1 // SPDX-License-Identifier: GPL-2.0+
3 * inode.c -- user mode filesystem api for usb gadget controllers
5 * Copyright (C) 2003-2004 David Brownell
6 * Copyright (C) 2003 Agilent Technologies
10 /* #define VERBOSE_DEBUG */
12 #include <linux/init.h>
13 #include <linux/module.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>
32 #include <linux/usb/gadgetfs.h>
33 #include <linux/usb/gadget.h>
37 * The gadgetfs API maps each endpoint to a file descriptor so that you
38 * can use standard synchronous read/write calls for I/O. There's some
39 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
40 * drivers show how this works in practice. You can also use AIO to
41 * eliminate I/O gaps between requests, to help when streaming data.
43 * Key parts that must be USB-specific are protocols defining how the
44 * read/write operations relate to the hardware state machines. There
45 * are two types of files. One type is for the device, implementing ep0.
46 * The other type is for each IN or OUT endpoint. In both cases, the
47 * user mode driver must configure the hardware before using it.
49 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
50 * (by writing configuration and device descriptors). Afterwards it
51 * may serve as a source of device events, used to handle all control
52 * requests other than basic enumeration.
54 * - Then, after a SET_CONFIGURATION control request, ep_config() is
55 * called when each /dev/gadget/ep* file is configured (by writing
56 * endpoint descriptors). Afterwards these files are used to write()
57 * IN data or to read() OUT data. To halt the endpoint, a "wrong
58 * direction" request is issued (like reading an IN endpoint).
60 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
61 * not possible on all hardware. For example, precise fault handling with
62 * respect to data left in endpoint fifos after aborted operations; or
63 * selective clearing of endpoint halts, to implement SET_INTERFACE.
66 #define DRIVER_DESC "USB Gadget filesystem"
67 #define DRIVER_VERSION "24 Aug 2004"
69 static const char driver_desc [] = DRIVER_DESC;
70 static const char shortname [] = "gadgetfs";
72 MODULE_DESCRIPTION (DRIVER_DESC);
73 MODULE_AUTHOR ("David Brownell");
74 MODULE_LICENSE ("GPL");
76 static int ep_open(struct inode *, struct file *);
79 /*----------------------------------------------------------------------*/
81 #define GADGETFS_MAGIC 0xaee71ee7
83 /* /dev/gadget/$CHIP represents ep0 and the whole device */
85 /* DISABLED is the initial state. */
86 STATE_DEV_DISABLED = 0,
88 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
89 * ep0/device i/o modes and binding to the controller. Driver
90 * must always write descriptors to initialize the device, then
91 * the device becomes UNCONNECTED until enumeration.
95 /* From then on, ep0 fd is in either of two basic modes:
96 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
97 * - SETUP: read/write will transfer control data and succeed;
98 * or if "wrong direction", performs protocol stall
100 STATE_DEV_UNCONNECTED,
104 /* UNBOUND means the driver closed ep0, so the device won't be
105 * accessible again (DEV_DISABLED) until all fds are closed.
110 /* enough for the whole queue: most events invalidate others */
113 #define RBUF_SIZE 256
119 enum ep0_state state; /* P: lock */
120 struct usb_gadgetfs_event event [N_EVENT];
122 struct fasync_struct *fasync;
125 /* drivers reading ep0 MUST handle control requests (SETUP)
126 * reported that way; else the host will time out.
128 unsigned usermode_setup : 1,
134 gadget_registered : 1;
135 unsigned setup_wLength;
137 /* the rest is basically write-once */
138 struct usb_config_descriptor *config, *hs_config;
139 struct usb_device_descriptor *dev;
140 struct usb_request *req;
141 struct usb_gadget *gadget;
142 struct list_head epfiles;
144 wait_queue_head_t wait;
145 struct super_block *sb;
146 struct dentry *dentry;
148 /* except this scratch i/o buffer for ep0 */
152 static inline void get_dev (struct dev_data *data)
154 refcount_inc (&data->count);
157 static void put_dev (struct dev_data *data)
159 if (likely (!refcount_dec_and_test (&data->count)))
161 /* needs no more cleanup */
162 BUG_ON (waitqueue_active (&data->wait));
166 static struct dev_data *dev_new (void)
168 struct dev_data *dev;
170 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
173 dev->state = STATE_DEV_DISABLED;
174 refcount_set (&dev->count, 1);
175 spin_lock_init (&dev->lock);
176 INIT_LIST_HEAD (&dev->epfiles);
177 init_waitqueue_head (&dev->wait);
181 /*----------------------------------------------------------------------*/
183 /* other /dev/gadget/$ENDPOINT files represent endpoints */
185 STATE_EP_DISABLED = 0,
195 struct dev_data *dev;
196 /* must hold dev->lock before accessing ep or req */
198 struct usb_request *req;
201 struct usb_endpoint_descriptor desc, hs_desc;
202 struct list_head epfiles;
203 wait_queue_head_t wait;
204 struct dentry *dentry;
207 static inline void get_ep (struct ep_data *data)
209 refcount_inc (&data->count);
212 static void put_ep (struct ep_data *data)
214 if (likely (!refcount_dec_and_test (&data->count)))
217 /* needs no more cleanup */
218 BUG_ON (!list_empty (&data->epfiles));
219 BUG_ON (waitqueue_active (&data->wait));
223 /*----------------------------------------------------------------------*/
225 /* most "how to use the hardware" policy choices are in userspace:
226 * mapping endpoint roles (which the driver needs) to the capabilities
227 * which the usb controller has. most of those capabilities are exposed
228 * implicitly, starting with the driver name and then endpoint names.
231 static const char *CHIP;
233 /*----------------------------------------------------------------------*/
235 /* NOTE: don't use dev_printk calls before binding to the gadget
236 * at the end of ep0 configuration, or after unbind.
239 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
240 #define xprintk(d,level,fmt,args...) \
241 printk(level "%s: " fmt , shortname , ## args)
244 #define DBG(dev,fmt,args...) \
245 xprintk(dev , KERN_DEBUG , fmt , ## args)
247 #define DBG(dev,fmt,args...) \
254 #define VDEBUG(dev,fmt,args...) \
258 #define ERROR(dev,fmt,args...) \
259 xprintk(dev , KERN_ERR , fmt , ## args)
260 #define INFO(dev,fmt,args...) \
261 xprintk(dev , KERN_INFO , fmt , ## args)
264 /*----------------------------------------------------------------------*/
266 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
268 * After opening, configure non-control endpoints. Then use normal
269 * stream read() and write() requests; and maybe ioctl() to get more
270 * precise FIFO status when recovering from cancellation.
