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>
28 #include <linux/device.h>
29 #include <linux/moduleparam.h>
31 #include <linux/usb/gadgetfs.h>
32 #include <linux/usb/gadget.h>
36 * The gadgetfs API maps each endpoint to a file descriptor so that you
37 * can use standard synchronous read/write calls for I/O. There's some
38 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
39 * drivers show how this works in practice. You can also use AIO to
40 * eliminate I/O gaps between requests, to help when streaming data.
42 * Key parts that must be USB-specific are protocols defining how the
43 * read/write operations relate to the hardware state machines. There
44 * are two types of files. One type is for the device, implementing ep0.
45 * The other type is for each IN or OUT endpoint. In both cases, the
46 * user mode driver must configure the hardware before using it.
48 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
49 * (by writing configuration and device descriptors). Afterwards it
50 * may serve as a source of device events, used to handle all control
51 * requests other than basic enumeration.
53 * - Then, after a SET_CONFIGURATION control request, ep_config() is
54 * called when each /dev/gadget/ep* file is configured (by writing
55 * endpoint descriptors). Afterwards these files are used to write()
56 * IN data or to read() OUT data. To halt the endpoint, a "wrong
57 * direction" request is issued (like reading an IN endpoint).
59 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
60 * not possible on all hardware. For example, precise fault handling with
61 * respect to data left in endpoint fifos after aborted operations; or
62 * selective clearing of endpoint halts, to implement SET_INTERFACE.
65 #define DRIVER_DESC "USB Gadget filesystem"
66 #define DRIVER_VERSION "24 Aug 2004"
68 static const char driver_desc [] = DRIVER_DESC;
69 static const char shortname [] = "gadgetfs";
71 MODULE_DESCRIPTION (DRIVER_DESC);
72 MODULE_AUTHOR ("David Brownell");
73 MODULE_LICENSE ("GPL");
76 /*----------------------------------------------------------------------*/
78 #define GADGETFS_MAGIC 0xaee71ee7
79 #define DMA_ADDR_INVALID (~(dma_addr_t)0)
81 /* /dev/gadget/$CHIP represents ep0 and the whole device */
83 /* DISBLED is the initial state.
85 STATE_DEV_DISABLED = 0,
87 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
88 * ep0/device i/o modes and binding to the controller. Driver
89 * must always write descriptors to initialize the device, then
90 * the device becomes UNCONNECTED until enumeration.
94 /* From then on, ep0 fd is in either of two basic modes:
95 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
96 * - SETUP: read/write will transfer control data and succeed;
97 * or if "wrong direction", performs protocol stall
99 STATE_DEV_UNCONNECTED,
103 /* UNBOUND means the driver closed ep0, so the device won't be
104 * accessible again (DEV_DISABLED) until all fds are closed.
109 /* enough for the whole queue: most events invalidate others */
115 enum ep0_state state; /* P: lock */
116 struct usb_gadgetfs_event event [N_EVENT];
118 struct fasync_struct *fasync;
121 /* drivers reading ep0 MUST handle control requests (SETUP)
122 * reported that way; else the host will time out.
124 unsigned usermode_setup : 1,
130 unsigned setup_wLength;
132 /* the rest is basically write-once */
133 struct usb_config_descriptor *config, *hs_config;
134 struct usb_device_descriptor *dev;
135 struct usb_request *req;
136 struct usb_gadget *gadget;
137 struct list_head epfiles;
139 wait_queue_head_t wait;
140 struct super_block *sb;
141 struct dentry *dentry;
143 /* except this scratch i/o buffer for ep0 */
147 static inline void get_dev (struct dev_data *data)
149 atomic_inc (&data->count);
152 static void put_dev (struct dev_data *data)
154 if (likely (!atomic_dec_and_test (&data->count)))
156 /* needs no more cleanup */
157 BUG_ON (waitqueue_active (&data->wait));
161 static struct dev_data *dev_new (void)
163 struct dev_data *dev;
165 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
168 dev->state = STATE_DEV_DISABLED;
169 atomic_set (&dev->count, 1);
170 spin_lock_init (&dev->lock);
171 INIT_LIST_HEAD (&dev->epfiles);
172 init_waitqueue_head (&dev->wait);
176 /*----------------------------------------------------------------------*/
178 /* other /dev/gadget/$ENDPOINT files represent endpoints */
180 STATE_EP_DISABLED = 0,
190 struct dev_data *dev;
191 /* must hold dev->lock before accessing ep or req */
193 struct usb_request *req;
196 struct usb_endpoint_descriptor desc, hs_desc;
197 struct list_head epfiles;
198 wait_queue_head_t wait;
199 struct dentry *dentry;
203 static inline void get_ep (struct ep_data *data)
205 atomic_inc (&data->count);
208 static void put_ep (struct ep_data *data)
210 if (likely (!atomic_dec_and_test (&data->count)))
213 /* needs no more cleanup */
214 BUG_ON (!list_empty (&data->epfiles));
215 BUG_ON (waitqueue_active (&data->wait));
219 /*----------------------------------------------------------------------*/
221 /* most "how to use the hardware" policy choices are in userspace:
222 * mapping endpoint roles (which the driver needs) to the capabilities
223 * which the usb controller has. most of those capabilities are exposed
224 * implicitly, starting with the driver name and then endpoint names.
227 static const char *CHIP;
229 /*----------------------------------------------------------------------*/
231 /* NOTE: don't use dev_printk calls before binding to the gadget
232 * at the end of ep0 configuration, or after unbind.
235 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
236 #define xprintk(d,level,fmt,args...) \
237 printk(level "%s: " fmt , shortname , ## args)
240 #define DBG(dev,fmt,args...) \
241 xprintk(dev , KERN_DEBUG , fmt , ## args)
243 #define DBG(dev,fmt,args...) \
250 #define VDEBUG(dev,fmt,args...) \
254 #define ERROR(dev,fmt,args...) \
255 xprintk(dev , KERN_ERR , fmt , ## args)
256 #define INFO(dev,fmt,args...) \
257 xprintk(dev , KERN_INFO , fmt , ## args)
260 /*----------------------------------------------------------------------*/
262 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
264 * After opening, configure non-control endpoints. Then use normal
265 * stream read() and write() requests; and maybe ioctl() to get more
266 * precise FIFO status when recovering from cancellation.
