--- /dev/null
+/*
+ * inode.c -- user mode filesystem api for usb gadget controllers
+ *
+ * Copyright (C) 2003-2004 David Brownell
+ * Copyright (C) 2003 Agilent Technologies
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+
+/* #define VERBOSE_DEBUG */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/uts.h>
+#include <linux/wait.h>
+#include <linux/compiler.h>
+#include <asm/uaccess.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+#include <linux/mmu_context.h>
+#include <linux/aio.h>
+#include <linux/uio.h>
+
+#include <linux/device.h>
+#include <linux/moduleparam.h>
+
+#include <linux/usb/gadgetfs.h>
+#include <linux/usb/gadget.h>
+
+
+/*
+ * The gadgetfs API maps each endpoint to a file descriptor so that you
+ * can use standard synchronous read/write calls for I/O. There's some
+ * O_NONBLOCK and O_ASYNC/FASYNC style i/o support. Example usermode
+ * drivers show how this works in practice. You can also use AIO to
+ * eliminate I/O gaps between requests, to help when streaming data.
+ *
+ * Key parts that must be USB-specific are protocols defining how the
+ * read/write operations relate to the hardware state machines. There
+ * are two types of files. One type is for the device, implementing ep0.
+ * The other type is for each IN or OUT endpoint. In both cases, the
+ * user mode driver must configure the hardware before using it.
+ *
+ * - First, dev_config() is called when /dev/gadget/$CHIP is configured
+ * (by writing configuration and device descriptors). Afterwards it
+ * may serve as a source of device events, used to handle all control
+ * requests other than basic enumeration.
+ *
+ * - Then, after a SET_CONFIGURATION control request, ep_config() is
+ * called when each /dev/gadget/ep* file is configured (by writing
+ * endpoint descriptors). Afterwards these files are used to write()
+ * IN data or to read() OUT data. To halt the endpoint, a "wrong
+ * direction" request is issued (like reading an IN endpoint).
+ *
+ * Unlike "usbfs" the only ioctl()s are for things that are rare, and maybe
+ * not possible on all hardware. For example, precise fault handling with
+ * respect to data left in endpoint fifos after aborted operations; or
+ * selective clearing of endpoint halts, to implement SET_INTERFACE.
+ */
+
+#define DRIVER_DESC "USB Gadget filesystem"
+#define DRIVER_VERSION "24 Aug 2004"
+
+static const char driver_desc [] = DRIVER_DESC;
+static const char shortname [] = "gadgetfs";
+
+MODULE_DESCRIPTION (DRIVER_DESC);
+MODULE_AUTHOR ("David Brownell");
+MODULE_LICENSE ("GPL");
+
+static int ep_open(struct inode *, struct file *);
+
+
+/*----------------------------------------------------------------------*/
+
+#define GADGETFS_MAGIC 0xaee71ee7
+
+/* /dev/gadget/$CHIP represents ep0 and the whole device */
+enum ep0_state {
+ /* DISBLED is the initial state.
+ */
+ STATE_DEV_DISABLED = 0,
+
+ /* Only one open() of /dev/gadget/$CHIP; only one file tracks
+ * ep0/device i/o modes and binding to the controller. Driver
+ * must always write descriptors to initialize the device, then
+ * the device becomes UNCONNECTED until enumeration.
+ */
+ STATE_DEV_OPENED,
+
+ /* From then on, ep0 fd is in either of two basic modes:
+ * - (UN)CONNECTED: read usb_gadgetfs_event(s) from it
+ * - SETUP: read/write will transfer control data and succeed;
+ * or if "wrong direction", performs protocol stall
+ */
+ STATE_DEV_UNCONNECTED,
+ STATE_DEV_CONNECTED,
+ STATE_DEV_SETUP,
+
+ /* UNBOUND means the driver closed ep0, so the device won't be
+ * accessible again (DEV_DISABLED) until all fds are closed.
+ */
+ STATE_DEV_UNBOUND,
+};
+
+/* enough for the whole queue: most events invalidate others */
+#define N_EVENT 5
+
+struct dev_data {
+ spinlock_t lock;
+ atomic_t count;
+ enum ep0_state state; /* P: lock */
+ struct usb_gadgetfs_event event [N_EVENT];
+ unsigned ev_next;
+ struct fasync_struct *fasync;
+ u8 current_config;
+
+ /* drivers reading ep0 MUST handle control requests (SETUP)
+ * reported that way; else the host will time out.
+ */
+ unsigned usermode_setup : 1,
+ setup_in : 1,
+ setup_can_stall : 1,
+ setup_out_ready : 1,
+ setup_out_error : 1,
+ setup_abort : 1;
+ unsigned setup_wLength;
+
+ /* the rest is basically write-once */
+ struct usb_config_descriptor *config, *hs_config;
+ struct usb_device_descriptor *dev;
+ struct usb_request *req;
+ struct usb_gadget *gadget;
+ struct list_head epfiles;
+ void *buf;
+ wait_queue_head_t wait;
+ struct super_block *sb;
+ struct dentry *dentry;
+
+ /* except this scratch i/o buffer for ep0 */
+ u8 rbuf [256];
+};
+
+static inline void get_dev (struct dev_data *data)
+{
+ atomic_inc (&data->count);
+}
+
+static void put_dev (struct dev_data *data)
+{
+ if (likely (!atomic_dec_and_test (&data->count)))
+ return;
+ /* needs no more cleanup */
+ BUG_ON (waitqueue_active (&data->wait));
+ kfree (data);
+}
+
+static struct dev_data *dev_new (void)
+{
+ struct dev_data *dev;
+
+ dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return NULL;
+ dev->state = STATE_DEV_DISABLED;
+ atomic_set (&dev->count, 1);
+ spin_lock_init (&dev->lock);
+ INIT_LIST_HEAD (&dev->epfiles);
+ init_waitqueue_head (&dev->wait);
+ return dev;
+}
+
+/*----------------------------------------------------------------------*/
+
+/* other /dev/gadget/$ENDPOINT files represent endpoints */
+enum ep_state {
+ STATE_EP_DISABLED = 0,
+ STATE_EP_READY,
+ STATE_EP_ENABLED,
+ STATE_EP_UNBOUND,
+};
+
+struct ep_data {
+ struct mutex lock;
+ enum ep_state state;
+ atomic_t count;
+ struct dev_data *dev;
+ /* must hold dev->lock before accessing ep or req */
+ struct usb_ep *ep;
+ struct usb_request *req;
+ ssize_t status;
+ char name [16];
+ struct usb_endpoint_descriptor desc, hs_desc;
+ struct list_head epfiles;
+ wait_queue_head_t wait;
+ struct dentry *dentry;
+};
+
+static inline void get_ep (struct ep_data *data)
+{
+ atomic_inc (&data->count);
+}
+
+static void put_ep (struct ep_data *data)
+{
+ if (likely (!atomic_dec_and_test (&data->count)))
+ return;
+ put_dev (data->dev);
+ /* needs no more cleanup */
+ BUG_ON (!list_empty (&data->epfiles));
+ BUG_ON (waitqueue_active (&data->wait));
+ kfree (data);
+}
+
+/*----------------------------------------------------------------------*/
+
+/* most "how to use the hardware" policy choices are in userspace:
+ * mapping endpoint roles (which the driver needs) to the capabilities
+ * which the usb controller has. most of those capabilities are exposed
+ * implicitly, starting with the driver name and then endpoint names.
+ */
+
+static const char *CHIP;
+
+/*----------------------------------------------------------------------*/
+
+/* NOTE: don't use dev_printk calls before binding to the gadget
+ * at the end of ep0 configuration, or after unbind.
+ */
+
+/* too wordy: dev_printk(level , &(d)->gadget->dev , fmt , ## args) */
+#define xprintk(d,level,fmt,args...) \
+ printk(level "%s: " fmt , shortname , ## args)
+
+#ifdef DEBUG
+#define DBG(dev,fmt,args...) \
+ xprintk(dev , KERN_DEBUG , fmt , ## args)
+#else
+#define DBG(dev,fmt,args...) \
+ do { } while (0)
+#endif /* DEBUG */
+
+#ifdef VERBOSE_DEBUG
+#define VDEBUG DBG
+#else
+#define VDEBUG(dev,fmt,args...) \
+ do { } while (0)
+#endif /* DEBUG */
+
+#define ERROR(dev,fmt,args...) \
+ xprintk(dev , KERN_ERR , fmt , ## args)
+#define INFO(dev,fmt,args...) \
+ xprintk(dev , KERN_INFO , fmt , ## args)
+
+
+/*----------------------------------------------------------------------*/
+
+/* SYNCHRONOUS ENDPOINT OPERATIONS (bulk/intr/iso)
+ *
+ * After opening, configure non-control endpoints. Then use normal
+ * stream read() and write() requests; and maybe ioctl() to get more
+ * precise FIFO status when recovering from cancellation.
