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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
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#include <linux/mmu_context.h>
28#include <linux/aio.h>
29#include <linux/uio.h>
30
31#include <linux/device.h>
32#include <linux/moduleparam.h>
33
34#include <linux/usb/gadgetfs.h>
35#include <linux/usb/gadget.h>
36
37
38/*
39 * The gadgetfs API maps each endpoint to a file descriptor so that you
40 * can use standard synchronous read/write calls for I/O. There's some
41 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
42 * drivers show how this works in practice. You can also use AIO to
43 * eliminate I/O gaps between requests, to help when streaming data.
44 *
45 * Key parts that must be USB-specific are protocols defining how the
46 * read/write operations relate to the hardware state machines. There
47 * are two types of files. One type is for the device, implementing ep0.
48 * The other type is for each IN or OUT endpoint. In both cases, the
49 * user mode driver must configure the hardware before using it.
50 *
51 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
52 * (by writing configuration and device descriptors). Afterwards it
53 * may serve as a source of device events, used to handle all control
54 * requests other than basic enumeration.
55 *
56 * - Then, after a SET_CONFIGURATION control request, ep_config() is
57 * called when each /dev/gadget/ep* file is configured (by writing
58 * endpoint descriptors). Afterwards these files are used to write()
59 * IN data or to read() OUT data. To halt the endpoint, a "wrong
60 * direction" request is issued (like reading an IN endpoint).
61 *
62 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
63 * not possible on all hardware. For example, precise fault handling with
64 * respect to data left in endpoint fifos after aborted operations; or
65 * selective clearing of endpoint halts, to implement SET_INTERFACE.
66 */
67
68#define DRIVER_DESC "USB Gadget filesystem"
69#define DRIVER_VERSION "24 Aug 2004"
70
71static const char driver_desc [] = DRIVER_DESC;
72static const char shortname [] = "gadgetfs";
73
74MODULE_DESCRIPTION (DRIVER_DESC);
75MODULE_AUTHOR ("David Brownell");
76MODULE_LICENSE ("GPL");
77
78static int ep_open(struct inode *, struct file *);
79
80
81/*----------------------------------------------------------------------*/
82
83#define GADGETFS_MAGIC 0xaee71ee7
84
85/* /dev/gadget/$CHIP represents ep0 and the whole device */
86enum ep0_state {
87 /* DISBLED is the initial state.
88 */
89 STATE_DEV_DISABLED = 0,
90
91 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
92 * ep0/device i/o modes and binding to the controller. Driver
93 * must always write descriptors to initialize the device, then
94 * the device becomes UNCONNECTED until enumeration.
95 */
96 STATE_DEV_OPENED,
97
98 /* From then on, ep0 fd is in either of two basic modes:
99 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
100 * - SETUP: read/write will transfer control data and succeed;
101 * or if "wrong direction", performs protocol stall
102 */
103 STATE_DEV_UNCONNECTED,
104 STATE_DEV_CONNECTED,
105 STATE_DEV_SETUP,
106
107 /* UNBOUND means the driver closed ep0, so the device won't be
108 * accessible again (DEV_DISABLED) until all fds are closed.
109 */
110 STATE_DEV_UNBOUND,
111};
112
113/* enough for the whole queue: most events invalidate others */
114#define N_EVENT 5
115
116struct dev_data {
117 spinlock_t lock;
118 atomic_t count;
119 enum ep0_state state; /* P: lock */
120 struct usb_gadgetfs_event event [N_EVENT];
121 unsigned ev_next;
122 struct fasync_struct *fasync;
123 u8 current_config;
124
125 /* drivers reading ep0 MUST handle control requests (SETUP)
126 * reported that way; else the host will time out.
127 */
128 unsigned usermode_setup : 1,
129 setup_in : 1,
130 setup_can_stall : 1,
131 setup_out_ready : 1,
132 setup_out_error : 1,
133 setup_abort : 1,
134 gadget_registered : 1;
135 unsigned setup_wLength;
136
137 /* the rest is basically write-once */
138 struct usb_config_descriptor *config, *hs_config;
139 struct usb_device_descriptor *dev;
140 struct usb_request *req;
141 struct usb_gadget *gadget;
142 struct list_head epfiles;
143 void *buf;
144 wait_queue_head_t wait;
145 struct super_block *sb;
146 struct dentry *dentry;
147
148 /* except this scratch i/o buffer for ep0 */
149 u8 rbuf [256];
150};
151
152static inline void get_dev (struct dev_data *data)
153{
154 atomic_inc (&data->count);
155}
156
157static void put_dev (struct dev_data *data)
158{
159 if (likely (!atomic_dec_and_test (&data->count)))
160 return;
161 /* needs no more cleanup */
162 BUG_ON (waitqueue_active (&data->wait));
163 kfree (data);
164}
165
166static struct dev_data *dev_new (void)
167{
168 struct dev_data *dev;
169
170 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
171 if (!dev)
172 return NULL;
173 dev->state = STATE_DEV_DISABLED;
174 atomic_set (&dev->count, 1);
175 spin_lock_init (&dev->lock);
176 INIT_LIST_HEAD (&dev->epfiles);
177 init_waitqueue_head (&dev->wait);
178 return dev;
179}
180
181/*----------------------------------------------------------------------*/
182
183/* other /dev/gadget/$ENDPOINT files represent endpoints */
184enum ep_state {
185 STATE_EP_DISABLED = 0,
186 STATE_EP_READY,
187 STATE_EP_ENABLED,
188 STATE_EP_UNBOUND,
189};
190
191struct ep_data {
192 struct mutex lock;
193 enum ep_state state;
194 atomic_t count;
195 struct dev_data *dev;
196 /* must hold dev->lock before accessing ep or req */
197 struct usb_ep *ep;
198 struct usb_request *req;
199 ssize_t status;
200 char name [16];
201 struct usb_endpoint_descriptor desc, hs_desc;
202 struct list_head epfiles;
203 wait_queue_head_t wait;
204 struct dentry *dentry;
205};
206
207static inline void get_ep (struct ep_data *data)
208{
209 atomic_inc (&data->count);
210}
211
212static void put_ep (struct ep_data *data)
213{
214 if (likely (!atomic_dec_and_test (&data->count)))
215 return;
216 put_dev (data->dev);
217 /* needs no more cleanup */
218 BUG_ON (!list_empty (&data->epfiles));
219 BUG_ON (waitqueue_active (&data->wait));
220 kfree (data);
221}
222
223/*----------------------------------------------------------------------*/
224
225/* most "how to use the hardware" policy choices are in userspace:
226 * mapping endpoint roles (which the driver needs) to the capabilities
227 * which the usb controller has. most of those capabilities are exposed
228 * implicitly, starting with the driver name and then endpoint names.
229 */
230
231static const char *CHIP;
232
233/*----------------------------------------------------------------------*/
234
235/* NOTE: don't use dev_printk calls before binding to the gadget
236 * at the end of ep0 configuration, or after unbind.
237 */
238
239/* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
240#define xprintk(d,level,fmt,args...) \
241 printk(level "%s: " fmt , shortname , ## args)
242
243#ifdef DEBUG
244#define DBG(dev,fmt,args...) \
245 xprintk(dev , KERN_DEBUG , fmt , ## args)
246#else
247#define DBG(dev,fmt,args...) \
248 do { } while (0)
249#endif /* DEBUG */
250
251#ifdef VERBOSE_DEBUG
252#define VDEBUG DBG
253#else
254#define VDEBUG(dev,fmt,args...) \
255 do { } while (0)
256#endif /* DEBUG */
257
258#define ERROR(dev,fmt,args...) \
259 xprintk(dev , KERN_ERR , fmt , ## args)
260#define INFO(dev,fmt,args...) \
261 xprintk(dev , KERN_INFO , fmt , ## args)
262
263
264/*----------------------------------------------------------------------*/
265
266/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
267 *
268 * After opening, configure non-control endpoints. Then use normal
269 * stream read() and write() requests; and maybe ioctl() to get more
270 * precise FIFO status when recovering from cancellation.
