jz4740-battery.c

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/*
 * Battery measurement code for Ingenic JZ SOC.
 *
 * Copyright (C) 2009 Jiejing Zhang <[email protected]>
 * Copyright (C) 2010, Lars-Peter Clausen <[email protected]>
 *
 * based on tosa_battery.c
 *
 * Copyright (C) 2008 Marek Vasut <[email protected]>
*
 * 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/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/io.h>

#include <linux/delay.h>
#include <linux/gpio.h>
#include <linux/mfd/core.h>
#include <linux/power_supply.h>

#include <linux/power/jz4740-battery.h>
#include <linux/jz4740-adc.h>

struct jz_battery {
    struct jz_battery_platform_data *pdata;
    struct platform_device *pdev;

    struct resource *mem;
    void __iomem *base;

    int irq;
    int charge_irq;

    const struct mfd_cell *cell;

    int status;
    long voltage;

    struct completion read_completion;

    struct power_supply battery;
    struct delayed_work work;

    struct mutex lock;
};

static inline struct jz_battery *psy_to_jz_battery(struct power_supply *psy)
{
    return container_of(psy, struct jz_battery, battery);
}

static irqreturn_t jz_battery_irq_handler(int irq, void *devid)
{
    struct jz_battery *battery = devid;

    complete(&battery->read_completion);
    return IRQ_HANDLED;
}

static long jz_battery_read_voltage(struct jz_battery *battery)
{
    long t;
    unsigned long val;
    long voltage;

    mutex_lock(&battery->lock);

    INIT_COMPLETION(battery->read_completion);

    enable_irq(battery->irq);
    battery->cell->enable(battery->pdev);

    t = wait_for_completion_interruptible_timeout(&battery->read_completion,
        HZ);

    if (t > 0) {
        val = readw(battery->base) & 0xfff;

        if (battery->pdata->info.voltage_max_design <= 2500000)
            val = (val * 78125UL) >> 7UL;
        else
            val = ((val * 924375UL) >> 9UL) + 33000;
        voltage = (long)val;
    } else {
        voltage = t ? t : -ETIMEDOUT;
    }

    battery->cell->disable(battery->pdev);
    disable_irq(battery->irq);

    mutex_unlock(&battery->lock);

    return voltage;
}

static int jz_battery_get_capacity(struct power_supply *psy)
{
    struct jz_battery *jz_battery = psy_to_jz_battery(psy);
    struct power_supply_info *info = &jz_battery->pdata->info;
    long voltage;
    int ret;
    int voltage_span;

    voltage = jz_battery_read_voltage(jz_battery);

    if (voltage < 0)
        return voltage;

    voltage_span = info->voltage_max_design - info->voltage_min_design;
    ret = ((voltage - info->voltage_min_design) * 100) / voltage_span;

    if (ret > 100)
        ret = 100;
    else if (ret < 0)
        ret = 0;

    return ret;
}

static int jz_battery_get_property(struct power_supply *psy,
    enum power_supply_property psp, union power_supply_propval *val)
{
    struct jz_battery *jz_battery = psy_to_jz_battery(psy);
    struct power_supply_info *info = &jz_battery->pdata->info;
    long voltage;

    switch (psp) {
    case POWER_SUPPLY_PROP_STATUS:
        val->intval = jz_battery->status;
        break;
    case POWER_SUPPLY_PROP_TECHNOLOGY:
        val->intval = jz_battery->pdata->info.technology;
        break;
    case POWER_SUPPLY_PROP_HEALTH:
        voltage = jz_battery_read_voltage(jz_battery);
        if (voltage < info->voltage_min_design)
            val->intval = POWER_SUPPLY_HEALTH_DEAD;
        else
            val->intval = POWER_SUPPLY_HEALTH_GOOD;
        break;
    case POWER_SUPPLY_PROP_CAPACITY:
        val->intval = jz_battery_get_capacity(psy);
        break;
    case POWER_SUPPLY_PROP_VOLTAGE_NOW:
        val->intval = jz_battery_read_voltage(jz_battery);
        if (val->intval < 0)
            return val->intval;
        break;
    case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
        val->intval = info->voltage_max_design;
        break;
    case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
        val->intval = info->voltage_min_design;
        break;
    case POWER_SUPPLY_PROP_PRESENT:
        val->intval = 1;
        break;
    default:
        return -EINVAL;
    }
    return 0;
}

static void jz_battery_external_power_changed(struct power_supply *psy)
{
    struct jz_battery *jz_battery = psy_to_jz_battery(psy);

