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

From: anish kumar
Date: Sun Sep 02 2012 - 11:40:48 EST


From: anish kumar <anish198519851985@xxxxxxxxx>

This patch is to use IIO to write a generic batttery driver.
There are some inherent assumptions here:
1.User is having both main battery and backup battery.
2.Both batteries use same channel to get the information.

Signed-off-by: anish kumar <anish198519851985@xxxxxxxxx>
---
drivers/power/Kconfig | 8 +
drivers/power/Makefile | 1 +
drivers/power/generic-battery.c | 374 +++++++++++++++++++++++++++++++++
include/linux/power/generic-battery.h | 26 +++
4 files changed, 409 insertions(+), 0 deletions(-)
create mode 100644 drivers/power/generic-battery.c
create mode 100644 include/linux/power/generic-battery.h

diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
index fcc1bb0..546e86b 100644
--- a/drivers/power/Kconfig
+++ b/drivers/power/Kconfig
@@ -309,6 +309,14 @@ config AB8500_BATTERY_THERM_ON_BATCTRL
help
Say Y to enable battery temperature measurements using
thermistor connected on BATCTRL ADC.
+
+config GENERIC_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 for it's main and backup
+ battery.
endif # POWER_SUPPLY

source "drivers/power/avs/Kconfig"
diff --git a/drivers/power/Makefile b/drivers/power/Makefile
index ee58afb..8284f9c 100644
--- a/drivers/power/Makefile
+++ b/drivers/power/Makefile
@@ -45,3 +45,4 @@ obj-$(CONFIG_CHARGER_MAX8997) += max8997_charger.o
obj-$(CONFIG_CHARGER_MAX8998) += max8998_charger.o
obj-$(CONFIG_POWER_AVS) += avs/
obj-$(CONFIG_CHARGER_SMB347) += smb347-charger.o
+obj-$(CONFIG_GENERIC_BATTERY) += generic-battery.o
diff --git a/drivers/power/generic-battery.c b/drivers/power/generic-battery.c
new file mode 100644
index 0000000..33170b7
--- /dev/null
+++ b/drivers/power/generic-battery.c
@@ -0,0 +1,374 @@
+/*
+ * Generice battery driver code using IIO
+ * Copyright (C) 2012, Anish Kumar <anish198519851985@xxxxxxxxx>
+ * 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-battery.h>
+
+#define BAT_POLL_INTERVAL 10000 /* ms */
+#define JITTER_DELAY 500 /* ms */
+
+enum BAT {
+ MAIN_BAT = 0,
+ BACKUP_BAT,
+ BAT_MAX,
+};
+
+struct generic_adc_bat {
+ struct power_supply psy;
+ struct iio_channel *channels;
+ int channel_index;
+};
+
+struct generic_bat {
+ struct generic_adc_bat bat[BAT_MAX];
+ struct generic_platform_data pdata;
+ int volt_value;
+ int cur_value;
+ unsigned int timestamp;
+ int level;
+ int status;
+ int cable_plugged:1;
+};
+
+static struct generic_bat generic_bat = {
+ .bat[MAIN_BAT] = {
+ .psy.name = "main-bat",
+ },
+ .bat[BACKUP_BAT] = {
+ .psy.name = "backup-bat",
+ },
+};
+
+static struct delayed_work bat_work;
+
+static void generic_adc_bat_ext_power_changed(struct power_supply *psy)
+{
+ schedule_delayed_work(&bat_work,
+ msecs_to_jiffies(JITTER_DELAY));
+}
+
+static enum power_supply_property generic_adc_main_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,
+};
+
+static int charge_finished(struct generic_bat *bat)
+{
+ return bat->pdata.gpio_inverted ?
+ !gpio_get_value(bat->pdata.gpio_charge_finished) :
+ gpio_get_value(bat->pdata.gpio_charge_finished);
+}
+
+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;
+ struct generic_bat *bat;
+ int ret, scaleint, scalepart, iio_val;
+ long result = 0;
+
+ if (!strcmp(psy->name, "main-battery")) {
+ adc_bat = container_of(psy,
+ struct generic_adc_bat, psy);
+ bat = container_of(adc_bat,
+ struct generic_bat, bat[MAIN_BAT]);
+ } else if (!strcmp(psy->name, "backup-battery")) {
+ adc_bat = container_of(psy, struct generic_adc_bat, psy);
+ bat = container_of(adc_bat,
+ struct generic_bat, bat[BACKUP_BAT]);
+ } else {
+ /* Ideally this should never happen */
+ WARN_ON(1);
+ return -EINVAL;
+ }
+
+ if (!bat) {
+ dev_err(psy->dev, "no battery infos ?!\n");
