generic-adc-battery.c

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/*
 * Generic battery driver code using IIO
 * Copyright (C) 2012, Anish Kumar <[email protected]>
 * based on jz4740-battery.c
 * based on s3c_adc_battery.c
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive for
 * more details.
 *
 */
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/gpio.h>
#include <linux/err.h>
#include <linux/timer.h>
#include <linux/jiffies.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/iio/consumer.h>
#include <linux/iio/types.h>
#include <linux/power/generic-adc-battery.h>

#define JITTER_DEFAULT 10 /* hope 10ms is enough */

enum gab_chan_type {
    GAB_VOLTAGE = 0,
    GAB_CURRENT,
    GAB_POWER,
    GAB_MAX_CHAN_TYPE
};

/*
 * gab_chan_name suggests the standard channel names for commonly used
 * channel types.
 */
static const char *const gab_chan_name[] = {
    [GAB_VOLTAGE]   = "voltage",
    [GAB_CURRENT]   = "current",
    [GAB_POWER]     = "power",
};

struct gab {
    struct power_supply psy;
    struct iio_channel  *channel[GAB_MAX_CHAN_TYPE];
    struct gab_platform_data    *pdata;
    struct delayed_work bat_work;
    int level;
    int status;
    bool cable_plugged;
};

static struct gab *to_generic_bat(struct power_supply *psy)
{
    return container_of(psy, struct gab, psy);
}

static void gab_ext_power_changed(struct power_supply *psy)
{
    struct gab *adc_bat = to_generic_bat(psy);

    schedule_delayed_work(&adc_bat->bat_work, msecs_to_jiffies(0));
}

static const enum power_supply_property gab_props[] = {
    POWER_SUPPLY_PROP_STATUS,
    POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
    POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN,
    POWER_SUPPLY_PROP_CHARGE_NOW,
    POWER_SUPPLY_PROP_VOLTAGE_NOW,
    POWER_SUPPLY_PROP_CURRENT_NOW,
    POWER_SUPPLY_PROP_TECHNOLOGY,
    POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
    POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
    POWER_SUPPLY_PROP_MODEL_NAME,
};

/*
 * This properties are set based on the received platform data and this
 * should correspond one-to-one with enum chan_type.
 */
static const enum power_supply_property gab_dyn_props[] = {
    POWER_SUPPLY_PROP_VOLTAGE_NOW,
    POWER_SUPPLY_PROP_CURRENT_NOW,
    POWER_SUPPLY_PROP_POWER_NOW,
};

static bool gab_charge_finished(struct gab *adc_bat)
{
    struct gab_platform_data *pdata = adc_bat->pdata;
    bool ret = gpio_get_value(pdata->gpio_charge_finished);
    bool inv = pdata->gpio_inverted;

    if (!gpio_is_valid(pdata->gpio_charge_finished))
        return false;
    return ret ^ inv;
}

static int gab_get_status(struct gab *adc_bat)
{
    struct gab_platform_data *pdata = adc_bat->pdata;
    struct power_supply_info *bat_info;

    bat_info = &pdata->battery_info;
    if (adc_bat->level == bat_info->charge_full_design)
        return POWER_SUPPLY_STATUS_FULL;
    return adc_bat->status;
}

static enum gab_chan_type gab_prop_to_chan(enum power_supply_property psp)
{
    switch (psp) {
    case POWER_SUPPLY_PROP_POWER_NOW:
        return GAB_POWER;
    case POWER_SUPPLY_PROP_VOLTAGE_NOW:
        return GAB_VOLTAGE;
    case POWER_SUPPLY_PROP_CURRENT_NOW:
        return GAB_CURRENT;
    default:
        WARN_ON(1);
        break;
    }
    return GAB_POWER;
}

static int read_channel(struct gab *adc_bat, enum power_supply_property psp,
        int *result)
{
    int ret;
    int chan_index;

    chan_index = gab_prop_to_chan(psp);
    ret = iio_read_channel_processed(adc_bat->channel[chan_index],
            result);
    if (ret < 0)
        pr_err("read channel error\n");
    return ret;
}

static int gab_get_property(struct power_supply *psy,
        enum power_supply_property psp, union power_supply_propval *val)
{
    struct gab *adc_bat;
    struct gab_platform_data *pdata;
    struct power_supply_info *bat_info;
    int result = 0;
    int ret = 0;

