drivers/power/supply/surface-rt-ec.c - linux/kernel/git/gregkh/usb - Git at Google

 // SPDX-License-Identifier: GPL-2.0+

 #include <linux/devm-helpers.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/property.h>
 #include <linux/power_supply.h>
 #include <linux/types.h>

 /* Register Addresses (B=byte; W=word; S=string) */
 #define REGB_STATUS			0x02
 #define REGW_VOLTAGE_NOW		0x20
 #define REGW_CURRENT_NOW		0x24
 #define REGW_CAPACITY			0x28
 #define REGW_CHARGE_NOW			0x2a
 #define REGW_CHARGE_FULL		0x2c
 #define REGW_CYCLE_COUNT		0x3a
 #define REGW_CHARGE_FULL_DESIGN		0x3c
 #define REGW_VOLTAGE_MAX_DESIGN		0x3e
 #define REGW_SERIAL_NUMBER		0x44
 #define REGS_MANUFACTURER		0x46
 #define REGS_MODEL_NAME			0x52
 #define REGS_TECHNOLOGY			0x5a
 #define REGB_ONLINE			0x67

 struct srt_ec_device {
 	struct i2c_client *client;

 	struct power_supply *bat;
 	struct power_supply *psy;

 	struct gpio_desc *enable_gpiod;
 	struct delayed_work poll_work;

 	unsigned int technology;
 	unsigned int capacity;

 	const char *serial;
 	char manufacturer[13];
 	char model_name[10];
 };

 static const enum power_supply_property srt_bat_power_supply_props[] = {
 	POWER_SUPPLY_PROP_CAPACITY,
 	POWER_SUPPLY_PROP_CHARGE_NOW,
 	POWER_SUPPLY_PROP_CHARGE_FULL,
 	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
 	POWER_SUPPLY_PROP_CURRENT_NOW,
 	POWER_SUPPLY_PROP_CYCLE_COUNT,
 	POWER_SUPPLY_PROP_MANUFACTURER,
 	POWER_SUPPLY_PROP_MODEL_NAME,
 	POWER_SUPPLY_PROP_ONLINE,
 	POWER_SUPPLY_PROP_PRESENT,
 	POWER_SUPPLY_PROP_SERIAL_NUMBER,
 	POWER_SUPPLY_PROP_STATUS,
 	POWER_SUPPLY_PROP_TECHNOLOGY,
 	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
 	POWER_SUPPLY_PROP_VOLTAGE_NOW,
 };

 static const enum power_supply_property srt_psy_power_supply_props[] = {
 	POWER_SUPPLY_PROP_ONLINE,
 	POWER_SUPPLY_PROP_PRESENT,
 };

 static int srt_bat_get_value(struct i2c_client *client, int reg, int *val)
 {
 	int ret;

 	switch (reg) {
 	case REGW_CHARGE_NOW:
 	case REGW_CHARGE_FULL_DESIGN:
 	case REGW_CHARGE_FULL:
 	case REGW_VOLTAGE_MAX_DESIGN:
 	case REGW_VOLTAGE_NOW:
 		ret = i2c_smbus_read_word_data(client, reg);
 		if (ret < 0)
 			return ret;

 		*val = ret * 1000;
 		break;

 	case REGW_CURRENT_NOW:
 		ret = i2c_smbus_read_word_data(client, reg);
 		if (ret < 0)
 			return ret;

 		*val = (s16)ret * 1000;
 		break;

 	case REGW_CAPACITY:
 	case REGW_CYCLE_COUNT:
 		ret = i2c_smbus_read_word_data(client, reg);
 		if (ret < 0)
 			return ret;

 		*val = ret;
 		break;

 	case REGB_STATUS:
 		ret = i2c_smbus_read_byte_data(client, reg);
 		if (ret < 0)
 			return ret;

 		if (ret & BIT(0))
 			*val = POWER_SUPPLY_STATUS_CHARGING;
 		else
 			*val =  POWER_SUPPLY_STATUS_DISCHARGING;
 		break;

 	case REGB_ONLINE:
 		ret = i2c_smbus_read_byte_data(client, reg);
 		if (ret < 0)
 			return ret;

 		*val = (ret & BIT(1)) >> 1;
 		break;

