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linux/drivers/net/wireless/ath/ath5k/pcu.c

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/*
* Copyright (c) 2004-2008 Reyk Floeter <reyk@openbsd.org>
* Copyright (c) 2006-2008 Nick Kossifidis <mickflemm@gmail.com>
* Copyright (c) 2007-2008 Matthew W. S. Bell <mentor@madwifi.org>
* Copyright (c) 2007-2008 Luis Rodriguez <mcgrof@winlab.rutgers.edu>
* Copyright (c) 2007-2008 Pavel Roskin <proski@gnu.org>
* Copyright (c) 2007-2008 Jiri Slaby <jirislaby@gmail.com>
*
* Permission to use, copy, modify, and 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.
*
*/
/*********************************\
* Protocol Control Unit Functions *
\*********************************/
#include <asm/unaligned.h>
#include "ath5k.h"
#include "reg.h"
#include "debug.h"
/**
* DOC: Protocol Control Unit (PCU) functions
*
* Protocol control unit is responsible to maintain various protocol
* properties before a frame is send and after a frame is received to/from
* baseband. To be more specific, PCU handles:
*
* - Buffering of RX and TX frames (after QCU/DCUs)
*
* - Encrypting and decrypting (using the built-in engine)
*
* - Generating ACKs, RTS/CTS frames
*
* - Maintaining TSF
*
* - FCS
*
* - Updating beacon data (with TSF etc)
*
* - Generating virtual CCA
*
* - RX/Multicast filtering
*
* - BSSID filtering
*
* - Various statistics
*
* -Different operating modes: AP, STA, IBSS
*
* Note: Most of these functions can be tweaked/bypassed so you can do
* them on sw above for debugging or research. For more infos check out PCU
* registers on reg.h.
*/
/**
* DOC: ACK rates
*
* AR5212+ can use higher rates for ack transmission
* based on current tx rate instead of the base rate.
* It does this to better utilize channel usage.
* There is a mapping between G rates (that cover both
* CCK and OFDM) and ack rates that we use when setting
* rate -> duration table. This mapping is hw-based so
* don't change anything.
*
* To enable this functionality we must set
* ah->ah_ack_bitrate_high to true else base rate is
* used (1Mb for CCK, 6Mb for OFDM).
*/
static const unsigned int ack_rates_high[] =
/* Tx -> ACK */
/* 1Mb -> 1Mb */ { 0,
/* 2MB -> 2Mb */ 1,
/* 5.5Mb -> 2Mb */ 1,
/* 11Mb -> 2Mb */ 1,
/* 6Mb -> 6Mb */ 4,
/* 9Mb -> 6Mb */ 4,
/* 12Mb -> 12Mb */ 6,
/* 18Mb -> 12Mb */ 6,
/* 24Mb -> 24Mb */ 8,
/* 36Mb -> 24Mb */ 8,
/* 48Mb -> 24Mb */ 8,
/* 54Mb -> 24Mb */ 8 };
/*******************\
* Helper functions *
\*******************/
/**
* ath5k_hw_get_frame_duration() - Get tx time of a frame
* @ah: The &struct ath5k_hw
* @len: Frame's length in bytes
* @rate: The @struct ieee80211_rate
* @shortpre: Indicate short preample
*
* Calculate tx duration of a frame given it's rate and length
* It extends ieee80211_generic_frame_duration for non standard
* bwmodes.
