platform/arm64/huawei-gaokun-ec.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * huawei-gaokun-ec - An EC driver for HUAWEI Matebook E Go
 *
 * Copyright (C) 2024-2025 Pengyu Luo <mitltlatltl@gmail.com>
 */

#include <linux/auxiliary_bus.h>
#include <linux/cleanup.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/notifier.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/platform_data/huawei-gaokun-ec.h>

#define EC_EVENT		0x06

/* Also can be found in ACPI specification 12.3 */
#define EC_READ			0x80
#define EC_WRITE		0x81
#define EC_BURST		0x82
#define EC_QUERY		0x84

#define EC_FN_LOCK_ON		0x5A
#define EC_FN_LOCK_OFF		0x55
#define EC_FN_LOCK_READ		0x6B
#define EC_FN_LOCK_WRITE	0x6C

#define EC_EVENT_LID		0x81

#define EC_LID_STATE		0x80
#define EC_LID_OPEN		BIT(1)

#define EC_TEMP_REG		0x61

#define EC_STANDBY_REG		0xB2
#define EC_STANDBY_ENTER	0xDB
#define EC_STANDBY_EXIT		0xEB

enum gaokun_ec_smart_charge_cmd {
	SMART_CHARGE_DATA_WRITE = 0xE3,
	SMART_CHARGE_DATA_READ,
	SMART_CHARGE_ENABLE_WRITE,
	SMART_CHARGE_ENABLE_READ,
};

enum gaokun_ec_ucsi_cmd {
	UCSI_REG_WRITE = 0xD2,
	UCSI_REG_READ,
	UCSI_DATA_WRITE,
	UCSI_DATA_READ,
};

#define UCSI_REG_SIZE		7

/*
 * For tx, command sequences are arranged as
 * {master_cmd, slave_cmd, data_len, data_seq}
 */
#define REQ_HDR_SIZE		3
#define INPUT_SIZE_OFFSET	2
#define REQ_LEN(req) (REQ_HDR_SIZE + (req)[INPUT_SIZE_OFFSET])

/*
 * For rx, data sequences are arranged as
 * {status, data_len(unreliable), data_seq}
 */
#define RESP_HDR_SIZE		2

#define MKREQ(REG0, REG1, SIZE, ...)			\
{							\
	REG0, REG1, SIZE,				\
	/* ## will remove comma when SIZE is 0 */	\
	## __VA_ARGS__,					\
	/* make sure len(pkt[3:]) >= SIZE */		\
	[3 + (SIZE)] = 0,				\
}

#define MKRESP(SIZE)				\
{						\
	[RESP_HDR_SIZE + (SIZE) - 1] = 0,	\
}

/* Possible size 1, 4, 20, 24. Most of the time, the size is 1. */
static inline void refill_req(u8 *dest, const u8 *src, size_t size)
{
	memcpy(dest + REQ_HDR_SIZE, src, size);
}

static inline void refill_req_byte(u8 *dest, const u8 *src)
{
	dest[REQ_HDR_SIZE] = *src;
}

/* Possible size 1, 2, 4, 7, 20. Most of the time, the size is 1. */
static inline void extr_resp(u8 *dest, const u8 *src, size_t size)
{
	memcpy(dest, src + RESP_HDR_SIZE, size);
}

static inline void extr_resp_byte(u8 *dest, const u8 *src)
{
	*dest = src[RESP_HDR_SIZE];
}

static inline void *extr_resp_shallow(const u8 *src)
{
	return (void *)(src + RESP_HDR_SIZE);
}

struct gaokun_ec {
	struct i2c_client *client;
	struct mutex lock; /* EC transaction lock */
	struct blocking_notifier_head notifier_list;
	struct device *hwmon_dev;
	struct input_dev *idev;
	bool suspended;
};

static int gaokun_ec_request(struct gaokun_ec *ec, const u8 *req,
			     size_t resp_len, u8 *resp)
{
	struct i2c_client *client = ec->client;
	struct i2c_msg msgs[] = {
		{
			.addr = client->addr,
			.flags = client->flags,
			.len = REQ_LEN(req),
			.buf = (void *)req,
		}, {
			.addr = client->addr,
			.flags = client->flags | I2C_M_RD,
			.len = resp_len,
			.buf = resp,
		},
	};
	int ret;

	guard(mutex)(&ec->lock);
	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	if (ret != ARRAY_SIZE(msgs)) {
		dev_err(&client->dev, "I2C transfer error %d\n", ret);
		goto out_after_break;
	}

	ret = *resp;
	if (ret)
		dev_err(&client->dev, "EC transaction error %d\n", ret);

out_after_break:
	usleep_range(2000, 2500); /* have a break, ACPI did this */

	return ret;
}

/* -------------------------------------------------------------------------- */
/* Common API */

