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 <asm/uaccess.h>
24 #include <linux/sched.h>
25 #include <linux/slab.h>
26 #include <linux/poll.h>
27 #include <linux/mmu_context.h>
28 #include <linux/aio.h>
30 #include <linux/device.h>
31 #include <linux/moduleparam.h>
33 #include <linux/usb/gadgetfs.h>
34 #include <linux/usb/gadget.h>
38 * The gadgetfs API maps each endpoint to a file descriptor so that you
39 * can use standard synchronous read/write calls for I/O. There's some
40 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
41 * drivers show how this works in practice. You can also use AIO to
42 * eliminate I/O gaps between requests, to help when streaming data.
44 * Key parts that must be USB-specific are protocols defining how the
45 * read/write operations relate to the hardware state machines. There
46 * are two types of files. One type is for the device, implementing ep0.
47 * The other type is for each IN or OUT endpoint. In both cases, the
48 * user mode driver must configure the hardware before using it.
50 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
51 * (by writing configuration and device descriptors). Afterwards it
52 * may serve as a source of device events, used to handle all control
53 * requests other than basic enumeration.
55 * - Then, after a SET_CONFIGURATION control request, ep_config() is
56 * called when each /dev/gadget/ep* file is configured (by writing
57 * endpoint descriptors). Afterwards these files are used to write()
58 * IN data or to read() OUT data. To halt the endpoint, a "wrong
59 * direction" request is issued (like reading an IN endpoint).
61 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
62 * not possible on all hardware. For example, precise fault handling with
63 * respect to data left in endpoint fifos after aborted operations; or
64 * selective clearing of endpoint halts, to implement SET_INTERFACE.
67 #define DRIVER_DESC "USB Gadget filesystem"
68 #define DRIVER_VERSION "24 Aug 2004"
70 static const char driver_desc [] = DRIVER_DESC;
71 static const char shortname [] = "gadgetfs";
73 MODULE_DESCRIPTION (DRIVER_DESC);
74 MODULE_AUTHOR ("David Brownell");
75 MODULE_LICENSE ("GPL");
77 static int ep_open(struct inode *, struct file *);
80 /*----------------------------------------------------------------------*/
82 #define GADGETFS_MAGIC 0xaee71ee7
84 /* /dev/gadget/$CHIP represents ep0 and the whole device */
86 /* DISBLED is the initial state.
88 STATE_DEV_DISABLED = 0,
90 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
91 * ep0/device i/o modes and binding to the controller. Driver
92 * must always write descriptors to initialize the device, then
93 * the device becomes UNCONNECTED until enumeration.
97 /* From then on, ep0 fd is in either of two basic modes:
98 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
99 * - SETUP: read/write will transfer control data and succeed;
100 * or if "wrong direction", performs protocol stall
102 STATE_DEV_UNCONNECTED,
106 /* UNBOUND means the driver closed ep0, so the device won't be
107 * accessible again (DEV_DISABLED) until all fds are closed.
112 /* enough for the whole queue: most events invalidate others */
118 enum ep0_state state; /* P: lock */
119 struct usb_gadgetfs_event event [N_EVENT];
121 struct fasync_struct *fasync;
124 /* drivers reading ep0 MUST handle control requests (SETUP)
125 * reported that way; else the host will time out.
127 unsigned usermode_setup : 1,
133 unsigned setup_wLength;
135 /* the rest is basically write-once */
136 struct usb_config_descriptor *config, *hs_config;
137 struct usb_device_descriptor *dev;
138 struct usb_request *req;
139 struct usb_gadget *gadget;
140 struct list_head epfiles;
142 wait_queue_head_t wait;
143 struct super_block *sb;
144 struct dentry *dentry;
146 /* except this scratch i/o buffer for ep0 */
150 static inline void get_dev (struct dev_data *data)
152 atomic_inc (&data->count);
155 static void put_dev (struct dev_data *data)
157 if (likely (!atomic_dec_and_test (&data->count)))
159 /* needs no more cleanup */
160 BUG_ON (waitqueue_active (&data->wait));
164 static struct dev_data *dev_new (void)
166 struct dev_data *dev;
168 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
171 dev->state = STATE_DEV_DISABLED;
172 atomic_set (&dev->count, 1);
173 spin_lock_init (&dev->lock);
174 INIT_LIST_HEAD (&dev->epfiles);
175 init_waitqueue_head (&dev->wait);
179 /*----------------------------------------------------------------------*/
181 /* other /dev/gadget/$ENDPOINT files represent endpoints */
183 STATE_EP_DISABLED = 0,
193 struct dev_data *dev;
194 /* must hold dev->lock before accessing ep or req */
196 struct usb_request *req;
199 struct usb_endpoint_descriptor desc, hs_desc;
200 struct list_head epfiles;
201 wait_queue_head_t wait;
202 struct dentry *dentry;
205 static inline void get_ep (struct ep_data *data)
207 atomic_inc (&data->count);
210 static void put_ep (struct ep_data *data)
212 if (likely (!atomic_dec_and_test (&data->count)))
215 /* needs no more cleanup */
216 BUG_ON (!list_empty (&data->epfiles));
217 BUG_ON (waitqueue_active (&data->wait));
221 /*----------------------------------------------------------------------*/
223 /* most "how to use the hardware" policy choices are in userspace:
224 * mapping endpoint roles (which the driver needs) to the capabilities
225 * which the usb controller has. most of those capabilities are exposed
226 * implicitly, starting with the driver name and then endpoint names.
229 static const char *CHIP;
231 /*----------------------------------------------------------------------*/
233 /* NOTE: don't use dev_printk calls before binding to the gadget
234 * at the end of ep0 configuration, or after unbind.
