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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * inode.c -- user mode filesystem api for usb gadget controllers
4 *
5 * Copyright (C) 2003-2004 David Brownell
6 * Copyright (C) 2003 Agilent Technologies
7 */
8
9
10/* #define VERBOSE_DEBUG */
11
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/fs.h>
15#include <linux/fs_context.h>
16#include <linux/pagemap.h>
17#include <linux/uts.h>
18#include <linux/wait.h>
19#include <linux/compiler.h>
20#include <linux/uaccess.h>
21#include <linux/sched.h>
22#include <linux/slab.h>
23#include <linux/poll.h>
24#include <linux/kthread.h>
25#include <linux/aio.h>
26#include <linux/uio.h>
27#include <linux/refcount.h>
28#include <linux/delay.h>
29#include <linux/device.h>
30#include <linux/moduleparam.h>
31
32#include <linux/usb/gadgetfs.h>
33#include <linux/usb/gadget.h>
34#include <linux/usb/composite.h> /* for USB_GADGET_DELAYED_STATUS */
35
36/* Undef helpers from linux/usb/composite.h as gadgetfs redefines them */
37#undef DBG
38#undef ERROR
39#undef INFO
40
41
42/*
43 * The gadgetfs API maps each endpoint to a file descriptor so that you
44 * can use standard synchronous read/write calls for I/O. There's some
45 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
46 * drivers show how this works in practice. You can also use AIO to
47 * eliminate I/O gaps between requests, to help when streaming data.
48 *
49 * Key parts that must be USB-specific are protocols defining how the
50 * read/write operations relate to the hardware state machines. There
51 * are two types of files. One type is for the device, implementing ep0.
52 * The other type is for each IN or OUT endpoint. In both cases, the
53 * user mode driver must configure the hardware before using it.
54 *
55 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
56 * (by writing configuration and device descriptors). Afterwards it
57 * may serve as a source of device events, used to handle all control
58 * requests other than basic enumeration.
59 *
60 * - Then, after a SET_CONFIGURATION control request, ep_config() is
61 * called when each /dev/gadget/ep* file is configured (by writing
62 * endpoint descriptors). Afterwards these files are used to write()
63 * IN data or to read() OUT data. To halt the endpoint, a "wrong
64 * direction" request is issued (like reading an IN endpoint).
65 *
66 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
67 * not possible on all hardware. For example, precise fault handling with
68 * respect to data left in endpoint fifos after aborted operations; or
69 * selective clearing of endpoint halts, to implement SET_INTERFACE.
70 */
71
72#define DRIVER_DESC "USB Gadget filesystem"
73#define DRIVER_VERSION "24 Aug 2004"
74
75static const char driver_desc [] = DRIVER_DESC;
76static const char shortname [] = "gadgetfs";
77
78MODULE_DESCRIPTION (DRIVER_DESC);
79MODULE_AUTHOR ("David Brownell");
80MODULE_LICENSE ("GPL");
81
82static int ep_open(struct inode *, struct file *);
83
84
85/*----------------------------------------------------------------------*/
86
87#define GADGETFS_MAGIC 0xaee71ee7
88
89/* /dev/gadget/$CHIP represents ep0 and the whole device */
90enum ep0_state {
91 /* DISABLED is the initial state. */
92 STATE_DEV_DISABLED = 0,
93
94 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
95 * ep0/device i/o modes and binding to the controller. Driver
96 * must always write descriptors to initialize the device, then
97 * the device becomes UNCONNECTED until enumeration.
98 */
99 STATE_DEV_OPENED,
100
101 /* From then on, ep0 fd is in either of two basic modes:
102 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
103 * - SETUP: read/write will transfer control data and succeed;
104 * or if "wrong direction", performs protocol stall
105 */
106 STATE_DEV_UNCONNECTED,
107 STATE_DEV_CONNECTED,
108 STATE_DEV_SETUP,
109
110 /* UNBOUND means the driver closed ep0, so the device won't be
111 * accessible again (DEV_DISABLED) until all fds are closed.
112 */
113 STATE_DEV_UNBOUND,
114};
115
116/* enough for the whole queue: most events invalidate others */
117#define N_EVENT 5
118
119#define RBUF_SIZE 256
120
121struct dev_data {
122 spinlock_t lock;
123 refcount_t count;
124 int udc_usage;
125 enum ep0_state state; /* P: lock */
126 struct usb_gadgetfs_event event [N_EVENT];
127 unsigned ev_next;
128 struct fasync_struct *fasync;
129 u8 current_config;
130
131 /* drivers reading ep0 MUST handle control requests (SETUP)
132 * reported that way; else the host will time out.
133 */
134 unsigned usermode_setup : 1,
135 setup_in : 1,
136 setup_can_stall : 1,
137 setup_out_ready : 1,
138 setup_out_error : 1,
139 setup_abort : 1,
140 gadget_registered : 1;
141 unsigned setup_wLength;
142
143 /* the rest is basically write-once */
144 struct usb_config_descriptor *config, *hs_config;
145 struct usb_device_descriptor *dev;
146 struct usb_request *req;
147 struct usb_gadget *gadget;
148 struct list_head epfiles;
149 void *buf;
150 wait_queue_head_t wait;
151 struct super_block *sb;
152 struct dentry *dentry;
153
154 /* except this scratch i/o buffer for ep0 */
155 u8 rbuf[RBUF_SIZE];
156};
157
158static inline void get_dev (struct dev_data *data)
159{
160 refcount_inc (&data->count);
161}
162
163static void put_dev (struct dev_data *data)
164{
165 if (likely (!refcount_dec_and_test (&data->count)))
166 return;
167 /* needs no more cleanup */
168 BUG_ON (waitqueue_active (&data->wait));
169 kfree (data);
170}
171
172static struct dev_data *dev_new (void)
173{
174 struct dev_data *dev;
175
176 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
177 if (!dev)
178 return NULL;
179 dev->state = STATE_DEV_DISABLED;
180 refcount_set (&dev->count, 1);
181 spin_lock_init (&dev->lock);
182 INIT_LIST_HEAD (&dev->epfiles);
183 init_waitqueue_head (&dev->wait);
184 return dev;
185}
186
187/*----------------------------------------------------------------------*/
188
189/* other /dev/gadget/$ENDPOINT files represent endpoints */
190enum ep_state {
191 STATE_EP_DISABLED = 0,
192 STATE_EP_READY,
193 STATE_EP_ENABLED,
194 STATE_EP_UNBOUND,
195};
196
197struct ep_data {
198 struct mutex lock;
199 enum ep_state state;
200 refcount_t count;
201 struct dev_data *dev;
202 /* must hold dev->lock before accessing ep or req */
203 struct usb_ep *ep;
204 struct usb_request *req;
205 ssize_t status;
206 char name [16];
207 struct usb_endpoint_descriptor desc, hs_desc;
208 struct list_head epfiles;
209 wait_queue_head_t wait;
210 struct dentry *dentry;
211};
212
213static inline void get_ep (struct ep_data *data)
214{
215 refcount_inc (&data->count);
216}
217
218static void put_ep (struct ep_data *data)
219{
220 if (likely (!refcount_dec_and_test (&data->count)))
221 return;
222 put_dev (data->dev);
223 /* needs no more cleanup */
224 BUG_ON (!list_empty (&data->epfiles));
225 BUG_ON (waitqueue_active (&data->wait));
226 kfree (data);
227}
228
229/*----------------------------------------------------------------------*/
230
231/* most "how to use the hardware" policy choices are in userspace:
232 * mapping endpoint roles (which the driver needs) to the capabilities
233 * which the usb controller has. most of those capabilities are exposed
234 * implicitly, starting with the driver name and then endpoint names.
235 */
236
237static const char *CHIP;
238static DEFINE_MUTEX(sb_mutex); /* Serialize superblock operations */
239
240/*----------------------------------------------------------------------*/
241
242/* NOTE: don't use dev_printk calls before binding to the gadget
243 * at the end of ep0 configuration, or after unbind.
244 */
245
246/* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
247#define xprintk(d,level,fmt,args...) \
248 printk(level "%s: " fmt , shortname , ## args)
249
250#ifdef DEBUG
251#define DBG(dev,fmt,args...) \
252 xprintk(dev , KERN_DEBUG , fmt , ## args)
253#else
254#define DBG(dev,fmt,args...) \
255 do { } while (0)
256#endif /* DEBUG */
257
258#ifdef VERBOSE_DEBUG
259#define VDEBUG DBG
260#else
261#define VDEBUG(dev,fmt,args...) \
262 do { } while (0)
263#endif /* DEBUG */
264
265#define ERROR(dev,fmt,args...) \
266 xprintk(dev , KERN_ERR , fmt , ## args)
267#define INFO(dev,fmt,args...) \
268 xprintk(dev , KERN_INFO , fmt , ## args)
269
270
271/*----------------------------------------------------------------------*/
272
273/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
274 *
275 * After opening, configure non-control endpoints. Then use normal
276 * stream read() and write() requests; and maybe ioctl() to get more
277 * precise FIFO status when recovering from cancellation.