273 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
275 struct ep_data *epdata = ep->driver_data;
280 epdata->status = req->status;
282 epdata->status = req->actual;
283 complete ((struct completion *)req->context);
286 /* tasklock endpoint, returning when it's connected.
287 * still need dev->lock to use epdata->ep.
290 get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
294 if (f_flags & O_NONBLOCK) {
295 if (!mutex_trylock(&epdata->lock))
297 if (epdata->state != STATE_EP_ENABLED &&
298 (!is_write || epdata->state != STATE_EP_READY)) {
299 mutex_unlock(&epdata->lock);
307 val = mutex_lock_interruptible(&epdata->lock);
311 switch (epdata->state) {
312 case STATE_EP_ENABLED:
314 case STATE_EP_READY: /* not configured yet */
318 case STATE_EP_UNBOUND: /* clean disconnect */
320 // case STATE_EP_DISABLED: /* "can't happen" */
321 default: /* error! */
322 pr_debug ("%s: ep %p not available, state %d\n",
323 shortname, epdata, epdata->state);
325 mutex_unlock(&epdata->lock);
330 ep_io (struct ep_data *epdata, void *buf, unsigned len)
332 DECLARE_COMPLETION_ONSTACK (done);
335 spin_lock_irq (&epdata->dev->lock);
336 if (likely (epdata->ep != NULL)) {
337 struct usb_request *req = epdata->req;
339 req->context = &done;
340 req->complete = epio_complete;
343 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
346 spin_unlock_irq (&epdata->dev->lock);
348 if (likely (value == 0)) {
349 value = wait_for_completion_interruptible(&done);
351 spin_lock_irq (&epdata->dev->lock);
352 if (likely (epdata->ep != NULL)) {
353 DBG (epdata->dev, "%s i/o interrupted\n",
355 usb_ep_dequeue (epdata->ep, epdata->req);
356 spin_unlock_irq (&epdata->dev->lock);
358 wait_for_completion(&done);
359 if (epdata->status == -ECONNRESET)
360 epdata->status = -EINTR;
362 spin_unlock_irq (&epdata->dev->lock);
364 DBG (epdata->dev, "endpoint gone\n");
365 epdata->status = -ENODEV;
368 return epdata->status;
374 ep_release (struct inode *inode, struct file *fd)
376 struct ep_data *data = fd->private_data;
379 value = mutex_lock_interruptible(&data->lock);
383 /* clean up if this can be reopened */
384 if (data->state != STATE_EP_UNBOUND) {
385 data->state = STATE_EP_DISABLED;
386 data->desc.bDescriptorType = 0;
387 data->hs_desc.bDescriptorType = 0;
388 usb_ep_disable(data->ep);
390 mutex_unlock(&data->lock);
395 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
397 struct ep_data *data = fd->private_data;
400 if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
403 spin_lock_irq (&data->dev->lock);
404 if (likely (data->ep != NULL)) {
406 case GADGETFS_FIFO_STATUS:
407 status = usb_ep_fifo_status (data->ep);
409 case GADGETFS_FIFO_FLUSH:
410 usb_ep_fifo_flush (data->ep);
412 case GADGETFS_CLEAR_HALT:
413 status = usb_ep_clear_halt (data->ep);
420 spin_unlock_irq (&data->dev->lock);
421 mutex_unlock(&data->lock);
425 /*----------------------------------------------------------------------*/
427 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
430 struct usb_request *req;
431 struct ep_data *epdata;
433 struct mm_struct *mm;
434 struct work_struct work;
441 static int ep_aio_cancel(struct kiocb *iocb)
443 struct kiocb_priv *priv = iocb->private;
444 struct ep_data *epdata;
448 epdata = priv->epdata;
449 // spin_lock(&epdata->dev->lock);
450 if (likely(epdata && epdata->ep && priv->req))
451 value = usb_ep_dequeue (epdata->ep, priv->req);
454 // spin_unlock(&epdata->dev->lock);
460 static void ep_user_copy_worker(struct work_struct *work)
462 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
463 struct mm_struct *mm = priv->mm;
464 struct kiocb *iocb = priv->iocb;
468 ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
469 kthread_unuse_mm(mm);
473 /* completing the iocb can drop the ctx and mm, don't touch mm after */
474 iocb->ki_complete(iocb, ret);
477 kfree(priv->to_free);
481 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
483 struct kiocb *iocb = req->context;
484 struct kiocb_priv *priv = iocb->private;
485 struct ep_data *epdata = priv->epdata;
487 /* lock against disconnect (and ideally, cancel) */
488 spin_lock(&epdata->dev->lock);
492 /* if this was a write or a read returning no data then we
493 * don't need to copy anything to userspace, so we can
494 * complete the aio request immediately.
496 if (priv->to_free == NULL || unlikely(req->actual == 0)) {
498 kfree(priv->to_free);
500 iocb->private = NULL;
501 iocb->ki_complete(iocb,
502 req->actual ? req->actual : (long)req->status);
504 /* ep_copy_to_user() won't report both; we hide some faults */
505 if (unlikely(0 != req->status))
506 DBG(epdata->dev, "%s fault %d len %d\n",
507 ep->name, req->status, req->actual);
509 priv->buf = req->buf;
510 priv->actual = req->actual;
511 INIT_WORK(&priv->work, ep_user_copy_worker);
512 schedule_work(&priv->work);
515 usb_ep_free_request(ep, req);
516 spin_unlock(&epdata->dev->lock);
520 static ssize_t ep_aio(struct kiocb *iocb,
521 struct kiocb_priv *priv,
522 struct ep_data *epdata,
526 struct usb_request *req;
529 iocb->private = priv;
532 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
534 priv->epdata = epdata;
536 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
538 /* each kiocb is coupled to one usb_request, but we can't
539 * allocate or submit those if the host disconnected.
