drivers/hwmon/ltc2991.c - linux/kernel/git/dhowells/linux-fs - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2023 Analog Devices, Inc.
  * Author: Antoniu Miclaus <antoniu.miclaus@analog.com>
  */

 #include <linux/bitops.h>
 #include <linux/err.h>
 #include <linux/hwmon.h>
 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>

 #define LTC2991_STATUS_LOW		0x00
 #define LTC2991_CH_EN_TRIGGER		0x01
 #define LTC2991_V1_V4_CTRL		0x06
 #define LTC2991_V5_V8_CTRL		0x07
 #define LTC2991_PWM_TH_LSB_T_INT	0x08
 #define LTC2991_PWM_TH_MSB		0x09
 #define LTC2991_CHANNEL_V_MSB(x)	(0x0A + ((x) * 2))
 #define LTC2991_CHANNEL_T_MSB(x)	(0x0A + ((x) * 4))
 #define LTC2991_CHANNEL_C_MSB(x)	(0x0C + ((x) * 4))
 #define LTC2991_T_INT_MSB		0x1A
 #define LTC2991_VCC_MSB			0x1C

 #define LTC2991_V7_V8_EN		BIT(7)
 #define LTC2991_V5_V6_EN		BIT(6)
 #define LTC2991_V3_V4_EN		BIT(5)
 #define LTC2991_V1_V2_EN		BIT(4)
 #define LTC2991_T_INT_VCC_EN		BIT(3)

 #define LTC2991_V3_V4_FILT_EN		BIT(7)
 #define LTC2991_V3_V4_TEMP_EN		BIT(5)
 #define LTC2991_V3_V4_DIFF_EN		BIT(4)
 #define LTC2991_V1_V2_FILT_EN		BIT(3)
 #define LTC2991_V1_V2_TEMP_EN		BIT(1)
 #define LTC2991_V1_V2_DIFF_EN		BIT(0)

 #define LTC2991_V7_V8_FILT_EN		BIT(7)
 #define LTC2991_V7_V8_TEMP_EN		BIT(5)
 #define LTC2991_V7_V8_DIFF_EN		BIT(4)
 #define LTC2991_V5_V6_FILT_EN		BIT(7)
 #define LTC2991_V5_V6_TEMP_EN		BIT(5)
 #define LTC2991_V5_V6_DIFF_EN		BIT(4)

 #define LTC2991_REPEAT_ACQ_EN		BIT(4)
 #define LTC2991_T_INT_FILT_EN		BIT(3)

 #define LTC2991_MAX_CHANNEL		4
 #define LTC2991_T_INT_CH_NR		4
 #define LTC2991_VCC_CH_NR		0

 struct ltc2991_state {
 	struct regmap		*regmap;
 	u32			r_sense_uohm[LTC2991_MAX_CHANNEL];
 	bool			temp_en[LTC2991_MAX_CHANNEL];
 };

 static int ltc2991_read_reg(struct ltc2991_state *st, u8 addr, u8 reg_len,
 			    int *val)
 {
 	__be16 regvals;
 	int ret;

 	if (reg_len < 2)
 		return regmap_read(st->regmap, addr, val);

 	ret = regmap_bulk_read(st->regmap, addr, &regvals, reg_len);
 	if (ret)
 		return ret;

 	*val = be16_to_cpu(regvals);

 	return 0;
 }

 static int ltc2991_get_voltage(struct ltc2991_state *st, u32 reg, long *val)
 {
 	int reg_val, ret, offset = 0;

 	ret = ltc2991_read_reg(st, reg, 2, &reg_val);
 	if (ret)
 		return ret;

 	if (reg == LTC2991_VCC_MSB)
 		/* Vcc 2.5V offset */
 		offset = 2500;

