[PATCH] power: battery: Generic battery driver using IIO

anish kumar
2012-09-13T16:17:08Z

From: anish kumar <anish198519851985@gmail.com>

In this version:
Addressed concerns raised by lars:
a. made the adc_bat per device.
b. get the IIO channel using hardcoded channel names.
c. Minor issues related to gpio_is_valid and some code
refactoring.

Signed-off-by: anish kumar <anish198519851985@gmail.com>
---
drivers/power/generic-adc-battery.c | 460 +++++++++++++++++++++++++++++
include/linux/power/generic-adc-battery.h | 33 ++
2 files changed, 493 insertions(+), 0 deletions(-)
create mode 100644 drivers/power/generic-adc-battery.c
create mode 100644 include/linux/power/generic-adc-battery.h

diff --git a/drivers/power/generic-adc-battery.c b/drivers/power/generic-adc-battery.c
new file mode 100644
index 0000000..003e0e1
--- /dev/null
+++ b/drivers/power/generic-adc-battery.c
@@ -0,0 +1,460 @@
+/*
+ * 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 to_generic_bat(ptr) \
+ container_of(ptr, struct generic_adc_bat, ptr)
+
+enum chan_type {
+ VOLTAGE = 0,
+ CURRENT,
+ POWER,
+ MAX_CHAN_TYPE
+};
+
+#define CHAN_MAX_NAME 30
+/*
+ * channel_name suggests the standard channel names for commonly used
+ * channel types.
+ */
+char channel_name[][CHAN_MAX_NAME + 1] = {
+ [VOLTAGE] = "voltage",
+ [CURRENT] = "current",
+ [POWER] = "power",
+};
+
+struct generic_adc_bat {
+ struct power_supply psy;
+ struct iio_channel **channel;
+ struct iio_battery_platform_data *pdata;
+ struct delayed_work bat_work;
+ int was_plugged;
+ int volt_value;
+ int cur_value;
+ int level;
+ int status;
+ int cable_plugged:1;
+};
+
+static void generic_adc_bat_ext_power_changed(struct power_supply *psy)
+{
+ struct generic_adc_bat *adc_bat;
+ adc_bat = to_generic_bat(psy);
+
+ schedule_delayed_work(&adc_bat->bat_work,
+ msecs_to_jiffies(adc_bat->pdata->jitter_delay));
+}
+
+static enum power_supply_property bat_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 enum power_supply_property dyn_props[] = {
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+ POWER_SUPPLY_PROP_CURRENT_NOW,
+ POWER_SUPPLY_PROP_POWER_NOW,
+};
+
+static int charge_finished(struct generic_adc_bat *adc_bat)
+{
+ return adc_bat->pdata->gpio_inverted ?
+ !gpio_get_value(adc_bat->pdata->gpio_charge_finished) :
+ gpio_get_value(adc_bat->pdata->gpio_charge_finished);
+}
+
+long read_scale_channel(struct generic_adc_bat *adc_bat,
+ enum power_supply_property psp)
+{
+ int scaleint, scalepart, iio_val, ret = 0;
+ int result = 0;
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_POWER_NOW:
+ ret = iio_read_channel_raw(adc_bat->channel[POWER],
+ &iio_val);
+ ret = iio_read_channel_scale(adc_bat->channel[POWER],
+ &scaleint, &scalepart);
+ if (ret < 0)
+ return ret;
+ break;
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ ret = iio_read_channel_raw(adc_bat->channel[VOLTAGE],
+ &iio_val);
+ ret = iio_read_channel_scale(adc_bat->channel[VOLTAGE],
+ &scaleint, &scalepart);
+ if (ret < 0)
+ return ret;
+ break;
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ ret = iio_read_channel_raw(adc_bat->channel[CURRENT],
+ &iio_val);
+ ret = iio_read_channel_scale(adc_bat->channel[CURRENT],
+ &scaleint, &scalepart);
+ if (ret < 0)
+ return ret;
+ break;
+ default:
+ break;
+ }
+
+ switch (ret) {
+ case IIO_VAL_INT:
+ result = iio_val * scaleint;
+ break;
+ case IIO_VAL_INT_PLUS_MICRO:
+ result = (s64)iio_val * (s64)scaleint +
+ div_s64((s64)iio_val * (s64)scalepart, 1000000LL);
+ break;
+ case IIO_VAL_INT_PLUS_NANO:
+ result = (s64)iio_val * (s64)scaleint +
+ div_s64((s64)iio_val * (s64)scalepart, 1000000000LL);
+ break;
+ }
+ return result;
+}
+
+static int generic_adc_bat_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct generic_adc_bat *adc_bat;
+ int ret = 0;
+ long result;
+
+ adc_bat = to_generic_bat(psy);
+ if (!adc_bat) {
+ dev_err(psy->dev, "no battery infos ?!\n");
+ return -EINVAL;
+ }
+
+ result = read_scale_channel(adc_bat, psp);
+ if (result < 0) {
+ dev_err(psy->dev, "read channel error\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_STATUS:
