// SPDX-License-Identifier: GPL-2.0-only
/*
 *  Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
 *
 *  Copyright (C) 2008, 2010 Pengutronix
 *
 *  TODO: SPI, use power-down mode for suspend?, interrupt handling?
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/slab.h>

#define ADT7411_REG_STAT_1			0x00
#define ADT7411_STAT_1_INT_TEMP_HIGH		BIT(0)
#define ADT7411_STAT_1_INT_TEMP_LOW		BIT(1)
#define ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1	BIT(2)
#define ADT7411_STAT_1_EXT_TEMP_LOW		BIT(3)
#define ADT7411_STAT_1_EXT_TEMP_FAULT		BIT(4)
#define ADT7411_STAT_1_AIN2			BIT(5)
#define ADT7411_STAT_1_AIN3			BIT(6)
#define ADT7411_STAT_1_AIN4			BIT(7)
#define ADT7411_REG_STAT_2			0x01
#define ADT7411_STAT_2_AIN5			BIT(0)
#define ADT7411_STAT_2_AIN6			BIT(1)
#define ADT7411_STAT_2_AIN7			BIT(2)
#define ADT7411_STAT_2_AIN8			BIT(3)
#define ADT7411_STAT_2_VDD			BIT(4)
#define ADT7411_REG_INT_TEMP_VDD_LSB		0x03
#define ADT7411_REG_EXT_TEMP_AIN14_LSB		0x04
#define ADT7411_REG_VDD_MSB			0x06
#define ADT7411_REG_INT_TEMP_MSB		0x07
#define ADT7411_REG_EXT_TEMP_AIN1_MSB		0x08

#define ADT7411_REG_CFG1			0x18
#define ADT7411_CFG1_START_MONITOR		BIT(0)
#define ADT7411_CFG1_RESERVED_BIT1		BIT(1)
#define ADT7411_CFG1_EXT_TDM			BIT(2)
#define ADT7411_CFG1_RESERVED_BIT3		BIT(3)

#define ADT7411_REG_CFG2			0x19
#define ADT7411_CFG2_DISABLE_AVG		BIT(5)

#define ADT7411_REG_CFG3			0x1a
#define ADT7411_CFG3_ADC_CLK_225		BIT(0)
#define ADT7411_CFG3_RESERVED_BIT1		BIT(1)
#define ADT7411_CFG3_RESERVED_BIT2		BIT(2)
#define ADT7411_CFG3_RESERVED_BIT3		BIT(3)
#define ADT7411_CFG3_REF_VDD			BIT(4)

#define ADT7411_REG_VDD_HIGH			0x23
#define ADT7411_REG_VDD_LOW			0x24
#define ADT7411_REG_TEMP_HIGH(nr)		(0x25 + 2 * (nr))
#define ADT7411_REG_TEMP_LOW(nr)		(0x26 + 2 * (nr))
#define ADT7411_REG_IN_HIGH(nr)		((nr) > 1 \
						  ? 0x2b + 2 * ((nr)-2) \
						  : 0x27)
#define ADT7411_REG_IN_LOW(nr)			((nr) > 1 \
						  ? 0x2c + 2 * ((nr)-2) \
						  : 0x28)

#define ADT7411_REG_DEVICE_ID			0x4d
#define ADT7411_REG_MANUFACTURER_ID		0x4e

#define ADT7411_DEVICE_ID			0x2
#define ADT7411_MANUFACTURER_ID			0x41

static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };

static const u8 adt7411_in_alarm_reg[] = {
	ADT7411_REG_STAT_2,
	ADT7411_REG_STAT_1,
	ADT7411_REG_STAT_1,
	ADT7411_REG_STAT_1,
	ADT7411_REG_STAT_1,
	ADT7411_REG_STAT_2,
	ADT7411_REG_STAT_2,
	ADT7411_REG_STAT_2,
	ADT7411_REG_STAT_2,
};

static const u8 adt7411_in_alarm_bits[] = {
	ADT7411_STAT_2_VDD,
	ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1,
	ADT7411_STAT_1_AIN2,
	ADT7411_STAT_1_AIN3,
	ADT7411_STAT_1_AIN4,
	ADT7411_STAT_2_AIN5,
	ADT7411_STAT_2_AIN6,
	ADT7411_STAT_2_AIN7,
	ADT7411_STAT_2_AIN8,
};

struct adt7411_data {
	unsigned long next_update;
	long vref_cached;
	struct i2c_client *client;
	bool use_ext_temp;
};