 	/* Vx, 305.18uV/LSB */
 	*val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) * 30518,
 				 1000 * 100) + offset;

 	return 0;
 }

 static int ltc2991_read_in(struct device *dev, u32 attr, int channel, long *val)
 {
 	struct ltc2991_state *st = dev_get_drvdata(dev);
 	u32 reg;

 	switch (attr) {
 	case hwmon_in_input:
 		if (channel == LTC2991_VCC_CH_NR)
 			reg = LTC2991_VCC_MSB;
 		else
 			reg = LTC2991_CHANNEL_V_MSB(channel - 1);

 		return ltc2991_get_voltage(st, reg, val);
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static int ltc2991_get_curr(struct ltc2991_state *st, u32 reg, int channel,
 			    long *val)
 {
 	int reg_val, ret;

 	ret = ltc2991_read_reg(st, reg, 2, &reg_val);
 	if (ret)
 		return ret;

 	/* Vx-Vy, 19.075uV/LSB */
 	*val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) * 19075,
 				 st->r_sense_uohm[channel]);

 	return 0;
 }

 static int ltc2991_read_curr(struct device *dev, u32 attr, int channel,
 			     long *val)
 {
 	struct ltc2991_state *st = dev_get_drvdata(dev);
 	u32 reg;

 	switch (attr) {
 	case hwmon_curr_input:
 		reg = LTC2991_CHANNEL_C_MSB(channel);
 		return ltc2991_get_curr(st, reg, channel, val);
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static int ltc2991_get_temp(struct ltc2991_state *st, u32 reg, int channel,
 			    long *val)
 {
 	int reg_val, ret;

 	ret = ltc2991_read_reg(st, reg, 2, &reg_val);
 	if (ret)
 		return ret;

 	/* Temp LSB = 0.0625 Degrees */
 	*val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 12) * 1000, 16);

 	return 0;
 }

 static int ltc2991_read_temp(struct device *dev, u32 attr, int channel,
 			     long *val)
 {
 	struct ltc2991_state *st = dev_get_drvdata(dev);
 	u32 reg;

 	switch (attr) {
 	case hwmon_temp_input:
 		if (channel == LTC2991_T_INT_CH_NR)
 			reg = LTC2991_T_INT_MSB;
 		else
 			reg = LTC2991_CHANNEL_T_MSB(channel);

 		return ltc2991_get_temp(st, reg, channel, val);
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static int ltc2991_read(struct device *dev, enum hwmon_sensor_types type,
 			u32 attr, int channel, long *val)
 {
 	switch (type) {
 	case hwmon_in:
 		return ltc2991_read_in(dev, attr, channel, val);
 	case hwmon_curr:
 		return ltc2991_read_curr(dev, attr, channel, val);
 	case hwmon_temp:
 		return ltc2991_read_temp(dev, attr, channel, val);
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static umode_t ltc2991_is_visible(const void *data,
 				  enum hwmon_sensor_types type, u32 attr,
 				  int channel)
 {
 	const struct ltc2991_state *st = data;

 	switch (type) {
 	case hwmon_in:
 		switch (attr) {
 		case hwmon_in_input:
 			if (channel == LTC2991_VCC_CH_NR)
 				return 0444;
 			if (st->temp_en[(channel - 1) / 2])
 				break;
 			if (channel % 2)
 				return 0444;
 			if (!st->r_sense_uohm[(channel - 1) / 2])
 				return 0444;
 		}
 		break;
 	case hwmon_curr:
 		switch (attr) {
 		case hwmon_curr_input:
 			if (st->r_sense_uohm[channel])
 				return 0444;
 			break;
 		}
 		break;
 	case hwmon_temp:
 		switch (attr) {
 		case hwmon_temp_input:
 			if (st->temp_en[channel] ||
 			    channel == LTC2991_T_INT_CH_NR)
 				return 0444;
 			break;
 		}
 		break;
 	default:
 		break;
 	}

 	return 0;
 }

 static const struct hwmon_ops ltc2991_hwmon_ops = {
 	.is_visible = ltc2991_is_visible,
 	.read = ltc2991_read,
 };

