2 * inode.c -- user mode filesystem api for usb gadget controllers
4 * Copyright (C) 2003-2004 David Brownell
5 * Copyright (C) 2003 Agilent Technologies
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
14 /* #define VERBOSE_DEBUG */
16 #include <linux/init.h>
17 #include <linux/module.h>
19 #include <linux/pagemap.h>
20 #include <linux/uts.h>
21 #include <linux/wait.h>
22 #include <linux/compiler.h>
23 #include <linux/uaccess.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/poll.h>
27 #include <linux/mmu_context.h>
28 #include <linux/aio.h>
29 #include <linux/uio.h>
30 #include <linux/refcount.h>
32 #include <linux/device.h>
33 #include <linux/moduleparam.h>
35 #include <linux/usb/gadgetfs.h>
36 #include <linux/usb/gadget.h>
40 * The gadgetfs API maps each endpoint to a file descriptor so that you
41 * can use standard synchronous read/write calls for I/O. There's some
42 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
43 * drivers show how this works in practice. You can also use AIO to
44 * eliminate I/O gaps between requests, to help when streaming data.
46 * Key parts that must be USB-specific are protocols defining how the
47 * read/write operations relate to the hardware state machines. There
48 * are two types of files. One type is for the device, implementing ep0.
49 * The other type is for each IN or OUT endpoint. In both cases, the
50 * user mode driver must configure the hardware before using it.
52 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
53 * (by writing configuration and device descriptors). Afterwards it
54 * may serve as a source of device events, used to handle all control
55 * requests other than basic enumeration.
57 * - Then, after a SET_CONFIGURATION control request, ep_config() is
58 * called when each /dev/gadget/ep* file is configured (by writing
59 * endpoint descriptors). Afterwards these files are used to write()
60 * IN data or to read() OUT data. To halt the endpoint, a "wrong
61 * direction" request is issued (like reading an IN endpoint).
63 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
64 * not possible on all hardware. For example, precise fault handling with
65 * respect to data left in endpoint fifos after aborted operations; or
66 * selective clearing of endpoint halts, to implement SET_INTERFACE.
69 #define DRIVER_DESC "USB Gadget filesystem"
70 #define DRIVER_VERSION "24 Aug 2004"
72 static const char driver_desc [] = DRIVER_DESC;
73 static const char shortname [] = "gadgetfs";
75 MODULE_DESCRIPTION (DRIVER_DESC);
76 MODULE_AUTHOR ("David Brownell");
77 MODULE_LICENSE ("GPL");
79 static int ep_open(struct inode *, struct file *);
82 /*----------------------------------------------------------------------*/
84 #define GADGETFS_MAGIC 0xaee71ee7
86 /* /dev/gadget/$CHIP represents ep0 and the whole device */
88 /* DISABLED is the initial state. */
89 STATE_DEV_DISABLED = 0,
91 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
92 * ep0/device i/o modes and binding to the controller. Driver
93 * must always write descriptors to initialize the device, then
94 * the device becomes UNCONNECTED until enumeration.
98 /* From then on, ep0 fd is in either of two basic modes:
99 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
100 * - SETUP: read/write will transfer control data and succeed;
101 * or if "wrong direction", performs protocol stall
103 STATE_DEV_UNCONNECTED,
107 /* UNBOUND means the driver closed ep0, so the device won't be
108 * accessible again (DEV_DISABLED) until all fds are closed.
113 /* enough for the whole queue: most events invalidate others */
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_event_interruptible (done.wait, done.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_event (done.wait, done.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);
473 /* completing the iocb can drop the ctx and mm, don't touch mm after */
474 iocb->ki_complete(iocb, ret, 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 /* aio_complete() reports bytes-transferred _and_ faults */
503 iocb->ki_complete(iocb, req->actual ? req->actual : req->status,
506 /* ep_copy_to_user() won't report both; we hide some faults */
507 if (unlikely(0 != req->status))
508 DBG(epdata->dev, "%s fault %d len %d\n",
509 ep->name, req->status, req->actual);
511 priv->buf = req->buf;
512 priv->actual = req->actual;
513 INIT_WORK(&priv->work, ep_user_copy_worker);
514 schedule_work(&priv->work);
516 spin_unlock(&epdata->dev->lock);
518 usb_ep_free_request(ep, req);
522 static ssize_t ep_aio(struct kiocb *iocb,
523 struct kiocb_priv *priv,
524 struct ep_data *epdata,
528 struct usb_request *req;
531 iocb->private = priv;
534 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
536 priv->epdata = epdata;
538 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
540 /* each kiocb is coupled to one usb_request, but we can't
541 * allocate or submit those if the host disconnected.