237 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
238 #define xprintk(d,level,fmt,args...) \
239 printk(level "%s: " fmt , shortname , ## args)
242 #define DBG(dev,fmt,args...) \
243 xprintk(dev , KERN_DEBUG , fmt , ## args)
245 #define DBG(dev,fmt,args...) \
252 #define VDEBUG(dev,fmt,args...) \
256 #define ERROR(dev,fmt,args...) \
257 xprintk(dev , KERN_ERR , fmt , ## args)
258 #define INFO(dev,fmt,args...) \
259 xprintk(dev , KERN_INFO , fmt , ## args)
262 /*----------------------------------------------------------------------*/
264 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
266 * After opening, configure non-control endpoints. Then use normal
267 * stream read() and write() requests; and maybe ioctl() to get more
268 * precise FIFO status when recovering from cancellation.
271 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
273 struct ep_data *epdata = ep->driver_data;
278 epdata->status = req->status;
280 epdata->status = req->actual;
281 complete ((struct completion *)req->context);
284 /* tasklock endpoint, returning when it's connected.
285 * still need dev->lock to use epdata->ep.
288 get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
292 if (f_flags & O_NONBLOCK) {
293 if (!mutex_trylock(&epdata->lock))
295 if (epdata->state != STATE_EP_ENABLED &&
296 (!is_write || epdata->state != STATE_EP_READY)) {
297 mutex_unlock(&epdata->lock);
305 val = mutex_lock_interruptible(&epdata->lock);
309 switch (epdata->state) {
310 case STATE_EP_ENABLED:
312 case STATE_EP_READY: /* not configured yet */
316 case STATE_EP_UNBOUND: /* clean disconnect */
318 // case STATE_EP_DISABLED: /* "can't happen" */
319 default: /* error! */
320 pr_debug ("%s: ep %p not available, state %d\n",
321 shortname, epdata, epdata->state);
323 mutex_unlock(&epdata->lock);
328 ep_io (struct ep_data *epdata, void *buf, unsigned len)
330 DECLARE_COMPLETION_ONSTACK (done);
333 spin_lock_irq (&epdata->dev->lock);
334 if (likely (epdata->ep != NULL)) {
335 struct usb_request *req = epdata->req;
337 req->context = &done;
338 req->complete = epio_complete;
341 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
344 spin_unlock_irq (&epdata->dev->lock);
346 if (likely (value == 0)) {
347 value = wait_event_interruptible (done.wait, done.done);
349 spin_lock_irq (&epdata->dev->lock);
350 if (likely (epdata->ep != NULL)) {
351 DBG (epdata->dev, "%s i/o interrupted\n",
353 usb_ep_dequeue (epdata->ep, epdata->req);
354 spin_unlock_irq (&epdata->dev->lock);
356 wait_event (done.wait, done.done);
357 if (epdata->status == -ECONNRESET)
358 epdata->status = -EINTR;
360 spin_unlock_irq (&epdata->dev->lock);
362 DBG (epdata->dev, "endpoint gone\n");
363 epdata->status = -ENODEV;
366 return epdata->status;
372 ep_release (struct inode *inode, struct file *fd)
374 struct ep_data *data = fd->private_data;
377 value = mutex_lock_interruptible(&data->lock);
381 /* clean up if this can be reopened */
382 if (data->state != STATE_EP_UNBOUND) {
383 data->state = STATE_EP_DISABLED;
384 data->desc.bDescriptorType = 0;
385 data->hs_desc.bDescriptorType = 0;
386 usb_ep_disable(data->ep);
388 mutex_unlock(&data->lock);
393 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
395 struct ep_data *data = fd->private_data;
398 if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
401 spin_lock_irq (&data->dev->lock);
402 if (likely (data->ep != NULL)) {
404 case GADGETFS_FIFO_STATUS:
405 status = usb_ep_fifo_status (data->ep);
407 case GADGETFS_FIFO_FLUSH:
408 usb_ep_fifo_flush (data->ep);
410 case GADGETFS_CLEAR_HALT:
411 status = usb_ep_clear_halt (data->ep);
418 spin_unlock_irq (&data->dev->lock);
419 mutex_unlock(&data->lock);
423 /*----------------------------------------------------------------------*/
425 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
428 struct usb_request *req;
429 struct ep_data *epdata;
431 struct mm_struct *mm;
432 struct work_struct work;
439 static int ep_aio_cancel(struct kiocb *iocb)
441 struct kiocb_priv *priv = iocb->private;
442 struct ep_data *epdata;
446 epdata = priv->epdata;
447 // spin_lock(&epdata->dev->lock);
448 if (likely(epdata && epdata->ep && priv->req))
449 value = usb_ep_dequeue (epdata->ep, priv->req);
452 // spin_unlock(&epdata->dev->lock);
458 static void ep_user_copy_worker(struct work_struct *work)
460 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
461 struct mm_struct *mm = priv->mm;
462 struct kiocb *iocb = priv->iocb;
466 ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
471 /* completing the iocb can drop the ctx and mm, don't touch mm after */
472 aio_complete(iocb, ret, ret);
475 kfree(priv->to_free);
479 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
481 struct kiocb *iocb = req->context;
482 struct kiocb_priv *priv = iocb->private;
483 struct ep_data *epdata = priv->epdata;
485 /* lock against disconnect (and ideally, cancel) */
486 spin_lock(&epdata->dev->lock);
490 /* if this was a write or a read returning no data then we
491 * don't need to copy anything to userspace, so we can
492 * complete the aio request immediately.
494 if (priv->to_free == NULL || unlikely(req->actual == 0)) {
496 kfree(priv->to_free);
498 iocb->private = NULL;
499 /* aio_complete() reports bytes-transferred _and_ faults */
500 aio_complete(iocb, req->actual ? req->actual : req->status,
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);
508 priv->buf = req->buf;
509 priv->actual = req->actual;
510 INIT_WORK(&priv->work, ep_user_copy_worker);
511 schedule_work(&priv->work);
513 spin_unlock(&epdata->dev->lock);
515 usb_ep_free_request(ep, req);
519 static ssize_t ep_aio(struct kiocb *iocb,
520 struct kiocb_priv *priv,
521 struct ep_data *epdata,
525 struct usb_request *req;
528 iocb->private = priv;
531 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
533 priv->epdata = epdata;
535 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
537 /* each kiocb is coupled to one usb_request, but we can't
538 * allocate or submit those if the host disconnected.
