drivers/net/wireless/rt2x00/rt2x00usb.c - kernel/msm-4.9 - Gitiles

 /*
 	Copyright (C) 2010 Willow Garage <http://www.willowgarage.com>
 	Copyright (C) 2004 - 2010 Ivo van Doorn <IvDoorn@gmail.com>
 	<http://rt2x00.serialmonkey.com>

 	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.

 	This program is distributed in the hope that it will be useful,
 	but WITHOUT ANY WARRANTY; without even the implied warranty of
 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 	GNU General Public License for more details.

 	You should have received a copy of the GNU General Public License
 	along with this program; if not, write to the
 	Free Software Foundation, Inc.,
 	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */

 /*
 	Module: rt2x00usb
 	Abstract: rt2x00 generic usb device routines.
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/usb.h>
 #include <linux/bug.h>

 #include "rt2x00.h"
 #include "rt2x00usb.h"

 /*
  * Interfacing with the HW.
  */
 int rt2x00usb_vendor_request(struct rt2x00_dev *rt2x00dev,
 			     const u8 request, const u8 requesttype,
 			     const u16 offset, const u16 value,
 			     void *buffer, const u16 buffer_length,
 			     const int timeout)
 {
 	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
 	int status;
 	unsigned int i;
 	unsigned int pipe =
 	    (requesttype == USB_VENDOR_REQUEST_IN) ?
 	    usb_rcvctrlpipe(usb_dev, 0) : usb_sndctrlpipe(usb_dev, 0);

 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
 		return -ENODEV;

 	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
 		status = usb_control_msg(usb_dev, pipe, request, requesttype,
 					 value, offset, buffer, buffer_length,
 					 timeout);
 		if (status >= 0)
 			return 0;

 		/*
 		 * Check for errors
 		 * -ENODEV: Device has disappeared, no point continuing.
 		 * All other errors: Try again.
 		 */
 		else if (status == -ENODEV) {
 			clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
 			break;
 		}
 	}

 	ERROR(rt2x00dev,
 	      "Vendor Request 0x%02x failed for offset 0x%04x with error %d.\n",
 	      request, offset, status);

 	return status;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request);

 int rt2x00usb_vendor_req_buff_lock(struct rt2x00_dev *rt2x00dev,
 				   const u8 request, const u8 requesttype,
 				   const u16 offset, void *buffer,
 				   const u16 buffer_length, const int timeout)
 {
 	int status;

 	BUG_ON(!mutex_is_locked(&rt2x00dev->csr_mutex));

 	/*
 	 * Check for Cache availability.
 	 */
 	if (unlikely(!rt2x00dev->csr.cache || buffer_length > CSR_CACHE_SIZE)) {
 		ERROR(rt2x00dev, "CSR cache not available.\n");
 		return -ENOMEM;
 	}

 	if (requesttype == USB_VENDOR_REQUEST_OUT)
 		memcpy(rt2x00dev->csr.cache, buffer, buffer_length);

 	status = rt2x00usb_vendor_request(rt2x00dev, request, requesttype,
 					  offset, 0, rt2x00dev->csr.cache,
 					  buffer_length, timeout);

 	if (!status && requesttype == USB_VENDOR_REQUEST_IN)
 		memcpy(buffer, rt2x00dev->csr.cache, buffer_length);

 	return status;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_req_buff_lock);

 int rt2x00usb_vendor_request_buff(struct rt2x00_dev *rt2x00dev,
 				  const u8 request, const u8 requesttype,
 				  const u16 offset, void *buffer,
 				  const u16 buffer_length, const int timeout)
 {
 	int status = 0;
 	unsigned char *tb;
 	u16 off, len, bsize;

 	mutex_lock(&rt2x00dev->csr_mutex);

 	tb  = (char *)buffer;
 	off = offset;
 	len = buffer_length;
 	while (len && !status) {
 		bsize = min_t(u16, CSR_CACHE_SIZE, len);
 		status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
 							requesttype, off, tb,
 							bsize, timeout);

 		tb  += bsize;
 		len -= bsize;
 		off += bsize;
 	}

 	mutex_unlock(&rt2x00dev->csr_mutex);

 	return status;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_buff);

 int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev,
 			   const unsigned int offset,
 			   const struct rt2x00_field32 field,
 			   u32 *reg)
 {
 	unsigned int i;

 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
 		return -ENODEV;

 	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
 		rt2x00usb_register_read_lock(rt2x00dev, offset, reg);
 		if (!rt2x00_get_field32(*reg, field))
 			return 1;
 		udelay(REGISTER_BUSY_DELAY);
 	}

 	ERROR(rt2x00dev, "Indirect register access failed: "
 	      "offset=0x%.08x, value=0x%.08x\n", offset, *reg);
 	*reg = ~0;

 	return 0;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_regbusy_read);

 /*
  * TX data handlers.
  */
 static void rt2x00usb_work_txdone_entry(struct queue_entry *entry)
 {
 	/*
 	 * If the transfer to hardware succeeded, it does not mean the
 	 * frame was send out correctly. It only means the frame
 	 * was succesfully pushed to the hardware, we have no
 	 * way to determine the transmission status right now.
 	 * (Only indirectly by looking at the failed TX counters
 	 * in the register).
 	 */
 	if (test_bit(ENTRY_DATA_IO_FAILED, &entry->flags))
 		rt2x00lib_txdone_noinfo(entry, TXDONE_FAILURE);
 	else
 		rt2x00lib_txdone_noinfo(entry, TXDONE_UNKNOWN);
 }

 static void rt2x00usb_work_txdone(struct work_struct *work)
 {
 	struct rt2x00_dev *rt2x00dev =
 	    container_of(work, struct rt2x00_dev, txdone_work);
 	struct data_queue *queue;
 	struct queue_entry *entry;

 	tx_queue_for_each(rt2x00dev, queue) {
 		while (!rt2x00queue_empty(queue)) {
 			entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);

 			if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 				break;

 			rt2x00usb_work_txdone_entry(entry);
 		}
 	}
 }

 static void rt2x00usb_interrupt_txdone(struct urb *urb)
 {
 	struct queue_entry *entry = (struct queue_entry *)urb->context;
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;

 	if (!test_and_clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 		return;

