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

 /*
 	Copyright (C) 2004 - 2007 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 =
 	    interface_to_usbdev(rt2x00dev_usb(rt2x00dev));
 	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);

 /*
  * TX data handlers.
  */
 static void rt2x00usb_interrupt_txdone(struct urb *urb)
 {
 	struct data_entry *entry = (struct data_entry *)urb->context;
 	struct data_ring *ring = entry->ring;
 	struct rt2x00_dev *rt2x00dev = ring->rt2x00dev;
 	__le32 *txd = (__le32 *)entry->skb->data;
 	u32 word;
 	int tx_status;

 	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) ||
 	    !__test_and_clear_bit(ENTRY_OWNER_NIC, &entry->flags))
 		return;

 	rt2x00_desc_read(txd, 0, &word);

 	/*
 	 * Remove the descriptor data from the buffer.
 	 */
 	skb_pull(entry->skb, ring->desc_size);

 	/*
 	 * Obtain the status about this packet.
 	 */
 	tx_status = !urb->status ? TX_SUCCESS : TX_FAIL_RETRY;

 	rt2x00lib_txdone(entry, tx_status, 0);

 	/*
 	 * Make this entry available for reuse.
 	 */
 	entry->flags = 0;
 	rt2x00_ring_index_done_inc(entry->ring);

 	/*
 	 * If the data ring was full before the txdone handler
 	 * we must make sure the packet queue in the mac80211 stack
 	 * is reenabled when the txdone handler has finished.
 	 */
 	if (!rt2x00_ring_full(ring))
 		ieee80211_wake_queue(rt2x00dev->hw,
 				     entry->tx_status.control.queue);
 }

 int rt2x00usb_write_tx_data(struct rt2x00_dev *rt2x00dev,
 			    struct data_ring *ring, struct sk_buff *skb,
 			    struct ieee80211_tx_control *control)
 {
 	struct usb_device *usb_dev =
 	    interface_to_usbdev(rt2x00dev_usb(rt2x00dev));
 	struct data_entry *entry = rt2x00_get_data_entry(ring);
 	struct skb_desc *desc;
 	u32 length;

 	if (rt2x00_ring_full(ring))
 		return -EINVAL;

 	if (test_bit(ENTRY_OWNER_NIC, &entry->flags)) {
 		ERROR(rt2x00dev,
 		      "Arrived at non-free entry in the non-full queue %d.\n"
 		      "Please file bug report to %s.\n",
 		      control->queue, DRV_PROJECT);
 		return -EINVAL;
 	}

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

 	/*
 	 * Fill in skb descriptor
 	 */
 	desc = get_skb_desc(skb);
 	desc->desc_len = ring->desc_size;
 	desc->data_len = skb->len - ring->desc_size;
 	desc->desc = skb->data;
 	desc->data = skb->data + ring->desc_size;
 	desc->ring = ring;
 	desc->entry = entry;

 	rt2x00lib_write_tx_desc(rt2x00dev, skb, control);

 	/*
 	 * 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, skb);

 	/*
 	 * Initialize URB and send the frame to the device.
 	 */
 	__set_bit(ENTRY_OWNER_NIC, &entry->flags);
 	usb_fill_bulk_urb(entry->priv, usb_dev, usb_sndbulkpipe(usb_dev, 1),
 			  skb->data, length, rt2x00usb_interrupt_txdone, entry);
 	usb_submit_urb(entry->priv, GFP_ATOMIC);

 	rt2x00_ring_index_inc(ring);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_write_tx_data);

 /*
  * RX data handlers.
  */
 static void rt2x00usb_interrupt_rxdone(struct urb *urb)
 {
 	struct data_entry *entry = (struct data_entry *)urb->context;
 	struct data_ring *ring = entry->ring;
 	struct rt2x00_dev *rt2x00dev = ring->rt2x00dev;
 	struct sk_buff *skb;
 	struct ieee80211_hdr *hdr;
 	struct skb_desc *skbdesc;
 	struct rxdata_entry_desc desc;
 	int header_size;
 	int frame_size;

 	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) ||
 	    !test_and_clear_bit(ENTRY_OWNER_NIC, &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->ring->desc_size || urb->status)
 		goto skip_entry;

