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/kernel.h>
12#include <linux/iio/iio.h>
13#include <linux/interrupt.h>
14#include <linux/list.h>
15#include <linux/mod_devicetable.h>
16#include <linux/module.h>
17#include <linux/property.h>
18#include <linux/regmap.h>
19#include <linux/spi/spi.h>
20
21#include <asm/byteorder.h>
22#include <asm/unaligned.h>
23
24/* register map */
25#define LTC2983_STATUS_REG			0x0000
26#define LTC2983_TEMP_RES_START_REG		0x0010
27#define LTC2983_TEMP_RES_END_REG		0x005F
28#define LTC2983_EEPROM_KEY_REG			0x00B0
29#define LTC2983_EEPROM_READ_STATUS_REG		0x00D0
30#define LTC2983_GLOBAL_CONFIG_REG		0x00F0
31#define LTC2983_MULT_CHANNEL_START_REG		0x00F4
32#define LTC2983_MULT_CHANNEL_END_REG		0x00F7
33#define LTC2986_EEPROM_STATUS_REG		0x00F9
34#define LTC2983_MUX_CONFIG_REG			0x00FF
35#define LTC2983_CHAN_ASSIGN_START_REG		0x0200
36#define LTC2983_CHAN_ASSIGN_END_REG		0x024F
37#define LTC2983_CUST_SENS_TBL_START_REG		0x0250
38#define LTC2983_CUST_SENS_TBL_END_REG		0x03CF
39
40#define LTC2983_DIFFERENTIAL_CHAN_MIN		2
41#define LTC2983_MIN_CHANNELS_NR			1
42#define LTC2983_SLEEP				0x97
43#define LTC2983_CUSTOM_STEINHART_SIZE		24
44#define LTC2983_CUSTOM_SENSOR_ENTRY_SZ		6
45#define LTC2983_CUSTOM_STEINHART_ENTRY_SZ	4
46
47#define LTC2983_EEPROM_KEY			0xA53C0F5A
48#define LTC2983_EEPROM_WRITE_CMD		0x15
49#define LTC2983_EEPROM_READ_CMD			0x16
50#define LTC2983_EEPROM_STATUS_FAILURE_MASK	GENMASK(3, 1)
51#define LTC2983_EEPROM_READ_FAILURE_MASK	GENMASK(7, 0)
52
53#define LTC2983_EEPROM_WRITE_TIME_MS		2600
54#define LTC2983_EEPROM_READ_TIME_MS		20
55
56#define LTC2983_CHAN_START_ADDR(chan) \
57			(((chan - 1) * 4) + LTC2983_CHAN_ASSIGN_START_REG)
58#define LTC2983_CHAN_RES_ADDR(chan) \
59			(((chan - 1) * 4) + LTC2983_TEMP_RES_START_REG)
60#define LTC2983_THERMOCOUPLE_DIFF_MASK		BIT(3)
61#define LTC2983_THERMOCOUPLE_SGL(x) \
62				FIELD_PREP(LTC2983_THERMOCOUPLE_DIFF_MASK, x)
63#define LTC2983_THERMOCOUPLE_OC_CURR_MASK	GENMASK(1, 0)
64#define LTC2983_THERMOCOUPLE_OC_CURR(x) \
65				FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CURR_MASK, x)
66#define LTC2983_THERMOCOUPLE_OC_CHECK_MASK	BIT(2)
67#define LTC2983_THERMOCOUPLE_OC_CHECK(x) \
68			FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CHECK_MASK, x)
69
70#define LTC2983_THERMISTOR_DIFF_MASK		BIT(2)
71#define LTC2983_THERMISTOR_SGL(x) \
72				FIELD_PREP(LTC2983_THERMISTOR_DIFF_MASK, x)
73#define LTC2983_THERMISTOR_R_SHARE_MASK		BIT(1)
74#define LTC2983_THERMISTOR_R_SHARE(x) \
75				FIELD_PREP(LTC2983_THERMISTOR_R_SHARE_MASK, x)
76#define LTC2983_THERMISTOR_C_ROTATE_MASK	BIT(0)
77#define LTC2983_THERMISTOR_C_ROTATE(x) \
78				FIELD_PREP(LTC2983_THERMISTOR_C_ROTATE_MASK, x)
79
80#define LTC2983_DIODE_DIFF_MASK			BIT(2)
81#define LTC2983_DIODE_SGL(x) \
82			FIELD_PREP(LTC2983_DIODE_DIFF_MASK, x)
83#define LTC2983_DIODE_3_CONV_CYCLE_MASK		BIT(1)
84#define LTC2983_DIODE_3_CONV_CYCLE(x) \
85				FIELD_PREP(LTC2983_DIODE_3_CONV_CYCLE_MASK, x)
86#define LTC2983_DIODE_AVERAGE_ON_MASK		BIT(0)
87#define LTC2983_DIODE_AVERAGE_ON(x) \
88				FIELD_PREP(LTC2983_DIODE_AVERAGE_ON_MASK, x)
89
90#define LTC2983_RTD_4_WIRE_MASK			BIT(3)
91#define LTC2983_RTD_ROTATION_MASK		BIT(1)
92#define LTC2983_RTD_C_ROTATE(x) \
93			FIELD_PREP(LTC2983_RTD_ROTATION_MASK, x)
94#define LTC2983_RTD_KELVIN_R_SENSE_MASK		GENMASK(3, 2)
95#define LTC2983_RTD_N_WIRES_MASK		GENMASK(3, 2)
96#define LTC2983_RTD_N_WIRES(x) \
97			FIELD_PREP(LTC2983_RTD_N_WIRES_MASK, x)
98#define LTC2983_RTD_R_SHARE_MASK		BIT(0)
99#define LTC2983_RTD_R_SHARE(x) \
100			FIELD_PREP(LTC2983_RTD_R_SHARE_MASK, 1)
101
102#define LTC2983_COMMON_HARD_FAULT_MASK	GENMASK(31, 30)
103#define LTC2983_COMMON_SOFT_FAULT_MASK	GENMASK(27, 25)
104
105#define	LTC2983_STATUS_START_MASK	BIT(7)
106#define	LTC2983_STATUS_START(x)		FIELD_PREP(LTC2983_STATUS_START_MASK, x)
107#define	LTC2983_STATUS_UP_MASK		GENMASK(7, 6)
108#define	LTC2983_STATUS_UP(reg)		FIELD_GET(LTC2983_STATUS_UP_MASK, reg)
109
110#define	LTC2983_STATUS_CHAN_SEL_MASK	GENMASK(4, 0)
111#define	LTC2983_STATUS_CHAN_SEL(x) \
112				FIELD_PREP(LTC2983_STATUS_CHAN_SEL_MASK, x)
113
114#define LTC2983_TEMP_UNITS_MASK		BIT(2)
115#define LTC2983_TEMP_UNITS(x)		FIELD_PREP(LTC2983_TEMP_UNITS_MASK, x)
116
117#define LTC2983_NOTCH_FREQ_MASK		GENMASK(1, 0)
118#define LTC2983_NOTCH_FREQ(x)		FIELD_PREP(LTC2983_NOTCH_FREQ_MASK, x)
119
120#define LTC2983_RES_VALID_MASK		BIT(24)
121#define LTC2983_DATA_MASK		GENMASK(23, 0)
122#define LTC2983_DATA_SIGN_BIT		23
123
124#define LTC2983_CHAN_TYPE_MASK		GENMASK(31, 27)
125#define LTC2983_CHAN_TYPE(x)		FIELD_PREP(LTC2983_CHAN_TYPE_MASK, x)
126
127/* cold junction for thermocouples and rsense for rtd's and thermistor's */
128#define LTC2983_CHAN_ASSIGN_MASK	GENMASK(26, 22)
129#define LTC2983_CHAN_ASSIGN(x)		FIELD_PREP(LTC2983_CHAN_ASSIGN_MASK, x)
130
131#define LTC2983_CUSTOM_LEN_MASK		GENMASK(5, 0)
132#define LTC2983_CUSTOM_LEN(x)		FIELD_PREP(LTC2983_CUSTOM_LEN_MASK, x)
133
134#define LTC2983_CUSTOM_ADDR_MASK	GENMASK(11, 6)
135#define LTC2983_CUSTOM_ADDR(x)		FIELD_PREP(LTC2983_CUSTOM_ADDR_MASK, x)
136
137#define LTC2983_THERMOCOUPLE_CFG_MASK	GENMASK(21, 18)
138#define LTC2983_THERMOCOUPLE_CFG(x) \
139				FIELD_PREP(LTC2983_THERMOCOUPLE_CFG_MASK, x)
