google_dual_batt_gauge.c - kernel/google-modules/bms - Git at Google

 /* SPDX-License-Identifier: GPL-2.0 */
 /*
  * Copyright 2021 Google, LLC
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * 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.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/kernel.h>
 #include <linux/printk.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/pm_runtime.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <misc/gvotable.h>
 #include "gbms_power_supply.h"
 #include "google_bms.h"
 #include "google_psy.h"

 #define MAX(x, y)	((x) < (y) ? (y) : (x))
 #define DUAL_FG_DELAY_INIT_MS	500
 #define DUAL_FG_WORK_PERIOD_MS	10000
 #define DUAL_BATT_TEMP_VOTER	"daul_batt_temp"

 #define DUAL_BATT_VFLIP_OFFSET		50000
 #define DUAL_BATT_VFLIP_OFFSET_IDX	0

 struct dual_fg_drv {
 	struct device *device;
 	struct power_supply *psy;

 	const char *first_fg_psy_name;
 	const char *second_fg_psy_name;

 	struct power_supply *first_fg_psy;
 	struct power_supply *second_fg_psy;

 	struct mutex fg_lock;

 	struct delayed_work init_work;
 	struct delayed_work gdbatt_work;
 	struct gvotable_election *fcc_votable;

 	struct gbms_chg_profile chg_profile;

 	struct notifier_block fg_nb;

 	u32 battery_capacity;
 	int cc_max;

 	int base_charge_full;
 	int flip_charge_full;

 	bool init_complete;
 	bool resume_complete;
 	bool cable_in;

 	u32 vflip_offset;
 };

 static int gdbatt_resume_check(struct dual_fg_drv *dual_fg_drv) {
 	int ret = 0;

 	pm_runtime_get_sync(dual_fg_drv->device);
 	if (!dual_fg_drv->init_complete || !dual_fg_drv->resume_complete)
 		ret = -EAGAIN;
 	pm_runtime_put_sync(dual_fg_drv->device);

 	return ret;
 }

 static enum power_supply_property gdbatt_fg_props[] = {
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_HEALTH,
 	POWER_SUPPLY_PROP_CAPACITY,		/* replace with _RAW */
 	POWER_SUPPLY_PROP_CHARGE_COUNTER,
 	POWER_SUPPLY_PROP_CHARGE_FULL,
 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,	/* used from gbattery */
 	POWER_SUPPLY_PROP_CURRENT_AVG,		/* candidate for tier switch */
 	POWER_SUPPLY_PROP_CURRENT_NOW,
 	POWER_SUPPLY_PROP_CYCLE_COUNT,
 	POWER_SUPPLY_PROP_PRESENT,
 	POWER_SUPPLY_PROP_TEMP,
 	POWER_SUPPLY_PROP_VOLTAGE_AVG,
 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 	POWER_SUPPLY_PROP_VOLTAGE_OCV,
 	POWER_SUPPLY_PROP_TECHNOLOGY,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
 };

 static int gdbatt_get_temp(struct power_supply *fg_psy, int *temp)
 {
 	int err = 0;
 	union power_supply_propval val;

 	if (!fg_psy)
 		return -EINVAL;

 	err = power_supply_get_property(fg_psy,
 					POWER_SUPPLY_PROP_TEMP, &val);
 	if (err == 0)
 		*temp = val.intval;

 	return err;
 }

 static int gdbatt_select_temp_idx(struct gbms_chg_profile *profile, int temp)
 {
 	if (temp < profile->temp_limits[0] ||
 	    temp > profile->temp_limits[profile->temp_nb_limits - 1])
 		return -1;
 	else
 		return gbms_msc_temp_idx(profile, temp);
 }

 static int gdbatt_select_voltage_idx(struct gbms_chg_profile *profile, int vbatt)
 {
 	int vbatt_idx = 0;

 	while (vbatt_idx < profile->volt_nb_limits - 1 &&
 	       vbatt > profile->volt_limits[vbatt_idx])
 		vbatt_idx++;

 	return vbatt_idx;
 }

 static void gdbatt_select_cc_max(struct dual_fg_drv *dual_fg_drv)
 {
 	struct gbms_chg_profile *profile = &dual_fg_drv->chg_profile;
 	int base_temp, flip_temp, base_vbatt, flip_vbatt;
 	int base_temp_idx, flip_temp_idx, base_vbatt_idx, flip_vbatt_idx;
 	int base_cc_max, flip_cc_max, cc_max;
 	struct power_supply *base_psy = dual_fg_drv->first_fg_psy;
 	struct power_supply *flip_psy = dual_fg_drv->second_fg_psy;
 	int ret = 0;

 	if (!dual_fg_drv->cable_in)
 		goto check_done;

 	ret = gdbatt_get_temp(base_psy, &base_temp);
 	if (ret < 0)
 		goto check_done;

 	ret = gdbatt_get_temp(flip_psy, &flip_temp);
 	if (ret < 0)
 		goto check_done;

 	base_vbatt = GPSY_GET_PROP(base_psy, POWER_SUPPLY_PROP_VOLTAGE_NOW);
 	if (base_vbatt < 0)
 		goto check_done;

 	flip_vbatt = GPSY_GET_PROP(flip_psy, POWER_SUPPLY_PROP_VOLTAGE_NOW);
 	if (flip_vbatt < 0)
 		goto check_done;

 	base_temp_idx = gdbatt_select_temp_idx(profile, base_temp);
 	flip_temp_idx = gdbatt_select_temp_idx(profile, flip_temp);

 	base_vbatt_idx = gdbatt_select_voltage_idx(profile, base_vbatt);
 	flip_vbatt_idx = gdbatt_select_voltage_idx(profile,
 					  flip_vbatt - dual_fg_drv->vflip_offset);

 	/* only apply offset in allowed idx */
 	if (flip_vbatt_idx > DUAL_BATT_VFLIP_OFFSET_IDX)
 		flip_vbatt_idx = gdbatt_select_voltage_idx(profile, flip_vbatt);

 	base_cc_max = GBMS_CCCM_LIMITS(profile, base_temp_idx, base_vbatt_idx);
 	flip_cc_max = GBMS_CCCM_LIMITS(profile, flip_temp_idx, flip_vbatt_idx);
 	cc_max = (base_cc_max <= flip_cc_max) ? base_cc_max : flip_cc_max;
 	if (cc_max == dual_fg_drv->cc_max)
 		goto check_done;