278 */
279
280static void epio_complete (struct usb_ep *ep, struct usb_request *req)
281{
282 struct ep_data *epdata = ep->driver_data;
283
284 if (!req->context)
285 return;
286 if (req->status)
287 epdata->status = req->status;
288 else
289 epdata->status = req->actual;
290 complete ((struct completion *)req->context);
291}
292
293/* tasklock endpoint, returning when it's connected.
294 * still need dev->lock to use epdata->ep.
295 */
296static int
297get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
298{
299 int val;
300
301 if (f_flags & O_NONBLOCK) {
302 if (!mutex_trylock(&epdata->lock))
303 goto nonblock;
304 if (epdata->state != STATE_EP_ENABLED &&
305 (!is_write || epdata->state != STATE_EP_READY)) {
306 mutex_unlock(&epdata->lock);
307nonblock:
308 val = -EAGAIN;
309 } else
310 val = 0;
311 return val;
312 }
313
314 val = mutex_lock_interruptible(&epdata->lock);
315 if (val < 0)
316 return val;
317
318 switch (epdata->state) {
319 case STATE_EP_ENABLED:
320 return 0;
321 case STATE_EP_READY: /* not configured yet */
322 if (is_write)
323 return 0;
324 fallthrough;
325 case STATE_EP_UNBOUND: /* clean disconnect */
326 break;
327 // case STATE_EP_DISABLED: /* "can't happen" */
328 default: /* error! */
329 pr_debug ("%s: ep %p not available, state %d\n",
330 shortname, epdata, epdata->state);
331 }
332 mutex_unlock(&epdata->lock);
333 return -ENODEV;
334}
335
336static ssize_t
337ep_io (struct ep_data *epdata, void *buf, unsigned len)
338{
339 DECLARE_COMPLETION_ONSTACK (done);
340 int value;
341
342 spin_lock_irq (&epdata->dev->lock);
343 if (likely (epdata->ep != NULL)) {
344 struct usb_request *req = epdata->req;
345
346 req->context = &done;
347 req->complete = epio_complete;
348 req->buf = buf;
349 req->length = len;
350 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
351 } else
352 value = -ENODEV;
353 spin_unlock_irq (&epdata->dev->lock);
354
355 if (likely (value == 0)) {
356 value = wait_for_completion_interruptible(&done);
357 if (value != 0) {
358 spin_lock_irq (&epdata->dev->lock);
359 if (likely (epdata->ep != NULL)) {
360 DBG (epdata->dev, "%s i/o interrupted\n",
361 epdata->name);
362 usb_ep_dequeue (epdata->ep, epdata->req);
363 spin_unlock_irq (&epdata->dev->lock);
364
365 wait_for_completion(&done);
366 if (epdata->status == -ECONNRESET)
367 epdata->status = -EINTR;
368 } else {
369 spin_unlock_irq (&epdata->dev->lock);
370
371 DBG (epdata->dev, "endpoint gone\n");
372 wait_for_completion(&done);
373 epdata->status = -ENODEV;
374 }
375 }
376 return epdata->status;
377 }
378 return value;
379}
380
381static int
382ep_release (struct inode *inode, struct file *fd)
383{
384 struct ep_data *data = fd->private_data;
385 int value;
386
387 value = mutex_lock_interruptible(&data->lock);
388 if (value < 0)
389 return value;
390
391 /* clean up if this can be reopened */
392 if (data->state != STATE_EP_UNBOUND) {
393 data->state = STATE_EP_DISABLED;
394 data->desc.bDescriptorType = 0;
395 data->hs_desc.bDescriptorType = 0;
396 usb_ep_disable(data->ep);
397 }
398 mutex_unlock(&data->lock);
399 put_ep (data);
400 return 0;
401}
402
403static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
404{
405 struct ep_data *data = fd->private_data;
406 int status;
407
408 if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
409 return status;
410
411 spin_lock_irq (&data->dev->lock);
412 if (likely (data->ep != NULL)) {
413 switch (code) {
414 case GADGETFS_FIFO_STATUS:
415 status = usb_ep_fifo_status (data->ep);
416 break;
417 case GADGETFS_FIFO_FLUSH:
418 usb_ep_fifo_flush (data->ep);
419 break;
420 case GADGETFS_CLEAR_HALT:
421 status = usb_ep_clear_halt (data->ep);
422 break;
423 default:
424 status = -ENOTTY;
425 }
426 } else
427 status = -ENODEV;
428 spin_unlock_irq (&data->dev->lock);
429 mutex_unlock(&data->lock);
430 return status;
431}
432
433/*----------------------------------------------------------------------*/
434
435/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
436
437struct kiocb_priv {
438 struct usb_request *req;
439 struct ep_data *epdata;
440 struct kiocb *iocb;
441 struct mm_struct *mm;
442 struct work_struct work;
443 void *buf;
444 struct iov_iter to;
445 const void *to_free;
446 unsigned actual;
447};
448
449static int ep_aio_cancel(struct kiocb *iocb)
450{
451 struct kiocb_priv *priv = iocb->private;
452 struct ep_data *epdata;
453 int value;
454
455 local_irq_disable();
456 epdata = priv->epdata;
457 // spin_lock(&epdata->dev->lock);
458 if (likely(epdata && epdata->ep && priv->req))
459 value = usb_ep_dequeue (epdata->ep, priv->req);
460 else
461 value = -EINVAL;
462 // spin_unlock(&epdata->dev->lock);
463 local_irq_enable();
464
465 return value;
466}
467
468static void ep_user_copy_worker(struct work_struct *work)
469{
470 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
471 struct mm_struct *mm = priv->mm;
472 struct kiocb *iocb = priv->iocb;
473 size_t ret;
474
475 kthread_use_mm(mm);
476 ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
477 kthread_unuse_mm(mm);
478 if (!ret)
479 ret = -EFAULT;
480
481 /* completing the iocb can drop the ctx and mm, don't touch mm after */
482 iocb->ki_complete(iocb, ret);
483
484 kfree(priv->buf);
485 kfree(priv->to_free);
486 kfree(priv);
487}
488
489static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
490{
491 struct kiocb *iocb = req->context;
492 struct kiocb_priv *priv = iocb->private;
493 struct ep_data *epdata = priv->epdata;
494
495 /* lock against disconnect (and ideally, cancel) */
496 spin_lock(&epdata->dev->lock);
497 priv->req = NULL;
498 priv->epdata = NULL;
499
500 /* if this was a write or a read returning no data then we
501 * don't need to copy anything to userspace, so we can
502 * complete the aio request immediately.
503 */
504 if (priv->to_free == NULL || unlikely(req->actual == 0)) {
505 kfree(req->buf);
506 kfree(priv->to_free);
507 kfree(priv);
508 iocb->private = NULL;
509 iocb->ki_complete(iocb,
510 req->actual ? req->actual : (long)req->status);
511 } else {
512 /* ep_copy_to_user() won't report both; we hide some faults */
513 if (unlikely(0 != req->status))
514 DBG(epdata->dev, "%s fault %d len %d\n",
515 ep->name, req->status, req->actual);
516
517 priv->buf = req->buf;
518 priv->actual = req->actual;
519 INIT_WORK(&priv->work, ep_user_copy_worker);
520 schedule_work(&priv->work);
521 }
522
523 usb_ep_free_request(ep, req);
524 spin_unlock(&epdata->dev->lock);
525 put_ep(epdata);
526}
527
528static ssize_t ep_aio(struct kiocb *iocb,
529 struct kiocb_priv *priv,
530 struct ep_data *epdata,
531 char *buf,
532 size_t len)
533{
534 struct usb_request *req;
535 ssize_t value;
536
537 iocb->private = priv;
538 priv->iocb = iocb;
539
540 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
541 get_ep(epdata);
542 priv->epdata = epdata;
543 priv->actual = 0;
544 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
545
546 /* each kiocb is coupled to one usb_request, but we can't
547 * allocate or submit those if the host disconnected.
