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[mirror_ubuntu-jammy-kernel.git] / drivers / iio / temperature / ltc2983.c
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f110f318
NS		 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/module.h>
16#include <linux/of_gpio.h>
17#include <linux/regmap.h>
18#include <linux/spi/spi.h>
19
20/* register map */
21#define LTC2983_STATUS_REG 0x0000
22#define LTC2983_TEMP_RES_START_REG 0x0010
23#define LTC2983_TEMP_RES_END_REG 0x005F
24#define LTC2983_GLOBAL_CONFIG_REG 0x00F0
25#define LTC2983_MULT_CHANNEL_START_REG 0x00F4
26#define LTC2983_MULT_CHANNEL_END_REG 0x00F7
27#define LTC2983_MUX_CONFIG_REG 0x00FF
28#define LTC2983_CHAN_ASSIGN_START_REG 0x0200
29#define LTC2983_CHAN_ASSIGN_END_REG 0x024F
30#define LTC2983_CUST_SENS_TBL_START_REG 0x0250
31#define LTC2983_CUST_SENS_TBL_END_REG 0x03CF
32
33#define LTC2983_DIFFERENTIAL_CHAN_MIN 2
34#define LTC2983_MAX_CHANNELS_NR 20
35#define LTC2983_MIN_CHANNELS_NR 1
36#define LTC2983_SLEEP 0x97
37#define LTC2983_CUSTOM_STEINHART_SIZE 24
38#define LTC2983_CUSTOM_SENSOR_ENTRY_SZ 6
39#define LTC2983_CUSTOM_STEINHART_ENTRY_SZ 4
40
41#define LTC2983_CHAN_START_ADDR(chan) \
42 (((chan - 1) * 4) + LTC2983_CHAN_ASSIGN_START_REG)
43#define LTC2983_CHAN_RES_ADDR(chan) \
44 (((chan - 1) * 4) + LTC2983_TEMP_RES_START_REG)
45#define LTC2983_THERMOCOUPLE_DIFF_MASK BIT(3)
46#define LTC2983_THERMOCOUPLE_SGL(x) \
47 FIELD_PREP(LTC2983_THERMOCOUPLE_DIFF_MASK, x)
48#define LTC2983_THERMOCOUPLE_OC_CURR_MASK GENMASK(1, 0)
49#define LTC2983_THERMOCOUPLE_OC_CURR(x) \
50 FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CURR_MASK, x)
51#define LTC2983_THERMOCOUPLE_OC_CHECK_MASK BIT(2)
52#define LTC2983_THERMOCOUPLE_OC_CHECK(x) \
53 FIELD_PREP(LTC2983_THERMOCOUPLE_OC_CHECK_MASK, x)
54
55#define LTC2983_THERMISTOR_DIFF_MASK BIT(2)
56#define LTC2983_THERMISTOR_SGL(x) \
57 FIELD_PREP(LTC2983_THERMISTOR_DIFF_MASK, x)
58#define LTC2983_THERMISTOR_R_SHARE_MASK BIT(1)
59#define LTC2983_THERMISTOR_R_SHARE(x) \
60 FIELD_PREP(LTC2983_THERMISTOR_R_SHARE_MASK, x)
61#define LTC2983_THERMISTOR_C_ROTATE_MASK BIT(0)
62#define LTC2983_THERMISTOR_C_ROTATE(x) \
63 FIELD_PREP(LTC2983_THERMISTOR_C_ROTATE_MASK, x)
64
65#define LTC2983_DIODE_DIFF_MASK BIT(2)
66#define LTC2983_DIODE_SGL(x) \
67 FIELD_PREP(LTC2983_DIODE_DIFF_MASK, x)
68#define LTC2983_DIODE_3_CONV_CYCLE_MASK BIT(1)
69#define LTC2983_DIODE_3_CONV_CYCLE(x) \
70 FIELD_PREP(LTC2983_DIODE_3_CONV_CYCLE_MASK, x)
71#define LTC2983_DIODE_AVERAGE_ON_MASK BIT(0)
72#define LTC2983_DIODE_AVERAGE_ON(x) \
73 FIELD_PREP(LTC2983_DIODE_AVERAGE_ON_MASK, x)
74
75#define LTC2983_RTD_4_WIRE_MASK BIT(3)
76#define LTC2983_RTD_ROTATION_MASK BIT(1)
77#define LTC2983_RTD_C_ROTATE(x) \
78 FIELD_PREP(LTC2983_RTD_ROTATION_MASK, x)
79#define LTC2983_RTD_KELVIN_R_SENSE_MASK GENMASK(3, 2)
80#define LTC2983_RTD_N_WIRES_MASK GENMASK(3, 2)
81#define LTC2983_RTD_N_WIRES(x) \
82 FIELD_PREP(LTC2983_RTD_N_WIRES_MASK, x)
83#define LTC2983_RTD_R_SHARE_MASK BIT(0)
84#define LTC2983_RTD_R_SHARE(x) \
85 FIELD_PREP(LTC2983_RTD_R_SHARE_MASK, 1)
86
87#define LTC2983_COMMON_HARD_FAULT_MASK GENMASK(31, 30)
88#define LTC2983_COMMON_SOFT_FAULT_MASK GENMASK(27, 25)
89
90#define LTC2983_STATUS_START_MASK BIT(7)
91#define LTC2983_STATUS_START(x) FIELD_PREP(LTC2983_STATUS_START_MASK, x)
92
93#define LTC2983_STATUS_CHAN_SEL_MASK GENMASK(4, 0)
94#define LTC2983_STATUS_CHAN_SEL(x) \
95 FIELD_PREP(LTC2983_STATUS_CHAN_SEL_MASK, x)
96
97#define LTC2983_TEMP_UNITS_MASK BIT(2)
98#define LTC2983_TEMP_UNITS(x) FIELD_PREP(LTC2983_TEMP_UNITS_MASK, x)
99
100#define LTC2983_NOTCH_FREQ_MASK GENMASK(1, 0)
101#define LTC2983_NOTCH_FREQ(x) FIELD_PREP(LTC2983_NOTCH_FREQ_MASK, x)
102
103#define LTC2983_RES_VALID_MASK BIT(24)
104#define LTC2983_DATA_MASK GENMASK(23, 0)
105#define LTC2983_DATA_SIGN_BIT 23
106
107#define LTC2983_CHAN_TYPE_MASK GENMASK(31, 27)
108#define LTC2983_CHAN_TYPE(x) FIELD_PREP(LTC2983_CHAN_TYPE_MASK, x)
109
110/* cold junction for thermocouples and rsense for rtd's and thermistor's */
111#define LTC2983_CHAN_ASSIGN_MASK GENMASK(26, 22)
112#define LTC2983_CHAN_ASSIGN(x) FIELD_PREP(LTC2983_CHAN_ASSIGN_MASK, x)
113
114#define LTC2983_CUSTOM_LEN_MASK GENMASK(5, 0)
115#define LTC2983_CUSTOM_LEN(x) FIELD_PREP(LTC2983_CUSTOM_LEN_MASK, x)
116
117#define LTC2983_CUSTOM_ADDR_MASK GENMASK(11, 6)
118#define LTC2983_CUSTOM_ADDR(x) FIELD_PREP(LTC2983_CUSTOM_ADDR_MASK, x)
119
120#define LTC2983_THERMOCOUPLE_CFG_MASK GENMASK(21, 18)
121#define LTC2983_THERMOCOUPLE_CFG(x) \
122 FIELD_PREP(LTC2983_THERMOCOUPLE_CFG_MASK, x)
123#define LTC2983_THERMOCOUPLE_HARD_FAULT_MASK GENMASK(31, 29)
124#define LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK GENMASK(28, 25)
125
126#define LTC2983_RTD_CFG_MASK GENMASK(21, 18)
127#define LTC2983_RTD_CFG(x) FIELD_PREP(LTC2983_RTD_CFG_MASK, x)
128#define LTC2983_RTD_EXC_CURRENT_MASK GENMASK(17, 14)
129#define LTC2983_RTD_EXC_CURRENT(x) \
130 FIELD_PREP(LTC2983_RTD_EXC_CURRENT_MASK, x)
131#define LTC2983_RTD_CURVE_MASK GENMASK(13, 12)
132#define LTC2983_RTD_CURVE(x) FIELD_PREP(LTC2983_RTD_CURVE_MASK, x)
133
134#define LTC2983_THERMISTOR_CFG_MASK GENMASK(21, 19)
135#define LTC2983_THERMISTOR_CFG(x) \
136 FIELD_PREP(LTC2983_THERMISTOR_CFG_MASK, x)
137#define LTC2983_THERMISTOR_EXC_CURRENT_MASK GENMASK(18, 15)
138#define LTC2983_THERMISTOR_EXC_CURRENT(x) \
139 FIELD_PREP(LTC2983_THERMISTOR_EXC_CURRENT_MASK, x)
140
141#define LTC2983_DIODE_CFG_MASK GENMASK(26, 24)
142#define LTC2983_DIODE_CFG(x) FIELD_PREP(LTC2983_DIODE_CFG_MASK, x)
143#define LTC2983_DIODE_EXC_CURRENT_MASK GENMASK(23, 22)
144#define LTC2983_DIODE_EXC_CURRENT(x) \
