// SPDX-License-Identifier: GPL-2.0
/*
 * Analog Devices LTC2947 high precision power and energy monitor
 *
 * Copyright 2019 Analog Devices Inc.
 */
#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/regmap.h>

#include "ltc2947.h"

/* register's */
#define LTC2947_REG_PAGE_CTRL		0xFF
#define LTC2947_REG_CTRL		0xF0
#define LTC2947_REG_TBCTL		0xE9
#define LTC2947_CONT_MODE_MASK		BIT(3)
#define LTC2947_CONT_MODE(x)		FIELD_PREP(LTC2947_CONT_MODE_MASK, x)
#define LTC2947_PRE_MASK		GENMASK(2, 0)
#define LTC2947_PRE(x)			FIELD_PREP(LTC2947_PRE_MASK, x)
#define LTC2947_DIV_MASK		GENMASK(7, 3)
#define LTC2947_DIV(x)			FIELD_PREP(LTC2947_DIV_MASK, x)
#define LTC2947_SHUTDOWN_MASK		BIT(0)
#define LTC2947_REG_ACCUM_POL		0xE1
#define LTC2947_ACCUM_POL_1_MASK	GENMASK(1, 0)
#define LTC2947_ACCUM_POL_1(x)		FIELD_PREP(LTC2947_ACCUM_POL_1_MASK, x)
#define LTC2947_ACCUM_POL_2_MASK	GENMASK(3, 2)
#define LTC2947_ACCUM_POL_2(x)		FIELD_PREP(LTC2947_ACCUM_POL_2_MASK, x)
#define LTC2947_REG_ACCUM_DEADBAND	0xE4
#define LTC2947_REG_GPIOSTATCTL		0x67
#define LTC2947_GPIO_EN_MASK		BIT(0)
#define LTC2947_GPIO_EN(x)		FIELD_PREP(LTC2947_GPIO_EN_MASK, x)
#define LTC2947_GPIO_FAN_EN_MASK	BIT(6)
#define LTC2947_GPIO_FAN_EN(x)		FIELD_PREP(LTC2947_GPIO_FAN_EN_MASK, x)
#define LTC2947_GPIO_FAN_POL_MASK	BIT(7)
#define LTC2947_GPIO_FAN_POL(x)		FIELD_PREP(LTC2947_GPIO_FAN_POL_MASK, x)
#define LTC2947_REG_GPIO_ACCUM		0xE3
/* 200Khz */
#define LTC2947_CLK_MIN			200000
/* 25Mhz */
#define LTC2947_CLK_MAX			25000000
#define LTC2947_PAGE0			0
#define LTC2947_PAGE1			1
/* Voltage registers */
#define LTC2947_REG_VOLTAGE		0xA0
#define LTC2947_REG_VOLTAGE_MAX		0x50
#define LTC2947_REG_VOLTAGE_MIN		0x52
#define LTC2947_REG_VOLTAGE_THRE_H	0x90
#define LTC2947_REG_VOLTAGE_THRE_L	0x92
#define LTC2947_REG_DVCC		0xA4
#define LTC2947_REG_DVCC_MAX		0x58
#define LTC2947_REG_DVCC_MIN		0x5A
#define LTC2947_REG_DVCC_THRE_H		0x98
#define LTC2947_REG_DVCC_THRE_L		0x9A
#define LTC2947_VOLTAGE_GEN_CHAN	0
#define LTC2947_VOLTAGE_DVCC_CHAN	1
/* in mV */
#define VOLTAGE_MAX			15500
#define VOLTAGE_MIN			-300
#define VDVCC_MAX			15000
#define VDVCC_MIN			4750
/* Current registers */
#define LTC2947_REG_CURRENT		0x90
#define LTC2947_REG_CURRENT_MAX		0x40
#define LTC2947_REG_CURRENT_MIN		0x42
#define LTC2947_REG_CURRENT_THRE_H	0x80
#define LTC2947_REG_CURRENT_THRE_L	0x82
/* in mA */
#define CURRENT_MAX			30000
#define CURRENT_MIN			-30000
/* Power registers */
#define LTC2947_REG_POWER		0x93
#define LTC2947_REG_POWER_MAX		0x44
#define LTC2947_REG_POWER_MIN		0x46
#define LTC2947_REG_POWER_THRE_H	0x84
#define LTC2947_REG_POWER_THRE_L	0x86
/* in uW */
#define POWER_MAX			450000000
#define POWER_MIN			-450000000
/* Temperature registers */
#define LTC2947_REG_TEMP		0xA2
#define LTC2947_REG_TEMP_MAX		0x54
#define LTC2947_REG_TEMP_MIN		0x56
#define LTC2947_REG_TEMP_THRE_H		0x94
#define LTC2947_REG_TEMP_THRE_L		0x96
#define LTC2947_REG_TEMP_FAN_THRE_H	0x9C
#define LTC2947_REG_TEMP_FAN_THRE_L	0x9E
#define LTC2947_TEMP_FAN_CHAN		1
/* in millidegress Celsius */
#define TEMP_MAX			85000
#define TEMP_MIN			-40000
/* Energy registers */
#define LTC2947_REG_ENERGY1		0x06
#define LTC2947_REG_ENERGY2		0x16
/* Status/Alarm/Overflow registers */
#define LTC2947_REG_STATUS		0x80
#define LTC2947_REG_STATVT		0x81
#define LTC2947_REG_STATIP		0x82
#define LTC2947_REG_STATVDVCC		0x87