 	if (!dual_fg_drv->fcc_votable)
 		dual_fg_drv->fcc_votable =
 			gvotable_election_get_handle(VOTABLE_MSC_FCC);
 	if (dual_fg_drv->fcc_votable) {
 		pr_info("temp:%d/%d(%d/%d), vbatt:%d/%d(%d/%d), cc_max:%d/%d(%d)\n",
 			base_temp, flip_temp, base_temp_idx, flip_temp_idx, base_vbatt,
 			flip_vbatt, base_vbatt_idx, flip_vbatt_idx, base_cc_max,
 			flip_cc_max, cc_max);
 		gvotable_cast_int_vote(dual_fg_drv->fcc_votable,
 				       DUAL_BATT_TEMP_VOTER, cc_max, true);
 		dual_fg_drv->cc_max = cc_max;
 		power_supply_changed(dual_fg_drv->psy);
 	}

 check_done:
 	pr_debug("check done. cable_in=%d (%d)\n", dual_fg_drv->cable_in, ret);
 }

 static int gdbatt_get_capacity(struct dual_fg_drv *dual_fg_drv, int base_soc, int flip_soc)
 {
 	const int base_full = dual_fg_drv->base_charge_full / 1000;
 	const int flip_full = dual_fg_drv->flip_charge_full / 1000;
 	const int full_sum = base_full + flip_full;

 	if (!base_full || !flip_full)
 		return (base_soc + flip_soc) / 2;

 	return (base_soc * base_full + flip_soc * flip_full) / full_sum;
 }

 static void google_dual_batt_work(struct work_struct *work)
 {
 	struct dual_fg_drv *dual_fg_drv = container_of(work, struct dual_fg_drv,
 						 gdbatt_work.work);
 	struct power_supply *base_psy = dual_fg_drv->first_fg_psy;
 	struct power_supply *flip_psy = dual_fg_drv->second_fg_psy;
 	int base_data, flip_data;

 	mutex_lock(&dual_fg_drv->fg_lock);

 	if (!dual_fg_drv->init_complete)
 		goto error_done;

 	if (!base_psy || !flip_psy)
 		goto error_done;

 	gdbatt_select_cc_max(dual_fg_drv);

 	base_data = GPSY_GET_PROP(base_psy, POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN);
 	flip_data = GPSY_GET_PROP(flip_psy, POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN);

 	if (base_data <= 0 || flip_data <= 0)
 		goto error_done;

 	dual_fg_drv->base_charge_full = base_data;
 	dual_fg_drv->flip_charge_full = flip_data;

 error_done:
 	mod_delayed_work(system_wq, &dual_fg_drv->gdbatt_work,
 			 msecs_to_jiffies(DUAL_FG_WORK_PERIOD_MS));

 	mutex_unlock(&dual_fg_drv->fg_lock);
 }

 static int gdbatt_get_property(struct power_supply *psy,
 				 enum power_supply_property psp,
 				 union power_supply_propval *val)
 {
 	struct dual_fg_drv *dual_fg_drv = (struct dual_fg_drv *)
 					power_supply_get_drvdata(psy);
 	int err = 0;
 	union power_supply_propval fg_1;
 	union power_supply_propval fg_2;

 	err = gdbatt_resume_check(dual_fg_drv);
 	if (err != 0)
 		return err;

 	if (!dual_fg_drv->first_fg_psy && !dual_fg_drv->second_fg_psy)
 		return -EAGAIN;

 	if (!dual_fg_drv->first_fg_psy || !dual_fg_drv->second_fg_psy)
 		goto single_fg;

 	mutex_lock(&dual_fg_drv->fg_lock);

 	err = power_supply_get_property(dual_fg_drv->first_fg_psy, psp, &fg_1);
 	if (err != 0) {
 		pr_debug("error %d reading first fg prop %d\n", err, psp);
 		mutex_unlock(&dual_fg_drv->fg_lock);
 		return err;
 	}

 	err = power_supply_get_property(dual_fg_drv->second_fg_psy, psp, &fg_2);
 	if (err != 0) {
 		pr_debug("error %d reading second fg prop %d\n", err, psp);
 		mutex_unlock(&dual_fg_drv->fg_lock);
 		return err;
 	}

 	switch (psp) {
 	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
 	case POWER_SUPPLY_PROP_CHARGE_FULL:
 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 	case POWER_SUPPLY_PROP_CURRENT_AVG:
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
 		val->intval = fg_1.intval + fg_2.intval;
 		break;
 	case POWER_SUPPLY_PROP_TEMP:
 		val->intval = MAX(fg_1.intval, fg_2.intval);
 		break;
 	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
 	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
 		val->intval = MAX(fg_1.intval, fg_2.intval);
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 		val->intval = (fg_1.intval + fg_2.intval)/2;
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
 	case POWER_SUPPLY_PROP_VOLTAGE_OCV:
 		val->intval = (fg_1.intval + fg_2.intval)/2;
 		break;
 	case GBMS_PROP_CAPACITY_RAW:
 	case POWER_SUPPLY_PROP_CAPACITY:
 		val->intval = gdbatt_get_capacity(dual_fg_drv, fg_1.intval, fg_2.intval);
 		break;
 	case POWER_SUPPLY_PROP_HEALTH:
 		/* larger one is bad. TODO: confirm its priority */
 		val->intval = MAX(fg_1.intval, fg_2.intval);
 		break;
 	case POWER_SUPPLY_PROP_STATUS:
 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
 	case POWER_SUPPLY_PROP_TECHNOLOGY:
 		val->intval = fg_1.intval;
 		if (fg_1.intval != fg_2.intval)
 			pr_debug("case %d not align: %d/%d",
 				psp, fg_1.intval, fg_2.intval);
 		break;
 	case POWER_SUPPLY_PROP_PRESENT:
 		val->intval = fg_1.intval && fg_2.intval;
 		if (fg_1.intval != fg_2.intval)
 			pr_debug("PRESENT different: %d/%d", fg_1.intval, fg_2.intval);
 		break;
 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 		/* TODO: need hash SN */
 		val->strval = fg_1.strval;
 		break;
 	/* support bhi */
 	case GBMS_PROP_HEALTH_ACT_IMPEDANCE:
 	case GBMS_PROP_HEALTH_IMPEDANCE:
 	case GBMS_PROP_RESISTANCE:
 	case GBMS_PROP_RESISTANCE_RAW:
 	case GBMS_PROP_RESISTANCE_AVG:
 	case GBMS_PROP_BATTERY_AGE:
 	case GBMS_PROP_CHARGE_FULL_ESTIMATE:
 	case GBMS_PROP_CAPACITY_FADE_RATE:
 		val->intval = fg_1.intval;
 		break;
 	default:
 		pr_debug("getting unsupported property: %d\n", psp);
 		break;
 	}

 	mutex_unlock(&dual_fg_drv->fg_lock);

 	return 0;