269 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
271 struct ep_data *epdata = ep->driver_data;
276 epdata->status = req->status;
278 epdata->status = req->actual;
279 complete ((struct completion *)req->context);
282 /* tasklock endpoint, returning when it's connected.
283 * still need dev->lock to use epdata->ep.
286 get_ready_ep (unsigned f_flags, struct ep_data *epdata)
290 if (f_flags & O_NONBLOCK) {
291 if (!mutex_trylock(&epdata->lock))
293 if (epdata->state != STATE_EP_ENABLED) {
294 mutex_unlock(&epdata->lock);
302 val = mutex_lock_interruptible(&epdata->lock);
306 switch (epdata->state) {
307 case STATE_EP_ENABLED:
309 // case STATE_EP_DISABLED: /* "can't happen" */
310 // case STATE_EP_READY: /* "can't happen" */
311 default: /* error! */
312 pr_debug ("%s: ep %p not available, state %d\n",
313 shortname, epdata, epdata->state);
315 case STATE_EP_UNBOUND: /* clean disconnect */
317 mutex_unlock(&epdata->lock);
323 ep_io (struct ep_data *epdata, void *buf, unsigned len)
325 DECLARE_COMPLETION_ONSTACK (done);
328 spin_lock_irq (&epdata->dev->lock);
329 if (likely (epdata->ep != NULL)) {
330 struct usb_request *req = epdata->req;
332 req->context = &done;
333 req->complete = epio_complete;
336 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
339 spin_unlock_irq (&epdata->dev->lock);
341 if (likely (value == 0)) {
342 value = wait_event_interruptible (done.wait, done.done);
344 spin_lock_irq (&epdata->dev->lock);
345 if (likely (epdata->ep != NULL)) {
346 DBG (epdata->dev, "%s i/o interrupted\n",
348 usb_ep_dequeue (epdata->ep, epdata->req);
349 spin_unlock_irq (&epdata->dev->lock);
351 wait_event (done.wait, done.done);
352 if (epdata->status == -ECONNRESET)
353 epdata->status = -EINTR;
355 spin_unlock_irq (&epdata->dev->lock);
357 DBG (epdata->dev, "endpoint gone\n");
358 epdata->status = -ENODEV;
361 return epdata->status;
367 /* handle a synchronous OUT bulk/intr/iso transfer */
369 ep_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
371 struct ep_data *data = fd->private_data;
375 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
378 /* halt any endpoint by doing a "wrong direction" i/o call */
379 if (usb_endpoint_dir_in(&data->desc)) {
380 if (usb_endpoint_xfer_isoc(&data->desc)) {
381 mutex_unlock(&data->lock);
384 DBG (data->dev, "%s halt\n", data->name);
385 spin_lock_irq (&data->dev->lock);
386 if (likely (data->ep != NULL))
387 usb_ep_set_halt (data->ep);
388 spin_unlock_irq (&data->dev->lock);
389 mutex_unlock(&data->lock);
393 /* FIXME readahead for O_NONBLOCK and poll(); careful with ZLPs */
396 kbuf = kmalloc (len, GFP_KERNEL);
397 if (unlikely (!kbuf))
400 value = ep_io (data, kbuf, len);
401 VDEBUG (data->dev, "%s read %zu OUT, status %d\n",
402 data->name, len, (int) value);
403 if (value >= 0 && copy_to_user (buf, kbuf, value))
407 mutex_unlock(&data->lock);
412 /* handle a synchronous IN bulk/intr/iso transfer */
414 ep_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
416 struct ep_data *data = fd->private_data;
420 if ((value = get_ready_ep (fd->f_flags, data)) < 0)
423 /* halt any endpoint by doing a "wrong direction" i/o call */
424 if (!usb_endpoint_dir_in(&data->desc)) {
425 if (usb_endpoint_xfer_isoc(&data->desc)) {
426 mutex_unlock(&data->lock);
429 DBG (data->dev, "%s halt\n", data->name);
430 spin_lock_irq (&data->dev->lock);
431 if (likely (data->ep != NULL))
432 usb_ep_set_halt (data->ep);
433 spin_unlock_irq (&data->dev->lock);
434 mutex_unlock(&data->lock);
438 /* FIXME writebehind for O_NONBLOCK and poll(), qlen = 1 */
441 kbuf = kmalloc (len, GFP_KERNEL);
444 if (copy_from_user (kbuf, buf, len)) {
449 value = ep_io (data, kbuf, len);
450 VDEBUG (data->dev, "%s write %zu IN, status %d\n",
451 data->name, len, (int) value);
453 mutex_unlock(&data->lock);
459 ep_release (struct inode *inode, struct file *fd)
461 struct ep_data *data = fd->private_data;
464 value = mutex_lock_interruptible(&data->lock);
468 /* clean up if this can be reopened */
469 if (data->state != STATE_EP_UNBOUND) {
470 data->state = STATE_EP_DISABLED;
471 data->desc.bDescriptorType = 0;
472 data->hs_desc.bDescriptorType = 0;
473 usb_ep_disable(data->ep);
475 mutex_unlock(&data->lock);
480 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
482 struct ep_data *data = fd->private_data;
485 if ((status = get_ready_ep (fd->f_flags, data)) < 0)
488 spin_lock_irq (&data->dev->lock);
489 if (likely (data->ep != NULL)) {
491 case GADGETFS_FIFO_STATUS:
492 status = usb_ep_fifo_status (data->ep);
494 case GADGETFS_FIFO_FLUSH:
495 usb_ep_fifo_flush (data->ep);
497 case GADGETFS_CLEAR_HALT:
498 status = usb_ep_clear_halt (data->ep);
505 spin_unlock_irq (&data->dev->lock);
506 mutex_unlock(&data->lock);
510 /*----------------------------------------------------------------------*/
512 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
515 struct usb_request *req;
516 struct ep_data *epdata;
518 const struct iovec *iv;
519 unsigned long nr_segs;
523 static int ep_aio_cancel(struct kiocb *iocb, struct io_event *e)
525 struct kiocb_priv *priv = iocb->private;
526 struct ep_data *epdata;
530 epdata = priv->epdata;
531 // spin_lock(&epdata->dev->lock);
532 kiocbSetCancelled(iocb);
533 if (likely(epdata && epdata->ep && priv->req))
534 value = usb_ep_dequeue (epdata->ep, priv->req);
537 // spin_unlock(&epdata->dev->lock);
544 static ssize_t ep_aio_read_retry(struct kiocb *iocb)
546 struct kiocb_priv *priv = iocb->private;
551 /* we "retry" to get the right mm context for this: */
553 /* copy stuff into user buffers */
554 total = priv->actual;
557 for (i=0; i < priv->nr_segs; i++) {
558 ssize_t this = min((ssize_t)(priv->iv[i].iov_len), total);
560 if (copy_to_user(priv->iv[i].iov_base, to_copy, this)) {
578 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
580 struct kiocb *iocb = req->context;
581 struct kiocb_priv *priv = iocb->private;
582 struct ep_data *epdata = priv->epdata;
584 /* lock against disconnect (and ideally, cancel) */
585 spin_lock(&epdata->dev->lock);
589 /* if this was a write or a read returning no data then we
590 * don't need to copy anything to userspace, so we can
591 * complete the aio request immediately.
