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