 single_fg:
 	mutex_lock(&dual_fg_drv->fg_lock);
 	if (dual_fg_drv->first_fg_psy)
 		err = power_supply_get_property(dual_fg_drv->first_fg_psy, psp, val);
 	else if (dual_fg_drv->second_fg_psy)
 		err = power_supply_get_property(dual_fg_drv->second_fg_psy, psp, val);
 	mutex_unlock(&dual_fg_drv->fg_lock);

 	if (err < 0)
 		pr_debug("error %d reading single prop %d\n", err, psp);

 	return 0;
 }

 static int gdbatt_set_property(struct power_supply *psy,
 				 enum power_supply_property psp,
 				 const union power_supply_propval *val)
 {
 	struct dual_fg_drv *dual_fg_drv = (struct dual_fg_drv *)
 					power_supply_get_drvdata(psy);
 	int ret = 0;

 	ret = gdbatt_resume_check(dual_fg_drv);
 	if (ret != 0)
 		return ret;

 	switch (psp) {
 	case GBMS_PROP_BATT_CE_CTRL:
 		if (dual_fg_drv->first_fg_psy) {
 			ret = GPSY_SET_PROP(dual_fg_drv->first_fg_psy, psp, val->intval);
 			if (ret < 0)
 				pr_err("Cannot set the first BATT_CE_CTRL, ret=%d\n", ret);
 		}
 		if (dual_fg_drv->second_fg_psy) {
 			ret = GPSY_SET_PROP(dual_fg_drv->second_fg_psy, psp, val->intval);
 			if (ret < 0)
 				pr_err("Cannot set the second BATT_CE_CTRL, ret=%d\n", ret);
 		}
 		dual_fg_drv->cable_in = !!val->intval;
 		break;
 	case GBMS_PROP_HEALTH_ACT_IMPEDANCE:
 		/* TODO: discuss with BattEng to decide save data */
 		/* if (dual_fg_drv->first_fg_psy) {
 			ret = GPSY_SET_PROP(dual_fg_drv->first_fg_psy, psp, val->intval);
 			if (ret < 0)
 				pr_err("Cannot set the first HEALTH_ACT_IMPEDANCE, ret=%d\n", ret);
 		} */
 		break;
 	default:
 		return -EINVAL;
 	}

 	if (ret < 0) {
 		pr_debug("gdbatt: set_prop cannot write psp=%d\n", psp);
 		return ret;
 	}

 	return 0;
 }

 static int gdbatt_property_is_writeable(struct power_supply *psy,
 					  enum power_supply_property psp)
 {
 	switch (psp) {
 	case GBMS_PROP_BATT_CE_CTRL:
 		return 1;
 	default:
 		break;
 	}

 	return 0;
 }

 static struct power_supply_desc gdbatt_psy_desc = {
 	.name = "dualbatt",
 	.type = POWER_SUPPLY_TYPE_BATTERY,
 	.get_property = gdbatt_get_property,
 	.set_property = gdbatt_set_property,
 	.property_is_writeable = gdbatt_property_is_writeable,
 	.properties = gdbatt_fg_props,
 	.num_properties = ARRAY_SIZE(gdbatt_fg_props),
 };

 /* ------------------------------------------------------------------------ */

 static int gdbatt_init_chg_profile(struct dual_fg_drv *dual_fg_drv)
 {
 	struct device_node *node = of_find_node_by_name(NULL, "google,battery");
 	struct gbms_chg_profile *profile = &dual_fg_drv->chg_profile;
 	int ret = 0;

 	if (profile->cccm_limits)
 		return 0;

 	ret = gbms_init_chg_profile(profile, node);
 	if (ret < 0)
 		return -EINVAL;

 	ret = of_property_read_u32(node, "google,chg-battery-capacity",
 				   &dual_fg_drv->battery_capacity);
 	if (ret < 0)
 		pr_warn("battery not present, no default capacity, zero charge table\n");

 	gbms_init_chg_table(profile, node, dual_fg_drv->battery_capacity);

 	return ret;
 }

 static int psy_changed(struct notifier_block *nb,
 		       unsigned long action, void *data)
 {
 	struct power_supply *psy = data;
 	struct dual_fg_drv *dual_fg_drv = container_of(nb, struct dual_fg_drv, fg_nb);

 	if ((action != PSY_EVENT_PROP_CHANGED) || (psy == NULL) || (psy->desc == NULL) ||
 	    (psy->desc->name == NULL))
 		return NOTIFY_OK;

 	pr_debug("name=%s evt=%lu\n", psy->desc->name, action);

 	if (action == PSY_EVENT_PROP_CHANGED) {
 		bool is_first_fg = (dual_fg_drv->first_fg_psy_name != NULL) &&
 				   !strcmp(psy->desc->name, dual_fg_drv->first_fg_psy_name);
 		bool is_second_fg = (dual_fg_drv->second_fg_psy_name != NULL) &&
 				    !strcmp(psy->desc->name, dual_fg_drv->second_fg_psy_name);

 		if (is_first_fg || is_second_fg)
 			power_supply_changed(dual_fg_drv->psy);
 	}

 	return NOTIFY_OK;
 }

 static void google_dual_batt_gauge_init_work(struct work_struct *work)
 {
 	struct dual_fg_drv *dual_fg_drv = container_of(work, struct dual_fg_drv,
 						 init_work.work);
 	struct power_supply *first_fg_psy = dual_fg_drv->first_fg_psy;
 	struct power_supply *second_fg_psy = dual_fg_drv->second_fg_psy;
 	union power_supply_propval val;
 	int err = 0;

 	if (!dual_fg_drv->first_fg_psy && dual_fg_drv->first_fg_psy_name) {
 		first_fg_psy = power_supply_get_by_name(dual_fg_drv->first_fg_psy_name);
 		if (!first_fg_psy) {
 			dev_info(dual_fg_drv->device,
 				"failed to get \"%s\" power supply, retrying...\n",
 				dual_fg_drv->first_fg_psy_name);
 			goto retry_init_work;
 		}

 		dual_fg_drv->first_fg_psy = first_fg_psy;

 		/* Don't use it if battery not present */
 		err = power_supply_get_property(first_fg_psy,
 						POWER_SUPPLY_PROP_PRESENT, &val);
 		if (err == -EAGAIN)
 			goto retry_init_work;
 		if (err == 0 && val.intval == 0) {
 			dev_info(dual_fg_drv->device, "First battery not PRESENT\n");
 			dual_fg_drv->first_fg_psy_name = NULL;
 			dual_fg_drv->first_fg_psy = NULL;
 		}
 	}

 	if (!dual_fg_drv->second_fg_psy && dual_fg_drv->second_fg_psy_name) {
 		second_fg_psy = power_supply_get_by_name(dual_fg_drv->second_fg_psy_name);
 		if (!second_fg_psy) {
 			pr_info("failed to get \"%s\" power supply, retrying...\n",
 				dual_fg_drv->second_fg_psy_name);
 			goto retry_init_work;
 		}

 		dual_fg_drv->second_fg_psy = second_fg_psy;