 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int srt_bat_power_supply_get_property(struct power_supply *psy,
 					     enum power_supply_property psp,
 					     union power_supply_propval *val)
 {
 	struct srt_ec_device *srt = power_supply_get_drvdata(psy);
 	struct i2c_client *client = srt->client;
 	int ret = 0;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_MANUFACTURER:
 		val->strval = srt->manufacturer;
 		break;
 	case POWER_SUPPLY_PROP_MODEL_NAME:
 		val->strval = srt->model_name;
 		break;
 	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
 		val->strval = srt->serial;
 		break;
 	case POWER_SUPPLY_PROP_CAPACITY:
 		ret = srt_bat_get_value(client, REGW_CAPACITY, &val->intval);
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_NOW:
 		ret = srt_bat_get_value(client, REGW_CHARGE_NOW, &val->intval);
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_FULL:
 		ret = srt_bat_get_value(client, REGW_CHARGE_FULL, &val->intval);
 		break;
 	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
 		ret = srt_bat_get_value(client, REGW_CHARGE_FULL_DESIGN,
 					&val->intval);
 		break;
 	case POWER_SUPPLY_PROP_CURRENT_NOW:
 		ret = srt_bat_get_value(client, REGW_CURRENT_NOW, &val->intval);
 		break;
 	case POWER_SUPPLY_PROP_CYCLE_COUNT:
 		ret = srt_bat_get_value(client, REGW_CYCLE_COUNT, &val->intval);
 		break;
 	case POWER_SUPPLY_PROP_PRESENT:
 		val->intval = 1;
 		break;
 	case POWER_SUPPLY_PROP_ONLINE:
 		ret = srt_bat_get_value(client, REGB_ONLINE, &val->intval);
 		break;
 	case POWER_SUPPLY_PROP_STATUS:
 		if (srt->capacity < 100)
 			ret = srt_bat_get_value(client, REGB_STATUS, &val->intval);
 		else
 			val->intval = POWER_SUPPLY_STATUS_FULL;
 		break;
 	case POWER_SUPPLY_PROP_TECHNOLOGY:
 		val->intval = srt->technology;
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
 		ret = srt_bat_get_value(client, REGW_VOLTAGE_MAX_DESIGN,
 					&val->intval);
 		break;
 	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
 		ret = srt_bat_get_value(client, REGW_VOLTAGE_NOW, &val->intval);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return ret;
 }

 static int srt_psy_power_supply_get_property(struct power_supply *psy,
 					     enum power_supply_property psp,
 					     union power_supply_propval *val)
 {
 	struct srt_ec_device *srt = power_supply_get_drvdata(psy);
 	struct i2c_client *client = srt->client;
 	int ret;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_ONLINE:
 	case POWER_SUPPLY_PROP_PRESENT:
 		ret = i2c_smbus_read_byte_data(client, REGB_ONLINE);
 		if (ret < 0)
 			return ret;

 		val->intval = ret & BIT(0);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static void srt_bat_poll_work(struct work_struct *work)
 {
 	struct srt_ec_device *srt =
 		container_of(work, struct srt_ec_device, poll_work.work);
 	int ret, capacity;

 	ret = srt_bat_get_value(srt->client, REGW_CAPACITY, &capacity);
 	if (!ret && capacity != srt->capacity) {
 		srt->capacity = capacity;
 		power_supply_changed(srt->bat);
 	}

 	/* continuously send uevent notification */
 	schedule_delayed_work(&srt->poll_work, 30 * HZ);
 }

 static irqreturn_t srt_psy_detect_irq(int irq, void *dev_id)
 {
 	struct srt_ec_device *srt = dev_id;

 	power_supply_changed(srt->psy);

 	return IRQ_HANDLED;
 }

 static const struct power_supply_desc srt_bat_power_supply_desc = {
 	.name = "surface-rt-battery",
 	.type = POWER_SUPPLY_TYPE_BATTERY,
 	.properties = srt_bat_power_supply_props,
 	.num_properties = ARRAY_SIZE(srt_bat_power_supply_props),
 	.get_property = srt_bat_power_supply_get_property,
 	.external_power_changed = power_supply_changed,
 };

 static const struct power_supply_desc srt_psy_power_supply_desc = {
 	.name = "surface-rt-ac-adapter",
 	.type = POWER_SUPPLY_TYPE_MAINS,
 	.properties = srt_psy_power_supply_props,
 	.num_properties = ARRAY_SIZE(srt_psy_power_supply_props),
 	.get_property = srt_psy_power_supply_get_property,
 };