+ */
+
+static void epio_complete (struct usb_ep *ep, struct usb_request *req)
+{
+ struct ep_data *epdata = ep->driver_data;
+
+ if (!req->context)
+ return;
+ if (req->status)
+ epdata->status = req->status;
+ else
+ epdata->status = req->actual;
+ complete ((struct completion *)req->context);
+}
+
+/* tasklock endpoint, returning when it's connected.
+ * still need dev->lock to use epdata->ep.
+ */
+static int
+get_ready_ep (unsigned f_flags, struct ep_data *epdata, bool is_write)
+{
+ int val;
+
+ if (f_flags & O_NONBLOCK) {
+ if (!mutex_trylock(&epdata->lock))
+ goto nonblock;
+ if (epdata->state != STATE_EP_ENABLED &&
+ (!is_write || epdata->state != STATE_EP_READY)) {
+ mutex_unlock(&epdata->lock);
+nonblock:
+ val = -EAGAIN;
+ } else
+ val = 0;
+ return val;
+ }
+
+ val = mutex_lock_interruptible(&epdata->lock);
+ if (val < 0)
+ return val;
+
+ switch (epdata->state) {
+ case STATE_EP_ENABLED:
+ return 0;
+ case STATE_EP_READY: /* not configured yet */
+ if (is_write)
+ return 0;
+ // FALLTHRU
+ case STATE_EP_UNBOUND: /* clean disconnect */
+ break;
+ // case STATE_EP_DISABLED: /* "can't happen" */
+ default: /* error! */
+ pr_debug ("%s: ep %p not available, state %d\n",
+ shortname, epdata, epdata->state);
+ }
+ mutex_unlock(&epdata->lock);
+ return -ENODEV;
+}
+
+static ssize_t
+ep_io (struct ep_data *epdata, void *buf, unsigned len)
+{
+ DECLARE_COMPLETION_ONSTACK (done);
+ int value;
+
+ spin_lock_irq (&epdata->dev->lock);
+ if (likely (epdata->ep != NULL)) {
+ struct usb_request *req = epdata->req;
+
+ req->context = &done;
+ req->complete = epio_complete;
+ req->buf = buf;
+ req->length = len;
+ value = usb_ep_queue (epdata->ep, req, GFP_ATOMIC);
+ } else
+ value = -ENODEV;
+ spin_unlock_irq (&epdata->dev->lock);
+
+ if (likely (value == 0)) {
+ value = swait_event_interruptible (done.wait, done.done);
+ if (value != 0) {
+ spin_lock_irq (&epdata->dev->lock);
+ if (likely (epdata->ep != NULL)) {
+ DBG (epdata->dev, "%s i/o interrupted\n",
+ epdata->name);
+ usb_ep_dequeue (epdata->ep, epdata->req);
+ spin_unlock_irq (&epdata->dev->lock);
+
+ swait_event (done.wait, done.done);
+ if (epdata->status == -ECONNRESET)
+ epdata->status = -EINTR;
+ } else {
+ spin_unlock_irq (&epdata->dev->lock);
+
+ DBG (epdata->dev, "endpoint gone\n");
+ epdata->status = -ENODEV;
+ }
+ }
+ return epdata->status;
+ }
+ return value;
+}
+
+static int
+ep_release (struct inode *inode, struct file *fd)
+{
+ struct ep_data *data = fd->private_data;
+ int value;
+
+ value = mutex_lock_interruptible(&data->lock);
+ if (value < 0)
+ return value;
+
+ /* clean up if this can be reopened */
+ if (data->state != STATE_EP_UNBOUND) {
+ data->state = STATE_EP_DISABLED;
+ data->desc.bDescriptorType = 0;
+ data->hs_desc.bDescriptorType = 0;
+ usb_ep_disable(data->ep);
+ }
+ mutex_unlock(&data->lock);
+ put_ep (data);
+ return 0;
+}
+
+static long ep_ioctl(struct file *fd, unsigned code, unsigned long value)
+{
+ struct ep_data *data = fd->private_data;
+ int status;
+
+ if ((status = get_ready_ep (fd->f_flags, data, false)) < 0)
+ return status;
+
+ spin_lock_irq (&data->dev->lock);
+ if (likely (data->ep != NULL)) {
+ switch (code) {
+ case GADGETFS_FIFO_STATUS:
+ status = usb_ep_fifo_status (data->ep);
+ break;
+ case GADGETFS_FIFO_FLUSH:
+ usb_ep_fifo_flush (data->ep);
+ break;
+ case GADGETFS_CLEAR_HALT:
+ status = usb_ep_clear_halt (data->ep);
+ break;
+ default:
+ status = -ENOTTY;
+ }
+ } else
+ status = -ENODEV;
+ spin_unlock_irq (&data->dev->lock);
+ mutex_unlock(&data->lock);
+ return status;
+}
+
+/*----------------------------------------------------------------------*/
+
+/* ASYNCHRONOUS ENDPOINT I/O OPERATIONS (bulk/intr/iso) */
+
+struct kiocb_priv {
+ struct usb_request *req;
+ struct ep_data *epdata;
+ struct kiocb *iocb;
+ struct mm_struct *mm;
+ struct work_struct work;
+ void *buf;
+ struct iov_iter to;
+ const void *to_free;
+ unsigned actual;
+};
+
+static int ep_aio_cancel(struct kiocb *iocb)
+{
+ struct kiocb_priv *priv = iocb->private;
+ struct ep_data *epdata;
+ int value;
+
+ local_irq_disable();
+ epdata = priv->epdata;
+ // spin_lock(&epdata->dev->lock);
+ if (likely(epdata && epdata->ep && priv->req))
+ value = usb_ep_dequeue (epdata->ep, priv->req);
+ else
+ value = -EINVAL;
+ // spin_unlock(&epdata->dev->lock);
+ local_irq_enable();
+
+ return value;
+}
+
+static void ep_user_copy_worker(struct work_struct *work)
+{
+ struct kiocb_priv *priv = container_of(work, struct kiocb_priv, work);
+ struct mm_struct *mm = priv->mm;
+ struct kiocb *iocb = priv->iocb;
+ size_t ret;
+
+ use_mm(mm);
+ ret = copy_to_iter(priv->buf, priv->actual, &priv->to);
+ unuse_mm(mm);
+ if (!ret)
+ ret = -EFAULT;
+
+ /* completing the iocb can drop the ctx and mm, don't touch mm after */
+ iocb->ki_complete(iocb, ret, ret);
+
+ kfree(priv->buf);
+ kfree(priv->to_free);
+ kfree(priv);
+}
+
+static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
+{
+ struct kiocb *iocb = req->context;
+ struct kiocb_priv *priv = iocb->private;
+ struct ep_data *epdata = priv->epdata;
+
+ /* lock against disconnect (and ideally, cancel) */
+ spin_lock(&epdata->dev->lock);
+ priv->req = NULL;
+ priv->epdata = NULL;
+
+ /* if this was a write or a read returning no data then we
+ * don't need to copy anything to userspace, so we can
+ * complete the aio request immediately.
+ */
+ if (priv->to_free == NULL || unlikely(req->actual == 0)) {
+ kfree(req->buf);
+ kfree(priv->to_free);
+ kfree(priv);
+ iocb->private = NULL;
+ /* aio_complete() reports bytes-transferred _and_ faults */
+
+ iocb->ki_complete(iocb, req->actual ? req->actual : req->status,
+ req->status);
+ } else {
+ /* ep_copy_to_user() won't report both; we hide some faults */
+ if (unlikely(0 != req->status))
+ DBG(epdata->dev, "%s fault %d len %d\n",
+ ep->name, req->status, req->actual);
+
+ priv->buf = req->buf;
+ priv->actual = req->actual;
+ INIT_WORK(&priv->work, ep_user_copy_worker);
+ schedule_work(&priv->work);
+ }
+ spin_unlock(&epdata->dev->lock);
+
+ usb_ep_free_request(ep, req);
+ put_ep(epdata);
+}
+
+static ssize_t ep_aio(struct kiocb *iocb,
+ struct kiocb_priv *priv,
+ struct ep_data *epdata,
+ char *buf,
+ size_t len)
+{
+ struct usb_request *req;
+ ssize_t value;
+
+ iocb->private = priv;
+ priv->iocb = iocb;
+
+ kiocb_set_cancel_fn(iocb, ep_aio_cancel);
+ get_ep(epdata);
+ priv->epdata = epdata;
+ priv->actual = 0;
+ priv->mm = current->mm; /* mm teardown waits for iocbs in exit_aio() */
+
+ /* each kiocb is coupled to one usb_request, but we can't
+ * allocate or submit those if the host disconnected.
