path: root/drivers/net/wireless/ath/ath9k/mac.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.
 */

#include "hw.h"

static void ath9k_hw_set_txq_interrupts(struct ath_hw *ah,
					struct ath9k_tx_queue_info *qi)
{
	ath_print(ath9k_hw_common(ah), ATH_DBG_INTERRUPT,
		  "tx ok 0x%x err 0x%x desc 0x%x eol 0x%x urn 0x%x\n",
		  ah->txok_interrupt_mask, ah->txerr_interrupt_mask,
		  ah->txdesc_interrupt_mask, ah->txeol_interrupt_mask,
		  ah->txurn_interrupt_mask);

	REG_WRITE(ah, AR_IMR_S0,
		  SM(ah->txok_interrupt_mask, AR_IMR_S0_QCU_TXOK)
		  | SM(ah->txdesc_interrupt_mask, AR_IMR_S0_QCU_TXDESC));
	REG_WRITE(ah, AR_IMR_S1,
		  SM(ah->txerr_interrupt_mask, AR_IMR_S1_QCU_TXERR)
		  | SM(ah->txeol_interrupt_mask, AR_IMR_S1_QCU_TXEOL));
	REG_RMW_FIELD(ah, AR_IMR_S2,
		      AR_IMR_S2_QCU_TXURN, ah->txurn_interrupt_mask);
}

u32 ath9k_hw_gettxbuf(struct ath_hw *ah, u32 q)
{
	return REG_READ(ah, AR_QTXDP(q));
}
EXPORT_SYMBOL(ath9k_hw_gettxbuf);

void ath9k_hw_puttxbuf(struct ath_hw *ah, u32 q, u32 txdp)
{
	REG_WRITE(ah, AR_QTXDP(q), txdp);
}
EXPORT_SYMBOL(ath9k_hw_puttxbuf);

void ath9k_hw_txstart(struct ath_hw *ah, u32 q)
{
	ath_print(ath9k_hw_common(ah), ATH_DBG_QUEUE,
		  "Enable TXE on queue: %u\n", q);
	REG_WRITE(ah, AR_Q_TXE, 1 << q);
}
EXPORT_SYMBOL(ath9k_hw_txstart);

u32 ath9k_hw_numtxpending(struct ath_hw *ah, u32 q)
{
	u32 npend;

	npend = REG_READ(ah, AR_QSTS(q)) & AR_Q_STS_PEND_FR_CNT;
	if (npend == 0) {

		if (REG_READ(ah, AR_Q_TXE) & (1 << q))
			npend = 1;
	}

	return npend;
}
EXPORT_SYMBOL(ath9k_hw_numtxpending);

/**
 * ath9k_hw_updatetxtriglevel - adjusts the frame trigger level
 *
 * @ah: atheros hardware struct
 * @bIncTrigLevel: whether or not the frame trigger level should be updated
 *
 * The frame trigger level specifies the minimum number of bytes,
 * in units of 64 bytes, that must be DMA'ed into the PCU TX FIFO
 * before the PCU will initiate sending the frame on the air. This can
 * mean we initiate transmit before a full frame is on the PCU TX FIFO.
 * Resets to 0x1 (meaning 64 bytes or a full frame, whichever occurs
 * first)
 *
 * Caution must be taken to ensure to set the frame trigger level based
 * on the DMA request size. For example if the DMA request size is set to
 * 128 bytes the trigger level cannot exceed 6 * 64 = 384. This is because
 * there need to be enough space in the tx FIFO for the requested transfer
 * size. Hence the tx FIFO will stop with 512 - 128 = 384 bytes. If we set
 * the threshold to a value beyond 6, then the transmit will hang.
 *
 * Current dual   stream devices have a PCU TX FIFO size of 8 KB.
 * Current single stream devices have a PCU TX FIFO size of 4 KB, however,
 * there is a hardware issue which forces us to use 2 KB instead so the
 * frame trigger level must not exceed 2 KB for these chipsets.
 */
bool ath9k_hw_updatetxtriglevel(struct ath_hw *ah, bool bIncTrigLevel)
{
	u32 txcfg, curLevel, newLevel;
	enum ath9k_int omask;

	if (ah->tx_trig_level >= ah->config.max_txtrig_level)
		return false;

	omask = ath9k_hw_set_interrupts(ah, ah->mask_reg & ~ATH9K_INT_GLOBAL);

	txcfg = REG_READ(ah, AR_TXCFG);
	curLevel = MS(txcfg, AR_FTRIG);
	newLevel = curLevel;
	if (bIncTrigLevel) {
		if (curLevel < ah->config.max_txtrig_level)
			newLevel++;
	} else if (curLevel > MIN_TX_FIFO_THRESHOLD)
		newLevel--;
	if (newLevel != curLevel)
		REG_WRITE(ah, AR_TXCFG,
			  (txcfg & ~AR_FTRIG) | SM(newLevel, AR_FTRIG));

	ath9k_hw_set_interrupts(ah, omask);

	ah->tx_trig_level = newLevel;

	return newLevel != curLevel;
}
EXPORT_SYMBOL(ath9k_hw_updatetxtriglevel);

bool ath9k_hw_stoptxdma(struct ath_hw *ah, u32 q)
{
#define ATH9K_TX_STOP_DMA_TIMEOUT	4000    /* usec */
#define ATH9K_TIME_QUANTUM		100     /* usec */
	struct ath_common *common = ath9k_hw_common(ah);
	struct ath9k_hw_capabilities *pCap = &ah->caps;
	struct