145 FIELD_PREP(LTC2983_DIODE_EXC_CURRENT_MASK, x)
146#define LTC2983_DIODE_IDEAL_FACTOR_MASK GENMASK(21, 0)
147#define LTC2983_DIODE_IDEAL_FACTOR(x) \
148 FIELD_PREP(LTC2983_DIODE_IDEAL_FACTOR_MASK, x)
149
150#define LTC2983_R_SENSE_VAL_MASK GENMASK(26, 0)
151#define LTC2983_R_SENSE_VAL(x) FIELD_PREP(LTC2983_R_SENSE_VAL_MASK, x)
152
153#define LTC2983_ADC_SINGLE_ENDED_MASK BIT(26)
154#define LTC2983_ADC_SINGLE_ENDED(x) \
155 FIELD_PREP(LTC2983_ADC_SINGLE_ENDED_MASK, x)
156
157enum {
158 LTC2983_SENSOR_THERMOCOUPLE = 1,
159 LTC2983_SENSOR_THERMOCOUPLE_CUSTOM = 9,
160 LTC2983_SENSOR_RTD = 10,
161 LTC2983_SENSOR_RTD_CUSTOM = 18,
162 LTC2983_SENSOR_THERMISTOR = 19,
163 LTC2983_SENSOR_THERMISTOR_STEINHART = 26,
164 LTC2983_SENSOR_THERMISTOR_CUSTOM = 27,
165 LTC2983_SENSOR_DIODE = 28,
166 LTC2983_SENSOR_SENSE_RESISTOR = 29,
167 LTC2983_SENSOR_DIRECT_ADC = 30,
168};
169
170#define to_thermocouple(_sensor) \
171 container_of(_sensor, struct ltc2983_thermocouple, sensor)
172
173#define to_rtd(_sensor) \
174 container_of(_sensor, struct ltc2983_rtd, sensor)
175
176#define to_thermistor(_sensor) \
177 container_of(_sensor, struct ltc2983_thermistor, sensor)
178
179#define to_diode(_sensor) \
180 container_of(_sensor, struct ltc2983_diode, sensor)
181
182#define to_rsense(_sensor) \
183 container_of(_sensor, struct ltc2983_rsense, sensor)
184
185#define to_adc(_sensor) \
186 container_of(_sensor, struct ltc2983_adc, sensor)
187
188struct ltc2983_data {
189 struct regmap *regmap;
190 struct spi_device *spi;
191 struct mutex lock;
192 struct completion completion;
193 struct iio_chan_spec *iio_chan;
194 struct ltc2983_sensor **sensors;
195 u32 mux_delay_config;
196 u32 filter_notch_freq;
197 u16 custom_table_size;
198 u8 num_channels;
199 u8 iio_channels;
200 /*
201 * DMA (thus cache coherency maintenance) requires the
202 * transfer buffers to live in their own cache lines.
203 * Holds the converted temperature
204 */
205 __be32 temp ____cacheline_aligned;
206};
207
208struct ltc2983_sensor {
209 int (*fault_handler)(const struct ltc2983_data *st, const u32 result);
210 int (*assign_chan)(struct ltc2983_data *st,
211 const struct ltc2983_sensor *sensor);
212 /* specifies the sensor channel */
213 u32 chan;
214 /* sensor type */
215 u32 type;
216};
217
218struct ltc2983_custom_sensor {
219 /* raw table sensor data */
220 u8 *table;
221 size_t size;
222 /* address offset */
223 s8 offset;
224 bool is_steinhart;
225};
226
227struct ltc2983_thermocouple {
228 struct ltc2983_sensor sensor;
229 struct ltc2983_custom_sensor *custom;
230 u32 sensor_config;
231 u32 cold_junction_chan;
232};
233
234struct ltc2983_rtd {
235 struct ltc2983_sensor sensor;
236 struct ltc2983_custom_sensor *custom;
237 u32 sensor_config;
238 u32 r_sense_chan;
239 u32 excitation_current;
240 u32 rtd_curve;
241};
242
243struct ltc2983_thermistor {
244 struct ltc2983_sensor sensor;
245 struct ltc2983_custom_sensor *custom;
246 u32 sensor_config;
247 u32 r_sense_chan;
248 u32 excitation_current;
249};
250
251struct ltc2983_diode {
252 struct ltc2983_sensor sensor;
253 u32 sensor_config;
254 u32 excitation_current;
255 u32 ideal_factor_value;
256};
257
258struct ltc2983_rsense {
259 struct ltc2983_sensor sensor;
260 u32 r_sense_val;
261};
262
263struct ltc2983_adc {
264 struct ltc2983_sensor sensor;
265 bool single_ended;
266};
267
268/*
269 * Convert to Q format numbers. These number's are integers where
270 * the number of integer and fractional bits are specified. The resolution
271 * is given by 1/@resolution and tell us the number of fractional bits. For
272 * instance a resolution of 2^-10 means we have 10 fractional bits.
273 */
274static u32 __convert_to_raw(const u64 val, const u32 resolution)
275{
276 u64 __res = val * resolution;
277
278 /* all values are multiplied by 1000000 to remove the fraction */
279 do_div(__res, 1000000);
280
281 return __res;
282}
283
284static u32 __convert_to_raw_sign(const u64 val, const u32 resolution)
285{
286 s64 __res = -(s32)val;
287
288 __res = __convert_to_raw(__res, resolution);
289
290 return (u32)-__res;
291}
292
293static int __ltc2983_fault_handler(const struct ltc2983_data *st,
294 const u32 result, const u32 hard_mask,
295 const u32 soft_mask)
296{
297 const struct device *dev = &st->spi->dev;
298
299 if (result & hard_mask) {
300 dev_err(dev, "Invalid conversion: Sensor HARD fault\n");
301 return -EIO;
302 } else if (result & soft_mask) {
303 /* just print a warning */
304 dev_warn(dev, "Suspicious conversion: Sensor SOFT fault\n");
305 }
306
307 return 0;
308}
309
310static int __ltc2983_chan_assign_common(const struct ltc2983_data *st,
311 const struct ltc2983_sensor *sensor,
312 u32 chan_val)
313{
314 u32 reg = LTC2983_CHAN_START_ADDR(sensor->chan);
315 __be32 __chan_val;
316
317 chan_val |= LTC2983_CHAN_TYPE(sensor->type);
318 dev_dbg(&st->spi->dev, "Assign reg:0x%04X, val:0x%08X\n", reg,
319 chan_val);
320 __chan_val = cpu_to_be32(chan_val);
321 return regmap_bulk_write(st->regmap, reg, &__chan_val,
322 sizeof(__chan_val));
323}
324
325static int __ltc2983_chan_custom_sensor_assign(struct ltc2983_data *st,
326 struct ltc2983_custom_sensor *custom,
327 u32 *chan_val)
328{
329 u32 reg;
330 u8 mult = custom->is_steinhart ? LTC2983_CUSTOM_STEINHART_ENTRY_SZ :
331 LTC2983_CUSTOM_SENSOR_ENTRY_SZ;
332 const struct device *dev = &st->spi->dev;
333 /*
334 * custom->size holds the raw size of the table. However, when
335 * configuring the sensor channel, we must write the number of
336 * entries of the table minus 1. For steinhart sensors 0 is written
337 * since the size is constant!
