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 */
117 enum ep0_state state; /* P: lock */
118 struct usb_gadgetfs_event event [N_EVENT];
120 struct fasync_struct *fasync;
123 /* drivers reading ep0 MUST handle control requests (SETUP)
124 * reported that way; else the host will time out.
126 unsigned usermode_setup : 1,
132 gadget_registered : 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 refcount_inc (&data->count);
155 static void put_dev (struct dev_data *data)
157 if (likely (!refcount_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 refcount_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 refcount_inc (&data->count);
210 static void put_ep (struct ep_data *data)
212 if (likely (!refcount_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_for_completion_interruptible(&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_for_completion(&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);
467 kthread_unuse_mm(mm);
471 /* completing the iocb can drop the ctx and mm, don't touch mm after */
472 iocb->ki_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 */
501 iocb->ki_complete(iocb,
502 req->actual ? req->actual : (long)req->status,
505 /* ep_copy_to_user() won't report both; we hide some faults */
506 if (unlikely(0 != req->status))
507 DBG(epdata->dev, "%s fault %d len %d\n",
508 ep->name, req->status, req->actual);
510 priv->buf = req->buf;
511 priv->actual = req->actual;
512 INIT_WORK(&priv->work, ep_user_copy_worker);
513 schedule_work(&priv->work);
516 usb_ep_free_request(ep, req);
517 spin_unlock(&epdata->dev->lock);
521 static ssize_t ep_aio(struct kiocb *iocb,
522 struct kiocb_priv *priv,
523 struct ep_data *epdata,
527 struct usb_request *req;
530 iocb->private = priv;
533 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
535 priv->epdata = epdata;
537 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
539 /* each kiocb is coupled to one usb_request, but we can't
540 * allocate or submit those if the host disconnected.
542 spin_lock_irq(&epdata->dev->lock);
544 if (unlikely(epdata->ep == NULL))
547 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
555 req->complete = ep_aio_complete;
557 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
558 if (unlikely(0 != value)) {
559 usb_ep_free_request(epdata->ep, req);
562 spin_unlock_irq(&epdata->dev->lock);
566 spin_unlock_irq(&epdata->dev->lock);
567 kfree(priv->to_free);
574 ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
576 struct file *file = iocb->ki_filp;
577 struct ep_data *epdata = file->private_data;
578 size_t len = iov_iter_count(to);
582 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
585 /* halt any endpoint by doing a "wrong direction" i/o call */
586 if (usb_endpoint_dir_in(&epdata->desc)) {
587 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
588 !is_sync_kiocb(iocb)) {
589 mutex_unlock(&epdata->lock);
592 DBG (epdata->dev, "%s halt\n", epdata->name);
593 spin_lock_irq(&epdata->dev->lock);
594 if (likely(epdata->ep != NULL))
595 usb_ep_set_halt(epdata->ep);
596 spin_unlock_irq(&epdata->dev->lock);
597 mutex_unlock(&epdata->lock);
601 buf = kmalloc(len, GFP_KERNEL);
602 if (unlikely(!buf)) {
603 mutex_unlock(&epdata->lock);
606 if (is_sync_kiocb(iocb)) {
607 value = ep_io(epdata, buf, len);
608 if (value >= 0 && (copy_to_iter(buf, value, to) != value))
611 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
615 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
616 if (!priv->to_free) {
620 value = ep_aio(iocb, priv, epdata, buf, len);
621 if (value == -EIOCBQUEUED)
626 mutex_unlock(&epdata->lock);
630 static ssize_t ep_config(struct ep_data *, const char *, size_t);
633 ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
635 struct file *file = iocb->ki_filp;
636 struct ep_data *epdata = file->private_data;
637 size_t len = iov_iter_count(from);
642 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
645 configured = epdata->state == STATE_EP_ENABLED;
647 /* halt any endpoint by doing a "wrong direction" i/o call */
648 if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
649 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
650 !is_sync_kiocb(iocb)) {
651 mutex_unlock(&epdata->lock);
654 DBG (epdata->dev, "%s halt\n", epdata->name);
655 spin_lock_irq(&epdata->dev->lock);
656 if (likely(epdata->ep != NULL))
657 usb_ep_set_halt(epdata->ep);
658 spin_unlock_irq(&epdata->dev->lock);
659 mutex_unlock(&epdata->lock);
663 buf = kmalloc(len, GFP_KERNEL);
