drivers/hwmon/max1668.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * Copyright (c) 2011 David George <david.george@ska.ac.za>
  *
  * based on adm1021.c
  * some credit to Christoph Scheurer, but largely a rewrite
  */

 #include <linux/bitops.h>
 #include <linux/bits.h>
 #include <linux/err.h>
 #include <linux/hwmon.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>

 /* Addresses to scan */
 static const unsigned short max1668_addr_list[] = {
 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };

 /* max1668 registers */

 #define MAX1668_REG_TEMP(nr)	(nr)
 #define MAX1668_REG_STAT1	0x05
 #define MAX1668_REG_STAT2	0x06
 #define MAX1668_REG_MAN_ID	0xfe
 #define MAX1668_REG_DEV_ID	0xff

 /* limits */

 /* high limits */
 #define MAX1668_REG_LIMH(nr)	(0x08 + 2 * (nr))
 /* read low limits */
 #define MAX1668_REG_LIML(nr)	(0x09 + 2 * (nr))

 /* manufacturer and device ID Constants */
 #define MAN_ID_MAXIM		0x4d
 #define DEV_ID_MAX1668		0x3
 #define DEV_ID_MAX1805		0x5
 #define DEV_ID_MAX1989		0xb

 /* read only mode module parameter */
 static bool read_only;
 module_param(read_only, bool, 0);
 MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");

 struct max1668_data {
 	struct regmap *regmap;
 	int channels;
 };

 static int max1668_read(struct device *dev, enum hwmon_sensor_types type,
 			u32 attr, int channel, long *val)
 {
 	struct max1668_data *data = dev_get_drvdata(dev);
 	struct regmap *regmap = data->regmap;
 	u32 regs[2] = { MAX1668_REG_STAT1, MAX1668_REG_TEMP(channel) };
 	u8 regvals[2];
 	u32 regval;
 	int ret;

 	switch (attr) {
 	case hwmon_temp_input:
 		ret = regmap_read(regmap, MAX1668_REG_TEMP(channel), &regval);
 		if (ret)
 			return ret;
 		*val = sign_extend32(regval, 7) * 1000;
 		break;
 	case hwmon_temp_min:
 		ret = regmap_read(regmap, MAX1668_REG_LIML(channel), &regval);
 		if (ret)
 			return ret;
 		*val = sign_extend32(regval, 7) * 1000;
 		break;
 	case hwmon_temp_max:
 		ret = regmap_read(regmap, MAX1668_REG_LIMH(channel), &regval);
 		if (ret)
 			return ret;
 		*val = sign_extend32(regval, 7) * 1000;
 		break;
 	case hwmon_temp_min_alarm:
 		ret = regmap_read(regmap,
 				  channel ? MAX1668_REG_STAT2 : MAX1668_REG_STAT1,
 				  &regval);
 		if (ret)
 			return ret;
 		if (channel)
 			*val = !!(regval & BIT(9 - channel * 2));
 		else
 			*val = !!(regval & BIT(5));
 		break;
 	case hwmon_temp_max_alarm:
 		ret = regmap_read(regmap,
 				  channel ? MAX1668_REG_STAT2 : MAX1668_REG_STAT1,
 				  &regval);
 		if (ret)
 			return ret;
 		if (channel)
 			*val = !!(regval & BIT(8 - channel * 2));
 		else
 			*val = !!(regval & BIT(6));
 		break;
 	case hwmon_temp_fault:
 		ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
 		if (ret)
 			return ret;
 		*val = !!((regvals[0] & BIT(4)) && regvals[1] == 127);
 		break;
 	default:
 		return -EOPNOTSUPP;
 	}
 	return 0;
 }

 static int max1668_write(struct device *dev, enum hwmon_sensor_types type,
 			 u32 attr, int channel, long val)
 {
 	struct max1668_data *data = dev_get_drvdata(dev);
 	struct regmap *regmap = data->regmap;

 	val = clamp_val(val / 1000, -128, 127);

 	switch (attr) {
 	case hwmon_temp_min:
 		return regmap_write(regmap, MAX1668_REG_LIML(channel), val);
 	case hwmon_temp_max:
 		return regmap_write(regmap, MAX1668_REG_LIMH(channel), val);
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static umode_t max1668_is_visible(const void *_data, enum hwmon_sensor_types type,
 				  u32 attr, int channel)
 {
 	const struct max1668_data *data = _data;

 	if (channel >= data->channels)
 		return 0;

 	switch (attr) {
 	case hwmon_temp_min:
 	case hwmon_temp_max:
 		return read_only ? 0444 : 0644;
 	case hwmon_temp_input:
 	case hwmon_temp_min_alarm:
 	case hwmon_temp_max_alarm:
 		return 0444;
 	case hwmon_temp_fault:
 		if (channel)
 			return 0444;
 		break;
 	default:
 		break;
 	}
 	return 0;
 }