140#define LTC2983_THERMOCOUPLE_HARD_FAULT_MASK	GENMASK(31, 29)
141#define LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK	GENMASK(28, 25)
142
143#define LTC2983_RTD_CFG_MASK		GENMASK(21, 18)
144#define LTC2983_RTD_CFG(x)		FIELD_PREP(LTC2983_RTD_CFG_MASK, x)
145#define LTC2983_RTD_EXC_CURRENT_MASK	GENMASK(17, 14)
146#define LTC2983_RTD_EXC_CURRENT(x) \
147				FIELD_PREP(LTC2983_RTD_EXC_CURRENT_MASK, x)
148#define LTC2983_RTD_CURVE_MASK		GENMASK(13, 12)
149#define LTC2983_RTD_CURVE(x)		FIELD_PREP(LTC2983_RTD_CURVE_MASK, x)
150
151#define LTC2983_THERMISTOR_CFG_MASK	GENMASK(21, 19)
152#define LTC2983_THERMISTOR_CFG(x) \
153				FIELD_PREP(LTC2983_THERMISTOR_CFG_MASK, x)
154#define LTC2983_THERMISTOR_EXC_CURRENT_MASK	GENMASK(18, 15)
155#define LTC2983_THERMISTOR_EXC_CURRENT(x) \
156			FIELD_PREP(LTC2983_THERMISTOR_EXC_CURRENT_MASK, x)
157
158#define LTC2983_DIODE_CFG_MASK		GENMASK(26, 24)
159#define LTC2983_DIODE_CFG(x)		FIELD_PREP(LTC2983_DIODE_CFG_MASK, x)
160#define LTC2983_DIODE_EXC_CURRENT_MASK	GENMASK(23, 22)
161#define LTC2983_DIODE_EXC_CURRENT(x) \
162				FIELD_PREP(LTC2983_DIODE_EXC_CURRENT_MASK, x)
163#define LTC2983_DIODE_IDEAL_FACTOR_MASK	GENMASK(21, 0)
164#define LTC2983_DIODE_IDEAL_FACTOR(x) \
165				FIELD_PREP(LTC2983_DIODE_IDEAL_FACTOR_MASK, x)
166
167#define LTC2983_R_SENSE_VAL_MASK	GENMASK(26, 0)
168#define LTC2983_R_SENSE_VAL(x)		FIELD_PREP(LTC2983_R_SENSE_VAL_MASK, x)
169
170#define LTC2983_ADC_SINGLE_ENDED_MASK	BIT(26)
171#define LTC2983_ADC_SINGLE_ENDED(x) \
172				FIELD_PREP(LTC2983_ADC_SINGLE_ENDED_MASK, x)
173
174enum {
175	LTC2983_SENSOR_THERMOCOUPLE = 1,
176	LTC2983_SENSOR_THERMOCOUPLE_CUSTOM = 9,
177	LTC2983_SENSOR_RTD = 10,
178	LTC2983_SENSOR_RTD_CUSTOM = 18,
179	LTC2983_SENSOR_THERMISTOR = 19,
180	LTC2983_SENSOR_THERMISTOR_STEINHART = 26,
181	LTC2983_SENSOR_THERMISTOR_CUSTOM = 27,
182	LTC2983_SENSOR_DIODE = 28,
183	LTC2983_SENSOR_SENSE_RESISTOR = 29,
184	LTC2983_SENSOR_DIRECT_ADC = 30,
185	LTC2983_SENSOR_ACTIVE_TEMP = 31,
186};
187
188#define to_thermocouple(_sensor) \
189		container_of(_sensor, struct ltc2983_thermocouple, sensor)
190
191#define to_rtd(_sensor) \
192		container_of(_sensor, struct ltc2983_rtd, sensor)
193
194#define to_thermistor(_sensor) \
195		container_of(_sensor, struct ltc2983_thermistor, sensor)
196
197#define to_diode(_sensor) \
198		container_of(_sensor, struct ltc2983_diode, sensor)
199
200#define to_rsense(_sensor) \
201		container_of(_sensor, struct ltc2983_rsense, sensor)
202
203#define to_adc(_sensor) \
204		container_of(_sensor, struct ltc2983_adc, sensor)
205
206#define to_temp(_sensor) \
207		container_of(_sensor, struct ltc2983_temp, sensor)
208
209struct ltc2983_chip_info {
210	const char *name;
211	unsigned int max_channels_nr;
212	bool has_temp;
213	bool has_eeprom;
214};
215
216struct ltc2983_data {
217	const struct ltc2983_chip_info *info;
218	struct regmap *regmap;
219	struct spi_device *spi;
220	struct mutex lock;
221	struct completion completion;
222	struct iio_chan_spec *iio_chan;
223	struct ltc2983_sensor **sensors;
224	u32 mux_delay_config;
225	u32 filter_notch_freq;
226	u16 custom_table_size;
227	u8 num_channels;
228	u8 iio_channels;
229	/*
230	 * DMA (thus cache coherency maintenance) may require the
231	 * transfer buffers to live in their own cache lines.
232	 * Holds the converted temperature
233	 */
234	__be32 temp __aligned(IIO_DMA_MINALIGN);
235	__be32 chan_val;
236	__be32 eeprom_key;
237};
238
239struct ltc2983_sensor {
240	int (*fault_handler)(const struct ltc2983_data *st, const u32 result);
241	int (*assign_chan)(struct ltc2983_data *st,
242			   const struct ltc2983_sensor *sensor);
243	/* specifies the sensor channel */
244	u32 chan;
245	/* sensor type */
246	u32 type;
247};
248
249struct ltc2983_custom_sensor {
250	/* raw table sensor data */
251	void *table;
252	size_t size;
253	/* address offset */
254	s8 offset;
255	bool is_steinhart;
256};
257
258struct ltc2983_thermocouple {
259	struct ltc2983_sensor sensor;
260	struct ltc2983_custom_sensor *custom;
261	u32 sensor_config;
262	u32 cold_junction_chan;
263};
264
265struct ltc2983_rtd {
266	struct ltc2983_sensor sensor;
267	struct ltc2983_custom_sensor *custom;
268	u32 sensor_config;
269	u32 r_sense_chan;
270	u32 excitation_current;
271	u32 rtd_curve;
272};
273
274struct ltc2983_thermistor {
275	struct ltc2983_sensor sensor;
276	struct ltc2983_custom_sensor *custom;
277	u32 sensor_config;
278	u32 r_sense_chan;
279	u32 excitation_current;
280};
281
282struct ltc2983_diode {
283	struct ltc2983_sensor sensor;
284	u32 sensor_config;
285	u32 excitation_current;
286	u32 ideal_factor_value;
287};
288
289struct ltc2983_rsense {
290	struct ltc2983_sensor sensor;
291	u32 r_sense_val;
292};
293
294struct ltc2983_adc {
295	struct ltc2983_sensor sensor;
296	bool single_ended;
297};
298
299struct ltc2983_temp {
300	struct ltc2983_sensor sensor;
301	struct ltc2983_custom_sensor *custom;
302	bool single_ended;
303};
304
305/*
306 * Convert to Q format numbers. These number's are integers where
307 * the number of integer and fractional bits are specified. The resolution
308 * is given by 1/@resolution and tell us the number of fractional bits. For
309 * instance a resolution of 2^-10 means we have 10 fractional bits.
