drivers/hwmon/tmp464.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later

 /* Driver for the Texas Instruments TMP464 SMBus temperature sensor IC.
  * Supported models: TMP464, TMP468

  * Copyright (C) 2022 Agathe Porte <agathe.porte@nokia.com>
  * Preliminary support by:
  * Lionel Pouliquen <lionel.lp.pouliquen@nokia.com>
  */

 #include <linux/err.h>
 #include <linux/hwmon.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>

 /* Addresses to scan */
 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END };

 #define TMP464_NUM_CHANNELS		5	/* chan 0 is internal, 1-4 are remote */
 #define TMP468_NUM_CHANNELS		9	/* chan 0 is internal, 1-8 are remote */

 #define MAX_CHANNELS			9

 #define TMP464_TEMP_REG(channel)	(channel)
 #define TMP464_TEMP_OFFSET_REG(channel)	(0x40 + ((channel) - 1) * 8)
 #define TMP464_N_FACTOR_REG(channel)	(0x41 + ((channel) - 1) * 8)

 static const u8 TMP464_THERM_LIMIT[MAX_CHANNELS] = {
 	0x39, 0x42, 0x4A, 0x52, 0x5A, 0x62, 0x6a, 0x72, 0x7a };
 static const u8 TMP464_THERM2_LIMIT[MAX_CHANNELS] = {
 	0x3A, 0x43, 0x4B, 0x53, 0x5B, 0x63, 0x6b, 0x73, 0x7b };

 #define TMP464_THERM_STATUS_REG			0x21
 #define TMP464_THERM2_STATUS_REG		0x22
 #define TMP464_REMOTE_OPEN_REG			0x23
 #define TMP464_CONFIG_REG			0x30
 #define TMP464_TEMP_HYST_REG			0x38
 #define TMP464_LOCK_REG				0xc4

 /* Identification */
 #define TMP464_MANUFACTURER_ID_REG		0xFE
 #define TMP464_DEVICE_ID_REG			0xFF

 /* Flags */
 #define TMP464_CONFIG_SHUTDOWN			BIT(5)
 #define TMP464_CONFIG_RANGE			0x04
 #define TMP464_CONFIG_REG_REN(x)		(BIT(7 + (x)))
 #define TMP464_CONFIG_REG_REN_MASK		GENMASK(15, 7)
 #define TMP464_CONFIG_CONVERSION_RATE_B0	2
 #define TMP464_CONFIG_CONVERSION_RATE_B2	4
 #define TMP464_CONFIG_CONVERSION_RATE_MASK      GENMASK(TMP464_CONFIG_CONVERSION_RATE_B2, \
 							TMP464_CONFIG_CONVERSION_RATE_B0)

 #define TMP464_UNLOCK_VAL			0xeb19
 #define TMP464_LOCK_VAL				0x5ca6
 #define TMP464_LOCKED				0x8000

 /* Manufacturer / Device ID's */
 #define TMP464_MANUFACTURER_ID			0x5449
 #define TMP464_DEVICE_ID			0x1468
 #define TMP468_DEVICE_ID			0x0468

 static const struct i2c_device_id tmp464_id[] = {
 	{ "tmp464", TMP464_NUM_CHANNELS },
 	{ "tmp468", TMP468_NUM_CHANNELS },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, tmp464_id);

 static const struct of_device_id __maybe_unused tmp464_of_match[] = {
 	{
 		.compatible = "ti,tmp464",
 		.data = (void *)TMP464_NUM_CHANNELS
 	},
 	{
 		.compatible = "ti,tmp468",
 		.data = (void *)TMP468_NUM_CHANNELS
 	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, tmp464_of_match);

 struct tmp464_channel {
 	const char *label;
 	bool enabled;
 };

 struct tmp464_data {
 	struct regmap *regmap;
 	struct mutex update_lock;
 	int channels;
 	s16 config_orig;
 	u16 open_reg;
 	unsigned long last_updated;
 	bool valid;
 	int update_interval;
 	struct tmp464_channel channel[MAX_CHANNELS];
 };

 static int temp_from_reg(s16 reg)
 {
 	return DIV_ROUND_CLOSEST((reg >> 3) * 625, 10);
 }

 static s16 temp_to_limit_reg(long temp)
 {
 	return DIV_ROUND_CLOSEST(temp, 500) << 6;
 }

 static s16 temp_to_offset_reg(long temp)
 {
 	return DIV_ROUND_CLOSEST(temp * 10, 625) << 3;
 }

 static int tmp464_enable_channels(struct tmp464_data *data)
 {
 	struct regmap *regmap = data->regmap;
 	u16 enable = 0;
 	int i;

 	for (i = 0; i < data->channels; i++)
 		if (data->channel[i].enabled)
 			enable |= TMP464_CONFIG_REG_REN(i);

 	return regmap_update_bits(regmap, TMP464_CONFIG_REG, TMP464_CONFIG_REG_REN_MASK, enable);
 }

 static int tmp464_chip_read(struct device *dev, u32 attr, int channel, long *val)
 {
 	struct tmp464_data *data = dev_get_drvdata(dev);

 	switch (attr) {
 	case hwmon_chip_update_interval:
 		*val = data->update_interval;
 		return 0;
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static int tmp464_temp_read(struct device *dev, u32 attr, int channel, long *val)
 {
 	struct tmp464_data *data = dev_get_drvdata(dev);
 	struct regmap *regmap = data->regmap;
 	unsigned int regs[2];
 	unsigned int regval;
 	u16 regvals[2];
 	int err = 0;