/**
 * gaokun_ec_read - Read from EC
 * @ec: The gaokun_ec structure
 * @req: The sequence to request
 * @resp_len: The size to read
 * @resp: The buffer to store response sequence
 *
 * This function is used to read data after writing a magic sequence to EC.
 * All EC operations depend on this function.
 *
 * Huawei uses magic sequences everywhere to complete various functions, all
 * these sequences are passed to ECCD(a ACPI method which is quiet similar
 * to gaokun_ec_request), there is no good abstraction to generalize these
 * sequences, so just wrap it for now. Almost all magic sequences are kept
 * in this file.
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_read(struct gaokun_ec *ec, const u8 *req,
		   size_t resp_len, u8 *resp)
{
	return gaokun_ec_request(ec, req, resp_len, resp);
}
EXPORT_SYMBOL_GPL(gaokun_ec_read);

/**
 * gaokun_ec_write - Write to EC
 * @ec: The gaokun_ec structure
 * @req: The sequence to request
 *
 * This function has no big difference from gaokun_ec_read. When caller care
 * only write status and no actual data are returned, then use it.
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_write(struct gaokun_ec *ec, const u8 *req)
{
	u8 ec_resp[] = MKRESP(0);

	return gaokun_ec_request(ec, req, sizeof(ec_resp), ec_resp);
}
EXPORT_SYMBOL_GPL(gaokun_ec_write);

int gaokun_ec_read_byte(struct gaokun_ec *ec, const u8 *req, u8 *byte)
{
	int ret;
	u8 ec_resp[] = MKRESP(sizeof(*byte));

	ret = gaokun_ec_read(ec, req, sizeof(ec_resp), ec_resp);
	extr_resp_byte(byte, ec_resp);

	return ret;
}
EXPORT_SYMBOL_GPL(gaokun_ec_read_byte);

/**
 * gaokun_ec_register_notify - Register a notifier callback for EC events.
 * @ec: The gaokun_ec structure
 * @nb: Notifier block pointer to register
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_register_notify(struct gaokun_ec *ec, struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&ec->notifier_list, nb);
}
EXPORT_SYMBOL_GPL(gaokun_ec_register_notify);

/**
 * gaokun_ec_unregister_notify - Unregister notifier callback for EC events.
 * @ec: The gaokun_ec structure
 * @nb: Notifier block pointer to unregister
 *
 * Unregister a notifier callback that was previously registered with
 * gaokun_ec_register_notify().
 */
void gaokun_ec_unregister_notify(struct gaokun_ec *ec, struct notifier_block *nb)
{
	blocking_notifier_chain_unregister(&ec->notifier_list, nb);
}
EXPORT_SYMBOL_GPL(gaokun_ec_unregister_notify);

/* -------------------------------------------------------------------------- */
/* API for PSY */

/**
 * gaokun_ec_psy_multi_read - Read contiguous registers
 * @ec: The gaokun_ec structure
 * @reg: The start register
 * @resp_len: The number of registers to be read
 * @resp: The buffer to store response sequence
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_psy_multi_read(struct gaokun_ec *ec, u8 reg,
			     size_t resp_len, u8 *resp)
{
	u8 ec_req[] = MKREQ(0x02, EC_READ, 1, 0);
	u8 ec_resp[] = MKRESP(1);
	int i, ret;

	for (i = 0; i < resp_len; ++i, reg++) {
		refill_req_byte(ec_req, &reg);
		ret = gaokun_ec_read(ec, ec_req, sizeof(ec_resp), ec_resp);
		if (ret)
			return ret;
		extr_resp_byte(&resp[i], ec_resp);
	}

	return 0;
}
EXPORT_SYMBOL_GPL(gaokun_ec_psy_multi_read);