 		/* Don't use it if battery not present */
 		err = power_supply_get_property(second_fg_psy,
 						POWER_SUPPLY_PROP_PRESENT, &val);
 		if (err == -EAGAIN)
 			goto retry_init_work;
 		if (err == 0 && val.intval == 0) {
 			dev_info(dual_fg_drv->device, "Second battery not PRESENT\n");
 			dual_fg_drv->second_fg_psy_name = NULL;
 			dual_fg_drv->second_fg_psy = NULL;
 		}
 	}

 	dual_fg_drv->cc_max = -1;
 	err = gdbatt_init_chg_profile(dual_fg_drv);
 	if (err < 0)
 		dev_info(dual_fg_drv->device,"fail to init chg profile (%d)\n", err);

 	dual_fg_drv->fg_nb.notifier_call = psy_changed;
 	err = power_supply_reg_notifier(&dual_fg_drv->fg_nb);
 	if (err < 0)
 		pr_err("cannot register power supply notifer (%d)\n", err);

 	dual_fg_drv->init_complete = true;
 	dual_fg_drv->resume_complete = true;
 	mod_delayed_work(system_wq, &dual_fg_drv->gdbatt_work, 0);
 	dev_info(dual_fg_drv->device, "google_dual_batt_gauge_init_work done\n");

 	return;

 retry_init_work:
 	schedule_delayed_work(&dual_fg_drv->init_work,
 			      msecs_to_jiffies(DUAL_FG_DELAY_INIT_MS));
 }

 static int google_dual_batt_gauge_probe(struct platform_device *pdev)
 {
 	const char *first_fg_psy_name;
 	const char *second_fg_psy_name;
 	struct dual_fg_drv *dual_fg_drv;
 	struct power_supply_config psy_cfg = {};
 	int ret;

 	dual_fg_drv = devm_kzalloc(&pdev->dev, sizeof(*dual_fg_drv), GFP_KERNEL);
 	if (!dual_fg_drv)
 		return -ENOMEM;

 	dual_fg_drv->device = &pdev->dev;

 	ret = of_property_read_string(pdev->dev.of_node, "google,first-fg-psy-name",
 				      &first_fg_psy_name);
 	if (ret == 0) {
 		pr_info("google,first-fg-psy-name=%s\n", first_fg_psy_name);
 		dual_fg_drv->first_fg_psy_name = devm_kstrdup(&pdev->dev,
 							first_fg_psy_name, GFP_KERNEL);
 		if (!dual_fg_drv->first_fg_psy_name)
 			return -ENOMEM;
 	}

 	ret = of_property_read_string(pdev->dev.of_node, "google,second-fg-psy-name",
 				      &second_fg_psy_name);
 	if (ret == 0) {
 		pr_info("google,second-fg-psy-name=%s\n", second_fg_psy_name);
 		dual_fg_drv->second_fg_psy_name = devm_kstrdup(&pdev->dev, second_fg_psy_name,
 							GFP_KERNEL);
 		if (!dual_fg_drv->second_fg_psy_name)
 			return -ENOMEM;
 	}

 	if (!dual_fg_drv->first_fg_psy_name && !dual_fg_drv->second_fg_psy_name) {
 		pr_err("no dual gauge setting\n");
 		return -EINVAL;
 	}

 	ret = of_property_read_u32(pdev->dev.of_node, "google,vflip-offset",
 				   &dual_fg_drv->vflip_offset);
 	if (ret < 0) {
 		pr_debug("Couldn't set vflip_offset (%d)\n", ret);
 		dual_fg_drv->vflip_offset = DUAL_BATT_VFLIP_OFFSET;
 	}

 	INIT_DELAYED_WORK(&dual_fg_drv->init_work, google_dual_batt_gauge_init_work);
 	INIT_DELAYED_WORK(&dual_fg_drv->gdbatt_work, google_dual_batt_work);
 	mutex_init(&dual_fg_drv->fg_lock);
 	platform_set_drvdata(pdev, dual_fg_drv);

 	psy_cfg.drv_data = dual_fg_drv;
 	psy_cfg.of_node = pdev->dev.of_node;

 	if (of_property_read_bool(pdev->dev.of_node, "google,psy-type-unknown"))
 		gdbatt_psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;

 	dual_fg_drv->psy = devm_power_supply_register(dual_fg_drv->device,
 						   &gdbatt_psy_desc, &psy_cfg);
 	if (IS_ERR(dual_fg_drv->psy)) {
 		ret = PTR_ERR(dual_fg_drv->psy);
 		if (ret == -EPROBE_DEFER)
 			return -EPROBE_DEFER;

 		/* TODO: fail with -ENODEV */
 		dev_err(dual_fg_drv->device,
 			"Couldn't register as power supply, ret=%d\n", ret);
 	}

 	schedule_delayed_work(&dual_fg_drv->init_work,
 					msecs_to_jiffies(DUAL_FG_DELAY_INIT_MS));

 	pr_info("google_dual_batt_gauge_probe done\n");

 	return 0;
 }

 static int google_dual_batt_gauge_remove(struct platform_device *pdev)
 {
 	struct dual_fg_drv *dual_fg_drv = platform_get_drvdata(pdev);

 	gbms_free_chg_profile(&dual_fg_drv->chg_profile);

 	return 0;
 }

 static int __maybe_unused google_dual_batt_pm_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct dual_fg_drv *dual_fg_drv = platform_get_drvdata(pdev);

 	pm_runtime_get_sync(dual_fg_drv->device);
 	dual_fg_drv->resume_complete = false;
 	pm_runtime_put_sync(dual_fg_drv->device);

 	return 0;
 }

 static int __maybe_unused google_dual_batt_pm_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct dual_fg_drv *dual_fg_drv = platform_get_drvdata(pdev);

 	pm_runtime_get_sync(dual_fg_drv->device);
 	dual_fg_drv->resume_complete = true;
 	pm_runtime_put_sync(dual_fg_drv->device);

 	return 0;
 }

 static SIMPLE_DEV_PM_OPS(google_dual_batt_pm_ops,
 			 google_dual_batt_pm_suspend,
 			 google_dual_batt_pm_resume);

 static const struct of_device_id google_dual_batt_gauge_of_match[] = {
 	{.compatible = "google,dual_batt_gauge"},
 	{},
 };
 MODULE_DEVICE_TABLE(of, google_dual_batt_gauge_of_match);

 static struct platform_driver google_dual_batt_gauge_driver = {
 	.driver = {
 		   .name = "google,dual_batt_gauge",
 		   .owner = THIS_MODULE,
 		   .of_match_table = google_dual_batt_gauge_of_match,
 		   .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 		   .pm = &google_dual_batt_pm_ops,
 		   },
 	.probe = google_dual_batt_gauge_probe,
 	.remove = google_dual_batt_gauge_remove,
 };

 module_platform_driver(google_dual_batt_gauge_driver);