593 if (priv->iv == NULL || unlikely(req->actual == 0)) {
597 iocb->private = NULL;
598 /* aio_complete() reports bytes-transferred _and_ faults */
599 aio_complete(iocb, req->actual ? req->actual : req->status,
602 /* retry() won't report both; so we hide some faults */
603 if (unlikely(0 != req->status))
604 DBG(epdata->dev, "%s fault %d len %d\n",
605 ep->name, req->status, req->actual);
607 priv->buf = req->buf;
608 priv->actual = req->actual;
611 spin_unlock(&epdata->dev->lock);
613 usb_ep_free_request(ep, req);
622 struct ep_data *epdata,
623 const struct iovec *iv,
624 unsigned long nr_segs
627 struct kiocb_priv *priv;
628 struct usb_request *req;
631 priv = kzalloc(sizeof *priv, GFP_KERNEL);
638 iocb->private = priv;
640 priv->iv = kmemdup(iv, nr_segs * sizeof(struct iovec),
647 priv->nr_segs = nr_segs;
649 value = get_ready_ep(iocb->ki_filp->f_flags, epdata);
650 if (unlikely(value < 0)) {
656 iocb->ki_cancel = ep_aio_cancel;
658 priv->epdata = epdata;
661 /* each kiocb is coupled to one usb_request, but we can't
662 * allocate or submit those if the host disconnected.
664 spin_lock_irq(&epdata->dev->lock);
665 if (likely(epdata->ep)) {
666 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
671 req->complete = ep_aio_complete;
673 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
674 if (unlikely(0 != value))
675 usb_ep_free_request(epdata->ep, req);
680 spin_unlock_irq(&epdata->dev->lock);
682 mutex_unlock(&epdata->lock);
684 if (unlikely(value)) {
689 value = (iv ? -EIOCBRETRY : -EIOCBQUEUED);
694 ep_aio_read(struct kiocb *iocb, const struct iovec *iov,
695 unsigned long nr_segs, loff_t o)
697 struct ep_data *epdata = iocb->ki_filp->private_data;
700 if (unlikely(usb_endpoint_dir_in(&epdata->desc)))
703 buf = kmalloc(iocb->ki_left, GFP_KERNEL);
707 iocb->ki_retry = ep_aio_read_retry;
708 return ep_aio_rwtail(iocb, buf, iocb->ki_left, epdata, iov, nr_segs);
712 ep_aio_write(struct kiocb *iocb, const struct iovec *iov,
713 unsigned long nr_segs, loff_t o)
715 struct ep_data *epdata = iocb->ki_filp->private_data;
720 if (unlikely(!usb_endpoint_dir_in(&epdata->desc)))
723 buf = kmalloc(iocb->ki_left, GFP_KERNEL);
727 for (i=0; i < nr_segs; i++) {
728 if (unlikely(copy_from_user(&buf[len], iov[i].iov_base,
729 iov[i].iov_len) != 0)) {
733 len += iov[i].iov_len;
735 return ep_aio_rwtail(iocb, buf, len, epdata, NULL, 0);
738 /*----------------------------------------------------------------------*/
740 /* used after endpoint configuration */
741 static const struct file_operations ep_io_operations = {
742 .owner = THIS_MODULE,
747 .unlocked_ioctl = ep_ioctl,
748 .release = ep_release,
750 .aio_read = ep_aio_read,
751 .aio_write = ep_aio_write,
754 /* ENDPOINT INITIALIZATION
756 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
757 * status = write (fd, descriptors, sizeof descriptors)
759 * That write establishes the endpoint configuration, configuring
760 * the controller to process bulk, interrupt, or isochronous transfers
761 * at the right maxpacket size, and so on.
763 * The descriptors are message type 1, identified by a host order u32
764 * at the beginning of what's written. Descriptor order is: full/low
765 * speed descriptor, then optional high speed descriptor.
768 ep_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
770 struct ep_data *data = fd->private_data;
773 int value, length = len;
775 value = mutex_lock_interruptible(&data->lock);
779 if (data->state != STATE_EP_READY) {
785 if (len < USB_DT_ENDPOINT_SIZE + 4)
788 /* we might need to change message format someday */
789 if (copy_from_user (&tag, buf, 4)) {
793 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
799 /* NOTE: audio endpoint extensions not accepted here;
800 * just don't include the extra bytes.
803 /* full/low speed descriptor, then high speed */
804 if (copy_from_user (&data->desc, buf, USB_DT_ENDPOINT_SIZE)) {
807 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
808 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
810 if (len != USB_DT_ENDPOINT_SIZE) {
811 if (len != 2 * USB_DT_ENDPOINT_SIZE)
813 if (copy_from_user (&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
814 USB_DT_ENDPOINT_SIZE)) {
817 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
818 || data->hs_desc.bDescriptorType
819 != USB_DT_ENDPOINT) {
820 DBG(data->dev, "config %s, bad hs length or type\n",
826 spin_lock_irq (&data->dev->lock);
827 if (data->dev->state == STATE_DEV_UNBOUND) {
830 } else if ((ep = data->ep) == NULL) {
834 switch (data->dev->gadget->speed) {
837 ep->desc = &data->desc;
838 value = usb_ep_enable(ep);
840 data->state = STATE_EP_ENABLED;
842 #ifdef CONFIG_USB_GADGET_DUALSPEED
844 /* fails if caller didn't provide that descriptor... */
845 ep->desc = &data->hs_desc;
846 value = usb_ep_enable(ep);
848 data->state = STATE_EP_ENABLED;
852 DBG(data->dev, "unconnected, %s init abandoned\n",
857 fd->f_op = &ep_io_operations;
861 spin_unlock_irq (&data->dev->lock);
864 data->desc.bDescriptorType = 0;
865 data->hs_desc.bDescriptorType = 0;
867 mutex_unlock(&data->lock);
878 ep_open (struct inode *inode, struct file *fd)
880 struct ep_data *data = inode->i_private;
883 if (mutex_lock_interruptible(&data->lock) != 0)
885 spin_lock_irq (&data->dev->lock);
886 if (data->dev->state == STATE_DEV_UNBOUND)
888 else if (data->state == STATE_EP_DISABLED) {
890 data->state = STATE_EP_READY;
892 fd->private_data = data;
893 VDEBUG (data->dev, "%s ready\n", data->name);
895 DBG (data->dev, "%s state %d\n",
896 data->name, data->state);
897 spin_unlock_irq (&data->dev->lock);
898 mutex_unlock(&data->lock);
902 /* used before endpoint configuration */
903 static const struct file_operations ep_config_operations = {
904 .owner = THIS_MODULE,
909 .release = ep_release,
912 /*----------------------------------------------------------------------*/
914 /* EP0 IMPLEMENTATION can be partly in userspace.
916 * Drivers that use this facility receive various events, including
917 * control requests the kernel doesn't handle. Drivers that don't
918 * use this facility may be too simple-minded for real applications.
921 static inline void ep0_readable (struct dev_data *dev)
923 wake_up (&dev->wait);
924 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
927 static void clean_req (struct usb_ep *ep, struct usb_request *req)
929 struct dev_data *dev = ep->driver_data;
931 if (req->buf != dev->rbuf) {
933 req->buf = dev->rbuf;
934 req->dma = DMA_ADDR_INVALID;
936 req->complete = epio_complete;
937 dev->setup_out_ready = 0;
940 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
942 struct dev_data *dev = ep->driver_data;
946 /* for control OUT, data must still get to userspace */
947 spin_lock_irqsave(&dev->lock, flags);
948 if (!dev->setup_in) {
949 dev->setup_out_error = (req->status != 0);
950 if (!dev->setup_out_error)
952 dev->setup_out_ready = 1;
956 /* clean up as appropriate */
957 if (free && req->buf != &dev->rbuf)
959 req->complete = epio_complete;
960 spin_unlock_irqrestore(&dev->lock, flags);
963 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
965 struct dev_data *dev = ep->driver_data;
967 if (dev->setup_out_ready) {
968 DBG (dev, "ep0 request busy!\n");
971 if (len > sizeof (dev->rbuf))
972 req->buf = kmalloc(len, GFP_ATOMIC);
973 if (req->buf == NULL) {
974 req->buf = dev->rbuf;
977 req->complete = ep0_complete;
984 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
986 struct dev_data *dev = fd->private_data;
988 enum ep0_state state;
990 spin_lock_irq (&dev->lock);
992 /* report fd mode change before acting on it */
993 if (dev->setup_abort) {
994 dev->setup_abort = 0;
999 /* control DATA stage */
1000 if ((state = dev->state) == STATE_DEV_SETUP) {
1002 if (dev->setup_in) { /* stall IN */
1003 VDEBUG(dev, "ep0in stall\n");
1004 (void) usb_ep_set_halt (dev->gadget->ep0);
1006 dev->state = STATE_DEV_CONNECTED;
1008 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
1009 struct usb_ep *ep = dev->gadget->ep0;
1010 struct usb_request *req = dev->req;
1012 if ((retval = setup_req (ep, req, 0)) == 0)
1013 retval = usb_ep_queue (ep, req, GFP_ATOMIC);
1014 dev->state = STATE_DEV_CONNECTED;
1016 /* assume that was SET_CONFIGURATION */
1017 if (dev->current_config) {
1020 if (gadget_is_dualspeed(dev->gadget)
1021 && (dev->gadget->speed
1023 power = dev->hs_config->bMaxPower;
1025 power = dev->config->bMaxPower;
1026 usb_gadget_vbus_draw(dev->gadget, 2 * power);
1029 } else { /* collect OUT data */
1030 if ((fd->f_flags & O_NONBLOCK) != 0
1031 && !dev->setup_out_ready) {
1035 spin_unlock_irq (&dev->lock);
1036 retval = wait_event_interruptible (dev->wait,
1037 dev->setup_out_ready != 0);
1039 /* FIXME state could change from under us */
1040 spin_lock_irq (&dev->lock);
1044 if (dev->state != STATE_DEV_SETUP) {
1045 retval = -ECANCELED;
1048 dev->state = STATE_DEV_CONNECTED;
1050 if (dev->setup_out_error)
1053 len = min (len, (size_t)dev->req->actual);
1054 // FIXME don't call this with the spinlock held ...
1055 if (copy_to_user (buf, dev->req->buf, len))
1059 clean_req (dev->gadget->ep0, dev->req);
1060 /* NOTE userspace can't yet choose to stall */
1066 /* else normal: return event data */
1067 if (len < sizeof dev->event [0]) {
1071 len -= len % sizeof (struct usb_gadgetfs_event);
1072 dev->usermode_setup = 1;
1075 /* return queued events right away */
1076 if (dev->ev_next != 0) {
1079 n = len / sizeof (struct usb_gadgetfs_event);
1080 if (dev->ev_next < n)
1083 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1084 for (i = 0; i < n; i++) {
1085 if (dev->event [i].type == GADGETFS_SETUP) {
1086 dev->state = STATE_DEV_SETUP;
1091 spin_unlock_irq (&dev->lock);
1092 len = n * sizeof (struct usb_gadgetfs_event);
1093 if (copy_to_user (buf, &dev->event, len))
1098 /* NOTE this doesn't guard against broken drivers;
1099 * concurrent ep0 readers may lose events.
1101 spin_lock_irq (&dev->lock);
1102 if (dev->ev_next > n) {
1103 memmove(&dev->event[0], &dev->event[n],
1104 sizeof (struct usb_gadgetfs_event)
1105 * (dev->ev_next - n));
1108 spin_unlock_irq (&dev->lock);
1112 if (fd->f_flags & O_NONBLOCK) {
1119 DBG (dev, "fail %s, state %d\n", __func__, state);
1122 case STATE_DEV_UNCONNECTED:
1123 case STATE_DEV_CONNECTED:
1124 spin_unlock_irq (&dev->lock);
1125 DBG (dev, "%s wait\n", __func__);
1127 /* wait for events */
1128 retval = wait_event_interruptible (dev->wait,
1132 spin_lock_irq (&dev->lock);
1137 spin_unlock_irq (&dev->lock);
1141 static struct usb_gadgetfs_event *
1142 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1144 struct usb_gadgetfs_event *event;
1148 /* these events purge the queue */
1149 case GADGETFS_DISCONNECT:
1150 if (dev->state == STATE_DEV_SETUP)
1151 dev->setup_abort = 1;
1153 case GADGETFS_CONNECT:
1156 case GADGETFS_SETUP: /* previous request timed out */
1157 case GADGETFS_SUSPEND: /* same effect */
1158 /* these events can't be repeated */
1159 for (i = 0; i != dev->ev_next; i++) {
1160 if (dev->event [i].type != type)
1162 DBG(dev, "discard old event[%d] %d\n", i, type);
1164 if (i == dev->ev_next)
1166 /* indices start at zero, for simplicity */
1167 memmove (&dev->event [i], &dev->event [i + 1],
1168 sizeof (struct usb_gadgetfs_event)
1169 * (dev->ev_next - i));
1175 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1176 event = &dev->event [dev->ev_next++];
1177 BUG_ON (dev->ev_next > N_EVENT);
1178 memset (event, 0, sizeof *event);
1184 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1186 struct dev_data *dev = fd->private_data;
1187 ssize_t retval = -ESRCH;
1189 spin_lock_irq (&dev->lock);
1191 /* report fd mode change before acting on it */
1192 if (dev->setup_abort) {
1193 dev->setup_abort = 0;
1196 /* data and/or status stage for control request */
1197 } else if (dev->state == STATE_DEV_SETUP) {
1199 /* IN DATA+STATUS caller makes len <= wLength */
1200 if (dev->setup_in) {
1201 retval = setup_req (dev->gadget->ep0, dev->req, len);
1203 dev->state = STATE_DEV_CONNECTED;
1204 spin_unlock_irq (&dev->lock);
1205 if (copy_from_user (dev->req->buf, buf, len))
1208 if (len < dev->setup_wLength)
1210 retval = usb_ep_queue (
1211 dev->gadget->ep0, dev->req,
1215 spin_lock_irq (&dev->lock);
1216 clean_req (dev->gadget->ep0, dev->req);
1217 spin_unlock_irq (&dev->lock);
1224 /* can stall some OUT transfers */
1225 } else if (dev->setup_can_stall) {
1226 VDEBUG(dev, "ep0out stall\n");
1227 (void) usb_ep_set_halt (dev->gadget->ep0);
1229 dev->state = STATE_DEV_CONNECTED;
1231 DBG(dev, "bogus ep0out stall!\n");
1234 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1236 spin_unlock_irq (&dev->lock);
1241 ep0_fasync (int f, struct file *fd, int on)
1243 struct dev_data *dev = fd->private_data;
1244 // caller must F_SETOWN before signal delivery happens
1245 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1246 return fasync_helper (f, fd, on, &dev->fasync);
1249 static struct usb_gadget_driver gadgetfs_driver;
1252 dev_release (struct inode *inode, struct file *fd)
1254 struct dev_data *dev = fd->private_data;
1256 /* closing ep0 === shutdown all */
1258 usb_gadget_unregister_driver (&gadgetfs_driver);
1260 /* at this point "good" hardware has disconnected the
1261 * device from USB; the host won't see it any more.
1262 * alternatively, all host requests will time out.
1269 /* other endpoints were all decoupled from this device */
1270 spin_lock_irq(&dev->lock);
1271 dev->state = STATE_DEV_DISABLED;
1272 spin_unlock_irq(&dev->lock);
1277 ep0_poll (struct file *fd, poll_table *wait)
1279 struct dev_data *dev = fd->private_data;
1282 poll_wait(fd, &dev->wait, wait);
1284 spin_lock_irq (&dev->lock);
1286 /* report fd mode change before acting on it */
1287 if (dev->setup_abort) {
1288 dev->setup_abort = 0;
1293 if (dev->state == STATE_DEV_SETUP) {
1294 if (dev->setup_in || dev->setup_can_stall)
1297 if (dev->ev_next != 0)
1301 spin_unlock_irq(&dev->lock);
1305 static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1307 struct dev_data *dev = fd->private_data;
1308 struct usb_gadget *gadget = dev->gadget;
1311 if (gadget->ops->ioctl)
1312 ret = gadget->ops->ioctl (gadget, code, value);
1317 /* used after device configuration */
1318 static const struct file_operations ep0_io_operations = {
1319 .owner = THIS_MODULE,
1320 .llseek = no_llseek,
1324 .fasync = ep0_fasync,
1326 .unlocked_ioctl = dev_ioctl,
1327 .release = dev_release,
1330 /*----------------------------------------------------------------------*/
1332 /* The in-kernel gadget driver handles most ep0 issues, in particular
1333 * enumerating the single configuration (as provided from user space).
1335 * Unrecognized ep0 requests may be handled in user space.
1338 #ifdef CONFIG_USB_GADGET_DUALSPEED
1339 static void make_qualifier (struct dev_data *dev)
1341 struct usb_qualifier_descriptor qual;
1342 struct usb_device_descriptor *desc;
1344 qual.bLength = sizeof qual;
1345 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1346 qual.bcdUSB = cpu_to_le16 (0x0200);
1349 qual.bDeviceClass = desc->bDeviceClass;
1350 qual.bDeviceSubClass = desc->bDeviceSubClass;
1351 qual.bDeviceProtocol = desc->bDeviceProtocol;
1353 /* assumes ep0 uses the same value for both speeds ... */
1354 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1356 qual.bNumConfigurations = 1;
1359 memcpy (dev->rbuf, &qual, sizeof qual);
1364 config_buf (struct dev_data *dev, u8 type, unsigned index)
1369 /* only one configuration */
1373 if (gadget_is_dualspeed(dev->gadget)) {
1374 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1375 if (type == USB_DT_OTHER_SPEED_CONFIG)
1379 dev->req->buf = dev->hs_config;
1380 len = le16_to_cpu(dev->hs_config->wTotalLength);
1382 dev->req->buf = dev->config;
1383 len = le16_to_cpu(dev->config->wTotalLength);
1385 ((u8 *)dev->req->buf) [1] = type;
1390 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1392 struct dev_data *dev = get_gadget_data (gadget);
1393 struct usb_request *req = dev->req;
1394 int value = -EOPNOTSUPP;
1395 struct usb_gadgetfs_event *event;
1396 u16 w_value = le16_to_cpu(ctrl->wValue);
1397 u16 w_length = le16_to_cpu(ctrl->wLength);
1399 spin_lock (&dev->lock);
1400 dev->setup_abort = 0;
1401 if (dev->state == STATE_DEV_UNCONNECTED) {
1402 if (gadget_is_dualspeed(gadget)
1403 && gadget->speed == USB_SPEED_HIGH
1404 && dev->hs_config == NULL) {
1405 spin_unlock(&dev->lock);
1406 ERROR (dev, "no high speed config??\n");
1410 dev->state = STATE_DEV_CONNECTED;
1412 INFO (dev, "connected\n");
1413 event = next_event (dev, GADGETFS_CONNECT);
1414 event->u.speed = gadget->speed;
1417 /* host may have given up waiting for response. we can miss control
1418 * requests handled lower down (device/endpoint status and features);
1419 * then ep0_{read,write} will report the wrong status. controller
1420 * driver will have aborted pending i/o.
1422 } else if (dev->state == STATE_DEV_SETUP)
1423 dev->setup_abort = 1;
1425 req->buf = dev->rbuf;
1426 req->dma = DMA_ADDR_INVALID;
1427 req->context = NULL;
1428 value = -EOPNOTSUPP;
1429 switch (ctrl->bRequest) {
1431 case USB_REQ_GET_DESCRIPTOR:
1432 if (ctrl->bRequestType != USB_DIR_IN)
1434 switch (w_value >> 8) {
1437 value = min (w_length, (u16) sizeof *dev->dev);
1438 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1439 req->buf = dev->dev;
1441 #ifdef CONFIG_USB_GADGET_DUALSPEED
1442 case USB_DT_DEVICE_QUALIFIER:
1443 if (!dev->hs_config)
1445 value = min (w_length, (u16)
1446 sizeof (struct usb_qualifier_descriptor));
1447 make_qualifier (dev);
1449 case USB_DT_OTHER_SPEED_CONFIG:
1453 value = config_buf (dev,
1457 value = min (w_length, (u16) value);
1462 default: // all others are errors
1467 /* currently one config, two speeds */
1468 case USB_REQ_SET_CONFIGURATION:
1469 if (ctrl->bRequestType != 0)
1471 if (0 == (u8) w_value) {
1473 dev->current_config = 0;
1474 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1475 // user mode expected to disable endpoints
1479 if (gadget_is_dualspeed(gadget)
1480 && gadget->speed == USB_SPEED_HIGH) {
1481 config = dev->hs_config->bConfigurationValue;
1482 power = dev->hs_config->bMaxPower;
1484 config = dev->config->bConfigurationValue;
1485 power = dev->config->bMaxPower;
1488 if (config == (u8) w_value) {
1490 dev->current_config = config;
1491 usb_gadget_vbus_draw(gadget, 2 * power);
1495 /* report SET_CONFIGURATION like any other control request,
1496 * except that usermode may not stall this. the next
1497 * request mustn't be allowed start until this finishes:
1498 * endpoints and threads set up, etc.
1500 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1501 * has bad/racey automagic that prevents synchronizing here.
1502 * even kernel mode drivers often miss them.
1505 INFO (dev, "configuration #%d\n", dev->current_config);
1506 if (dev->usermode_setup) {
1507 dev->setup_can_stall = 0;
1513 #ifndef CONFIG_USB_GADGET_PXA25X
1514 /* PXA automagically handles this request too */
1515 case USB_REQ_GET_CONFIGURATION:
1516 if (ctrl->bRequestType != 0x80)
1518 *(u8 *)req->buf = dev->current_config;
1519 value = min (w_length, (u16) 1);
1525 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1526 dev->usermode_setup ? "delegate" : "fail",
1527 ctrl->bRequestType, ctrl->bRequest,
1528 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1530 /* if there's an ep0 reader, don't stall */
1531 if (dev->usermode_setup) {
1532 dev->setup_can_stall = 1;
1534 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1536 dev->setup_wLength = w_length;
1537 dev->setup_out_ready = 0;
1538 dev->setup_out_error = 0;
1541 /* read DATA stage for OUT right away */
1542 if (unlikely (!dev->setup_in && w_length)) {
1543 value = setup_req (gadget->ep0, dev->req,
1547 value = usb_ep_queue (gadget->ep0, dev->req,
1550 clean_req (gadget->ep0, dev->req);
1554 /* we can't currently stall these */
1555 dev->setup_can_stall = 0;
1558 /* state changes when reader collects event */
1559 event = next_event (dev, GADGETFS_SETUP);
1560 event->u.setup = *ctrl;
1562 spin_unlock (&dev->lock);
1567 /* proceed with data transfer and status phases? */
1568 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1569 req->length = value;
1570 req->zero = value < w_length;
1571 value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
1573 DBG (dev, "ep_queue --> %d\n", value);
1578 /* device stalls when value < 0 */
1579 spin_unlock (&dev->lock);
1583 static void destroy_ep_files (struct dev_data *dev)
1585 struct list_head *entry, *tmp;
1587 DBG (dev, "%s %d\n", __func__, dev->state);
1589 /* dev->state must prevent interference */
1591 spin_lock_irq (&dev->lock);
1592 list_for_each_safe (entry, tmp, &dev->epfiles) {
1594 struct inode *parent;
1595 struct dentry *dentry;
1597 /* break link to FS */
1598 ep = list_entry (entry, struct ep_data, epfiles);
1599 list_del_init (&ep->epfiles);
1600 dentry = ep->dentry;
1602 parent = dentry->d_parent->d_inode;
1604 /* break link to controller */
1605 if (ep->state == STATE_EP_ENABLED)
1606 (void) usb_ep_disable (ep->ep);
1607 ep->state = STATE_EP_UNBOUND;
1608 usb_ep_free_request (ep->ep, ep->req);
1610 wake_up (&ep->wait);
1613 spin_unlock_irq (&dev->lock);
1615 /* break link to dcache */
1616 mutex_lock (&parent->i_mutex);
1619 mutex_unlock (&parent->i_mutex);
1621 /* fds may still be open */
1624 spin_unlock_irq (&dev->lock);
1628 static struct inode *
1629 gadgetfs_create_file (struct super_block *sb, char const *name,
1630 void *data, const struct file_operations *fops,
1631 struct dentry **dentry_p);
1633 static int activate_ep_files (struct dev_data *dev)
1636 struct ep_data *data;
1638 gadget_for_each_ep (ep, dev->gadget) {
1640 data = kzalloc(sizeof(*data), GFP_KERNEL);
1643 data->state = STATE_EP_DISABLED;
1644 mutex_init(&data->lock);
1645 init_waitqueue_head (&data->wait);
1647 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1648 atomic_set (&data->count, 1);
1653 ep->driver_data = data;
1655 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1659 data->inode = gadgetfs_create_file (dev->sb, data->name,
1660 data, &ep_config_operations,
1664 list_add_tail (&data->epfiles, &dev->epfiles);
1669 usb_ep_free_request (ep, data->req);
1674 DBG (dev, "%s enomem\n", __func__);
1675 destroy_ep_files (dev);
1680 gadgetfs_unbind (struct usb_gadget *gadget)
1682 struct dev_data *dev = get_gadget_data (gadget);
1684 DBG (dev, "%s\n", __func__);
1686 spin_lock_irq (&dev->lock);
1687 dev->state = STATE_DEV_UNBOUND;
1688 spin_unlock_irq (&dev->lock);
1690 destroy_ep_files (dev);
1691 gadget->ep0->driver_data = NULL;
1692 set_gadget_data (gadget, NULL);
1694 /* we've already been disconnected ... no i/o is active */
1696 usb_ep_free_request (gadget->ep0, dev->req);
1697 DBG (dev, "%s done\n", __func__);
1701 static struct dev_data *the_device;
1704 gadgetfs_bind (struct usb_gadget *gadget)
1706 struct dev_data *dev = the_device;
1710 if (0 != strcmp (CHIP, gadget->name)) {
1711 pr_err("%s expected %s controller not %s\n",
1712 shortname, CHIP, gadget->name);
1716 set_gadget_data (gadget, dev);
1717 dev->gadget = gadget;
1718 gadget->ep0->driver_data = dev;
1720 /* preallocate control response and buffer */
1721 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1724 dev->req->context = NULL;
1725 dev->req->complete = epio_complete;
1727 if (activate_ep_files (dev) < 0)
1730 INFO (dev, "bound to %s driver\n", gadget->name);
1731 spin_lock_irq(&dev->lock);
1732 dev->state = STATE_DEV_UNCONNECTED;
1733 spin_unlock_irq(&dev->lock);
1738 gadgetfs_unbind (gadget);
1743 gadgetfs_disconnect (struct usb_gadget *gadget)
1745 struct dev_data *dev = get_gadget_data (gadget);
1746 unsigned long flags;
1748 spin_lock_irqsave (&dev->lock, flags);
1749 if (dev->state == STATE_DEV_UNCONNECTED)
1751 dev->state = STATE_DEV_UNCONNECTED;
1753 INFO (dev, "disconnected\n");
1754 next_event (dev, GADGETFS_DISCONNECT);
1757 spin_unlock_irqrestore (&dev->lock, flags);
1761 gadgetfs_suspend (struct usb_gadget *gadget)
1763 struct dev_data *dev = get_gadget_data (gadget);
1765 INFO (dev, "suspended from state %d\n", dev->state);
1766 spin_lock (&dev->lock);
1767 switch (dev->state) {
1768 case STATE_DEV_SETUP: // VERY odd... host died??
1769 case STATE_DEV_CONNECTED:
1770 case STATE_DEV_UNCONNECTED:
1771 next_event (dev, GADGETFS_SUSPEND);
1777 spin_unlock (&dev->lock);
1780 static struct usb_gadget_driver gadgetfs_driver = {
1781 #ifdef CONFIG_USB_GADGET_DUALSPEED
1782 .speed = USB_SPEED_HIGH,
1784 .speed = USB_SPEED_FULL,
1786 .function = (char *) driver_desc,
1787 .unbind = gadgetfs_unbind,
1788 .setup = gadgetfs_setup,
1789 .disconnect = gadgetfs_disconnect,
1790 .suspend = gadgetfs_suspend,
1793 .name = (char *) shortname,
1797 /*----------------------------------------------------------------------*/
1799 static void gadgetfs_nop(struct usb_gadget *arg) { }
1801 static int gadgetfs_probe (struct usb_gadget *gadget)
1803 CHIP = gadget->name;
1807 static struct usb_gadget_driver probe_driver = {
1808 .speed = USB_SPEED_HIGH,
1809 .unbind = gadgetfs_nop,
1810 .setup = (void *)gadgetfs_nop,
1811 .disconnect = gadgetfs_nop,
1818 /* DEVICE INITIALIZATION
1820 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1821 * status = write (fd, descriptors, sizeof descriptors)
1823 * That write establishes the device configuration, so the kernel can
1824 * bind to the controller ... guaranteeing it can handle enumeration
1825 * at all necessary speeds. Descriptor order is:
1827 * . message tag (u32, host order) ... for now, must be zero; it
1828 * would change to support features like multi-config devices
1829 * . full/low speed config ... all wTotalLength bytes (with interface,
1830 * class, altsetting, endpoint, and other descriptors)
1831 * . high speed config ... all descriptors, for high speed operation;
1832 * this one's optional except for high-speed hardware
1833 * . device descriptor
1835 * Endpoints are not yet enabled. Drivers must wait until device
1836 * configuration and interface altsetting changes create
1837 * the need to configure (or unconfigure) them.
1839 * After initialization, the device stays active for as long as that
1840 * $CHIP file is open. Events must then be read from that descriptor,
1841 * such as configuration notifications.