 static const struct hwmon_channel_info *ltc2991_info[] = {
 	HWMON_CHANNEL_INFO(temp,
 			   HWMON_T_INPUT,
 			   HWMON_T_INPUT,
 			   HWMON_T_INPUT,
 			   HWMON_T_INPUT,
 			   HWMON_T_INPUT
 			   ),
 	HWMON_CHANNEL_INFO(curr,
 			   HWMON_C_INPUT,
 			   HWMON_C_INPUT,
 			   HWMON_C_INPUT,
 			   HWMON_C_INPUT
 			   ),
 	HWMON_CHANNEL_INFO(in,
 			   HWMON_I_INPUT,
 			   HWMON_I_INPUT,
 			   HWMON_I_INPUT,
 			   HWMON_I_INPUT,
 			   HWMON_I_INPUT,
 			   HWMON_I_INPUT,
 			   HWMON_I_INPUT,
 			   HWMON_I_INPUT,
 			   HWMON_I_INPUT
 			   ),
 	NULL
 };

 static const struct hwmon_chip_info ltc2991_chip_info = {
 	.ops = &ltc2991_hwmon_ops,
 	.info = ltc2991_info,
 };

 static const struct regmap_config ltc2991_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.max_register = 0x1D,
 };

 static int ltc2991_init(struct ltc2991_state *st, struct device *dev)
 {
 	struct fwnode_handle *child;
 	int ret;
 	u32 val, addr;
 	u8 v5_v8_reg_data = 0, v1_v4_reg_data = 0;

 	ret = devm_regulator_get_enable(dev, "vcc");
 	if (ret)
 		return dev_err_probe(dev, ret,
 				     "failed to enable regulator\n");

 	device_for_each_child_node(dev, child) {
 		ret = fwnode_property_read_u32(child, "reg", &addr);
 		if (ret < 0) {
 			fwnode_handle_put(child);
 			return ret;
 		}

 		if (addr > 3) {
 			fwnode_handle_put(child);
 			return -EINVAL;
 		}

 		ret = fwnode_property_read_u32(child,
 					       "shunt-resistor-micro-ohms",
 					       &val);
 		if (!ret) {
 			if (!val)
 				return dev_err_probe(dev, -EINVAL,
 						     "shunt resistor value cannot be zero\n");

 			st->r_sense_uohm[addr] = val;

 			switch (addr) {
 			case 0:
 				v1_v4_reg_data |= LTC2991_V1_V2_DIFF_EN;
 				break;
 			case 1:
 				v1_v4_reg_data |= LTC2991_V3_V4_DIFF_EN;
 				break;
 			case 2:
 				v5_v8_reg_data |= LTC2991_V5_V6_DIFF_EN;
 				break;
 			case 3:
 				v5_v8_reg_data |= LTC2991_V7_V8_DIFF_EN;
 				break;
 			default:
 				break;
 			}
 		}

 		ret = fwnode_property_read_bool(child,
 						"adi,temperature-enable");
 		if (ret) {
 			st->temp_en[addr] = ret;

 			switch (addr) {
 			case 0:
 				v1_v4_reg_data |= LTC2991_V1_V2_TEMP_EN;
 				break;
 			case 1:
 				v1_v4_reg_data |= LTC2991_V3_V4_TEMP_EN;
 				break;
 			case 2:
 				v5_v8_reg_data |= LTC2991_V5_V6_TEMP_EN;
 				break;
 			case 3:
 				v5_v8_reg_data |= LTC2991_V7_V8_TEMP_EN;
 				break;
 			default:
 				break;
 			}
 		}
 	}

 	ret = regmap_write(st->regmap, LTC2991_V5_V8_CTRL, v5_v8_reg_data);
 	if (ret)
 		return dev_err_probe(dev, ret,
 				     "Error: Failed to set V5-V8 CTRL reg.\n");

 	ret = regmap_write(st->regmap, LTC2991_V1_V4_CTRL, v1_v4_reg_data);
 	if (ret)
 		return dev_err_probe(dev, ret,
 				     "Error: Failed to set V1-V4 CTRL reg.\n");

 	ret = regmap_write(st->regmap, LTC2991_PWM_TH_LSB_T_INT,
 			   LTC2991_REPEAT_ACQ_EN);
 	if (ret)
 		return dev_err_probe(dev, ret,
 				     "Error: Failed to set continuous mode.\n");