 static char *battery_supplied_to[] = { "surface-rt-battery" };

 static int srt_ec_probe(struct i2c_client *client)
 {
 	struct power_supply_config bat_cfg = {};
 	struct power_supply_config psy_cfg = {};
 	struct device *dev = &client->dev;
 	struct srt_ec_device *srt;
 	char str_buf[4];
 	int ret;

 	srt = devm_kzalloc(dev, sizeof(*srt), GFP_KERNEL);
 	if (!srt)
 		return -ENOMEM;

 	i2c_set_clientdata(client, srt);
 	srt->client = client;

 	srt->enable_gpiod = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
 	if (IS_ERR(srt->enable_gpiod))
 		return dev_err_probe(dev, PTR_ERR(srt->enable_gpiod),
 				     "failed to get enable gpio\n");

 	/* wait till EC is ready */
 	usleep_range(1000, 1500);

 	ret = i2c_smbus_read_word_data(client, REGW_SERIAL_NUMBER);
 	if (ret < 0)
 		return ret;

 	srt->serial = devm_kasprintf(dev, GFP_KERNEL, "%04x", ret);
 	if (!srt->serial)
 		return -ENOMEM;

 	ret = i2c_smbus_read_i2c_block_data(client, REGS_MANUFACTURER,
 					    sizeof(srt->manufacturer) - 1,
 					    srt->manufacturer);
 	if (ret < 0)
 		return ret;

 	ret = i2c_smbus_read_i2c_block_data(client, REGS_MODEL_NAME,
 					    sizeof(srt->model_name) - 1,
 					    srt->model_name);
 	if (ret < 0)
 		return ret;

 	ret = i2c_smbus_read_i2c_block_data(client, REGS_TECHNOLOGY,
 					    sizeof(str_buf), str_buf);
 	if (ret < 0)
 		return ret;

 	if (!strncmp(str_buf, "LION", 4))
 		srt->technology = POWER_SUPPLY_TECHNOLOGY_LION;
 	else
 		srt->technology = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;

 	bat_cfg.drv_data = srt;
 	bat_cfg.fwnode = dev_fwnode(dev);

 	srt->bat = devm_power_supply_register(dev, &srt_bat_power_supply_desc,
 					      &bat_cfg);
 	if (IS_ERR(srt->bat))
 		return dev_err_probe(dev, PTR_ERR(srt->bat),
 				     "failed to register battery power supply\n");

 	psy_cfg.drv_data = srt;
 	psy_cfg.fwnode = dev_fwnode(dev);
 	psy_cfg.supplied_to = battery_supplied_to;
 	psy_cfg.num_supplicants = ARRAY_SIZE(battery_supplied_to);

 	srt->psy = devm_power_supply_register(dev, &srt_psy_power_supply_desc,
 					      &psy_cfg);
 	if (IS_ERR(srt->psy))
 		return dev_err_probe(dev, PTR_ERR(srt->psy),
 				     "failed to register AC power supply\n");

 	ret = devm_request_threaded_irq(dev, client->irq, NULL, srt_psy_detect_irq,
 					IRQF_ONESHOT, client->name, srt);
 	if (ret < 0)
 		return dev_err_probe(dev, ret, "failed to request interrupt\n");

 	ret = devm_delayed_work_autocancel(dev, &srt->poll_work, srt_bat_poll_work);
 	if (ret < 0)
 		return ret;

 	schedule_delayed_work(&srt->poll_work, HZ);

 	return 0;
 }

 static int srt_ec_suspend(struct device *dev)
 {
 	struct srt_ec_device *srt = dev_get_drvdata(dev);

 	cancel_delayed_work_sync(&srt->poll_work);

 	return 0;
 }

 static int srt_ec_resume(struct device *dev)
 {
 	struct srt_ec_device *srt = dev_get_drvdata(dev);

 	schedule_delayed_work(&srt->poll_work, HZ);

 	return 0;
 }

 static DEFINE_SIMPLE_DEV_PM_OPS(srt_ec_pm_ops, srt_ec_suspend, srt_ec_resume);

 static const struct of_device_id srt_ec_of_match[] = {
 	{ .compatible = "microsoft,surface-rt-ec" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, srt_ec_of_match);

 static struct i2c_driver srt_ec_driver = {
 	.driver = {
 		.name = "surface-rt-ec",
 		.of_match_table = srt_ec_of_match,
 		.pm = &srt_ec_pm_ops,
 	},
 	.probe = srt_ec_probe,
 };
 module_i2c_driver(srt_ec_driver);