 static const struct hwmon_channel_info * const max1668_info[] = {
 	HWMON_CHANNEL_INFO(temp,
 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
 			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM,
 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
 			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
 			   HWMON_T_FAULT,
 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
 			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
 			   HWMON_T_FAULT,
 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
 			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
 			   HWMON_T_FAULT,
 			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
 			   HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
 			   HWMON_T_FAULT),
 	NULL
 };

 static const struct hwmon_ops max1668_hwmon_ops = {
 	.is_visible = max1668_is_visible,
 	.read = max1668_read,
 	.write = max1668_write,
 };

 static const struct hwmon_chip_info max1668_chip_info = {
 	.ops = &max1668_hwmon_ops,
 	.info = max1668_info,
 };

 /* Return 0 if detection is successful, -ENODEV otherwise */
 static int max1668_detect(struct i2c_client *client,
 			  struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = client->adapter;
 	const char *type_name;
 	int man_id, dev_id;

 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 		return -ENODEV;

 	/* Check for unsupported part */
 	man_id = i2c_smbus_read_byte_data(client, MAX1668_REG_MAN_ID);
 	if (man_id != MAN_ID_MAXIM)
 		return -ENODEV;

 	dev_id = i2c_smbus_read_byte_data(client, MAX1668_REG_DEV_ID);
 	if (dev_id < 0)
 		return -ENODEV;

 	type_name = NULL;
 	if (dev_id == DEV_ID_MAX1668)
 		type_name = "max1668";
 	else if (dev_id == DEV_ID_MAX1805)
 		type_name = "max1805";
 	else if (dev_id == DEV_ID_MAX1989)
 		type_name = "max1989";

 	if (!type_name)
 		return -ENODEV;

 	strscpy(info->type, type_name, I2C_NAME_SIZE);

 	return 0;
 }

 /* regmap */

 static int max1668_reg_read(void *context, unsigned int reg, unsigned int *val)
 {
 	int ret;

 	ret = i2c_smbus_read_byte_data(context, reg);
 	if (ret < 0)
 		return ret;

 	*val = ret;
 	return 0;
 }

 static int max1668_reg_write(void *context, unsigned int reg, unsigned int val)
 {
 	return i2c_smbus_write_byte_data(context, reg + 11, val);
 }

 static bool max1668_regmap_is_volatile(struct device *dev, unsigned int reg)
 {
 	return reg <= MAX1668_REG_STAT2;
 }

 static bool max1668_regmap_is_writeable(struct device *dev, unsigned int reg)
 {
 	return reg > MAX1668_REG_STAT2 && reg <= MAX1668_REG_LIML(4);
 }

 static const struct regmap_config max1668_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 	.cache_type = REGCACHE_MAPLE,
 	.volatile_reg = max1668_regmap_is_volatile,
 	.writeable_reg = max1668_regmap_is_writeable,
 };

 static const struct regmap_bus max1668_regmap_bus = {
 	.reg_write = max1668_reg_write,
 	.reg_read = max1668_reg_read,
 };

 static int max1668_probe(struct i2c_client *client)
 {
 	struct i2c_adapter *adapter = client->adapter;
 	struct device *dev = &client->dev;
 	struct device *hwmon_dev;
 	struct max1668_data *data;

 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 		return -ENODEV;

 	data = devm_kzalloc(dev, sizeof(struct max1668_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	data->regmap = devm_regmap_init(dev, &max1668_regmap_bus, client,
 					&max1668_regmap_config);
 	if (IS_ERR(data->regmap))
 		return PTR_ERR(data->regmap);

 	data->channels = (uintptr_t)i2c_get_match_data(client);

 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
 							 &max1668_chip_info, NULL);
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }

 static const struct i2c_device_id max1668_id[] = {
 	{ "max1668", 5 },
 	{ "max1805", 3 },
 	{ "max1989", 5 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, max1668_id);

 /* This is the driver that will be inserted */
 static struct i2c_driver max1668_driver = {
 	.class = I2C_CLASS_HWMON,
 	.driver = {
 		  .name	= "max1668",
 		  },
 	.probe = max1668_probe,
 	.id_table = max1668_id,
 	.detect	= max1668_detect,
 	.address_list = max1668_addr_list,
 };

 module_i2c_driver(max1668_driver);

 MODULE_AUTHOR("David George <david.george@ska.ac.za>");
 MODULE_DESCRIPTION("MAX1668 remote temperature sensor driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* Copyright (c) 2011 David George <david.george@ska.ac.za>
	*
	* based on adm1021.c
	* some credit to Christoph Scheurer, but largely a rewrite
	*/