#define LTC2947_ALERTS_SIZE	(LTC2947_REG_STATVDVCC - LTC2947_REG_STATUS)
#define LTC2947_MAX_VOLTAGE_MASK	BIT(0)
#define LTC2947_MIN_VOLTAGE_MASK	BIT(1)
#define LTC2947_MAX_CURRENT_MASK	BIT(0)
#define LTC2947_MIN_CURRENT_MASK	BIT(1)
#define LTC2947_MAX_POWER_MASK		BIT(2)
#define LTC2947_MIN_POWER_MASK		BIT(3)
#define LTC2947_MAX_TEMP_MASK		BIT(2)
#define LTC2947_MIN_TEMP_MASK		BIT(3)
#define LTC2947_MAX_TEMP_FAN_MASK	BIT(4)
#define LTC2947_MIN_TEMP_FAN_MASK	BIT(5)

struct ltc2947_data {
	struct regmap *map;
	struct device *dev;
	/*
	 * The mutex is needed because the device has 2 memory pages. When
	 * reading/writing the correct page needs to be set so that, the
	 * complete sequence select_page->read/write needs to be protected.
	 */
	struct mutex lock;
	u32 lsb_energy;
	bool gpio_out;
};

static int __ltc2947_val_read16(const struct ltc2947_data *st, const u8 reg,
				u64 *val)
{
	__be16 __val = 0;
	int ret;

	ret = regmap_bulk_read(st->map, reg, &__val, 2);
	if (ret)
		return ret;

	*val = be16_to_cpu(__val);

	return 0;
}

static int __ltc2947_val_read24(const struct ltc2947_data *st, const u8 reg,
				u64 *val)
{
	__be32 __val = 0;
	int ret;

	ret = regmap_bulk_read(st->map, reg, &__val, 3);
	if (ret)
		return ret;

	*val = be32_to_cpu(__val) >> 8;

	return 0;
}

static int __ltc2947_val_read64(const struct ltc2947_data *st, const u8 reg,
				u64 *val)
{
	__be64 __val = 0;
	int ret;

	ret = regmap_bulk_read(st->map, reg, &__val, 6);
	if (ret)
		return ret;

	*val = be64_to_cpu(__val) >> 16;

	return 0;
}

static int ltc2947_val_read(struct ltc2947_data *st, const u8 reg,
			    const u8 page, const size_t size, s64 *val)
{
	int ret;
	u64 __val = 0;

	mutex_lock(&st->lock);

	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, page);
	if (ret) {
		mutex_unlock(&st->lock);
		return ret;
	}

	dev_dbg(st->dev, "Read val, reg:%02X, p:%d sz:%zu\n", reg, page,
		size);

	switch (size) {
	case 2:
		ret = __ltc2947_val_read16(st, reg, &__val);
		break;
	case 3:
		ret = __ltc2947_val_read24(st, reg, &__val);
		break;
	case 6:
		ret = __ltc2947_val_read64(st, reg, &__val);
		break;
	default:
		ret = -EINVAL;
		break;
	}

	mutex_unlock(&st->lock);

	if (ret)
		return ret;

	*val = sign_extend64(__val, (8 * size) - 1);

	dev_dbg(st->dev, "Got s:%lld, u:%016llX\n", *val, __val);

	return 0;
}

static int __ltc2947_val_write64(const struct ltc2947_data *st, const u8 reg,
				 const u64 val)
{
	__be64 __val;

	__val = cpu_to_be64(val << 16);
	return regmap_bulk_write(st->map, reg, &__val, 6);
}

static int __ltc2947_val_write16(const struct ltc2947_data *st, const u8 reg,
				 const u16 val)
{
	__be16 __val;

	__val = cpu_to_be16(val);
	return regmap_bulk_write(st->map, reg, &__val, 2);
}

static int ltc2947_val_write(struct ltc2947_data *st, const u8 reg,
			     const u8 page, const size_t size, const u64 val)
{
	int ret;

	mutex_lock(&st->lock);
	/* set device on correct page */
	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, page);
	if (ret) {
		mutex_unlock(&st->lock);
		return ret;
	}

	dev_dbg(st->dev, "Write val, r:%02X, p:%d, sz:%zu, val:%016llX\n",
		reg, page, size, val);

	switch (size) {
	case 2:
		ret = __ltc2947_val_write16(st, reg, val);
		break;
	case 6:
		ret = __ltc2947_val_write64(st, reg, val);
		break;
	default:
		ret = -EINVAL;
		break;
	}

	mutex_unlock(&st->lock);

	return ret;
}

static int ltc2947_reset_history(struct ltc2947_data *st, const u8 reg_h,
				 const u8 reg_l)
{
	int ret;
	/*
	 * let's reset the tracking register's. Tracking register's have all
	 * 2 bytes size
	 */
	ret = ltc2947_val_write(st, reg_h, LTC2947_PAGE0, 2, 0x8000U);
	if (ret)
		return ret;

	return ltc2947_val_write(st, reg_l, LTC2947_PAGE0, 2, 0x7FFFU);
}

static int ltc2947_alarm_read(struct ltc2947_data *st, const u8 reg,
			      const u32 mask, long *val)
{
	u8 offset = reg - LTC2947_REG_STATUS;
	/* +1 to include status reg */
	char alarms[LTC2947_ALERTS_SIZE + 1];
	int ret = 0;

	memset(alarms, 0, sizeof(alarms));

	mutex_lock(&st->lock);