 	/*
 	 * Fill in skb descriptor
 	 */
 	skbdesc = get_skb_desc(entry->skb);
 	skbdesc->ring = ring;
 	skbdesc->entry = entry;

 	memset(&desc, 0, sizeof(desc));
 	rt2x00dev->ops->lib->fill_rxdone(entry, &desc);

 	/*
 	 * Allocate a new sk buffer to replace the current one.
 	 * If allocation fails, we should drop the current frame
 	 * so we can recycle the existing sk buffer for the new frame.
 	 * As alignment we use 2 and not NET_IP_ALIGN because we need
 	 * to be sure we have 2 bytes room in the head. (NET_IP_ALIGN
 	 * can be 0 on some hardware). We use these 2 bytes for frame
 	 * alignment later, we assume that the chance that
 	 * header_size % 4 == 2 is bigger then header_size % 2 == 0
 	 * and thus optimize alignment by reserving the 2 bytes in
 	 * advance.
 	 */
 	frame_size = entry->ring->data_size + entry->ring->desc_size;
 	skb = dev_alloc_skb(frame_size + 2);
 	if (!skb)
 		goto skip_entry;

 	skb_reserve(skb, 2);
 	skb_put(skb, frame_size);

 	/*
 	 * The data behind the ieee80211 header must be
 	 * aligned on a 4 byte boundary.
 	 */
 	hdr = (struct ieee80211_hdr *)entry->skb->data;
 	header_size =
 	    ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control));

 	if (header_size % 4 == 0) {
 		skb_push(entry->skb, 2);
 		memmove(entry->skb->data, entry->skb->data + 2, skb->len - 2);
 	}

 	/*
 	 * Trim the entire buffer down to only contain the valid frame data
 	 * excluding the device descriptor. The position of the descriptor
 	 * varies. This means that we should check where the descriptor is
 	 * and decide if we need to pull the data pointer to exclude the
 	 * device descriptor.
 	 */
 	if (skbdesc->data > skbdesc->desc)
 		skb_pull(entry->skb, skbdesc->desc_len);
 	skb_trim(entry->skb, desc.size);

 	/*
 	 * Send the frame to rt2x00lib for further processing.
 	 */
 	rt2x00lib_rxdone(entry, entry->skb, &desc);

 	/*
 	 * Replace current entry's skb with the newly allocated one,
 	 * and reinitialize the urb.
 	 */
 	entry->skb = skb;
 	urb->transfer_buffer = entry->skb->data;
 	urb->transfer_buffer_length = entry->skb->len;

 skip_entry:
 	if (test_bit(DEVICE_ENABLED_RADIO, &ring->rt2x00dev->flags)) {
 		__set_bit(ENTRY_OWNER_NIC, &entry->flags);
 		usb_submit_urb(urb, GFP_ATOMIC);
 	}

 	rt2x00_ring_index_inc(ring);
 }

 /*
  * Radio handlers
  */
 void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
 {
 	struct data_ring *ring;
 	unsigned int i;

 	rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0x0000, 0x0000,
 				    REGISTER_TIMEOUT);

 	/*
 	 * Cancel all rings.
 	 */
 	ring_for_each(rt2x00dev, ring) {
 		for (i = 0; i < ring->stats.limit; i++)
 			usb_kill_urb(ring->entry[i].priv);
 	}
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);

 /*
  * Device initialization handlers.
  */
 void rt2x00usb_init_rxentry(struct rt2x00_dev *rt2x00dev,
 			    struct data_entry *entry)
 {
 	struct usb_device *usb_dev =
 	     interface_to_usbdev(rt2x00dev_usb(rt2x00dev));

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

 	__set_bit(ENTRY_OWNER_NIC, &entry->flags);
 	usb_submit_urb(entry->priv, GFP_ATOMIC);
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_init_rxentry);

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

 static int rt2x00usb_alloc_urb(struct rt2x00_dev *rt2x00dev,
 			       struct data_ring *ring)
 {
 	unsigned int i;

