drivers/hwmon/adc128d818.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Driver for TI ADC128D818 System Monitor with Temperature Sensor
  *
  * Copyright (c) 2014 Guenter Roeck
  *
  * Derived from lm80.c
  * Copyright (C) 1998, 1999  Frodo Looijaard <frodol@dds.nl>
  *			     and Philip Edelbrock <phil@netroedge.com>
  */

 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/jiffies.h>
 #include <linux/i2c.h>
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/regulator/consumer.h>
 #include <linux/mutex.h>
 #include <linux/bitops.h>
 #include <linux/of.h>

 /* Addresses to scan
  * The chip also supports addresses 0x35..0x37. Don't scan those addresses
  * since they are also used by some EEPROMs, which may result in false
  * positives.
  */
 static const unsigned short normal_i2c[] = {
 	0x1d, 0x1e, 0x1f, 0x2d, 0x2e, 0x2f, I2C_CLIENT_END };

 /* registers */
 #define ADC128_REG_IN_MAX(nr)		(0x2a + (nr) * 2)
 #define ADC128_REG_IN_MIN(nr)		(0x2b + (nr) * 2)
 #define ADC128_REG_IN(nr)		(0x20 + (nr))

 #define ADC128_REG_TEMP			0x27
 #define ADC128_REG_TEMP_MAX		0x38
 #define ADC128_REG_TEMP_HYST		0x39

 #define ADC128_REG_CONFIG		0x00
 #define ADC128_REG_ALARM		0x01
 #define ADC128_REG_MASK			0x03
 #define ADC128_REG_CONV_RATE		0x07
 #define ADC128_REG_ONESHOT		0x09
 #define ADC128_REG_SHUTDOWN		0x0a
 #define ADC128_REG_CONFIG_ADV		0x0b
 #define ADC128_REG_BUSY_STATUS		0x0c

 #define ADC128_REG_MAN_ID		0x3e
 #define ADC128_REG_DEV_ID		0x3f

 /* No. of voltage entries in adc128_attrs */
 #define ADC128_ATTR_NUM_VOLT		(8 * 4)

 /* Voltage inputs visible per operation mode */
 static const u8 num_inputs[] = { 7, 8, 4, 6 };

 struct adc128_data {
 	struct i2c_client *client;
 	int vref;		/* Reference voltage in mV */
 	struct mutex update_lock;
 	u8 mode;		/* Operation mode */
 	bool valid;		/* true if following fields are valid */
 	unsigned long last_updated;	/* In jiffies */

 	u16 in[3][8];		/* Register value, normalized to 12 bit
 				 * 0: input voltage
 				 * 1: min limit
 				 * 2: max limit
 				 */
 	s16 temp[3];		/* Register value, normalized to 9 bit
 				 * 0: sensor 1: limit 2: hyst
 				 */
 	u8 alarms;		/* alarm register value */
 };

 static struct adc128_data *adc128_update_device(struct device *dev)
 {
 	struct adc128_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;
 	struct adc128_data *ret = data;
 	int i, rv;

 	mutex_lock(&data->update_lock);

 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
 		for (i = 0; i < num_inputs[data->mode]; i++) {
 			rv = i2c_smbus_read_word_swapped(client,
 							 ADC128_REG_IN(i));
 			if (rv < 0)
 				goto abort;
 			data->in[0][i] = rv >> 4;

 			rv = i2c_smbus_read_byte_data(client,
 						      ADC128_REG_IN_MIN(i));
 			if (rv < 0)
 				goto abort;
 			data->in[1][i] = rv << 4;

 			rv = i2c_smbus_read_byte_data(client,
 						      ADC128_REG_IN_MAX(i));
 			if (rv < 0)
 				goto abort;
 			data->in[2][i] = rv << 4;
 		}

 		if (data->mode != 1) {
 			rv = i2c_smbus_read_word_swapped(client,
 							 ADC128_REG_TEMP);
 			if (rv < 0)
 				goto abort;
 			data->temp[0] = rv >> 7;

 			rv = i2c_smbus_read_byte_data(client,
 						      ADC128_REG_TEMP_MAX);
 			if (rv < 0)
 				goto abort;
 			data->temp[1] = rv << 1;

 			rv = i2c_smbus_read_byte_data(client,
 						      ADC128_REG_TEMP_HYST);
 			if (rv < 0)
 				goto abort;
 			data->temp[2] = rv << 1;
 		}

 		rv = i2c_smbus_read_byte_data(client, ADC128_REG_ALARM);
 		if (rv < 0)
 			goto abort;
 		data->alarms |= rv;

 		data->last_updated = jiffies;
 		data->valid = true;
 	}
 	goto done;

 abort:
 	ret = ERR_PTR(rv);
 	data->valid = false;
 done:
 	mutex_unlock(&data->update_lock);
 	return ret;
 }