541 spin_lock_irq(&epdata->dev->lock);
543 if (unlikely(epdata->ep == NULL))
546 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
554 req->complete = ep_aio_complete;
556 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
557 if (unlikely(0 != value)) {
558 usb_ep_free_request(epdata->ep, req);
561 spin_unlock_irq(&epdata->dev->lock);
565 spin_unlock_irq(&epdata->dev->lock);
566 kfree(priv->to_free);
573 ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
575 struct file *file = iocb->ki_filp;
576 struct ep_data *epdata = file->private_data;
577 size_t len = iov_iter_count(to);
581 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
584 /* halt any endpoint by doing a "wrong direction" i/o call */
585 if (usb_endpoint_dir_in(&epdata->desc)) {
586 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
587 !is_sync_kiocb(iocb)) {
588 mutex_unlock(&epdata->lock);
591 DBG (epdata->dev, "%s halt\n", epdata->name);
592 spin_lock_irq(&epdata->dev->lock);
593 if (likely(epdata->ep != NULL))
594 usb_ep_set_halt(epdata->ep);
595 spin_unlock_irq(&epdata->dev->lock);
596 mutex_unlock(&epdata->lock);
600 buf = kmalloc(len, GFP_KERNEL);
601 if (unlikely(!buf)) {
602 mutex_unlock(&epdata->lock);
605 if (is_sync_kiocb(iocb)) {
606 value = ep_io(epdata, buf, len);
607 if (value >= 0 && (copy_to_iter(buf, value, to) != value))
610 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
614 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
615 if (!priv->to_free) {
619 value = ep_aio(iocb, priv, epdata, buf, len);
620 if (value == -EIOCBQUEUED)
625 mutex_unlock(&epdata->lock);
629 static ssize_t ep_config(struct ep_data *, const char *, size_t);
632 ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
634 struct file *file = iocb->ki_filp;
635 struct ep_data *epdata = file->private_data;
636 size_t len = iov_iter_count(from);
641 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
644 configured = epdata->state == STATE_EP_ENABLED;
646 /* halt any endpoint by doing a "wrong direction" i/o call */
647 if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
648 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
649 !is_sync_kiocb(iocb)) {
650 mutex_unlock(&epdata->lock);
653 DBG (epdata->dev, "%s halt\n", epdata->name);
654 spin_lock_irq(&epdata->dev->lock);
655 if (likely(epdata->ep != NULL))
656 usb_ep_set_halt(epdata->ep);
657 spin_unlock_irq(&epdata->dev->lock);
658 mutex_unlock(&epdata->lock);
662 buf = kmalloc(len, GFP_KERNEL);
663 if (unlikely(!buf)) {
664 mutex_unlock(&epdata->lock);
668 if (unlikely(!copy_from_iter_full(buf, len, from))) {
673 if (unlikely(!configured)) {
674 value = ep_config(epdata, buf, len);
675 } else if (is_sync_kiocb(iocb)) {
676 value = ep_io(epdata, buf, len);
678 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
681 value = ep_aio(iocb, priv, epdata, buf, len);
682 if (value == -EIOCBQUEUED)
688 mutex_unlock(&epdata->lock);
692 /*----------------------------------------------------------------------*/
694 /* used after endpoint configuration */
695 static const struct file_operations ep_io_operations = {
696 .owner = THIS_MODULE,
699 .release = ep_release,
701 .unlocked_ioctl = ep_ioctl,
702 .read_iter = ep_read_iter,
703 .write_iter = ep_write_iter,
706 /* ENDPOINT INITIALIZATION
708 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
709 * status = write (fd, descriptors, sizeof descriptors)
711 * That write establishes the endpoint configuration, configuring
712 * the controller to process bulk, interrupt, or isochronous transfers
713 * at the right maxpacket size, and so on.
715 * The descriptors are message type 1, identified by a host order u32
716 * at the beginning of what's written. Descriptor order is: full/low
717 * speed descriptor, then optional high speed descriptor.
720 ep_config (struct ep_data *data, const char *buf, size_t len)
724 int value, length = len;
726 if (data->state != STATE_EP_READY) {
732 if (len < USB_DT_ENDPOINT_SIZE + 4)
735 /* we might need to change message format someday */
736 memcpy(&tag, buf, 4);
738 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
744 /* NOTE: audio endpoint extensions not accepted here;
745 * just don't include the extra bytes.
748 /* full/low speed descriptor, then high speed */
749 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
750 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
751 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
753 if (len != USB_DT_ENDPOINT_SIZE) {
754 if (len != 2 * USB_DT_ENDPOINT_SIZE)
756 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
757 USB_DT_ENDPOINT_SIZE);
758 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
759 || data->hs_desc.bDescriptorType
760 != USB_DT_ENDPOINT) {
761 DBG(data->dev, "config %s, bad hs length or type\n",
767 spin_lock_irq (&data->dev->lock);
768 if (data->dev->state == STATE_DEV_UNBOUND) {
778 switch (data->dev->gadget->speed) {
781 ep->desc = &data->desc;
784 /* fails if caller didn't provide that descriptor... */
785 ep->desc = &data->hs_desc;
788 DBG(data->dev, "unconnected, %s init abandoned\n",
793 value = usb_ep_enable(ep);
795 data->state = STATE_EP_ENABLED;
799 spin_unlock_irq (&data->dev->lock);
802 data->desc.bDescriptorType = 0;
803 data->hs_desc.bDescriptorType = 0;
812 ep_open (struct inode *inode, struct file *fd)
814 struct ep_data *data = inode->i_private;
817 if (mutex_lock_interruptible(&data->lock) != 0)
819 spin_lock_irq (&data->dev->lock);
820 if (data->dev->state == STATE_DEV_UNBOUND)
822 else if (data->state == STATE_EP_DISABLED) {
824 data->state = STATE_EP_READY;
826 fd->private_data = data;
827 VDEBUG (data->dev, "%s ready\n", data->name);
829 DBG (data->dev, "%s state %d\n",
830 data->name, data->state);
831 spin_unlock_irq (&data->dev->lock);
832 mutex_unlock(&data->lock);
836 /*----------------------------------------------------------------------*/
838 /* EP0 IMPLEMENTATION can be partly in userspace.
840 * Drivers that use this facility receive various events, including
841 * control requests the kernel doesn't handle. Drivers that don't
842 * use this facility may be too simple-minded for real applications.
