1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * MAX11410 SPI ADC driver
4 *
5 * Copyright 2022 Analog Devices Inc.
6 */
7 #include <linux/bitfield.h>
8 #include <linux/delay.h>
9 #include <linux/device.h>
10 #include <linux/err.h>
11 #include <linux/interrupt.h>
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/regmap.h>
15 #include <linux/regulator/consumer.h>
16 #include <linux/spi/spi.h>
17
18 #include <linux/unaligned.h>
19
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/trigger.h>
23 #include <linux/iio/trigger_consumer.h>
24 #include <linux/iio/triggered_buffer.h>
25
26 #define MAX11410_REG_CONV_START 0x01
27 #define MAX11410_CONV_TYPE_SINGLE 0x00
28 #define MAX11410_CONV_TYPE_CONTINUOUS 0x01
29 #define MAX11410_REG_CAL_START 0x03
30 #define MAX11410_CAL_START_SELF 0x00
31 #define MAX11410_CAL_START_PGA 0x01
32 #define MAX11410_REG_GPIO_CTRL(ch) ((ch) ? 0x05 : 0x04)
33 #define MAX11410_GPIO_INTRB 0xC1
34 #define MAX11410_REG_FILTER 0x08
35 #define MAX11410_FILTER_RATE_MASK GENMASK(3, 0)
36 #define MAX11410_FILTER_RATE_MAX 0x0F
37 #define MAX11410_FILTER_LINEF_MASK GENMASK(5, 4)
38 #define MAX11410_FILTER_50HZ BIT(5)
39 #define MAX11410_FILTER_60HZ BIT(4)
40 #define MAX11410_REG_CTRL 0x09
41 #define MAX11410_CTRL_REFSEL_MASK GENMASK(2, 0)
42 #define MAX11410_CTRL_VREFN_BUF_BIT BIT(3)
43 #define MAX11410_CTRL_VREFP_BUF_BIT BIT(4)
44 #define MAX11410_CTRL_FORMAT_BIT BIT(5)
45 #define MAX11410_CTRL_UNIPOLAR_BIT BIT(6)
46 #define MAX11410_REG_MUX_CTRL0 0x0B
47 #define MAX11410_REG_PGA 0x0E
48 #define MAX11410_PGA_GAIN_MASK GENMASK(2, 0)
49 #define MAX11410_PGA_SIG_PATH_MASK GENMASK(5, 4)
50 #define MAX11410_PGA_SIG_PATH_BUFFERED 0x00
51 #define MAX11410_PGA_SIG_PATH_BYPASS 0x01
52 #define MAX11410_PGA_SIG_PATH_PGA 0x02
53 #define MAX11410_REG_DATA0 0x30
54 #define MAX11410_REG_STATUS 0x38
55 #define MAX11410_STATUS_CONV_READY_BIT BIT(0)
56 #define MAX11410_STATUS_CAL_READY_BIT BIT(2)
57
58 #define MAX11410_REFSEL_AVDD_AGND 0x03
59 #define MAX11410_REFSEL_MAX 0x06
60 #define MAX11410_SIG_PATH_MAX 0x02
61 #define MAX11410_CHANNEL_INDEX_MAX 0x0A
62 #define MAX11410_AINP_AVDD 0x0A
63 #define MAX11410_AINN_GND 0x0A
64
65 #define MAX11410_CONVERSION_TIMEOUT_MS 2000
66 #define MAX11410_CALIB_TIMEOUT_MS 2000
67
68 #define MAX11410_SCALE_AVAIL_SIZE 8
69
70 enum max11410_filter {
71 MAX11410_FILTER_FIR5060,
72 MAX11410_FILTER_FIR50,
73 MAX11410_FILTER_FIR60,
74 MAX11410_FILTER_SINC4,
75 };
76
77 static const u8 max11410_sampling_len[] = {
78 [MAX11410_FILTER_FIR5060] = 5,
79 [MAX11410_FILTER_FIR50] = 6,
80 [MAX11410_FILTER_FIR60] = 6,
81 [MAX11410_FILTER_SINC4] = 10,
82 };
83
84 static const int max11410_sampling_rates[4][10][2] = {
85 [MAX11410_FILTER_FIR5060] = {
86 { 1, 100000 },
87 { 2, 100000 },
88 { 4, 200000 },
89 { 8, 400000 },
90 { 16, 800000 }
91 },
92 [MAX11410_FILTER_FIR50] = {
93 { 1, 300000 },
94 { 2, 700000 },
95 { 5, 300000 },
96 { 10, 700000 },
97 { 21, 300000 },
98 { 40 }
99 },
100 [MAX11410_FILTER_FIR60] = {
101 { 1, 300000 },
102 { 2, 700000 },
103 { 5, 300000 },
104 { 10, 700000 },
105 { 21, 300000 },
106 { 40 }
107 },
108 [MAX11410_FILTER_SINC4] = {
109 { 4 },
110 { 10 },
111 { 20 },
112 { 40 },
113 { 60 },
114 { 120 },
115 { 240 },
116 { 480 },
117 { 960 },
118 { 1920 }
119 }
120 };
121
122 struct max11410_channel_config {
123 u32 settling_time_us;
124 u32 *scale_avail;
125 u8 refsel;
126 u8 sig_path;
127 u8 gain;
128 bool bipolar;
129 bool buffered_vrefp;
130 bool buffered_vrefn;
131 };
132
133 struct max11410_state {
134 struct spi_device *spi_dev;
135 struct iio_trigger *trig;
136 struct completion completion;
137 struct mutex lock; /* Prevent changing channel config during sampling */
138 struct regmap *regmap;
139 struct regulator *avdd;
140 struct regulator *vrefp[3];
141 struct regulator *vrefn[3];
142 struct max11410_channel_config *channels;
143 int irq;