548 */
549 spin_lock_irq(&epdata->dev->lock);
550 value = -ENODEV;
551 if (unlikely(epdata->ep == NULL))
552 goto fail;
553
554 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
555 value = -ENOMEM;
556 if (unlikely(!req))
557 goto fail;
558
559 priv->req = req;
560 req->buf = buf;
561 req->length = len;
562 req->complete = ep_aio_complete;
563 req->context = iocb;
564 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
565 if (unlikely(0 != value)) {
566 usb_ep_free_request(epdata->ep, req);
567 goto fail;
568 }
569 spin_unlock_irq(&epdata->dev->lock);
570 return -EIOCBQUEUED;
571
572fail:
573 spin_unlock_irq(&epdata->dev->lock);
574 kfree(priv->to_free);
575 kfree(priv);
576 put_ep(epdata);
577 return value;
578}
579
580static ssize_t
581ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
582{
583 struct file *file = iocb->ki_filp;
584 struct ep_data *epdata = file->private_data;
585 size_t len = iov_iter_count(to);
586 ssize_t value;
587 char *buf;
588
589 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
590 return value;
591
592 /* halt any endpoint by doing a "wrong direction" i/o call */
593 if (usb_endpoint_dir_in(&epdata->desc)) {
594 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
595 !is_sync_kiocb(iocb)) {
596 mutex_unlock(&epdata->lock);
597 return -EINVAL;
598 }
599 DBG (epdata->dev, "%s halt\n", epdata->name);
600 spin_lock_irq(&epdata->dev->lock);
601 if (likely(epdata->ep != NULL))
602 usb_ep_set_halt(epdata->ep);
603 spin_unlock_irq(&epdata->dev->lock);
604 mutex_unlock(&epdata->lock);
605 return -EBADMSG;
606 }
607
608 buf = kmalloc(len, GFP_KERNEL);
609 if (unlikely(!buf)) {
610 mutex_unlock(&epdata->lock);
611 return -ENOMEM;
612 }
613 if (is_sync_kiocb(iocb)) {
614 value = ep_io(epdata, buf, len);
615 if (value >= 0 && (copy_to_iter(buf, value, to) != value))
616 value = -EFAULT;
617 } else {
618 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
619 value = -ENOMEM;
620 if (!priv)
621 goto fail;
622 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
623 if (!iter_is_ubuf(&priv->to) && !priv->to_free) {
624 kfree(priv);
625 goto fail;
626 }
627 value = ep_aio(iocb, priv, epdata, buf, len);
628 if (value == -EIOCBQUEUED)
629 buf = NULL;
630 }
631fail:
632 kfree(buf);
633 mutex_unlock(&epdata->lock);
634 return value;
635}
636
637static ssize_t ep_config(struct ep_data *, const char *, size_t);
638
639static ssize_t
640ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
641{
642 struct file *file = iocb->ki_filp;
643 struct ep_data *epdata = file->private_data;
644 size_t len = iov_iter_count(from);
645 bool configured;
646 ssize_t value;
647 char *buf;
648
649 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
650 return value;
651
652 configured = epdata->state == STATE_EP_ENABLED;
653
654 /* halt any endpoint by doing a "wrong direction" i/o call */
655 if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
656 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
657 !is_sync_kiocb(iocb)) {
658 mutex_unlock(&epdata->lock);
659 return -EINVAL;
660 }
661 DBG (epdata->dev, "%s halt\n", epdata->name);
662 spin_lock_irq(&epdata->dev->lock);
663 if (likely(epdata->ep != NULL))
664 usb_ep_set_halt(epdata->ep);
665 spin_unlock_irq(&epdata->dev->lock);
666 mutex_unlock(&epdata->lock);
667 return -EBADMSG;
668 }
669
670 buf = kmalloc(len, GFP_KERNEL);
671 if (unlikely(!buf)) {
672 mutex_unlock(&epdata->lock);
673 return -ENOMEM;
674 }
675
676 if (unlikely(!copy_from_iter_full(buf, len, from))) {
677 value = -EFAULT;
678 goto out;
679 }
680
681 if (unlikely(!configured)) {
682 value = ep_config(epdata, buf, len);
683 } else if (is_sync_kiocb(iocb)) {
684 value = ep_io(epdata, buf, len);
685 } else {
686 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
687 value = -ENOMEM;
688 if (priv) {
689 value = ep_aio(iocb, priv, epdata, buf, len);
690 if (value == -EIOCBQUEUED)
691 buf = NULL;
692 }
693 }
694out:
695 kfree(buf);
696 mutex_unlock(&epdata->lock);
697 return value;
698}
699
700/*----------------------------------------------------------------------*/
701
702/* used after endpoint configuration */
703static const struct file_operations ep_io_operations = {
704 .owner = THIS_MODULE,
705
706 .open = ep_open,
707 .release = ep_release,
708 .llseek = no_llseek,
709 .unlocked_ioctl = ep_ioctl,
710 .read_iter = ep_read_iter,
711 .write_iter = ep_write_iter,
712};
713
714/* ENDPOINT INITIALIZATION
715 *
716 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
717 * status = write (fd, descriptors, sizeof descriptors)
718 *
719 * That write establishes the endpoint configuration, configuring
720 * the controller to process bulk, interrupt, or isochronous transfers
721 * at the right maxpacket size, and so on.
722 *
723 * The descriptors are message type 1, identified by a host order u32
724 * at the beginning of what's written. Descriptor order is: full/low
725 * speed descriptor, then optional high speed descriptor.
726 */
727static ssize_t
728ep_config (struct ep_data *data, const char *buf, size_t len)
729{
730 struct usb_ep *ep;
731 u32 tag;
732 int value, length = len;
733
734 if (data->state != STATE_EP_READY) {
735 value = -EL2HLT;
736 goto fail;
737 }
738
739 value = len;
740 if (len < USB_DT_ENDPOINT_SIZE + 4)
741 goto fail0;
742
743 /* we might need to change message format someday */
744 memcpy(&tag, buf, 4);
745 if (tag != 1) {
746 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
747 goto fail0;
748 }
749 buf += 4;
750 len -= 4;
751
752 /* NOTE: audio endpoint extensions not accepted here;
753 * just don't include the extra bytes.
754 */
755
756 /* full/low speed descriptor, then high speed */
757 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
758 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
759 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
760 goto fail0;
761 if (len != USB_DT_ENDPOINT_SIZE) {
762 if (len != 2 * USB_DT_ENDPOINT_SIZE)
763 goto fail0;
764 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
765 USB_DT_ENDPOINT_SIZE);
766 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
767 || data->hs_desc.bDescriptorType
768 != USB_DT_ENDPOINT) {
769 DBG(data->dev, "config %s, bad hs length or type\n",
770 data->name);
771 goto fail0;
772 }
773 }
774
775 spin_lock_irq (&data->dev->lock);
776 if (data->dev->state == STATE_DEV_UNBOUND) {
777 value = -ENOENT;
778 goto gone;
779 } else {
780 ep = data->ep;
781 if (ep == NULL) {
782 value = -ENODEV;
783 goto gone;
784 }
785 }
786 switch (data->dev->gadget->speed) {
787 case USB_SPEED_LOW:
788 case USB_SPEED_FULL:
789 ep->desc = &data->desc;
790 break;
791 case USB_SPEED_HIGH:
792 /* fails if caller didn't provide that descriptor... */
793 ep->desc = &data->hs_desc;
794 break;
795 default:
796 DBG(data->dev, "unconnected, %s init abandoned\n",
797 data->name);
798 value = -EINVAL;
799 goto gone;
800 }
801 value = usb_ep_enable(ep);
802 if (value == 0) {
803 data->state = STATE_EP_ENABLED;
804 value = length;
805 }
806gone:
807 spin_unlock_irq (&data->dev->lock);
808 if (value < 0) {
809fail:
810 data->desc.bDescriptorType = 0;
811 data->hs_desc.bDescriptorType = 0;
812 }
813 return value;
814fail0:
815 value = -EINVAL;
816 goto fail;
817}
818
819static int
820ep_open (struct inode *inode, struct file *fd)
821{
822 struct ep_data *data = inode->i_private;
823 int value = -EBUSY;
824
825 if (mutex_lock_interruptible(&data->lock) != 0)
826 return -EINTR;
827 spin_lock_irq (&data->dev->lock);
828 if (data->dev->state == STATE_DEV_UNBOUND)
829 value = -ENOENT;
830 else if (data->state == STATE_EP_DISABLED) {
831 value = 0;
832 data->state = STATE_EP_READY;
833 get_ep (data);
834 fd->private_data = data;
835 VDEBUG (data->dev, "%s ready\n", data->name);
836 } else
837 DBG (data->dev, "%s state %d\n",
838 data->name, data->state);
839 spin_unlock_irq (&data->dev->lock);
840 mutex_unlock(&data->lock);
841 return value;
842}
843
844/*----------------------------------------------------------------------*/
845
846/* EP0 IMPLEMENTATION can be partly in userspace.