 	/*
 	 * Allocate the URB's
 	 */
 	for (i = 0; i < ring->stats.limit; i++) {
 		ring->entry[i].priv = usb_alloc_urb(0, GFP_KERNEL);
 		if (!ring->entry[i].priv)
 			return -ENOMEM;
 	}

 	return 0;
 }

 static void rt2x00usb_free_urb(struct rt2x00_dev *rt2x00dev,
 			       struct data_ring *ring)
 {
 	unsigned int i;

 	if (!ring->entry)
 		return;

 	for (i = 0; i < ring->stats.limit; i++) {
 		usb_kill_urb(ring->entry[i].priv);
 		usb_free_urb(ring->entry[i].priv);
 		if (ring->entry[i].skb)
 			kfree_skb(ring->entry[i].skb);
 	}
 }

 int rt2x00usb_initialize(struct rt2x00_dev *rt2x00dev)
 {
 	struct data_ring *ring;
 	struct sk_buff *skb;
 	unsigned int entry_size;
 	unsigned int i;
 	int uninitialized_var(status);

 	/*
 	 * Allocate DMA
 	 */
 	ring_for_each(rt2x00dev, ring) {
 		status = rt2x00usb_alloc_urb(rt2x00dev, ring);
 		if (status)
 			goto exit;
 	}

 	/*
 	 * For the RX ring, skb's should be allocated.
 	 */
 	entry_size = rt2x00dev->rx->data_size + rt2x00dev->rx->desc_size;
 	for (i = 0; i < rt2x00dev->rx->stats.limit; i++) {
 		skb = dev_alloc_skb(NET_IP_ALIGN + entry_size);
 		if (!skb)
 			goto exit;

 		skb_reserve(skb, NET_IP_ALIGN);
 		skb_put(skb, entry_size);

 		rt2x00dev->rx->entry[i].skb = skb;
 	}

 	return 0;

 exit:
 	rt2x00usb_uninitialize(rt2x00dev);

 	return status;
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_initialize);

 void rt2x00usb_uninitialize(struct rt2x00_dev *rt2x00dev)
 {
 	struct data_ring *ring;

 	ring_for_each(rt2x00dev, ring)
 		rt2x00usb_free_urb(rt2x00dev, ring);
 }
 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;
 	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 */

 /*
  * rt2x00pci module information.
  */
 MODULE_AUTHOR(DRV_PROJECT);
 MODULE_VERSION(DRV_VERSION);
 MODULE_DESCRIPTION("rt2x00 library");
 MODULE_LICENSE("GPL");
	/*
	Copyright (C) 2004 - 2007 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 =
	interface_to_usbdev(rt2x00dev_usb(rt2x00dev));
	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);

	/*
	* TX data handlers.
	*/
	static void rt2x00usb_interrupt_txdone(struct urb *urb)
	{
	struct data_entry entry = (struct data_entry )urb->context;
	struct data_ring *ring = entry->ring;
	struct rt2x00_dev *rt2x00dev = ring->rt2x00dev;
	__le32 txd = (__le32 )entry->skb->data;
	u32 word;
	int tx_status;

	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) \|\|
	!__test_and_clear_bit(ENTRY_OWNER_NIC, &entry->flags))
	return;

	rt2x00_desc_read(txd, 0, &word);

	/*
	* Remove the descriptor data from the buffer.
	*/
	skb_pull(entry->skb, ring->desc_size);

	/*
	* Obtain the status about this packet.
	*/
	tx_status = !urb->status ? TX_SUCCESS : TX_FAIL_RETRY;

	rt2x00lib_txdone(entry, tx_status, 0);

	/*
	* Make this entry available for reuse.
	*/
	entry->flags = 0;
	rt2x00_ring_index_done_inc(entry->ring);

	/*
	* If the data ring was full before the txdone handler
	* we must make sure the packet queue in the mac80211 stack
	* is reenabled when the txdone handler has finished.
	*/
	if (!rt2x00_ring_full(ring))
	ieee80211_wake_queue(rt2x00dev->hw,
	entry->tx_status.control.queue);
	}

	int rt2x00usb_write_tx_data(struct rt2x00_dev *rt2x00dev,
	struct data_ring ring, struct sk_buff skb,
	struct ieee80211_tx_control *control)
	{
	struct usb_device *usb_dev =
	interface_to_usbdev(rt2x00dev_usb(rt2x00dev));
	struct data_entry *entry = rt2x00_get_data_entry(ring);
	struct skb_desc *desc;
	u32 length;

	if (rt2x00_ring_full(ring))
	return -EINVAL;

	if (test_bit(ENTRY_OWNER_NIC, &entry->flags)) {
	ERROR(rt2x00dev,
	"Arrived at non-free entry in the non-full queue %d.\n"
	"Please file bug report to %s.\n",
	control->queue, DRV_PROJECT);
	return -EINVAL;
	}

