drivers/net/wireless/rt2x00/rt2x00usb.c - maze/linux - Git at Google

 /*
 	Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
 	<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/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);


 	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)
 			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->usb_cache_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;

 	mutex_lock(&rt2x00dev->usb_cache_mutex);

 	status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
 						requesttype, offset, buffer,
 						buffer_length, timeout);

 	mutex_unlock(&rt2x00dev->usb_cache_mutex);

 	return status;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_buff);

 int rt2x00usb_vendor_request_large_buff(struct rt2x00_dev *rt2x00dev,
 					const u8 request, const u8 requesttype,
 					const u16 offset, const void *buffer,
 					const u16 buffer_length,
 					const int timeout)
 {
 	int status = 0;
 	unsigned char *tb;
 	u16 off, len, bsize;

 	mutex_lock(&rt2x00dev->usb_cache_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->usb_cache_mutex);

 	return status;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_large_buff);

 /*
  * TX data handlers.
  */
 static void rt2x00usb_interrupt_txdone(struct urb *urb)
 {
 	struct queue_entry *entry = (struct queue_entry *)urb->context;
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 	struct txdone_entry_desc txdesc;

 	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
 	    !test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 		return;

 	/*
 	 * Obtain the status about this packet.
 	 * Note that when the status is 0 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).
 	 */
 	txdesc.flags = 0;
 	if (!urb->status)
 		__set_bit(TXDONE_UNKNOWN, &txdesc.flags);
 	else
 		__set_bit(TXDONE_FAILURE, &txdesc.flags);
 	txdesc.retry = 0;

 	rt2x00lib_txdone(entry, &txdesc);
 }

 int rt2x00usb_write_tx_data(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;
 	struct skb_frame_desc *skbdesc;
 	u32 length;

 	/*
 	 * Add the descriptor in front of the skb.
 	 */
 	skb_push(entry->skb, entry->queue->desc_size);
 	memset(entry->skb->data, 0, entry->queue->desc_size);

 	/*
 	 * Fill in skb descriptor
 	 */
 	skbdesc = get_skb_frame_desc(entry->skb);
 	skbdesc->desc = entry->skb->data;
 	skbdesc->desc_len = entry->queue->desc_size;

 	/*
 	 * 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(rt2x00dev, entry->skb);

 	usb_fill_bulk_urb(entry_priv->urb, usb_dev,
 			  usb_sndbulkpipe(usb_dev, 1),
 			  entry->skb->data, length,
 			  rt2x00usb_interrupt_txdone, entry);

 	/*
 	 * Make sure the skb->data pointer points to the frame, not the
 	 * descriptor.
 	 */
 	skb_pull(entry->skb, entry->queue->desc_size);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_write_tx_data);

 static inline void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
 {
 	struct queue_entry_priv_usb *entry_priv = entry->priv_data;

 	if (test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
 		usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
 }

 void rt2x00usb_kick_tx_queue(struct rt2x00_dev *rt2x00dev,
 			     const enum data_queue_qid qid)
 {
 	struct data_queue *queue = rt2x00queue_get_queue(rt2x00dev, qid);
 	unsigned long irqflags;
 	unsigned int index;
 	unsigned int index_done;
 	unsigned int i;

 	/*
 	 * Only protect the range we are going to loop over,
 	 * if during our loop a extra entry is set to pending
 	 * it should not be kicked during this run, since it
 	 * is part of another TX operation.
 	 */
 	spin_lock_irqsave(&queue->lock, irqflags);
 	index = queue->index[Q_INDEX];
 	index_done = queue->index[Q_INDEX_DONE];
 	spin_unlock_irqrestore(&queue->lock, irqflags);

