// SPDX-License-Identifier: GPL-2.0-only
/*
 * Battery and Power Management code for the Sharp SL-5x00
 *
 * Copyright (C) 2009 Thomas Kunze
 *
 * based on tosa_battery.c
 */
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/power_supply.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/gpio/consumer.h>
#include <linux/mfd/ucb1x00.h>

#include <asm/mach/sharpsl_param.h>
#include <asm/mach-types.h>
#include <mach/collie.h>

static DEFINE_MUTEX(bat_lock); /* protects gpio pins */
static struct work_struct bat_work;
static struct ucb1x00 *ucb;

struct collie_bat {
        int status;
        struct power_supply *psy;
        int full_chrg;

        struct mutex work_lock; /* protects data */

        bool (*is_present)(struct collie_bat *bat);
        struct gpio_desc *gpio_full;
        struct gpio_desc *gpio_charge_on;

        int technology;

        struct gpio_desc *gpio_bat;
        int adc_bat;
        int adc_bat_divider;
        int bat_max;
        int bat_min;

        struct gpio_desc *gpio_temp;
        int adc_temp;
        int adc_temp_divider;
};

static struct collie_bat collie_bat_main;

static unsigned long collie_read_bat(struct collie_bat *bat)
{
        unsigned long value = 0;

        if (!bat->gpio_bat || bat->adc_bat < 0)
                return 0;
        mutex_lock(&bat_lock);
        gpiod_set_value(bat->gpio_bat, 1);
        msleep(5);
        ucb1x00_adc_enable(ucb);
        value = ucb1x00_adc_read(ucb, bat->adc_bat, UCB_SYNC);
        ucb1x00_adc_disable(ucb);
        gpiod_set_value(bat->gpio_bat, 0);
        mutex_unlock(&bat_lock);
        value = value * 1000000 / bat->adc_bat_divider;

        return value;
}

static unsigned long collie_read_temp(struct collie_bat *bat)
{
        unsigned long value = 0;
        if (!bat->gpio_temp || bat->adc_temp < 0)
                return 0;

        mutex_lock(&bat_lock);
        gpiod_set_value(bat->gpio_temp, 1);
        msleep(5);
        ucb1x00_adc_enable(ucb);
        value = ucb1x00_adc_read(ucb, bat->adc_temp, UCB_SYNC);
        ucb1x00_adc_disable(ucb);
        gpiod_set_value(bat->gpio_temp, 0);
        mutex_unlock(&bat_lock);

        value = value * 10000 / bat->adc_temp_divider;

        return value;
}

static int collie_bat_get_property(struct power_supply *psy,
                            enum power_supply_property psp,
                            union power_supply_propval *val)
{
        int ret = 0;
        struct collie_bat *bat = power_supply_get_drvdata(psy);

        if (bat->is_present && !bat->is_present(bat)
                        && psp != POWER_SUPPLY_PROP_PRESENT) {
                return -ENODEV;
        }

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                val->intval = bat->status;
                break;
        case POWER_SUPPLY_PROP_TECHNOLOGY:
                val->intval = bat->technology;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                val->intval = collie_read_bat(bat);
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_MAX:
                if (bat->full_chrg == -1)
                        val->intval = bat->bat_max;
                else
                        val->intval = bat->full_chrg;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
                val->intval = bat->bat_max;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
                val->intval = bat->bat_min;
                break;
        case POWER_SUPPLY_PROP_TEMP:
                val->intval = collie_read_temp(bat);
                break;
        case POWER_SUPPLY_PROP_PRESENT:
                val->intval = bat->is_present ? bat->is_present(bat) : 1;
                break;
        default:
                ret = -EINVAL;
                break;
        }
        return ret;
}

static void collie_bat_external_power_changed(struct power_supply *psy)
{
        schedule_work(&bat_work);
}

