ltc2983.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Analog Devices LTC2983 Multi-Sensor Digital Temperature Measurement System
   4 * driver
   5 *
   6 * Copyright 2019 Analog Devices Inc.
   7 */
   8#include <linux/bitfield.h>
   9#include <linux/completion.h>
  10#include <linux/device.h>
  11#include <linux/err.h>
  12#include <linux/errno.h>
  13#include <linux/kernel.h>
  14#include <linux/iio/iio.h>
  15#include <linux/interrupt.h>
  16#include <linux/list.h>
  17#include <linux/mod_devicetable.h>
  18#include <linux/module.h>
  19#include <linux/property.h>
  20#include <linux/regmap.h>
  21#include <linux/regulator/consumer.h>
  22#include <linux/spi/spi.h>
  23
  24#include <asm/byteorder.h>
  25#include <linux/unaligned.h>
  26
  27/* register map */
  28#define LTC2983_STATUS_REG			0x0000
  29#define LTC2983_TEMP_RES_START_REG		0x0010
  30#define LTC2983_TEMP_RES_END_REG		0x005F
  31#define LTC2983_EEPROM_KEY_REG			0x00B0
  32#define LTC2983_EEPROM_READ_STATUS_REG		0x00D0
  33#define LTC2983_GLOBAL_CONFIG_REG		0x00F0
  34#define LTC2983_MULT_CHANNEL_START_REG		0x00F4
  35#define LTC2983_MULT_CHANNEL_END_REG		0x00F7
  36#define LTC2986_EEPROM_STATUS_REG		0x00F9
  37#define LTC2983_MUX_CONFIG_REG			0x00FF
  38#define LTC2983_CHAN_ASSIGN_START_REG		0x0200
  39#define LTC2983_CHAN_ASSIGN_END_REG		0x024F
  40#define LTC2983_CUST_SENS_TBL_START_REG		0x0250
  41#define LTC2983_CUST_SENS_TBL_END_REG		0x03CF
  42
  43#define LTC2983_DIFFERENTIAL_CHAN_MIN		2
  44#define LTC2983_MIN_CHANNELS_NR			1
  45#define LTC2983_SLEEP				0x97
  46#define LTC2983_CUSTOM_STEINHART_SIZE		24
  47#define LTC2983_CUSTOM_SENSOR_ENTRY_SZ		6
  48#define LTC2983_CUSTOM_STEINHART_ENTRY_SZ	4
  49
  50#define LTC2983_EEPROM_KEY			0xA53C0F5A
  51#define LTC2983_EEPROM_WRITE_CMD		0x15
  52#define LTC2983_EEPROM_READ_CMD			0x16
  53#define LTC2983_EEPROM_STATUS_FAILURE_MASK	GENMASK(3, 1)
  54#define LTC2983_EEPROM_READ_FAILURE_MASK	GENMASK(7, 0)
  55
  56#define LTC2983_EEPROM_WRITE_TIME_MS		2600
  57#define LTC2983_EEPROM_READ_TIME_MS		20
  58
  59#define LTC2983_CHAN_START_ADDR(chan) \
  60			(((chan - 1) * 4) + LTC2983_CHAN_ASSIGN_START_REG)
  61#define LTC2983_CHAN_RES_ADDR(chan) \
  62			(((chan - 1) * 4) + LTC2983_TEMP_RES_START_REG)
  63#define LTC2983_THERMOCOUPLE_DIFF_MASK		BIT(3)
  64#define LTC2983_THERMOCOUPLE_SGL(x) \
  65				FIELD_PREP(LTC2983_THERMOCOUPLE_DIFF_MASK, x)
  66#define LTC2983_THERMOCOUPLE_OC_CURR_MASK	GENMASK(1, 0)
  67#define LTC2983_THERMOCOUPLE_OC_CURR(x) \
  68				FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CURR_MASK, x)
  69#define LTC2983_THERMOCOUPLE_OC_CHECK_MASK	BIT(2)
  70#define LTC2983_THERMOCOUPLE_OC_CHECK(x) \
  71			FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CHECK_MASK, x)
  72
  73#define LTC2983_THERMISTOR_DIFF_MASK		BIT(2)
  74#define LTC2983_THERMISTOR_SGL(x) \
  75				FIELD_PREP(LTC2983_THERMISTOR_DIFF_MASK, x)
  76#define LTC2983_THERMISTOR_R_SHARE_MASK		BIT(1)
  77#define LTC2983_THERMISTOR_R_SHARE(x) \
  78				FIELD_PREP(LTC2983_THERMISTOR_R_SHARE_MASK, x)
  79#define LTC2983_THERMISTOR_C_ROTATE_MASK	BIT(0)
  80#define LTC2983_THERMISTOR_C_ROTATE(x) \
  81				FIELD_PREP(LTC2983_THERMISTOR_C_ROTATE_MASK, x)
  82
  83#define LTC2983_DIODE_DIFF_MASK			BIT(2)
  84#define LTC2983_DIODE_SGL(x) \
  85			FIELD_PREP(LTC2983_DIODE_DIFF_MASK, x)
  86#define LTC2983_DIODE_3_CONV_CYCLE_MASK		BIT(1)
  87#define LTC2983_DIODE_3_CONV_CYCLE(x) \
  88				FIELD_PREP(LTC2983_DIODE_3_CONV_CYCLE_MASK, x)
  89#define LTC2983_DIODE_AVERAGE_ON_MASK		BIT(0)
  90#define LTC2983_DIODE_AVERAGE_ON(x) \
  91				FIELD_PREP(LTC2983_DIODE_AVERAGE_ON_MASK, x)
  92
  93#define LTC2983_RTD_4_WIRE_MASK			BIT(3)
  94#define LTC2983_RTD_ROTATION_MASK		BIT(1)
  95#define LTC2983_RTD_C_ROTATE(x) \
  96			FIELD_PREP(LTC2983_RTD_ROTATION_MASK, x)
  97#define LTC2983_RTD_KELVIN_R_SENSE_MASK		GENMASK(3, 2)
  98#define LTC2983_RTD_N_WIRES_MASK		GENMASK(3, 2)
  99#define LTC2983_RTD_N_WIRES(x) \
 100			FIELD_PREP(LTC2983_RTD_N_WIRES_MASK, x)
 101#define LTC2983_RTD_R_SHARE_MASK		BIT(0)
 102#define LTC2983_RTD_R_SHARE(x) \
 103			FIELD_PREP(LTC2983_RTD_R_SHARE_MASK, 1)
 104
 105#define LTC2983_COMMON_HARD_FAULT_MASK	GENMASK(31, 30)
 106#define LTC2983_COMMON_SOFT_FAULT_MASK	GENMASK(27, 25)
 107
 108#define	LTC2983_STATUS_START_MASK	BIT(7)
 109#define	LTC2983_STATUS_START(x)		FIELD_PREP(LTC2983_STATUS_START_MASK, x)
 110#define	LTC2983_STATUS_UP_MASK		GENMASK(7, 6)
 111#define	LTC2983_STATUS_UP(reg)		FIELD_GET(LTC2983_STATUS_UP_MASK, reg)
 112
 113#define	LTC2983_STATUS_CHAN_SEL_MASK	GENMASK(4, 0)
 114#define	LTC2983_STATUS_CHAN_SEL(x) \
 115				FIELD_PREP(LTC2983_STATUS_CHAN_SEL_MASK, x)
 116
 117#define LTC2983_TEMP_UNITS_MASK		BIT(2)
 118#define LTC2983_TEMP_UNITS(x)		FIELD_PREP(LTC2983_TEMP_UNITS_MASK, x)
 119
 120#define LTC2983_NOTCH_FREQ_MASK		GENMASK(1, 0)
 121#define LTC2983_NOTCH_FREQ(x)		FIELD_PREP(LTC2983_NOTCH_FREQ_MASK, x)
 122
 123#define LTC2983_RES_VALID_MASK		BIT(24)
 124#define LTC2983_DATA_MASK		GENMASK(23, 0)
 125#define LTC2983_DATA_SIGN_BIT		23
 126
 127#define LTC2983_CHAN_TYPE_MASK		GENMASK(31, 27)
 128#define LTC2983_CHAN_TYPE(x)		FIELD_PREP(LTC2983_CHAN_TYPE_MASK, x)
 129
 130/* cold junction for thermocouples and rsense for rtd's and thermistor's */
 131#define LTC2983_CHAN_ASSIGN_MASK	GENMASK(26, 22)
 132#define LTC2983_CHAN_ASSIGN(x)		FIELD_PREP(LTC2983_CHAN_ASSIGN_MASK, x)
 133
 134#define LTC2983_CUSTOM_LEN_MASK		GENMASK(5, 0)
 135#define LTC2983_CUSTOM_LEN(x)		FIELD_PREP(LTC2983_CUSTOM_LEN_MASK, x)
 136
 137#define LTC2983_CUSTOM_ADDR_MASK	GENMASK(11, 6)