271 */
272
273static void epio_complete (struct usb_ep *ep, struct usb_request *req)
274{
275 struct ep_data *epdata = ep->driver_data;
276
277 if (!req->context)
278 return;
279 if (req->status)
280 epdata->status = req->status;
281 else
282 epdata->status = req->actual;
283 complete ((struct completion *)req->context);
284}
285
286/* tasklock endpoint, returning when it's connected.
287 * still need dev->lock to use epdata->ep.
288 */
289static int
290get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
291{
292 int val;
293
294 if (f_flags & O_NONBLOCK) {
295 if (!mutex_trylock(&epdata->lock))
296 goto nonblock;
297 if (epdata->state != STATE_EP_ENABLED &&
298 (!is_write || epdata->state != STATE_EP_READY)) {
299 mutex_unlock(&epdata->lock);
300nonblock:
301 val = -EAGAIN;
302 } else
303 val = 0;
304 return val;
305 }
306
307 val = mutex_lock_interruptible(&epdata->lock);
308 if (val < 0)
309 return val;
310
311 switch (epdata->state) {
312 case STATE_EP_ENABLED:
313 return 0;
314 case STATE_EP_READY: /* not configured yet */
315 if (is_write)
316 return 0;
317 // FALLTHRU
318 case STATE_EP_UNBOUND: /* clean disconnect */
319 break;
320 // case STATE_EP_DISABLED: /* "can't happen" */
321 default: /* error! */
322 pr_debug ("%s: ep %p not available, state %d\n",
323 shortname, epdata, epdata->state);
324 }
325 mutex_unlock(&epdata->lock);
326 return -ENODEV;
327}
328
329static ssize_t
330ep_io (struct ep_data *epdata, void *buf, unsigned len)
331{
332 DECLARE_COMPLETION_ONSTACK (done);
333 int value;
334
335 spin_lock_irq (&epdata->dev->lock);
336 if (likely (epdata->ep != NULL)) {
337 struct usb_request *req = epdata->req;
338
339 req->context = &done;
340 req->complete = epio_complete;
341 req->buf = buf;
342 req->length = len;
343 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
344 } else
345 value = -ENODEV;
346 spin_unlock_irq (&epdata->dev->lock);
347
348 if (likely (value == 0)) {
349 value = wait_event_interruptible (done.wait, done.done);
350 if (value != 0) {
351 spin_lock_irq (&epdata->dev->lock);
352 if (likely (epdata->ep != NULL)) {
353 DBG (epdata->dev, "%s i/o interrupted\n",
354 epdata->name);
355 usb_ep_dequeue (epdata->ep, epdata->req);
356 spin_unlock_irq (&epdata->dev->lock);
357
358 wait_event (done.wait, done.done);
359 if (epdata->status == -ECONNRESET)
360 epdata->status = -EINTR;
361 } else {
362 spin_unlock_irq (&epdata->dev->lock);
363
364 DBG (epdata->dev, "endpoint gone\n");
365 epdata->status = -ENODEV;
366 }
367 }
368 return epdata->status;
369 }
370 return value;
371}
372
373static int
374ep_release (struct inode *inode, struct file *fd)
375{
376 struct ep_data *data = fd->private_data;
377 int value;
378
379 value = mutex_lock_interruptible(&data->lock);
380 if (value < 0)
381 return value;
382
383 /* clean up if this can be reopened */
384 if (data->state != STATE_EP_UNBOUND) {
385 data->state = STATE_EP_DISABLED;
386 data->desc.bDescriptorType = 0;
387 data->hs_desc.bDescriptorType = 0;
388 usb_ep_disable(data->ep);
389 }
390 mutex_unlock(&data->lock);
391 put_ep (data);
392 return 0;
393}
394
395static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
396{
397 struct ep_data *data = fd->private_data;
398 int status;
399
400 if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
401 return status;
402
403 spin_lock_irq (&data->dev->lock);
404 if (likely (data->ep != NULL)) {
405 switch (code) {
406 case GADGETFS_FIFO_STATUS:
407 status = usb_ep_fifo_status (data->ep);
408 break;
409 case GADGETFS_FIFO_FLUSH:
410 usb_ep_fifo_flush (data->ep);
411 break;
412 case GADGETFS_CLEAR_HALT:
413 status = usb_ep_clear_halt (data->ep);
414 break;
415 default:
416 status = -ENOTTY;
417 }
418 } else
419 status = -ENODEV;
420 spin_unlock_irq (&data->dev->lock);
421 mutex_unlock(&data->lock);
422 return status;
423}
424
425/*----------------------------------------------------------------------*/
426
427/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
428
429struct kiocb_priv {
430 struct usb_request *req;
431 struct ep_data *epdata;
432 struct kiocb *iocb;
433 struct mm_struct *mm;
434 struct work_struct work;
435 void *buf;
436 struct iov_iter to;
437 const void *to_free;
438 unsigned actual;
439};
440
441static int ep_aio_cancel(struct kiocb *iocb)
442{
443 struct kiocb_priv *priv = iocb->private;
444 struct ep_data *epdata;
445 int value;
446
447 local_irq_disable();
448 epdata = priv->epdata;
449 // spin_lock(&epdata->dev->lock);
450 if (likely(epdata && epdata->ep && priv->req))
451 value = usb_ep_dequeue (epdata->ep, priv->req);
452 else
453 value = -EINVAL;
454 // spin_unlock(&epdata->dev->lock);
455 local_irq_enable();
456
457 return value;
458}
459
460static void ep_user_copy_worker(struct work_struct *work)
461{
462 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
463 struct mm_struct *mm = priv->mm;
464 struct kiocb *iocb = priv->iocb;
465 size_t ret;
466
467 use_mm(mm);
468 ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
469 unuse_mm(mm);
470 if (!ret)
471 ret = -EFAULT;
472
473 /* completing the iocb can drop the ctx and mm, don't touch mm after */
474 iocb->ki_complete(iocb, ret, ret);
475
476 kfree(priv->buf);
477 kfree(priv->to_free);
478 kfree(priv);
479}
480
481static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
482{
483 struct kiocb *iocb = req->context;
484 struct kiocb_priv *priv = iocb->private;
485 struct ep_data *epdata = priv->epdata;
486
487 /* lock against disconnect (and ideally, cancel) */
488 spin_lock(&epdata->dev->lock);
489 priv->req = NULL;
490 priv->epdata = NULL;
491
492 /* if this was a write or a read returning no data then we
493 * don't need to copy anything to userspace, so we can
494 * complete the aio request immediately.
495 */
496 if (priv->to_free == NULL || unlikely(req->actual == 0)) {
497 kfree(req->buf);
498 kfree(priv->to_free);
499 kfree(priv);
500 iocb->private = NULL;
501 /* aio_complete() reports bytes-transferred _and_ faults */
502
503 iocb->ki_complete(iocb, req->actual ? req->actual : req->status,
504 req->status);
505 } else {
506 /* ep_copy_to_user() won't report both; we hide some faults */
507 if (unlikely(0 != req->status))
508 DBG(epdata->dev, "%s fault %d len %d\n",
509 ep->name, req->status, req->actual);
510
511 priv->buf = req->buf;
512 priv->actual = req->actual;
513 INIT_WORK(&priv->work, ep_user_copy_worker);
514 schedule_work(&priv->work);
515 }
516 spin_unlock(&epdata->dev->lock);
517
518 usb_ep_free_request(ep, req);
519 put_ep(epdata);
520}
521
522static ssize_t ep_aio(struct kiocb *iocb,
523 struct kiocb_priv *priv,
524 struct ep_data *epdata,
525 char *buf,
526 size_t len)
527{
528 struct usb_request *req;
529 ssize_t value;
530
531 iocb->private = priv;
532 priv->iocb = iocb;
533
534 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
535 get_ep(epdata);
536 priv->epdata = epdata;
537 priv->actual = 0;
538 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
539
540 /* each kiocb is coupled to one usb_request, but we can't
541 * allocate or submit those if the host disconnected.