/* Smart charge */

/**
 * gaokun_ec_psy_get_smart_charge - Get smart charge data from EC
 * @ec: The gaokun_ec structure
 * @resp: The buffer to store response sequence (mode, delay, start, end)
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_psy_get_smart_charge(struct gaokun_ec *ec,
				   u8 resp[GAOKUN_SMART_CHARGE_DATA_SIZE])
{
	/* GBCM */
	u8 ec_req[] = MKREQ(0x02, SMART_CHARGE_DATA_READ, 0);
	u8 ec_resp[] = MKRESP(GAOKUN_SMART_CHARGE_DATA_SIZE);
	int ret;

	ret = gaokun_ec_read(ec, ec_req, sizeof(ec_resp), ec_resp);
	if (ret)
		return ret;

	extr_resp(resp, ec_resp, GAOKUN_SMART_CHARGE_DATA_SIZE);

	return 0;
}
EXPORT_SYMBOL_GPL(gaokun_ec_psy_get_smart_charge);

static inline bool validate_battery_threshold_range(u8 start, u8 end)
{
	return end != 0 && start <= end && end <= 100;
}

/**
 * gaokun_ec_psy_set_smart_charge - Set smart charge data
 * @ec: The gaokun_ec structure
 * @req: The sequence to request (mode, delay, start, end)
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_psy_set_smart_charge(struct gaokun_ec *ec,
				   const u8 req[GAOKUN_SMART_CHARGE_DATA_SIZE])
{
	/* SBCM */
	u8 ec_req[] = MKREQ(0x02, SMART_CHARGE_DATA_WRITE,
			    GAOKUN_SMART_CHARGE_DATA_SIZE);

	if (!validate_battery_threshold_range(req[2], req[3]))
		return -EINVAL;

	refill_req(ec_req, req, GAOKUN_SMART_CHARGE_DATA_SIZE);

	return gaokun_ec_write(ec, ec_req);
}
EXPORT_SYMBOL_GPL(gaokun_ec_psy_set_smart_charge);

/* Smart charge enable */

/**
 * gaokun_ec_psy_get_smart_charge_enable - Get smart charge state
 * @ec: The gaokun_ec structure
 * @on: The state
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_psy_get_smart_charge_enable(struct gaokun_ec *ec, bool *on)
{
	/* GBAC */
	u8 ec_req[] = MKREQ(0x02, SMART_CHARGE_ENABLE_READ, 0);
	u8 state;
	int ret;

	ret = gaokun_ec_read_byte(ec, ec_req, &state);
	if (ret)
		return ret;

	*on = !!state;

	return 0;
}
EXPORT_SYMBOL_GPL(gaokun_ec_psy_get_smart_charge_enable);

/**
 * gaokun_ec_psy_set_smart_charge_enable - Set smart charge state
 * @ec: The gaokun_ec structure
 * @on: The state
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_psy_set_smart_charge_enable(struct gaokun_ec *ec, bool on)
{
	/* SBAC */
	u8 ec_req[] = MKREQ(0x02, SMART_CHARGE_ENABLE_WRITE, 1, on);

	return gaokun_ec_write(ec, ec_req);
}
EXPORT_SYMBOL_GPL(gaokun_ec_psy_set_smart_charge_enable);

/* -------------------------------------------------------------------------- */
/* API for UCSI */

/**
 * gaokun_ec_ucsi_read - Read UCSI data from EC
 * @ec: The gaokun_ec structure
 * @resp: The buffer to store response sequence
 *
 * Read CCI and MSGI (used by UCSI subdriver).
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_ucsi_read(struct gaokun_ec *ec,
			u8 resp[GAOKUN_UCSI_READ_SIZE])
{
	u8 ec_req[] = MKREQ(0x03, UCSI_DATA_READ, 0);
	u8 ec_resp[] = MKRESP(GAOKUN_UCSI_READ_SIZE);
	int ret;

	ret = gaokun_ec_read(ec, ec_req, sizeof(ec_resp), ec_resp);
	if (ret)
		return ret;

	extr_resp(resp, ec_resp, GAOKUN_UCSI_READ_SIZE);
	return 0;
}
EXPORT_SYMBOL_GPL(gaokun_ec_ucsi_read);

