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>
34 #include <linux/usb/composite.h> /* for USB_GADGET_DELAYED_STATUS */
36 /* Undef helpers from linux/usb/composite.h as gadgetfs redefines them */
43 * The gadgetfs API maps each endpoint to a file descriptor so that you
44 * can use standard synchronous read/write calls for I/O. There's some
45 * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
46 * drivers show how this works in practice. You can also use AIO to
47 * eliminate I/O gaps between requests, to help when streaming data.
49 * Key parts that must be USB-specific are protocols defining how the
50 * read/write operations relate to the hardware state machines. There
51 * are two types of files. One type is for the device, implementing ep0.
52 * The other type is for each IN or OUT endpoint. In both cases, the
53 * user mode driver must configure the hardware before using it.
55 * - First, dev_config() is called when /dev/gadget/$CHIP is configured
56 * (by writing configuration and device descriptors). Afterwards it
57 * may serve as a source of device events, used to handle all control
58 * requests other than basic enumeration.
60 * - Then, after a SET_CONFIGURATION control request, ep_config() is
61 * called when each /dev/gadget/ep* file is configured (by writing
62 * endpoint descriptors). Afterwards these files are used to write()
63 * IN data or to read() OUT data. To halt the endpoint, a "wrong
64 * direction" request is issued (like reading an IN endpoint).
66 * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
67 * not possible on all hardware. For example, precise fault handling with
68 * respect to data left in endpoint fifos after aborted operations; or
69 * selective clearing of endpoint halts, to implement SET_INTERFACE.
72 #define DRIVER_DESC "USB Gadget filesystem"
73 #define DRIVER_VERSION "24 Aug 2004"
75 static const char driver_desc [] = DRIVER_DESC;
76 static const char shortname [] = "gadgetfs";
78 MODULE_DESCRIPTION (DRIVER_DESC);
79 MODULE_AUTHOR ("David Brownell");
80 MODULE_LICENSE ("GPL");
82 static int ep_open(struct inode *, struct file *);
85 /*----------------------------------------------------------------------*/
87 #define GADGETFS_MAGIC 0xaee71ee7
89 /* /dev/gadget/$CHIP represents ep0 and the whole device */
91 /* DISABLED is the initial state. */
92 STATE_DEV_DISABLED = 0,
94 /* Only one open() of /dev/gadget/$CHIP; only one file tracks
95 * ep0/device i/o modes and binding to the controller. Driver
96 * must always write descriptors to initialize the device, then
97 * the device becomes UNCONNECTED until enumeration.
101 /* From then on, ep0 fd is in either of two basic modes:
102 * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
103 * - SETUP: read/write will transfer control data and succeed;
104 * or if "wrong direction", performs protocol stall
106 STATE_DEV_UNCONNECTED,
110 /* UNBOUND means the driver closed ep0, so the device won't be
111 * accessible again (DEV_DISABLED) until all fds are closed.
116 /* enough for the whole queue: most events invalidate others */
119 #define RBUF_SIZE 256
125 enum ep0_state state; /* P: lock */
126 struct usb_gadgetfs_event event [N_EVENT];
128 struct fasync_struct *fasync;
131 /* drivers reading ep0 MUST handle control requests (SETUP)
132 * reported that way; else the host will time out.
134 unsigned usermode_setup : 1,
140 gadget_registered : 1;
141 unsigned setup_wLength;
143 /* the rest is basically write-once */
144 struct usb_config_descriptor *config, *hs_config;
145 struct usb_device_descriptor *dev;
146 struct usb_request *req;
147 struct usb_gadget *gadget;
148 struct list_head epfiles;
150 wait_queue_head_t wait;
151 struct super_block *sb;
152 struct dentry *dentry;
154 /* except this scratch i/o buffer for ep0 */
158 static inline void get_dev (struct dev_data *data)
160 refcount_inc (&data->count);
163 static void put_dev (struct dev_data *data)
165 if (likely (!refcount_dec_and_test (&data->count)))
167 /* needs no more cleanup */
168 BUG_ON (waitqueue_active (&data->wait));
172 static struct dev_data *dev_new (void)
174 struct dev_data *dev;
176 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
179 dev->state = STATE_DEV_DISABLED;
180 refcount_set (&dev->count, 1);
181 spin_lock_init (&dev->lock);
182 INIT_LIST_HEAD (&dev->epfiles);
183 init_waitqueue_head (&dev->wait);
187 /*----------------------------------------------------------------------*/
189 /* other /dev/gadget/$ENDPOINT files represent endpoints */
191 STATE_EP_DISABLED = 0,
201 struct dev_data *dev;
202 /* must hold dev->lock before accessing ep or req */
204 struct usb_request *req;
207 struct usb_endpoint_descriptor desc, hs_desc;
208 struct list_head epfiles;
209 wait_queue_head_t wait;
210 struct dentry *dentry;
213 static inline void get_ep (struct ep_data *data)
215 refcount_inc (&data->count);
218 static void put_ep (struct ep_data *data)
220 if (likely (!refcount_dec_and_test (&data->count)))
223 /* needs no more cleanup */
224 BUG_ON (!list_empty (&data->epfiles));
225 BUG_ON (waitqueue_active (&data->wait));
229 /*----------------------------------------------------------------------*/
231 /* most "how to use the hardware" policy choices are in userspace:
232 * mapping endpoint roles (which the driver needs) to the capabilities
233 * which the usb controller has. most of those capabilities are exposed
234 * implicitly, starting with the driver name and then endpoint names.
237 static const char *CHIP;
238 static DEFINE_MUTEX(sb_mutex); /* Serialize superblock operations */
240 /*----------------------------------------------------------------------*/
242 /* NOTE: don't use dev_printk calls before binding to the gadget
243 * at the end of ep0 configuration, or after unbind.
246 /* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
247 #define xprintk(d,level,fmt,args...) \
248 printk(level "%s: " fmt , shortname , ## args)
251 #define DBG(dev,fmt,args...) \
252 xprintk(dev , KERN_DEBUG , fmt , ## args)
254 #define DBG(dev,fmt,args...) \
261 #define VDEBUG(dev,fmt,args...) \
265 #define ERROR(dev,fmt,args...) \
266 xprintk(dev , KERN_ERR , fmt , ## args)
267 #define INFO(dev,fmt,args...) \
268 xprintk(dev , KERN_INFO , fmt , ## args)
271 /*----------------------------------------------------------------------*/
273 /* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
275 * After opening, configure non-control endpoints. Then use normal
276 * stream read() and write() requests; and maybe ioctl() to get more
277 * precise FIFO status when recovering from cancellation.
