linux/drivers/hwmon/max31760.c

// SPDX-License-Identifier: GPL-2.0-only

#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/util_macros.h>

#define REG_CR1		0x00
#define CR1_HYST	BIT(5)
#define CR1_DRV		GENMASK(4, 3)
#define CR1_TEMP_SRC	GENMASK(1, 0)
#define REG_CR2		0x01
#define CR2_STBY	BIT(7)
#define CR2_ALERTS	BIT(6)
#define CR2_DFC		BIT(0)
#define REG_CR3		0x02
#define REG_PWMR	0x50
#define REG_PWMV	0x51
#define REG_STATUS	0x5A
#define STATUS_ALARM_CRIT(ch)	BIT(2 + 2 * (ch))
#define STATUS_ALARM_MAX(ch)	BIT(3 + 2 * (ch))
#define STATUS_RDFA		BIT(6)

#define REG_TACH(ch)		(0x52 + (ch) * 2)
#define REG_TEMP_INPUT(ch)	(0x56 + (ch) * 2)
#define REG_TEMP_MAX(ch)	(0x06 + (ch) * 2)
#define REG_TEMP_CRIT(ch)	(0x0A + (ch) * 2)

#define TEMP11_FROM_REG(reg)	((reg) / 32 * 125)
#define TEMP11_TO_REG(val)	(DIV_ROUND_CLOSEST(clamp_val((val), -128000, \
							     127875), 125) * 32)

#define LUT_SIZE	48

#define REG_LUT(index)		(0x20 + (index))

struct max31760_state {
	struct regmap *regmap;

	struct lut_attribute {
		char name[24];
		struct sensor_device_attribute sda;
	} lut[LUT_SIZE];

	struct attribute *attrs[LUT_SIZE + 2];
	struct attribute_group group;
	const struct attribute_group *groups[2];
};

static bool max31760_volatile_reg(struct device *dev, unsigned int reg)
{
	return reg > 0x50;
}

static const struct regmap_config regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = 0x5B,
	.cache_type = REGCACHE_RBTREE,
	.volatile_reg = max31760_volatile_reg,
};

static const int max31760_pwm_freq[] = {33, 150, 1500, 25000};

static int tach_to_rpm(u16 tach)
{
	if (tach == 0)
		tach = 1;

	return 60 * 100000 / tach / 2;
}

static int max31760_read(struct device *dev, enum hwmon_sensor_types type,
			 u32 attr, int channel, long *val)
{
	struct max31760_state *state = dev_get_drvdata(dev);
	unsigned int regval;
	unsigned int reg_temp;
	s16 temp;
	u8 reg[2];
	int ret;

	switch (type) {
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp_fault:
			ret = regmap_read(state->regmap, REG_STATUS, &regval);
			if (ret)
				return ret;

			*val = FIELD_GET(STATUS_RDFA, regval);

			return 0;
		case hwmon_temp_max_alarm:
			ret = regmap_read(state->regmap, REG_STATUS, &regval);
			if (ret)
				return ret;

			if (channel)
				*val = FIELD_GET(STATUS_ALARM_MAX(1), regval);
			else
				*val = FIELD_GET(STATUS_ALARM_MAX(0), regval);

			return 0;
		case hwmon_temp_crit_alarm:
			ret = regmap_read(state->regmap, REG_STATUS, &regval);
			if (ret)
				return ret;

			if (channel)
				*val = FIELD_GET(STATUS_ALARM_CRIT(1), regval);
			else
				*val = FIELD_GET(STATUS_ALARM_CRIT(0), regval);

			return 0;
		case hwmon_temp_input:
			reg_temp = REG_TEMP_INPUT(channel);
			break;
		case hwmon_temp_max:
			reg_temp = REG_TEMP_MAX(channel);
			break;
		case hwmon_temp_crit:
			reg_temp = REG_TEMP_CRIT(channel);
			break;
		default:
			return -EOPNOTSUPP;
		}

		ret = regmap_bulk_read(state->regmap, reg_temp, reg, 2);
		if (ret)
			return ret;

		temp = (reg[0] << 8) | reg[1];