 	/* Enable all channels and trigger conversions */
 	return regmap_write(st->regmap, LTC2991_CH_EN_TRIGGER,
 			    LTC2991_V7_V8_EN | LTC2991_V5_V6_EN |
 			    LTC2991_V3_V4_EN | LTC2991_V1_V2_EN |
 			    LTC2991_T_INT_VCC_EN);
 }

 static int ltc2991_i2c_probe(struct i2c_client *client)
 {
 	int ret;
 	struct device *hwmon_dev;
 	struct ltc2991_state *st;

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

 	st->regmap = devm_regmap_init_i2c(client, &ltc2991_regmap_config);
 	if (IS_ERR(st->regmap))
 		return PTR_ERR(st->regmap);

 	ret = ltc2991_init(st, &client->dev);
 	if (ret)
 		return ret;

 	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
 							 client->name, st,
 							 &ltc2991_chip_info,
 							 NULL);

 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }

 static const struct of_device_id ltc2991_of_match[] = {
 	{ .compatible = "adi,ltc2991" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, ltc2991_of_match);

 static const struct i2c_device_id ltc2991_i2c_id[] = {
 	{ "ltc2991", 0 },
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, ltc2991_i2c_id);

 static struct i2c_driver ltc2991_i2c_driver = {
 	.driver = {
 		.name = "ltc2991",
 		.of_match_table = ltc2991_of_match,
 	},
 	.probe = ltc2991_i2c_probe,
 	.id_table = ltc2991_i2c_id,
 };

 module_i2c_driver(ltc2991_i2c_driver);

 MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
 MODULE_DESCRIPTION("Analog Devices LTC2991 HWMON Driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) 2023 Analog Devices, Inc.
	* Author: Antoniu Miclaus <antoniu.miclaus@analog.com>
	*/

	#include <linux/bitops.h>
	#include <linux/err.h>
	#include <linux/hwmon.h>
	#include <linux/i2c.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/property.h>
	#include <linux/regmap.h>
	#include <linux/regulator/consumer.h>

	#define LTC2991_STATUS_LOW 0x00
	#define LTC2991_CH_EN_TRIGGER 0x01
	#define LTC2991_V1_V4_CTRL 0x06
	#define LTC2991_V5_V8_CTRL 0x07
	#define LTC2991_PWM_TH_LSB_T_INT 0x08
	#define LTC2991_PWM_TH_MSB 0x09
	#define LTC2991_CHANNEL_V_MSB(x) (0x0A + ((x) * 2))
	#define LTC2991_CHANNEL_T_MSB(x) (0x0A + ((x) * 4))
	#define LTC2991_CHANNEL_C_MSB(x) (0x0C + ((x) * 4))
	#define LTC2991_T_INT_MSB 0x1A
	#define LTC2991_VCC_MSB 0x1C

	#define LTC2991_V7_V8_EN BIT(7)
	#define LTC2991_V5_V6_EN BIT(6)
	#define LTC2991_V3_V4_EN BIT(5)
	#define LTC2991_V1_V2_EN BIT(4)
	#define LTC2991_T_INT_VCC_EN BIT(3)

	#define LTC2991_V3_V4_FILT_EN BIT(7)
	#define LTC2991_V3_V4_TEMP_EN BIT(5)
	#define LTC2991_V3_V4_DIFF_EN BIT(4)
	#define LTC2991_V1_V2_FILT_EN BIT(3)
	#define LTC2991_V1_V2_TEMP_EN BIT(1)
	#define LTC2991_V1_V2_DIFF_EN BIT(0)

