// SPDX-License-Identifier: GPL-2.0
/*
 * nvec_power: power supply driver for a NVIDIA compliant embedded controller
 *
 * Copyright (C) 2011 The AC100 Kernel Team <ac100@lists.launchpad.net>
 *
 * Authors:  Ilya Petrov <ilya.muromec@gmail.com>
 *           Marc Dietrich <marvin24@gmx.de>
 */

#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/power_supply.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/delay.h>

#include "nvec.h"

#define GET_SYSTEM_STATUS 0x00

struct nvec_power {
        struct notifier_block notifier;
        struct delayed_work poller;
        struct nvec_chip *nvec;
        int on;
        int bat_present;
        int bat_status;
        int bat_voltage_now;
        int bat_current_now;
        int bat_current_avg;
        int time_remain;
        int charge_full_design;
        int charge_last_full;
        int critical_capacity;
        int capacity_remain;
        int bat_temperature;
        int bat_cap;
        int bat_type_enum;
        char bat_manu[30];
        char bat_model[30];
        char bat_type[30];
};

enum {
        SLOT_STATUS,
        VOLTAGE,
        TIME_REMAINING,
        CURRENT,
        AVERAGE_CURRENT,
        AVERAGING_TIME_INTERVAL,
        CAPACITY_REMAINING,
        LAST_FULL_CHARGE_CAPACITY,
        DESIGN_CAPACITY,
        CRITICAL_CAPACITY,
        TEMPERATURE,
        MANUFACTURER,
        MODEL,
        TYPE,
};

enum {
        AC,
        BAT,
};

struct bat_response {
        u8 event_type;
        u8 length;
        u8 sub_type;
        u8 status;
        /* payload */
        union {
                char plc[30];
                u16 plu;
                s16 pls;
        };
};

static struct power_supply *nvec_bat_psy;
static struct power_supply *nvec_psy;

static int nvec_power_notifier(struct notifier_block *nb,
                               unsigned long event_type, void *data)
{
        struct nvec_power *power =
            container_of(nb, struct nvec_power, notifier);
        struct bat_response *res = data;

        if (event_type != NVEC_SYS)
                return NOTIFY_DONE;

        if (res->sub_type == 0) {
                if (power->on != res->plu) {
                        power->on = res->plu;
                        power_supply_changed(nvec_psy);
                }
                return NOTIFY_STOP;
        }
        return NOTIFY_OK;
}

static const int bat_init[] = {
        LAST_FULL_CHARGE_CAPACITY, DESIGN_CAPACITY, CRITICAL_CAPACITY,
        MANUFACTURER, MODEL, TYPE,
};

static void get_bat_mfg_data(struct nvec_power *power)
{
        int i;
        char buf[] = { NVEC_BAT, SLOT_STATUS };

        for (i = 0; i < ARRAY_SIZE(bat_init); i++) {
                buf[1] = bat_init[i];
                nvec_write_async(power->nvec, buf, 2);
        }
}

static int nvec_power_bat_notifier(struct notifier_block *nb,
                                   unsigned long event_type, void *data)
{
        struct nvec_power *power =
            container_of(nb, struct nvec_power, notifier);
        struct bat_response *res = data;
        int status_changed = 0;

        if (event_type != NVEC_BAT)
                return NOTIFY_DONE;

        switch (res->sub_type) {
        case SLOT_STATUS:
                if (res->plc[0] & 1) {
                        if (power->bat_present == 0) {
                                status_changed = 1;
                                get_bat_mfg_data(power);
                        }

                        power->bat_present = 1;

                        switch ((res->plc[0] >> 1) & 3) {
                        case 0:
                                power->bat_status =
                                    POWER_SUPPLY_STATUS_NOT_CHARGING;
                                break;
                        case 1:
                                power->bat_status =
                                    POWER_SUPPLY_STATUS_CHARGING;
                                break;
                        case 2:
                                power->bat_status =
                                    POWER_SUPPLY_STATUS_DISCHARGING;
                                break;
                        default:
                                power->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
                        }
                } else {
                        if (power->bat_present == 1)
                                status_changed = 1;