144 struct {
145 u32 data __aligned(IIO_DMA_MINALIGN);
146 s64 ts __aligned(8);
147 } scan;
148 };
149
150 static const struct iio_chan_spec chanspec_template = {
151 .type = IIO_VOLTAGE,
152 .indexed = 1,
153 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
154 BIT(IIO_CHAN_INFO_SCALE) |
155 BIT(IIO_CHAN_INFO_OFFSET),
156 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
157 .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
158 .scan_type = {
159 .sign = 's',
160 .realbits = 24,
161 .storagebits = 32,
162 .endianness = IIO_LE,
163 },
164 };
165
max11410_reg_size(unsigned int reg)166 static unsigned int max11410_reg_size(unsigned int reg)
167 {
168 /* Registers from 0x00 to 0x10 are 1 byte, the rest are 3 bytes long. */
169 return reg <= 0x10 ? 1 : 3;
170 }
171
max11410_write_reg(struct max11410_state * st,unsigned int reg,unsigned int val)172 static int max11410_write_reg(struct max11410_state *st, unsigned int reg,
173 unsigned int val)
174 {
175 /* This driver only needs to write 8-bit registers */
176 if (max11410_reg_size(reg) != 1)
177 return -EINVAL;
178
179 return regmap_write(st->regmap, reg, val);
180 }
181
max11410_read_reg(struct max11410_state * st,unsigned int reg,int * val)182 static int max11410_read_reg(struct max11410_state *st, unsigned int reg,
183 int *val)
184 {
185 int ret;
186
187 if (max11410_reg_size(reg) == 3) {
188 ret = regmap_bulk_read(st->regmap, reg, &st->scan.data, 3);
189 if (ret)
190 return ret;
191
192 *val = get_unaligned_be24(&st->scan.data);
193 return 0;
194 }
195
196 return regmap_read(st->regmap, reg, val);
197 }
198
max11410_get_vrefp(struct max11410_state * st,u8 refsel)199 static struct regulator *max11410_get_vrefp(struct max11410_state *st,
200 u8 refsel)
201 {
202 refsel = refsel % 4;
203 if (refsel == 3)
204 return st->avdd;
205
206 return st->vrefp[refsel];
207 }
208
max11410_get_vrefn(struct max11410_state * st,u8 refsel)209 static struct regulator *max11410_get_vrefn(struct max11410_state *st,
210 u8 refsel)
211 {
212 if (refsel > 2)
213 return NULL;
214
215 return st->vrefn[refsel];
216 }
217
218 static const struct regmap_config regmap_config = {
219 .reg_bits = 8,
220 .val_bits = 8,
221 .max_register = 0x39,
222 };
223
max11410_notch_en_show(struct device * dev,struct device_attribute * devattr,char * buf)224 static ssize_t max11410_notch_en_show(struct device *dev,
225 struct device_attribute *devattr,
226 char *buf)
227 {
228 struct iio_dev *indio_dev = dev_get_drvdata(dev);
229 struct max11410_state *state = iio_priv(indio_dev);
230 struct iio_dev_attr *iio_attr = to_iio_dev_attr(devattr);
231 unsigned int val;
232 int ret;
233
234 ret = max11410_read_reg(state, MAX11410_REG_FILTER, &val);
235 if (ret)
236 return ret;
237
238 switch (iio_attr->address) {
239 case 0:
240 val = !FIELD_GET(MAX11410_FILTER_50HZ, val);
241 break;
242 case 1:
243 val = !FIELD_GET(MAX11410_FILTER_60HZ, val);
244 break;
245 case 2:
246 val = FIELD_GET(MAX11410_FILTER_LINEF_MASK, val) == 3;
247 break;
248 default:
249 return -EINVAL;
250 }
251
252 return sysfs_emit(buf, "%d\n", val);
253 }
254
max11410_notch_en_store(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)255 static ssize_t max11410_notch_en_store(struct device *dev,
256 struct device_attribute *devattr,
257 const char *buf, size_t count)
258 {
259 struct iio_dev_attr *iio_attr = to_iio_dev_attr(devattr);
260 struct iio_dev *indio_dev = dev_get_drvdata(dev);
261 struct max11410_state *state = iio_priv(indio_dev);
262 unsigned int filter_bits;
263 bool enable;
264 int ret;
265
266 ret = kstrtobool(buf, &enable);
267 if (ret)
268 return ret;
269
270 switch (iio_attr->address) {
271 case 0:
272 filter_bits = MAX11410_FILTER_50HZ;
273 break;
274 case 1:
275 filter_bits = MAX11410_FILTER_60HZ;
276 break;
277 case 2:
278 default:
279 filter_bits = MAX11410_FILTER_50HZ | MAX11410_FILTER_60HZ;
