBLOCK) != 0
1029 && !dev->setup_out_ready) {
1030 retval = -EAGAIN;
1031 goto done;
1032 }
1033 spin_unlock_irq (&dev->lock);
1034 retval = wait_event_interruptible (dev->wait,
1035 dev->setup_out_ready != 0);
1036
1037 /* FIXME state could change from under us */
1038 spin_lock_irq (&dev->lock);
1039 if (retval)
1040 goto done;
1041
1042 if (dev->state != STATE_DEV_SETUP) {
1043 retval = -ECANCELED;
1044 goto done;
1045 }
1046 dev->state = STATE_DEV_CONNECTED;
1047
1048 if (dev->setup_out_error)
1049 retval = -EIO;
1050 else {
1051 len = min (len, (size_t)dev->req->actual);
1052// FIXME don't call this with the spinlock held ...
1053 if (copy_to_user (buf, dev->req->buf, len))
1054 retval = -EFAULT;
1055 clean_req (dev->gadget->ep0, dev->req);
1056 /* NOTE userspace can't yet choose to stall */
1057 }
1058 }
1059 goto done;
1060 }
1061
1062 /* else normal: return event data */
1063 if (len < sizeof dev->event [0]) {
1064 retval = -EINVAL;
1065 goto done;
1066 }
1067 len -= len % sizeof (struct usb_gadgetfs_event);
1068 dev->usermode_setup = 1;
1069
1070scan:
1071 /* return queued events right away */
1072 if (dev->ev_next != 0) {
1073 unsigned i, n;
1074
1075 n = len / sizeof (struct usb_gadgetfs_event);
1076 if (dev->ev_next < n)
1077 n = dev->ev_next;
1078
1079 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1080 for (i = 0; i < n; i++) {
1081 if (dev->event [i].type == GADGETFS_SETUP) {
1082 dev->state = STATE_DEV_SETUP;
1083 n = i + 1;
1084 break;
1085 }
1086 }
1087 spin_unlock_irq (&dev->lock);
1088 len = n * sizeof (struct usb_gadgetfs_event);
1089 if (copy_to_user (buf, &dev->event, len))
1090 retval = -EFAULT;
1091 else
1092 retval = len;
1093 if (len > 0) {
1094 /* NOTE this doesn't guard against broken drivers;
1095 * concurrent ep0 readers may lose events.
1096 */
1097 spin_lock_irq (&dev->lock);
1098 if (dev->ev_next > n) {
1099 memmove(&dev->event[0], &dev->event[n],
1100 sizeof (struct usb_gadgetfs_event)
1101 * (dev->ev_next - n));
1102 }
1103 dev->ev_next -= n;
1104 spin_unlock_irq (&dev->lock);
1105 }
1106 return retval;
1107 }
1108 if (fd->f_flags & O_NONBLOCK) {
1109 retval = -EAGAIN;
1110 goto done;
1111 }
1112
1113 switch (state) {
1114 default:
1115 DBG (dev, "fail %s, state %d\n", __func__, state);
1116 retval = -ESRCH;
1117 break;
1118 case STATE_DEV_UNCONNECTED:
1119 case STATE_DEV_CONNECTED:
1120 spin_unlock_irq (&dev->lock);
1121 DBG (dev, "%s wait\n", __func__);
1122
1123 /* wait for events */
1124 retval = wait_event_interruptible (dev->wait,
1125 dev->ev_next != 0);
1126 if (retval < 0)
1127 return retval;
1128 spin_lock_irq (&dev->lock);
1129 goto scan;
1130 }
1131
1132done:
1133 spin_unlock_irq (&dev->lock);
1134 return retval;
1135}
1136
1137static struct usb_gadgetfs_event *
1138next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1139{
1140 struct usb_gadgetfs_event *event;
1141 unsigned i;
1142
1143 switch (type) {
1144 /* these events purge the queue */
1145 case GADGETFS_DISCONNECT:
1146 if (dev->state == STATE_DEV_SETUP)
1147 dev->setup_abort = 1;
1148 // FALL THROUGH
1149 case GADGETFS_CONNECT:
1150 dev->ev_next = 0;
1151 break;
1152 case GADGETFS_SETUP: /* previous request timed out */
1153 case GADGETFS_SUSPEND: /* same effect */
1154 /* these events can't be repeated */
1155 for (i = 0; i != dev->ev_next; i++) {
1156 if (dev->event [i].type != type)
1157 continue;
1158 DBG(dev, "discard old event[%d] %d\n", i, type);
1159 dev->ev_next--;
1160 if (i == dev->ev_next)
1161 break;
1162 /* indices start at zero, for simplicity */
1163 memmove (&dev->event [i], &dev->event [i + 1],
1164 sizeof (struct usb_gadgetfs_event)
1165 * (dev->ev_next - i));
1166 }
1167 break;
1168 default:
1169 BUG ();
1170 }
1171 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1172 event = &dev->event [dev->ev_next++];
1173 BUG_ON (dev->ev_next > N_EVENT);
1174 memset (event, 0, sizeof *event);
1175 event->type = type;
1176 return event;
1177}
1178
1179static ssize_t
1180ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1181{