/*
 * When reading a register containing (up to 4) lsb, all associated
 * msb-registers get locked by the hardware. After _one_ of those msb is read,
 * _all_ are unlocked.
 */
static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
			       u8 msb_reg, u8 lsb_shift)
{
	int val, tmp;

	val = i2c_smbus_read_byte_data(client, lsb_reg);
	if (val < 0)
		return val;

	tmp = (val >> lsb_shift) & 3;
	val = i2c_smbus_read_byte_data(client, msb_reg);
	if (val < 0)
		return val;

	val = (val << 2) | tmp;
	return val;
}

static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
			      bool flag)
{
	int ret, val;

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

	if (flag)
		val = ret | bit;
	else
		val = ret & ~bit;

	return i2c_smbus_write_byte_data(client, reg, val);
}

static ssize_t adt7411_show_bit(struct device *dev,
				struct device_attribute *attr, char *buf)
{
	struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret = i2c_smbus_read_byte_data(client, attr2->index);

	return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
}

static ssize_t adt7411_set_bit(struct device *dev,
			       struct device_attribute *attr, const char *buf,
			       size_t count)
{
	struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret;
	unsigned long flag;

	ret = kstrtoul(buf, 0, &flag);
	if (ret || flag > 1)
		return -EINVAL;

	hwmon_lock(dev);
	ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
	/* force update */
	data->next_update = jiffies;
	hwmon_unlock(dev);

	return ret < 0 ? ret : count;
}

#define ADT7411_BIT_ATTR(__name, __reg, __bit) \
	SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
	adt7411_set_bit, __bit, __reg)

static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);

static struct attribute *adt7411_attrs[] = {
	&sensor_dev_attr_no_average.dev_attr.attr,
	&sensor_dev_attr_fast_sampling.dev_attr.attr,
	&sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
	NULL
};
ATTRIBUTE_GROUPS(adt7411);

static int adt7411_read_in_alarm(struct device *dev, int channel, long *val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret;

	ret = i2c_smbus_read_byte_data(client, adt7411_in_alarm_reg[channel]);
	if (ret < 0)
		return ret;
	*val = !!(ret & adt7411_in_alarm_bits[channel]);
	return 0;
}

static int adt7411_read_in_vdd(struct device *dev, u32 attr, long *val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret;

	switch (attr) {
	case hwmon_in_input:
		ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
					  ADT7411_REG_VDD_MSB, 2);
		if (ret < 0)
			return ret;
		*val = ret * 7000 / 1024;
		return 0;
	case hwmon_in_min:
		ret = i2c_smbus_read_byte_data(client, ADT7411_REG_VDD_LOW);
		if (ret < 0)
			return ret;
		*val = ret * 7000 / 256;
		return 0;
	case hwmon_in_max:
		ret = i2c_smbus_read_byte_data(client, ADT7411_REG_VDD_HIGH);
		if (ret < 0)
			return ret;
		*val = ret * 7000 / 256;
		return 0;
	case hwmon_in_alarm:
		return adt7411_read_in_alarm(dev, 0, val);
	default:
		return -EOPNOTSUPP;
	}
}

static int adt7411_update_vref(struct device *dev)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int val;

	if (time_after_eq(jiffies, data->next_update)) {
		val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
		if (val < 0)
			return val;

		if (val & ADT7411_CFG3_REF_VDD) {
			val = adt7411_read_in_vdd(dev, hwmon_in_input,
						  &data->vref_cached);
			if (val < 0)
				return val;
		} else {
			data->vref_cached = 2250;
		}