280 enable = !enable;
281 break;
282 }
283
284 if (enable)
285 ret = regmap_clear_bits(state->regmap, MAX11410_REG_FILTER,
286 filter_bits);
287 else
288 ret = regmap_set_bits(state->regmap, MAX11410_REG_FILTER,
289 filter_bits);
290
291 if (ret)
292 return ret;
293
294 return count;
295 }
296
in_voltage_filter2_notch_center_show(struct device * dev,struct device_attribute * devattr,char * buf)297 static ssize_t in_voltage_filter2_notch_center_show(struct device *dev,
298 struct device_attribute *devattr,
299 char *buf)
300 {
301 struct iio_dev *indio_dev = dev_get_drvdata(dev);
302 struct max11410_state *state = iio_priv(indio_dev);
303 int ret, reg, rate, filter;
304
305 ret = regmap_read(state->regmap, MAX11410_REG_FILTER, ®);
306 if (ret)
307 return ret;
308
309 rate = FIELD_GET(MAX11410_FILTER_RATE_MASK, reg);
310 rate = clamp_val(rate, 0,
311 max11410_sampling_len[MAX11410_FILTER_SINC4] - 1);
312 filter = max11410_sampling_rates[MAX11410_FILTER_SINC4][rate][0];
313
314 return sysfs_emit(buf, "%d\n", filter);
315 }
316
317 static IIO_CONST_ATTR(in_voltage_filter0_notch_center, "50");
318 static IIO_CONST_ATTR(in_voltage_filter1_notch_center, "60");
319 static IIO_DEVICE_ATTR_RO(in_voltage_filter2_notch_center, 2);
320
321 static IIO_DEVICE_ATTR(in_voltage_filter0_notch_en, 0644,
322 max11410_notch_en_show, max11410_notch_en_store, 0);
323 static IIO_DEVICE_ATTR(in_voltage_filter1_notch_en, 0644,
324 max11410_notch_en_show, max11410_notch_en_store, 1);
325 static IIO_DEVICE_ATTR(in_voltage_filter2_notch_en, 0644,
326 max11410_notch_en_show, max11410_notch_en_store, 2);
327
328 static struct attribute *max11410_attributes[] = {
329 &iio_const_attr_in_voltage_filter0_notch_center.dev_attr.attr,
330 &iio_const_attr_in_voltage_filter1_notch_center.dev_attr.attr,
331 &iio_dev_attr_in_voltage_filter2_notch_center.dev_attr.attr,
332 &iio_dev_attr_in_voltage_filter0_notch_en.dev_attr.attr,
333 &iio_dev_attr_in_voltage_filter1_notch_en.dev_attr.attr,
334 &iio_dev_attr_in_voltage_filter2_notch_en.dev_attr.attr,
335 NULL
336 };
337
338 static const struct attribute_group max11410_attribute_group = {
339 .attrs = max11410_attributes,
340 };
341
max11410_set_input_mux(struct max11410_state * st,u8 ainp,u8 ainn)342 static int max11410_set_input_mux(struct max11410_state *st, u8 ainp, u8 ainn)
343 {
344 if (ainp > MAX11410_CHANNEL_INDEX_MAX ||
345 ainn > MAX11410_CHANNEL_INDEX_MAX)
346 return -EINVAL;
347
348 return max11410_write_reg(st, MAX11410_REG_MUX_CTRL0,
349 (ainp << 4) | ainn);
350 }
351
max11410_configure_channel(struct max11410_state * st,struct iio_chan_spec const * chan)352 static int max11410_configure_channel(struct max11410_state *st,
353 struct iio_chan_spec const *chan)
354 {
355 struct max11410_channel_config cfg = st->channels[chan->address];
356 unsigned int regval;
357 int ret;
358
359 if (chan->differential)
360 ret = max11410_set_input_mux(st, chan->channel, chan->channel2);
361 else
362 ret = max11410_set_input_mux(st, chan->channel,
363 MAX11410_AINN_GND);
364
365 if (ret)
366 return ret;
367
368 regval = FIELD_PREP(MAX11410_CTRL_VREFP_BUF_BIT, cfg.buffered_vrefp) |
369 FIELD_PREP(MAX11410_CTRL_VREFN_BUF_BIT, cfg.buffered_vrefn) |
370 FIELD_PREP(MAX11410_CTRL_REFSEL_MASK, cfg.refsel) |
371 FIELD_PREP(MAX11410_CTRL_UNIPOLAR_BIT, cfg.bipolar ? 0 : 1);
372 ret = regmap_update_bits(st->regmap, MAX11410_REG_CTRL,
373 MAX11410_CTRL_REFSEL_MASK |
374 MAX11410_CTRL_VREFP_BUF_BIT |
375 MAX11410_CTRL_VREFN_BUF_BIT |
376 MAX11410_CTRL_UNIPOLAR_BIT, regval);
377 if (ret)
378 return ret;
379
380 regval = FIELD_PREP(MAX11410_PGA_SIG_PATH_MASK, cfg.sig_path) |
381 FIELD_PREP(MAX11410_PGA_GAIN_MASK, cfg.gain);
382 ret = regmap_write(st->regmap, MAX11410_REG_PGA, regval);
383 if (ret)
384 return ret;
385
386 if (cfg.settling_time_us)
387 fsleep(cfg.settling_time_us);
388
389 return 0;
