// SPDX-License-Identifier: GPL-2.0-only
/*
 * Battery charger driver for Dialog Semiconductor DA9030
 *
 * Copyright (C) 2008 Compulab, Ltd.
 *      Mike Rapoport <mike@compulab.co.il>
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/workqueue.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/string_choices.h>
#include <linux/mfd/da903x.h>

#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/notifier.h>

#define DA9030_FAULT_LOG                0x0a
#define DA9030_FAULT_LOG_OVER_TEMP      (1 << 7)
#define DA9030_FAULT_LOG_VBAT_OVER      (1 << 4)

#define DA9030_CHARGE_CONTROL           0x28
#define DA9030_CHRG_CHARGER_ENABLE      (1 << 7)

#define DA9030_ADC_MAN_CONTROL          0x30
#define DA9030_ADC_TBATREF_ENABLE       (1 << 5)
#define DA9030_ADC_LDO_INT_ENABLE       (1 << 4)

#define DA9030_ADC_AUTO_CONTROL         0x31
#define DA9030_ADC_TBAT_ENABLE          (1 << 5)
#define DA9030_ADC_VBAT_IN_TXON         (1 << 4)
#define DA9030_ADC_VCH_ENABLE           (1 << 3)
#define DA9030_ADC_ICH_ENABLE           (1 << 2)
#define DA9030_ADC_VBAT_ENABLE          (1 << 1)
#define DA9030_ADC_AUTO_SLEEP_ENABLE    (1 << 0)

#define DA9030_VBATMON          0x32
#define DA9030_VBATMONTXON      0x33
#define DA9030_TBATHIGHP        0x34
#define DA9030_TBATHIGHN        0x35
#define DA9030_TBATLOW          0x36

#define DA9030_VBAT_RES         0x41
#define DA9030_VBATMIN_RES      0x42
#define DA9030_VBATMINTXON_RES  0x43
#define DA9030_ICHMAX_RES       0x44
#define DA9030_ICHMIN_RES       0x45
#define DA9030_ICHAVERAGE_RES   0x46
#define DA9030_VCHMAX_RES       0x47
#define DA9030_VCHMIN_RES       0x48
#define DA9030_TBAT_RES         0x49

struct da9030_adc_res {
        uint8_t vbat_res;
        uint8_t vbatmin_res;
        uint8_t vbatmintxon;
        uint8_t ichmax_res;
        uint8_t ichmin_res;
        uint8_t ichaverage_res;
        uint8_t vchmax_res;
        uint8_t vchmin_res;
        uint8_t tbat_res;
        uint8_t adc_in4_res;
        uint8_t adc_in5_res;
};

struct da9030_battery_thresholds {
        int tbat_low;
        int tbat_high;
        int tbat_restart;

        int vbat_low;
        int vbat_crit;
        int vbat_charge_start;
        int vbat_charge_stop;
        int vbat_charge_restart;

        int vcharge_min;
        int vcharge_max;
};

struct da9030_charger {
        struct power_supply *psy;
        struct power_supply_desc psy_desc;

        struct device *master;

        struct da9030_adc_res adc;
        struct delayed_work work;
        unsigned int interval;

        struct power_supply_info *battery_info;

        struct da9030_battery_thresholds thresholds;

        unsigned int charge_milliamp;
        unsigned int charge_millivolt;

        /* charger status */
        bool chdet;
        uint8_t fault;
        int mA;
        int mV;
        bool is_on;

        struct notifier_block nb;

        /* platform callbacks for battery low and critical events */
        void (*battery_low)(void);
        void (*battery_critical)(void);

        struct dentry *debug_file;
};

static inline int da9030_reg_to_mV(int reg)
{
        return ((reg * 2650) >> 8) + 2650;
}

static inline int da9030_millivolt_to_reg(int mV)
{
        return ((mV - 2650) << 8) / 2650;
}

static inline int da9030_reg_to_mA(int reg)
{
        return ((reg * 24000) >> 8) / 15;
}