*/
int
ath5k_hw_get_frame_duration(struct ath5k_hw *ah, enum nl80211_band band,
int len, struct ieee80211_rate *rate, bool shortpre)
{
int sifs, preamble, plcp_bits, sym_time;
int bitrate, bits, symbols, symbol_bits;
int dur;
/* Fallback */
if (!ah->ah_bwmode) {
__le16 raw_dur = ieee80211_generic_frame_duration(ah->hw,
NULL, band, len, rate);
/* subtract difference between long and short preamble */
dur = le16_to_cpu(raw_dur);
if (shortpre)
dur -= 96;
return dur;
}
bitrate = rate->bitrate;
preamble = AR5K_INIT_OFDM_PREAMPLE_TIME;
plcp_bits = AR5K_INIT_OFDM_PLCP_BITS;
sym_time = AR5K_INIT_OFDM_SYMBOL_TIME;
switch (ah->ah_bwmode) {
case AR5K_BWMODE_40MHZ:
sifs = AR5K_INIT_SIFS_TURBO;
preamble = AR5K_INIT_OFDM_PREAMBLE_TIME_MIN;
break;
case AR5K_BWMODE_10MHZ:
sifs = AR5K_INIT_SIFS_HALF_RATE;
preamble *= 2;
sym_time *= 2;
bitrate = DIV_ROUND_UP(bitrate, 2);
break;
case AR5K_BWMODE_5MHZ:
sifs = AR5K_INIT_SIFS_QUARTER_RATE;
preamble *= 4;
sym_time *= 4;
bitrate = DIV_ROUND_UP(bitrate, 4);
break;
default:
sifs = AR5K_INIT_SIFS_DEFAULT_BG;
break;
}
bits = plcp_bits + (len << 3);
/* Bit rate is in 100Kbits */
symbol_bits = bitrate * sym_time;
symbols = DIV_ROUND_UP(bits * 10, symbol_bits);
dur = sifs + preamble + (sym_time * symbols);
return dur;
}
/**
* ath5k_hw_get_default_slottime() - Get the default slot time for current mode
* @ah: The &struct ath5k_hw
*/
unsigned int
ath5k_hw_get_default_slottime(struct ath5k_hw *ah)
{
struct ieee80211_channel *channel = ah->ah_current_channel;
unsigned int slot_time;
switch (ah->ah_bwmode) {
case AR5K_BWMODE_40MHZ:
slot_time = AR5K_INIT_SLOT_TIME_TURBO;
break;
case AR5K_BWMODE_10MHZ:
slot_time = AR5K_INIT_SLOT_TIME_HALF_RATE;
break;
case AR5K_BWMODE_5MHZ:
slot_time = AR5K_INIT_SLOT_TIME_QUARTER_RATE;
break;
case AR5K_BWMODE_DEFAULT:
default:
slot_time = AR5K_INIT_SLOT_TIME_DEFAULT;
if ((channel->hw_value == AR5K_MODE_11B) && !ah->ah_short_slot)
slot_time = AR5K_INIT_SLOT_TIME_B;
break;
}
return slot_time;
}
/**
* ath5k_hw_get_default_sifs() - Get the default SIFS for current mode
* @ah: The &struct ath5k_hw
*/
unsigned int
ath5k_hw_get_default_sifs(struct ath5k_hw *ah)
{
struct ieee80211_channel *channel = ah->ah_current_channel;
unsigned int sifs;
switch (ah->ah_bwmode) {
case AR5K_BWMODE_40MHZ:
sifs = AR5K_INIT_SIFS_TURBO;
break;
case AR5K_BWMODE_10MHZ:
sifs = AR5K_INIT_SIFS_HALF_RATE;
break;
case AR5K_BWMODE_5MHZ:
sifs = AR5K_INIT_SIFS_QUARTER_RATE;
break;
case AR5K_BWMODE_DEFAULT:
default:
sifs = AR5K_INIT_SIFS_DEFAULT_BG;
if (channel->band == NL80211_BAND_5GHZ)
sifs = AR5K_INIT_SIFS_DEFAULT_A;
break;
}
return sifs;
}
/**
* ath5k_hw_update_mib_counters() - Update MIB counters (mac layer statistics)
* @ah: The &struct ath5k_hw
*
* Reads MIB counters from PCU and updates sw statistics. Is called after a
* MIB interrupt, because one of these counters might have reached their maximum
* and triggered the MIB interrupt, to let us read and clear the counter.
*
* NOTE: Is called in interrupt context!
*/
void
ath5k_hw_update_mib_counters(struct ath5k_hw *ah)
{
struct ath5k_statistics *stats = &ah->stats;
/* Read-And-Clear */
stats->ack_fail += ath5k_hw_reg_read(ah, AR5K_ACK_FAIL);
stats->rts_fail += ath5k_hw_reg_read(ah, AR5K_RTS_FAIL);
stats->rts_ok += ath5k_hw_reg_read(ah, AR5K_RTS_OK);
stats->fcs_error += ath5k_hw_reg_read(ah, AR5K_FCS_FAIL);
stats->beacons += ath5k_hw_reg_read(ah, AR5K_BEACON_CNT);
}
/******************\
* ACK/CTS Timeouts *
\******************/
/**
* ath5k_hw_write_rate_duration() - Fill rate code to duration table
* @ah: The &struct ath5k_hw
*
* Write the rate code to duration table upon hw reset. This is a helper for
* ath5k_hw_pcu_init(). It seems all this is doing is setting an ACK timeout on
* the hardware, based on current mode, for each rate. The rates which are
* capable of short preamble (802.11b rates 2Mbps, 5.5Mbps, and 11Mbps) have
* different rate code so we write their value twice (one for long preamble
* and one for short).
*
* Note: Band doesn't matter here, if we set the values for OFDM it works
* on both a and g modes. So all we have to do is set values for all g rates
* that include all OFDM and CCK rates.