 static ssize_t adc128_in_show(struct device *dev,
 			      struct device_attribute *attr, char *buf)
 {
 	struct adc128_data *data = adc128_update_device(dev);
 	int index = to_sensor_dev_attr_2(attr)->index;
 	int nr = to_sensor_dev_attr_2(attr)->nr;
 	int val;

 	if (IS_ERR(data))
 		return PTR_ERR(data);

 	val = DIV_ROUND_CLOSEST(data->in[index][nr] * data->vref, 4095);
 	return sprintf(buf, "%d\n", val);
 }

 static ssize_t adc128_in_store(struct device *dev,
 			       struct device_attribute *attr, const char *buf,
 			       size_t count)
 {
 	struct adc128_data *data = dev_get_drvdata(dev);
 	int index = to_sensor_dev_attr_2(attr)->index;
 	int nr = to_sensor_dev_attr_2(attr)->nr;
 	u8 reg, regval;
 	long val;
 	int err;

 	err = kstrtol(buf, 10, &val);
 	if (err < 0)
 		return err;

 	mutex_lock(&data->update_lock);
 	/* 10 mV LSB on limit registers */
 	regval = clamp_val(DIV_ROUND_CLOSEST(val, 10), 0, 255);
 	data->in[index][nr] = regval << 4;
 	reg = index == 1 ? ADC128_REG_IN_MIN(nr) : ADC128_REG_IN_MAX(nr);
 	i2c_smbus_write_byte_data(data->client, reg, regval);
 	mutex_unlock(&data->update_lock);

 	return count;
 }

 static ssize_t adc128_temp_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	struct adc128_data *data = adc128_update_device(dev);
 	int index = to_sensor_dev_attr(attr)->index;
 	int temp;

 	if (IS_ERR(data))
 		return PTR_ERR(data);

 	temp = sign_extend32(data->temp[index], 8);
 	return sprintf(buf, "%d\n", temp * 500);/* 0.5 degrees C resolution */
 }

 static ssize_t adc128_temp_store(struct device *dev,
 				 struct device_attribute *attr,
 				 const char *buf, size_t count)
 {
 	struct adc128_data *data = dev_get_drvdata(dev);
 	int index = to_sensor_dev_attr(attr)->index;
 	long val;
 	int err;
 	s8 regval;

 	err = kstrtol(buf, 10, &val);
 	if (err < 0)
 		return err;

 	mutex_lock(&data->update_lock);
 	regval = clamp_val(DIV_ROUND_CLOSEST(val, 1000), -128, 127);
 	data->temp[index] = regval << 1;
 	i2c_smbus_write_byte_data(data->client,
 				  index == 1 ? ADC128_REG_TEMP_MAX
 					     : ADC128_REG_TEMP_HYST,
 				  regval);
 	mutex_unlock(&data->update_lock);

 	return count;
 }

 static ssize_t adc128_alarm_show(struct device *dev,
 				 struct device_attribute *attr, char *buf)
 {
 	struct adc128_data *data = adc128_update_device(dev);
 	int mask = 1 << to_sensor_dev_attr(attr)->index;
 	u8 alarms;

 	if (IS_ERR(data))
 		return PTR_ERR(data);

 	/*
 	 * Clear an alarm after reporting it to user space. If it is still
 	 * active, the next update sequence will set the alarm bit again.
 	 */
 	alarms = data->alarms;
 	data->alarms &= ~mask;

 	return sprintf(buf, "%u\n", !!(alarms & mask));
 }

 static umode_t adc128_is_visible(struct kobject *kobj,
 				 struct attribute *attr, int index)
 {
 	struct device *dev = kobj_to_dev(kobj);
 	struct adc128_data *data = dev_get_drvdata(dev);

 	if (index < ADC128_ATTR_NUM_VOLT) {
 		/* Voltage, visible according to num_inputs[] */
 		if (index >= num_inputs[data->mode] * 4)
 			return 0;
 	} else {
 		/* Temperature, visible if not in mode 1 */
 		if (data->mode == 1)
 			return 0;
 	}

 	return attr->mode;
 }

 static SENSOR_DEVICE_ATTR_2_RO(in0_input, adc128_in, 0, 0);
 static SENSOR_DEVICE_ATTR_2_RW(in0_min, adc128_in, 0, 1);
 static SENSOR_DEVICE_ATTR_2_RW(in0_max, adc128_in, 0, 2);

 static SENSOR_DEVICE_ATTR_2_RO(in1_input, adc128_in, 1, 0);
 static SENSOR_DEVICE_ATTR_2_RW(in1_min, adc128_in, 1, 1);
 static SENSOR_DEVICE_ATTR_2_RW(in1_max, adc128_in, 1, 2);