	#define LTC2991_V7_V8_FILT_EN BIT(7)
	#define LTC2991_V7_V8_TEMP_EN BIT(5)
	#define LTC2991_V7_V8_DIFF_EN BIT(4)
	#define LTC2991_V5_V6_FILT_EN BIT(7)
	#define LTC2991_V5_V6_TEMP_EN BIT(5)
	#define LTC2991_V5_V6_DIFF_EN BIT(4)

	#define LTC2991_REPEAT_ACQ_EN BIT(4)
	#define LTC2991_T_INT_FILT_EN BIT(3)

	#define LTC2991_MAX_CHANNEL 4
	#define LTC2991_T_INT_CH_NR 4
	#define LTC2991_VCC_CH_NR 0

	struct ltc2991_state {
	struct regmap *regmap;
	u32 r_sense_uohm[LTC2991_MAX_CHANNEL];
	bool temp_en[LTC2991_MAX_CHANNEL];
	};

	static int ltc2991_read_reg(struct ltc2991_state *st, u8 addr, u8 reg_len,
	int *val)
	{
	__be16 regvals;
	int ret;

	if (reg_len < 2)
	return regmap_read(st->regmap, addr, val);

	ret = regmap_bulk_read(st->regmap, addr, &regvals, reg_len);
	if (ret)
	return ret;

	*val = be16_to_cpu(regvals);

	return 0;
	}

	static int ltc2991_get_voltage(struct ltc2991_state st, u32 reg, long val)
	{
	int reg_val, ret, offset = 0;

	ret = ltc2991_read_reg(st, reg, 2, &reg_val);
	if (ret)
	return ret;

	if (reg == LTC2991_VCC_MSB)
	/* Vcc 2.5V offset */
	offset = 2500;

	/* Vx, 305.18uV/LSB */
	val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) 30518,
	1000 * 100) + offset;

	return 0;
	}

	static int ltc2991_read_in(struct device dev, u32 attr, int channel, long val)
	{
	struct ltc2991_state *st = dev_get_drvdata(dev);
	u32 reg;

	switch (attr) {
	case hwmon_in_input:
	if (channel == LTC2991_VCC_CH_NR)
	reg = LTC2991_VCC_MSB;
	else
	reg = LTC2991_CHANNEL_V_MSB(channel - 1);

	return ltc2991_get_voltage(st, reg, val);
	default:
	return -EOPNOTSUPP;
	}
	}

	static int ltc2991_get_curr(struct ltc2991_state *st, u32 reg, int channel,
	long *val)
	{
	int reg_val, ret;

	ret = ltc2991_read_reg(st, reg, 2, &reg_val);
	if (ret)
	return ret;

	/* Vx-Vy, 19.075uV/LSB */
	val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) 19075,
	st->r_sense_uohm[channel]);

	return 0;
	}

	static int ltc2991_read_curr(struct device *dev, u32 attr, int channel,
	long *val)
	{
	struct ltc2991_state *st = dev_get_drvdata(dev);
	u32 reg;

	switch (attr) {
	case hwmon_curr_input:
	reg = LTC2991_CHANNEL_C_MSB(channel);
	return ltc2991_get_curr(st, reg, channel, val);
	default:
	return -EOPNOTSUPP;
	}
	}

	static int ltc2991_get_temp(struct ltc2991_state *st, u32 reg, int channel,
	long *val)
	{
	int reg_val, ret;

	ret = ltc2991_read_reg(st, reg, 2, &reg_val);
	if (ret)
	return ret;