664 if (unlikely(!buf)) {
665 mutex_unlock(&epdata->lock);
669 if (unlikely(!copy_from_iter_full(buf, len, from))) {
674 if (unlikely(!configured)) {
675 value = ep_config(epdata, buf, len);
676 } else if (is_sync_kiocb(iocb)) {
677 value = ep_io(epdata, buf, len);
679 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
682 value = ep_aio(iocb, priv, epdata, buf, len);
683 if (value == -EIOCBQUEUED)
689 mutex_unlock(&epdata->lock);
693 /*----------------------------------------------------------------------*/
695 /* used after endpoint configuration */
696 static const struct file_operations ep_io_operations = {
697 .owner = THIS_MODULE,
700 .release = ep_release,
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) {
779 switch (data->dev->gadget->speed) {
782 ep->desc = &data->desc;
785 /* fails if caller didn't provide that descriptor... */
786 ep->desc = &data->hs_desc;
789 DBG(data->dev, "unconnected, %s init abandoned\n",
794 value = usb_ep_enable(ep);
796 data->state = STATE_EP_ENABLED;
800 spin_unlock_irq (&data->dev->lock);
803 data->desc.bDescriptorType = 0;
804 data->hs_desc.bDescriptorType = 0;
813 ep_open (struct inode *inode, struct file *fd)
815 struct ep_data *data = inode->i_private;
818 if (mutex_lock_interruptible(&data->lock) != 0)
820 spin_lock_irq (&data->dev->lock);
821 if (data->dev->state == STATE_DEV_UNBOUND)
823 else if (data->state == STATE_EP_DISABLED) {
825 data->state = STATE_EP_READY;
827 fd->private_data = data;
828 VDEBUG (data->dev, "%s ready\n", data->name);
830 DBG (data->dev, "%s state %d\n",
831 data->name, data->state);
832 spin_unlock_irq (&data->dev->lock);
833 mutex_unlock(&data->lock);
837 /*----------------------------------------------------------------------*/
839 /* EP0 IMPLEMENTATION can be partly in userspace.
841 * Drivers that use this facility receive various events, including
842 * control requests the kernel doesn't handle. Drivers that don't
843 * use this facility may be too simple-minded for real applications.
846 static inline void ep0_readable (struct dev_data *dev)
848 wake_up (&dev->wait);
849 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
852 static void clean_req (struct usb_ep *ep, struct usb_request *req)
854 struct dev_data *dev = ep->driver_data;
856 if (req->buf != dev->rbuf) {
858 req->buf = dev->rbuf;
860 req->complete = epio_complete;
861 dev->setup_out_ready = 0;
864 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
866 struct dev_data *dev = ep->driver_data;
870 /* for control OUT, data must still get to userspace */
871 spin_lock_irqsave(&dev->lock, flags);
872 if (!dev->setup_in) {
873 dev->setup_out_error = (req->status != 0);
874 if (!dev->setup_out_error)
876 dev->setup_out_ready = 1;
880 /* clean up as appropriate */
881 if (free && req->buf != &dev->rbuf)
883 req->complete = epio_complete;
884 spin_unlock_irqrestore(&dev->lock, flags);
887 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
889 struct dev_data *dev = ep->driver_data;
891 if (dev->setup_out_ready) {
892 DBG (dev, "ep0 request busy!\n");
895 if (len > sizeof (dev->rbuf))
896 req->buf = kmalloc(len, GFP_ATOMIC);
897 if (req->buf == NULL) {
898 req->buf = dev->rbuf;
901 req->complete = ep0_complete;
908 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
910 struct dev_data *dev = fd->private_data;
912 enum ep0_state state;
914 spin_lock_irq (&dev->lock);
915 if (dev->state <= STATE_DEV_OPENED) {
920 /* report fd mode change before acting on it */
921 if (dev->setup_abort) {
922 dev->setup_abort = 0;
927 /* control DATA stage */
928 if ((state = dev->state) == STATE_DEV_SETUP) {
930 if (dev->setup_in) { /* stall IN */
931 VDEBUG(dev, "ep0in stall\n");
932 (void) usb_ep_set_halt (dev->gadget->ep0);
934 dev->state = STATE_DEV_CONNECTED;
936 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
937 struct usb_ep *ep = dev->gadget->ep0;
938 struct usb_request *req = dev->req;
940 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);
947 dev->state = STATE_DEV_CONNECTED;
949 /* assume that was SET_CONFIGURATION */
950 if (dev->current_config) {
953 if (gadget_is_dualspeed(dev->gadget)
954 && (dev->gadget->speed
956 power = dev->hs_config->bMaxPower;
958 power = dev->config->bMaxPower;
959 usb_gadget_vbus_draw(dev->gadget, 2 * power);
962 } else { /* collect OUT data */
963 if ((fd->f_flags & O_NONBLOCK) != 0
964 && !dev->setup_out_ready) {
968 spin_unlock_irq (&dev->lock);
969 retval = wait_event_interruptible (dev->wait,
970 dev->setup_out_ready != 0);