 MODULE_DESCRIPTION("Google Dual Gauge Driver");
 MODULE_AUTHOR("Jenny Ho <[email protected]>");
 MODULE_LICENSE("GPL");
	/* SPDX-License-Identifier: GPL-2.0 */
	/*
	* Copyright 2021 Google, LLC
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* 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.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/kernel.h>
	#include <linux/printk.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/pm_runtime.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>
	#include <misc/gvotable.h>
	#include "gbms_power_supply.h"
	#include "google_bms.h"
	#include "google_psy.h"

	#define MAX(x, y) ((x) < (y) ? (y) : (x))
	#define DUAL_FG_DELAY_INIT_MS 500
	#define DUAL_FG_WORK_PERIOD_MS 10000
	#define DUAL_BATT_TEMP_VOTER "daul_batt_temp"

	#define DUAL_BATT_VFLIP_OFFSET 50000
	#define DUAL_BATT_VFLIP_OFFSET_IDX 0

	struct dual_fg_drv {
	struct device *device;
	struct power_supply *psy;

	const char *first_fg_psy_name;
	const char *second_fg_psy_name;

	struct power_supply *first_fg_psy;
	struct power_supply *second_fg_psy;

	struct mutex fg_lock;

	struct delayed_work init_work;
	struct delayed_work gdbatt_work;
	struct gvotable_election *fcc_votable;

	struct gbms_chg_profile chg_profile;

	struct notifier_block fg_nb;

	u32 battery_capacity;
	int cc_max;

	int base_charge_full;
	int flip_charge_full;

	bool init_complete;
	bool resume_complete;
	bool cable_in;

	u32 vflip_offset;
	};

	static int gdbatt_resume_check(struct dual_fg_drv *dual_fg_drv) {
	int ret = 0;

	pm_runtime_get_sync(dual_fg_drv->device);
	if (!dual_fg_drv->init_complete \|\| !dual_fg_drv->resume_complete)
	ret = -EAGAIN;
	pm_runtime_put_sync(dual_fg_drv->device);

	return ret;
	}

	static enum power_supply_property gdbatt_fg_props[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_HEALTH,
	POWER_SUPPLY_PROP_CAPACITY, /* replace with _RAW */
	POWER_SUPPLY_PROP_CHARGE_COUNTER,
	POWER_SUPPLY_PROP_CHARGE_FULL,
	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, /* used from gbattery */
	POWER_SUPPLY_PROP_CURRENT_AVG, /* candidate for tier switch */
	POWER_SUPPLY_PROP_CURRENT_NOW,
	POWER_SUPPLY_PROP_CYCLE_COUNT,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_TEMP,
	POWER_SUPPLY_PROP_VOLTAGE_AVG,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	POWER_SUPPLY_PROP_VOLTAGE_OCV,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_SERIAL_NUMBER,
	};

	static int gdbatt_get_temp(struct power_supply fg_psy, int temp)
	{
	int err = 0;
	union power_supply_propval val;

	if (!fg_psy)
	return -EINVAL;

	err = power_supply_get_property(fg_psy,
	POWER_SUPPLY_PROP_TEMP, &val);
	if (err == 0)
	*temp = val.intval;

	return err;
	}

	static int gdbatt_select_temp_idx(struct gbms_chg_profile *profile, int temp)
	{
	if (temp < profile->temp_limits[0] \|\|
	temp > profile->temp_limits[profile->temp_nb_limits - 1])
	return -1;
	else
	return gbms_msc_temp_idx(profile, temp);
	}

	static int gdbatt_select_voltage_idx(struct gbms_chg_profile *profile, int vbatt)
	{
	int vbatt_idx = 0;

	while (vbatt_idx < profile->volt_nb_limits - 1 &&
	vbatt > profile->volt_limits[vbatt_idx])
	vbatt_idx++;

	return vbatt_idx;
	}

	static void gdbatt_select_cc_max(struct dual_fg_drv *dual_fg_drv)
	{
	struct gbms_chg_profile *profile = &dual_fg_drv->chg_profile;
	int base_temp, flip_temp, base_vbatt, flip_vbatt;
	int base_temp_idx, flip_temp_idx, base_vbatt_idx, flip_vbatt_idx;
	int base_cc_max, flip_cc_max, cc_max;
	struct power_supply *base_psy = dual_fg_drv->first_fg_psy;
	struct power_supply *flip_psy = dual_fg_drv->second_fg_psy;
	int ret = 0;

	if (!dual_fg_drv->cable_in)
	goto check_done;

	ret = gdbatt_get_temp(base_psy, &base_temp);
	if (ret < 0)
	goto check_done;

	ret = gdbatt_get_temp(flip_psy, &flip_temp);
	if (ret < 0)
	goto check_done;

	base_vbatt = GPSY_GET_PROP(base_psy, POWER_SUPPLY_PROP_VOLTAGE_NOW);
	if (base_vbatt < 0)
	goto check_done;

	flip_vbatt = GPSY_GET_PROP(flip_psy, POWER_SUPPLY_PROP_VOLTAGE_NOW);
	if (flip_vbatt < 0)
	goto check_done;

	base_temp_idx = gdbatt_select_temp_idx(profile, base_temp);
	flip_temp_idx = gdbatt_select_temp_idx(profile, flip_temp);

	base_vbatt_idx = gdbatt_select_voltage_idx(profile, base_vbatt);
	flip_vbatt_idx = gdbatt_select_voltage_idx(profile,
	flip_vbatt - dual_fg_drv->vflip_offset);