1182 struct dev_data *dev = fd->private_data;
1183 ssize_t retval = -ESRCH;
1184
1185 spin_lock_irq (&dev->lock);
1186
1187 /* report fd mode change before acting on it */
1188 if (dev->setup_abort) {
1189 dev->setup_abort = 0;
1190 retval = -EIDRM;
1191
1192 /* data and/or status stage for control request */
1193 } else if (dev->state == STATE_DEV_SETUP) {
1194
1195 /* IN DATA+STATUS caller makes len <= wLength */
1196 if (dev->setup_in) {
1197 retval = setup_req (dev->gadget->ep0, dev->req, len);
1198 if (retval == 0) {
1199 dev->state = STATE_DEV_CONNECTED;
1200 spin_unlock_irq (&dev->lock);
1201 if (copy_from_user (dev->req->buf, buf, len))
1202 retval = -EFAULT;
1203 else {
1204 if (len < dev->setup_wLength)
1205 dev->req->zero = 1;
1206 retval = usb_ep_queue (
1207 dev->gadget->ep0, dev->req,
1208 GFP_KERNEL);
1209 }
1210 if (retval < 0) {
1211 spin_lock_irq (&dev->lock);
1212 clean_req (dev->gadget->ep0, dev->req);
1213 spin_unlock_irq (&dev->lock);
1214 } else
1215 retval = len;
1216
1217 return retval;
1218 }
1219
1220 /* can stall some OUT transfers */
1221 } else if (dev->setup_can_stall) {
1222 VDEBUG(dev, "ep0out stall\n");
1223 (void) usb_ep_set_halt (dev->gadget->ep0);
1224 retval = -EL2HLT;
1225 dev->state = STATE_DEV_CONNECTED;
1226 } else {
1227 DBG(dev, "bogus ep0out stall!\n");
1228 }
1229 } else
1230 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1231
1232 spin_unlock_irq (&dev->lock);
1233 return retval;
1234}
1235
1236static int
1237ep0_fasync (int f, struct file *fd, int on)
1238{
1239 struct dev_data *dev = fd->private_data;
1240 // caller must F_SETOWN before signal delivery happens
1241 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1242 return fasync_helper (f, fd, on, &dev->fasync);
1243}
1244
1245static struct usb_gadget_driver gadgetfs_driver;
1246
1247static int
1248dev_release (struct inode *inode, struct file *fd)
1249{
1250 struct dev_data *dev = fd->private_data;
1251
1252 /* closing ep0 === shutdown all */
1253
1254 usb_gadget_unregister_driver (&gadgetfs_driver);
1255
1256 /* at this point "good" hardware has disconnected the
1257 * device from USB; the host won't see it any more.
1258 * alternatively, all host requests will time out.
1259 */
1260
1261 kfree (dev->buf);
1262 dev->buf = NULL;
1263 put_dev (dev);
1264
1265 /* other endpoints were all decoupled from this device */
1266 spin_lock_irq(&dev->lock);
1267 dev->state = STATE_DEV_DISABLED;
1268 spin_unlock_irq(&dev->lock);
1269 return 0;
1270}
1271
1272static unsigned int
1273ep0_poll (struct file *fd, poll_table *wait)
1274{
1275 struct dev_data *dev = fd->private_data;
1276 int mask = 0;
1277
1278 poll_wait(fd, &dev->wait, wait);
1279
1280 spin_lock_irq (&dev->lock);
1281
1282 /* report fd mode change before acting on it */
1283 if (dev->setup_abort) {
1284 dev->setup_abort = 0;
1285 mask = POLLHUP;
1286 goto out;
1287 }
1288
1289 if (dev->state == STATE_DEV_SETUP) {
1290 if (dev->setup_in || dev->setup_can_stall)
1291 mask = POLLOUT;
1292 } else {
1293 if (dev->ev_next != 0)
1294 mask = POLLIN;
1295 }
1296out:
1297 spin_unlock_irq(&dev->lock);
1298 return mask;
1299}
1300
1301static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1302{
1303 struct dev_data *dev = fd->private_data;
1304 struct usb_gadget *gadget = dev->gadget;
1305 long ret = -ENOTTY;
1306
1307 if (gadget->ops->ioctl)
1308 ret = gadget->ops->ioctl (gadget, code, value);
1309
1310 return ret;
1311}
1312
1313/* used after device configuration */
1314static const struct file_operations ep0_io_operations = {
1315 .owner = THIS_MODULE,
1316 .llseek = no_llseek,
1317
1318 .read = ep0_read,
1319 .write = ep0_write,
1320 .fasync = ep0_fasync,
1321 .poll = ep0_poll,
1322 .unlocked_ioctl = dev_ioctl,
1323 .release = dev_release,
1324};
1325
1326/*----------------------------------------------------------------------*/
1327
1328/* The in-kernel gadget driver handles most ep0 issues, in particular
1329 * enumerating the single configuration (as provided from user space).
