// SPDX-License-Identifier: GPL-2.0
/*
* Generic battery driver using IIO
* Copyright (C) 2012, Anish Kumar <[email protected]>
* Copyright (c) 2023, Sebastian Reichel <[email protected]>
*/
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/gpio/consumer.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/of.h>
#include <linux/devm-helpers.h>
#define JITTER_DEFAULT 10 /* hope 10ms is enough */
enum gab_chan_type {
GAB_VOLTAGE = 0,
GAB_CURRENT,
GAB_POWER,
GAB_TEMP,
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",
[GAB_TEMP] = "temperature",
};
struct gab {
struct power_supply *psy;
struct power_supply_desc psy_desc;
struct iio_channel *channel[GAB_MAX_CHAN_TYPE];
struct delayed_work bat_work;
int status;
struct gpio_desc *charge_finished;
};
static struct gab *to_generic_bat(struct power_supply *psy)
{
return power_supply_get_drvdata(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,
};
/*
* 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,
POWER_SUPPLY_PROP_TEMP,
};
static bool gab_charge_finished(struct gab *adc_bat)
{
if (!adc_bat->charge_finished)
return false;
return gpiod_get_value(adc_bat->charge_finished);
}
static int gab_read_channel(struct gab *adc_bat, enum gab_chan_type channel,
int *result)
{
int ret;
ret = iio_read_channel_processed(adc_bat->channel[channel], result);
if (ret < 0)
dev_err(&adc_bat->psy->dev, "read channel error: %d\n", ret);
else
*result *= 1000;
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 = to_generic_bat(psy);
switch (psp) {
case POWER_SUPPLY_PROP_STATUS:
val->intval = adc_bat->status;
return 0;
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
return gab_read_channel(adc_bat, GAB_VOLTAGE, &val->intval);
case POWER_SUPPLY_PROP_CURRENT_NOW:
return gab_read_channel(adc_bat, GAB_CURRENT, &val->intval);
case POWER_SUPPLY_PROP_POWER_NOW:
return gab_read_channel(adc_bat, GAB_POWER, &val->intval);
case POWER_SUPPLY_PROP_TEMP:
return gab_read_channel(adc_bat, GAB_TEMP, &val->intval);
default:
return -EINVAL;
}
}
static void gab_work(struct work_struct *work)
{
struct gab *adc_bat;
struct delayed_work *delayed_work;
int status;
delayed_work = to_delayed_work(work);
adc_bat = container_of(delayed_work, struct gab, bat_work);
status = adc_bat->status;
if (!power_supply_am_i_supplied(adc_bat->psy))
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;
schedule_delayed_work(&adc_bat->bat_work,
msecs_to_jiffies(JITTER_DEFAULT));
return IRQ_HANDLED;
}
static int gab_probe(struct platform_device *pdev)
{
struct gab *adc_bat;
struct power_supply_desc *psy_desc;
struct power_supply_config psy_cfg = {};
enum power_supply_property *properties;
int ret = 0;
int chan;
int index = ARRAY_SIZE(gab_props);
bool any = false;
adc_bat = devm_kzalloc(&pdev->dev, sizeof(*adc_bat), GFP_KERNEL);
if (!adc_bat)
return -ENOMEM;
psy_cfg.of_node = pdev->dev.of_node;
psy_cfg.drv_data = adc_bat;
psy_desc = &adc_bat->psy_desc;
psy_desc->name = dev_name(&pdev->dev);
/* bootup default values for the battery */
adc_bat->status = POWER_SUPPLY_STATUS_DISCHARGING;
psy_desc->type = POWER_SUPPLY_TYPE_BATTERY;
psy_desc->get_property = gab_get_property;
psy_desc->external_power_changed = gab_ext_power_changed;
/*
* copying the static properties and allocating extra memory for holding
* the extra configurable properties received from platform data.
*/
properties = devm_kcalloc(&pdev->dev,
ARRAY_SIZE(gab_props) +
ARRAY_SIZE(gab_chan_name),
sizeof(*properties),
GFP_KERNEL);
if (!properties)
return -ENOMEM;
memcpy(properties, gab_props, 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] = devm_iio_channel_get(&pdev->dev, gab_chan_name[chan]);
if (IS_ERR(adc_bat->channel[chan])) {
ret = PTR_ERR(adc_bat->channel[chan]);
if (ret != -ENODEV)
return dev_err_probe(&pdev->dev, ret, "Failed to get ADC channel %s\n", gab_chan_name[chan]);
adc_bat->channel[chan] = NULL;
} else if (adc_bat->channel[chan]) {
/* copying properties for supported channels only */
int index2;
for (index2 = 0; index2 < index; index2++) {
if (properties[index2] == gab_dyn_props[chan])
break; /* already known */
}
if (index2 == index) /* really new */
properties[index++] = gab_dyn_props[chan];
any = true;
}
}
/* none of the channels are supported so let's bail out */
if (!any)
return dev_err_probe(&pdev->dev, -ENODEV, "Failed to get any ADC channel\n");
/*
* 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_desc->properties = properties;
psy_desc->num_properties = index;
adc_bat->psy = devm_power_supply_register(&pdev->dev, psy_desc, &psy_cfg);
if (IS_ERR(adc_bat->psy))
return dev_err_probe(&pdev->dev, PTR_ERR(adc_bat->psy), "Failed to register power-supply device\n");
ret = devm_delayed_work_autocancel(&pdev->dev, &adc_bat->bat_work, gab_work);
if (ret)
return dev_err_probe(&pdev->dev, ret, "Failed to register delayed work\n");
adc_bat->charge_finished = devm_gpiod_get_optional(&pdev->dev, "charged", GPIOD_IN);
if (adc_bat->charge_finished) {
int irq;
irq = gpiod_to_irq(adc_bat->charge_finished);
ret = devm_request_any_context_irq(&pdev->dev, irq, gab_charged,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
"battery charged", adc_bat);
if (ret < 0)
return dev_err_probe(&pdev->dev, ret, "Failed to register irq\n");
}
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;
}
static int __maybe_unused 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 __maybe_unused gab_resume(struct device *dev)
{
struct gab *adc_bat = dev_get_drvdata(dev);
/* Schedule timer to check current status */
schedule_delayed_work(&adc_bat->bat_work,
msecs_to_jiffies(JITTER_DEFAULT));
return 0;
}
static SIMPLE_DEV_PM_OPS(gab_pm_ops, gab_suspend, gab_resume);
static const struct of_device_id gab_match[] = {
{ .compatible = "adc-battery" },
{ }
};
MODULE_DEVICE_TABLE(of, gab_match);
static struct platform_driver gab_driver = {
.driver = {
.name = "generic-adc-battery",
.pm = &gab_pm_ops,
.of_match_table = gab_match,
},
.probe = gab_probe,
};
module_platform_driver(gab_driver);
MODULE_AUTHOR("anish kumar <[email protected]>");
MODULE_DESCRIPTION("generic battery driver using IIO");
MODULE_LICENSE("GPL");
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