310 */
311static u32 __convert_to_raw(const u64 val, const u32 resolution)
312{
313	u64 __res = val * resolution;
314
315	/* all values are multiplied by 1000000 to remove the fraction */
316	do_div(__res, 1000000);
317
318	return __res;
319}
320
321static u32 __convert_to_raw_sign(const u64 val, const u32 resolution)
322{
323	s64 __res = -(s32)val;
324
325	__res = __convert_to_raw(__res, resolution);
326
327	return (u32)-__res;
328}
329
330static int __ltc2983_fault_handler(const struct ltc2983_data *st,
331				   const u32 result, const u32 hard_mask,
332				   const u32 soft_mask)
333{
334	const struct device *dev = &st->spi->dev;
335
336	if (result & hard_mask) {
337		dev_err(dev, "Invalid conversion: Sensor HARD fault\n");
338		return -EIO;
339	} else if (result & soft_mask) {
340		/* just print a warning */
341		dev_warn(dev, "Suspicious conversion: Sensor SOFT fault\n");
342	}
343
344	return 0;
345}
346
347static int __ltc2983_chan_assign_common(struct ltc2983_data *st,
348					const struct ltc2983_sensor *sensor,
349					u32 chan_val)
350{
351	u32 reg = LTC2983_CHAN_START_ADDR(sensor->chan);
352
353	chan_val |= LTC2983_CHAN_TYPE(sensor->type);
354	dev_dbg(&st->spi->dev, "Assign reg:0x%04X, val:0x%08X\n", reg,
355		chan_val);
356	st->chan_val = cpu_to_be32(chan_val);
357	return regmap_bulk_write(st->regmap, reg, &st->chan_val,
358				 sizeof(st->chan_val));
359}
360
361static int __ltc2983_chan_custom_sensor_assign(struct ltc2983_data *st,
362					  struct ltc2983_custom_sensor *custom,
363					  u32 *chan_val)
364{
365	u32 reg;
366	u8 mult = custom->is_steinhart ? LTC2983_CUSTOM_STEINHART_ENTRY_SZ :
367		LTC2983_CUSTOM_SENSOR_ENTRY_SZ;
368	const struct device *dev = &st->spi->dev;
369	/*
370	 * custom->size holds the raw size of the table. However, when
371	 * configuring the sensor channel, we must write the number of
372	 * entries of the table minus 1. For steinhart sensors 0 is written
373	 * since the size is constant!
374	 */
375	const u8 len = custom->is_steinhart ? 0 :
376		(custom->size / LTC2983_CUSTOM_SENSOR_ENTRY_SZ) - 1;
377	/*
378	 * Check if the offset was assigned already. It should be for steinhart
379	 * sensors. When coming from sleep, it should be assigned for all.
380	 */
381	if (custom->offset < 0) {
382		/*
383		 * This needs to be done again here because, from the moment
384		 * when this test was done (successfully) for this custom
385		 * sensor, a steinhart sensor might have been added changing
386		 * custom_table_size...
387		 */
388		if (st->custom_table_size + custom->size >
389		    (LTC2983_CUST_SENS_TBL_END_REG -
390		     LTC2983_CUST_SENS_TBL_START_REG) + 1) {
391			dev_err(dev,
392				"Not space left(%d) for new custom sensor(%zu)",
393				st->custom_table_size,
394				custom->size);
395			return -EINVAL;
396		}
397
398		custom->offset = st->custom_table_size /
399					LTC2983_CUSTOM_SENSOR_ENTRY_SZ;
400		st->custom_table_size += custom->size;
401	}
402
403	reg = (custom->offset * mult) + LTC2983_CUST_SENS_TBL_START_REG;
404
405	*chan_val |= LTC2983_CUSTOM_LEN(len);
406	*chan_val |= LTC2983_CUSTOM_ADDR(custom->offset);
407	dev_dbg(dev, "Assign custom sensor, reg:0x%04X, off:%d, sz:%zu",
408		reg, custom->offset,
409		custom->size);
410	/* write custom sensor table */
411	return regmap_bulk_write(st->regmap, reg, custom->table, custom->size);
412}
413
414static struct ltc2983_custom_sensor *
415__ltc2983_custom_sensor_new(struct ltc2983_data *st, const struct fwnode_handle *fn,
416			    const char *propname, const bool is_steinhart,
417			    const u32 resolution, const bool has_signed)
418{
419	struct ltc2983_custom_sensor *new_custom;
420	struct device *dev = &st->spi->dev;
421	/*
422	 * For custom steinhart, the full u32 is taken. For all the others
423	 * the MSB is discarded.
424	 */
425	const u8 n_size = is_steinhart ? 4 : 3;
426	u8 index, n_entries;
427	int ret;
428
429	if (is_steinhart)
430		n_entries = fwnode_property_count_u32(fn, propname);
431	else
432		n_entries = fwnode_property_count_u64(fn, propname);
433	/* n_entries must be an even number */
434	if (!n_entries || (n_entries % 2) != 0) {
435		dev_err(dev, "Number of entries either 0 or not even\n");
436		return ERR_PTR(-EINVAL);
437	}
438
439	new_custom = devm_kzalloc(dev, sizeof(*new_custom), GFP_KERNEL);
440	if (!new_custom)
441		return ERR_PTR(-ENOMEM);
442
443	new_custom->size = n_entries * n_size;
444	/* check Steinhart size */
445	if (is_steinhart && new_custom->size != LTC2983_CUSTOM_STEINHART_SIZE) {
446		dev_err(dev, "Steinhart sensors size(%zu) must be %u\n", new_custom->size,
447			LTC2983_CUSTOM_STEINHART_SIZE);
448		return ERR_PTR(-EINVAL);
449	}
450	/* Check space on the table. */
451	if (st->custom_table_size + new_custom->size >
452	    (LTC2983_CUST_SENS_TBL_END_REG -
453	     LTC2983_CUST_SENS_TBL_START_REG) + 1) {
454		dev_err(dev, "No space left(%d) for new custom sensor(%zu)",
455				st->custom_table_size, new_custom->size);
456		return ERR_PTR(-EINVAL);
457	}
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	struct fwnode_handle *ref;
661	u32 oc_current;
662	int ret;
663
664	thermo = devm_kzalloc(&st->spi->dev, sizeof(*thermo), GFP_KERNEL);
665	if (!thermo)
666		return ERR_PTR(-ENOMEM);
667
668	if (fwnode_property_read_bool(child, "adi,single-ended"))
669		thermo->sensor_config = LTC2983_THERMOCOUPLE_SGL(1);
670
671	ret = fwnode_property_read_u32(child, "adi,sensor-oc-current-microamp", &oc_current);
672	if (!ret) {
673		switch (oc_current) {
674		case 10:
675			thermo->sensor_config |=
676					LTC2983_THERMOCOUPLE_OC_CURR(0);
677			break;
678		case 100:
679			thermo->sensor_config |=
680					LTC2983_THERMOCOUPLE_OC_CURR(1);
681			break;
682		case 500:
683			thermo->sensor_config |=
684					LTC2983_THERMOCOUPLE_OC_CURR(2);
685			break;
686		case 1000:
687			thermo->sensor_config |=
688					LTC2983_THERMOCOUPLE_OC_CURR(3);
689			break;
690		default:
691			dev_err(&st->spi->dev,
692				"Invalid open circuit current:%u", oc_current);
693			return ERR_PTR(-EINVAL);
694		}
695
696		thermo->sensor_config |= LTC2983_THERMOCOUPLE_OC_CHECK(1);
697	}
698	/* validate channel index */
699	if (!(thermo->sensor_config & LTC2983_THERMOCOUPLE_DIFF_MASK) &&
700	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
701		dev_err(&st->spi->dev,
702			"Invalid chann:%d for differential thermocouple",
703			sensor->chan);
704		return ERR_PTR(-EINVAL);
705	}
706
707	ref = fwnode_find_reference(child, "adi,cold-junction-handle", 0);
708	if (IS_ERR(ref)) {
709		ref = NULL;
710	} else {
711		ret = fwnode_property_read_u32(ref, "reg", &thermo->cold_junction_chan);
712		if (ret) {
713			/*
714			 * This would be catched later but we can just return
715			 * the error right away.