280 static void epio_complete (struct usb_ep *ep, struct usb_request *req)
282 struct ep_data *epdata = ep->driver_data;
287 epdata->status = req->status;
289 epdata->status = req->actual;
290 complete ((struct completion *)req->context);
293 /* tasklock endpoint, returning when it's connected.
294 * still need dev->lock to use epdata->ep.
297 get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
301 if (f_flags & O_NONBLOCK) {
302 if (!mutex_trylock(&epdata->lock))
304 if (epdata->state != STATE_EP_ENABLED &&
305 (!is_write || epdata->state != STATE_EP_READY)) {
306 mutex_unlock(&epdata->lock);
314 val = mutex_lock_interruptible(&epdata->lock);
318 switch (epdata->state) {
319 case STATE_EP_ENABLED:
321 case STATE_EP_READY: /* not configured yet */
325 case STATE_EP_UNBOUND: /* clean disconnect */
327 // case STATE_EP_DISABLED: /* "can't happen" */
328 default: /* error! */
329 pr_debug ("%s: ep %p not available, state %d\n",
330 shortname, epdata, epdata->state);
332 mutex_unlock(&epdata->lock);
337 ep_io (struct ep_data *epdata, void *buf, unsigned len)
339 DECLARE_COMPLETION_ONSTACK (done);
342 spin_lock_irq (&epdata->dev->lock);
343 if (likely (epdata->ep != NULL)) {
344 struct usb_request *req = epdata->req;
346 req->context = &done;
347 req->complete = epio_complete;
350 value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
353 spin_unlock_irq (&epdata->dev->lock);
355 if (likely (value == 0)) {
356 value = wait_for_completion_interruptible(&done);
358 spin_lock_irq (&epdata->dev->lock);
359 if (likely (epdata->ep != NULL)) {
360 DBG (epdata->dev, "%s i/o interrupted\n",
362 usb_ep_dequeue (epdata->ep, epdata->req);
363 spin_unlock_irq (&epdata->dev->lock);
365 wait_for_completion(&done);
366 if (epdata->status == -ECONNRESET)
367 epdata->status = -EINTR;
369 spin_unlock_irq (&epdata->dev->lock);
371 DBG (epdata->dev, "endpoint gone\n");
372 wait_for_completion(&done);
373 epdata->status = -ENODEV;
376 return epdata->status;
382 ep_release (struct inode *inode, struct file *fd)
384 struct ep_data *data = fd->private_data;
387 value = mutex_lock_interruptible(&data->lock);
391 /* clean up if this can be reopened */
392 if (data->state != STATE_EP_UNBOUND) {
393 data->state = STATE_EP_DISABLED;
394 data->desc.bDescriptorType = 0;
395 data->hs_desc.bDescriptorType = 0;
396 usb_ep_disable(data->ep);
398 mutex_unlock(&data->lock);
403 static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
405 struct ep_data *data = fd->private_data;
408 if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
411 spin_lock_irq (&data->dev->lock);
412 if (likely (data->ep != NULL)) {
414 case GADGETFS_FIFO_STATUS:
415 status = usb_ep_fifo_status (data->ep);
417 case GADGETFS_FIFO_FLUSH:
418 usb_ep_fifo_flush (data->ep);
420 case GADGETFS_CLEAR_HALT:
421 status = usb_ep_clear_halt (data->ep);
428 spin_unlock_irq (&data->dev->lock);
429 mutex_unlock(&data->lock);
433 /*----------------------------------------------------------------------*/
435 /* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
438 struct usb_request *req;
439 struct ep_data *epdata;
441 struct mm_struct *mm;
442 struct work_struct work;
449 static int ep_aio_cancel(struct kiocb *iocb)
451 struct kiocb_priv *priv = iocb->private;
452 struct ep_data *epdata;
456 epdata = priv->epdata;
457 // spin_lock(&epdata->dev->lock);
458 if (likely(epdata && epdata->ep && priv->req))
459 value = usb_ep_dequeue (epdata->ep, priv->req);
462 // spin_unlock(&epdata->dev->lock);
468 static void ep_user_copy_worker(struct work_struct *work)
470 struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
471 struct mm_struct *mm = priv->mm;
472 struct kiocb *iocb = priv->iocb;
476 ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
477 kthread_unuse_mm(mm);
481 /* completing the iocb can drop the ctx and mm, don't touch mm after */
482 iocb->ki_complete(iocb, ret);
485 kfree(priv->to_free);
489 static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
491 struct kiocb *iocb = req->context;
492 struct kiocb_priv *priv = iocb->private;
493 struct ep_data *epdata = priv->epdata;
495 /* lock against disconnect (and ideally, cancel) */
496 spin_lock(&epdata->dev->lock);
500 /* if this was a write or a read returning no data then we
501 * don't need to copy anything to userspace, so we can
502 * complete the aio request immediately.
504 if (priv->to_free == NULL || unlikely(req->actual == 0)) {
506 kfree(priv->to_free);
508 iocb->private = NULL;
509 iocb->ki_complete(iocb,
510 req->actual ? req->actual : (long)req->status);
512 /* ep_copy_to_user() won't report both; we hide some faults */
513 if (unlikely(0 != req->status))
514 DBG(epdata->dev, "%s fault %d len %d\n",
515 ep->name, req->status, req->actual);
517 priv->buf = req->buf;
518 priv->actual = req->actual;
519 INIT_WORK(&priv->work, ep_user_copy_worker);
520 schedule_work(&priv->work);
523 usb_ep_free_request(ep, req);
524 spin_unlock(&epdata->dev->lock);
528 static ssize_t ep_aio(struct kiocb *iocb,
529 struct kiocb_priv *priv,
530 struct ep_data *epdata,
534 struct usb_request *req;
537 iocb->private = priv;
540 kiocb_set_cancel_fn(iocb, ep_aio_cancel);
542 priv->epdata = epdata;
544 priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
546 /* each kiocb is coupled to one usb_request, but we can't
547 * allocate or submit those if the host disconnected.
