path: root/drivers/net/wireless/ath/ath9k/phy.c

/*
 * Copyright (c) 2008-2009 Atheros Communications Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/**
 * DOC: Programming Atheros 802.11n analog front end radios
 *
 * AR5416 MAC based PCI devices and AR518 MAC based PCI-Express
 * devices have either an external AR2133 analog front end radio for single
 * band 2.4 GHz communication or an AR5133 analog front end radio for dual
 * band 2.4 GHz / 5 GHz communication.
 *
 * All devices after the AR5416 and AR5418 family starting with the AR9280
 * have their analog front radios, MAC/BB and host PCIe/USB interface embedded
 * into a single-chip and require less programming.
 *
 * The following single-chips exist with a respective embedded radio:
 *
 * AR9280 - 11n dual-band 2x2 MIMO for PCIe
 * AR9281 - 11n single-band 1x2 MIMO for PCIe
 * AR9285 - 11n single-band 1x1 for PCIe
 * AR9287 - 11n single-band 2x2 MIMO for PCIe
 *
 * AR9220 - 11n dual-band 2x2 MIMO for PCI
 * AR9223 - 11n single-band 2x2 MIMO for PCI
 *
 * AR9287 - 11n single-band 1x1 MIMO for USB
 */

#include "hw.h"

/**
 * ath9k_hw_write_regs - ??
 *
 * @ah: atheros hardware structure
 * @freqIndex:
 * @regWrites:
 *
 * Used for both the chipsets with an external AR2133/AR5133 radios and
 * single-chip devices.
 */
void ath9k_hw_write_regs(struct ath_hw *ah, u32 freqIndex, int regWrites)
{
	REG_WRITE_ARRAY(&ah->iniBB_RfGain, freqIndex, regWrites);
}

/**
 * ath9k_hw_ar9280_set_channel - set channel on single-chip device
 * @ah: atheros hardware structure
 * @chan:
 *
 * This is the function to change channel on single-chip devices, that is
 * all devices after ar9280.
 *
 * This function takes the channel value in MHz and sets
 * hardware channel value. Assumes writes have been enabled to analog bus.
 *
 * Actual Expression,
 *
 * For 2GHz channel,
 * Channel Frequency = (3/4) * freq_ref * (chansel[8:0] + chanfrac[16:0]/2^17)
 * (freq_ref = 40MHz)
 *
 * For 5GHz channel,
 * Channel Frequency = (3/2) * freq_ref * (chansel[8:0] + chanfrac[16:0]/2^10)
 * (freq_ref = 40MHz/(24>>amodeRefSel))
 */
int ath9k_hw_ar9280_set_channel(struct ath_hw *ah, struct ath9k_channel *chan)
{
	u16 bMode, fracMode, aModeRefSel = 0;
	u32 freq, ndiv, channelSel = 0, channelFrac = 0, reg32 = 0;
	struct chan_centers centers;
	u32 refDivA = 24;

	ath9k_hw_get_channel_centers(ah, chan, &centers);
	freq = centers.synth_center;

	reg32 = REG_READ(ah, AR_PHY_SYNTH_CONTROL);
	reg32 &= 0xc0000000;

	if (freq < 4800) { /* 2 GHz, fractional mode */
		u32 txctl;
		int regWrites = 0;

		bMode = 1;
		fracMode = 1;
		aModeRefSel = 0;
		channelSel = (freq * 0x10000) / 15;

		if (AR_SREV_9287_11_OR_LATER(ah)) {
			if (freq == 2484) {
				/* Enable channel spreading for channel 14 */
				REG_WRITE_ARRAY(&ah->iniCckfirJapan2484,
						1, regWrites);
			} else {
				REG_WRITE_ARRAY(&ah->iniCckfirNormal,
						1, regWrites);
			}
		} else {
			txctl = REG_READ(ah, AR_PHY_CCK_TX_CTRL);
			if (freq == 2484) {
				/* Enable channel spreading for channel 14 */
				REG_WRITE(ah, AR_PHY_CCK_TX_CTRL,
					  txctl | AR_PHY_CCK_TX_CTRL_JAPAN);
			} else {
				REG_WRITE(ah, AR_PHY_CCK_TX_CTRL,
					  txctl &~ AR_PHY_CCK_TX_CTRL_JAPAN);
			}
		}
	} else {
		bMode = 0;
		fracMode = 0;

		switch(ah->eep_ops->get_eeprom(ah, EEP_FRAC_N_5G)) {
		case 0:
			if ((freq % 20) == 0) {
				aModeRefSel = 3;
			} else if ((freq % 10) == 0) {
				aModeRefSel = 2;
			}
			if (aModeRefSel)
				break;
		case 1:
		default:
			aModeRefSel = 0;
			/*
			 * Enable 2G (fractional) mode for channels
			 * which are 5MHz spaced.
			 */
			fracMode = 1;
			refDivA = 1;
			channelSel = (freq * 0x8000) / 15;

			/* RefDivA setting */
			REG_RMW_FIELD(ah, AR_AN_SYNTH9,
				      AR_AN_SYNTH9_REFDIVA, refDivA);

		}

		if (!fracMode) {
			ndiv = (freq * (refDivA >> aModeRefSel)) / 60;
			channelSel = ndiv & 0x1ff;
			channelFrac = (ndiv & 0xfffffe00) * 2;
			channelSel = (channelSel << 17)