	/* only apply offset in allowed idx */
	if (flip_vbatt_idx > DUAL_BATT_VFLIP_OFFSET_IDX)
	flip_vbatt_idx = gdbatt_select_voltage_idx(profile, flip_vbatt);

	base_cc_max = GBMS_CCCM_LIMITS(profile, base_temp_idx, base_vbatt_idx);
	flip_cc_max = GBMS_CCCM_LIMITS(profile, flip_temp_idx, flip_vbatt_idx);
	cc_max = (base_cc_max <= flip_cc_max) ? base_cc_max : flip_cc_max;
	if (cc_max == dual_fg_drv->cc_max)
	goto check_done;

	if (!dual_fg_drv->fcc_votable)
	dual_fg_drv->fcc_votable =
	gvotable_election_get_handle(VOTABLE_MSC_FCC);
	if (dual_fg_drv->fcc_votable) {
	pr_info("temp:%d/%d(%d/%d), vbatt:%d/%d(%d/%d), cc_max:%d/%d(%d)\n",
	base_temp, flip_temp, base_temp_idx, flip_temp_idx, base_vbatt,
	flip_vbatt, base_vbatt_idx, flip_vbatt_idx, base_cc_max,
	flip_cc_max, cc_max);
	gvotable_cast_int_vote(dual_fg_drv->fcc_votable,
	DUAL_BATT_TEMP_VOTER, cc_max, true);
	dual_fg_drv->cc_max = cc_max;
	power_supply_changed(dual_fg_drv->psy);
	}

	check_done:
	pr_debug("check done. cable_in=%d (%d)\n", dual_fg_drv->cable_in, ret);
	}

	static int gdbatt_get_capacity(struct dual_fg_drv *dual_fg_drv, int base_soc, int flip_soc)
	{
	const int base_full = dual_fg_drv->base_charge_full / 1000;
	const int flip_full = dual_fg_drv->flip_charge_full / 1000;
	const int full_sum = base_full + flip_full;

	if (!base_full \|\| !flip_full)
	return (base_soc + flip_soc) / 2;

	return (base_soc * base_full + flip_soc * flip_full) / full_sum;
	}

	static void google_dual_batt_work(struct work_struct *work)
	{
	struct dual_fg_drv *dual_fg_drv = container_of(work, struct dual_fg_drv,
	gdbatt_work.work);
	struct power_supply *base_psy = dual_fg_drv->first_fg_psy;
	struct power_supply *flip_psy = dual_fg_drv->second_fg_psy;
	int base_data, flip_data;

	mutex_lock(&dual_fg_drv->fg_lock);

	if (!dual_fg_drv->init_complete)
	goto error_done;

	if (!base_psy \|\| !flip_psy)
	goto error_done;

	gdbatt_select_cc_max(dual_fg_drv);

	base_data = GPSY_GET_PROP(base_psy, POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN);
	flip_data = GPSY_GET_PROP(flip_psy, POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN);

	if (base_data <= 0 \|\| flip_data <= 0)
	goto error_done;

	dual_fg_drv->base_charge_full = base_data;
	dual_fg_drv->flip_charge_full = flip_data;

	error_done:
	mod_delayed_work(system_wq, &dual_fg_drv->gdbatt_work,
	msecs_to_jiffies(DUAL_FG_WORK_PERIOD_MS));

	mutex_unlock(&dual_fg_drv->fg_lock);
	}

	static int gdbatt_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	struct dual_fg_drv dual_fg_drv = (struct dual_fg_drv )
	power_supply_get_drvdata(psy);
	int err = 0;
	union power_supply_propval fg_1;
	union power_supply_propval fg_2;

	err = gdbatt_resume_check(dual_fg_drv);
	if (err != 0)
	return err;

	if (!dual_fg_drv->first_fg_psy && !dual_fg_drv->second_fg_psy)
	return -EAGAIN;

	if (!dual_fg_drv->first_fg_psy \|\| !dual_fg_drv->second_fg_psy)
	goto single_fg;

	mutex_lock(&dual_fg_drv->fg_lock);

	err = power_supply_get_property(dual_fg_drv->first_fg_psy, psp, &fg_1);
	if (err != 0) {
	pr_debug("error %d reading first fg prop %d\n", err, psp);
	mutex_unlock(&dual_fg_drv->fg_lock);
	return err;
	}

	err = power_supply_get_property(dual_fg_drv->second_fg_psy, psp, &fg_2);
	if (err != 0) {
	pr_debug("error %d reading second fg prop %d\n", err, psp);
	mutex_unlock(&dual_fg_drv->fg_lock);
	return err;
	}

	switch (psp) {
	case POWER_SUPPLY_PROP_CHARGE_COUNTER:
	case POWER_SUPPLY_PROP_CHARGE_FULL:
	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
	case POWER_SUPPLY_PROP_CURRENT_AVG:
	case POWER_SUPPLY_PROP_CURRENT_NOW:
	val->intval = fg_1.intval + fg_2.intval;
	break;
	case POWER_SUPPLY_PROP_TEMP:
	val->intval = MAX(fg_1.intval, fg_2.intval);
	break;
	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
	val->intval = MAX(fg_1.intval, fg_2.intval);
	break;
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	val->intval = (fg_1.intval + fg_2.intval)/2;
	break;
	case POWER_SUPPLY_PROP_VOLTAGE_AVG:
	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
	case POWER_SUPPLY_PROP_VOLTAGE_OCV:
	val->intval = (fg_1.intval + fg_2.intval)/2;
	break;
	case GBMS_PROP_CAPACITY_RAW:
	case POWER_SUPPLY_PROP_CAPACITY:
	val->intval = gdbatt_get_capacity(dual_fg_drv, fg_1.intval, fg_2.intval);
	break;
	case POWER_SUPPLY_PROP_HEALTH:
	/* larger one is bad. TODO: confirm its priority */
	val->intval = MAX(fg_1.intval, fg_2.intval);
	break;
	case POWER_SUPPLY_PROP_STATUS:
	case POWER_SUPPLY_PROP_CYCLE_COUNT:
	case POWER_SUPPLY_PROP_TECHNOLOGY:
	val->intval = fg_1.intval;
	if (fg_1.intval != fg_2.intval)
	pr_debug("case %d not align: %d/%d",
	psp, fg_1.intval, fg_2.intval);
	break;
	case POWER_SUPPLY_PROP_PRESENT:
	val->intval = fg_1.intval && fg_2.intval;
	if (fg_1.intval != fg_2.intval)
	pr_debug("PRESENT different: %d/%d", fg_1.intval, fg_2.intval);
	break;
	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
	/* TODO: need hash SN */
	val->strval = fg_1.strval;
	break;
	/* support bhi */
	case GBMS_PROP_HEALTH_ACT_IMPEDANCE:
	case GBMS_PROP_HEALTH_IMPEDANCE:
	case GBMS_PROP_RESISTANCE:
	case GBMS_PROP_RESISTANCE_RAW:
	case GBMS_PROP_RESISTANCE_AVG:
	case GBMS_PROP_BATTERY_AGE:
	case GBMS_PROP_CHARGE_FULL_ESTIMATE:
	case GBMS_PROP_CAPACITY_FADE_RATE:
	val->intval = fg_1.intval;
	break;
	default:
	pr_debug("getting unsupported property: %d\n", psp);
	break;
	}

	mutex_unlock(&dual_fg_drv->fg_lock);

	return 0;

	single_fg:
	mutex_lock(&dual_fg_drv->fg_lock);
	if (dual_fg_drv->first_fg_psy)
	err = power_supply_get_property(dual_fg_drv->first_fg_psy, psp, val);
	else if (dual_fg_drv->second_fg_psy)
	err = power_supply_get_property(dual_fg_drv->second_fg_psy, psp, val);
	mutex_unlock(&dual_fg_drv->fg_lock);