847 *
848 * Drivers that use this facility receive various events, including
849 * control requests the kernel doesn't handle. Drivers that don't
850 * use this facility may be too simple-minded for real applications.
851 */
852
853static inline void ep0_readable (struct dev_data *dev)
854{
855 wake_up (&dev->wait);
856 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
857}
858
859static void clean_req (struct usb_ep *ep, struct usb_request *req)
860{
861 struct dev_data *dev = ep->driver_data;
862
863 if (req->buf != dev->rbuf) {
864 kfree(req->buf);
865 req->buf = dev->rbuf;
866 }
867 req->complete = epio_complete;
868 dev->setup_out_ready = 0;
869}
870
871static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
872{
873 struct dev_data *dev = ep->driver_data;
874 unsigned long flags;
875 int free = 1;
876
877 /* for control OUT, data must still get to userspace */
878 spin_lock_irqsave(&dev->lock, flags);
879 if (!dev->setup_in) {
880 dev->setup_out_error = (req->status != 0);
881 if (!dev->setup_out_error)
882 free = 0;
883 dev->setup_out_ready = 1;
884 ep0_readable (dev);
885 }
886
887 /* clean up as appropriate */
888 if (free && req->buf != &dev->rbuf)
889 clean_req (ep, req);
890 req->complete = epio_complete;
891 spin_unlock_irqrestore(&dev->lock, flags);
892}
893
894static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
895{
896 struct dev_data *dev = ep->driver_data;
897
898 if (dev->setup_out_ready) {
899 DBG (dev, "ep0 request busy!\n");
900 return -EBUSY;
901 }
902 if (len > sizeof (dev->rbuf))
903 req->buf = kmalloc(len, GFP_ATOMIC);
904 if (req->buf == NULL) {
905 req->buf = dev->rbuf;
906 return -ENOMEM;
907 }
908 req->complete = ep0_complete;
909 req->length = len;
910 req->zero = 0;
911 return 0;
912}
913
914static ssize_t
915ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
916{
917 struct dev_data *dev = fd->private_data;
918 ssize_t retval;
919 enum ep0_state state;
920
921 spin_lock_irq (&dev->lock);
922 if (dev->state <= STATE_DEV_OPENED) {
923 retval = -EINVAL;
924 goto done;
925 }
926
927 /* report fd mode change before acting on it */
928 if (dev->setup_abort) {
929 dev->setup_abort = 0;
930 retval = -EIDRM;
931 goto done;
932 }
933
934 /* control DATA stage */
935 if ((state = dev->state) == STATE_DEV_SETUP) {
936
937 if (dev->setup_in) { /* stall IN */
938 VDEBUG(dev, "ep0in stall\n");
939 (void) usb_ep_set_halt (dev->gadget->ep0);
940 retval = -EL2HLT;
941 dev->state = STATE_DEV_CONNECTED;
942
943 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
944 struct usb_ep *ep = dev->gadget->ep0;
945 struct usb_request *req = dev->req;
946
947 if ((retval = setup_req (ep, req, 0)) == 0) {
948 ++dev->udc_usage;
949 spin_unlock_irq (&dev->lock);
950 retval = usb_ep_queue (ep, req, GFP_KERNEL);
951 spin_lock_irq (&dev->lock);
952 --dev->udc_usage;
953 }
954 dev->state = STATE_DEV_CONNECTED;
955
956 /* assume that was SET_CONFIGURATION */
957 if (dev->current_config) {
958 unsigned power;
959
960 if (gadget_is_dualspeed(dev->gadget)
961 && (dev->gadget->speed
962 == USB_SPEED_HIGH))
963 power = dev->hs_config->bMaxPower;
964 else
965 power = dev->config->bMaxPower;
966 usb_gadget_vbus_draw(dev->gadget, 2 * power);
967 }
968
969 } else { /* collect OUT data */
970 if ((fd->f_flags & O_NONBLOCK) != 0
971 && !dev->setup_out_ready) {
972 retval = -EAGAIN;
973 goto done;
974 }
975 spin_unlock_irq (&dev->lock);
976 retval = wait_event_interruptible (dev->wait,
977 dev->setup_out_ready != 0);
978
979 /* FIXME state could change from under us */
980 spin_lock_irq (&dev->lock);
981 if (retval)
982 goto done;
983
984 if (dev->state != STATE_DEV_SETUP) {
985 retval = -ECANCELED;
986 goto done;
987 }
988 dev->state = STATE_DEV_CONNECTED;
989
990 if (dev->setup_out_error)
991 retval = -EIO;
992 else {
993 len = min (len, (size_t)dev->req->actual);
994 ++dev->udc_usage;
995 spin_unlock_irq(&dev->lock);
996 if (copy_to_user (buf, dev->req->buf, len))
997 retval = -EFAULT;
998 else
999 retval = len;
1000 spin_lock_irq(&dev->lock);
1001 --dev->udc_usage;
1002 clean_req (dev->gadget->ep0, dev->req);
1003 /* NOTE userspace can't yet choose to stall */
1004 }
1005 }
1006 goto done;
1007 }
1008
1009 /* else normal: return event data */
1010 if (len < sizeof dev->event [0]) {
1011 retval = -EINVAL;
1012 goto done;
1013 }
1014 len -= len % sizeof (struct usb_gadgetfs_event);
1015 dev->usermode_setup = 1;
1016
1017scan:
1018 /* return queued events right away */
1019 if (dev->ev_next != 0) {
1020 unsigned i, n;
1021
1022 n = len / sizeof (struct usb_gadgetfs_event);
1023 if (dev->ev_next < n)
1024 n = dev->ev_next;
1025
1026 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1027 for (i = 0; i < n; i++) {
1028 if (dev->event [i].type == GADGETFS_SETUP) {
1029 dev->state = STATE_DEV_SETUP;
1030 n = i + 1;
1031 break;
1032 }
1033 }
1034 spin_unlock_irq (&dev->lock);
1035 len = n * sizeof (struct usb_gadgetfs_event);
1036 if (copy_to_user (buf, &dev->event, len))
1037 retval = -EFAULT;
1038 else
1039 retval = len;
1040 if (len > 0) {
1041 /* NOTE this doesn't guard against broken drivers;
1042 * concurrent ep0 readers may lose events.