540 spin_lock_irq(&epdata->dev->lock);
542 if (unlikely(epdata->ep))
545 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
553 req->complete = ep_aio_complete;
555 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
556 if (unlikely(0 != value)) {
557 usb_ep_free_request(epdata->ep, req);
560 spin_unlock_irq(&epdata->dev->lock);
564 spin_unlock_irq(&epdata->dev->lock);
565 kfree(priv->to_free);
572 ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
574 struct file *file = iocb->ki_filp;
575 struct ep_data *epdata = file->private_data;
576 size_t len = iov_iter_count(to);
580 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
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);
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);
599 buf = kmalloc(len, GFP_KERNEL);
600 if (unlikely(!buf)) {
601 mutex_unlock(&epdata->lock);
604 if (is_sync_kiocb(iocb)) {
605 value = ep_io(epdata, buf, len);
606 if (value >= 0 && copy_to_iter(buf, value, to))
609 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
613 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
614 if (!priv->to_free) {
618 value = ep_aio(iocb, priv, epdata, buf, len);
619 if (value == -EIOCBQUEUED)
624 mutex_unlock(&epdata->lock);
628 static ssize_t ep_config(struct ep_data *, const char *, size_t);
631 ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
633 struct file *file = iocb->ki_filp;
634 struct ep_data *epdata = file->private_data;
635 size_t len = iov_iter_count(from);
640 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
643 configured = epdata->state == STATE_EP_ENABLED;
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);
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);
661 buf = kmalloc(len, GFP_KERNEL);
662 if (unlikely(!buf)) {
663 mutex_unlock(&epdata->lock);
667 if (unlikely(copy_from_iter(buf, len, from) != len)) {
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);
677 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
680 value = ep_aio(iocb, priv, epdata, buf, len);
681 if (value == -EIOCBQUEUED)
687 mutex_unlock(&epdata->lock);
691 /*----------------------------------------------------------------------*/
693 /* used after endpoint configuration */
694 static const struct file_operations ep_io_operations = {
695 .owner = THIS_MODULE,
698 .release = ep_release,
700 .read = new_sync_read,
701 .write = new_sync_write,
702 .unlocked_ioctl = ep_ioctl,
703 .read_iter = ep_read_iter,
704 .write_iter = ep_write_iter,
707 /* ENDPOINT INITIALIZATION
709 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
710 * status = write (fd, descriptors, sizeof descriptors)
712 * That write establishes the endpoint configuration, configuring
713 * the controller to process bulk, interrupt, or isochronous transfers
714 * at the right maxpacket size, and so on.
716 * The descriptors are message type 1, identified by a host order u32
717 * at the beginning of what's written. Descriptor order is: full/low
718 * speed descriptor, then optional high speed descriptor.
721 ep_config (struct ep_data *data, const char *buf, size_t len)
725 int value, length = len;
727 if (data->state != STATE_EP_READY) {
733 if (len < USB_DT_ENDPOINT_SIZE + 4)
736 /* we might need to change message format someday */
737 memcpy(&tag, buf, 4);
739 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
745 /* NOTE: audio endpoint extensions not accepted here;
746 * just don't include the extra bytes.
749 /* full/low speed descriptor, then high speed */
750 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
751 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
752 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
754 if (len != USB_DT_ENDPOINT_SIZE) {
755 if (len != 2 * USB_DT_ENDPOINT_SIZE)
757 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
758 USB_DT_ENDPOINT_SIZE);
759 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
760 || data->hs_desc.bDescriptorType
761 != USB_DT_ENDPOINT) {
762 DBG(data->dev, "config %s, bad hs length or type\n",
768 spin_lock_irq (&data->dev->lock);
769 if (data->dev->state == STATE_DEV_UNBOUND) {
772 } else if ((ep = data->ep) == NULL) {
776 switch (data->dev->gadget->speed) {
779 ep->desc = &data->desc;
782 /* fails if caller didn't provide that descriptor... */
783 ep->desc = &data->hs_desc;
786 DBG(data->dev, "unconnected, %s init abandoned\n",
791 value = usb_ep_enable(ep);
793 data->state = STATE_EP_ENABLED;
797 spin_unlock_irq (&data->dev->lock);
800 data->desc.bDescriptorType = 0;
801 data->hs_desc.bDescriptorType = 0;
810 ep_open (struct inode *inode, struct file *fd)
812 struct ep_data *data = inode->i_private;
815 if (mutex_lock_interruptible(&data->lock) != 0)
817 spin_lock_irq (&data->dev->lock);
818 if (data->dev->state == STATE_DEV_UNBOUND)
820 else if (data->state == STATE_EP_DISABLED) {
822 data->state = STATE_EP_READY;
824 fd->private_data = data;
825 VDEBUG (data->dev, "%s ready\n", data->name);
827 DBG (data->dev, "%s state %d\n",
828 data->name, data->state);
829 spin_unlock_irq (&data->dev->lock);
830 mutex_unlock(&data->lock);
834 /*----------------------------------------------------------------------*/
836 /* EP0 IMPLEMENTATION can be partly in userspace.
838 * Drivers that use this facility receive various events, including
839 * control requests the kernel doesn't handle. Drivers that don't
840 * use this facility may be too simple-minded for real applications.