972 /* FIXME state could change from under us */
973 spin_lock_irq (&dev->lock);
977 if (dev->state != STATE_DEV_SETUP) {
981 dev->state = STATE_DEV_CONNECTED;
983 if (dev->setup_out_error)
986 len = min (len, (size_t)dev->req->actual);
988 spin_unlock_irq(&dev->lock);
989 if (copy_to_user (buf, dev->req->buf, len))
993 spin_lock_irq(&dev->lock);
995 clean_req (dev->gadget->ep0, dev->req);
996 /* NOTE userspace can't yet choose to stall */
1002 /* else normal: return event data */
1003 if (len < sizeof dev->event [0]) {
1007 len -= len % sizeof (struct usb_gadgetfs_event);
1008 dev->usermode_setup = 1;
1011 /* return queued events right away */
1012 if (dev->ev_next != 0) {
1015 n = len / sizeof (struct usb_gadgetfs_event);
1016 if (dev->ev_next < n)
1019 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1020 for (i = 0; i < n; i++) {
1021 if (dev->event [i].type == GADGETFS_SETUP) {
1022 dev->state = STATE_DEV_SETUP;
1027 spin_unlock_irq (&dev->lock);
1028 len = n * sizeof (struct usb_gadgetfs_event);
1029 if (copy_to_user (buf, &dev->event, len))
1034 /* NOTE this doesn't guard against broken drivers;
1035 * concurrent ep0 readers may lose events.
1037 spin_lock_irq (&dev->lock);
1038 if (dev->ev_next > n) {
1039 memmove(&dev->event[0], &dev->event[n],
1040 sizeof (struct usb_gadgetfs_event)
1041 * (dev->ev_next - n));
1044 spin_unlock_irq (&dev->lock);
1048 if (fd->f_flags & O_NONBLOCK) {
1055 DBG (dev, "fail %s, state %d\n", __func__, state);
1058 case STATE_DEV_UNCONNECTED:
1059 case STATE_DEV_CONNECTED:
1060 spin_unlock_irq (&dev->lock);
1061 DBG (dev, "%s wait\n", __func__);
1063 /* wait for events */
1064 retval = wait_event_interruptible (dev->wait,
1068 spin_lock_irq (&dev->lock);
1073 spin_unlock_irq (&dev->lock);
1077 static struct usb_gadgetfs_event *
1078 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1080 struct usb_gadgetfs_event *event;
1084 /* these events purge the queue */
1085 case GADGETFS_DISCONNECT:
1086 if (dev->state == STATE_DEV_SETUP)
1087 dev->setup_abort = 1;
1089 case GADGETFS_CONNECT:
1092 case GADGETFS_SETUP: /* previous request timed out */
1093 case GADGETFS_SUSPEND: /* same effect */
1094 /* these events can't be repeated */
1095 for (i = 0; i != dev->ev_next; i++) {
1096 if (dev->event [i].type != type)
1098 DBG(dev, "discard old event[%d] %d\n", i, type);
1100 if (i == dev->ev_next)
1102 /* indices start at zero, for simplicity */
1103 memmove (&dev->event [i], &dev->event [i + 1],
1104 sizeof (struct usb_gadgetfs_event)
1105 * (dev->ev_next - i));
1111 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1112 event = &dev->event [dev->ev_next++];
1113 BUG_ON (dev->ev_next > N_EVENT);
1114 memset (event, 0, sizeof *event);
1120 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1122 struct dev_data *dev = fd->private_data;
1123 ssize_t retval = -ESRCH;
1125 /* report fd mode change before acting on it */
1126 if (dev->setup_abort) {
1127 dev->setup_abort = 0;
1130 /* data and/or status stage for control request */
1131 } else if (dev->state == STATE_DEV_SETUP) {
1133 len = min_t(size_t, len, dev->setup_wLength);
1134 if (dev->setup_in) {
1135 retval = setup_req (dev->gadget->ep0, dev->req, len);
1137 dev->state = STATE_DEV_CONNECTED;
1139 spin_unlock_irq (&dev->lock);
1140 if (copy_from_user (dev->req->buf, buf, len))
1143 if (len < dev->setup_wLength)
1145 retval = usb_ep_queue (
1146 dev->gadget->ep0, dev->req,
1149 spin_lock_irq(&dev->lock);
1152 clean_req (dev->gadget->ep0, dev->req);
1159 /* can stall some OUT transfers */
1160 } else if (dev->setup_can_stall) {
1161 VDEBUG(dev, "ep0out stall\n");
1162 (void) usb_ep_set_halt (dev->gadget->ep0);
1164 dev->state = STATE_DEV_CONNECTED;
1166 DBG(dev, "bogus ep0out stall!\n");
1169 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1175 ep0_fasync (int f, struct file *fd, int on)
1177 struct dev_data *dev = fd->private_data;
1178 // caller must F_SETOWN before signal delivery happens
1179 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1180 return fasync_helper (f, fd, on, &dev->fasync);
1183 static struct usb_gadget_driver gadgetfs_driver;
1186 dev_release (struct inode *inode, struct file *fd)
1188 struct dev_data *dev = fd->private_data;
1190 /* closing ep0 === shutdown all */
1192 if (dev->gadget_registered) {
1193 usb_gadget_unregister_driver (&gadgetfs_driver);
1194 dev->gadget_registered = false;
1197 /* at this point "good" hardware has disconnected the
1198 * device from USB; the host won't see it any more.