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

	/*
	* Fill in skb descriptor
	*/
	desc = get_skb_desc(skb);
	desc->desc_len = ring->desc_size;
	desc->data_len = skb->len - ring->desc_size;
	desc->desc = skb->data;
	desc->data = skb->data + ring->desc_size;
	desc->ring = ring;
	desc->entry = entry;

	rt2x00lib_write_tx_desc(rt2x00dev, skb, control);

	/*
	* 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, skb);

	/*
	* Initialize URB and send the frame to the device.
	*/
	__set_bit(ENTRY_OWNER_NIC, &entry->flags);
	usb_fill_bulk_urb(entry->priv, usb_dev, usb_sndbulkpipe(usb_dev, 1),
	skb->data, length, rt2x00usb_interrupt_txdone, entry);
	usb_submit_urb(entry->priv, GFP_ATOMIC);

	rt2x00_ring_index_inc(ring);

	return 0;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_write_tx_data);

	/*
	* RX data handlers.
	*/
	static void rt2x00usb_interrupt_rxdone(struct urb *urb)
	{
	struct data_entry entry = (struct data_entry )urb->context;
	struct data_ring *ring = entry->ring;
	struct rt2x00_dev *rt2x00dev = ring->rt2x00dev;
	struct sk_buff *skb;
	struct ieee80211_hdr *hdr;
	struct skb_desc *skbdesc;
	struct rxdata_entry_desc desc;
	int header_size;
	int frame_size;

	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) \|\|
	!test_and_clear_bit(ENTRY_OWNER_NIC, &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->ring->desc_size \|\| urb->status)
	goto skip_entry;

	/*
	* Fill in skb descriptor
	*/
	skbdesc = get_skb_desc(entry->skb);
	skbdesc->ring = ring;
	skbdesc->entry = entry;

	memset(&desc, 0, sizeof(desc));
	rt2x00dev->ops->lib->fill_rxdone(entry, &desc);

	/*
	* Allocate a new sk buffer to replace the current one.
	* If allocation fails, we should drop the current frame
	* so we can recycle the existing sk buffer for the new frame.
	* As alignment we use 2 and not NET_IP_ALIGN because we need
	* to be sure we have 2 bytes room in the head. (NET_IP_ALIGN
	* can be 0 on some hardware). We use these 2 bytes for frame
	* alignment later, we assume that the chance that
	* header_size % 4 == 2 is bigger then header_size % 2 == 0
	* and thus optimize alignment by reserving the 2 bytes in
	* advance.
	*/
	frame_size = entry->ring->data_size + entry->ring->desc_size;
	skb = dev_alloc_skb(frame_size + 2);
	if (!skb)
	goto skip_entry;

	skb_reserve(skb, 2);
	skb_put(skb, frame_size);

	/*
	* The data behind the ieee80211 header must be
	* aligned on a 4 byte boundary.
	*/
	hdr = (struct ieee80211_hdr *)entry->skb->data;
	header_size =
	ieee80211_get_hdrlen(le16_to_cpu(hdr->frame_control));

	if (header_size % 4 == 0) {
	skb_push(entry->skb, 2);
	memmove(entry->skb->data, entry->skb->data + 2, skb->len - 2);
	}

	/*
	* Trim the entire buffer down to only contain the valid frame data
	* excluding the device descriptor. The position of the descriptor
	* varies. This means that we should check where the descriptor is
	* and decide if we need to pull the data pointer to exclude the
	* device descriptor.
	*/
	if (skbdesc->data > skbdesc->desc)
	skb_pull(entry->skb, skbdesc->desc_len);
	skb_trim(entry->skb, desc.size);