*
*/
static inline void
ath5k_hw_write_rate_duration(struct ath5k_hw *ah)
{
struct ieee80211_rate *rate;
unsigned int i;
/* 802.11g covers both OFDM and CCK */
u8 band = NL80211_BAND_2GHZ;
/* Write rate duration table */
for (i = 0; i < ah->sbands[band].n_bitrates; i++) {
u32 reg;
u16 tx_time;
if (ah->ah_ack_bitrate_high)
rate = &ah->sbands[band].bitrates[ack_rates_high[i]];
/* CCK -> 1Mb */
else if (i < 4)
rate = &ah->sbands[band].bitrates[0];
/* OFDM -> 6Mb */
else
rate = &ah->sbands[band].bitrates[4];
/* Set ACK timeout */
reg = AR5K_RATE_DUR(rate->hw_value);
/* An ACK frame consists of 10 bytes. If you add the FCS,
* which ieee80211_generic_frame_duration() adds,
* its 14 bytes. Note we use the control rate and not the
* actual rate for this rate. See mac80211 tx.c
* ieee80211_duration() for a brief description of
* what rate we should choose to TX ACKs. */
tx_time = ath5k_hw_get_frame_duration(ah, band, 10,
rate, false);
ath5k_hw_reg_write(ah, tx_time, reg);
if (!(rate->flags & IEEE80211_RATE_SHORT_PREAMBLE))
continue;
tx_time = ath5k_hw_get_frame_duration(ah, band, 10, rate, true);
ath5k_hw_reg_write(ah, tx_time,
reg + (AR5K_SET_SHORT_PREAMBLE << 2));
}
}
/**
* ath5k_hw_set_ack_timeout() - Set ACK timeout on PCU
* @ah: The &struct ath5k_hw
* @timeout: Timeout in usec
*/
static int
ath5k_hw_set_ack_timeout(struct ath5k_hw *ah, unsigned int timeout)
{
if (ath5k_hw_clocktoh(ah, AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_ACK))
<= timeout)
return -EINVAL;
AR5K_REG_WRITE_BITS(ah, AR5K_TIME_OUT, AR5K_TIME_OUT_ACK,
ath5k_hw_htoclock(ah, timeout));
return 0;
}
/**
* ath5k_hw_set_cts_timeout() - Set CTS timeout on PCU
* @ah: The &struct ath5k_hw
* @timeout: Timeout in usec
*/
static int
ath5k_hw_set_cts_timeout(struct ath5k_hw *ah, unsigned int timeout)
{
if (ath5k_hw_clocktoh(ah, AR5K_REG_MS(0xffffffff, AR5K_TIME_OUT_CTS))
<= timeout)
return -EINVAL;
AR5K_REG_WRITE_BITS(ah, AR5K_TIME_OUT, AR5K_TIME_OUT_CTS,
ath5k_hw_htoclock(ah, timeout));
return 0;
}
/*******************\
* RX filter Control *
\*******************/
/**
* ath5k_hw_set_lladdr() - Set station id
* @ah: The &struct ath5k_hw
* @mac: The card's mac address (array of octets)
*
* Set station id on hw using the provided mac address
*/
int
ath5k_hw_set_lladdr(struct ath5k_hw *ah, const u8 *mac)
{
struct ath_common *common = ath5k_hw_common(ah);
u32 low_id, high_id;
u32 pcu_reg;
/* Set new station ID */
memcpy(common->macaddr, mac, ETH_ALEN);
pcu_reg = ath5k_hw_reg_read(ah, AR5K_STA_ID1) & 0xffff0000;
low_id = get_unaligned_le32(mac);
high_id = get_unaligned_le16(mac + 4);
ath5k_hw_reg_write(ah, low_id, AR5K_STA_ID0);
ath5k_hw_reg_write(ah, pcu_reg | high_id, AR5K_STA_ID1);
return 0;
}
/**
* ath5k_hw_set_bssid() - Set current BSSID on hw
* @ah: The &struct ath5k_hw
*
* Sets the current BSSID and BSSID mask we have from the
* common struct into the hardware
*/
void
ath5k_hw_set_bssid(struct ath5k_hw *ah)
{
struct ath_common *common = ath5k_hw_common(ah);
u16 tim_offset = 0;
/*
* Set BSSID mask on 5212
*/
if (ah->ah_version == AR5K_AR5212)
ath_hw_setbssidmask(common);
/*
* Set BSSID
*/
ath5k_hw_reg_write(ah,
get_unaligned_le32(common->curbssid),
AR5K_BSS_ID0);
ath5k_hw_reg_write(ah,
get_unaligned_le16(common->curbssid + 4) |
((common->curaid & 0x3fff) << AR5K_BSS_ID1_AID_S),
AR5K_BSS_ID1);
if (common->curaid == 0) {
ath5k_hw_disable_pspoll(ah);
return;
}
AR5K_REG_WRITE_BITS(ah, AR5K_BEACON, AR5K_BEACON_TIM,
tim_offset ? tim_offset + 4 : 0);
ath5k_hw_enable_pspoll(ah, NULL, 0);
}
/**
* ath5k_hw_set_bssid_mask() - Filter out bssids we listen
* @ah: The &struct ath5k_hw
* @mask: The BSSID mask to set (array of octets)
*
* BSSID masking is a method used by AR5212 and newer hardware to inform PCU
* which bits of the interface's MAC address should be looked at when trying
* to decide which packets to ACK. In station mode and AP mode with a single
* BSS every bit matters since we lock to only one BSS. In AP mode with
* multiple BSSes (virtual interfaces) not every bit matters because hw must
* accept frames for all BSSes and so we tweak some bits of our mac address
* in order to have multiple BSSes.