 	/*
 	 * Report the frame as DMA done
 	 */
 	rt2x00lib_dmadone(entry);

 	/*
 	 * Check if the frame was correctly uploaded
 	 */
 	if (urb->status)
 		set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);

 	/*
 	 * Schedule the delayed work for reading the TX status
 	 * from the device.
 	 */
 	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
 	    test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		ieee80211_queue_work(rt2x00dev->hw, &rt2x00dev->txdone_work);
 }

 static void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
 {
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
 	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
 	u32 length;

 	if (!test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
 		return;

 	/*
 	 * USB devices cannot blindly pass the skb->len as the
 	 * length of the data to usb_fill_bulk_urb. Pass the skb
 	 * to the driver to determine what the length should be.
 	 */
 	length = rt2x00dev->ops->lib->get_tx_data_len(entry);

 	usb_fill_bulk_urb(entry_priv->urb, usb_dev,
 			  usb_sndbulkpipe(usb_dev, entry->queue->usb_endpoint),
 			  entry->skb->data, length,
 			  rt2x00usb_interrupt_txdone, entry);

 	if (usb_submit_urb(entry_priv->urb, GFP_ATOMIC)) {
 		set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
 		rt2x00lib_dmadone(entry);
 	}
 }

 void rt2x00usb_kick_tx_queue(struct data_queue *queue)
 {
 	rt2x00queue_for_each_entry(queue, Q_INDEX_DONE, Q_INDEX,
 				   rt2x00usb_kick_tx_entry);
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_kick_tx_queue);

 static void rt2x00usb_kill_tx_entry(struct queue_entry *entry)
 {
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
 	struct queue_entry_priv_usb_bcn *bcn_priv = entry->priv_data;

 	if (!test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 		return;

 	usb_kill_urb(entry_priv->urb);

 	/*
 	 * Kill guardian urb (if required by driver).
 	 */
 	if ((entry->queue->qid == QID_BEACON) &&
 	    (test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags)))
 		usb_kill_urb(bcn_priv->guardian_urb);
 }

 void rt2x00usb_kill_tx_queue(struct data_queue *queue)
 {
 	rt2x00queue_for_each_entry(queue, Q_INDEX_DONE, Q_INDEX,
 				   rt2x00usb_kill_tx_entry);
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_kill_tx_queue);

 static void rt2x00usb_watchdog_tx_dma(struct data_queue *queue)
 {
 	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
 	unsigned short threshold = queue->threshold;

 	WARNING(queue->rt2x00dev, "TX queue %d DMA timed out,"
 		" invoke forced forced reset", queue->qid);

 	/*
 	 * Temporarily disable the TX queue, this will force mac80211
 	 * to use the other queues until this queue has been restored.
 	 *
 	 * Set the queue threshold to the queue limit. This prevents the
 	 * queue from being enabled during the txdone handler.
 	 */
 	queue->threshold = queue->limit;
 	ieee80211_stop_queue(rt2x00dev->hw, queue->qid);

 	/*
 	 * Kill all entries in the queue, afterwards we need to
 	 * wait a bit for all URBs to be cancelled.
 	 */
 	rt2x00usb_kill_tx_queue(queue);

 	/*
 	 * In case that a driver has overriden the txdone_work
 	 * function, we invoke the TX done through there.
 	 */
 	rt2x00dev->txdone_work.func(&rt2x00dev->txdone_work);

 	/*
 	 * The queue has been reset, and mac80211 is allowed to use the
 	 * queue again.
 	 */
 	queue->threshold = threshold;
 	ieee80211_wake_queue(rt2x00dev->hw, queue->qid);
 }

 static void rt2x00usb_watchdog_tx_status(struct data_queue *queue)
 {
 	WARNING(queue->rt2x00dev, "TX queue %d status timed out,"
 		" invoke forced tx handler", queue->qid);

 	ieee80211_queue_work(queue->rt2x00dev->hw, &queue->rt2x00dev->txdone_work);
 }

 void rt2x00usb_watchdog(struct rt2x00_dev *rt2x00dev)
 {
 	struct data_queue *queue;

 	tx_queue_for_each(rt2x00dev, queue) {
 		if (!rt2x00queue_empty(queue)) {
 			if (rt2x00queue_dma_timeout(queue))
 				rt2x00usb_watchdog_tx_dma(queue);
 			if (rt2x00queue_status_timeout(queue))
 				rt2x00usb_watchdog_tx_status(queue);
 		}
 	}
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_watchdog);

 /*
  * RX data handlers.
  */
 static void rt2x00usb_work_rxdone(struct work_struct *work)
 {
 	struct rt2x00_dev *rt2x00dev =
 	    container_of(work, struct rt2x00_dev, rxdone_work);
 	struct queue_entry *entry;
 	struct skb_frame_desc *skbdesc;
 	u8 rxd[32];

 	while (!rt2x00queue_empty(rt2x00dev->rx)) {
 		entry = rt2x00queue_get_entry(rt2x00dev->rx, Q_INDEX_DONE);

 		if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 			break;

 		/*
 		 * Fill in desc fields of the skb descriptor
 		 */
 		skbdesc = get_skb_frame_desc(entry->skb);
 		skbdesc->desc = rxd;
 		skbdesc->desc_len = entry->queue->desc_size;

 		/*
 		 * Send the frame to rt2x00lib for further processing.
 		 */
 		rt2x00lib_rxdone(entry);
 	}
 }

 static void rt2x00usb_interrupt_rxdone(struct urb *urb)
 {
 	struct queue_entry *entry = (struct queue_entry *)urb->context;
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;

 	if (!test_and_clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 		return;

