// SPDX-License-Identifier: GPL-2.0-only
/*
 *
 * h3xxx atmel micro companion support, battery subdevice
 * based on previous kernel 2.4 version
 * Author : Alessandro Gardich <gremlin@gremlin.it>
 * Author : Linus Walleij <linus.walleij@linaro.org>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/mfd/ipaq-micro.h>
#include <linux/power_supply.h>
#include <linux/workqueue.h>

#define BATT_PERIOD 100000 /* 100 seconds in milliseconds */

#define MICRO_BATT_CHEM_ALKALINE        0x01
#define MICRO_BATT_CHEM_NICD            0x02
#define MICRO_BATT_CHEM_NIMH            0x03
#define MICRO_BATT_CHEM_LION            0x04
#define MICRO_BATT_CHEM_LIPOLY          0x05
#define MICRO_BATT_CHEM_NOT_INSTALLED   0x06
#define MICRO_BATT_CHEM_UNKNOWN         0xff

#define MICRO_BATT_STATUS_HIGH          0x01
#define MICRO_BATT_STATUS_LOW           0x02
#define MICRO_BATT_STATUS_CRITICAL      0x04
#define MICRO_BATT_STATUS_CHARGING      0x08
#define MICRO_BATT_STATUS_CHARGEMAIN    0x10
#define MICRO_BATT_STATUS_DEAD          0x20 /* Battery will not charge */
#define MICRO_BATT_STATUS_NOTINSTALLED  0x20 /* For expansion pack batteries */
#define MICRO_BATT_STATUS_FULL          0x40 /* Battery fully charged */
#define MICRO_BATT_STATUS_NOBATTERY     0x80
#define MICRO_BATT_STATUS_UNKNOWN       0xff

struct micro_battery {
        struct ipaq_micro *micro;
        struct workqueue_struct *wq;
        struct delayed_work update;
        u8 ac;
        u8 chemistry;
        unsigned int voltage;
        u16 temperature;
        u8 flag;
};

static void micro_battery_work(struct work_struct *work)
{
        struct micro_battery *mb = container_of(work,
                                struct micro_battery, update.work);
        struct ipaq_micro_msg msg_battery = {
                .id = MSG_BATTERY,
        };
        struct ipaq_micro_msg msg_sensor = {
                .id = MSG_THERMAL_SENSOR,
        };

        /* First send battery message */
        ipaq_micro_tx_msg_sync(mb->micro, &msg_battery);
        if (msg_battery.rx_len < 4)
                pr_info("ERROR");

        /*
         * Returned message format:
         * byte 0:   0x00 = Not plugged in
         *           0x01 = AC adapter plugged in
         * byte 1:   chemistry
         * byte 2:   voltage LSB
         * byte 3:   voltage MSB
         * byte 4:   flags
         * byte 5-9: same for battery 2
         */
        mb->ac = msg_battery.rx_data[0];
        mb->chemistry = msg_battery.rx_data[1];
        mb->voltage = ((((unsigned short)msg_battery.rx_data[3] << 8) +
                        msg_battery.rx_data[2]) * 5000L) * 1000 / 1024;
        mb->flag = msg_battery.rx_data[4];

        if (msg_battery.rx_len == 9)
                pr_debug("second battery ignored\n");

        /* Then read the sensor */
        ipaq_micro_tx_msg_sync(mb->micro, &msg_sensor);
        mb->temperature = msg_sensor.rx_data[1] << 8 | msg_sensor.rx_data[0];

        queue_delayed_work(mb->wq, &mb->update, msecs_to_jiffies(BATT_PERIOD));
}

static int get_capacity(struct power_supply *b)
{
        struct micro_battery *mb = dev_get_drvdata(b->dev.parent);

        switch (mb->flag & 0x07) {
        case MICRO_BATT_STATUS_HIGH:
                return 100;
                break;
        case MICRO_BATT_STATUS_LOW:
                return 50;
                break;
        case MICRO_BATT_STATUS_CRITICAL:
                return 5;
                break;
        default:
                break;
        }
        return 0;
}

static int get_status(struct power_supply *b)
{
        struct micro_battery *mb = dev_get_drvdata(b->dev.parent);

        if (mb->flag == MICRO_BATT_STATUS_UNKNOWN)
                return POWER_SUPPLY_STATUS_UNKNOWN;

        if (mb->flag & MICRO_BATT_STATUS_FULL)
                return POWER_SUPPLY_STATUS_FULL;

        if ((mb->flag & MICRO_BATT_STATUS_CHARGING) ||
                (mb->flag & MICRO_BATT_STATUS_CHARGEMAIN))
                return POWER_SUPPLY_STATUS_CHARGING;

        return POWER_SUPPLY_STATUS_DISCHARGING;
}

static int micro_batt_get_property(struct power_supply *b,
                                        enum power_supply_property psp,
                                        union power_supply_propval *val)
{
        struct micro_battery *mb = dev_get_drvdata(b->dev.parent);