338 */
339 const u8 len = custom->is_steinhart ? 0 :
340 (custom->size / LTC2983_CUSTOM_SENSOR_ENTRY_SZ) - 1;
341 /*
342 * Check if the offset was assigned already. It should be for steinhart
343 * sensors. When coming from sleep, it should be assigned for all.
344 */
345 if (custom->offset < 0) {
346 /*
347 * This needs to be done again here because, from the moment
348 * when this test was done (successfully) for this custom
349 * sensor, a steinhart sensor might have been added changing
350 * custom_table_size...
351 */
352 if (st->custom_table_size + custom->size >
353 (LTC2983_CUST_SENS_TBL_END_REG -
354 LTC2983_CUST_SENS_TBL_START_REG) + 1) {
355 dev_err(dev,
356 "Not space left(%d) for new custom sensor(%zu)",
357 st->custom_table_size,
358 custom->size);
359 return -EINVAL;
360 }
361
362 custom->offset = st->custom_table_size /
363 LTC2983_CUSTOM_SENSOR_ENTRY_SZ;
364 st->custom_table_size += custom->size;
365 }
366
367 reg = (custom->offset * mult) + LTC2983_CUST_SENS_TBL_START_REG;
368
369 *chan_val |= LTC2983_CUSTOM_LEN(len);
370 *chan_val |= LTC2983_CUSTOM_ADDR(custom->offset);
371 dev_dbg(dev, "Assign custom sensor, reg:0x%04X, off:%d, sz:%zu",
372 reg, custom->offset,
373 custom->size);
374 /* write custom sensor table */
375 return regmap_bulk_write(st->regmap, reg, custom->table, custom->size);
376}
377
378static struct ltc2983_custom_sensor *__ltc2983_custom_sensor_new(
379 struct ltc2983_data *st,
380 const struct device_node *np,
381 const char *propname,
382 const bool is_steinhart,
383 const u32 resolution,
384 const bool has_signed)
385{
386 struct ltc2983_custom_sensor *new_custom;
387 u8 index, n_entries, tbl = 0;
388 struct device *dev = &st->spi->dev;
389 /*
390 * For custom steinhart, the full u32 is taken. For all the others
391 * the MSB is discarded.
392 */
393 const u8 n_size = (is_steinhart == true) ? 4 : 3;
394 const u8 e_size = (is_steinhart == true) ? sizeof(u32) : sizeof(u64);
395
396 n_entries = of_property_count_elems_of_size(np, propname, e_size);
397 /* n_entries must be an even number */
398 if (!n_entries || (n_entries % 2) != 0) {
399 dev_err(dev, "Number of entries either 0 or not even\n");
400 return ERR_PTR(-EINVAL);
401 }
402
403 new_custom = devm_kzalloc(dev, sizeof(*new_custom), GFP_KERNEL);
404 if (!new_custom)
405 return ERR_PTR(-ENOMEM);
406
407 new_custom->size = n_entries * n_size;
408 /* check Steinhart size */
409 if (is_steinhart && new_custom->size != LTC2983_CUSTOM_STEINHART_SIZE) {
410 dev_err(dev, "Steinhart sensors size(%zu) must be 24",
411 new_custom->size);
412 return ERR_PTR(-EINVAL);
413 }
414 /* Check space on the table. */
415 if (st->custom_table_size + new_custom->size >
416 (LTC2983_CUST_SENS_TBL_END_REG -
417 LTC2983_CUST_SENS_TBL_START_REG) + 1) {
418 dev_err(dev, "No space left(%d) for new custom sensor(%zu)",
419 st->custom_table_size, new_custom->size);
420 return ERR_PTR(-EINVAL);
421 }
422
423 /* allocate the table */
424 new_custom->table = devm_kzalloc(dev, new_custom->size, GFP_KERNEL);
425 if (!new_custom->table)
426 return ERR_PTR(-ENOMEM);
427
428 for (index = 0; index < n_entries; index++) {
429 u64 temp = 0, j;
430 /*
431 * Steinhart sensors are configured with raw values in the
432 * devicetree. For the other sensors we must convert the
433 * value to raw. The odd index's correspond to temperarures
434 * and always have 1/1024 of resolution. Temperatures also
435 * come in kelvin, so signed values is not possible
436 */
437 if (!is_steinhart) {
438 of_property_read_u64_index(np, propname, index, &temp);
439
440 if ((index % 2) != 0)
441 temp = __convert_to_raw(temp, 1024);
442 else if (has_signed && (s64)temp < 0)
443 temp = __convert_to_raw_sign(temp, resolution);
444 else
445 temp = __convert_to_raw(temp, resolution);
446 } else {
2e19b6c3
CIK		 447 u32 t32;
448
449 of_property_read_u32_index(np, propname, index, &t32);
450 temp = t32;
f110f318
NS		 451 }
452
453 for (j = 0; j < n_size; j++)
454 new_custom->table[tbl++] =
455 temp >> (8 * (n_size - j - 1));
456 }
457
458 new_custom->is_steinhart = is_steinhart;
459 /*
460 * This is done to first add all the steinhart sensors to the table,
461 * in order to maximize the table usage. If we mix adding steinhart
462 * with the other sensors, we might have to do some roundup to make
463 * sure that sensor_addr - 0x250(start address) is a multiple of 4
464 * (for steinhart), and a multiple of 6 for all the other sensors.
465 * Since we have const 24 bytes for steinhart sensors and 24 is
466 * also a multiple of 6, we guarantee that the first non-steinhart
467 * sensor will sit in a correct address without the need of filling
468 * addresses.