 138#define LTC2983_CUSTOM_ADDR(x)		FIELD_PREP(LTC2983_CUSTOM_ADDR_MASK, x)
 139
 140#define LTC2983_THERMOCOUPLE_CFG_MASK	GENMASK(21, 18)
 141#define LTC2983_THERMOCOUPLE_CFG(x) \
 142				FIELD_PREP(LTC2983_THERMOCOUPLE_CFG_MASK, x)
 143#define LTC2983_THERMOCOUPLE_HARD_FAULT_MASK	GENMASK(31, 29)
 144#define LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK	GENMASK(28, 25)
 145
 146#define LTC2983_RTD_CFG_MASK		GENMASK(21, 18)
 147#define LTC2983_RTD_CFG(x)		FIELD_PREP(LTC2983_RTD_CFG_MASK, x)
 148#define LTC2983_RTD_EXC_CURRENT_MASK	GENMASK(17, 14)
 149#define LTC2983_RTD_EXC_CURRENT(x) \
 150				FIELD_PREP(LTC2983_RTD_EXC_CURRENT_MASK, x)
 151#define LTC2983_RTD_CURVE_MASK		GENMASK(13, 12)
 152#define LTC2983_RTD_CURVE(x)		FIELD_PREP(LTC2983_RTD_CURVE_MASK, x)
 153
 154#define LTC2983_THERMISTOR_CFG_MASK	GENMASK(21, 19)
 155#define LTC2983_THERMISTOR_CFG(x) \
 156				FIELD_PREP(LTC2983_THERMISTOR_CFG_MASK, x)
 157#define LTC2983_THERMISTOR_EXC_CURRENT_MASK	GENMASK(18, 15)
 158#define LTC2983_THERMISTOR_EXC_CURRENT(x) \
 159			FIELD_PREP(LTC2983_THERMISTOR_EXC_CURRENT_MASK, x)
 160
 161#define LTC2983_DIODE_CFG_MASK		GENMASK(26, 24)
 162#define LTC2983_DIODE_CFG(x)		FIELD_PREP(LTC2983_DIODE_CFG_MASK, x)
 163#define LTC2983_DIODE_EXC_CURRENT_MASK	GENMASK(23, 22)
 164#define LTC2983_DIODE_EXC_CURRENT(x) \
 165				FIELD_PREP(LTC2983_DIODE_EXC_CURRENT_MASK, x)
 166#define LTC2983_DIODE_IDEAL_FACTOR_MASK	GENMASK(21, 0)
 167#define LTC2983_DIODE_IDEAL_FACTOR(x) \
 168				FIELD_PREP(LTC2983_DIODE_IDEAL_FACTOR_MASK, x)
 169
 170#define LTC2983_R_SENSE_VAL_MASK	GENMASK(26, 0)
 171#define LTC2983_R_SENSE_VAL(x)		FIELD_PREP(LTC2983_R_SENSE_VAL_MASK, x)
 172
 173#define LTC2983_ADC_SINGLE_ENDED_MASK	BIT(26)
 174#define LTC2983_ADC_SINGLE_ENDED(x) \
 175				FIELD_PREP(LTC2983_ADC_SINGLE_ENDED_MASK, x)
 176
 177enum {
 178	LTC2983_SENSOR_THERMOCOUPLE = 1,
 179	LTC2983_SENSOR_THERMOCOUPLE_CUSTOM = 9,
 180	LTC2983_SENSOR_RTD = 10,
 181	LTC2983_SENSOR_RTD_CUSTOM = 18,
 182	LTC2983_SENSOR_THERMISTOR = 19,
 183	LTC2983_SENSOR_THERMISTOR_STEINHART = 26,
 184	LTC2983_SENSOR_THERMISTOR_CUSTOM = 27,
 185	LTC2983_SENSOR_DIODE = 28,
 186	LTC2983_SENSOR_SENSE_RESISTOR = 29,
 187	LTC2983_SENSOR_DIRECT_ADC = 30,
 188	LTC2983_SENSOR_ACTIVE_TEMP = 31,
 189};
 190
 191#define to_thermocouple(_sensor) \
 192		container_of(_sensor, struct ltc2983_thermocouple, sensor)
 193
 194#define to_rtd(_sensor) \
 195		container_of(_sensor, struct ltc2983_rtd, sensor)
 196
 197#define to_thermistor(_sensor) \
 198		container_of(_sensor, struct ltc2983_thermistor, sensor)
 199
 200#define to_diode(_sensor) \
 201		container_of(_sensor, struct ltc2983_diode, sensor)
 202
 203#define to_rsense(_sensor) \
 204		container_of(_sensor, struct ltc2983_rsense, sensor)
 205
 206#define to_adc(_sensor) \
 207		container_of(_sensor, struct ltc2983_adc, sensor)
 208
 209#define to_temp(_sensor) \
 210		container_of(_sensor, struct ltc2983_temp, sensor)
 211
 212struct ltc2983_chip_info {
 213	const char *name;
 214	unsigned int max_channels_nr;
 215	bool has_temp;
 216	bool has_eeprom;
 217};
 218
 219struct ltc2983_data {
 220	const struct ltc2983_chip_info *info;
 221	struct regmap *regmap;
 222	struct spi_device *spi;
 223	struct mutex lock;
 224	struct completion completion;
 225	struct iio_chan_spec *iio_chan;
 226	struct ltc2983_sensor **sensors;
 227	u32 mux_delay_config;
 228	u32 filter_notch_freq;
 229	u16 custom_table_size;
 230	u8 num_channels;
 231	u8 iio_channels;
 232	/*
 233	 * DMA (thus cache coherency maintenance) may require the
 234	 * transfer buffers to live in their own cache lines.
 235	 * Holds the converted temperature
 236	 */
 237	__be32 temp __aligned(IIO_DMA_MINALIGN);
 238	__be32 chan_val;
 239	__be32 eeprom_key;
 240};
 241
 242struct ltc2983_sensor {
 243	int (*fault_handler)(const struct ltc2983_data *st, const u32 result);
 244	int (*assign_chan)(struct ltc2983_data *st,
 245			   const struct ltc2983_sensor *sensor);
 246	/* specifies the sensor channel */
 247	u32 chan;
 248	/* sensor type */
 249	u32 type;
 250};
 251
 252struct ltc2983_custom_sensor {
 253	/* raw table sensor data */
 254	void *table;
 255	size_t size;
 256	/* address offset */
 257	s8 offset;
 258	bool is_steinhart;
 259};
 260
 261struct ltc2983_thermocouple {
 262	struct ltc2983_sensor sensor;
 263	struct ltc2983_custom_sensor *custom;
 264	u32 sensor_config;
 265	u32 cold_junction_chan;
 266};
 267
 268struct ltc2983_rtd {
 269	struct ltc2983_sensor sensor;
 270	struct ltc2983_custom_sensor *custom;
 271	u32 sensor_config;
 272	u32 r_sense_chan;
 273	u32 excitation_current;
 274	u32 rtd_curve;
 275};
 276
 277struct ltc2983_thermistor {
 278	struct ltc2983_sensor sensor;
 279	struct ltc2983_custom_sensor *custom;
 280	u32 sensor_config;
 281	u32 r_sense_chan;
 282	u32 excitation_current;
 283};
 284
 285struct ltc2983_diode {
 286	struct ltc2983_sensor sensor;
 287	u32 sensor_config;
 288	u32 excitation_current;
 289	u32 ideal_factor_value;
 290};
 291
 292struct ltc2983_rsense {
 293	struct ltc2983_sensor sensor;
 294	u32 r_sense_val;
 295};
 296
 297struct ltc2983_adc {
 298	struct ltc2983_sensor sensor;
 299	bool single_ended;
 300};
 301
 302struct ltc2983_temp {
 303	struct ltc2983_sensor sensor;
 304	struct ltc2983_custom_sensor *custom;
 305	bool single_ended;
 306};
 307
 308/*
 309 * Convert to Q format numbers. These number's are integers where
 310 * the number of integer and fractional bits are specified. The resolution
 311 * is given by 1/@resolution and tell us the number of fractional bits. For
 312 * instance a resolution of 2^-10 means we have 10 fractional bits.