 	/*
 	 * Report the frame as DMA done
 	 */
 	rt2x00lib_dmadone(entry);

 	/*
 	 * Check if the received data is simply too small
 	 * to be actually valid, or if the urb is signaling
 	 * a problem.
 	 */
 	if (urb->actual_length < entry->queue->desc_size || urb->status)
 		set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);

 	/*
 	 * Schedule the delayed work for reading the RX status
 	 * from the device.
 	 */
 	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
 	    test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		ieee80211_queue_work(rt2x00dev->hw, &rt2x00dev->rxdone_work);
 }

 /*
  * Radio handlers
  */
 void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
 {
 	rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0, 0,
 				    REGISTER_TIMEOUT);

 	/*
 	 * The USB version of kill_tx_queue also works
 	 * on the RX queue.
 	 */
 	rt2x00dev->ops->lib->kill_tx_queue(rt2x00dev->rx);
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);

 /*
  * Device initialization handlers.
  */
 void rt2x00usb_clear_entry(struct queue_entry *entry)
 {
 	struct usb_device *usb_dev =
 	    to_usb_device_intf(entry->queue->rt2x00dev->dev);
 	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
 	int pipe;

 	entry->flags = 0;

 	if (entry->queue->qid == QID_RX) {
 		pipe = usb_rcvbulkpipe(usb_dev, entry->queue->usb_endpoint);
 		usb_fill_bulk_urb(entry_priv->urb, usb_dev, pipe,
 				entry->skb->data, entry->skb->len,
 				rt2x00usb_interrupt_rxdone, entry);

 		set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 		if (usb_submit_urb(entry_priv->urb, GFP_ATOMIC)) {
 			set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
 			rt2x00lib_dmadone(entry);
 		}
 	}
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_clear_entry);

 static void rt2x00usb_assign_endpoint(struct data_queue *queue,
 				      struct usb_endpoint_descriptor *ep_desc)
 {
 	struct usb_device *usb_dev = to_usb_device_intf(queue->rt2x00dev->dev);
 	int pipe;

 	queue->usb_endpoint = usb_endpoint_num(ep_desc);

 	if (queue->qid == QID_RX) {
 		pipe = usb_rcvbulkpipe(usb_dev, queue->usb_endpoint);
 		queue->usb_maxpacket = usb_maxpacket(usb_dev, pipe, 0);
 	} else {
 		pipe = usb_sndbulkpipe(usb_dev, queue->usb_endpoint);
 		queue->usb_maxpacket = usb_maxpacket(usb_dev, pipe, 1);
 	}

 	if (!queue->usb_maxpacket)
 		queue->usb_maxpacket = 1;
 }

 static int rt2x00usb_find_endpoints(struct rt2x00_dev *rt2x00dev)
 {
 	struct usb_interface *intf = to_usb_interface(rt2x00dev->dev);
 	struct usb_host_interface *intf_desc = intf->cur_altsetting;
 	struct usb_endpoint_descriptor *ep_desc;
 	struct data_queue *queue = rt2x00dev->tx;
 	struct usb_endpoint_descriptor *tx_ep_desc = NULL;
 	unsigned int i;

 	/*
 	 * Walk through all available endpoints to search for "bulk in"
 	 * and "bulk out" endpoints. When we find such endpoints collect
 	 * the information we need from the descriptor and assign it
 	 * to the queue.
 	 */
 	for (i = 0; i < intf_desc->desc.bNumEndpoints; i++) {
 		ep_desc = &intf_desc->endpoint[i].desc;

 		if (usb_endpoint_is_bulk_in(ep_desc)) {
 			rt2x00usb_assign_endpoint(rt2x00dev->rx, ep_desc);
 		} else if (usb_endpoint_is_bulk_out(ep_desc) &&
 			   (queue != queue_end(rt2x00dev))) {
 			rt2x00usb_assign_endpoint(queue, ep_desc);
 			queue = queue_next(queue);

 			tx_ep_desc = ep_desc;
 		}
 	}

 	/*
 	 * At least 1 endpoint for RX and 1 endpoint for TX must be available.
 	 */
 	if (!rt2x00dev->rx->usb_endpoint || !rt2x00dev->tx->usb_endpoint) {
 		ERROR(rt2x00dev, "Bulk-in/Bulk-out endpoints not found\n");
 		return -EPIPE;
 	}

 	/*
 	 * It might be possible not all queues have a dedicated endpoint.
 	 * Loop through all TX queues and copy the endpoint information
 	 * which we have gathered from already assigned endpoints.
 	 */
 	txall_queue_for_each(rt2x00dev, queue) {
 		if (!queue->usb_endpoint)
 			rt2x00usb_assign_endpoint(queue, tx_ep_desc);
 	}

 	return 0;
 }

 static int rt2x00usb_alloc_entries(struct data_queue *queue)
 {
 	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
 	struct queue_entry_priv_usb *entry_priv;
 	struct queue_entry_priv_usb_bcn *bcn_priv;
 	unsigned int i;

 	for (i = 0; i < queue->limit; i++) {
 		entry_priv = queue->entries[i].priv_data;
 		entry_priv->urb = usb_alloc_urb(0, GFP_KERNEL);
 		if (!entry_priv->urb)
 			return -ENOMEM;
 	}