#ifdef CONFIG_DEBUG_FS
static int bat_debug_show(struct seq_file *s, void *data)
{
        struct da9030_charger *charger = s->private;

        seq_printf(s, "charger is %s\n", str_on_off(charger->is_on));
        if (charger->chdet) {
                seq_printf(s, "iset = %dmA, vset = %dmV\n",
                           charger->mA, charger->mV);
        }

        seq_printf(s, "vbat_res = %d (%dmV)\n",
                   charger->adc.vbat_res,
                   da9030_reg_to_mV(charger->adc.vbat_res));
        seq_printf(s, "vbatmin_res = %d (%dmV)\n",
                   charger->adc.vbatmin_res,
                   da9030_reg_to_mV(charger->adc.vbatmin_res));
        seq_printf(s, "vbatmintxon = %d (%dmV)\n",
                   charger->adc.vbatmintxon,
                   da9030_reg_to_mV(charger->adc.vbatmintxon));
        seq_printf(s, "ichmax_res = %d (%dmA)\n",
                   charger->adc.ichmax_res,
                   da9030_reg_to_mV(charger->adc.ichmax_res));
        seq_printf(s, "ichmin_res = %d (%dmA)\n",
                   charger->adc.ichmin_res,
                   da9030_reg_to_mA(charger->adc.ichmin_res));
        seq_printf(s, "ichaverage_res = %d (%dmA)\n",
                   charger->adc.ichaverage_res,
                   da9030_reg_to_mA(charger->adc.ichaverage_res));
        seq_printf(s, "vchmax_res = %d (%dmV)\n",
                   charger->adc.vchmax_res,
                   da9030_reg_to_mA(charger->adc.vchmax_res));
        seq_printf(s, "vchmin_res = %d (%dmV)\n",
                   charger->adc.vchmin_res,
                   da9030_reg_to_mV(charger->adc.vchmin_res));

        return 0;
}

DEFINE_SHOW_ATTRIBUTE(bat_debug);

static struct dentry *da9030_bat_create_debugfs(struct da9030_charger *charger)
{
        charger->debug_file = debugfs_create_file("charger", 0666, NULL,
                                                  charger, &bat_debug_fops);
        return charger->debug_file;
}

static void da9030_bat_remove_debugfs(struct da9030_charger *charger)
{
        debugfs_remove(charger->debug_file);
}
#else
static inline struct dentry *da9030_bat_create_debugfs(struct da9030_charger *charger)
{
        return NULL;
}
static inline void da9030_bat_remove_debugfs(struct da9030_charger *charger)
{
}
#endif

static inline void da9030_read_adc(struct da9030_charger *charger,
                                   struct da9030_adc_res *adc)
{
        da903x_reads(charger->master, DA9030_VBAT_RES,
                     sizeof(*adc), (uint8_t *)adc);
}

static void da9030_charger_update_state(struct da9030_charger *charger)
{
        uint8_t val;

        da903x_read(charger->master, DA9030_CHARGE_CONTROL, &val);
        charger->is_on = (val & DA9030_CHRG_CHARGER_ENABLE) ? 1 : 0;
        charger->mA = ((val >> 3) & 0xf) * 100;
        charger->mV = (val & 0x7) * 50 + 4000;

        da9030_read_adc(charger, &charger->adc);
        da903x_read(charger->master, DA9030_FAULT_LOG, &charger->fault);
        charger->chdet = da903x_query_status(charger->master,
                                                     DA9030_STATUS_CHDET);
}

static void da9030_set_charge(struct da9030_charger *charger, int on)
{
        uint8_t val;

        if (on) {
                val = DA9030_CHRG_CHARGER_ENABLE;
                val |= (charger->charge_milliamp / 100) << 3;
                val |= (charger->charge_millivolt - 4000) / 50;
                charger->is_on = 1;
        } else {
                val = 0;
                charger->is_on = 0;
        }

        da903x_write(charger->master, DA9030_CHARGE_CONTROL, val);

        power_supply_changed(charger->psy);
}

static void da9030_charger_check_state(struct da9030_charger *charger)
{
        da9030_charger_update_state(charger);