542 */
543 spin_lock_irq(&epdata->dev->lock);
544 value = -ENODEV;
545 if (unlikely(epdata->ep))
546 goto fail;
547
548 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
549 value = -ENOMEM;
550 if (unlikely(!req))
551 goto fail;
552
553 priv->req = req;
554 req->buf = buf;
555 req->length = len;
556 req->complete = ep_aio_complete;
557 req->context = iocb;
558 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
559 if (unlikely(0 != value)) {
560 usb_ep_free_request(epdata->ep, req);
561 goto fail;
562 }
563 spin_unlock_irq(&epdata->dev->lock);
564 return -EIOCBQUEUED;
565
566fail:
567 spin_unlock_irq(&epdata->dev->lock);
568 kfree(priv->to_free);
569 kfree(priv);
570 put_ep(epdata);
571 return value;
572}
573
574static ssize_t
575ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
576{
577 struct file *file = iocb->ki_filp;
578 struct ep_data *epdata = file->private_data;
579 size_t len = iov_iter_count(to);
580 ssize_t value;
581 char *buf;
582
583 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
584 return value;
585
586 /* halt any endpoint by doing a "wrong direction" i/o call */
587 if (usb_endpoint_dir_in(&epdata->desc)) {
588 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
589 !is_sync_kiocb(iocb)) {
590 mutex_unlock(&epdata->lock);
591 return -EINVAL;
592 }
593 DBG (epdata->dev, "%s halt\n", epdata->name);
594 spin_lock_irq(&epdata->dev->lock);
595 if (likely(epdata->ep != NULL))
596 usb_ep_set_halt(epdata->ep);
597 spin_unlock_irq(&epdata->dev->lock);
598 mutex_unlock(&epdata->lock);
599 return -EBADMSG;
600 }
601
602 buf = kmalloc(len, GFP_KERNEL);
603 if (unlikely(!buf)) {
604 mutex_unlock(&epdata->lock);
605 return -ENOMEM;
606 }
607 if (is_sync_kiocb(iocb)) {
608 value = ep_io(epdata, buf, len);
609 if (value >= 0 && copy_to_iter(buf, value, to))
610 value = -EFAULT;
611 } else {
612 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
613 value = -ENOMEM;
614 if (!priv)
615 goto fail;
616 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
617 if (!priv->to_free) {
618 kfree(priv);
619 goto fail;
620 }
621 value = ep_aio(iocb, priv, epdata, buf, len);
622 if (value == -EIOCBQUEUED)
623 buf = NULL;
624 }
625fail:
626 kfree(buf);
627 mutex_unlock(&epdata->lock);
628 return value;
629}
630
631static ssize_t ep_config(struct ep_data *, const char *, size_t);
632
633static ssize_t
634ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
635{
636 struct file *file = iocb->ki_filp;
637 struct ep_data *epdata = file->private_data;
638 size_t len = iov_iter_count(from);
639 bool configured;
640 ssize_t value;
641 char *buf;
642
643 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
644 return value;
645
646 configured = epdata->state == STATE_EP_ENABLED;
647
648 /* halt any endpoint by doing a "wrong direction" i/o call */
649 if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
650 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
651 !is_sync_kiocb(iocb)) {
652 mutex_unlock(&epdata->lock);
653 return -EINVAL;
654 }
655 DBG (epdata->dev, "%s halt\n", epdata->name);
656 spin_lock_irq(&epdata->dev->lock);
657 if (likely(epdata->ep != NULL))
658 usb_ep_set_halt(epdata->ep);
659 spin_unlock_irq(&epdata->dev->lock);
660 mutex_unlock(&epdata->lock);
661 return -EBADMSG;
662 }
663
664 buf = kmalloc(len, GFP_KERNEL);
665 if (unlikely(!buf)) {
666 mutex_unlock(&epdata->lock);
667 return -ENOMEM;
668 }
669
670 if (unlikely(copy_from_iter(buf, len, from) != len)) {
671 value = -EFAULT;
672 goto out;
673 }
674
675 if (unlikely(!configured)) {
676 value = ep_config(epdata, buf, len);
677 } else if (is_sync_kiocb(iocb)) {
678 value = ep_io(epdata, buf, len);
679 } else {
680 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
681 value = -ENOMEM;
682 if (priv) {
683 value = ep_aio(iocb, priv, epdata, buf, len);
684 if (value == -EIOCBQUEUED)
685 buf = NULL;
686 }
687 }
688out:
689 kfree(buf);
690 mutex_unlock(&epdata->lock);
691 return value;
692}
693
694/*----------------------------------------------------------------------*/
695
696/* used after endpoint configuration */
697static const struct file_operations ep_io_operations = {
698 .owner = THIS_MODULE,
699
700 .open = ep_open,
701 .release = ep_release,
702 .llseek = no_llseek,
703 .unlocked_ioctl = ep_ioctl,
704 .read_iter = ep_read_iter,
705 .write_iter = ep_write_iter,
706};
707
708/* ENDPOINT INITIALIZATION
709 *
710 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
711 * status = write (fd, descriptors, sizeof descriptors)
712 *
713 * That write establishes the endpoint configuration, configuring
714 * the controller to process bulk, interrupt, or isochronous transfers
715 * at the right maxpacket size, and so on.
716 *
717 * The descriptors are message type 1, identified by a host order u32
718 * at the beginning of what's written. Descriptor order is: full/low
719 * speed descriptor, then optional high speed descriptor.
720 */
721static ssize_t
722ep_config (struct ep_data *data, const char *buf, size_t len)
723{
724 struct usb_ep *ep;
725 u32 tag;
726 int value, length = len;
727
728 if (data->state != STATE_EP_READY) {
729 value = -EL2HLT;
730 goto fail;
731 }
732
733 value = len;
734 if (len < USB_DT_ENDPOINT_SIZE + 4)
735 goto fail0;
736
737 /* we might need to change message format someday */
738 memcpy(&tag, buf, 4);
739 if (tag != 1) {
740 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
741 goto fail0;
742 }
743 buf += 4;
744 len -= 4;
745
746 /* NOTE: audio endpoint extensions not accepted here;
747 * just don't include the extra bytes.
748 */
749
750 /* full/low speed descriptor, then high speed */
751 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
752 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
753 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
754 goto fail0;
755 if (len != USB_DT_ENDPOINT_SIZE) {
756 if (len != 2 * USB_DT_ENDPOINT_SIZE)
757 goto fail0;
758 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
759 USB_DT_ENDPOINT_SIZE);
760 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
761 || data->hs_desc.bDescriptorType
762 != USB_DT_ENDPOINT) {
763 DBG(data->dev, "config %s, bad hs length or type\n",
764 data->name);
765 goto fail0;
766 }
767 }
768
769 spin_lock_irq (&data->dev->lock);
770 if (data->dev->state == STATE_DEV_UNBOUND) {
771 value = -ENOENT;
772 goto gone;
773 } else {
774 ep = data->ep;
775 if (ep == NULL) {
776 value = -ENODEV;
777 goto gone;
778 }
779 }
780 switch (data->dev->gadget->speed) {
781 case USB_SPEED_LOW:
782 case USB_SPEED_FULL:
783 ep->desc = &data->desc;
784 break;
785 case USB_SPEED_HIGH:
786 /* fails if caller didn't provide that descriptor... */
787 ep->desc = &data->hs_desc;
788 break;
789 default:
790 DBG(data->dev, "unconnected, %s init abandoned\n",
791 data->name);
792 value = -EINVAL;
793 goto gone;
794 }
795 value = usb_ep_enable(ep);
796 if (value == 0) {
797 data->state = STATE_EP_ENABLED;
798 value = length;
799 }
800gone:
801 spin_unlock_irq (&data->dev->lock);
802 if (value < 0) {
803fail:
804 data->desc.bDescriptorType = 0;
805 data->hs_desc.bDescriptorType = 0;
806 }
807 return value;
808fail0:
809 value = -EINVAL;
810 goto fail;
811}
812
813static int
814ep_open (struct inode *inode, struct file *fd)
815{
816 struct ep_data *data = inode->i_private;
817 int value = -EBUSY;
818
819 if (mutex_lock_interruptible(&data->lock) != 0)
820 return -EINTR;
821 spin_lock_irq (&data->dev->lock);
822 if (data->dev->state == STATE_DEV_UNBOUND)
823 value = -ENOENT;
824 else if (data->state == STATE_EP_DISABLED) {
825 value = 0;
826 data->state = STATE_EP_READY;
827 get_ep (data);
828 fd->private_data = data;
829 VDEBUG (data->dev, "%s ready\n", data->name);
830 } else
831 DBG (data->dev, "%s state %d\n",
832 data->name, data->state);
833 spin_unlock_irq (&data->dev->lock);
834 mutex_unlock(&data->lock);
835 return value;
836}
837
838/*----------------------------------------------------------------------*/
839
840/* EP0 IMPLEMENTATION can be partly in userspace.