1043 */
1044 spin_lock_irq (&dev->lock);
1045 if (dev->ev_next > n) {
1046 memmove(&dev->event[0], &dev->event[n],
1047 sizeof (struct usb_gadgetfs_event)
1048 * (dev->ev_next - n));
1049 }
1050 dev->ev_next -= n;
1051 spin_unlock_irq (&dev->lock);
1052 }
1053 return retval;
1054 }
1055 if (fd->f_flags & O_NONBLOCK) {
1056 retval = -EAGAIN;
1057 goto done;
1058 }
1059
1060 switch (state) {
1061 default:
1062 DBG (dev, "fail %s, state %d\n", __func__, state);
1063 retval = -ESRCH;
1064 break;
1065 case STATE_DEV_UNCONNECTED:
1066 case STATE_DEV_CONNECTED:
1067 spin_unlock_irq (&dev->lock);
1068 DBG (dev, "%s wait\n", __func__);
1069
1070 /* wait for events */
1071 retval = wait_event_interruptible (dev->wait,
1072 dev->ev_next != 0);
1073 if (retval < 0)
1074 return retval;
1075 spin_lock_irq (&dev->lock);
1076 goto scan;
1077 }
1078
1079done:
1080 spin_unlock_irq (&dev->lock);
1081 return retval;
1082}
1083
1084static struct usb_gadgetfs_event *
1085next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1086{
1087 struct usb_gadgetfs_event *event;
1088 unsigned i;
1089
1090 switch (type) {
1091 /* these events purge the queue */
1092 case GADGETFS_DISCONNECT:
1093 if (dev->state == STATE_DEV_SETUP)
1094 dev->setup_abort = 1;
1095 fallthrough;
1096 case GADGETFS_CONNECT:
1097 dev->ev_next = 0;
1098 break;
1099 case GADGETFS_SETUP: /* previous request timed out */
1100 case GADGETFS_SUSPEND: /* same effect */
1101 /* these events can't be repeated */
1102 for (i = 0; i != dev->ev_next; i++) {
1103 if (dev->event [i].type != type)
1104 continue;
1105 DBG(dev, "discard old event[%d] %d\n", i, type);
1106 dev->ev_next--;
1107 if (i == dev->ev_next)
1108 break;
1109 /* indices start at zero, for simplicity */
1110 memmove (&dev->event [i], &dev->event [i + 1],
1111 sizeof (struct usb_gadgetfs_event)
1112 * (dev->ev_next - i));
1113 }
1114 break;
1115 default:
1116 BUG ();
1117 }
1118 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1119 event = &dev->event [dev->ev_next++];
1120 BUG_ON (dev->ev_next > N_EVENT);
1121 memset (event, 0, sizeof *event);
1122 event->type = type;
1123 return event;
1124}
1125
1126static ssize_t
1127ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1128{
1129 struct dev_data *dev = fd->private_data;
1130 ssize_t retval = -ESRCH;
1131
1132 /* report fd mode change before acting on it */
1133 if (dev->setup_abort) {
1134 dev->setup_abort = 0;
1135 retval = -EIDRM;
1136
1137 /* data and/or status stage for control request */
1138 } else if (dev->state == STATE_DEV_SETUP) {
1139
1140 len = min_t(size_t, len, dev->setup_wLength);
1141 if (dev->setup_in) {
1142 retval = setup_req (dev->gadget->ep0, dev->req, len);
1143 if (retval == 0) {
1144 dev->state = STATE_DEV_CONNECTED;
1145 ++dev->udc_usage;
1146 spin_unlock_irq (&dev->lock);
1147 if (copy_from_user (dev->req->buf, buf, len))
1148 retval = -EFAULT;
1149 else {
1150 if (len < dev->setup_wLength)
1151 dev->req->zero = 1;
1152 retval = usb_ep_queue (
1153 dev->gadget->ep0, dev->req,
1154 GFP_KERNEL);
1155 }
1156 spin_lock_irq(&dev->lock);
1157 --dev->udc_usage;
1158 if (retval < 0) {
1159 clean_req (dev->gadget->ep0, dev->req);
1160 } else
1161 retval = len;
1162
1163 return retval;
1164 }
1165
1166 /* can stall some OUT transfers */
1167 } else if (dev->setup_can_stall) {
1168 VDEBUG(dev, "ep0out stall\n");
1169 (void) usb_ep_set_halt (dev->gadget->ep0);
1170 retval = -EL2HLT;
1171 dev->state = STATE_DEV_CONNECTED;
1172 } else {
1173 DBG(dev, "bogus ep0out stall!\n");
1174 }
1175 } else
1176 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1177
1178 return retval;
1179}
1180
1181static int
1182ep0_fasync (int f, struct file *fd, int on)
1183{
1184 struct dev_data *dev = fd->private_data;
1185 // caller must F_SETOWN before signal delivery happens
1186 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1187 return fasync_helper (f, fd, on, &dev->fasync);
1188}
1189
1190static struct usb_gadget_driver gadgetfs_driver;
1191
1192static int
1193dev_release (struct inode *inode, struct file *fd)
1194{
1195 struct dev_data *dev = fd->private_data;
1196
1197 /* closing ep0 === shutdown all */
1198
1199 if (dev->gadget_registered) {
1200 usb_gadget_unregister_driver (&gadgetfs_driver);
1201 dev->gadget_registered = false;
1202 }
1203
1204 /* at this point "good" hardware has disconnected the
1205 * device from USB; the host won't see it any more.
1206 * alternatively, all host requests will time out.
1207 */
1208
1209 kfree (dev->buf);
1210 dev->buf = NULL;
1211
1212 /* other endpoints were all decoupled from this device */
1213 spin_lock_irq(&dev->lock);
1214 dev->state = STATE_DEV_DISABLED;
1215 spin_unlock_irq(&dev->lock);
1216
1217 put_dev (dev);
1218 return 0;
1219}
1220
1221static __poll_t
1222ep0_poll (struct file *fd, poll_table *wait)
1223{
1224 struct dev_data *dev = fd->private_data;
1225 __poll_t mask = 0;
1226
1227 if (dev->state <= STATE_DEV_OPENED)
1228 return DEFAULT_POLLMASK;
1229
1230 poll_wait(fd, &dev->wait, wait);
1231
1232 spin_lock_irq(&dev->lock);
1233
1234 /* report fd mode change before acting on it */
1235 if (dev->setup_abort) {
1236 dev->setup_abort = 0;
1237 mask = EPOLLHUP;
1238 goto out;
1239 }
1240
1241 if (dev->state == STATE_DEV_SETUP) {
1242 if (dev->setup_in || dev->setup_can_stall)
1243 mask = EPOLLOUT;
1244 } else {
1245 if (dev->ev_next != 0)
1246 mask = EPOLLIN;
1247 }
1248out:
1249 spin_unlock_irq(&dev->lock);
1250 return mask;
1251}
1252
1253static long gadget_dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1254{
1255 struct dev_data *dev = fd->private_data;
1256 struct usb_gadget *gadget = dev->gadget;
1257 long ret = -ENOTTY;
1258
1259 spin_lock_irq(&dev->lock);
1260 if (dev->state == STATE_DEV_OPENED ||
1261 dev->state == STATE_DEV_UNBOUND) {
1262 /* Not bound to a UDC */
1263 } else if (gadget->ops->ioctl) {
1264 ++dev->udc_usage;
1265 spin_unlock_irq(&dev->lock);
1266
1267 ret = gadget->ops->ioctl (gadget, code, value);
1268
1269 spin_lock_irq(&dev->lock);
1270 --dev->udc_usage;
1271 }
1272 spin_unlock_irq(&dev->lock);
1273
1274 return ret;
1275}
1276
1277/*----------------------------------------------------------------------*/
1278
1279/* The in-kernel gadget driver handles most ep0 issues, in particular
1280 * enumerating the single configuration (as provided from user space).
1281 *
1282 * Unrecognized ep0 requests may be handled in user space.
1283 */
1284
1285static void make_qualifier (struct dev_data *dev)
1286{
1287 struct usb_qualifier_descriptor qual;
1288 struct usb_device_descriptor *desc;
1289
1290 qual.bLength = sizeof qual;
1291 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1292 qual.bcdUSB = cpu_to_le16 (0x0200);
1293
1294 desc = dev->dev;
1295 qual.bDeviceClass = desc->bDeviceClass;
1296 qual.bDeviceSubClass = desc->bDeviceSubClass;
1297 qual.bDeviceProtocol = desc->bDeviceProtocol;
1298
1299 /* assumes ep0 uses the same value for both speeds ... */
1300 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1301
1302 qual.bNumConfigurations = 1;
1303 qual.bRESERVED = 0;
1304
1305 memcpy (dev->rbuf, &qual, sizeof qual);
1306}
1307
1308static int
1309config_buf (struct dev_data *dev, u8 type, unsigned index)
1310{
1311 int len;
1312 int hs = 0;
1313
1314 /* only one configuration */
1315 if (index > 0)
1316 return -EINVAL;
1317
1318 if (gadget_is_dualspeed(dev->gadget)) {
1319 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1320 if (type == USB_DT_OTHER_SPEED_CONFIG)
1321 hs = !hs;
1322 }
1323 if (hs) {
1324 dev->req->buf = dev->hs_config;
1325 len = le16_to_cpu(dev->hs_config->wTotalLength);
1326 } else {
1327 dev->req->buf = dev->config;
1328 len = le16_to_cpu(dev->config->wTotalLength);
1329 }
1330 ((u8 *)dev->req->buf) [1] = type;
1331 return len;
1332}
1333
1334static int
1335gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1336{
1337 struct dev_data *dev = get_gadget_data (gadget);
1338 struct usb_request *req = dev->req;
1339 int value = -EOPNOTSUPP;
1340 struct usb_gadgetfs_event *event;
1341 u16 w_value = le16_to_cpu(ctrl->wValue);
1342 u16 w_length = le16_to_cpu(ctrl->wLength);
1343
1344 if (w_length > RBUF_SIZE) {
1345 if (ctrl->bRequestType & USB_DIR_IN) {
1346 /* Cast away the const, we are going to overwrite on purpose. */
1347 __le16 *temp = (__le16 *)&ctrl->wLength;
1348
1349 *temp = cpu_to_le16(RBUF_SIZE);
1350 w_length = RBUF_SIZE;
1351 } else {
1352 return value;
1353 }
1354 }
1355
1356 spin_lock (&dev->lock);
1357 dev->setup_abort = 0;
1358 if (dev->state == STATE_DEV_UNCONNECTED) {
1359 if (gadget_is_dualspeed(gadget)
1360 && gadget->speed == USB_SPEED_HIGH
1361 && dev->hs_config == NULL) {
1362 spin_unlock(&dev->lock);
1363 ERROR (dev, "no high speed config??\n");
1364 return -EINVAL;
1365 }
1366
1367 dev->state = STATE_DEV_CONNECTED;
1368
1369 INFO (dev, "connected\n");
1370 event = next_event (dev, GADGETFS_CONNECT);
1371 event->u.speed = gadget->speed;
1372 ep0_readable (dev);
1373
1374 /* host may have given up waiting for response. we can miss control
1375 * requests handled lower down (device/endpoint status and features);
1376 * then ep0_{read,write} will report the wrong status. controller
1377 * driver will have aborted pending i/o.