	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, LTC2947_PAGE0);
	if (ret)
		goto unlock;

	dev_dbg(st->dev, "Read alarm, reg:%02X, mask:%02X\n", reg, mask);
	/*
	 * As stated in the datasheet, when Threshold and Overflow registers
	 * are used, the status and all alert registers must be read in one
	 * multi-byte transaction.
	 */
	ret = regmap_bulk_read(st->map, LTC2947_REG_STATUS, alarms,
			       sizeof(alarms));
	if (ret)
		goto unlock;

	/* get the alarm */
	*val = !!(alarms[offset] & mask);
unlock:
	mutex_unlock(&st->lock);
	return ret;
}

static ssize_t ltc2947_show_value(struct device *dev,
				  struct device_attribute *da, char *buf)
{
	struct ltc2947_data *st = dev_get_drvdata(dev);
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	int ret;
	s64 val = 0;

	ret = ltc2947_val_read(st, attr->index, LTC2947_PAGE0, 6, &val);
	if (ret)
		return ret;

	/* value in microJoule. st->lsb_energy was multiplied by 10E9 */
	val = div_s64(val * st->lsb_energy, 1000);

	return sprintf(buf, "%lld\n", val);
}

static int ltc2947_read_temp(struct device *dev, const u32 attr, long *val,
			     const int channel)
{
	int ret;
	struct ltc2947_data *st = dev_get_drvdata(dev);
	s64 __val = 0;

	switch (attr) {
	case hwmon_temp_input:
		ret = ltc2947_val_read(st, LTC2947_REG_TEMP, LTC2947_PAGE0,
				       2, &__val);
		break;
	case hwmon_temp_highest:
		ret = ltc2947_val_read(st, LTC2947_REG_TEMP_MAX, LTC2947_PAGE0,
				       2, &__val);
		break;
	case hwmon_temp_lowest:
		ret = ltc2947_val_read(st, LTC2947_REG_TEMP_MIN, LTC2947_PAGE0,
				       2, &__val);
		break;
	case hwmon_temp_max_alarm:
		if (channel == LTC2947_TEMP_FAN_CHAN)
			return ltc2947_alarm_read(st, LTC2947_REG_STATVT,
						  LTC2947_MAX_TEMP_FAN_MASK,
						  val);

		return ltc2947_alarm_read(st, LTC2947_REG_STATVT,
					  LTC2947_MAX_TEMP_MASK, val);
	case hwmon_temp_min_alarm:
		if (channel == LTC2947_TEMP_FAN_CHAN)
			return	ltc2947_alarm_read(st, LTC2947_REG_STATVT,
						   LTC2947_MIN_TEMP_FAN_MASK,
						   val);

		return	ltc2947_alarm_read(st, LTC2947_REG_STATVT,
					   LTC2947_MIN_TEMP_MASK, val);
	case hwmon_temp_max:
		if (channel == LTC2947_TEMP_FAN_CHAN)
			ret = ltc2947_val_read(st, LTC2947_REG_TEMP_FAN_THRE_H,
					       LTC2947_PAGE1, 2, &__val);
		else
			ret = ltc2947_val_read(st, LTC2947_REG_TEMP_THRE_H,
					       LTC2947_PAGE1, 2, &__val);
		break;
	case hwmon_temp_min:
		if (channel == LTC2947_TEMP_FAN_CHAN)
			ret = ltc2947_val_read(st, LTC2947_REG_TEMP_FAN_THRE_L,
					       LTC2947_PAGE1, 2, &__val);
		else
			ret = ltc2947_val_read(st, LTC2947_REG_TEMP_THRE_L,
					       LTC2947_PAGE1, 2, &__val);
		break;
	default:
		return -ENOTSUPP;
	}

	if (ret)
		return ret;

	/* in milidegrees celcius, temp is given by: */
	*val = (__val * 204) + 5500;

	return 0;
}

static int ltc2947_read_power(struct device *dev, const u32 attr, long *val)
{
	struct ltc2947_data *st = dev_get_drvdata(dev);
	int ret;
	u32 lsb = 200000; /* in uW */
	s64 __val = 0;

	switch (attr) {
	case hwmon_power_input:
		ret = ltc2947_val_read(st, LTC2947_REG_POWER, LTC2947_PAGE0,
				       3, &__val);
		lsb = 50000;
		break;
	case hwmon_power_input_highest:
		ret = ltc2947_val_read(st, LTC2947_REG_POWER_MAX, LTC2947_PAGE0,
				       2, &__val);
		break;
	case hwmon_power_input_lowest:
		ret = ltc2947_val_read(st, LTC2947_REG_POWER_MIN, LTC2947_PAGE0,
				       2, &__val);
		break;
	case hwmon_power_max_alarm:
		return ltc2947_alarm_read(st, LTC2947_REG_STATIP,
					  LTC2947_MAX_POWER_MASK, val);
	case hwmon_power_min_alarm:
		return ltc2947_alarm_read(st, LTC2947_REG_STATIP,
					  LTC2947_MIN_POWER_MASK, val);
	case hwmon_power_max:
		ret = ltc2947_val_read(st, LTC2947_REG_POWER_THRE_H,
				       LTC2947_PAGE1, 2, &__val);
		break;
	case hwmon_power_min:
		ret = ltc2947_val_read(st, LTC2947_REG_POWER_THRE_L,
				       LTC2947_PAGE1, 2, &__val);
		break;
	default:
		return -ENOTSUPP;
	}

	if (ret)
		return ret;