 313 */
 314static u32 __convert_to_raw(const u64 val, const u32 resolution)
 315{
 316	u64 __res = val * resolution;
 317
 318	/* all values are multiplied by 1000000 to remove the fraction */
 319	do_div(__res, 1000000);
 320
 321	return __res;
 322}
 323
 324static u32 __convert_to_raw_sign(const u64 val, const u32 resolution)
 325{
 326	s64 __res = -(s32)val;
 327
 328	__res = __convert_to_raw(__res, resolution);
 329
 330	return (u32)-__res;
 331}
 332
 333static int __ltc2983_fault_handler(const struct ltc2983_data *st,
 334				   const u32 result, const u32 hard_mask,
 335				   const u32 soft_mask)
 336{
 337	const struct device *dev = &st->spi->dev;
 338
 339	if (result & hard_mask) {
 340		dev_err(dev, "Invalid conversion: Sensor HARD fault\n");
 341		return -EIO;
 342	} else if (result & soft_mask) {
 343		/* just print a warning */
 344		dev_warn(dev, "Suspicious conversion: Sensor SOFT fault\n");
 345	}
 346
 347	return 0;
 348}
 349
 350static int __ltc2983_chan_assign_common(struct ltc2983_data *st,
 351					const struct ltc2983_sensor *sensor,
 352					u32 chan_val)
 353{
 354	u32 reg = LTC2983_CHAN_START_ADDR(sensor->chan);
 355
 356	chan_val |= LTC2983_CHAN_TYPE(sensor->type);
 357	dev_dbg(&st->spi->dev, "Assign reg:0x%04X, val:0x%08X\n", reg,
 358		chan_val);
 359	st->chan_val = cpu_to_be32(chan_val);
 360	return regmap_bulk_write(st->regmap, reg, &st->chan_val,
 361				 sizeof(st->chan_val));
 362}
 363
 364static int __ltc2983_chan_custom_sensor_assign(struct ltc2983_data *st,
 365					  struct ltc2983_custom_sensor *custom,
 366					  u32 *chan_val)
 367{
 368	u32 reg;
 369	u8 mult = custom->is_steinhart ? LTC2983_CUSTOM_STEINHART_ENTRY_SZ :
 370		LTC2983_CUSTOM_SENSOR_ENTRY_SZ;
 371	const struct device *dev = &st->spi->dev;
 372	/*
 373	 * custom->size holds the raw size of the table. However, when
 374	 * configuring the sensor channel, we must write the number of
 375	 * entries of the table minus 1. For steinhart sensors 0 is written
 376	 * since the size is constant!
 377	 */
 378	const u8 len = custom->is_steinhart ? 0 :
 379		(custom->size / LTC2983_CUSTOM_SENSOR_ENTRY_SZ) - 1;
 380	/*
 381	 * Check if the offset was assigned already. It should be for steinhart
 382	 * sensors. When coming from sleep, it should be assigned for all.
 383	 */
 384	if (custom->offset < 0) {
 385		/*
 386		 * This needs to be done again here because, from the moment
 387		 * when this test was done (successfully) for this custom
 388		 * sensor, a steinhart sensor might have been added changing
 389		 * custom_table_size...
 390		 */
 391		if (st->custom_table_size + custom->size >
 392		    (LTC2983_CUST_SENS_TBL_END_REG -
 393		     LTC2983_CUST_SENS_TBL_START_REG) + 1) {
 394			dev_err(dev,
 395				"Not space left(%d) for new custom sensor(%zu)",
 396				st->custom_table_size,
 397				custom->size);
 398			return -EINVAL;
 399		}
 400
 401		custom->offset = st->custom_table_size /
 402					LTC2983_CUSTOM_SENSOR_ENTRY_SZ;
 403		st->custom_table_size += custom->size;
 404	}
 405
 406	reg = (custom->offset * mult) + LTC2983_CUST_SENS_TBL_START_REG;
 407
 408	*chan_val |= LTC2983_CUSTOM_LEN(len);
 409	*chan_val |= LTC2983_CUSTOM_ADDR(custom->offset);
 410	dev_dbg(dev, "Assign custom sensor, reg:0x%04X, off:%d, sz:%zu",
 411		reg, custom->offset,
 412		custom->size);
 413	/* write custom sensor table */
 414	return regmap_bulk_write(st->regmap, reg, custom->table, custom->size);
 415}
 416
 417static struct ltc2983_custom_sensor *
 418__ltc2983_custom_sensor_new(struct ltc2983_data *st, const struct fwnode_handle *fn,
 419			    const char *propname, const bool is_steinhart,
 420			    const u32 resolution, const bool has_signed)
 421{
 422	struct ltc2983_custom_sensor *new_custom;
 423	struct device *dev = &st->spi->dev;
 424	/*
 425	 * For custom steinhart, the full u32 is taken. For all the others
 426	 * the MSB is discarded.
 427	 */
 428	const u8 n_size = is_steinhart ? 4 : 3;
 429	u8 index, n_entries;
 430	int ret;
 431
 432	if (is_steinhart)
 433		n_entries = fwnode_property_count_u32(fn, propname);
 434	else
 435		n_entries = fwnode_property_count_u64(fn, propname);
 436	/* n_entries must be an even number */
 437	if (!n_entries || (n_entries % 2) != 0)
 438		return dev_err_ptr_probe(dev, -EINVAL,
 439					 "Number of entries either 0 or not even\n");
 440
 441	new_custom = devm_kzalloc(dev, sizeof(*new_custom), GFP_KERNEL);
 442	if (!new_custom)
 443		return ERR_PTR(-ENOMEM);
 444
 445	new_custom->size = n_entries * n_size;
 446	/* check Steinhart size */
 447	if (is_steinhart && new_custom->size != LTC2983_CUSTOM_STEINHART_SIZE)
 448		return dev_err_ptr_probe(dev, -EINVAL,
 449					 "Steinhart sensors size(%zu) must be %u\n",
 450					 new_custom->size, LTC2983_CUSTOM_STEINHART_SIZE);
 451
 452	/* Check space on the table. */
 453	if (st->custom_table_size + new_custom->size >
 454	    (LTC2983_CUST_SENS_TBL_END_REG - LTC2983_CUST_SENS_TBL_START_REG) + 1)
 455		return dev_err_ptr_probe(dev, -EINVAL,
 456					 "No space left(%d) for new custom sensor(%zu)\n",
 457					 st->custom_table_size, new_custom->size);
 458
 459	/* allocate the table */
 460	if (is_steinhart)
 461		new_custom->table = devm_kcalloc(dev, n_entries, sizeof(u32), GFP_KERNEL);
 462	else
 463		new_custom->table = devm_kcalloc(dev, n_entries, sizeof(u64), GFP_KERNEL);
 464	if (!new_custom->table)
 465		return ERR_PTR(-ENOMEM);
 466
 467	/*
 468	 * Steinhart sensors are configured with raw values in the firmware
 469	 * node. For the other sensors we must convert the value to raw.
 470	 * The odd index's correspond to temperatures and always have 1/1024
 471	 * of resolution. Temperatures also come in Kelvin, so signed values
 472	 * are not possible.
 473	 */
 474	if (is_steinhart) {
 475		ret = fwnode_property_read_u32_array(fn, propname, new_custom->table, n_entries);
 476		if (ret < 0)
 477			return ERR_PTR(ret);
 478
 479		cpu_to_be32_array(new_custom->table, new_custom->table, n_entries);
 480	} else {
 481		ret = fwnode_property_read_u64_array(fn, propname, new_custom->table, n_entries);
 482		if (ret < 0)
 483			return ERR_PTR(ret);
 484
 485		for (index = 0; index < n_entries; index++) {
 486			u64 temp = ((u64 *)new_custom->table)[index];
 487
 488			if ((index % 2) != 0)
 489				temp = __convert_to_raw(temp, 1024);
 490			else if (has_signed && (s64)temp < 0)
 491				temp = __convert_to_raw_sign(temp, resolution);
 492			else
 493				temp = __convert_to_raw(temp, resolution);
 494
 495			put_unaligned_be24(temp, new_custom->table + index * 3);
 496		}
 497	}
 498
 499	new_custom->is_steinhart = is_steinhart;
 500	/*
 501	 * This is done to first add all the steinhart sensors to the table,
 502	 * in order to maximize the table usage. If we mix adding steinhart
 503	 * with the other sensors, we might have to do some roundup to make
 504	 * sure that sensor_addr - 0x250(start address) is a multiple of 4
 505	 * (for steinhart), and a multiple of 6 for all the other sensors.
 506	 * Since we have const 24 bytes for steinhart sensors and 24 is
 507	 * also a multiple of 6, we guarantee that the first non-steinhart
 508	 * sensor will sit in a correct address without the need of filling
 509	 * addresses.