469 */
470 if (is_steinhart) {
471 new_custom->offset = st->custom_table_size /
472 LTC2983_CUSTOM_STEINHART_ENTRY_SZ;
473 st->custom_table_size += new_custom->size;
474 } else {
475 /* mark as unset. This is checked later on the assign phase */
476 new_custom->offset = -1;
477 }
478
479 return new_custom;
480}
481
482static int ltc2983_thermocouple_fault_handler(const struct ltc2983_data *st,
483 const u32 result)
484{
485 return __ltc2983_fault_handler(st, result,
486 LTC2983_THERMOCOUPLE_HARD_FAULT_MASK,
487 LTC2983_THERMOCOUPLE_SOFT_FAULT_MASK);
488}
489
490static int ltc2983_common_fault_handler(const struct ltc2983_data *st,
491 const u32 result)
492{
493 return __ltc2983_fault_handler(st, result,
494 LTC2983_COMMON_HARD_FAULT_MASK,
495 LTC2983_COMMON_SOFT_FAULT_MASK);
496}
497
498static int ltc2983_thermocouple_assign_chan(struct ltc2983_data *st,
499 const struct ltc2983_sensor *sensor)
500{
501 struct ltc2983_thermocouple *thermo = to_thermocouple(sensor);
502 u32 chan_val;
503
504 chan_val = LTC2983_CHAN_ASSIGN(thermo->cold_junction_chan);
505 chan_val |= LTC2983_THERMOCOUPLE_CFG(thermo->sensor_config);
506
507 if (thermo->custom) {
508 int ret;
509
510 ret = __ltc2983_chan_custom_sensor_assign(st, thermo->custom,
511 &chan_val);
512 if (ret)
513 return ret;
514 }
515 return __ltc2983_chan_assign_common(st, sensor, chan_val);
516}
517
518static int ltc2983_rtd_assign_chan(struct ltc2983_data *st,
519 const struct ltc2983_sensor *sensor)
520{
521 struct ltc2983_rtd *rtd = to_rtd(sensor);
522 u32 chan_val;
523
524 chan_val = LTC2983_CHAN_ASSIGN(rtd->r_sense_chan);
525 chan_val |= LTC2983_RTD_CFG(rtd->sensor_config);
526 chan_val |= LTC2983_RTD_EXC_CURRENT(rtd->excitation_current);
527 chan_val |= LTC2983_RTD_CURVE(rtd->rtd_curve);
528
529 if (rtd->custom) {
530 int ret;
531
532 ret = __ltc2983_chan_custom_sensor_assign(st, rtd->custom,
533 &chan_val);
534 if (ret)
535 return ret;
536 }
537 return __ltc2983_chan_assign_common(st, sensor, chan_val);
538}
539
540static int ltc2983_thermistor_assign_chan(struct ltc2983_data *st,
541 const struct ltc2983_sensor *sensor)
542{
543 struct ltc2983_thermistor *thermistor = to_thermistor(sensor);
544 u32 chan_val;
545
546 chan_val = LTC2983_CHAN_ASSIGN(thermistor->r_sense_chan);
547 chan_val |= LTC2983_THERMISTOR_CFG(thermistor->sensor_config);
548 chan_val |=
549 LTC2983_THERMISTOR_EXC_CURRENT(thermistor->excitation_current);
550
551 if (thermistor->custom) {
552 int ret;
553
554 ret = __ltc2983_chan_custom_sensor_assign(st,
555 thermistor->custom,
556 &chan_val);
557 if (ret)
558 return ret;
559 }
560 return __ltc2983_chan_assign_common(st, sensor, chan_val);
561}
562
563static int ltc2983_diode_assign_chan(struct ltc2983_data *st,
564 const struct ltc2983_sensor *sensor)
565{
566 struct ltc2983_diode *diode = to_diode(sensor);
567 u32 chan_val;
568
569 chan_val = LTC2983_DIODE_CFG(diode->sensor_config);
570 chan_val |= LTC2983_DIODE_EXC_CURRENT(diode->excitation_current);
571 chan_val |= LTC2983_DIODE_IDEAL_FACTOR(diode->ideal_factor_value);
572
573 return __ltc2983_chan_assign_common(st, sensor, chan_val);
574}
575
576static int ltc2983_r_sense_assign_chan(struct ltc2983_data *st,
577 const struct ltc2983_sensor *sensor)
578{
579 struct ltc2983_rsense *rsense = to_rsense(sensor);
580 u32 chan_val;
581
582 chan_val = LTC2983_R_SENSE_VAL(rsense->r_sense_val);
583
584 return __ltc2983_chan_assign_common(st, sensor, chan_val);
585}
586
587static int ltc2983_adc_assign_chan(struct ltc2983_data *st,
588 const struct ltc2983_sensor *sensor)
589{
590 struct ltc2983_adc *adc = to_adc(sensor);
591 u32 chan_val;
592
593 chan_val = LTC2983_ADC_SINGLE_ENDED(adc->single_ended);
594
595 return __ltc2983_chan_assign_common(st, sensor, chan_val);
596}
597
598static struct ltc2983_sensor *ltc2983_thermocouple_new(
599 const struct device_node *child,
600 struct ltc2983_data *st,
601 const struct ltc2983_sensor *sensor)
602{
603 struct ltc2983_thermocouple *thermo;
604 struct device_node *phandle;
605 u32 oc_current;
606 int ret;
607
608 thermo = devm_kzalloc(&st->spi->dev, sizeof(*thermo), GFP_KERNEL);
609 if (!thermo)
610 return ERR_PTR(-ENOMEM);
611
612 if (of_property_read_bool(child, "adi,single-ended"))
613 thermo->sensor_config = LTC2983_THERMOCOUPLE_SGL(1);
614
615 ret = of_property_read_u32(child, "adi,sensor-oc-current-microamp",
616 &oc_current);
617 if (!ret) {
618 switch (oc_current) {
619 case 10:
620 thermo->sensor_config |=
621 LTC2983_THERMOCOUPLE_OC_CURR(0);
622 break;
623 case 100:
624 thermo->sensor_config |=
625 LTC2983_THERMOCOUPLE_OC_CURR(1);
626 break;
627 case 500:
628 thermo->sensor_config |=
629 LTC2983_THERMOCOUPLE_OC_CURR(2);
630 break;
631 case 1000:
632 thermo->sensor_config |=
633 LTC2983_THERMOCOUPLE_OC_CURR(3);
634 break;
635 default:
636 dev_err(&st->spi->dev,
637 "Invalid open circuit current:%u", oc_current);
638 return ERR_PTR(-EINVAL);
639 }
640
641 thermo->sensor_config |= LTC2983_THERMOCOUPLE_OC_CHECK(1);
642 }
643 /* validate channel index */
644 if (!(thermo->sensor_config & LTC2983_THERMOCOUPLE_DIFF_MASK) &&
645 sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
646 dev_err(&st->spi->dev,
647 "Invalid chann:%d for differential thermocouple",
648 sensor->chan);
649 return ERR_PTR(-EINVAL);
650 }
651
652 phandle = of_parse_phandle(child, "adi,cold-junction-handle", 0);
653 if (phandle) {
654 int ret;
655
656 ret = of_property_read_u32(phandle, "reg",
657 &thermo->cold_junction_chan);
658 if (ret) {
659 /*
660 * This would be catched later but we can just return
661 * the error right away.
662 */
663 dev_err(&st->spi->dev, "Property reg must be given\n");
664 of_node_put(phandle);
665 return ERR_PTR(-EINVAL);
666 }
667 }
668
669 /* check custom sensor */
670 if (sensor->type == LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
671 const char *propname = "adi,custom-thermocouple";
672
673 thermo->custom = __ltc2983_custom_sensor_new(st, child,
674 propname, false,
675 16384, true);
676 if (IS_ERR(thermo->custom)) {
677 of_node_put(phandle);
678 return ERR_CAST(thermo->custom);
679 }
680 }
681
682 /* set common parameters */
683 thermo->sensor.fault_handler = ltc2983_thermocouple_fault_handler;
684 thermo->sensor.assign_chan = ltc2983_thermocouple_assign_chan;
685
686 of_node_put(phandle);
687 return &thermo->sensor;
688}
689
690static struct ltc2983_sensor *ltc2983_rtd_new(const struct device_node *child,
691 struct ltc2983_data *st,
692 const struct ltc2983_sensor *sensor)
693{
694 struct ltc2983_rtd *rtd;
695 int ret = 0;
696 struct device *dev = &st->spi->dev;
697 struct device_node *phandle;
698 u32 excitation_current = 0, n_wires = 0;
699
700 rtd = devm_kzalloc(dev, sizeof(*rtd), GFP_KERNEL);
701 if (!rtd)
702 return ERR_PTR(-ENOMEM);
703
704 phandle = of_parse_phandle(child, "adi,rsense-handle", 0);
705 if (!phandle) {
706 dev_err(dev, "Property adi,rsense-handle missing or invalid");
707 return ERR_PTR(-EINVAL);
708 }
709
710 ret = of_property_read_u32(phandle, "reg", &rtd->r_sense_chan);
711 if (ret) {
712 dev_err(dev, "Property reg must be given\n");
713 goto fail;
714 }
715
716 ret = of_property_read_u32(child, "adi,number-of-wires", &n_wires);
717 if (!ret) {
718 switch (n_wires) {
719 case 2:
720 rtd->sensor_config = LTC2983_RTD_N_WIRES(0);
721 break;
722 case 3:
723 rtd->sensor_config = LTC2983_RTD_N_WIRES(1);
724 break;
725 case 4:
726 rtd->sensor_config = LTC2983_RTD_N_WIRES(2);
727 break;
728 case 5:
729 /* 4 wires, Kelvin Rsense */
730 rtd->sensor_config = LTC2983_RTD_N_WIRES(3);
731 break;
732 default:
733 dev_err(dev, "Invalid number of wires:%u\n", n_wires);
734 ret = -EINVAL;
735 goto fail;
736 }
737 }
738
739 if (of_property_read_bool(child, "adi,rsense-share")) {
740 /* Current rotation is only available with rsense sharing */
741 if (of_property_read_bool(child, "adi,current-rotate")) {
742 if (n_wires == 2 || n_wires == 3) {
743 dev_err(dev,
744 "Rotation not allowed for 2/3 Wire RTDs");
745 ret = -EINVAL;
746 goto fail;
747 }
748 rtd->sensor_config |= LTC2983_RTD_C_ROTATE(1);
749 } else {
750 rtd->sensor_config |= LTC2983_RTD_R_SHARE(1);
751 }
752 }
753 /*
754 * rtd channel indexes are a bit more complicated to validate.