845 static inline void ep0_readable (struct dev_data *dev)
847 wake_up (&dev->wait);
848 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
851 static void clean_req (struct usb_ep *ep, struct usb_request *req)
853 struct dev_data *dev = ep->driver_data;
855 if (req->buf != dev->rbuf) {
857 req->buf = dev->rbuf;
859 req->complete = epio_complete;
860 dev->setup_out_ready = 0;
863 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
865 struct dev_data *dev = ep->driver_data;
869 /* for control OUT, data must still get to userspace */
870 spin_lock_irqsave(&dev->lock, flags);
871 if (!dev->setup_in) {
872 dev->setup_out_error = (req->status != 0);
873 if (!dev->setup_out_error)
875 dev->setup_out_ready = 1;
879 /* clean up as appropriate */
880 if (free && req->buf != &dev->rbuf)
882 req->complete = epio_complete;
883 spin_unlock_irqrestore(&dev->lock, flags);
886 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
888 struct dev_data *dev = ep->driver_data;
890 if (dev->setup_out_ready) {
891 DBG (dev, "ep0 request busy!\n");
894 if (len > sizeof (dev->rbuf))
895 req->buf = kmalloc(len, GFP_ATOMIC);
896 if (req->buf == NULL) {
897 req->buf = dev->rbuf;
900 req->complete = ep0_complete;
907 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
909 struct dev_data *dev = fd->private_data;
911 enum ep0_state state;
913 spin_lock_irq (&dev->lock);
914 if (dev->state <= STATE_DEV_OPENED) {
919 /* report fd mode change before acting on it */
920 if (dev->setup_abort) {
921 dev->setup_abort = 0;
926 /* control DATA stage */
927 if ((state = dev->state) == STATE_DEV_SETUP) {
929 if (dev->setup_in) { /* stall IN */
930 VDEBUG(dev, "ep0in stall\n");
931 (void) usb_ep_set_halt (dev->gadget->ep0);
933 dev->state = STATE_DEV_CONNECTED;
935 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
936 struct usb_ep *ep = dev->gadget->ep0;
937 struct usb_request *req = dev->req;
939 if ((retval = setup_req (ep, req, 0)) == 0) {
941 spin_unlock_irq (&dev->lock);
942 retval = usb_ep_queue (ep, req, GFP_KERNEL);
943 spin_lock_irq (&dev->lock);
946 dev->state = STATE_DEV_CONNECTED;
948 /* assume that was SET_CONFIGURATION */
949 if (dev->current_config) {
952 if (gadget_is_dualspeed(dev->gadget)
953 && (dev->gadget->speed
955 power = dev->hs_config->bMaxPower;
957 power = dev->config->bMaxPower;
958 usb_gadget_vbus_draw(dev->gadget, 2 * power);
961 } else { /* collect OUT data */
962 if ((fd->f_flags & O_NONBLOCK) != 0
963 && !dev->setup_out_ready) {
967 spin_unlock_irq (&dev->lock);
968 retval = wait_event_interruptible (dev->wait,
969 dev->setup_out_ready != 0);
971 /* FIXME state could change from under us */
972 spin_lock_irq (&dev->lock);
976 if (dev->state != STATE_DEV_SETUP) {
980 dev->state = STATE_DEV_CONNECTED;
982 if (dev->setup_out_error)
985 len = min (len, (size_t)dev->req->actual);
987 spin_unlock_irq(&dev->lock);
988 if (copy_to_user (buf, dev->req->buf, len))
992 spin_lock_irq(&dev->lock);
994 clean_req (dev->gadget->ep0, dev->req);
995 /* NOTE userspace can't yet choose to stall */
1001 /* else normal: return event data */
1002 if (len < sizeof dev->event [0]) {
1006 len -= len % sizeof (struct usb_gadgetfs_event);
1007 dev->usermode_setup = 1;
1010 /* return queued events right away */
1011 if (dev->ev_next != 0) {
1014 n = len / sizeof (struct usb_gadgetfs_event);
1015 if (dev->ev_next < n)
1018 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1019 for (i = 0; i < n; i++) {
1020 if (dev->event [i].type == GADGETFS_SETUP) {
1021 dev->state = STATE_DEV_SETUP;
1026 spin_unlock_irq (&dev->lock);
1027 len = n * sizeof (struct usb_gadgetfs_event);
1028 if (copy_to_user (buf, &dev->event, len))
1033 /* NOTE this doesn't guard against broken drivers;
1034 * concurrent ep0 readers may lose events.
