tt.c

/******************************************************************************
 *
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2013 - 2014 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110,
 * USA
 *
 * The full GNU General Public License is included in this distribution
 * in the file called COPYING.
 *
 * Contact Information:
 *  Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 * BSD LICENSE
 *
 * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  * Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *  * Neither the name Intel Corporation nor the names of its
 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *****************************************************************************/

#include "mvm.h"
#include "iwl-config.h"
#include "iwl-io.h"
#include "iwl-csr.h"
#include "iwl-prph.h"

#define OTP_DTS_DIODE_DEVIATION 96 /*in words*/
/* VBG - Voltage Band Gap error data (temperature offset) */
#define OTP_WP_DTS_VBG			(OTP_DTS_DIODE_DEVIATION + 2)
#define MEAS_VBG_MIN_VAL		2300
#define MEAS_VBG_MAX_VAL		3000
#define MEAS_VBG_DEFAULT_VAL		2700
#define DTS_DIODE_VALID(flags)		(flags & DTS_DIODE_REG_FLAGS_PASS_ONCE)
#define MIN_TEMPERATURE			0
#define MAX_TEMPERATURE			125
#define TEMPERATURE_ERROR		(MAX_TEMPERATURE + 1)
#define PTAT_DIGITAL_VALUE_MIN_VALUE	0
#define PTAT_DIGITAL_VALUE_MAX_VALUE	0xFF
#define DTS_VREFS_NUM			5
static inline u32 DTS_DIODE_GET_VREFS_ID(u32 flags)
{
	return (flags & DTS_DIODE_REG_FLAGS_VREFS_ID) >>
					DTS_DIODE_REG_FLAGS_VREFS_ID_POS;
}

#define CALC_VREFS_MIN_DIFF	43
#define CALC_VREFS_MAX_DIFF	51
#define CALC_LUT_SIZE		(1 + CALC_VREFS_MAX_DIFF - CALC_VREFS_MIN_DIFF)
#define CALC_LUT_INDEX_OFFSET	CALC_VREFS_MIN_DIFF
#define CALC_TEMPERATURE_RESULT_SHIFT_OFFSET	23

/*
 * @digital_value: The diode's digital-value sampled (temperature/voltage)
 * @vref_low: The lower voltage-reference (the vref just below the diode's
 *	sampled digital-value)
 * @vref_high: The higher voltage-reference (the vref just above the diode's
 *	sampled digital-value)
 * @flags: bits[1:0]: The ID of the Vrefs pair (lowVref,highVref)
 *	bits[6:2]: Reserved.
 *	bits[7:7]: Indicates completion of at least 1 successful sample
 *	since last DTS reset.
 */
struct iwl_mvm_dts_diode_bits {
	u8 digital_value;
	u8 vref_low;
	u8 vref_high;
	u8 flags;
} __packed;

union dts_diode_results {
	u32 reg_value;
	struct iwl_mvm_dts_diode_bits bits;
} __packed;

static s16 iwl_mvm_dts_get_volt_band_gap(struct iwl_mvm *mvm)
{
	struct iwl_nvm_section calib_sec;
	const __le16 *calib;
	u16 vbg;

	/* TODO: move parsing to NVM code */
	calib_sec = mvm->nvm_sections[NVM_SECTION_TYPE_CALIBRATION];
	calib = (__le16 *)calib_sec.data;

	vbg = le16_to_cpu(calib[OTP_WP_DTS_VBG]);

	if (vbg < MEAS_VBG_MIN_VAL || vbg > MEAS_VBG_MAX_VAL)
		vbg = MEAS_VBG_DEFAULT_VAL;

	return vbg;
}

static u16 iwl_mvm_dts_get_ptat_deviation_offset(struct iwl_mvm *mvm)
{
	const u8 *calib;
	u8 ptat, pa1, pa2, median;

	/* TODO: move parsing to NVM code */
	calib = mvm->nvm_sections[NVM_SECTION_TYPE_CALIBRATION].data;
	ptat = calib[OTP_DTS_DIODE_DEVIATION];
	pa1 = calib[OTP_DTS_DIODE_DEVIATION + 1];
	pa2 = calib[OTP_DTS_DIODE_DEVIATION + 2];