*
* For more information check out ../hw.c of the common ath module.
*/
void
ath5k_hw_set_bssid_mask(struct ath5k_hw *ah, const u8 *mask)
{
struct ath_common *common = ath5k_hw_common(ah);
/* Cache bssid mask so that we can restore it
* on reset */
memcpy(common->bssidmask, mask, ETH_ALEN);
if (ah->ah_version == AR5K_AR5212)
ath_hw_setbssidmask(common);
}
/**
* ath5k_hw_set_mcast_filter() - Set multicast filter
* @ah: The &struct ath5k_hw
* @filter0: Lower 32bits of muticast filter
* @filter1: Higher 16bits of multicast filter
*/
void
ath5k_hw_set_mcast_filter(struct ath5k_hw *ah, u32 filter0, u32 filter1)
{
ath5k_hw_reg_write(ah, filter0, AR5K_MCAST_FILTER0);
ath5k_hw_reg_write(ah, filter1, AR5K_MCAST_FILTER1);
}
/**
* ath5k_hw_get_rx_filter() - Get current rx filter
* @ah: The &struct ath5k_hw
*
* Returns the RX filter by reading rx filter and
* phy error filter registers. RX filter is used
* to set the allowed frame types that PCU will accept
* and pass to the driver. For a list of frame types
* check out reg.h.
*/
u32
ath5k_hw_get_rx_filter(struct ath5k_hw *ah)
{
u32 data, filter = 0;
filter = ath5k_hw_reg_read(ah, AR5K_RX_FILTER);
/*Radar detection for 5212*/
if (ah->ah_version == AR5K_AR5212) {
data = ath5k_hw_reg_read(ah, AR5K_PHY_ERR_FIL);
if (data & AR5K_PHY_ERR_FIL_RADAR)
filter |= AR5K_RX_FILTER_RADARERR;
if (data & (AR5K_PHY_ERR_FIL_OFDM | AR5K_PHY_ERR_FIL_CCK))
filter |= AR5K_RX_FILTER_PHYERR;
}
return filter;
}
/**
* ath5k_hw_set_rx_filter() - Set rx filter
* @ah: The &struct ath5k_hw
* @filter: RX filter mask (see reg.h)
*
* Sets RX filter register and also handles PHY error filter
* register on 5212 and newer chips so that we have proper PHY
* error reporting.