		data->next_update = jiffies + HZ;
	}

	return 0;
}

static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
				long *val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;

	int ret;
	int reg, lsb_reg, lsb_shift;
	int nr = channel - 1;

	ret = adt7411_update_vref(dev);
	if (ret < 0)
		return ret;

	switch (attr) {
	case hwmon_in_input:
		lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
		lsb_shift = 2 * (nr & 0x03);
		ret = adt7411_read_10_bit(client, lsb_reg,
					  ADT7411_REG_EXT_TEMP_AIN1_MSB + nr,
					  lsb_shift);
		if (ret < 0)
			return ret;
		*val = ret * data->vref_cached / 1024;
		ret = 0;
		break;
	case hwmon_in_min:
	case hwmon_in_max:
		reg = (attr == hwmon_in_min)
			? ADT7411_REG_IN_LOW(channel)
			: ADT7411_REG_IN_HIGH(channel);
		ret = i2c_smbus_read_byte_data(client, reg);
		if (ret < 0)
			return ret;
		*val = ret * data->vref_cached / 256;
		ret = 0;
		break;
	case hwmon_in_alarm:
		ret = adt7411_read_in_alarm(dev, channel, val);
		break;
	default:
		ret = -EOPNOTSUPP;
		break;
	}
	return ret;
}

static int adt7411_read_in(struct device *dev, u32 attr, int channel,
			   long *val)
{
	if (channel == 0)
		return adt7411_read_in_vdd(dev, attr, val);
	else
		return adt7411_read_in_chan(dev, attr, channel, val);
}


static int adt7411_read_temp_alarm(struct device *dev, u32 attr, int channel,
				   long *val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret, bit;

	ret = i2c_smbus_read_byte_data(client, ADT7411_REG_STAT_1);
	if (ret < 0)
		return ret;

	switch (attr) {
	case hwmon_temp_min_alarm:
		bit = channel ? ADT7411_STAT_1_EXT_TEMP_LOW
			      : ADT7411_STAT_1_INT_TEMP_LOW;
		break;
	case hwmon_temp_max_alarm:
		bit = channel ? ADT7411_STAT_1_EXT_TEMP_HIGH_AIN1
			      : ADT7411_STAT_1_INT_TEMP_HIGH;
		break;
	case hwmon_temp_fault:
		bit = ADT7411_STAT_1_EXT_TEMP_FAULT;
		break;
	default:
		return -EOPNOTSUPP;
	}

	*val = !!(ret & bit);
	return 0;
}

static int adt7411_read_temp(struct device *dev, u32 attr, int channel,
			     long *val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret, reg, regl, regh;

	switch (attr) {
	case hwmon_temp_input:
		regl = channel ? ADT7411_REG_EXT_TEMP_AIN14_LSB :
				 ADT7411_REG_INT_TEMP_VDD_LSB;
		regh = channel ? ADT7411_REG_EXT_TEMP_AIN1_MSB :
				 ADT7411_REG_INT_TEMP_MSB;
		ret = adt7411_read_10_bit(client, regl, regh, 0);
		if (ret < 0)
			return ret;
		ret = ret & 0x200 ? ret - 0x400 : ret; /* 10 bit signed */
		*val = ret * 250;
		return 0;
	case hwmon_temp_min:
	case hwmon_temp_max:
		reg = (attr == hwmon_temp_min)
			? ADT7411_REG_TEMP_LOW(channel)
			: ADT7411_REG_TEMP_HIGH(channel);
		ret = i2c_smbus_read_byte_data(client, reg);
		if (ret < 0)
			return ret;
		ret = ret & 0x80 ? ret - 0x100 : ret; /* 8 bit signed */
		*val = ret * 1000;
		return 0;
	case hwmon_temp_min_alarm:
	case hwmon_temp_max_alarm:
	case hwmon_temp_fault:
		return adt7411_read_temp_alarm(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static int adt7411_read(struct device *dev, enum hwmon_sensor_types type,
			u32 attr, int channel, long *val)
{
	switch (type) {
	case hwmon_in:
		return adt7411_read_in(dev, attr, channel, val);
	case hwmon_temp:
		return adt7411_read_temp(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static int adt7411_write_in_vdd(struct device *dev, u32 attr, long val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int reg;