716			 */
717			dev_err(&st->spi->dev, "Property reg must be given\n");
718			goto fail;
719		}
720	}
721
722	/* check custom sensor */
723	if (sensor->type == LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
724		const char *propname = "adi,custom-thermocouple";
725
726		thermo->custom = __ltc2983_custom_sensor_new(st, child,
727							     propname, false,
728							     16384, true);
729		if (IS_ERR(thermo->custom)) {
730			ret = PTR_ERR(thermo->custom);
731			goto fail;
732		}
733	}
734
735	/* set common parameters */
736	thermo->sensor.fault_handler = ltc2983_thermocouple_fault_handler;
737	thermo->sensor.assign_chan = ltc2983_thermocouple_assign_chan;
738
739	fwnode_handle_put(ref);
740	return &thermo->sensor;
741
742fail:
743	fwnode_handle_put(ref);
744	return ERR_PTR(ret);
745}
746
747static struct ltc2983_sensor *
748ltc2983_rtd_new(const struct fwnode_handle *child, struct ltc2983_data *st,
749		const struct ltc2983_sensor *sensor)
750{
751	struct ltc2983_rtd *rtd;
752	int ret = 0;
753	struct device *dev = &st->spi->dev;
754	struct fwnode_handle *ref;
755	u32 excitation_current = 0, n_wires = 0;
756
757	rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL);
758	if (!rtd)
759		return ERR_PTR(-ENOMEM);
760
761	ref = fwnode_find_reference(child, "adi,rsense-handle", 0);
762	if (IS_ERR(ref)) {
763		dev_err(dev, "Property adi,rsense-handle missing or invalid");
764		return ERR_CAST(ref);
765	}
766
767	ret = fwnode_property_read_u32(ref, "reg", &rtd->r_sense_chan);
768	if (ret) {
769		dev_err(dev, "Property reg must be given\n");
770		goto fail;
771	}
772
773	ret = fwnode_property_read_u32(child, "adi,number-of-wires", &n_wires);
774	if (!ret) {
775		switch (n_wires) {
776		case 2:
777			rtd->sensor_config = LTC2983_RTD_N_WIRES(0);
778			break;
779		case 3:
780			rtd->sensor_config = LTC2983_RTD_N_WIRES(1);
781			break;
782		case 4:
783			rtd->sensor_config = LTC2983_RTD_N_WIRES(2);
784			break;
785		case 5:
786			/* 4 wires, Kelvin Rsense */
787			rtd->sensor_config = LTC2983_RTD_N_WIRES(3);
788			break;
789		default:
790			dev_err(dev, "Invalid number of wires:%u\n", n_wires);
791			ret = -EINVAL;
792			goto fail;
793		}
794	}
795
796	if (fwnode_property_read_bool(child, "adi,rsense-share")) {
797		/* Current rotation is only available with rsense sharing */
798		if (fwnode_property_read_bool(child, "adi,current-rotate")) {
799			if (n_wires == 2 || n_wires == 3) {
800				dev_err(dev,
801					"Rotation not allowed for 2/3 Wire RTDs");
802				ret = -EINVAL;
803				goto fail;
804			}
805			rtd->sensor_config |= LTC2983_RTD_C_ROTATE(1);
806		} else {
807			rtd->sensor_config |= LTC2983_RTD_R_SHARE(1);
808		}
809	}
810	/*
811	 * rtd channel indexes are a bit more complicated to validate.
812	 * For 4wire RTD with rotation, the channel selection cannot be
813	 * >=19 since the chann + 1 is used in this configuration.
814	 * For 4wire RTDs with kelvin rsense, the rsense channel cannot be
815	 * <=1 since chanel - 1 and channel - 2 are used.
816	 */
817	if (rtd->sensor_config & LTC2983_RTD_4_WIRE_MASK) {
818		/* 4-wire */
819		u8 min = LTC2983_DIFFERENTIAL_CHAN_MIN,
820			max = st->info->max_channels_nr;
821
822		if (rtd->sensor_config & LTC2983_RTD_ROTATION_MASK)
823			max = st->info->max_channels_nr - 1;
824
825		if (((rtd->sensor_config & LTC2983_RTD_KELVIN_R_SENSE_MASK)
826		     == LTC2983_RTD_KELVIN_R_SENSE_MASK) &&
827		    (rtd->r_sense_chan <=  min)) {
828			/* kelvin rsense*/
829			dev_err(dev,
830				"Invalid rsense chann:%d to use in kelvin rsense",
831				rtd->r_sense_chan);
832
833			ret = -EINVAL;
834			goto fail;
835		}
836
837		if (sensor->chan < min || sensor->chan > max) {
838			dev_err(dev, "Invalid chann:%d for the rtd config",
839				sensor->chan);
840
841			ret = -EINVAL;
842			goto fail;
843		}
844	} else {
845		/* same as differential case */
846		if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
847			dev_err(&st->spi->dev,
848				"Invalid chann:%d for RTD", sensor->chan);
849
850			ret = -EINVAL;
851			goto fail;
852		}
853	}
854
855	/* check custom sensor */
856	if (sensor->type == LTC2983_SENSOR_RTD_CUSTOM) {
857		rtd->custom = __ltc2983_custom_sensor_new(st, child,
858							  "adi,custom-rtd",
859							  false, 2048, false);
860		if (IS_ERR(rtd->custom)) {
861			ret = PTR_ERR(rtd->custom);
862			goto fail;
863		}
864	}
865
866	/* set common parameters */
867	rtd->sensor.fault_handler = ltc2983_common_fault_handler;
868	rtd->sensor.assign_chan = ltc2983_rtd_assign_chan;
869
870	ret = fwnode_property_read_u32(child, "adi,excitation-current-microamp",
871				       &excitation_current);
872	if (ret) {
873		/* default to 5uA */
874		rtd->excitation_current = 1;
875	} else {
876		switch (excitation_current) {
877		case 5:
878			rtd->excitation_current = 0x01;
879			break;
880		case 10:
881			rtd->excitation_current = 0x02;
882			break;
883		case 25:
884			rtd->excitation_current = 0x03;
885			break;
886		case 50:
887			rtd->excitation_current = 0x04;
888			break;
889		case 100:
890			rtd->excitation_current = 0x05;
891			break;
892		case 250:
893			rtd->excitation_current = 0x06;
894			break;
895		case 500:
896			rtd->excitation_current = 0x07;
897			break;
898		case 1000:
899			rtd->excitation_current = 0x08;
900			break;
901		default:
902			dev_err(&st->spi->dev,
903				"Invalid value for excitation current(%u)",
904				excitation_current);
905			ret = -EINVAL;
906			goto fail;
907		}
908	}
909
910	fwnode_property_read_u32(child, "adi,rtd-curve", &rtd->rtd_curve);
911
912	fwnode_handle_put(ref);
913	return &rtd->sensor;
914fail:
915	fwnode_handle_put(ref);
916	return ERR_PTR(ret);
917}
918
919static struct ltc2983_sensor *
920ltc2983_thermistor_new(const struct fwnode_handle *child, struct ltc2983_data *st,
921		       const struct ltc2983_sensor *sensor)
922{
923	struct ltc2983_thermistor *thermistor;
924	struct device *dev = &st->spi->dev;
925	struct fwnode_handle *ref;
926	u32 excitation_current = 0;
927	int ret = 0;
928
929	thermistor = devm_kzalloc(dev, sizeof(*thermistor), GFP_KERNEL);
930	if (!thermistor)
931		return ERR_PTR(-ENOMEM);
932
933	ref = fwnode_find_reference(child, "adi,rsense-handle", 0);
934	if (IS_ERR(ref)) {
935		dev_err(dev, "Property adi,rsense-handle missing or invalid");
936		return ERR_CAST(ref);
937	}
938
939	ret = fwnode_property_read_u32(ref, "reg", &thermistor->r_sense_chan);
940	if (ret) {
941		dev_err(dev, "rsense channel must be configured...\n");
942		goto fail;
943	}
944
945	if (fwnode_property_read_bool(child, "adi,single-ended")) {