 	/*
 	 * If this is not the beacon queue or
 	 * no guardian byte was required for the beacon,
 	 * then we are done.
 	 */
 	if (queue->qid != QID_BEACON ||
 	    !test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
 		return 0;

 	for (i = 0; i < queue->limit; i++) {
 		bcn_priv = queue->entries[i].priv_data;
 		bcn_priv->guardian_urb = usb_alloc_urb(0, GFP_KERNEL);
 		if (!bcn_priv->guardian_urb)
 			return -ENOMEM;
 	}

 	return 0;
 }

 static void rt2x00usb_free_entries(struct data_queue *queue)
 {
 	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
 	struct queue_entry_priv_usb *entry_priv;
 	struct queue_entry_priv_usb_bcn *bcn_priv;
 	unsigned int i;

 	if (!queue->entries)
 		return;

 	for (i = 0; i < queue->limit; i++) {
 		entry_priv = queue->entries[i].priv_data;
 		usb_kill_urb(entry_priv->urb);
 		usb_free_urb(entry_priv->urb);
 	}

 	/*
 	 * If this is not the beacon queue or
 	 * no guardian byte was required for the beacon,
 	 * then we are done.
 	 */
 	if (queue->qid != QID_BEACON ||
 	    !test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
 		return;

 	for (i = 0; i < queue->limit; i++) {
 		bcn_priv = queue->entries[i].priv_data;
 		usb_kill_urb(bcn_priv->guardian_urb);
 		usb_free_urb(bcn_priv->guardian_urb);
 	}
 }

 int rt2x00usb_initialize(struct rt2x00_dev *rt2x00dev)
 {
 	struct data_queue *queue;
 	int status;

 	/*
 	 * Find endpoints for each queue
 	 */
 	status = rt2x00usb_find_endpoints(rt2x00dev);
 	if (status)
 		goto exit;

 	/*
 	 * Allocate DMA
 	 */
 	queue_for_each(rt2x00dev, queue) {
 		status = rt2x00usb_alloc_entries(queue);
 		if (status)
 			goto exit;
 	}

 	return 0;

 exit:
 	rt2x00usb_uninitialize(rt2x00dev);

 	return status;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_initialize);

 void rt2x00usb_uninitialize(struct rt2x00_dev *rt2x00dev)
 {
 	struct data_queue *queue;

 	queue_for_each(rt2x00dev, queue)
 		rt2x00usb_free_entries(queue);
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_uninitialize);

 /*
  * USB driver handlers.
  */
 static void rt2x00usb_free_reg(struct rt2x00_dev *rt2x00dev)
 {
 	kfree(rt2x00dev->rf);
 	rt2x00dev->rf = NULL;

 	kfree(rt2x00dev->eeprom);
 	rt2x00dev->eeprom = NULL;

 	kfree(rt2x00dev->csr.cache);
 	rt2x00dev->csr.cache = NULL;
 }

 static int rt2x00usb_alloc_reg(struct rt2x00_dev *rt2x00dev)
 {
 	rt2x00dev->csr.cache = kzalloc(CSR_CACHE_SIZE, GFP_KERNEL);
 	if (!rt2x00dev->csr.cache)
 		goto exit;

 	rt2x00dev->eeprom = kzalloc(rt2x00dev->ops->eeprom_size, GFP_KERNEL);
 	if (!rt2x00dev->eeprom)
 		goto exit;

 	rt2x00dev->rf = kzalloc(rt2x00dev->ops->rf_size, GFP_KERNEL);
 	if (!rt2x00dev->rf)
 		goto exit;

 	return 0;

 exit:
 	ERROR_PROBE("Failed to allocate registers.\n");

 	rt2x00usb_free_reg(rt2x00dev);

 	return -ENOMEM;
 }

 int rt2x00usb_probe(struct usb_interface *usb_intf,
 		    const struct usb_device_id *id)
 {
 	struct usb_device *usb_dev = interface_to_usbdev(usb_intf);
 	struct rt2x00_ops *ops = (struct rt2x00_ops *)id->driver_info;
 	struct ieee80211_hw *hw;
 	struct rt2x00_dev *rt2x00dev;
 	int retval;

 	usb_dev = usb_get_dev(usb_dev);

 	hw = ieee80211_alloc_hw(sizeof(struct rt2x00_dev), ops->hw);
 	if (!hw) {
 		ERROR_PROBE("Failed to allocate hardware.\n");
 		retval = -ENOMEM;
 		goto exit_put_device;
 	}

 	usb_set_intfdata(usb_intf, hw);

 	rt2x00dev = hw->priv;
 	rt2x00dev->dev = &usb_intf->dev;
 	rt2x00dev->ops = ops;
 	rt2x00dev->hw = hw;

 	rt2x00_set_chip_intf(rt2x00dev, RT2X00_CHIP_INTF_USB);

 	INIT_WORK(&rt2x00dev->rxdone_work, rt2x00usb_work_rxdone);
 	INIT_WORK(&rt2x00dev->txdone_work, rt2x00usb_work_txdone);

 	retval = rt2x00usb_alloc_reg(rt2x00dev);
 	if (retval)
 		goto exit_free_device;

 	retval = rt2x00lib_probe_dev(rt2x00dev);
 	if (retval)
 		goto exit_free_reg;

 	return 0;

 exit_free_reg:
 	rt2x00usb_free_reg(rt2x00dev);

 exit_free_device:
 	ieee80211_free_hw(hw);

 exit_put_device:
 	usb_put_dev(usb_dev);

 	usb_set_intfdata(usb_intf, NULL);

 	return retval;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_probe);

 void rt2x00usb_disconnect(struct usb_interface *usb_intf)
 {
 	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
 	struct rt2x00_dev *rt2x00dev = hw->priv;

 	/*
 	 * Free all allocated data.
 	 */
 	rt2x00lib_remove_dev(rt2x00dev);
 	rt2x00usb_free_reg(rt2x00dev);
 	ieee80211_free_hw(hw);

 	/*
 	 * Free the USB device data.
 	 */
 	usb_set_intfdata(usb_intf, NULL);
 	usb_put_dev(interface_to_usbdev(usb_intf));
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_disconnect);

 #ifdef CONFIG_PM
 int rt2x00usb_suspend(struct usb_interface *usb_intf, pm_message_t state)
 {
 	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
 	struct rt2x00_dev *rt2x00dev = hw->priv;
 	int retval;

 	retval = rt2x00lib_suspend(rt2x00dev, state);
 	if (retval)
 		return retval;

