From 6f3b414aca060a847e243f676b8601731938eb48 Mon Sep 17 00:00:00 2001 From: Nick Kossifidis Date: Mon, 9 Feb 2009 06:03:41 +0200 Subject: ath5k: Update gain_F calibration code and add documentation * Update and cleanup rf gain optimization code * Add comments and refferences to docs and use sane function names * Use only step index on ath5k_gain, no need to have a pointer to the current step since we can determine te step from it's index, this also allows us to put all other structs on rfgain.h and cleanup ath5k.h a little * No need for ah_rfgain variable, we use ah_gain.g_state for everything * Tested on RF2112B chip but gain_F calibration is not yet done (we will finish this on the next patch where we'll rewrite rf-buffer handling) * Use initial rf gain settings for 2316 and 2317 SoCs introduced on a previous patch It seems big but it's mostly cleanup, very few functional changes have been made on phy.c Signed-off-by: Nick Kossifidis Signed-off-by: John W. Linville --- drivers/net/wireless/ath5k/phy.c | 403 +++++++++++++++++++++++++-------------- 1 file changed, 264 insertions(+), 139 deletions(-) (limited to 'drivers/net/wireless/ath5k/phy.c') diff --git a/drivers/net/wireless/ath5k/phy.c b/drivers/net/wireless/ath5k/phy.c index 5021749a439..2543a718fe3 100644 --- a/drivers/net/wireless/ath5k/phy.c +++ b/drivers/net/wireless/ath5k/phy.c @@ -78,10 +78,104 @@ static unsigned int ath5k_hw_rfregs_op(u32 *rf, u32 offset, u32 reg, u32 bits, return data; } -static u32 ath5k_hw_rfregs_gainf_corr(struct ath5k_hw *ah) +/**********************\ +* RF Gain optimization * +\**********************/ + +/* + * This code is used to optimize rf gain on different environments + * (temprature mostly) based on feedback from a power detector. + * + * It's only used on RF5111 and RF5112, later RF chips seem to have + * auto adjustment on hw -notice they have a much smaller BANK 7 and + * no gain optimization ladder-. + * + * For more infos check out this patent doc + * http://www.freepatentsonline.com/7400691.html + * + * This paper describes power drops as seen on the receiver due to + * probe packets + * http://www.cnri.dit.ie/publications/ICT08%20-%20Practical%20Issues + * %20of%20Power%20Control.pdf + * + * And this is the MadWiFi bug entry related to the above + * http://madwifi-project.org/ticket/1659 + * with various measurements and diagrams + * + * TODO: Deal with power drops due to probes by setting an apropriate + * tx power on the probe packets ! Make this part of the calibration process. + */ + +/* Initialize ah_gain durring attach */ +int ath5k_hw_rfgain_opt_init(struct ath5k_hw *ah) +{ + /* Initialize the gain optimization values */ + switch (ah->ah_radio) { + case AR5K_RF5111: + ah->ah_gain.g_step_idx = rfgain_opt_5111.go_default; + ah->ah_gain.g_low = 20; + ah->ah_gain.g_high = 35; + ah->ah_gain.g_state = AR5K_RFGAIN_ACTIVE; + break; + case AR5K_RF5112: + ah->ah_gain.g_step_idx = rfgain_opt_5112.go_default; + ah->ah_gain.g_low = 20; + ah->ah_gain.g_high = 85; + ah->ah_gain.g_state = AR5K_RFGAIN_ACTIVE; + break; + default: + return -EINVAL; + } + + return 0; +} + +/* Schedule