+ return -EINVAL;
+ }
+ ret = iio_read_channel_raw(&adc_bat->channels[adc_bat->channel_index],
+ &iio_val);
+ ret = iio_read_channel_scale(&adc_bat->channels[adc_bat->channel_index],
+ &scaleint, &scalepart);
+ if (ret < 0)
+ return ret;
+
+ 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;
+ }
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_STATUS:
+ if (bat->pdata.gpio_charge_finished < 0)
+ val->intval = bat->level == 100000 ?
+ POWER_SUPPLY_STATUS_FULL : bat->status;
+ else
+ val->intval = bat->status;
+ return 0;
+ case POWER_SUPPLY_PROP_CHARGE_EMPTY_DESIGN:
+ val->intval = 0;
+ return 0;
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ val->intval = bat->pdata.cal_charge(result);
+ return 0;
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ val->intval = result;
+ return 0;
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ val->intval = result;
+ return 0;
+ case POWER_SUPPLY_PROP_TECHNOLOGY:
+ val->intval = bat->pdata.battery_info.technology;
+ break;
+ case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+ val->intval = bat->pdata.battery_info.voltage_min_design;
+ break;
+ case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
+ val->intval = bat->pdata.battery_info.voltage_max_design;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+ val->intval = bat->pdata.battery_info.charge_full_design;
+ break;
+ case POWER_SUPPLY_PROP_MODEL_NAME:
+ val->strval = bat->pdata.battery_info.name;
+ break;
+ default:
+ return -EINVAL;
+ }
+ return ret;
+}
+
+static void generic_adc_bat_work(struct work_struct *work)
+{
+ struct generic_bat *bat = &generic_bat;
+ int is_charged;
+ int is_plugged;
+ static int was_plugged;
+
+ /* backup battery doesn't have current monitoring capability anyway */
+ is_plugged = power_supply_am_i_supplied(&bat->bat[MAIN_BAT].psy);
+ bat->cable_plugged = is_plugged;
+ if (is_plugged != was_plugged) {
+ was_plugged = is_plugged;
+ if (is_plugged)
+ bat->status = POWER_SUPPLY_STATUS_CHARGING;
+ else
+ bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
+ } else {
+ if ((bat->pdata.gpio_charge_finished >= 0) && is_plugged) {
+ is_charged = charge_finished(&generic_bat);
+ if (is_charged)
+ bat->status = POWER_SUPPLY_STATUS_FULL;
+ else
+ bat->status = POWER_SUPPLY_STATUS_CHARGING;
+ }
+ }
+
+ power_supply_changed(&bat->bat[MAIN_BAT].psy);
+}
+
+static irqreturn_t generic_adc_bat_charged(int irq, void *dev_id)
+{
+ schedule_delayed_work(&bat_work,
+ msecs_to_jiffies(JITTER_DELAY));
+ return IRQ_HANDLED;
+}
+
+static int __devinit generic_adc_bat_probe(struct platform_device *pdev)
+{
+ struct generic_platform_data *pdata = pdev->dev.platform_data;
+ struct iio_channel *channels;
+ int num_channels = 0;
+ int ret, i, j, k = 0;
+ enum iio_chan_type type;
+
+ for (i = 0; i < ARRAY_SIZE(generic_bat.bat); i++) {
+ generic_bat.bat[i].psy.type = POWER_SUPPLY_TYPE_BATTERY;
+ generic_bat.bat[i].psy.properties =
+ generic_adc_main_bat_props;
+ generic_bat.bat[i].psy.num_properties =
+ ARRAY_SIZE(generic_adc_main_bat_props);
+ generic_bat.bat[i].psy.get_property =
+ generic_adc_bat_get_property;
+ generic_bat.bat[i].psy.external_power_changed =
+ generic_adc_bat_ext_power_changed;
+ }
+
+ generic_bat.volt_value = -1;
+ generic_bat.cur_value = -1;
+ generic_bat.cable_plugged = 0;
+ generic_bat.status = POWER_SUPPLY_STATUS_DISCHARGING;
+
+ memcpy(&generic_bat.pdata, pdata, sizeof(struct generic_platform_data));
+
+ for (i = 0; i < ARRAY_SIZE(generic_bat.bat); i++) {
+ ret = power_supply_register(&pdev->dev,
+ &generic_bat.bat[i].psy);
+ if (ret)
+ goto err_reg_main;
+ }
+
+ channels = iio_channel_get_all(dev_name(&pdev->dev));
+ if (IS_ERR(channels)) {
+ ret = PTR_ERR(channels);
+ goto err_reg_backup;
+ }
+
+ while (channels[num_channels].indio_dev)
+ num_channels++;
+