/**
 * gaokun_ec_ucsi_write - Write UCSI data to EC
 * @ec: The gaokun_ec structure
 * @req: The sequence to request
 *
 * Write CTRL and MSGO (used by UCSI subdriver).
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_ucsi_write(struct gaokun_ec *ec,
			 const u8 req[GAOKUN_UCSI_WRITE_SIZE])
{
	u8 ec_req[] = MKREQ(0x03, UCSI_DATA_WRITE, GAOKUN_UCSI_WRITE_SIZE);

	refill_req(ec_req, req, GAOKUN_UCSI_WRITE_SIZE);

	return gaokun_ec_write(ec, ec_req);
}
EXPORT_SYMBOL_GPL(gaokun_ec_ucsi_write);

/**
 * gaokun_ec_ucsi_get_reg - Get UCSI register from EC
 * @ec: The gaokun_ec structure
 * @ureg: The gaokun ucsi register
 *
 * Get UCSI register data (used by UCSI subdriver).
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_ucsi_get_reg(struct gaokun_ec *ec, struct gaokun_ucsi_reg *ureg)
{
	u8 ec_req[] = MKREQ(0x03, UCSI_REG_READ, 0);
	u8 ec_resp[] = MKRESP(UCSI_REG_SIZE);
	int ret;

	ret = gaokun_ec_read(ec, ec_req, sizeof(ec_resp), ec_resp);
	if (ret)
		return ret;

	extr_resp((u8 *)ureg, ec_resp, UCSI_REG_SIZE);

	return 0;
}
EXPORT_SYMBOL_GPL(gaokun_ec_ucsi_get_reg);

/**
 * gaokun_ec_ucsi_pan_ack - Ack pin assignment notifications from EC
 * @ec: The gaokun_ec structure
 * @port_id: The port id receiving and handling the notifications
 *
 * Ack pin assignment notifications (used by UCSI subdriver).
 *
 * Return: 0 on success or negative error code.
 */
int gaokun_ec_ucsi_pan_ack(struct gaokun_ec *ec, int port_id)
{
	u8 ec_req[] = MKREQ(0x03, UCSI_REG_WRITE, 1);
	u8 data = 1 << port_id;

	if (port_id == GAOKUN_UCSI_NO_PORT_UPDATE)
		data = 0;

	refill_req_byte(ec_req, &data);

	return gaokun_ec_write(ec, ec_req);
}
EXPORT_SYMBOL_GPL(gaokun_ec_ucsi_pan_ack);

/* -------------------------------------------------------------------------- */
/* EC Sysfs */

/* Fn lock */
static int gaokun_ec_get_fn_lock(struct gaokun_ec *ec, bool *on)
{
	/* GFRS */
	u8 ec_req[] = MKREQ(0x02, EC_FN_LOCK_READ, 0);
	int ret;
	u8 state;

	ret = gaokun_ec_read_byte(ec, ec_req, &state);
	if (ret)
		return ret;

	if (state == EC_FN_LOCK_ON)
		*on = true;
	else if (state == EC_FN_LOCK_OFF)
		*on = false;
	else
		return -EIO;

	return 0;
}

static int gaokun_ec_set_fn_lock(struct gaokun_ec *ec, bool on)
{
	/* SFRS */
	u8 ec_req[] = MKREQ(0x02, EC_FN_LOCK_WRITE, 1,
			    on ? EC_FN_LOCK_ON : EC_FN_LOCK_OFF);

	return gaokun_ec_write(ec, ec_req);
}

static ssize_t fn_lock_show(struct device *dev,
			    struct device_attribute *attr,
			    char *buf)
{
	struct gaokun_ec *ec = dev_get_drvdata(dev);
	bool on;
	int ret;

	ret = gaokun_ec_get_fn_lock(ec, &on);
	if (ret)
		return ret;

	return sysfs_emit(buf, "%d\n", on);
}

static ssize_t fn_lock_store(struct device *dev,
			     struct device_attribute *attr,
			     const char *buf, size_t size)
{
	struct gaokun_ec *ec = dev_get_drvdata(dev);
	bool on;
	int ret;

	if (kstrtobool(buf, &on))
		return -EINVAL;

	ret = gaokun_ec_set_fn_lock(ec, on);
	if (ret)
		return ret;

	return size;
}

static DEVICE_ATTR_RW(fn_lock);

static struct attribute *gaokun_ec_attrs[] = {
	&dev_attr_fn_lock.attr,
	NULL,
};
ATTRIBUTE_GROUPS(gaokun_ec);