static irqreturn_t collie_bat_gpio_isr(int irq, void *data)
{
        pr_info("collie_bat_gpio irq\n");
        schedule_work(&bat_work);
        return IRQ_HANDLED;
}

static void collie_bat_update(struct collie_bat *bat)
{
        int old;
        struct power_supply *psy = bat->psy;

        mutex_lock(&bat->work_lock);

        old = bat->status;

        if (bat->is_present && !bat->is_present(bat)) {
                printk(KERN_NOTICE "%s not present\n", psy->desc->name);
                bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
                bat->full_chrg = -1;
        } else if (power_supply_am_i_supplied(psy)) {
                if (bat->status == POWER_SUPPLY_STATUS_DISCHARGING) {
                        gpiod_set_value(bat->gpio_charge_on, 1);
                        mdelay(15);
                }

                if (gpiod_get_value(bat->gpio_full)) {
                        if (old == POWER_SUPPLY_STATUS_CHARGING ||
                                        bat->full_chrg == -1)
                                bat->full_chrg = collie_read_bat(bat);

                        gpiod_set_value(bat->gpio_charge_on, 0);
                        bat->status = POWER_SUPPLY_STATUS_FULL;
                } else {
                        gpiod_set_value(bat->gpio_charge_on, 1);
                        bat->status = POWER_SUPPLY_STATUS_CHARGING;
                }
        } else {
                gpiod_set_value(bat->gpio_charge_on, 0);
                bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
        }

        if (old != bat->status)
                power_supply_changed(psy);

        mutex_unlock(&bat->work_lock);
}

static void collie_bat_work(struct work_struct *work)
{
        collie_bat_update(&collie_bat_main);
}


static enum power_supply_property collie_bat_main_props[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_TECHNOLOGY,
        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
        POWER_SUPPLY_PROP_VOLTAGE_MAX,
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_TEMP,
};

static enum power_supply_property collie_bat_bu_props[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_TECHNOLOGY,
        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
        POWER_SUPPLY_PROP_VOLTAGE_MAX,
        POWER_SUPPLY_PROP_PRESENT,
};

static const struct power_supply_desc collie_bat_main_desc = {
        .name           = "main-battery",
        .type           = POWER_SUPPLY_TYPE_BATTERY,
        .properties     = collie_bat_main_props,
        .num_properties = ARRAY_SIZE(collie_bat_main_props),
        .get_property   = collie_bat_get_property,
        .external_power_changed = collie_bat_external_power_changed,
        .use_for_apm    = 1,
};

static struct collie_bat collie_bat_main = {
        .status = POWER_SUPPLY_STATUS_DISCHARGING,
        .full_chrg = -1,
        .psy = NULL,

        .gpio_full = NULL,
        .gpio_charge_on = NULL,

        .technology = POWER_SUPPLY_TECHNOLOGY_LIPO,

        .gpio_bat = NULL,
        .adc_bat = UCB_ADC_INP_AD1,
        .adc_bat_divider = 155,
        .bat_max = 4310000,
        .bat_min = 1551 * 1000000 / 414,

        .gpio_temp = NULL,
        .adc_temp = UCB_ADC_INP_AD0,
        .adc_temp_divider = 10000,
};

static const struct power_supply_desc collie_bat_bu_desc = {
        .name           = "backup-battery",
        .type           = POWER_SUPPLY_TYPE_BATTERY,
        .properties     = collie_bat_bu_props,
        .num_properties = ARRAY_SIZE(collie_bat_bu_props),
        .get_property   = collie_bat_get_property,
        .external_power_changed = collie_bat_external_power_changed,
};

static struct collie_bat collie_bat_bu = {
        .status = POWER_SUPPLY_STATUS_UNKNOWN,
        .full_chrg = -1,
        .psy = NULL,

        .gpio_full = NULL,
        .gpio_charge_on = NULL,

        .technology = POWER_SUPPLY_TECHNOLOGY_LiMn,

        .gpio_bat = NULL,
        .adc_bat = UCB_ADC_INP_AD1,
        .adc_bat_divider = 155,
        .bat_max = 3000000,
        .bat_min = 1900000,