390 }
391
max11410_sample(struct max11410_state * st,int * sample_raw,struct iio_chan_spec const * chan)392 static int max11410_sample(struct max11410_state *st, int *sample_raw,
393 struct iio_chan_spec const *chan)
394 {
395 int val, ret;
396
397 ret = max11410_configure_channel(st, chan);
398 if (ret)
399 return ret;
400
401 if (st->irq > 0)
402 reinit_completion(&st->completion);
403
404 /* Start Conversion */
405 ret = max11410_write_reg(st, MAX11410_REG_CONV_START,
406 MAX11410_CONV_TYPE_SINGLE);
407 if (ret)
408 return ret;
409
410 if (st->irq > 0) {
411 /* Wait for an interrupt. */
412 ret = wait_for_completion_timeout(&st->completion,
413 msecs_to_jiffies(MAX11410_CONVERSION_TIMEOUT_MS));
414 if (!ret)
415 return -ETIMEDOUT;
416 } else {
417 int ret2;
418
419 /* Wait for status register Conversion Ready flag */
420 ret = read_poll_timeout(max11410_read_reg, ret2,
421 ret2 || (val & MAX11410_STATUS_CONV_READY_BIT),
422 5000, MAX11410_CONVERSION_TIMEOUT_MS * 1000,
423 true, st, MAX11410_REG_STATUS, &val);
424 if (ret)
425 return ret;
426 if (ret2)
427 return ret2;
428 }
429
430 /* Read ADC Data */
431 return max11410_read_reg(st, MAX11410_REG_DATA0, sample_raw);
432 }
433
max11410_get_scale(struct max11410_state * state,struct max11410_channel_config cfg)434 static int max11410_get_scale(struct max11410_state *state,
435 struct max11410_channel_config cfg)
436 {
437 struct regulator *vrefp, *vrefn;
438 int scale;
439
440 vrefp = max11410_get_vrefp(state, cfg.refsel);
441
442 scale = regulator_get_voltage(vrefp) / 1000;
443 vrefn = max11410_get_vrefn(state, cfg.refsel);
444 if (vrefn)
445 scale -= regulator_get_voltage(vrefn) / 1000;
446
447 if (cfg.bipolar)
448 scale *= 2;
449
450 return scale >> cfg.gain;
451 }
452
max11410_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long info)453 static int max11410_read_raw(struct iio_dev *indio_dev,
454 struct iio_chan_spec const *chan,
455 int *val, int *val2, long info)
456 {
457 struct max11410_state *state = iio_priv(indio_dev);
458 struct max11410_channel_config cfg = state->channels[chan->address];
459 int ret, reg_val, filter, rate;
460
461 switch (info) {
462 case IIO_CHAN_INFO_SCALE:
463 *val = max11410_get_scale(state, cfg);
464 *val2 = chan->scan_type.realbits;
465 return IIO_VAL_FRACTIONAL_LOG2;
466 case IIO_CHAN_INFO_OFFSET:
467 if (cfg.bipolar)
468 *val = -BIT(chan->scan_type.realbits - 1);
469 else
470 *val = 0;
471
472 return IIO_VAL_INT;
473 case IIO_CHAN_INFO_RAW:
474 ret = iio_device_claim_direct_mode(indio_dev);
475 if (ret)
476 return ret;
477
478 mutex_lock(&state->lock);
479
480 ret = max11410_sample(state, ®_val, chan);
481
482 mutex_unlock(&state->lock);
483
484 iio_device_release_direct_mode(indio_dev);
485
486 if (ret)
487 return ret;
488
489 *val = reg_val;
490
491 return IIO_VAL_INT;
492 case IIO_CHAN_INFO_SAMP_FREQ:
493 ret = regmap_read(state->regmap, MAX11410_REG_FILTER, ®_val);
494 if (ret)
495 return ret;
496
497 filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
498 rate = reg_val & MAX11410_FILTER_RATE_MASK;
499 if (rate >= max11410_sampling_len[filter])
500 rate = max11410_sampling_len[filter] - 1;
501
502 *val = max11410_sampling_rates[filter][rate][0];
503 *val2 = max11410_sampling_rates[filter][rate][1];
504
505 return IIO_VAL_INT_PLUS_MICRO;
506 }
507 return -EINVAL;
508 }
509
max11410_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)510 static int max11410_write_raw(struct iio_dev *indio_dev,
511 struct iio_chan_spec const *chan,
512 int val, int val2, long mask)
513 {
514 struct max11410_state *st = iio_priv(indio_dev);
515 int i, ret, reg_val, filter, gain;
516 u32 *scale_avail;
517
518 switch (mask) {
519 case IIO_CHAN_INFO_SCALE:
520 scale_avail = st->channels[chan->address].scale_avail;
521 if (!scale_avail)
522 return -EOPNOTSUPP;
523
524 /* Accept values in range 0.000001 <= scale < 1.000000 */