    mod_delayed_work(system_wq, &jz_battery->work, 0);
}

static irqreturn_t jz_battery_charge_irq(int irq, void *data)
{
    struct jz_battery *jz_battery = data;

    mod_delayed_work(system_wq, &jz_battery->work, 0);

    return IRQ_HANDLED;
}

static void jz_battery_update(struct jz_battery *jz_battery)
{
    int status;
    long voltage;
    bool has_changed = false;
    int is_charging;

    if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
        is_charging = gpio_get_value(jz_battery->pdata->gpio_charge);
        is_charging ^= jz_battery->pdata->gpio_charge_active_low;
        if (is_charging)
            status = POWER_SUPPLY_STATUS_CHARGING;
        else
            status = POWER_SUPPLY_STATUS_NOT_CHARGING;

        if (status != jz_battery->status) {
            jz_battery->status = status;
            has_changed = true;
        }
    }

    voltage = jz_battery_read_voltage(jz_battery);
    if (abs(voltage - jz_battery->voltage) < 50000) {
        jz_battery->voltage = voltage;
        has_changed = true;
    }

    if (has_changed)
        power_supply_changed(&jz_battery->battery);
}

static enum power_supply_property jz_battery_properties[] = {
    POWER_SUPPLY_PROP_STATUS,
    POWER_SUPPLY_PROP_TECHNOLOGY,
    POWER_SUPPLY_PROP_HEALTH,
    POWER_SUPPLY_PROP_CAPACITY,
    POWER_SUPPLY_PROP_VOLTAGE_NOW,
    POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
    POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
    POWER_SUPPLY_PROP_PRESENT,
};

static void jz_battery_work(struct work_struct *work)
{
    /* Too small interval will increase system workload */
    const int interval = HZ * 30;
    struct jz_battery *jz_battery = container_of(work, struct jz_battery,
                        work.work);

    jz_battery_update(jz_battery);
    schedule_delayed_work(&jz_battery->work, interval);
}

static int __devinit jz_battery_probe(struct platform_device *pdev)
{
    int ret = 0;
    struct jz_battery_platform_data *pdata = pdev->dev.parent->platform_data;
    struct jz_battery *jz_battery;
    struct power_supply *battery;

    if (!pdata) {
        dev_err(&pdev->dev, "No platform_data supplied\n");
        return -ENXIO;
    }

    jz_battery = kzalloc(sizeof(*jz_battery), GFP_KERNEL);
    if (!jz_battery) {
        dev_err(&pdev->dev, "Failed to allocate driver structure\n");
        return -ENOMEM;
    }

    jz_battery->cell = mfd_get_cell(pdev);

    jz_battery->irq = platform_get_irq(pdev, 0);
    if (jz_battery->irq < 0) {
        ret = jz_battery->irq;
        dev_err(&pdev->dev, "Failed to get platform irq: %d\n", ret);
        goto err_free;
    }

    jz_battery->mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!jz_battery->mem) {
        ret = -ENOENT;
        dev_err(&pdev->dev, "Failed to get platform mmio resource\n");
        goto err_free;
    }

    jz_battery->mem = request_mem_region(jz_battery->mem->start,
                resource_size(jz_battery->mem), pdev->name);
    if (!jz_battery->mem) {
        ret = -EBUSY;
        dev_err(&pdev->dev, "Failed to request mmio memory region\n");
        goto err_free;
    }

    jz_battery->base = ioremap_nocache(jz_battery->mem->start,
                resource_size(jz_battery->mem));
    if (!jz_battery->base) {
        ret = -EBUSY;
        dev_err(&pdev->dev, "Failed to ioremap mmio memory\n");
        goto err_release_mem_region;
    }

    battery = &jz_battery->battery;
    battery->name = pdata->info.name;
    battery->type = POWER_SUPPLY_TYPE_BATTERY;
    battery->properties = jz_battery_properties;
    battery->num_properties = ARRAY_SIZE(jz_battery_properties);
    battery->get_property = jz_battery_get_property;
    battery->external_power_changed = jz_battery_external_power_changed;
    battery->use_for_apm = 1;

    jz_battery->pdata = pdata;
    jz_battery->pdev = pdev;

    init_completion(&jz_battery->read_completion);
    mutex_init(&jz_battery->lock);