1036 spin_lock_irq (&dev->lock);
1037 if (dev->ev_next > n) {
1038 memmove(&dev->event[0], &dev->event[n],
1039 sizeof (struct usb_gadgetfs_event)
1040 * (dev->ev_next - n));
1043 spin_unlock_irq (&dev->lock);
1047 if (fd->f_flags & O_NONBLOCK) {
1054 DBG (dev, "fail %s, state %d\n", __func__, state);
1057 case STATE_DEV_UNCONNECTED:
1058 case STATE_DEV_CONNECTED:
1059 spin_unlock_irq (&dev->lock);
1060 DBG (dev, "%s wait\n", __func__);
1062 /* wait for events */
1063 retval = wait_event_interruptible (dev->wait,
1067 spin_lock_irq (&dev->lock);
1072 spin_unlock_irq (&dev->lock);
1076 static struct usb_gadgetfs_event *
1077 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1079 struct usb_gadgetfs_event *event;
1083 /* these events purge the queue */
1084 case GADGETFS_DISCONNECT:
1085 if (dev->state == STATE_DEV_SETUP)
1086 dev->setup_abort = 1;
1088 case GADGETFS_CONNECT:
1091 case GADGETFS_SETUP: /* previous request timed out */
1092 case GADGETFS_SUSPEND: /* same effect */
1093 /* these events can't be repeated */
1094 for (i = 0; i != dev->ev_next; i++) {
1095 if (dev->event [i].type != type)
1097 DBG(dev, "discard old event[%d] %d\n", i, type);
1099 if (i == dev->ev_next)
1101 /* indices start at zero, for simplicity */
1102 memmove (&dev->event [i], &dev->event [i + 1],
1103 sizeof (struct usb_gadgetfs_event)
1104 * (dev->ev_next - i));
1110 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1111 event = &dev->event [dev->ev_next++];
1112 BUG_ON (dev->ev_next > N_EVENT);
1113 memset (event, 0, sizeof *event);
1119 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1121 struct dev_data *dev = fd->private_data;
1122 ssize_t retval = -ESRCH;
1124 /* report fd mode change before acting on it */
1125 if (dev->setup_abort) {
1126 dev->setup_abort = 0;
1129 /* data and/or status stage for control request */
1130 } else if (dev->state == STATE_DEV_SETUP) {
1132 len = min_t(size_t, len, dev->setup_wLength);
1133 if (dev->setup_in) {
1134 retval = setup_req (dev->gadget->ep0, dev->req, len);
1136 dev->state = STATE_DEV_CONNECTED;
1138 spin_unlock_irq (&dev->lock);
1139 if (copy_from_user (dev->req->buf, buf, len))
1142 if (len < dev->setup_wLength)
1144 retval = usb_ep_queue (
1145 dev->gadget->ep0, dev->req,
1148 spin_lock_irq(&dev->lock);
1151 clean_req (dev->gadget->ep0, dev->req);
1158 /* can stall some OUT transfers */
1159 } else if (dev->setup_can_stall) {
1160 VDEBUG(dev, "ep0out stall\n");
1161 (void) usb_ep_set_halt (dev->gadget->ep0);
1163 dev->state = STATE_DEV_CONNECTED;
1165 DBG(dev, "bogus ep0out stall!\n");
1168 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1174 ep0_fasync (int f, struct file *fd, int on)
1176 struct dev_data *dev = fd->private_data;
1177 // caller must F_SETOWN before signal delivery happens
1178 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1179 return fasync_helper (f, fd, on, &dev->fasync);
1182 static struct usb_gadget_driver gadgetfs_driver;
1185 dev_release (struct inode *inode, struct file *fd)
1187 struct dev_data *dev = fd->private_data;
1189 /* closing ep0 === shutdown all */
1191 if (dev->gadget_registered) {
1192 usb_gadget_unregister_driver (&gadgetfs_driver);
1193 dev->gadget_registered = false;
1196 /* at this point "good" hardware has disconnected the
1197 * device from USB; the host won't see it any more.
1198 * alternatively, all host requests will time out.
1204 /* other endpoints were all decoupled from this device */
1205 spin_lock_irq(&dev->lock);
1206 dev->state = STATE_DEV_DISABLED;
1207 spin_unlock_irq(&dev->lock);
1214 ep0_poll (struct file *fd, poll_table *wait)
1216 struct dev_data *dev = fd->private_data;
1219 if (dev->state <= STATE_DEV_OPENED)
1220 return DEFAULT_POLLMASK;
1222 poll_wait(fd, &dev->wait, wait);
1224 spin_lock_irq(&dev->lock);
1226 /* report fd mode change before acting on it */
1227 if (dev->setup_abort) {
1228 dev->setup_abort = 0;
1233 if (dev->state == STATE_DEV_SETUP) {
1234 if (dev->setup_in || dev->setup_can_stall)
1237 if (dev->ev_next != 0)
1241 spin_unlock_irq(&dev->lock);
1245 static long gadget_dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1247 struct dev_data *dev = fd->private_data;
1248 struct usb_gadget *gadget = dev->gadget;
1251 spin_lock_irq(&dev->lock);
1252 if (dev->state == STATE_DEV_OPENED ||
1253 dev->state == STATE_DEV_UNBOUND) {
1254 /* Not bound to a UDC */
1255 } else if (gadget->ops->ioctl) {
1257 spin_unlock_irq(&dev->lock);
1259 ret = gadget->ops->ioctl (gadget, code, value);
1261 spin_lock_irq(&dev->lock);
1264 spin_unlock_irq(&dev->lock);
1269 /*----------------------------------------------------------------------*/
1271 /* The in-kernel gadget driver handles most ep0 issues, in particular
1272 * enumerating the single configuration (as provided from user space).
1274 * Unrecognized ep0 requests may be handled in user space.
1277 static void make_qualifier (struct dev_data *dev)
1279 struct usb_qualifier_descriptor qual;
1280 struct usb_device_descriptor *desc;
1282 qual.bLength = sizeof qual;
1283 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1284 qual.bcdUSB = cpu_to_le16 (0x0200);
1287 qual.bDeviceClass = desc->bDeviceClass;
1288 qual.bDeviceSubClass = desc->bDeviceSubClass;
1289 qual.bDeviceProtocol = desc->bDeviceProtocol;
1291 /* assumes ep0 uses the same value for both speeds ... */
1292 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1294 qual.bNumConfigurations = 1;
1297 memcpy (dev->rbuf, &qual, sizeof qual);
1301 config_buf (struct dev_data *dev, u8 type, unsigned index)
1306 /* only one configuration */
1310 if (gadget_is_dualspeed(dev->gadget)) {
1311 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1312 if (type == USB_DT_OTHER_SPEED_CONFIG)
1316 dev->req->buf = dev->hs_config;
1317 len = le16_to_cpu(dev->hs_config->wTotalLength);
1319 dev->req->buf = dev->config;
1320 len = le16_to_cpu(dev->config->wTotalLength);
1322 ((u8 *)dev->req->buf) [1] = type;
1327 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1329 struct dev_data *dev = get_gadget_data (gadget);
1330 struct usb_request *req = dev->req;
1331 int value = -EOPNOTSUPP;
1332 struct usb_gadgetfs_event *event;
1333 u16 w_value = le16_to_cpu(ctrl->wValue);
1334 u16 w_length = le16_to_cpu(ctrl->wLength);
1336 if (w_length > RBUF_SIZE) {
1337 if (ctrl->bRequestType & USB_DIR_IN) {
1338 /* Cast away the const, we are going to overwrite on purpose. */
1339 __le16 *temp = (__le16 *)&ctrl->wLength;
1341 *temp = cpu_to_le16(RBUF_SIZE);
1342 w_length = RBUF_SIZE;
1348 spin_lock (&dev->lock);
1349 dev->setup_abort = 0;
1350 if (dev->state == STATE_DEV_UNCONNECTED) {
1351 if (gadget_is_dualspeed(gadget)
1352 && gadget->speed == USB_SPEED_HIGH
1353 && dev->hs_config == NULL) {
1354 spin_unlock(&dev->lock);
1355 ERROR (dev, "no high speed config??\n");
1359 dev->state = STATE_DEV_CONNECTED;
1361 INFO (dev, "connected\n");
1362 event = next_event (dev, GADGETFS_CONNECT);
1363 event->u.speed = gadget->speed;
1366 /* host may have given up waiting for response. we can miss control
1367 * requests handled lower down (device/endpoint status and features);
1368 * then ep0_{read,write} will report the wrong status. controller
1369 * driver will have aborted pending i/o.