525 if (val != 0 || val2 == 0)
526 return -EINVAL;
527
528 ret = iio_device_claim_direct_mode(indio_dev);
529 if (ret)
530 return ret;
531
532 /* Convert from INT_PLUS_MICRO to FRACTIONAL_LOG2 */
533 val2 = val2 * DIV_ROUND_CLOSEST(BIT(24), 1000000);
534 val2 = DIV_ROUND_CLOSEST(scale_avail[0], val2);
535 gain = order_base_2(val2);
536
537 st->channels[chan->address].gain = clamp_val(gain, 0, 7);
538
539 iio_device_release_direct_mode(indio_dev);
540
541 return 0;
542 case IIO_CHAN_INFO_SAMP_FREQ:
543 ret = iio_device_claim_direct_mode(indio_dev);
544 if (ret)
545 return ret;
546
547 mutex_lock(&st->lock);
548
549 ret = regmap_read(st->regmap, MAX11410_REG_FILTER, ®_val);
550 if (ret)
551 goto out;
552
553 filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
554
555 for (i = 0; i < max11410_sampling_len[filter]; ++i) {
556 if (val == max11410_sampling_rates[filter][i][0] &&
557 val2 == max11410_sampling_rates[filter][i][1])
558 break;
559 }
560 if (i == max11410_sampling_len[filter]) {
561 ret = -EINVAL;
562 goto out;
563 }
564
565 ret = regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
566 MAX11410_FILTER_RATE_MASK, i);
567
568 out:
569 mutex_unlock(&st->lock);
570 iio_device_release_direct_mode(indio_dev);
571
572 return ret;
573 default:
574 return -EINVAL;
575 }
576 }
577
max11410_read_avail(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,const int ** vals,int * type,int * length,long info)578 static int max11410_read_avail(struct iio_dev *indio_dev,
579 struct iio_chan_spec const *chan,
580 const int **vals, int *type, int *length,
581 long info)
582 {
583 struct max11410_state *st = iio_priv(indio_dev);
584 struct max11410_channel_config cfg;
585 int ret, reg_val, filter;
586
587 switch (info) {
588 case IIO_CHAN_INFO_SAMP_FREQ:
589 ret = regmap_read(st->regmap, MAX11410_REG_FILTER, ®_val);
590 if (ret)
591 return ret;
592
593 filter = FIELD_GET(MAX11410_FILTER_LINEF_MASK, reg_val);
594
595 *vals = (const int *)max11410_sampling_rates[filter];
596 *length = max11410_sampling_len[filter] * 2;
597 *type = IIO_VAL_INT_PLUS_MICRO;
598
599 return IIO_AVAIL_LIST;
600 case IIO_CHAN_INFO_SCALE:
601 cfg = st->channels[chan->address];
602
603 if (!cfg.scale_avail)
604 return -EINVAL;
605
606 *vals = cfg.scale_avail;
607 *length = MAX11410_SCALE_AVAIL_SIZE * 2;
608 *type = IIO_VAL_FRACTIONAL_LOG2;
609
610 return IIO_AVAIL_LIST;
611 }
612 return -EINVAL;
613 }
614
615 static const struct iio_info max11410_info = {
616 .read_raw = max11410_read_raw,
617 .write_raw = max11410_write_raw,
618 .read_avail = max11410_read_avail,
619 .attrs = &max11410_attribute_group,
620 };
621
max11410_trigger_handler(int irq,void * p)622 static irqreturn_t max11410_trigger_handler(int irq, void *p)
623 {
624 struct iio_poll_func *pf = p;
625 struct iio_dev *indio_dev = pf->indio_dev;
626 struct max11410_state *st = iio_priv(indio_dev);
627 int ret;
628
629 ret = max11410_read_reg(st, MAX11410_REG_DATA0, &st->scan.data);
630 if (ret) {
631 dev_err(&indio_dev->dev, "cannot read data\n");
632 goto out;
633 }
634
635 iio_push_to_buffers_with_timestamp(indio_dev, &st->scan,
636 iio_get_time_ns(indio_dev));
637
638 out:
639 iio_trigger_notify_done(indio_dev->trig);
640
641 return IRQ_HANDLED;
642 }
643
max11410_buffer_postenable(struct iio_dev * indio_dev)644 static int max11410_buffer_postenable(struct iio_dev *indio_dev)
645 {
646 struct max11410_state *st = iio_priv(indio_dev);
647 int scan_ch, ret;
648
649 scan_ch = ffs(*indio_dev->active_scan_mask) - 1;
650
651 ret = max11410_configure_channel(st, &indio_dev->channels[scan_ch]);
652 if (ret)
653 return ret;
654
655 /* Start continuous conversion. */
656 return max11410_write_reg(st, MAX11410_REG_CONV_START,
657 MAX11410_CONV_TYPE_CONTINUOUS);
658 }
659
max11410_buffer_predisable(struct iio_dev * indio_dev)660 static int max11410_buffer_predisable(struct iio_dev *indio_dev)