 	switch (attr) {
 	case hwmon_temp_max_alarm:
 		err = regmap_read(regmap, TMP464_THERM_STATUS_REG, &regval);
 		if (err < 0)
 			break;
 		*val = !!(regval & BIT(channel + 7));
 		break;
 	case hwmon_temp_crit_alarm:
 		err = regmap_read(regmap, TMP464_THERM2_STATUS_REG, &regval);
 		if (err < 0)
 			break;
 		*val = !!(regval & BIT(channel + 7));
 		break;
 	case hwmon_temp_fault:
 		/*
 		 * The chip clears TMP464_REMOTE_OPEN_REG after it is read
 		 * and only updates it after the next measurement cycle is
 		 * complete. That means we have to cache the value internally
 		 * for one measurement cycle and report the cached value.
 		 */
 		mutex_lock(&data->update_lock);
 		if (!data->valid || time_after(jiffies, data->last_updated +
 					       msecs_to_jiffies(data->update_interval))) {
 			err = regmap_read(regmap, TMP464_REMOTE_OPEN_REG, &regval);
 			if (err < 0)
 				goto unlock;
 			data->open_reg = regval;
 			data->last_updated = jiffies;
 			data->valid = true;
 		}
 		*val = !!(data->open_reg & BIT(channel + 7));
 unlock:
 		mutex_unlock(&data->update_lock);
 		break;
 	case hwmon_temp_max_hyst:
 		regs[0] = TMP464_THERM_LIMIT[channel];
 		regs[1] = TMP464_TEMP_HYST_REG;
 		err = regmap_multi_reg_read(regmap, regs, regvals, 2);
 		if (err < 0)
 			break;
 		*val = temp_from_reg(regvals[0] - regvals[1]);
 		break;
 	case hwmon_temp_max:
 		err = regmap_read(regmap, TMP464_THERM_LIMIT[channel], &regval);
 		if (err < 0)
 			break;
 		*val = temp_from_reg(regval);
 		break;
 	case hwmon_temp_crit_hyst:
 		regs[0] = TMP464_THERM2_LIMIT[channel];
 		regs[1] = TMP464_TEMP_HYST_REG;
 		err = regmap_multi_reg_read(regmap, regs, regvals, 2);
 		if (err < 0)
 			break;
 		*val = temp_from_reg(regvals[0] - regvals[1]);
 		break;
 	case hwmon_temp_crit:
 		err = regmap_read(regmap, TMP464_THERM2_LIMIT[channel], &regval);
 		if (err < 0)
 			break;
 		*val = temp_from_reg(regval);
 		break;
 	case hwmon_temp_offset:
 		err = regmap_read(regmap, TMP464_TEMP_OFFSET_REG(channel), &regval);
 		if (err < 0)
 			break;
 		*val = temp_from_reg(regval);
 		break;
 	case hwmon_temp_input:
 		if (!data->channel[channel].enabled) {
 			err = -ENODATA;
 			break;
 		}
 		err = regmap_read(regmap, TMP464_TEMP_REG(channel), &regval);
 		if (err < 0)
 			break;
 		*val = temp_from_reg(regval);
 		break;
 	case hwmon_temp_enable:
 		*val = data->channel[channel].enabled;
 		break;
 	default:
 		err = -EOPNOTSUPP;
 		break;
 	}

 	return err;
 }

 static int tmp464_read(struct device *dev, enum hwmon_sensor_types type,
 		       u32 attr, int channel, long *val)
 {
 	switch (type) {
 	case hwmon_chip:
 		return tmp464_chip_read(dev, attr, channel, val);
 	case hwmon_temp:
 		return tmp464_temp_read(dev, attr, channel, val);
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static int tmp464_read_string(struct device *dev, enum hwmon_sensor_types type,
 			      u32 attr, int channel, const char **str)
 {
 	struct tmp464_data *data = dev_get_drvdata(dev);

 	*str = data->channel[channel].label;

 	return 0;
 }

 static int tmp464_set_convrate(struct tmp464_data *data, long interval)
 {
 	int rate;

 	/*
 	 * For valid rates, interval in milli-seconds can be calculated as
 	 *      interval = 125 << (7 - rate);
 	 * or
 	 *      interval = (1 << (7 - rate)) * 125;
 	 * The rate is therefore
 	 *      rate = 7 - __fls(interval / 125);
 	 * and the rounded rate is
 	 *      rate = 7 - __fls(interval * 4 / (125 * 3));
 	 * Use clamp_val() to avoid overflows, and to ensure valid input
 	 * for __fls.
 	 */
 	interval = clamp_val(interval, 125, 16000);
 	rate = 7 - __fls(interval * 4 / (125 * 3));
 	data->update_interval = 125 << (7 - rate);

 	return regmap_update_bits(data->regmap, TMP464_CONFIG_REG,
 				  TMP464_CONFIG_CONVERSION_RATE_MASK,
 				  rate << TMP464_CONFIG_CONVERSION_RATE_B0);
 }

 static int tmp464_chip_write(struct tmp464_data *data, u32 attr, int channel, long val)
 {
 	switch (attr) {
 	case hwmon_chip_update_interval:
 		return tmp464_set_convrate(data, val);
 	default:
 		return -EOPNOTSUPP;
 	}
 }

 static int tmp464_temp_write(struct tmp464_data *data, u32 attr, int channel, long val)
 {
 	struct regmap *regmap = data->regmap;
 	unsigned int regval;
 	int err = 0;

 	switch (attr) {
 	case hwmon_temp_max_hyst:
 		err = regmap_read(regmap, TMP464_THERM_LIMIT[0], &regval);
 		if (err < 0)
 			break;
 		val = clamp_val(val, -256000, 256000);	/* prevent overflow/underflow */
 		val = clamp_val(temp_from_reg(regval) - val, 0, 255000);
 		err = regmap_write(regmap, TMP464_TEMP_HYST_REG,
 				   DIV_ROUND_CLOSEST(val, 1000) << 7);
 		break;
 	case hwmon_temp_max:
 		val = temp_to_limit_reg(clamp_val(val, -255000, 255500));
 		err = regmap_write(regmap, TMP464_THERM_LIMIT[channel], val);
 		break;
 	case hwmon_temp_crit:
 		val = temp_to_limit_reg(clamp_val(val, -255000, 255500));
 		err = regmap_write(regmap, TMP464_THERM2_LIMIT[channel], val);
 		break;
 	case hwmon_temp_offset:
 		val = temp_to_offset_reg(clamp_val(val, -128000, 127937));
 		err = regmap_write(regmap, TMP464_TEMP_OFFSET_REG(channel), val);
 		break;
 	case hwmon_temp_enable:
 		data->channel[channel].enabled = !!val;
 		err = tmp464_enable_channels(data);
 		break;
 	default:
 		err = -EOPNOTSUPP;
 		break;
 	}

 	return err;
 }

 static int tmp464_write(struct device *dev, enum hwmon_sensor_types type,
 			u32 attr, int channel, long val)
 {
 	struct tmp464_data *data = dev_get_drvdata(dev);
 	int err;

 	mutex_lock(&data->update_lock);

 	switch (type) {
 	case hwmon_chip:
 		err = tmp464_chip_write(data, attr, channel, val);
 		break;
 	case hwmon_temp:
 		err = tmp464_temp_write(data, attr, channel, val);
 		break;
 	default:
 		err = -EOPNOTSUPP;
 		break;
 	}

 	mutex_unlock(&data->update_lock);

 	return err;
 }

 static umode_t tmp464_is_visible(const void *_data, enum hwmon_sensor_types type,
 				 u32 attr, int channel)
 {
 	const struct tmp464_data *data = _data;

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

 	if (type == hwmon_chip) {
 		if (attr == hwmon_chip_update_interval)
 			return 0644;
 		return 0;
 	}

 	switch (attr) {
 	case hwmon_temp_input:
 	case hwmon_temp_max_alarm:
 	case hwmon_temp_crit_alarm:
 	case hwmon_temp_crit_hyst:
 		return 0444;
 	case hwmon_temp_enable:
 	case hwmon_temp_max:
 	case hwmon_temp_crit:
 		return 0644;
 	case hwmon_temp_max_hyst:
 		if (!channel)
 			return 0644;
 		return 0444;
 	case hwmon_temp_label:
 		if (data->channel[channel].label)
 			return 0444;
 		return 0;
 	case hwmon_temp_fault:
 		if (channel)
 			return 0444;
 		return 0;
 	case hwmon_temp_offset:
 		if (channel)
 			return 0644;
 		return 0;
 	default:
 		return 0;
 	}
 }

 static void tmp464_restore_lock(void *regmap)
 {
 	regmap_write(regmap, TMP464_LOCK_REG, TMP464_LOCK_VAL);
 }

 static void tmp464_restore_config(void *_data)
 {
 	struct tmp464_data *data = _data;

 	regmap_write(data->regmap, TMP464_CONFIG_REG, data->config_orig);
 }

 static int tmp464_init_client(struct device *dev, struct tmp464_data *data)
 {
 	struct regmap *regmap = data->regmap;
 	unsigned int regval;
 	int err;

 	err = regmap_read(regmap, TMP464_LOCK_REG, &regval);
 	if (err)
 		return err;
 	if (regval == TMP464_LOCKED) {
 		/* Explicitly unlock chip if it is locked */
 		err = regmap_write(regmap, TMP464_LOCK_REG, TMP464_UNLOCK_VAL);
 		if (err)
 			return err;
 		/* and lock it again when unloading the driver */
 		err = devm_add_action_or_reset(dev, tmp464_restore_lock, regmap);
 		if (err)
 			return err;
 	}

 	err = regmap_read(regmap, TMP464_CONFIG_REG, &regval);
 	if (err)
 		return err;
 	data->config_orig = regval;
 	err = devm_add_action_or_reset(dev, tmp464_restore_config, data);
 	if (err)
 		return err;

 	/* Default to 500 ms update interval */
 	err = regmap_update_bits(regmap, TMP464_CONFIG_REG,
 				 TMP464_CONFIG_CONVERSION_RATE_MASK | TMP464_CONFIG_SHUTDOWN,
 				 BIT(TMP464_CONFIG_CONVERSION_RATE_B0) |
 				 BIT(TMP464_CONFIG_CONVERSION_RATE_B2));
 	if (err)
 		return err;

 	data->update_interval = 500;

 	return tmp464_enable_channels(data);
 }

 static int tmp464_detect(struct i2c_client *client,
 			 struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = client->adapter;
 	char *name, *chip;
 	int reg;

 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
 		return -ENODEV;

 	reg = i2c_smbus_read_word_swapped(client, TMP464_MANUFACTURER_ID_REG);
 	if (reg < 0)
 		return reg;
 	if (reg != TMP464_MANUFACTURER_ID)
 		return -ENODEV;

 	/* Check for "always return zero" bits */
 	reg = i2c_smbus_read_word_swapped(client, TMP464_THERM_STATUS_REG);
 	if (reg < 0)
 		return reg;
 	if (reg & 0x1f)
 		return -ENODEV;
 	reg = i2c_smbus_read_word_swapped(client, TMP464_THERM2_STATUS_REG);
 	if (reg < 0)
 		return reg;
 	if (reg & 0x1f)
 		return -ENODEV;

 	reg = i2c_smbus_read_word_swapped(client, TMP464_DEVICE_ID_REG);
 	if (reg < 0)
 		return reg;
 	switch (reg) {
 	case TMP464_DEVICE_ID:
 		name = "tmp464";
 		chip = "TMP464";
 		break;
 	case TMP468_DEVICE_ID:
 		name = "tmp468";
 		chip = "TMP468";
 		break;
 	default:
 		return -ENODEV;
 	}

 	strscpy(info->type, name, I2C_NAME_SIZE);
 	dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n", chip, client->addr);

 	return 0;
 }

 static int tmp464_probe_child_from_dt(struct device *dev,
 				      struct device_node *child,
 				      struct tmp464_data *data)

 {
 	struct regmap *regmap = data->regmap;
 	u32 channel;
 	s32 nfactor;
 	int err;

 	err = of_property_read_u32(child, "reg", &channel);
 	if (err) {
 		dev_err(dev, "missing reg property of %pOFn\n", child);
 		return err;
 	}

 	if (channel >= data->channels) {
 		dev_err(dev, "invalid reg %d of %pOFn\n", channel, child);
 		return -EINVAL;
 	}

 	of_property_read_string(child, "label", &data->channel[channel].label);

 	data->channel[channel].enabled = of_device_is_available(child);

 	err = of_property_read_s32(child, "ti,n-factor", &nfactor);
 	if (err && err != -EINVAL)
 		return err;
 	if (!err) {
 		if (channel == 0) {
 			dev_err(dev, "n-factor can't be set for internal channel\n");
 			return -EINVAL;
 		}
 		if (nfactor > 127 || nfactor < -128) {
 			dev_err(dev, "n-factor for channel %d invalid (%d)\n",
 				channel, nfactor);
 			return -EINVAL;
 		}
 		err = regmap_write(regmap, TMP464_N_FACTOR_REG(channel),
 				   (nfactor << 8) & 0xff00);
 		if (err)
 			return err;
 	}

 	return 0;
 }

 static int tmp464_probe_from_dt(struct device *dev, struct tmp464_data *data)
 {
 	const struct device_node *np = dev->of_node;
 	int err;

 	for_each_child_of_node_scoped(np, child) {
 		if (strcmp(child->name, "channel"))
 			continue;

 		err = tmp464_probe_child_from_dt(dev, child, data);
 		if (err)
 			return err;
 	}

 	return 0;
 }

 static const struct hwmon_ops tmp464_ops = {
 	.is_visible = tmp464_is_visible,
 	.read = tmp464_read,
 	.read_string = tmp464_read_string,
 	.write = tmp464_write,
 };

 static const struct hwmon_channel_info * const tmp464_info[] = {
 	HWMON_CHANNEL_INFO(chip,
 			   HWMON_C_UPDATE_INTERVAL),
 	HWMON_CHANNEL_INFO(temp,
 			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST | HWMON_T_CRIT |
 			   HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM |
 			   HWMON_T_LABEL | HWMON_T_ENABLE,
 			   HWMON_T_INPUT | HWMON_T_OFFSET | HWMON_T_MAX | HWMON_T_MAX_HYST |
 			   HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM |
 			   HWMON_T_CRIT_ALARM | HWMON_T_FAULT | HWMON_T_LABEL | HWMON_T_ENABLE,
 			   HWMON_T_INPUT | HWMON_T_OFFSET | HWMON_T_MAX | HWMON_T_MAX_HYST |
 			   HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM |
 			   HWMON_T_CRIT_ALARM | HWMON_T_FAULT | HWMON_T_LABEL | HWMON_T_ENABLE,
 			   HWMON_T_INPUT | HWMON_T_OFFSET | HWMON_T_MAX | HWMON_T_MAX_HYST |
 			   HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM |
 			   HWMON_T_CRIT_ALARM | HWMON_T_FAULT | HWMON_T_LABEL | HWMON_T_ENABLE,
 			   HWMON_T_INPUT | HWMON_T_OFFSET | HWMON_T_MAX | HWMON_T_MAX_HYST |
 			   HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM |
 			   HWMON_T_CRIT_ALARM | HWMON_T_FAULT | HWMON_T_LABEL | HWMON_T_ENABLE,
 			   HWMON_T_INPUT | HWMON_T_OFFSET | HWMON_T_MAX | HWMON_T_MAX_HYST |
 			   HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM |
 			   HWMON_T_CRIT_ALARM | HWMON_T_FAULT | HWMON_T_LABEL | HWMON_T_ENABLE,
 			   HWMON_T_INPUT | HWMON_T_OFFSET | HWMON_T_MAX | HWMON_T_MAX_HYST |
 			   HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM |
 			   HWMON_T_CRIT_ALARM | HWMON_T_FAULT | HWMON_T_LABEL | HWMON_T_ENABLE,
 			   HWMON_T_INPUT | HWMON_T_OFFSET | HWMON_T_MAX | HWMON_T_MAX_HYST |
 			   HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM |
 			   HWMON_T_CRIT_ALARM | HWMON_T_FAULT | HWMON_T_LABEL | HWMON_T_ENABLE,
 			   HWMON_T_INPUT | HWMON_T_OFFSET | HWMON_T_MAX | HWMON_T_MAX_HYST |
 			   HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_MAX_ALARM |
 			   HWMON_T_CRIT_ALARM | HWMON_T_FAULT | HWMON_T_LABEL | HWMON_T_ENABLE),
 	NULL
 };

 static const struct hwmon_chip_info tmp464_chip_info = {
 	.ops = &tmp464_ops,
 	.info = tmp464_info,
 };

 /* regmap */

 static bool tmp464_is_volatile_reg(struct device *dev, unsigned int reg)
 {
 	return (reg < TMP464_TEMP_REG(TMP468_NUM_CHANNELS) ||
 		reg == TMP464_THERM_STATUS_REG ||
 		reg == TMP464_THERM2_STATUS_REG ||
 		reg == TMP464_REMOTE_OPEN_REG);
 }

 static const struct regmap_config tmp464_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 16,
 	.max_register = TMP464_DEVICE_ID_REG,
 	.volatile_reg = tmp464_is_volatile_reg,
 	.val_format_endian = REGMAP_ENDIAN_BIG,
 	.cache_type = REGCACHE_MAPLE,
 	.use_single_read = true,
 	.use_single_write = true,
 };

 static int tmp464_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
 	struct device *hwmon_dev;
 	struct tmp464_data *data;
 	int i, err;

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
 		dev_err(&client->dev, "i2c functionality check failed\n");
 		return -ENODEV;
 	}
 	data = devm_kzalloc(dev, sizeof(struct tmp464_data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	mutex_init(&data->update_lock);

 	data->channels = (int)(unsigned long)i2c_get_match_data(client);

 	data->regmap = devm_regmap_init_i2c(client, &tmp464_regmap_config);
 	if (IS_ERR(data->regmap))
 		return PTR_ERR(data->regmap);

 	for (i = 0; i < data->channels; i++)
 		data->channel[i].enabled = true;

 	err = tmp464_init_client(dev, data);
 	if (err)
 		return err;

 	if (dev->of_node) {
 		err = tmp464_probe_from_dt(dev, data);
 		if (err)
 			return err;
 	}

 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 							 data, &tmp464_chip_info, NULL);
 	return PTR_ERR_OR_ZERO(hwmon_dev);
 }

 static struct i2c_driver tmp464_driver = {
 	.class = I2C_CLASS_HWMON,
 	.driver = {
 		.name	= "tmp464",
 		.of_match_table = of_match_ptr(tmp464_of_match),
 	},
 	.probe = tmp464_probe,
 	.id_table = tmp464_id,
 	.detect = tmp464_detect,
 	.address_list = normal_i2c,
 };

 module_i2c_driver(tmp464_driver);

 MODULE_AUTHOR("Agathe Porte <agathe.porte@nokia.com>");
 MODULE_DESCRIPTION("Texas Instruments TMP464 temperature sensor driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later

	/* Driver for the Texas Instruments TMP464 SMBus temperature sensor IC.
	* Supported models: TMP464, TMP468

	* Copyright (C) 2022 Agathe Porte <agathe.porte@nokia.com>
	* Preliminary support by:
	* Lionel Pouliquen <lionel.lp.pouliquen@nokia.com>
	*/

	#include <linux/err.h>
	#include <linux/hwmon.h>
	#include <linux/i2c.h>
	#include <linux/init.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/of.h>
	#include <linux/regmap.h>
	#include <linux/slab.h>

	/* Addresses to scan */
	static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END };

	#define TMP464_NUM_CHANNELS 5 /* chan 0 is internal, 1-4 are remote */
	#define TMP468_NUM_CHANNELS 9 /* chan 0 is internal, 1-8 are remote */

	#define MAX_CHANNELS 9

	#define TMP464_TEMP_REG(channel) (channel)
	#define TMP464_TEMP_OFFSET_REG(channel) (0x40 + ((channel) - 1) * 8)
	#define TMP464_N_FACTOR_REG(channel) (0x41 + ((channel) - 1) * 8)

	static const u8 TMP464_THERM_LIMIT[MAX_CHANNELS] = {
	0x39, 0x42, 0x4A, 0x52, 0x5A, 0x62, 0x6a, 0x72, 0x7a };
	static const u8 TMP464_THERM2_LIMIT[MAX_CHANNELS] = {
	0x3A, 0x43, 0x4B, 0x53, 0x5B, 0x63, 0x6b, 0x73, 0x7b };

	#define TMP464_THERM_STATUS_REG 0x21
	#define TMP464_THERM2_STATUS_REG 0x22
	#define TMP464_REMOTE_OPEN_REG 0x23
	#define TMP464_CONFIG_REG 0x30
	#define TMP464_TEMP_HYST_REG 0x38
	#define TMP464_LOCK_REG 0xc4

	/* Identification */
	#define TMP464_MANUFACTURER_ID_REG 0xFE
	#define TMP464_DEVICE_ID_REG 0xFF

	/* Flags */
	#define TMP464_CONFIG_SHUTDOWN BIT(5)
	#define TMP464_CONFIG_RANGE 0x04
	#define TMP464_CONFIG_REG_REN(x) (BIT(7 + (x)))
	#define TMP464_CONFIG_REG_REN_MASK GENMASK(15, 7)
	#define TMP464_CONFIG_CONVERSION_RATE_B0 2
	#define TMP464_CONFIG_CONVERSION_RATE_B2 4
	#define TMP464_CONFIG_CONVERSION_RATE_MASK GENMASK(TMP464_CONFIG_CONVERSION_RATE_B2, \
	TMP464_CONFIG_CONVERSION_RATE_B0)

	#define TMP464_UNLOCK_VAL 0xeb19
	#define TMP464_LOCK_VAL 0x5ca6
	#define TMP464_LOCKED 0x8000

	/* Manufacturer / Device ID's */
	#define TMP464_MANUFACTURER_ID 0x5449
	#define TMP464_DEVICE_ID 0x1468
	#define TMP468_DEVICE_ID 0x0468

	static const struct i2c_device_id tmp464_id[] = {
	{ "tmp464", TMP464_NUM_CHANNELS },
	{ "tmp468", TMP468_NUM_CHANNELS },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, tmp464_id);

	static const struct of_device_id __maybe_unused tmp464_of_match[] = {
	{
	.compatible = "ti,tmp464",
	.data = (void *)TMP464_NUM_CHANNELS
	},
	{
	.compatible = "ti,tmp468",
	.data = (void *)TMP468_NUM_CHANNELS
	},
	{},
	};
	MODULE_DEVICE_TABLE(of, tmp464_of_match);

	struct tmp464_channel {
	const char *label;
	bool enabled;
	};

	struct tmp464_data {
	struct regmap *regmap;
	struct mutex update_lock;
	int channels;
	s16 config_orig;
	u16 open_reg;
	unsigned long last_updated;
	bool valid;
	int update_interval;
	struct tmp464_channel channel[MAX_CHANNELS];
	};

	static int temp_from_reg(s16 reg)
	{
	return DIV_ROUND_CLOSEST((reg >> 3) * 625, 10);
	}

	static s16 temp_to_limit_reg(long temp)
	{
	return DIV_ROUND_CLOSEST(temp, 500) << 6;
	}

	static s16 temp_to_offset_reg(long temp)
	{
	return DIV_ROUND_CLOSEST(temp * 10, 625) << 3;
	}

	static int tmp464_enable_channels(struct tmp464_data *data)
	{
	struct regmap *regmap = data->regmap;
	u16 enable = 0;
	int i;

	for (i = 0; i < data->channels; i++)
	if (data->channel[i].enabled)
	enable \|= TMP464_CONFIG_REG_REN(i);

	return regmap_update_bits(regmap, TMP464_CONFIG_REG, TMP464_CONFIG_REG_REN_MASK, enable);
	}

	static int tmp464_chip_read(struct device dev, u32 attr, int channel, long val)
	{
	struct tmp464_data *data = dev_get_drvdata(dev);

	switch (attr) {
	case hwmon_chip_update_interval:
	*val = data->update_interval;
	return 0;
	default:
	return -EOPNOTSUPP;
	}
	}

	static int tmp464_temp_read(struct device dev, u32 attr, int channel, long val)
	{
	struct tmp464_data *data = dev_get_drvdata(dev);
	struct regmap *regmap = data->regmap;
	unsigned int regs[2];
	unsigned int regval;
	u16 regvals[2];
	int err = 0;

	switch (attr) {
	case hwmon_temp_max_alarm:
	err = regmap_read(regmap, TMP464_THERM_STATUS_REG, &regval);
	if (err < 0)
	break;
	*val = !!(regval & BIT(channel + 7));
	break;
	case hwmon_temp_crit_alarm:
	err = regmap_read(regmap, TMP464_THERM2_STATUS_REG, &regval);
	if (err < 0)
	break;
	*val = !!(regval & BIT(channel + 7));
	break;
	case hwmon_temp_fault:
	/*
	* The chip clears TMP464_REMOTE_OPEN_REG after it is read
	* and only updates it after the next measurement cycle is
	* complete. That means we have to cache the value internally
	* for one measurement cycle and report the cached value.
	*/
	mutex_lock(&data->update_lock);
	if (!data->valid \|\| time_after(jiffies, data->last_updated +
	msecs_to_jiffies(data->update_interval))) {
	err = regmap_read(regmap, TMP464_REMOTE_OPEN_REG, &regval);
	if (err < 0)
	goto unlock;
	data->open_reg = regval;
	data->last_updated = jiffies;
	data->valid = true;
	}
	*val = !!(data->open_reg & BIT(channel + 7));
	unlock:
	mutex_unlock(&data->update_lock);
	break;
	case hwmon_temp_max_hyst:
	regs[0] = TMP464_THERM_LIMIT[channel];
	regs[1] = TMP464_TEMP_HYST_REG;
	err = regmap_multi_reg_read(regmap, regs, regvals, 2);
	if (err < 0)
	break;
	*val = temp_from_reg(regvals[0] - regvals[1]);
	break;
	case hwmon_temp_max:
	err = regmap_read(regmap, TMP464_THERM_LIMIT[channel], &regval);
	if (err < 0)
	break;
	*val = temp_from_reg(regval);
	break;
	case hwmon_temp_crit_hyst:
	regs[0] = TMP464_THERM2_LIMIT[channel];
	regs[1] = TMP464_TEMP_HYST_REG;
	err = regmap_multi_reg_read(regmap, regs, regvals, 2);
	if (err < 0)
	break;
	*val = temp_from_reg(regvals[0] - regvals[1]);
	break;
	case hwmon_temp_crit:
	err = regmap_read(regmap, TMP464_THERM2_LIMIT[channel], &regval);
	if (err < 0)
	break;
	*val = temp_from_reg(regval);
	break;
	case hwmon_temp_offset:
	err = regmap_read(regmap, TMP464_TEMP_OFFSET_REG(channel), &regval);
	if (err < 0)
	break;
	*val = temp_from_reg(regval);
	break;
	case hwmon_temp_input:
	if (!data->channel[channel].enabled) {
	err = -ENODATA;
	break;
	}
	err = regmap_read(regmap, TMP464_TEMP_REG(channel), &regval);
	if (err < 0)
	break;
	*val = temp_from_reg(regval);
	break;
	case hwmon_temp_enable:
	*val = data->channel[channel].enabled;
	break;
	default:
	err = -EOPNOTSUPP;
	break;
	}

	return err;
	}

	static int tmp464_read(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long *val)
	{
	switch (type) {
	case hwmon_chip:
	return tmp464_chip_read(dev, attr, channel, val);
	case hwmon_temp:
	return tmp464_temp_read(dev, attr, channel, val);
	default:
	return -EOPNOTSUPP;
	}
	}

	static int tmp464_read_string(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, const char **str)
	{
	struct tmp464_data *data = dev_get_drvdata(dev);

	*str = data->channel[channel].label;

	return 0;
	}

	static int tmp464_set_convrate(struct tmp464_data *data, long interval)
	{
	int rate;

	/*
	* For valid rates, interval in milli-seconds can be calculated as
	* interval = 125 << (7 - rate);
	* or
	* interval = (1 << (7 - rate)) * 125;
	* The rate is therefore
	* rate = 7 - __fls(interval / 125);
	* and the rounded rate is
	* rate = 7 - __fls(interval * 4 / (125 * 3));
	* Use clamp_val() to avoid overflows, and to ensure valid input
	* for __fls.
	*/
	interval = clamp_val(interval, 125, 16000);
	rate = 7 - __fls(interval * 4 / (125 * 3));
	data->update_interval = 125 << (7 - rate);

	return regmap_update_bits(data->regmap, TMP464_CONFIG_REG,
	TMP464_CONFIG_CONVERSION_RATE_MASK,
	rate << TMP464_CONFIG_CONVERSION_RATE_B0);
	}

	static int tmp464_chip_write(struct tmp464_data *data, u32 attr, int channel, long val)
	{
	switch (attr) {
	case hwmon_chip_update_interval:
	return tmp464_set_convrate(data, val);
	default:
	return -EOPNOTSUPP;
	}
	}

	static int tmp464_temp_write(struct tmp464_data *data, u32 attr, int channel, long val)
	{
	struct regmap *regmap = data->regmap;
	unsigned int regval;
	int err = 0;

	switch (attr) {
	case hwmon_temp_max_hyst:
	err = regmap_read(regmap, TMP464_THERM_LIMIT[0], &regval);
	if (err < 0)
	break;
	val = clamp_val(val, -256000, 256000); /* prevent overflow/underflow */
	val = clamp_val(temp_from_reg(regval) - val, 0, 255000);
	err = regmap_write(regmap, TMP464_TEMP_HYST_REG,
	DIV_ROUND_CLOSEST(val, 1000) << 7);
	break;
	case hwmon_temp_max:
	val = temp_to_limit_reg(clamp_val(val, -255000, 255500));
	err = regmap_write(regmap, TMP464_THERM_LIMIT[channel], val);
	break;
	case hwmon_temp_crit:
	val = temp_to_limit_reg(clamp_val(val, -255000, 255500));
	err = regmap_write(regmap, TMP464_THERM2_LIMIT[channel], val);
	break;
	case hwmon_temp_offset:
	val = temp_to_offset_reg(clamp_val(val, -128000, 127937));
	err = regmap_write(regmap, TMP464_TEMP_OFFSET_REG(channel), val);
	break;
	case hwmon_temp_enable:
	data->channel[channel].enabled = !!val;
	err = tmp464_enable_channels(data);
	break;
	default:
	err = -EOPNOTSUPP;
	break;
	}

	return err;
	}

	static int tmp464_write(struct device *dev, enum hwmon_sensor_types type,
	u32 attr, int channel, long val)
	{
	struct tmp464_data *data = dev_get_drvdata(dev);
	int err;

	mutex_lock(&data->update_lock);

	switch (type) {
	case hwmon_chip:
	err = tmp464_chip_write(data, attr, channel, val);
	break;
	case hwmon_temp:
	err = tmp464_temp_write(data, attr, channel, val);
	break;
	default:
	err = -EOPNOTSUPP;
	break;
	}

	mutex_unlock(&data->update_lock);

	return err;
	}

	static umode_t tmp464_is_visible(const void *_data, enum hwmon_sensor_types type,
	u32 attr, int channel)
	{
	const struct tmp464_data *data = _data;

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

	if (type == hwmon_chip) {
	if (attr == hwmon_chip_update_interval)
	return 0644;
	return 0;
	}

	switch (attr) {
	case hwmon_temp_input:
	case hwmon_temp_max_alarm:
	case hwmon_temp_crit_alarm:
	case hwmon_temp_crit_hyst:
	return 0444;
	case hwmon_temp_enable:
	case hwmon_temp_max:
	case hwmon_temp_crit:
	return 0644;
	case hwmon_temp_max_hyst:
	if (!channel)
	return 0644;
	return 0444;
	case hwmon_temp_label:
	if (data->channel[channel].label)
	return 0444;
	return 0;
	case hwmon_temp_fault:
	if (channel)
	return 0444;
	return 0;
	case hwmon_temp_offset:
	if (channel)
	return 0644;
	return 0;
	default:
	return 0;
	}
	}

	static void tmp464_restore_lock(void *regmap)
	{
	regmap_write(regmap, TMP464_LOCK_REG, TMP464_LOCK_VAL);
	}

	static void tmp464_restore_config(void *_data)
	{
	struct tmp464_data *data = _data;

	regmap_write(data->regmap, TMP464_CONFIG_REG, data->config_orig);
	}

	static int tmp464_init_client(struct device dev, struct tmp464_data data)
	{
	struct regmap *regmap = data->regmap;
	unsigned int regval;
	int err;

	err = regmap_read(regmap, TMP464_LOCK_REG, &regval);
	if (err)
	return err;
	if (regval == TMP464_LOCKED) {
	/* Explicitly unlock chip if it is locked */
	err = regmap_write(regmap, TMP464_LOCK_REG, TMP464_UNLOCK_VAL);
	if (err)
	return err;
	/* and lock it again when unloading the driver */
	err = devm_add_action_or_reset(dev, tmp464_restore_lock, regmap);
	if (err)
	return err;
	}

	err = regmap_read(regmap, TMP464_CONFIG_REG, &regval);
	if (err)
	return err;
	data->config_orig = regval;
	err = devm_add_action_or_reset(dev, tmp464_restore_config, data);
	if (err)
	return err;

	/* Default to 500 ms update interval */
	err = regmap_update_bits(regmap, TMP464_CONFIG_REG,
	TMP464_CONFIG_CONVERSION_RATE_MASK \| TMP464_CONFIG_SHUTDOWN,
	BIT(TMP464_CONFIG_CONVERSION_RATE_B0) \|
	BIT(TMP464_CONFIG_CONVERSION_RATE_B2));
	if (err)
	return err;

	data->update_interval = 500;

	return tmp464_enable_channels(data);
	}

	static int tmp464_detect(struct i2c_client *client,
	struct i2c_board_info *info)
	{
	struct i2c_adapter *adapter = client->adapter;
	char name, chip;
	int reg;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
	return -ENODEV;

	reg = i2c_smbus_read_word_swapped(client, TMP464_MANUFACTURER_ID_REG);
	if (reg < 0)
	return reg;
	if (reg != TMP464_MANUFACTURER_ID)
	return -ENODEV;

	/* Check for "always return zero" bits */
	reg = i2c_smbus_read_word_swapped(client, TMP464_THERM_STATUS_REG);
	if (reg < 0)
	return reg;
	if (reg & 0x1f)
	return -ENODEV;
	reg = i2c_smbus_read_word_swapped(client, TMP464_THERM2_STATUS_REG);
	if (reg < 0)
	return reg;
	if (reg & 0x1f)
	return -ENODEV;

	reg = i2c_smbus_read_word_swapped(client, TMP464_DEVICE_ID_REG);
	if (reg < 0)
	return reg;
	switch (reg) {
	case TMP464_DEVICE_ID:
	name = "tmp464";
	chip = "TMP464";
	break;
	case TMP468_DEVICE_ID:
	name = "tmp468";
	chip = "TMP468";
	break;
	default:
	return -ENODEV;
	}

	strscpy(info->type, name, I2C_NAME_SIZE);
	dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n", chip, client->addr);

	return 0;
	}

	static int tmp464_probe_child_from_dt(struct device *dev,
	struct device_node *child,
	struct tmp464_data *data)

	{
	struct regmap *regmap = data->regmap;
	u32 channel;
	s32 nfactor;
	int err;

	err = of_property_read_u32(child, "reg", &channel);
	if (err) {
	dev_err(dev, "missing reg property of %pOFn\n", child);
	return err;
	}

	if (channel >= data->channels) {
	dev_err(dev, "invalid reg %d of %pOFn\n", channel, child);
	return -EINVAL;
	}

	of_property_read_string(child, "label", &data->channel[channel].label);

	data->channel[channel].enabled = of_device_is_available(child);

	err = of_property_read_s32(child, "ti,n-factor", &nfactor);
	if (err && err != -EINVAL)
	return err;
	if (!err) {
	if (channel == 0) {
	dev_err(dev, "n-factor can't be set for internal channel\n");
	return -EINVAL;
	}
	if (nfactor > 127 \|\| nfactor < -128) {
	dev_err(dev, "n-factor for channel %d invalid (%d)\n",
	channel, nfactor);
	return -EINVAL;
	}
	err = regmap_write(regmap, TMP464_N_FACTOR_REG(channel),
	(nfactor << 8) & 0xff00);
	if (err)
	return err;
	}

	return 0;
	}

	static int tmp464_probe_from_dt(struct device dev, struct tmp464_data data)
	{
	const struct device_node *np = dev->of_node;
	int err;

	for_each_child_of_node_scoped(np, child) {
	if (strcmp(child->name, "channel"))
	continue;

	err = tmp464_probe_child_from_dt(dev, child, data);
	if (err)
	return err;
	}

	return 0;
	}

	static const struct hwmon_ops tmp464_ops = {
	.is_visible = tmp464_is_visible,
	.read = tmp464_read,
	.read_string = tmp464_read_string,
	.write = tmp464_write,
	};