549 spin_lock_irq(&epdata->dev->lock);
551 if (unlikely(epdata->ep == NULL))
554 req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
562 req->complete = ep_aio_complete;
564 value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
565 if (unlikely(0 != value)) {
566 usb_ep_free_request(epdata->ep, req);
569 spin_unlock_irq(&epdata->dev->lock);
573 spin_unlock_irq(&epdata->dev->lock);
574 kfree(priv->to_free);
581 ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
583 struct file *file = iocb->ki_filp;
584 struct ep_data *epdata = file->private_data;
585 size_t len = iov_iter_count(to);
589 if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
592 /* halt any endpoint by doing a "wrong direction" i/o call */
593 if (usb_endpoint_dir_in(&epdata->desc)) {
594 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
595 !is_sync_kiocb(iocb)) {
596 mutex_unlock(&epdata->lock);
599 DBG (epdata->dev, "%s halt\n", epdata->name);
600 spin_lock_irq(&epdata->dev->lock);
601 if (likely(epdata->ep != NULL))
602 usb_ep_set_halt(epdata->ep);
603 spin_unlock_irq(&epdata->dev->lock);
604 mutex_unlock(&epdata->lock);
608 buf = kmalloc(len, GFP_KERNEL);
609 if (unlikely(!buf)) {
610 mutex_unlock(&epdata->lock);
613 if (is_sync_kiocb(iocb)) {
614 value = ep_io(epdata, buf, len);
615 if (value >= 0 && (copy_to_iter(buf, value, to) != value))
618 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
622 priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
623 if (!iter_is_ubuf(&priv->to) && !priv->to_free) {
627 value = ep_aio(iocb, priv, epdata, buf, len);
628 if (value == -EIOCBQUEUED)
633 mutex_unlock(&epdata->lock);
637 static ssize_t ep_config(struct ep_data *, const char *, size_t);
640 ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
642 struct file *file = iocb->ki_filp;
643 struct ep_data *epdata = file->private_data;
644 size_t len = iov_iter_count(from);
649 if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
652 configured = epdata->state == STATE_EP_ENABLED;
654 /* halt any endpoint by doing a "wrong direction" i/o call */
655 if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
656 if (usb_endpoint_xfer_isoc(&epdata->desc) ||
657 !is_sync_kiocb(iocb)) {
658 mutex_unlock(&epdata->lock);
661 DBG (epdata->dev, "%s halt\n", epdata->name);
662 spin_lock_irq(&epdata->dev->lock);
663 if (likely(epdata->ep != NULL))
664 usb_ep_set_halt(epdata->ep);
665 spin_unlock_irq(&epdata->dev->lock);
666 mutex_unlock(&epdata->lock);
670 buf = kmalloc(len, GFP_KERNEL);
671 if (unlikely(!buf)) {
672 mutex_unlock(&epdata->lock);
676 if (unlikely(!copy_from_iter_full(buf, len, from))) {
681 if (unlikely(!configured)) {
682 value = ep_config(epdata, buf, len);
683 } else if (is_sync_kiocb(iocb)) {
684 value = ep_io(epdata, buf, len);
686 struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
689 value = ep_aio(iocb, priv, epdata, buf, len);
690 if (value == -EIOCBQUEUED)
696 mutex_unlock(&epdata->lock);
700 /*----------------------------------------------------------------------*/
702 /* used after endpoint configuration */
703 static const struct file_operations ep_io_operations = {
704 .owner = THIS_MODULE,
707 .release = ep_release,
709 .unlocked_ioctl = ep_ioctl,
710 .read_iter = ep_read_iter,
711 .write_iter = ep_write_iter,
714 /* ENDPOINT INITIALIZATION
716 * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
717 * status = write (fd, descriptors, sizeof descriptors)
719 * That write establishes the endpoint configuration, configuring
720 * the controller to process bulk, interrupt, or isochronous transfers
721 * at the right maxpacket size, and so on.
723 * The descriptors are message type 1, identified by a host order u32
724 * at the beginning of what's written. Descriptor order is: full/low
725 * speed descriptor, then optional high speed descriptor.
728 ep_config (struct ep_data *data, const char *buf, size_t len)
732 int value, length = len;
734 if (data->state != STATE_EP_READY) {
740 if (len < USB_DT_ENDPOINT_SIZE + 4)
743 /* we might need to change message format someday */
744 memcpy(&tag, buf, 4);
746 DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
752 /* NOTE: audio endpoint extensions not accepted here;
753 * just don't include the extra bytes.
756 /* full/low speed descriptor, then high speed */
757 memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
758 if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
759 || data->desc.bDescriptorType != USB_DT_ENDPOINT)
761 if (len != USB_DT_ENDPOINT_SIZE) {
762 if (len != 2 * USB_DT_ENDPOINT_SIZE)
764 memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
765 USB_DT_ENDPOINT_SIZE);
766 if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
767 || data->hs_desc.bDescriptorType
768 != USB_DT_ENDPOINT) {
769 DBG(data->dev, "config %s, bad hs length or type\n",
775 spin_lock_irq (&data->dev->lock);
776 if (data->dev->state == STATE_DEV_UNBOUND) {
786 switch (data->dev->gadget->speed) {
789 ep->desc = &data->desc;
792 /* fails if caller didn't provide that descriptor... */
793 ep->desc = &data->hs_desc;
796 DBG(data->dev, "unconnected, %s init abandoned\n",
801 value = usb_ep_enable(ep);
803 data->state = STATE_EP_ENABLED;
807 spin_unlock_irq (&data->dev->lock);
810 data->desc.bDescriptorType = 0;
811 data->hs_desc.bDescriptorType = 0;
820 ep_open (struct inode *inode, struct file *fd)
822 struct ep_data *data = inode->i_private;
825 if (mutex_lock_interruptible(&data->lock) != 0)
827 spin_lock_irq (&data->dev->lock);
828 if (data->dev->state == STATE_DEV_UNBOUND)
830 else if (data->state == STATE_EP_DISABLED) {
832 data->state = STATE_EP_READY;
834 fd->private_data = data;
835 VDEBUG (data->dev, "%s ready\n", data->name);
837 DBG (data->dev, "%s state %d\n",
838 data->name, data->state);
839 spin_unlock_irq (&data->dev->lock);
840 mutex_unlock(&data->lock);
844 /*----------------------------------------------------------------------*/
846 /* EP0 IMPLEMENTATION can be partly in userspace.
848 * Drivers that use this facility receive various events, including
849 * control requests the kernel doesn't handle. Drivers that don't
850 * use this facility may be too simple-minded for real applications.