	if (err < 0)
	pr_debug("error %d reading single prop %d\n", err, psp);

	return 0;
	}

	static int gdbatt_set_property(struct power_supply *psy,
	enum power_supply_property psp,
	const union power_supply_propval *val)
	{
	struct dual_fg_drv dual_fg_drv = (struct dual_fg_drv )
	power_supply_get_drvdata(psy);
	int ret = 0;

	ret = gdbatt_resume_check(dual_fg_drv);
	if (ret != 0)
	return ret;

	switch (psp) {
	case GBMS_PROP_BATT_CE_CTRL:
	if (dual_fg_drv->first_fg_psy) {
	ret = GPSY_SET_PROP(dual_fg_drv->first_fg_psy, psp, val->intval);
	if (ret < 0)
	pr_err("Cannot set the first BATT_CE_CTRL, ret=%d\n", ret);
	}
	if (dual_fg_drv->second_fg_psy) {
	ret = GPSY_SET_PROP(dual_fg_drv->second_fg_psy, psp, val->intval);
	if (ret < 0)
	pr_err("Cannot set the second BATT_CE_CTRL, ret=%d\n", ret);
	}
	dual_fg_drv->cable_in = !!val->intval;
	break;
	case GBMS_PROP_HEALTH_ACT_IMPEDANCE:
	/* TODO: discuss with BattEng to decide save data */
	/* if (dual_fg_drv->first_fg_psy) {
	ret = GPSY_SET_PROP(dual_fg_drv->first_fg_psy, psp, val->intval);
	if (ret < 0)
	pr_err("Cannot set the first HEALTH_ACT_IMPEDANCE, ret=%d\n", ret);
	} */
	break;
	default:
	return -EINVAL;
	}

	if (ret < 0) {
	pr_debug("gdbatt: set_prop cannot write psp=%d\n", psp);
	return ret;
	}

	return 0;
	}

	static int gdbatt_property_is_writeable(struct power_supply *psy,
	enum power_supply_property psp)
	{
	switch (psp) {
	case GBMS_PROP_BATT_CE_CTRL:
	return 1;
	default:
	break;
	}

	return 0;
	}

	static struct power_supply_desc gdbatt_psy_desc = {
	.name = "dualbatt",
	.type = POWER_SUPPLY_TYPE_BATTERY,
	.get_property = gdbatt_get_property,
	.set_property = gdbatt_set_property,
	.property_is_writeable = gdbatt_property_is_writeable,
	.properties = gdbatt_fg_props,
	.num_properties = ARRAY_SIZE(gdbatt_fg_props),
	};

	/* ------------------------------------------------------------------------ */

	static int gdbatt_init_chg_profile(struct dual_fg_drv *dual_fg_drv)
	{
	struct device_node *node = of_find_node_by_name(NULL, "google,battery");
	struct gbms_chg_profile *profile = &dual_fg_drv->chg_profile;
	int ret = 0;

	if (profile->cccm_limits)
	return 0;

	ret = gbms_init_chg_profile(profile, node);
	if (ret < 0)
	return -EINVAL;

	ret = of_property_read_u32(node, "google,chg-battery-capacity",
	&dual_fg_drv->battery_capacity);
	if (ret < 0)
	pr_warn("battery not present, no default capacity, zero charge table\n");

	gbms_init_chg_table(profile, node, dual_fg_drv->battery_capacity);

	return ret;
	}

	static int psy_changed(struct notifier_block *nb,
	unsigned long action, void *data)
	{
	struct power_supply *psy = data;
	struct dual_fg_drv *dual_fg_drv = container_of(nb, struct dual_fg_drv, fg_nb);

	if ((action != PSY_EVENT_PROP_CHANGED) \|\| (psy == NULL) \|\| (psy->desc == NULL) \|\|
	(psy->desc->name == NULL))
	return NOTIFY_OK;

	pr_debug("name=%s evt=%lu\n", psy->desc->name, action);

	if (action == PSY_EVENT_PROP_CHANGED) {
	bool is_first_fg = (dual_fg_drv->first_fg_psy_name != NULL) &&
	!strcmp(psy->desc->name, dual_fg_drv->first_fg_psy_name);
	bool is_second_fg = (dual_fg_drv->second_fg_psy_name != NULL) &&
	!strcmp(psy->desc->name, dual_fg_drv->second_fg_psy_name);

	if (is_first_fg \|\| is_second_fg)
	power_supply_changed(dual_fg_drv->psy);
	}

	return NOTIFY_OK;
	}

	static void google_dual_batt_gauge_init_work(struct work_struct *work)
	{
	struct dual_fg_drv *dual_fg_drv = container_of(work, struct dual_fg_drv,
	init_work.work);
	struct power_supply *first_fg_psy = dual_fg_drv->first_fg_psy;
	struct power_supply *second_fg_psy = dual_fg_drv->second_fg_psy;
	union power_supply_propval val;
	int err = 0;

	if (!dual_fg_drv->first_fg_psy && dual_fg_drv->first_fg_psy_name) {
	first_fg_psy = power_supply_get_by_name(dual_fg_drv->first_fg_psy_name);
	if (!first_fg_psy) {
	dev_info(dual_fg_drv->device,
	"failed to get \"%s\" power supply, retrying...\n",
	dual_fg_drv->first_fg_psy_name);
	goto retry_init_work;
	}

	dual_fg_drv->first_fg_psy = first_fg_psy;

	/* Don't use it if battery not present */
	err = power_supply_get_property(first_fg_psy,
	POWER_SUPPLY_PROP_PRESENT, &val);
	if (err == -EAGAIN)
	goto retry_init_work;
	if (err == 0 && val.intval == 0) {
	dev_info(dual_fg_drv->device, "First battery not PRESENT\n");
	dual_fg_drv->first_fg_psy_name = NULL;
	dual_fg_drv->first_fg_psy = NULL;
	}
	}

	if (!dual_fg_drv->second_fg_psy && dual_fg_drv->second_fg_psy_name) {
	second_fg_psy = power_supply_get_by_name(dual_fg_drv->second_fg_psy_name);
	if (!second_fg_psy) {
	pr_info("failed to get \"%s\" power supply, retrying...\n",
	dual_fg_drv->second_fg_psy_name);
	goto retry_init_work;
	}

	dual_fg_drv->second_fg_psy = second_fg_psy;