843 static inline void ep0_readable (struct dev_data *dev)
845 wake_up (&dev->wait);
846 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
849 static void clean_req (struct usb_ep *ep, struct usb_request *req)
851 struct dev_data *dev = ep->driver_data;
853 if (req->buf != dev->rbuf) {
855 req->buf = dev->rbuf;
857 req->complete = epio_complete;
858 dev->setup_out_ready = 0;
861 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
863 struct dev_data *dev = ep->driver_data;
867 /* for control OUT, data must still get to userspace */
868 spin_lock_irqsave(&dev->lock, flags);
869 if (!dev->setup_in) {
870 dev->setup_out_error = (req->status != 0);
871 if (!dev->setup_out_error)
873 dev->setup_out_ready = 1;
877 /* clean up as appropriate */
878 if (free && req->buf != &dev->rbuf)
880 req->complete = epio_complete;
881 spin_unlock_irqrestore(&dev->lock, flags);
884 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
886 struct dev_data *dev = ep->driver_data;
888 if (dev->setup_out_ready) {
889 DBG (dev, "ep0 request busy!\n");
892 if (len > sizeof (dev->rbuf))
893 req->buf = kmalloc(len, GFP_ATOMIC);
894 if (req->buf == NULL) {
895 req->buf = dev->rbuf;
898 req->complete = ep0_complete;
905 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
907 struct dev_data *dev = fd->private_data;
909 enum ep0_state state;
911 spin_lock_irq (&dev->lock);
912 if (dev->state <= STATE_DEV_OPENED) {
917 /* report fd mode change before acting on it */
918 if (dev->setup_abort) {
919 dev->setup_abort = 0;
924 /* control DATA stage */
925 if ((state = dev->state) == STATE_DEV_SETUP) {
927 if (dev->setup_in) { /* stall IN */
928 VDEBUG(dev, "ep0in stall\n");
929 (void) usb_ep_set_halt (dev->gadget->ep0);
931 dev->state = STATE_DEV_CONNECTED;
933 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
934 struct usb_ep *ep = dev->gadget->ep0;
935 struct usb_request *req = dev->req;
937 if ((retval = setup_req (ep, req, 0)) == 0)
938 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
939 dev->state = STATE_DEV_CONNECTED;
941 /* assume that was SET_CONFIGURATION */
942 if (dev->current_config) {
945 if (gadget_is_dualspeed(dev->gadget)
946 && (dev->gadget->speed
948 power = dev->hs_config->bMaxPower;
950 power = dev->config->bMaxPower;
951 usb_gadget_vbus_draw(dev->gadget, 2 * power);
954 } else { /* collect OUT data */
955 if ((fd->f_flags & O_NONBLOCK) != 0
956 && !dev->setup_out_ready) {
960 spin_unlock_irq (&dev->lock);
961 retval = wait_event_interruptible (dev->wait,
962 dev->setup_out_ready != 0);
964 /* FIXME state could change from under us */
965 spin_lock_irq (&dev->lock);
969 if (dev->state != STATE_DEV_SETUP) {
973 dev->state = STATE_DEV_CONNECTED;
975 if (dev->setup_out_error)
978 len = min (len, (size_t)dev->req->actual);
979 // FIXME don't call this with the spinlock held ...
980 if (copy_to_user (buf, dev->req->buf, len))
984 clean_req (dev->gadget->ep0, dev->req);
985 /* NOTE userspace can't yet choose to stall */
991 /* else normal: return event data */
992 if (len < sizeof dev->event [0]) {
996 len -= len % sizeof (struct usb_gadgetfs_event);
997 dev->usermode_setup = 1;
1000 /* return queued events right away */
1001 if (dev->ev_next != 0) {
1004 n = len / sizeof (struct usb_gadgetfs_event);
1005 if (dev->ev_next < n)
1008 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1009 for (i = 0; i < n; i++) {
1010 if (dev->event [i].type == GADGETFS_SETUP) {
1011 dev->state = STATE_DEV_SETUP;
1016 spin_unlock_irq (&dev->lock);
1017 len = n * sizeof (struct usb_gadgetfs_event);
1018 if (copy_to_user (buf, &dev->event, len))
1023 /* NOTE this doesn't guard against broken drivers;
1024 * concurrent ep0 readers may lose events.
1026 spin_lock_irq (&dev->lock);
1027 if (dev->ev_next > n) {
1028 memmove(&dev->event[0], &dev->event[n],
1029 sizeof (struct usb_gadgetfs_event)
1030 * (dev->ev_next - n));
1033 spin_unlock_irq (&dev->lock);
1037 if (fd->f_flags & O_NONBLOCK) {
1044 DBG (dev, "fail %s, state %d\n", __func__, state);
1047 case STATE_DEV_UNCONNECTED:
1048 case STATE_DEV_CONNECTED:
1049 spin_unlock_irq (&dev->lock);
1050 DBG (dev, "%s wait\n", __func__);
1052 /* wait for events */
1053 retval = wait_event_interruptible (dev->wait,
1057 spin_lock_irq (&dev->lock);
1062 spin_unlock_irq (&dev->lock);
1066 static struct usb_gadgetfs_event *
1067 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1069 struct usb_gadgetfs_event *event;
1073 /* these events purge the queue */
1074 case GADGETFS_DISCONNECT:
1075 if (dev->state == STATE_DEV_SETUP)
1076 dev->setup_abort = 1;
1078 case GADGETFS_CONNECT:
1081 case GADGETFS_SETUP: /* previous request timed out */
1082 case GADGETFS_SUSPEND: /* same effect */
1083 /* these events can't be repeated */
1084 for (i = 0; i != dev->ev_next; i++) {
1085 if (dev->event [i].type != type)
1087 DBG(dev, "discard old event[%d] %d\n", i, type);
1089 if (i == dev->ev_next)
1091 /* indices start at zero, for simplicity */
1092 memmove (&dev->event [i], &dev->event [i + 1],
1093 sizeof (struct usb_gadgetfs_event)
1094 * (dev->ev_next - i));
1100 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1101 event = &dev->event [dev->ev_next++];
1102 BUG_ON (dev->ev_next > N_EVENT);
1103 memset (event, 0, sizeof *event);
1109 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1111 struct dev_data *dev = fd->private_data;
1112 ssize_t retval = -ESRCH;
1114 /* report fd mode change before acting on it */
1115 if (dev->setup_abort) {
1116 dev->setup_abort = 0;
1119 /* data and/or status stage for control request */
1120 } else if (dev->state == STATE_DEV_SETUP) {
1122 /* IN DATA+STATUS caller makes len <= wLength */
1123 if (dev->setup_in) {
1124 retval = setup_req (dev->gadget->ep0, dev->req, len);
1126 dev->state = STATE_DEV_CONNECTED;
1127 spin_unlock_irq (&dev->lock);
1128 if (copy_from_user (dev->req->buf, buf, len))
1131 if (len < dev->setup_wLength)
1133 retval = usb_ep_queue (
1134 dev->gadget->ep0, dev->req,
1138 spin_lock_irq (&dev->lock);
1139 clean_req (dev->gadget->ep0, dev->req);
1140 spin_unlock_irq (&dev->lock);
1147 /* can stall some OUT transfers */
1148 } else if (dev->setup_can_stall) {
1149 VDEBUG(dev, "ep0out stall\n");
1150 (void) usb_ep_set_halt (dev->gadget->ep0);
1152 dev->state = STATE_DEV_CONNECTED;
1154 DBG(dev, "bogus ep0out stall!\n");
1157 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1163 ep0_fasync (int f, struct file *fd, int on)
1165 struct dev_data *dev = fd->private_data;
1166 // caller must F_SETOWN before signal delivery happens
1167 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1168 return fasync_helper (f, fd, on, &dev->fasync);
1171 static struct usb_gadget_driver gadgetfs_driver;
1174 dev_release (struct inode *inode, struct file *fd)
1176 struct dev_data *dev = fd->private_data;
1178 /* closing ep0 === shutdown all */
1180 usb_gadget_unregister_driver (&gadgetfs_driver);
1182 /* at this point "good" hardware has disconnected the
1183 * device from USB; the host won't see it any more.
1184 * alternatively, all host requests will time out.
1190 /* other endpoints were all decoupled from this device */
1191 spin_lock_irq(&dev->lock);
1192 dev->state = STATE_DEV_DISABLED;
1193 spin_unlock_irq(&dev->lock);
1200 ep0_poll (struct file *fd, poll_table *wait)
1202 struct dev_data *dev = fd->private_data;
1205 if (dev->state <= STATE_DEV_OPENED)
1206 return DEFAULT_POLLMASK;
1208 poll_wait(fd, &dev->wait, wait);
1210 spin_lock_irq (&dev->lock);
1212 /* report fd mode change before acting on it */
1213 if (dev->setup_abort) {
1214 dev->setup_abort = 0;
1219 if (dev->state == STATE_DEV_SETUP) {
1220 if (dev->setup_in || dev->setup_can_stall)
1223 if (dev->ev_next != 0)
1227 spin_unlock_irq(&dev->lock);
1231 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1233 struct dev_data *dev = fd->private_data;
1234 struct usb_gadget *gadget = dev->gadget;
1237 if (gadget->ops->ioctl)
1238 ret = gadget->ops->ioctl (gadget, code, value);
1243 /*----------------------------------------------------------------------*/
1245 /* The in-kernel gadget driver handles most ep0 issues, in particular
1246 * enumerating the single configuration (as provided from user space).
1248 * Unrecognized ep0 requests may be handled in user space.
1251 static void make_qualifier (struct dev_data *dev)
1253 struct usb_qualifier_descriptor qual;
1254 struct usb_device_descriptor *desc;
1256 qual.bLength = sizeof qual;
1257 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1258 qual.bcdUSB = cpu_to_le16 (0x0200);
1261 qual.bDeviceClass = desc->bDeviceClass;
1262 qual.bDeviceSubClass = desc->bDeviceSubClass;
1263 qual.bDeviceProtocol = desc->bDeviceProtocol;
1265 /* assumes ep0 uses the same value for both speeds ... */
1266 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1268 qual.bNumConfigurations = 1;
1271 memcpy (dev->rbuf, &qual, sizeof qual);
1275 config_buf (struct dev_data *dev, u8 type, unsigned index)
1280 /* only one configuration */
1284 if (gadget_is_dualspeed(dev->gadget)) {
1285 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1286 if (type == USB_DT_OTHER_SPEED_CONFIG)
1290 dev->req->buf = dev->hs_config;
1291 len = le16_to_cpu(dev->hs_config->wTotalLength);
1293 dev->req->buf = dev->config;
1294 len = le16_to_cpu(dev->config->wTotalLength);
1296 ((u8 *)dev->req->buf) [1] = type;
1301 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1303 struct dev_data *dev = get_gadget_data (gadget);
1304 struct usb_request *req = dev->req;
1305 int value = -EOPNOTSUPP;
1306 struct usb_gadgetfs_event *event;
1307 u16 w_value = le16_to_cpu(ctrl->wValue);
1308 u16 w_length = le16_to_cpu(ctrl->wLength);
1310 spin_lock (&dev->lock);
1311 dev->setup_abort = 0;
1312 if (dev->state == STATE_DEV_UNCONNECTED) {
1313 if (gadget_is_dualspeed(gadget)
1314 && gadget->speed == USB_SPEED_HIGH
1315 && dev->hs_config == NULL) {
1316 spin_unlock(&dev->lock);
1317 ERROR (dev, "no high speed config??\n");
1321 dev->state = STATE_DEV_CONNECTED;
1323 INFO (dev, "connected\n");
1324 event = next_event (dev, GADGETFS_CONNECT);
1325 event->u.speed = gadget->speed;
1328 /* host may have given up waiting for response. we can miss control
1329 * requests handled lower down (device/endpoint status and features);
1330 * then ep0_{read,write} will report the wrong status. controller
1331 * driver will have aborted pending i/o.
1333 } else if (dev->state == STATE_DEV_SETUP)
1334 dev->setup_abort = 1;
1336 req->buf = dev->rbuf;
1337 req->context = NULL;
1338 value = -EOPNOTSUPP;
1339 switch (ctrl->bRequest) {
1341 case USB_REQ_GET_DESCRIPTOR:
1342 if (ctrl->bRequestType != USB_DIR_IN)
1344 switch (w_value >> 8) {
1347 value = min (w_length, (u16) sizeof *dev->dev);
1348 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1349 req->buf = dev->dev;
1351 case USB_DT_DEVICE_QUALIFIER:
1352 if (!dev->hs_config)
1354 value = min (w_length, (u16)
1355 sizeof (struct usb_qualifier_descriptor));
1356 make_qualifier (dev);
1358 case USB_DT_OTHER_SPEED_CONFIG:
1361 value = config_buf (dev,
1365 value = min (w_length, (u16) value);
1370 default: // all others are errors
1375 /* currently one config, two speeds */
1376 case USB_REQ_SET_CONFIGURATION:
1377 if (ctrl->bRequestType != 0)
1379 if (0 == (u8) w_value) {
1381 dev->current_config = 0;
1382 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1383 // user mode expected to disable endpoints
1387 if (gadget_is_dualspeed(gadget)
1388 && gadget->speed == USB_SPEED_HIGH) {
1389 config = dev->hs_config->bConfigurationValue;
1390 power = dev->hs_config->bMaxPower;
1392 config = dev->config->bConfigurationValue;
1393 power = dev->config->bMaxPower;
1396 if (config == (u8) w_value) {
1398 dev->current_config = config;
1399 usb_gadget_vbus_draw(gadget, 2 * power);
1403 /* report SET_CONFIGURATION like any other control request,
1404 * except that usermode may not stall this. the next
1405 * request mustn't be allowed start until this finishes:
1406 * endpoints and threads set up, etc.
1408 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1409 * has bad/racey automagic that prevents synchronizing here.
1410 * even kernel mode drivers often miss them.
1413 INFO (dev, "configuration #%d\n", dev->current_config);
1414 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1415 if (dev->usermode_setup) {
1416 dev->setup_can_stall = 0;
1422 #ifndef CONFIG_USB_PXA25X
1423 /* PXA automagically handles this request too */
1424 case USB_REQ_GET_CONFIGURATION:
1425 if (ctrl->bRequestType != 0x80)
1427 *(u8 *)req->buf = dev->current_config;
1428 value = min (w_length, (u16) 1);
1434 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1435 dev->usermode_setup ? "delegate" : "fail",
1436 ctrl->bRequestType, ctrl->bRequest,
1437 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1439 /* if there's an ep0 reader, don't stall */
1440 if (dev->usermode_setup) {
1441 dev->setup_can_stall = 1;
1443 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1445 dev->setup_wLength = w_length;
1446 dev->setup_out_ready = 0;
1447 dev->setup_out_error = 0;
1450 /* read DATA stage for OUT right away */
1451 if (unlikely (!dev->setup_in && w_length)) {
1452 value = setup_req (gadget->ep0, dev->req,
1456 value = usb_ep_queue (gadget->ep0, dev->req,
1459 clean_req (gadget->ep0, dev->req);
1463 /* we can't currently stall these */
1464 dev->setup_can_stall = 0;
1467 /* state changes when reader collects event */
1468 event = next_event (dev, GADGETFS_SETUP);
1469 event->u.setup = *ctrl;
1471 spin_unlock (&dev->lock);
1476 /* proceed with data transfer and status phases? */
1477 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1478 req->length = value;
1479 req->zero = value < w_length;
1480 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1482 DBG (dev, "ep_queue --> %d\n", value);
1487 /* device stalls when value < 0 */
1488 spin_unlock (&dev->lock);
1492 static void destroy_ep_files (struct dev_data *dev)
1494 DBG (dev, "%s %d\n", __func__, dev->state);
1496 /* dev->state must prevent interference */
1497 spin_lock_irq (&dev->lock);
1498 while (!list_empty(&dev->epfiles)) {
1500 struct inode *parent;
1501 struct dentry *dentry;
1503 /* break link to FS */
1504 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1505 list_del_init (&ep->epfiles);
1506 dentry = ep->dentry;
1508 parent = dentry->d_parent->d_inode;
1510 /* break link to controller */
1511 if (ep->state == STATE_EP_ENABLED)
1512 (void) usb_ep_disable (ep->ep);
1513 ep->state = STATE_EP_UNBOUND;
1514 usb_ep_free_request (ep->ep, ep->req);
1516 wake_up (&ep->wait);
1519 spin_unlock_irq (&dev->lock);
1521 /* break link to dcache */
1522 mutex_lock (&parent->i_mutex);
1525 mutex_unlock (&parent->i_mutex);
1527 spin_lock_irq (&dev->lock);
1529 spin_unlock_irq (&dev->lock);
1533 static struct dentry *
1534 gadgetfs_create_file (struct super_block *sb, char const *name,
1535 void *data, const struct file_operations *fops);
1537 static int activate_ep_files (struct dev_data *dev)
1540 struct ep_data *data;
1542 gadget_for_each_ep (ep, dev->gadget) {