1199 * alternatively, all host requests will time out.
1205 /* other endpoints were all decoupled from this device */
1206 spin_lock_irq(&dev->lock);
1207 dev->state = STATE_DEV_DISABLED;
1208 spin_unlock_irq(&dev->lock);
1215 ep0_poll (struct file *fd, poll_table *wait)
1217 struct dev_data *dev = fd->private_data;
1220 if (dev->state <= STATE_DEV_OPENED)
1221 return DEFAULT_POLLMASK;
1223 poll_wait(fd, &dev->wait, wait);
1225 spin_lock_irq(&dev->lock);
1227 /* report fd mode change before acting on it */
1228 if (dev->setup_abort) {
1229 dev->setup_abort = 0;
1234 if (dev->state == STATE_DEV_SETUP) {
1235 if (dev->setup_in || dev->setup_can_stall)
1238 if (dev->ev_next != 0)
1242 spin_unlock_irq(&dev->lock);
1246 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1248 struct dev_data *dev = fd->private_data;
1249 struct usb_gadget *gadget = dev->gadget;
1252 spin_lock_irq(&dev->lock);
1253 if (dev->state == STATE_DEV_OPENED ||
1254 dev->state == STATE_DEV_UNBOUND) {
1255 /* Not bound to a UDC */
1256 } else if (gadget->ops->ioctl) {
1258 spin_unlock_irq(&dev->lock);
1260 ret = gadget->ops->ioctl (gadget, code, value);
1262 spin_lock_irq(&dev->lock);
1265 spin_unlock_irq(&dev->lock);
1270 /*----------------------------------------------------------------------*/
1272 /* The in-kernel gadget driver handles most ep0 issues, in particular
1273 * enumerating the single configuration (as provided from user space).
1275 * Unrecognized ep0 requests may be handled in user space.
1278 static void make_qualifier (struct dev_data *dev)
1280 struct usb_qualifier_descriptor qual;
1281 struct usb_device_descriptor *desc;
1283 qual.bLength = sizeof qual;
1284 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1285 qual.bcdUSB = cpu_to_le16 (0x0200);
1288 qual.bDeviceClass = desc->bDeviceClass;
1289 qual.bDeviceSubClass = desc->bDeviceSubClass;
1290 qual.bDeviceProtocol = desc->bDeviceProtocol;
1292 /* assumes ep0 uses the same value for both speeds ... */
1293 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1295 qual.bNumConfigurations = 1;
1298 memcpy (dev->rbuf, &qual, sizeof qual);
1302 config_buf (struct dev_data *dev, u8 type, unsigned index)
1307 /* only one configuration */
1311 if (gadget_is_dualspeed(dev->gadget)) {
1312 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1313 if (type == USB_DT_OTHER_SPEED_CONFIG)
1317 dev->req->buf = dev->hs_config;
1318 len = le16_to_cpu(dev->hs_config->wTotalLength);
1320 dev->req->buf = dev->config;
1321 len = le16_to_cpu(dev->config->wTotalLength);
1323 ((u8 *)dev->req->buf) [1] = type;
1328 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1330 struct dev_data *dev = get_gadget_data (gadget);
1331 struct usb_request *req = dev->req;
1332 int value = -EOPNOTSUPP;
1333 struct usb_gadgetfs_event *event;
1334 u16 w_value = le16_to_cpu(ctrl->wValue);
1335 u16 w_length = le16_to_cpu(ctrl->wLength);
1337 spin_lock (&dev->lock);
1338 dev->setup_abort = 0;
1339 if (dev->state == STATE_DEV_UNCONNECTED) {
1340 if (gadget_is_dualspeed(gadget)
1341 && gadget->speed == USB_SPEED_HIGH
1342 && dev->hs_config == NULL) {
1343 spin_unlock(&dev->lock);
1344 ERROR (dev, "no high speed config??\n");
1348 dev->state = STATE_DEV_CONNECTED;
1350 INFO (dev, "connected\n");
1351 event = next_event (dev, GADGETFS_CONNECT);
1352 event->u.speed = gadget->speed;
1355 /* host may have given up waiting for response. we can miss control
1356 * requests handled lower down (device/endpoint status and features);
1357 * then ep0_{read,write} will report the wrong status. controller
1358 * driver will have aborted pending i/o.