+ */
+ spin_lock_irq(&epdata->dev->lock);
+ value = -ENODEV;
+ if (unlikely(epdata->ep))
+ goto fail;
+
+ req = usb_ep_alloc_request(epdata->ep, GFP_ATOMIC);
+ value = -ENOMEM;
+ if (unlikely(!req))
+ goto fail;
+
+ priv->req = req;
+ req->buf = buf;
+ req->length = len;
+ req->complete = ep_aio_complete;
+ req->context = iocb;
+ value = usb_ep_queue(epdata->ep, req, GFP_ATOMIC);
+ if (unlikely(0 != value)) {
+ usb_ep_free_request(epdata->ep, req);
+ goto fail;
+ }
+ spin_unlock_irq(&epdata->dev->lock);
+ return -EIOCBQUEUED;
+
+fail:
+ spin_unlock_irq(&epdata->dev->lock);
+ kfree(priv->to_free);
+ kfree(priv);
+ put_ep(epdata);
+ return value;
+}
+
+static ssize_t
+ep_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct file *file = iocb->ki_filp;
+ struct ep_data *epdata = file->private_data;
+ size_t len = iov_iter_count(to);
+ ssize_t value;
+ char *buf;
+
+ if ((value = get_ready_ep(file->f_flags, epdata, false)) < 0)
+ return value;
+
+ /* halt any endpoint by doing a "wrong direction" i/o call */
+ if (usb_endpoint_dir_in(&epdata->desc)) {
+ if (usb_endpoint_xfer_isoc(&epdata->desc) ||
+ !is_sync_kiocb(iocb)) {
+ mutex_unlock(&epdata->lock);
+ return -EINVAL;
+ }
+ DBG (epdata->dev, "%s halt\n", epdata->name);
+ spin_lock_irq(&epdata->dev->lock);
+ if (likely(epdata->ep != NULL))
+ usb_ep_set_halt(epdata->ep);
+ spin_unlock_irq(&epdata->dev->lock);
+ mutex_unlock(&epdata->lock);
+ return -EBADMSG;
+ }
+
+ buf = kmalloc(len, GFP_KERNEL);
+ if (unlikely(!buf)) {
+ mutex_unlock(&epdata->lock);
+ return -ENOMEM;
+ }
+ if (is_sync_kiocb(iocb)) {
+ value = ep_io(epdata, buf, len);
+ if (value >= 0 && copy_to_iter(buf, value, to))
+ value = -EFAULT;
+ } else {
+ struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
+ value = -ENOMEM;
+ if (!priv)
+ goto fail;
+ priv->to_free = dup_iter(&priv->to, to, GFP_KERNEL);
+ if (!priv->to_free) {
+ kfree(priv);
+ goto fail;
+ }
+ value = ep_aio(iocb, priv, epdata, buf, len);
+ if (value == -EIOCBQUEUED)
+ buf = NULL;
+ }
+fail:
+ kfree(buf);
+ mutex_unlock(&epdata->lock);
+ return value;
+}
+
+static ssize_t ep_config(struct ep_data *, const char *, size_t);
+
+static ssize_t
+ep_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct ep_data *epdata = file->private_data;
+ size_t len = iov_iter_count(from);
+ bool configured;
+ ssize_t value;
+ char *buf;
+
+ if ((value = get_ready_ep(file->f_flags, epdata, true)) < 0)
+ return value;
+
+ configured = epdata->state == STATE_EP_ENABLED;
+
+ /* halt any endpoint by doing a "wrong direction" i/o call */
+ if (configured && !usb_endpoint_dir_in(&epdata->desc)) {
+ if (usb_endpoint_xfer_isoc(&epdata->desc) ||
+ !is_sync_kiocb(iocb)) {
+ mutex_unlock(&epdata->lock);
+ return -EINVAL;
+ }
+ DBG (epdata->dev, "%s halt\n", epdata->name);
+ spin_lock_irq(&epdata->dev->lock);
+ if (likely(epdata->ep != NULL))
+ usb_ep_set_halt(epdata->ep);
+ spin_unlock_irq(&epdata->dev->lock);
+ mutex_unlock(&epdata->lock);
+ return -EBADMSG;
+ }
+
+ buf = kmalloc(len, GFP_KERNEL);
+ if (unlikely(!buf)) {
+ mutex_unlock(&epdata->lock);
+ return -ENOMEM;
+ }
+
+ if (unlikely(copy_from_iter(buf, len, from) != len)) {
+ value = -EFAULT;
+ goto out;
+ }
+
+ if (unlikely(!configured)) {
+ value = ep_config(epdata, buf, len);
+ } else if (is_sync_kiocb(iocb)) {
+ value = ep_io(epdata, buf, len);
+ } else {
+ struct kiocb_priv *priv = kzalloc(sizeof *priv, GFP_KERNEL);
+ value = -ENOMEM;
+ if (priv) {
+ value = ep_aio(iocb, priv, epdata, buf, len);
+ if (value == -EIOCBQUEUED)
+ buf = NULL;
+ }
+ }
+out:
+ kfree(buf);
+ mutex_unlock(&epdata->lock);
+ return value;
+}
+
+/*----------------------------------------------------------------------*/
+
+/* used after endpoint configuration */
+static const struct file_operations ep_io_operations = {
+ .owner = THIS_MODULE,
+
+ .open = ep_open,
+ .release = ep_release,
+ .llseek = no_llseek,
+ .unlocked_ioctl = ep_ioctl,
+ .read_iter = ep_read_iter,
+ .write_iter = ep_write_iter,
+};
+
+/* ENDPOINT INITIALIZATION
+ *
+ * fd = open ("/dev/gadget/$ENDPOINT", O_RDWR)
+ * status = write (fd, descriptors, sizeof descriptors)
+ *
+ * That write establishes the endpoint configuration, configuring
+ * the controller to process bulk, interrupt, or isochronous transfers
+ * at the right maxpacket size, and so on.
+ *
+ * The descriptors are message type 1, identified by a host order u32
+ * at the beginning of what's written. Descriptor order is: full/low
+ * speed descriptor, then optional high speed descriptor.
+ */
+static ssize_t
+ep_config (struct ep_data *data, const char *buf, size_t len)
+{
+ struct usb_ep *ep;
+ u32 tag;
+ int value, length = len;
+
+ if (data->state != STATE_EP_READY) {
+ value = -EL2HLT;
+ goto fail;
+ }
+
+ value = len;
+ if (len < USB_DT_ENDPOINT_SIZE + 4)
+ goto fail0;
+
+ /* we might need to change message format someday */
+ memcpy(&tag, buf, 4);
+ if (tag != 1) {
+ DBG(data->dev, "config %s, bad tag %d\n", data->name, tag);
+ goto fail0;
+ }
+ buf += 4;
+ len -= 4;
+
+ /* NOTE: audio endpoint extensions not accepted here;
+ * just don't include the extra bytes.