/* -------------------------------------------------------------------------- */
/* Thermal Zone HwMon */

/* Range from 0 to 0x2C, partially valid */
static const u8 temp_reg[] = {
	0x05, 0x07, 0x08, 0x0E, 0x0F, 0x12, 0x15, 0x1E,
	0x1F, 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26,
	0x27, 0x28, 0x29, 0x2A
};

static int gaokun_ec_get_temp(struct gaokun_ec *ec, u8 idx, long *temp)
{
	/* GTMP */
	u8 ec_req[] = MKREQ(0x02, EC_TEMP_REG, 1, temp_reg[idx]);
	u8 ec_resp[] = MKRESP(sizeof(__le16));
	__le16 *tmp;
	int ret;

	ret = gaokun_ec_read(ec, ec_req, sizeof(ec_resp), ec_resp);
	if (ret)
		return ret;

	tmp = (__le16 *)extr_resp_shallow(ec_resp);
	*temp = le16_to_cpu(*tmp) * 100; /* convert to HwMon's unit */

	return 0;
}

static umode_t
gaokun_ec_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
			   u32 attr, int channel)
{
	return type == hwmon_temp ? 0444 : 0;
}

static int
gaokun_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
		     u32 attr, int channel, long *val)
{
	struct gaokun_ec *ec = dev_get_drvdata(dev);

	if (type == hwmon_temp)
		return gaokun_ec_get_temp(ec, channel, val);

	return -EINVAL;
}

static const struct hwmon_ops gaokun_ec_hwmon_ops = {
	.is_visible = gaokun_ec_hwmon_is_visible,
	.read = gaokun_ec_hwmon_read,
};

static u32 gaokun_ec_temp_config[] = {
	[0 ... ARRAY_SIZE(temp_reg) - 1] = HWMON_T_INPUT,
	0
};

static const struct hwmon_channel_info gaokun_ec_temp = {
	.type = hwmon_temp,
	.config = gaokun_ec_temp_config,
};

static const struct hwmon_channel_info * const gaokun_ec_hwmon_info[] = {
	&gaokun_ec_temp,
	NULL
};

static const struct hwmon_chip_info gaokun_ec_hwmon_chip_info = {
	.ops = &gaokun_ec_hwmon_ops,
	.info = gaokun_ec_hwmon_info,
};

/* -------------------------------------------------------------------------- */
/* Modern Standby */

static int gaokun_ec_suspend(struct device *dev)
{
	struct gaokun_ec *ec = dev_get_drvdata(dev);
	u8 ec_req[] = MKREQ(0x02, EC_STANDBY_REG, 1, EC_STANDBY_ENTER);
	int ret;

	if (ec->suspended)
		return 0;

	ret = gaokun_ec_write(ec, ec_req);
	if (ret)
		return ret;

	ec->suspended = true;

	return 0;
}

static int gaokun_ec_resume(struct device *dev)
{
	struct gaokun_ec *ec = dev_get_drvdata(dev);
	u8 ec_req[] = MKREQ(0x02, EC_STANDBY_REG, 1, EC_STANDBY_EXIT);
	int ret;
	int i;

	if (!ec->suspended)
		return 0;

	for (i = 0; i < 3; ++i) {
		ret = gaokun_ec_write(ec, ec_req);
		if (ret == 0)
			break;

		msleep(100); /* EC need time to resume */
	}

	ec->suspended = false;

	return 0;
}

static void gaokun_aux_release(struct device *dev)
{
	struct auxiliary_device *adev = to_auxiliary_dev(dev);

	kfree(adev);
}

static void gaokun_aux_remove(void *data)
{
	struct auxiliary_device *adev = data;

	auxiliary_device_delete(adev);
	auxiliary_device_uninit(adev);
}

static int gaokun_aux_init(struct device *parent, const char *name,
			   struct gaokun_ec *ec)
{
	struct auxiliary_device *adev;
	int ret;

	adev = kzalloc(sizeof(*adev), GFP_KERNEL);
	if (!adev)
		return -ENOMEM;

	adev->name = name;
	adev->id = 0;
	adev->dev.parent = parent;
	adev->dev.release = gaokun_aux_release;
	adev->dev.platform_data = ec;
	/* Allow aux devices to access parent's DT nodes directly */
	device_set_of_node_from_dev(&adev->dev, parent);