 	/*
 	 * Decrease usbdev refcount.
 	 */
 	usb_put_dev(interface_to_usbdev(usb_intf));

 	return 0;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_suspend);

 int rt2x00usb_resume(struct usb_interface *usb_intf)
 {
 	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
 	struct rt2x00_dev *rt2x00dev = hw->priv;

 	usb_get_dev(interface_to_usbdev(usb_intf));

 	return rt2x00lib_resume(rt2x00dev);
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_resume);
 #endif /* CONFIG_PM */

 /*
  * rt2x00usb module information.
  */
 MODULE_AUTHOR(DRV_PROJECT);
 MODULE_VERSION(DRV_VERSION);
 MODULE_DESCRIPTION("rt2x00 usb library");
 MODULE_LICENSE("GPL");
	/*
	Copyright (C) 2010 Willow Garage <http://www.willowgarage.com>
	Copyright (C) 2004 - 2010 Ivo van Doorn <IvDoorn@gmail.com>
	<http://rt2x00.serialmonkey.com>

	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.

	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the
	Free Software Foundation, Inc.,
	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	*/

	/*
	Module: rt2x00usb
	Abstract: rt2x00 generic usb device routines.
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/usb.h>
	#include <linux/bug.h>

	#include "rt2x00.h"
	#include "rt2x00usb.h"

	/*
	* Interfacing with the HW.
	*/
	int rt2x00usb_vendor_request(struct rt2x00_dev *rt2x00dev,
	const u8 request, const u8 requesttype,
	const u16 offset, const u16 value,
	void *buffer, const u16 buffer_length,
	const int timeout)
	{
	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
	int status;
	unsigned int i;
	unsigned int pipe =
	(requesttype == USB_VENDOR_REQUEST_IN) ?
	usb_rcvctrlpipe(usb_dev, 0) : usb_sndctrlpipe(usb_dev, 0);

	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
	return -ENODEV;

	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
	status = usb_control_msg(usb_dev, pipe, request, requesttype,
	value, offset, buffer, buffer_length,
	timeout);
	if (status >= 0)
	return 0;

	/*
	* Check for errors
	* -ENODEV: Device has disappeared, no point continuing.
	* All other errors: Try again.
	*/
	else if (status == -ENODEV) {
	clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
	break;
	}
	}

	ERROR(rt2x00dev,
	"Vendor Request 0x%02x failed for offset 0x%04x with error %d.\n",
	request, offset, status);

	return status;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request);

	int rt2x00usb_vendor_req_buff_lock(struct rt2x00_dev *rt2x00dev,
	const u8 request, const u8 requesttype,
	const u16 offset, void *buffer,
	const u16 buffer_length, const int timeout)
	{
	int status;

	BUG_ON(!mutex_is_locked(&rt2x00dev->csr_mutex));

	/*
	* Check for Cache availability.
	*/
	if (unlikely(!rt2x00dev->csr.cache \|\| buffer_length > CSR_CACHE_SIZE)) {
	ERROR(rt2x00dev, "CSR cache not available.\n");
	return -ENOMEM;
	}

	if (requesttype == USB_VENDOR_REQUEST_OUT)
	memcpy(rt2x00dev->csr.cache, buffer, buffer_length);

	status = rt2x00usb_vendor_request(rt2x00dev, request, requesttype,
	offset, 0, rt2x00dev->csr.cache,
	buffer_length, timeout);

	if (!status && requesttype == USB_VENDOR_REQUEST_IN)
	memcpy(buffer, rt2x00dev->csr.cache, buffer_length);

	return status;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_vendor_req_buff_lock);

	int rt2x00usb_vendor_request_buff(struct rt2x00_dev *rt2x00dev,
	const u8 request, const u8 requesttype,
	const u16 offset, void *buffer,
	const u16 buffer_length, const int timeout)
	{
	int status = 0;
	unsigned char *tb;
	u16 off, len, bsize;

	mutex_lock(&rt2x00dev->csr_mutex);

	tb = (char *)buffer;
	off = offset;
	len = buffer_length;
	while (len && !status) {
	bsize = min_t(u16, CSR_CACHE_SIZE, len);
	status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
	requesttype, off, tb,
	bsize, timeout);

	tb += bsize;
	len -= bsize;
	off += bsize;
	}

	mutex_unlock(&rt2x00dev->csr_mutex);

	return status;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_buff);

	int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev,
	const unsigned int offset,
	const struct rt2x00_field32 field,
	u32 *reg)
	{
	unsigned int i;

	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
	return -ENODEV;

	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
	rt2x00usb_register_read_lock(rt2x00dev, offset, reg);
	if (!rt2x00_get_field32(*reg, field))
	return 1;
	udelay(REGISTER_BUSY_DELAY);
	}

	ERROR(rt2x00dev, "Indirect register access failed: "
	"offset=0x%.08x, value=0x%.08x\n", offset, *reg);
	*reg = ~0;

	return 0;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_regbusy_read);

	/*
	* TX data handlers.
	*/
	static void rt2x00usb_work_txdone_entry(struct queue_entry *entry)
	{
	/*
	* If the transfer to hardware succeeded, it does not mean the
	* frame was send out correctly. It only means the frame
	* was succesfully pushed to the hardware, we have no
	* way to determine the transmission status right now.
	* (Only indirectly by looking at the failed TX counters
	* in the register).
	*/
	if (test_bit(ENTRY_DATA_IO_FAILED, &entry->flags))
	rt2x00lib_txdone_noinfo(entry, TXDONE_FAILURE);
	else
	rt2x00lib_txdone_noinfo(entry, TXDONE_UNKNOWN);
	}

	static void rt2x00usb_work_txdone(struct work_struct *work)
	{
	struct rt2x00_dev *rt2x00dev =
	container_of(work, struct rt2x00_dev, txdone_work);
	struct data_queue *queue;
	struct queue_entry *entry;

	tx_queue_for_each(rt2x00dev, queue) {
	while (!rt2x00queue_empty(queue)) {
	entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);

	if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
	break;

	rt2x00usb_work_txdone_entry(entry);
	}
	}
	}

	static void rt2x00usb_interrupt_txdone(struct urb *urb)
	{
	struct queue_entry entry = (struct queue_entry )urb->context;
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;

	if (!test_and_clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
	return;