    adc_bat = to_generic_bat(psy);
    if (!adc_bat) {
        dev_err(psy->dev, "no battery infos ?!\n");
        return -EINVAL;
    }
    pdata = adc_bat->pdata;
    bat_info = &pdata->battery_info;

    switch (psp) {
    case POWER_SUPPLY_PROP_STATUS:
        gab_get_status(adc_bat);
        break;
    case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
        val->intval = 0;
        break;
    case POWER_SUPPLY_PROP_CHARGE_NOW:
        val->intval = pdata->cal_charge(result);
        break;
    case POWER_SUPPLY_PROP_VOLTAGE_NOW:
    case POWER_SUPPLY_PROP_CURRENT_NOW:
    case POWER_SUPPLY_PROP_POWER_NOW:
        ret = read_channel(adc_bat, psp, &result);
        if (ret < 0)
            goto err;
        val->intval = result;
        break;
    case POWER_SUPPLY_PROP_TECHNOLOGY:
        val->intval = bat_info->technology;
        break;
    case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
        val->intval = bat_info->voltage_min_design;
        break;
    case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
        val->intval = bat_info->voltage_max_design;
        break;
    case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
        val->intval = bat_info->charge_full_design;
        break;
    case POWER_SUPPLY_PROP_MODEL_NAME:
        val->strval = bat_info->name;
        break;
    default:
        return -EINVAL;
    }
err:
    return ret;
}

static void gab_work(struct work_struct *work)
{
    struct gab *adc_bat;
    struct gab_platform_data *pdata;
    struct delayed_work *delayed_work;
    bool is_plugged;
    int status;

    delayed_work = container_of(work, struct delayed_work, work);
    adc_bat = container_of(delayed_work, struct gab, bat_work);
    pdata = adc_bat->pdata;
    status = adc_bat->status;

    is_plugged = power_supply_am_i_supplied(&adc_bat->psy);
    adc_bat->cable_plugged = is_plugged;

    if (!is_plugged)
        adc_bat->status =  POWER_SUPPLY_STATUS_DISCHARGING;
    else if (gab_charge_finished(adc_bat))
        adc_bat->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
    else
        adc_bat->status = POWER_SUPPLY_STATUS_CHARGING;

    if (status != adc_bat->status)
        power_supply_changed(&adc_bat->psy);
}

static irqreturn_t gab_charged(int irq, void *dev_id)
{
    struct gab *adc_bat = dev_id;
    struct gab_platform_data *pdata = adc_bat->pdata;
    int delay;

    delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;
    schedule_delayed_work(&adc_bat->bat_work,
            msecs_to_jiffies(delay));
    return IRQ_HANDLED;
}

static int __devinit gab_probe(struct platform_device *pdev)
{
    struct gab *adc_bat;
    struct power_supply *psy;
    struct gab_platform_data *pdata = pdev->dev.platform_data;
    enum power_supply_property *properties;
    int ret = 0;
    int chan;
    int index = 0;

    adc_bat = devm_kzalloc(&pdev->dev, sizeof(*adc_bat), GFP_KERNEL);
    if (!adc_bat) {
        dev_err(&pdev->dev, "failed to allocate memory\n");
        return -ENOMEM;
    }

    psy = &adc_bat->psy;
    psy->name = pdata->battery_info.name;

    /* bootup default values for the battery */
    adc_bat->cable_plugged = false;
    adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
    psy->type = POWER_SUPPLY_TYPE_BATTERY;
    psy->get_property = gab_get_property;
    psy->external_power_changed = gab_ext_power_changed;
    adc_bat->pdata = pdata;

    /* calculate the total number of channels */
    chan = ARRAY_SIZE(gab_chan_name);

    /*
     * copying the static properties and allocating extra memory for holding
     * the extra configurable properties received from platform data.
     */
    psy->properties = kcalloc(ARRAY_SIZE(gab_props) +
                    ARRAY_SIZE(gab_chan_name),
                    sizeof(*psy->properties), GFP_KERNEL);
    if (!psy->properties) {
        ret = -ENOMEM;
        goto first_mem_fail;
    }

    memcpy(psy->properties, gab_props, sizeof(gab_props));
    properties = psy->properties + sizeof(gab_props);