 static SENSOR_DEVICE_ATTR_2_RO(in2_input, adc128_in, 2, 0);
 static SENSOR_DEVICE_ATTR_2_RW(in2_min, adc128_in, 2, 1);
 static SENSOR_DEVICE_ATTR_2_RW(in2_max, adc128_in, 2, 2);

 static SENSOR_DEVICE_ATTR_2_RO(in3_input, adc128_in, 3, 0);
 static SENSOR_DEVICE_ATTR_2_RW(in3_min, adc128_in, 3, 1);
 static SENSOR_DEVICE_ATTR_2_RW(in3_max, adc128_in, 3, 2);

 static SENSOR_DEVICE_ATTR_2_RO(in4_input, adc128_in, 4, 0);
 static SENSOR_DEVICE_ATTR_2_RW(in4_min, adc128_in, 4, 1);
 static SENSOR_DEVICE_ATTR_2_RW(in4_max, adc128_in, 4, 2);

 static SENSOR_DEVICE_ATTR_2_RO(in5_input, adc128_in, 5, 0);
 static SENSOR_DEVICE_ATTR_2_RW(in5_min, adc128_in, 5, 1);
 static SENSOR_DEVICE_ATTR_2_RW(in5_max, adc128_in, 5, 2);

 static SENSOR_DEVICE_ATTR_2_RO(in6_input, adc128_in, 6, 0);
 static SENSOR_DEVICE_ATTR_2_RW(in6_min, adc128_in, 6, 1);
 static SENSOR_DEVICE_ATTR_2_RW(in6_max, adc128_in, 6, 2);

 static SENSOR_DEVICE_ATTR_2_RO(in7_input, adc128_in, 7, 0);
 static SENSOR_DEVICE_ATTR_2_RW(in7_min, adc128_in, 7, 1);
 static SENSOR_DEVICE_ATTR_2_RW(in7_max, adc128_in, 7, 2);

 static SENSOR_DEVICE_ATTR_RO(temp1_input, adc128_temp, 0);
 static SENSOR_DEVICE_ATTR_RW(temp1_max, adc128_temp, 1);
 static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, adc128_temp, 2);

 static SENSOR_DEVICE_ATTR_RO(in0_alarm, adc128_alarm, 0);
 static SENSOR_DEVICE_ATTR_RO(in1_alarm, adc128_alarm, 1);
 static SENSOR_DEVICE_ATTR_RO(in2_alarm, adc128_alarm, 2);
 static SENSOR_DEVICE_ATTR_RO(in3_alarm, adc128_alarm, 3);
 static SENSOR_DEVICE_ATTR_RO(in4_alarm, adc128_alarm, 4);
 static SENSOR_DEVICE_ATTR_RO(in5_alarm, adc128_alarm, 5);
 static SENSOR_DEVICE_ATTR_RO(in6_alarm, adc128_alarm, 6);
 static SENSOR_DEVICE_ATTR_RO(in7_alarm, adc128_alarm, 7);
 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, adc128_alarm, 7);

 static struct attribute *adc128_attrs[] = {
 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
 	&sensor_dev_attr_in0_input.dev_attr.attr,
 	&sensor_dev_attr_in0_max.dev_attr.attr,
 	&sensor_dev_attr_in0_min.dev_attr.attr,
 	&sensor_dev_attr_in1_alarm.dev_attr.attr,
 	&sensor_dev_attr_in1_input.dev_attr.attr,
 	&sensor_dev_attr_in1_max.dev_attr.attr,
 	&sensor_dev_attr_in1_min.dev_attr.attr,
 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
 	&sensor_dev_attr_in2_input.dev_attr.attr,
 	&sensor_dev_attr_in2_max.dev_attr.attr,
 	&sensor_dev_attr_in2_min.dev_attr.attr,
 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
 	&sensor_dev_attr_in3_input.dev_attr.attr,
 	&sensor_dev_attr_in3_max.dev_attr.attr,
 	&sensor_dev_attr_in3_min.dev_attr.attr,
 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
 	&sensor_dev_attr_in4_input.dev_attr.attr,
 	&sensor_dev_attr_in4_max.dev_attr.attr,
 	&sensor_dev_attr_in4_min.dev_attr.attr,
 	&sensor_dev_attr_in5_alarm.dev_attr.attr,
 	&sensor_dev_attr_in5_input.dev_attr.attr,
 	&sensor_dev_attr_in5_max.dev_attr.attr,
 	&sensor_dev_attr_in5_min.dev_attr.attr,
 	&sensor_dev_attr_in6_alarm.dev_attr.attr,
 	&sensor_dev_attr_in6_input.dev_attr.attr,
 	&sensor_dev_attr_in6_max.dev_attr.attr,
 	&sensor_dev_attr_in6_min.dev_attr.attr,
 	&sensor_dev_attr_in7_alarm.dev_attr.attr,
 	&sensor_dev_attr_in7_input.dev_attr.attr,
 	&sensor_dev_attr_in7_max.dev_attr.attr,
 	&sensor_dev_attr_in7_min.dev_attr.attr,
 	&sensor_dev_attr_temp1_input.dev_attr.attr,
 	&sensor_dev_attr_temp1_max.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
 	NULL
 };