	/*
	* Send the frame to rt2x00lib for further processing.
	*/
	rt2x00lib_rxdone(entry, entry->skb, &desc);

	/*
	* Replace current entry's skb with the newly allocated one,
	* and reinitialize the urb.
	*/
	entry->skb = skb;
	urb->transfer_buffer = entry->skb->data;
	urb->transfer_buffer_length = entry->skb->len;

	skip_entry:
	if (test_bit(DEVICE_ENABLED_RADIO, &ring->rt2x00dev->flags)) {
	__set_bit(ENTRY_OWNER_NIC, &entry->flags);
	usb_submit_urb(urb, GFP_ATOMIC);
	}

	rt2x00_ring_index_inc(ring);
	}

	/*
	* Radio handlers
	*/
	void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
	{
	struct data_ring *ring;
	unsigned int i;

	rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0x0000, 0x0000,
	REGISTER_TIMEOUT);

	/*
	* Cancel all rings.
	*/
	ring_for_each(rt2x00dev, ring) {
	for (i = 0; i < ring->stats.limit; i++)
	usb_kill_urb(ring->entry[i].priv);
	}
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);

	/*
	* Device initialization handlers.
	*/
	void rt2x00usb_init_rxentry(struct rt2x00_dev *rt2x00dev,
	struct data_entry *entry)
	{
	struct usb_device *usb_dev =
	interface_to_usbdev(rt2x00dev_usb(rt2x00dev));

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

	__set_bit(ENTRY_OWNER_NIC, &entry->flags);
	usb_submit_urb(entry->priv, GFP_ATOMIC);
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_init_rxentry);

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

	static int rt2x00usb_alloc_urb(struct rt2x00_dev *rt2x00dev,
	struct data_ring *ring)
	{
	unsigned int i;

	/*
	* Allocate the URB's
	*/
	for (i = 0; i < ring->stats.limit; i++) {
	ring->entry[i].priv = usb_alloc_urb(0, GFP_KERNEL);
	if (!ring->entry[i].priv)
	return -ENOMEM;
	}

	return 0;
	}

	static void rt2x00usb_free_urb(struct rt2x00_dev *rt2x00dev,
	struct data_ring *ring)
	{
	unsigned int i;

	if (!ring->entry)
	return;

	for (i = 0; i < ring->stats.limit; i++) {
	usb_kill_urb(ring->entry[i].priv);
	usb_free_urb(ring->entry[i].priv);
	if (ring->entry[i].skb)
	kfree_skb(ring->entry[i].skb);
	}
	}

	int rt2x00usb_initialize(struct rt2x00_dev *rt2x00dev)
	{
	struct data_ring *ring;
	struct sk_buff *skb;
	unsigned int entry_size;
	unsigned int i;
	int uninitialized_var(status);

	/*
	* Allocate DMA
	*/
	ring_for_each(rt2x00dev, ring) {
	status = rt2x00usb_alloc_urb(rt2x00dev, ring);
	if (status)
	goto exit;
	}

	/*
	* For the RX ring, skb's should be allocated.
	*/
	entry_size = rt2x00dev->rx->data_size + rt2x00dev->rx->desc_size;
	for (i = 0; i < rt2x00dev->rx->stats.limit; i++) {
	skb = dev_alloc_skb(NET_IP_ALIGN + entry_size);
	if (!skb)
	goto exit;

	skb_reserve(skb, NET_IP_ALIGN);
	skb_put(skb, entry_size);

	rt2x00dev->rx->entry[i].skb = skb;
	}

	return 0;

	exit:
	rt2x00usb_uninitialize(rt2x00dev);

	return status;
	}
	EXPORT_SYMBOL_GPL(rt2x00usb_initialize);

	void rt2x00usb_uninitialize(struct rt2x00_dev *rt2x00dev)
	{
	struct data_ring *ring;

	ring_for_each(rt2x00dev, ring)
	rt2x00usb_free_urb(rt2x00dev, ring);
	}
	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;
	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 */

	/*
	* rt2x00pci module information.
	*/
	MODULE_AUTHOR(DRV_PROJECT);
	MODULE_VERSION(DRV_VERSION);
	MODULE_DESCRIPTION("rt2x00 library");
	MODULE_LICENSE("GPL");