rt73usb.c

/*
	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: rt73usb
	Abstract: rt73usb device specific routines.
	Supported chipsets: rt2571W & rt2671.
 */

#include <linux/crc-itu-t.h>
#include <linux/delay.h>
#include <linux/etherdevice.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/usb.h>

#include "rt2x00.h"
#include "rt2x00usb.h"
#include "rt73usb.h"

/*
 * Allow hardware encryption to be disabled.
 */
static int modparam_nohwcrypt = 0;
module_param_named(nohwcrypt, modparam_nohwcrypt, bool, S_IRUGO);
MODULE_PARM_DESC(nohwcrypt, "Disable hardware encryption.");

/*
 * Register access.
 * All access to the CSR registers will go through the methods
 * rt73usb_register_read and rt73usb_register_write.
 * BBP and RF register require indirect register access,
 * and use the CSR registers BBPCSR and RFCSR to achieve this.
 * These indirect registers work with busy bits,
 * and we will try maximal REGISTER_BUSY_COUNT times to access
 * the register while taking a REGISTER_BUSY_DELAY us delay
 * between each attampt. When the busy bit is still set at that time,
 * the access attempt is considered to have failed,
 * and we will print an error.
 * The _lock versions must be used if you already hold the usb_cache_mutex
 */
static inline void rt73usb_register_read(struct rt2x00_dev *rt2x00dev,
					 const unsigned int offset, u32 *value)
{
	__le32 reg;
	rt2x00usb_vendor_request_buff(rt2x00dev, USB_MULTI_READ,
				      USB_VENDOR_REQUEST_IN, offset,
				      &reg, sizeof(u32), REGISTER_TIMEOUT);
	*value = le32_to_cpu(reg);
}

static inline void rt73usb_register_read_lock(struct rt2x00_dev *rt2x00dev,
					      const unsigned int offset, u32 *value)
{
	__le32 reg;
	rt2x00usb_vendor_req_buff_lock(rt2x00dev, USB_MULTI_READ,
				       USB_VENDOR_REQUEST_IN, offset,
				       &reg, sizeof(u32), REGISTER_TIMEOUT);
	*value = le32_to_cpu(reg);
}

static inline void rt73usb_register_multiread(struct rt2x00_dev *rt2x00dev,
					      const unsigned int offset,
					      void *value, const u32 length)
{
	rt2x00usb_vendor_request_buff(rt2x00dev, USB_MULTI_READ,
				      USB_VENDOR_REQUEST_IN, offset,
				      value, length,
				      REGISTER_TIMEOUT32(length));
}

static inline void rt73usb_register_write(struct rt2x00_dev *rt2x00dev,
					  const unsigned int offset, u32 value)
{
	__le32 reg = cpu_to_le32(value);
	rt2x00usb_vendor_request_buff(rt2x00dev, USB_MULTI_WRITE,
				      USB_VENDOR_REQUEST_OUT, offset,
				      &reg, sizeof(u32), REGISTER_TIMEOUT);
}

static inline void rt73usb_register_write_lock(struct rt2x00_dev *rt2x00dev,
					       const unsigned int offset, u32 value)
{
	__le32 reg = cpu_to_le32(value);
	rt2x00usb_vendor_req_buff_lock(rt2x00dev, USB_MULTI_WRITE,
				       USB_VENDOR_REQUEST_OUT, offset,
				      &reg, sizeof(u32), REGISTER_TIMEOUT);
}

static inline void rt73usb_register_multiwrite(struct rt2x00_dev *rt2x00dev,
					       const unsigned int offset,
					       void *value, const u32 length)
{
	rt2x00usb_vendor_request_buff(rt2x00dev, USB_MULTI_WRITE,
				      USB_VENDOR_REQUEST_OUT, offset,
				      value, length,
				      REGISTER_TIMEOUT32(length));
}

static u32 rt73usb_bbp_check(struct rt2x00_dev *rt2x00dev)
{
	u32 reg;
	unsigned int i;

	for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
		rt73usb_register_read_lock(rt2x00dev, PHY_CSR3, &reg);
		if (!rt2x00_get_field32(reg, PHY_CSR3_BUSY))
			break;
		udelay(REGISTER_BUSY_DELAY);
	}

	return reg;
}

static void rt73usb_bbp_write(struct rt2x00_dev *rt2x00dev,
			      const unsigned int word, const u8 value)
{
	u32 reg;

	mutex_lock(&rt2x00dev->usb_cache_mutex);

	/*
	 * Wait until the BBP becomes ready.
	 */
	reg = rt73usb_bbp_check(rt2x00dev);
	if (rt2x00_get_field32(reg, PHY_CSR3_BUSY))
		goto exit_fail;

	/*
	 * Write the data into the BBP.
	 */
	reg = 0;
	rt2x00_set_field32(&reg, PHY_CSR3_VALUE, value);
	rt2x00_set_field32(&reg, PHY_CSR3_REGNUM, word);
	rt2x00_set_field32(&reg, PHY_CSR3_BUSY, 1);
	rt2x00_set_field32(&reg, PHY_CSR3_READ_CONTROL, 0);

	rt73usb_register_write_lock(rt2x00dev, PHY_CSR3, reg);
	mutex_unlock(&rt2x00dev->usb_cache_mutex);

	return;

exit_fail:
	mutex_unlock(&rt2x00dev->usb_cache_mutex);

	ERROR(rt2x00dev, "PHY_CSR3 register busy. Write failed.\n");
}

static void rt73usb_bbp_read(struct rt2x00_dev *rt2x00dev,
			     const unsigned int word, u8 *value)
{
	u32 reg;

	mutex_lock(&rt2x00dev->usb_cache_mutex);

	/*
	 * Wait until the BBP becomes ready.
	 */
	reg = rt73usb_bbp_check(rt2x00dev);
	if (rt2x00_get_field32(reg, PHY_CSR3_BUSY))
		goto exit_fail;

	/*
	 * Write the request into the BBP.
	 */
	reg = 0;
	rt2x00_set_field32(&reg, PHY_CSR3_REGNUM, word);
	rt2x00_set_field32(&reg, PHY_CSR3_BUSY, 1);
	rt2x00_set_field32(&reg, PHY_CSR3_READ_CONTROL, 1);

	rt73usb_register_write_lock(rt2x00dev, PHY_CSR3, reg);

	/*
	 * Wait until the BBP becomes ready.
	 */
	reg = rt73usb_bbp_check(rt2x00dev);
	if (rt2x00_get_field32(reg, PHY_CSR3_BUSY))
		goto exit_fail;

	*value = rt2x00_get_field32(reg, PHY_CSR3_VALUE);
	mutex_unlock(&rt2x00dev->usb_cache_mutex);