    INIT_DELAYED_WORK(&jz_battery->work, jz_battery_work);

    ret = request_irq(jz_battery->irq, jz_battery_irq_handler, 0, pdev->name,
            jz_battery);
    if (ret) {
        dev_err(&pdev->dev, "Failed to request irq %d\n", ret);
        goto err_iounmap;
    }
    disable_irq(jz_battery->irq);

    if (gpio_is_valid(pdata->gpio_charge)) {
        ret = gpio_request(pdata->gpio_charge, dev_name(&pdev->dev));
        if (ret) {
            dev_err(&pdev->dev, "charger state gpio request failed.\n");
            goto err_free_irq;
        }
        ret = gpio_direction_input(pdata->gpio_charge);
        if (ret) {
            dev_err(&pdev->dev, "charger state gpio set direction failed.\n");
            goto err_free_gpio;
        }

        jz_battery->charge_irq = gpio_to_irq(pdata->gpio_charge);

        if (jz_battery->charge_irq >= 0) {
            ret = request_irq(jz_battery->charge_irq,
                    jz_battery_charge_irq,
                    IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
                    dev_name(&pdev->dev), jz_battery);
            if (ret) {
                dev_err(&pdev->dev, "Failed to request charge irq: %d\n", ret);
                goto err_free_gpio;
            }
        }
    } else {
        jz_battery->charge_irq = -1;
    }

    if (jz_battery->pdata->info.voltage_max_design <= 2500000)
        jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB,
            JZ_ADC_CONFIG_BAT_MB);
    else
        jz4740_adc_set_config(pdev->dev.parent, JZ_ADC_CONFIG_BAT_MB, 0);

    ret = power_supply_register(&pdev->dev, &jz_battery->battery);
    if (ret) {
        dev_err(&pdev->dev, "power supply battery register failed.\n");
        goto err_free_charge_irq;
    }

    platform_set_drvdata(pdev, jz_battery);
    schedule_delayed_work(&jz_battery->work, 0);

    return 0;

err_free_charge_irq:
    if (jz_battery->charge_irq >= 0)
        free_irq(jz_battery->charge_irq, jz_battery);
err_free_gpio:
    if (gpio_is_valid(pdata->gpio_charge))
        gpio_free(jz_battery->pdata->gpio_charge);
err_free_irq:
    free_irq(jz_battery->irq, jz_battery);
err_iounmap:
    platform_set_drvdata(pdev, NULL);
    iounmap(jz_battery->base);
err_release_mem_region:
    release_mem_region(jz_battery->mem->start, resource_size(jz_battery->mem));
err_free:
    kfree(jz_battery);
    return ret;
}

static int __devexit jz_battery_remove(struct platform_device *pdev)
{
    struct jz_battery *jz_battery = platform_get_drvdata(pdev);

    cancel_delayed_work_sync(&jz_battery->work);

    if (gpio_is_valid(jz_battery->pdata->gpio_charge)) {
        if (jz_battery->charge_irq >= 0)
            free_irq(jz_battery->charge_irq, jz_battery);
        gpio_free(jz_battery->pdata->gpio_charge);
    }

    power_supply_unregister(&jz_battery->battery);

    free_irq(jz_battery->irq, jz_battery);

    iounmap(jz_battery->base);
    release_mem_region(jz_battery->mem->start, resource_size(jz_battery->mem));
    kfree(jz_battery);

    return 0;
}

#ifdef CONFIG_PM
static int jz_battery_suspend(struct device *dev)
{
    struct jz_battery *jz_battery = dev_get_drvdata(dev);

    cancel_delayed_work_sync(&jz_battery->work);
    jz_battery->status = POWER_SUPPLY_STATUS_UNKNOWN;

    return 0;
}

static int jz_battery_resume(struct device *dev)
{
    struct jz_battery *jz_battery = dev_get_drvdata(dev);

    schedule_delayed_work(&jz_battery->work, 0);

    return 0;
}

static const struct dev_pm_ops jz_battery_pm_ops = {
    .suspend    = jz_battery_suspend,
    .resume     = jz_battery_resume,
};

#define JZ_BATTERY_PM_OPS (&jz_battery_pm_ops)
#else
#define JZ_BATTERY_PM_OPS NULL
#endif

static struct platform_driver jz_battery_driver = {
    .probe      = jz_battery_probe,
    .remove     = __devexit_p(jz_battery_remove),
    .driver = {
        .name = "jz4740-battery",
        .owner = THIS_MODULE,
        .pm = JZ_BATTERY_PM_OPS,
    },
};

module_platform_driver(jz_battery_driver);

MODULE_ALIAS("platform:jz4740-battery");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Lars-Peter Clausen <[email protected]>");
MODULE_DESCRIPTION("JZ4740 SoC battery driver");