	/*
	* Report the frame as DMA done
	*/
	rt2x00lib_dmadone(entry);

	/*
	* Check if the frame was correctly uploaded
	*/
	if (urb->status)
	set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);

	/*
	* Schedule the delayed work for reading the TX status
	* from the device.
	*/
	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
	test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
	ieee80211_queue_work(rt2x00dev->hw, &rt2x00dev->txdone_work);
	}

	static void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
	{
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
	u32 length;

	if (!test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
	return;

	/*
	* USB devices cannot blindly pass the skb->len as the
	* length of the data to usb_fill_bulk_urb. Pass the skb
	* to the driver to determine what the length should be.
	*/
	length = rt2x00dev->ops->lib->get_tx_data_len(entry);

	usb_fill_bulk_urb(entry_priv->urb, usb_dev,
	usb_sndbulkpipe(usb_dev, entry->queue->usb_endpoint),
	entry->skb->data, length,
	rt2x00usb_interrupt_txdone, entry);

	if (usb_submit_urb(entry_priv->urb, GFP_ATOMIC)) {
	set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
	rt2x00lib_dmadone(entry);
	}
	}

	void rt2x00usb_kick_tx_queue(struct data_queue *queue)
	{
	rt2x00queue_for_each_entry(queue, Q_INDEX_DONE, Q_INDEX,
	rt2x00usb_kick_tx_entry);
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_kick_tx_queue);

	static void rt2x00usb_kill_tx_entry(struct queue_entry *entry)
	{
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
	struct queue_entry_priv_usb_bcn *bcn_priv = entry->priv_data;

	if (!test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
	return;

	usb_kill_urb(entry_priv->urb);

	/*
	* Kill guardian urb (if required by driver).
	*/
	if ((entry->queue->qid == QID_BEACON) &&
	(test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags)))
	usb_kill_urb(bcn_priv->guardian_urb);
	}

	void rt2x00usb_kill_tx_queue(struct data_queue *queue)
	{
	rt2x00queue_for_each_entry(queue, Q_INDEX_DONE, Q_INDEX,
	rt2x00usb_kill_tx_entry);
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_kill_tx_queue);

	static void rt2x00usb_watchdog_tx_dma(struct data_queue *queue)
	{
	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
	unsigned short threshold = queue->threshold;

	WARNING(queue->rt2x00dev, "TX queue %d DMA timed out,"
	" invoke forced forced reset", queue->qid);

	/*
	* Temporarily disable the TX queue, this will force mac80211
	* to use the other queues until this queue has been restored.
	*
	* Set the queue threshold to the queue limit. This prevents the
	* queue from being enabled during the txdone handler.
	*/
	queue->threshold = queue->limit;
	ieee80211_stop_queue(rt2x00dev->hw, queue->qid);

	/*
	* Kill all entries in the queue, afterwards we need to
	* wait a bit for all URBs to be cancelled.
	*/
	rt2x00usb_kill_tx_queue(queue);

	/*
	* In case that a driver has overriden the txdone_work
	* function, we invoke the TX done through there.
	*/
	rt2x00dev->txdone_work.func(&rt2x00dev->txdone_work);

	/*
	* The queue has been reset, and mac80211 is allowed to use the
	* queue again.
	*/
	queue->threshold = threshold;
	ieee80211_wake_queue(rt2x00dev->hw, queue->qid);
	}

	static void rt2x00usb_watchdog_tx_status(struct data_queue *queue)
	{
	WARNING(queue->rt2x00dev, "TX queue %d status timed out,"
	" invoke forced tx handler", queue->qid);

	ieee80211_queue_work(queue->rt2x00dev->hw, &queue->rt2x00dev->txdone_work);
	}

	void rt2x00usb_watchdog(struct rt2x00_dev *rt2x00dev)
	{
	struct data_queue *queue;

	tx_queue_for_each(rt2x00dev, queue) {
	if (!rt2x00queue_empty(queue)) {
	if (rt2x00queue_dma_timeout(queue))
	rt2x00usb_watchdog_tx_dma(queue);
	if (rt2x00queue_status_timeout(queue))
	rt2x00usb_watchdog_tx_status(queue);
	}
	}
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_watchdog);

	/*
	* RX data handlers.
	*/
	static void rt2x00usb_work_rxdone(struct work_struct *work)
	{
	struct rt2x00_dev *rt2x00dev =
	container_of(work, struct rt2x00_dev, rxdone_work);
	struct queue_entry *entry;
	struct skb_frame_desc *skbdesc;
	u8 rxd[32];

	while (!rt2x00queue_empty(rt2x00dev->rx)) {
	entry = rt2x00queue_get_entry(rt2x00dev->rx, Q_INDEX_DONE);

	if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
	break;

	/*
	* Fill in desc fields of the skb descriptor
	*/
	skbdesc = get_skb_frame_desc(entry->skb);
	skbdesc->desc = rxd;
	skbdesc->desc_len = entry->queue->desc_size;

	/*
	* Send the frame to rt2x00lib for further processing.
	*/
	rt2x00lib_rxdone(entry);
	}
	}

	static void rt2x00usb_interrupt_rxdone(struct urb *urb)
	{
	struct queue_entry entry = (struct queue_entry )urb->context;
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;

	if (!test_and_clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
	return;