1378 */
1379 } else if (dev->state == STATE_DEV_SETUP)
1380 dev->setup_abort = 1;
1381
1382 req->buf = dev->rbuf;
1383 req->context = NULL;
1384 switch (ctrl->bRequest) {
1385
1386 case USB_REQ_GET_DESCRIPTOR:
1387 if (ctrl->bRequestType != USB_DIR_IN)
1388 goto unrecognized;
1389 switch (w_value >> 8) {
1390
1391 case USB_DT_DEVICE:
1392 value = min (w_length, (u16) sizeof *dev->dev);
1393 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1394 req->buf = dev->dev;
1395 break;
1396 case USB_DT_DEVICE_QUALIFIER:
1397 if (!dev->hs_config)
1398 break;
1399 value = min (w_length, (u16)
1400 sizeof (struct usb_qualifier_descriptor));
1401 make_qualifier (dev);
1402 break;
1403 case USB_DT_OTHER_SPEED_CONFIG:
1404 case USB_DT_CONFIG:
1405 value = config_buf (dev,
1406 w_value >> 8,
1407 w_value & 0xff);
1408 if (value >= 0)
1409 value = min (w_length, (u16) value);
1410 break;
1411 case USB_DT_STRING:
1412 goto unrecognized;
1413
1414 default: // all others are errors
1415 break;
1416 }
1417 break;
1418
1419 /* currently one config, two speeds */
1420 case USB_REQ_SET_CONFIGURATION:
1421 if (ctrl->bRequestType != 0)
1422 goto unrecognized;
1423 if (0 == (u8) w_value) {
1424 value = 0;
1425 dev->current_config = 0;
1426 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1427 // user mode expected to disable endpoints
1428 } else {
1429 u8 config, power;
1430
1431 if (gadget_is_dualspeed(gadget)
1432 && gadget->speed == USB_SPEED_HIGH) {
1433 config = dev->hs_config->bConfigurationValue;
1434 power = dev->hs_config->bMaxPower;
1435 } else {
1436 config = dev->config->bConfigurationValue;
1437 power = dev->config->bMaxPower;
1438 }
1439
1440 if (config == (u8) w_value) {
1441 value = 0;
1442 dev->current_config = config;
1443 usb_gadget_vbus_draw(gadget, 2 * power);
1444 }
1445 }
1446
1447 /* report SET_CONFIGURATION like any other control request,
1448 * except that usermode may not stall this. the next
1449 * request mustn't be allowed start until this finishes:
1450 * endpoints and threads set up, etc.
1451 *
1452 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1453 * has bad/racey automagic that prevents synchronizing here.
1454 * even kernel mode drivers often miss them.
1455 */
1456 if (value == 0) {
1457 INFO (dev, "configuration #%d\n", dev->current_config);
1458 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1459 if (dev->usermode_setup) {
1460 dev->setup_can_stall = 0;
1461 goto delegate;
1462 }
1463 }
1464 break;
1465
1466#ifndef CONFIG_USB_PXA25X
1467 /* PXA automagically handles this request too */
1468 case USB_REQ_GET_CONFIGURATION:
1469 if (ctrl->bRequestType != 0x80)
1470 goto unrecognized;
1471 *(u8 *)req->buf = dev->current_config;
1472 value = min (w_length, (u16) 1);
1473 break;
1474#endif
1475
1476 default:
1477unrecognized:
1478 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1479 dev->usermode_setup ? "delegate" : "fail",
1480 ctrl->bRequestType, ctrl->bRequest,
1481 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1482
1483 /* if there's an ep0 reader, don't stall */
1484 if (dev->usermode_setup) {
1485 dev->setup_can_stall = 1;
1486delegate:
1487 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1488 ? 1 : 0;
1489 dev->setup_wLength = w_length;
1490 dev->setup_out_ready = 0;
1491 dev->setup_out_error = 0;
1492
1493 /* read DATA stage for OUT right away */
1494 if (unlikely (!dev->setup_in && w_length)) {
1495 value = setup_req (gadget->ep0, dev->req,
1496 w_length);
1497 if (value < 0)
1498 break;
1499
1500 ++dev->udc_usage;
1501 spin_unlock (&dev->lock);
1502 value = usb_ep_queue (gadget->ep0, dev->req,
1503 GFP_KERNEL);
1504 spin_lock (&dev->lock);
1505 --dev->udc_usage;
1506 if (value < 0) {
1507 clean_req (gadget->ep0, dev->req);
1508 break;
1509 }
1510
1511 /* we can't currently stall these */
1512 dev->setup_can_stall = 0;
1513 }
1514
1515 /* state changes when reader collects event */
1516 event = next_event (dev, GADGETFS_SETUP);
1517 event->u.setup = *ctrl;
1518 ep0_readable (dev);
1519 spin_unlock (&dev->lock);
1520 /*
1521 * Return USB_GADGET_DELAYED_STATUS as a workaround to
1522 * stop some UDC drivers (e.g. dwc3) from automatically
1523 * proceeding with the status stage for 0-length
1524 * transfers.
1525 * Should be removed once all UDC drivers are fixed to
1526 * always delay the status stage until a response is
1527 * queued to EP0.
1528 */
1529 return w_length == 0 ? USB_GADGET_DELAYED_STATUS : 0;
1530 }
1531 }
1532
1533 /* proceed with data transfer and status phases? */
1534 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1535 req->length = value;
1536 req->zero = value < w_length;
1537
1538 ++dev->udc_usage;
1539 spin_unlock (&dev->lock);
1540 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL);
1541 spin_lock(&dev->lock);
1542 --dev->udc_usage;
1543 spin_unlock(&dev->lock);
1544 if (value < 0) {
1545 DBG (dev, "ep_queue --> %d\n", value);
1546 req->status = 0;
1547 }
1548 return value;
1549 }
1550
1551 /* device stalls when value < 0 */
1552 spin_unlock (&dev->lock);
1553 return value;
1554}
1555
1556static void destroy_ep_files (struct dev_data *dev)
1557{
1558 DBG (dev, "%s %d\n", __func__, dev->state);
1559
1560 /* dev->state must prevent interference */
1561 spin_lock_irq (&dev->lock);
1562 while (!list_empty(&dev->epfiles)) {
1563 struct ep_data *ep;
1564 struct inode *parent;
1565 struct dentry *dentry;
1566
1567 /* break link to FS */
1568 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1569 list_del_init (&ep->epfiles);
1570 spin_unlock_irq (&dev->lock);
1571
1572 dentry = ep->dentry;
1573 ep->dentry = NULL;
1574 parent = d_inode(dentry->d_parent);
1575
1576 /* break link to controller */
1577 mutex_lock(&ep->lock);
1578 if (ep->state == STATE_EP_ENABLED)
1579 (void) usb_ep_disable (ep->ep);
1580 ep->state = STATE_EP_UNBOUND;
1581 usb_ep_free_request (ep->ep, ep->req);
1582 ep->ep = NULL;
1583 mutex_unlock(&ep->lock);
1584
1585 wake_up (&ep->wait);
1586 put_ep (ep);
1587
1588 /* break link to dcache */
1589 inode_lock(parent);
1590 d_delete (dentry);
1591 dput (dentry);
1592 inode_unlock(parent);
1593
1594 spin_lock_irq (&dev->lock);
1595 }
1596 spin_unlock_irq (&dev->lock);
1597}
1598
1599
1600static struct dentry *
1601gadgetfs_create_file (struct super_block *sb, char const *name,
1602 void *data, const struct file_operations *fops);
1603
1604static int activate_ep_files (struct dev_data *dev)
1605{
1606 struct usb_ep *ep;
1607 struct ep_data *data;
1608
1609 gadget_for_each_ep (ep, dev->gadget) {
1610
1611 data = kzalloc(sizeof(*data), GFP_KERNEL);
1612 if (!data)
1613 goto enomem0;
1614 data->state = STATE_EP_DISABLED;
1615 mutex_init(&data->lock);
1616 init_waitqueue_head (&data->wait);
1617
1618 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1619 refcount_set (&data->count, 1);
1620 data->dev = dev;
1621 get_dev (dev);
1622
1623 data->ep = ep;
1624 ep->driver_data = data;
1625
1626 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1627 if (!data->req)
1628 goto enomem1;
1629
1630 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1631 data, &ep_io_operations);
1632 if (!data->dentry)
1633 goto enomem2;
1634 list_add_tail (&data->epfiles, &dev->epfiles);
1635 }
1636 return 0;
1637
1638enomem2:
1639 usb_ep_free_request (ep, data->req);
1640enomem1:
1641 put_dev (dev);
1642 kfree (data);
1643enomem0:
1644 DBG (dev, "%s enomem\n", __func__);
1645 destroy_ep_files (dev);
1646 return -ENOMEM;
1647}
1648
1649static void
1650gadgetfs_unbind (struct usb_gadget *gadget)
1651{
1652 struct dev_data *dev = get_gadget_data (gadget);