543 spin_lock_irq(&epdata->dev->lock);
545 if (unlikely(epdata->ep == NULL))
548 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
556 req->complete = ep_aio_complete;
558 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
559 if (unlikely(0 != value)) {
560 usb_ep_free_request(epdata->ep, req);
563 spin_unlock_irq(&epdata->dev->lock);
567 spin_unlock_irq(&epdata->dev->lock);
568 kfree(priv->to_free);
575 ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
577 struct file *file = iocb->ki_filp;
578 struct ep_data *epdata = file->private_data;
579 size_t len = iov_iter_count(to);
583 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
586 /* halt any endpoint by doing a "wrong direction" i/o call */
587 if (usb_endpoint_dir_in(&epdata->desc)) {
588 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
589 !is_sync_kiocb(iocb)) {
590 mutex_unlock(&epdata->lock);
593 DBG (epdata->dev, "%s halt\n", epdata->name);
594 spin_lock_irq(&epdata->dev->lock);
595 if (likely(epdata->ep != NULL))
596 usb_ep_set_halt(epdata->ep);
597 spin_unlock_irq(&epdata->dev->lock);
598 mutex_unlock(&epdata->lock);
602 buf = kmalloc(len, GFP_KERNEL);
603 if (unlikely(!buf)) {
604 mutex_unlock(&epdata->lock);
607 if (is_sync_kiocb(iocb)) {
608 value = ep_io(epdata, buf, len);
609 if (value >= 0 && (copy_to_iter(buf, value, to) != value))
612 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
616 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
617 if (!priv->to_free) {
621 value = ep_aio(iocb, priv, epdata, buf, len);
622 if (value == -EIOCBQUEUED)
627 mutex_unlock(&epdata->lock);
631 static ssize_t ep_config(struct ep_data *, const char *, size_t);
634 ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
636 struct file *file = iocb->ki_filp;
637 struct ep_data *epdata = file->private_data;
638 size_t len = iov_iter_count(from);
643 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
646 configured = epdata->state == STATE_EP_ENABLED;
648 /* halt any endpoint by doing a "wrong direction" i/o call */
649 if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
650 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
651 !is_sync_kiocb(iocb)) {
652 mutex_unlock(&epdata->lock);
655 DBG (epdata->dev, "%s halt\n", epdata->name);
656 spin_lock_irq(&epdata->dev->lock);
657 if (likely(epdata->ep != NULL))
658 usb_ep_set_halt(epdata->ep);
659 spin_unlock_irq(&epdata->dev->lock);
660 mutex_unlock(&epdata->lock);
664 buf = kmalloc(len, GFP_KERNEL);
665 if (unlikely(!buf)) {
666 mutex_unlock(&epdata->lock);
670 if (unlikely(!copy_from_iter_full(buf, len, from))) {
675 if (unlikely(!configured)) {
676 value = ep_config(epdata, buf, len);
677 } else if (is_sync_kiocb(iocb)) {
678 value = ep_io(epdata, buf, len);
680 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
683 value = ep_aio(iocb, priv, epdata, buf, len);
684 if (value == -EIOCBQUEUED)
690 mutex_unlock(&epdata->lock);
694 /*----------------------------------------------------------------------*/
696 /* used after endpoint configuration */
697 static const struct file_operations ep_io_operations = {
698 .owner = THIS_MODULE,
701 .release = ep_release,
703 .unlocked_ioctl = ep_ioctl,
704 .read_iter = ep_read_iter,
705 .write_iter = ep_write_iter,
708 /* ENDPOINT INITIALIZATION
710 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
711 * status = write (fd, descriptors, sizeof descriptors)
713 * That write establishes the endpoint configuration, configuring
714 * the controller to process bulk, interrupt, or isochronous transfers
715 * at the right maxpacket size, and so on.
717 * The descriptors are message type 1, identified by a host order u32
718 * at the beginning of what's written. Descriptor order is: full/low
719 * speed descriptor, then optional high speed descriptor.
722 ep_config (struct ep_data *data, const char *buf, size_t len)
726 int value, length = len;
728 if (data->state != STATE_EP_READY) {
734 if (len < USB_DT_ENDPOINT_SIZE + 4)
737 /* we might need to change message format someday */
738 memcpy(&tag, buf, 4);
740 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
746 /* NOTE: audio endpoint extensions not accepted here;
747 * just don't include the extra bytes.
750 /* full/low speed descriptor, then high speed */
751 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
752 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
753 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
755 if (len != USB_DT_ENDPOINT_SIZE) {
756 if (len != 2 * USB_DT_ENDPOINT_SIZE)
758 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
759 USB_DT_ENDPOINT_SIZE);
760 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
761 || data->hs_desc.bDescriptorType
762 != USB_DT_ENDPOINT) {
763 DBG(data->dev, "config %s, bad hs length or type\n",
769 spin_lock_irq (&data->dev->lock);
770 if (data->dev->state == STATE_DEV_UNBOUND) {
780 switch (data->dev->gadget->speed) {
783 ep->desc = &data->desc;
786 /* fails if caller didn't provide that descriptor... */
787 ep->desc = &data->hs_desc;
790 DBG(data->dev, "unconnected, %s init abandoned\n",
795 value = usb_ep_enable(ep);
797 data->state = STATE_EP_ENABLED;
801 spin_unlock_irq (&data->dev->lock);
804 data->desc.bDescriptorType = 0;
805 data->hs_desc.bDescriptorType = 0;
814 ep_open (struct inode *inode, struct file *fd)
816 struct ep_data *data = inode->i_private;
819 if (mutex_lock_interruptible(&data->lock) != 0)
821 spin_lock_irq (&data->dev->lock);
822 if (data->dev->state == STATE_DEV_UNBOUND)
824 else if (data->state == STATE_EP_DISABLED) {
826 data->state = STATE_EP_READY;
828 fd->private_data = data;
829 VDEBUG (data->dev, "%s ready\n", data->name);
831 DBG (data->dev, "%s state %d\n",
832 data->name, data->state);
833 spin_unlock_irq (&data->dev->lock);
834 mutex_unlock(&data->lock);
838 /*----------------------------------------------------------------------*/
840 /* EP0 IMPLEMENTATION can be partly in userspace.