1360 } else if (dev->state == STATE_DEV_SETUP)
1361 dev->setup_abort = 1;
1363 req->buf = dev->rbuf;
1364 req->context = NULL;
1365 switch (ctrl->bRequest) {
1367 case USB_REQ_GET_DESCRIPTOR:
1368 if (ctrl->bRequestType != USB_DIR_IN)
1370 switch (w_value >> 8) {
1373 value = min (w_length, (u16) sizeof *dev->dev);
1374 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1375 req->buf = dev->dev;
1377 case USB_DT_DEVICE_QUALIFIER:
1378 if (!dev->hs_config)
1380 value = min (w_length, (u16)
1381 sizeof (struct usb_qualifier_descriptor));
1382 make_qualifier (dev);
1384 case USB_DT_OTHER_SPEED_CONFIG:
1386 value = config_buf (dev,
1390 value = min (w_length, (u16) value);
1395 default: // all others are errors
1400 /* currently one config, two speeds */
1401 case USB_REQ_SET_CONFIGURATION:
1402 if (ctrl->bRequestType != 0)
1404 if (0 == (u8) w_value) {
1406 dev->current_config = 0;
1407 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1408 // user mode expected to disable endpoints
1412 if (gadget_is_dualspeed(gadget)
1413 && gadget->speed == USB_SPEED_HIGH) {
1414 config = dev->hs_config->bConfigurationValue;
1415 power = dev->hs_config->bMaxPower;
1417 config = dev->config->bConfigurationValue;
1418 power = dev->config->bMaxPower;
1421 if (config == (u8) w_value) {
1423 dev->current_config = config;
1424 usb_gadget_vbus_draw(gadget, 2 * power);
1428 /* report SET_CONFIGURATION like any other control request,
1429 * except that usermode may not stall this. the next
1430 * request mustn't be allowed start until this finishes:
1431 * endpoints and threads set up, etc.
1433 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1434 * has bad/racey automagic that prevents synchronizing here.
1435 * even kernel mode drivers often miss them.
1438 INFO (dev, "configuration #%d\n", dev->current_config);
1439 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1440 if (dev->usermode_setup) {
1441 dev->setup_can_stall = 0;
1447 #ifndef CONFIG_USB_PXA25X
1448 /* PXA automagically handles this request too */
1449 case USB_REQ_GET_CONFIGURATION:
1450 if (ctrl->bRequestType != 0x80)
1452 *(u8 *)req->buf = dev->current_config;
1453 value = min (w_length, (u16) 1);
1459 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1460 dev->usermode_setup ? "delegate" : "fail",
1461 ctrl->bRequestType, ctrl->bRequest,
1462 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1464 /* if there's an ep0 reader, don't stall */
1465 if (dev->usermode_setup) {
1466 dev->setup_can_stall = 1;
1468 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1470 dev->setup_wLength = w_length;
1471 dev->setup_out_ready = 0;
1472 dev->setup_out_error = 0;
1474 /* read DATA stage for OUT right away */
1475 if (unlikely (!dev->setup_in && w_length)) {
1476 value = setup_req (gadget->ep0, dev->req,
1482 spin_unlock (&dev->lock);
1483 value = usb_ep_queue (gadget->ep0, dev->req,
1485 spin_lock (&dev->lock);
1488 clean_req (gadget->ep0, dev->req);
1492 /* we can't currently stall these */
1493 dev->setup_can_stall = 0;
1496 /* state changes when reader collects event */
1497 event = next_event (dev, GADGETFS_SETUP);
1498 event->u.setup = *ctrl;
1500 spin_unlock (&dev->lock);
1505 /* proceed with data transfer and status phases? */
1506 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1507 req->length = value;
1508 req->zero = value < w_length;
1511 spin_unlock (&dev->lock);
1512 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL);
1513 spin_lock(&dev->lock);
1515 spin_unlock(&dev->lock);
1517 DBG (dev, "ep_queue --> %d\n", value);
1523 /* device stalls when value < 0 */
1524 spin_unlock (&dev->lock);
1528 static void destroy_ep_files (struct dev_data *dev)
1530 DBG (dev, "%s %d\n", __func__, dev->state);
1532 /* dev->state must prevent interference */