	#include <linux/bitops.h>
	#include <linux/bits.h>
	#include <linux/err.h>
	#include <linux/hwmon.h>
	#include <linux/i2c.h>
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/regmap.h>
	#include <linux/slab.h>

	/* Addresses to scan */
	static const unsigned short max1668_addr_list[] = {
	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };

	/* max1668 registers */

	#define MAX1668_REG_TEMP(nr) (nr)
	#define MAX1668_REG_STAT1 0x05
	#define MAX1668_REG_STAT2 0x06
	#define MAX1668_REG_MAN_ID 0xfe
	#define MAX1668_REG_DEV_ID 0xff

	/* limits */

	/* high limits */
	#define MAX1668_REG_LIMH(nr) (0x08 + 2 * (nr))
	/* read low limits */
	#define MAX1668_REG_LIML(nr) (0x09 + 2 * (nr))

	/* manufacturer and device ID Constants */
	#define MAN_ID_MAXIM 0x4d
	#define DEV_ID_MAX1668 0x3
	#define DEV_ID_MAX1805 0x5
	#define DEV_ID_MAX1989 0xb

	/* read only mode module parameter */
	static bool read_only;
	module_param(read_only, bool, 0);
	MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");

	struct max1668_data {
	struct regmap *regmap;
	int channels;
	};

	static int max1668_read(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long *val)
	{
	struct max1668_data *data = dev_get_drvdata(dev);
	struct regmap *regmap = data->regmap;
	u32 regs[2] = { MAX1668_REG_STAT1, MAX1668_REG_TEMP(channel) };
	u8 regvals[2];
	u32 regval;
	int ret;

	switch (attr) {
	case hwmon_temp_input:
	ret = regmap_read(regmap, MAX1668_REG_TEMP(channel), &regval);
	if (ret)
	return ret;
	val = sign_extend32(regval, 7) 1000;
	break;
	case hwmon_temp_min:
	ret = regmap_read(regmap, MAX1668_REG_LIML(channel), &regval);
	if (ret)
	return ret;
	val = sign_extend32(regval, 7) 1000;
	break;
	case hwmon_temp_max:
	ret = regmap_read(regmap, MAX1668_REG_LIMH(channel), &regval);
	if (ret)
	return ret;
	val = sign_extend32(regval, 7) 1000;
	break;
	case hwmon_temp_min_alarm:
	ret = regmap_read(regmap,
	channel ? MAX1668_REG_STAT2 : MAX1668_REG_STAT1,
	&regval);
	if (ret)
	return ret;
	if (channel)
	val = !!(regval & BIT(9 - channel 2));
	else
	*val = !!(regval & BIT(5));
	break;
	case hwmon_temp_max_alarm:
	ret = regmap_read(regmap,
	channel ? MAX1668_REG_STAT2 : MAX1668_REG_STAT1,
	&regval);
	if (ret)
	return ret;
	if (channel)
	val = !!(regval & BIT(8 - channel 2));
	else
	*val = !!(regval & BIT(6));
	break;
	case hwmon_temp_fault:
	ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
	if (ret)
	return ret;
	*val = !!((regvals[0] & BIT(4)) && regvals[1] == 127);
	break;
	default:
	return -EOPNOTSUPP;
	}
	return 0;
	}

	static int max1668_write(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long val)
	{
	struct max1668_data *data = dev_get_drvdata(dev);
	struct regmap *regmap = data->regmap;

	val = clamp_val(val / 1000, -128, 127);

	switch (attr) {
	case hwmon_temp_min:
	return regmap_write(regmap, MAX1668_REG_LIML(channel), val);
	case hwmon_temp_max:
	return regmap_write(regmap, MAX1668_REG_LIMH(channel), val);
	default:
	return -EOPNOTSUPP;
	}
	}

	static umode_t max1668_is_visible(const void *_data, enum hwmon_sensor_types type,
	u32 attr, int channel)
	{
	const struct max1668_data *data = _data;

	if (channel >= data->channels)
	return 0;

	switch (attr) {
	case hwmon_temp_min:
	case hwmon_temp_max:
	return read_only ? 0444 : 0644;
	case hwmon_temp_input:
	case hwmon_temp_min_alarm:
	case hwmon_temp_max_alarm:
	return 0444;
	case hwmon_temp_fault:
	if (channel)
	return 0444;
	break;
	default:
	break;
	}
	return 0;
	}