842 * Drivers that use this facility receive various events, including
843 * control requests the kernel doesn't handle. Drivers that don't
844 * use this facility may be too simple-minded for real applications.
847 static inline void ep0_readable (struct dev_data *dev)
849 wake_up (&dev->wait);
850 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
853 static void clean_req (struct usb_ep *ep, struct usb_request *req)
855 struct dev_data *dev = ep->driver_data;
857 if (req->buf != dev->rbuf) {
859 req->buf = dev->rbuf;
861 req->complete = epio_complete;
862 dev->setup_out_ready = 0;
865 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
867 struct dev_data *dev = ep->driver_data;
871 /* for control OUT, data must still get to userspace */
872 spin_lock_irqsave(&dev->lock, flags);
873 if (!dev->setup_in) {
874 dev->setup_out_error = (req->status != 0);
875 if (!dev->setup_out_error)
877 dev->setup_out_ready = 1;
881 /* clean up as appropriate */
882 if (free && req->buf != &dev->rbuf)
884 req->complete = epio_complete;
885 spin_unlock_irqrestore(&dev->lock, flags);
888 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
890 struct dev_data *dev = ep->driver_data;
892 if (dev->setup_out_ready) {
893 DBG (dev, "ep0 request busy!\n");
896 if (len > sizeof (dev->rbuf))
897 req->buf = kmalloc(len, GFP_ATOMIC);
898 if (req->buf == NULL) {
899 req->buf = dev->rbuf;
902 req->complete = ep0_complete;
909 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
911 struct dev_data *dev = fd->private_data;
913 enum ep0_state state;
915 spin_lock_irq (&dev->lock);
916 if (dev->state <= STATE_DEV_OPENED) {
921 /* report fd mode change before acting on it */
922 if (dev->setup_abort) {
923 dev->setup_abort = 0;
928 /* control DATA stage */
929 if ((state = dev->state) == STATE_DEV_SETUP) {
931 if (dev->setup_in) { /* stall IN */
932 VDEBUG(dev, "ep0in stall\n");
933 (void) usb_ep_set_halt (dev->gadget->ep0);
935 dev->state = STATE_DEV_CONNECTED;
937 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
938 struct usb_ep *ep = dev->gadget->ep0;
939 struct usb_request *req = dev->req;
941 if ((retval = setup_req (ep, req, 0)) == 0) {
942 spin_unlock_irq (&dev->lock);
943 retval = usb_ep_queue (ep, req, GFP_KERNEL);
944 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);
986 // FIXME don't call this with the spinlock held ...
987 if (copy_to_user (buf, dev->req->buf, len))
991 clean_req (dev->gadget->ep0, dev->req);
992 /* NOTE userspace can't yet choose to stall */
998 /* else normal: return event data */
999 if (len < sizeof dev->event [0]) {
1003 len -= len % sizeof (struct usb_gadgetfs_event);
1004 dev->usermode_setup = 1;
1007 /* return queued events right away */
1008 if (dev->ev_next != 0) {
1011 n = len / sizeof (struct usb_gadgetfs_event);
1012 if (dev->ev_next < n)
1015 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1016 for (i = 0; i < n; i++) {
1017 if (dev->event [i].type == GADGETFS_SETUP) {
1018 dev->state = STATE_DEV_SETUP;
1023 spin_unlock_irq (&dev->lock);
1024 len = n * sizeof (struct usb_gadgetfs_event);
1025 if (copy_to_user (buf, &dev->event, len))
1030 /* NOTE this doesn't guard against broken drivers;
1031 * concurrent ep0 readers may lose events.