755 * For 4wire RTD with rotation, the channel selection cannot be
756 * >=19 since the chann + 1 is used in this configuration.
757 * For 4wire RTDs with kelvin rsense, the rsense channel cannot be
758 * <=1 since chanel - 1 and channel - 2 are used.
759 */
760 if (rtd->sensor_config & LTC2983_RTD_4_WIRE_MASK) {
761 /* 4-wire */
762 u8 min = LTC2983_DIFFERENTIAL_CHAN_MIN,
763 max = LTC2983_MAX_CHANNELS_NR;
764
765 if (rtd->sensor_config & LTC2983_RTD_ROTATION_MASK)
766 max = LTC2983_MAX_CHANNELS_NR - 1;
767
768 if (((rtd->sensor_config & LTC2983_RTD_KELVIN_R_SENSE_MASK)
769 == LTC2983_RTD_KELVIN_R_SENSE_MASK) &&
770 (rtd->r_sense_chan <= min)) {
771 /* kelvin rsense*/
772 dev_err(dev,
773 "Invalid rsense chann:%d to use in kelvin rsense",
774 rtd->r_sense_chan);
775
776 ret = -EINVAL;
777 goto fail;
778 }
779
780 if (sensor->chan < min || sensor->chan > max) {
781 dev_err(dev, "Invalid chann:%d for the rtd config",
782 sensor->chan);
783
784 ret = -EINVAL;
785 goto fail;
786 }
787 } else {
788 /* same as differential case */
789 if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
790 dev_err(&st->spi->dev,
791 "Invalid chann:%d for RTD", sensor->chan);
792
793 ret = -EINVAL;
794 goto fail;
795 }
796 }
797
798 /* check custom sensor */
799 if (sensor->type == LTC2983_SENSOR_RTD_CUSTOM) {
800 rtd->custom = __ltc2983_custom_sensor_new(st, child,
801 "adi,custom-rtd",
802 false, 2048, false);
803 if (IS_ERR(rtd->custom)) {
804 of_node_put(phandle);
805 return ERR_CAST(rtd->custom);
806 }
807 }
808
809 /* set common parameters */
810 rtd->sensor.fault_handler = ltc2983_common_fault_handler;
811 rtd->sensor.assign_chan = ltc2983_rtd_assign_chan;
812
813 ret = of_property_read_u32(child, "adi,excitation-current-microamp",
814 &excitation_current);
815 if (ret) {
816 /* default to 5uA */
817 rtd->excitation_current = 1;
818 } else {
819 switch (excitation_current) {
820 case 5:
821 rtd->excitation_current = 0x01;
822 break;
823 case 10:
824 rtd->excitation_current = 0x02;
825 break;
826 case 25:
827 rtd->excitation_current = 0x03;
828 break;
829 case 50:
830 rtd->excitation_current = 0x04;
831 break;
832 case 100:
833 rtd->excitation_current = 0x05;
834 break;
835 case 250:
836 rtd->excitation_current = 0x06;
837 break;
838 case 500:
839 rtd->excitation_current = 0x07;
840 break;
841 case 1000:
842 rtd->excitation_current = 0x08;
843 break;
844 default:
845 dev_err(&st->spi->dev,
846 "Invalid value for excitation current(%u)",
847 excitation_current);
848 ret = -EINVAL;
849 goto fail;
850 }
851 }
852
853 of_property_read_u32(child, "adi,rtd-curve", &rtd->rtd_curve);
854
855 of_node_put(phandle);
856 return &rtd->sensor;
857fail:
858 of_node_put(phandle);
859 return ERR_PTR(ret);
860}
861
862static struct ltc2983_sensor *ltc2983_thermistor_new(
863 const struct device_node *child,
864 struct ltc2983_data *st,
865 const struct ltc2983_sensor *sensor)
866{
867 struct ltc2983_thermistor *thermistor;
868 struct device *dev = &st->spi->dev;
869 struct device_node *phandle;
870 u32 excitation_current = 0;
871 int ret = 0;
872
873 thermistor = devm_kzalloc(dev, sizeof(*thermistor), GFP_KERNEL);
874 if (!thermistor)
875 return ERR_PTR(-ENOMEM);
876
877 phandle = of_parse_phandle(child, "adi,rsense-handle", 0);
878 if (!phandle) {
879 dev_err(dev, "Property adi,rsense-handle missing or invalid");
880 return ERR_PTR(-EINVAL);
881 }
882
883 ret = of_property_read_u32(phandle, "reg", &thermistor->r_sense_chan);
884 if (ret) {
885 dev_err(dev, "rsense channel must be configured...\n");
886 goto fail;
887 }
888
889 if (of_property_read_bool(child, "adi,single-ended")) {
890 thermistor->sensor_config = LTC2983_THERMISTOR_SGL(1);
891 } else if (of_property_read_bool(child, "adi,rsense-share")) {
892 /* rotation is only possible if sharing rsense */
893 if (of_property_read_bool(child, "adi,current-rotate"))
894 thermistor->sensor_config =
895 LTC2983_THERMISTOR_C_ROTATE(1);
896 else
897 thermistor->sensor_config =
898 LTC2983_THERMISTOR_R_SHARE(1);
899 }
900 /* validate channel index */
901 if (!(thermistor->sensor_config & LTC2983_THERMISTOR_DIFF_MASK) &&
902 sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
903 dev_err(&st->spi->dev,
904 "Invalid chann:%d for differential thermistor",
905 sensor->chan);
906 ret = -EINVAL;
907 goto fail;
908 }
909
910 /* check custom sensor */
911 if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART) {
912 bool steinhart = false;
913 const char *propname;
914
915 if (sensor->type == LTC2983_SENSOR_THERMISTOR_STEINHART) {
916 steinhart = true;
917 propname = "adi,custom-steinhart";
918 } else {
919 propname = "adi,custom-thermistor";
920 }
921
922 thermistor->custom = __ltc2983_custom_sensor_new(st, child,
923 propname,
924 steinhart,
925 64, false);
926 if (IS_ERR(thermistor->custom)) {
927 of_node_put(phandle);
928 return ERR_CAST(thermistor->custom);
929 }
930 }
931 /* set common parameters */
932 thermistor->sensor.fault_handler = ltc2983_common_fault_handler;
933 thermistor->sensor.assign_chan = ltc2983_thermistor_assign_chan;
934
935 ret = of_property_read_u32(child, "adi,excitation-current-nanoamp",
936 &excitation_current);
937 if (ret) {
938 /* Auto range is not allowed for custom sensors */
939 if (sensor->type >= LTC2983_SENSOR_THERMISTOR_STEINHART)
940 /* default to 1uA */
941 thermistor->excitation_current = 0x03;
942 else
943 /* default to auto-range */
944 thermistor->excitation_current = 0x0c;
945 } else {
946 switch (excitation_current) {
947 case 0:
948 /* auto range */
949 if (sensor->type >=
950 LTC2983_SENSOR_THERMISTOR_STEINHART) {
951 dev_err(&st->spi->dev,
952 "Auto Range not allowed for custom sensors\n");
953 ret = -EINVAL;
954 goto fail;
955 }
956 thermistor->excitation_current = 0x0c;
957 break;
958 case 250:
959 thermistor->excitation_current = 0x01;