1330 *
1331 * Unrecognized ep0 requests may be handled in user space.
1332 */
1333
1334#ifdef CONFIG_USB_GADGET_DUALSPEED
1335static void make_qualifier (struct dev_data *dev)
1336{
1337 struct usb_qualifier_descriptor qual;
1338 struct usb_device_descriptor *desc;
1339
1340 qual.bLength = sizeof qual;
1341 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1342 qual.bcdUSB = cpu_to_le16 (0x0200);
1343
1344 desc = dev->dev;
1345 qual.bDeviceClass = desc->bDeviceClass;
1346 qual.bDeviceSubClass = desc->bDeviceSubClass;
1347 qual.bDeviceProtocol = desc->bDeviceProtocol;
1348
1349 /* assumes ep0 uses the same value for both speeds ... */
1350 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1351
1352 qual.bNumConfigurations = 1;
1353 qual.bRESERVED = 0;
1354
1355 memcpy (dev->rbuf, &qual, sizeof qual);
1356}
1357#endif
1358
1359static int
1360config_buf (struct dev_data *dev, u8 type, unsigned index)
1361{
1362 int len;
1363 int hs = 0;
1364
1365 /* only one configuration */
1366 if (index > 0)
1367 return -EINVAL;
1368
1369 if (gadget_is_dualspeed(dev->gadget)) {
1370 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1371 if (type == USB_DT_OTHER_SPEED_CONFIG)
1372 hs = !hs;
1373 }
1374 if (hs) {
1375 dev->req->buf = dev->hs_config;
1376 len = le16_to_cpu(dev->hs_config->wTotalLength);
1377 } else {
1378 dev->req->buf = dev->config;
1379 len = le16_to_cpu(dev->config->wTotalLength);
1380 }
1381 ((u8 *)dev->req->buf) [1] = type;
1382 return len;
1383}
1384
1385static int
1386gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1387{
1388 struct dev_data *dev = get_gadget_data (gadget);
1389 struct usb_request *req = dev->req;
1390 int value = -EOPNOTSUPP;
1391 struct usb_gadgetfs_event *event;
1392 u16 w_value = le16_to_cpu(ctrl->wValue);
1393 u16 w_length = le16_to_cpu(ctrl->wLength);
1394
1395 spin_lock (&dev->lock);
1396 dev->setup_abort = 0;
1397 if (dev->state == STATE_DEV_UNCONNECTED) {
1398 if (gadget_is_dualspeed(gadget)
1399 && gadget->speed == USB_SPEED_HIGH
1400 && dev->hs_config == NULL) {
1401 spin_unlock(&dev->lock);
1402 ERROR (dev, "no high speed config??\n");
1403 return -EINVAL;
1404 }
1405
1406 dev->state = STATE_DEV_CONNECTED;
1407
1408 INFO (dev, "connected\n");
1409 event = next_event (dev, GADGETFS_CONNECT);
1410 event->u.speed = gadget->speed;
1411 ep0_readable (dev);
1412
1413 /* host may have given up waiting for response. we can miss control
1414 * requests handled lower down (device/endpoint status and features);
1415 * then ep0_{read,write} will report the wrong status. controller
1416 * driver will have aborted pending i/o.