	*val = __val * lsb;

	return 0;
}

static int ltc2947_read_curr(struct device *dev, const u32 attr, long *val)
{
	struct ltc2947_data *st = dev_get_drvdata(dev);
	int ret;
	u8 lsb = 12; /* in mA */
	s64 __val = 0;

	switch (attr) {
	case hwmon_curr_input:
		ret = ltc2947_val_read(st, LTC2947_REG_CURRENT,
				       LTC2947_PAGE0, 3, &__val);
		lsb = 3;
		break;
	case hwmon_curr_highest:
		ret = ltc2947_val_read(st, LTC2947_REG_CURRENT_MAX,
				       LTC2947_PAGE0, 2, &__val);
		break;
	case hwmon_curr_lowest:
		ret = ltc2947_val_read(st, LTC2947_REG_CURRENT_MIN,
				       LTC2947_PAGE0, 2, &__val);
		break;
	case hwmon_curr_max_alarm:
		return ltc2947_alarm_read(st, LTC2947_REG_STATIP,
					  LTC2947_MAX_CURRENT_MASK, val);
	case hwmon_curr_min_alarm:
		return ltc2947_alarm_read(st, LTC2947_REG_STATIP,
					  LTC2947_MIN_CURRENT_MASK, val);
	case hwmon_curr_max:
		ret = ltc2947_val_read(st, LTC2947_REG_CURRENT_THRE_H,
				       LTC2947_PAGE1, 2, &__val);
		break;
	case hwmon_curr_min:
		ret = ltc2947_val_read(st, LTC2947_REG_CURRENT_THRE_L,
				       LTC2947_PAGE1, 2, &__val);
		break;
	default:
		return -ENOTSUPP;
	}

	if (ret)
		return ret;

	*val = __val * lsb;

	return 0;
}

static int ltc2947_read_in(struct device *dev, const u32 attr, long *val,
			   const int channel)
{
	struct ltc2947_data *st = dev_get_drvdata(dev);
	int ret;
	u8 lsb = 2; /* in mV */
	s64 __val = 0;

	if (channel < 0 || channel > LTC2947_VOLTAGE_DVCC_CHAN) {
		dev_err(st->dev, "Invalid chan%d for voltage", channel);
		return -EINVAL;
	}

	switch (attr) {
	case hwmon_in_input:
		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
			ret = ltc2947_val_read(st, LTC2947_REG_DVCC,
					       LTC2947_PAGE0, 2, &__val);
			lsb = 145;
		} else {
			ret = ltc2947_val_read(st, LTC2947_REG_VOLTAGE,
					       LTC2947_PAGE0, 2, &__val);
		}
		break;
	case hwmon_in_highest:
		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
			ret = ltc2947_val_read(st, LTC2947_REG_DVCC_MAX,
					       LTC2947_PAGE0, 2, &__val);
			lsb = 145;
		} else {
			ret = ltc2947_val_read(st, LTC2947_REG_VOLTAGE_MAX,
					       LTC2947_PAGE0, 2, &__val);
		}
		break;
	case hwmon_in_lowest:
		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
			ret = ltc2947_val_read(st, LTC2947_REG_DVCC_MIN,
					       LTC2947_PAGE0, 2, &__val);
			lsb = 145;
		} else {
			ret = ltc2947_val_read(st, LTC2947_REG_VOLTAGE_MIN,
					       LTC2947_PAGE0, 2, &__val);
		}
		break;
	case hwmon_in_max_alarm:
		if (channel == LTC2947_VOLTAGE_DVCC_CHAN)
			return ltc2947_alarm_read(st, LTC2947_REG_STATVDVCC,
						  LTC2947_MAX_VOLTAGE_MASK,
						  val);

		return ltc2947_alarm_read(st, LTC2947_REG_STATVT,
					  LTC2947_MAX_VOLTAGE_MASK, val);
	case hwmon_in_min_alarm:
		if (channel == LTC2947_VOLTAGE_DVCC_CHAN)
			return ltc2947_alarm_read(st, LTC2947_REG_STATVDVCC,
						  LTC2947_MIN_VOLTAGE_MASK,
						  val);

		return ltc2947_alarm_read(st, LTC2947_REG_STATVT,
					  LTC2947_MIN_VOLTAGE_MASK, val);
	case hwmon_in_max:
		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
			ret = ltc2947_val_read(st, LTC2947_REG_DVCC_THRE_H,
					       LTC2947_PAGE1, 2, &__val);
			lsb = 145;
		} else {
			ret = ltc2947_val_read(st, LTC2947_REG_VOLTAGE_THRE_H,
					       LTC2947_PAGE1, 2, &__val);
		}
		break;
	case hwmon_in_min:
		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
			ret = ltc2947_val_read(st, LTC2947_REG_DVCC_THRE_L,
					       LTC2947_PAGE1, 2, &__val);
			lsb = 145;
		} else {
			ret = ltc2947_val_read(st, LTC2947_REG_VOLTAGE_THRE_L,
					       LTC2947_PAGE1, 2, &__val);
		}
		break;
	default:
		return -ENOTSUPP;
	}

	if (ret)
		return ret;

	*val = __val * lsb;

	return 0;
}

static int ltc2947_read(struct device *dev, enum hwmon_sensor_types type,
			u32 attr, int channel, long *val)
{
	switch (type) {
	case hwmon_in:
		return ltc2947_read_in(dev, attr, val, channel);
	case hwmon_curr:
		return ltc2947_read_curr(dev, attr, val);
	case hwmon_power:
		return ltc2947_read_power(dev, attr, val);
	case hwmon_temp:
		return ltc2947_read_temp(dev, attr, val, channel);
	default:
		return -ENOTSUPP;
	}
}

static int ltc2947_write_temp(struct device *dev, const u32 attr,
			      long val, const int channel)
{
	struct ltc2947_data *st = dev_get_drvdata(dev);

	if (channel < 0 || channel > LTC2947_TEMP_FAN_CHAN) {
		dev_err(st->dev, "Invalid chan%d for temperature", channel);
		return -EINVAL;
	}

	switch (attr) {
	case hwmon_temp_reset_history:
		if (val != 1)
			return -EINVAL;
		return ltc2947_reset_history(st, LTC2947_REG_TEMP_MAX,
					     LTC2947_REG_TEMP_MIN);
	case hwmon_temp_max:
		val = clamp_val(val, TEMP_MIN, TEMP_MAX);
		if (channel == LTC2947_TEMP_FAN_CHAN) {
			if (!st->gpio_out)
				return -ENOTSUPP;

			return ltc2947_val_write(st,
					LTC2947_REG_TEMP_FAN_THRE_H,
					LTC2947_PAGE1, 2,
					DIV_ROUND_CLOSEST(val - 550, 204));
		}

		return ltc2947_val_write(st, LTC2947_REG_TEMP_THRE_H,
					 LTC2947_PAGE1, 2,
					 DIV_ROUND_CLOSEST(val - 550, 204));
	case hwmon_temp_min:
		val = clamp_val(val, TEMP_MIN, TEMP_MAX);
		if (channel == LTC2947_TEMP_FAN_CHAN) {
			if (!st->gpio_out)
				return -ENOTSUPP;

			return ltc2947_val_write(st,
					LTC2947_REG_TEMP_FAN_THRE_L,
					LTC2947_PAGE1, 2,
					DIV_ROUND_CLOSEST(val - 550, 204));
		}

		return ltc2947_val_write(st, LTC2947_REG_TEMP_THRE_L,
					 LTC2947_PAGE1, 2,
					 DIV_ROUND_CLOSEST(val - 550, 204));
	default:
		return -ENOTSUPP;
	}
}

static int ltc2947_write_power(struct device *dev, const u32 attr,
			       long val)
{
	struct ltc2947_data *st = dev_get_drvdata(dev);

	switch (attr) {
	case hwmon_power_reset_history:
		if (val != 1)
			return -EINVAL;
		return ltc2947_reset_history(st, LTC2947_REG_POWER_MAX,
					     LTC2947_REG_POWER_MIN);
	case hwmon_power_max:
		val = clamp_val(val, POWER_MIN, POWER_MAX);
		return ltc2947_val_write(st, LTC2947_REG_POWER_THRE_H,
					 LTC2947_PAGE1, 2,
					 DIV_ROUND_CLOSEST(val, 200000));
	case hwmon_power_min:
		val = clamp_val(val, POWER_MIN, POWER_MAX);
		return ltc2947_val_write(st, LTC2947_REG_POWER_THRE_L,
					 LTC2947_PAGE1, 2,
					 DIV_ROUND_CLOSEST(val, 200000));
	default:
		return -ENOTSUPP;
	}
}

static int ltc2947_write_curr(struct device *dev, const u32 attr,
			      long val)
{
	struct ltc2947_data *st = dev_get_drvdata(dev);

	switch (attr) {
	case hwmon_curr_reset_history:
		if (val != 1)
			return -EINVAL;
		return ltc2947_reset_history(st, LTC2947_REG_CURRENT_MAX,
					     LTC2947_REG_CURRENT_MIN);
	case hwmon_curr_max:
		val = clamp_val(val, CURRENT_MIN, CURRENT_MAX);
		return ltc2947_val_write(st, LTC2947_REG_CURRENT_THRE_H,
					 LTC2947_PAGE1, 2,
					 DIV_ROUND_CLOSEST(val, 12));
	case hwmon_curr_min:
		val = clamp_val(val, CURRENT_MIN, CURRENT_MAX);
		return ltc2947_val_write(st, LTC2947_REG_CURRENT_THRE_L,
					 LTC2947_PAGE1, 2,
					 DIV_ROUND_CLOSEST(val, 12));
	default:
		return -ENOTSUPP;
	}
}

static int ltc2947_write_in(struct device *dev, const u32 attr, long val,
			    const int channel)
{
	struct ltc2947_data *st = dev_get_drvdata(dev);

	if (channel > LTC2947_VOLTAGE_DVCC_CHAN) {
		dev_err(st->dev, "Invalid chan%d for voltage", channel);
		return -EINVAL;
	}

	switch (attr) {
	case hwmon_in_reset_history:
		if (val != 1)
			return -EINVAL;

		if (channel == LTC2947_VOLTAGE_DVCC_CHAN)
			return ltc2947_reset_history(st, LTC2947_REG_DVCC_MAX,
						     LTC2947_REG_DVCC_MIN);

		return ltc2947_reset_history(st, LTC2947_REG_VOLTAGE_MAX,
					     LTC2947_REG_VOLTAGE_MIN);
	case hwmon_in_max:
		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
			val = clamp_val(val, VDVCC_MIN, VDVCC_MAX);
			return ltc2947_val_write(st, LTC2947_REG_DVCC_THRE_H,
						 LTC2947_PAGE1, 2,
						 DIV_ROUND_CLOSEST(val, 145));
		}

		val = clamp_val(val, VOLTAGE_MIN, VOLTAGE_MAX);
		return ltc2947_val_write(st, LTC2947_REG_VOLTAGE_THRE_H,
					 LTC2947_PAGE1, 2,
					 DIV_ROUND_CLOSEST(val, 2));
	case hwmon_in_min:
		if (channel == LTC2947_VOLTAGE_DVCC_CHAN) {
			val = clamp_val(val, VDVCC_MIN, VDVCC_MAX);
			return ltc2947_val_write(st, LTC2947_REG_DVCC_THRE_L,
						 LTC2947_PAGE1, 2,
						 DIV_ROUND_CLOSEST(val, 145));
		}

		val = clamp_val(val, VOLTAGE_MIN, VOLTAGE_MAX);
		return ltc2947_val_write(st, LTC2947_REG_VOLTAGE_THRE_L,
					 LTC2947_PAGE1, 2,
					 DIV_ROUND_CLOSEST(val, 2));
	default:
		return -ENOTSUPP;
	}
}

static int ltc2947_write(struct device *dev,
			 enum hwmon_sensor_types type,
			 u32 attr, int channel, long val)
{
	switch (type) {
	case hwmon_in:
		return ltc2947_write_in(dev, attr, val, channel);
	case hwmon_curr:
		return ltc2947_write_curr(dev, attr, val);
	case hwmon_power:
		return ltc2947_write_power(dev, attr, val);
	case hwmon_temp:
		return ltc2947_write_temp(dev, attr, val, channel);
	default:
		return -ENOTSUPP;
	}
}

static int ltc2947_read_labels(struct device *dev,
			       enum hwmon_sensor_types type,
			       u32 attr, int channel, const char **str)
{
	switch (type) {
	case hwmon_in:
		if (channel == LTC2947_VOLTAGE_DVCC_CHAN)
			*str = "DVCC";
		else
			*str = "VP-VM";
		return 0;
	case hwmon_curr:
		*str = "IP-IM";
		return 0;
	case hwmon_temp:
		if (channel == LTC2947_TEMP_FAN_CHAN)
			*str = "TEMPFAN";
		else
			*str = "Ambient";
		return 0;
	case hwmon_power:
		*str = "Power";
		return 0;
	default:
		return -ENOTSUPP;
	}
}

static int ltc2947_in_is_visible(const u32 attr)
{
	switch (attr) {
	case hwmon_in_input:
	case hwmon_in_highest:
	case hwmon_in_lowest:
	case hwmon_in_max_alarm:
	case hwmon_in_min_alarm:
	case hwmon_in_label:
		return 0444;
	case hwmon_in_reset_history:
		return 0200;
	case hwmon_in_max:
	case hwmon_in_min:
		return 0644;
	default:
		return 0;
	}
}

static int ltc2947_curr_is_visible(const u32 attr)
{
	switch (attr) {
	case hwmon_curr_input:
	case hwmon_curr_highest:
	case hwmon_curr_lowest:
	case hwmon_curr_max_alarm:
	case hwmon_curr_min_alarm:
	case hwmon_curr_label:
		return 0444;
	case hwmon_curr_reset_history:
		return 0200;
	case hwmon_curr_max:
	case hwmon_curr_min:
		return 0644;
	default:
		return 0;
	}
}

static int ltc2947_power_is_visible(const u32 attr)
{
	switch (attr) {
	case hwmon_power_input:
	case hwmon_power_input_highest:
	case hwmon_power_input_lowest:
	case hwmon_power_label:
	case hwmon_power_max_alarm:
	case hwmon_power_min_alarm:
		return 0444;
	case hwmon_power_reset_history:
		return 0200;
	case hwmon_power_max:
	case hwmon_power_min:
		return 0644;
	default:
		return 0;
	}
}

static int ltc2947_temp_is_visible(const u32 attr)
{
	switch (attr) {
	case hwmon_temp_input:
	case hwmon_temp_highest:
	case hwmon_temp_lowest:
	case hwmon_temp_max_alarm:
	case hwmon_temp_min_alarm:
	case hwmon_temp_label:
		return 0444;
	case hwmon_temp_reset_history:
		return 0200;
	case hwmon_temp_max:
	case hwmon_temp_min:
		return 0644;
	default:
		return 0;
	}
}

static umode_t ltc2947_is_visible(const void *data,
				  enum hwmon_sensor_types type,
				  u32 attr, int channel)
{
	switch (type) {
	case hwmon_in:
		return ltc2947_in_is_visible(attr);
	case hwmon_curr:
		return ltc2947_curr_is_visible(attr);
	case hwmon_power:
		return ltc2947_power_is_visible(attr);
	case hwmon_temp:
		return ltc2947_temp_is_visible(attr);
	default:
		return 0;
	}
}

static const struct hwmon_channel_info * const ltc2947_info[] = {
	HWMON_CHANNEL_INFO(in,
			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_RESET_HISTORY |
			   HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM |
			   HWMON_I_LABEL,
			   HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
			   HWMON_I_MAX | HWMON_I_MIN | HWMON_I_RESET_HISTORY |
			   HWMON_I_MIN_ALARM | HWMON_I_MAX_ALARM |
			   HWMON_I_LABEL),
	HWMON_CHANNEL_INFO(curr,
			   HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST |
			   HWMON_C_MAX | HWMON_C_MIN | HWMON_C_RESET_HISTORY |
			   HWMON_C_MIN_ALARM | HWMON_C_MAX_ALARM |
			   HWMON_C_LABEL),
	HWMON_CHANNEL_INFO(power,
			   HWMON_P_INPUT | HWMON_P_INPUT_LOWEST |
			   HWMON_P_INPUT_HIGHEST | HWMON_P_MAX | HWMON_P_MIN |
			   HWMON_P_RESET_HISTORY | HWMON_P_MAX_ALARM |
			   HWMON_P_MIN_ALARM | HWMON_P_LABEL),
	HWMON_CHANNEL_INFO(temp,
			   HWMON_T_INPUT | HWMON_T_LOWEST | HWMON_T_HIGHEST |
			   HWMON_T_MAX | HWMON_T_MIN | HWMON_T_RESET_HISTORY |
			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
			   HWMON_T_LABEL,
			   HWMON_T_MAX_ALARM | HWMON_T_MIN_ALARM | HWMON_T_MAX |
			   HWMON_T_MIN | HWMON_T_LABEL),
	NULL
};

static const struct hwmon_ops ltc2947_hwmon_ops = {
	.is_visible = ltc2947_is_visible,
	.read = ltc2947_read,
	.write = ltc2947_write,
	.read_string = ltc2947_read_labels,
};

static const struct hwmon_chip_info ltc2947_chip_info = {
	.ops = &ltc2947_hwmon_ops,
	.info = ltc2947_info,
};

/* energy attributes are 6bytes wide so we need u64 */
static SENSOR_DEVICE_ATTR(energy1_input, 0444, ltc2947_show_value, NULL,
			  LTC2947_REG_ENERGY1);
static SENSOR_DEVICE_ATTR(energy2_input, 0444, ltc2947_show_value, NULL,
			  LTC2947_REG_ENERGY2);

static struct attribute *ltc2947_attrs[] = {
	&sensor_dev_attr_energy1_input.dev_attr.attr,
	&sensor_dev_attr_energy2_input.dev_attr.attr,
	NULL,
};
ATTRIBUTE_GROUPS(ltc2947);

static int ltc2947_setup(struct ltc2947_data *st)
{
	int ret;
	struct clk *extclk;
	u32 dummy, deadband, pol;
	u32 accum[2];

	/* clear status register by reading it */
	ret = regmap_read(st->map, LTC2947_REG_STATUS, &dummy);
	if (ret)
		return ret;
	/*
	 * Set max/min for power here since the default values x scale
	 * would overflow on 32bit arch
	 */
	ret = ltc2947_val_write(st, LTC2947_REG_POWER_THRE_H, LTC2947_PAGE1, 2,
				POWER_MAX / 200000);
	if (ret)
		return ret;

	ret = ltc2947_val_write(st, LTC2947_REG_POWER_THRE_L, LTC2947_PAGE1, 2,
				POWER_MIN / 200000);
	if (ret)
		return ret;

	/* check external clock presence */
	extclk = devm_clk_get_optional_enabled(st->dev, NULL);
	if (IS_ERR(extclk))
		return dev_err_probe(st->dev, PTR_ERR(extclk),
				     "Failed to get external clock\n");

	if (extclk) {
		unsigned long rate_hz;
		u8 pre = 0, div, tbctl;
		u64 aux;

		/* let's calculate and set the right valus in TBCTL */
		rate_hz = clk_get_rate(extclk);
		if (rate_hz < LTC2947_CLK_MIN || rate_hz > LTC2947_CLK_MAX) {
			dev_err(st->dev, "Invalid rate:%lu for external clock",
				rate_hz);
			return -EINVAL;
		}

		/* as in table 1 of the datasheet */
		if (rate_hz >= LTC2947_CLK_MIN && rate_hz <= 1000000)
			pre = 0;
		else if (rate_hz > 1000000 && rate_hz <= 2000000)
			pre = 1;
		else if (rate_hz > 2000000 && rate_hz <= 4000000)
			pre = 2;
		else if (rate_hz > 4000000 && rate_hz <= 8000000)
			pre = 3;
		else if (rate_hz > 8000000 && rate_hz <= 16000000)
			pre = 4;
		else if (rate_hz > 16000000 && rate_hz <= LTC2947_CLK_MAX)
			pre = 5;
		/*
		 * Div is given by:
		 *	floor(fref / (2^PRE * 32768))
		 */
		div = rate_hz / ((1 << pre) * 32768);
		tbctl = LTC2947_PRE(pre) | LTC2947_DIV(div);

		ret = regmap_write(st->map, LTC2947_REG_TBCTL, tbctl);
		if (ret)
			return ret;
		/*
		 * The energy lsb is given by (in W*s):
		 *      06416 * (1/fref) * 2^PRE * (DIV + 1)
		 * The value is multiplied by 10E9
		 */
		aux = (div + 1) * ((1 << pre) * 641600000ULL);
		st->lsb_energy = DIV_ROUND_CLOSEST_ULL(aux, rate_hz);
	} else {
		/* 19.89E-6 * 10E9 */
		st->lsb_energy = 19890;
	}
	ret = of_property_read_u32_array(st->dev->of_node,
					 "adi,accumulator-ctl-pol", accum,
					  ARRAY_SIZE(accum));
	if (!ret) {
		u32 accum_reg = LTC2947_ACCUM_POL_1(accum[0]) |
				LTC2947_ACCUM_POL_2(accum[1]);

		ret = regmap_write(st->map, LTC2947_REG_ACCUM_POL, accum_reg);
		if (ret)
			return ret;
	}
	ret = of_property_read_u32(st->dev->of_node,
				   "adi,accumulation-deadband-microamp",
				   &deadband);
	if (!ret) {
		/* the LSB is the same as the current, so 3mA */
		ret = regmap_write(st->map, LTC2947_REG_ACCUM_DEADBAND,
				   deadband / (1000 * 3));
		if (ret)
			return ret;
	}
	/* check gpio cfg */
	ret = of_property_read_u32(st->dev->of_node, "adi,gpio-out-pol", &pol);
	if (!ret) {
		/* setup GPIO as output */
		u32 gpio_ctl = LTC2947_GPIO_EN(1) | LTC2947_GPIO_FAN_EN(1) |
			LTC2947_GPIO_FAN_POL(pol);

		st->gpio_out = true;
		ret = regmap_write(st->map, LTC2947_REG_GPIOSTATCTL, gpio_ctl);
		if (ret)
			return ret;
	}
	ret = of_property_read_u32_array(st->dev->of_node, "adi,gpio-in-accum",
					 accum, ARRAY_SIZE(accum));
	if (!ret) {
		/*
		 * Setup the accum options. The gpioctl is already defined as
		 * input by default.
		 */
		u32 accum_val = LTC2947_ACCUM_POL_1(accum[0]) |
				LTC2947_ACCUM_POL_2(accum[1]);

		if (st->gpio_out) {
			dev_err(st->dev,
				"Cannot have input gpio config if already configured as output");
			return -EINVAL;
		}

		ret = regmap_write(st->map, LTC2947_REG_GPIO_ACCUM, accum_val);
		if (ret)
			return ret;
	}

	/* set continuos mode */
	return regmap_update_bits(st->map, LTC2947_REG_CTRL,
				  LTC2947_CONT_MODE_MASK, LTC2947_CONT_MODE(1));
}

int ltc2947_core_probe(struct regmap *map, const char *name)
{
	struct ltc2947_data *st;
	struct device *dev = regmap_get_device(map);
	struct device *hwmon;
	int ret;

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

	st->map = map;
	st->dev = dev;
	dev_set_drvdata(dev, st);
	mutex_init(&st->lock);

	ret = ltc2947_setup(st);
	if (ret)
		return ret;

	hwmon = devm_hwmon_device_register_with_info(dev, name, st,
						     &ltc2947_chip_info,
						     ltc2947_groups);
	return PTR_ERR_OR_ZERO(hwmon);
}
EXPORT_SYMBOL_GPL(ltc2947_core_probe);

static int ltc2947_resume(struct device *dev)
{
	struct ltc2947_data *st = dev_get_drvdata(dev);
	u32 ctrl = 0;
	int ret;

	/* dummy read to wake the device */
	ret = regmap_read(st->map, LTC2947_REG_CTRL, &ctrl);
	if (ret)
		return ret;
	/*
	 * Wait for the device. It takes 100ms to wake up so, 10ms extra
	 * should be enough.
	 */
	msleep(110);
	ret = regmap_read(st->map, LTC2947_REG_CTRL, &ctrl);
	if (ret)
		return ret;
	/* ctrl should be 0 */
	if (ctrl != 0) {
		dev_err(st->dev, "Device failed to wake up, ctl:%02X\n", ctrl);
		return -ETIMEDOUT;
	}

	/* set continuous mode */
	return regmap_update_bits(st->map, LTC2947_REG_CTRL,
				  LTC2947_CONT_MODE_MASK, LTC2947_CONT_MODE(1));
}

static int ltc2947_suspend(struct device *dev)
{
	struct ltc2947_data *st = dev_get_drvdata(dev);

	return regmap_update_bits(st->map, LTC2947_REG_CTRL,
				  LTC2947_SHUTDOWN_MASK, 1);
}

EXPORT_SIMPLE_DEV_PM_OPS(ltc2947_pm_ops, ltc2947_suspend, ltc2947_resume);

const struct of_device_id ltc2947_of_match[] = {
	{ .compatible = "adi,ltc2947" },
	{}
};
EXPORT_SYMBOL_GPL(ltc2947_of_match);
MODULE_DEVICE_TABLE(of, ltc2947_of_match);

MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
MODULE_DESCRIPTION("LTC2947 power and energy monitor core driver");
MODULE_LICENSE("GPL");