	/* get the median: */
	if (ptat > pa1) {
		if (ptat > pa2)
			median = (pa1 > pa2) ? pa1 : pa2;
		else
			median = ptat;
	} else {
		if (pa1 > pa2)
			median = (ptat > pa2) ? ptat : pa2;
		else
			median = pa1;
	}

	return ptat - median;
}

static u8 iwl_mvm_dts_calibrate_ptat_deviation(struct iwl_mvm *mvm, u8 value)
{
	/* Calibrate the PTAT digital value, based on PTAT deviation data: */
	s16 new_val = value - iwl_mvm_dts_get_ptat_deviation_offset(mvm);

	if (new_val > PTAT_DIGITAL_VALUE_MAX_VALUE)
		new_val = PTAT_DIGITAL_VALUE_MAX_VALUE;
	else if (new_val < PTAT_DIGITAL_VALUE_MIN_VALUE)
		new_val = PTAT_DIGITAL_VALUE_MIN_VALUE;

	return new_val;
}

static bool dts_get_adjacent_vrefs(struct iwl_mvm *mvm,
				   union dts_diode_results *avg_ptat)
{
	u8 vrefs_results[DTS_VREFS_NUM];
	u8 low_vref_index = 0, flags;
	u32 reg;

	reg = iwl_read_prph(mvm->trans, DTSC_VREF_AVG);
	memcpy(vrefs_results, &reg, sizeof(reg));
	reg = iwl_read_prph(mvm->trans, DTSC_VREF5_AVG);
	vrefs_results[4] = reg & 0xff;

	if (avg_ptat->bits.digital_value < vrefs_results[0] ||
	    avg_ptat->bits.digital_value > vrefs_results[4])
		return false;

	if (avg_ptat->bits.digital_value > vrefs_results[3])
		low_vref_index = 3;
	else if (avg_ptat->bits.digital_value > vrefs_results[2])
		low_vref_index = 2;
	else if (avg_ptat->bits.digital_value > vrefs_results[1])
		low_vref_index = 1;

	avg_ptat->bits.vref_low  = vrefs_results[low_vref_index];
	avg_ptat->bits.vref_high = vrefs_results[low_vref_index + 1];
	flags = avg_ptat->bits.flags;
	avg_ptat->bits.flags =
		(flags & ~DTS_DIODE_REG_FLAGS_VREFS_ID) |
		(low_vref_index & DTS_DIODE_REG_FLAGS_VREFS_ID);
	return true;
}

/*
 * return true it the results are valid, and false otherwise.
 */
static bool dts_read_ptat_avg_results(struct iwl_mvm *mvm,
				      union dts_diode_results *avg_ptat)
{
	u32 reg;
	u8 tmp;

	/* fill the diode value and pass_once with avg-reg results */
	reg = iwl_read_prph(mvm->trans, DTSC_PTAT_AVG);
	reg &= DTS_DIODE_REG_DIG_VAL | DTS_DIODE_REG_PASS_ONCE;
	avg_ptat->reg_value = reg;

	/* calibrate the PTAT digital value */
	tmp = avg_ptat->bits.digital_value;
	tmp = iwl_mvm_dts_calibrate_ptat_deviation(mvm, tmp);
	avg_ptat->bits.digital_value = tmp;

	/*
	 * fill vrefs fields, based on the avgVrefs results
	 * and the diode value
	 */
	return dts_get_adjacent_vrefs(mvm, avg_ptat) &&
		DTS_DIODE_VALID(avg_ptat->bits.flags);
}

static s32 calculate_nic_temperature(union dts_diode_results avg_ptat,
				     u16 volt_band_gap)
{
	u32 tmp_result;
	u8 vrefs_diff;
	/*
	 * For temperature calculation (at the end, shift right by 23)
	 * LUT[(D2-D1)] = ROUND{ 2^23 / ((D2-D1)*9*10) }
	 * (D2-D1) ==   43    44    45    46    47    48    49    50    51
	 */
	static const u16 calc_lut[CALC_LUT_SIZE] = {
		2168, 2118, 2071, 2026, 1983, 1942, 1902, 1864, 1828,
	};