960 break;
961 case 500:
962 thermistor->excitation_current = 0x02;
963 break;
964 case 1000:
965 thermistor->excitation_current = 0x03;
966 break;
967 case 5000:
968 thermistor->excitation_current = 0x04;
969 break;
970 case 10000:
971 thermistor->excitation_current = 0x05;
972 break;
973 case 25000:
974 thermistor->excitation_current = 0x06;
975 break;
976 case 50000:
977 thermistor->excitation_current = 0x07;
978 break;
979 case 100000:
980 thermistor->excitation_current = 0x08;
981 break;
982 case 250000:
983 thermistor->excitation_current = 0x09;
984 break;
985 case 500000:
986 thermistor->excitation_current = 0x0a;
987 break;
988 case 1000000:
989 thermistor->excitation_current = 0x0b;
990 break;
991 default:
992 dev_err(&st->spi->dev,
993 "Invalid value for excitation current(%u)",
994 excitation_current);
995 ret = -EINVAL;
996 goto fail;
997 }
998 }
999
1000 of_node_put(phandle);
1001 return &thermistor->sensor;
1002fail:
1003 of_node_put(phandle);
1004 return ERR_PTR(ret);
1005}
1006
1007static struct ltc2983_sensor *ltc2983_diode_new(
1008 const struct device_node *child,
1009 const struct ltc2983_data *st,
1010 const struct ltc2983_sensor *sensor)
1011{
1012 struct ltc2983_diode *diode;
1013 u32 temp = 0, excitation_current = 0;
1014 int ret;
1015
1016 diode = devm_kzalloc(&st->spi->dev, sizeof(*diode), GFP_KERNEL);
1017 if (!diode)
1018 return ERR_PTR(-ENOMEM);
1019
1020 if (of_property_read_bool(child, "adi,single-ended"))
1021 diode->sensor_config = LTC2983_DIODE_SGL(1);
1022
1023 if (of_property_read_bool(child, "adi,three-conversion-cycles"))
1024 diode->sensor_config |= LTC2983_DIODE_3_CONV_CYCLE(1);
1025
1026 if (of_property_read_bool(child, "adi,average-on"))
1027 diode->sensor_config |= LTC2983_DIODE_AVERAGE_ON(1);
1028
1029 /* validate channel index */
1030 if (!(diode->sensor_config & LTC2983_DIODE_DIFF_MASK) &&
1031 sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
1032 dev_err(&st->spi->dev,
1033 "Invalid chann:%d for differential thermistor",
1034 sensor->chan);
1035 return ERR_PTR(-EINVAL);
1036 }
1037 /* set common parameters */
1038 diode->sensor.fault_handler = ltc2983_common_fault_handler;
1039 diode->sensor.assign_chan = ltc2983_diode_assign_chan;
1040
1041 ret = of_property_read_u32(child, "adi,excitation-current-microamp",
1042 &excitation_current);
1043 if (!ret) {
1044 switch (excitation_current) {
1045 case 10:
1046 diode->excitation_current = 0x00;
1047 break;
1048 case 20:
1049 diode->excitation_current = 0x01;
1050 break;
1051 case 40:
1052 diode->excitation_current = 0x02;
1053 break;
1054 case 80:
1055 diode->excitation_current = 0x03;
1056 break;
1057 default:
1058 dev_err(&st->spi->dev,
1059 "Invalid value for excitation current(%u)",
1060 excitation_current);
1061 return ERR_PTR(-EINVAL);
1062 }
1063 }
1064
1065 of_property_read_u32(child, "adi,ideal-factor-value", &temp);
1066
1067 /* 2^20 resolution */
1068 diode->ideal_factor_value = __convert_to_raw(temp, 1048576);
1069
1070 return &diode->sensor;
1071}
1072
1073static struct ltc2983_sensor *ltc2983_r_sense_new(struct device_node *child,
1074 struct ltc2983_data *st,
1075 const struct ltc2983_sensor *sensor)
1076{
1077 struct ltc2983_rsense *rsense;
1078 int ret;
1079 u32 temp;
1080
1081 rsense = devm_kzalloc(&st->spi->dev, sizeof(*rsense), GFP_KERNEL);
1082 if (!rsense)
1083 return ERR_PTR(-ENOMEM);
1084
1085 /* validate channel index */
1086 if (sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
1087 dev_err(&st->spi->dev, "Invalid chann:%d for r_sense",
1088 sensor->chan);
1089 return ERR_PTR(-EINVAL);
1090 }
1091
1092 ret = of_property_read_u32(child, "adi,rsense-val-milli-ohms", &temp);
1093 if (ret) {
1094 dev_err(&st->spi->dev, "Property adi,rsense-val-milli-ohms missing\n");
1095 return ERR_PTR(-EINVAL);
1096 }
1097 /*
1098 * Times 1000 because we have milli-ohms and __convert_to_raw
1099 * expects scales of 1000000 which are used for all other
1100 * properties.
1101 * 2^10 resolution
1102 */
1103 rsense->r_sense_val = __convert_to_raw((u64)temp * 1000, 1024);
1104
1105 /* set common parameters */
1106 rsense->sensor.assign_chan = ltc2983_r_sense_assign_chan;
1107
1108 return &rsense->sensor;
1109}
1110
1111static struct ltc2983_sensor *ltc2983_adc_new(struct device_node *child,
1112 struct ltc2983_data *st,
1113 const struct ltc2983_sensor *sensor)
1114{
1115 struct ltc2983_adc *adc;
1116
1117 adc = devm_kzalloc(&st->spi->dev, sizeof(*adc), GFP_KERNEL);
1118 if (!adc)
1119 return ERR_PTR(-ENOMEM);
1120
1121 if (of_property_read_bool(child, "adi,single-ended"))
1122 adc->single_ended = true;
1123
1124 if (!adc->single_ended &&
1125 sensor->chan < LTC2983_DIFFERENTIAL_CHAN_MIN) {
1126 dev_err(&st->spi->dev, "Invalid chan:%d for differential adc\n",
1127 sensor->chan);
1128 return ERR_PTR(-EINVAL);
1129 }
1130 /* set common parameters */
1131 adc->sensor.assign_chan = ltc2983_adc_assign_chan;
1132 adc->sensor.fault_handler = ltc2983_common_fault_handler;
1133
1134 return &adc->sensor;
1135}
1136
1137static int ltc2983_chan_read(struct ltc2983_data *st,
1138 const struct ltc2983_sensor *sensor, int *val)
1139{
1140 u32 start_conversion = 0;
1141 int ret;
1142 unsigned long time;
1143
1144 start_conversion = LTC2983_STATUS_START(true);
1145 start_conversion |= LTC2983_STATUS_CHAN_SEL(sensor->chan);
1146 dev_dbg(&st->spi->dev, "Start conversion on chan:%d, status:%02X\n",
1147 sensor->chan, start_conversion);
1148 /* start conversion */
1149 ret = regmap_write(st->regmap, LTC2983_STATUS_REG, start_conversion);
1150 if (ret)
1151 return ret;
1152
1153 reinit_completion(&st->completion);
1154 /*
1155 * wait for conversion to complete.
1156 * 300 ms should be more than enough to complete the conversion.
1157 * Depending on the sensor configuration, there are 2/3 conversions
1158 * cycles of 82ms.