841 *
842 * Drivers that use this facility receive various events, including
843 * control requests the kernel doesn't handle. Drivers that don't
844 * use this facility may be too simple-minded for real applications.
845 */
846
847static inline void ep0_readable (struct dev_data *dev)
848{
849 wake_up (&dev->wait);
850 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
851}
852
853static void clean_req (struct usb_ep *ep, struct usb_request *req)
854{
855 struct dev_data *dev = ep->driver_data;
856
857 if (req->buf != dev->rbuf) {
858 kfree(req->buf);
859 req->buf = dev->rbuf;
860 }
861 req->complete = epio_complete;
862 dev->setup_out_ready = 0;
863}
864
865static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
866{
867 struct dev_data *dev = ep->driver_data;
868 unsigned long flags;
869 int free = 1;
870
871 /* for control OUT, data must still get to userspace */
872 spin_lock_irqsave(&dev->lock, flags);
873 if (!dev->setup_in) {
874 dev->setup_out_error = (req->status != 0);
875 if (!dev->setup_out_error)
876 free = 0;
877 dev->setup_out_ready = 1;
878 ep0_readable (dev);
879 }
880
881 /* clean up as appropriate */
882 if (free && req->buf != &dev->rbuf)
883 clean_req (ep, req);
884 req->complete = epio_complete;
885 spin_unlock_irqrestore(&dev->lock, flags);
886}
887
888static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
889{
890 struct dev_data *dev = ep->driver_data;
891
892 if (dev->setup_out_ready) {
893 DBG (dev, "ep0 request busy!\n");
894 return -EBUSY;
895 }
896 if (len > sizeof (dev->rbuf))
897 req->buf = kmalloc(len, GFP_ATOMIC);
898 if (req->buf == NULL) {
899 req->buf = dev->rbuf;
900 return -ENOMEM;
901 }
902 req->complete = ep0_complete;
903 req->length = len;
904 req->zero = 0;
905 return 0;
906}
907
908static ssize_t
909ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
910{
911 struct dev_data *dev = fd->private_data;
912 ssize_t retval;
913 enum ep0_state state;
914
915 spin_lock_irq (&dev->lock);
916 if (dev->state <= STATE_DEV_OPENED) {
917 retval = -EINVAL;
918 goto done;
919 }
920
921 /* report fd mode change before acting on it */
922 if (dev->setup_abort) {
923 dev->setup_abort = 0;
924 retval = -EIDRM;
925 goto done;
926 }
927
928 /* control DATA stage */
929 if ((state = dev->state) == STATE_DEV_SETUP) {
930
931 if (dev->setup_in) { /* stall IN */
932 VDEBUG(dev, "ep0in stall\n");
933 (void) usb_ep_set_halt (dev->gadget->ep0);
934 retval = -EL2HLT;
935 dev->state = STATE_DEV_CONNECTED;
936
937 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
938 struct usb_ep *ep = dev->gadget->ep0;
939 struct usb_request *req = dev->req;
940
941 if ((retval = setup_req (ep, req, 0)) == 0)
942 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
943 dev->state = STATE_DEV_CONNECTED;
944
945 /* assume that was SET_CONFIGURATION */
946 if (dev->current_config) {
947 unsigned power;
948
949 if (gadget_is_dualspeed(dev->gadget)
950 && (dev->gadget->speed
951 == USB_SPEED_HIGH))
952 power = dev->hs_config->bMaxPower;
953 else
954 power = dev->config->bMaxPower;
955 usb_gadget_vbus_draw(dev->gadget, 2 * power);
956 }
957
958 } else { /* collect OUT data */
959 if ((fd->f_flags & O_NONBLOCK) != 0
960 && !dev->setup_out_ready) {
961 retval = -EAGAIN;
962 goto done;
963 }
964 spin_unlock_irq (&dev->lock);
965 retval = wait_event_interruptible (dev->wait,
966 dev->setup_out_ready != 0);
967
968 /* FIXME state could change from under us */
969 spin_lock_irq (&dev->lock);
970 if (retval)
971 goto done;
972
973 if (dev->state != STATE_DEV_SETUP) {
974 retval = -ECANCELED;
975 goto done;
976 }
977 dev->state = STATE_DEV_CONNECTED;
978
979 if (dev->setup_out_error)
980 retval = -EIO;
981 else {
982 len = min (len, (size_t)dev->req->actual);
983// FIXME don't call this with the spinlock held ...
984 if (copy_to_user (buf, dev->req->buf, len))
985 retval = -EFAULT;
986 else
987 retval = len;
988 clean_req (dev->gadget->ep0, dev->req);
989 /* NOTE userspace can't yet choose to stall */
990 }
991 }
992 goto done;
993 }
994
995 /* else normal: return event data */
996 if (len < sizeof dev->event [0]) {
997 retval = -EINVAL;
998 goto done;
999 }
1000 len -= len % sizeof (struct usb_gadgetfs_event);
1001 dev->usermode_setup = 1;
1002
1003scan:
1004 /* return queued events right away */
1005 if (dev->ev_next != 0) {
1006 unsigned i, n;
1007
1008 n = len / sizeof (struct usb_gadgetfs_event);
1009 if (dev->ev_next < n)
1010 n = dev->ev_next;
1011
1012 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1013 for (i = 0; i < n; i++) {
1014 if (dev->event [i].type == GADGETFS_SETUP) {
1015 dev->state = STATE_DEV_SETUP;
1016 n = i + 1;
1017 break;
1018 }
1019 }
1020 spin_unlock_irq (&dev->lock);
1021 len = n * sizeof (struct usb_gadgetfs_event);
1022 if (copy_to_user (buf, &dev->event, len))
1023 retval = -EFAULT;
1024 else
1025 retval = len;
1026 if (len > 0) {
1027 /* NOTE this doesn't guard against broken drivers;
1028 * concurrent ep0 readers may lose events.