	/*
	 * The diff between the high and low voltage-references is assumed
	 * to be strictly be in range of [60,68]
	 */
	vrefs_diff = avg_ptat.bits.vref_high - avg_ptat.bits.vref_low;

	if (vrefs_diff < CALC_VREFS_MIN_DIFF ||
	    vrefs_diff > CALC_VREFS_MAX_DIFF)
		return TEMPERATURE_ERROR;

	/* calculate the result: */
	tmp_result =
		vrefs_diff * (DTS_DIODE_GET_VREFS_ID(avg_ptat.bits.flags) + 9);
	tmp_result += avg_ptat.bits.digital_value;
	tmp_result -= avg_ptat.bits.vref_high;

	/* multiply by the LUT value (based on the diff) */
	tmp_result *= calc_lut[vrefs_diff - CALC_LUT_INDEX_OFFSET];

	/*
	 * Get the BandGap (the voltage refereces source) error data
	 * (temperature offset)
	 */
	tmp_result *= volt_band_gap;

	/*
	 * here, tmp_result value can be up to 32-bits. We want to right-shift
	 * it *without* sign-extend.
	 */
	tmp_result = tmp_result >> CALC_TEMPERATURE_RESULT_SHIFT_OFFSET;

	/*
	 * at this point, tmp_result should be in the range:
	 * 200 <= tmp_result <= 365
	 */
	return (s16)tmp_result - 240;
}

static s32 check_nic_temperature(struct iwl_mvm *mvm)
{
	u16 volt_band_gap;
	union dts_diode_results avg_ptat;

	volt_band_gap = iwl_mvm_dts_get_volt_band_gap(mvm);

	/* disable DTS */
	iwl_write_prph(mvm->trans, SHR_MISC_WFM_DTS_EN, 0);

	/* SV initialization */
	iwl_write_prph(mvm->trans, SHR_MISC_WFM_DTS_EN, 1);
	iwl_write_prph(mvm->trans, DTSC_CFG_MODE,
		       DTSC_CFG_MODE_PERIODIC);

	/* wait for results */
	msleep(100);
	if (!dts_read_ptat_avg_results(mvm, &avg_ptat))
		return TEMPERATURE_ERROR;

	/* disable DTS */
	iwl_write_prph(mvm->trans, SHR_MISC_WFM_DTS_EN, 0);

	return calculate_nic_temperature(avg_ptat, volt_band_gap);
}

static void iwl_mvm_enter_ctkill(struct iwl_mvm *mvm)
{
	u32 duration = mvm->thermal_throttle.params->ct_kill_duration;

	IWL_ERR(mvm, "Enter CT Kill\n");
	iwl_mvm_set_hw_ctkill_state(mvm, true);
	schedule_delayed_work(&mvm->thermal_throttle.ct_kill_exit,
			      round_jiffies_relative(duration * HZ));
}

static void iwl_mvm_exit_ctkill(struct iwl_mvm *mvm)
{
	IWL_ERR(mvm, "Exit CT Kill\n");
	iwl_mvm_set_hw_ctkill_state(mvm, false);
}

static void check_exit_ctkill(struct work_struct *work)
{
	struct iwl_mvm_tt_mgmt *tt;
	struct iwl_mvm *mvm;
	u32 duration;
	s32 temp;

	tt = container_of(work, struct iwl_mvm_tt_mgmt, ct_kill_exit.work);
	mvm = container_of(tt, struct iwl_mvm, thermal_throttle);

	duration = tt->params->ct_kill_duration;

	iwl_trans_start_hw(mvm->trans);
	temp = check_nic_temperature(mvm);
	iwl_trans_stop_device(mvm->trans);

	if (temp < MIN_TEMPERATURE || temp > MAX_TEMPERATURE) {
		IWL_DEBUG_TEMP(mvm, "Failed to measure NIC temperature\n");
		goto reschedule;
	}
	IWL_DEBUG_TEMP(mvm, "NIC temperature: %d\n", temp);