 	/*
 	 * Start from the TX done pointer, this guarentees that we will
 	 * send out all frames in the correct order.
 	 */
 	if (index_done < index) {
 		for (i = index_done; i < index; i++)
 			rt2x00usb_kick_tx_entry(&queue->entries[i]);
 	} else {
 		for (i = index_done; i < queue->limit; i++)
 			rt2x00usb_kick_tx_entry(&queue->entries[i]);

 		for (i = 0; i < index; i++)
 			rt2x00usb_kick_tx_entry(&queue->entries[i]);
 	}
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_kick_tx_queue);

 /*
  * RX data handlers.
  */
 static void rt2x00usb_interrupt_rxdone(struct urb *urb)
 {
 	struct queue_entry *entry = (struct queue_entry *)urb->context;
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 	u8 rxd[32];

 	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
 	    !test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 		return;

 	/*
 	 * 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_OWNER_DEVICE_DATA, &entry->flags);
 		usb_submit_urb(urb, GFP_ATOMIC);
 		return;
 	}

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

 	/*
 	 * Send the frame to rt2x00lib for further processing.
 	 */
 	rt2x00lib_rxdone(rt2x00dev, entry);
 }

 /*
  * Radio handlers
  */
 void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
 {
 	struct queue_entry_priv_usb *entry_priv;
 	struct queue_entry_priv_usb_bcn *bcn_priv;
 	struct data_queue *queue;
 	unsigned int i;

 	rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0, 0,
 				    REGISTER_TIMEOUT);

 	/*
 	 * Cancel all queues.
 	 */
 	queue_for_each(rt2x00dev, queue) {
 		for (i = 0; i < queue->limit; i++) {
 			entry_priv = queue->entries[i].priv_data;
 			usb_kill_urb(entry_priv->urb);
 		}
 	}

 	/*
 	 * Kill guardian urb (if required by driver).
 	 */
 	if (!test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
 		return;

 	for (i = 0; i < rt2x00dev->bcn->limit; i++) {
 		bcn_priv = rt2x00dev->bcn->entries[i].priv_data;
 		if (bcn_priv->guardian_urb)
 			usb_kill_urb(bcn_priv->guardian_urb);
 	}
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);

 /*
  * Device initialization handlers.
  */
 void rt2x00usb_init_rxentry(struct rt2x00_dev *rt2x00dev,
 			    struct queue_entry *entry)
 {
 	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
 	struct queue_entry_priv_usb *entry_priv = entry->priv_data;

 	usb_fill_bulk_urb(entry_priv->urb, usb_dev,
 			  usb_rcvbulkpipe(usb_dev, 1),
 			  entry->skb->data, entry->skb->len,
 			  rt2x00usb_interrupt_rxdone, entry);

 	set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 	usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_init_rxentry);

 void rt2x00usb_init_txentry(struct rt2x00_dev *rt2x00dev,
 			    struct queue_entry *entry)
 {
 	entry->flags = 0;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_init_txentry);

 static int rt2x00usb_alloc_urb(struct rt2x00_dev *rt2x00dev,
 			       struct data_queue *queue)
 {
 	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 (rt2x00dev->bcn != queue ||
 	    !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_urb(struct rt2x00_dev *rt2x00dev,
 			       struct data_queue *queue)
 {
 	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 (rt2x00dev->bcn != queue ||
 	    !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;

 	/*
 	 * Allocate DMA
 	 */
 	queue_for_each(rt2x00dev, queue) {
 		status = rt2x00usb_alloc_urb(rt2x00dev, 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_urb(rt2x00dev, 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;
 	mutex_init(&rt2x00dev->usb_cache_mutex);

 	rt2x00dev->usb_maxpacket =
 	    usb_maxpacket(usb_dev, usb_sndbulkpipe(usb_dev, 1), 1);
 	if (!rt2x00dev->usb_maxpacket)
 		rt2x00dev->usb_maxpacket = 1;

 	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;

 	rt2x00usb_free_reg(rt2x00dev);