		*val = TEMP11_FROM_REG(temp);

		return 0;
	case hwmon_fan:
		switch (attr) {
		case hwmon_fan_input:
			ret = regmap_bulk_read(state->regmap, REG_TACH(channel), reg, 2);
			if (ret)
				return ret;

			*val = tach_to_rpm(reg[0] * 256 + reg[1]);

			return 0;
		case hwmon_fan_fault:
			ret = regmap_read(state->regmap, REG_STATUS, &regval);
			if (ret)
				return ret;

			if (channel)
				*val = FIELD_GET(BIT(1), regval);
			else
				*val = FIELD_GET(BIT(0), regval);

			return 0;
		case hwmon_fan_enable:
			ret = regmap_read(state->regmap, REG_CR3, &regval);
			if (ret)
				return ret;

			if (channel)
				*val = FIELD_GET(BIT(1), regval);
			else
				*val = FIELD_GET(BIT(0), regval);

			return 0;
		default:
			return -EOPNOTSUPP;
		}
	case hwmon_pwm:
		switch (attr) {
		case hwmon_pwm_input:
			ret = regmap_read(state->regmap, REG_PWMV, &regval);
			if (ret)
				return ret;

			*val = regval;

			return 0;
		case hwmon_pwm_freq:
			ret = regmap_read(state->regmap, REG_CR1, &regval);
			if (ret)
				return ret;

			regval = FIELD_GET(CR1_DRV, regval);
			if (regval >= ARRAY_SIZE(max31760_pwm_freq))
				return -EINVAL;

			*val = max31760_pwm_freq[regval];

			return 0;
		case hwmon_pwm_enable:
			ret = regmap_read(state->regmap, REG_CR2, &regval);
			if (ret)
				return ret;

			*val = 2 - FIELD_GET(CR2_DFC, regval);

			return 0;
		case hwmon_pwm_auto_channels_temp:
			ret = regmap_read(state->regmap, REG_CR1, &regval);
			if (ret)
				return ret;

			switch (FIELD_GET(CR1_TEMP_SRC, regval)) {
			case 0:
				*val = 2;
				break;
			case 1:
				*val = 1;
				break;
			case 2:
			case 3:
				*val = 3;
				break;
			default:
				return -EINVAL;
			}

			return 0;
		default:
			return -EOPNOTSUPP;
		}
	default:
		return -EOPNOTSUPP;
	}
}

static int max31760_write(struct device *dev, enum hwmon_sensor_types type,
			  u32 attr, int channel, long val)
{
	struct max31760_state *state = dev_get_drvdata(dev);
	unsigned int pwm_index;
	unsigned int reg_temp;
	int temp;
	u8 reg_val[2];

	switch (type) {
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp_max:
			reg_temp = REG_TEMP_MAX(channel);
			break;
		case hwmon_temp_crit:
			reg_temp = REG_TEMP_CRIT(channel);
			break;
		default:
			return -EOPNOTSUPP;
		}

		temp = TEMP11_TO_REG(val);
		reg_val[0] = temp >> 8;
		reg_val[1] = temp & 0xFF;

		return regmap_bulk_write(state->regmap, reg_temp, reg_val, 2);
	case hwmon_fan:
		switch (attr) {
		case hwmon_fan_enable:
			if (val == 0)
				return regmap_clear_bits(state->regmap, REG_CR3, BIT(channel));

			if (val == 1)
				return regmap_set_bits(state->regmap, REG_CR3, BIT(channel));

			return -EINVAL;
		default:
			return -EOPNOTSUPP;
		}
	case hwmon_pwm:
		switch (attr) {
		case hwmon_pwm_input:
			if (val < 0 || val > 255)
				return -EINVAL;

			return regmap_write(state->regmap, REG_PWMR, val);
		case hwmon_pwm_enable:
			if (val == 1)
				return regmap_set_bits(state->regmap, REG_CR2, CR2_DFC);

			if (val == 2)
				return regmap_clear_bits(state->regmap, REG_CR2, CR2_DFC);

			return -EINVAL;
		case hwmon_pwm_freq:
			pwm_index = find_closest(val, max31760_pwm_freq,
						 ARRAY_SIZE(max31760_pwm_freq));