+ if (gpio_is_valid(adc_bat->pdata->gpio_charge_finished)) {
+ if (adc_bat->pdata->gpio_charge_finished < 0)
+ val->intval = adc_bat->level == 100000 ?
+ POWER_SUPPLY_STATUS_FULL :
+ adc_bat->status;
+ else
+ val->intval = adc_bat->status;
+ }
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
+ val->intval = 0;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ val->intval = adc_bat->pdata->cal_charge(result);
+ break;
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ val->intval = result;
+ break;
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ val->intval = result;
+ break;
+ case POWER_SUPPLY_PROP_POWER_NOW:
+ val->intval = result;
+ break;
+ case POWER_SUPPLY_PROP_TECHNOLOGY:
+ val->intval = adc_bat->pdata->battery_info.technology;
+ break;
+ case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+ val->intval = adc_bat->pdata->battery_info.voltage_min_design;
+ break;
+ case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+ val->intval = adc_bat->pdata->battery_info.voltage_max_design;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+ val->intval = adc_bat->pdata->battery_info.charge_full_design;
+ break;
+ case POWER_SUPPLY_PROP_MODEL_NAME:
+ val->strval = adc_bat->pdata->battery_info.name;
+ break;
+ default:
+ return -EINVAL;
+ }
+err:
+ return ret;
+}
+
+static void generic_adc_bat_work(struct work_struct *work)
+{
+ struct generic_adc_bat *adc_bat;
+ struct delayed_work *delayed_work;
+ int is_charged;
+ int is_plugged;
+
+ delayed_work = container_of(work,
+ struct delayed_work, work);
+ adc_bat = container_of(delayed_work,
+ struct generic_adc_bat, bat_work);
+
+ is_plugged = power_supply_am_i_supplied(&adc_bat->psy);
+ adc_bat->cable_plugged = is_plugged;
+ if (is_plugged != adc_bat->was_plugged) {
+ adc_bat->was_plugged = is_plugged;
+ if (is_plugged)
+ adc_bat->status = POWER_SUPPLY_STATUS_CHARGING;
+ else
+ adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
+ } else {
+ if (gpio_is_valid(adc_bat->pdata->gpio_charge_finished)) {
+ if ((adc_bat->pdata->gpio_charge_finished >= 0) &&
+ is_plugged) {
+ is_charged = charge_finished(adc_bat);
+ if (is_charged)
+ adc_bat->status =
+ POWER_SUPPLY_STATUS_FULL;
+ else
+ adc_bat->status =
+ POWER_SUPPLY_STATUS_CHARGING;
+ }
+ }
+ }
+
+ power_supply_changed(&adc_bat->psy);
+}
+
+static irqreturn_t generic_adc_bat_charged(int irq, void *dev_id)
+{
+ struct generic_adc_bat *adc_bat = dev_id;
+ adc_bat = container_of(&adc_bat->bat_work,
+ struct generic_adc_bat, bat_work);
+ schedule_delayed_work(&adc_bat->bat_work,
+ msecs_to_jiffies(adc_bat->pdata->jitter_delay));
+ return IRQ_HANDLED;
+}
+
+static int __devinit generic_adc_bat_probe(struct platform_device *pdev)
+{
+ struct generic_adc_bat *adc_bat;
+ struct iio_battery_platform_data *pdata = pdev->dev.platform_data;
+ int ret, chan_index, fail = 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;
+ }
+
+ /* copying the battery name from platform data */
+ adc_bat->psy.name = pdata->battery_name;
+
+ /* bootup default values for the battery */
+ adc_bat->volt_value = -1;
+ adc_bat->cur_value = -1;
+ adc_bat->cable_plugged = 0;
+ adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
+ adc_bat->psy.type = POWER_SUPPLY_TYPE_BATTERY;
+ adc_bat->psy.get_property =
+ generic_adc_bat_get_property;
+ adc_bat->psy.external_power_changed =
+ generic_adc_bat_ext_power_changed;
+
+ adc_bat->pdata = pdata;
+
+ /* calculate the total number of channels */
+ for (chan_index = 0; channel_name[chan_index]; chan_index++)
+ ;
+
+ if (!chan_index) {
+ pr_err("atleast provide one channel\n");
+ return -EINVAL;
+ }
+
+ /*
+ * copying the static properties and allocating extra memory for holding
+ * the extra configurable properties received from platform data.
+ */
+ adc_bat->psy.properties = kzalloc(sizeof(bat_props)
+ + sizeof(int)*chan_index, GFP_KERNEL);
+ if (!adc_bat->psy.properties) {
+ ret = -ENOMEM;
+ goto first_mem_fail;
+ }
+ memcpy(adc_bat->psy.properties, bat_props, sizeof(bat_props));
+
+ /* allocating memory for iio channels */
+ adc_bat->channel = kzalloc(chan_index * sizeof(struct iio_channel),