1533 spin_lock_irq (&dev->lock);
1534 while (!list_empty(&dev->epfiles)) {
1536 struct inode *parent;
1537 struct dentry *dentry;
1539 /* break link to FS */
1540 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1541 list_del_init (&ep->epfiles);
1542 spin_unlock_irq (&dev->lock);
1544 dentry = ep->dentry;
1546 parent = d_inode(dentry->d_parent);
1548 /* break link to controller */
1549 mutex_lock(&ep->lock);
1550 if (ep->state == STATE_EP_ENABLED)
1551 (void) usb_ep_disable (ep->ep);
1552 ep->state = STATE_EP_UNBOUND;
1553 usb_ep_free_request (ep->ep, ep->req);
1555 mutex_unlock(&ep->lock);
1557 wake_up (&ep->wait);
1560 /* break link to dcache */
1564 inode_unlock(parent);
1566 spin_lock_irq (&dev->lock);
1568 spin_unlock_irq (&dev->lock);
1572 static struct dentry *
1573 gadgetfs_create_file (struct super_block *sb, char const *name,
1574 void *data, const struct file_operations *fops);
1576 static int activate_ep_files (struct dev_data *dev)
1579 struct ep_data *data;
1581 gadget_for_each_ep (ep, dev->gadget) {
1583 data = kzalloc(sizeof(*data), GFP_KERNEL);
1586 data->state = STATE_EP_DISABLED;
1587 mutex_init(&data->lock);
1588 init_waitqueue_head (&data->wait);
1590 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1591 refcount_set (&data->count, 1);
1596 ep->driver_data = data;
1598 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1602 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1603 data, &ep_io_operations);
1606 list_add_tail (&data->epfiles, &dev->epfiles);
1611 usb_ep_free_request (ep, data->req);
1616 DBG (dev, "%s enomem\n", __func__);
1617 destroy_ep_files (dev);
1622 gadgetfs_unbind (struct usb_gadget *gadget)
1624 struct dev_data *dev = get_gadget_data (gadget);
1626 DBG (dev, "%s\n", __func__);
1628 spin_lock_irq (&dev->lock);
1629 dev->state = STATE_DEV_UNBOUND;
1630 while (dev->udc_usage > 0) {
1631 spin_unlock_irq(&dev->lock);
1632 usleep_range(1000, 2000);
1633 spin_lock_irq(&dev->lock);
1635 spin_unlock_irq (&dev->lock);
1637 destroy_ep_files (dev);
1638 gadget->ep0->driver_data = NULL;
1639 set_gadget_data (gadget, NULL);
1641 /* we've already been disconnected ... no i/o is active */
1643 usb_ep_free_request (gadget->ep0, dev->req);
1644 DBG (dev, "%s done\n", __func__);
1648 static struct dev_data *the_device;
1650 static int gadgetfs_bind(struct usb_gadget *gadget,
1651 struct usb_gadget_driver *driver)
1653 struct dev_data *dev = the_device;
1657 if (0 != strcmp (CHIP, gadget->name)) {
1658 pr_err("%s expected %s controller not %s\n",
1659 shortname, CHIP, gadget->name);
1663 set_gadget_data (gadget, dev);
1664 dev->gadget = gadget;
1665 gadget->ep0->driver_data = dev;
1667 /* preallocate control response and buffer */
1668 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1671 dev->req->context = NULL;
1672 dev->req->complete = epio_complete;
1674 if (activate_ep_files (dev) < 0)
1677 INFO (dev, "bound to %s driver\n", gadget->name);
1678 spin_lock_irq(&dev->lock);
1679 dev->state = STATE_DEV_UNCONNECTED;
1680 spin_unlock_irq(&dev->lock);
1685 gadgetfs_unbind (gadget);
1690 gadgetfs_disconnect (struct usb_gadget *gadget)
1692 struct dev_data *dev = get_gadget_data (gadget);
1693 unsigned long flags;
1695 spin_lock_irqsave (&dev->lock, flags);
1696 if (dev->state == STATE_DEV_UNCONNECTED)
1698 dev->state = STATE_DEV_UNCONNECTED;
1700 INFO (dev, "disconnected\n");
1701 next_event (dev, GADGETFS_DISCONNECT);
1704 spin_unlock_irqrestore (&dev->lock, flags);
1708 gadgetfs_suspend (struct usb_gadget *gadget)
1710 struct dev_data *dev = get_gadget_data (gadget);
1711 unsigned long flags;
1713 INFO (dev, "suspended from state %d\n", dev->state);
1714 spin_lock_irqsave(&dev->lock, flags);
1715 switch (dev->state) {
1716 case STATE_DEV_SETUP: // VERY odd... host died??