+ */
+
+ /* full/low speed descriptor, then high speed */
+ memcpy(&data->desc, buf, USB_DT_ENDPOINT_SIZE);
+ if (data->desc.bLength != USB_DT_ENDPOINT_SIZE
+ || data->desc.bDescriptorType != USB_DT_ENDPOINT)
+ goto fail0;
+ if (len != USB_DT_ENDPOINT_SIZE) {
+ if (len != 2 * USB_DT_ENDPOINT_SIZE)
+ goto fail0;
+ memcpy(&data->hs_desc, buf + USB_DT_ENDPOINT_SIZE,
+ USB_DT_ENDPOINT_SIZE);
+ if (data->hs_desc.bLength != USB_DT_ENDPOINT_SIZE
+ || data->hs_desc.bDescriptorType
+ != USB_DT_ENDPOINT) {
+ DBG(data->dev, "config %s, bad hs length or type\n",
+ data->name);
+ goto fail0;
+ }
+ }
+
+ spin_lock_irq (&data->dev->lock);
+ if (data->dev->state == STATE_DEV_UNBOUND) {
+ value = -ENOENT;
+ goto gone;
+ } else if ((ep = data->ep) == NULL) {
+ value = -ENODEV;
+ goto gone;
+ }
+ switch (data->dev->gadget->speed) {
+ case USB_SPEED_LOW:
+ case USB_SPEED_FULL:
+ ep->desc = &data->desc;
+ break;
+ case USB_SPEED_HIGH:
+ /* fails if caller didn't provide that descriptor... */
+ ep->desc = &data->hs_desc;
+ break;
+ default:
+ DBG(data->dev, "unconnected, %s init abandoned\n",
+ data->name);
+ value = -EINVAL;
+ goto gone;
+ }
+ value = usb_ep_enable(ep);
+ if (value == 0) {
+ data->state = STATE_EP_ENABLED;
+ value = length;
+ }
+gone:
+ spin_unlock_irq (&data->dev->lock);
+ if (value < 0) {
+fail:
+ data->desc.bDescriptorType = 0;
+ data->hs_desc.bDescriptorType = 0;
+ }
+ return value;
+fail0:
+ value = -EINVAL;
+ goto fail;
+}
+
+static int
+ep_open (struct inode *inode, struct file *fd)
+{
+ struct ep_data *data = inode->i_private;
+ int value = -EBUSY;
+
+ if (mutex_lock_interruptible(&data->lock) != 0)
+ return -EINTR;
+ spin_lock_irq (&data->dev->lock);
+ if (data->dev->state == STATE_DEV_UNBOUND)
+ value = -ENOENT;
+ else if (data->state == STATE_EP_DISABLED) {
+ value = 0;
+ data->state = STATE_EP_READY;
+ get_ep (data);
+ fd->private_data = data;
+ VDEBUG (data->dev, "%s ready\n", data->name);
+ } else
+ DBG (data->dev, "%s state %d\n",
+ data->name, data->state);
+ spin_unlock_irq (&data->dev->lock);
+ mutex_unlock(&data->lock);
+ return value;
+}
+
+/*----------------------------------------------------------------------*/
+
+/* EP0 IMPLEMENTATION can be partly in userspace.
+ *
+ * Drivers that use this facility receive various events, including
+ * control requests the kernel doesn't handle. Drivers that don't
+ * use this facility may be too simple-minded for real applications.
+ */
+
+static inline void ep0_readable (struct dev_data *dev)
+{
+ wake_up (&dev->wait);
+ kill_fasync (&dev->fasync, SIGIO, POLL_IN);
+}
+
+static void clean_req (struct usb_ep *ep, struct usb_request *req)
+{
+ struct dev_data *dev = ep->driver_data;
+
+ if (req->buf != dev->rbuf) {
+ kfree(req->buf);
+ req->buf = dev->rbuf;
+ }
+ req->complete = epio_complete;
+ dev->setup_out_ready = 0;
+}
+
+static void ep0_complete (struct usb_ep *ep, struct usb_request *req)
+{
+ struct dev_data *dev = ep->driver_data;
+ unsigned long flags;
+ int free = 1;
+
+ /* for control OUT, data must still get to userspace */
+ spin_lock_irqsave(&dev->lock, flags);
+ if (!dev->setup_in) {
+ dev->setup_out_error = (req->status != 0);
+ if (!dev->setup_out_error)
+ free = 0;
+ dev->setup_out_ready = 1;
+ ep0_readable (dev);
+ }
+
+ /* clean up as appropriate */
+ if (free && req->buf != &dev->rbuf)
+ clean_req (ep, req);
+ req->complete = epio_complete;
+ spin_unlock_irqrestore(&dev->lock, flags);
+}
+
+static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
+{
+ struct dev_data *dev = ep->driver_data;
+
+ if (dev->setup_out_ready) {
+ DBG (dev, "ep0 request busy!\n");
+ return -EBUSY;
+ }
+ if (len > sizeof (dev->rbuf))
+ req->buf = kmalloc(len, GFP_ATOMIC);
+ if (req->buf == NULL) {
+ req->buf = dev->rbuf;
+ return -ENOMEM;
+ }
+ req->complete = ep0_complete;
+ req->length = len;
+ req->zero = 0;
+ return 0;
+}
+
+static ssize_t
+ep0_read (struct file *fd, char __user *buf, size_t len, loff_t *ptr)
+{
+ struct dev_data *dev = fd->private_data;
+ ssize_t retval;
+ enum ep0_state state;
+
+ spin_lock_irq (&dev->lock);
+ if (dev->state <= STATE_DEV_OPENED) {
+ retval = -EINVAL;
+ goto done;
+ }
+
+ /* report fd mode change before acting on it */
+ if (dev->setup_abort) {
+ dev->setup_abort = 0;
+ retval = -EIDRM;
+ goto done;
+ }
+
+ /* control DATA stage */
+ if ((state = dev->state) == STATE_DEV_SETUP) {
+
+ if (dev->setup_in) { /* stall IN */
+ VDEBUG(dev, "ep0in stall\n");
+ (void) usb_ep_set_halt (dev->gadget->ep0);
+ retval = -EL2HLT;
+ dev->state = STATE_DEV_CONNECTED;
+
+ } else if (len == 0) { /* ack SET_CONFIGURATION etc */
+ struct usb_ep *ep = dev->gadget->ep0;
+ struct usb_request *req = dev->req;
+
+ if ((retval = setup_req (ep, req, 0)) == 0)
+ retval = usb_ep_queue (ep, req, GFP_ATOMIC);
+ dev->state = STATE_DEV_CONNECTED;
+
+ /* assume that was SET_CONFIGURATION */
+ if (dev->current_config) {
+ unsigned power;
+
+ if (gadget_is_dualspeed(dev->gadget)
+ && (dev->gadget->speed
+ == USB_SPEED_HIGH))
+ power = dev->hs_config->bMaxPower;
+ else
+ power = dev->config->bMaxPower;
+ usb_gadget_vbus_draw(dev->gadget, 2 * power);
+ }
+
+ } else { /* collect OUT data */
+ if ((fd->f_flags & O_NONBLOCK) != 0
+ && !dev->setup_out_ready) {
+ retval = -EAGAIN;
+ goto done;
+ }
+ spin_unlock_irq (&dev->lock);
+ retval = wait_event_interruptible (dev->wait,
+ dev->setup_out_ready != 0);
+
+ /* FIXME state could change from under us */
+ spin_lock_irq (&dev->lock);
+ if (retval)
+ goto done;
+
+ if (dev->state != STATE_DEV_SETUP) {
+ retval = -ECANCELED;
+ goto done;
+ }
+ dev->state = STATE_DEV_CONNECTED;
+
+ if (dev->setup_out_error)
+ retval = -EIO;
+ else {
+ len = min (len, (size_t)dev->req->actual);
+// FIXME don't call this with the spinlock held ...
+ if (copy_to_user (buf, dev->req->buf, len))
+ retval = -EFAULT;
+ else
+ retval = len;
+ clean_req (dev->gadget->ep0, dev->req);
+ /* NOTE userspace can't yet choose to stall */
+ }
+ }
+ goto done;
+ }
+
+ /* else normal: return event data */
+ if (len < sizeof dev->event [0]) {
+ retval = -EINVAL;
+ goto done;
+ }
+ len -= len % sizeof (struct usb_gadgetfs_event);
+ dev->usermode_setup = 1;
+
+scan:
+ /* return queued events right away */
+ if (dev->ev_next != 0) {
+ unsigned i, n;
+
+ n = len / sizeof (struct usb_gadgetfs_event);
+ if (dev->ev_next < n)
+ n = dev->ev_next;
+
+ /* ep0 i/o has special semantics during STATE_DEV_SETUP */
+ for (i = 0; i < n; i++) {
+ if (dev->event [i].type == GADGETFS_SETUP) {
+ dev->state = STATE_DEV_SETUP;
+ n = i + 1;
+ break;
+ }
+ }
+ spin_unlock_irq (&dev->lock);
+ len = n * sizeof (struct usb_gadgetfs_event);
+ if (copy_to_user (buf, &dev->event, len))
+ retval = -EFAULT;
+ else
+ retval = len;
+ if (len > 0) {
+ /* NOTE this doesn't guard against broken drivers;
+ * concurrent ep0 readers may lose events.