1417 */
1418 } else if (dev->state == STATE_DEV_SETUP)
1419 dev->setup_abort = 1;
1420
1421 req->buf = dev->rbuf;
1422 req->dma = DMA_ADDR_INVALID;
1423 req->context = NULL;
1424 value = -EOPNOTSUPP;
1425 switch (ctrl->bRequest) {
1426
1427 case USB_REQ_GET_DESCRIPTOR:
1428 if (ctrl->bRequestType != USB_DIR_IN)
1429 goto unrecognized;
1430 switch (w_value >> 8) {
1431
1432 case USB_DT_DEVICE:
1433 value = min (w_length, (u16) sizeof *dev->dev);
1434 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1435 req->buf = dev->dev;
1436 break;
1437#ifdef CONFIG_USB_GADGET_DUALSPEED
1438 case USB_DT_DEVICE_QUALIFIER:
1439 if (!dev->hs_config)
1440 break;
1441 value = min (w_length, (u16)
1442 sizeof (struct usb_qualifier_descriptor));
1443 make_qualifier (dev);
1444 break;
1445 case USB_DT_OTHER_SPEED_CONFIG:
1446 // FALLTHROUGH
1447#endif
1448 case USB_DT_CONFIG:
1449 value = config_buf (dev,
1450 w_value >> 8,
1451 w_value & 0xff);
1452 if (value >= 0)
1453 value = min (w_length, (u16) value);
1454 break;
1455 case USB_DT_STRING:
1456 goto unrecognized;
1457
1458 default: // all others are errors
1459 break;
1460 }
1461 break;
1462
1463 /* currently one config, two speeds */
1464 case USB_REQ_SET_CONFIGURATION:
1465 if (ctrl->bRequestType != 0)
1466 goto unrecognized;
1467 if (0 == (u8) w_value) {
1468 value = 0;
1469 dev->current_config = 0;
1470 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1471 // user mode expected to disable endpoints
1472 } else {
1473 u8 config, power;
1474
1475 if (gadget_is_dualspeed(gadget)
1476 && gadget->speed == USB_SPEED_HIGH) {
1477 config = dev->hs_config->bConfigurationValue;
1478 power = dev->hs_config->bMaxPower;
1479 } else {
1480 config = dev->config->bConfigurationValue;
1481 power = dev->config->bMaxPower;
1482 }
1483
1484 if (config == (u8) w_value) {
1485 value = 0;
1486 dev->current_config = config;
1487 usb_gadget_vbus_draw(gadget, 2 * power);
1488 }
1489 }
1490
1491 /* report SET_CONFIGURATION like any other control request,
1492 * except that usermode may not stall this. the next
1493 * request mustn't be allowed start until this finishes:
1494 * endpoints and threads set up, etc.
1495 *
1496 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1497 * has bad/racey automagic that prevents synchronizing here.
1498 * even kernel mode drivers often miss them.
1499 */
1500 if (value == 0) {
1501 INFO (dev, "configuration #%d\n", dev->current_config);
1502 if (dev->usermode_setup) {
1503 dev->setup_can_stall = 0;
1504 goto delegate;
1505 }
1506 }
1507 break;
1508
1509#ifndef CONFIG_USB_GADGET_PXA25X
1510 /* PXA automagically handles this request too */
1511 case USB_REQ_GET_CONFIGURATION:
1512 if (ctrl->bRequestType != 0x80)
1513 goto unrecognized;
1514 *(u8 *)req->buf = dev->current_config;
1515 value = min (w_length, (u16) 1);
1516 break;
1517#endif
1518
1519 default:
1520unrecognized:
1521 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1522 dev->usermode_setup ? "delegate" : "fail",
1523 ctrl->bRequestType, ctrl->bRequest,
1524 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1525
1526 /* if there's an ep0 reader, don't stall */
1527 if (dev->usermode_setup) {
1528 dev->setup_can_stall = 1;
1529delegate:
1530 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1531 ? 1 : 0;
1532 dev->setup_wLength = w_length;
1533 dev->setup_out_ready = 0;
1534 dev->setup_out_error = 0;
1535 value = 0;
1536
1537 /* read DATA stage for OUT right away */
1538 if (unlikely (!dev->setup_in && w_length)) {
1539 value = setup_req (gadget->ep0, dev->req,
1540 w_length);
1541 if (value < 0)
1542 break;
1543 value = usb_ep_queue (gadget->ep0, dev->req,
1544 GFP_ATOMIC);
1545 if (value < 0) {
1546 clean_req (gadget->ep0, dev->req);
1547 break;
1548 }
1549
1550 /* we can't currently stall these */
1551 dev->setup_can_stall = 0;
1552 }
1553
1554 /* state changes when reader collects event */