			return regmap_update_bits(state->regmap,
						  REG_CR1, CR1_DRV,
						  FIELD_PREP(CR1_DRV, pwm_index));
		case hwmon_pwm_auto_channels_temp:
			switch (val) {
			case 1:
				break;
			case 2:
				val = 0;
				break;
			case 3:
				val = 2;
				break;
			default:
				return -EINVAL;
			}

			return regmap_update_bits(state->regmap, REG_CR1, CR1_TEMP_SRC, val);
		default:
			return -EOPNOTSUPP;
		}
	default:
		return -EOPNOTSUPP;
	}
}

static const struct hwmon_channel_info * const max31760_info[] = {
	HWMON_CHANNEL_INFO(chip,
			   HWMON_C_REGISTER_TZ),
	HWMON_CHANNEL_INFO(fan,
			   HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_ENABLE,
			   HWMON_F_INPUT | HWMON_F_FAULT | HWMON_F_ENABLE),
	HWMON_CHANNEL_INFO(temp,
			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT | HWMON_T_FAULT |
			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_LABEL,
			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_LABEL),
	HWMON_CHANNEL_INFO(pwm,
			   HWMON_PWM_ENABLE | HWMON_PWM_FREQ | HWMON_PWM_INPUT |
			   HWMON_PWM_AUTO_CHANNELS_TEMP),
	NULL
};

static umode_t max31760_is_visible(const void *data,
				   enum hwmon_sensor_types type,
				   u32 attr, int channel)
{
	switch (type) {
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp_input:
		case hwmon_temp_max_alarm:
		case hwmon_temp_crit_alarm:
		case hwmon_temp_fault:
		case hwmon_temp_label:
			return 0444;
		case hwmon_temp_max:
		case hwmon_temp_crit:
			return 0644;
		default:
			return 0;
		}
	case hwmon_fan:
		switch (attr) {
		case hwmon_fan_input:
		case hwmon_fan_fault:
			return 0444;
		case hwmon_fan_enable:
			return 0644;
		default:
			return 0;
		}
	case hwmon_pwm:
		switch (attr) {
		case hwmon_pwm_enable:
		case hwmon_pwm_input:
		case hwmon_pwm_freq:
		case hwmon_pwm_auto_channels_temp:
			return 0644;
		default:
			return 0;
		}
	default:
		return 0;
	}
}

static int max31760_read_string(struct device *dev,
				enum hwmon_sensor_types type,
				u32 attr, int channel, const char **str)
{
	switch (type) {
	case hwmon_temp:
		if (attr != hwmon_temp_label)
			return -EOPNOTSUPP;

		*str = channel ? "local" : "remote";

		return 0;
	default:
		return -EOPNOTSUPP;
	}
}

static const struct hwmon_ops max31760_hwmon_ops = {
	.is_visible = max31760_is_visible,
	.read = max31760_read,
	.write = max31760_write,
	.read_string = max31760_read_string
};

static const struct hwmon_chip_info max31760_chip_info = {
	.ops = &max31760_hwmon_ops,
	.info = max31760_info,
};

static ssize_t lut_show(struct device *dev,
			struct device_attribute *devattr, char *buf)
{
	struct sensor_device_attribute *sda = to_sensor_dev_attr(devattr);
	struct max31760_state *state = dev_get_drvdata(dev);
	int ret;
	unsigned int regval;

	ret = regmap_read(state->regmap, REG_LUT(sda->index), &regval);
	if (ret)
		return ret;

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

static ssize_t lut_store(struct device *dev,
			 struct device_attribute *devattr,
			 const char *buf, size_t count)
{
	struct sensor_device_attribute *sda = to_sensor_dev_attr(devattr);
	struct max31760_state *state = dev_get_drvdata(dev);
	int ret;
	u8 pwm;

	ret = kstrtou8(buf, 10, &pwm);
	if (ret)
		return ret;

	ret = regmap_write(state->regmap, REG_LUT(sda->index), pwm);
	if (ret)
		return ret;

	return count;
}

static ssize_t pwm1_auto_point_temp_hyst_show(struct device *dev,
					      struct device_attribute *attr,
					      char *buf)
{
	struct max31760_state *state = dev_get_drvdata(dev);
	unsigned int regval;
	int ret;