	if (temp <= tt->params->ct_kill_exit) {
		iwl_mvm_exit_ctkill(mvm);
		return;
	}

reschedule:
	schedule_delayed_work(&mvm->thermal_throttle.ct_kill_exit,
			      round_jiffies(duration * HZ));
}

static void iwl_mvm_tt_smps_iterator(void *_data, u8 *mac,
				     struct ieee80211_vif *vif)
{
	struct iwl_mvm *mvm = _data;
	enum ieee80211_smps_mode smps_mode;

	lockdep_assert_held(&mvm->mutex);

	if (mvm->thermal_throttle.dynamic_smps)
		smps_mode = IEEE80211_SMPS_DYNAMIC;
	else
		smps_mode = IEEE80211_SMPS_AUTOMATIC;

	if (vif->type != NL80211_IFTYPE_STATION)
		return;

	iwl_mvm_update_smps(mvm, vif, IWL_MVM_SMPS_REQ_TT, smps_mode);
}

static void iwl_mvm_tt_tx_protection(struct iwl_mvm *mvm, bool enable)
{
	struct ieee80211_sta *sta;
	struct iwl_mvm_sta *mvmsta;
	int i, err;

	for (i = 0; i < IWL_MVM_STATION_COUNT; i++) {
		sta = rcu_dereference_protected(mvm->fw_id_to_mac_id[i],
						lockdep_is_held(&mvm->mutex));
		if (IS_ERR_OR_NULL(sta))
			continue;
		mvmsta = iwl_mvm_sta_from_mac80211(sta);
		if (enable == mvmsta->tt_tx_protection)
			continue;
		err = iwl_mvm_tx_protection(mvm, mvmsta, enable);
		if (err) {
			IWL_ERR(mvm, "Failed to %s Tx protection\n",
				enable ? "enable" : "disable");
		} else {
			IWL_DEBUG_TEMP(mvm, "%s Tx protection\n",
				       enable ? "Enable" : "Disable");
			mvmsta->tt_tx_protection = enable;
		}
	}
}

void iwl_mvm_tt_tx_backoff(struct iwl_mvm *mvm, u32 backoff)
{
	struct iwl_host_cmd cmd = {
		.id = REPLY_THERMAL_MNG_BACKOFF,
		.len = { sizeof(u32), },
		.data = { &backoff, },
		.flags = CMD_SYNC,
	};

	backoff = max(backoff, mvm->thermal_throttle.min_backoff);

	if (iwl_mvm_send_cmd(mvm, &cmd) == 0) {
		IWL_DEBUG_TEMP(mvm, "Set Thermal Tx backoff to: %u\n",
			       backoff);
		mvm->thermal_throttle.tx_backoff = backoff;
	} else {
		IWL_ERR(mvm, "Failed to change Thermal Tx backoff\n");
	}
}

void iwl_mvm_tt_handler(struct iwl_mvm *mvm)
{
	const struct iwl_tt_params *params = mvm->thermal_throttle.params;
	struct iwl_mvm_tt_mgmt *tt = &mvm->thermal_throttle;
	s32 temperature = mvm->temperature;
	bool throttle_enable = false;
	int i;
	u32 tx_backoff;

	IWL_DEBUG_TEMP(mvm, "NIC temperature: %d\n", mvm->temperature);

	if (params->support_ct_kill && temperature >= params->ct_kill_entry) {
		iwl_mvm_enter_ctkill(mvm);
		return;
	}

	if (params->support_dynamic_smps) {
		if (!tt->dynamic_smps &&
		    temperature >= params->dynamic_smps_entry) {
			IWL_DEBUG_TEMP(mvm, "Enable dynamic SMPS\n");
			tt->dynamic_smps = true;
			ieee80211_iterate_active_interfaces_atomic(
					mvm->hw, IEEE80211_IFACE_ITER_NORMAL,
					iwl_mvm_tt_smps_iterator, mvm);
			throttle_enable = true;
		} else if (tt->dynamic_smps &&
			   temperature <= params->dynamic_smps_exit) {
			IWL_DEBUG_TEMP(mvm, "Disable dynamic SMPS\n");
			tt->dynamic_smps = false;
			ieee80211_iterate_active_interfaces_atomic(
					mvm->hw, IEEE80211_IFACE_ITER_NORMAL,
					iwl_mvm_tt_smps_iterator, mvm);
		}
	}

	if (params->support_tx_protection) {
		if (temperature >= params->tx_protection_entry) {
			iwl_mvm_tt_tx_protection(mvm, true);
			throttle_enable = true;
		} else if (temperature <= params->tx_protection_exit) {
			iwl_mvm_tt_tx_protection(mvm, false);
		}
	}

	if (params->support_tx_backoff) {
		tx_backoff = 0;
		for (i = 0; i < TT_TX_BACKOFF_SIZE; i++) {
			if (temperature < params->tx_backoff[i].temperature)
				break;
			tx_backoff = params->tx_backoff[i].backoff;
		}
		if (tx_backoff != 0)
			throttle_enable = true;
		if (tt->tx_backoff != tx_backoff)
			iwl_mvm_tt_tx_backoff(mvm, tx_backoff);
	}

	if (!tt->throttle && throttle_enable) {
		IWL_WARN(mvm,
			 "Due to high temperature thermal throttling initiated\n");
		tt->throttle = true;
	} else if (tt->throttle && !tt->dynamic_smps && tt->tx_backoff == 0 &&
		   temperature <= params->tx_protection_exit) {
		IWL_WARN(mvm,
			 "Temperature is back to normal thermal throttling stopped\n");
		tt->throttle = false;
	}
}

static const struct iwl_tt_params iwl7000_tt_params = {
	.ct_kill_entry = 118,
	.ct_kill_exit = 96,
	.ct_kill_duration = 5,
	.dynamic_smps_entry = 114,
	.dynamic_smps_exit = 110,
	.tx_protection_entry = 114,
	.tx_protection_exit = 108,
	.tx_backoff = {
		{.temperature = 112, .backoff = 200},
		{.temperature = 113, .backoff = 600},
		{.temperature = 114, .backoff = 1200},
		{.temperature = 115, .backoff = 2000},
		{.temperature = 116, .backoff = 4000},
		{.temperature = 117, .backoff = 10000},
	},
	.support_ct_kill = true,
	.support_dynamic_smps = true,
	.support_tx_protection = true,
	.support_tx_backoff = true,
};

static const struct iwl_tt_params iwl7000_high_temp_tt_params = {
	.ct_kill_entry = 118,
	.ct_kill_exit = 96,
	.ct_kill_duration = 5,
	.dynamic_smps_entry = 114,
	.dynamic_smps_exit = 110,
	.tx_protection_entry = 114,
	.tx_protection_exit = 108,
	.tx_backoff = {
		{.temperature = 112, .backoff = 300},
		{.temperature = 113, .backoff = 800},
		{.temperature = 114, .backoff = 1500},
		{.temperature = 115, .backoff = 3000},
		{.temperature = 116, .backoff = 5000},
		{.temperature = 117, .backoff = 10000},
	},
	.support_ct_kill = true,
	.support_dynamic_smps = true,
	.support_tx_protection = true,
	.support_tx_backoff = true,
};

void iwl_mvm_tt_initialize(struct iwl_mvm *mvm, u32 min_backoff)
{
	struct iwl_mvm_tt_mgmt *tt = &mvm->thermal_throttle;

	IWL_DEBUG_TEMP(mvm, "Initialize Thermal Throttling\n");

	if (mvm->cfg->high_temp)
		tt->params = &iwl7000_high_temp_tt_params;
	else
		tt->params = &iwl7000_tt_params;

	tt->throttle = false;
	tt->min_backoff = min_backoff;
	INIT_DELAYED_WORK(&tt->ct_kill_exit, check_exit_ctkill);
}

void iwl_mvm_tt_exit(struct iwl_mvm *mvm)
{
	cancel_delayed_work_sync(&mvm->thermal_throttle.ct_kill_exit);
	IWL_DEBUG_TEMP(mvm, "Exit Thermal Throttling\n");
}