1371 } else if (dev->state == STATE_DEV_SETUP)
1372 dev->setup_abort = 1;
1374 req->buf = dev->rbuf;
1375 req->context = NULL;
1376 switch (ctrl->bRequest) {
1378 case USB_REQ_GET_DESCRIPTOR:
1379 if (ctrl->bRequestType != USB_DIR_IN)
1381 switch (w_value >> 8) {
1384 value = min (w_length, (u16) sizeof *dev->dev);
1385 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1386 req->buf = dev->dev;
1388 case USB_DT_DEVICE_QUALIFIER:
1389 if (!dev->hs_config)
1391 value = min (w_length, (u16)
1392 sizeof (struct usb_qualifier_descriptor));
1393 make_qualifier (dev);
1395 case USB_DT_OTHER_SPEED_CONFIG:
1397 value = config_buf (dev,
1401 value = min (w_length, (u16) value);
1406 default: // all others are errors
1411 /* currently one config, two speeds */
1412 case USB_REQ_SET_CONFIGURATION:
1413 if (ctrl->bRequestType != 0)
1415 if (0 == (u8) w_value) {
1417 dev->current_config = 0;
1418 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1419 // user mode expected to disable endpoints
1423 if (gadget_is_dualspeed(gadget)
1424 && gadget->speed == USB_SPEED_HIGH) {
1425 config = dev->hs_config->bConfigurationValue;
1426 power = dev->hs_config->bMaxPower;
1428 config = dev->config->bConfigurationValue;
1429 power = dev->config->bMaxPower;
1432 if (config == (u8) w_value) {
1434 dev->current_config = config;
1435 usb_gadget_vbus_draw(gadget, 2 * power);
1439 /* report SET_CONFIGURATION like any other control request,
1440 * except that usermode may not stall this. the next
1441 * request mustn't be allowed start until this finishes:
1442 * endpoints and threads set up, etc.
1444 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1445 * has bad/racey automagic that prevents synchronizing here.
1446 * even kernel mode drivers often miss them.
1449 INFO (dev, "configuration #%d\n", dev->current_config);
1450 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1451 if (dev->usermode_setup) {
1452 dev->setup_can_stall = 0;
1458 #ifndef CONFIG_USB_PXA25X
1459 /* PXA automagically handles this request too */
1460 case USB_REQ_GET_CONFIGURATION:
1461 if (ctrl->bRequestType != 0x80)
1463 *(u8 *)req->buf = dev->current_config;
1464 value = min (w_length, (u16) 1);
1470 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1471 dev->usermode_setup ? "delegate" : "fail",
1472 ctrl->bRequestType, ctrl->bRequest,
1473 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1475 /* if there's an ep0 reader, don't stall */
1476 if (dev->usermode_setup) {
1477 dev->setup_can_stall = 1;
1479 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1481 dev->setup_wLength = w_length;
1482 dev->setup_out_ready = 0;
1483 dev->setup_out_error = 0;
1485 /* read DATA stage for OUT right away */
1486 if (unlikely (!dev->setup_in && w_length)) {
1487 value = setup_req (gadget->ep0, dev->req,
1493 spin_unlock (&dev->lock);
1494 value = usb_ep_queue (gadget->ep0, dev->req,
1496 spin_lock (&dev->lock);
1499 clean_req (gadget->ep0, dev->req);
1503 /* we can't currently stall these */
1504 dev->setup_can_stall = 0;
1507 /* state changes when reader collects event */
1508 event = next_event (dev, GADGETFS_SETUP);
1509 event->u.setup = *ctrl;
1511 spin_unlock (&dev->lock);
1516 /* proceed with data transfer and status phases? */
1517 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1518 req->length = value;
1519 req->zero = value < w_length;
1522 spin_unlock (&dev->lock);
1523 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL);
1524 spin_lock(&dev->lock);
1526 spin_unlock(&dev->lock);
1528 DBG (dev, "ep_queue --> %d\n", value);
1534 /* device stalls when value < 0 */
1535 spin_unlock (&dev->lock);
1539 static void destroy_ep_files (struct dev_data *dev)
1541 DBG (dev, "%s %d\n", __func__, dev->state);
1543 /* dev->state must prevent interference */
1544 spin_lock_irq (&dev->lock);
1545 while (!list_empty(&dev->epfiles)) {
1547 struct inode *parent;
1548 struct dentry *dentry;
1550 /* break link to FS */
1551 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1552 list_del_init (&ep->epfiles);
1553 spin_unlock_irq (&dev->lock);
1555 dentry = ep->dentry;
1557 parent = d_inode(dentry->d_parent);
1559 /* break link to controller */
1560 mutex_lock(&ep->lock);
1561 if (ep->state == STATE_EP_ENABLED)
1562 (void) usb_ep_disable (ep->ep);
1563 ep->state = STATE_EP_UNBOUND;
1564 usb_ep_free_request (ep->ep, ep->req);
1566 mutex_unlock(&ep->lock);
1568 wake_up (&ep->wait);
1571 /* break link to dcache */
1575 inode_unlock(parent);
1577 spin_lock_irq (&dev->lock);
1579 spin_unlock_irq (&dev->lock);
1583 static struct dentry *
1584 gadgetfs_create_file (struct super_block *sb, char const *name,
1585 void *data, const struct file_operations *fops);
1587 static int activate_ep_files (struct dev_data *dev)
1590 struct ep_data *data;
1592 gadget_for_each_ep (ep, dev->gadget) {
1594 data = kzalloc(sizeof(*data), GFP_KERNEL);
1597 data->state = STATE_EP_DISABLED;
1598 mutex_init(&data->lock);
1599 init_waitqueue_head (&data->wait);
1601 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1602 refcount_set (&data->count, 1);
1607 ep->driver_data = data;
1609 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1613 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1614 data, &ep_io_operations);
1617 list_add_tail (&data->epfiles, &dev->epfiles);
1622 usb_ep_free_request (ep, data->req);
1627 DBG (dev, "%s enomem\n", __func__);
1628 destroy_ep_files (dev);
1633 gadgetfs_unbind (struct usb_gadget *gadget)
1635 struct dev_data *dev = get_gadget_data (gadget);
1637 DBG (dev, "%s\n", __func__);
1639 spin_lock_irq (&dev->lock);
1640 dev->state = STATE_DEV_UNBOUND;
1641 while (dev->udc_usage > 0) {
1642 spin_unlock_irq(&dev->lock);
1643 usleep_range(1000, 2000);
1644 spin_lock_irq(&dev->lock);
1646 spin_unlock_irq (&dev->lock);
1648 destroy_ep_files (dev);
1649 gadget->ep0->driver_data = NULL;