	ret = regmap_read(state->regmap, REG_CR1, &regval);
	if (ret)
		return ret;

	return sysfs_emit(buf, "%d\n", (1 + (int)FIELD_GET(CR1_HYST, regval)) * 2000);
}

static ssize_t pwm1_auto_point_temp_hyst_store(struct device *dev,
					       struct device_attribute *attr,
					       const char *buf,
					       size_t count)
{
	struct max31760_state *state = dev_get_drvdata(dev);
	unsigned int hyst;
	int ret;

	ret = kstrtou32(buf, 10, &hyst);
	if (ret)
		return ret;

	if (hyst < 3000)
		ret = regmap_clear_bits(state->regmap, REG_CR1, CR1_HYST);
	else
		ret = regmap_set_bits(state->regmap, REG_CR1, CR1_HYST);

	if (ret)
		return ret;

	return count;
}

static DEVICE_ATTR_RW(pwm1_auto_point_temp_hyst);

static void max31760_create_lut_nodes(struct max31760_state *state)
{
	int i;
	struct sensor_device_attribute *sda;
	struct lut_attribute *lut;

	for (i = 0; i < LUT_SIZE; ++i) {
		lut = &state->lut[i];
		sda = &lut->sda;

		snprintf(lut->name, sizeof(lut->name),
			 "pwm1_auto_point%d_pwm", i + 1);

		sda->dev_attr.attr.mode = 0644;
		sda->index = i;
		sda->dev_attr.show = lut_show;
		sda->dev_attr.store = lut_store;
		sda->dev_attr.attr.name = lut->name;

		sysfs_attr_init(&sda->dev_attr.attr);

		state->attrs[i] = &sda->dev_attr.attr;
	}

	state->attrs[i] = &dev_attr_pwm1_auto_point_temp_hyst.attr;

	state->group.attrs = state->attrs;
	state->groups[0] = &state->group;
}

static int max31760_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct max31760_state *state;
	struct device *hwmon_dev;
	int ret;

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

	state->regmap = devm_regmap_init_i2c(client, &regmap_config);
	if (IS_ERR(state->regmap))
		return dev_err_probe(dev,
				     PTR_ERR(state->regmap),
				     "regmap initialization failed\n");

	dev_set_drvdata(dev, state);

	/* Set alert output to comparator mode */
	ret = regmap_set_bits(state->regmap, REG_CR2, CR2_ALERTS);
	if (ret)
		return dev_err_probe(dev, ret, "cannot write register\n");

	max31760_create_lut_nodes(state);

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
							 state,
							 &max31760_chip_info,
							 state->groups);

	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct of_device_id max31760_of_match[] = {
	{.compatible = "adi,max31760"},
	{ }
};
MODULE_DEVICE_TABLE(of, max31760_of_match);

static const struct i2c_device_id max31760_id[] = {
	{"max31760"},
	{ }
};
MODULE_DEVICE_TABLE(i2c, max31760_id);

static int max31760_suspend(struct device *dev)
{
	struct max31760_state *state = dev_get_drvdata(dev);

	return regmap_set_bits(state->regmap, REG_CR2, CR2_STBY);
}

static int max31760_resume(struct device *dev)
{
	struct max31760_state *state = dev_get_drvdata(dev);

	return regmap_clear_bits(state->regmap, REG_CR2, CR2_STBY);
}

static DEFINE_SIMPLE_DEV_PM_OPS(max31760_pm_ops, max31760_suspend,
				max31760_resume);

static struct i2c_driver max31760_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "max31760",
		.of_match_table = max31760_of_match,
		.pm = pm_ptr(&max31760_pm_ops)
	},
	.probe_new	= max31760_probe,
	.id_table	= max31760_id
};
module_i2c_driver(max31760_driver);

MODULE_AUTHOR("Ibrahim Tilki <Ibrahim.Tilki@analog.com>");
MODULE_DESCRIPTION("Analog Devices MAX31760 Fan Speed Controller");
MODULE_SOFTDEP("pre: regmap_i2c");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL");