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1// SPDX-License-Identifier: GPL-2.0+2/*3 * hdc3020.c - Support for the TI HDC3020,HDC3021 and HDC30224 * temperature + relative humidity sensors5 *6 * Copyright (C) 20237 *8 * Copyright (C) 2024 Liebherr-Electronics and Drives GmbH9 *10 * Datasheet: https://www.ti.com/lit/ds/symlink/hdc3020.pdf11 */12 13#include <linux/bitfield.h>14#include <linux/bitops.h>15#include <linux/cleanup.h>16#include <linux/crc8.h>17#include <linux/delay.h>18#include <linux/gpio/consumer.h>19#include <linux/i2c.h>20#include <linux/init.h>21#include <linux/interrupt.h>22#include <linux/math64.h>23#include <linux/module.h>24#include <linux/mutex.h>25#include <linux/pm.h>26#include <linux/regulator/consumer.h>27#include <linux/units.h>28 29#include <linux/unaligned.h>30 31#include <linux/iio/events.h>32#include <linux/iio/iio.h>33 34#define HDC3020_S_AUTO_10HZ_MOD0	0x273735#define HDC3020_S_STATUS		0x304136#define HDC3020_HEATER_DISABLE		0x306637#define HDC3020_HEATER_ENABLE		0x306D38#define HDC3020_HEATER_CONFIG		0x306E39#define HDC3020_EXIT_AUTO		0x309340#define HDC3020_S_T_RH_THRESH_LOW	0x610041#define HDC3020_S_T_RH_THRESH_LOW_CLR	0x610B42#define HDC3020_S_T_RH_THRESH_HIGH_CLR	0x611643#define HDC3020_S_T_RH_THRESH_HIGH	0x611D44#define HDC3020_R_T_RH_AUTO		0xE00045#define HDC3020_R_T_LOW_AUTO		0xE00246#define HDC3020_R_T_HIGH_AUTO		0xE00347#define HDC3020_R_RH_LOW_AUTO		0xE00448#define HDC3020_R_RH_HIGH_AUTO		0xE00549#define HDC3020_R_T_RH_THRESH_LOW	0xE10250#define HDC3020_R_T_RH_THRESH_LOW_CLR	0xE10951#define HDC3020_R_T_RH_THRESH_HIGH_CLR	0xE11452#define HDC3020_R_T_RH_THRESH_HIGH	0xE11F53#define HDC3020_R_STATUS		0xF32D54 55#define HDC3020_THRESH_TEMP_MASK	GENMASK(8, 0)56#define HDC3020_THRESH_TEMP_TRUNC_SHIFT	757#define HDC3020_THRESH_HUM_MASK		GENMASK(15, 9)58#define HDC3020_THRESH_HUM_TRUNC_SHIFT	959 60#define HDC3020_STATUS_T_LOW_ALERT	BIT(6)61#define HDC3020_STATUS_T_HIGH_ALERT	BIT(7)62#define HDC3020_STATUS_RH_LOW_ALERT	BIT(8)63#define HDC3020_STATUS_RH_HIGH_ALERT	BIT(9)64 65#define HDC3020_READ_RETRY_TIMES	1066#define HDC3020_BUSY_DELAY_MS		1067 68#define HDC3020_CRC8_POLYNOMIAL		0x3169 70#define HDC3020_MIN_TEMP_MICRO		-3987296871#define HDC3020_MAX_TEMP_MICRO		12487563972#define HDC3020_MAX_TEMP_HYST_MICRO	16474860773#define HDC3020_MAX_HUM_MICRO		9922026474 75struct hdc3020_data {76	struct i2c_client *client;77	struct gpio_desc *reset_gpio;78	struct regulator *vdd_supply;79	/*80	 * Ensure that the sensor configuration (currently only heater is81	 * supported) will not be changed during the process of reading82	 * sensor data (this driver will try HDC3020_READ_RETRY_TIMES times83	 * if the device does not respond).84	 */85	struct mutex lock;86};87 88static const int hdc3020_heater_vals[] = {0, 1, 0x3FFF};89 90static const struct iio_event_spec hdc3020_t_rh_event[] = {91	{92		.type = IIO_EV_TYPE_THRESH,93		.dir = IIO_EV_DIR_RISING,94		.mask_separate = BIT(IIO_EV_INFO_VALUE) |95		BIT(IIO_EV_INFO_HYSTERESIS),96	},97	{98		.type = IIO_EV_TYPE_THRESH,99		.dir = IIO_EV_DIR_FALLING,100		.mask_separate = BIT(IIO_EV_INFO_VALUE) |101		BIT(IIO_EV_INFO_HYSTERESIS),102	},103};104 105static const struct iio_chan_spec hdc3020_channels[] = {106	{107		.type = IIO_TEMP,108		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |109		BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) |110		BIT(IIO_CHAN_INFO_TROUGH) | BIT(IIO_CHAN_INFO_OFFSET),111		.event_spec = hdc3020_t_rh_event,112		.num_event_specs = ARRAY_SIZE(hdc3020_t_rh_event),113	},114	{115		.type = IIO_HUMIDITYRELATIVE,116		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |117		BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_PEAK) |118		BIT(IIO_CHAN_INFO_TROUGH),119		.event_spec = hdc3020_t_rh_event,120		.num_event_specs = ARRAY_SIZE(hdc3020_t_rh_event),121	},122	{123		/*124		 * For setting the internal heater, which can be switched on to125		 * prevent or remove any condensation that may develop when the126		 * ambient environment approaches its dew point temperature.127		 */128		.type = IIO_CURRENT,129		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),130		.info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),131		.output = 1,132	},133};134 135DECLARE_CRC8_TABLE(hdc3020_crc8_table);136 137static int hdc3020_write_bytes(struct hdc3020_data *data, u8 *buf, u8 len)138{139	struct i2c_client *client = data->client;140	struct i2c_msg msg;141	int ret, cnt;142 143	msg.addr = client->addr;144	msg.flags = 0;145	msg.buf = buf;146	msg.len = len;147 148	/*149	 * During the measurement process, HDC3020 will not return data.150	 * So wait for a while and try again151	 */152	for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) {153		ret = i2c_transfer(client->adapter, &msg, 1);154		if (ret == 1)155			return 0;156 157		mdelay(HDC3020_BUSY_DELAY_MS);158	}159	dev_err(&client->dev, "Could not write sensor command\n");160 161	return -ETIMEDOUT;162}163 164static165int hdc3020_read_bytes(struct hdc3020_data *data, u16 reg, u8 *buf, int len)166{167	u8 reg_buf[2];168	int ret, cnt;169	struct i2c_client *client = data->client;170	struct i2c_msg msg[2] = {171		[0] = {172			.addr = client->addr,173			.flags = 0,174			.buf = reg_buf,175			.len = 2,176		},177		[1] = {178			.addr = client->addr,179			.flags = I2C_M_RD,180			.buf = buf,181			.len = len,182		},183	};184 185	put_unaligned_be16(reg, reg_buf);186	/*187	 * During the measurement process, HDC3020 will not return data.188	 * So wait for a while and try again189	 */190	for (cnt = 0; cnt < HDC3020_READ_RETRY_TIMES; cnt++) {191		ret = i2c_transfer(client->adapter, msg, 2);192		if (ret == 2)193			return 0;194 195		mdelay(HDC3020_BUSY_DELAY_MS);196	}197	dev_err(&client->dev, "Could not read sensor data\n");198 199	return -ETIMEDOUT;200}201 202static int hdc3020_read_be16(struct hdc3020_data *data, u16 reg)203{204	u8 crc, buf[3];205	int ret;206 207	ret = hdc3020_read_bytes(data, reg, buf, 3);208	if (ret < 0)209		return ret;210 211	crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);212	if (crc != buf[2])213		return -EINVAL;214 215	return get_unaligned_be16(buf);216}217 218static int hdc3020_exec_cmd(struct hdc3020_data *data, u16 reg)219{220	u8 reg_buf[2];221 222	put_unaligned_be16(reg, reg_buf);223	return hdc3020_write_bytes(data, reg_buf, 2);224}225 226static int hdc3020_read_measurement(struct hdc3020_data *data,227				    enum iio_chan_type type, int *val)228{229	u8 crc, buf[6];230	int ret;231 232	ret = hdc3020_read_bytes(data, HDC3020_R_T_RH_AUTO, buf, 6);233	if (ret < 0)234		return ret;235 236	/* CRC check of the temperature measurement */237	crc = crc8(hdc3020_crc8_table, buf, 2, CRC8_INIT_VALUE);238	if (crc != buf[2])239		return -EINVAL;240 241	/* CRC check of the relative humidity measurement */242	crc = crc8(hdc3020_crc8_table, buf + 3, 2, CRC8_INIT_VALUE);243	if (crc != buf[5])244		return -EINVAL;245 246	if (type == IIO_TEMP)247		*val = get_unaligned_be16(buf);248	else if (type == IIO_HUMIDITYRELATIVE)249		*val = get_unaligned_be16(&buf[3]);250	else251		return -EINVAL;252 253	return 0;254}255 256static int hdc3020_read_raw(struct iio_dev *indio_dev,257			    struct iio_chan_spec const *chan, int *val,258			    int *val2, long mask)259{260	struct hdc3020_data *data = iio_priv(indio_dev);261	int ret;262 263	if (chan->type != IIO_TEMP && chan->type != IIO_HUMIDITYRELATIVE)264		return -EINVAL;265 266	switch (mask) {267	case IIO_CHAN_INFO_RAW: {268		guard(mutex)(&data->lock);269		ret = hdc3020_read_measurement(data, chan->type, val);270		if (ret < 0)271			return ret;272 273		return IIO_VAL_INT;274	}275	case IIO_CHAN_INFO_PEAK: {276		guard(mutex)(&data->lock);277		if (chan->type == IIO_TEMP)278			ret = hdc3020_read_be16(data, HDC3020_R_T_HIGH_AUTO);279		else280			ret = hdc3020_read_be16(data, HDC3020_R_RH_HIGH_AUTO);281 282		if (ret < 0)283			return ret;284 285		*val = ret;286		return IIO_VAL_INT;287	}288	case IIO_CHAN_INFO_TROUGH: {289		guard(mutex)(&data->lock);290		if (chan->type == IIO_TEMP)291			ret = hdc3020_read_be16(data, HDC3020_R_T_LOW_AUTO);292		else293			ret = hdc3020_read_be16(data, HDC3020_R_RH_LOW_AUTO);294 295		if (ret < 0)296			return ret;297 298		*val = ret;299		return IIO_VAL_INT;300	}301	case IIO_CHAN_INFO_SCALE:302		*val2 = 65536;303		if (chan->type == IIO_TEMP)304			*val = 175;305		else306			*val = 100;307		return IIO_VAL_FRACTIONAL;308 309	case IIO_CHAN_INFO_OFFSET:310		if (chan->type != IIO_TEMP)311			return -EINVAL;312 313		*val = -16852;314		return IIO_VAL_INT;315 316	default:317		return -EINVAL;318	}319}320 321static int hdc3020_read_available(struct iio_dev *indio_dev,322				  struct iio_chan_spec const *chan,323				  const int **vals,324				  int *type, int *length, long mask)325{326	if (mask != IIO_CHAN_INFO_RAW || chan->type != IIO_CURRENT)327		return -EINVAL;328 329	*vals = hdc3020_heater_vals;330	*type = IIO_VAL_INT;331 332	return IIO_AVAIL_RANGE;333}334 335static int hdc3020_update_heater(struct hdc3020_data *data, int val)336{337	u8 buf[5];338	int ret;339 340	if (val < hdc3020_heater_vals[0] || val > hdc3020_heater_vals[2])341		return -EINVAL;342 343	if (!val)344		hdc3020_exec_cmd(data, HDC3020_HEATER_DISABLE);345 346	put_unaligned_be16(HDC3020_HEATER_CONFIG, buf);347	put_unaligned_be16(val & GENMASK(13, 0), &buf[2]);348	buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);349	ret = hdc3020_write_bytes(data, buf, 5);350	if (ret < 0)351		return ret;352 353	return hdc3020_exec_cmd(data, HDC3020_HEATER_ENABLE);354}355 356static int hdc3020_write_raw(struct iio_dev *indio_dev,357			     struct iio_chan_spec const *chan,358			     int val, int val2, long mask)359{360	struct hdc3020_data *data = iio_priv(indio_dev);361 362	switch (mask) {363	case IIO_CHAN_INFO_RAW:364		if (chan->type != IIO_CURRENT)365			return -EINVAL;366 367		guard(mutex)(&data->lock);368		return hdc3020_update_heater(data, val);369	}370 371	return -EINVAL;372}373 374static int hdc3020_thresh_get_temp(u16 thresh)375{376	int temp;377 378	/*379	 * Get the temperature threshold from 9 LSBs, shift them to get380	 * the truncated temperature threshold representation and381	 * calculate the threshold according to the formula in the382	 * datasheet. Result is degree celsius scaled by 65535.383	 */384	temp = FIELD_GET(HDC3020_THRESH_TEMP_MASK, thresh) <<385	       HDC3020_THRESH_TEMP_TRUNC_SHIFT;386 387	return -2949075 + (175 * temp);388}389 390static int hdc3020_thresh_get_hum(u16 thresh)391{392	int hum;393 394	/*395	 * Get the humidity threshold from 7 MSBs, shift them to get the396	 * truncated humidity threshold representation and calculate the397	 * threshold according to the formula in the datasheet. Result is398	 * percent scaled by 65535.399	 */400	hum = FIELD_GET(HDC3020_THRESH_HUM_MASK, thresh) <<401	      HDC3020_THRESH_HUM_TRUNC_SHIFT;402 403	return hum * 100;404}405 406static u16 hdc3020_thresh_set_temp(int s_temp, u16 curr_thresh)407{408	u64 temp;409	u16 thresh;410 411	/*412	 * Calculate temperature threshold, shift it down to get the413	 * truncated threshold representation in the 9LSBs while keeping414	 * the current humidity threshold in the 7 MSBs.415	 */416	temp = (u64)(s_temp + 45000000) * 65535ULL;417	temp = div_u64(temp, 1000000 * 175) >> HDC3020_THRESH_TEMP_TRUNC_SHIFT;418	thresh = FIELD_PREP(HDC3020_THRESH_TEMP_MASK, temp);419	thresh |= (FIELD_GET(HDC3020_THRESH_HUM_MASK, curr_thresh) <<420		  HDC3020_THRESH_HUM_TRUNC_SHIFT);421 422	return thresh;423}424 425static u16 hdc3020_thresh_set_hum(int s_hum, u16 curr_thresh)426{427	u64 hum;428	u16 thresh;429 430	/*431	 * Calculate humidity threshold, shift it down and up to get the432	 * truncated threshold representation in the 7MSBs while keeping433	 * the current temperature threshold in the 9 LSBs.434	 */435	hum = (u64)(s_hum) * 65535ULL;436	hum = div_u64(hum, 1000000 * 100) >> HDC3020_THRESH_HUM_TRUNC_SHIFT;437	thresh = FIELD_PREP(HDC3020_THRESH_HUM_MASK, hum);438	thresh |= FIELD_GET(HDC3020_THRESH_TEMP_MASK, curr_thresh);439 440	return thresh;441}442 443static444int hdc3020_thresh_clr(s64 s_thresh, s64 s_hyst, enum iio_event_direction dir)445{446	s64 s_clr;447 448	/*449	 * Include directions when calculation the clear value,450	 * since hysteresis is unsigned by definition and the451	 * clear value is an absolute value which is signed.452	 */453	if (dir == IIO_EV_DIR_RISING)454		s_clr = s_thresh - s_hyst;455	else456		s_clr = s_thresh + s_hyst;457 458	/* Divide by 65535 to get units of micro */459	return div_s64(s_clr, 65535);460}461 462static int _hdc3020_write_thresh(struct hdc3020_data *data, u16 reg, u16 val)463{464	u8 buf[5];465 466	put_unaligned_be16(reg, buf);467	put_unaligned_be16(val, buf + 2);468	buf[4] = crc8(hdc3020_crc8_table, buf + 2, 2, CRC8_INIT_VALUE);469 470	return hdc3020_write_bytes(data, buf, 5);471}472 473static int hdc3020_write_thresh(struct iio_dev *indio_dev,474				const struct iio_chan_spec *chan,475				enum iio_event_type type,476				enum iio_event_direction dir,477				enum iio_event_info info,478				int val, int val2)479{480	struct hdc3020_data *data = iio_priv(indio_dev);481	u16 reg, reg_val, reg_thresh_rd, reg_clr_rd, reg_thresh_wr, reg_clr_wr;482	s64 s_thresh, s_hyst, s_clr;483	int s_val, thresh, clr, ret;484 485	/* Select threshold registers */486	if (dir == IIO_EV_DIR_RISING) {487		reg_thresh_rd = HDC3020_R_T_RH_THRESH_HIGH;488		reg_thresh_wr = HDC3020_S_T_RH_THRESH_HIGH;489		reg_clr_rd = HDC3020_R_T_RH_THRESH_HIGH_CLR;490		reg_clr_wr = HDC3020_S_T_RH_THRESH_HIGH_CLR;491	} else {492		reg_thresh_rd = HDC3020_R_T_RH_THRESH_LOW;493		reg_thresh_wr = HDC3020_S_T_RH_THRESH_LOW;494		reg_clr_rd = HDC3020_R_T_RH_THRESH_LOW_CLR;495		reg_clr_wr = HDC3020_S_T_RH_THRESH_LOW_CLR;496	}497 498	guard(mutex)(&data->lock);499	ret = hdc3020_read_be16(data, reg_thresh_rd);500	if (ret < 0)501		return ret;502 503	thresh = ret;504	ret = hdc3020_read_be16(data, reg_clr_rd);505	if (ret < 0)506		return ret;507 508	clr = ret;509	/* Scale value to include decimal part into calculations */510	s_val = (val < 0) ? (val * 1000000 - val2) : (val * 1000000 + val2);511	switch (chan->type) {512	case IIO_TEMP:513		switch (info) {514		case IIO_EV_INFO_VALUE:515			s_val = max(s_val, HDC3020_MIN_TEMP_MICRO);516			s_val = min(s_val, HDC3020_MAX_TEMP_MICRO);517			reg = reg_thresh_wr;518			reg_val = hdc3020_thresh_set_temp(s_val, thresh);519			ret = _hdc3020_write_thresh(data, reg, reg_val);520			if (ret < 0)521				return ret;522 523			/* Calculate old hysteresis */524			s_thresh = (s64)hdc3020_thresh_get_temp(thresh) * 1000000;525			s_clr = (s64)hdc3020_thresh_get_temp(clr) * 1000000;526			s_hyst = div_s64(abs(s_thresh - s_clr), 65535);527			/* Set new threshold */528			thresh = reg_val;529			/* Set old hysteresis */530			s_val = s_hyst;531			fallthrough;532		case IIO_EV_INFO_HYSTERESIS:533			/*534			 * Function hdc3020_thresh_get_temp returns temperature535			 * in degree celsius scaled by 65535. Scale by 1000000536			 * to be able to subtract scaled hysteresis value.537			 */538			s_thresh = (s64)hdc3020_thresh_get_temp(thresh) * 1000000;539			/*540			 * Units of s_val are in micro degree celsius, scale by541			 * 65535 to get same units as s_thresh.542			 */543			s_val = min(abs(s_val), HDC3020_MAX_TEMP_HYST_MICRO);544			s_hyst = (s64)s_val * 65535;545			s_clr = hdc3020_thresh_clr(s_thresh, s_hyst, dir);546			s_clr = max(s_clr, HDC3020_MIN_TEMP_MICRO);547			s_clr = min(s_clr, HDC3020_MAX_TEMP_MICRO);548			reg = reg_clr_wr;549			reg_val = hdc3020_thresh_set_temp(s_clr, clr);550			break;551		default:552			return -EOPNOTSUPP;553		}554		break;555	case IIO_HUMIDITYRELATIVE:556		s_val = (s_val < 0) ? 0 : min(s_val, HDC3020_MAX_HUM_MICRO);557		switch (info) {558		case IIO_EV_INFO_VALUE:559			reg = reg_thresh_wr;560			reg_val = hdc3020_thresh_set_hum(s_val, thresh);561			ret = _hdc3020_write_thresh(data, reg, reg_val);562			if (ret < 0)563				return ret;564 565			/* Calculate old hysteresis */566			s_thresh = (s64)hdc3020_thresh_get_hum(thresh) * 1000000;567			s_clr = (s64)hdc3020_thresh_get_hum(clr) * 1000000;568			s_hyst = div_s64(abs(s_thresh - s_clr), 65535);569			/* Set new threshold */570			thresh = reg_val;571			/* Try to set old hysteresis */572			s_val = min(abs(s_hyst), HDC3020_MAX_HUM_MICRO);573			fallthrough;574		case IIO_EV_INFO_HYSTERESIS:575			/*576			 * Function hdc3020_thresh_get_hum returns relative577			 * humidity in percent scaled by 65535. Scale by 1000000578			 * to be able to subtract scaled hysteresis value.579			 */580			s_thresh = (s64)hdc3020_thresh_get_hum(thresh) * 1000000;581			/*582			 * Units of s_val are in micro percent, scale by 65535583			 * to get same units as s_thresh.584			 */585			s_hyst = (s64)s_val * 65535;586			s_clr = hdc3020_thresh_clr(s_thresh, s_hyst, dir);587			s_clr = max(s_clr, 0);588			s_clr = min(s_clr, HDC3020_MAX_HUM_MICRO);589			reg = reg_clr_wr;590			reg_val = hdc3020_thresh_set_hum(s_clr, clr);591			break;592		default:593			return -EOPNOTSUPP;594		}595		break;596	default:597		return -EOPNOTSUPP;598	}599 600	return _hdc3020_write_thresh(data, reg, reg_val);601}602 603static int hdc3020_read_thresh(struct iio_dev *indio_dev,604			       const struct iio_chan_spec *chan,605			       enum iio_event_type type,606			       enum iio_event_direction dir,607			       enum iio_event_info info,608			       int *val, int *val2)609{610	struct hdc3020_data *data = iio_priv(indio_dev);611	u16 reg_thresh, reg_clr;612	int thresh, clr, ret;613 614	/* Select threshold registers */615	if (dir == IIO_EV_DIR_RISING) {616		reg_thresh = HDC3020_R_T_RH_THRESH_HIGH;617		reg_clr = HDC3020_R_T_RH_THRESH_HIGH_CLR;618	} else {619		reg_thresh = HDC3020_R_T_RH_THRESH_LOW;620		reg_clr = HDC3020_R_T_RH_THRESH_LOW_CLR;621	}622 623	guard(mutex)(&data->lock);624	ret = hdc3020_read_be16(data, reg_thresh);625	if (ret < 0)626		return ret;627 628	switch (chan->type) {629	case IIO_TEMP:630		thresh = hdc3020_thresh_get_temp(ret);631		switch (info) {632		case IIO_EV_INFO_VALUE:633			*val = thresh;634			break;635		case IIO_EV_INFO_HYSTERESIS:636			ret = hdc3020_read_be16(data, reg_clr);637			if (ret < 0)638				return ret;639 640			clr = hdc3020_thresh_get_temp(ret);641			*val = abs(thresh - clr);642			break;643		default:644			return -EOPNOTSUPP;645		}646		*val2 = 65535;647		return IIO_VAL_FRACTIONAL;648	case IIO_HUMIDITYRELATIVE:649		thresh = hdc3020_thresh_get_hum(ret);650		switch (info) {651		case IIO_EV_INFO_VALUE:652			*val = thresh;653			break;654		case IIO_EV_INFO_HYSTERESIS:655			ret = hdc3020_read_be16(data, reg_clr);656			if (ret < 0)657				return ret;658 659			clr = hdc3020_thresh_get_hum(ret);660			*val = abs(thresh - clr);661			break;662		default:663			return -EOPNOTSUPP;664		}665		*val2 = 65535;666		return IIO_VAL_FRACTIONAL;667	default:668		return -EOPNOTSUPP;669	}670}671 672static irqreturn_t hdc3020_interrupt_handler(int irq, void *private)673{674	struct iio_dev *indio_dev = private;675	struct hdc3020_data *data;676	s64 time;677	int ret;678 679	data = iio_priv(indio_dev);680	ret = hdc3020_read_be16(data, HDC3020_R_STATUS);681	if (ret < 0)682		return IRQ_HANDLED;683 684	if (!(ret & (HDC3020_STATUS_T_HIGH_ALERT | HDC3020_STATUS_T_LOW_ALERT |685		HDC3020_STATUS_RH_HIGH_ALERT | HDC3020_STATUS_RH_LOW_ALERT)))686		return IRQ_NONE;687 688	time = iio_get_time_ns(indio_dev);689	if (ret & HDC3020_STATUS_T_HIGH_ALERT)690		iio_push_event(indio_dev,691			       IIO_MOD_EVENT_CODE(IIO_TEMP, 0,692						  IIO_NO_MOD,693						  IIO_EV_TYPE_THRESH,694						  IIO_EV_DIR_RISING),695						  time);696 697	if (ret & HDC3020_STATUS_T_LOW_ALERT)698		iio_push_event(indio_dev,699			       IIO_MOD_EVENT_CODE(IIO_TEMP, 0,700						  IIO_NO_MOD,701						  IIO_EV_TYPE_THRESH,702						  IIO_EV_DIR_FALLING),703						  time);704 705	if (ret & HDC3020_STATUS_RH_HIGH_ALERT)706		iio_push_event(indio_dev,707			       IIO_MOD_EVENT_CODE(IIO_HUMIDITYRELATIVE, 0,708						  IIO_NO_MOD,709						  IIO_EV_TYPE_THRESH,710						  IIO_EV_DIR_RISING),711						  time);712 713	if (ret & HDC3020_STATUS_RH_LOW_ALERT)714		iio_push_event(indio_dev,715			       IIO_MOD_EVENT_CODE(IIO_HUMIDITYRELATIVE, 0,716						  IIO_NO_MOD,717						  IIO_EV_TYPE_THRESH,718						  IIO_EV_DIR_FALLING),719						  time);720 721	return IRQ_HANDLED;722}723 724static const struct iio_info hdc3020_info = {725	.read_raw = hdc3020_read_raw,726	.write_raw = hdc3020_write_raw,727	.read_avail = hdc3020_read_available,728	.read_event_value = hdc3020_read_thresh,729	.write_event_value = hdc3020_write_thresh,730};731 732static int hdc3020_power_off(struct hdc3020_data *data)733{734	hdc3020_exec_cmd(data, HDC3020_EXIT_AUTO);735 736	if (data->reset_gpio)737		gpiod_set_value_cansleep(data->reset_gpio, 1);738 739	return regulator_disable(data->vdd_supply);740}741 742static int hdc3020_power_on(struct hdc3020_data *data)743{744	int ret;745 746	ret = regulator_enable(data->vdd_supply);747	if (ret)748		return ret;749 750	fsleep(5000);751 752	if (data->reset_gpio) {753		gpiod_set_value_cansleep(data->reset_gpio, 0);754		fsleep(3000);755	}756 757	if (data->client->irq) {758		/*759		 * The alert output is activated by default upon power up,760		 * hardware reset, and soft reset. Clear the status register.761		 */762		ret = hdc3020_exec_cmd(data, HDC3020_S_STATUS);763		if (ret) {764			hdc3020_power_off(data);765			return ret;766		}767	}768 769	ret = hdc3020_exec_cmd(data, HDC3020_S_AUTO_10HZ_MOD0);770	if (ret)771		hdc3020_power_off(data);772 773	return ret;774}775 776static void hdc3020_exit(void *data)777{778	hdc3020_power_off(data);779}780 781static int hdc3020_probe(struct i2c_client *client)782{783	struct iio_dev *indio_dev;784	struct hdc3020_data *data;785	int ret;786 787	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))788		return -EOPNOTSUPP;789 790	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));791	if (!indio_dev)792		return -ENOMEM;793 794	dev_set_drvdata(&client->dev, indio_dev);795 796	data = iio_priv(indio_dev);797	data->client = client;798	mutex_init(&data->lock);799 800	crc8_populate_msb(hdc3020_crc8_table, HDC3020_CRC8_POLYNOMIAL);801 802	indio_dev->name = "hdc3020";803	indio_dev->modes = INDIO_DIRECT_MODE;804	indio_dev->info = &hdc3020_info;805	indio_dev->channels = hdc3020_channels;806	indio_dev->num_channels = ARRAY_SIZE(hdc3020_channels);807 808	data->vdd_supply = devm_regulator_get(&client->dev, "vdd");809	if (IS_ERR(data->vdd_supply))810		return dev_err_probe(&client->dev, PTR_ERR(data->vdd_supply),811				     "Unable to get VDD regulator\n");812 813	data->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",814						   GPIOD_OUT_HIGH);815	if (IS_ERR(data->reset_gpio))816		return dev_err_probe(&client->dev, PTR_ERR(data->reset_gpio),817				     "Cannot get reset GPIO\n");818 819	ret = hdc3020_power_on(data);820	if (ret)821		return dev_err_probe(&client->dev, ret, "Power on failed\n");822 823	ret = devm_add_action_or_reset(&data->client->dev, hdc3020_exit, data);824	if (ret)825		return ret;826 827	if (client->irq) {828		ret = devm_request_threaded_irq(&client->dev, client->irq,829						NULL, hdc3020_interrupt_handler,830						IRQF_ONESHOT, "hdc3020",831						indio_dev);832		if (ret)833			return dev_err_probe(&client->dev, ret,834					     "Failed to request IRQ\n");835	}836 837	ret = devm_iio_device_register(&data->client->dev, indio_dev);838	if (ret)839		return dev_err_probe(&client->dev, ret, "Failed to add device");840 841	return 0;842}843 844static int hdc3020_suspend(struct device *dev)845{846	struct iio_dev *iio_dev = dev_get_drvdata(dev);847	struct hdc3020_data *data = iio_priv(iio_dev);848 849	return hdc3020_power_off(data);850}851 852static int hdc3020_resume(struct device *dev)853{854	struct iio_dev *iio_dev = dev_get_drvdata(dev);855	struct hdc3020_data *data = iio_priv(iio_dev);856 857	return hdc3020_power_on(data);858}859 860static DEFINE_SIMPLE_DEV_PM_OPS(hdc3020_pm_ops, hdc3020_suspend, hdc3020_resume);861 862static const struct i2c_device_id hdc3020_id[] = {863	{ "hdc3020" },864	{ "hdc3021" },865	{ "hdc3022" },866	{ }867};868MODULE_DEVICE_TABLE(i2c, hdc3020_id);869 870static const struct of_device_id hdc3020_dt_ids[] = {871	{ .compatible = "ti,hdc3020" },872	{ .compatible = "ti,hdc3021" },873	{ .compatible = "ti,hdc3022" },874	{ }875};876MODULE_DEVICE_TABLE(of, hdc3020_dt_ids);877 878static struct i2c_driver hdc3020_driver = {879	.driver = {880		.name = "hdc3020",881		.pm = pm_sleep_ptr(&hdc3020_pm_ops),882		.of_match_table = hdc3020_dt_ids,883	},884	.probe = hdc3020_probe,885	.id_table = hdc3020_id,886};887module_i2c_driver(hdc3020_driver);888 889MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>");890MODULE_AUTHOR("Li peiyu <579lpy@gmail.com>");891MODULE_DESCRIPTION("TI HDC3020 humidity and temperature sensor driver");892MODULE_LICENSE("GPL");893