1029 */
1030 spin_lock_irq (&dev->lock);
1031 if (dev->ev_next > n) {
1032 memmove(&dev->event[0], &dev->event[n],
1033 sizeof (struct usb_gadgetfs_event)
1034 * (dev->ev_next - n));
1035 }
1036 dev->ev_next -= n;
1037 spin_unlock_irq (&dev->lock);
1038 }
1039 return retval;
1040 }
1041 if (fd->f_flags & O_NONBLOCK) {
1042 retval = -EAGAIN;
1043 goto done;
1044 }
1045
1046 switch (state) {
1047 default:
1048 DBG (dev, "fail %s, state %d\n", __func__, state);
1049 retval = -ESRCH;
1050 break;
1051 case STATE_DEV_UNCONNECTED:
1052 case STATE_DEV_CONNECTED:
1053 spin_unlock_irq (&dev->lock);
1054 DBG (dev, "%s wait\n", __func__);
1055
1056 /* wait for events */
1057 retval = wait_event_interruptible (dev->wait,
1058 dev->ev_next != 0);
1059 if (retval < 0)
1060 return retval;
1061 spin_lock_irq (&dev->lock);
1062 goto scan;
1063 }
1064
1065done:
1066 spin_unlock_irq (&dev->lock);
1067 return retval;
1068}
1069
1070static struct usb_gadgetfs_event *
1071next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1072{
1073 struct usb_gadgetfs_event *event;
1074 unsigned i;
1075
1076 switch (type) {
1077 /* these events purge the queue */
1078 case GADGETFS_DISCONNECT:
1079 if (dev->state == STATE_DEV_SETUP)
1080 dev->setup_abort = 1;
1081 // FALL THROUGH
1082 case GADGETFS_CONNECT:
1083 dev->ev_next = 0;
1084 break;
1085 case GADGETFS_SETUP: /* previous request timed out */
1086 case GADGETFS_SUSPEND: /* same effect */
1087 /* these events can't be repeated */
1088 for (i = 0; i != dev->ev_next; i++) {
1089 if (dev->event [i].type != type)
1090 continue;
1091 DBG(dev, "discard old event[%d] %d\n", i, type);
1092 dev->ev_next--;
1093 if (i == dev->ev_next)
1094 break;
1095 /* indices start at zero, for simplicity */
1096 memmove (&dev->event [i], &dev->event [i + 1],
1097 sizeof (struct usb_gadgetfs_event)
1098 * (dev->ev_next - i));
1099 }
1100 break;
1101 default:
1102 BUG ();
1103 }
1104 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1105 event = &dev->event [dev->ev_next++];
1106 BUG_ON (dev->ev_next > N_EVENT);
1107 memset (event, 0, sizeof *event);
1108 event->type = type;
1109 return event;
1110}
1111
1112static ssize_t
1113ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1114{
1115 struct dev_data *dev = fd->private_data;
1116 ssize_t retval = -ESRCH;
1117
1118 /* report fd mode change before acting on it */
1119 if (dev->setup_abort) {
1120 dev->setup_abort = 0;
1121 retval = -EIDRM;
1122
1123 /* data and/or status stage for control request */
1124 } else if (dev->state == STATE_DEV_SETUP) {
1125
1126 /* IN DATA+STATUS caller makes len <= wLength */
1127 if (dev->setup_in) {
1128 retval = setup_req (dev->gadget->ep0, dev->req, len);
1129 if (retval == 0) {
1130 dev->state = STATE_DEV_CONNECTED;
1131 spin_unlock_irq (&dev->lock);
1132 if (copy_from_user (dev->req->buf, buf, len))
1133 retval = -EFAULT;
1134 else {
1135 if (len < dev->setup_wLength)
1136 dev->req->zero = 1;
1137 retval = usb_ep_queue (
1138 dev->gadget->ep0, dev->req,
1139 GFP_KERNEL);
1140 }
1141 spin_lock_irq(&dev->lock);
1142 if (retval < 0) {
1143 clean_req (dev->gadget->ep0, dev->req);
1144 } else
1145 retval = len;
1146
1147 return retval;
1148 }
1149
1150 /* can stall some OUT transfers */
1151 } else if (dev->setup_can_stall) {
1152 VDEBUG(dev, "ep0out stall\n");
1153 (void) usb_ep_set_halt (dev->gadget->ep0);
1154 retval = -EL2HLT;
1155 dev->state = STATE_DEV_CONNECTED;
1156 } else {
1157 DBG(dev, "bogus ep0out stall!\n");
1158 }
1159 } else
1160 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1161
1162 return retval;
1163}
1164
1165static int
1166ep0_fasync (int f, struct file *fd, int on)
1167{
1168 struct dev_data *dev = fd->private_data;
1169 // caller must F_SETOWN before signal delivery happens
1170 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1171 return fasync_helper (f, fd, on, &dev->fasync);
1172}
1173
1174static struct usb_gadget_driver gadgetfs_driver;
1175
1176static int
1177dev_release (struct inode *inode, struct file *fd)
1178{
1179 struct dev_data *dev = fd->private_data;
1180
1181 /* closing ep0 === shutdown all */
1182
1183 if (dev->gadget_registered)
1184 usb_gadget_unregister_driver (&gadgetfs_driver);
1185
1186 /* at this point "good" hardware has disconnected the
1187 * device from USB; the host won't see it any more.
1188 * alternatively, all host requests will time out.
1189 */
1190
1191 kfree (dev->buf);
1192 dev->buf = NULL;
1193
1194 /* other endpoints were all decoupled from this device */
1195 spin_lock_irq(&dev->lock);
1196 dev->state = STATE_DEV_DISABLED;
1197 spin_unlock_irq(&dev->lock);
1198
1199 put_dev (dev);
1200 return 0;
1201}
1202
1203static unsigned int
1204ep0_poll (struct file *fd, poll_table *wait)
1205{
1206 struct dev_data *dev = fd->private_data;
1207 int mask = 0;
1208
1209 if (dev->state <= STATE_DEV_OPENED)
1210 return DEFAULT_POLLMASK;
1211
1212 poll_wait(fd, &dev->wait, wait);
1213
1214 spin_lock_irq (&dev->lock);
1215
1216 /* report fd mode change before acting on it */
1217 if (dev->setup_abort) {
1218 dev->setup_abort = 0;
1219 mask = POLLHUP;
1220 goto out;
1221 }
1222
1223 if (dev->state == STATE_DEV_SETUP) {
1224 if (dev->setup_in || dev->setup_can_stall)
1225 mask = POLLOUT;
1226 } else {
1227 if (dev->ev_next != 0)
1228 mask = POLLIN;
1229 }
1230out:
1231 spin_unlock_irq(&dev->lock);
1232 return mask;
1233}
1234
1235static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1236{
1237 struct dev_data *dev = fd->private_data;
1238 struct usb_gadget *gadget = dev->gadget;
1239 long ret = -ENOTTY;
1240
1241 if (gadget->ops->ioctl)
1242 ret = gadget->ops->ioctl (gadget, code, value);
1243
1244 return ret;
1245}
1246
1247/*----------------------------------------------------------------------*/
1248
1249/* The in-kernel gadget driver handles most ep0 issues, in particular
1250 * enumerating the single configuration (as provided from user space).
1251 *
1252 * Unrecognized ep0 requests may be handled in user space.
1253 */
1254
1255static void make_qualifier (struct dev_data *dev)
1256{
1257 struct usb_qualifier_descriptor qual;
1258 struct usb_device_descriptor *desc;
1259
1260 qual.bLength = sizeof qual;
1261 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1262 qual.bcdUSB = cpu_to_le16 (0x0200);
1263
1264 desc = dev->dev;
1265 qual.bDeviceClass = desc->bDeviceClass;
1266 qual.bDeviceSubClass = desc->bDeviceSubClass;
1267 qual.bDeviceProtocol = desc->bDeviceProtocol;
1268
1269 /* assumes ep0 uses the same value for both speeds ... */
1270 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1271
1272 qual.bNumConfigurations = 1;
1273 qual.bRESERVED = 0;
1274
1275 memcpy (dev->rbuf, &qual, sizeof qual);
1276}
1277
1278static int
1279config_buf (struct dev_data *dev, u8 type, unsigned index)
1280{
1281 int len;
1282 int hs = 0;
1283
1284 /* only one configuration */
1285 if (index > 0)
1286 return -EINVAL;
1287
1288 if (gadget_is_dualspeed(dev->gadget)) {
1289 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1290 if (type == USB_DT_OTHER_SPEED_CONFIG)
1291 hs = !hs;
1292 }
1293 if (hs) {
1294 dev->req->buf = dev->hs_config;
1295 len = le16_to_cpu(dev->hs_config->wTotalLength);
1296 } else {
1297 dev->req->buf = dev->config;
1298 len = le16_to_cpu(dev->config->wTotalLength);
1299 }
1300 ((u8 *)dev->req->buf) [1] = type;
1301 return len;
1302}
1303
1304static int
1305gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1306{
1307 struct dev_data *dev = get_gadget_data (gadget);
1308 struct usb_request *req = dev->req;
1309 int value = -EOPNOTSUPP;
1310 struct usb_gadgetfs_event *event;
1311 u16 w_value = le16_to_cpu(ctrl->wValue);
1312 u16 w_length = le16_to_cpu(ctrl->wLength);
1313
1314 spin_lock (&dev->lock);
1315 dev->setup_abort = 0;
1316 if (dev->state == STATE_DEV_UNCONNECTED) {
1317 if (gadget_is_dualspeed(gadget)
1318 && gadget->speed == USB_SPEED_HIGH
1319 && dev->hs_config == NULL) {
1320 spin_unlock(&dev->lock);
1321 ERROR (dev, "no high speed config??\n");
1322 return -EINVAL;
1323 }
1324
1325 dev->state = STATE_DEV_CONNECTED;
1326
1327 INFO (dev, "connected\n");
1328 event = next_event (dev, GADGETFS_CONNECT);
1329 event->u.speed = gadget->speed;
1330 ep0_readable (dev);
1331
1332 /* host may have given up waiting for response. we can miss control
1333 * requests handled lower down (device/endpoint status and features);
1334 * then ep0_{read,write} will report the wrong status. controller
1335 * driver will have aborted pending i/o.