 	/*
 	 * 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;
 	int retval;

 	usb_get_dev(interface_to_usbdev(usb_intf));

 	retval = rt2x00usb_alloc_reg(rt2x00dev);
 	if (retval)
 		return retval;

 	retval = rt2x00lib_resume(rt2x00dev);
 	if (retval)
 		goto exit_free_reg;

 	return 0;

 exit_free_reg:
 	rt2x00usb_free_reg(rt2x00dev);

 	return retval;
 }
 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) 2004 - 2008 rt2x00 SourceForge Project
	<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/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);


	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)
	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->usb_cache_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;

	mutex_lock(&rt2x00dev->usb_cache_mutex);

	status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
	requesttype, offset, buffer,
	buffer_length, timeout);

	mutex_unlock(&rt2x00dev->usb_cache_mutex);

	return status;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_buff);

	int rt2x00usb_vendor_request_large_buff(struct rt2x00_dev *rt2x00dev,
	const u8 request, const u8 requesttype,
	const u16 offset, const void *buffer,
	const u16 buffer_length,
	const int timeout)
	{
	int status = 0;
	unsigned char *tb;
	u16 off, len, bsize;

	mutex_lock(&rt2x00dev->usb_cache_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->usb_cache_mutex);

	return status;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_large_buff);

	/*
	* TX data handlers.
	*/
	static void rt2x00usb_interrupt_txdone(struct urb *urb)
	{
	struct queue_entry entry = (struct queue_entry )urb->context;
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct txdone_entry_desc txdesc;

	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) \|\|
	!test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
	return;

	/*
	* Obtain the status about this packet.
	* Note that when the status is 0 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).
	*/
	txdesc.flags = 0;
	if (!urb->status)
	__set_bit(TXDONE_UNKNOWN, &txdesc.flags);
	else
	__set_bit(TXDONE_FAILURE, &txdesc.flags);
	txdesc.retry = 0;

	rt2x00lib_txdone(entry, &txdesc);
	}

	int rt2x00usb_write_tx_data(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;
	struct skb_frame_desc *skbdesc;
	u32 length;

	/*
	* Add the descriptor in front of the skb.
	*/
	skb_push(entry->skb, entry->queue->desc_size);
	memset(entry->skb->data, 0, entry->queue->desc_size);

	/*
	* Fill in skb descriptor
	*/
	skbdesc = get_skb_frame_desc(entry->skb);
	skbdesc->desc = entry->skb->data;
	skbdesc->desc_len = entry->queue->desc_size;

	/*
	* 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(rt2x00dev, entry->skb);

	usb_fill_bulk_urb(entry_priv->urb, usb_dev,
	usb_sndbulkpipe(usb_dev, 1),
	entry->skb->data, length,
	rt2x00usb_interrupt_txdone, entry);

	/*
	* Make sure the skb->data pointer points to the frame, not the
	* descriptor.
	*/
	skb_pull(entry->skb, entry->queue->desc_size);

	return 0;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_write_tx_data);

	static inline void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
	{
	struct queue_entry_priv_usb *entry_priv = entry->priv_data;

	if (test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
	usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
	}

	void rt2x00usb_kick_tx_queue(struct rt2x00_dev *rt2x00dev,
	const enum data_queue_qid qid)
	{
	struct data_queue *queue = rt2x00queue_get_queue(rt2x00dev, qid);
	unsigned long irqflags;
	unsigned int index;
	unsigned int index_done;
	unsigned int i;

	/*
	* Only protect the range we are going to loop over,
	* if during our loop a extra entry is set to pending
	* it should not be kicked during this run, since it
	* is part of another TX operation.
	*/
	spin_lock_irqsave(&queue->lock, irqflags);
	index = queue->index[Q_INDEX];
	index_done = queue->index[Q_INDEX_DONE];
	spin_unlock_irqrestore(&queue->lock, irqflags);

	/*
	* Start from the TX done pointer, this guarentees that we will
	* send out all frames in the correct order.
	*/
	if (index_done < index) {
	for (i = index_done; i < index; i++)
	rt2x00usb_kick_tx_entry(&queue->entries[i]);
	} else {
	for (i = index_done; i < queue->limit; i++)
	rt2x00usb_kick_tx_entry(&queue->entries[i]);

	for (i = 0; i < index; i++)
	rt2x00usb_kick_tx_entry(&queue->entries[i]);
	}
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_kick_tx_queue);