1653
1654 DBG (dev, "%s\n", __func__);
1655
1656 spin_lock_irq (&dev->lock);
1657 dev->state = STATE_DEV_UNBOUND;
1658 while (dev->udc_usage > 0) {
1659 spin_unlock_irq(&dev->lock);
1660 usleep_range(1000, 2000);
1661 spin_lock_irq(&dev->lock);
1662 }
1663 spin_unlock_irq (&dev->lock);
1664
1665 destroy_ep_files (dev);
1666 gadget->ep0->driver_data = NULL;
1667 set_gadget_data (gadget, NULL);
1668
1669 /* we've already been disconnected ... no i/o is active */
1670 if (dev->req)
1671 usb_ep_free_request (gadget->ep0, dev->req);
1672 DBG (dev, "%s done\n", __func__);
1673 put_dev (dev);
1674}
1675
1676static struct dev_data *the_device;
1677
1678static int gadgetfs_bind(struct usb_gadget *gadget,
1679 struct usb_gadget_driver *driver)
1680{
1681 struct dev_data *dev = the_device;
1682
1683 if (!dev)
1684 return -ESRCH;
1685 if (0 != strcmp (CHIP, gadget->name)) {
1686 pr_err("%s expected %s controller not %s\n",
1687 shortname, CHIP, gadget->name);
1688 return -ENODEV;
1689 }
1690
1691 set_gadget_data (gadget, dev);
1692 dev->gadget = gadget;
1693 gadget->ep0->driver_data = dev;
1694
1695 /* preallocate control response and buffer */
1696 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1697 if (!dev->req)
1698 goto enomem;
1699 dev->req->context = NULL;
1700 dev->req->complete = epio_complete;
1701
1702 if (activate_ep_files (dev) < 0)
1703 goto enomem;
1704
1705 INFO (dev, "bound to %s driver\n", gadget->name);
1706 spin_lock_irq(&dev->lock);
1707 dev->state = STATE_DEV_UNCONNECTED;
1708 spin_unlock_irq(&dev->lock);
1709 get_dev (dev);
1710 return 0;
1711
1712enomem:
1713 gadgetfs_unbind (gadget);
1714 return -ENOMEM;
1715}
1716
1717static void
1718gadgetfs_disconnect (struct usb_gadget *gadget)
1719{
1720 struct dev_data *dev = get_gadget_data (gadget);
1721 unsigned long flags;
1722
1723 spin_lock_irqsave (&dev->lock, flags);
1724 if (dev->state == STATE_DEV_UNCONNECTED)
1725 goto exit;
1726 dev->state = STATE_DEV_UNCONNECTED;
1727
1728 INFO (dev, "disconnected\n");
1729 next_event (dev, GADGETFS_DISCONNECT);
1730 ep0_readable (dev);
1731exit:
1732 spin_unlock_irqrestore (&dev->lock, flags);
1733}
1734
1735static void
1736gadgetfs_suspend (struct usb_gadget *gadget)
1737{
1738 struct dev_data *dev = get_gadget_data (gadget);
1739 unsigned long flags;
1740
1741 INFO (dev, "suspended from state %d\n", dev->state);
1742 spin_lock_irqsave(&dev->lock, flags);
1743 switch (dev->state) {
1744 case STATE_DEV_SETUP: // VERY odd... host died??
1745 case STATE_DEV_CONNECTED:
1746 case STATE_DEV_UNCONNECTED:
1747 next_event (dev, GADGETFS_SUSPEND);
1748 ep0_readable (dev);
1749 fallthrough;
1750 default:
1751 break;
1752 }
1753 spin_unlock_irqrestore(&dev->lock, flags);
1754}
1755
1756static struct usb_gadget_driver gadgetfs_driver = {
1757 .function = (char *) driver_desc,
1758 .bind = gadgetfs_bind,
1759 .unbind = gadgetfs_unbind,
1760 .setup = gadgetfs_setup,
1761 .reset = gadgetfs_disconnect,
1762 .disconnect = gadgetfs_disconnect,
1763 .suspend = gadgetfs_suspend,
1764
1765 .driver = {
1766 .name = shortname,
1767 },
1768};
1769
1770/*----------------------------------------------------------------------*/
1771/* DEVICE INITIALIZATION
1772 *
1773 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1774 * status = write (fd, descriptors, sizeof descriptors)
1775 *
1776 * That write establishes the device configuration, so the kernel can
1777 * bind to the controller ... guaranteeing it can handle enumeration
1778 * at all necessary speeds. Descriptor order is:
1779 *
1780 * . message tag (u32, host order) ... for now, must be zero; it
1781 * would change to support features like multi-config devices
1782 * . full/low speed config ... all wTotalLength bytes (with interface,
1783 * class, altsetting, endpoint, and other descriptors)
1784 * . high speed config ... all descriptors, for high speed operation;
1785 * this one's optional except for high-speed hardware
1786 * . device descriptor
1787 *
1788 * Endpoints are not yet enabled. Drivers must wait until device
1789 * configuration and interface altsetting changes create
1790 * the need to configure (or unconfigure) them.
1791 *
1792 * After initialization, the device stays active for as long as that
1793 * $CHIP file is open. Events must then be read from that descriptor,
1794 * such as configuration notifications.
1795 */
1796
1797static int is_valid_config(struct usb_config_descriptor *config,
1798 unsigned int total)
1799{
1800 return config->bDescriptorType == USB_DT_CONFIG
1801 && config->bLength == USB_DT_CONFIG_SIZE
1802 && total >= USB_DT_CONFIG_SIZE
1803 && config->bConfigurationValue != 0
1804 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1805 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1806 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1807 /* FIXME check lengths: walk to end */
1808}
1809
1810static ssize_t
1811dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1812{
1813 struct dev_data *dev = fd->private_data;
1814 ssize_t value, length = len;
1815 unsigned total;
1816 u32 tag;
1817 char *kbuf;
1818
1819 spin_lock_irq(&dev->lock);
1820 if (dev->state > STATE_DEV_OPENED) {
1821 value = ep0_write(fd, buf, len, ptr);
1822 spin_unlock_irq(&dev->lock);
1823 return value;
1824 }
1825 spin_unlock_irq(&dev->lock);
1826
1827 if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
1828 (len > PAGE_SIZE * 4))
1829 return -EINVAL;
1830
1831 /* we might need to change message format someday */
1832 if (copy_from_user (&tag, buf, 4))
1833 return -EFAULT;
1834 if (tag != 0)
1835 return -EINVAL;
1836 buf += 4;
1837 length -= 4;
1838
1839 kbuf = memdup_user(buf, length);
1840 if (IS_ERR(kbuf))
1841 return PTR_ERR(kbuf);
1842
1843 spin_lock_irq (&dev->lock);
1844 value = -EINVAL;
1845 if (dev->buf) {
1846 spin_unlock_irq(&dev->lock);
1847 kfree(kbuf);
1848 return value;
1849 }
1850 dev->buf = kbuf;
1851
1852 /* full or low speed config */
1853 dev->config = (void *) kbuf;
1854 total = le16_to_cpu(dev->config->wTotalLength);
1855 if (!is_valid_config(dev->config, total) ||
1856 total > length - USB_DT_DEVICE_SIZE)
1857 goto fail;
1858 kbuf += total;
1859 length -= total;
1860
1861 /* optional high speed config */
1862 if (kbuf [1] == USB_DT_CONFIG) {
1863 dev->hs_config = (void *) kbuf;
1864 total = le16_to_cpu(dev->hs_config->wTotalLength);
1865 if (!is_valid_config(dev->hs_config, total) ||
1866 total > length - USB_DT_DEVICE_SIZE)
1867 goto fail;
1868 kbuf += total;
1869 length -= total;
1870 } else {
1871 dev->hs_config = NULL;
1872 }
1873
1874 /* could support multiple configs, using another encoding! */
1875
1876 /* device descriptor (tweaked for paranoia) */
1877 if (length != USB_DT_DEVICE_SIZE)
1878 goto fail;
1879 dev->dev = (void *)kbuf;
1880 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1881 || dev->dev->bDescriptorType != USB_DT_DEVICE
1882 || dev->dev->bNumConfigurations != 1)
1883 goto fail;
1884 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1885
1886 /* triggers gadgetfs_bind(); then we can enumerate. */
1887 spin_unlock_irq (&dev->lock);
1888 if (dev->hs_config)
1889 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1890 else
1891 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1892
1893 value = usb_gadget_register_driver(&gadgetfs_driver);
1894 if (value != 0) {
1895 spin_lock_irq(&dev->lock);
1896 goto fail;
1897 } else {
1898 /* at this point "good" hardware has for the first time
1899 * let the USB the host see us. alternatively, if users
1900 * unplug/replug that will clear all the error state.