1336 */
1337 } else if (dev->state == STATE_DEV_SETUP)
1338 dev->setup_abort = 1;
1339
1340 req->buf = dev->rbuf;
1341 req->context = NULL;
1342 value = -EOPNOTSUPP;
1343 switch (ctrl->bRequest) {
1344
1345 case USB_REQ_GET_DESCRIPTOR:
1346 if (ctrl->bRequestType != USB_DIR_IN)
1347 goto unrecognized;
1348 switch (w_value >> 8) {
1349
1350 case USB_DT_DEVICE:
1351 value = min (w_length, (u16) sizeof *dev->dev);
1352 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1353 req->buf = dev->dev;
1354 break;
1355 case USB_DT_DEVICE_QUALIFIER:
1356 if (!dev->hs_config)
1357 break;
1358 value = min (w_length, (u16)
1359 sizeof (struct usb_qualifier_descriptor));
1360 make_qualifier (dev);
1361 break;
1362 case USB_DT_OTHER_SPEED_CONFIG:
1363 // FALLTHROUGH
1364 case USB_DT_CONFIG:
1365 value = config_buf (dev,
1366 w_value >> 8,
1367 w_value & 0xff);
1368 if (value >= 0)
1369 value = min (w_length, (u16) value);
1370 break;
1371 case USB_DT_STRING:
1372 goto unrecognized;
1373
1374 default: // all others are errors
1375 break;
1376 }
1377 break;
1378
1379 /* currently one config, two speeds */
1380 case USB_REQ_SET_CONFIGURATION:
1381 if (ctrl->bRequestType != 0)
1382 goto unrecognized;
1383 if (0 == (u8) w_value) {
1384 value = 0;
1385 dev->current_config = 0;
1386 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1387 // user mode expected to disable endpoints
1388 } else {
1389 u8 config, power;
1390
1391 if (gadget_is_dualspeed(gadget)
1392 && gadget->speed == USB_SPEED_HIGH) {
1393 config = dev->hs_config->bConfigurationValue;
1394 power = dev->hs_config->bMaxPower;
1395 } else {
1396 config = dev->config->bConfigurationValue;
1397 power = dev->config->bMaxPower;
1398 }
1399
1400 if (config == (u8) w_value) {
1401 value = 0;
1402 dev->current_config = config;
1403 usb_gadget_vbus_draw(gadget, 2 * power);
1404 }
1405 }
1406
1407 /* report SET_CONFIGURATION like any other control request,
1408 * except that usermode may not stall this. the next
1409 * request mustn't be allowed start until this finishes:
1410 * endpoints and threads set up, etc.
1411 *
1412 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1413 * has bad/racey automagic that prevents synchronizing here.
1414 * even kernel mode drivers often miss them.
1415 */
1416 if (value == 0) {
1417 INFO (dev, "configuration #%d\n", dev->current_config);
1418 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1419 if (dev->usermode_setup) {
1420 dev->setup_can_stall = 0;
1421 goto delegate;
1422 }
1423 }
1424 break;
1425
1426#ifndef CONFIG_USB_PXA25X
1427 /* PXA automagically handles this request too */
1428 case USB_REQ_GET_CONFIGURATION:
1429 if (ctrl->bRequestType != 0x80)
1430 goto unrecognized;
1431 *(u8 *)req->buf = dev->current_config;
1432 value = min (w_length, (u16) 1);
1433 break;
1434#endif
1435
1436 default:
1437unrecognized:
1438 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1439 dev->usermode_setup ? "delegate" : "fail",
1440 ctrl->bRequestType, ctrl->bRequest,
1441 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1442
1443 /* if there's an ep0 reader, don't stall */
1444 if (dev->usermode_setup) {
1445 dev->setup_can_stall = 1;
1446delegate:
1447 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1448 ? 1 : 0;
1449 dev->setup_wLength = w_length;
1450 dev->setup_out_ready = 0;
1451 dev->setup_out_error = 0;
1452 value = 0;
1453
1454 /* read DATA stage for OUT right away */
1455 if (unlikely (!dev->setup_in && w_length)) {
1456 value = setup_req (gadget->ep0, dev->req,
1457 w_length);
1458 if (value < 0)
1459 break;
1460 value = usb_ep_queue (gadget->ep0, dev->req,
1461 GFP_ATOMIC);
1462 if (value < 0) {
1463 clean_req (gadget->ep0, dev->req);
1464 break;
1465 }
1466
1467 /* we can't currently stall these */
1468 dev->setup_can_stall = 0;
1469 }
1470
1471 /* state changes when reader collects event */
1472 event = next_event (dev, GADGETFS_SETUP);
1473 event->u.setup = *ctrl;
1474 ep0_readable (dev);
1475 spin_unlock (&dev->lock);
1476 return 0;
1477 }
1478 }
1479
1480 /* proceed with data transfer and status phases? */
1481 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1482 req->length = value;
1483 req->zero = value < w_length;
1484 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1485 if (value < 0) {
1486 DBG (dev, "ep_queue --> %d\n", value);
1487 req->status = 0;
1488 }
1489 }
1490
1491 /* device stalls when value < 0 */
1492 spin_unlock (&dev->lock);
1493 return value;
1494}
1495
1496static void destroy_ep_files (struct dev_data *dev)
1497{
1498 DBG (dev, "%s %d\n", __func__, dev->state);
1499
1500 /* dev->state must prevent interference */
1501 spin_lock_irq (&dev->lock);
1502 while (!list_empty(&dev->epfiles)) {
1503 struct ep_data *ep;
1504 struct inode *parent;
1505 struct dentry *dentry;
1506
1507 /* break link to FS */
1508 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1509 list_del_init (&ep->epfiles);
1510 dentry = ep->dentry;
1511 ep->dentry = NULL;
1512 parent = d_inode(dentry->d_parent);
1513
1514 /* break link to controller */
1515 if (ep->state == STATE_EP_ENABLED)
1516 (void) usb_ep_disable (ep->ep);
1517 ep->state = STATE_EP_UNBOUND;
1518 usb_ep_free_request (ep->ep, ep->req);
1519 ep->ep = NULL;
1520 wake_up (&ep->wait);
1521 put_ep (ep);
1522
1523 spin_unlock_irq (&dev->lock);
1524
1525 /* break link to dcache */
1526 inode_lock(parent);
1527 d_delete (dentry);
1528 dput (dentry);
1529 inode_unlock(parent);
1530
1531 spin_lock_irq (&dev->lock);
1532 }
1533 spin_unlock_irq (&dev->lock);
1534}
1535
1536
1537static struct dentry *
1538gadgetfs_create_file (struct super_block *sb, char const *name,
1539 void *data, const struct file_operations *fops);
1540
1541static int activate_ep_files (struct dev_data *dev)
1542{
1543 struct usb_ep *ep;
1544 struct ep_data *data;
1545
1546 gadget_for_each_ep (ep, dev->gadget) {
1547
1548 data = kzalloc(sizeof(*data), GFP_KERNEL);
1549 if (!data)
1550 goto enomem0;
1551 data->state = STATE_EP_DISABLED;
1552 mutex_init(&data->lock);
1553 init_waitqueue_head (&data->wait);
1554
1555 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1556 atomic_set (&data->count, 1);
1557 data->dev = dev;
1558 get_dev (dev);
1559
1560 data->ep = ep;
1561 ep->driver_data = data;
1562
1563 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1564 if (!data->req)
1565 goto enomem1;
1566
1567 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1568 data, &ep_io_operations);
1569 if (!data->dentry)
1570 goto enomem2;
1571 list_add_tail (&data->epfiles, &dev->epfiles);
1572 }
1573 return 0;
1574
1575enomem2:
1576 usb_ep_free_request (ep, data->req);
1577enomem1:
1578 put_dev (dev);
1579 kfree (data);
1580enomem0:
1581 DBG (dev, "%s enomem\n", __func__);
1582 destroy_ep_files (dev);
1583 return -ENOMEM;
1584}
1585
1586static void
1587gadgetfs_unbind (struct usb_gadget *gadget)
1588{
1589 struct dev_data *dev = get_gadget_data (gadget);
1590
1591 DBG (dev, "%s\n", __func__);
1592
1593 spin_lock_irq (&dev->lock);
1594 dev->state = STATE_DEV_UNBOUND;
