xref: /linux/drivers/iio/temperature/ltc2983.c (revision 7ec462100ef9142344ddbf86f2c3008b97acddbe)
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 
177 enum {
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 
212 struct ltc2983_chip_info {
213 	const char *name;
214 	unsigned int max_channels_nr;
215 	bool has_temp;
216 	bool has_eeprom;
217 };
218 
219 struct 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 
242 struct 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 
252 struct 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 
261 struct ltc2983_thermocouple {
262 	struct ltc2983_sensor sensor;
263 	struct ltc2983_custom_sensor *custom;
264 	u32 sensor_config;
265 	u32 cold_junction_chan;
266 };
267 
268 struct 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 
277 struct 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 
285 struct ltc2983_diode {
286 	struct ltc2983_sensor sensor;
287 	u32 sensor_config;
288 	u32 excitation_current;
289 	u32 ideal_factor_value;
290 };
291 
292 struct ltc2983_rsense {
293 	struct ltc2983_sensor sensor;
294 	u32 r_sense_val;
295 };
296 
297 struct ltc2983_adc {
298 	struct ltc2983_sensor sensor;
299 	bool single_ended;
300 };
301 
302 struct 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  */
__convert_to_raw(const u64 val,const u32 resolution)314 static 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 
__convert_to_raw_sign(const u64 val,const u32 resolution)324 static 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 
__ltc2983_fault_handler(const struct ltc2983_data * st,const u32 result,const u32 hard_mask,const u32 soft_mask)333 static 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 
__ltc2983_chan_assign_common(struct ltc2983_data * st,const struct ltc2983_sensor * sensor,u32 chan_val)350 static 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 
__ltc2983_chan_custom_sensor_assign(struct ltc2983_data * st,struct ltc2983_custom_sensor * custom,u32 * chan_val)364 static 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 
417 static struct ltc2983_custom_sensor *
__ltc2983_custom_sensor_new(struct ltc2983_data * st,const struct fwnode_handle * fn,const char * propname,const bool is_steinhart,const u32 resolution,const bool has_signed)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 
ltc2983_thermocouple_fault_handler(const struct ltc2983_data * st,const u32 result)523 static 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 
ltc2983_common_fault_handler(const struct ltc2983_data * st,const u32 result)531 static 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 
ltc2983_thermocouple_assign_chan(struct ltc2983_data * st,const struct ltc2983_sensor * sensor)539 static 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 
ltc2983_rtd_assign_chan(struct ltc2983_data * st,const struct ltc2983_sensor * sensor)559 static 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 
ltc2983_thermistor_assign_chan(struct ltc2983_data * st,const struct ltc2983_sensor * sensor)581 static 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 
ltc2983_diode_assign_chan(struct ltc2983_data * st,const struct ltc2983_sensor * sensor)604 static 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 
ltc2983_r_sense_assign_chan(struct ltc2983_data * st,const struct ltc2983_sensor * sensor)617 static 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 
ltc2983_adc_assign_chan(struct ltc2983_data * st,const struct ltc2983_sensor * sensor)628 static 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 
ltc2983_temp_assign_chan(struct ltc2983_data * st,const struct ltc2983_sensor * sensor)639 static 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 
655 static struct ltc2983_sensor *
ltc2983_thermocouple_new(const struct fwnode_handle * child,struct ltc2983_data * st,const struct ltc2983_sensor * sensor)656 ltc2983_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 
737 static struct ltc2983_sensor *
ltc2983_rtd_new(const struct fwnode_handle * child,struct ltc2983_data * st,const struct ltc2983_sensor * sensor)738 ltc2983_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 
887 static struct ltc2983_sensor *
ltc2983_thermistor_new(const struct fwnode_handle * child,struct ltc2983_data * st,const struct ltc2983_sensor * sensor)888 ltc2983_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 
1015 static struct ltc2983_sensor *
ltc2983_diode_new(const struct fwnode_handle * child,const struct ltc2983_data * st,const struct ltc2983_sensor * sensor)1016 ltc2983_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 
ltc2983_r_sense_new(struct fwnode_handle * child,struct ltc2983_data * st,const struct ltc2983_sensor * sensor)1078 static 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 
ltc2983_adc_new(struct fwnode_handle * child,struct ltc2983_data * st,const struct ltc2983_sensor * sensor)1114 static 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 
ltc2983_temp_new(struct fwnode_handle * child,struct ltc2983_data * st,const struct ltc2983_sensor * sensor)1139 static 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 
ltc2983_chan_read(struct ltc2983_data * st,const struct ltc2983_sensor * sensor,int * val)1169 static 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 
ltc2983_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)1220 static 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 
ltc2983_reg_access(struct iio_dev * indio_dev,unsigned int reg,unsigned int writeval,unsigned int * readval)1262 static 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 
ltc2983_irq_handler(int irq,void * data)1275 static 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 
ltc2983_parse_fw(struct ltc2983_data * st)1295 static 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 
ltc2983_eeprom_cmd(struct ltc2983_data * st,unsigned int cmd,unsigned int wait_time,unsigned int status_reg,unsigned long status_fail_mask)1390 static 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 
ltc2983_setup(struct ltc2983_data * st,bool assign_iio)1427 static 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 
1496 static 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 
1513 static 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  */
1522 static 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 
1531 static const struct  iio_info ltc2983_iio_info = {
1532 	.read_raw = ltc2983_read_raw,
1533 	.debugfs_reg_access = ltc2983_reg_access,
1534 };
1535 
ltc2983_probe(struct spi_device * spi)1536 static 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 
ltc2983_resume(struct device * dev)1616 static 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 
ltc2983_suspend(struct device * dev)1627 static 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 
1634 static DEFINE_SIMPLE_DEV_PM_OPS(ltc2983_pm_ops, ltc2983_suspend,
1635 				ltc2983_resume);
1636 
1637 static const struct ltc2983_chip_info ltc2983_chip_info_data = {
1638 	.name = "ltc2983",
1639 	.max_channels_nr = 20,
1640 };
1641 
1642 static const struct ltc2983_chip_info ltc2984_chip_info_data = {
1643 	.name = "ltc2984",
1644 	.max_channels_nr = 20,
1645 	.has_eeprom = true,
1646 };
1647 
1648 static 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 
1655 static 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 
1662 static 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 };
1669 MODULE_DEVICE_TABLE(spi, ltc2983_id_table);
1670 
1671 static 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 };
1678 MODULE_DEVICE_TABLE(of, ltc2983_of_match);
1679 
1680 static 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 
1690 module_spi_driver(ltc2983_driver);
1691 
1692 MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
1693 MODULE_DESCRIPTION("Analog Devices LTC2983 SPI Temperature sensors");
1694 MODULE_LICENSE("GPL");
1695