+ */
+ spin_lock_irq (&dev->lock);
+ if (dev->ev_next > n) {
+ memmove(&dev->event[0], &dev->event[n],
+ sizeof (struct usb_gadgetfs_event)
+ * (dev->ev_next - n));
+ }
+ dev->ev_next -= n;
+ spin_unlock_irq (&dev->lock);
+ }
+ return retval;
+ }
+ if (fd->f_flags & O_NONBLOCK) {
+ retval = -EAGAIN;
+ goto done;
+ }
+
+ switch (state) {
+ default:
+ DBG (dev, "fail %s, state %d\n", __func__, state);
+ retval = -ESRCH;
+ break;
+ case STATE_DEV_UNCONNECTED:
+ case STATE_DEV_CONNECTED:
+ spin_unlock_irq (&dev->lock);
+ DBG (dev, "%s wait\n", __func__);
+
+ /* wait for events */
+ retval = wait_event_interruptible (dev->wait,
+ dev->ev_next != 0);
+ if (retval < 0)
+ return retval;
+ spin_lock_irq (&dev->lock);
+ goto scan;
+ }
+
+done:
+ spin_unlock_irq (&dev->lock);
+ return retval;
+}
+
+static struct usb_gadgetfs_event *
+next_event (struct dev_data *dev, enum usb_gadgetfs_event_type type)
+{
+ struct usb_gadgetfs_event *event;
+ unsigned i;
+
+ switch (type) {
+ /* these events purge the queue */
+ case GADGETFS_DISCONNECT:
+ if (dev->state == STATE_DEV_SETUP)
+ dev->setup_abort = 1;
+ // FALL THROUGH
+ case GADGETFS_CONNECT:
+ dev->ev_next = 0;
+ break;
+ case GADGETFS_SETUP: /* previous request timed out */
+ case GADGETFS_SUSPEND: /* same effect */
+ /* these events can't be repeated */
+ for (i = 0; i != dev->ev_next; i++) {
+ if (dev->event [i].type != type)
+ continue;
+ DBG(dev, "discard old event[%d] %d\n", i, type);
+ dev->ev_next--;
+ if (i == dev->ev_next)
+ break;
+ /* indices start at zero, for simplicity */
+ memmove (&dev->event [i], &dev->event [i + 1],
+ sizeof (struct usb_gadgetfs_event)
+ * (dev->ev_next - i));
+ }
+ break;
+ default:
+ BUG ();
+ }
+ VDEBUG(dev, "event[%d] = %d\n", dev->ev_next, type);
+ event = &dev->event [dev->ev_next++];
+ BUG_ON (dev->ev_next > N_EVENT);
+ memset (event, 0, sizeof *event);
+ event->type = type;
+ return event;
+}
+
+static ssize_t
+ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
+{
+ struct dev_data *dev = fd->private_data;
+ ssize_t retval = -ESRCH;
+
+ /* report fd mode change before acting on it */
+ if (dev->setup_abort) {
+ dev->setup_abort = 0;
+ retval = -EIDRM;
+
+ /* data and/or status stage for control request */
+ } else if (dev->state == STATE_DEV_SETUP) {
+
+ /* IN DATA+STATUS caller makes len <= wLength */
+ if (dev->setup_in) {
+ retval = setup_req (dev->gadget->ep0, dev->req, len);
+ if (retval == 0) {
+ dev->state = STATE_DEV_CONNECTED;
+ spin_unlock_irq (&dev->lock);
+ if (copy_from_user (dev->req->buf, buf, len))
+ retval = -EFAULT;
+ else {
+ if (len < dev->setup_wLength)
+ dev->req->zero = 1;
+ retval = usb_ep_queue (
+ dev->gadget->ep0, dev->req,
+ GFP_KERNEL);
+ }
+ if (retval < 0) {
+ spin_lock_irq (&dev->lock);
+ clean_req (dev->gadget->ep0, dev->req);
+ spin_unlock_irq (&dev->lock);
+ } else
+ retval = len;
+
+ return retval;
+ }
+
+ /* can stall some OUT transfers */
+ } else if (dev->setup_can_stall) {
+ VDEBUG(dev, "ep0out stall\n");
+ (void) usb_ep_set_halt (dev->gadget->ep0);
+ retval = -EL2HLT;
+ dev->state = STATE_DEV_CONNECTED;
+ } else {
+ DBG(dev, "bogus ep0out stall!\n");
+ }
+ } else
+ DBG (dev, "fail %s, state %d\n", __func__, dev->state);
+
+ return retval;
+}
+
+static int
+ep0_fasync (int f, struct file *fd, int on)
+{
+ struct dev_data *dev = fd->private_data;
+ // caller must F_SETOWN before signal delivery happens
+ VDEBUG (dev, "%s %s\n", __func__, on ? "on" : "off");
+ return fasync_helper (f, fd, on, &dev->fasync);
+}
+
+static struct usb_gadget_driver gadgetfs_driver;
+
+static int
+dev_release (struct inode *inode, struct file *fd)
+{
+ struct dev_data *dev = fd->private_data;
+
+ /* closing ep0 === shutdown all */
+
+ usb_gadget_unregister_driver (&gadgetfs_driver);
+
+ /* at this point "good" hardware has disconnected the
+ * device from USB; the host won't see it any more.
+ * alternatively, all host requests will time out.
+ */
+
+ kfree (dev->buf);
+ dev->buf = NULL;
+
+ /* other endpoints were all decoupled from this device */
+ spin_lock_irq(&dev->lock);
+ dev->state = STATE_DEV_DISABLED;
+ spin_unlock_irq(&dev->lock);
+
+ put_dev (dev);
+ return 0;
+}
+
+static unsigned int
+ep0_poll (struct file *fd, poll_table *wait)
+{
+ struct dev_data *dev = fd->private_data;
+ int mask = 0;
+
+ if (dev->state <= STATE_DEV_OPENED)
+ return DEFAULT_POLLMASK;
+
+ poll_wait(fd, &dev->wait, wait);
+
+ spin_lock_irq (&dev->lock);
+
+ /* report fd mode change before acting on it */
+ if (dev->setup_abort) {
+ dev->setup_abort = 0;
+ mask = POLLHUP;
+ goto out;
+ }
+
+ if (dev->state == STATE_DEV_SETUP) {
+ if (dev->setup_in || dev->setup_can_stall)
+ mask = POLLOUT;
+ } else {
+ if (dev->ev_next != 0)
+ mask = POLLIN;
+ }
+out:
+ spin_unlock_irq(&dev->lock);
+ return mask;
+}
+
+static long dev_ioctl (struct file *fd, unsigned code, unsigned long value)
+{
+ struct dev_data *dev = fd->private_data;
+ struct usb_gadget *gadget = dev->gadget;
+ long ret = -ENOTTY;
+
+ if (gadget->ops->ioctl)
+ ret = gadget->ops->ioctl (gadget, code, value);
+
+ return ret;
+}
+
+/*----------------------------------------------------------------------*/
+
+/* The in-kernel gadget driver handles most ep0 issues, in particular
+ * enumerating the single configuration (as provided from user space).
+ *
+ * Unrecognized ep0 requests may be handled in user space.
+ */
+
+static void make_qualifier (struct dev_data *dev)
+{
+ struct usb_qualifier_descriptor qual;
+ struct usb_device_descriptor *desc;
+
+ qual.bLength = sizeof qual;
+ qual.bDescriptorType = USB_DT_DEVICE_QUALIFIER;
+ qual.bcdUSB = cpu_to_le16 (0x0200);
+
+ desc = dev->dev;
+ qual.bDeviceClass = desc->bDeviceClass;
+ qual.bDeviceSubClass = desc->bDeviceSubClass;
+ qual.bDeviceProtocol = desc->bDeviceProtocol;
+
+ /* assumes ep0 uses the same value for both speeds ... */
+ qual.bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
+
+ qual.bNumConfigurations = 1;
+ qual.bRESERVED = 0;
+
+ memcpy (dev->rbuf, &qual, sizeof qual);
+}
+
+static int
+config_buf (struct dev_data *dev, u8 type, unsigned index)
+{
+ int len;
+ int hs = 0;
+
+ /* only one configuration */
+ if (index > 0)
+ return -EINVAL;
+
+ if (gadget_is_dualspeed(dev->gadget)) {
+ hs = (dev->gadget->speed == USB_SPEED_HIGH);
+ if (type == USB_DT_OTHER_SPEED_CONFIG)
+ hs = !hs;
+ }
+ if (hs) {
+ dev->req->buf = dev->hs_config;
+ len = le16_to_cpu(dev->hs_config->wTotalLength);
+ } else {
+ dev->req->buf = dev->config;
+ len = le16_to_cpu(dev->config->wTotalLength);
+ }
+ ((u8 *)dev->req->buf) [1] = type;
+ return len;
+}
+
+static int
+gadgetfs_setup (struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
+{
+ struct dev_data *dev = get_gadget_data (gadget);
+ struct usb_request *req = dev->req;
+ int value = -EOPNOTSUPP;
+ struct usb_gadgetfs_event *event;
+ u16 w_value = le16_to_cpu(ctrl->wValue);
+ u16 w_length = le16_to_cpu(ctrl->wLength);
+
+ spin_lock (&dev->lock);
+ dev->setup_abort = 0;
+ if (dev->state == STATE_DEV_UNCONNECTED) {
+ if (gadget_is_dualspeed(gadget)
+ && gadget->speed == USB_SPEED_HIGH
+ && dev->hs_config == NULL) {
+ spin_unlock(&dev->lock);
+ ERROR (dev, "no high speed config??\n");
+ return -EINVAL;
+ }
+
+ dev->state = STATE_DEV_CONNECTED;
+
+ INFO (dev, "connected\n");
+ event = next_event (dev, GADGETFS_CONNECT);
+ event->u.speed = gadget->speed;
+ ep0_readable (dev);
+
+ /* host may have given up waiting for response. we can miss control
+ * requests handled lower down (device/endpoint status and features);
+ * then ep0_{read,write} will report the wrong status. controller
+ * driver will have aborted pending i/o.
+ */
+ } else if (dev->state == STATE_DEV_SETUP)
+ dev->setup_abort = 1;
+
+ req->buf = dev->rbuf;
+ req->context = NULL;
+ value = -EOPNOTSUPP;
+ switch (ctrl->bRequest) {
+
+ case USB_REQ_GET_DESCRIPTOR:
+ if (ctrl->bRequestType != USB_DIR_IN)
+ goto unrecognized;
+ switch (w_value >> 8) {
+
+ case USB_DT_DEVICE:
+ value = min (w_length, (u16) sizeof *dev->dev);
+ dev->dev->bMaxPacketSize0 = dev->gadget->ep0->maxpacket;
+ req->buf = dev->dev;
+ break;
+ case USB_DT_DEVICE_QUALIFIER:
+ if (!dev->hs_config)
+ break;
+ value = min (w_length, (u16)
+ sizeof (struct usb_qualifier_descriptor));
+ make_qualifier (dev);
+ break;
+ case USB_DT_OTHER_SPEED_CONFIG:
+ // FALLTHROUGH
+ case USB_DT_CONFIG:
+ value = config_buf (dev,
+ w_value >> 8,
+ w_value & 0xff);
+ if (value >= 0)
+ value = min (w_length, (u16) value);
+ break;
+ case USB_DT_STRING:
+ goto unrecognized;
+
+ default: // all others are errors
+ break;
+ }
+ break;
+
+ /* currently one config, two speeds */
+ case USB_REQ_SET_CONFIGURATION:
+ if (ctrl->bRequestType != 0)
+ goto unrecognized;
+ if (0 == (u8) w_value) {
+ value = 0;
+ dev->current_config = 0;
+ usb_gadget_vbus_draw(gadget, 8 /* mA */ );
+ // user mode expected to disable endpoints
+ } else {
+ u8 config, power;
+
+ if (gadget_is_dualspeed(gadget)
+ && gadget->speed == USB_SPEED_HIGH) {
+ config = dev->hs_config->bConfigurationValue;
+ power = dev->hs_config->bMaxPower;
+ } else {
+ config = dev->config->bConfigurationValue;
+ power = dev->config->bMaxPower;
+ }
+
+ if (config == (u8) w_value) {
+ value = 0;
+ dev->current_config = config;
+ usb_gadget_vbus_draw(gadget, 2 * power);
+ }
+ }
+
+ /* report SET_CONFIGURATION like any other control request,
+ * except that usermode may not stall this. the next
+ * request mustn't be allowed start until this finishes:
+ * endpoints and threads set up, etc.
+ *
+ * NOTE: older PXA hardware (before PXA 255: without UDCCFR)
+ * has bad/racey automagic that prevents synchronizing here.
+ * even kernel mode drivers often miss them.
+ */
+ if (value == 0) {
+ INFO (dev, "configuration #%d\n", dev->current_config);
+ usb_gadget_set_state(gadget, USB_STATE_CONFIGURED);
+ if (dev->usermode_setup) {
+ dev->setup_can_stall = 0;
+ goto delegate;
+ }
+ }
+ break;
+
+#ifndef CONFIG_USB_PXA25X
+ /* PXA automagically handles this request too */
+ case USB_REQ_GET_CONFIGURATION:
+ if (ctrl->bRequestType != 0x80)
+ goto unrecognized;
+ *(u8 *)req->buf = dev->current_config;
+ value = min (w_length, (u16) 1);
+ break;
+#endif
+
+ default:
+unrecognized:
+ VDEBUG (dev, "%s req%02x.%02x v%04x i%04x l%d\n",
+ dev->usermode_setup ? "delegate" : "fail",
+ ctrl->bRequestType, ctrl->bRequest,
+ w_value, le16_to_cpu(ctrl->wIndex), w_length);
+
+ /* if there's an ep0 reader, don't stall */
+ if (dev->usermode_setup) {
+ dev->setup_can_stall = 1;
+delegate:
+ dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
+ ? 1 : 0;
+ dev->setup_wLength = w_length;
+ dev->setup_out_ready = 0;
+ dev->setup_out_error = 0;
+ value = 0;
+
+ /* read DATA stage for OUT right away */
+ if (unlikely (!dev->setup_in && w_length)) {
+ value = setup_req (gadget->ep0, dev->req,
+ w_length);
+ if (value < 0)
+ break;
+ value = usb_ep_queue (gadget->ep0, dev->req,
+ GFP_ATOMIC);
+ if (value < 0) {
+ clean_req (gadget->ep0, dev->req);
+ break;
+ }
+
+ /* we can't currently stall these */
+ dev->setup_can_stall = 0;
+ }
+
+ /* state changes when reader collects event */
+ event = next_event (dev, GADGETFS_SETUP);
+ event->u.setup = *ctrl;
+ ep0_readable (dev);
+ spin_unlock (&dev->lock);
+ return 0;
+ }
+ }
+
+ /* proceed with data transfer and status phases? */
+ if (value >= 0 && dev->state != STATE_DEV_SETUP) {
+ req->length = value;
+ req->zero = value < w_length;
+ value = usb_ep_queue (gadget->ep0, req, GFP_ATOMIC);
+ if (value < 0) {
+ DBG (dev, "ep_queue --> %d\n", value);
+ req->status = 0;
+ }
+ }
+
+ /* device stalls when value < 0 */
+ spin_unlock (&dev->lock);
+ return value;
+}
+
+static void destroy_ep_files (struct dev_data *dev)
+{
+ DBG (dev, "%s %d\n", __func__, dev->state);
+
+ /* dev->state must prevent interference */
+ spin_lock_irq (&dev->lock);
+ while (!list_empty(&dev->epfiles)) {
+ struct ep_data *ep;
+ struct inode *parent;
+ struct dentry *dentry;
+
+ /* break link to FS */
+ ep = list_first_entry (&dev->epfiles, struct ep_data, epfiles);
+ list_del_init (&ep->epfiles);
+ dentry = ep->dentry;
+ ep->dentry = NULL;
+ parent = d_inode(dentry->d_parent);
+
+ /* break link to controller */
+ if (ep->state == STATE_EP_ENABLED)
+ (void) usb_ep_disable (ep->ep);
+ ep->state = STATE_EP_UNBOUND;
+ usb_ep_free_request (ep->ep, ep->req);
+ ep->ep = NULL;
+ wake_up (&ep->wait);
+ put_ep (ep);
+
+ spin_unlock_irq (&dev->lock);
+
+ /* break link to dcache */
+ mutex_lock (&parent->i_mutex);
+ d_delete (dentry);
+ dput (dentry);
+ mutex_unlock (&parent->i_mutex);
+
+ spin_lock_irq (&dev->lock);
+ }
+ spin_unlock_irq (&dev->lock);
+}
+
+
+static struct dentry *
+gadgetfs_create_file (struct super_block *sb, char const *name,
+ void *data, const struct file_operations *fops);
+
+static int activate_ep_files (struct dev_data *dev)
+{
+ struct usb_ep *ep;
+ struct ep_data *data;
+
+ gadget_for_each_ep (ep, dev->gadget) {
+
+ data = kzalloc(sizeof(*data), GFP_KERNEL);
+ if (!data)
+ goto enomem0;
+ data->state = STATE_EP_DISABLED;
+ mutex_init(&data->lock);
+ init_waitqueue_head (&data->wait);
+
+ strncpy (data->name, ep->name, sizeof (data->name) - 1);
+ atomic_set (&data->count, 1);
+ data->dev = dev;
+ get_dev (dev);
+
+ data->ep = ep;
+ ep->driver_data = data;
+
+ data->req = usb_ep_alloc_request (ep, GFP_KERNEL);
+ if (!data->req)
+ goto enomem1;
+
+ data->dentry = gadgetfs_create_file (dev->sb, data->name,
+ data, &ep_io_operations);
+ if (!data->dentry)
+ goto enomem2;
+ list_add_tail (&data->epfiles, &dev->epfiles);
+ }
+ return 0;
+
+enomem2:
+ usb_ep_free_request (ep, data->req);
+enomem1:
+ put_dev (dev);
+ kfree (data);
+enomem0:
+ DBG (dev, "%s enomem\n", __func__);
+ destroy_ep_files (dev);
+ return -ENOMEM;
+}
+
+static void
+gadgetfs_unbind (struct usb_gadget *gadget)
+{
+ struct dev_data *dev = get_gadget_data (gadget);
+
+ DBG (dev, "%s\n", __func__);
+
+ spin_lock_irq (&dev->lock);
+ dev->state = STATE_DEV_UNBOUND;
+ spin_unlock_irq (&dev->lock);
+
+ destroy_ep_files (dev);
+ gadget->ep0->driver_data = NULL;
+ set_gadget_data (gadget, NULL);
+
+ /* we've already been disconnected ... no i/o is active */
+ if (dev->req)
+ usb_ep_free_request (gadget->ep0, dev->req);
+ DBG (dev, "%s done\n", __func__);
+ put_dev (dev);
+}
+
+static struct dev_data *the_device;
+
+static int gadgetfs_bind(struct usb_gadget *gadget,
+ struct usb_gadget_driver *driver)
+{
+ struct dev_data *dev = the_device;
+
+ if (!dev)
+ return -ESRCH;
+ if (0 != strcmp (CHIP, gadget->name)) {
+ pr_err("%s expected %s controller not %s\n",
+ shortname, CHIP, gadget->name);
+ return -ENODEV;
+ }
+
+ set_gadget_data (gadget, dev);
+ dev->gadget = gadget;
+ gadget->ep0->driver_data = dev;
+
+ /* preallocate control response and buffer */
+ dev->req = usb_ep_alloc_request (gadget->ep0, GFP_KERNEL);
+ if (!dev->req)
+ goto enomem;
+ dev->req->context = NULL;
+ dev->req->complete = epio_complete;
+
+ if (activate_ep_files (dev) < 0)
+ goto enomem;
+
+ INFO (dev, "bound to %s driver\n", gadget->name);
+ spin_lock_irq(&dev->lock);
+ dev->state = STATE_DEV_UNCONNECTED;
+ spin_unlock_irq(&dev->lock);
+ get_dev (dev);
+ return 0;
+
+enomem:
+ gadgetfs_unbind (gadget);
+ return -ENOMEM;
+}
+
+static void
+gadgetfs_disconnect (struct usb_gadget *gadget)
+{
+ struct dev_data *dev = get_gadget_data (gadget);
+ unsigned long flags;
+
+ spin_lock_irqsave (&dev->lock, flags);
+ if (dev->state == STATE_DEV_UNCONNECTED)
+ goto exit;
+ dev->state = STATE_DEV_UNCONNECTED;
+
+ INFO (dev, "disconnected\n");
+ next_event (dev, GADGETFS_DISCONNECT);
+ ep0_readable (dev);
+exit:
+ spin_unlock_irqrestore (&dev->lock, flags);
+}
+
+static void
+gadgetfs_suspend (struct usb_gadget *gadget)
+{
+ struct dev_data *dev = get_gadget_data (gadget);
+
+ INFO (dev, "suspended from state %d\n", dev->state);
+ spin_lock (&dev->lock);
+ switch (dev->state) {
+ case STATE_DEV_SETUP: // VERY odd... host died??
+ case STATE_DEV_CONNECTED:
+ case STATE_DEV_UNCONNECTED:
+ next_event (dev, GADGETFS_SUSPEND);
+ ep0_readable (dev);
+ /* FALLTHROUGH */
+ default:
+ break;
+ }
+ spin_unlock (&dev->lock);
+}
+
+static struct usb_gadget_driver gadgetfs_driver = {
+ .function = (char *) driver_desc,
+ .bind = gadgetfs_bind,
+ .unbind = gadgetfs_unbind,
+ .setup = gadgetfs_setup,
+ .reset = gadgetfs_disconnect,
+ .disconnect = gadgetfs_disconnect,
+ .suspend = gadgetfs_suspend,
+
+ .driver = {
+ .name = (char *) shortname,
+ },
+};
+
+/*----------------------------------------------------------------------*/
+
+static void gadgetfs_nop(struct usb_gadget *arg) { }
+
+static int gadgetfs_probe(struct usb_gadget *gadget,
+ struct usb_gadget_driver *driver)
+{
+ CHIP = gadget->name;
+ return -EISNAM;
+}
+
+static struct usb_gadget_driver probe_driver = {
+ .max_speed = USB_SPEED_HIGH,
+ .bind = gadgetfs_probe,
+ .unbind = gadgetfs_nop,
+ .setup = (void *)gadgetfs_nop,
+ .disconnect = gadgetfs_nop,
+ .driver = {
+ .name = "nop",
+ },
+};
+
+
+/* DEVICE INITIALIZATION
+ *
+ * fd = open ("/dev/gadget/$CHIP", O_RDWR)
+ * status = write (fd, descriptors, sizeof descriptors)
+ *
+ * That write establishes the device configuration, so the kernel can
+ * bind to the controller ... guaranteeing it can handle enumeration
+ * at all necessary speeds. Descriptor order is:
+ *
+ * . message tag (u32, host order) ... for now, must be zero; it
+ * would change to support features like multi-config devices
+ * . full/low speed config ... all wTotalLength bytes (with interface,
+ * class, altsetting, endpoint, and other descriptors)
+ * . high speed config ... all descriptors, for high speed operation;
+ * this one's optional except for high-speed hardware
+ * . device descriptor
+ *
+ * Endpoints are not yet enabled. Drivers must wait until device
+ * configuration and interface altsetting changes create
+ * the need to configure (or unconfigure) them.
+ *
+ * After initialization, the device stays active for as long as that
+ * $CHIP file is open. Events must then be read from that descriptor,
+ * such as configuration notifications.
+ */
+
+static int is_valid_config (struct usb_config_descriptor *config)
+{
+ return config->bDescriptorType == USB_DT_CONFIG
+ && config->bLength == USB_DT_CONFIG_SIZE
+ && config->bConfigurationValue != 0
+ && (config->bmAttributes & USB_CONFIG_ATT_ONE) != 0
+ && (config->bmAttributes & USB_CONFIG_ATT_WAKEUP) == 0;
+ /* FIXME if gadget->is_otg, _must_ include an otg descriptor */
+ /* FIXME check lengths: walk to end */
+}
+
+static ssize_t
+dev_config (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
+{
+ struct dev_data *dev = fd->private_data;
+ ssize_t value = len, length = len;
+ unsigned total;
+ u32 tag;
+ char *kbuf;
+
+ spin_lock_irq(&dev->lock);
+ if (dev->state > STATE_DEV_OPENED) {
+ value = ep0_write(fd, buf, len, ptr);
+ spin_unlock_irq(&dev->lock);
+ return value;
+ }
+ spin_unlock_irq(&dev->lock);
+
+ if (len < (USB_DT_CONFIG_SIZE + USB_DT_DEVICE_SIZE + 4))
+ return -EINVAL;
+
+ /* we might need to change message format someday */
+ if (copy_from_user (&tag, buf, 4))
+ return -EFAULT;
+ if (tag != 0)
+ return -EINVAL;
+ buf += 4;
+ length -= 4;
+
+ kbuf = memdup_user(buf, length);
+ if (IS_ERR(kbuf))
+ return PTR_ERR(kbuf);
+
+ spin_lock_irq (&dev->lock);
+ value = -EINVAL;
+ if (dev->buf)
+ goto fail;
+ dev->buf = kbuf;
+
+ /* full or low speed config */
+ dev->config = (void *) kbuf;
+ total = le16_to_cpu(dev->config->wTotalLength);
+ if (!is_valid_config (dev->config) || total >= length)
+ goto fail;
+ kbuf += total;
+ length -= total;
+
+ /* optional high speed config */
+ if (kbuf [1] == USB_DT_CONFIG) {
+ dev->hs_config = (void *) kbuf;
+ total = le16_to_cpu(dev->hs_config->wTotalLength);
+ if (!is_valid_config (dev->hs_config) || total >= length)
+ goto fail;
+ kbuf += total;
+ length -= total;
+ }
+
+ /* could support multiple configs, using another encoding! */
+
+ /* device descriptor (tweaked for paranoia) */
+ if (length != USB_DT_DEVICE_SIZE)
+ goto fail;
+ dev->dev = (void *)kbuf;
+ if (dev->dev->bLength != USB_DT_DEVICE_SIZE
+ || dev->dev->bDescriptorType != USB_DT_DEVICE
+ || dev->dev->bNumConfigurations != 1)
+ goto fail;
+ dev->dev->bNumConfigurations = 1;
+ dev->dev->bcdUSB = cpu_to_le16 (0x0200);
+
+ /* triggers gadgetfs_bind(); then we can enumerate. */
+ spin_unlock_irq (&dev->lock);
+ if (dev->hs_config)
+ gadgetfs_driver.max_speed = USB_SPEED_HIGH;
+ else
+ gadgetfs_driver.max_speed = USB_SPEED_FULL;
+
+ value = usb_gadget_probe_driver(&gadgetfs_driver);
+ if (value != 0) {
+ kfree (dev->buf);
+ dev->buf = NULL;
+ } else {
+ /* at this point "good" hardware has for the first time
+ * let the USB the host see us. alternatively, if users
+ * unplug/replug that will clear all the error state.
+ *
+ * note: everything running before here was guaranteed
+ * to choke driver model style diagnostics. from here
+ * on, they can work ... except in cleanup paths that
+ * kick in after the ep0 descriptor is closed.
+ */
+ value = len;
+ }
+ return value;
+
+fail:
+ spin_unlock_irq (&dev->lock);
+ pr_debug ("%s: %s fail %Zd, %p\n", shortname, __func__, value, dev);
+ kfree (dev->buf);
+ dev->buf = NULL;
+ return value;
+}
+
+static int
+dev_open (struct inode *inode, struct file *fd)
+{
+ struct dev_data *dev = inode->i_private;
+ int value = -EBUSY;
+
+ spin_lock_irq(&dev->lock);
+ if (dev->state == STATE_DEV_DISABLED) {
+ dev->ev_next = 0;
+ dev->state = STATE_DEV_OPENED;
+ fd->private_data = dev;
+ get_dev (dev);
+ value = 0;
+ }
+ spin_unlock_irq(&dev->lock);
+ return value;
+}
+
+static const struct file_operations ep0_operations = {
+ .llseek = no_llseek,
+
+ .open = dev_open,
+ .read = ep0_read,
+ .write = dev_config,
+ .fasync = ep0_fasync,
+ .poll = ep0_poll,
+ .unlocked_ioctl = dev_ioctl,
+ .release = dev_release,
+};
+
+/*----------------------------------------------------------------------*/
+
+/* FILESYSTEM AND SUPERBLOCK OPERATIONS
+ *
+ * Mounting the filesystem creates a controller file, used first for
+ * device configuration then later for event monitoring.
+ */
+
+
+/* FIXME PAM etc could set this security policy without mount options
+ * if epfiles inherited ownership and permissons from ep0 ...
+ */
+
+static unsigned default_uid;
+static unsigned default_gid;
+static unsigned default_perm = S_IRUSR | S_IWUSR;
+
+module_param (default_uid, uint, 0644);
+module_param (default_gid, uint, 0644);
+module_param (default_perm, uint, 0644);
+
+
+static struct inode *
+gadgetfs_make_inode (struct super_block *sb,
+ void *data, const struct file_operations *fops,
+ int mode)
+{
+ struct inode *inode = new_inode (sb);
+
+ if (inode) {
+ inode->i_ino = get_next_ino();
+ inode->i_mode = mode;
+ inode->i_uid = make_kuid(&init_user_ns, default_uid);
+ inode->i_gid = make_kgid(&init_user_ns, default_gid);
+ inode->i_atime = inode->i_mtime = inode->i_ctime
+ = CURRENT_TIME;
+ inode->i_private = data;
+ inode->i_fop = fops;
+ }
+ return inode;
+}
+
+/* creates in fs root directory, so non-renamable and non-linkable.
+ * so inode and dentry are paired, until device reconfig.
+ */
+static struct dentry *
+gadgetfs_create_file (struct super_block *sb, char const *name,
+ void *data, const struct file_operations *fops)
+{
+ struct dentry *dentry;
+ struct inode *inode;
+
+ dentry = d_alloc_name(sb->s_root, name);
+ if (!dentry)
+ return NULL;
+
+ inode = gadgetfs_make_inode (sb, data, fops,
+ S_IFREG | (default_perm & S_IRWXUGO));
+ if (!inode) {
+ dput(dentry);
+ return NULL;
+ }
+ d_add (dentry, inode);
+ return dentry;
+}
+
+static const struct super_operations gadget_fs_operations = {
+ .statfs = simple_statfs,
+ .drop_inode = generic_delete_inode,
+};
+
+static int
+gadgetfs_fill_super (struct super_block *sb, void *opts, int silent)
+{
+ struct inode *inode;
+ struct dev_data *dev;
+
+ if (the_device)
+ return -ESRCH;
+
+ /* fake probe to determine $CHIP */
+ CHIP = NULL;
+ usb_gadget_probe_driver(&probe_driver);
+ if (!CHIP)
+ return -ENODEV;
+
+ /* superblock */
+ sb->s_blocksize = PAGE_CACHE_SIZE;
+ sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+ sb->s_magic = GADGETFS_MAGIC;
+ sb->s_op = &gadget_fs_operations;
+ sb->s_time_gran = 1;
+
+ /* root inode */
+ inode = gadgetfs_make_inode (sb,
+ NULL, &simple_dir_operations,
+ S_IFDIR | S_IRUGO | S_IXUGO);
+ if (!inode)
+ goto Enomem;
+ inode->i_op = &simple_dir_inode_operations;
+ if (!(sb->s_root = d_make_root (inode)))
+ goto Enomem;
+
+ /* the ep0 file is named after the controller we expect;
+ * user mode code can use it for sanity checks, like we do.
+ */
+ dev = dev_new ();
+ if (!dev)
+ goto Enomem;
+
+ dev->sb = sb;
+ dev->dentry = gadgetfs_create_file(sb, CHIP, dev, &ep0_operations);
+ if (!dev->dentry) {
+ put_dev(dev);
+ goto Enomem;
+ }
+
+ /* other endpoint files are available after hardware setup,
+ * from binding to a controller.
+ */
+ the_device = dev;
+ return 0;
+
+Enomem:
+ return -ENOMEM;
+}
+
+/* "mount -t gadgetfs path /dev/gadget" ends up here */
+static struct dentry *
+gadgetfs_mount (struct file_system_type *t, int flags,
+ const char *path, void *opts)
+{
+ return mount_single (t, flags, opts, gadgetfs_fill_super);
+}
+
+static void
+gadgetfs_kill_sb (struct super_block *sb)
+{
+ kill_litter_super (sb);
+ if (the_device) {
+ put_dev (the_device);
+ the_device = NULL;
+ }
+}
+
+/*----------------------------------------------------------------------*/
+
+static struct file_system_type gadgetfs_type = {
+ .owner = THIS_MODULE,
+ .name = shortname,
+ .mount = gadgetfs_mount,
+ .kill_sb = gadgetfs_kill_sb,
+};
+MODULE_ALIAS_FS("gadgetfs");
+
+/*----------------------------------------------------------------------*/
+
+static int __init init (void)
+{
+ int status;
+
+ status = register_filesystem (&gadgetfs_type);
+ if (status == 0)
+ pr_info ("%s: %s, version " DRIVER_VERSION "\n",
+ shortname, driver_desc);
+ return status;
+}
+module_init (init);
+
+static void __exit cleanup (void)
+{
+ pr_debug ("unregister %s\n", shortname);
+ unregister_filesystem (&gadgetfs_type);
+}
+module_exit (cleanup);
+
Code Review / kvmfornfv.git / blobdiff