 510	 */
 511	if (is_steinhart) {
 512		new_custom->offset = st->custom_table_size /
 513					LTC2983_CUSTOM_STEINHART_ENTRY_SZ;
 514		st->custom_table_size += new_custom->size;
 515	} else {
 516		/* mark as unset. This is checked later on the assign phase */
 517		new_custom->offset = -1;
 518	}
 519
 520	return new_custom;
 521}
 522
 523static int ltc2983_thermocouple_fault_handler(const struct ltc2983_data *st,
 524					      const u32 result)
 525{
 526	return __ltc2983_fault_handler(st, result,
 527				       LTC2983_THERMOCOUPLE_HARD_FAULT_MASK,
 528				       LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK);
 529}
 530
 531static int ltc2983_common_fault_handler(const struct ltc2983_data *st,
 532					const u32 result)
 533{
 534	return __ltc2983_fault_handler(st, result,
 535				       LTC2983_COMMON_HARD_FAULT_MASK,
 536				       LTC2983_COMMON_SOFT_FAULT_MASK);
 537}
 538
 539static int ltc2983_thermocouple_assign_chan(struct ltc2983_data *st,
 540				const struct ltc2983_sensor *sensor)
 541{
 542	struct ltc2983_thermocouple *thermo = to_thermocouple(sensor);
 543	u32 chan_val;
 544
 545	chan_val = LTC2983_CHAN_ASSIGN(thermo->cold_junction_chan);
 546	chan_val |= LTC2983_THERMOCOUPLE_CFG(thermo->sensor_config);
 547
 548	if (thermo->custom) {
 549		int ret;
 550
 551		ret = __ltc2983_chan_custom_sensor_assign(st, thermo->custom,
 552							  &chan_val);
 553		if (ret)
 554			return ret;
 555	}
 556	return __ltc2983_chan_assign_common(st, sensor, chan_val);
 557}
 558
 559static int ltc2983_rtd_assign_chan(struct ltc2983_data *st,
 560				   const struct ltc2983_sensor *sensor)
 561{
 562	struct ltc2983_rtd *rtd = to_rtd(sensor);
 563	u32 chan_val;
 564
 565	chan_val = LTC2983_CHAN_ASSIGN(rtd->r_sense_chan);
 566	chan_val |= LTC2983_RTD_CFG(rtd->sensor_config);
 567	chan_val |= LTC2983_RTD_EXC_CURRENT(rtd->excitation_current);
 568	chan_val |= LTC2983_RTD_CURVE(rtd->rtd_curve);
 569
 570	if (rtd->custom) {
 571		int ret;
 572
 573		ret = __ltc2983_chan_custom_sensor_assign(st, rtd->custom,
 574							  &chan_val);
 575		if (ret)
 576			return ret;
 577	}
 578	return __ltc2983_chan_assign_common(st, sensor, chan_val);
 579}
 580
 581static int ltc2983_thermistor_assign_chan(struct ltc2983_data *st,
 582					  const struct ltc2983_sensor *sensor)
 583{
 584	struct ltc2983_thermistor *thermistor = to_thermistor(sensor);
 585	u32 chan_val;
 586
 587	chan_val = LTC2983_CHAN_ASSIGN(thermistor->r_sense_chan);
 588	chan_val |= LTC2983_THERMISTOR_CFG(thermistor->sensor_config);
 589	chan_val |=
 590		LTC2983_THERMISTOR_EXC_CURRENT(thermistor->excitation_current);
 591
 592	if (thermistor->custom) {
 593		int ret;
 594
 595		ret = __ltc2983_chan_custom_sensor_assign(st,
 596							  thermistor->custom,
 597							  &chan_val);
 598		if (ret)
 599			return ret;
 600	}
 601	return __ltc2983_chan_assign_common(st, sensor, chan_val);
 602}
 603
 604static int ltc2983_diode_assign_chan(struct ltc2983_data *st,
 605				     const struct ltc2983_sensor *sensor)
 606{
 607	struct ltc2983_diode *diode = to_diode(sensor);
 608	u32 chan_val;
 609
 610	chan_val = LTC2983_DIODE_CFG(diode->sensor_config);
 611	chan_val |= LTC2983_DIODE_EXC_CURRENT(diode->excitation_current);
 612	chan_val |= LTC2983_DIODE_IDEAL_FACTOR(diode->ideal_factor_value);
 613
 614	return __ltc2983_chan_assign_common(st, sensor, chan_val);
 615}
 616
 617static int ltc2983_r_sense_assign_chan(struct ltc2983_data *st,
 618				       const struct ltc2983_sensor *sensor)
 619{
 620	struct ltc2983_rsense *rsense = to_rsense(sensor);
 621	u32 chan_val;
 622
 623	chan_val = LTC2983_R_SENSE_VAL(rsense->r_sense_val);
 624
 625	return __ltc2983_chan_assign_common(st, sensor, chan_val);
 626}
 627
 628static int ltc2983_adc_assign_chan(struct ltc2983_data *st,
 629				   const struct ltc2983_sensor *sensor)
 630{
 631	struct ltc2983_adc *adc = to_adc(sensor);
 632	u32 chan_val;
 633
 634	chan_val = LTC2983_ADC_SINGLE_ENDED(adc->single_ended);
 635
 636	return __ltc2983_chan_assign_common(st, sensor, chan_val);
 637}
 638
 639static int ltc2983_temp_assign_chan(struct ltc2983_data *st,
 640				    const struct ltc2983_sensor *sensor)
 641{
 642	struct ltc2983_temp *temp = to_temp(sensor);
 643	u32 chan_val;
 644	int ret;
 645
 646	chan_val = LTC2983_ADC_SINGLE_ENDED(temp->single_ended);
 647
 648	ret = __ltc2983_chan_custom_sensor_assign(st, temp->custom, &chan_val);
 649	if (ret)
 650		return ret;
 651
 652	return __ltc2983_chan_assign_common(st, sensor, chan_val);
 653}
 654
 655static struct ltc2983_sensor *
 656ltc2983_thermocouple_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 657			 const struct ltc2983_sensor *sensor)
 658{
 659	struct ltc2983_thermocouple *thermo;
 660	u32 oc_current;
 661	int ret;
 662
 663	thermo = devm_kzalloc(&st->spi->dev, sizeof(*thermo), GFP_KERNEL);
 664	if (!thermo)
 665		return ERR_PTR(-ENOMEM);
 666
 667	if (fwnode_property_read_bool(child, "adi,single-ended"))
 668		thermo->sensor_config = LTC2983_THERMOCOUPLE_SGL(1);
 669
 670	ret = fwnode_property_read_u32(child, "adi,sensor-oc-current-microamp", &oc_current);
 671	if (!ret) {
 672		switch (oc_current) {
 673		case 10:
 674			thermo->sensor_config |=
 675					LTC2983_THERMOCOUPLE_OC_CURR(0);
 676			break;
 677		case 100:
 678			thermo->sensor_config |=
 679					LTC2983_THERMOCOUPLE_OC_CURR(1);
 680			break;
 681		case 500:
 682			thermo->sensor_config |=
 683					LTC2983_THERMOCOUPLE_OC_CURR(2);
 684			break;
 685		case 1000:
 686			thermo->sensor_config |=
 687					LTC2983_THERMOCOUPLE_OC_CURR(3);
 688			break;
 689		default:
 690			return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
 691						 "Invalid open circuit current:%u\n",
 692						 oc_current);
 693		}
 694
 695		thermo->sensor_config |= LTC2983_THERMOCOUPLE_OC_CHECK(1);
 696	}
 697	/* validate channel index */
 698	if (!(thermo->sensor_config & LTC2983_THERMOCOUPLE_DIFF_MASK) &&
 699	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
 700		return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
 701					 "Invalid chann:%d for differential thermocouple\n",
 702					 sensor->chan);
 703
 704	struct fwnode_handle *ref __free(fwnode_handle) =
 705		fwnode_find_reference(child, "adi,cold-junction-handle", 0);
 706	if (IS_ERR(ref)) {
 707		ref = NULL;
 708	} else {
 709		ret = fwnode_property_read_u32(ref, "reg", &thermo->cold_junction_chan);
 710		if (ret)
 711			/*
 712			 * This would be catched later but we can just return
 713			 * the error right away.
 714			 */
 715			return dev_err_ptr_probe(&st->spi->dev, ret,
 716						 "Property reg must be given\n");
 717	}
 718
 719	/* check custom sensor */
 720	if (sensor->type == LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
 721		const char *propname = "adi,custom-thermocouple";
 722
 723		thermo->custom = __ltc2983_custom_sensor_new(st, child,
 724							     propname, false,
 725							     16384, true);
 726		if (IS_ERR(thermo->custom))
 727			return ERR_CAST(thermo->custom);
 728	}
 729
 730	/* set common parameters */
 731	thermo->sensor.fault_handler = ltc2983_thermocouple_fault_handler;
 732	thermo->sensor.assign_chan = ltc2983_thermocouple_assign_chan;
 733
 734	return &thermo->sensor;
 735}
 736
 737static struct ltc2983_sensor *
 738ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 739		const struct ltc2983_sensor *sensor)
 740{
 741	struct ltc2983_rtd *rtd;
 742	int ret = 0;
 743	struct device *dev = &st->spi->dev;
 744	u32 excitation_current = 0, n_wires = 0;
 745
 746	rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL);
 747	if (!rtd)
 748		return ERR_PTR(-ENOMEM);
 749
 750	struct fwnode_handle *ref __free(fwnode_handle) =
 751		fwnode_find_reference(child, "adi,rsense-handle", 0);
 752	if (IS_ERR(ref))
 753		return dev_err_cast_probe(dev, ref,
 754					  "Property adi,rsense-handle missing or invalid\n");
 755
 756	ret = fwnode_property_read_u32(ref, "reg", &rtd->r_sense_chan);
 757	if (ret)
 758		return dev_err_ptr_probe(dev, ret,
 759					 "Property reg must be given\n");
 760
 761	ret = fwnode_property_read_u32(child, "adi,number-of-wires", &n_wires);
 762	if (!ret) {
 763		switch (n_wires) {
 764		case 2:
 765			rtd->sensor_config = LTC2983_RTD_N_WIRES(0);
 766			break;
 767		case 3:
 768			rtd->sensor_config = LTC2983_RTD_N_WIRES(1);
 769			break;
 770		case 4:
 771			rtd->sensor_config = LTC2983_RTD_N_WIRES(2);
 772			break;
 773		case 5:
 774			/* 4 wires, Kelvin Rsense */
 775			rtd->sensor_config = LTC2983_RTD_N_WIRES(3);
 776			break;
 777		default:
 778			return dev_err_ptr_probe(dev, -EINVAL,
 779						 "Invalid number of wires:%u\n",
 780						 n_wires);
 781		}
 782	}
 783
 784	if (fwnode_property_read_bool(child, "adi,rsense-share")) {
 785		/* Current rotation is only available with rsense sharing */
 786		if (fwnode_property_read_bool(child, "adi,current-rotate")) {
 787			if (n_wires == 2 || n_wires == 3)
 788				return dev_err_ptr_probe(dev, -EINVAL,
 789							 "Rotation not allowed for 2/3 Wire RTDs\n");
 790
 791			rtd->sensor_config |= LTC2983_RTD_C_ROTATE(1);
 792		} else {
 793			rtd->sensor_config |= LTC2983_RTD_R_SHARE(1);
 794		}
 795	}
 796	/*
 797	 * rtd channel indexes are a bit more complicated to validate.