853 static inline void ep0_readable (struct dev_data *dev)
855 wake_up (&dev->wait);
856 kill_fasync (&dev->fasync, SIGIO, POLL_IN);
859 static void clean_req (struct usb_ep *ep, struct usb_request *req)
861 struct dev_data *dev = ep->driver_data;
863 if (req->buf != dev->rbuf) {
865 req->buf = dev->rbuf;
867 req->complete = epio_complete;
868 dev->setup_out_ready = 0;
871 static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
873 struct dev_data *dev = ep->driver_data;
877 /* for control OUT, data must still get to userspace */
878 spin_lock_irqsave(&dev->lock, flags);
879 if (!dev->setup_in) {
880 dev->setup_out_error = (req->status != 0);
881 if (!dev->setup_out_error)
883 dev->setup_out_ready = 1;
887 /* clean up as appropriate */
888 if (free && req->buf != &dev->rbuf)
890 req->complete = epio_complete;
891 spin_unlock_irqrestore(&dev->lock, flags);
894 static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
896 struct dev_data *dev = ep->driver_data;
898 if (dev->setup_out_ready) {
899 DBG (dev, "ep0 request busy!\n");
902 if (len > sizeof (dev->rbuf))
903 req->buf = kmalloc(len, GFP_ATOMIC);
904 if (req->buf == NULL) {
905 req->buf = dev->rbuf;
908 req->complete = ep0_complete;
915 ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
917 struct dev_data *dev = fd->private_data;
919 enum ep0_state state;
921 spin_lock_irq (&dev->lock);
922 if (dev->state <= STATE_DEV_OPENED) {
927 /* report fd mode change before acting on it */
928 if (dev->setup_abort) {
929 dev->setup_abort = 0;
934 /* control DATA stage */
935 if ((state = dev->state) == STATE_DEV_SETUP) {
937 if (dev->setup_in) { /* stall IN */
938 VDEBUG(dev, "ep0in stall\n");
939 (void) usb_ep_set_halt (dev->gadget->ep0);
941 dev->state = STATE_DEV_CONNECTED;
943 } else if (len == 0) { /* ack SET_CONFIGURATION etc */
944 struct usb_ep *ep = dev->gadget->ep0;
945 struct usb_request *req = dev->req;
947 if ((retval = setup_req (ep, req, 0)) == 0) {
949 spin_unlock_irq (&dev->lock);
950 retval = usb_ep_queue (ep, req, GFP_KERNEL);
951 spin_lock_irq (&dev->lock);
954 dev->state = STATE_DEV_CONNECTED;
956 /* assume that was SET_CONFIGURATION */
957 if (dev->current_config) {
960 if (gadget_is_dualspeed(dev->gadget)
961 && (dev->gadget->speed
963 power = dev->hs_config->bMaxPower;
965 power = dev->config->bMaxPower;
966 usb_gadget_vbus_draw(dev->gadget, 2 * power);
969 } else { /* collect OUT data */
970 if ((fd->f_flags & O_NONBLOCK) != 0
971 && !dev->setup_out_ready) {
975 spin_unlock_irq (&dev->lock);
976 retval = wait_event_interruptible (dev->wait,
977 dev->setup_out_ready != 0);
979 /* FIXME state could change from under us */
980 spin_lock_irq (&dev->lock);
984 if (dev->state != STATE_DEV_SETUP) {
988 dev->state = STATE_DEV_CONNECTED;
990 if (dev->setup_out_error)
993 len = min (len, (size_t)dev->req->actual);
995 spin_unlock_irq(&dev->lock);
996 if (copy_to_user (buf, dev->req->buf, len))
1000 spin_lock_irq(&dev->lock);
1002 clean_req (dev->gadget->ep0, dev->req);
1003 /* NOTE userspace can't yet choose to stall */
1009 /* else normal: return event data */
1010 if (len < sizeof dev->event [0]) {
1014 len -= len % sizeof (struct usb_gadgetfs_event);
1015 dev->usermode_setup = 1;
1018 /* return queued events right away */
1019 if (dev->ev_next != 0) {
1022 n = len / sizeof (struct usb_gadgetfs_event);
1023 if (dev->ev_next < n)
1026 /* ep0 i/o has special semantics during STATE_DEV_SETUP */
1027 for (i = 0; i < n; i++) {
1028 if (dev->event [i].type == GADGETFS_SETUP) {
1029 dev->state = STATE_DEV_SETUP;
1034 spin_unlock_irq (&dev->lock);
1035 len = n * sizeof (struct usb_gadgetfs_event);
1036 if (copy_to_user (buf, &dev->event, len))
1041 /* NOTE this doesn't guard against broken drivers;
1042 * concurrent ep0 readers may lose events.
1044 spin_lock_irq (&dev->lock);
1045 if (dev->ev_next > n) {
1046 memmove(&dev->event[0], &dev->event[n],
1047 sizeof (struct usb_gadgetfs_event)
1048 * (dev->ev_next - n));
1051 spin_unlock_irq (&dev->lock);
1055 if (fd->f_flags & O_NONBLOCK) {
1062 DBG (dev, "fail %s, state %d\n", __func__, state);
1065 case STATE_DEV_UNCONNECTED:
1066 case STATE_DEV_CONNECTED:
1067 spin_unlock_irq (&dev->lock);
1068 DBG (dev, "%s wait\n", __func__);
1070 /* wait for events */
1071 retval = wait_event_interruptible (dev->wait,
1075 spin_lock_irq (&dev->lock);
1080 spin_unlock_irq (&dev->lock);
1084 static struct usb_gadgetfs_event *
1085 next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
1087 struct usb_gadgetfs_event *event;
1091 /* these events purge the queue */
1092 case GADGETFS_DISCONNECT:
1093 if (dev->state == STATE_DEV_SETUP)
1094 dev->setup_abort = 1;
1096 case GADGETFS_CONNECT:
1099 case GADGETFS_SETUP: /* previous request timed out */
1100 case GADGETFS_SUSPEND: /* same effect */
1101 /* these events can't be repeated */
1102 for (i = 0; i != dev->ev_next; i++) {
1103 if (dev->event [i].type != type)
1105 DBG(dev, "discard old event[%d] %d\n", i, type);
1107 if (i == dev->ev_next)
1109 /* indices start at zero, for simplicity */
1110 memmove (&dev->event [i], &dev->event [i + 1],
1111 sizeof (struct usb_gadgetfs_event)
1112 * (dev->ev_next - i));
1118 VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
1119 event = &dev->event [dev->ev_next++];
1120 BUG_ON (dev->ev_next > N_EVENT);
1121 memset (event, 0, sizeof *event);
1127 ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1129 struct dev_data *dev = fd->private_data;
1130 ssize_t retval = -ESRCH;
1132 /* report fd mode change before acting on it */
1133 if (dev->setup_abort) {
1134 dev->setup_abort = 0;
1137 /* data and/or status stage for control request */
1138 } else if (dev->state == STATE_DEV_SETUP) {
1140 len = min_t(size_t, len, dev->setup_wLength);
1141 if (dev->setup_in) {
1142 retval = setup_req (dev->gadget->ep0, dev->req, len);
1144 dev->state = STATE_DEV_CONNECTED;
1146 spin_unlock_irq (&dev->lock);
1147 if (copy_from_user (dev->req->buf, buf, len))
1150 if (len < dev->setup_wLength)
1152 retval = usb_ep_queue (
1153 dev->gadget->ep0, dev->req,
1156 spin_lock_irq(&dev->lock);
1159 clean_req (dev->gadget->ep0, dev->req);
1166 /* can stall some OUT transfers */
1167 } else if (dev->setup_can_stall) {
1168 VDEBUG(dev, "ep0out stall\n");
1169 (void) usb_ep_set_halt (dev->gadget->ep0);
1171 dev->state = STATE_DEV_CONNECTED;
1173 DBG(dev, "bogus ep0out stall!\n");
1176 DBG (dev, "fail %s, state %d\n", __func__, dev->state);
1182 ep0_fasync (int f, struct file *fd, int on)
1184 struct dev_data *dev = fd->private_data;
1185 // caller must F_SETOWN before signal delivery happens
1186 VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
1187 return fasync_helper (f, fd, on, &dev->fasync);
1190 static struct usb_gadget_driver gadgetfs_driver;
1193 dev_release (struct inode *inode, struct file *fd)
1195 struct dev_data *dev = fd->private_data;
1197 /* closing ep0 === shutdown all */
1199 if (dev->gadget_registered) {
1200 usb_gadget_unregister_driver (&gadgetfs_driver);
1201 dev->gadget_registered = false;
1204 /* at this point "good" hardware has disconnected the
1205 * device from USB; the host won't see it any more.