        /* we wake or boot with external power on */
        if (!charger->is_on) {
                if ((charger->chdet) &&
                    (charger->adc.vbat_res <
                     charger->thresholds.vbat_charge_start)) {
                        da9030_set_charge(charger, 1);
                }
        } else {
                /* Charger has been pulled out */
                if (!charger->chdet) {
                        da9030_set_charge(charger, 0);
                        return;
                }

                if (charger->adc.vbat_res >=
                    charger->thresholds.vbat_charge_stop) {
                        da9030_set_charge(charger, 0);
                        da903x_write(charger->master, DA9030_VBATMON,
                                       charger->thresholds.vbat_charge_restart);
                } else if (charger->adc.vbat_res >
                           charger->thresholds.vbat_low) {
                        /* we are charging and passed LOW_THRESH,
                           so upate DA9030 VBAT threshold
                         */
                        da903x_write(charger->master, DA9030_VBATMON,
                                     charger->thresholds.vbat_low);
                }
                if (charger->adc.vchmax_res > charger->thresholds.vcharge_max ||
                    charger->adc.vchmin_res < charger->thresholds.vcharge_min ||
                    /* Temperature readings are negative */
                    charger->adc.tbat_res < charger->thresholds.tbat_high ||
                    charger->adc.tbat_res > charger->thresholds.tbat_low) {
                        /* disable charger */
                        da9030_set_charge(charger, 0);
                }
        }
}

static void da9030_charging_monitor(struct work_struct *work)
{
        struct da9030_charger *charger;

        charger = container_of(work, struct da9030_charger, work.work);

        da9030_charger_check_state(charger);

        /* reschedule for the next time */
        schedule_delayed_work(&charger->work, charger->interval);
}

static enum power_supply_property da9030_battery_props[] = {
        POWER_SUPPLY_PROP_MODEL_NAME,
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_HEALTH,
        POWER_SUPPLY_PROP_TECHNOLOGY,
        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_CURRENT_AVG,
};

static void da9030_battery_check_status(struct da9030_charger *charger,
                                    union power_supply_propval *val)
{
        if (charger->chdet) {
                if (charger->is_on)
                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
                else
                        val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
        } else {
                val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
        }
}

static void da9030_battery_check_health(struct da9030_charger *charger,
                                    union power_supply_propval *val)
{
        if (charger->fault & DA9030_FAULT_LOG_OVER_TEMP)
                val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
        else if (charger->fault & DA9030_FAULT_LOG_VBAT_OVER)
                val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
        else
                val->intval = POWER_SUPPLY_HEALTH_GOOD;
}

static int da9030_battery_get_property(struct power_supply *psy,
                                   enum power_supply_property psp,
                                   union power_supply_propval *val)
{
        struct da9030_charger *charger = power_supply_get_drvdata(psy);

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                da9030_battery_check_status(charger, val);
                break;
        case POWER_SUPPLY_PROP_HEALTH:
                da9030_battery_check_health(charger, val);
                break;
        case POWER_SUPPLY_PROP_TECHNOLOGY:
                val->intval = charger->battery_info->technology;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
                val->intval = charger->battery_info->voltage_max_design;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
                val->intval = charger->battery_info->voltage_min_design;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                val->intval = da9030_reg_to_mV(charger->adc.vbat_res) * 1000;
                break;
        case POWER_SUPPLY_PROP_CURRENT_AVG:
                val->intval =
                        da9030_reg_to_mA(charger->adc.ichaverage_res) * 1000;
                break;
        case POWER_SUPPLY_PROP_MODEL_NAME:
                val->strval = charger->battery_info->name;
                break;
        default:
                break;
        }