 798	 * For 4wire RTD with rotation, the channel selection cannot be
 799	 * >=19 since the chann + 1 is used in this configuration.
 800	 * For 4wire RTDs with kelvin rsense, the rsense channel cannot be
 801	 * <=1 since chanel - 1 and channel - 2 are used.
 802	 */
 803	if (rtd->sensor_config & LTC2983_RTD_4_WIRE_MASK) {
 804		/* 4-wire */
 805		u8 min = LTC2983_DIFFERENTIAL_CHAN_MIN,
 806			max = st->info->max_channels_nr;
 807
 808		if (rtd->sensor_config & LTC2983_RTD_ROTATION_MASK)
 809			max = st->info->max_channels_nr - 1;
 810
 811		if (((rtd->sensor_config & LTC2983_RTD_KELVIN_R_SENSE_MASK)
 812		     == LTC2983_RTD_KELVIN_R_SENSE_MASK) &&
 813		    (rtd->r_sense_chan <=  min))
 814			/* kelvin rsense*/
 815			return dev_err_ptr_probe(dev, -EINVAL,
 816						 "Invalid rsense chann:%d to use in kelvin rsense\n",
 817						 rtd->r_sense_chan);
 818
 819		if (sensor->chan < min || sensor->chan > max)
 820			return dev_err_ptr_probe(dev, -EINVAL,
 821						 "Invalid chann:%d for the rtd config\n",
 822						 sensor->chan);
 823	} else {
 824		/* same as differential case */
 825		if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
 826			return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
 827						 "Invalid chann:%d for RTD\n",
 828						 sensor->chan);
 829	}
 830
 831	/* check custom sensor */
 832	if (sensor->type == LTC2983_SENSOR_RTD_CUSTOM) {
 833		rtd->custom = __ltc2983_custom_sensor_new(st, child,
 834							  "adi,custom-rtd",
 835							  false, 2048, false);
 836		if (IS_ERR(rtd->custom))
 837			return ERR_CAST(rtd->custom);
 838	}
 839
 840	/* set common parameters */
 841	rtd->sensor.fault_handler = ltc2983_common_fault_handler;
 842	rtd->sensor.assign_chan = ltc2983_rtd_assign_chan;
 843
 844	ret = fwnode_property_read_u32(child, "adi,excitation-current-microamp",
 845				       &excitation_current);
 846	if (ret) {
 847		/* default to 5uA */
 848		rtd->excitation_current = 1;
 849	} else {
 850		switch (excitation_current) {
 851		case 5:
 852			rtd->excitation_current = 0x01;
 853			break;
 854		case 10:
 855			rtd->excitation_current = 0x02;
 856			break;
 857		case 25:
 858			rtd->excitation_current = 0x03;
 859			break;
 860		case 50:
 861			rtd->excitation_current = 0x04;
 862			break;
 863		case 100:
 864			rtd->excitation_current = 0x05;
 865			break;
 866		case 250:
 867			rtd->excitation_current = 0x06;
 868			break;
 869		case 500:
 870			rtd->excitation_current = 0x07;
 871			break;
 872		case 1000:
 873			rtd->excitation_current = 0x08;
 874			break;
 875		default:
 876			return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
 877						 "Invalid value for excitation current(%u)\n",
 878						 excitation_current);
 879		}
 880	}
 881
 882	fwnode_property_read_u32(child, "adi,rtd-curve", &rtd->rtd_curve);
 883
 884	return &rtd->sensor;
 885}
 886
 887static struct ltc2983_sensor *
 888ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *st,
 889		       const struct ltc2983_sensor *sensor)
 890{
 891	struct ltc2983_thermistor *thermistor;
 892	struct device *dev = &st->spi->dev;
 893	u32 excitation_current = 0;
 894	int ret = 0;
 895
 896	thermistor = devm_kzalloc(dev, sizeof(*thermistor), GFP_KERNEL);
 897	if (!thermistor)
 898		return ERR_PTR(-ENOMEM);
 899
 900	struct fwnode_handle *ref __free(fwnode_handle) =
 901		fwnode_find_reference(child, "adi,rsense-handle", 0);
 902	if (IS_ERR(ref))
 903		return dev_err_cast_probe(dev, ref,
 904					  "Property adi,rsense-handle missing or invalid\n");
 905
 906	ret = fwnode_property_read_u32(ref, "reg", &thermistor->r_sense_chan);
 907	if (ret)
 908		return dev_err_ptr_probe(dev, ret,
 909					 "rsense channel must be configured...\n");
 910
 911	if (fwnode_property_read_bool(child, "adi,single-ended")) {
 912		thermistor->sensor_config = LTC2983_THERMISTOR_SGL(1);
 913	} else if (fwnode_property_read_bool(child, "adi,rsense-share")) {
 914		/* rotation is only possible if sharing rsense */
 915		if (fwnode_property_read_bool(child, "adi,current-rotate"))
 916			thermistor->sensor_config =
 917						LTC2983_THERMISTOR_C_ROTATE(1);
 918		else
 919			thermistor->sensor_config =
 920						LTC2983_THERMISTOR_R_SHARE(1);
 921	}
 922	/* validate channel index */
 923	if (!(thermistor->sensor_config & LTC2983_THERMISTOR_DIFF_MASK) &&
 924	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
 925		return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
 926					 "Invalid chann:%d for differential thermistor\n",
 927					 sensor->chan);
 928
 929	/* check custom sensor */
 930	if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART) {
 931		bool steinhart = false;
 932		const char *propname;
 933
 934		if (sensor->type == LTC2983_SENSOR_THERMISTOR_STEINHART) {
 935			steinhart = true;
 936			propname = "adi,custom-steinhart";
 937		} else {
 938			propname = "adi,custom-thermistor";
 939		}
 940
 941		thermistor->custom = __ltc2983_custom_sensor_new(st, child,
 942								 propname,
 943								 steinhart,
 944								 64, false);
 945		if (IS_ERR(thermistor->custom))
 946			return ERR_CAST(thermistor->custom);
 947	}
 948	/* set common parameters */
 949	thermistor->sensor.fault_handler = ltc2983_common_fault_handler;
 950	thermistor->sensor.assign_chan = ltc2983_thermistor_assign_chan;
 951
 952	ret = fwnode_property_read_u32(child, "adi,excitation-current-nanoamp",
 953				       &excitation_current);
 954	if (ret) {
 955		/* Auto range is not allowed for custom sensors */
 956		if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART)
 957			/* default to 1uA */
 958			thermistor->excitation_current = 0x03;
 959		else
 960			/* default to auto-range */
 961			thermistor->excitation_current = 0x0c;
 962	} else {
 963		switch (excitation_current) {
 964		case 0:
 965			/* auto range */
 966			if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART)
 967				return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
 968							 "Auto Range not allowed for custom sensors\n");
 969
 970			thermistor->excitation_current = 0x0c;
 971			break;
 972		case 250:
 973			thermistor->excitation_current = 0x01;
 974			break;
 975		case 500:
 976			thermistor->excitation_current = 0x02;
 977			break;
 978		case 1000:
 979			thermistor->excitation_current = 0x03;
 980			break;
 981		case 5000:
 982			thermistor->excitation_current = 0x04;
 983			break;
 984		case 10000:
 985			thermistor->excitation_current = 0x05;
 986			break;
 987		case 25000:
 988			thermistor->excitation_current = 0x06;
 989			break;
 990		case 50000:
 991			thermistor->excitation_current = 0x07;
 992			break;