	/*
	* Report the frame as DMA done
	*/
	rt2x00lib_dmadone(entry);

	/*
	* Check if the received data is simply too small
	* to be actually valid, or if the urb is signaling
	* a problem.
	*/
	if (urb->actual_length < entry->queue->desc_size \|\| urb->status)
	set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);

	/*
	* Schedule the delayed work for reading the RX status
	* from the device.
	*/
	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
	test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
	ieee80211_queue_work(rt2x00dev->hw, &rt2x00dev->rxdone_work);
	}

	/*
	* Radio handlers
	*/
	void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
	{
	rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0, 0,
	REGISTER_TIMEOUT);

	/*
	* The USB version of kill_tx_queue also works
	* on the RX queue.
	*/
	rt2x00dev->ops->lib->kill_tx_queue(rt2x00dev->rx);
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);

	/*
	* Device initialization handlers.
	*/
	void rt2x00usb_clear_entry(struct queue_entry *entry)
	{
	struct usb_device *usb_dev =
	to_usb_device_intf(entry->queue->rt2x00dev->dev);
	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
	int pipe;

	entry->flags = 0;

	if (entry->queue->qid == QID_RX) {
	pipe = usb_rcvbulkpipe(usb_dev, entry->queue->usb_endpoint);
	usb_fill_bulk_urb(entry_priv->urb, usb_dev, pipe,
	entry->skb->data, entry->skb->len,
	rt2x00usb_interrupt_rxdone, entry);

	set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
	if (usb_submit_urb(entry_priv->urb, GFP_ATOMIC)) {
	set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
	rt2x00lib_dmadone(entry);
	}
	}
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_clear_entry);

	static void rt2x00usb_assign_endpoint(struct data_queue *queue,
	struct usb_endpoint_descriptor *ep_desc)
	{
	struct usb_device *usb_dev = to_usb_device_intf(queue->rt2x00dev->dev);
	int pipe;

	queue->usb_endpoint = usb_endpoint_num(ep_desc);

	if (queue->qid == QID_RX) {
	pipe = usb_rcvbulkpipe(usb_dev, queue->usb_endpoint);
	queue->usb_maxpacket = usb_maxpacket(usb_dev, pipe, 0);
	} else {
	pipe = usb_sndbulkpipe(usb_dev, queue->usb_endpoint);
	queue->usb_maxpacket = usb_maxpacket(usb_dev, pipe, 1);
	}

	if (!queue->usb_maxpacket)
	queue->usb_maxpacket = 1;
	}

	static int rt2x00usb_find_endpoints(struct rt2x00_dev *rt2x00dev)
	{
	struct usb_interface *intf = to_usb_interface(rt2x00dev->dev);
	struct usb_host_interface *intf_desc = intf->cur_altsetting;
	struct usb_endpoint_descriptor *ep_desc;
	struct data_queue *queue = rt2x00dev->tx;
	struct usb_endpoint_descriptor *tx_ep_desc = NULL;
	unsigned int i;

	/*
	* Walk through all available endpoints to search for "bulk in"
	* and "bulk out" endpoints. When we find such endpoints collect
	* the information we need from the descriptor and assign it
	* to the queue.
	*/
	for (i = 0; i < intf_desc->desc.bNumEndpoints; i++) {
	ep_desc = &intf_desc->endpoint[i].desc;

	if (usb_endpoint_is_bulk_in(ep_desc)) {
	rt2x00usb_assign_endpoint(rt2x00dev->rx, ep_desc);
	} else if (usb_endpoint_is_bulk_out(ep_desc) &&
	(queue != queue_end(rt2x00dev))) {
	rt2x00usb_assign_endpoint(queue, ep_desc);
	queue = queue_next(queue);

	tx_ep_desc = ep_desc;
	}
	}

	/*
	* At least 1 endpoint for RX and 1 endpoint for TX must be available.
	*/
	if (!rt2x00dev->rx->usb_endpoint \|\| !rt2x00dev->tx->usb_endpoint) {
	ERROR(rt2x00dev, "Bulk-in/Bulk-out endpoints not found\n");
	return -EPIPE;
	}

	/*
	* It might be possible not all queues have a dedicated endpoint.
	* Loop through all TX queues and copy the endpoint information
	* which we have gathered from already assigned endpoints.
	*/
	txall_queue_for_each(rt2x00dev, queue) {
	if (!queue->usb_endpoint)
	rt2x00usb_assign_endpoint(queue, tx_ep_desc);
	}

	return 0;
	}

	static int rt2x00usb_alloc_entries(struct data_queue *queue)
	{
	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
	struct queue_entry_priv_usb *entry_priv;
	struct queue_entry_priv_usb_bcn *bcn_priv;
	unsigned int i;

	for (i = 0; i < queue->limit; i++) {
	entry_priv = queue->entries[i].priv_data;
	entry_priv->urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!entry_priv->urb)
	return -ENOMEM;
	}

	/*
	* If this is not the beacon queue or
	* no guardian byte was required for the beacon,
	* then we are done.
	*/
	if (queue->qid != QID_BEACON \|\|
	!test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
	return 0;

	for (i = 0; i < queue->limit; i++) {
	bcn_priv = queue->entries[i].priv_data;
	bcn_priv->guardian_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!bcn_priv->guardian_urb)
	return -ENOMEM;
	}

	return 0;
	}

	static void rt2x00usb_free_entries(struct data_queue *queue)
	{
	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
	struct queue_entry_priv_usb *entry_priv;
	struct queue_entry_priv_usb_bcn *bcn_priv;
	unsigned int i;

	if (!queue->entries)
	return;

	for (i = 0; i < queue->limit; i++) {
	entry_priv = queue->entries[i].priv_data;
	usb_kill_urb(entry_priv->urb);
	usb_free_urb(entry_priv->urb);
	}

