1 files changed, 300 insertions, 0 deletions

diff --git a/drivers/power/supply/generic-adc-battery.c b/drivers/power/supply/generic-adc-battery.c
new file mode 100644
index 0000000000..7bdc6b2636
--- /dev/null
+++ b/drivers/power/supply/generic-adc-battery.c
@@ -0,0 +1,300 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Generic battery driver using IIO
+ * Copyright (C) 2012, Anish Kumar <anish198519851985@gmail.com>
+ * Copyright (c) 2023, Sebastian Reichel <sre@kernel.org>
+ */
+#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 <anish198519851985@gmail.com>");
+MODULE_DESCRIPTION("generic battery driver using IIO");
+MODULE_LICENSE("GPL");