1555 event = next_event (dev, GADGETFS_SETUP);
1556 event->u.setup = *ctrl;
1557 ep0_readable (dev);
1558 spin_unlock (&dev->lock);
1559 return 0;
1560 }
1561 }
1562
1563 /* proceed with data transfer and status phases? */
1564 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1565 req->length = value;
1566 req->zero = value < w_length;
1567 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1568 if (value < 0) {
1569 DBG (dev, "ep_queue --> %d\n", value);
1570 req->status = 0;
1571 }
1572 }
1573
1574 /* device stalls when value < 0 */
1575 spin_unlock (&dev->lock);
1576 return value;
1577}
1578
1579static void destroy_ep_files (struct dev_data *dev)
1580{
1581 struct list_head *entry, *tmp;
1582
1583 DBG (dev, "%s %d\n", __func__, dev->state);
1584
1585 /* dev->state must prevent interference */
1586restart:
1587 spin_lock_irq (&dev->lock);
1588 list_for_each_safe (entry, tmp, &dev->epfiles) {
1589 struct ep_data *ep;
1590 struct inode *parent;
1591 struct dentry *dentry;
1592
1593 /* break link to FS */
1594 ep = list_entry (entry, struct ep_data, epfiles);
1595 list_del_init (&ep->epfiles);
1596 dentry = ep->dentry;
1597 ep->dentry = NULL;
1598 parent = dentry->d_parent->d_inode;
1599
1600 /* break link to controller */
1601 if (ep->state == STATE_EP_ENABLED)
1602 (void) usb_ep_disable (ep->ep);
1603 ep->state = STATE_EP_UNBOUND;
1604 usb_ep_free_request (ep->ep, ep->req);
1605 ep->ep = NULL;
1606 wake_up (&ep->wait);
1607 put_ep (ep);
1608
1609 spin_unlock_irq (&dev->lock);
1610
1611 /* break link to dcache */
1612 mutex_lock (&parent->i_mutex);
1613 d_delete (dentry);
1614 dput (dentry);
1615 mutex_unlock (&parent->i_mutex);
1616
1617 /* fds may still be open */
1618 goto restart;
1619 }
1620 spin_unlock_irq (&dev->lock);
1621}
1622
1623
1624static struct inode *
1625gadgetfs_create_file (struct super_block *sb, char const *name,
1626 void *data, const struct file_operations *fops,
1627 struct dentry **dentry_p);
1628
1629static int activate_ep_files (struct dev_data *dev)
1630{
1631 struct usb_ep *ep;
1632 struct ep_data *data;
1633
1634 gadget_for_each_ep (ep, dev->gadget) {
1635
1636 data = kzalloc(sizeof(*data), GFP_KERNEL);
1637 if (!data)
1638 goto enomem0;
1639 data->state = STATE_EP_DISABLED;
1640 mutex_init(&data->lock);
1641 init_waitqueue_head (&data->wait);
1642
1643 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1644 atomic_set (&data->count, 1);
1645 data->dev = dev;
1646 get_dev (dev);
1647
1648 data->ep = ep;
1649 ep->driver_data = data;
1650
1651 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1652 if (!data->req)
1653 goto enomem1;
1654
1655 data->inode = gadgetfs_create_file (dev->sb, data->name,
1656 data, &ep_config_operations,
1657 &data->dentry);
1658 if (!data->inode)
1659 goto enomem2;
1660 list_add_tail (&data->epfiles, &dev->epfiles);
1661 }
1662 return 0;
1663
1664enomem2:
1665 usb_ep_free_request (ep, data->req);
1666enomem1:
1667 put_dev (dev);
1668 kfree (data);
1669enomem0:
1670 DBG (dev, "%s enomem\n", __func__);
1671 destroy_ep_files (dev);
1672 return -ENOMEM;
1673}
1674
1675static void
1676gadgetfs_unbind (struct usb_gadget *gadget)
1677{
1678 struct dev_data *dev = get_gadget_data (gadget);
1679
1680 DBG (dev, "%s\n", __func__);
1681
1682 spin_lock_irq (&dev->lock);
1683 dev->state = STATE_DEV_UNBOUND;
1684 spin_unlock_irq (&dev->lock);
1685
1686 destroy_ep_files (dev);
1687 gadget->ep0->driver_data = NULL;
1688 set_gadget_data (gadget, NULL);
1689
1690 /* we've already been disconnected ... no i/o is active */
1691 if (dev->req)
1692 usb_ep_free_request (gadget->ep0, dev->req);
1693 DBG (dev, "%s done\n", __func__);
1694 put_dev (dev);
1695}
1696
1697static struct dev_data *the_device;
1698
1699static int
1700gadgetfs_bind (struct usb_gadget *gadget)
1701{
1702 struct dev_data *dev = the_device;
1703
1704 if (!dev)
1705 return -ESRCH;