1033 spin_lock_irq (&dev->lock);
1034 if (dev->ev_next > n) {
1035 memmove(&dev->event[0], &dev->event[n],
1036 sizeof (struct usb_gadgetfs_event)
1037 * (dev->ev_next - n));
1040 spin_unlock_irq (&dev->lock);
1044 if (fd->f_flags & O_NONBLOCK) {
1051 DBG (dev, "fail %s, state %d\n", __func__, state);
1054 case STATE_DEV_UNCONNECTED:
1055 case STATE_DEV_CONNECTED:
1056 spin_unlock_irq (&dev->lock);
1057 DBG (dev, "%s wait\n", __func__);
1059 /* wait for events */
1060 retval = wait_event_interruptible (dev->wait,
1064 spin_lock_irq (&dev->lock);
1069 spin_unlock_irq (&dev->lock);
1073 static struct usb_gadgetfs_event *
1074 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1076 struct usb_gadgetfs_event *event;
1080 /* these events purge the queue */
1081 case GADGETFS_DISCONNECT:
1082 if (dev->state == STATE_DEV_SETUP)
1083 dev->setup_abort = 1;
1085 case GADGETFS_CONNECT:
1088 case GADGETFS_SETUP: /* previous request timed out */
1089 case GADGETFS_SUSPEND: /* same effect */
1090 /* these events can't be repeated */
1091 for (i = 0; i != dev->ev_next; i++) {
1092 if (dev->event [i].type != type)
1094 DBG(dev, "discard old event[%d] %d\n", i, type);
1096 if (i == dev->ev_next)
1098 /* indices start at zero, for simplicity */
1099 memmove (&dev->event [i], &dev->event [i + 1],
1100 sizeof (struct usb_gadgetfs_event)
1101 * (dev->ev_next - i));
1107 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1108 event = &dev->event [dev->ev_next++];
1109 BUG_ON (dev->ev_next > N_EVENT);
1110 memset (event, 0, sizeof *event);
1116 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1118 struct dev_data *dev = fd->private_data;
1119 ssize_t retval = -ESRCH;
1121 /* report fd mode change before acting on it */
1122 if (dev->setup_abort) {
1123 dev->setup_abort = 0;
1126 /* data and/or status stage for control request */
1127 } else if (dev->state == STATE_DEV_SETUP) {
1129 len = min_t(size_t, len, dev->setup_wLength);
1130 if (dev->setup_in) {
1131 retval = setup_req (dev->gadget->ep0, dev->req, len);
1133 dev->state = STATE_DEV_CONNECTED;
1134 spin_unlock_irq (&dev->lock);
1135 if (copy_from_user (dev->req->buf, buf, len))
1138 if (len < dev->setup_wLength)
1140 retval = usb_ep_queue (
1141 dev->gadget->ep0, dev->req,
1144 spin_lock_irq(&dev->lock);
1146 clean_req (dev->gadget->ep0, dev->req);
1153 /* can stall some OUT transfers */
1154 } else if (dev->setup_can_stall) {
1155 VDEBUG(dev, "ep0out stall\n");
1156 (void) usb_ep_set_halt (dev->gadget->ep0);
1158 dev->state = STATE_DEV_CONNECTED;
1160 DBG(dev, "bogus ep0out stall!\n");
1163 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1169 ep0_fasync (int f, struct file *fd, int on)
1171 struct dev_data *dev = fd->private_data;
1172 // caller must F_SETOWN before signal delivery happens
1173 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1174 return fasync_helper (f, fd, on, &dev->fasync);
1177 static struct usb_gadget_driver gadgetfs_driver;
1180 dev_release (struct inode *inode, struct file *fd)
1182 struct dev_data *dev = fd->private_data;
1184 /* closing ep0 === shutdown all */
1186 if (dev->gadget_registered) {
1187 usb_gadget_unregister_driver (&gadgetfs_driver);
1188 dev->gadget_registered = false;
1191 /* at this point "good" hardware has disconnected the
1192 * device from USB; the host won't see it any more.
1193 * alternatively, all host requests will time out.
1199 /* other endpoints were all decoupled from this device */
1200 spin_lock_irq(&dev->lock);
1201 dev->state = STATE_DEV_DISABLED;
1202 spin_unlock_irq(&dev->lock);
1209 ep0_poll (struct file *fd, poll_table *wait)
1211 struct dev_data *dev = fd->private_data;
1214 if (dev->state <= STATE_DEV_OPENED)
1215 return DEFAULT_POLLMASK;
1217 poll_wait(fd, &dev->wait, wait);
1219 spin_lock_irq (&dev->lock);
1221 /* report fd mode change before acting on it */
1222 if (dev->setup_abort) {
1223 dev->setup_abort = 0;
1228 if (dev->state == STATE_DEV_SETUP) {
1229 if (dev->setup_in || dev->setup_can_stall)
1232 if (dev->ev_next != 0)
1236 spin_unlock_irq(&dev->lock);
1240 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1242 struct dev_data *dev = fd->private_data;
1243 struct usb_gadget *gadget = dev->gadget;
1246 if (gadget->ops->ioctl)
1247 ret = gadget->ops->ioctl (gadget, code, value);
1252 /*----------------------------------------------------------------------*/
1254 /* The in-kernel gadget driver handles most ep0 issues, in particular
1255 * enumerating the single configuration (as provided from user space).
1257 * Unrecognized ep0 requests may be handled in user space.
1260 static void make_qualifier (struct dev_data *dev)
1262 struct usb_qualifier_descriptor qual;
1263 struct usb_device_descriptor *desc;
1265 qual.bLength = sizeof qual;
1266 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1267 qual.bcdUSB = cpu_to_le16 (0x0200);
1270 qual.bDeviceClass = desc->bDeviceClass;
1271 qual.bDeviceSubClass = desc->bDeviceSubClass;
1272 qual.bDeviceProtocol = desc->bDeviceProtocol;
1274 /* assumes ep0 uses the same value for both speeds ... */
1275 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1277 qual.bNumConfigurations = 1;
1280 memcpy (dev->rbuf, &qual, sizeof qual);
1284 config_buf (struct dev_data *dev, u8 type, unsigned index)
1289 /* only one configuration */
1293 if (gadget_is_dualspeed(dev->gadget)) {
1294 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1295 if (type == USB_DT_OTHER_SPEED_CONFIG)
1299 dev->req->buf = dev->hs_config;
1300 len = le16_to_cpu(dev->hs_config->wTotalLength);
1302 dev->req->buf = dev->config;
1303 len = le16_to_cpu(dev->config->wTotalLength);
1305 ((u8 *)dev->req->buf) [1] = type;
1310 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1312 struct dev_data *dev = get_gadget_data (gadget);
1313 struct usb_request *req = dev->req;
1314 int value = -EOPNOTSUPP;
1315 struct usb_gadgetfs_event *event;
1316 u16 w_value = le16_to_cpu(ctrl->wValue);
1317 u16 w_length = le16_to_cpu(ctrl->wLength);
1319 spin_lock (&dev->lock);
1320 dev->setup_abort = 0;
1321 if (dev->state == STATE_DEV_UNCONNECTED) {
1322 if (gadget_is_dualspeed(gadget)
1323 && gadget->speed == USB_SPEED_HIGH
1324 && dev->hs_config == NULL) {
1325 spin_unlock(&dev->lock);
1326 ERROR (dev, "no high speed config??\n");
1330 dev->state = STATE_DEV_CONNECTED;
1332 INFO (dev, "connected\n");
1333 event = next_event (dev, GADGETFS_CONNECT);
1334 event->u.speed = gadget->speed;
1337 /* host may have given up waiting for response. we can miss control
1338 * requests handled lower down (device/endpoint status and features);
1339 * then ep0_{read,write} will report the wrong status. controller
1340 * driver will have aborted pending i/o.
1342 } else if (dev->state == STATE_DEV_SETUP)
1343 dev->setup_abort = 1;
1345 req->buf = dev->rbuf;
1346 req->context = NULL;
1347 value = -EOPNOTSUPP;
1348 switch (ctrl->bRequest) {
1350 case USB_REQ_GET_DESCRIPTOR:
1351 if (ctrl->bRequestType != USB_DIR_IN)
1353 switch (w_value >> 8) {
1356 value = min (w_length, (u16) sizeof *dev->dev);
1357 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1358 req->buf = dev->dev;
1360 case USB_DT_DEVICE_QUALIFIER:
1361 if (!dev->hs_config)
1363 value = min (w_length, (u16)
1364 sizeof (struct usb_qualifier_descriptor));
1365 make_qualifier (dev);
1367 case USB_DT_OTHER_SPEED_CONFIG:
1370 value = config_buf (dev,
1374 value = min (w_length, (u16) value);
1379 default: // all others are errors
1384 /* currently one config, two speeds */
1385 case USB_REQ_SET_CONFIGURATION:
1386 if (ctrl->bRequestType != 0)
1388 if (0 == (u8) w_value) {
1390 dev->current_config = 0;
1391 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1392 // user mode expected to disable endpoints
1396 if (gadget_is_dualspeed(gadget)
1397 && gadget->speed == USB_SPEED_HIGH) {
1398 config = dev->hs_config->bConfigurationValue;
1399 power = dev->hs_config->bMaxPower;
1401 config = dev->config->bConfigurationValue;
1402 power = dev->config->bMaxPower;
1405 if (config == (u8) w_value) {
1407 dev->current_config = config;
1408 usb_gadget_vbus_draw(gadget, 2 * power);
1412 /* report SET_CONFIGURATION like any other control request,
1413 * except that usermode may not stall this. the next
1414 * request mustn't be allowed start until this finishes:
1415 * endpoints and threads set up, etc.
1417 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1418 * has bad/racey automagic that prevents synchronizing here.
1419 * even kernel mode drivers often miss them.
1422 INFO (dev, "configuration #%d\n", dev->current_config);
1423 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1424 if (dev->usermode_setup) {
1425 dev->setup_can_stall = 0;
1431 #ifndef CONFIG_USB_PXA25X
1432 /* PXA automagically handles this request too */
1433 case USB_REQ_GET_CONFIGURATION:
1434 if (ctrl->bRequestType != 0x80)
1436 *(u8 *)req->buf = dev->current_config;
1437 value = min (w_length, (u16) 1);
1443 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1444 dev->usermode_setup ? "delegate" : "fail",
1445 ctrl->bRequestType, ctrl->bRequest,
1446 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1448 /* if there's an ep0 reader, don't stall */
1449 if (dev->usermode_setup) {
1450 dev->setup_can_stall = 1;
1452 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1454 dev->setup_wLength = w_length;
1455 dev->setup_out_ready = 0;
1456 dev->setup_out_error = 0;
1459 /* read DATA stage for OUT right away */
1460 if (unlikely (!dev->setup_in && w_length)) {
1461 value = setup_req (gadget->ep0, dev->req,
1466 spin_unlock (&dev->lock);
1467 value = usb_ep_queue (gadget->ep0, dev->req,
1469 spin_lock (&dev->lock);
1471 clean_req (gadget->ep0, dev->req);
1475 /* we can't currently stall these */
1476 dev->setup_can_stall = 0;
1479 /* state changes when reader collects event */
1480 event = next_event (dev, GADGETFS_SETUP);
1481 event->u.setup = *ctrl;
1483 spin_unlock (&dev->lock);
1488 /* proceed with data transfer and status phases? */
1489 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1490 req->length = value;
1491 req->zero = value < w_length;
1493 spin_unlock (&dev->lock);
1494 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL);
1496 DBG (dev, "ep_queue --> %d\n", value);
1502 /* device stalls when value < 0 */
1503 spin_unlock (&dev->lock);
1507 static void destroy_ep_files (struct dev_data *dev)
1509 DBG (dev, "%s %d\n", __func__, dev->state);
1511 /* dev->state must prevent interference */
1512 spin_lock_irq (&dev->lock);
1513 while (!list_empty(&dev->epfiles)) {
1515 struct inode *parent;
1516 struct dentry *dentry;
1518 /* break link to FS */
1519 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1520 list_del_init (&ep->epfiles);
1521 dentry = ep->dentry;
1523 parent = d_inode(dentry->d_parent);
1525 /* break link to controller */
1526 if (ep->state == STATE_EP_ENABLED)
1527 (void) usb_ep_disable (ep->ep);
1528 ep->state = STATE_EP_UNBOUND;
1529 usb_ep_free_request (ep->ep, ep->req);
1531 wake_up (&ep->wait);
1534 spin_unlock_irq (&dev->lock);
1536 /* break link to dcache */
1540 inode_unlock(parent);
1542 spin_lock_irq (&dev->lock);
1544 spin_unlock_irq (&dev->lock);
1548 static struct dentry *
1549 gadgetfs_create_file (struct super_block *sb, char const *name,
1550 void *data, const struct file_operations *fops);
1552 static int activate_ep_files (struct dev_data *dev)
1555 struct ep_data *data;
1557 gadget_for_each_ep (ep, dev->gadget) {
1559 data = kzalloc(sizeof(*data), GFP_KERNEL);
1562 data->state = STATE_EP_DISABLED;
1563 mutex_init(&data->lock);
1564 init_waitqueue_head (&data->wait);
1566 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1567 refcount_set (&data->count, 1);
1572 ep->driver_data = data;
1574 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1578 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1579 data, &ep_io_operations);
1582 list_add_tail (&data->epfiles, &dev->epfiles);
1587 usb_ep_free_request (ep, data->req);
1592 DBG (dev, "%s enomem\n", __func__);
1593 destroy_ep_files (dev);
1598 gadgetfs_unbind (struct usb_gadget *gadget)
1600 struct dev_data *dev = get_gadget_data (gadget);
1602 DBG (dev, "%s\n", __func__);
1604 spin_lock_irq (&dev->lock);
1605 dev->state = STATE_DEV_UNBOUND;
1606 spin_unlock_irq (&dev->lock);
1608 destroy_ep_files (dev);
1609 gadget->ep0->driver_data = NULL;
1610 set_gadget_data (gadget, NULL);
1612 /* we've already been disconnected ... no i/o is active */
1614 usb_ep_free_request (gadget->ep0, dev->req);
1615 DBG (dev, "%s done\n", __func__);
1619 static struct dev_data *the_device;
1621 static int gadgetfs_bind(struct usb_gadget *gadget,
1622 struct usb_gadget_driver *driver)
1624 struct dev_data *dev = the_device;
1628 if (0 != strcmp (CHIP, gadget->name)) {
1629 pr_err("%s expected %s controller not %s\n",
1630 shortname, CHIP, gadget->name);
1634 set_gadget_data (gadget, dev);
1635 dev->gadget = gadget;
1636 gadget->ep0->driver_data = dev;
1638 /* preallocate control response and buffer */
1639 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1642 dev->req->context = NULL;
1643 dev->req->complete = epio_complete;
1645 if (activate_ep_files (dev) < 0)
1648 INFO (dev, "bound to %s driver\n", gadget->name);
1649 spin_lock_irq(&dev->lock);
1650 dev->state = STATE_DEV_UNCONNECTED;
1651 spin_unlock_irq(&dev->lock);
1656 gadgetfs_unbind (gadget);
1661 gadgetfs_disconnect (struct usb_gadget *gadget)
1663 struct dev_data *dev = get_gadget_data (gadget);
1664 unsigned long flags;
1666 spin_lock_irqsave (&dev->lock, flags);
1667 if (dev->state == STATE_DEV_UNCONNECTED)
1669 dev->state = STATE_DEV_UNCONNECTED;
1671 INFO (dev, "disconnected\n");
1672 next_event (dev, GADGETFS_DISCONNECT);
1675 spin_unlock_irqrestore (&dev->lock, flags);
1679 gadgetfs_suspend (struct usb_gadget *gadget)
1681 struct dev_data *dev = get_gadget_data (gadget);
1682 unsigned long flags;
1684 INFO (dev, "suspended from state %d\n", dev->state);
1685 spin_lock_irqsave(&dev->lock, flags);
1686 switch (dev->state) {
1687 case STATE_DEV_SETUP: // VERY odd... host died??