        return 0;
}

static void da9030_battery_vbat_event(struct da9030_charger *charger)
{
        da9030_read_adc(charger, &charger->adc);

        if (charger->is_on)
                return;

        if (charger->adc.vbat_res < charger->thresholds.vbat_low) {
                /* set VBAT threshold for critical */
                da903x_write(charger->master, DA9030_VBATMON,
                             charger->thresholds.vbat_crit);
                if (charger->battery_low)
                        charger->battery_low();
        } else if (charger->adc.vbat_res <
                   charger->thresholds.vbat_crit) {
                /* notify the system of battery critical */
                if (charger->battery_critical)
                        charger->battery_critical();
        }
}

static int da9030_battery_event(struct notifier_block *nb, unsigned long event,
                                void *data)
{
        struct da9030_charger *charger =
                container_of(nb, struct da9030_charger, nb);

        switch (event) {
        case DA9030_EVENT_CHDET:
                cancel_delayed_work_sync(&charger->work);
                schedule_work(&charger->work.work);
                break;
        case DA9030_EVENT_VBATMON:
                da9030_battery_vbat_event(charger);
                break;
        case DA9030_EVENT_CHIOVER:
        case DA9030_EVENT_TBAT:
                da9030_set_charge(charger, 0);
                break;
        }

        return 0;
}

static void da9030_battery_convert_thresholds(struct da9030_charger *charger,
                                              struct da9030_battery_info *pdata)
{
        charger->thresholds.tbat_low = pdata->tbat_low;
        charger->thresholds.tbat_high = pdata->tbat_high;
        charger->thresholds.tbat_restart  = pdata->tbat_restart;

        charger->thresholds.vbat_low =
                da9030_millivolt_to_reg(pdata->vbat_low);
        charger->thresholds.vbat_crit =
                da9030_millivolt_to_reg(pdata->vbat_crit);
        charger->thresholds.vbat_charge_start =
                da9030_millivolt_to_reg(pdata->vbat_charge_start);
        charger->thresholds.vbat_charge_stop =
                da9030_millivolt_to_reg(pdata->vbat_charge_stop);
        charger->thresholds.vbat_charge_restart =
                da9030_millivolt_to_reg(pdata->vbat_charge_restart);

        charger->thresholds.vcharge_min =
                da9030_millivolt_to_reg(pdata->vcharge_min);
        charger->thresholds.vcharge_max =
                da9030_millivolt_to_reg(pdata->vcharge_max);
}

static void da9030_battery_setup_psy(struct da9030_charger *charger)
{
        struct power_supply_desc *psy_desc = &charger->psy_desc;
        struct power_supply_info *info = charger->battery_info;

        psy_desc->name = info->name;
        psy_desc->use_for_apm = info->use_for_apm;
        psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
        psy_desc->get_property = da9030_battery_get_property;

        psy_desc->properties = da9030_battery_props;
        psy_desc->num_properties = ARRAY_SIZE(da9030_battery_props);
};

static int da9030_battery_charger_init(struct da9030_charger *charger)
{
        char v[5];
        int ret;

        v[0] = v[1] = charger->thresholds.vbat_low;
        v[2] = charger->thresholds.tbat_high;
        v[3] = charger->thresholds.tbat_restart;
        v[4] = charger->thresholds.tbat_low;

        ret = da903x_writes(charger->master, DA9030_VBATMON, 5, v);
        if (ret)
                return ret;

        /*
         * Enable reference voltage supply for ADC from the LDO_INTERNAL
         * regulator. Must be set before ADC measurements can be made.
         */
        ret = da903x_write(charger->master, DA9030_ADC_MAN_CONTROL,
                           DA9030_ADC_LDO_INT_ENABLE |
                           DA9030_ADC_TBATREF_ENABLE);
        if (ret)
                return ret;