+ GFP_KERNEL);
+ if (!adc_bat->channel) {
+ ret = -ENOMEM;
+ goto second_mem_fail;
+ }
+
+ /*
+ * getting channel from iio and copying the battery properties
+ * based on the channel supported by consumer device.
+ */
+ for (chan_index = 0; channel_name[chan_index]; chan_index++) {
+ adc_bat->channel[chan_index] =
+ iio_channel_get(dev_name(&pdev->dev),
+ channel_name[chan_index]);
+ /* we skip for channels which fail */
+ if (IS_ERR(adc_bat->channel[chan_index]))
+ fail++;
+ else {
+ static int index;
+ memcpy(adc_bat->psy.properties +
+ sizeof(bat_props) + sizeof(int)*index,
+ &dyn_props[chan_index],
+ sizeof(dyn_props[chan_index]));
+ index++;
+ }
+ }
+
+ /* none of the channels are supported so let's bail out */
+ if (fail == chan_index) {
+ ret = PTR_ERR(adc_bat->channel[chan_index]);
+ goto second_mem_fail;
+ }
+
+ ret = power_supply_register(&pdev->dev, &adc_bat->psy);
+ if (ret)
+ goto err_reg_fail;
+
+ INIT_DELAYED_WORK(&adc_bat->bat_work, generic_adc_bat_work);
+
+ if (gpio_is_valid(pdata->gpio_charge_finished)) {
+ ret = gpio_request(pdata->gpio_charge_finished, "charged");
+ if (ret)
+ goto err_gpio;
+
+ ret = request_any_context_irq(gpio_to_irq
+ (pdata->gpio_charge_finished),
+ generic_adc_bat_charged,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ "battery charged", &adc_bat);
+ if (ret)
+ goto err_gpio;
+ } else
+ goto err_gpio; /* let's bail out */
+
+ 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:
+ power_supply_unregister(&adc_bat->psy);
+err_reg_fail:
+ for (chan_index = 0; channel_name[chan_index]; chan_index++)
+ iio_channel_release(adc_bat->channel[chan_index]);
+ kfree(adc_bat->channel);
+second_mem_fail:
+ kfree(adc_bat->psy.properties);
+first_mem_fail:
+ return ret;
+}
+
+static int generic_adc_bat_remove(struct platform_device *pdev)
+{
+ int chan_index;
+ struct generic_adc_bat *adc_bat = platform_get_drvdata(pdev);
+
+ power_supply_unregister(&adc_bat->psy);
+
+ if (gpio_is_valid(adc_bat->pdata->gpio_charge_finished)) {
+ if (adc_bat->pdata->gpio_charge_finished >= 0) {
+ free_irq(gpio_to_irq(
+ adc_bat->pdata->gpio_charge_finished),
+ NULL);
+ gpio_free(adc_bat->pdata->gpio_charge_finished);
+ }
+ }
+
+ for (chan_index = 0; channel_name[chan_index]; chan_index++)
+ iio_channel_release(adc_bat->channel[chan_index]);
+ cancel_delayed_work(&adc_bat->bat_work);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int generic_adc_bat_suspend(struct device *dev)
+{
+ struct generic_adc_bat *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 generic_adc_bat_resume(struct device *dev)
+{
+ struct generic_adc_bat *adc_bat = dev_get_drvdata(dev);
+
+ /* Schedule timer to check current status */
+ schedule_delayed_work(&adc_bat->bat_work,
+ msecs_to_jiffies(adc_bat->pdata->jitter_delay));
+ return 0;
+}
+
+static const struct dev_pm_ops generic_adc_battery_pm_ops = {
+ .suspend = generic_adc_bat_suspend,
+ .resume = generic_adc_bat_resume,
+};
+
+#define GENERIC_ADC_BATTERY_PM_OPS (&generic_adc_battery_pm_ops)
+#else
+#define GENERIC_ADC_BATTERY_PM_OPS (NULL)
+#endif
+
+static struct platform_driver generic_adc_bat_driver = {
+ .driver = {
+ .name = "generic-adc-battery",
+ .owner = THIS_MODULE,
+ .pm = GENERIC_ADC_BATTERY_PM_OPS
+ },
+ .probe = generic_adc_bat_probe,
+ .remove = generic_adc_bat_remove,
+};
+
+module_platform_driver(generic_adc_bat_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 0000000..d7c6d20
--- /dev/null
+++ b/include/linux/power/generic-adc-battery.h
@@ -0,0 +1,33 @@
+/*
+ * 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
+
+/* should be enough for the channel names */
+#define BAT_MAX_NAME 30
+
+enum chan_type {
+ VOLTAGE = 0,
+ CURRENT,
+ POWER,
+ MAX_CHAN_TYPE
+};
+
+extern char channel_name[][BAT_MAX_NAME + 1];
+
+struct iio_battery_platform_data {
+ struct power_supply_info battery_info;
+ char **channel_name;
+ char *battery_name;
+ int (*cal_charge)(long);
+ int gpio_charge_finished;
+ int gpio_inverted;
+ int bat_poll_interval;
+ int jitter_delay;
+};
+
+#endif /* GENERIC_ADC_BATTERY_H */
--
1.7.1