        .gpio_temp = NULL,
        .adc_temp = -1,
        .adc_temp_divider = -1,
};

/* Obtained but unused GPIO */
static struct gpio_desc *collie_mbat_low;

#ifdef CONFIG_PM
static int wakeup_enabled;

static int collie_bat_suspend(struct ucb1x00_dev *dev)
{
        /* flush all pending status updates */
        flush_work(&bat_work);

        if (device_may_wakeup(&dev->ucb->dev) &&
            collie_bat_main.status == POWER_SUPPLY_STATUS_CHARGING)
                wakeup_enabled = !enable_irq_wake(gpiod_to_irq(collie_bat_main.gpio_full));
        else
                wakeup_enabled = 0;

        return 0;
}

static int collie_bat_resume(struct ucb1x00_dev *dev)
{
        if (wakeup_enabled)
                disable_irq_wake(gpiod_to_irq(collie_bat_main.gpio_full));

        /* things may have changed while we were away */
        schedule_work(&bat_work);
        return 0;
}
#else
#define collie_bat_suspend NULL
#define collie_bat_resume NULL
#endif

static int collie_bat_probe(struct ucb1x00_dev *dev)
{
        int ret;
        struct power_supply_config psy_main_cfg = {}, psy_bu_cfg = {};
        struct gpio_chip *gc = &dev->ucb->gpio;

        if (!machine_is_collie())
                return -ENODEV;

        ucb = dev->ucb;

        /* Obtain all the main battery GPIOs */
        collie_bat_main.gpio_full = gpiod_get(&dev->ucb->dev,
                                              "main battery full",
                                              GPIOD_IN);
        if (IS_ERR(collie_bat_main.gpio_full))
                return PTR_ERR(collie_bat_main.gpio_full);

        collie_mbat_low = gpiod_get(&dev->ucb->dev,
                                    "main battery low",
                                    GPIOD_IN);
        if (IS_ERR(collie_mbat_low)) {
                ret = PTR_ERR(collie_mbat_low);
                goto err_put_gpio_full;
        }

        collie_bat_main.gpio_charge_on = gpiod_get(&dev->ucb->dev,
                                                   "main charge on",
                                                   GPIOD_OUT_LOW);
        if (IS_ERR(collie_bat_main.gpio_charge_on)) {
                ret = PTR_ERR(collie_bat_main.gpio_charge_on);
                goto err_put_mbat_low;
        }

        /* COLLIE_GPIO_MBAT_ON = GPIO 7 on the UCB (TC35143) */
        collie_bat_main.gpio_bat = gpiochip_request_own_desc(gc,
                                                7,
                                                "main battery",
                                                GPIO_ACTIVE_HIGH,
                                                GPIOD_OUT_LOW);
        if (IS_ERR(collie_bat_main.gpio_bat)) {
                ret = PTR_ERR(collie_bat_main.gpio_bat);
                goto err_put_gpio_charge_on;
        }

        /* COLLIE_GPIO_TMP_ON = GPIO 9 on the UCB (TC35143) */
        collie_bat_main.gpio_temp = gpiochip_request_own_desc(gc,
                                                9,
                                                "main battery temp",
                                                GPIO_ACTIVE_HIGH,
                                                GPIOD_OUT_LOW);
        if (IS_ERR(collie_bat_main.gpio_temp)) {
                ret = PTR_ERR(collie_bat_main.gpio_temp);
                goto err_free_gpio_bat;
        }

        /*
         * Obtain the backup battery COLLIE_GPIO_BBAT_ON which is
         * GPIO 8 on the UCB (TC35143)
         */
        collie_bat_bu.gpio_bat = gpiochip_request_own_desc(gc,
                                                8,
                                                "backup battery",
                                                GPIO_ACTIVE_HIGH,
                                                GPIOD_OUT_LOW);
        if (IS_ERR(collie_bat_bu.gpio_bat)) {
                ret = PTR_ERR(collie_bat_bu.gpio_bat);
                goto err_free_gpio_temp;
        }

        mutex_init(&collie_bat_main.work_lock);