        /* enable auto ADC measurements */
        return da903x_write(charger->master, DA9030_ADC_AUTO_CONTROL,
                            DA9030_ADC_TBAT_ENABLE | DA9030_ADC_VBAT_IN_TXON |
                            DA9030_ADC_VCH_ENABLE | DA9030_ADC_ICH_ENABLE |
                            DA9030_ADC_VBAT_ENABLE |
                            DA9030_ADC_AUTO_SLEEP_ENABLE);
}

static int da9030_battery_probe(struct platform_device *pdev)
{
        struct da9030_charger *charger;
        struct power_supply_config psy_cfg = {};
        struct da9030_battery_info *pdata = pdev->dev.platform_data;
        int ret;

        if (pdata == NULL)
                return -EINVAL;

        if (pdata->charge_milliamp >= 1500 ||
            pdata->charge_millivolt < 4000 ||
            pdata->charge_millivolt > 4350)
                return -EINVAL;

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

        charger->master = pdev->dev.parent;

        /* 10 seconds between monitor runs unless platform defines other
           interval */
        charger->interval = secs_to_jiffies(pdata->batmon_interval ? : 10);

        charger->charge_milliamp = pdata->charge_milliamp;
        charger->charge_millivolt = pdata->charge_millivolt;
        charger->battery_info = pdata->battery_info;
        charger->battery_low = pdata->battery_low;
        charger->battery_critical = pdata->battery_critical;

        da9030_battery_convert_thresholds(charger, pdata);

        ret = da9030_battery_charger_init(charger);
        if (ret)
                goto err_charger_init;

        INIT_DELAYED_WORK(&charger->work, da9030_charging_monitor);
        schedule_delayed_work(&charger->work, charger->interval);

        charger->nb.notifier_call = da9030_battery_event;
        ret = da903x_register_notifier(charger->master, &charger->nb,
                                       DA9030_EVENT_CHDET |
                                       DA9030_EVENT_VBATMON |
                                       DA9030_EVENT_CHIOVER |
                                       DA9030_EVENT_TBAT);
        if (ret)
                goto err_notifier;

        da9030_battery_setup_psy(charger);
        psy_cfg.drv_data = charger;
        charger->psy = devm_power_supply_register(&pdev->dev,
                                                  &charger->psy_desc,
                                                  &psy_cfg);
        if (IS_ERR(charger->psy)) {
                ret = PTR_ERR(charger->psy);
                goto err_ps_register;
        }

        charger->debug_file = da9030_bat_create_debugfs(charger);
        platform_set_drvdata(pdev, charger);
        return 0;

err_ps_register:
        da903x_unregister_notifier(charger->master, &charger->nb,
                                   DA9030_EVENT_CHDET | DA9030_EVENT_VBATMON |
                                   DA9030_EVENT_CHIOVER | DA9030_EVENT_TBAT);
err_notifier:
        cancel_delayed_work(&charger->work);

err_charger_init:
        return ret;
}

static void da9030_battery_remove(struct platform_device *dev)
{
        struct da9030_charger *charger = platform_get_drvdata(dev);

        da9030_bat_remove_debugfs(charger);

        da903x_unregister_notifier(charger->master, &charger->nb,
                                   DA9030_EVENT_CHDET | DA9030_EVENT_VBATMON |
                                   DA9030_EVENT_CHIOVER | DA9030_EVENT_TBAT);
        cancel_delayed_work_sync(&charger->work);
        da9030_set_charge(charger, 0);
}

static struct platform_driver da903x_battery_driver = {
        .driver = {
                .name   = "da903x-battery",
        },
        .probe = da9030_battery_probe,
        .remove = da9030_battery_remove,
};

module_platform_driver(da903x_battery_driver);

MODULE_DESCRIPTION("DA9030 battery charger driver");
MODULE_AUTHOR("Mike Rapoport, CompuLab");
MODULE_LICENSE("GPL");