1595 spin_unlock_irq (&dev->lock);
1596
1597 destroy_ep_files (dev);
1598 gadget->ep0->driver_data = NULL;
1599 set_gadget_data (gadget, NULL);
1600
1601 /* we've already been disconnected ... no i/o is active */
1602 if (dev->req)
1603 usb_ep_free_request (gadget->ep0, dev->req);
1604 DBG (dev, "%s done\n", __func__);
1605 put_dev (dev);
1606}
1607
1608static struct dev_data *the_device;
1609
1610static int gadgetfs_bind(struct usb_gadget *gadget,
1611 struct usb_gadget_driver *driver)
1612{
1613 struct dev_data *dev = the_device;
1614
1615 if (!dev)
1616 return -ESRCH;
1617 if (0 != strcmp (CHIP, gadget->name)) {
1618 pr_err("%s expected %s controller not %s\n",
1619 shortname, CHIP, gadget->name);
1620 return -ENODEV;
1621 }
1622
1623 set_gadget_data (gadget, dev);
1624 dev->gadget = gadget;
1625 gadget->ep0->driver_data = dev;
1626
1627 /* preallocate control response and buffer */
1628 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1629 if (!dev->req)
1630 goto enomem;
1631 dev->req->context = NULL;
1632 dev->req->complete = epio_complete;
1633
1634 if (activate_ep_files (dev) < 0)
1635 goto enomem;
1636
1637 INFO (dev, "bound to %s driver\n", gadget->name);
1638 spin_lock_irq(&dev->lock);
1639 dev->state = STATE_DEV_UNCONNECTED;
1640 spin_unlock_irq(&dev->lock);
1641 get_dev (dev);
1642 return 0;
1643
1644enomem:
1645 gadgetfs_unbind (gadget);
1646 return -ENOMEM;
1647}
1648
1649static void
1650gadgetfs_disconnect (struct usb_gadget *gadget)
1651{
1652 struct dev_data *dev = get_gadget_data (gadget);
1653 unsigned long flags;
1654
1655 spin_lock_irqsave (&dev->lock, flags);
1656 if (dev->state == STATE_DEV_UNCONNECTED)
1657 goto exit;
1658 dev->state = STATE_DEV_UNCONNECTED;
1659
1660 INFO (dev, "disconnected\n");
1661 next_event (dev, GADGETFS_DISCONNECT);
1662 ep0_readable (dev);
1663exit:
1664 spin_unlock_irqrestore (&dev->lock, flags);
1665}
1666
1667static void
1668gadgetfs_suspend (struct usb_gadget *gadget)
1669{
1670 struct dev_data *dev = get_gadget_data (gadget);
1671
1672 INFO (dev, "suspended from state %d\n", dev->state);
1673 spin_lock (&dev->lock);
1674 switch (dev->state) {
1675 case STATE_DEV_SETUP: // VERY odd... host died??
1676 case STATE_DEV_CONNECTED:
1677 case STATE_DEV_UNCONNECTED:
1678 next_event (dev, GADGETFS_SUSPEND);
1679 ep0_readable (dev);
1680 /* FALLTHROUGH */
1681 default:
1682 break;
1683 }
1684 spin_unlock (&dev->lock);
1685}
1686
1687static struct usb_gadget_driver gadgetfs_driver = {
1688 .function = (char *) driver_desc,
1689 .bind = gadgetfs_bind,
1690 .unbind = gadgetfs_unbind,
1691 .setup = gadgetfs_setup,
1692 .reset = gadgetfs_disconnect,
1693 .disconnect = gadgetfs_disconnect,
1694 .suspend = gadgetfs_suspend,
1695
1696 .driver = {
1697 .name = (char *) shortname,
1698 },
1699};
1700
1701/*----------------------------------------------------------------------*/
1702/* DEVICE INITIALIZATION
1703 *
1704 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1705 * status = write (fd, descriptors, sizeof descriptors)
1706 *
1707 * That write establishes the device configuration, so the kernel can
1708 * bind to the controller ... guaranteeing it can handle enumeration
1709 * at all necessary speeds. Descriptor order is:
1710 *
1711 * . message tag (u32, host order) ... for now, must be zero; it
1712 * would change to support features like multi-config devices
1713 * . full/low speed config ... all wTotalLength bytes (with interface,
1714 * class, altsetting, endpoint, and other descriptors)
1715 * . high speed config ... all descriptors, for high speed operation;
1716 * this one's optional except for high-speed hardware
1717 * . device descriptor
1718 *
1719 * Endpoints are not yet enabled. Drivers must wait until device
1720 * configuration and interface altsetting changes create
1721 * the need to configure (or unconfigure) them.
1722 *
1723 * After initialization, the device stays active for as long as that
1724 * $CHIP file is open. Events must then be read from that descriptor,
1725 * such as configuration notifications.
1726 */
1727
1728static int is_valid_config (struct usb_config_descriptor *config)
1729{
1730 return config->bDescriptorType == USB_DT_CONFIG
1731 && config->bLength == USB_DT_CONFIG_SIZE
1732 && config->bConfigurationValue != 0
1733 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1734 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1735 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1736 /* FIXME check lengths: walk to end */
1737}
1738
1739static ssize_t
1740dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1741{
1742 struct dev_data *dev = fd->private_data;
1743 ssize_t value = len, length = len;
1744 unsigned total;
1745 u32 tag;
1746 char *kbuf;
1747
1748 spin_lock_irq(&dev->lock);
1749 if (dev->state > STATE_DEV_OPENED) {
1750 value = ep0_write(fd, buf, len, ptr);
1751 spin_unlock_irq(&dev->lock);
1752 return value;
1753 }
1754 spin_unlock_irq(&dev->lock);
1755
1756 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1757 return -EINVAL;
1758
1759 /* we might need to change message format someday */
1760 if (copy_from_user (&tag, buf, 4))
1761 return -EFAULT;
1762 if (tag != 0)
1763 return -EINVAL;
1764 buf += 4;
1765 length -= 4;
1766
1767 kbuf = memdup_user(buf, length);
1768 if (IS_ERR(kbuf))
1769 return PTR_ERR(kbuf);
1770
1771 spin_lock_irq (&dev->lock);
1772 value = -EINVAL;
1773 if (dev->buf)
1774 goto fail;
1775 dev->buf = kbuf;
1776
1777 /* full or low speed config */
1778 dev->config = (void *) kbuf;
1779 total = le16_to_cpu(dev->config->wTotalLength);
1780 if (!is_valid_config (dev->config) || total >= length)
1781 goto fail;
1782 kbuf += total;
1783 length -= total;
1784
1785 /* optional high speed config */
1786 if (kbuf [1] == USB_DT_CONFIG) {
1787 dev->hs_config = (void *) kbuf;
1788 total = le16_to_cpu(dev->hs_config->wTotalLength);
1789 if (!is_valid_config (dev->hs_config) || total >= length)
1790 goto fail;
1791 kbuf += total;
1792 length -= total;
1793 }
1794
1795 /* could support multiple configs, using another encoding! */
1796
1797 /* device descriptor (tweaked for paranoia) */
1798 if (length != USB_DT_DEVICE_SIZE)
1799 goto fail;
1800 dev->dev = (void *)kbuf;
1801 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1802 || dev->dev->bDescriptorType != USB_DT_DEVICE
1803 || dev->dev->bNumConfigurations != 1)
1804 goto fail;
1805 dev->dev->bNumConfigurations = 1;
1806 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1807
1808 /* triggers gadgetfs_bind(); then we can enumerate. */
1809 spin_unlock_irq (&dev->lock);
1810 if (dev->hs_config)
1811 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1812 else
1813 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1814
1815 value = usb_gadget_probe_driver(&gadgetfs_driver);
1816 if (value != 0) {
1817 kfree (dev->buf);
1818 dev->buf = NULL;
1819 } else {
1820 /* at this point "good" hardware has for the first time
1821 * let the USB the host see us. alternatively, if users
1822 * unplug/replug that will clear all the error state.