	/*
	* If this is not the beacon queue or
	* no guardian byte was required for the beacon,
	* then we are done.
	*/
	if (queue->qid != QID_BEACON \|\|
	!test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
	return;

	for (i = 0; i < queue->limit; i++) {
	bcn_priv = queue->entries[i].priv_data;
	usb_kill_urb(bcn_priv->guardian_urb);
	usb_free_urb(bcn_priv->guardian_urb);
	}
	}

	int rt2x00usb_initialize(struct rt2x00_dev *rt2x00dev)
	{
	struct data_queue *queue;
	int status;

	/*
	* Find endpoints for each queue
	*/
	status = rt2x00usb_find_endpoints(rt2x00dev);
	if (status)
	goto exit;

	/*
	* Allocate DMA
	*/
	queue_for_each(rt2x00dev, queue) {
	status = rt2x00usb_alloc_entries(queue);
	if (status)
	goto exit;
	}

	return 0;

	exit:
	rt2x00usb_uninitialize(rt2x00dev);

	return status;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_initialize);

	void rt2x00usb_uninitialize(struct rt2x00_dev *rt2x00dev)
	{
	struct data_queue *queue;

	queue_for_each(rt2x00dev, queue)
	rt2x00usb_free_entries(queue);
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_uninitialize);

	/*
	* USB driver handlers.
	*/
	static void rt2x00usb_free_reg(struct rt2x00_dev *rt2x00dev)
	{
	kfree(rt2x00dev->rf);
	rt2x00dev->rf = NULL;

	kfree(rt2x00dev->eeprom);
	rt2x00dev->eeprom = NULL;

	kfree(rt2x00dev->csr.cache);
	rt2x00dev->csr.cache = NULL;
	}

	static int rt2x00usb_alloc_reg(struct rt2x00_dev *rt2x00dev)
	{
	rt2x00dev->csr.cache = kzalloc(CSR_CACHE_SIZE, GFP_KERNEL);
	if (!rt2x00dev->csr.cache)
	goto exit;

	rt2x00dev->eeprom = kzalloc(rt2x00dev->ops->eeprom_size, GFP_KERNEL);
	if (!rt2x00dev->eeprom)
	goto exit;

	rt2x00dev->rf = kzalloc(rt2x00dev->ops->rf_size, GFP_KERNEL);
	if (!rt2x00dev->rf)
	goto exit;

	return 0;

	exit:
	ERROR_PROBE("Failed to allocate registers.\n");

	rt2x00usb_free_reg(rt2x00dev);

	return -ENOMEM;
	}

	int rt2x00usb_probe(struct usb_interface *usb_intf,
	const struct usb_device_id *id)
	{
	struct usb_device *usb_dev = interface_to_usbdev(usb_intf);
	struct rt2x00_ops ops = (struct rt2x00_ops )id->driver_info;
	struct ieee80211_hw *hw;
	struct rt2x00_dev *rt2x00dev;
	int retval;

	usb_dev = usb_get_dev(usb_dev);

	hw = ieee80211_alloc_hw(sizeof(struct rt2x00_dev), ops->hw);
	if (!hw) {
	ERROR_PROBE("Failed to allocate hardware.\n");
	retval = -ENOMEM;
	goto exit_put_device;
	}

	usb_set_intfdata(usb_intf, hw);

	rt2x00dev = hw->priv;
	rt2x00dev->dev = &usb_intf->dev;
	rt2x00dev->ops = ops;
	rt2x00dev->hw = hw;

	rt2x00_set_chip_intf(rt2x00dev, RT2X00_CHIP_INTF_USB);

	INIT_WORK(&rt2x00dev->rxdone_work, rt2x00usb_work_rxdone);
	INIT_WORK(&rt2x00dev->txdone_work, rt2x00usb_work_txdone);

	retval = rt2x00usb_alloc_reg(rt2x00dev);
	if (retval)
	goto exit_free_device;

	retval = rt2x00lib_probe_dev(rt2x00dev);
	if (retval)
	goto exit_free_reg;

	return 0;

	exit_free_reg:
	rt2x00usb_free_reg(rt2x00dev);

	exit_free_device:
	ieee80211_free_hw(hw);

	exit_put_device:
	usb_put_dev(usb_dev);

	usb_set_intfdata(usb_intf, NULL);

	return retval;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_probe);

	void rt2x00usb_disconnect(struct usb_interface *usb_intf)
	{
	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
	struct rt2x00_dev *rt2x00dev = hw->priv;

	/*
	* Free all allocated data.
	*/
	rt2x00lib_remove_dev(rt2x00dev);
	rt2x00usb_free_reg(rt2x00dev);
	ieee80211_free_hw(hw);

	/*
	* Free the USB device data.
	*/
	usb_set_intfdata(usb_intf, NULL);
	usb_put_dev(interface_to_usbdev(usb_intf));
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_disconnect);

	#ifdef CONFIG_PM
	int rt2x00usb_suspend(struct usb_interface *usb_intf, pm_message_t state)
	{
	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
	struct rt2x00_dev *rt2x00dev = hw->priv;
	int retval;

	retval = rt2x00lib_suspend(rt2x00dev, state);
	if (retval)
	return retval;

	/*
	* Decrease usbdev refcount.
	*/
	usb_put_dev(interface_to_usbdev(usb_intf));

	return 0;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_suspend);

	int rt2x00usb_resume(struct usb_interface *usb_intf)
	{
	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
	struct rt2x00_dev *rt2x00dev = hw->priv;

	usb_get_dev(interface_to_usbdev(usb_intf));

	return rt2x00lib_resume(rt2x00dev);
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_resume);
	#endif /* CONFIG_PM */

	/*
	* rt2x00usb module information.
	*/
	MODULE_AUTHOR(DRV_PROJECT);
	MODULE_VERSION(DRV_VERSION);
	MODULE_DESCRIPTION("rt2x00 usb library");
	MODULE_LICENSE("GPL");