 MODULE_AUTHOR("Jonas Schwöbel <jonasschwoebel@yahoo.de>");
 MODULE_DESCRIPTION("Surface RT Embedded Controller driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0+

	#include <linux/devm-helpers.h>
	#include <linux/delay.h>
	#include <linux/gpio/consumer.h>
	#include <linux/i2c.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/property.h>
	#include <linux/power_supply.h>
	#include <linux/types.h>

	/* Register Addresses (B=byte; W=word; S=string) */
	#define REGB_STATUS 0x02
	#define REGW_VOLTAGE_NOW 0x20
	#define REGW_CURRENT_NOW 0x24
	#define REGW_CAPACITY 0x28
	#define REGW_CHARGE_NOW 0x2a
	#define REGW_CHARGE_FULL 0x2c
	#define REGW_CYCLE_COUNT 0x3a
	#define REGW_CHARGE_FULL_DESIGN 0x3c
	#define REGW_VOLTAGE_MAX_DESIGN 0x3e
	#define REGW_SERIAL_NUMBER 0x44
	#define REGS_MANUFACTURER 0x46
	#define REGS_MODEL_NAME 0x52
	#define REGS_TECHNOLOGY 0x5a
	#define REGB_ONLINE 0x67

	struct srt_ec_device {
	struct i2c_client *client;

	struct power_supply *bat;
	struct power_supply *psy;

	struct gpio_desc *enable_gpiod;
	struct delayed_work poll_work;

	unsigned int technology;
	unsigned int capacity;

	const char *serial;
	char manufacturer[13];
	char model_name[10];
	};

	static const enum power_supply_property srt_bat_power_supply_props[] = {
	POWER_SUPPLY_PROP_CAPACITY,
	POWER_SUPPLY_PROP_CHARGE_NOW,
	POWER_SUPPLY_PROP_CHARGE_FULL,
	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
	POWER_SUPPLY_PROP_CURRENT_NOW,
	POWER_SUPPLY_PROP_CYCLE_COUNT,
	POWER_SUPPLY_PROP_MANUFACTURER,
	POWER_SUPPLY_PROP_MODEL_NAME,
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_SERIAL_NUMBER,
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_TECHNOLOGY,
	POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	};

	static const enum power_supply_property srt_psy_power_supply_props[] = {
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_PRESENT,
	};

	static int srt_bat_get_value(struct i2c_client client, int reg, int val)
	{
	int ret;

	switch (reg) {
	case REGW_CHARGE_NOW:
	case REGW_CHARGE_FULL_DESIGN:
	case REGW_CHARGE_FULL:
	case REGW_VOLTAGE_MAX_DESIGN:
	case REGW_VOLTAGE_NOW:
	ret = i2c_smbus_read_word_data(client, reg);
	if (ret < 0)
	return ret;

	val = ret 1000;
	break;

	case REGW_CURRENT_NOW:
	ret = i2c_smbus_read_word_data(client, reg);
	if (ret < 0)
	return ret;

	val = (s16)ret 1000;
	break;

	case REGW_CAPACITY:
	case REGW_CYCLE_COUNT:
	ret = i2c_smbus_read_word_data(client, reg);
	if (ret < 0)
	return ret;

	*val = ret;
	break;

	case REGB_STATUS:
	ret = i2c_smbus_read_byte_data(client, reg);
	if (ret < 0)
	return ret;

	if (ret & BIT(0))
	*val = POWER_SUPPLY_STATUS_CHARGING;
	else
	*val = POWER_SUPPLY_STATUS_DISCHARGING;
	break;

	case REGB_ONLINE:
	ret = i2c_smbus_read_byte_data(client, reg);
	if (ret < 0)
	return ret;