946		thermistor->sensor_config = LTC2983_THERMISTOR_SGL(1);
947	} else if (fwnode_property_read_bool(child, "adi,rsense-share")) {
948		/* rotation is only possible if sharing rsense */
949		if (fwnode_property_read_bool(child, "adi,current-rotate"))
950			thermistor->sensor_config =
951						LTC2983_THERMISTOR_C_ROTATE(1);
952		else
953			thermistor->sensor_config =
954						LTC2983_THERMISTOR_R_SHARE(1);
955	}
956	/* validate channel index */
957	if (!(thermistor->sensor_config & LTC2983_THERMISTOR_DIFF_MASK) &&
958	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
959		dev_err(&st->spi->dev,
960			"Invalid chann:%d for differential thermistor",
961			sensor->chan);
962		ret = -EINVAL;
963		goto fail;
964	}
965
966	/* check custom sensor */
967	if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART) {
968		bool steinhart = false;
969		const char *propname;
970
971		if (sensor->type == LTC2983_SENSOR_THERMISTOR_STEINHART) {
972			steinhart = true;
973			propname = "adi,custom-steinhart";
974		} else {
975			propname = "adi,custom-thermistor";
976		}
977
978		thermistor->custom = __ltc2983_custom_sensor_new(st, child,
979								 propname,
980								 steinhart,
981								 64, false);
982		if (IS_ERR(thermistor->custom)) {
983			ret = PTR_ERR(thermistor->custom);
984			goto fail;
985		}
986	}
987	/* set common parameters */
988	thermistor->sensor.fault_handler = ltc2983_common_fault_handler;
989	thermistor->sensor.assign_chan = ltc2983_thermistor_assign_chan;
990
991	ret = fwnode_property_read_u32(child, "adi,excitation-current-nanoamp",
992				       &excitation_current);
993	if (ret) {
994		/* Auto range is not allowed for custom sensors */
995		if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART)
996			/* default to 1uA */
997			thermistor->excitation_current = 0x03;
998		else
999			/* default to auto-range */
1000			thermistor->excitation_current = 0x0c;
1001	} else {
1002		switch (excitation_current) {
1003		case 0:
1004			/* auto range */
1005			if (sensor->type >=
1006			    LTC2983_SENSOR_THERMISTOR_STEINHART) {
1007				dev_err(&st->spi->dev,
1008					"Auto Range not allowed for custom sensors\n");
1009				ret = -EINVAL;
1010				goto fail;
1011			}
1012			thermistor->excitation_current = 0x0c;
1013			break;
1014		case 250:
1015			thermistor->excitation_current = 0x01;
1016			break;
1017		case 500:
1018			thermistor->excitation_current = 0x02;
1019			break;
1020		case 1000:
1021			thermistor->excitation_current = 0x03;
1022			break;
1023		case 5000:
1024			thermistor->excitation_current = 0x04;
1025			break;
1026		case 10000:
1027			thermistor->excitation_current = 0x05;
1028			break;
1029		case 25000:
1030			thermistor->excitation_current = 0x06;
1031			break;
1032		case 50000:
1033			thermistor->excitation_current = 0x07;
1034			break;
1035		case 100000:
1036			thermistor->excitation_current = 0x08;
1037			break;
1038		case 250000:
1039			thermistor->excitation_current = 0x09;
1040			break;
1041		case 500000:
1042			thermistor->excitation_current = 0x0a;
1043			break;
1044		case 1000000:
1045			thermistor->excitation_current = 0x0b;
1046			break;
1047		default:
1048			dev_err(&st->spi->dev,
1049				"Invalid value for excitation current(%u)",
1050				excitation_current);
1051			ret = -EINVAL;
1052			goto fail;
1053		}
1054	}
1055
1056	fwnode_handle_put(ref);
1057	return &thermistor->sensor;
1058fail:
1059	fwnode_handle_put(ref);
1060	return ERR_PTR(ret);
1061}
1062
1063static struct ltc2983_sensor *
1064ltc2983_diode_new(const struct fwnode_handle *child, const struct ltc2983_data *st,
1065		  const struct ltc2983_sensor *sensor)
1066{
1067	struct ltc2983_diode *diode;
1068	u32 temp = 0, excitation_current = 0;
1069	int ret;
1070
1071	diode = devm_kzalloc(&st->spi->dev, sizeof(*diode), GFP_KERNEL);
1072	if (!diode)
1073		return ERR_PTR(-ENOMEM);
1074
1075	if (fwnode_property_read_bool(child, "adi,single-ended"))
1076		diode->sensor_config = LTC2983_DIODE_SGL(1);
1077
1078	if (fwnode_property_read_bool(child, "adi,three-conversion-cycles"))
1079		diode->sensor_config |= LTC2983_DIODE_3_CONV_CYCLE(1);
1080
1081	if (fwnode_property_read_bool(child, "adi,average-on"))
1082		diode->sensor_config |= LTC2983_DIODE_AVERAGE_ON(1);
1083
1084	/* validate channel index */
1085	if (!(diode->sensor_config & LTC2983_DIODE_DIFF_MASK) &&
1086	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
1087		dev_err(&st->spi->dev,
1088			"Invalid chann:%d for differential thermistor",
1089			sensor->chan);
1090		return ERR_PTR(-EINVAL);
1091	}
1092	/* set common parameters */
1093	diode->sensor.fault_handler = ltc2983_common_fault_handler;
1094	diode->sensor.assign_chan = ltc2983_diode_assign_chan;
1095
1096	ret = fwnode_property_read_u32(child, "adi,excitation-current-microamp",
1097				       &excitation_current);
1098	if (!ret) {
1099		switch (excitation_current) {
1100		case 10:
1101			diode->excitation_current = 0x00;
1102			break;
1103		case 20:
1104			diode->excitation_current = 0x01;
1105			break;
1106		case 40:
1107			diode->excitation_current = 0x02;
1108			break;
1109		case 80:
1110			diode->excitation_current = 0x03;
1111			break;
1112		default:
1113			dev_err(&st->spi->dev,
1114				"Invalid value for excitation current(%u)",
1115				excitation_current);
1116			return ERR_PTR(-EINVAL);
1117		}
1118	}
1119
1120	fwnode_property_read_u32(child, "adi,ideal-factor-value", &temp);
1121
1122	/* 2^20 resolution */
1123	diode->ideal_factor_value = __convert_to_raw(temp, 1048576);
1124
1125	return &diode->sensor;
1126}
1127
1128static struct ltc2983_sensor *ltc2983_r_sense_new(struct fwnode_handle *child,
1129					struct ltc2983_data *st,
1130					const struct ltc2983_sensor *sensor)
1131{
1132	struct ltc2983_rsense *rsense;
1133	int ret;
1134	u32 temp;
1135
1136	rsense = devm_kzalloc(&st->spi->dev, sizeof(*rsense), GFP_KERNEL);
1137	if (!rsense)
1138		return ERR_PTR(-ENOMEM);
1139
1140	/* validate channel index */
1141	if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
1142		dev_err(&st->spi->dev, "Invalid chann:%d for r_sense",
1143			sensor->chan);
1144		return ERR_PTR(-EINVAL);
1145	}
1146
1147	ret = fwnode_property_read_u32(child, "adi,rsense-val-milli-ohms", &temp);
1148	if (ret) {
1149		dev_err(&st->spi->dev, "Property adi,rsense-val-milli-ohms missing\n");
1150		return ERR_PTR(-EINVAL);
1151	}
1152	/*
1153	 * Times 1000 because we have milli-ohms and __convert_to_raw
1154	 * expects scales of 1000000 which are used for all other
1155	 * properties.