1706 if (0 != strcmp (CHIP, gadget->name)) {
1707 pr_err("%s expected %s controller not %s\n",
1708 shortname, CHIP, gadget->name);
1709 return -ENODEV;
1710 }
1711
1712 set_gadget_data (gadget, dev);
1713 dev->gadget = gadget;
1714 gadget->ep0->driver_data = dev;
1715
1716 /* preallocate control response and buffer */
1717 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1718 if (!dev->req)
1719 goto enomem;
1720 dev->req->context = NULL;
1721 dev->req->complete = epio_complete;
1722
1723 if (activate_ep_files (dev) < 0)
1724 goto enomem;
1725
1726 INFO (dev, "bound to %s driver\n", gadget->name);
1727 spin_lock_irq(&dev->lock);
1728 dev->state = STATE_DEV_UNCONNECTED;
1729 spin_unlock_irq(&dev->lock);
1730 get_dev (dev);
1731 return 0;
1732
1733enomem:
1734 gadgetfs_unbind (gadget);
1735 return -ENOMEM;
1736}
1737
1738static void
1739gadgetfs_disconnect (struct usb_gadget *gadget)
1740{
1741 struct dev_data *dev = get_gadget_data (gadget);
1742
1743 spin_lock (&dev->lock);
1744 if (dev->state == STATE_DEV_UNCONNECTED)
1745 goto exit;
1746 dev->state = STATE_DEV_UNCONNECTED;
1747
1748 INFO (dev, "disconnected\n");
1749 next_event (dev, GADGETFS_DISCONNECT);
1750 ep0_readable (dev);
1751exit:
1752 spin_unlock (&dev->lock);
1753}
1754
1755static void
1756gadgetfs_suspend (struct usb_gadget *gadget)
1757{
1758 struct dev_data *dev = get_gadget_data (gadget);
1759
1760 INFO (dev, "suspended from state %d\n", dev->state);
1761 spin_lock (&dev->lock);
1762 switch (dev->state) {
1763 case STATE_DEV_SETUP: // VERY odd... host died??
1764 case STATE_DEV_CONNECTED:
1765 case STATE_DEV_UNCONNECTED:
1766 next_event (dev, GADGETFS_SUSPEND);
1767 ep0_readable (dev);
1768 /* FALLTHROUGH */
1769 default:
1770 break;
1771 }
1772 spin_unlock (&dev->lock);
1773}
1774
1775static struct usb_gadget_driver gadgetfs_driver = {
1776#ifdef CONFIG_USB_GADGET_DUALSPEED
1777 .speed = USB_SPEED_HIGH,
1778#else
1779 .speed = USB_SPEED_FULL,
1780#endif
1781 .function = (char *) driver_desc,
1782 .unbind = gadgetfs_unbind,
1783 .setup = gadgetfs_setup,
1784 .disconnect = gadgetfs_disconnect,
1785 .suspend = gadgetfs_suspend,
1786
1787 .driver = {
1788 .name = (char *) shortname,
1789 },
1790};
1791
1792/*----------------------------------------------------------------------*/
1793
1794static void gadgetfs_nop(struct usb_gadget *arg) { }
1795
1796static int gadgetfs_probe (struct usb_gadget *gadget)
1797{
1798 CHIP = gadget->name;
1799 return -EISNAM;
1800}
1801
1802static struct usb_gadget_driver probe_driver = {
1803 .speed = USB_SPEED_HIGH,
1804 .unbind = gadgetfs_nop,
1805 .setup = (void *)gadgetfs_nop,
1806 .disconnect = gadgetfs_nop,
1807 .driver = {
1808 .name = "nop",
1809 },
1810};
1811
1812
1813/* DEVICE INITIALIZATION
1814 *
1815 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1816 * status = write (fd, descriptors, sizeof descriptors)
1817 *
1818 * That write establishes the device configuration, so the kernel can
1819 * bind to the controller ... guaranteeing it can handle enumeration
1820 * at all necessary speeds. Descriptor order is:
1821 *
1822 * . message tag (u32, host order) ... for now, must be zero; it
1823 * would change to support features like multi-config devices
1824 * . full/low speed config ... all wTotalLength bytes (with interface,
1825 * class, altsetting, endpoint, and other descriptors)
1826 * . high speed config ... all descriptors, for high speed operation;
1827 * this one's optional except for high-speed hardware
1828 * . device descriptor
1829 *
1830 * Endpoints are not yet enabled. Drivers must wait until device
1831 * configuration and interface altsetting changes create
1832 * the need to configure (or unconfigure) them.
1833 *
1834 * After initialization, the device stays active for as long as that
1835 * $CHIP file is open. Events must then be read from that descriptor,
1836 * such as configuration notifications.
1837 */
1838
1839static int is_valid_config (struct usb_config_descriptor *config)
1840{
1841 return config->bDescriptorType == USB_DT_CONFIG
1842 && config->bLength == USB_DT_CONFIG_SIZE
1843 && config->bConfigurationValue != 0
1844 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1845 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1846 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1847 /* FIXME check lengths: walk to end */
1848}
1849
1850static ssize_t
1851dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1852{
1853 struct dev_data *dev = fd->private_data;
1854 ssize_t value = len, length = len;
1855 unsigned total;
1856 u32 tag;
1857 char *kbuf;
1858
1859 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1860 return -EINVAL;
1861
1862 /* we might need to change message format someday */
1863 if (copy_from_user (&tag, buf, 4))
1864 return -EFAULT;
1865 if (tag != 0)
1866 return -EINVAL;
1867 buf += 4;
1868 length -= 4;
1869
1870 kbuf = memdup_user(buf, length);
1871 if (IS_ERR(kbuf))
1872 return PTR_ERR(kbuf);
1873
1874 spin_lock_irq (&dev->lock);
1875 value = -EINVAL;
1876 if (dev->buf)
1877 goto fail;
1878 dev->buf = kbuf;
1879
1880 /* full or low speed config */
1881 dev->config = (void *) kbuf;
1882 total = le16_to_cpu(dev->config->wTotalLength);
1883 if (!is_valid_config (dev->config) || total >= length)
1884 goto fail;
1885 kbuf += total;
1886 length -= total;
1887
1888 /* optional high speed config */
1889 if (kbuf [1] == USB_DT_CONFIG) {
1890 dev->hs_config = (void *) kbuf;
1891 total = le16_to_cpu(dev->hs_config->wTotalLength);
1892 if (!is_valid_config (dev->hs_config) || total >= length)
1893 goto fail;
1894 kbuf += total;
1895 length -= total;
1896 }
1897
1898 /* could support multiple configs, using another encoding! */
1899
1900 /* device descriptor (tweaked for paranoia) */
1901 if (length != USB_DT_DEVICE_SIZE)
1902 goto fail;
1903 dev->dev = (void *)kbuf;
1904 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1905 || dev->dev->bDescriptorType != USB_DT_DEVICE
1906 || dev->dev->bNumConfigurations != 1)
1907 goto fail;
1908 dev->dev->bNumConfigurations = 1;
1909 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1910
1911 /* triggers gadgetfs_bind(); then we can enumerate. */
1912 spin_unlock_irq (&dev->lock);
1913 value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1914 if (value != 0) {
1915 kfree (dev->buf);
1916 dev->buf = NULL;
1917 } else {
1918 /* at this point "good" hardware has for the first time
1919 * let the USB the host see us. alternatively, if users
1920 * unplug/replug that will clear all the error state.
1921 *
1922 * note: everything running before here was guaranteed
1923 * to choke driver model style diagnostics. from here
1924 * on, they can work ... except in cleanup paths that
1925 * kick in after the ep0 descriptor is closed.
1926 */
1927 fd->f_op = &ep0_io_operations;
1928 value = len;
1929 }
1930 return value;
1931
1932fail:
1933 spin_unlock_irq (&dev->lock);
1934 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1935 kfree (dev->buf);
1936 dev->buf = NULL;
1937 return value;
1938}
1939
1940static int
1941dev_open (struct inode *inode, struct file *fd)
1942{
1943 struct dev_data *dev = inode->i_private;
1944 int value = -EBUSY;
1945
1946 spin_lock_irq(&dev->lock);
1947 if (dev->state == STATE_DEV_DISABLED) {
1948 dev->ev_next = 0;
1949 dev->state = STATE_DEV_OPENED;
1950 fd->private_data = dev;
1951 get_dev (dev);
1952 value = 0;
1953 }
1954 spin_unlock_irq(&dev->lock);
1955 return value;
1956}
1957
1958static const struct file_operations dev_init_operations = {
1959 .owner = THIS_MODULE,
1960 .llseek = no_llseek,
1961
1962 .open = dev_open,
1963 .write = dev_config,
1964 .fasync = ep0_fasync,
1965 .unlocked_ioctl = dev_ioctl,
1966 .release = dev_release,
1967};
1968
1969/*----------------------------------------------------------------------*/
1970
1971/* FILESYSTEM AND SUPERBLOCK OPERATIONS
1972 *
1973 * Mounting the filesystem creates a controller file, used first for
1974 * device configuration then later for event monitoring.
1975 */
1976
1977
1978/* FIXME PAM etc could set this security policy without mount options
1979 * if epfiles inherited ownership and permissons from ep0 ...