 static const struct attribute_group adc128_group = {
 	.attrs = adc128_attrs,
 	.is_visible = adc128_is_visible,
 };
 __ATTRIBUTE_GROUPS(adc128);

 static int adc128_detect(struct i2c_client *client, struct i2c_board_info *info)
 {
 	int man_id, dev_id;

 	if (!i2c_check_functionality(client->adapter,
 				     I2C_FUNC_SMBUS_BYTE_DATA |
 				     I2C_FUNC_SMBUS_WORD_DATA))
 		return -ENODEV;

 	man_id = i2c_smbus_read_byte_data(client, ADC128_REG_MAN_ID);
 	dev_id = i2c_smbus_read_byte_data(client, ADC128_REG_DEV_ID);
 	if (man_id != 0x01 || dev_id != 0x09)
 		return -ENODEV;

 	/* Check unused bits for confirmation */
 	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG) & 0xf4)
 		return -ENODEV;
 	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONV_RATE) & 0xfe)
 		return -ENODEV;
 	if (i2c_smbus_read_byte_data(client, ADC128_REG_ONESHOT) & 0xfe)
 		return -ENODEV;
 	if (i2c_smbus_read_byte_data(client, ADC128_REG_SHUTDOWN) & 0xfe)
 		return -ENODEV;
 	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG_ADV) & 0xf8)
 		return -ENODEV;
 	if (i2c_smbus_read_byte_data(client, ADC128_REG_BUSY_STATUS) & 0xfc)
 		return -ENODEV;

 	strscpy(info->type, "adc128d818", I2C_NAME_SIZE);

 	return 0;
 }

 static int adc128_init_client(struct adc128_data *data, bool external_vref)
 {
 	struct i2c_client *client = data->client;
 	int err;
 	u8 regval = 0x0;

 	/*
 	 * Reset chip to defaults.
 	 * This makes most other initializations unnecessary.
 	 */
 	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x80);
 	if (err)
 		return err;

 	/* Set operation mode, if non-default */
 	if (data->mode != 0)
 		regval |= data->mode << 1;

 	/* If external vref is selected, configure the chip to use it */
 	if (external_vref)
 		regval |= 0x01;

 	/* Write advanced configuration register */
 	if (regval != 0x0) {
 		err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG_ADV,
 						regval);
 		if (err)
 			return err;
 	}

 	/* Start monitoring */
 	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x01);
 	if (err)
 		return err;

 	return 0;
 }

 static int adc128_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct device *hwmon_dev;
 	struct adc128_data *data;
 	bool external_vref;
 	int err, vref;

 	data = devm_kzalloc(dev, sizeof(struct adc128_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	/* vref is optional. If specified, is used as chip reference voltage */
 	vref = devm_regulator_get_enable_read_voltage(dev, "vref");
 	if (vref == -ENODEV) {
 		external_vref = false;
 		data->vref = 2560;	/* 2.56V, in mV */
 	} else if (vref < 0) {
 		return vref;
 	} else {
 		external_vref = true;
 		data->vref = DIV_ROUND_CLOSEST(vref, 1000);
 	}

 	/* Operation mode is optional. If unspecified, keep current mode */
 	if (of_property_read_u8(dev->of_node, "ti,mode", &data->mode) == 0) {
 		if (data->mode > 3) {
 			dev_err(dev, "invalid operation mode %d\n",
 				data->mode);
 			return -EINVAL;
 		}
 	} else {
 		err = i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG_ADV);
 		if (err < 0)
 			return err;
 		data->mode = (err >> 1) & ADC128_REG_MASK;
 	}

 	data->client = client;
 	i2c_set_clientdata(client, data);
 	mutex_init(&data->update_lock);

 	/* Initialize the chip */
 	err = adc128_init_client(data, external_vref);
 	if (err < 0)
 		return err;

 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
 							   data, adc128_groups);

 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }

 static const struct i2c_device_id adc128_id[] = {
 	{ "adc128d818" },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, adc128_id);

 static const struct of_device_id __maybe_unused adc128_of_match[] = {
 	{ .compatible = "ti,adc128d818" },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, adc128_of_match);

 static struct i2c_driver adc128_driver = {
 	.class		= I2C_CLASS_HWMON,
 	.driver = {
 		.name	= "adc128d818",
 		.of_match_table = of_match_ptr(adc128_of_match),
 	},
 	.probe		= adc128_probe,
 	.id_table	= adc128_id,
 	.detect		= adc128_detect,
 	.address_list	= normal_i2c,
 };

 module_i2c_driver(adc128_driver);