1206 * alternatively, all host requests will time out.
1212 /* other endpoints were all decoupled from this device */
1213 spin_lock_irq(&dev->lock);
1214 dev->state = STATE_DEV_DISABLED;
1215 spin_unlock_irq(&dev->lock);
1222 ep0_poll (struct file *fd, poll_table *wait)
1224 struct dev_data *dev = fd->private_data;
1227 if (dev->state <= STATE_DEV_OPENED)
1228 return DEFAULT_POLLMASK;
1230 poll_wait(fd, &dev->wait, wait);
1232 spin_lock_irq(&dev->lock);
1234 /* report fd mode change before acting on it */
1235 if (dev->setup_abort) {
1236 dev->setup_abort = 0;
1241 if (dev->state == STATE_DEV_SETUP) {
1242 if (dev->setup_in || dev->setup_can_stall)
1245 if (dev->ev_next != 0)
1249 spin_unlock_irq(&dev->lock);
1253 static long gadget_dev_ioctl (struct file *fd, unsigned code, unsigned long value)
1255 struct dev_data *dev = fd->private_data;
1256 struct usb_gadget *gadget = dev->gadget;
1259 spin_lock_irq(&dev->lock);
1260 if (dev->state == STATE_DEV_OPENED ||
1261 dev->state == STATE_DEV_UNBOUND) {
1262 /* Not bound to a UDC */
1263 } else if (gadget->ops->ioctl) {
1265 spin_unlock_irq(&dev->lock);
1267 ret = gadget->ops->ioctl (gadget, code, value);
1269 spin_lock_irq(&dev->lock);
1272 spin_unlock_irq(&dev->lock);
1277 /*----------------------------------------------------------------------*/
1279 /* The in-kernel gadget driver handles most ep0 issues, in particular
1280 * enumerating the single configuration (as provided from user space).
1282 * Unrecognized ep0 requests may be handled in user space.
1285 static void make_qualifier (struct dev_data *dev)
1287 struct usb_qualifier_descriptor qual;
1288 struct usb_device_descriptor *desc;
1290 qual.bLength = sizeof qual;
1291 qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
1292 qual.bcdUSB = cpu_to_le16 (0x0200);
1295 qual.bDeviceClass = desc->bDeviceClass;
1296 qual.bDeviceSubClass = desc->bDeviceSubClass;
1297 qual.bDeviceProtocol = desc->bDeviceProtocol;
1299 /* assumes ep0 uses the same value for both speeds ... */
1300 qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1302 qual.bNumConfigurations = 1;
1305 memcpy (dev->rbuf, &qual, sizeof qual);
1309 config_buf (struct dev_data *dev, u8 type, unsigned index)
1314 /* only one configuration */
1318 if (gadget_is_dualspeed(dev->gadget)) {
1319 hs = (dev->gadget->speed == USB_SPEED_HIGH);
1320 if (type == USB_DT_OTHER_SPEED_CONFIG)
1324 dev->req->buf = dev->hs_config;
1325 len = le16_to_cpu(dev->hs_config->wTotalLength);
1327 dev->req->buf = dev->config;
1328 len = le16_to_cpu(dev->config->wTotalLength);
1330 ((u8 *)dev->req->buf) [1] = type;
1335 gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
1337 struct dev_data *dev = get_gadget_data (gadget);
1338 struct usb_request *req = dev->req;
1339 int value = -EOPNOTSUPP;
1340 struct usb_gadgetfs_event *event;
1341 u16 w_value = le16_to_cpu(ctrl->wValue);
1342 u16 w_length = le16_to_cpu(ctrl->wLength);
1344 if (w_length > RBUF_SIZE) {
1345 if (ctrl->bRequestType & USB_DIR_IN) {
1346 /* Cast away the const, we are going to overwrite on purpose. */
1347 __le16 *temp = (__le16 *)&ctrl->wLength;
1349 *temp = cpu_to_le16(RBUF_SIZE);
1350 w_length = RBUF_SIZE;
1356 spin_lock (&dev->lock);
1357 dev->setup_abort = 0;
1358 if (dev->state == STATE_DEV_UNCONNECTED) {
1359 if (gadget_is_dualspeed(gadget)
1360 && gadget->speed == USB_SPEED_HIGH
1361 && dev->hs_config == NULL) {
1362 spin_unlock(&dev->lock);
1363 ERROR (dev, "no high speed config??\n");
1367 dev->state = STATE_DEV_CONNECTED;
1369 INFO (dev, "connected\n");
1370 event = next_event (dev, GADGETFS_CONNECT);
1371 event->u.speed = gadget->speed;
1374 /* host may have given up waiting for response. we can miss control
1375 * requests handled lower down (device/endpoint status and features);
1376 * then ep0_{read,write} will report the wrong status. controller
1377 * driver will have aborted pending i/o.