*/
void
ath5k_hw_set_rx_filter(struct ath5k_hw *ah, u32 filter)
{
u32 data = 0;
/* Set PHY error filter register on 5212*/
if (ah->ah_version == AR5K_AR5212) {
if (filter & AR5K_RX_FILTER_RADARERR)
data |= AR5K_PHY_ERR_FIL_RADAR;
if (filter & AR5K_RX_FILTER_PHYERR)
data |= AR5K_PHY_ERR_FIL_OFDM | AR5K_PHY_ERR_FIL_CCK;
}
/*
* The AR5210 uses promiscuous mode to detect radar activity
*/
if (ah->ah_version == AR5K_AR5210 &&
(filter & AR5K_RX_FILTER_RADARERR)) {
filter &= ~AR5K_RX_FILTER_RADARERR;
filter |= AR5K_RX_FILTER_PROM;
}
/*Zero length DMA (phy error reporting) */
if (data)
AR5K_REG_ENABLE_BITS(ah, AR5K_RXCFG, AR5K_RXCFG_ZLFDMA);
else
AR5K_REG_DISABLE_BITS(ah, AR5K_RXCFG, AR5K_RXCFG_ZLFDMA);
/*Write RX Filter register*/
ath5k_hw_reg_write(ah, filter & 0xff, AR5K_RX_FILTER);
/*Write PHY error filter register on 5212*/
if (ah->ah_version == AR5K_AR5212)
ath5k_hw_reg_write(ah, data, AR5K_PHY_ERR_FIL);
}
/****************\
* Beacon control *
\****************/
#define ATH5K_MAX_TSF_READ 10
/**
* ath5k_hw_get_tsf64() - Get the full 64bit TSF
* @ah: The &struct ath5k_hw
*
* Returns the current TSF
*/
u64
ath5k_hw_get_tsf64(struct ath5k_hw *ah)
{
u32 tsf_lower, tsf_upper1, tsf_upper2;
int i;
unsigned long flags;
/* This code is time critical - we don't want to be interrupted here */
local_irq_save(flags);
/*
* While reading TSF upper and then lower part, the clock is still
* counting (or jumping in case of IBSS merge) so we might get
* inconsistent values. To avoid this, we read the upper part again
* and check it has not been changed. We make the hypothesis that a
* maximum of 3 changes can happens in a row (we use 10 as a safe
* value).
*
* Impact on performance is pretty small, since in most cases, only
* 3 register reads are needed.
*/
tsf_upper1 = ath5k_hw_reg_read(ah, AR5K_TSF_U32);
for (i = 0; i < ATH5K_MAX_TSF_READ; i++) {
tsf_lower = ath5k_hw_reg_read(ah, AR5K_TSF_L32);
tsf_upper2 = ath5k_hw_reg_read(ah, AR5K_TSF_U32);
if (tsf_upper2 == tsf_upper1)
break;
tsf_upper1 = tsf_upper2;
}
local_irq_restore(flags);
WARN_ON(i == ATH5K_MAX_TSF_READ);
return ((u64)tsf_upper1 << 32) | tsf_lower;
}
#undef ATH5K_MAX_TSF_READ
/**
* ath5k_hw_set_tsf64() - Set a new 64bit TSF
* @ah: The &struct ath5k_hw
* @tsf64: The new 64bit TSF
*
* Sets the new TSF
*/
void
ath5k_hw_set_tsf64(struct ath5k_hw *ah, u64 tsf64)
{
ath5k_hw_reg_write(ah, tsf64 & 0xffffffff, AR5K_TSF_L32);
ath5k_hw_reg_write(ah, (tsf64 >> 32) & 0xffffffff, AR5K_TSF_U32);
}
/**
* ath5k_hw_reset_tsf() - Force a TSF reset
* @ah: The &struct ath5k_hw
*
* Forces a TSF reset on PCU
*/
void
ath5k_hw_reset_tsf(struct ath5k_hw *ah)
{
u32 val;
val = ath5k_hw_reg_read(ah, AR5K_BEACON) | AR5K_BEACON_RESET_TSF;
/*
* Each write to the RESET_TSF bit toggles a hardware internal
* signal to reset TSF, but if left high it will cause a TSF reset
* on the next chip reset as well. Thus we always write the value
* twice to clear the signal.
*/
ath5k_hw_reg_write(ah, val, AR5K_BEACON);
ath5k_hw_reg_write(ah, val, AR5K_BEACON);
}
/**
* ath5k_hw_init_beacon_timers() - Initialize beacon timers
* @ah: The &struct ath5k_hw
* @next_beacon: Next TBTT
* @interval: Current beacon interval
*
* This function is used to initialize beacon timers based on current
* operation mode and settings.
*/
void
ath5k_hw_init_beacon_timers(struct ath5k_hw *ah, u32 next_beacon, u32 interval)
{
u32 timer1, timer2, timer3;
/*
* Set the additional timers by mode
*/
switch (ah->opmode) {
case NL80211_IFTYPE_MONITOR:
case NL80211_IFTYPE_STATION:
/* In STA mode timer1 is used as next wakeup
* timer and timer2 as next CFP duration start
* timer. Both in 1/8TUs. */
/* TODO: PCF handling */
if (ah->ah_version == AR5K_AR5210) {
timer1 = 0xffffffff;
timer2 = 0xffffffff;
} else {
timer1 = 0x0000ffff;
timer2 = 0x0007ffff;
}
/* Mark associated AP as PCF incapable for now */
AR5K_REG_DISABLE_BITS(ah, AR5K_STA_ID1, AR5K_STA_ID1_PCF);
break;
case NL80211_IFTYPE_ADHOC:
AR5K_REG_ENABLE_BITS(ah, AR5K_TXCFG, AR5K_TXCFG_ADHOC_BCN_ATIM);
/* fall through */
default:
/* On non-STA modes timer1 is used as next DMA
* beacon alert (DBA) timer and timer2 as next
* software beacon alert. Both in 1/8TUs. */
timer1 = (next_beacon - AR5K_TUNE_DMA_BEACON_RESP) << 3;
timer2 = (next_beacon - AR5K_TUNE_SW_BEACON_RESP) << 3;
break;
}
/* Timer3 marks the end of our ATIM window
* a zero length window is not allowed because
* we 'll get no beacons */
timer3 = next_beacon + 1;
/*
* Set the beacon register and enable all timers.