                        power->bat_present = 0;
                        power->bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
                }
                power->bat_cap = res->plc[1];
                if (status_changed)
                        power_supply_changed(nvec_bat_psy);
                break;
        case VOLTAGE:
                power->bat_voltage_now = res->plu * 1000;
                break;
        case TIME_REMAINING:
                power->time_remain = res->plu * 3600;
                break;
        case CURRENT:
                power->bat_current_now = res->pls * 1000;
                break;
        case AVERAGE_CURRENT:
                power->bat_current_avg = res->pls * 1000;
                break;
        case CAPACITY_REMAINING:
                power->capacity_remain = res->plu * 1000;
                break;
        case LAST_FULL_CHARGE_CAPACITY:
                power->charge_last_full = res->plu * 1000;
                break;
        case DESIGN_CAPACITY:
                power->charge_full_design = res->plu * 1000;
                break;
        case CRITICAL_CAPACITY:
                power->critical_capacity = res->plu * 1000;
                break;
        case TEMPERATURE:
                power->bat_temperature = res->plu - 2732;
                break;
        case MANUFACTURER:
                memcpy(power->bat_manu, &res->plc, res->length - 2);
                power->bat_manu[res->length - 2] = '\0';
                break;
        case MODEL:
                memcpy(power->bat_model, &res->plc, res->length - 2);
                power->bat_model[res->length - 2] = '\0';
                break;
        case TYPE:
                memcpy(power->bat_type, &res->plc, res->length - 2);
                power->bat_type[res->length - 2] = '\0';
                /*
                 * This differs a little from the spec fill in more if you find
                 * some.
                 */
                if (!strncmp(power->bat_type, "Li", 30))
                        power->bat_type_enum = POWER_SUPPLY_TECHNOLOGY_LION;
                else
                        power->bat_type_enum = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
                break;
        default:
                return NOTIFY_STOP;
        }

        return NOTIFY_STOP;
}

static int nvec_power_get_property(struct power_supply *psy,
                                   enum power_supply_property psp,
                                   union power_supply_propval *val)
{
        struct nvec_power *power = dev_get_drvdata(psy->dev.parent);

        switch (psp) {
        case POWER_SUPPLY_PROP_ONLINE:
                val->intval = power->on;
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static int nvec_battery_get_property(struct power_supply *psy,
                                     enum power_supply_property psp,
                                     union power_supply_propval *val)
{
        struct nvec_power *power = dev_get_drvdata(psy->dev.parent);

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                val->intval = power->bat_status;
                break;
        case POWER_SUPPLY_PROP_CAPACITY:
                val->intval = power->bat_cap;
                break;
        case POWER_SUPPLY_PROP_PRESENT:
                val->intval = power->bat_present;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                val->intval = power->bat_voltage_now;
                break;
        case POWER_SUPPLY_PROP_CURRENT_NOW:
                val->intval = power->bat_current_now;
                break;
        case POWER_SUPPLY_PROP_CURRENT_AVG:
                val->intval = power->bat_current_avg;
                break;
        case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
                val->intval = power->time_remain;
                break;
        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
                val->intval = power->charge_full_design;
                break;
        case POWER_SUPPLY_PROP_CHARGE_FULL:
                val->intval = power->charge_last_full;
                break;
        case POWER_SUPPLY_PROP_CHARGE_EMPTY:
                val->intval = power->critical_capacity;
                break;
        case POWER_SUPPLY_PROP_CHARGE_NOW:
                val->intval = power->capacity_remain;
                break;
        case POWER_SUPPLY_PROP_TEMP:
                val->intval = power->bat_temperature;
                break;
        case POWER_SUPPLY_PROP_MANUFACTURER:
                val->strval = power->bat_manu;
                break;
        case POWER_SUPPLY_PROP_MODEL_NAME:
                val->strval = power->bat_model;
                break;
        case POWER_SUPPLY_PROP_TECHNOLOGY:
                val->intval = power->bat_type_enum;
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static enum power_supply_property nvec_power_props[] = {
        POWER_SUPPLY_PROP_ONLINE,
};

static enum power_supply_property nvec_battery_props[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_CURRENT_NOW,
#ifdef EC_FULL_DIAG
        POWER_SUPPLY_PROP_CURRENT_AVG,
        POWER_SUPPLY_PROP_TEMP,
        POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
#endif
        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
        POWER_SUPPLY_PROP_CHARGE_FULL,
        POWER_SUPPLY_PROP_CHARGE_EMPTY,
        POWER_SUPPLY_PROP_CHARGE_NOW,
        POWER_SUPPLY_PROP_MANUFACTURER,
        POWER_SUPPLY_PROP_MODEL_NAME,
        POWER_SUPPLY_PROP_TECHNOLOGY,
};