1159 */
1160 time = wait_for_completion_timeout(&st->completion,
1161 msecs_to_jiffies(300));
1162 if (!time) {
1163 dev_warn(&st->spi->dev, "Conversion timed out\n");
1164 return -ETIMEDOUT;
1165 }
1166
1167 /* read the converted data */
1168 ret = regmap_bulk_read(st->regmap, LTC2983_CHAN_RES_ADDR(sensor->chan),
1169 &st->temp, sizeof(st->temp));
1170 if (ret)
1171 return ret;
1172
1173 *val = __be32_to_cpu(st->temp);
1174
1175 if (!(LTC2983_RES_VALID_MASK & *val)) {
1176 dev_err(&st->spi->dev, "Invalid conversion detected\n");
1177 return -EIO;
1178 }
1179
1180 ret = sensor->fault_handler(st, *val);
1181 if (ret)
1182 return ret;
1183
1184 *val = sign_extend32((*val) & LTC2983_DATA_MASK, LTC2983_DATA_SIGN_BIT);
1185 return 0;
1186}
1187
1188static int ltc2983_read_raw(struct iio_dev *indio_dev,
1189 struct iio_chan_spec const *chan,
1190 int *val, int *val2, long mask)
1191{
1192 struct ltc2983_data *st = iio_priv(indio_dev);
1193 int ret;
1194
1195 /* sanity check */
1196 if (chan->address >= st->num_channels) {
1197 dev_err(&st->spi->dev, "Invalid chan address:%ld",
1198 chan->address);
1199 return -EINVAL;
1200 }
1201
1202 switch (mask) {
1203 case IIO_CHAN_INFO_RAW:
1204 mutex_lock(&st->lock);
1205 ret = ltc2983_chan_read(st, st->sensors[chan->address], val);
1206 mutex_unlock(&st->lock);
1207 return ret ?: IIO_VAL_INT;
1208 case IIO_CHAN_INFO_SCALE:
1209 switch (chan->type) {
1210 case IIO_TEMP:
1211 /* value in milli degrees */
1212 *val = 1000;
1213 /* 2^10 */
1214 *val2 = 1024;
1215 return IIO_VAL_FRACTIONAL;
1216 case IIO_VOLTAGE:
1217 /* value in millivolt */
1218 *val = 1000;
1219 /* 2^21 */
1220 *val2 = 2097152;
1221 return IIO_VAL_FRACTIONAL;
1222 default:
1223 return -EINVAL;
1224 }
1225 }
1226
1227 return -EINVAL;
1228}
1229
1230static int ltc2983_reg_access(struct iio_dev *indio_dev,
1231 unsigned int reg,
1232 unsigned int writeval,
1233 unsigned int *readval)
1234{
1235 struct ltc2983_data *st = iio_priv(indio_dev);
1236
1237 if (readval)
1238 return regmap_read(st->regmap, reg, readval);
1239 else
1240 return regmap_write(st->regmap, reg, writeval);
1241}
1242
1243static irqreturn_t ltc2983_irq_handler(int irq, void *data)
1244{
1245 struct ltc2983_data *st = data;
1246
1247 complete(&st->completion);
1248 return IRQ_HANDLED;
1249}
1250
1251#define LTC2983_CHAN(__type, index, __address) ({ \
1252 struct iio_chan_spec __chan = { \
1253 .type = __type, \
1254 .indexed = 1, \
1255 .channel = index, \
1256 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
1257 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
1258 .address = __address, \
1259 }; \
1260 __chan; \
1261})
1262
1263static int ltc2983_parse_dt(struct ltc2983_data *st)
1264{
1265 struct device_node *child;
1266 struct device *dev = &st->spi->dev;
1267 int ret = 0, chan = 0, channel_avail_mask = 0;
1268
1269 of_property_read_u32(dev->of_node, "adi,mux-delay-config-us",
1270 &st->mux_delay_config);
1271
1272 of_property_read_u32(dev->of_node, "adi,filter-notch-freq",
1273 &st->filter_notch_freq);
1274
1275 st->num_channels = of_get_available_child_count(dev->of_node);
1276 st->sensors = devm_kcalloc(dev, st->num_channels, sizeof(*st->sensors),
1277 GFP_KERNEL);
1278 if (!st->sensors)
1279 return -ENOMEM;
1280
1281 st->iio_channels = st->num_channels;
1282 for_each_available_child_of_node(dev->of_node, child) {
1283 struct ltc2983_sensor sensor;
1284
1285 ret = of_property_read_u32(child, "reg", &sensor.chan);
1286 if (ret) {
1287 dev_err(dev, "reg property must given for child nodes\n");
1288 return ret;
1289 }
1290
1291 /* check if we have a valid channel */
1292 if (sensor.chan < LTC2983_MIN_CHANNELS_NR ||
1293 sensor.chan > LTC2983_MAX_CHANNELS_NR) {
1294 dev_err(dev,
1295 "chan:%d must be from 1 to 20\n", sensor.chan);
1296 return -EINVAL;
1297 } else if (channel_avail_mask & BIT(sensor.chan)) {
1298 dev_err(dev, "chan:%d already in use\n", sensor.chan);
1299 return -EINVAL;
1300 }
1301
1302 ret = of_property_read_u32(child, "adi,sensor-type",
1303 &sensor.type);
1304 if (ret) {
1305 dev_err(dev,
1306 "adi,sensor-type property must given for child nodes\n");
1307 return ret;
1308 }
1309
1310 dev_dbg(dev, "Create new sensor, type %u, chann %u",
1311 sensor.type,
1312 sensor.chan);
1313
1314 if (sensor.type >= LTC2983_SENSOR_THERMOCOUPLE &&
1315 sensor.type <= LTC2983_SENSOR_THERMOCOUPLE_CUSTOM) {
1316 st->sensors[chan] = ltc2983_thermocouple_new(child, st,
1317 &sensor);
1318 } else if (sensor.type >= LTC2983_SENSOR_RTD &&
1319 sensor.type <= LTC2983_SENSOR_RTD_CUSTOM) {
1320 st->sensors[chan] = ltc2983_rtd_new(child, st, &sensor);
1321 } else if (sensor.type >= LTC2983_SENSOR_THERMISTOR &&
1322 sensor.type <= LTC2983_SENSOR_THERMISTOR_CUSTOM) {
1323 st->sensors[chan] = ltc2983_thermistor_new(child, st,
1324 &sensor);
1325 } else if (sensor.type == LTC2983_SENSOR_DIODE) {
1326 st->sensors[chan] = ltc2983_diode_new(child, st,
1327 &sensor);
1328 } else if (sensor.type == LTC2983_SENSOR_SENSE_RESISTOR) {
1329 st->sensors[chan] = ltc2983_r_sense_new(child, st,
1330 &sensor);
1331 /* don't add rsense to iio */
1332 st->iio_channels--;
1333 } else if (sensor.type == LTC2983_SENSOR_DIRECT_ADC) {
1334 st->sensors[chan] = ltc2983_adc_new(child, st, &sensor);
1335 } else {
1336 dev_err(dev, "Unknown sensor type %d\n", sensor.type);
1337 return -EINVAL;
1338 }
1339
1340 if (IS_ERR(st->sensors[chan])) {
1341 dev_err(dev, "Failed to create sensor %ld",
1342 PTR_ERR(st->sensors[chan]));
1343 return PTR_ERR(st->sensors[chan]);
1344 }
1345 /* set generic sensor parameters */
1346 st->sensors[chan]->chan = sensor.chan;
1347 st->sensors[chan]->type = sensor.type;
1348
1349 channel_avail_mask |= BIT(sensor.chan);
1350 chan++;
1351 }
1352
1353 return 0;
1354}
1355
1356static int ltc2983_setup(struct ltc2983_data *st, bool assign_iio)
1357{
1358 u32 iio_chan_t = 0, iio_chan_v = 0, chan, iio_idx = 0;
1359 int ret;
1360 unsigned long time;
1361
1362 /* make sure the device is up */
1363 time = wait_for_completion_timeout(&st->completion,
1364 msecs_to_jiffies(250));
1365
1366 if (!time) {
1367 dev_err(&st->spi->dev, "Device startup timed out\n");
1368 return -ETIMEDOUT;
1369 }
1370
1371 st->iio_chan = devm_kzalloc(&st->spi->dev,
1372 st->iio_channels * sizeof(*st->iio_chan),
1373 GFP_KERNEL);
1374
1375 if (!st->iio_chan)
1376 return -ENOMEM;
1377
1378 ret = regmap_update_bits(st->regmap, LTC2983_GLOBAL_CONFIG_REG,
1379 LTC2983_NOTCH_FREQ_MASK,
1380 LTC2983_NOTCH_FREQ(st->filter_notch_freq));
1381 if (ret)
1382 return ret;
1383
1384 ret = regmap_write(st->regmap, LTC2983_MUX_CONFIG_REG,
1385 st->mux_delay_config);
1386 if (ret)
1387 return ret;
1388
1389 for (chan = 0; chan < st->num_channels; chan++) {
1390 u32 chan_type = 0, *iio_chan;
1391
1392 ret = st->sensors[chan]->assign_chan(st, st->sensors[chan]);
1393 if (ret)
1394 return ret;
1395 /*
1396 * The assign_iio flag is necessary for when the device is
1397 * coming out of sleep. In that case, we just need to
1398 * re-configure the device channels.