	val = clamp_val(val, 0, 255 * 7000 / 256);
	val = DIV_ROUND_CLOSEST(val * 256, 7000);

	switch (attr) {
	case hwmon_in_min:
		reg = ADT7411_REG_VDD_LOW;
		break;
	case hwmon_in_max:
		reg = ADT7411_REG_VDD_HIGH;
		break;
	default:
		return -EOPNOTSUPP;
	}

	return i2c_smbus_write_byte_data(client, reg, val);
}

static int adt7411_write_in_chan(struct device *dev, u32 attr, int channel,
				 long val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int ret, reg;

	ret = adt7411_update_vref(dev);
	if (ret < 0)
		return ret;
	val = clamp_val(val, 0, 255 * data->vref_cached / 256);
	val = DIV_ROUND_CLOSEST(val * 256, data->vref_cached);

	switch (attr) {
	case hwmon_in_min:
		reg = ADT7411_REG_IN_LOW(channel);
		break;
	case hwmon_in_max:
		reg = ADT7411_REG_IN_HIGH(channel);
		break;
	default:
		return -EOPNOTSUPP;
	}

	ret = i2c_smbus_write_byte_data(client, reg, val);
	return ret;
}

static int adt7411_write_in(struct device *dev, u32 attr, int channel,
			    long val)
{
	if (channel == 0)
		return adt7411_write_in_vdd(dev, attr, val);
	else
		return adt7411_write_in_chan(dev, attr, channel, val);
}

static int adt7411_write_temp(struct device *dev, u32 attr, int channel,
			      long val)
{
	struct adt7411_data *data = dev_get_drvdata(dev);
	struct i2c_client *client = data->client;
	int reg;

	val = clamp_val(val, -128000, 127000);
	val = DIV_ROUND_CLOSEST(val, 1000);

	switch (attr) {
	case hwmon_temp_min:
		reg = ADT7411_REG_TEMP_LOW(channel);
		break;
	case hwmon_temp_max:
		reg = ADT7411_REG_TEMP_HIGH(channel);
		break;
	default:
		return -EOPNOTSUPP;
	}

	return i2c_smbus_write_byte_data(client, reg, val);
}

static int adt7411_write(struct device *dev, enum hwmon_sensor_types type,
			 u32 attr, int channel, long val)
{
	switch (type) {
	case hwmon_in:
		return adt7411_write_in(dev, attr, channel, val);
	case hwmon_temp:
		return adt7411_write_temp(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static umode_t adt7411_is_visible(const void *_data,
				  enum hwmon_sensor_types type,
				  u32 attr, int channel)
{
	const struct adt7411_data *data = _data;
	bool visible;

	switch (type) {
	case hwmon_in:
		visible = channel == 0 || channel >= 3 || !data->use_ext_temp;
		switch (attr) {
		case hwmon_in_input:
		case hwmon_in_alarm:
			return visible ? S_IRUGO : 0;
		case hwmon_in_min:
		case hwmon_in_max:
			return visible ? S_IRUGO | S_IWUSR : 0;
		}
		break;
	case hwmon_temp:
		visible = channel == 0 || data->use_ext_temp;
		switch (attr) {
		case hwmon_temp_input:
		case hwmon_temp_min_alarm:
		case hwmon_temp_max_alarm:
		case hwmon_temp_fault:
			return visible ? S_IRUGO : 0;
		case hwmon_temp_min:
		case hwmon_temp_max:
			return visible ? S_IRUGO | S_IWUSR : 0;
		}
		break;
	default:
		break;
	}
	return 0;
}

static int adt7411_detect(struct i2c_client *client,
			  struct i2c_board_info *info)
{
	int val;