+ for (i = 0; i < ARRAY_SIZE(generic_bat.bat); i++)
+ generic_bat.bat[i].channels = kzalloc(sizeof(struct iio_channel)
+ * BAT_MAX, GFP_KERNEL);
+
+ /* assuming main battery and backup battery is using the same channel */
+ for (i = 0; i < num_channels; i++) {
+ ret = iio_get_channel_type(&channels[i], &type);
+ if (ret < 0)
+ goto err_gpio;
+
+ if (type == IIO_VOLTAGE || type == IIO_CURRENT) {
+ for (j = 0; j < BAT_MAX; j++) {
+ generic_bat.bat[j].channel_index = k;
+ generic_bat.bat[j].channels[k] = channels[i];
+ }
+ k++;
+ }
+ continue;
+ }
+
+ INIT_DELAYED_WORK(&bat_work, generic_adc_bat_work);
+
+ if (pdata->gpio_charge_finished >= 0) {
+ ret = gpio_request(pdata->gpio_charge_finished, "charged");
+ if (ret)
+ goto err_gpio;
+
+ ret = request_irq(gpio_to_irq(pdata->gpio_charge_finished),
+ generic_adc_bat_charged,
+ IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+ "battery charged", NULL);
+ if (ret)
+ goto err_gpio;
+ }
+
+ dev_info(&pdev->dev, "successfully loaded\n");
+
+ /* Schedule timer to check current status */
+ schedule_delayed_work(&bat_work,
+ msecs_to_jiffies(JITTER_DELAY));
+
+ iio_channel_release_all(channels);
+
+ return 0;
+
+err_gpio:
+ iio_channel_release_all(channels);
+err_reg_backup:
+ for (i = 0; i < ARRAY_SIZE(generic_bat.bat); i++)
+ power_supply_unregister(&generic_bat.bat[i].psy);
+err_reg_main:
+ return ret;
+}
+
+static int generic_adc_bat_remove(struct platform_device *pdev)
+{
+ int i;
+ struct generic_platform_data *pdata = pdev->dev.platform_data;
+
+ for (i = 0; i < ARRAY_SIZE(generic_bat.bat); i++)
+ power_supply_unregister(&generic_bat.bat[i].psy);
+
+ if (pdata->gpio_charge_finished >= 0) {
+ free_irq(gpio_to_irq(pdata->gpio_charge_finished), NULL);
+ gpio_free(pdata->gpio_charge_finished);
+ }
+
+ cancel_delayed_work(&bat_work);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int generic_adc_bat_suspend(struct platform_device *pdev,
+ pm_message_t state)
+{
+ struct generic_platform_data *pdata = pdev->dev.platform_data;
+ struct generic_bat *bat = container_of(pdata,
+ struct generic_bat, pdata);
+
+ cancel_delayed_work_sync(&bat_work);
+ bat->status = POWER_SUPPLY_STATUS_UNKNOWN;
+
+ return 0;
+}
+
+static int generic_adc_bat_resume(struct platform_device *pdev)
+{
+ /* Schedule timer to check current status */
+ schedule_delayed_work(&bat_work,
+ msecs_to_jiffies(JITTER_DELAY));
+
+ return 0;
+}
+#else
+#define generic_adc_bat_suspend NULL
+#define generic_adc_bat_resume NULL
+#endif
+
+static struct platform_driver generic_adc_bat_driver = {
+ .driver = {
+ .name = "generic-adc-battery",
+ },
+ .probe = generic_adc_bat_probe,
+ .remove = generic_adc_bat_remove,
+ .suspend = generic_adc_bat_suspend,
+ .resume = generic_adc_bat_resume,
+};
+
+module_platform_driver(generic_adc_bat_driver);
+
+MODULE_AUTHOR("anish kumar <anish198519851985@xxxxxxxxx>");
+MODULE_DESCRIPTION("generic battery driver using IIO");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/power/generic-battery.h b/include/linux/power/generic-battery.h
new file mode 100644
index 0000000..7a43aa0
--- /dev/null
+++ b/include/linux/power/generic-battery.h
@@ -0,0 +1,26 @@
+/*
+ * 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_BATTERY_H
+#define GENERIC_BATTERY_H
+
+#include <linux/power_supply.h>
+
+/**
+ * struct generic_platform_data - platform data for generic battery
+ * @battery_info: Information about the battery
+ * @cal_charge: platform callback to calculate charge
+ * @gpio_charge_finished: GPIO number used for interrupts
+ * @gpio_inverted: Is the gpio inverted?
+ */
+struct generic_platform_data {
+ struct power_supply_info battery_info;
+ int (*cal_charge)(long);
+ int gpio_charge_finished;
+ int gpio_inverted;
+};
+
+#endif /* GENERIC_BATTERY_H */
--
1.7.1

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