 993		case 100000:
 994			thermistor->excitation_current = 0x08;
 995			break;
 996		case 250000:
 997			thermistor->excitation_current = 0x09;
 998			break;
 999		case 500000:
1000			thermistor->excitation_current = 0x0a;
1001			break;
1002		case 1000000:
1003			thermistor->excitation_current = 0x0b;
1004			break;
1005		default:
1006			return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
1007						 "Invalid value for excitation current(%u)\n",
1008						 excitation_current);
1009		}
1010	}
1011
1012	return &thermistor->sensor;
1013}
1014
1015static struct ltc2983_sensor *
1016ltc2983_diode_new(const struct fwnode_handle *child, const struct ltc2983_data *st,
1017		  const struct ltc2983_sensor *sensor)
1018{
1019	struct ltc2983_diode *diode;
1020	u32 temp = 0, excitation_current = 0;
1021	int ret;
1022
1023	diode = devm_kzalloc(&st->spi->dev, sizeof(*diode), GFP_KERNEL);
1024	if (!diode)
1025		return ERR_PTR(-ENOMEM);
1026
1027	if (fwnode_property_read_bool(child, "adi,single-ended"))
1028		diode->sensor_config = LTC2983_DIODE_SGL(1);
1029
1030	if (fwnode_property_read_bool(child, "adi,three-conversion-cycles"))
1031		diode->sensor_config |= LTC2983_DIODE_3_CONV_CYCLE(1);
1032
1033	if (fwnode_property_read_bool(child, "adi,average-on"))
1034		diode->sensor_config |= LTC2983_DIODE_AVERAGE_ON(1);
1035
1036	/* validate channel index */
1037	if (!(diode->sensor_config & LTC2983_DIODE_DIFF_MASK) &&
1038	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
1039		return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
1040					 "Invalid chann:%d for differential thermistor\n",
1041					 sensor->chan);
1042
1043	/* set common parameters */
1044	diode->sensor.fault_handler = ltc2983_common_fault_handler;
1045	diode->sensor.assign_chan = ltc2983_diode_assign_chan;
1046
1047	ret = fwnode_property_read_u32(child, "adi,excitation-current-microamp",
1048				       &excitation_current);
1049	if (!ret) {
1050		switch (excitation_current) {
1051		case 10:
1052			diode->excitation_current = 0x00;
1053			break;
1054		case 20:
1055			diode->excitation_current = 0x01;
1056			break;
1057		case 40:
1058			diode->excitation_current = 0x02;
1059			break;
1060		case 80:
1061			diode->excitation_current = 0x03;
1062			break;
1063		default:
1064			return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
1065						 "Invalid value for excitation current(%u)\n",
1066						 excitation_current);
1067		}
1068	}
1069
1070	fwnode_property_read_u32(child, "adi,ideal-factor-value", &temp);
1071
1072	/* 2^20 resolution */
1073	diode->ideal_factor_value = __convert_to_raw(temp, 1048576);
1074
1075	return &diode->sensor;
1076}
1077
1078static struct ltc2983_sensor *ltc2983_r_sense_new(struct fwnode_handle *child,
1079					struct ltc2983_data *st,
1080					const struct ltc2983_sensor *sensor)
1081{
1082	struct ltc2983_rsense *rsense;
1083	int ret;
1084	u32 temp;
1085
1086	rsense = devm_kzalloc(&st->spi->dev, sizeof(*rsense), GFP_KERNEL);
1087	if (!rsense)
1088		return ERR_PTR(-ENOMEM);
1089
1090	/* validate channel index */
1091	if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
1092		return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
1093					 "Invalid chann:%d for r_sense\n",
1094					 sensor->chan);
1095
1096	ret = fwnode_property_read_u32(child, "adi,rsense-val-milli-ohms", &temp);
1097	if (ret)
1098		return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
1099					 "Property adi,rsense-val-milli-ohms missing\n");
1100	/*
1101	 * Times 1000 because we have milli-ohms and __convert_to_raw
1102	 * expects scales of 1000000 which are used for all other
1103	 * properties.
1104	 * 2^10 resolution
1105	 */
1106	rsense->r_sense_val = __convert_to_raw((u64)temp * 1000, 1024);
1107
1108	/* set common parameters */
1109	rsense->sensor.assign_chan = ltc2983_r_sense_assign_chan;
1110
1111	return &rsense->sensor;
1112}
1113
1114static struct ltc2983_sensor *ltc2983_adc_new(struct fwnode_handle *child,
1115					 struct ltc2983_data *st,
1116					 const struct ltc2983_sensor *sensor)
1117{
1118	struct ltc2983_adc *adc;
1119
1120	adc = devm_kzalloc(&st->spi->dev, sizeof(*adc), GFP_KERNEL);
1121	if (!adc)
1122		return ERR_PTR(-ENOMEM);
1123
1124	if (fwnode_property_read_bool(child, "adi,single-ended"))
1125		adc->single_ended = true;
1126
1127	if (!adc->single_ended && sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
1128		return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
1129					 "Invalid chan:%d for differential adc\n",
1130					 sensor->chan);
1131
1132	/* set common parameters */
1133	adc->sensor.assign_chan = ltc2983_adc_assign_chan;
1134	adc->sensor.fault_handler = ltc2983_common_fault_handler;
1135
1136	return &adc->sensor;
1137}
1138
1139static struct ltc2983_sensor *ltc2983_temp_new(struct fwnode_handle *child,
1140					       struct ltc2983_data *st,
1141					       const struct ltc2983_sensor *sensor)
1142{
1143	struct ltc2983_temp *temp;
1144
1145	temp = devm_kzalloc(&st->spi->dev, sizeof(*temp), GFP_KERNEL);
1146	if (!temp)
1147		return ERR_PTR(-ENOMEM);
1148
1149	if (fwnode_property_read_bool(child, "adi,single-ended"))
1150		temp->single_ended = true;
1151
1152	if (!temp->single_ended && sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN)
1153		return dev_err_ptr_probe(&st->spi->dev, -EINVAL,
1154					 "Invalid chan:%d for differential temp\n",
1155					 sensor->chan);
1156
1157	temp->custom = __ltc2983_custom_sensor_new(st, child, "adi,custom-temp",
1158						   false, 4096, true);
1159	if (IS_ERR(temp->custom))
1160		return ERR_CAST(temp->custom);
1161
1162	/* set common parameters */
1163	temp->sensor.assign_chan = ltc2983_temp_assign_chan;
1164	temp->sensor.fault_handler = ltc2983_common_fault_handler;
1165
1166	return &temp->sensor;
1167}
1168
1169static int ltc2983_chan_read(struct ltc2983_data *st,
1170			const struct ltc2983_sensor *sensor, int *val)
1171{
1172	u32 start_conversion = 0;
1173	int ret;
1174	unsigned long time;
1175
1176	start_conversion = LTC2983_STATUS_START(true);
1177	start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor->chan);
1178	dev_dbg(&st->spi->dev, "Start conversion on chan:%d, status:%02X\n",
1179		sensor->chan, start_conversion);
1180	/* start conversion */
1181	ret = regmap_write(st->regmap, LTC2983_STATUS_REG, start_conversion);
1182	if (ret)
1183		return ret;
1184
1185	reinit_completion(&st->completion);
1186	/*
1187	 * wait for conversion to complete.
1188	 * 300 ms should be more than enough to complete the conversion.
1189	 * Depending on the sensor configuration, there are 2/3 conversions
1190	 * cycles of 82ms.