 MODULE_AUTHOR("Guenter Roeck");
 MODULE_DESCRIPTION("Driver for ADC128D818");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Driver for TI ADC128D818 System Monitor with Temperature Sensor
	*
	* Copyright (c) 2014 Guenter Roeck
	*
	* Derived from lm80.c
	* Copyright (C) 1998, 1999 Frodo Looijaard <frodol@dds.nl>
	* and Philip Edelbrock <phil@netroedge.com>
	*/

	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/jiffies.h>
	#include <linux/i2c.h>
	#include <linux/hwmon.h>
	#include <linux/hwmon-sysfs.h>
	#include <linux/err.h>
	#include <linux/regulator/consumer.h>
	#include <linux/mutex.h>
	#include <linux/bitops.h>
	#include <linux/of.h>

	/* Addresses to scan
	* The chip also supports addresses 0x35..0x37. Don't scan those addresses
	* since they are also used by some EEPROMs, which may result in false
	* positives.
	*/
	static const unsigned short normal_i2c[] = {
	0x1d, 0x1e, 0x1f, 0x2d, 0x2e, 0x2f, I2C_CLIENT_END };

	/* registers */
	#define ADC128_REG_IN_MAX(nr) (0x2a + (nr) * 2)
	#define ADC128_REG_IN_MIN(nr) (0x2b + (nr) * 2)
	#define ADC128_REG_IN(nr) (0x20 + (nr))

	#define ADC128_REG_TEMP 0x27
	#define ADC128_REG_TEMP_MAX 0x38
	#define ADC128_REG_TEMP_HYST 0x39

	#define ADC128_REG_CONFIG 0x00
	#define ADC128_REG_ALARM 0x01
	#define ADC128_REG_MASK 0x03
	#define ADC128_REG_CONV_RATE 0x07
	#define ADC128_REG_ONESHOT 0x09
	#define ADC128_REG_SHUTDOWN 0x0a
	#define ADC128_REG_CONFIG_ADV 0x0b
	#define ADC128_REG_BUSY_STATUS 0x0c

	#define ADC128_REG_MAN_ID 0x3e
	#define ADC128_REG_DEV_ID 0x3f

	/* No. of voltage entries in adc128_attrs */
	#define ADC128_ATTR_NUM_VOLT (8 * 4)

	/* Voltage inputs visible per operation mode */
	static const u8 num_inputs[] = { 7, 8, 4, 6 };

	struct adc128_data {
	struct i2c_client *client;
	int vref; /* Reference voltage in mV */
	struct mutex update_lock;
	u8 mode; /* Operation mode */
	bool valid; /* true if following fields are valid */
	unsigned long last_updated; /* In jiffies */

	u16 in[3][8]; /* Register value, normalized to 12 bit
	* 0: input voltage
	* 1: min limit
	* 2: max limit
	*/
	s16 temp[3]; /* Register value, normalized to 9 bit
	* 0: sensor 1: limit 2: hyst
	*/
	u8 alarms; /* alarm register value */
	};

	static struct adc128_data adc128_update_device(struct device dev)
	{
	struct adc128_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	struct adc128_data *ret = data;
	int i, rv;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ) \|\| !data->valid) {
	for (i = 0; i < num_inputs[data->mode]; i++) {
	rv = i2c_smbus_read_word_swapped(client,
	ADC128_REG_IN(i));
	if (rv < 0)
	goto abort;
	data->in[0][i] = rv >> 4;

	rv = i2c_smbus_read_byte_data(client,
	ADC128_REG_IN_MIN(i));
	if (rv < 0)
	goto abort;
	data->in[1][i] = rv << 4;

	rv = i2c_smbus_read_byte_data(client,
	ADC128_REG_IN_MAX(i));
	if (rv < 0)
	goto abort;
	data->in[2][i] = rv << 4;
	}

	if (data->mode != 1) {
	rv = i2c_smbus_read_word_swapped(client,
	ADC128_REG_TEMP);
	if (rv < 0)
	goto abort;
	data->temp[0] = rv >> 7;

	rv = i2c_smbus_read_byte_data(client,
	ADC128_REG_TEMP_MAX);
	if (rv < 0)
	goto abort;
	data->temp[1] = rv << 1;

	rv = i2c_smbus_read_byte_data(client,
	ADC128_REG_TEMP_HYST);
	if (rv < 0)
	goto abort;
	data->temp[2] = rv << 1;
	}

	rv = i2c_smbus_read_byte_data(client, ADC128_REG_ALARM);
	if (rv < 0)
	goto abort;
	data->alarms \|= rv;