1717 case STATE_DEV_CONNECTED:
1718 case STATE_DEV_UNCONNECTED:
1719 next_event (dev, GADGETFS_SUSPEND);
1725 spin_unlock_irqrestore(&dev->lock, flags);
1728 static struct usb_gadget_driver gadgetfs_driver = {
1729 .function = (char *) driver_desc,
1730 .bind = gadgetfs_bind,
1731 .unbind = gadgetfs_unbind,
1732 .setup = gadgetfs_setup,
1733 .reset = gadgetfs_disconnect,
1734 .disconnect = gadgetfs_disconnect,
1735 .suspend = gadgetfs_suspend,
1742 /*----------------------------------------------------------------------*/
1743 /* DEVICE INITIALIZATION
1745 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1746 * status = write (fd, descriptors, sizeof descriptors)
1748 * That write establishes the device configuration, so the kernel can
1749 * bind to the controller ... guaranteeing it can handle enumeration
1750 * at all necessary speeds. Descriptor order is:
1752 * . message tag (u32, host order) ... for now, must be zero; it
1753 * would change to support features like multi-config devices
1754 * . full/low speed config ... all wTotalLength bytes (with interface,
1755 * class, altsetting, endpoint, and other descriptors)
1756 * . high speed config ... all descriptors, for high speed operation;
1757 * this one's optional except for high-speed hardware
1758 * . device descriptor
1760 * Endpoints are not yet enabled. Drivers must wait until device
1761 * configuration and interface altsetting changes create
1762 * the need to configure (or unconfigure) them.
1764 * After initialization, the device stays active for as long as that
1765 * $CHIP file is open. Events must then be read from that descriptor,
1766 * such as configuration notifications.
1769 static int is_valid_config(struct usb_config_descriptor *config,
1772 return config->bDescriptorType == USB_DT_CONFIG
1773 && config->bLength == USB_DT_CONFIG_SIZE
1774 && total >= USB_DT_CONFIG_SIZE
1775 && config->bConfigurationValue != 0
1776 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1777 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1778 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1779 /* FIXME check lengths: walk to end */
1783 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1785 struct dev_data *dev = fd->private_data;
1786 ssize_t value, length = len;
1791 spin_lock_irq(&dev->lock);
1792 if (dev->state > STATE_DEV_OPENED) {
1793 value = ep0_write(fd, buf, len, ptr);
1794 spin_unlock_irq(&dev->lock);
1797 spin_unlock_irq(&dev->lock);
1799 if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
1800 (len > PAGE_SIZE * 4))
1803 /* we might need to change message format someday */
1804 if (copy_from_user (&tag, buf, 4))
1811 kbuf = memdup_user(buf, length);
1813 return PTR_ERR(kbuf);
1815 spin_lock_irq (&dev->lock);
1823 /* full or low speed config */
1824 dev->config = (void *) kbuf;
1825 total = le16_to_cpu(dev->config->wTotalLength);
1826 if (!is_valid_config(dev->config, total) ||
1827 total > length - USB_DT_DEVICE_SIZE)
1832 /* optional high speed config */
1833 if (kbuf [1] == USB_DT_CONFIG) {
1834 dev->hs_config = (void *) kbuf;
1835 total = le16_to_cpu(dev->hs_config->wTotalLength);
1836 if (!is_valid_config(dev->hs_config, total) ||
1837 total > length - USB_DT_DEVICE_SIZE)
1842 dev->hs_config = NULL;
1845 /* could support multiple configs, using another encoding! */
1847 /* device descriptor (tweaked for paranoia) */
1848 if (length != USB_DT_DEVICE_SIZE)
1850 dev->dev = (void *)kbuf;
1851 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1852 || dev->dev->bDescriptorType != USB_DT_DEVICE
1853 || dev->dev->bNumConfigurations != 1)
1855 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1857 /* triggers gadgetfs_bind(); then we can enumerate. */
1858 spin_unlock_irq (&dev->lock);
1860 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1862 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1864 value = usb_gadget_probe_driver(&gadgetfs_driver);
1869 /* at this point "good" hardware has for the first time
1870 * let the USB the host see us. alternatively, if users
1871 * unplug/replug that will clear all the error state.
1873 * note: everything running before here was guaranteed
1874 * to choke driver model style diagnostics. from here
1875 * on, they can work ... except in cleanup paths that
1876 * kick in after the ep0 descriptor is closed.