1650 set_gadget_data (gadget, NULL);
1652 /* we've already been disconnected ... no i/o is active */
1654 usb_ep_free_request (gadget->ep0, dev->req);
1655 DBG (dev, "%s done\n", __func__);
1659 static struct dev_data *the_device;
1661 static int gadgetfs_bind(struct usb_gadget *gadget,
1662 struct usb_gadget_driver *driver)
1664 struct dev_data *dev = the_device;
1668 if (0 != strcmp (CHIP, gadget->name)) {
1669 pr_err("%s expected %s controller not %s\n",
1670 shortname, CHIP, gadget->name);
1674 set_gadget_data (gadget, dev);
1675 dev->gadget = gadget;
1676 gadget->ep0->driver_data = dev;
1678 /* preallocate control response and buffer */
1679 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1682 dev->req->context = NULL;
1683 dev->req->complete = epio_complete;
1685 if (activate_ep_files (dev) < 0)
1688 INFO (dev, "bound to %s driver\n", gadget->name);
1689 spin_lock_irq(&dev->lock);
1690 dev->state = STATE_DEV_UNCONNECTED;
1691 spin_unlock_irq(&dev->lock);
1696 gadgetfs_unbind (gadget);
1701 gadgetfs_disconnect (struct usb_gadget *gadget)
1703 struct dev_data *dev = get_gadget_data (gadget);
1704 unsigned long flags;
1706 spin_lock_irqsave (&dev->lock, flags);
1707 if (dev->state == STATE_DEV_UNCONNECTED)
1709 dev->state = STATE_DEV_UNCONNECTED;
1711 INFO (dev, "disconnected\n");
1712 next_event (dev, GADGETFS_DISCONNECT);
1715 spin_unlock_irqrestore (&dev->lock, flags);
1719 gadgetfs_suspend (struct usb_gadget *gadget)
1721 struct dev_data *dev = get_gadget_data (gadget);
1722 unsigned long flags;
1724 INFO (dev, "suspended from state %d\n", dev->state);
1725 spin_lock_irqsave(&dev->lock, flags);
1726 switch (dev->state) {
1727 case STATE_DEV_SETUP: // VERY odd... host died??
1728 case STATE_DEV_CONNECTED:
1729 case STATE_DEV_UNCONNECTED:
1730 next_event (dev, GADGETFS_SUSPEND);
1736 spin_unlock_irqrestore(&dev->lock, flags);
1739 static struct usb_gadget_driver gadgetfs_driver = {
1740 .function = (char *) driver_desc,
1741 .bind = gadgetfs_bind,
1742 .unbind = gadgetfs_unbind,
1743 .setup = gadgetfs_setup,
1744 .reset = gadgetfs_disconnect,
1745 .disconnect = gadgetfs_disconnect,
1746 .suspend = gadgetfs_suspend,
1753 /*----------------------------------------------------------------------*/
1754 /* DEVICE INITIALIZATION
1756 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1757 * status = write (fd, descriptors, sizeof descriptors)
1759 * That write establishes the device configuration, so the kernel can
1760 * bind to the controller ... guaranteeing it can handle enumeration
1761 * at all necessary speeds. Descriptor order is:
1763 * . message tag (u32, host order) ... for now, must be zero; it
1764 * would change to support features like multi-config devices
1765 * . full/low speed config ... all wTotalLength bytes (with interface,
1766 * class, altsetting, endpoint, and other descriptors)
1767 * . high speed config ... all descriptors, for high speed operation;
1768 * this one's optional except for high-speed hardware
1769 * . device descriptor
1771 * Endpoints are not yet enabled. Drivers must wait until device
1772 * configuration and interface altsetting changes create
1773 * the need to configure (or unconfigure) them.
1775 * After initialization, the device stays active for as long as that
1776 * $CHIP file is open. Events must then be read from that descriptor,
1777 * such as configuration notifications.
1780 static int is_valid_config(struct usb_config_descriptor *config,
1783 return config->bDescriptorType == USB_DT_CONFIG
1784 && config->bLength == USB_DT_CONFIG_SIZE
1785 && total >= USB_DT_CONFIG_SIZE
1786 && config->bConfigurationValue != 0
1787 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1788 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1789 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1790 /* FIXME check lengths: walk to end */
1794 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1796 struct dev_data *dev = fd->private_data;
1797 ssize_t value, length = len;
1802 spin_lock_irq(&dev->lock);
1803 if (dev->state > STATE_DEV_OPENED) {
1804 value = ep0_write(fd, buf, len, ptr);
1805 spin_unlock_irq(&dev->lock);
1808 spin_unlock_irq(&dev->lock);
1810 if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
1811 (len > PAGE_SIZE * 4))
1814 /* we might need to change message format someday */
1815 if (copy_from_user (&tag, buf, 4))
1822 kbuf = memdup_user(buf, length);
1824 return PTR_ERR(kbuf);
1826 spin_lock_irq (&dev->lock);
1829 spin_unlock_irq(&dev->lock);
1835 /* full or low speed config */
1836 dev->config = (void *) kbuf;
1837 total = le16_to_cpu(dev->config->wTotalLength);
1838 if (!is_valid_config(dev->config, total) ||
1839 total > length - USB_DT_DEVICE_SIZE)
1844 /* optional high speed config */
1845 if (kbuf [1] == USB_DT_CONFIG) {
1846 dev->hs_config = (void *) kbuf;
1847 total = le16_to_cpu(dev->hs_config->wTotalLength);
1848 if (!is_valid_config(dev->hs_config, total) ||
1849 total > length - USB_DT_DEVICE_SIZE)
1854 dev->hs_config = NULL;
1857 /* could support multiple configs, using another encoding! */
1859 /* device descriptor (tweaked for paranoia) */
1860 if (length != USB_DT_DEVICE_SIZE)
1862 dev->dev = (void *)kbuf;
1863 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1864 || dev->dev->bDescriptorType != USB_DT_DEVICE
1865 || dev->dev->bNumConfigurations != 1)
1867 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1869 /* triggers gadgetfs_bind(); then we can enumerate. */
1870 spin_unlock_irq (&dev->lock);
1872 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1874 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1876 value = usb_gadget_register_driver(&gadgetfs_driver);
1878 spin_lock_irq(&dev->lock);
1881 /* at this point "good" hardware has for the first time
1882 * let the USB the host see us. alternatively, if users
1883 * unplug/replug that will clear all the error state.