	/*
	* RX data handlers.
	*/
	static void rt2x00usb_interrupt_rxdone(struct urb *urb)
	{
	struct queue_entry entry = (struct queue_entry )urb->context;
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
	u8 rxd[32];

	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) \|\|
	!test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
	return;

	/*
	* 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_OWNER_DEVICE_DATA, &entry->flags);
	usb_submit_urb(urb, GFP_ATOMIC);
	return;
	}

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

	/*
	* Send the frame to rt2x00lib for further processing.
	*/
	rt2x00lib_rxdone(rt2x00dev, entry);
	}

	/*
	* Radio handlers
	*/
	void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
	{
	struct queue_entry_priv_usb *entry_priv;
	struct queue_entry_priv_usb_bcn *bcn_priv;
	struct data_queue *queue;
	unsigned int i;

	rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0, 0,
	REGISTER_TIMEOUT);

	/*
	* Cancel all queues.
	*/
	queue_for_each(rt2x00dev, queue) {
	for (i = 0; i < queue->limit; i++) {
	entry_priv = queue->entries[i].priv_data;
	usb_kill_urb(entry_priv->urb);
	}
	}

	/*
	* Kill guardian urb (if required by driver).
	*/
	if (!test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
	return;

	for (i = 0; i < rt2x00dev->bcn->limit; i++) {
	bcn_priv = rt2x00dev->bcn->entries[i].priv_data;
	if (bcn_priv->guardian_urb)
	usb_kill_urb(bcn_priv->guardian_urb);
	}
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);

	/*
	* Device initialization handlers.
	*/
	void rt2x00usb_init_rxentry(struct rt2x00_dev *rt2x00dev,
	struct queue_entry *entry)
	{
	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
	struct queue_entry_priv_usb *entry_priv = entry->priv_data;

	usb_fill_bulk_urb(entry_priv->urb, usb_dev,
	usb_rcvbulkpipe(usb_dev, 1),
	entry->skb->data, entry->skb->len,
	rt2x00usb_interrupt_rxdone, entry);

	set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
	usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_init_rxentry);

	void rt2x00usb_init_txentry(struct rt2x00_dev *rt2x00dev,
	struct queue_entry *entry)
	{
	entry->flags = 0;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_init_txentry);

	static int rt2x00usb_alloc_urb(struct rt2x00_dev *rt2x00dev,
	struct data_queue *queue)
	{
	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 (rt2x00dev->bcn != queue \|\|
	!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_urb(struct rt2x00_dev *rt2x00dev,
	struct data_queue *queue)
	{
	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 (rt2x00dev->bcn != queue \|\|
	!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;

	/*
	* Allocate DMA
	*/
	queue_for_each(rt2x00dev, queue) {
	status = rt2x00usb_alloc_urb(rt2x00dev, 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_urb(rt2x00dev, 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;
	mutex_init(&rt2x00dev->usb_cache_mutex);

	rt2x00dev->usb_maxpacket =
	usb_maxpacket(usb_dev, usb_sndbulkpipe(usb_dev, 1), 1);
	if (!rt2x00dev->usb_maxpacket)
	rt2x00dev->usb_maxpacket = 1;

	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;

	rt2x00usb_free_reg(rt2x00dev);

	/*
	* 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;
	int retval;

	usb_get_dev(interface_to_usbdev(usb_intf));

	retval = rt2x00usb_alloc_reg(rt2x00dev);
	if (retval)
	return retval;

	retval = rt2x00lib_resume(rt2x00dev);
	if (retval)
	goto exit_free_reg;

	return 0;

	exit_free_reg:
	rt2x00usb_free_reg(rt2x00dev);

	return retval;
	}
	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");