*/
/* When in AP or Mesh Point mode zero timer0 to start TSF */
if (ah->opmode == NL80211_IFTYPE_AP ||
ah->opmode == NL80211_IFTYPE_MESH_POINT)
ath5k_hw_reg_write(ah, 0, AR5K_TIMER0);
ath5k_hw_reg_write(ah, next_beacon, AR5K_TIMER0);
ath5k_hw_reg_write(ah, timer1, AR5K_TIMER1);
ath5k_hw_reg_write(ah, timer2, AR5K_TIMER2);
ath5k_hw_reg_write(ah, timer3, AR5K_TIMER3);
/* Force a TSF reset if requested and enable beacons */
if (interval & AR5K_BEACON_RESET_TSF)
ath5k_hw_reset_tsf(ah);
ath5k_hw_reg_write(ah, interval & (AR5K_BEACON_PERIOD |
AR5K_BEACON_ENABLE),
AR5K_BEACON);
/* Flush any pending BMISS interrupts on ISR by
* performing a clear-on-write operation on PISR
* register for the BMISS bit (writing a bit on
* ISR toggles a reset for that bit and leaves
* the remaining bits intact) */
if (ah->ah_version == AR5K_AR5210)
ath5k_hw_reg_write(ah, AR5K_ISR_BMISS, AR5K_ISR);
else
ath5k_hw_reg_write(ah, AR5K_ISR_BMISS, AR5K_PISR);
/* TODO: Set enhanced sleep registers on AR5212
* based on vif->bss_conf params, until then
* disable power save reporting.*/
AR5K_REG_DISABLE_BITS(ah, AR5K_STA_ID1, AR5K_STA_ID1_PWR_SV);
}
/**
* ath5k_check_timer_win() - Check if timer B is timer A + window
* @a: timer a (before b)
* @b: timer b (after a)
* @window: difference between a and b
* @intval: timers are increased by this interval
*
* This helper function checks if timer B is timer A + window and covers
* cases where timer A or B might have already been updated or wrapped
* around (Timers are 16 bit).
*
* Returns true if O.K.
*/
static inline bool
ath5k_check_timer_win(int a, int b, int window, int intval)
{
/*
* 1.) usually B should be A + window
* 2.) A already updated, B not updated yet
* 3.) A already updated and has wrapped around
* 4.) B has wrapped around
*/
if ((b - a == window) || /* 1.) */
(a - b == intval - window) || /* 2.) */
((a | 0x10000) - b == intval - window) || /* 3.) */
((b | 0x10000) - a == window)) /* 4.) */
return true; /* O.K. */
return false;
}
/**
* ath5k_hw_check_beacon_timers() - Check if the beacon timers are correct
* @ah: The &struct ath5k_hw
* @intval: beacon interval
*
* This is a workaround for IBSS mode
*
* The need for this function arises from the fact that we have 4 separate
* HW timer registers (TIMER0 - TIMER3), which are closely related to the
* next beacon target time (NBTT), and that the HW updates these timers
* separately based on the current TSF value. The hardware increments each
* timer by the beacon interval, when the local TSF converted to TU is equal
* to the value stored in the timer.
*
* The reception of a beacon with the same BSSID can update the local HW TSF
* at any time - this is something we can't avoid. If the TSF jumps to a
* time which is later than the time stored in a timer, this timer will not
* be updated until the TSF in TU wraps around at 16 bit (the size of the
* timers) and reaches the time which is stored in the timer.
*
* The problem is that these timers are closely related to TIMER0 (NBTT) and
* that they define a time "window". When the TSF jumps between two timers
* (e.g. ATIM and NBTT), the one in the past will be left behind (not
* updated), while the one in the future will be updated every beacon
* interval. This causes the window to get larger, until the TSF wraps
* around as described above and the timer which was left behind gets
* updated again. But - because the beacon interval is usually not an exact
* divisor of the size of the timers (16 bit), an unwanted "window" between
* these timers has developed!