1191	 */
1192	time = wait_for_completion_timeout(&st->completion,
1193					   msecs_to_jiffies(300));
1194	if (!time) {
1195		dev_warn(&st->spi->dev, "Conversion timed out\n");
1196		return -ETIMEDOUT;
1197	}
1198
1199	/* read the converted data */
1200	ret = regmap_bulk_read(st->regmap, LTC2983_CHAN_RES_ADDR(sensor->chan),
1201			       &st->temp, sizeof(st->temp));
1202	if (ret)
1203		return ret;
1204
1205	*val = __be32_to_cpu(st->temp);
1206
1207	if (!(LTC2983_RES_VALID_MASK & *val)) {
1208		dev_err(&st->spi->dev, "Invalid conversion detected\n");
1209		return -EIO;
1210	}
1211
1212	ret = sensor->fault_handler(st, *val);
1213	if (ret)
1214		return ret;
1215
1216	*val = sign_extend32((*val) & LTC2983_DATA_MASK, LTC2983_DATA_SIGN_BIT);
1217	return 0;
1218}
1219
1220static int ltc2983_read_raw(struct iio_dev *indio_dev,
1221			    struct iio_chan_spec const *chan,
1222			    int *val, int *val2, long mask)
1223{
1224	struct ltc2983_data *st = iio_priv(indio_dev);
1225	int ret;
1226
1227	/* sanity check */
1228	if (chan->address >= st->num_channels) {
1229		dev_err(&st->spi->dev, "Invalid chan address:%ld",
1230			chan->address);
1231		return -EINVAL;
1232	}
1233
1234	switch (mask) {
1235	case IIO_CHAN_INFO_RAW:
1236		mutex_lock(&st->lock);
1237		ret = ltc2983_chan_read(st, st->sensors[chan->address], val);
1238		mutex_unlock(&st->lock);
1239		return ret ?: IIO_VAL_INT;
1240	case IIO_CHAN_INFO_SCALE:
1241		switch (chan->type) {
1242		case IIO_TEMP:
1243			/* value in milli degrees */
1244			*val = 1000;
1245			/* 2^10 */
1246			*val2 = 1024;
1247			return IIO_VAL_FRACTIONAL;
1248		case IIO_VOLTAGE:
1249			/* value in millivolt */
1250			*val = 1000;
1251			/* 2^21 */
1252			*val2 = 2097152;
1253			return IIO_VAL_FRACTIONAL;
1254		default:
1255			return -EINVAL;
1256		}
1257	}
1258
1259	return -EINVAL;
1260}
1261
1262static int ltc2983_reg_access(struct iio_dev *indio_dev,
1263			      unsigned int reg,
1264			      unsigned int writeval,
1265			      unsigned int *readval)
1266{
1267	struct ltc2983_data *st = iio_priv(indio_dev);
1268
1269	if (readval)
1270		return regmap_read(st->regmap, reg, readval);
1271
1272	return regmap_write(st->regmap, reg, writeval);
1273}
1274
1275static irqreturn_t ltc2983_irq_handler(int irq, void *data)
1276{
1277	struct ltc2983_data *st = data;
1278
1279	complete(&st->completion);
1280	return IRQ_HANDLED;
1281}
1282
1283#define LTC2983_CHAN(__type, index, __address) ({ \
1284	struct iio_chan_spec __chan = { \
1285		.type = __type, \
1286		.indexed = 1, \
1287		.channel = index, \
1288		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
1289		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
1290		.address = __address, \
1291	}; \
1292	__chan; \
1293})
1294
1295static int ltc2983_parse_fw(struct ltc2983_data *st)
1296{
1297	struct device *dev = &st->spi->dev;
1298	int ret, chan = 0, channel_avail_mask = 0;
1299
1300	device_property_read_u32(dev, "adi,mux-delay-config-us", &st->mux_delay_config);
1301
1302	device_property_read_u32(dev, "adi,filter-notch-freq", &st->filter_notch_freq);
1303
1304	st->num_channels = device_get_child_node_count(dev);
1305	if (!st->num_channels)
1306		return dev_err_probe(&st->spi->dev, -EINVAL,
1307				     "At least one channel must be given!\n");
1308
1309	st->sensors = devm_kcalloc(dev, st->num_channels, sizeof(*st->sensors),
1310				   GFP_KERNEL);
1311	if (!st->sensors)
1312		return -ENOMEM;
1313
1314	st->iio_channels = st->num_channels;
1315	device_for_each_child_node_scoped(dev, child) {
1316		struct ltc2983_sensor sensor;
1317
1318		ret = fwnode_property_read_u32(child, "reg", &sensor.chan);
1319		if (ret)
1320			return dev_err_probe(dev, ret,
1321				"reg property must given for child nodes\n");
1322
1323		/* check if we have a valid channel */
1324		if (sensor.chan < LTC2983_MIN_CHANNELS_NR ||
1325		    sensor.chan > st->info->max_channels_nr)
1326			return dev_err_probe(dev, -EINVAL,
1327					     "chan:%d must be from %u to %u\n",
1328					     sensor.chan,
1329					     LTC2983_MIN_CHANNELS_NR,
1330					     st->info->max_channels_nr);
1331
1332		if (channel_avail_mask & BIT(sensor.chan))
1333			return dev_err_probe(dev, -EINVAL,
1334					     "chan:%d already in use\n",
1335					     sensor.chan);
1336
1337		ret = fwnode_property_read_u32(child, "adi,sensor-type", &sensor.type);
1338		if (ret)
1339			return dev_err_probe(dev, ret,
1340				"adi,sensor-type property must given for child nodes\n");
1341
1342		dev_dbg(dev, "Create new sensor, type %u, chann %u",
1343			sensor.type, sensor.chan);
1344
1345		if (sensor.type >= LTC2983_SENSOR_THERMOCOUPLE &&
1346		    sensor.type <= LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
1347			st->sensors[chan] = ltc2983_thermocouple_new(child, st,
1348								     &sensor);
1349		} else if (sensor.type >= LTC2983_SENSOR_RTD &&
1350			   sensor.type <= LTC2983_SENSOR_RTD_CUSTOM) {
1351			st->sensors[chan] = ltc2983_rtd_new(child, st, &sensor);
1352		} else if (sensor.type >= LTC2983_SENSOR_THERMISTOR &&
1353			   sensor.type <= LTC2983_SENSOR_THERMISTOR_CUSTOM) {
1354			st->sensors[chan] = ltc2983_thermistor_new(child, st,
1355								   &sensor);
1356		} else if (sensor.type == LTC2983_SENSOR_DIODE) {
1357			st->sensors[chan] = ltc2983_diode_new(child, st,
1358							      &sensor);
1359		} else if (sensor.type == LTC2983_SENSOR_SENSE_RESISTOR) {
1360			st->sensors[chan] = ltc2983_r_sense_new(child, st,
1361								&sensor);
1362			/* don't add rsense to iio */
1363			st->iio_channels--;
1364		} else if (sensor.type == LTC2983_SENSOR_DIRECT_ADC) {
1365			st->sensors[chan] = ltc2983_adc_new(child, st, &sensor);
1366		} else if (st->info->has_temp &&
1367			   sensor.type == LTC2983_SENSOR_ACTIVE_TEMP) {
1368			st->sensors[chan] = ltc2983_temp_new(child, st, &sensor);
1369		} else {
1370			return dev_err_probe(dev, -EINVAL,
1371					     "Unknown sensor type %d\n",
1372					     sensor.type);
1373		}
1374
1375		if (IS_ERR(st->sensors[chan]))
1376			return dev_err_probe(dev, PTR_ERR(st->sensors[chan]),
1377					     "Failed to create sensor\n");
1378
1379		/* set generic sensor parameters */
1380		st->sensors[chan]->chan = sensor.chan;
1381		st->sensors[chan]->type = sensor.type;
1382
1383		channel_avail_mask |= BIT(sensor.chan);
1384		chan++;
1385	}
1386
1387	return 0;
1388}
1389
1390static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,
1391			      unsigned int wait_time, unsigned int status_reg,
1392			      unsigned long status_fail_mask)
1393{
1394	unsigned long time;
1395	unsigned int val;
1396	int ret;
1397
1398	ret = regmap_bulk_write(st->regmap, LTC2983_EEPROM_KEY_REG,
1399				&st->eeprom_key, sizeof(st->eeprom_key));
1400	if (ret)
1401		return ret;
1402
1403	reinit_completion(&st->completion);
1404
1405	ret = regmap_write(st->regmap, LTC2983_STATUS_REG,
1406			   LTC2983_STATUS_START(true) | cmd);
1407	if (ret)
1408		return ret;
1409
1410	time = wait_for_completion_timeout(&st->completion,
1411					   msecs_to_jiffies(wait_time));
1412	if (!time)
1413		return dev_err_probe(&st->spi->dev, -ETIMEDOUT,
1414				     "EEPROM command timed out\n");
1415
1416	ret = regmap_read(st->regmap, status_reg, &val);
1417	if (ret)
1418		return ret;
1419
1420	if (val & status_fail_mask)
1421		return dev_err_probe(&st->spi->dev, -EINVAL,
1422				     "EEPROM command failed: 0x%02X\n", val);
1423
1424	return 0;
1425}
1426
1427static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
1428{
1429	u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0, status;
1430	int ret;
1431
1432	/* make sure the device is up: start bit (7) is 0 and done bit (6) is 1 */
1433	ret = regmap_read_poll_timeout(st->regmap, LTC2983_STATUS_REG, status,
1434				       LTC2983_STATUS_UP(status) == 1, 25000,
1435				       25000 * 10);
1436	if (ret)
1437		return dev_err_probe(&st->spi->dev, ret,
1438				     "Device startup timed out\n");
1439
1440	ret = regmap_update_bits(st->regmap, LTC2983_GLOBAL_CONFIG_REG,
1441				 LTC2983_NOTCH_FREQ_MASK,
1442				 LTC2983_NOTCH_FREQ(st->filter_notch_freq));
1443	if (ret)
1444		return ret;
1445
1446	ret = regmap_write(st->regmap, LTC2983_MUX_CONFIG_REG,
1447			   st->mux_delay_config);
1448	if (ret)
1449		return ret;
1450
1451	if (st->info->has_eeprom && !assign_iio) {
1452		ret = ltc2983_eeprom_cmd(st, LTC2983_EEPROM_READ_CMD,
1453					 LTC2983_EEPROM_READ_TIME_MS,
1454					 LTC2983_EEPROM_READ_STATUS_REG,
1455					 LTC2983_EEPROM_READ_FAILURE_MASK);
1456		if (!ret)
1457			return 0;
1458	}
1459
1460	for (chan = 0; chan < st->num_channels; chan++) {
1461		u32 chan_type = 0, *iio_chan;
1462
1463		ret = st->sensors[chan]->assign_chan(st, st->sensors[chan]);
1464		if (ret)
1465			return ret;
1466		/*
1467		 * The assign_iio flag is necessary for when the device is
1468		 * coming out of sleep. In that case, we just need to
1469		 * re-configure the device channels.
1470		 * We also don't assign iio channels for rsense.