661 {
662 struct max11410_state *st = iio_priv(indio_dev);
663
664 /* Stop continuous conversion. */
665 return max11410_write_reg(st, MAX11410_REG_CONV_START,
666 MAX11410_CONV_TYPE_SINGLE);
667 }
668
669 static const struct iio_buffer_setup_ops max11410_buffer_ops = {
670 .postenable = &max11410_buffer_postenable,
671 .predisable = &max11410_buffer_predisable,
672 .validate_scan_mask = &iio_validate_scan_mask_onehot,
673 };
674
675 static const struct iio_trigger_ops max11410_trigger_ops = {
676 .validate_device = iio_trigger_validate_own_device,
677 };
678
max11410_interrupt(int irq,void * dev_id)679 static irqreturn_t max11410_interrupt(int irq, void *dev_id)
680 {
681 struct iio_dev *indio_dev = dev_id;
682 struct max11410_state *st = iio_priv(indio_dev);
683
684 if (iio_buffer_enabled(indio_dev))
685 iio_trigger_poll_nested(st->trig);
686 else
687 complete(&st->completion);
688
689 return IRQ_HANDLED;
690 };
691
max11410_parse_channels(struct max11410_state * st,struct iio_dev * indio_dev)692 static int max11410_parse_channels(struct max11410_state *st,
693 struct iio_dev *indio_dev)
694 {
695 struct iio_chan_spec chanspec = chanspec_template;
696 struct device *dev = &st->spi_dev->dev;
697 struct max11410_channel_config *cfg;
698 struct iio_chan_spec *channels;
699 u32 reference, sig_path;
700 const char *node_name;
701 u32 inputs[2], scale;
702 unsigned int num_ch;
703 int chan_idx = 0;
704 int ret, i;
705
706 num_ch = device_get_child_node_count(dev);
707 if (num_ch == 0)
708 return dev_err_probe(&indio_dev->dev, -ENODEV,
709 "FW has no channels defined\n");
710
711 /* Reserve space for soft timestamp channel */
712 num_ch++;
713 channels = devm_kcalloc(dev, num_ch, sizeof(*channels), GFP_KERNEL);
714 if (!channels)
715 return -ENOMEM;
716
717 st->channels = devm_kcalloc(dev, num_ch, sizeof(*st->channels),
718 GFP_KERNEL);
719 if (!st->channels)
720 return -ENOMEM;
721
722 device_for_each_child_node_scoped(dev, child) {
723 node_name = fwnode_get_name(child);
724 if (fwnode_property_present(child, "diff-channels")) {
725 ret = fwnode_property_read_u32_array(child,
726 "diff-channels",
727 inputs,
728 ARRAY_SIZE(inputs));
729
730 chanspec.differential = 1;
731 } else {
732 ret = fwnode_property_read_u32(child, "reg", &inputs[0]);
733
734 inputs[1] = 0;
735 chanspec.differential = 0;
736 }
737 if (ret)
738 return ret;
739
740 if (inputs[0] > MAX11410_CHANNEL_INDEX_MAX ||
741 inputs[1] > MAX11410_CHANNEL_INDEX_MAX)
742 return dev_err_probe(&indio_dev->dev, -EINVAL,
743 "Invalid channel index for %s, should be less than %d\n",
744 node_name,
745 MAX11410_CHANNEL_INDEX_MAX + 1);
746
747 cfg = &st->channels[chan_idx];
748
749 reference = MAX11410_REFSEL_AVDD_AGND;
750 fwnode_property_read_u32(child, "adi,reference", &reference);
751 if (reference > MAX11410_REFSEL_MAX)
752 return dev_err_probe(&indio_dev->dev, -EINVAL,
753 "Invalid adi,reference value for %s, should be less than %d.\n",
754 node_name, MAX11410_REFSEL_MAX + 1);
755
756 if (!max11410_get_vrefp(st, reference) ||
757 (!max11410_get_vrefn(st, reference) && reference <= 2))
758 return dev_err_probe(&indio_dev->dev, -EINVAL,
759 "Invalid VREF configuration for %s, either specify corresponding VREF regulators or change adi,reference property.\n",
760 node_name);
761
762 sig_path = MAX11410_PGA_SIG_PATH_BUFFERED;
763 fwnode_property_read_u32(child, "adi,input-mode", &sig_path);
764 if (sig_path > MAX11410_SIG_PATH_MAX)
765 return dev_err_probe(&indio_dev->dev, -EINVAL,
766 "Invalid adi,input-mode value for %s, should be less than %d.\n",
767 node_name, MAX11410_SIG_PATH_MAX + 1);
768
769 fwnode_property_read_u32(child, "settling-time-us",
770 &cfg->settling_time_us);
771 cfg->bipolar = fwnode_property_read_bool(child, "bipolar");
772 cfg->buffered_vrefp = fwnode_property_read_bool(child, "adi,buffered-vrefp");