	*val = (ret & BIT(1)) >> 1;
	break;

	default:
	return -EINVAL;
	}

	return 0;
	}

	static int srt_bat_power_supply_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	struct srt_ec_device *srt = power_supply_get_drvdata(psy);
	struct i2c_client *client = srt->client;
	int ret = 0;

	switch (psp) {
	case POWER_SUPPLY_PROP_MANUFACTURER:
	val->strval = srt->manufacturer;
	break;
	case POWER_SUPPLY_PROP_MODEL_NAME:
	val->strval = srt->model_name;
	break;
	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
	val->strval = srt->serial;
	break;
	case POWER_SUPPLY_PROP_CAPACITY:
	ret = srt_bat_get_value(client, REGW_CAPACITY, &val->intval);
	break;
	case POWER_SUPPLY_PROP_CHARGE_NOW:
	ret = srt_bat_get_value(client, REGW_CHARGE_NOW, &val->intval);
	break;
	case POWER_SUPPLY_PROP_CHARGE_FULL:
	ret = srt_bat_get_value(client, REGW_CHARGE_FULL, &val->intval);
	break;
	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
	ret = srt_bat_get_value(client, REGW_CHARGE_FULL_DESIGN,
	&val->intval);
	break;
	case POWER_SUPPLY_PROP_CURRENT_NOW:
	ret = srt_bat_get_value(client, REGW_CURRENT_NOW, &val->intval);
	break;
	case POWER_SUPPLY_PROP_CYCLE_COUNT:
	ret = srt_bat_get_value(client, REGW_CYCLE_COUNT, &val->intval);
	break;
	case POWER_SUPPLY_PROP_PRESENT:
	val->intval = 1;
	break;
	case POWER_SUPPLY_PROP_ONLINE:
	ret = srt_bat_get_value(client, REGB_ONLINE, &val->intval);
	break;
	case POWER_SUPPLY_PROP_STATUS:
	if (srt->capacity < 100)
	ret = srt_bat_get_value(client, REGB_STATUS, &val->intval);
	else
	val->intval = POWER_SUPPLY_STATUS_FULL;
	break;
	case POWER_SUPPLY_PROP_TECHNOLOGY:
	val->intval = srt->technology;
	break;
	case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
	ret = srt_bat_get_value(client, REGW_VOLTAGE_MAX_DESIGN,
	&val->intval);
	break;
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
	ret = srt_bat_get_value(client, REGW_VOLTAGE_NOW, &val->intval);
	break;
	default:
	return -EINVAL;
	}

	return ret;
	}

	static int srt_psy_power_supply_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	struct srt_ec_device *srt = power_supply_get_drvdata(psy);
	struct i2c_client *client = srt->client;
	int ret;

	switch (psp) {
	case POWER_SUPPLY_PROP_ONLINE:
	case POWER_SUPPLY_PROP_PRESENT:
	ret = i2c_smbus_read_byte_data(client, REGB_ONLINE);
	if (ret < 0)
	return ret;

	val->intval = ret & BIT(0);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static void srt_bat_poll_work(struct work_struct *work)
	{
	struct srt_ec_device *srt =
	container_of(work, struct srt_ec_device, poll_work.work);
	int ret, capacity;

	ret = srt_bat_get_value(srt->client, REGW_CAPACITY, &capacity);
	if (!ret && capacity != srt->capacity) {
	srt->capacity = capacity;
	power_supply_changed(srt->bat);
	}

	/* continuously send uevent notification */
	schedule_delayed_work(&srt->poll_work, 30 * HZ);
	}

	static irqreturn_t srt_psy_detect_irq(int irq, void *dev_id)
	{
	struct srt_ec_device *srt = dev_id;

	power_supply_changed(srt->psy);

	return IRQ_HANDLED;
	}

	static const struct power_supply_desc srt_bat_power_supply_desc = {
	.name = "surface-rt-battery",
	.type = POWER_SUPPLY_TYPE_BATTERY,
	.properties = srt_bat_power_supply_props,
	.num_properties = ARRAY_SIZE(srt_bat_power_supply_props),
	.get_property = srt_bat_power_supply_get_property,
	.external_power_changed = power_supply_changed,
	};

	static const struct power_supply_desc srt_psy_power_supply_desc = {
	.name = "surface-rt-ac-adapter",
	.type = POWER_SUPPLY_TYPE_MAINS,
	.properties = srt_psy_power_supply_props,
	.num_properties = ARRAY_SIZE(srt_psy_power_supply_props),
	.get_property = srt_psy_power_supply_get_property,
	};

	static char *battery_supplied_to[] = { "surface-rt-battery" };

	static int srt_ec_probe(struct i2c_client *client)
	{
	struct power_supply_config bat_cfg = {};
	struct power_supply_config psy_cfg = {};
	struct device *dev = &client->dev;
	struct srt_ec_device *srt;
	char str_buf[4];
	int ret;

	srt = devm_kzalloc(dev, sizeof(*srt), GFP_KERNEL);
	if (!srt)
	return -ENOMEM;

	i2c_set_clientdata(client, srt);
	srt->client = client;

	srt->enable_gpiod = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
	if (IS_ERR(srt->enable_gpiod))
	return dev_err_probe(dev, PTR_ERR(srt->enable_gpiod),
	"failed to get enable gpio\n");