1544 data = kzalloc(sizeof(*data), GFP_KERNEL);
1547 data->state = STATE_EP_DISABLED;
1548 mutex_init(&data->lock);
1549 init_waitqueue_head (&data->wait);
1551 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1552 atomic_set (&data->count, 1);
1557 ep->driver_data = data;
1559 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1563 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1564 data, &ep_io_operations);
1567 list_add_tail (&data->epfiles, &dev->epfiles);
1572 usb_ep_free_request (ep, data->req);
1577 DBG (dev, "%s enomem\n", __func__);
1578 destroy_ep_files (dev);
1583 gadgetfs_unbind (struct usb_gadget *gadget)
1585 struct dev_data *dev = get_gadget_data (gadget);
1587 DBG (dev, "%s\n", __func__);
1589 spin_lock_irq (&dev->lock);
1590 dev->state = STATE_DEV_UNBOUND;
1591 spin_unlock_irq (&dev->lock);
1593 destroy_ep_files (dev);
1594 gadget->ep0->driver_data = NULL;
1595 set_gadget_data (gadget, NULL);
1597 /* we've already been disconnected ... no i/o is active */
1599 usb_ep_free_request (gadget->ep0, dev->req);
1600 DBG (dev, "%s done\n", __func__);
1604 static struct dev_data *the_device;
1606 static int gadgetfs_bind(struct usb_gadget *gadget,
1607 struct usb_gadget_driver *driver)
1609 struct dev_data *dev = the_device;
1613 if (0 != strcmp (CHIP, gadget->name)) {
1614 pr_err("%s expected %s controller not %s\n",
1615 shortname, CHIP, gadget->name);
1619 set_gadget_data (gadget, dev);
1620 dev->gadget = gadget;
1621 gadget->ep0->driver_data = dev;
1623 /* preallocate control response and buffer */
1624 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1627 dev->req->context = NULL;
1628 dev->req->complete = epio_complete;
1630 if (activate_ep_files (dev) < 0)
1633 INFO (dev, "bound to %s driver\n", gadget->name);
1634 spin_lock_irq(&dev->lock);
1635 dev->state = STATE_DEV_UNCONNECTED;
1636 spin_unlock_irq(&dev->lock);
1641 gadgetfs_unbind (gadget);
1646 gadgetfs_disconnect (struct usb_gadget *gadget)
1648 struct dev_data *dev = get_gadget_data (gadget);
1649 unsigned long flags;
1651 spin_lock_irqsave (&dev->lock, flags);
1652 if (dev->state == STATE_DEV_UNCONNECTED)
1654 dev->state = STATE_DEV_UNCONNECTED;
1656 INFO (dev, "disconnected\n");
1657 next_event (dev, GADGETFS_DISCONNECT);
1660 spin_unlock_irqrestore (&dev->lock, flags);
1664 gadgetfs_suspend (struct usb_gadget *gadget)
1666 struct dev_data *dev = get_gadget_data (gadget);
1668 INFO (dev, "suspended from state %d\n", dev->state);
1669 spin_lock (&dev->lock);
1670 switch (dev->state) {
1671 case STATE_DEV_SETUP: // VERY odd... host died??
1672 case STATE_DEV_CONNECTED:
1673 case STATE_DEV_UNCONNECTED:
1674 next_event (dev, GADGETFS_SUSPEND);
1680 spin_unlock (&dev->lock);
1683 static struct usb_gadget_driver gadgetfs_driver = {
1684 .function = (char *) driver_desc,
1685 .bind = gadgetfs_bind,
1686 .unbind = gadgetfs_unbind,
1687 .setup = gadgetfs_setup,
1688 .reset = gadgetfs_disconnect,
1689 .disconnect = gadgetfs_disconnect,
1690 .suspend = gadgetfs_suspend,
1693 .name = (char *) shortname,
1697 /*----------------------------------------------------------------------*/
1699 static void gadgetfs_nop(struct usb_gadget *arg) { }
1701 static int gadgetfs_probe(struct usb_gadget *gadget,
1702 struct usb_gadget_driver *driver)
1704 CHIP = gadget->name;
1708 static struct usb_gadget_driver probe_driver = {
1709 .max_speed = USB_SPEED_HIGH,
1710 .bind = gadgetfs_probe,
1711 .unbind = gadgetfs_nop,
1712 .setup = (void *)gadgetfs_nop,
1713 .disconnect = gadgetfs_nop,
1720 /* DEVICE INITIALIZATION
1722 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1723 * status = write (fd, descriptors, sizeof descriptors)
1725 * That write establishes the device configuration, so the kernel can
1726 * bind to the controller ... guaranteeing it can handle enumeration
1727 * at all necessary speeds. Descriptor order is:
1729 * . message tag (u32, host order) ... for now, must be zero; it
1730 * would change to support features like multi-config devices
1731 * . full/low speed config ... all wTotalLength bytes (with interface,
1732 * class, altsetting, endpoint, and other descriptors)
1733 * . high speed config ... all descriptors, for high speed operation;
1734 * this one's optional except for high-speed hardware
1735 * . device descriptor
1737 * Endpoints are not yet enabled. Drivers must wait until device
1738 * configuration and interface altsetting changes create
1739 * the need to configure (or unconfigure) them.
1741 * After initialization, the device stays active for as long as that
1742 * $CHIP file is open. Events must then be read from that descriptor,
1743 * such as configuration notifications.