*
* This is especially important with the ATIM window, because during
* the ATIM window only ATIM frames and no data frames are allowed to be
* sent, which creates transmission pauses after each beacon. This symptom
* has been described as "ramping ping" because ping times increase linearly
* for some time and then drop down again. A wrong window on the DMA beacon
* timer has the same effect, so we check for these two conditions.
*
* Returns true if O.K.
*/
bool
ath5k_hw_check_beacon_timers(struct ath5k_hw *ah, int intval)
{
unsigned int nbtt, atim, dma;
nbtt = ath5k_hw_reg_read(ah, AR5K_TIMER0);
atim = ath5k_hw_reg_read(ah, AR5K_TIMER3);
dma = ath5k_hw_reg_read(ah, AR5K_TIMER1) >> 3;
/* NOTE: SWBA is different. Having a wrong window there does not
* stop us from sending data and this condition is caught by
* other means (SWBA interrupt) */
if (ath5k_check_timer_win(nbtt, atim, 1, intval) &&
ath5k_check_timer_win(dma, nbtt, AR5K_TUNE_DMA_BEACON_RESP,
intval))
return true; /* O.K. */
return false;
}
/**
* ath5k_hw_set_coverage_class() - Set IEEE 802.11 coverage class
* @ah: The &struct ath5k_hw
* @coverage_class: IEEE 802.11 coverage class number
*
* Sets IFS intervals and ACK/CTS timeouts for given coverage class.
*/
void
ath5k_hw_set_coverage_class(struct ath5k_hw *ah, u8 coverage_class)
{
/* As defined by IEEE 802.11-2007 17.3.8.6 */
int slot_time = ath5k_hw_get_default_slottime(ah) + 3 * coverage_class;
int ack_timeout = ath5k_hw_get_default_sifs(ah) + slot_time;
int cts_timeout = ack_timeout;
ath5k_hw_set_ifs_intervals(ah, slot_time);
ath5k_hw_set_ack_timeout(ah, ack_timeout);
ath5k_hw_set_cts_timeout(ah, cts_timeout);
ah->ah_coverage_class = coverage_class;
}
/***************************\
* Init/Start/Stop functions *
\***************************/
/**
* ath5k_hw_start_rx_pcu() - Start RX engine
* @ah: The &struct ath5k_hw
*
* Starts RX engine on PCU so that hw can process RXed frames
* (ACK etc).
*
* NOTE: RX DMA should be already enabled using ath5k_hw_start_rx_dma
*/
void
ath5k_hw_start_rx_pcu(struct ath5k_hw *ah)
{
AR5K_REG_DISABLE_BITS(ah, AR5K_DIAG_SW, AR5K_DIAG_SW_DIS_RX);
}
/**
* at5k_hw_stop_rx_pcu() - Stop RX engine
* @ah: The &struct ath5k_hw
*
* Stops RX engine on PCU
*/
void
ath5k_hw_stop_rx_pcu(struct ath5k_hw *ah)
{
AR5K_REG_ENABLE_BITS(ah, AR5K_DIAG_SW, AR5K_DIAG_SW_DIS_RX);
}
/**
* ath5k_hw_set_opmode() - Set PCU operating mode
* @ah: The &struct ath5k_hw
* @op_mode: One of enum nl80211_iftype
*
* Configure PCU for the various operating modes (AP/STA etc)
*/
int
ath5k_hw_set_opmode(struct ath5k_hw *ah, enum nl80211_iftype op_mode)
{
struct ath_common *common = ath5k_hw_common(ah);
u32 pcu_reg, beacon_reg, low_id, high_id;
ATH5K_DBG(ah, ATH5K_DEBUG_MODE, "mode %d\n", op_mode);
/* Preserve rest settings */
pcu_reg = ath5k_hw_reg_read(ah, AR5K_STA_ID1) & 0xffff0000;
pcu_reg &= ~(AR5K_STA_ID1_ADHOC | AR5K_STA_ID1_AP
| AR5K_STA_ID1_KEYSRCH_MODE
| (ah->ah_version == AR5K_AR5210 ?