	/* wait till EC is ready */
	usleep_range(1000, 1500);

	ret = i2c_smbus_read_word_data(client, REGW_SERIAL_NUMBER);
	if (ret < 0)
	return ret;

	srt->serial = devm_kasprintf(dev, GFP_KERNEL, "%04x", ret);
	if (!srt->serial)
	return -ENOMEM;

	ret = i2c_smbus_read_i2c_block_data(client, REGS_MANUFACTURER,
	sizeof(srt->manufacturer) - 1,
	srt->manufacturer);
	if (ret < 0)
	return ret;

	ret = i2c_smbus_read_i2c_block_data(client, REGS_MODEL_NAME,
	sizeof(srt->model_name) - 1,
	srt->model_name);
	if (ret < 0)
	return ret;

	ret = i2c_smbus_read_i2c_block_data(client, REGS_TECHNOLOGY,
	sizeof(str_buf), str_buf);
	if (ret < 0)
	return ret;

	if (!strncmp(str_buf, "LION", 4))
	srt->technology = POWER_SUPPLY_TECHNOLOGY_LION;
	else
	srt->technology = POWER_SUPPLY_TECHNOLOGY_UNKNOWN;

	bat_cfg.drv_data = srt;
	bat_cfg.fwnode = dev_fwnode(dev);

	srt->bat = devm_power_supply_register(dev, &srt_bat_power_supply_desc,
	&bat_cfg);
	if (IS_ERR(srt->bat))
	return dev_err_probe(dev, PTR_ERR(srt->bat),
	"failed to register battery power supply\n");

	psy_cfg.drv_data = srt;
	psy_cfg.fwnode = dev_fwnode(dev);
	psy_cfg.supplied_to = battery_supplied_to;
	psy_cfg.num_supplicants = ARRAY_SIZE(battery_supplied_to);

	srt->psy = devm_power_supply_register(dev, &srt_psy_power_supply_desc,
	&psy_cfg);
	if (IS_ERR(srt->psy))
	return dev_err_probe(dev, PTR_ERR(srt->psy),
	"failed to register AC power supply\n");

	ret = devm_request_threaded_irq(dev, client->irq, NULL, srt_psy_detect_irq,
	IRQF_ONESHOT, client->name, srt);
	if (ret < 0)
	return dev_err_probe(dev, ret, "failed to request interrupt\n");

	ret = devm_delayed_work_autocancel(dev, &srt->poll_work, srt_bat_poll_work);
	if (ret < 0)
	return ret;

	schedule_delayed_work(&srt->poll_work, HZ);

	return 0;
	}

	static int srt_ec_suspend(struct device *dev)
	{
	struct srt_ec_device *srt = dev_get_drvdata(dev);

	cancel_delayed_work_sync(&srt->poll_work);

	return 0;
	}

	static int srt_ec_resume(struct device *dev)
	{
	struct srt_ec_device *srt = dev_get_drvdata(dev);

	schedule_delayed_work(&srt->poll_work, HZ);

	return 0;
	}

	static DEFINE_SIMPLE_DEV_PM_OPS(srt_ec_pm_ops, srt_ec_suspend, srt_ec_resume);

	static const struct of_device_id srt_ec_of_match[] = {
	{ .compatible = "microsoft,surface-rt-ec" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, srt_ec_of_match);

	static struct i2c_driver srt_ec_driver = {
	.driver = {
	.name = "surface-rt-ec",
	.of_match_table = srt_ec_of_match,
	.pm = &srt_ec_pm_ops,
	},
	.probe = srt_ec_probe,
	};
	module_i2c_driver(srt_ec_driver);

	MODULE_AUTHOR("Jonas Schwöbel <jonasschwoebel@yahoo.de>");
	MODULE_DESCRIPTION("Surface RT Embedded Controller driver");
	MODULE_LICENSE("GPL");