collie_battery.c

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/*
 * Battery and Power Management code for the Sharp SL-5x00
 *
 * Copyright (C) 2009 Thomas Kunze
 *
 * based on tosa_battery.c
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */
#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.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);
    int gpio_full;
    int gpio_charge_on;

    int technology;

    int gpio_bat;
    int adc_bat;
    int adc_bat_divider;
    int bat_max;
    int bat_min;

    int 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 < 0 || bat->adc_bat < 0)
        return 0;
    mutex_lock(&bat_lock);
    gpio_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);
    gpio_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 < 0 || bat->adc_temp < 0)
        return 0;

    mutex_lock(&bat_lock);
    gpio_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);
    gpio_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 = container_of(psy, struct collie_bat, 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->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) {
            gpio_set_value(bat->gpio_charge_on, 1);
            mdelay(15);
        }

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

            gpio_set_value(bat->gpio_charge_on, 0);
            bat->status = POWER_SUPPLY_STATUS_FULL;
        } else {
            gpio_set_value(bat->gpio_charge_on, 1);
            bat->status = POWER_SUPPLY_STATUS_CHARGING;
        }
    } else {
        gpio_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 struct collie_bat collie_bat_main = {
    .status = POWER_SUPPLY_STATUS_DISCHARGING,
    .full_chrg = -1,
    .psy = {
        .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,
    },

    .gpio_full = COLLIE_GPIO_CO,
    .gpio_charge_on = COLLIE_GPIO_CHARGE_ON,

    .technology = POWER_SUPPLY_TECHNOLOGY_LIPO,

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

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

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

    .psy = {
        .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,
    },

    .gpio_full = -1,
    .gpio_charge_on = -1,

    .technology = POWER_SUPPLY_TECHNOLOGY_LiMn,

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

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

static struct gpio collie_batt_gpios[] = {
    { COLLIE_GPIO_CO,       GPIOF_IN,       "main battery full" },
    { COLLIE_GPIO_MAIN_BAT_LOW, GPIOF_IN,       "main battery low" },
    { COLLIE_GPIO_CHARGE_ON,    GPIOF_OUT_INIT_LOW, "main charge on" },
    { COLLIE_GPIO_MBAT_ON,      GPIOF_OUT_INIT_LOW, "main battery" },
    { COLLIE_GPIO_TMP_ON,       GPIOF_OUT_INIT_LOW, "main battery temp" },
    { COLLIE_GPIO_BBAT_ON,      GPIOF_OUT_INIT_LOW, "backup battery" },
};

#ifdef CONFIG_PM
static int collie_bat_suspend(struct ucb1x00_dev *dev, pm_message_t state)
{
    /* flush all pending status updates */
    flush_work(&bat_work);
    return 0;
}

static int collie_bat_resume(struct ucb1x00_dev *dev)
{
    /* 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 __devinit collie_bat_probe(struct ucb1x00_dev *dev)
{
    int ret;

    if (!machine_is_collie())
        return -ENODEV;

    ucb = dev->ucb;

    ret = gpio_request_array(collie_batt_gpios,
                 ARRAY_SIZE(collie_batt_gpios));
    if (ret)
        return ret;

    mutex_init(&collie_bat_main.work_lock);

    INIT_WORK(&bat_work, collie_bat_work);

    ret = power_supply_register(&dev->ucb->dev, &collie_bat_main.psy);
    if (ret)
        goto err_psy_reg_main;
    ret = power_supply_register(&dev->ucb->dev, &collie_bat_bu.psy);
    if (ret)
        goto err_psy_reg_bu;

    ret = request_irq(gpio_to_irq(COLLIE_GPIO_CO),
                collie_bat_gpio_isr,
                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
                "main full", &collie_bat_main);
    if (!ret) {
        schedule_work(&bat_work);
        return 0;
    }
    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);
    gpio_free_array(collie_batt_gpios, ARRAY_SIZE(collie_batt_gpios));
    return ret;
}

static void __devexit collie_bat_remove(struct ucb1x00_dev *dev)
{
    free_irq(gpio_to_irq(COLLIE_GPIO_CO), &collie_bat_main);

    power_supply_unregister(&collie_bat_bu.psy);
    power_supply_unregister(&collie_bat_main.psy);

    /*
     * 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);
    gpio_free_array(collie_batt_gpios, ARRAY_SIZE(collie_batt_gpios));
}

static struct ucb1x00_driver collie_bat_driver = {
    .add        = collie_bat_probe,
    .remove     = __devexit_p(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");