a gain probe check on the next transmited packet. + * That means our next packet is going to be sent with lower + * tx power and a Peak to Average Power Detector (PAPD) will try + * to measure the gain. + * + * TODO: Use propper tx power setting for the probe packet so + * that we don't observe a serious power drop on the receiver + * + * XXX: How about forcing a tx packet (bypassing PCU arbitrator etc) + * just after we enable the probe so that we don't mess with + * standard traffic ? Maybe it's time to use sw interrupts and + * a probe tasklet !!! + */ +static void ath5k_hw_request_rfgain_probe(struct ath5k_hw *ah) +{ + + /* Skip if gain calibration is inactive or + * we already handle a probe request */ + if (ah->ah_gain.g_state != AR5K_RFGAIN_ACTIVE) + return; + + ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txpower.txp_max, + AR5K_PHY_PAPD_PROBE_TXPOWER) | + AR5K_PHY_PAPD_PROBE_TX_NEXT, AR5K_PHY_PAPD_PROBE); + + ah->ah_gain.g_state = AR5K_RFGAIN_READ_REQUESTED; + +} + +/* Calculate gain_F measurement correction + * based on the current step for RF5112 rev. 2 */ +static u32 ath5k_hw_rf_gainf_corr(struct ath5k_hw *ah) { u32 mix, step; u32 *rf; + const struct ath5k_gain_opt *go; + const struct ath5k_gain_opt_step *g_step; + + /* Only RF5112 Rev. 2 supports it */ + if ((ah->ah_radio != AR5K_RF5112) || + (ah->ah_radio_5ghz_revision <= AR5K_SREV_RAD_5112A)) + return 0; + + go = &rfgain_opt_5112; + + g_step = &go->go_step[ah->ah_gain.g_step_idx]; if (ah->ah_rf_banks == NULL) return 0; @@ -89,11 +183,15 @@ static u32 ath5k_hw_rfregs_gainf_corr(struct ath5k_hw *ah) rf = ah->ah_rf_banks; ah->ah_gain.g_f_corr = 0; + /* No VGA (Variable Gain Amplifier) override, skip */ if (ath5k_hw_rfregs_op(rf, ah->ah_offset[7], 0, 1, 36, 0, false) != 1) return 0; + /* Mix gain stepping */ step = ath5k_hw_rfregs_op(rf, ah->ah_offset[7], 0, 4, 32, 0, false); - mix = ah->ah_gain.g_step->gos_param[0]; + + /* Mix gain override */ + mix = g_step->gos_param[0]; switch (mix) { case 3: @@ -113,9 +211,13 @@ static u32 ath5k_hw_rfregs_gainf_corr(struct ath5k_hw *ah) return ah->ah_gain.g_f_corr; } -static bool ath5k_hw_rfregs_gain_readback(struct ath5k_hw *ah) +/* Check if current gain_F measurement is in the range of our + * power detector windows. If we get a measurement outside range + * we know it's not accurate (detectors can't measure anything outside + * their detection window) so we must ignore it */ +static bool ath5k_hw_rf_check_gainf_readback(struct ath5k_hw *ah) { - u32 step, mix, level[4]; + u32 step, mix_ovr, level[4]; u32 *rf; if (ah->ah_rf_banks == NULL) @@ -127,20 +229,20 @@ static bool ath5k_hw_rfregs_gain_readback(struct ath5k_hw *ah) step = ath5k_hw_rfregs_op(rf, ah->ah_offset[7], 0, 6, 37, 0, false); level[0] = 0; - level[1] = (step == 0x3f) ? 0x32 : step + 4; - level[2] = (step != 0x3f) ? 0x40 : level[0]; - level[3] = level[2] + 0x32; + level[1] = (step == 63) ? 50 : step + 4; + level[2] = (step != 63) ? 