1980 */
1981
1982static unsigned default_uid;
1983static unsigned default_gid;
1984static unsigned default_perm = S_IRUSR | S_IWUSR;
1985
1986module_param (default_uid, uint, 0644);
1987module_param (default_gid, uint, 0644);
1988module_param (default_perm, uint, 0644);
1989
1990
1991static struct inode *
1992gadgetfs_make_inode (struct super_block *sb,
1993 void *data, const struct file_operations *fops,
1994 int mode)
1995{
1996 struct inode *inode = new_inode (sb);
1997
1998 if (inode) {
1999 inode->i_ino = get_next_ino();
2000 inode->i_mode = mode;
2001 inode->i_uid = default_uid;
2002 inode->i_gid = default_gid;
2003 inode->i_atime = inode->i_mtime = inode->i_ctime
2004 = CURRENT_TIME;
2005 inode->i_private = data;
2006 inode->i_fop = fops;
2007 }
2008 return inode;
2009}
2010
2011/* creates in fs root directory, so non-renamable and non-linkable.
2012 * so inode and dentry are paired, until device reconfig.
2013 */
2014static struct inode *
2015gadgetfs_create_file (struct super_block *sb, char const *name,
2016 void *data, const struct file_operations *fops,
2017 struct dentry **dentry_p)
2018{
2019 struct dentry *dentry;
2020 struct inode *inode;
2021
2022 dentry = d_alloc_name(sb->s_root, name);
2023 if (!dentry)
2024 return NULL;
2025
2026 inode = gadgetfs_make_inode (sb, data, fops,
2027 S_IFREG | (default_perm & S_IRWXUGO));
2028 if (!inode) {
2029 dput(dentry);
2030 return NULL;
2031 }
2032 d_add (dentry, inode);
2033 *dentry_p = dentry;
2034 return inode;
2035}
2036
2037static const struct super_operations gadget_fs_operations = {
2038 .statfs = simple_statfs,
2039 .drop_inode = generic_delete_inode,
2040};
2041
2042static int
2043gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2044{
2045 struct inode *inode;
2046 struct dentry *d;
2047 struct dev_data *dev;
2048
2049 if (the_device)
2050 return -ESRCH;
2051
2052 /* fake probe to determine $CHIP */
2053 (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2054 if (!CHIP)
2055 return -ENODEV;
2056
2057 /* superblock */
2058 sb->s_blocksize = PAGE_CACHE_SIZE;
2059 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2060 sb->s_magic = GADGETFS_MAGIC;
2061 sb->s_op = &gadget_fs_operations;
2062 sb->s_time_gran = 1;
2063
2064 /* root inode */
2065 inode = gadgetfs_make_inode (sb,
2066 NULL, &simple_dir_operations,
2067 S_IFDIR | S_IRUGO | S_IXUGO);
2068 if (!inode)
2069 goto enomem0;
2070 inode->i_op = &simple_dir_inode_operations;
2071 if (!(d = d_alloc_root (inode)))
2072 goto enomem1;
2073 sb->s_root = d;
2074
2075 /* the ep0 file is named after the controller we expect;
2076 * user mode code can use it for sanity checks, like we do.
2077 */
2078 dev = dev_new ();
2079 if (!dev)
2080 goto enomem2;
2081
2082 dev->sb = sb;
2083 if (!gadgetfs_create_file (sb, CHIP,
2084 dev, &dev_init_operations,
2085 &dev->dentry))
2086 goto enomem3;
2087
2088 /* other endpoint files are available after hardware setup,
2089 * from binding to a controller.
2090 */
2091 the_device = dev;
2092 return 0;
2093
2094enomem3:
2095 put_dev (dev);
2096enomem2:
2097 dput (d);
2098enomem1:
2099 iput (inode);
2100enomem0:
2101 return -ENOMEM;
2102}
2103
2104/* "mount -t gadgetfs path /dev/gadget" ends up here */
2105static struct dentry *
2106gadgetfs_mount (struct file_system_type *t, int flags,
2107 const char *path, void *opts)
2108{
2109 return mount_single (t, flags, opts, gadgetfs_fill_super);
2110}
2111
2112static void
2113gadgetfs_kill_sb (struct super_block *sb)
2114{
2115 kill_litter_super (sb);
2116 if (the_device) {
2117 put_dev (the_device);
2118 the_device = NULL;
2119 }
2120}
2121
2122/*----------------------------------------------------------------------*/
2123
2124static struct file_system_type gadgetfs_type = {
2125 .owner = THIS_MODULE,
2126 .name = shortname,
2127 .mount = gadgetfs_mount,
2128 .kill_sb = gadgetfs_kill_sb,
2129};
2130
2131/*----------------------------------------------------------------------*/
2132
2133static int __init init (void)
2134{
2135 int status;
2136
2137 status = register_filesystem (&gadgetfs_type);
2138 if (status == 0)
2139 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2140 shortname, driver_desc);
2141 return status;
2142}
2143module_init (init);
2144
2145static void __exit cleanup (void)
2146{
2147 pr_debug ("unregister %s\n", shortname);
2148 unregister_filesystem (&gadgetfs_type);
2149}
2150module_exit (cleanup);
2151