        switch (psp) {
        case POWER_SUPPLY_PROP_TECHNOLOGY:
                switch (mb->chemistry) {
                case MICRO_BATT_CHEM_NICD:
                        val->intval = POWER_SUPPLY_TECHNOLOGY_NiCd;
                        break;
                case MICRO_BATT_CHEM_NIMH:
                        val->intval = POWER_SUPPLY_TECHNOLOGY_NiMH;
                        break;
                case MICRO_BATT_CHEM_LION:
                        val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
                        break;
                case MICRO_BATT_CHEM_LIPOLY:
                        val->intval = POWER_SUPPLY_TECHNOLOGY_LIPO;
                        break;
                default:
                        val->intval = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
                        break;
                }
                break;
        case POWER_SUPPLY_PROP_STATUS:
                val->intval = get_status(b);
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
                val->intval = 4700000;
                break;
        case POWER_SUPPLY_PROP_CAPACITY:
                val->intval = get_capacity(b);
                break;
        case POWER_SUPPLY_PROP_TEMP:
                val->intval = mb->temperature;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                val->intval = mb->voltage;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int micro_ac_get_property(struct power_supply *b,
                                 enum power_supply_property psp,
                                 union power_supply_propval *val)
{
        struct micro_battery *mb = dev_get_drvdata(b->dev.parent);

        switch (psp) {
        case POWER_SUPPLY_PROP_ONLINE:
                val->intval = mb->ac;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static enum power_supply_property micro_batt_power_props[] = {
        POWER_SUPPLY_PROP_TECHNOLOGY,
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_TEMP,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
};

static const struct power_supply_desc micro_batt_power_desc = {
        .name                   = "main-battery",
        .type                   = POWER_SUPPLY_TYPE_BATTERY,
        .properties             = micro_batt_power_props,
        .num_properties         = ARRAY_SIZE(micro_batt_power_props),
        .get_property           = micro_batt_get_property,
        .use_for_apm            = 1,
};

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

static const struct power_supply_desc micro_ac_power_desc = {
        .name                   = "ac",
        .type                   = POWER_SUPPLY_TYPE_MAINS,
        .properties             = micro_ac_power_props,
        .num_properties         = ARRAY_SIZE(micro_ac_power_props),
        .get_property           = micro_ac_get_property,
};

static struct power_supply *micro_batt_power, *micro_ac_power;

static int micro_batt_probe(struct platform_device *pdev)
{
        struct micro_battery *mb;
        int ret;

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

        mb->micro = dev_get_drvdata(pdev->dev.parent);
        mb->wq = alloc_workqueue("ipaq-battery-wq",
                                 WQ_MEM_RECLAIM | WQ_PERCPU, 0);
        if (!mb->wq)
                return -ENOMEM;

        INIT_DELAYED_WORK(&mb->update, micro_battery_work);
        platform_set_drvdata(pdev, mb);
        queue_delayed_work(mb->wq, &mb->update, 1);

        micro_batt_power = power_supply_register(&pdev->dev,
                                                 &micro_batt_power_desc, NULL);
        if (IS_ERR(micro_batt_power)) {
                ret = PTR_ERR(micro_batt_power);
                goto batt_err;
        }

        micro_ac_power = power_supply_register(&pdev->dev,
                                               &micro_ac_power_desc, NULL);
        if (IS_ERR(micro_ac_power)) {
                ret = PTR_ERR(micro_ac_power);
                goto ac_err;
        }

        dev_info(&pdev->dev, "iPAQ micro battery driver\n");
        return 0;

ac_err:
        power_supply_unregister(micro_batt_power);
batt_err:
        cancel_delayed_work_sync(&mb->update);
        destroy_workqueue(mb->wq);
        return ret;
}

static void micro_batt_remove(struct platform_device *pdev)

{
        struct micro_battery *mb = platform_get_drvdata(pdev);

        power_supply_unregister(micro_ac_power);
        power_supply_unregister(micro_batt_power);
        cancel_delayed_work_sync(&mb->update);
        destroy_workqueue(mb->wq);
}

static int __maybe_unused micro_batt_suspend(struct device *dev)
{
        struct micro_battery *mb = dev_get_drvdata(dev);

        cancel_delayed_work_sync(&mb->update);
        return 0;
}

static int __maybe_unused micro_batt_resume(struct device *dev)
{
        struct micro_battery *mb = dev_get_drvdata(dev);

        queue_delayed_work(mb->wq, &mb->update, msecs_to_jiffies(BATT_PERIOD));
        return 0;
}

static const struct dev_pm_ops micro_batt_dev_pm_ops = {
        SET_SYSTEM_SLEEP_PM_OPS(micro_batt_suspend, micro_batt_resume)
};

static struct platform_driver micro_batt_device_driver = {
        .driver         = {
                .name   = "ipaq-micro-battery",
                .pm     = &micro_batt_dev_pm_ops,
        },
        .probe          = micro_batt_probe,
        .remove         = micro_batt_remove,
};
module_platform_driver(micro_batt_device_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("driver for iPAQ Atmel micro battery");
MODULE_ALIAS("platform:ipaq-micro-battery");