64 : level[0]; + level[3] = level[2] + 50 ; ah->ah_gain.g_high = level[3] - - (step == 0x3f ? AR5K_GAIN_DYN_ADJUST_HI_MARGIN : -5); + (step == 63 ? AR5K_GAIN_DYN_ADJUST_HI_MARGIN : -5); ah->ah_gain.g_low = level[0] + - (step == 0x3f ? AR5K_GAIN_DYN_ADJUST_LO_MARGIN : 0); + (step == 63 ? AR5K_GAIN_DYN_ADJUST_LO_MARGIN : 0); } else { - mix = ath5k_hw_rfregs_op(rf, ah->ah_offset[7], 0, 1, 36, 0, + mix_ovr = ath5k_hw_rfregs_op(rf, ah->ah_offset[7], 0, 1, 36, 0, false); level[0] = level[2] = 0; - if (mix == 1) { + if (mix_ovr == 1) { level[1] = level[3] = 83; } else { level[1] = level[3] = 107; @@ -154,9 +256,12 @@ static bool ath5k_hw_rfregs_gain_readback(struct ath5k_hw *ah) ah->ah_gain.g_current <= level[3]); } -static s32 ath5k_hw_rfregs_gain_adjust(struct ath5k_hw *ah) +/* Perform gain_F adjustment by choosing the right set + * of parameters from rf gain optimization ladder */ +static s8 ath5k_hw_rf_gainf_adjust(struct ath5k_hw *ah) { const struct ath5k_gain_opt *go; + const struct ath5k_gain_opt_step *g_step; int ret = 0; switch (ah->ah_radio) { @@ -170,35 +275,39 @@ static s32 ath5k_hw_rfregs_gain_adjust(struct ath5k_hw *ah) return 0; } - ah->ah_gain.g_step = &go->go_step[ah->ah_gain.g_step_idx]; + g_step = &go->go_step[ah->ah_gain.g_step_idx]; if (ah->ah_gain.g_current >= ah->ah_gain.g_high) { + + /* Reached maximum */ if (ah->ah_gain.g_step_idx == 0) return -1; + for (ah->ah_gain.g_target = ah->ah_gain.g_current; ah->ah_gain.g_target >= ah->ah_gain.g_high && ah->ah_gain.g_step_idx > 0; - ah->ah_gain.g_step = - &go->go_step[ah->ah_gain.g_step_idx]) + g_step = &go->go_step[ah->ah_gain.g_step_idx]) ah->ah_gain.g_target -= 2 * (go->go_step[--(ah->ah_gain.g_step_idx)].gos_gain - - ah->ah_gain.g_step->gos_gain); + g_step->gos_gain); ret = 1; goto done; } if (ah->ah_gain.g_current <= ah->ah_gain.g_low) { + + /* Reached minimum */ if (ah->ah_gain.g_step_idx == (go->go_steps_count - 1)) return -2; + for (ah->ah_gain.g_target = ah->ah_gain.g_current; ah->ah_gain.g_target <= ah->ah_gain.g_low && ah->ah_gain.g_step_idx < go->go_steps_count-1; - ah->ah_gain.g_step = - &go->go_step[ah->ah_gain.g_step_idx]) + g_step = &go->go_step[ah->ah_gain.g_step_idx]) ah->ah_gain.g_target -= 2 * (go->go_step[++ah->ah_gain.g_step_idx].gos_gain - - ah->ah_gain.g_step->gos_gain); + g_step->gos_gain); ret = 2; goto done; @@ -213,6 +322,135 @@ done: return ret; } +/* Main callback for thermal rf gain calibration engine + * Check for a new gain reading and schedule an adjustment + * if needed. + * + * TODO: Use sw interrupt to schedule reset if gain_F needs + * adjustment */ +enum ath5k_rfgain ath5k_hw_gainf_calibrate(struct ath5k_hw *ah) +{ + u32 data, type; + struct ath5k_eeprom_info *ee = &ah->ah_capabilities.cap_eeprom; + + ATH5K_TRACE(ah->ah_sc); + + if (ah->ah_rf_banks == NULL || + ah->ah_gain.g_state == AR5K_RFGAIN_INACTIVE) + return AR5K_RFGAIN_INACTIVE; + + /* No check requested, either engine is inactive + * or an adjustment is already requested */ + if (ah->ah_gain.g_state != AR5K_RFGAIN_READ_REQUESTED) + goto done; + + /* Read the PAPD (Peak to Average Power Detector) + * register */ + data = ath5k_hw_reg_read(ah, AR5K_PHY_PAPD_PROBE); + + /* No probe is scheduled, read gain_F measurement */ + if (!