	static const struct hwmon_channel_info * const tmp464_info[] = {
	HWMON_CHANNEL_INFO(chip,
	HWMON_C_UPDATE_INTERVAL),
	HWMON_CHANNEL_INFO(temp,
	HWMON_T_INPUT \| HWMON_T_MAX \| HWMON_T_MAX_HYST \| HWMON_T_CRIT \|
	HWMON_T_CRIT_HYST \| HWMON_T_MAX_ALARM \| HWMON_T_CRIT_ALARM \|
	HWMON_T_LABEL \| HWMON_T_ENABLE,
	HWMON_T_INPUT \| HWMON_T_OFFSET \| HWMON_T_MAX \| HWMON_T_MAX_HYST \|
	HWMON_T_CRIT \| HWMON_T_CRIT_HYST \| HWMON_T_MAX_ALARM \|
	HWMON_T_CRIT_ALARM \| HWMON_T_FAULT \| HWMON_T_LABEL \| HWMON_T_ENABLE,
	HWMON_T_INPUT \| HWMON_T_OFFSET \| HWMON_T_MAX \| HWMON_T_MAX_HYST \|
	HWMON_T_CRIT \| HWMON_T_CRIT_HYST \| HWMON_T_MAX_ALARM \|
	HWMON_T_CRIT_ALARM \| HWMON_T_FAULT \| HWMON_T_LABEL \| HWMON_T_ENABLE,
	HWMON_T_INPUT \| HWMON_T_OFFSET \| HWMON_T_MAX \| HWMON_T_MAX_HYST \|
	HWMON_T_CRIT \| HWMON_T_CRIT_HYST \| HWMON_T_MAX_ALARM \|
	HWMON_T_CRIT_ALARM \| HWMON_T_FAULT \| HWMON_T_LABEL \| HWMON_T_ENABLE,
	HWMON_T_INPUT \| HWMON_T_OFFSET \| HWMON_T_MAX \| HWMON_T_MAX_HYST \|
	HWMON_T_CRIT \| HWMON_T_CRIT_HYST \| HWMON_T_MAX_ALARM \|
	HWMON_T_CRIT_ALARM \| HWMON_T_FAULT \| HWMON_T_LABEL \| HWMON_T_ENABLE,
	HWMON_T_INPUT \| HWMON_T_OFFSET \| HWMON_T_MAX \| HWMON_T_MAX_HYST \|
	HWMON_T_CRIT \| HWMON_T_CRIT_HYST \| HWMON_T_MAX_ALARM \|
	HWMON_T_CRIT_ALARM \| HWMON_T_FAULT \| HWMON_T_LABEL \| HWMON_T_ENABLE,
	HWMON_T_INPUT \| HWMON_T_OFFSET \| HWMON_T_MAX \| HWMON_T_MAX_HYST \|
	HWMON_T_CRIT \| HWMON_T_CRIT_HYST \| HWMON_T_MAX_ALARM \|
	HWMON_T_CRIT_ALARM \| HWMON_T_FAULT \| HWMON_T_LABEL \| HWMON_T_ENABLE,
	HWMON_T_INPUT \| HWMON_T_OFFSET \| HWMON_T_MAX \| HWMON_T_MAX_HYST \|
	HWMON_T_CRIT \| HWMON_T_CRIT_HYST \| HWMON_T_MAX_ALARM \|
	HWMON_T_CRIT_ALARM \| HWMON_T_FAULT \| HWMON_T_LABEL \| HWMON_T_ENABLE,
	HWMON_T_INPUT \| HWMON_T_OFFSET \| HWMON_T_MAX \| HWMON_T_MAX_HYST \|
	HWMON_T_CRIT \| HWMON_T_CRIT_HYST \| HWMON_T_MAX_ALARM \|
	HWMON_T_CRIT_ALARM \| HWMON_T_FAULT \| HWMON_T_LABEL \| HWMON_T_ENABLE),
	NULL
	};

	static const struct hwmon_chip_info tmp464_chip_info = {
	.ops = &tmp464_ops,
	.info = tmp464_info,
	};

	/* regmap */

	static bool tmp464_is_volatile_reg(struct device *dev, unsigned int reg)
	{
	return (reg < TMP464_TEMP_REG(TMP468_NUM_CHANNELS) \|\|
	reg == TMP464_THERM_STATUS_REG \|\|
	reg == TMP464_THERM2_STATUS_REG \|\|
	reg == TMP464_REMOTE_OPEN_REG);
	}

	static const struct regmap_config tmp464_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
	.max_register = TMP464_DEVICE_ID_REG,
	.volatile_reg = tmp464_is_volatile_reg,
	.val_format_endian = REGMAP_ENDIAN_BIG,
	.cache_type = REGCACHE_MAPLE,
	.use_single_read = true,
	.use_single_write = true,
	};

	static int tmp464_probe(struct i2c_client *client)
	{
	struct device *dev = &client->dev;
	struct device *hwmon_dev;
	struct tmp464_data *data;
	int i, err;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) {
	dev_err(&client->dev, "i2c functionality check failed\n");
	return -ENODEV;
	}
	data = devm_kzalloc(dev, sizeof(struct tmp464_data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	mutex_init(&data->update_lock);

	data->channels = (int)(unsigned long)i2c_get_match_data(client);

	data->regmap = devm_regmap_init_i2c(client, &tmp464_regmap_config);
	if (IS_ERR(data->regmap))
	return PTR_ERR(data->regmap);

	for (i = 0; i < data->channels; i++)
	data->channel[i].enabled = true;

	err = tmp464_init_client(dev, data);
	if (err)
	return err;

	if (dev->of_node) {
	err = tmp464_probe_from_dt(dev, data);
	if (err)
	return err;
	}

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
	data, &tmp464_chip_info, NULL);
	return PTR_ERR_OR_ZERO(hwmon_dev);
	}

	static struct i2c_driver tmp464_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
	.name = "tmp464",
	.of_match_table = of_match_ptr(tmp464_of_match),
	},
	.probe = tmp464_probe,
	.id_table = tmp464_id,
	.detect = tmp464_detect,
	.address_list = normal_i2c,
	};

	module_i2c_driver(tmp464_driver);

	MODULE_AUTHOR("Agathe Porte <agathe.porte@nokia.com>");
	MODULE_DESCRIPTION("Texas Instruments TMP464 temperature sensor driver");
	MODULE_LICENSE("GPL");