inode.c

linux-2.6.15.6

			 */
			spin_lock_irq (&dev->lock);
			dev->ev_next -= len;
			if (dev->ev_next != 0)
				memmove (&dev->event, &dev->event [len],
					sizeof (struct usb_gadgetfs_event)
						* (tmp - len));
			if (n == 0)
				dev->state = STATE_SETUP;
			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", __FUNCTION__, state);
		retval = -ESRCH;
		break;
	case STATE_UNCONNECTED:
	case STATE_CONNECTED:
		spin_unlock_irq (&dev->lock);
		DBG (dev, "%s wait\n", __FUNCTION__);

		/* 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_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\n", 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 ();
	}
	event = &dev->event [dev->ev_next++];
	BUG_ON (dev->ev_next > N_EVENT);
	VDEBUG (dev, "ev %d, next %d\n", type, dev->ev_next);
	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;

	spin_lock_irq (&dev->lock);

	/* 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_SETUP) {

		/* IN DATA+STATUS caller makes len <= wLength */
		if (dev->setup_in) {
			retval = setup_req (dev->gadget->ep0, dev->req, len);
			if (retval == 0) {
				spin_unlock_irq (&dev->lock);
				if (copy_from_user (dev->req->buf, buf, len))
					retval = -EFAULT;
				else
					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_CONNECTED;
		} else {
			DBG(dev, "bogus ep0out stall!\n");
		}
	} else
		DBG (dev, "fail %s, state %d\n", __FUNCTION__, dev->state);

	spin_unlock_irq (&dev->lock);
	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", __FUNCTION__, 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.
	 */

	fasync_helper (-1, fd, 0, &dev->fasync);
	kfree (dev->buf);
	dev->buf = NULL;
	put_dev (dev);

	/* other endpoints were all decoupled from this device */
	dev->state = STATE_DEV_DISABLED;
	return 0;
}

static int dev_ioctl (struct inode *inode, struct file *fd,
		unsigned code, unsigned long value)
{
	struct dev_data		*dev = fd->private_data;
	struct usb_gadget	*gadget = dev->gadget;

	if (gadget->ops->ioctl)
		return gadget->ops->ioctl (gadget, code, value);
	return -ENOTTY;
}

/* used after device configuration */
static struct file_operations ep0_io_operations = {
	.owner =	THIS_MODULE,
	.llseek =	no_llseek,

	.read =		ep0_read,
	.write =	ep0_write,
	.fasync =	ep0_fasync,
	// .poll =	ep0_poll,
	.ioctl =	dev_ioctl,
	.release =	dev_release,
};

/*----------------------------------------------------------------------*/

/* 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.
 */

#ifdef	HIGHSPEED
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 = __constant_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 = desc->bMaxPacketSize0;

	qual.bNumConfigurations = 1;
	qual.bRESERVED = 0;

	memcpy (dev->rbuf, &qual, sizeof qual);
}
#endif

static int
config_buf (struct dev_data *dev, u8 type, unsigned index)
{
	int		len;
#ifdef HIGHSPEED
	int		hs;
#endif

	/* only one configuration */
	if (index > 0)
		return -EINVAL;

#ifdef HIGHSPEED
	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_cpup (&dev->hs_config->wTotalLength);
	} else
#endif
	{
		dev->req->buf = dev->config;
		len = le16_to_cpup (&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_UNCONNECTED) {
		struct usb_ep	*ep;
		struct ep_data	*data;

		dev->state = STATE_CONNECTED;
		dev->dev->bMaxPacketSize0 = gadget->ep0->maxpacket;

#ifdef	HIGHSPEED
		if (gadget->speed == USB_SPEED_HIGH && dev->hs_config == 0) {
			ERROR (dev, "no high speed config??\n");
			return -EINVAL;
		}
#endif	/* HIGHSPEED */

		INFO (dev, "connected\n");
		event = next_event (dev, GADGETFS_CONNECT);
		event->u.speed = gadget->speed;
		ep0_readable (dev);

		list_for_each_entry (ep, &gadget->ep_list, ep_list) {
			data = ep->driver_data;
			/* ... down_trylock (&data->lock) ... */
			if (data->state != STATE_EP_DEFER_ENABLE)
				continue;
#ifdef	HIGHSPEED
			if (gadget->speed == USB_SPEED_HIGH)
				value = usb_ep_enable (ep, &data->hs_desc);
			else
#endif	/* HIGHSPEED */
				value = usb_ep_enable (ep, &data->desc);
			if (value) {
				ERROR (dev, "deferred %s enable --> %d\n",
					data->name, value);
				continue;
			}
			data->state = STATE_EP_ENABLED;
			wake_up (&data->wait);
			DBG (dev, "woke up %s waiters\n", data->name);
		}

	/* 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_SETUP)
		dev->setup_abort = 1;

	req->buf = dev->rbuf;
	req->dma = DMA_ADDR_INVALID;
	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);
			req->buf = dev->dev;
			break;
#ifdef	HIGHSPEED
		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
#endif
		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)
			break;
		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;
#ifdef	HIGHSPEED
			if (gadget->speed == USB_SPEED_HIGH) {
				config = dev->hs_config->bConfigurationValue;
				power = dev->hs_config->bMaxPower;
			} else
#endif
			{
				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);
			if (dev->usermode_setup) {
				dev->setup_can_stall = 0;
				goto delegate;
			}
		}
		break;

#ifndef	CONFIG_USB_GADGETFS_PXA2XX
	/* PXA automagically handles this request too */
	case USB_REQ_GET_CONFIGURATION:
		if (ctrl->bRequestType != 0x80)
			break;
		*(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_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_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)
{
	struct list_head	*entry, *tmp;

	DBG (dev, "%s %d\n", __FUNCTION__, dev->state);

	/* dev->state must prevent interference */
restart:
	spin_lock_irq (&dev->lock);
	list_for_each_safe (entry, tmp, &dev->epfiles) {
		struct ep_data	*ep;
		struct inode	*parent;
		struct dentry	*dentry;

		/* break link to FS */
		ep = list_entry (entry, struct ep_data, epfiles);
		list_del_init (&ep->epfiles);
		dentry = ep->dentry;
		ep->dentry = NULL;
		parent = dentry->d_parent->d_inode;

		/* 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 */
		down (&parent->i_sem);
		d_delete (dentry);
		dput (dentry);
		up (&parent->i_sem);

		/* fds may still be open */
		goto restart;
	}
	spin_unlock_irq (&dev->lock);
}


static struct inode *
gadgetfs_create_file (struct super_block *sb, char const *name,
		void *data, struct file_operations *fops,
		struct dentry **dentry_p);

static int activate_ep_files (struct dev_data *dev)
{
	struct usb_ep	*ep;