static char *nvec_power_supplied_to[] = {
        "battery",
};

static const struct power_supply_desc nvec_bat_psy_desc = {
        .name = "battery",
        .type = POWER_SUPPLY_TYPE_BATTERY,
        .properties = nvec_battery_props,
        .num_properties = ARRAY_SIZE(nvec_battery_props),
        .get_property = nvec_battery_get_property,
};

static const struct power_supply_desc nvec_psy_desc = {
        .name = "ac",
        .type = POWER_SUPPLY_TYPE_MAINS,
        .properties = nvec_power_props,
        .num_properties = ARRAY_SIZE(nvec_power_props),
        .get_property = nvec_power_get_property,
};

static int counter;
static const int bat_iter[] = {
        SLOT_STATUS, VOLTAGE, CURRENT, CAPACITY_REMAINING,
#ifdef EC_FULL_DIAG
        AVERAGE_CURRENT, TEMPERATURE, TIME_REMAINING,
#endif
};

static void nvec_power_poll(struct work_struct *work)
{
        char buf[] = { NVEC_SYS, GET_SYSTEM_STATUS };
        struct nvec_power *power = container_of(work, struct nvec_power,
                                                poller.work);

        if (counter >= ARRAY_SIZE(bat_iter))
                counter = 0;

        /* AC status via sys req */
        nvec_write_async(power->nvec, buf, 2);
        msleep(100);

        /*
         * Select a battery request function via round robin doing it all at
         * once seems to overload the power supply.
         */
        buf[0] = NVEC_BAT;
        buf[1] = bat_iter[counter++];
        nvec_write_async(power->nvec, buf, 2);

        schedule_delayed_work(to_delayed_work(work), msecs_to_jiffies(5000));
};

static int nvec_power_probe(struct platform_device *pdev)
{
        struct power_supply **psy;
        const struct power_supply_desc *psy_desc;
        struct nvec_power *power;
        struct nvec_chip *nvec = dev_get_drvdata(pdev->dev.parent);
        struct power_supply_config psy_cfg = {};

        power = devm_kzalloc(&pdev->dev, sizeof(struct nvec_power), GFP_NOWAIT);
        if (!power)
                return -ENOMEM;

        dev_set_drvdata(&pdev->dev, power);
        power->nvec = nvec;

        switch (pdev->id) {
        case AC:
                psy = &nvec_psy;
                psy_desc = &nvec_psy_desc;
                psy_cfg.supplied_to = nvec_power_supplied_to;
                psy_cfg.num_supplicants = ARRAY_SIZE(nvec_power_supplied_to);

                power->notifier.notifier_call = nvec_power_notifier;

                INIT_DELAYED_WORK(&power->poller, nvec_power_poll);
                schedule_delayed_work(&power->poller, msecs_to_jiffies(5000));
                break;
        case BAT:
                psy = &nvec_bat_psy;
                psy_desc = &nvec_bat_psy_desc;

                power->notifier.notifier_call = nvec_power_bat_notifier;
                break;
        default:
                return -ENODEV;
        }

        nvec_register_notifier(nvec, &power->notifier, NVEC_SYS);

        if (pdev->id == BAT)
                get_bat_mfg_data(power);

        *psy = power_supply_register(&pdev->dev, psy_desc, &psy_cfg);

        return PTR_ERR_OR_ZERO(*psy);
}

static void nvec_power_remove(struct platform_device *pdev)
{
        struct nvec_power *power = platform_get_drvdata(pdev);

        cancel_delayed_work_sync(&power->poller);
        nvec_unregister_notifier(power->nvec, &power->notifier);
        switch (pdev->id) {
        case AC:
                power_supply_unregister(nvec_psy);
                break;
        case BAT:
                power_supply_unregister(nvec_bat_psy);
        }
}

static struct platform_driver nvec_power_driver = {
        .probe = nvec_power_probe,
        .remove = nvec_power_remove,
        .driver = {
                   .name = "nvec-power",
        }
};

module_platform_driver(nvec_power_driver);

MODULE_AUTHOR("Ilya Petrov <ilya.muromec@gmail.com>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("NVEC battery and AC driver");
MODULE_ALIAS("platform:nvec-power");