	/* Temp LSB = 0.0625 Degrees */
	val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 12) 1000, 16);

	return 0;
	}

	static int ltc2991_read_temp(struct device *dev, u32 attr, int channel,
	long *val)
	{
	struct ltc2991_state *st = dev_get_drvdata(dev);
	u32 reg;

	switch (attr) {
	case hwmon_temp_input:
	if (channel == LTC2991_T_INT_CH_NR)
	reg = LTC2991_T_INT_MSB;
	else
	reg = LTC2991_CHANNEL_T_MSB(channel);

	return ltc2991_get_temp(st, reg, channel, val);
	default:
	return -EOPNOTSUPP;
	}
	}

	static int ltc2991_read(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long *val)
	{
	switch (type) {
	case hwmon_in:
	return ltc2991_read_in(dev, attr, channel, val);
	case hwmon_curr:
	return ltc2991_read_curr(dev, attr, channel, val);
	case hwmon_temp:
	return ltc2991_read_temp(dev, attr, channel, val);
	default:
	return -EOPNOTSUPP;
	}
	}

	static umode_t ltc2991_is_visible(const void *data,
	enum hwmon_sensor_types type, u32 attr,
	int channel)
	{
	const struct ltc2991_state *st = data;

	switch (type) {
	case hwmon_in:
	switch (attr) {
	case hwmon_in_input:
	if (channel == LTC2991_VCC_CH_NR)
	return 0444;
	if (st->temp_en[(channel - 1) / 2])
	break;
	if (channel % 2)
	return 0444;
	if (!st->r_sense_uohm[(channel - 1) / 2])
	return 0444;
	}
	break;
	case hwmon_curr:
	switch (attr) {
	case hwmon_curr_input:
	if (st->r_sense_uohm[channel])
	return 0444;
	break;
	}
	break;
	case hwmon_temp:
	switch (attr) {
	case hwmon_temp_input:
	if (st->temp_en[channel] \|\|
	channel == LTC2991_T_INT_CH_NR)
	return 0444;
	break;
	}
	break;
	default:
	break;
	}

	return 0;
	}

	static const struct hwmon_ops ltc2991_hwmon_ops = {
	.is_visible = ltc2991_is_visible,
	.read = ltc2991_read,
	};

	static const struct hwmon_channel_info *ltc2991_info[] = {
	HWMON_CHANNEL_INFO(temp,
	HWMON_T_INPUT,
	HWMON_T_INPUT,
	HWMON_T_INPUT,
	HWMON_T_INPUT,
	HWMON_T_INPUT
	),
	HWMON_CHANNEL_INFO(curr,
	HWMON_C_INPUT,
	HWMON_C_INPUT,
	HWMON_C_INPUT,
	HWMON_C_INPUT
	),
	HWMON_CHANNEL_INFO(in,
	HWMON_I_INPUT,
	HWMON_I_INPUT,
	HWMON_I_INPUT,
	HWMON_I_INPUT,
	HWMON_I_INPUT,
	HWMON_I_INPUT,
	HWMON_I_INPUT,
	HWMON_I_INPUT,
	HWMON_I_INPUT
	),
	NULL
	};

	static const struct hwmon_chip_info ltc2991_chip_info = {
	.ops = &ltc2991_hwmon_ops,
	.info = ltc2991_info,
	};

	static const struct regmap_config ltc2991_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = 0x1D,
	};

	static int ltc2991_init(struct ltc2991_state st, struct device dev)
	{
	struct fwnode_handle *child;
	int ret;
	u32 val, addr;
	u8 v5_v8_reg_data = 0, v1_v4_reg_data = 0;

	ret = devm_regulator_get_enable(dev, "vcc");
	if (ret)
	return dev_err_probe(dev, ret,
	"failed to enable regulator\n");

	device_for_each_child_node(dev, child) {
	ret = fwnode_property_read_u32(child, "reg", &addr);
	if (ret < 0) {
	fwnode_handle_put(child);
	return ret;
	}

	if (addr > 3) {
	fwnode_handle_put(child);
	return -EINVAL;
	}

	ret = fwnode_property_read_u32(child,
	"shunt-resistor-micro-ohms",
	&val);
	if (!ret) {
	if (!val)
	return dev_err_probe(dev, -EINVAL,
	"shunt resistor value cannot be zero\n");