1746 static int is_valid_config (struct usb_config_descriptor *config)
1748 return config->bDescriptorType == USB_DT_CONFIG
1749 && config->bLength == USB_DT_CONFIG_SIZE
1750 && config->bConfigurationValue != 0
1751 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1752 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1753 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1754 /* FIXME check lengths: walk to end */
1758 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1760 struct dev_data *dev = fd->private_data;
1761 ssize_t value = len, length = len;
1766 spin_lock_irq(&dev->lock);
1767 if (dev->state > STATE_DEV_OPENED) {
1768 value = ep0_write(fd, buf, len, ptr);
1769 spin_unlock_irq(&dev->lock);
1772 spin_unlock_irq(&dev->lock);
1774 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1777 /* we might need to change message format someday */
1778 if (copy_from_user (&tag, buf, 4))
1785 kbuf = memdup_user(buf, length);
1787 return PTR_ERR(kbuf);
1789 spin_lock_irq (&dev->lock);
1795 /* full or low speed config */
1796 dev->config = (void *) kbuf;
1797 total = le16_to_cpu(dev->config->wTotalLength);
1798 if (!is_valid_config (dev->config) || total >= length)
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 >= length)
1813 /* could support multiple configs, using another encoding! */
1815 /* device descriptor (tweaked for paranoia) */
1816 if (length != USB_DT_DEVICE_SIZE)
1818 dev->dev = (void *)kbuf;
1819 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1820 || dev->dev->bDescriptorType != USB_DT_DEVICE
1821 || dev->dev->bNumConfigurations != 1)
1823 dev->dev->bNumConfigurations = 1;
1824 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1826 /* triggers gadgetfs_bind(); then we can enumerate. */
1827 spin_unlock_irq (&dev->lock);
1829 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1831 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1833 value = usb_gadget_probe_driver(&gadgetfs_driver);
1838 /* at this point "good" hardware has for the first time
1839 * let the USB the host see us. alternatively, if users
1840 * unplug/replug that will clear all the error state.
1842 * note: everything running before here was guaranteed
1843 * to choke driver model style diagnostics. from here
1844 * on, they can work ... except in cleanup paths that
1845 * kick in after the ep0 descriptor is closed.
1852 spin_unlock_irq (&dev->lock);
1853 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1860 dev_open (struct inode *inode, struct file *fd)
1862 struct dev_data *dev = inode->i_private;
1865 spin_lock_irq(&dev->lock);
1866 if (dev->state == STATE_DEV_DISABLED) {
1868 dev->state = STATE_DEV_OPENED;
1869 fd->private_data = dev;
1873 spin_unlock_irq(&dev->lock);
1877 static const struct file_operations ep0_operations = {
1878 .llseek = no_llseek,
1882 .write = dev_config,
1883 .fasync = ep0_fasync,
1885 .unlocked_ioctl = dev_ioctl,
1886 .release = dev_release,
1889 /*----------------------------------------------------------------------*/
1891 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1893 * Mounting the filesystem creates a controller file, used first for
1894 * device configuration then later for event monitoring.
1898 /* FIXME PAM etc could set this security policy without mount options
1899 * if epfiles inherited ownership and permissons from ep0 ...
1902 static unsigned default_uid;
1903 static unsigned default_gid;
1904 static unsigned default_perm = S_IRUSR | S_IWUSR;
1906 module_param (default_uid, uint, 0644);
1907 module_param (default_gid, uint, 0644);
1908 module_param (default_perm, uint, 0644);
1911 static struct inode *
1912 gadgetfs_make_inode (struct super_block *sb,
1913 void *data, const struct file_operations *fops,
1916 struct inode *inode = new_inode (sb);
1919 inode->i_ino = get_next_ino();
1920 inode->i_mode = mode;
1921 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1922 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1923 inode->i_atime = inode->i_mtime = inode->i_ctime
1925 inode->i_private = data;
1926 inode->i_fop = fops;
1931 /* creates in fs root directory, so non-renamable and non-linkable.
1932 * so inode and dentry are paired, until device reconfig.
1934 static struct dentry *
1935 gadgetfs_create_file (struct super_block *sb, char const *name,
1936 void *data, const struct file_operations *fops)
1938 struct dentry *dentry;
1939 struct inode *inode;
1941 dentry = d_alloc_name(sb->s_root, name);
1945 inode = gadgetfs_make_inode (sb, data, fops,
1946 S_IFREG | (default_perm & S_IRWXUGO));
1951 d_add (dentry, inode);
1955 static const struct super_operations gadget_fs_operations = {
1956 .statfs = simple_statfs,
1957 .drop_inode = generic_delete_inode,
1961 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
1963 struct inode *inode;
1964 struct dev_data *dev;
1969 /* fake probe to determine $CHIP */
1971 usb_gadget_probe_driver(&probe_driver);
1976 sb->s_blocksize = PAGE_CACHE_SIZE;
1977 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1978 sb->s_magic = GADGETFS_MAGIC;
1979 sb->s_op = &gadget_fs_operations;
1980 sb->s_time_gran = 1;
1983 inode = gadgetfs_make_inode (sb,
1984 NULL, &simple_dir_operations,
1985 S_IFDIR | S_IRUGO | S_IXUGO);
1988 inode->i_op = &simple_dir_inode_operations;
1989 if (!(sb->s_root = d_make_root (inode)))
1992 /* the ep0 file is named after the controller we expect;
1993 * user mode code can use it for sanity checks, like we do.
2000 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2006 /* other endpoint files are available after hardware setup,
2007 * from binding to a controller.
2016 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2017 static struct dentry *
2018 gadgetfs_mount (struct file_system_type *t, int flags,
2019 const char *path, void *opts)
2021 return mount_single (t, flags, opts, gadgetfs_fill_super);
2025 gadgetfs_kill_sb (struct super_block *sb)
2027 kill_litter_super (sb);
2029 put_dev (the_device);
2034 /*----------------------------------------------------------------------*/
2036 static struct file_system_type gadgetfs_type = {
2037 .owner = THIS_MODULE,
2039 .mount = gadgetfs_mount,
2040 .kill_sb = gadgetfs_kill_sb,
2042 MODULE_ALIAS_FS("gadgetfs");
2044 /*----------------------------------------------------------------------*/
2046 static int __init init (void)
2050 status = register_filesystem (&gadgetfs_type);
2052 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2053 shortname, driver_desc);
2058 static void __exit cleanup (void)
2060 pr_debug ("unregister %s\n", shortname);
2061 unregister_filesystem (&gadgetfs_type);
2063 module_exit (cleanup);