1399 * We also don't assign iio channels for rsense.
1400 */
1401 if (st->sensors[chan]->type == LTC2983_SENSOR_SENSE_RESISTOR ||
1402 !assign_iio)
1403 continue;
1404
1405 /* assign iio channel */
1406 if (st->sensors[chan]->type != LTC2983_SENSOR_DIRECT_ADC) {
1407 chan_type = IIO_TEMP;
1408 iio_chan = &iio_chan_t;
1409 } else {
1410 chan_type = IIO_VOLTAGE;
1411 iio_chan = &iio_chan_v;
1412 }
1413
1414 /*
1415 * add chan as the iio .address so that, we can directly
1416 * reference the sensor given the iio_chan_spec
1417 */
1418 st->iio_chan[iio_idx++] = LTC2983_CHAN(chan_type, (*iio_chan)++,
1419 chan);
1420 }
1421
1422 return 0;
1423}
1424
1425static const struct regmap_range ltc2983_reg_ranges[] = {
1426 regmap_reg_range(LTC2983_STATUS_REG, LTC2983_STATUS_REG),
1427 regmap_reg_range(LTC2983_TEMP_RES_START_REG, LTC2983_TEMP_RES_END_REG),
1428 regmap_reg_range(LTC2983_GLOBAL_CONFIG_REG, LTC2983_GLOBAL_CONFIG_REG),
1429 regmap_reg_range(LTC2983_MULT_CHANNEL_START_REG,
1430 LTC2983_MULT_CHANNEL_END_REG),
1431 regmap_reg_range(LTC2983_MUX_CONFIG_REG, LTC2983_MUX_CONFIG_REG),
1432 regmap_reg_range(LTC2983_CHAN_ASSIGN_START_REG,
1433 LTC2983_CHAN_ASSIGN_END_REG),
1434 regmap_reg_range(LTC2983_CUST_SENS_TBL_START_REG,
1435 LTC2983_CUST_SENS_TBL_END_REG),
1436};
1437
1438static const struct regmap_access_table ltc2983_reg_table = {
1439 .yes_ranges = ltc2983_reg_ranges,
1440 .n_yes_ranges = ARRAY_SIZE(ltc2983_reg_ranges),
1441};
1442
1443/*
1444 * The reg_bits are actually 12 but the device needs the first *complete*
1445 * byte for the command (R/W).
1446 */
1447static const struct regmap_config ltc2983_regmap_config = {
1448 .reg_bits = 24,
1449 .val_bits = 8,
1450 .wr_table = &ltc2983_reg_table,
1451 .rd_table = &ltc2983_reg_table,
1452 .read_flag_mask = GENMASK(1, 0),
1453 .write_flag_mask = BIT(1),
1454};
1455
1456static const struct iio_info ltc2983_iio_info = {
1457 .read_raw = ltc2983_read_raw,
1458 .debugfs_reg_access = ltc2983_reg_access,
1459};
1460
1461static int ltc2983_probe(struct spi_device *spi)
1462{
1463 struct ltc2983_data *st;
1464 struct iio_dev *indio_dev;
1465 const char *name = spi_get_device_id(spi)->name;
1466 int ret;
1467
1468 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
1469 if (!indio_dev)
1470 return -ENOMEM;
1471
1472 st = iio_priv(indio_dev);
1473
1474 st->regmap = devm_regmap_init_spi(spi, &ltc2983_regmap_config);
1475 if (IS_ERR(st->regmap)) {
1476 dev_err(&spi->dev, "Failed to initialize regmap\n");
1477 return PTR_ERR(st->regmap);
1478 }
1479
1480 mutex_init(&st->lock);
1481 init_completion(&st->completion);
1482 st->spi = spi;
1483 spi_set_drvdata(spi, st);
1484
1485 ret = ltc2983_parse_dt(st);
1486 if (ret)
1487 return ret;
1488 /*
1489 * let's request the irq now so it is used to sync the device
1490 * startup in ltc2983_setup()
1491 */
1492 ret = devm_request_irq(&spi->dev, spi->irq, ltc2983_irq_handler,
1493 IRQF_TRIGGER_RISING, name, st);
1494 if (ret) {
1495 dev_err(&spi->dev, "failed to request an irq, %d", ret);
1496 return ret;
1497 }
1498
1499 ret = ltc2983_setup(st, true);
1500 if (ret)
1501 return ret;
1502
1503 indio_dev->dev.parent = &spi->dev;
1504 indio_dev->name = name;
1505 indio_dev->num_channels = st->iio_channels;
1506 indio_dev->channels = st->iio_chan;
1507 indio_dev->modes = INDIO_DIRECT_MODE;
1508 indio_dev->info = &ltc2983_iio_info;
1509
1510 return devm_iio_device_register(&spi->dev, indio_dev);
1511}
1512
1513static int __maybe_unused ltc2983_resume(struct device *dev)
1514{
1515 struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev));
1516 int dummy;
1517
1518 /* dummy read to bring the device out of sleep */
1519 regmap_read(st->regmap, LTC2983_STATUS_REG, &dummy);
1520 /* we need to re-assign the channels */
1521 return ltc2983_setup(st, false);
1522}
1523
1524static int __maybe_unused ltc2983_suspend(struct device *dev)
1525{
1526 struct ltc2983_data *st = spi_get_drvdata(to_spi_device(dev));
1527
1528 return regmap_write(st->regmap, LTC2983_STATUS_REG, LTC2983_SLEEP);
1529}
1530
1531static SIMPLE_DEV_PM_OPS(ltc2983_pm_ops, ltc2983_suspend, ltc2983_resume);
1532
1533static const struct spi_device_id ltc2983_id_table[] = {
1534 { "ltc2983" },
1535 {},
1536};
1537MODULE_DEVICE_TABLE(spi, ltc2983_id_table);
1538
1539static const struct of_device_id ltc2983_of_match[] = {
1540 { .compatible = "adi,ltc2983" },
1541 {},
1542};
1543MODULE_DEVICE_TABLE(of, ltc2983_of_match);
1544
1545static struct spi_driver ltc2983_driver = {
1546 .driver = {
1547 .name = "ltc2983",
1548 .of_match_table = ltc2983_of_match,
1549 .pm = &ltc2983_pm_ops,
1550 },
1551 .probe = ltc2983_probe,
1552 .id_table = ltc2983_id_table,
1553};
1554
1555module_spi_driver(ltc2983_driver);
1556
1557MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
1558MODULE_DESCRIPTION("Analog Devices LTC2983 SPI Temperature sensors");
1559MODULE_LICENSE("GPL");
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