1156	 * 2^10 resolution
1157	 */
1158	rsense->r_sense_val = __convert_to_raw((u64)temp * 1000, 1024);
1159
1160	/* set common parameters */
1161	rsense->sensor.assign_chan = ltc2983_r_sense_assign_chan;
1162
1163	return &rsense->sensor;
1164}
1165
1166static struct ltc2983_sensor *ltc2983_adc_new(struct fwnode_handle *child,
1167					 struct ltc2983_data *st,
1168					 const struct ltc2983_sensor *sensor)
1169{
1170	struct ltc2983_adc *adc;
1171
1172	adc = devm_kzalloc(&st->spi->dev, sizeof(*adc), GFP_KERNEL);
1173	if (!adc)
1174		return ERR_PTR(-ENOMEM);
1175
1176	if (fwnode_property_read_bool(child, "adi,single-ended"))
1177		adc->single_ended = true;
1178
1179	if (!adc->single_ended &&
1180	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
1181		dev_err(&st->spi->dev, "Invalid chan:%d for differential adc\n",
1182			sensor->chan);
1183		return ERR_PTR(-EINVAL);
1184	}
1185	/* set common parameters */
1186	adc->sensor.assign_chan = ltc2983_adc_assign_chan;
1187	adc->sensor.fault_handler = ltc2983_common_fault_handler;
1188
1189	return &adc->sensor;
1190}
1191
1192static struct ltc2983_sensor *ltc2983_temp_new(struct fwnode_handle *child,
1193					       struct ltc2983_data *st,
1194					       const struct ltc2983_sensor *sensor)
1195{
1196	struct ltc2983_temp *temp;
1197
1198	temp = devm_kzalloc(&st->spi->dev, sizeof(*temp), GFP_KERNEL);
1199	if (!temp)
1200		return ERR_PTR(-ENOMEM);
1201
1202	if (fwnode_property_read_bool(child, "adi,single-ended"))
1203		temp->single_ended = true;
1204
1205	if (!temp->single_ended &&
1206	    sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
1207		dev_err(&st->spi->dev, "Invalid chan:%d for differential temp\n",
1208			sensor->chan);
1209		return ERR_PTR(-EINVAL);
1210	}
1211
1212	temp->custom = __ltc2983_custom_sensor_new(st, child, "adi,custom-temp",
1213						   false, 4096, true);
1214	if (IS_ERR(temp->custom))
1215		return ERR_CAST(temp->custom);
1216
1217	/* set common parameters */
1218	temp->sensor.assign_chan = ltc2983_temp_assign_chan;
1219	temp->sensor.fault_handler = ltc2983_common_fault_handler;
1220
1221	return &temp->sensor;
1222}
1223
1224static int ltc2983_chan_read(struct ltc2983_data *st,
1225			const struct ltc2983_sensor *sensor, int *val)
1226{
1227	u32 start_conversion = 0;
1228	int ret;
1229	unsigned long time;
1230
1231	start_conversion = LTC2983_STATUS_START(true);
1232	start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor->chan);
1233	dev_dbg(&st->spi->dev, "Start conversion on chan:%d, status:%02X\n",
1234		sensor->chan, start_conversion);
1235	/* start conversion */
1236	ret = regmap_write(st->regmap, LTC2983_STATUS_REG, start_conversion);
1237	if (ret)
1238		return ret;
1239
1240	reinit_completion(&st->completion);
1241	/*
1242	 * wait for conversion to complete.
1243	 * 300 ms should be more than enough to complete the conversion.
1244	 * Depending on the sensor configuration, there are 2/3 conversions
1245	 * cycles of 82ms.
1246	 */
1247	time = wait_for_completion_timeout(&st->completion,
1248					   msecs_to_jiffies(300));
1249	if (!time) {
1250		dev_warn(&st->spi->dev, "Conversion timed out\n");
1251		return -ETIMEDOUT;
1252	}
1253
1254	/* read the converted data */
1255	ret = regmap_bulk_read(st->regmap, LTC2983_CHAN_RES_ADDR(sensor->chan),
1256			       &st->temp, sizeof(st->temp));
1257	if (ret)
1258		return ret;
1259
1260	*val = __be32_to_cpu(st->temp);
1261
1262	if (!(LTC2983_RES_VALID_MASK & *val)) {
1263		dev_err(&st->spi->dev, "Invalid conversion detected\n");
1264		return -EIO;
1265	}
1266
1267	ret = sensor->fault_handler(st, *val);
1268	if (ret)
1269		return ret;
1270
1271	*val = sign_extend32((*val) & LTC2983_DATA_MASK, LTC2983_DATA_SIGN_BIT);
1272	return 0;
1273}
1274
1275static int ltc2983_read_raw(struct iio_dev *indio_dev,
1276			    struct iio_chan_spec const *chan,
1277			    int *val, int *val2, long mask)
1278{
1279	struct ltc2983_data *st = iio_priv(indio_dev);
1280	int ret;
1281
1282	/* sanity check */
1283	if (chan->address >= st->num_channels) {
1284		dev_err(&st->spi->dev, "Invalid chan address:%ld",
1285			chan->address);
1286		return -EINVAL;
1287	}
1288
1289	switch (mask) {
1290	case IIO_CHAN_INFO_RAW:
1291		mutex_lock(&st->lock);
1292		ret = ltc2983_chan_read(st, st->sensors[chan->address], val);
1293		mutex_unlock(&st->lock);
1294		return ret ?: IIO_VAL_INT;
1295	case IIO_CHAN_INFO_SCALE:
1296		switch (chan->type) {
1297		case IIO_TEMP:
1298			/* value in milli degrees */
1299			*val = 1000;
1300			/* 2^10 */
1301			*val2 = 1024;
1302			return IIO_VAL_FRACTIONAL;
1303		case IIO_VOLTAGE:
1304			/* value in millivolt */
1305			*val = 1000;
1306			/* 2^21 */
1307			*val2 = 2097152;
1308			return IIO_VAL_FRACTIONAL;
1309		default:
1310			return -EINVAL;
1311		}
1312	}
1313
1314	return -EINVAL;
1315}
1316
1317static int ltc2983_reg_access(struct iio_dev *indio_dev,
1318			      unsigned int reg,
1319			      unsigned int writeval,
1320			      unsigned int *readval)
1321{
1322	struct ltc2983_data *st = iio_priv(indio_dev);
1323
1324	if (readval)
1325		return regmap_read(st->regmap, reg, readval);
1326	else
1327		return regmap_write(st->regmap, reg, writeval);
1328}
1329
1330static irqreturn_t ltc2983_irq_handler(int irq, void *data)
1331{
1332	struct ltc2983_data *st = data;
1333
1334	complete(&st->completion);
1335	return IRQ_HANDLED;
1336}
1337
1338#define LTC2983_CHAN(__type, index, __address) ({ \
1339	struct iio_chan_spec __chan = { \
1340		.type = __type, \
1341		.indexed = 1, \
1342		.channel = index, \
1343		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
1344		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
1345		.address = __address, \
1346	}; \
1347	__chan; \
1348})
1349
1350static int ltc2983_parse_fw(struct ltc2983_data *st)
1351{
1352	struct device *dev = &st->spi->dev;
1353	struct fwnode_handle *child;
1354	int ret = 0, chan = 0, channel_avail_mask = 0;
1355
1356	device_property_read_u32(dev, "adi,mux-delay-config-us", &st->mux_delay_config);
1357
1358	device_property_read_u32(dev, "adi,filter-notch-freq", &st->filter_notch_freq);
1359
1360	st->num_channels = device_get_child_node_count(dev);
1361	if (!st->num_channels) {
1362		dev_err(&st->spi->dev, "At least one channel must be given!");
1363		return -EINVAL;
1364	}
1365
1366	st->sensors = devm_kcalloc(dev, st->num_channels, sizeof(*st->sensors),
1367				   GFP_KERNEL);
1368	if (!st->sensors)
1369		return -ENOMEM;
1370
1371	st->iio_channels = st->num_channels;
1372	device_for_each_child_node(dev, child) {
1373		struct ltc2983_sensor sensor;
1374
1375		ret = fwnode_property_read_u32(child, "reg", &sensor.chan);
1376		if (ret) {
1377			dev_err(dev, "reg property must given for child nodes\n");
1378			goto put_child;
1379		}
1380
1381		/* check if we have a valid channel */
1382		if (sensor.chan < LTC2983_MIN_CHANNELS_NR ||
1383		    sensor.chan > st->info->max_channels_nr) {
1384			ret = -EINVAL;