(AR5K_STA_ID1_PWR_SV | AR5K_STA_ID1_NO_PSPOLL) : 0));
beacon_reg = 0;
switch (op_mode) {
case NL80211_IFTYPE_ADHOC:
pcu_reg |= AR5K_STA_ID1_ADHOC | AR5K_STA_ID1_KEYSRCH_MODE;
beacon_reg |= AR5K_BCR_ADHOC;
if (ah->ah_version == AR5K_AR5210)
pcu_reg |= AR5K_STA_ID1_NO_PSPOLL;
else
AR5K_REG_ENABLE_BITS(ah, AR5K_CFG, AR5K_CFG_IBSS);
break;
case NL80211_IFTYPE_AP:
case NL80211_IFTYPE_MESH_POINT:
pcu_reg |= AR5K_STA_ID1_AP | AR5K_STA_ID1_KEYSRCH_MODE;
beacon_reg |= AR5K_BCR_AP;
if (ah->ah_version == AR5K_AR5210)
pcu_reg |= AR5K_STA_ID1_NO_PSPOLL;
else
AR5K_REG_DISABLE_BITS(ah, AR5K_CFG, AR5K_CFG_IBSS);
break;
case NL80211_IFTYPE_STATION:
pcu_reg |= AR5K_STA_ID1_KEYSRCH_MODE
| (ah->ah_version == AR5K_AR5210 ?
AR5K_STA_ID1_PWR_SV : 0);
/* fall through */
case NL80211_IFTYPE_MONITOR:
pcu_reg |= AR5K_STA_ID1_KEYSRCH_MODE
| (ah->ah_version == AR5K_AR5210 ?
AR5K_STA_ID1_NO_PSPOLL : 0);
break;
default:
return -EINVAL;
}
/*
* Set PCU registers
*/
low_id = get_unaligned_le32(common->macaddr);
high_id = get_unaligned_le16(common->macaddr + 4);
ath5k_hw_reg_write(ah, low_id, AR5K_STA_ID0);
ath5k_hw_reg_write(ah, pcu_reg | high_id, AR5K_STA_ID1);
/*
* Set Beacon Control Register on 5210
*/
if (ah->ah_version == AR5K_AR5210)
ath5k_hw_reg_write(ah, beacon_reg, AR5K_BCR);
return 0;
}
/**
* ath5k_hw_pcu_init() - Initialize PCU
* @ah: The &struct ath5k_hw
* @op_mode: One of enum nl80211_iftype
* @mode: One of enum ath5k_driver_mode
*
* This function is used to initialize PCU by setting current
* operation mode and various other settings.
*/
void
ath5k_hw_pcu_init(struct ath5k_hw *ah, enum nl80211_iftype op_mode)
{
/* Set bssid and bssid mask */
ath5k_hw_set_bssid(ah);
/* Set PCU config */
ath5k_hw_set_opmode(ah, op_mode);
/* Write rate duration table only on AR5212 and if
* virtual interface has already been brought up
* XXX: rethink this after new mode changes to
* mac80211 are integrated */
if (ah->ah_version == AR5K_AR5212 &&
ah->nvifs)
ath5k_hw_write_rate_duration(ah);
/* Set RSSI/BRSSI thresholds
*
* Note: If we decide to set this value
* dynamically, have in mind that when AR5K_RSSI_THR
* register is read it might return 0x40 if we haven't
* wrote anything to it plus BMISS RSSI threshold is zeroed.
* So doing a save/restore procedure here isn't the right
* choice. Instead store it on ath5k_hw */
ath5k_hw_reg_write(ah, (AR5K_TUNE_RSSI_THRES |
AR5K_TUNE_BMISS_THRES <<
AR5K_RSSI_THR_BMISS_S),
AR5K_RSSI_THR);
/* MIC QoS support */
if (ah->ah_mac_srev >= AR5K_SREV_AR2413) {
ath5k_hw_reg_write(ah, 0x000100aa, AR5K_MIC_QOS_CTL);
ath5k_hw_reg_write(ah, 0x00003210, AR5K_MIC_QOS_SEL);
}
/* QoS NOACK Policy */
if (ah->ah_version == AR5K_AR5212) {
ath5k_hw_reg_write(ah,
AR5K_REG_SM(2, AR5K_QOS_NOACK_2BIT_VALUES) |
AR5K_REG_SM(5, AR5K_QOS_NOACK_BIT_OFFSET) |
AR5K_REG_SM(0, AR5K_QOS_NOACK_BYTE_OFFSET),
AR5K_QOS_NOACK);
}
/* Restore slot time and ACK timeouts */
if (ah->ah_coverage_class > 0)
ath5k_hw_set_coverage_class(ah, ah->ah_coverage_class);
/* Set ACK bitrate mode (see ack_rates_high) */
if (ah->ah_version == AR5K_AR5212) {
u32 val = AR5K_STA_ID1_BASE_RATE_11B | AR5K_STA_ID1_ACKCTS_6MB;
if (ah->ah_ack_bitrate_high)
AR5K_REG_DISABLE_BITS(ah, AR5K_STA_ID1, val);
else
AR5K_REG_ENABLE_BITS(ah, AR5K_STA_ID1, val);
}
return;
}
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