773 cfg->buffered_vrefn = fwnode_property_read_bool(child, "adi,buffered-vrefn");
774 cfg->refsel = reference;
775 cfg->sig_path = sig_path;
776 cfg->gain = 0;
777
778 /* Enable scale_available property if input mode is PGA */
779 if (sig_path == MAX11410_PGA_SIG_PATH_PGA) {
780 __set_bit(IIO_CHAN_INFO_SCALE,
781 &chanspec.info_mask_separate_available);
782 cfg->scale_avail = devm_kcalloc(dev, MAX11410_SCALE_AVAIL_SIZE * 2,
783 sizeof(*cfg->scale_avail),
784 GFP_KERNEL);
785 if (!cfg->scale_avail)
786 return -ENOMEM;
787
788 scale = max11410_get_scale(st, *cfg);
789 for (i = 0; i < MAX11410_SCALE_AVAIL_SIZE; i++) {
790 cfg->scale_avail[2 * i] = scale >> i;
791 cfg->scale_avail[2 * i + 1] = chanspec.scan_type.realbits;
792 }
793 } else {
794 __clear_bit(IIO_CHAN_INFO_SCALE,
795 &chanspec.info_mask_separate_available);
796 }
797
798 chanspec.address = chan_idx;
799 chanspec.scan_index = chan_idx;
800 chanspec.channel = inputs[0];
801 chanspec.channel2 = inputs[1];
802
803 channels[chan_idx] = chanspec;
804 chan_idx++;
805 }
806
807 channels[chan_idx] = (struct iio_chan_spec)IIO_CHAN_SOFT_TIMESTAMP(chan_idx);
808
809 indio_dev->num_channels = chan_idx + 1;
810 indio_dev->channels = channels;
811
812 return 0;
813 }
814
max11410_disable_reg(void * reg)815 static void max11410_disable_reg(void *reg)
816 {
817 regulator_disable(reg);
818 }
819
max11410_init_vref(struct device * dev,struct regulator ** vref,const char * id)820 static int max11410_init_vref(struct device *dev,
821 struct regulator **vref,
822 const char *id)
823 {
824 struct regulator *reg;
825 int ret;
826
827 reg = devm_regulator_get_optional(dev, id);
828 if (PTR_ERR(reg) == -ENODEV) {
829 *vref = NULL;
830 return 0;
831 } else if (IS_ERR(reg)) {
832 return PTR_ERR(reg);
833 }
834 ret = regulator_enable(reg);
835 if (ret)
836 return dev_err_probe(dev, ret,
837 "Failed to enable regulator %s\n", id);
838
839 *vref = reg;
840 return devm_add_action_or_reset(dev, max11410_disable_reg, reg);
841 }
842
max11410_calibrate(struct max11410_state * st,u32 cal_type)843 static int max11410_calibrate(struct max11410_state *st, u32 cal_type)
844 {
845 int ret, ret2, val;
846
847 ret = max11410_write_reg(st, MAX11410_REG_CAL_START, cal_type);
848 if (ret)
849 return ret;
850
851 /* Wait for status register Calibration Ready flag */
852 ret = read_poll_timeout(max11410_read_reg, ret2,
853 ret2 || (val & MAX11410_STATUS_CAL_READY_BIT),
854 50000, MAX11410_CALIB_TIMEOUT_MS * 1000, true,
855 st, MAX11410_REG_STATUS, &val);
856 if (ret)
857 return ret;
858
859 return ret2;
860 }
861
max11410_self_calibrate(struct max11410_state * st)862 static int max11410_self_calibrate(struct max11410_state *st)
863 {
864 int ret, i;
865
866 ret = regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
867 MAX11410_FILTER_RATE_MASK,
868 FIELD_PREP(MAX11410_FILTER_RATE_MASK,
869 MAX11410_FILTER_RATE_MAX));
870 if (ret)
871 return ret;
872
873 ret = max11410_calibrate(st, MAX11410_CAL_START_SELF);
874 if (ret)
875 return ret;
876
877 ret = regmap_write_bits(st->regmap, MAX11410_REG_PGA,
878 MAX11410_PGA_SIG_PATH_MASK,
879 FIELD_PREP(MAX11410_PGA_SIG_PATH_MASK,
880 MAX11410_PGA_SIG_PATH_PGA));
881 if (ret)
882 return ret;
883
884 /* PGA calibrations */
885 for (i = 1; i < 8; ++i) {
886 ret = regmap_write_bits(st->regmap, MAX11410_REG_PGA,
887 MAX11410_PGA_GAIN_MASK, i);
888 if (ret)
889 return ret;
890
891 ret = max11410_calibrate(st, MAX11410_CAL_START_PGA);
892 if (ret)
893 return ret;
894 }
895
896 /* Cleanup */
897 ret = regmap_write_bits(st->regmap, MAX11410_REG_PGA,
898 MAX11410_PGA_GAIN_MASK, 0);
899 if (ret)
900 return ret;
901
902 ret = regmap_write_bits(st->regmap, MAX11410_REG_FILTER,
903 MAX11410_FILTER_RATE_MASK, 0);
904 if (ret)
905 return ret;
906
907 return regmap_write_bits(st->regmap, MAX11410_REG_PGA,
