rt2x00dev.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: rt2x00lib
	Abstract: rt2x00 generic device routines.
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "rt2x00.h"
#include "rt2x00lib.h"
#include "rt2x00dump.h"

/*
 * Link tuning handlers
 */
void rt2x00lib_reset_link_tuner(struct rt2x00_dev *rt2x00dev)
{
	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
		return;

	/*
	 * Reset link information.
	 * Both the currently active vgc level as well as
	 * the link tuner counter should be reset. Resetting
	 * the counter is important for devices where the
	 * device should only perform link tuning during the
	 * first minute after being enabled.
	 */
	rt2x00dev->link.count = 0;
	rt2x00dev->link.vgc_level = 0;

	/*
	 * Reset the link tuner.
	 */
	rt2x00dev->ops->lib->reset_tuner(rt2x00dev);
}

static void rt2x00lib_start_link_tuner(struct rt2x00_dev *rt2x00dev)
{
	/*
	 * Clear all (possibly) pre-existing quality statistics.
	 */
	memset(&rt2x00dev->link.qual, 0, sizeof(rt2x00dev->link.qual));

	/*
	 * The RX and TX percentage should start at 50%
	 * this will assure we will get at least get some
	 * decent value when the link tuner starts.
	 * The value will be dropped and overwritten with
	 * the correct (measured )value anyway during the
	 * first run of the link tuner.
	 */
	rt2x00dev->link.qual.rx_percentage = 50;
	rt2x00dev->link.qual.tx_percentage = 50;

	rt2x00lib_reset_link_tuner(rt2x00dev);

	queue_delayed_work(rt2x00dev->hw->workqueue,
			   &rt2x00dev->link.work, LINK_TUNE_INTERVAL);
}

static void rt2x00lib_stop_link_tuner(struct rt2x00_dev *rt2x00dev)
{
	cancel_delayed_work_sync(&rt2x00dev->link.work);
}

/*
 * Radio control handlers.
 */
int rt2x00lib_enable_radio(struct rt2x00_dev *rt2x00dev)
{
	int status;

	/*
	 * Don't enable the radio twice.
	 * And check if the hardware button has been disabled.
	 */
	if (test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) ||
	    test_bit(DEVICE_DISABLED_RADIO_HW, &rt2x00dev->flags))
		return 0;

	/*
	 * Initialize all data queues.
	 */
	rt2x00queue_init_rx(rt2x00dev);
	rt2x00queue_init_tx(rt2x00dev);

	/*
	 * Enable radio.
	 */
	status = rt2x00dev->ops->lib->set_device_state(rt2x00dev,
						       STATE_RADIO_ON);
	if (status)
		return status;

	__set_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags);

	/*
	 * Enable RX.
	 */
	rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON);

	/*
	 * Start the TX queues.
	 */
	ieee80211_start_queues(rt2x00dev->hw);

	return 0;
}

void rt2x00lib_disable_radio(struct rt2x00_dev *rt2x00dev)
{
	if (!__test_and_clear_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
		return;

	/*
	 * Stop all scheduled work.
	 */
	if (work_pending(&rt2x00dev->intf_work))
		cancel_work_sync(&rt2x00dev->intf_work);
	if (work_pending(&rt2x00dev->filter_work))
		cancel_work_sync(&rt2x00dev->filter_work);

	/*
	 * Stop the TX queues.
	 */
	ieee80211_stop_queues(rt2x00dev->hw);

	/*
	 * Disable RX.
	 */
	rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_OFF);

	/*
	 * Disable radio.
	 */
	rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_RADIO_OFF);
}

void rt2x00lib_toggle_rx(struct rt2x00_dev *rt2x00dev, enum dev_state state)
{
	/*
	 * When we are disabling the RX, we should also stop the link tuner.
	 */
	if (state == STATE_RADIO_RX_OFF)
		rt2x00lib_stop_link_tuner(rt2x00dev);

	rt2x00dev->ops->lib->set_device_state(rt2x00dev, state);

	/*
	 * When we are enabling the RX, we should also start the link tuner.
	 */
	if (state == STATE_RADIO_RX_ON &&
	    (rt2x00dev->intf_ap_count || rt2x00dev->intf_sta_count))
		rt2x00lib_start_link_tuner(rt2x00dev);
}

static void rt2x00lib_evaluate_antenna_sample(struct rt2x00_dev *rt2x00dev)
{
	enum antenna rx = rt2x00dev->link.ant.active.rx;
	enum antenna tx = rt2x00dev->link.ant.active.tx;
	int sample_a =
	    rt2x00_get_link_ant_rssi_history(&rt2x00dev->link, ANTENNA_A);
	int sample_b =
	    rt2x00_get_link_ant_rssi_history(&rt2x00dev->link, ANTENNA_B);

	/*
	 * We are done sampling. Now we should evaluate the results.
	 */
	rt2x00dev->link.ant.flags &= ~ANTENNA_MODE_SAMPLE;

	/*
	 * During the last period we have sampled the RSSI
	 * from both antenna's. It now is time to determine
	 * which antenna demonstrated the best performance.
	 * When we are already on the antenna with the best
	 * performance, then there really is nothing for us
	 * left to do.
	 */
	if (sample_a == sample_b)