	data->last_updated = jiffies;
	data->valid = true;
	}
	goto done;

	abort:
	ret = ERR_PTR(rv);
	data->valid = false;
	done:
	mutex_unlock(&data->update_lock);
	return ret;
	}

	static ssize_t adc128_in_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct adc128_data *data = adc128_update_device(dev);
	int index = to_sensor_dev_attr_2(attr)->index;
	int nr = to_sensor_dev_attr_2(attr)->nr;
	int val;

	if (IS_ERR(data))
	return PTR_ERR(data);

	val = DIV_ROUND_CLOSEST(data->in[index][nr] * data->vref, 4095);
	return sprintf(buf, "%d\n", val);
	}

	static ssize_t adc128_in_store(struct device *dev,
	struct device_attribute attr, const char buf,
	size_t count)
	{
	struct adc128_data *data = dev_get_drvdata(dev);
	int index = to_sensor_dev_attr_2(attr)->index;
	int nr = to_sensor_dev_attr_2(attr)->nr;
	u8 reg, regval;
	long val;
	int err;

	err = kstrtol(buf, 10, &val);
	if (err < 0)
	return err;

	mutex_lock(&data->update_lock);
	/* 10 mV LSB on limit registers */
	regval = clamp_val(DIV_ROUND_CLOSEST(val, 10), 0, 255);
	data->in[index][nr] = regval << 4;
	reg = index == 1 ? ADC128_REG_IN_MIN(nr) : ADC128_REG_IN_MAX(nr);
	i2c_smbus_write_byte_data(data->client, reg, regval);
	mutex_unlock(&data->update_lock);

	return count;
	}

	static ssize_t adc128_temp_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct adc128_data *data = adc128_update_device(dev);
	int index = to_sensor_dev_attr(attr)->index;
	int temp;

	if (IS_ERR(data))
	return PTR_ERR(data);

	temp = sign_extend32(data->temp[index], 8);
	return sprintf(buf, "%d\n", temp * 500);/* 0.5 degrees C resolution */
	}

	static ssize_t adc128_temp_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct adc128_data *data = dev_get_drvdata(dev);
	int index = to_sensor_dev_attr(attr)->index;
	long val;
	int err;
	s8 regval;

	err = kstrtol(buf, 10, &val);
	if (err < 0)
	return err;

	mutex_lock(&data->update_lock);
	regval = clamp_val(DIV_ROUND_CLOSEST(val, 1000), -128, 127);
	data->temp[index] = regval << 1;
	i2c_smbus_write_byte_data(data->client,
	index == 1 ? ADC128_REG_TEMP_MAX
	: ADC128_REG_TEMP_HYST,
	regval);
	mutex_unlock(&data->update_lock);

	return count;
	}

	static ssize_t adc128_alarm_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct adc128_data *data = adc128_update_device(dev);
	int mask = 1 << to_sensor_dev_attr(attr)->index;
	u8 alarms;

	if (IS_ERR(data))
	return PTR_ERR(data);

	/*
	* Clear an alarm after reporting it to user space. If it is still
	* active, the next update sequence will set the alarm bit again.
	*/
	alarms = data->alarms;
	data->alarms &= ~mask;

	return sprintf(buf, "%u\n", !!(alarms & mask));
	}

	static umode_t adc128_is_visible(struct kobject *kobj,
	struct attribute *attr, int index)
	{
	struct device *dev = kobj_to_dev(kobj);
	struct adc128_data *data = dev_get_drvdata(dev);

	if (index < ADC128_ATTR_NUM_VOLT) {
	/* Voltage, visible according to num_inputs[] */
	if (index >= num_inputs[data->mode] * 4)
	return 0;
	} else {
	/* Temperature, visible if not in mode 1 */
	if (data->mode == 1)
	return 0;
	}

	return attr->mode;
	}

	static SENSOR_DEVICE_ATTR_2_RO(in0_input, adc128_in, 0, 0);
	static SENSOR_DEVICE_ATTR_2_RW(in0_min, adc128_in, 0, 1);
	static SENSOR_DEVICE_ATTR_2_RW(in0_max, adc128_in, 0, 2);

	static SENSOR_DEVICE_ATTR_2_RO(in1_input, adc128_in, 1, 0);
	static SENSOR_DEVICE_ATTR_2_RW(in1_min, adc128_in, 1, 1);
	static SENSOR_DEVICE_ATTR_2_RW(in1_max, adc128_in, 1, 2);

	static SENSOR_DEVICE_ATTR_2_RO(in2_input, adc128_in, 2, 0);
	static SENSOR_DEVICE_ATTR_2_RW(in2_min, adc128_in, 2, 1);
	static SENSOR_DEVICE_ATTR_2_RW(in2_max, adc128_in, 2, 2);