    /*
     * getting channel from iio and copying the battery properties
     * based on the channel supported by consumer device.
     */
    for (chan = 0; chan < ARRAY_SIZE(gab_chan_name); chan++) {
        adc_bat->channel[chan] = iio_channel_get(dev_name(&pdev->dev),
                        gab_chan_name[chan]);
        if (IS_ERR(adc_bat->channel[chan])) {
            ret = PTR_ERR(adc_bat->channel[chan]);
        } else {
            /* copying properties for supported channels only */
            memcpy(properties + sizeof(*(psy->properties)) * index,
                    &gab_dyn_props[chan],
                    sizeof(gab_dyn_props[chan]));
            index++;
        }
    }

    /* none of the channels are supported so let's bail out */
    if (index == ARRAY_SIZE(gab_chan_name))
        goto second_mem_fail;

    /*
     * Total number of properties is equal to static properties
     * plus the dynamic properties.Some properties may not be set
     * as come channels may be not be supported by the device.So
     * we need to take care of that.
     */
    psy->num_properties = ARRAY_SIZE(gab_props) + index;

    ret = power_supply_register(&pdev->dev, psy);
    if (ret)
        goto err_reg_fail;

    INIT_DELAYED_WORK(&adc_bat->bat_work, gab_work);

    if (gpio_is_valid(pdata->gpio_charge_finished)) {
        int irq;
        ret = gpio_request(pdata->gpio_charge_finished, "charged");
        if (ret)
            goto gpio_req_fail;

        irq = gpio_to_irq(pdata->gpio_charge_finished);
        ret = request_any_context_irq(irq, gab_charged,
                IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
                "battery charged", adc_bat);
        if (ret)
            goto err_gpio;
    }

    platform_set_drvdata(pdev, adc_bat);

    /* Schedule timer to check current status */
    schedule_delayed_work(&adc_bat->bat_work,
            msecs_to_jiffies(0));
    return 0;

err_gpio:
    gpio_free(pdata->gpio_charge_finished);
gpio_req_fail:
    power_supply_unregister(psy);
err_reg_fail:
    for (chan = 0; ARRAY_SIZE(gab_chan_name); chan++)
        iio_channel_release(adc_bat->channel[chan]);
second_mem_fail:
    kfree(psy->properties);
first_mem_fail:
    return ret;
}

static int __devexit gab_remove(struct platform_device *pdev)
{
    int chan;
    struct gab *adc_bat = platform_get_drvdata(pdev);
    struct gab_platform_data *pdata = adc_bat->pdata;

    power_supply_unregister(&adc_bat->psy);

    if (gpio_is_valid(pdata->gpio_charge_finished)) {
        free_irq(gpio_to_irq(pdata->gpio_charge_finished), adc_bat);
        gpio_free(pdata->gpio_charge_finished);
    }

    for (chan = 0; ARRAY_SIZE(gab_chan_name); chan++)
        iio_channel_release(adc_bat->channel[chan]);

    kfree(adc_bat->psy.properties);
    cancel_delayed_work(&adc_bat->bat_work);
    return 0;
}

#ifdef CONFIG_PM
static int gab_suspend(struct device *dev)
{
    struct gab *adc_bat = dev_get_drvdata(dev);

    cancel_delayed_work_sync(&adc_bat->bat_work);
    adc_bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
    return 0;
}

static int gab_resume(struct device *dev)
{
    struct gab *adc_bat = dev_get_drvdata(dev);
    struct gab_platform_data *pdata = adc_bat->pdata;
    int delay;

    delay = pdata->jitter_delay ? pdata->jitter_delay : JITTER_DEFAULT;

    /* Schedule timer to check current status */
    schedule_delayed_work(&adc_bat->bat_work,
            msecs_to_jiffies(delay));
    return 0;
}

static const struct dev_pm_ops gab_pm_ops = {
    .suspend        = gab_suspend,
    .resume         = gab_resume,
};

#define GAB_PM_OPS       (&gab_pm_ops)
#else
#define GAB_PM_OPS       (NULL)
#endif

static struct platform_driver gab_driver = {
    .driver     = {
        .name   = "generic-adc-battery",
        .owner  = THIS_MODULE,
        .pm = GAB_PM_OPS
    },
    .probe      = gab_probe,
    .remove     = __devexit_p(gab_remove),
};
module_platform_driver(gab_driver);

MODULE_AUTHOR("anish kumar <[email protected]>");
MODULE_DESCRIPTION("generic battery driver using IIO");
MODULE_LICENSE("GPL");