(data & AR5K_PHY_PAPD_PROBE_TX_NEXT)) { + ah->ah_gain.g_current = data >> AR5K_PHY_PAPD_PROBE_GAINF_S; + type = AR5K_REG_MS(data, AR5K_PHY_PAPD_PROBE_TYPE); + + /* If tx packet is CCK correct the gain_F measurement + * by cck ofdm gain delta */ + if (type == AR5K_PHY_PAPD_PROBE_TYPE_CCK) { + if (ah->ah_radio_5ghz_revision >= AR5K_SREV_RAD_5112A) + ah->ah_gain.g_current += + ee->ee_cck_ofdm_gain_delta; + else + ah->ah_gain.g_current += + AR5K_GAIN_CCK_PROBE_CORR; + } + + /* Further correct gain_F measurement for + * RF5112A radios */ + if (ah->ah_radio_5ghz_revision >= AR5K_SREV_RAD_5112A) { + ath5k_hw_rf_gainf_corr(ah); + ah->ah_gain.g_current = + ah->ah_gain.g_current >= ah->ah_gain.g_f_corr ? + (ah->ah_gain.g_current-ah->ah_gain.g_f_corr) : + 0; + } + + /* Check if measurement is ok and if we need + * to adjust gain, schedule a gain adjustment, + * else switch back to the acive state */ + if (ath5k_hw_rf_check_gainf_readback(ah) && + AR5K_GAIN_CHECK_ADJUST(&ah->ah_gain) && + ath5k_hw_rf_gainf_adjust(ah)) { + ah->ah_gain.g_state = AR5K_RFGAIN_NEED_CHANGE; + } else { + ah->ah_gain.g_state = AR5K_RFGAIN_ACTIVE; + } + } + +done: + return ah->ah_gain.g_state; +} + +/* Write initial rf gain table to set the RF sensitivity + * this one works on all RF chips and has nothing to do + * with gain_F calibration */ +int ath5k_hw_rfgain_init(struct ath5k_hw *ah, unsigned int freq) +{ + const struct ath5k_ini_rfgain *ath5k_rfg; + unsigned int i, size; + + switch (ah->ah_radio) { + case AR5K_RF5111: + ath5k_rfg = rfgain_5111; + size = ARRAY_SIZE(rfgain_5111); + break; + case AR5K_RF5112: + ath5k_rfg = rfgain_5112; + size = ARRAY_SIZE(rfgain_5112); + break; + case AR5K_RF2413: + ath5k_rfg = rfgain_2413; + size = ARRAY_SIZE(rfgain_2413); + break; + case AR5K_RF2316: + ath5k_rfg = rfgain_2316; + size = ARRAY_SIZE(rfgain_2316); + break; + case AR5K_RF5413: + ath5k_rfg = rfgain_5413; + size = ARRAY_SIZE(rfgain_5413); + break; + case AR5K_RF2317: + case AR5K_RF2425: + ath5k_rfg = rfgain_2425; + size = ARRAY_SIZE(rfgain_2425); + break; + default: + return -EINVAL; + } + + switch (freq) { + case AR5K_INI_RFGAIN_2GHZ: + case AR5K_INI_RFGAIN_5GHZ: + break; + default: + return -EINVAL; + } + + for (i = 0; i < size; i++) { + AR5K_REG_WAIT(i); + ath5k_hw_reg_write(ah, ath5k_rfg[i].rfg_value[freq], + (u32)ath5k_rfg[i].rfg_register); + } + + return 0; +} + + + +/********************\ +* RF Registers setup * +\********************/ + /* * Read EEPROM Calibration data, modify RF Banks and Initialize RF5111 */ @@ -311,6 +549,8 @@ static int ath5k_hw_rf5111_rfregs(struct ath5k_hw *ah, ath5k_hw_reg_write(ah, rf[i], rfb_5111[i].rfb_ctrl_register); } + ah->ah_gain.g_state = AR5K_RFGAIN_ACTIVE; + return 0; } @@ -407,6 +647,9 @@ static int ath5k_hw_rf5112_rfregs(struct ath5k_hw *ah, for (i = 0; i < rf_size; i++) ath5k_hw_reg_write(ah, rf[i], rf_ini[i].rfb_ctrl_register); + + ah->ah_gain.g_state = AR5K_RFGAIN_ACTIVE; + return 0; } @@ -536,125 +779,12 @@ int ath5k_hw_rfregs(struct ath5k_hw *ah, struct ieee80211_channel *channel, } ret = func(ah, channel, mode); - if (!ret) - ah->ah_rf_gain = AR5K_RFGAIN_INACTIVE; return ret; } -int ath5k_hw_rfgain(struct ath5k_hw *ah, unsigned int freq) -{ - const struct ath5k_ini_rfgain *ath5k_rfg; - unsigned int i, size; - switch (ah->ah_radio) { - case AR5K_RF5111: - ath5k_rfg = rfgain_5111; - size = ARRAY_SIZE(rfgain_5111); - break; - case AR5K_RF5112: - ath5k_rfg = rfgain_5112; - size = ARRAY_SIZE(rfgain_5112); - break; - case AR5K_RF5413: - ath5k_rfg = rfgain_5413; - size = ARRAY_SIZE(rfgain_5413); - break; - case AR5K_RF2413: - ath5k_rfg = rfgain_2413; - size = ARRAY_SIZE(rfgain_2413); - break; - case AR5K_RF2425: - ath5k_rfg = rfgain_2425; - size = ARRAY_SIZE(rfgain_2425); - break; - default: - return -EINVAL; - } - switch (freq) { - case AR5K_INI_RFGAIN_2GHZ: - case AR5K_INI_RFGAIN_5GHZ: - break; - default: - return -EINVAL; - } - - for (i = 0; i < size; i++) { - AR5K_REG_WAIT(i); - ath5k_hw_reg_write(ah, ath5k_rfg[i].rfg_value[freq], - (u32)ath5k_rfg[i].rfg_register); - } - - return 0; -} - -enum ath5k_rfgain ath5k_hw_get_rf_gain(struct ath5k_hw *ah) -{ - u32 data, type; - - ATH5K_TRACE(ah->ah_sc); - - if (ah->ah_rf_banks == NULL || !ah->ah_gain.g_active || - ah->ah_version <= AR5K_AR5211) - return AR5K_RFGAIN_INACTIVE; - - if (ah->ah_rf_gain != AR5K_RFGAIN_READ_REQUESTED) - goto done; - - data = ath5k_hw_reg_read(ah, AR5K_PHY_PAPD_PROBE); - - if (!(data & AR5K_PHY_PAPD_PROBE_TX_NEXT)) { - ah->ah_gain.g_current = data >> AR5K_PHY_PAPD_PROBE_GAINF_S; - type = AR5K_REG_MS(data, AR5K_PHY_PAPD_PROBE_TYPE); - - if (type == AR5K_PHY_PAPD_PROBE_TYPE_CCK) - ah->ah_gain.g_current += AR5K_GAIN_CCK_PROBE_CORR; - - if (ah->ah_radio >= AR5K_RF5112) { - ath5k_hw_rfregs_gainf_corr(ah); - ah->ah_gain.g_current = - ah->ah_gain.g_current >= ah->ah_gain.g_f_corr ? - (ah->ah_gain.g_current-ah->ah_gain.g_f_corr) : - 0; - } - - if (ath5k_hw_rfregs_gain_readback(ah) && - AR5K_GAIN_CHECK_ADJUST(&ah->ah_gain) && - ath5k_hw_rfregs_gain_adjust(ah)) - ah->ah_rf_gain = AR5K_RFGAIN_NEED_CHANGE; - } - -done: - return ah->ah_rf_gain; -} - -int ath5k_hw_set_rfgain_opt(struct ath5k_hw *ah) -{ - /* Initialize the gain optimization values */ - switch (ah->ah_radio) { - case AR5K_RF5111: - ah->ah_gain.g_step_idx = rfgain_opt_5111.go_default; - ah->ah_gain.g_step = - &rfgain_opt_5111.go_step[ah->ah_gain.g_step_idx]; - ah->ah_gain.g_low = 20; - ah->ah_gain.g_high = 35; - ah->ah_gain.g_active = 1; - break; - case AR5K_RF5112: - ah->ah_gain.g_step_idx = rfgain_opt_5112.go_default; - ah->ah_gain.g_step = - &rfgain_opt_5112.go_step[ah->ah_gain.g_step_idx]; - ah->ah_gain.g_low = 20; - ah->ah_gain.g_high = 85; - ah->ah_gain.g_active = 1; - break; - default: - return -EINVAL; - } - - return 0; -} /**************************\ PHY/RF channel functions @@ -1176,13 +1306,8 @@ done: * as often as I/Q calibration.*/ ath5k_hw_noise_floor_calibration(ah, channel->center_freq); - /* Request RF gain */ - if (channel->hw_value & CHANNEL_5GHZ) { - ath5k_hw_reg_write(ah, AR5K_REG_SM(ah->ah_txpower.txp_max, - AR5K_PHY_PAPD_PROBE_TXPOWER) | - AR5K_PHY_PAPD_PROBE_TX_NEXT, AR5K_PHY_PAPD_PROBE); - ah->ah_rf_gain = AR5K_RFGAIN_READ_REQUESTED; - } + /* Initiate a gain_F calibration */ + ath5k_hw_request_rfgain_probe(ah); return 0; } -- cgit v1.2.3-70-g09d2