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

	val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
	if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
		dev_dbg(&client->dev,
			"Wrong manufacturer ID. Got %d, expected %d\n",
			val, ADT7411_MANUFACTURER_ID);
		return -ENODEV;
	}

	val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
	if (val < 0 || val != ADT7411_DEVICE_ID) {
		dev_dbg(&client->dev,
			"Wrong device ID. Got %d, expected %d\n",
			val, ADT7411_DEVICE_ID);
		return -ENODEV;
	}

	strscpy(info->type, "adt7411", I2C_NAME_SIZE);

	return 0;
}

static int adt7411_init_device(struct adt7411_data *data)
{
	int ret;
	u8 val;

	ret = i2c_smbus_read_byte_data(data->client, ADT7411_REG_CFG3);
	if (ret < 0)
		return ret;

	/*
	 * We must only write zero to bit 1 and bit 2 and only one to bit 3
	 * according to the datasheet.
	 */
	val = ret;
	val &= ~(ADT7411_CFG3_RESERVED_BIT1 | ADT7411_CFG3_RESERVED_BIT2);
	val |= ADT7411_CFG3_RESERVED_BIT3;

	ret = i2c_smbus_write_byte_data(data->client, ADT7411_REG_CFG3, val);
	if (ret < 0)
		return ret;

	ret = i2c_smbus_read_byte_data(data->client, ADT7411_REG_CFG1);
	if (ret < 0)
		return ret;

	data->use_ext_temp = ret & ADT7411_CFG1_EXT_TDM;

	/*
	 * We must only write zero to bit 1 and only one to bit 3 according to
	 * the datasheet.
	 */
	val = ret;
	val &= ~ADT7411_CFG1_RESERVED_BIT1;
	val |= ADT7411_CFG1_RESERVED_BIT3;

	/* enable monitoring */
	val |= ADT7411_CFG1_START_MONITOR;

	return i2c_smbus_write_byte_data(data->client, ADT7411_REG_CFG1, val);
}

static const struct hwmon_channel_info * const adt7411_info[] = {
	HWMON_CHANNEL_INFO(in,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM,
			   HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX | HWMON_I_ALARM),
	HWMON_CHANNEL_INFO(temp,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MIN_ALARM |
			   HWMON_T_MAX | HWMON_T_MAX_ALARM,
			   HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MIN_ALARM |
			   HWMON_T_MAX | HWMON_T_MAX_ALARM | HWMON_T_FAULT),
	NULL
};

static const struct hwmon_ops adt7411_hwmon_ops = {
	.is_visible = adt7411_is_visible,
	.read = adt7411_read,
	.write = adt7411_write,
};

static const struct hwmon_chip_info adt7411_chip_info = {
	.ops = &adt7411_hwmon_ops,
	.info = adt7411_info,
};

static int adt7411_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct adt7411_data *data;
	struct device *hwmon_dev;
	int ret;

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

	i2c_set_clientdata(client, data);
	data->client = client;

	ret = adt7411_init_device(data);
	if (ret < 0)
		return ret;

	/* force update on first occasion */
	data->next_update = jiffies;

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
							 data,
							 &adt7411_chip_info,
							 adt7411_groups);
	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct i2c_device_id adt7411_id[] = {
	{ "adt7411" },
	{ }
};
MODULE_DEVICE_TABLE(i2c, adt7411_id);

static struct i2c_driver adt7411_driver = {
	.driver		= {
		.name		= "adt7411",
	},
	.probe = adt7411_probe,
	.id_table = adt7411_id,
	.detect = adt7411_detect,
	.address_list = normal_i2c,
	.class = I2C_CLASS_HWMON,
};

module_i2c_driver(adt7411_driver);

MODULE_AUTHOR("Sascha Hauer, Wolfram Sang <kernel@pengutronix.de>");
MODULE_DESCRIPTION("ADT7411 driver");
MODULE_LICENSE("GPL v2");