1844 static int is_valid_config (struct usb_config_descriptor *config)
1846 return config->bDescriptorType == USB_DT_CONFIG
1847 && config->bLength == USB_DT_CONFIG_SIZE
1848 && config->bConfigurationValue != 0
1849 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1850 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1851 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1852 /* FIXME check lengths: walk to end */
1856 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1858 struct dev_data *dev = fd->private_data;
1859 ssize_t value = len, length = len;
1864 if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
1867 /* we might need to change message format someday */
1868 if (copy_from_user (&tag, buf, 4))
1875 kbuf = memdup_user(buf, length);
1877 return PTR_ERR(kbuf);
1879 spin_lock_irq (&dev->lock);
1885 /* full or low speed config */
1886 dev->config = (void *) kbuf;
1887 total = le16_to_cpu(dev->config->wTotalLength);
1888 if (!is_valid_config (dev->config) || total >= length)
1893 /* optional high speed config */
1894 if (kbuf [1] == USB_DT_CONFIG) {
1895 dev->hs_config = (void *) kbuf;
1896 total = le16_to_cpu(dev->hs_config->wTotalLength);
1897 if (!is_valid_config (dev->hs_config) || total >= length)
1903 /* could support multiple configs, using another encoding! */
1905 /* device descriptor (tweaked for paranoia) */
1906 if (length != USB_DT_DEVICE_SIZE)
1908 dev->dev = (void *)kbuf;
1909 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1910 || dev->dev->bDescriptorType != USB_DT_DEVICE
1911 || dev->dev->bNumConfigurations != 1)
1913 dev->dev->bNumConfigurations = 1;
1914 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1916 /* triggers gadgetfs_bind(); then we can enumerate. */
1917 spin_unlock_irq (&dev->lock);
1918 value = usb_gadget_probe_driver(&gadgetfs_driver, gadgetfs_bind);
1923 /* at this point "good" hardware has for the first time
1924 * let the USB the host see us. alternatively, if users
1925 * unplug/replug that will clear all the error state.
1927 * note: everything running before here was guaranteed
1928 * to choke driver model style diagnostics. from here
1929 * on, they can work ... except in cleanup paths that
1930 * kick in after the ep0 descriptor is closed.
1932 fd->f_op = &ep0_io_operations;
1938 spin_unlock_irq (&dev->lock);
1939 pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
1946 dev_open (struct inode *inode, struct file *fd)
1948 struct dev_data *dev = inode->i_private;
1951 spin_lock_irq(&dev->lock);
1952 if (dev->state == STATE_DEV_DISABLED) {
1954 dev->state = STATE_DEV_OPENED;
1955 fd->private_data = dev;
1959 spin_unlock_irq(&dev->lock);
1963 static const struct file_operations dev_init_operations = {
1964 .owner = THIS_MODULE,
1965 .llseek = no_llseek,
1968 .write = dev_config,
1969 .fasync = ep0_fasync,
1970 .unlocked_ioctl = dev_ioctl,
1971 .release = dev_release,
1974 /*----------------------------------------------------------------------*/
1976 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1978 * Mounting the filesystem creates a controller file, used first for
1979 * device configuration then later for event monitoring.
1983 /* FIXME PAM etc could set this security policy without mount options
1984 * if epfiles inherited ownership and permissons from ep0 ...
1987 static unsigned default_uid;
1988 static unsigned default_gid;
1989 static unsigned default_perm = S_IRUSR | S_IWUSR;
1991 module_param (default_uid, uint, 0644);
1992 module_param (default_gid, uint, 0644);
1993 module_param (default_perm, uint, 0644);
1996 static struct inode *
1997 gadgetfs_make_inode (struct super_block *sb,
1998 void *data, const struct file_operations *fops,
2001 struct inode *inode = new_inode (sb);
2004 inode->i_ino = get_next_ino();
2005 inode->i_mode = mode;
2006 inode->i_uid = default_uid;
2007 inode->i_gid = default_gid;
2008 inode->i_atime = inode->i_mtime = inode->i_ctime
2010 inode->i_private = data;
2011 inode->i_fop = fops;
2016 /* creates in fs root directory, so non-renamable and non-linkable.
2017 * so inode and dentry are paired, until device reconfig.
2019 static struct inode *
2020 gadgetfs_create_file (struct super_block *sb, char const *name,
2021 void *data, const struct file_operations *fops,
2022 struct dentry **dentry_p)
2024 struct dentry *dentry;
2025 struct inode *inode;
2027 dentry = d_alloc_name(sb->s_root, name);
2031 inode = gadgetfs_make_inode (sb, data, fops,
2032 S_IFREG | (default_perm & S_IRWXUGO));
2037 d_add (dentry, inode);
2042 static const struct super_operations gadget_fs_operations = {
2043 .statfs = simple_statfs,
2044 .drop_inode = generic_delete_inode,
2048 gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
2050 struct inode *inode;
2052 struct dev_data *dev;
2057 /* fake probe to determine $CHIP */
2058 (void) usb_gadget_probe_driver(&probe_driver, gadgetfs_probe);
2063 sb->s_blocksize = PAGE_CACHE_SIZE;
2064 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
2065 sb->s_magic = GADGETFS_MAGIC;
2066 sb->s_op = &gadget_fs_operations;
2067 sb->s_time_gran = 1;
2070 inode = gadgetfs_make_inode (sb,
2071 NULL, &simple_dir_operations,
2072 S_IFDIR | S_IRUGO | S_IXUGO);
2075 inode->i_op = &simple_dir_inode_operations;
2076 if (!(d = d_alloc_root (inode)))
2080 /* the ep0 file is named after the controller we expect;
2081 * user mode code can use it for sanity checks, like we do.
2088 if (!gadgetfs_create_file (sb, CHIP,
2089 dev, &dev_init_operations,
2093 /* other endpoint files are available after hardware setup,
2094 * from binding to a controller.
2109 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2110 static struct dentry *
2111 gadgetfs_mount (struct file_system_type *t, int flags,
2112 const char *path, void *opts)
2114 return mount_single (t, flags, opts, gadgetfs_fill_super);
2118 gadgetfs_kill_sb (struct super_block *sb)
2120 kill_litter_super (sb);
2122 put_dev (the_device);
2127 /*----------------------------------------------------------------------*/
2129 static struct file_system_type gadgetfs_type = {
2130 .owner = THIS_MODULE,
2132 .mount = gadgetfs_mount,
2133 .kill_sb = gadgetfs_kill_sb,
2136 /*----------------------------------------------------------------------*/
2138 static int __init init (void)
2142 status = register_filesystem (&gadgetfs_type);
2144 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2145 shortname, driver_desc);
2150 static void __exit cleanup (void)
2152 pr_debug ("unregister %s\n", shortname);
2153 unregister_filesystem (&gadgetfs_type);
2155 module_exit (cleanup);