1688 case STATE_DEV_CONNECTED:
1689 case STATE_DEV_UNCONNECTED:
1690 next_event (dev, GADGETFS_SUSPEND);
1696 spin_unlock_irqrestore(&dev->lock, flags);
1699 static struct usb_gadget_driver gadgetfs_driver = {
1700 .function = (char *) driver_desc,
1701 .bind = gadgetfs_bind,
1702 .unbind = gadgetfs_unbind,
1703 .setup = gadgetfs_setup,
1704 .reset = gadgetfs_disconnect,
1705 .disconnect = gadgetfs_disconnect,
1706 .suspend = gadgetfs_suspend,
1709 .name = (char *) shortname,
1713 /*----------------------------------------------------------------------*/
1714 /* DEVICE INITIALIZATION
1716 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1717 * status = write (fd, descriptors, sizeof descriptors)
1719 * That write establishes the device configuration, so the kernel can
1720 * bind to the controller ... guaranteeing it can handle enumeration
1721 * at all necessary speeds. Descriptor order is:
1723 * . message tag (u32, host order) ... for now, must be zero; it
1724 * would change to support features like multi-config devices
1725 * . full/low speed config ... all wTotalLength bytes (with interface,
1726 * class, altsetting, endpoint, and other descriptors)
1727 * . high speed config ... all descriptors, for high speed operation;
1728 * this one's optional except for high-speed hardware
1729 * . device descriptor
1731 * Endpoints are not yet enabled. Drivers must wait until device
1732 * configuration and interface altsetting changes create
1733 * the need to configure (or unconfigure) them.
1735 * After initialization, the device stays active for as long as that
1736 * $CHIP file is open. Events must then be read from that descriptor,
1737 * such as configuration notifications.
1740 static int is_valid_config(struct usb_config_descriptor *config,
1743 return config->bDescriptorType == USB_DT_CONFIG
1744 && config->bLength == USB_DT_CONFIG_SIZE
1745 && total >= USB_DT_CONFIG_SIZE
1746 && config->bConfigurationValue != 0
1747 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1748 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1749 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1750 /* FIXME check lengths: walk to end */
1754 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1756 struct dev_data *dev = fd->private_data;
1757 ssize_t value = len, length = len;
1762 spin_lock_irq(&dev->lock);
1763 if (dev->state > STATE_DEV_OPENED) {
1764 value = ep0_write(fd, buf, len, ptr);
1765 spin_unlock_irq(&dev->lock);
1768 spin_unlock_irq(&dev->lock);
1770 if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
1771 (len > PAGE_SIZE * 4))
1774 /* we might need to change message format someday */
1775 if (copy_from_user (&tag, buf, 4))
1782 kbuf = memdup_user(buf, length);
1784 return PTR_ERR(kbuf);
1786 spin_lock_irq (&dev->lock);
1794 /* full or low speed config */
1795 dev->config = (void *) kbuf;
1796 total = le16_to_cpu(dev->config->wTotalLength);
1797 if (!is_valid_config(dev->config, total) ||
1798 total > length - USB_DT_DEVICE_SIZE)
1803 /* optional high speed config */
1804 if (kbuf [1] == USB_DT_CONFIG) {
1805 dev->hs_config = (void *) kbuf;
1806 total = le16_to_cpu(dev->hs_config->wTotalLength);
1807 if (!is_valid_config(dev->hs_config, total) ||
1808 total > length - USB_DT_DEVICE_SIZE)
1813 dev->hs_config = NULL;
1816 /* could support multiple configs, using another encoding! */
1818 /* device descriptor (tweaked for paranoia) */
1819 if (length != USB_DT_DEVICE_SIZE)
1821 dev->dev = (void *)kbuf;
1822 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1823 || dev->dev->bDescriptorType != USB_DT_DEVICE
1824 || dev->dev->bNumConfigurations != 1)
1826 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1828 /* triggers gadgetfs_bind(); then we can enumerate. */
1829 spin_unlock_irq (&dev->lock);
1831 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1833 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1835 value = usb_gadget_probe_driver(&gadgetfs_driver);
1840 /* at this point "good" hardware has for the first time
1841 * let the USB the host see us. alternatively, if users
1842 * unplug/replug that will clear all the error state.