1901 *
1902 * note: everything running before here was guaranteed
1903 * to choke driver model style diagnostics. from here
1904 * on, they can work ... except in cleanup paths that
1905 * kick in after the ep0 descriptor is closed.
1906 */
1907 value = len;
1908 dev->gadget_registered = true;
1909 }
1910 return value;
1911
1912fail:
1913 dev->config = NULL;
1914 dev->hs_config = NULL;
1915 dev->dev = NULL;
1916 spin_unlock_irq (&dev->lock);
1917 pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev);
1918 kfree (dev->buf);
1919 dev->buf = NULL;
1920 return value;
1921}
1922
1923static int
1924gadget_dev_open (struct inode *inode, struct file *fd)
1925{
1926 struct dev_data *dev = inode->i_private;
1927 int value = -EBUSY;
1928
1929 spin_lock_irq(&dev->lock);
1930 if (dev->state == STATE_DEV_DISABLED) {
1931 dev->ev_next = 0;
1932 dev->state = STATE_DEV_OPENED;
1933 fd->private_data = dev;
1934 get_dev (dev);
1935 value = 0;
1936 }
1937 spin_unlock_irq(&dev->lock);
1938 return value;
1939}
1940
1941static const struct file_operations ep0_operations = {
1942 .llseek = no_llseek,
1943
1944 .open = gadget_dev_open,
1945 .read = ep0_read,
1946 .write = dev_config,
1947 .fasync = ep0_fasync,
1948 .poll = ep0_poll,
1949 .unlocked_ioctl = gadget_dev_ioctl,
1950 .release = dev_release,
1951};
1952
1953/*----------------------------------------------------------------------*/
1954
1955/* FILESYSTEM AND SUPERBLOCK OPERATIONS
1956 *
1957 * Mounting the filesystem creates a controller file, used first for
1958 * device configuration then later for event monitoring.
1959 */
1960
1961
1962/* FIXME PAM etc could set this security policy without mount options
1963 * if epfiles inherited ownership and permissons from ep0 ...
1964 */
1965
1966static unsigned default_uid;
1967static unsigned default_gid;
1968static unsigned default_perm = S_IRUSR | S_IWUSR;
1969
1970module_param (default_uid, uint, 0644);
1971module_param (default_gid, uint, 0644);
1972module_param (default_perm, uint, 0644);
1973
1974
1975static struct inode *
1976gadgetfs_make_inode (struct super_block *sb,
1977 void *data, const struct file_operations *fops,
1978 int mode)
1979{
1980 struct inode *inode = new_inode (sb);
1981
1982 if (inode) {
1983 inode->i_ino = get_next_ino();
1984 inode->i_mode = mode;
1985 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1986 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1987 simple_inode_init_ts(inode);
1988 inode->i_private = data;
1989 inode->i_fop = fops;
1990 }
1991 return inode;
1992}
1993
1994/* creates in fs root directory, so non-renamable and non-linkable.
1995 * so inode and dentry are paired, until device reconfig.
1996 */
1997static struct dentry *
1998gadgetfs_create_file (struct super_block *sb, char const *name,
1999 void *data, const struct file_operations *fops)
2000{
2001 struct dentry *dentry;
2002 struct inode *inode;
2003
2004 dentry = d_alloc_name(sb->s_root, name);
2005 if (!dentry)
2006 return NULL;
2007
2008 inode = gadgetfs_make_inode (sb, data, fops,
2009 S_IFREG | (default_perm & S_IRWXUGO));
2010 if (!inode) {
2011 dput(dentry);
2012 return NULL;
2013 }
2014 d_add (dentry, inode);
2015 return dentry;
2016}
2017
2018static const struct super_operations gadget_fs_operations = {
2019 .statfs = simple_statfs,
2020 .drop_inode = generic_delete_inode,
2021};
2022
2023static int
2024gadgetfs_fill_super (struct super_block *sb, struct fs_context *fc)
2025{
2026 struct inode *inode;
2027 struct dev_data *dev;
2028 int rc;
2029
2030 mutex_lock(&sb_mutex);
2031
2032 if (the_device) {
2033 rc = -ESRCH;
2034 goto Done;
2035 }
2036
2037 CHIP = usb_get_gadget_udc_name();
2038 if (!CHIP) {
2039 rc = -ENODEV;
2040 goto Done;
2041 }
2042
2043 /* superblock */
2044 sb->s_blocksize = PAGE_SIZE;
2045 sb->s_blocksize_bits = PAGE_SHIFT;
2046 sb->s_magic = GADGETFS_MAGIC;
2047 sb->s_op = &gadget_fs_operations;
2048 sb->s_time_gran = 1;
2049
2050 /* root inode */
2051 inode = gadgetfs_make_inode (sb,
2052 NULL, &simple_dir_operations,
2053 S_IFDIR | S_IRUGO | S_IXUGO);
2054 if (!inode)
2055 goto Enomem;
2056 inode->i_op = &simple_dir_inode_operations;
2057 if (!(sb->s_root = d_make_root (inode)))
2058 goto Enomem;
2059
2060 /* the ep0 file is named after the controller we expect;
2061 * user mode code can use it for sanity checks, like we do.
2062 */
2063 dev = dev_new ();
2064 if (!dev)
2065 goto Enomem;
2066
2067 dev->sb = sb;
2068 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2069 if (!dev->dentry) {
2070 put_dev(dev);
2071 goto Enomem;
2072 }
2073
2074 /* other endpoint files are available after hardware setup,
2075 * from binding to a controller.
2076 */
2077 the_device = dev;
2078 rc = 0;
2079 goto Done;
2080
2081 Enomem:
2082 kfree(CHIP);
2083 CHIP = NULL;
2084 rc = -ENOMEM;
2085
2086 Done:
2087 mutex_unlock(&sb_mutex);
2088 return rc;
2089}
2090
2091/* "mount -t gadgetfs path /dev/gadget" ends up here */
2092static int gadgetfs_get_tree(struct fs_context *fc)
2093{
2094 return get_tree_single(fc, gadgetfs_fill_super);
2095}
2096
2097static const struct fs_context_operations gadgetfs_context_ops = {
2098 .get_tree = gadgetfs_get_tree,
2099};
2100
2101static int gadgetfs_init_fs_context(struct fs_context *fc)
2102{
2103 fc->ops = &gadgetfs_context_ops;
2104 return 0;
2105}
2106
2107static void
2108gadgetfs_kill_sb (struct super_block *sb)
2109{
2110 mutex_lock(&sb_mutex);
2111 kill_litter_super (sb);
2112 if (the_device) {
2113 put_dev (the_device);
2114 the_device = NULL;
2115 }
2116 kfree(CHIP);
2117 CHIP = NULL;
2118 mutex_unlock(&sb_mutex);
2119}
2120
2121/*----------------------------------------------------------------------*/
2122
2123static struct file_system_type gadgetfs_type = {
2124 .owner = THIS_MODULE,
2125 .name = shortname,
2126 .init_fs_context = gadgetfs_init_fs_context,
2127 .kill_sb = gadgetfs_kill_sb,
2128};
2129MODULE_ALIAS_FS("gadgetfs");
2130
2131/*----------------------------------------------------------------------*/
2132
2133static int __init gadgetfs_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 (gadgetfs_init);
2144
2145static void __exit gadgetfs_cleanup (void)
2146{
2147 pr_debug ("unregister %s\n", shortname);
2148 unregister_filesystem (&gadgetfs_type);
2149}
2150module_exit (gadgetfs_cleanup);
2151