	ret = auxiliary_device_init(adev);
	if (ret) {
		kfree(adev);
		return ret;
	}

	ret = auxiliary_device_add(adev);
	if (ret) {
		auxiliary_device_uninit(adev);
		return ret;
	}

	return devm_add_action_or_reset(parent, gaokun_aux_remove, adev);
}

/* -------------------------------------------------------------------------- */
/* EC */

static irqreturn_t gaokun_ec_irq_handler(int irq, void *data)
{
	struct gaokun_ec *ec = data;
	u8 ec_req[] = MKREQ(EC_EVENT, EC_QUERY, 0);
	u8 status, id;
	int ret;

	ret = gaokun_ec_read_byte(ec, ec_req, &id);
	if (ret)
		return IRQ_HANDLED;

	switch (id) {
	case 0x0: /* No event */
		break;

	case EC_EVENT_LID:
		gaokun_ec_psy_read_byte(ec, EC_LID_STATE, &status);
		status &= EC_LID_OPEN;
		input_report_switch(ec->idev, SW_LID, !status);
		input_sync(ec->idev);
		break;

	default:
		blocking_notifier_call_chain(&ec->notifier_list, id, ec);
	}

	return IRQ_HANDLED;
}

static int gaokun_ec_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct gaokun_ec *ec;
	int ret;

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

	ret = devm_mutex_init(dev, &ec->lock);
	if (ret)
		return ret;

	ec->client = client;
	i2c_set_clientdata(client, ec);
	BLOCKING_INIT_NOTIFIER_HEAD(&ec->notifier_list);

	/* Lid switch */
	ec->idev = devm_input_allocate_device(dev);
	if (!ec->idev)
		return -ENOMEM;

	ec->idev->name = "LID";
	ec->idev->phys = "gaokun-ec/input0";
	input_set_capability(ec->idev, EV_SW, SW_LID);

	ret = input_register_device(ec->idev);
	if (ret)
		return dev_err_probe(dev, ret, "Failed to register input device\n");

	ret = gaokun_aux_init(dev, GAOKUN_DEV_PSY, ec);
	if (ret)
		return ret;

	ret = gaokun_aux_init(dev, GAOKUN_DEV_UCSI, ec);
	if (ret)
		return ret;

	ret = devm_request_threaded_irq(dev, client->irq, NULL,
					gaokun_ec_irq_handler, IRQF_ONESHOT,
					dev_name(dev), ec);
	if (ret)
		return dev_err_probe(dev, ret, "Failed to request IRQ\n");

	ec->hwmon_dev = devm_hwmon_device_register_with_info(dev, "gaokun_ec_hwmon",
							     ec, &gaokun_ec_hwmon_chip_info, NULL);
	if (IS_ERR(ec->hwmon_dev))
		return dev_err_probe(dev, PTR_ERR(ec->hwmon_dev),
				     "Failed to register hwmon device\n");

	return 0;
}

static const struct i2c_device_id gaokun_ec_id[] = {
	{ "gaokun-ec", },
	{ }
};
MODULE_DEVICE_TABLE(i2c, gaokun_ec_id);

static const struct of_device_id gaokun_ec_of_match[] = {
	{ .compatible = "huawei,gaokun3-ec", },
	{ }
};
MODULE_DEVICE_TABLE(of, gaokun_ec_of_match);

static const struct dev_pm_ops gaokun_ec_pm_ops = {
	NOIRQ_SYSTEM_SLEEP_PM_OPS(gaokun_ec_suspend, gaokun_ec_resume)
};

static struct i2c_driver gaokun_ec_driver = {
	.driver = {
		.name = "gaokun-ec",
		.of_match_table = gaokun_ec_of_match,
		.pm = &gaokun_ec_pm_ops,
		.dev_groups = gaokun_ec_groups,
	},
	.probe = gaokun_ec_probe,
	.id_table = gaokun_ec_id,
};
module_i2c_driver(gaokun_ec_driver);

MODULE_DESCRIPTION("HUAWEI Matebook E Go EC driver");
MODULE_AUTHOR("Pengyu Luo <mitltlatltl@gmail.com>");
MODULE_LICENSE("GPL");