1879 dev->gadget_registered = true;
1884 spin_unlock_irq (&dev->lock);
1885 pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev);
1892 dev_open (struct inode *inode, struct file *fd)
1894 struct dev_data *dev = inode->i_private;
1897 spin_lock_irq(&dev->lock);
1898 if (dev->state == STATE_DEV_DISABLED) {
1900 dev->state = STATE_DEV_OPENED;
1901 fd->private_data = dev;
1905 spin_unlock_irq(&dev->lock);
1909 static const struct file_operations ep0_operations = {
1910 .llseek = no_llseek,
1914 .write = dev_config,
1915 .fasync = ep0_fasync,
1917 .unlocked_ioctl = dev_ioctl,
1918 .release = dev_release,
1921 /*----------------------------------------------------------------------*/
1923 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1925 * Mounting the filesystem creates a controller file, used first for
1926 * device configuration then later for event monitoring.
1930 /* FIXME PAM etc could set this security policy without mount options
1931 * if epfiles inherited ownership and permissons from ep0 ...
1934 static unsigned default_uid;
1935 static unsigned default_gid;
1936 static unsigned default_perm = S_IRUSR | S_IWUSR;
1938 module_param (default_uid, uint, 0644);
1939 module_param (default_gid, uint, 0644);
1940 module_param (default_perm, uint, 0644);
1943 static struct inode *
1944 gadgetfs_make_inode (struct super_block *sb,
1945 void *data, const struct file_operations *fops,
1948 struct inode *inode = new_inode (sb);
1951 inode->i_ino = get_next_ino();
1952 inode->i_mode = mode;
1953 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1954 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1955 inode->i_atime = inode->i_mtime = inode->i_ctime
1956 = current_time(inode);
1957 inode->i_private = data;
1958 inode->i_fop = fops;
1963 /* creates in fs root directory, so non-renamable and non-linkable.
1964 * so inode and dentry are paired, until device reconfig.
1966 static struct dentry *
1967 gadgetfs_create_file (struct super_block *sb, char const *name,
1968 void *data, const struct file_operations *fops)
1970 struct dentry *dentry;
1971 struct inode *inode;
1973 dentry = d_alloc_name(sb->s_root, name);
1977 inode = gadgetfs_make_inode (sb, data, fops,
1978 S_IFREG | (default_perm & S_IRWXUGO));
1983 d_add (dentry, inode);
1987 static const struct super_operations gadget_fs_operations = {
1988 .statfs = simple_statfs,
1989 .drop_inode = generic_delete_inode,
1993 gadgetfs_fill_super (struct super_block *sb, struct fs_context *fc)
1995 struct inode *inode;
1996 struct dev_data *dev;
2001 CHIP = usb_get_gadget_udc_name();
2006 sb->s_blocksize = PAGE_SIZE;
2007 sb->s_blocksize_bits = PAGE_SHIFT;
2008 sb->s_magic = GADGETFS_MAGIC;
2009 sb->s_op = &gadget_fs_operations;
2010 sb->s_time_gran = 1;
2013 inode = gadgetfs_make_inode (sb,
2014 NULL, &simple_dir_operations,
2015 S_IFDIR | S_IRUGO | S_IXUGO);
2018 inode->i_op = &simple_dir_inode_operations;
2019 if (!(sb->s_root = d_make_root (inode)))
2022 /* the ep0 file is named after the controller we expect;
2023 * user mode code can use it for sanity checks, like we do.
2030 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2036 /* other endpoint files are available after hardware setup,
2037 * from binding to a controller.
2049 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2050 static int gadgetfs_get_tree(struct fs_context *fc)
2052 return get_tree_single(fc, gadgetfs_fill_super);
2055 static const struct fs_context_operations gadgetfs_context_ops = {
2056 .get_tree = gadgetfs_get_tree,
2059 static int gadgetfs_init_fs_context(struct fs_context *fc)
2061 fc->ops = &gadgetfs_context_ops;
2066 gadgetfs_kill_sb (struct super_block *sb)
2068 kill_litter_super (sb);
2070 put_dev (the_device);
2077 /*----------------------------------------------------------------------*/
2079 static struct file_system_type gadgetfs_type = {
2080 .owner = THIS_MODULE,
2082 .init_fs_context = gadgetfs_init_fs_context,
2083 .kill_sb = gadgetfs_kill_sb,
2085 MODULE_ALIAS_FS("gadgetfs");
2087 /*----------------------------------------------------------------------*/
2089 static int __init init (void)
2093 status = register_filesystem (&gadgetfs_type);
2095 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2096 shortname, driver_desc);
2101 static void __exit cleanup (void)
2103 pr_debug ("unregister %s\n", shortname);
2104 unregister_filesystem (&gadgetfs_type);
2106 module_exit (cleanup);