1471		 */
1472		if (st->sensors[chan]->type == LTC2983_SENSOR_SENSE_RESISTOR ||
1473		    !assign_iio)
1474			continue;
1475
1476		/* assign iio channel */
1477		if (st->sensors[chan]->type != LTC2983_SENSOR_DIRECT_ADC) {
1478			chan_type = IIO_TEMP;
1479			iio_chan = &iio_chan_t;
1480		} else {
1481			chan_type = IIO_VOLTAGE;
1482			iio_chan = &iio_chan_v;
1483		}
1484
1485		/*
1486		 * add chan as the iio .address so that, we can directly
1487		 * reference the sensor given the iio_chan_spec
1488		 */
1489		st->iio_chan[iio_idx++] = LTC2983_CHAN(chan_type, (*iio_chan)++,
1490						       chan);
1491	}
1492
1493	return 0;
1494}
1495
1496static const struct regmap_range ltc2983_reg_ranges[] = {
1497	regmap_reg_range(LTC2983_STATUS_REG, LTC2983_STATUS_REG),
1498	regmap_reg_range(LTC2983_TEMP_RES_START_REG, LTC2983_TEMP_RES_END_REG),
1499	regmap_reg_range(LTC2983_EEPROM_KEY_REG, LTC2983_EEPROM_KEY_REG),
1500	regmap_reg_range(LTC2983_EEPROM_READ_STATUS_REG,
1501			 LTC2983_EEPROM_READ_STATUS_REG),
1502	regmap_reg_range(LTC2983_GLOBAL_CONFIG_REG, LTC2983_GLOBAL_CONFIG_REG),
1503	regmap_reg_range(LTC2983_MULT_CHANNEL_START_REG,
1504			 LTC2983_MULT_CHANNEL_END_REG),
1505	regmap_reg_range(LTC2986_EEPROM_STATUS_REG, LTC2986_EEPROM_STATUS_REG),
1506	regmap_reg_range(LTC2983_MUX_CONFIG_REG, LTC2983_MUX_CONFIG_REG),
1507	regmap_reg_range(LTC2983_CHAN_ASSIGN_START_REG,
1508			 LTC2983_CHAN_ASSIGN_END_REG),
1509	regmap_reg_range(LTC2983_CUST_SENS_TBL_START_REG,
1510			 LTC2983_CUST_SENS_TBL_END_REG),
1511};
1512
1513static const struct regmap_access_table ltc2983_reg_table = {
1514	.yes_ranges = ltc2983_reg_ranges,
1515	.n_yes_ranges = ARRAY_SIZE(ltc2983_reg_ranges),
1516};
1517
1518/*
1519 *  The reg_bits are actually 12 but the device needs the first *complete*
1520 *  byte for the command (R/W).
1521 */
1522static const struct regmap_config ltc2983_regmap_config = {
1523	.reg_bits = 24,
1524	.val_bits = 8,
1525	.wr_table = &ltc2983_reg_table,
1526	.rd_table = &ltc2983_reg_table,
1527	.read_flag_mask = GENMASK(1, 0),
1528	.write_flag_mask = BIT(1),
1529};
1530
1531static const struct  iio_info ltc2983_iio_info = {
1532	.read_raw = ltc2983_read_raw,
1533	.debugfs_reg_access = ltc2983_reg_access,
1534};
1535
1536static int ltc2983_probe(struct spi_device *spi)
1537{
1538	struct ltc2983_data *st;
1539	struct iio_dev *indio_dev;
1540	struct gpio_desc *gpio;
1541	int ret;
1542
1543	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
1544	if (!indio_dev)
1545		return -ENOMEM;
1546
1547	st = iio_priv(indio_dev);
1548
1549	st->info = spi_get_device_match_data(spi);
1550	if (!st->info)
1551		return -ENODEV;
1552
1553	st->regmap = devm_regmap_init_spi(spi, &ltc2983_regmap_config);
1554	if (IS_ERR(st->regmap))
1555		return dev_err_probe(&spi->dev, PTR_ERR(st->regmap),
1556				     "Failed to initialize regmap\n");
1557
1558	mutex_init(&st->lock);
1559	init_completion(&st->completion);
1560	st->spi = spi;
1561	st->eeprom_key = cpu_to_be32(LTC2983_EEPROM_KEY);
1562	spi_set_drvdata(spi, st);
1563
1564	ret = ltc2983_parse_fw(st);
1565	if (ret)
1566		return ret;
1567
1568	ret = devm_regulator_get_enable(&spi->dev, "vdd");
1569	if (ret)
1570		return ret;
1571
1572	gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
1573	if (IS_ERR(gpio))
1574		return PTR_ERR(gpio);
1575
1576	if (gpio) {
1577		/* bring the device out of reset */
1578		usleep_range(1000, 1200);
1579		gpiod_set_value_cansleep(gpio, 0);
1580	}
1581
1582	st->iio_chan = devm_kzalloc(&spi->dev,
1583				    st->iio_channels * sizeof(*st->iio_chan),
1584				    GFP_KERNEL);
1585	if (!st->iio_chan)
1586		return -ENOMEM;
1587
1588	ret = ltc2983_setup(st, true);
1589	if (ret)
1590		return ret;
1591
1592	ret = devm_request_irq(&spi->dev, spi->irq, ltc2983_irq_handler,
1593			       IRQF_TRIGGER_RISING, st->info->name, st);
1594	if (ret)
1595		return dev_err_probe(&spi->dev, ret,
1596				     "failed to request an irq\n");
1597
1598	if (st->info->has_eeprom) {
1599		ret = ltc2983_eeprom_cmd(st, LTC2983_EEPROM_WRITE_CMD,
1600					 LTC2983_EEPROM_WRITE_TIME_MS,
1601					 LTC2986_EEPROM_STATUS_REG,
1602					 LTC2983_EEPROM_STATUS_FAILURE_MASK);
1603		if (ret)
1604			return ret;
1605	}
1606
1607	indio_dev->name = st->info->name;
1608	indio_dev->num_channels = st->iio_channels;
1609	indio_dev->channels = st->iio_chan;
1610	indio_dev->modes = INDIO_DIRECT_MODE;
1611	indio_dev->info = &ltc2983_iio_info;
1612
1613	return devm_iio_device_register(&spi->dev, indio_dev);
1614}
1615
1616static int ltc2983_resume(struct device *dev)
1617{
1618	struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev));
1619	int dummy;
1620
1621	/* dummy read to bring the device out of sleep */
1622	regmap_read(st->regmap, LTC2983_STATUS_REG, &dummy);
1623	/* we need to re-assign the channels */
1624	return ltc2983_setup(st, false);
1625}
1626
1627static int ltc2983_suspend(struct device *dev)
1628{
1629	struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev));
1630
1631	return regmap_write(st->regmap, LTC2983_STATUS_REG, LTC2983_SLEEP);
1632}
1633
1634static DEFINE_SIMPLE_DEV_PM_OPS(ltc2983_pm_ops, ltc2983_suspend,
1635				ltc2983_resume);
1636
1637static const struct ltc2983_chip_info ltc2983_chip_info_data = {
1638	.name = "ltc2983",
1639	.max_channels_nr = 20,
1640};
1641
1642static const struct ltc2983_chip_info ltc2984_chip_info_data = {
1643	.name = "ltc2984",
1644	.max_channels_nr = 20,
1645	.has_eeprom = true,
1646};
1647
1648static const struct ltc2983_chip_info ltc2986_chip_info_data = {
1649	.name = "ltc2986",
1650	.max_channels_nr = 10,
1651	.has_temp = true,
1652	.has_eeprom = true,
1653};
1654
1655static const struct ltc2983_chip_info ltm2985_chip_info_data = {
1656	.name = "ltm2985",
1657	.max_channels_nr = 10,
1658	.has_temp = true,
1659	.has_eeprom = true,
1660};
1661
1662static const struct spi_device_id ltc2983_id_table[] = {
1663	{ "ltc2983", (kernel_ulong_t)&ltc2983_chip_info_data },
1664	{ "ltc2984", (kernel_ulong_t)&ltc2984_chip_info_data },
1665	{ "ltc2986", (kernel_ulong_t)&ltc2986_chip_info_data },
1666	{ "ltm2985", (kernel_ulong_t)&ltm2985_chip_info_data },
1667	{ }
1668};
1669MODULE_DEVICE_TABLE(spi, ltc2983_id_table);
1670
1671static const struct of_device_id ltc2983_of_match[] = {
1672	{ .compatible = "adi,ltc2983", .data = &ltc2983_chip_info_data },
1673	{ .compatible = "adi,ltc2984", .data = &ltc2984_chip_info_data },
1674	{ .compatible = "adi,ltc2986", .data = &ltc2986_chip_info_data },
1675	{ .compatible = "adi,ltm2985", .data = &ltm2985_chip_info_data },
1676	{ }
1677};
1678MODULE_DEVICE_TABLE(of, ltc2983_of_match);
1679
1680static struct spi_driver ltc2983_driver = {
1681	.driver = {
1682		.name = "ltc2983",
1683		.of_match_table = ltc2983_of_match,
1684		.pm = pm_sleep_ptr(&ltc2983_pm_ops),
1685	},
1686	.probe = ltc2983_probe,
1687	.id_table = ltc2983_id_table,
1688};
1689
1690module_spi_driver(ltc2983_driver);
1691
1692MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
1693MODULE_DESCRIPTION("Analog Devices LTC2983 SPI Temperature sensors");
1694MODULE_LICENSE("GPL");