	static SENSOR_DEVICE_ATTR_2_RO(in3_input, adc128_in, 3, 0);
	static SENSOR_DEVICE_ATTR_2_RW(in3_min, adc128_in, 3, 1);
	static SENSOR_DEVICE_ATTR_2_RW(in3_max, adc128_in, 3, 2);

	static SENSOR_DEVICE_ATTR_2_RO(in4_input, adc128_in, 4, 0);
	static SENSOR_DEVICE_ATTR_2_RW(in4_min, adc128_in, 4, 1);
	static SENSOR_DEVICE_ATTR_2_RW(in4_max, adc128_in, 4, 2);

	static SENSOR_DEVICE_ATTR_2_RO(in5_input, adc128_in, 5, 0);
	static SENSOR_DEVICE_ATTR_2_RW(in5_min, adc128_in, 5, 1);
	static SENSOR_DEVICE_ATTR_2_RW(in5_max, adc128_in, 5, 2);

	static SENSOR_DEVICE_ATTR_2_RO(in6_input, adc128_in, 6, 0);
	static SENSOR_DEVICE_ATTR_2_RW(in6_min, adc128_in, 6, 1);
	static SENSOR_DEVICE_ATTR_2_RW(in6_max, adc128_in, 6, 2);

	static SENSOR_DEVICE_ATTR_2_RO(in7_input, adc128_in, 7, 0);
	static SENSOR_DEVICE_ATTR_2_RW(in7_min, adc128_in, 7, 1);
	static SENSOR_DEVICE_ATTR_2_RW(in7_max, adc128_in, 7, 2);

	static SENSOR_DEVICE_ATTR_RO(temp1_input, adc128_temp, 0);
	static SENSOR_DEVICE_ATTR_RW(temp1_max, adc128_temp, 1);
	static SENSOR_DEVICE_ATTR_RW(temp1_max_hyst, adc128_temp, 2);

	static SENSOR_DEVICE_ATTR_RO(in0_alarm, adc128_alarm, 0);
	static SENSOR_DEVICE_ATTR_RO(in1_alarm, adc128_alarm, 1);
	static SENSOR_DEVICE_ATTR_RO(in2_alarm, adc128_alarm, 2);
	static SENSOR_DEVICE_ATTR_RO(in3_alarm, adc128_alarm, 3);
	static SENSOR_DEVICE_ATTR_RO(in4_alarm, adc128_alarm, 4);
	static SENSOR_DEVICE_ATTR_RO(in5_alarm, adc128_alarm, 5);
	static SENSOR_DEVICE_ATTR_RO(in6_alarm, adc128_alarm, 6);
	static SENSOR_DEVICE_ATTR_RO(in7_alarm, adc128_alarm, 7);
	static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, adc128_alarm, 7);

	static struct attribute *adc128_attrs[] = {
	&sensor_dev_attr_in0_alarm.dev_attr.attr,
	&sensor_dev_attr_in0_input.dev_attr.attr,
	&sensor_dev_attr_in0_max.dev_attr.attr,
	&sensor_dev_attr_in0_min.dev_attr.attr,
	&sensor_dev_attr_in1_alarm.dev_attr.attr,
	&sensor_dev_attr_in1_input.dev_attr.attr,
	&sensor_dev_attr_in1_max.dev_attr.attr,
	&sensor_dev_attr_in1_min.dev_attr.attr,
	&sensor_dev_attr_in2_alarm.dev_attr.attr,
	&sensor_dev_attr_in2_input.dev_attr.attr,
	&sensor_dev_attr_in2_max.dev_attr.attr,
	&sensor_dev_attr_in2_min.dev_attr.attr,
	&sensor_dev_attr_in3_alarm.dev_attr.attr,
	&sensor_dev_attr_in3_input.dev_attr.attr,
	&sensor_dev_attr_in3_max.dev_attr.attr,
	&sensor_dev_attr_in3_min.dev_attr.attr,
	&sensor_dev_attr_in4_alarm.dev_attr.attr,
	&sensor_dev_attr_in4_input.dev_attr.attr,
	&sensor_dev_attr_in4_max.dev_attr.attr,
	&sensor_dev_attr_in4_min.dev_attr.attr,
	&sensor_dev_attr_in5_alarm.dev_attr.attr,
	&sensor_dev_attr_in5_input.dev_attr.attr,
	&sensor_dev_attr_in5_max.dev_attr.attr,
	&sensor_dev_attr_in5_min.dev_attr.attr,
	&sensor_dev_attr_in6_alarm.dev_attr.attr,
	&sensor_dev_attr_in6_input.dev_attr.attr,
	&sensor_dev_attr_in6_max.dev_attr.attr,
	&sensor_dev_attr_in6_min.dev_attr.attr,
	&sensor_dev_attr_in7_alarm.dev_attr.attr,
	&sensor_dev_attr_in7_input.dev_attr.attr,
	&sensor_dev_attr_in7_max.dev_attr.attr,
	&sensor_dev_attr_in7_min.dev_attr.attr,
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
	NULL
	};