        INIT_WORK(&bat_work, collie_bat_work);

        psy_main_cfg.drv_data = &collie_bat_main;
        collie_bat_main.psy = power_supply_register(&dev->ucb->dev,
                                                    &collie_bat_main_desc,
                                                    &psy_main_cfg);
        if (IS_ERR(collie_bat_main.psy)) {
                ret = PTR_ERR(collie_bat_main.psy);
                goto err_psy_reg_main;
        }

        psy_bu_cfg.drv_data = &collie_bat_bu;
        collie_bat_bu.psy = power_supply_register(&dev->ucb->dev,
                                                  &collie_bat_bu_desc,
                                                  &psy_bu_cfg);
        if (IS_ERR(collie_bat_bu.psy)) {
                ret = PTR_ERR(collie_bat_bu.psy);
                goto err_psy_reg_bu;
        }

        ret = request_irq(gpiod_to_irq(collie_bat_main.gpio_full),
                                collie_bat_gpio_isr,
                                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
                                "main full", &collie_bat_main);
        if (ret)
                goto err_irq;

        device_init_wakeup(&ucb->dev, 1);
        schedule_work(&bat_work);

        return 0;

err_irq:
        power_supply_unregister(collie_bat_bu.psy);
err_psy_reg_bu:
        power_supply_unregister(collie_bat_main.psy);
err_psy_reg_main:
        /* see comment in collie_bat_remove */
        cancel_work_sync(&bat_work);
        gpiochip_free_own_desc(collie_bat_bu.gpio_bat);
err_free_gpio_temp:
        gpiochip_free_own_desc(collie_bat_main.gpio_temp);
err_free_gpio_bat:
        gpiochip_free_own_desc(collie_bat_main.gpio_bat);
err_put_gpio_charge_on:
        gpiod_put(collie_bat_main.gpio_charge_on);
err_put_mbat_low:
        gpiod_put(collie_mbat_low);
err_put_gpio_full:
        gpiod_put(collie_bat_main.gpio_full);

        return ret;
}

static void collie_bat_remove(struct ucb1x00_dev *dev)
{
        device_init_wakeup(&ucb->dev, 0);
        free_irq(gpiod_to_irq(collie_bat_main.gpio_full), &collie_bat_main);
        power_supply_unregister(collie_bat_bu.psy);
        power_supply_unregister(collie_bat_main.psy);

        /* These are obtained from the machine */
        gpiod_put(collie_bat_main.gpio_full);
        gpiod_put(collie_mbat_low);
        gpiod_put(collie_bat_main.gpio_charge_on);
        /* These are directly from the UCB so let's free them */
        gpiochip_free_own_desc(collie_bat_main.gpio_bat);
        gpiochip_free_own_desc(collie_bat_main.gpio_temp);
        gpiochip_free_own_desc(collie_bat_bu.gpio_bat);
        /*
         * Now cancel the bat_work.  We won't get any more schedules,
         * since all sources (isr and external_power_changed) are
         * unregistered now.
         */
        cancel_work_sync(&bat_work);
}

static struct ucb1x00_driver collie_bat_driver = {
        .add            = collie_bat_probe,
        .remove         = collie_bat_remove,
        .suspend        = collie_bat_suspend,
        .resume         = collie_bat_resume,
};

static int __init collie_bat_init(void)
{
        return ucb1x00_register_driver(&collie_bat_driver);
}

static void __exit collie_bat_exit(void)
{
        ucb1x00_unregister_driver(&collie_bat_driver);
}

module_init(collie_bat_init);
module_exit(collie_bat_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Thomas Kunze");
MODULE_DESCRIPTION("Collie battery driver");