1823 *
1824 * note: everything running before here was guaranteed
1825 * to choke driver model style diagnostics. from here
1826 * on, they can work ... except in cleanup paths that
1827 * kick in after the ep0 descriptor is closed.
1828 */
1829 value = len;
1830 dev->gadget_registered = true;
1831 }
1832 return value;
1833
1834fail:
1835 spin_unlock_irq (&dev->lock);
1836 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1837 kfree (dev->buf);
1838 dev->buf = NULL;
1839 return value;
1840}
1841
1842static int
1843dev_open (struct inode *inode, struct file *fd)
1844{
1845 struct dev_data *dev = inode->i_private;
1846 int value = -EBUSY;
1847
1848 spin_lock_irq(&dev->lock);
1849 if (dev->state == STATE_DEV_DISABLED) {
1850 dev->ev_next = 0;
1851 dev->state = STATE_DEV_OPENED;
1852 fd->private_data = dev;
1853 get_dev (dev);
1854 value = 0;
1855 }
1856 spin_unlock_irq(&dev->lock);
1857 return value;
1858}
1859
1860static const struct file_operations ep0_operations = {
1861 .llseek = no_llseek,
1862
1863 .open = dev_open,
1864 .read = ep0_read,
1865 .write = dev_config,
1866 .fasync = ep0_fasync,
1867 .poll = ep0_poll,
1868 .unlocked_ioctl = dev_ioctl,
1869 .release = dev_release,
1870};
1871
1872/*----------------------------------------------------------------------*/
1873
1874/* FILESYSTEM AND SUPERBLOCK OPERATIONS
1875 *
1876 * Mounting the filesystem creates a controller file, used first for
1877 * device configuration then later for event monitoring.
1878 */
1879
1880
1881/* FIXME PAM etc could set this security policy without mount options
1882 * if epfiles inherited ownership and permissons from ep0 ...
1883 */
1884
1885static unsigned default_uid;
1886static unsigned default_gid;
1887static unsigned default_perm = S_IRUSR | S_IWUSR;
1888
1889module_param (default_uid, uint, 0644);
1890module_param (default_gid, uint, 0644);
1891module_param (default_perm, uint, 0644);
1892
1893
1894static struct inode *
1895gadgetfs_make_inode (struct super_block *sb,
1896 void *data, const struct file_operations *fops,
1897 int mode)
1898{
1899 struct inode *inode = new_inode (sb);
1900
1901 if (inode) {
1902 inode->i_ino = get_next_ino();
1903 inode->i_mode = mode;
1904 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1905 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1906 inode->i_atime = inode->i_mtime = inode->i_ctime
1907 = CURRENT_TIME;
1908 inode->i_private = data;
1909 inode->i_fop = fops;
1910 }
1911 return inode;
1912}
1913
1914/* creates in fs root directory, so non-renamable and non-linkable.
1915 * so inode and dentry are paired, until device reconfig.
1916 */
1917static struct dentry *
1918gadgetfs_create_file (struct super_block *sb, char const *name,
1919 void *data, const struct file_operations *fops)
1920{
1921 struct dentry *dentry;
1922 struct inode *inode;
1923
1924 dentry = d_alloc_name(sb->s_root, name);
1925 if (!dentry)
1926 return NULL;
1927
1928 inode = gadgetfs_make_inode (sb, data, fops,
1929 S_IFREG | (default_perm & S_IRWXUGO));
1930 if (!inode) {
1931 dput(dentry);
1932 return NULL;
1933 }
1934 d_add (dentry, inode);
1935 return dentry;
1936}
1937
1938static const struct super_operations gadget_fs_operations = {
1939 .statfs = simple_statfs,
1940 .drop_inode = generic_delete_inode,
1941};
1942
1943static int
1944gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
1945{
1946 struct inode *inode;
1947 struct dev_data *dev;
1948
1949 if (the_device)
1950 return -ESRCH;
1951
1952 CHIP = usb_get_gadget_udc_name();
1953 if (!CHIP)
1954 return -ENODEV;
1955
1956 /* superblock */
1957 sb->s_blocksize = PAGE_SIZE;
1958 sb->s_blocksize_bits = PAGE_SHIFT;
1959 sb->s_magic = GADGETFS_MAGIC;
1960 sb->s_op = &gadget_fs_operations;
1961 sb->s_time_gran = 1;
1962
1963 /* root inode */
1964 inode = gadgetfs_make_inode (sb,
1965 NULL, &simple_dir_operations,
1966 S_IFDIR | S_IRUGO | S_IXUGO);
1967 if (!inode)
1968 goto Enomem;
1969 inode->i_op = &simple_dir_inode_operations;
1970 if (!(sb->s_root = d_make_root (inode)))
1971 goto Enomem;
1972
1973 /* the ep0 file is named after the controller we expect;
1974 * user mode code can use it for sanity checks, like we do.
1975 */
1976 dev = dev_new ();
1977 if (!dev)
1978 goto Enomem;
1979
1980 dev->sb = sb;
1981 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
1982 if (!dev->dentry) {
1983 put_dev(dev);
1984 goto Enomem;
1985 }
1986
1987 /* other endpoint files are available after hardware setup,
1988 * from binding to a controller.
1989 */
1990 the_device = dev;
1991 return 0;
1992
1993Enomem:
1994 return -ENOMEM;
1995}
1996
1997/* "mount -t gadgetfs path /dev/gadget" ends up here */
1998static struct dentry *
1999gadgetfs_mount (struct file_system_type *t, int flags,
2000 const char *path, void *opts)
2001{
2002 return mount_single (t, flags, opts, gadgetfs_fill_super);
2003}
2004
2005static void
2006gadgetfs_kill_sb (struct super_block *sb)
2007{
2008 kill_litter_super (sb);
2009 if (the_device) {
2010 put_dev (the_device);
2011 the_device = NULL;
2012 }
2013 kfree(CHIP);
2014 CHIP = NULL;
2015}
2016
2017/*----------------------------------------------------------------------*/
2018
2019static struct file_system_type gadgetfs_type = {
2020 .owner = THIS_MODULE,
2021 .name = shortname,
2022 .mount = gadgetfs_mount,
2023 .kill_sb = gadgetfs_kill_sb,
2024};
2025MODULE_ALIAS_FS("gadgetfs");
2026
2027/*----------------------------------------------------------------------*/
2028
2029static int __init init (void)
2030{
2031 int status;
2032
2033 status = register_filesystem (&gadgetfs_type);
2034 if (status == 0)
2035 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2036 shortname, driver_desc);
2037 return status;
2038}
2039module_init (init);
2040
2041static void __exit cleanup (void)
2042{
2043 pr_debug ("unregister %s\n", shortname);
2044 unregister_filesystem (&gadgetfs_type);
2045}
2046module_exit (cleanup);
2047