	/* Don't use it if battery not present */
	err = power_supply_get_property(second_fg_psy,
	POWER_SUPPLY_PROP_PRESENT, &val);
	if (err == -EAGAIN)
	goto retry_init_work;
	if (err == 0 && val.intval == 0) {
	dev_info(dual_fg_drv->device, "Second battery not PRESENT\n");
	dual_fg_drv->second_fg_psy_name = NULL;
	dual_fg_drv->second_fg_psy = NULL;
	}
	}

	dual_fg_drv->cc_max = -1;
	err = gdbatt_init_chg_profile(dual_fg_drv);
	if (err < 0)
	dev_info(dual_fg_drv->device,"fail to init chg profile (%d)\n", err);

	dual_fg_drv->fg_nb.notifier_call = psy_changed;
	err = power_supply_reg_notifier(&dual_fg_drv->fg_nb);
	if (err < 0)
	pr_err("cannot register power supply notifer (%d)\n", err);

	dual_fg_drv->init_complete = true;
	dual_fg_drv->resume_complete = true;
	mod_delayed_work(system_wq, &dual_fg_drv->gdbatt_work, 0);
	dev_info(dual_fg_drv->device, "google_dual_batt_gauge_init_work done\n");

	return;

	retry_init_work:
	schedule_delayed_work(&dual_fg_drv->init_work,
	msecs_to_jiffies(DUAL_FG_DELAY_INIT_MS));
	}

	static int google_dual_batt_gauge_probe(struct platform_device *pdev)
	{
	const char *first_fg_psy_name;
	const char *second_fg_psy_name;
	struct dual_fg_drv *dual_fg_drv;
	struct power_supply_config psy_cfg = {};
	int ret;

	dual_fg_drv = devm_kzalloc(&pdev->dev, sizeof(*dual_fg_drv), GFP_KERNEL);
	if (!dual_fg_drv)
	return -ENOMEM;

	dual_fg_drv->device = &pdev->dev;

	ret = of_property_read_string(pdev->dev.of_node, "google,first-fg-psy-name",
	&first_fg_psy_name);
	if (ret == 0) {
	pr_info("google,first-fg-psy-name=%s\n", first_fg_psy_name);
	dual_fg_drv->first_fg_psy_name = devm_kstrdup(&pdev->dev,
	first_fg_psy_name, GFP_KERNEL);
	if (!dual_fg_drv->first_fg_psy_name)
	return -ENOMEM;
	}

	ret = of_property_read_string(pdev->dev.of_node, "google,second-fg-psy-name",
	&second_fg_psy_name);
	if (ret == 0) {
	pr_info("google,second-fg-psy-name=%s\n", second_fg_psy_name);
	dual_fg_drv->second_fg_psy_name = devm_kstrdup(&pdev->dev, second_fg_psy_name,
	GFP_KERNEL);
	if (!dual_fg_drv->second_fg_psy_name)
	return -ENOMEM;
	}

	if (!dual_fg_drv->first_fg_psy_name && !dual_fg_drv->second_fg_psy_name) {
	pr_err("no dual gauge setting\n");
	return -EINVAL;
	}

	ret = of_property_read_u32(pdev->dev.of_node, "google,vflip-offset",
	&dual_fg_drv->vflip_offset);
	if (ret < 0) {
	pr_debug("Couldn't set vflip_offset (%d)\n", ret);
	dual_fg_drv->vflip_offset = DUAL_BATT_VFLIP_OFFSET;
	}

	INIT_DELAYED_WORK(&dual_fg_drv->init_work, google_dual_batt_gauge_init_work);
	INIT_DELAYED_WORK(&dual_fg_drv->gdbatt_work, google_dual_batt_work);
	mutex_init(&dual_fg_drv->fg_lock);
	platform_set_drvdata(pdev, dual_fg_drv);

	psy_cfg.drv_data = dual_fg_drv;
	psy_cfg.of_node = pdev->dev.of_node;

	if (of_property_read_bool(pdev->dev.of_node, "google,psy-type-unknown"))
	gdbatt_psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;

	dual_fg_drv->psy = devm_power_supply_register(dual_fg_drv->device,
	&gdbatt_psy_desc, &psy_cfg);
	if (IS_ERR(dual_fg_drv->psy)) {
	ret = PTR_ERR(dual_fg_drv->psy);
	if (ret == -EPROBE_DEFER)
	return -EPROBE_DEFER;

	/* TODO: fail with -ENODEV */
	dev_err(dual_fg_drv->device,
	"Couldn't register as power supply, ret=%d\n", ret);
	}

	schedule_delayed_work(&dual_fg_drv->init_work,
	msecs_to_jiffies(DUAL_FG_DELAY_INIT_MS));

	pr_info("google_dual_batt_gauge_probe done\n");

	return 0;
	}

	static int google_dual_batt_gauge_remove(struct platform_device *pdev)
	{
	struct dual_fg_drv *dual_fg_drv = platform_get_drvdata(pdev);

	gbms_free_chg_profile(&dual_fg_drv->chg_profile);

	return 0;
	}

	static int __maybe_unused google_dual_batt_pm_suspend(struct device *dev)
	{
	struct platform_device *pdev = to_platform_device(dev);
	struct dual_fg_drv *dual_fg_drv = platform_get_drvdata(pdev);

	pm_runtime_get_sync(dual_fg_drv->device);
	dual_fg_drv->resume_complete = false;
	pm_runtime_put_sync(dual_fg_drv->device);

	return 0;
	}

	static int __maybe_unused google_dual_batt_pm_resume(struct device *dev)
	{
	struct platform_device *pdev = to_platform_device(dev);
	struct dual_fg_drv *dual_fg_drv = platform_get_drvdata(pdev);

	pm_runtime_get_sync(dual_fg_drv->device);
	dual_fg_drv->resume_complete = true;
	pm_runtime_put_sync(dual_fg_drv->device);

	return 0;
	}

	static SIMPLE_DEV_PM_OPS(google_dual_batt_pm_ops,
	google_dual_batt_pm_suspend,
	google_dual_batt_pm_resume);

	static const struct of_device_id google_dual_batt_gauge_of_match[] = {
	{.compatible = "google,dual_batt_gauge"},
	{},
	};
	MODULE_DEVICE_TABLE(of, google_dual_batt_gauge_of_match);

	static struct platform_driver google_dual_batt_gauge_driver = {
	.driver = {
	.name = "google,dual_batt_gauge",
	.owner = THIS_MODULE,
	.of_match_table = google_dual_batt_gauge_of_match,
	.probe_type = PROBE_PREFER_ASYNCHRONOUS,
	.pm = &google_dual_batt_pm_ops,
	},
	.probe = google_dual_batt_gauge_probe,
	.remove = google_dual_batt_gauge_remove,
	};

	module_platform_driver(google_dual_batt_gauge_driver);

	MODULE_DESCRIPTION("Google Dual Gauge Driver");
	MODULE_AUTHOR("Jenny Ho <[email protected]>");
	MODULE_LICENSE("GPL");