1379 } else if (dev->state == STATE_DEV_SETUP)
1380 dev->setup_abort = 1;
1382 req->buf = dev->rbuf;
1383 req->context = NULL;
1384 switch (ctrl->bRequest) {
1386 case USB_REQ_GET_DESCRIPTOR:
1387 if (ctrl->bRequestType != USB_DIR_IN)
1389 switch (w_value >> 8) {
1392 value = min (w_length, (u16) sizeof *dev->dev);
1393 dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
1394 req->buf = dev->dev;
1396 case USB_DT_DEVICE_QUALIFIER:
1397 if (!dev->hs_config)
1399 value = min (w_length, (u16)
1400 sizeof (struct usb_qualifier_descriptor));
1401 make_qualifier (dev);
1403 case USB_DT_OTHER_SPEED_CONFIG:
1405 value = config_buf (dev,
1409 value = min (w_length, (u16) value);
1414 default: // all others are errors
1419 /* currently one config, two speeds */
1420 case USB_REQ_SET_CONFIGURATION:
1421 if (ctrl->bRequestType != 0)
1423 if (0 == (u8) w_value) {
1425 dev->current_config = 0;
1426 usb_gadget_vbus_draw(gadget, 8 /* mA */ );
1427 // user mode expected to disable endpoints
1431 if (gadget_is_dualspeed(gadget)
1432 && gadget->speed == USB_SPEED_HIGH) {
1433 config = dev->hs_config->bConfigurationValue;
1434 power = dev->hs_config->bMaxPower;
1436 config = dev->config->bConfigurationValue;
1437 power = dev->config->bMaxPower;
1440 if (config == (u8) w_value) {
1442 dev->current_config = config;
1443 usb_gadget_vbus_draw(gadget, 2 * power);
1447 /* report SET_CONFIGURATION like any other control request,
1448 * except that usermode may not stall this. the next
1449 * request mustn't be allowed start until this finishes:
1450 * endpoints and threads set up, etc.
1452 * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
1453 * has bad/racey automagic that prevents synchronizing here.
1454 * even kernel mode drivers often miss them.
1457 INFO (dev, "configuration #%d\n", dev->current_config);
1458 usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
1459 if (dev->usermode_setup) {
1460 dev->setup_can_stall = 0;
1466 #ifndef CONFIG_USB_PXA25X
1467 /* PXA automagically handles this request too */
1468 case USB_REQ_GET_CONFIGURATION:
1469 if (ctrl->bRequestType != 0x80)
1471 *(u8 *)req->buf = dev->current_config;
1472 value = min (w_length, (u16) 1);
1478 VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
1479 dev->usermode_setup ? "delegate" : "fail",
1480 ctrl->bRequestType, ctrl->bRequest,
1481 w_value, le16_to_cpu(ctrl->wIndex), w_length);
1483 /* if there's an ep0 reader, don't stall */
1484 if (dev->usermode_setup) {
1485 dev->setup_can_stall = 1;
1487 dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
1489 dev->setup_wLength = w_length;
1490 dev->setup_out_ready = 0;
1491 dev->setup_out_error = 0;
1493 /* read DATA stage for OUT right away */
1494 if (unlikely (!dev->setup_in && w_length)) {
1495 value = setup_req (gadget->ep0, dev->req,
1501 spin_unlock (&dev->lock);
1502 value = usb_ep_queue (gadget->ep0, dev->req,
1504 spin_lock (&dev->lock);
1507 clean_req (gadget->ep0, dev->req);
1511 /* we can't currently stall these */
1512 dev->setup_can_stall = 0;
1515 /* state changes when reader collects event */
1516 event = next_event (dev, GADGETFS_SETUP);
1517 event->u.setup = *ctrl;
1519 spin_unlock (&dev->lock);
1521 * Return USB_GADGET_DELAYED_STATUS as a workaround to
1522 * stop some UDC drivers (e.g. dwc3) from automatically
1523 * proceeding with the status stage for 0-length
1525 * Should be removed once all UDC drivers are fixed to
1526 * always delay the status stage until a response is
1529 return w_length == 0 ? USB_GADGET_DELAYED_STATUS : 0;
1533 /* proceed with data transfer and status phases? */
1534 if (value >= 0 && dev->state != STATE_DEV_SETUP) {
1535 req->length = value;
1536 req->zero = value < w_length;
1539 spin_unlock (&dev->lock);
1540 value = usb_ep_queue (gadget->ep0, req, GFP_KERNEL);
1541 spin_lock(&dev->lock);
1543 spin_unlock(&dev->lock);
1545 DBG (dev, "ep_queue --> %d\n", value);
1551 /* device stalls when value < 0 */
1552 spin_unlock (&dev->lock);
1556 static void destroy_ep_files (struct dev_data *dev)
1558 DBG (dev, "%s %d\n", __func__, dev->state);
1560 /* dev->state must prevent interference */
1561 spin_lock_irq (&dev->lock);
1562 while (!list_empty(&dev->epfiles)) {
1564 struct inode *parent;
1565 struct dentry *dentry;
1567 /* break link to FS */
1568 ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
1569 list_del_init (&ep->epfiles);
1570 spin_unlock_irq (&dev->lock);
1572 dentry = ep->dentry;
1574 parent = d_inode(dentry->d_parent);
1576 /* break link to controller */
1577 mutex_lock(&ep->lock);
1578 if (ep->state == STATE_EP_ENABLED)
1579 (void) usb_ep_disable (ep->ep);
1580 ep->state = STATE_EP_UNBOUND;
1581 usb_ep_free_request (ep->ep, ep->req);
1583 mutex_unlock(&ep->lock);
1585 wake_up (&ep->wait);
1588 /* break link to dcache */
1592 inode_unlock(parent);
1594 spin_lock_irq (&dev->lock);
1596 spin_unlock_irq (&dev->lock);
1600 static struct dentry *
1601 gadgetfs_create_file (struct super_block *sb, char const *name,
1602 void *data, const struct file_operations *fops);
1604 static int activate_ep_files (struct dev_data *dev)
1607 struct ep_data *data;
1609 gadget_for_each_ep (ep, dev->gadget) {
1611 data = kzalloc(sizeof(*data), GFP_KERNEL);
1614 data->state = STATE_EP_DISABLED;
1615 mutex_init(&data->lock);
1616 init_waitqueue_head (&data->wait);
1618 strncpy (data->name, ep->name, sizeof (data->name) - 1);
1619 refcount_set (&data->count, 1);
1624 ep->driver_data = data;
1626 data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
1630 data->dentry = gadgetfs_create_file (dev->sb, data->name,
1631 data, &ep_io_operations);
1634 list_add_tail (&data->epfiles, &dev->epfiles);
1639 usb_ep_free_request (ep, data->req);
1644 DBG (dev, "%s enomem\n", __func__);
1645 destroy_ep_files (dev);
1650 gadgetfs_unbind (struct usb_gadget *gadget)
1652 struct dev_data *dev = get_gadget_data (gadget);
1654 DBG (dev, "%s\n", __func__);
1656 spin_lock_irq (&dev->lock);
1657 dev->state = STATE_DEV_UNBOUND;
1658 while (dev->udc_usage > 0) {
1659 spin_unlock_irq(&dev->lock);
1660 usleep_range(1000, 2000);
1661 spin_lock_irq(&dev->lock);
1663 spin_unlock_irq (&dev->lock);
1665 destroy_ep_files (dev);
1666 gadget->ep0->driver_data = NULL;
1667 set_gadget_data (gadget, NULL);
1669 /* we've already been disconnected ... no i/o is active */
1671 usb_ep_free_request (gadget->ep0, dev->req);
1672 DBG (dev, "%s done\n", __func__);
1676 static struct dev_data *the_device;
1678 static int gadgetfs_bind(struct usb_gadget *gadget,
1679 struct usb_gadget_driver *driver)
1681 struct dev_data *dev = the_device;
1685 if (0 != strcmp (CHIP, gadget->name)) {
1686 pr_err("%s expected %s controller not %s\n",
1687 shortname, CHIP, gadget->name);
1691 set_gadget_data (gadget, dev);
1692 dev->gadget = gadget;
1693 gadget->ep0->driver_data = dev;
1695 /* preallocate control response and buffer */
1696 dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
1699 dev->req->context = NULL;
1700 dev->req->complete = epio_complete;
1702 if (activate_ep_files (dev) < 0)
1705 INFO (dev, "bound to %s driver\n", gadget->name);
1706 spin_lock_irq(&dev->lock);
1707 dev->state = STATE_DEV_UNCONNECTED;
1708 spin_unlock_irq(&dev->lock);
1713 gadgetfs_unbind (gadget);
1718 gadgetfs_disconnect (struct usb_gadget *gadget)
1720 struct dev_data *dev = get_gadget_data (gadget);
1721 unsigned long flags;
1723 spin_lock_irqsave (&dev->lock, flags);
1724 if (dev->state == STATE_DEV_UNCONNECTED)
1726 dev->state = STATE_DEV_UNCONNECTED;
1728 INFO (dev, "disconnected\n");
1729 next_event (dev, GADGETFS_DISCONNECT);
1732 spin_unlock_irqrestore (&dev->lock, flags);
1736 gadgetfs_suspend (struct usb_gadget *gadget)
1738 struct dev_data *dev = get_gadget_data (gadget);
1739 unsigned long flags;
1741 INFO (dev, "suspended from state %d\n", dev->state);
1742 spin_lock_irqsave(&dev->lock, flags);
1743 switch (dev->state) {
1744 case STATE_DEV_SETUP: // VERY odd... host died??
1745 case STATE_DEV_CONNECTED:
1746 case STATE_DEV_UNCONNECTED:
1747 next_event (dev, GADGETFS_SUSPEND);
1753 spin_unlock_irqrestore(&dev->lock, flags);
1756 static struct usb_gadget_driver gadgetfs_driver = {
1757 .function = (char *) driver_desc,
1758 .bind = gadgetfs_bind,
1759 .unbind = gadgetfs_unbind,
1760 .setup = gadgetfs_setup,
1761 .reset = gadgetfs_disconnect,
1762 .disconnect = gadgetfs_disconnect,
1763 .suspend = gadgetfs_suspend,
1770 /*----------------------------------------------------------------------*/
1771 /* DEVICE INITIALIZATION
1773 * fd = open ("/dev/gadget/$CHIP", O_RDWR)
1774 * status = write (fd, descriptors, sizeof descriptors)
1776 * That write establishes the device configuration, so the kernel can
1777 * bind to the controller ... guaranteeing it can handle enumeration
1778 * at all necessary speeds. Descriptor order is:
1780 * . message tag (u32, host order) ... for now, must be zero; it
1781 * would change to support features like multi-config devices
1782 * . full/low speed config ... all wTotalLength bytes (with interface,
1783 * class, altsetting, endpoint, and other descriptors)
1784 * . high speed config ... all descriptors, for high speed operation;
1785 * this one's optional except for high-speed hardware
1786 * . device descriptor
1788 * Endpoints are not yet enabled. Drivers must wait until device
1789 * configuration and interface altsetting changes create
1790 * the need to configure (or unconfigure) them.
1792 * After initialization, the device stays active for as long as that
1793 * $CHIP file is open. Events must then be read from that descriptor,
1794 * such as configuration notifications.
1797 static int is_valid_config(struct usb_config_descriptor *config,
1800 return config->bDescriptorType == USB_DT_CONFIG
1801 && config->bLength == USB_DT_CONFIG_SIZE
1802 && total >= USB_DT_CONFIG_SIZE
1803 && config->bConfigurationValue != 0
1804 && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
1805 && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
1806 /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
1807 /* FIXME check lengths: walk to end */
1811 dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
1813 struct dev_data *dev = fd->private_data;
1814 ssize_t value, length = len;
1819 spin_lock_irq(&dev->lock);
1820 if (dev->state > STATE_DEV_OPENED) {
1821 value = ep0_write(fd, buf, len, ptr);
1822 spin_unlock_irq(&dev->lock);
1825 spin_unlock_irq(&dev->lock);
1827 if ((len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4)) ||
1828 (len > PAGE_SIZE * 4))
1831 /* we might need to change message format someday */
1832 if (copy_from_user (&tag, buf, 4))
1839 kbuf = memdup_user(buf, length);
1841 return PTR_ERR(kbuf);
1843 spin_lock_irq (&dev->lock);
1846 spin_unlock_irq(&dev->lock);
1852 /* full or low speed config */
1853 dev->config = (void *) kbuf;
1854 total = le16_to_cpu(dev->config->wTotalLength);
1855 if (!is_valid_config(dev->config, total) ||
1856 total > length - USB_DT_DEVICE_SIZE)
1861 /* optional high speed config */
1862 if (kbuf [1] == USB_DT_CONFIG) {
1863 dev->hs_config = (void *) kbuf;
1864 total = le16_to_cpu(dev->hs_config->wTotalLength);
1865 if (!is_valid_config(dev->hs_config, total) ||
1866 total > length - USB_DT_DEVICE_SIZE)
1871 dev->hs_config = NULL;
1874 /* could support multiple configs, using another encoding! */
1876 /* device descriptor (tweaked for paranoia) */
1877 if (length != USB_DT_DEVICE_SIZE)
1879 dev->dev = (void *)kbuf;
1880 if (dev->dev->bLength != USB_DT_DEVICE_SIZE
1881 || dev->dev->bDescriptorType != USB_DT_DEVICE
1882 || dev->dev->bNumConfigurations != 1)
1884 dev->dev->bcdUSB = cpu_to_le16 (0x0200);
1886 /* triggers gadgetfs_bind(); then we can enumerate. */
1887 spin_unlock_irq (&dev->lock);
1889 gadgetfs_driver.max_speed = USB_SPEED_HIGH;
1891 gadgetfs_driver.max_speed = USB_SPEED_FULL;
1893 value = usb_gadget_register_driver(&gadgetfs_driver);
1895 spin_lock_irq(&dev->lock);
1898 /* at this point "good" hardware has for the first time
1899 * let the USB the host see us. alternatively, if users
1900 * unplug/replug that will clear all the error state.
1902 * note: everything running before here was guaranteed
1903 * to choke driver model style diagnostics. from here
1904 * on, they can work ... except in cleanup paths that
1905 * kick in after the ep0 descriptor is closed.
1908 dev->gadget_registered = true;
1914 dev->hs_config = NULL;
1916 spin_unlock_irq (&dev->lock);
1917 pr_debug ("%s: %s fail %zd, %p\n", shortname, __func__, value, dev);
1924 gadget_dev_open (struct inode *inode, struct file *fd)
1926 struct dev_data *dev = inode->i_private;
1929 spin_lock_irq(&dev->lock);
1930 if (dev->state == STATE_DEV_DISABLED) {
1932 dev->state = STATE_DEV_OPENED;
1933 fd->private_data = dev;
1937 spin_unlock_irq(&dev->lock);
1941 static const struct file_operations ep0_operations = {
1942 .llseek = no_llseek,
1944 .open = gadget_dev_open,
1946 .write = dev_config,
1947 .fasync = ep0_fasync,
1949 .unlocked_ioctl = gadget_dev_ioctl,
1950 .release = dev_release,
1953 /*----------------------------------------------------------------------*/
1955 /* FILESYSTEM AND SUPERBLOCK OPERATIONS
1957 * Mounting the filesystem creates a controller file, used first for
1958 * device configuration then later for event monitoring.
1962 /* FIXME PAM etc could set this security policy without mount options
1963 * if epfiles inherited ownership and permissons from ep0 ...
1966 static unsigned default_uid;
1967 static unsigned default_gid;
1968 static unsigned default_perm = S_IRUSR | S_IWUSR;
1970 module_param (default_uid, uint, 0644);
1971 module_param (default_gid, uint, 0644);
1972 module_param (default_perm, uint, 0644);
1975 static struct inode *
1976 gadgetfs_make_inode (struct super_block *sb,
1977 void *data, const struct file_operations *fops,
1980 struct inode *inode = new_inode (sb);
1983 inode->i_ino = get_next_ino();
1984 inode->i_mode = mode;
1985 inode->i_uid = make_kuid(&init_user_ns, default_uid);
1986 inode->i_gid = make_kgid(&init_user_ns, default_gid);
1987 simple_inode_init_ts(inode);
1988 inode->i_private = data;
1989 inode->i_fop = fops;
1994 /* creates in fs root directory, so non-renamable and non-linkable.
1995 * so inode and dentry are paired, until device reconfig.
1997 static struct dentry *
1998 gadgetfs_create_file (struct super_block *sb, char const *name,
1999 void *data, const struct file_operations *fops)
2001 struct dentry *dentry;
2002 struct inode *inode;
2004 dentry = d_alloc_name(sb->s_root, name);
2008 inode = gadgetfs_make_inode (sb, data, fops,
2009 S_IFREG | (default_perm & S_IRWXUGO));
2014 d_add (dentry, inode);
2018 static const struct super_operations gadget_fs_operations = {
2019 .statfs = simple_statfs,
2020 .drop_inode = generic_delete_inode,
2024 gadgetfs_fill_super (struct super_block *sb, struct fs_context *fc)
2026 struct inode *inode;
2027 struct dev_data *dev;
2030 mutex_lock(&sb_mutex);
2037 CHIP = usb_get_gadget_udc_name();
2044 sb->s_blocksize = PAGE_SIZE;
2045 sb->s_blocksize_bits = PAGE_SHIFT;
2046 sb->s_magic = GADGETFS_MAGIC;
2047 sb->s_op = &gadget_fs_operations;
2048 sb->s_time_gran = 1;
2051 inode = gadgetfs_make_inode (sb,
2052 NULL, &simple_dir_operations,
2053 S_IFDIR | S_IRUGO | S_IXUGO);
2056 inode->i_op = &simple_dir_inode_operations;
2057 if (!(sb->s_root = d_make_root (inode)))
2060 /* the ep0 file is named after the controller we expect;
2061 * user mode code can use it for sanity checks, like we do.
2068 dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
2074 /* other endpoint files are available after hardware setup,
2075 * from binding to a controller.
2087 mutex_unlock(&sb_mutex);
2091 /* "mount -t gadgetfs path /dev/gadget" ends up here */
2092 static int gadgetfs_get_tree(struct fs_context *fc)
2094 return get_tree_single(fc, gadgetfs_fill_super);
2097 static const struct fs_context_operations gadgetfs_context_ops = {
2098 .get_tree = gadgetfs_get_tree,
2101 static int gadgetfs_init_fs_context(struct fs_context *fc)
2103 fc->ops = &gadgetfs_context_ops;
2108 gadgetfs_kill_sb (struct super_block *sb)
2110 mutex_lock(&sb_mutex);
2111 kill_litter_super (sb);
2113 put_dev (the_device);
2118 mutex_unlock(&sb_mutex);
2121 /*----------------------------------------------------------------------*/
2123 static struct file_system_type gadgetfs_type = {
2124 .owner = THIS_MODULE,
2126 .init_fs_context = gadgetfs_init_fs_context,
2127 .kill_sb = gadgetfs_kill_sb,
2129 MODULE_ALIAS_FS("gadgetfs");
2131 /*----------------------------------------------------------------------*/
2133 static int __init gadgetfs_init (void)
2137 status = register_filesystem (&gadgetfs_type);
2139 pr_info ("%s: %s, version " DRIVER_VERSION "\n",
2140 shortname, driver_desc);
2143 module_init (gadgetfs_init);
2145 static void __exit gadgetfs_cleanup (void)
2147 pr_debug ("unregister %s\n", shortname);
2148 unregister_filesystem (&gadgetfs_type);
2150 module_exit (gadgetfs_cleanup);