1385			dev_err(dev, "chan:%d must be from %u to %u\n", sensor.chan,
1386				LTC2983_MIN_CHANNELS_NR, st->info->max_channels_nr);
1387			goto put_child;
1388		} else if (channel_avail_mask & BIT(sensor.chan)) {
1389			ret = -EINVAL;
1390			dev_err(dev, "chan:%d already in use\n", sensor.chan);
1391			goto put_child;
1392		}
1393
1394		ret = fwnode_property_read_u32(child, "adi,sensor-type", &sensor.type);
1395		if (ret) {
1396			dev_err(dev,
1397				"adi,sensor-type property must given for child nodes\n");
1398			goto put_child;
1399		}
1400
1401		dev_dbg(dev, "Create new sensor, type %u, chann %u",
1402								sensor.type,
1403								sensor.chan);
1404
1405		if (sensor.type >= LTC2983_SENSOR_THERMOCOUPLE &&
1406		    sensor.type <= LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
1407			st->sensors[chan] = ltc2983_thermocouple_new(child, st,
1408								     &sensor);
1409		} else if (sensor.type >= LTC2983_SENSOR_RTD &&
1410			   sensor.type <= LTC2983_SENSOR_RTD_CUSTOM) {
1411			st->sensors[chan] = ltc2983_rtd_new(child, st, &sensor);
1412		} else if (sensor.type >= LTC2983_SENSOR_THERMISTOR &&
1413			   sensor.type <= LTC2983_SENSOR_THERMISTOR_CUSTOM) {
1414			st->sensors[chan] = ltc2983_thermistor_new(child, st,
1415								   &sensor);
1416		} else if (sensor.type == LTC2983_SENSOR_DIODE) {
1417			st->sensors[chan] = ltc2983_diode_new(child, st,
1418							      &sensor);
1419		} else if (sensor.type == LTC2983_SENSOR_SENSE_RESISTOR) {
1420			st->sensors[chan] = ltc2983_r_sense_new(child, st,
1421								&sensor);
1422			/* don't add rsense to iio */
1423			st->iio_channels--;
1424		} else if (sensor.type == LTC2983_SENSOR_DIRECT_ADC) {
1425			st->sensors[chan] = ltc2983_adc_new(child, st, &sensor);
1426		} else if (st->info->has_temp &&
1427			   sensor.type == LTC2983_SENSOR_ACTIVE_TEMP) {
1428			st->sensors[chan] = ltc2983_temp_new(child, st, &sensor);
1429		} else {
1430			dev_err(dev, "Unknown sensor type %d\n", sensor.type);
1431			ret = -EINVAL;
1432			goto put_child;
1433		}
1434
1435		if (IS_ERR(st->sensors[chan])) {
1436			dev_err(dev, "Failed to create sensor %ld",
1437				PTR_ERR(st->sensors[chan]));
1438			ret = PTR_ERR(st->sensors[chan]);
1439			goto put_child;
1440		}
1441		/* set generic sensor parameters */
1442		st->sensors[chan]->chan = sensor.chan;
1443		st->sensors[chan]->type = sensor.type;
1444
1445		channel_avail_mask |= BIT(sensor.chan);
1446		chan++;
1447	}
1448
1449	return 0;
1450put_child:
1451	fwnode_handle_put(child);
1452	return ret;
1453}
1454
1455static int ltc2983_eeprom_cmd(struct ltc2983_data *st, unsigned int cmd,
1456			      unsigned int wait_time, unsigned int status_reg,
1457			      unsigned long status_fail_mask)
1458{
1459	unsigned long time;
1460	unsigned int val;
1461	int ret;
1462
1463	ret = regmap_bulk_write(st->regmap, LTC2983_EEPROM_KEY_REG,
1464				&st->eeprom_key, sizeof(st->eeprom_key));
1465	if (ret)
1466		return ret;
1467
1468	reinit_completion(&st->completion);
1469
1470	ret = regmap_write(st->regmap, LTC2983_STATUS_REG,
1471			   LTC2983_STATUS_START(true) | cmd);
1472	if (ret)
1473		return ret;
1474
1475	time = wait_for_completion_timeout(&st->completion,
1476					   msecs_to_jiffies(wait_time));
1477	if (!time) {
1478		dev_err(&st->spi->dev, "EEPROM command timed out\n");
1479		return -ETIMEDOUT;
1480	}
1481
1482	ret = regmap_read(st->regmap, status_reg, &val);
1483	if (ret)
1484		return ret;
1485
1486	if (val & status_fail_mask) {
1487		dev_err(&st->spi->dev, "EEPROM command failed: 0x%02X\n", val);
1488		return -EINVAL;
1489	}
1490
1491	return 0;
1492}
1493
1494static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
1495{
1496	u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0, status;
1497	int ret;
1498
1499	/* make sure the device is up: start bit (7) is 0 and done bit (6) is 1 */
1500	ret = regmap_read_poll_timeout(st->regmap, LTC2983_STATUS_REG, status,
1501				       LTC2983_STATUS_UP(status) == 1, 25000,
1502				       25000 * 10);
1503	if (ret) {
1504		dev_err(&st->spi->dev, "Device startup timed out\n");
1505		return ret;
1506	}
1507
1508	ret = regmap_update_bits(st->regmap, LTC2983_GLOBAL_CONFIG_REG,
1509				 LTC2983_NOTCH_FREQ_MASK,
1510				 LTC2983_NOTCH_FREQ(st->filter_notch_freq));
1511	if (ret)
1512		return ret;
1513
1514	ret = regmap_write(st->regmap, LTC2983_MUX_CONFIG_REG,
1515			   st->mux_delay_config);
1516	if (ret)
1517		return ret;
1518
1519	if (st->info->has_eeprom && !assign_iio) {
1520		ret = ltc2983_eeprom_cmd(st, LTC2983_EEPROM_READ_CMD,
1521					 LTC2983_EEPROM_READ_TIME_MS,
1522					 LTC2983_EEPROM_READ_STATUS_REG,
1523					 LTC2983_EEPROM_READ_FAILURE_MASK);
1524		if (!ret)
1525			return 0;
1526	}
1527
1528	for (chan = 0; chan < st->num_channels; chan++) {
1529		u32 chan_type = 0, *iio_chan;
1530
1531		ret = st->sensors[chan]->assign_chan(st, st->sensors[chan]);
1532		if (ret)
1533			return ret;
1534		/*
1535		 * The assign_iio flag is necessary for when the device is
1536		 * coming out of sleep. In that case, we just need to
1537		 * re-configure the device channels.
1538		 * We also don't assign iio channels for rsense.
1539		 */
1540		if (st->sensors[chan]->type == LTC2983_SENSOR_SENSE_RESISTOR ||
1541		    !assign_iio)
1542			continue;
1543
1544		/* assign iio channel */
1545		if (st->sensors[chan]->type != LTC2983_SENSOR_DIRECT_ADC) {
1546			chan_type = IIO_TEMP;
1547			iio_chan = &iio_chan_t;
1548		} else {
1549			chan_type = IIO_VOLTAGE;
1550			iio_chan = &iio_chan_v;
1551		}
1552
1553		/*
1554		 * add chan as the iio .address so that, we can directly
1555		 * reference the sensor given the iio_chan_spec
1556		 */
1557		st->iio_chan[iio_idx++] = LTC2983_CHAN(chan_type, (*iio_chan)++,
1558						       chan);
1559	}
1560
1561	return 0;
1562}
1563
1564static const struct regmap_range ltc2983_reg_ranges[] = {
1565	regmap_reg_range(LTC2983_STATUS_REG, LTC2983_STATUS_REG),
1566	regmap_reg_range(LTC2983_TEMP_RES_START_REG, LTC2983_TEMP_RES_END_REG),
1567	regmap_reg_range(LTC2983_EEPROM_KEY_REG, LTC2983_EEPROM_KEY_REG),
1568	regmap_reg_range(LTC2983_EEPROM_READ_STATUS_REG,
1569			 LTC2983_EEPROM_READ_STATUS_REG),
1570	regmap_reg_range(LTC2983_GLOBAL_CONFIG_REG, LTC2983_GLOBAL_CONFIG_REG),
1571	regmap_reg_range(LTC2983_MULT_CHANNEL_START_REG,
1572			 LTC2983_MULT_CHANNEL_END_REG),
1573	regmap_reg_range(LTC2986_EEPROM_STATUS_REG, LTC2986_EEPROM_STATUS_REG),
1574	regmap_reg_range(LTC2983_MUX_CONFIG_REG, LTC2983_MUX_CONFIG_REG),
1575	regmap_reg_range(LTC2983_CHAN_ASSIGN_START_REG,
1576			 LTC2983_CHAN_ASSIGN_END_REG),
1577	regmap_reg_range(LTC2983_CUST_SENS_TBL_START_REG,
1578			 LTC2983_CUST_SENS_TBL_END_REG),
1579};
1580
1581static const struct regmap_access_table ltc2983_reg_table = {
1582	.yes_ranges = ltc2983_reg_ranges,
1583	.n_yes_ranges = ARRAY_SIZE(ltc2983_reg_ranges),
1584};
1585
1586/*
1587 *  The reg_bits are actually 12 but the device needs the first *complete*
1588 *  byte for the command (R/W).