1844 * note: everything running before here was guaranteed
1845 * to choke driver model style diagnostics. from here
1846 * on, they can work ... except in cleanup paths that
1847 * kick in after the ep0 descriptor is closed.
1850 dev->gadget_registered = true;
1855 spin_unlock_irq (&dev->lock);
1856 pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev);
1863 dev_open (struct inode *inode, struct file *fd)
1865 struct dev_data *dev = inode->i_private;
1868 spin_lock_irq(&dev->lock);
1869 if (dev->state == STATE_DEV_DISABLED) {
1871 dev->state = STATE_DEV_OPENED;
1872 fd->private_data = dev;
1876 spin_unlock_irq(&dev->lock);
1880 static const struct file_operations ep0_operations = {
1881 .llseek = no_llseek,
1885 .write = dev_config,
1886 .fasync = ep0_fasync,
1888 .unlocked_ioctl = dev_ioctl,
1889 .release = dev_release,
1892 /*----------------------------------------------------------------------*/
1894 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1896 * Mounting the filesystem creates a controller file, used first for
1897 * device configuration then later for event monitoring.
1901 /* FIXME PAM etc could set this security policy without mount options
1902 * if epfiles inherited ownership and permissons from ep0 ...
1905 static unsigned default_uid;
1906 static unsigned default_gid;
1907 static unsigned default_perm = S_IRUSR | S_IWUSR;
1909 module_param (default_uid, uint, 0644);
1910 module_param (default_gid, uint, 0644);
1911 module_param (default_perm, uint, 0644);
1914 static struct inode *
1915 gadgetfs_make_inode (struct super_block *sb,
1916 void *data, const struct file_operations *fops,
1919 struct inode *inode = new_inode (sb);
1922 inode->i_ino = get_next_ino();
1923 inode->i_mode = mode;
1924 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1925 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1926 inode->i_atime = inode->i_mtime = inode->i_ctime
1927 = current_time(inode);
1928 inode->i_private = data;
1929 inode->i_fop = fops;
1934 /* creates in fs root directory, so non-renamable and non-linkable.
1935 * so inode and dentry are paired, until device reconfig.
1937 static struct dentry *
1938 gadgetfs_create_file (struct super_block *sb, char const *name,
1939 void *data, const struct file_operations *fops)
1941 struct dentry *dentry;
1942 struct inode *inode;
1944 dentry = d_alloc_name(sb->s_root, name);
1948 inode = gadgetfs_make_inode (sb, data, fops,
1949 S_IFREG | (default_perm & S_IRWXUGO));
1954 d_add (dentry, inode);
1958 static const struct super_operations gadget_fs_operations = {
1959 .statfs = simple_statfs,
1960 .drop_inode = generic_delete_inode,
1964 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
1966 struct inode *inode;
1967 struct dev_data *dev;
1972 CHIP = usb_get_gadget_udc_name();
1977 sb->s_blocksize = PAGE_SIZE;
1978 sb->s_blocksize_bits = PAGE_SHIFT;
1979 sb->s_magic = GADGETFS_MAGIC;
1980 sb->s_op = &gadget_fs_operations;
1981 sb->s_time_gran = 1;
1984 inode = gadgetfs_make_inode (sb,
1985 NULL, &simple_dir_operations,
1986 S_IFDIR | S_IRUGO | S_IXUGO);
1989 inode->i_op = &simple_dir_inode_operations;
1990 if (!(sb->s_root = d_make_root (inode)))
1993 /* the ep0 file is named after the controller we expect;
1994 * user mode code can use it for sanity checks, like we do.
2001 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2007 /* other endpoint files are available after hardware setup,
2008 * from binding to a controller.
2017 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2018 static struct dentry *
2019 gadgetfs_mount (struct file_system_type *t, int flags,
2020 const char *path, void *opts)
2022 return mount_single (t, flags, opts, gadgetfs_fill_super);
2026 gadgetfs_kill_sb (struct super_block *sb)
2028 kill_litter_super (sb);
2030 put_dev (the_device);
2037 /*----------------------------------------------------------------------*/
2039 static struct file_system_type gadgetfs_type = {
2040 .owner = THIS_MODULE,
2042 .mount = gadgetfs_mount,
2043 .kill_sb = gadgetfs_kill_sb,
2045 MODULE_ALIAS_FS("gadgetfs");
2047 /*----------------------------------------------------------------------*/
2049 static int __init init (void)
2053 status = register_filesystem (&gadgetfs_type);
2055 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2056 shortname, driver_desc);
2061 static void __exit cleanup (void)
2063 pr_debug ("unregister %s\n", shortname);
2064 unregister_filesystem (&gadgetfs_type);
2066 module_exit (cleanup);