	static const struct attribute_group adc128_group = {
	.attrs = adc128_attrs,
	.is_visible = adc128_is_visible,
	};
	__ATTRIBUTE_GROUPS(adc128);

	static int adc128_detect(struct i2c_client client, struct i2c_board_info info)
	{
	int man_id, dev_id;

	if (!i2c_check_functionality(client->adapter,
	I2C_FUNC_SMBUS_BYTE_DATA \|
	I2C_FUNC_SMBUS_WORD_DATA))
	return -ENODEV;

	man_id = i2c_smbus_read_byte_data(client, ADC128_REG_MAN_ID);
	dev_id = i2c_smbus_read_byte_data(client, ADC128_REG_DEV_ID);
	if (man_id != 0x01 \|\| dev_id != 0x09)
	return -ENODEV;

	/* Check unused bits for confirmation */
	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG) & 0xf4)
	return -ENODEV;
	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONV_RATE) & 0xfe)
	return -ENODEV;
	if (i2c_smbus_read_byte_data(client, ADC128_REG_ONESHOT) & 0xfe)
	return -ENODEV;
	if (i2c_smbus_read_byte_data(client, ADC128_REG_SHUTDOWN) & 0xfe)
	return -ENODEV;
	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG_ADV) & 0xf8)
	return -ENODEV;
	if (i2c_smbus_read_byte_data(client, ADC128_REG_BUSY_STATUS) & 0xfc)
	return -ENODEV;

	strscpy(info->type, "adc128d818", I2C_NAME_SIZE);

	return 0;
	}

	static int adc128_init_client(struct adc128_data *data, bool external_vref)
	{
	struct i2c_client *client = data->client;
	int err;
	u8 regval = 0x0;

	/*
	* Reset chip to defaults.
	* This makes most other initializations unnecessary.
	*/
	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x80);
	if (err)
	return err;

	/* Set operation mode, if non-default */
	if (data->mode != 0)
	regval \|= data->mode << 1;

	/* If external vref is selected, configure the chip to use it */
	if (external_vref)
	regval \|= 0x01;

	/* Write advanced configuration register */
	if (regval != 0x0) {
	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG_ADV,
	regval);
	if (err)
	return err;
	}

	/* Start monitoring */
	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x01);
	if (err)
	return err;

	return 0;
	}

	static int adc128_probe(struct i2c_client *client)
	{
	struct device *dev = &client->dev;
	struct device *hwmon_dev;
	struct adc128_data *data;
	bool external_vref;
	int err, vref;

	data = devm_kzalloc(dev, sizeof(struct adc128_data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	/* vref is optional. If specified, is used as chip reference voltage */
	vref = devm_regulator_get_enable_read_voltage(dev, "vref");
	if (vref == -ENODEV) {
	external_vref = false;
	data->vref = 2560; /* 2.56V, in mV */
	} else if (vref < 0) {
	return vref;
	} else {
	external_vref = true;
	data->vref = DIV_ROUND_CLOSEST(vref, 1000);
	}

	/* Operation mode is optional. If unspecified, keep current mode */
	if (of_property_read_u8(dev->of_node, "ti,mode", &data->mode) == 0) {
	if (data->mode > 3) {
	dev_err(dev, "invalid operation mode %d\n",
	data->mode);
	return -EINVAL;
	}
	} else {
	err = i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG_ADV);
	if (err < 0)
	return err;
	data->mode = (err >> 1) & ADC128_REG_MASK;
	}

	data->client = client;
	i2c_set_clientdata(client, data);
	mutex_init(&data->update_lock);

	/* Initialize the chip */
	err = adc128_init_client(data, external_vref);
	if (err < 0)
	return err;

	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
	data, adc128_groups);

	return PTR_ERR_OR_ZERO(hwmon_dev);
	}

	static const struct i2c_device_id adc128_id[] = {
	{ "adc128d818" },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, adc128_id);

	static const struct of_device_id __maybe_unused adc128_of_match[] = {
	{ .compatible = "ti,adc128d818" },
	{ },
	};
	MODULE_DEVICE_TABLE(of, adc128_of_match);

	static struct i2c_driver adc128_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "adc128d818",
	.of_match_table = of_match_ptr(adc128_of_match),
	},
	.probe = adc128_probe,
	.id_table = adc128_id,
	.detect = adc128_detect,
	.address_list = normal_i2c,
	};

	module_i2c_driver(adc128_driver);

	MODULE_AUTHOR("Guenter Roeck");
	MODULE_DESCRIPTION("Driver for ADC128D818");
	MODULE_LICENSE("GPL");