1885 * note: everything running before here was guaranteed
1886 * to choke driver model style diagnostics. from here
1887 * on, they can work ... except in cleanup paths that
1888 * kick in after the ep0 descriptor is closed.
1891 dev->gadget_registered = true;
1897 dev->hs_config = NULL;
1899 spin_unlock_irq (&dev->lock);
1900 pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev);
1907 gadget_dev_open (struct inode *inode, struct file *fd)
1909 struct dev_data *dev = inode->i_private;
1912 spin_lock_irq(&dev->lock);
1913 if (dev->state == STATE_DEV_DISABLED) {
1915 dev->state = STATE_DEV_OPENED;
1916 fd->private_data = dev;
1920 spin_unlock_irq(&dev->lock);
1924 static const struct file_operations ep0_operations = {
1925 .llseek = no_llseek,
1927 .open = gadget_dev_open,
1929 .write = dev_config,
1930 .fasync = ep0_fasync,
1932 .unlocked_ioctl = gadget_dev_ioctl,
1933 .release = dev_release,
1936 /*----------------------------------------------------------------------*/
1938 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1940 * Mounting the filesystem creates a controller file, used first for
1941 * device configuration then later for event monitoring.
1945 /* FIXME PAM etc could set this security policy without mount options
1946 * if epfiles inherited ownership and permissons from ep0 ...
1949 static unsigned default_uid;
1950 static unsigned default_gid;
1951 static unsigned default_perm = S_IRUSR | S_IWUSR;
1953 module_param (default_uid, uint, 0644);
1954 module_param (default_gid, uint, 0644);
1955 module_param (default_perm, uint, 0644);
1958 static struct inode *
1959 gadgetfs_make_inode (struct super_block *sb,
1960 void *data, const struct file_operations *fops,
1963 struct inode *inode = new_inode (sb);
1966 inode->i_ino = get_next_ino();
1967 inode->i_mode = mode;
1968 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1969 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1970 inode->i_atime = inode->i_mtime = inode->i_ctime
1971 = current_time(inode);
1972 inode->i_private = data;
1973 inode->i_fop = fops;
1978 /* creates in fs root directory, so non-renamable and non-linkable.
1979 * so inode and dentry are paired, until device reconfig.
1981 static struct dentry *
1982 gadgetfs_create_file (struct super_block *sb, char const *name,
1983 void *data, const struct file_operations *fops)
1985 struct dentry *dentry;
1986 struct inode *inode;
1988 dentry = d_alloc_name(sb->s_root, name);
1992 inode = gadgetfs_make_inode (sb, data, fops,
1993 S_IFREG | (default_perm & S_IRWXUGO));
1998 d_add (dentry, inode);
2002 static const struct super_operations gadget_fs_operations = {
2003 .statfs = simple_statfs,
2004 .drop_inode = generic_delete_inode,
2008 gadgetfs_fill_super (struct super_block *sb, struct fs_context *fc)
2010 struct inode *inode;
2011 struct dev_data *dev;
2016 CHIP = usb_get_gadget_udc_name();
2021 sb->s_blocksize = PAGE_SIZE;
2022 sb->s_blocksize_bits = PAGE_SHIFT;
2023 sb->s_magic = GADGETFS_MAGIC;
2024 sb->s_op = &gadget_fs_operations;
2025 sb->s_time_gran = 1;
2028 inode = gadgetfs_make_inode (sb,
2029 NULL, &simple_dir_operations,
2030 S_IFDIR | S_IRUGO | S_IXUGO);
2033 inode->i_op = &simple_dir_inode_operations;
2034 if (!(sb->s_root = d_make_root (inode)))
2037 /* the ep0 file is named after the controller we expect;
2038 * user mode code can use it for sanity checks, like we do.
2045 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2051 /* other endpoint files are available after hardware setup,
2052 * from binding to a controller.
2064 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2065 static int gadgetfs_get_tree(struct fs_context *fc)
2067 return get_tree_single(fc, gadgetfs_fill_super);
2070 static const struct fs_context_operations gadgetfs_context_ops = {
2071 .get_tree = gadgetfs_get_tree,
2074 static int gadgetfs_init_fs_context(struct fs_context *fc)
2076 fc->ops = &gadgetfs_context_ops;
2081 gadgetfs_kill_sb (struct super_block *sb)
2083 kill_litter_super (sb);
2085 put_dev (the_device);
2092 /*----------------------------------------------------------------------*/
2094 static struct file_system_type gadgetfs_type = {
2095 .owner = THIS_MODULE,
2097 .init_fs_context = gadgetfs_init_fs_context,
2098 .kill_sb = gadgetfs_kill_sb,
2100 MODULE_ALIAS_FS("gadgetfs");
2102 /*----------------------------------------------------------------------*/
2104 static int __init gadgetfs_init (void)
2108 status = register_filesystem (&gadgetfs_type);
2110 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2111 shortname, driver_desc);
2114 module_init (gadgetfs_init);
2116 static void __exit gadgetfs_cleanup (void)
2118 pr_debug ("unregister %s\n", shortname);
2119 unregister_filesystem (&gadgetfs_type);
2121 module_exit (gadgetfs_cleanup);