	st->r_sense_uohm[addr] = val;

	switch (addr) {
	case 0:
	v1_v4_reg_data \|= LTC2991_V1_V2_DIFF_EN;
	break;
	case 1:
	v1_v4_reg_data \|= LTC2991_V3_V4_DIFF_EN;
	break;
	case 2:
	v5_v8_reg_data \|= LTC2991_V5_V6_DIFF_EN;
	break;
	case 3:
	v5_v8_reg_data \|= LTC2991_V7_V8_DIFF_EN;
	break;
	default:
	break;
	}
	}

	ret = fwnode_property_read_bool(child,
	"adi,temperature-enable");
	if (ret) {
	st->temp_en[addr] = ret;

	switch (addr) {
	case 0:
	v1_v4_reg_data \|= LTC2991_V1_V2_TEMP_EN;
	break;
	case 1:
	v1_v4_reg_data \|= LTC2991_V3_V4_TEMP_EN;
	break;
	case 2:
	v5_v8_reg_data \|= LTC2991_V5_V6_TEMP_EN;
	break;
	case 3:
	v5_v8_reg_data \|= LTC2991_V7_V8_TEMP_EN;
	break;
	default:
	break;
	}
	}
	}

	ret = regmap_write(st->regmap, LTC2991_V5_V8_CTRL, v5_v8_reg_data);
	if (ret)
	return dev_err_probe(dev, ret,
	"Error: Failed to set V5-V8 CTRL reg.\n");

	ret = regmap_write(st->regmap, LTC2991_V1_V4_CTRL, v1_v4_reg_data);
	if (ret)
	return dev_err_probe(dev, ret,
	"Error: Failed to set V1-V4 CTRL reg.\n");

	ret = regmap_write(st->regmap, LTC2991_PWM_TH_LSB_T_INT,
	LTC2991_REPEAT_ACQ_EN);
	if (ret)
	return dev_err_probe(dev, ret,
	"Error: Failed to set continuous mode.\n");

	/* Enable all channels and trigger conversions */
	return regmap_write(st->regmap, LTC2991_CH_EN_TRIGGER,
	LTC2991_V7_V8_EN \| LTC2991_V5_V6_EN \|
	LTC2991_V3_V4_EN \| LTC2991_V1_V2_EN \|
	LTC2991_T_INT_VCC_EN);
	}

	static int ltc2991_i2c_probe(struct i2c_client *client)
	{
	int ret;
	struct device *hwmon_dev;
	struct ltc2991_state *st;

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

	st->regmap = devm_regmap_init_i2c(client, &ltc2991_regmap_config);
	if (IS_ERR(st->regmap))
	return PTR_ERR(st->regmap);

	ret = ltc2991_init(st, &client->dev);
	if (ret)
	return ret;

	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
	client->name, st,
	&ltc2991_chip_info,
	NULL);

	return PTR_ERR_OR_ZERO(hwmon_dev);
	}

	static const struct of_device_id ltc2991_of_match[] = {
	{ .compatible = "adi,ltc2991" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, ltc2991_of_match);

	static const struct i2c_device_id ltc2991_i2c_id[] = {
	{ "ltc2991", 0 },
	{}
	};
	MODULE_DEVICE_TABLE(i2c, ltc2991_i2c_id);

	static struct i2c_driver ltc2991_i2c_driver = {
	.driver = {
	.name = "ltc2991",
	.of_match_table = ltc2991_of_match,
	},
	.probe = ltc2991_i2c_probe,
	.id_table = ltc2991_i2c_id,
	};

	module_i2c_driver(ltc2991_i2c_driver);

	MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
	MODULE_DESCRIPTION("Analog Devices LTC2991 HWMON Driver");
	MODULE_LICENSE("GPL");