4 files changed, 459 insertions, 0 deletions

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index c1892f321c46..80978196aae8 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -29,6 +29,13 @@ config APM_POWER
           Say Y here to enable support APM status emulation using
           battery class devices.
 
+config GENERIC_ADC_BATTERY
+        tristate "Generic battery support using IIO"
+        depends on IIO
+        help
+          Say Y here to enable support for the generic battery driver
+          which uses IIO framework to read adc.
+
 config MAX8925_POWER
         tristate "MAX8925 battery charger support"
         depends on MFD_MAX8925
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index ee58afb1e71f..e0b4d4284e1d 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -5,6 +5,7 @@ power_supply-$(CONFIG_SYSFS)		+= power_supply_sysfs.o
 power_supply-$(CONFIG_LEDS_TRIGGERS)    += power_supply_leds.o
 
 obj-$(CONFIG_POWER_SUPPLY)      += power_supply.o
+obj-$(CONFIG_GENERIC_ADC_BATTERY)       += generic-adc-battery.o
 
 obj-$(CONFIG_PDA_POWER)         += pda_power.o
 obj-$(CONFIG_APM_POWER)         += apm_power.o
diff --git a/drivers/power/generic-adc-battery.c b/drivers/power/generic-adc-battery.c
new file mode 100644
index 000000000000..9bdf44470396
--- /dev/null
+++ b/drivers/power/generic-adc-battery.c
@@ -0,0 +1,422 @@
+/*
+ * Generic battery driver code using IIO
+ * Copyright (C) 2012, Anish Kumar <anish198519851985@gmail.com>
+ * 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 <anish198519851985@gmail.com>");
+MODULE_DESCRIPTION("generic battery driver using IIO");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/power/generic-adc-battery.h b/include/linux/power/generic-adc-battery.h
new file mode 100644
index 000000000000..b1ebe08533b6
--- /dev/null
+++ b/include/linux/power/generic-adc-battery.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2012, Anish Kumar <anish198519851985@gmail.com>
+ * 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.
+ */
+
+#ifndef GENERIC_ADC_BATTERY_H
+#define GENERIC_ADC_BATTERY_H
+
+/**
+ * struct gab_platform_data - platform_data for generic adc iio battery driver.
+ * @battery_info:         recommended structure to specify static power supply
+ *                         parameters
+ * @cal_charge:           calculate charge level.
+ * @gpio_charge_finished: gpio for the charger.
+ * @gpio_inverted:        Should be 1 if the GPIO is active low otherwise 0
+ * @jitter_delay:         delay required after the interrupt to check battery
+ *                        status.Default set is 10ms.
+ */
+struct gab_platform_data {
+        struct power_supply_info battery_info;
+        int     (*cal_charge)(long value);
+        int     gpio_charge_finished;
+        bool    gpio_inverted;
+        int     jitter_delay;
+};
+
+#endif /* GENERIC_ADC_BATTERY_H */