	static const struct hwmon_channel_info * const max1668_info[] = {
	HWMON_CHANNEL_INFO(temp,
	HWMON_T_INPUT \| HWMON_T_MIN \| HWMON_T_MAX \|
	HWMON_T_MIN_ALARM \| HWMON_T_MAX_ALARM,
	HWMON_T_INPUT \| HWMON_T_MIN \| HWMON_T_MAX \|
	HWMON_T_MIN_ALARM \| HWMON_T_MAX_ALARM \|
	HWMON_T_FAULT,
	HWMON_T_INPUT \| HWMON_T_MIN \| HWMON_T_MAX \|
	HWMON_T_MIN_ALARM \| HWMON_T_MAX_ALARM \|
	HWMON_T_FAULT,
	HWMON_T_INPUT \| HWMON_T_MIN \| HWMON_T_MAX \|
	HWMON_T_MIN_ALARM \| HWMON_T_MAX_ALARM \|
	HWMON_T_FAULT,
	HWMON_T_INPUT \| HWMON_T_MIN \| HWMON_T_MAX \|
	HWMON_T_MIN_ALARM \| HWMON_T_MAX_ALARM \|
	HWMON_T_FAULT),
	NULL
	};

	static const struct hwmon_ops max1668_hwmon_ops = {
	.is_visible = max1668_is_visible,
	.read = max1668_read,
	.write = max1668_write,
	};

	static const struct hwmon_chip_info max1668_chip_info = {
	.ops = &max1668_hwmon_ops,
	.info = max1668_info,
	};

	/* Return 0 if detection is successful, -ENODEV otherwise */
	static int max1668_detect(struct i2c_client *client,
	struct i2c_board_info *info)
	{
	struct i2c_adapter *adapter = client->adapter;
	const char *type_name;
	int man_id, dev_id;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
	return -ENODEV;

	/* Check for unsupported part */
	man_id = i2c_smbus_read_byte_data(client, MAX1668_REG_MAN_ID);
	if (man_id != MAN_ID_MAXIM)
	return -ENODEV;

	dev_id = i2c_smbus_read_byte_data(client, MAX1668_REG_DEV_ID);
	if (dev_id < 0)
	return -ENODEV;

	type_name = NULL;
	if (dev_id == DEV_ID_MAX1668)
	type_name = "max1668";
	else if (dev_id == DEV_ID_MAX1805)
	type_name = "max1805";
	else if (dev_id == DEV_ID_MAX1989)
	type_name = "max1989";

	if (!type_name)
	return -ENODEV;

	strscpy(info->type, type_name, I2C_NAME_SIZE);

	return 0;
	}

	/* regmap */

	static int max1668_reg_read(void context, unsigned int reg, unsigned int val)
	{
	int ret;

	ret = i2c_smbus_read_byte_data(context, reg);
	if (ret < 0)
	return ret;

	*val = ret;
	return 0;
	}

	static int max1668_reg_write(void *context, unsigned int reg, unsigned int val)
	{
	return i2c_smbus_write_byte_data(context, reg + 11, val);
	}

	static bool max1668_regmap_is_volatile(struct device *dev, unsigned int reg)
	{
	return reg <= MAX1668_REG_STAT2;
	}

	static bool max1668_regmap_is_writeable(struct device *dev, unsigned int reg)
	{
	return reg > MAX1668_REG_STAT2 && reg <= MAX1668_REG_LIML(4);
	}

	static const struct regmap_config max1668_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.cache_type = REGCACHE_MAPLE,
	.volatile_reg = max1668_regmap_is_volatile,
	.writeable_reg = max1668_regmap_is_writeable,
	};

	static const struct regmap_bus max1668_regmap_bus = {
	.reg_write = max1668_reg_write,
	.reg_read = max1668_reg_read,
	};

	static int max1668_probe(struct i2c_client *client)
	{
	struct i2c_adapter *adapter = client->adapter;
	struct device *dev = &client->dev;
	struct device *hwmon_dev;
	struct max1668_data *data;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
	return -ENODEV;

	data = devm_kzalloc(dev, sizeof(struct max1668_data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	data->regmap = devm_regmap_init(dev, &max1668_regmap_bus, client,
	&max1668_regmap_config);
	if (IS_ERR(data->regmap))
	return PTR_ERR(data->regmap);

	data->channels = (uintptr_t)i2c_get_match_data(client);

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
	&max1668_chip_info, NULL);
	return PTR_ERR_OR_ZERO(hwmon_dev);
	}

	static const struct i2c_device_id max1668_id[] = {
	{ "max1668", 5 },
	{ "max1805", 3 },
	{ "max1989", 5 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, max1668_id);

	/* This is the driver that will be inserted */
	static struct i2c_driver max1668_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "max1668",
	},
	.probe = max1668_probe,
	.id_table = max1668_id,
	.detect = max1668_detect,
	.address_list = max1668_addr_list,
	};

	module_i2c_driver(max1668_driver);

	MODULE_AUTHOR("David George <david.george@ska.ac.za>");
	MODULE_DESCRIPTION("MAX1668 remote temperature sensor driver");
	MODULE_LICENSE("GPL");