908 MAX11410_PGA_SIG_PATH_MASK,
909 FIELD_PREP(MAX11410_PGA_SIG_PATH_MASK,
910 MAX11410_PGA_SIG_PATH_BUFFERED));
911 }
912
max11410_probe(struct spi_device * spi)913 static int max11410_probe(struct spi_device *spi)
914 {
915 const char *vrefp_regs[] = { "vref0p", "vref1p", "vref2p" };
916 const char *vrefn_regs[] = { "vref0n", "vref1n", "vref2n" };
917 struct device *dev = &spi->dev;
918 struct max11410_state *st;
919 struct iio_dev *indio_dev;
920 int ret, irqs[2];
921 int i;
922
923 indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
924 if (!indio_dev)
925 return -ENOMEM;
926
927 st = iio_priv(indio_dev);
928 st->spi_dev = spi;
929 init_completion(&st->completion);
930 mutex_init(&st->lock);
931
932 indio_dev->name = "max11410";
933 indio_dev->modes = INDIO_DIRECT_MODE;
934 indio_dev->info = &max11410_info;
935
936 st->regmap = devm_regmap_init_spi(spi, ®map_config);
937 if (IS_ERR(st->regmap))
938 return dev_err_probe(dev, PTR_ERR(st->regmap),
939 "regmap initialization failed\n");
940
941 ret = max11410_init_vref(dev, &st->avdd, "avdd");
942 if (ret)
943 return ret;
944
945 for (i = 0; i < ARRAY_SIZE(vrefp_regs); i++) {
946 ret = max11410_init_vref(dev, &st->vrefp[i], vrefp_regs[i]);
947 if (ret)
948 return ret;
949
950 ret = max11410_init_vref(dev, &st->vrefn[i], vrefn_regs[i]);
951 if (ret)
952 return ret;
953 }
954
955 /*
956 * Regulators must be configured before parsing channels for
957 * validating "adi,reference" property of each channel.
958 */
959 ret = max11410_parse_channels(st, indio_dev);
960 if (ret)
961 return ret;
962
963 irqs[0] = fwnode_irq_get_byname(dev_fwnode(dev), "gpio0");
964 irqs[1] = fwnode_irq_get_byname(dev_fwnode(dev), "gpio1");
965
966 if (irqs[0] > 0) {
967 st->irq = irqs[0];
968 ret = regmap_write(st->regmap, MAX11410_REG_GPIO_CTRL(0),
969 MAX11410_GPIO_INTRB);
970 } else if (irqs[1] > 0) {
971 st->irq = irqs[1];
972 ret = regmap_write(st->regmap, MAX11410_REG_GPIO_CTRL(1),
973 MAX11410_GPIO_INTRB);
974 } else if (spi->irq > 0) {
975 return dev_err_probe(dev, -ENODEV,
976 "no interrupt name specified");
977 }
978
979 if (ret)
980 return ret;
981
982 ret = regmap_set_bits(st->regmap, MAX11410_REG_CTRL,
983 MAX11410_CTRL_FORMAT_BIT);
984 if (ret)
985 return ret;
986
987 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
988 &max11410_trigger_handler,
989 &max11410_buffer_ops);
990 if (ret)
991 return ret;
992
993 if (st->irq > 0) {
994 st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
995 indio_dev->name,
996 iio_device_id(indio_dev));
997 if (!st->trig)
998 return -ENOMEM;
999
1000 st->trig->ops = &max11410_trigger_ops;
1001 ret = devm_iio_trigger_register(dev, st->trig);
1002 if (ret)
1003 return ret;
1004
1005 ret = devm_request_threaded_irq(dev, st->irq, NULL,
1006 &max11410_interrupt,
1007 IRQF_ONESHOT, "max11410",
1008 indio_dev);
1009 if (ret)
1010 return ret;
1011 }
1012
1013 ret = max11410_self_calibrate(st);
1014 if (ret)
1015 return dev_err_probe(dev, ret,
1016 "cannot perform device self calibration\n");
1017
1018 return devm_iio_device_register(dev, indio_dev);
1019 }
1020
1021 static const struct of_device_id max11410_spi_of_id[] = {
1022 { .compatible = "adi,max11410" },
1023 { }
1024 };
1025 MODULE_DEVICE_TABLE(of, max11410_spi_of_id);
1026
1027 static const struct spi_device_id max11410_id[] = {
1028 { "max11410" },
1029 { }
1030 };
1031 MODULE_DEVICE_TABLE(spi, max11410_id);
1032
1033 static struct spi_driver max11410_driver = {
1034 .driver = {
1035 .name = "max11410",
1036 .of_match_table = max11410_spi_of_id,
1037 },
1038 .probe = max11410_probe,
1039 .id_table = max11410_id,
1040 };
1041 module_spi_driver(max11410_driver);
1042
1043 MODULE_AUTHOR("David Jung <David.Jung@analog.com>");
1044 MODULE_AUTHOR("Ibrahim Tilki <Ibrahim.Tilki@analog.com>");
1045 MODULE_DESCRIPTION("Analog Devices MAX11410 ADC");
1046 MODULE_LICENSE("GPL");
1047