1589 */
1590static const struct regmap_config ltc2983_regmap_config = {
1591	.reg_bits = 24,
1592	.val_bits = 8,
1593	.wr_table = &ltc2983_reg_table,
1594	.rd_table = &ltc2983_reg_table,
1595	.read_flag_mask = GENMASK(1, 0),
1596	.write_flag_mask = BIT(1),
1597};
1598
1599static const struct  iio_info ltc2983_iio_info = {
1600	.read_raw = ltc2983_read_raw,
1601	.debugfs_reg_access = ltc2983_reg_access,
1602};
1603
1604static int ltc2983_probe(struct spi_device *spi)
1605{
1606	struct ltc2983_data *st;
1607	struct iio_dev *indio_dev;
1608	struct gpio_desc *gpio;
1609	int ret;
1610
1611	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
1612	if (!indio_dev)
1613		return -ENOMEM;
1614
1615	st = iio_priv(indio_dev);
1616
1617	st->info = spi_get_device_match_data(spi);
1618	if (!st->info)
1619		return -ENODEV;
1620
1621	st->regmap = devm_regmap_init_spi(spi, &ltc2983_regmap_config);
1622	if (IS_ERR(st->regmap)) {
1623		dev_err(&spi->dev, "Failed to initialize regmap\n");
1624		return PTR_ERR(st->regmap);
1625	}
1626
1627	mutex_init(&st->lock);
1628	init_completion(&st->completion);
1629	st->spi = spi;
1630	st->eeprom_key = cpu_to_be32(LTC2983_EEPROM_KEY);
1631	spi_set_drvdata(spi, st);
1632
1633	ret = ltc2983_parse_fw(st);
1634	if (ret)
1635		return ret;
1636
1637	gpio = devm_gpiod_get_optional(&st->spi->dev, "reset", GPIOD_OUT_HIGH);
1638	if (IS_ERR(gpio))
1639		return PTR_ERR(gpio);
1640
1641	if (gpio) {
1642		/* bring the device out of reset */
1643		usleep_range(1000, 1200);
1644		gpiod_set_value_cansleep(gpio, 0);
1645	}
1646
1647	st->iio_chan = devm_kzalloc(&spi->dev,
1648				    st->iio_channels * sizeof(*st->iio_chan),
1649				    GFP_KERNEL);
1650	if (!st->iio_chan)
1651		return -ENOMEM;
1652
1653	ret = ltc2983_setup(st, true);
1654	if (ret)
1655		return ret;
1656
1657	ret = devm_request_irq(&spi->dev, spi->irq, ltc2983_irq_handler,
1658			       IRQF_TRIGGER_RISING, st->info->name, st);
1659	if (ret) {
1660		dev_err(&spi->dev, "failed to request an irq, %d", ret);
1661		return ret;
1662	}
1663
1664	if (st->info->has_eeprom) {
1665		ret = ltc2983_eeprom_cmd(st, LTC2983_EEPROM_WRITE_CMD,
1666					 LTC2983_EEPROM_WRITE_TIME_MS,
1667					 LTC2986_EEPROM_STATUS_REG,
1668					 LTC2983_EEPROM_STATUS_FAILURE_MASK);
1669		if (ret)
1670			return ret;
1671	}
1672
1673	indio_dev->name = st->info->name;
1674	indio_dev->num_channels = st->iio_channels;
1675	indio_dev->channels = st->iio_chan;
1676	indio_dev->modes = INDIO_DIRECT_MODE;
1677	indio_dev->info = &ltc2983_iio_info;
1678
1679	return devm_iio_device_register(&spi->dev, indio_dev);
1680}
1681
1682static int ltc2983_resume(struct device *dev)
1683{
1684	struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev));
1685	int dummy;
1686
1687	/* dummy read to bring the device out of sleep */
1688	regmap_read(st->regmap, LTC2983_STATUS_REG, &dummy);
1689	/* we need to re-assign the channels */
1690	return ltc2983_setup(st, false);
1691}
1692
1693static int ltc2983_suspend(struct device *dev)
1694{
1695	struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev));
1696
1697	return regmap_write(st->regmap, LTC2983_STATUS_REG, LTC2983_SLEEP);
1698}
1699
1700static DEFINE_SIMPLE_DEV_PM_OPS(ltc2983_pm_ops, ltc2983_suspend,
1701				ltc2983_resume);
1702
1703static const struct ltc2983_chip_info ltc2983_chip_info_data = {
1704	.name = "ltc2983",
1705	.max_channels_nr = 20,
1706};
1707
1708static const struct ltc2983_chip_info ltc2984_chip_info_data = {
1709	.name = "ltc2984",
1710	.max_channels_nr = 20,
1711	.has_eeprom = true,
1712};
1713
1714static const struct ltc2983_chip_info ltc2986_chip_info_data = {
1715	.name = "ltc2986",
1716	.max_channels_nr = 10,
1717	.has_temp = true,
1718	.has_eeprom = true,
1719};
1720
1721static const struct ltc2983_chip_info ltm2985_chip_info_data = {
1722	.name = "ltm2985",
1723	.max_channels_nr = 10,
1724	.has_temp = true,
1725	.has_eeprom = true,
1726};
1727
1728static const struct spi_device_id ltc2983_id_table[] = {
1729	{ "ltc2983", (kernel_ulong_t)&ltc2983_chip_info_data },
1730	{ "ltc2984", (kernel_ulong_t)&ltc2984_chip_info_data },
1731	{ "ltc2986", (kernel_ulong_t)&ltc2986_chip_info_data },
1732	{ "ltm2985", (kernel_ulong_t)&ltm2985_chip_info_data },
1733	{},
1734};
1735MODULE_DEVICE_TABLE(spi, ltc2983_id_table);
1736
1737static const struct of_device_id ltc2983_of_match[] = {
1738	{ .compatible = "adi,ltc2983", .data = &ltc2983_chip_info_data },
1739	{ .compatible = "adi,ltc2984", .data = &ltc2984_chip_info_data },
1740	{ .compatible = "adi,ltc2986", .data = &ltc2986_chip_info_data },
1741	{ .compatible = "adi,ltm2985", .data = &ltm2985_chip_info_data },
1742	{},
1743};
1744MODULE_DEVICE_TABLE(of, ltc2983_of_match);
1745
1746static struct spi_driver ltc2983_driver = {
1747	.driver = {
1748		.name = "ltc2983",
1749		.of_match_table = ltc2983_of_match,
1750		.pm = pm_sleep_ptr(&ltc2983_pm_ops),
1751	},
1752	.probe = ltc2983_probe,
1753	.id_table = ltc2983_id_table,
1754};
1755
1756module_spi_driver(ltc2983_driver);
1757
1758MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
1759MODULE_DESCRIPTION("Analog Devices LTC2983 SPI Temperature sensors");
1760MODULE_LICENSE("GPL");
1761