1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Texas Instruments ADS1119 ADC driver.
4  *
5  * Copyright 2024 Toradex
6  */
7 
8 #include <linux/bits.h>
9 #include <linux/bitfield.h>
10 #include <linux/completion.h>
11 #include <linux/delay.h>
12 #include <linux/dev_printk.h>
13 #include <linux/err.h>
14 #include <linux/gpio/consumer.h>
15 #include <linux/interrupt.h>
16 #include <linux/iopoll.h>
17 #include <linux/i2c.h>
18 #include <linux/kernel.h>
19 #include <linux/math.h>
20 #include <linux/module.h>
21 #include <linux/pm_runtime.h>
22 #include <linux/regulator/consumer.h>
23 #include <linux/units.h>
24 
25 #include <linux/iio/iio.h>
26 #include <linux/iio/buffer.h>
27 #include <linux/iio/trigger.h>
28 #include <linux/iio/triggered_buffer.h>
29 #include <linux/iio/trigger_consumer.h>
30 
31 #define ADS1119_CMD_RESET		0x06
32 #define ADS1119_CMD_POWERDOWN		0x02
33 #define ADS1119_CMD_START_SYNC		0x08
34 #define ADS1119_CMD_RDATA		0x10
35 #define ADS1119_CMD_RREG_CONFIG		0x20
36 #define ADS1119_CMD_RREG_STATUS		0x24
37 #define ADS1119_CMD_WREG		0x40
38 
39 #define ADS1119_CMD_RREG(reg)		(0x20 | (reg) << 2)
40 
41 /* Config register */
42 #define ADS1119_REG_CONFIG	0x00
43 #define ADS1119_CONFIG_VREF_FIELD	BIT(0)
44 #define ADS1119_CONFIG_CM_FIELD		BIT(1)
45 #define ADS1119_CONFIG_DR_FIELD		GENMASK(3, 2)
46 #define ADS1119_CONFIG_GAIN_FIELD	BIT(4)
47 #define ADS1119_CONFIG_MUX_FIELD	GENMASK(7, 5)
48 
49 #define ADS1119_VREF_INTERNAL	0
50 #define ADS1119_VREF_EXTERNAL	1
51 #define ADS1119_VREF_INTERNAL_VAL 2048000
52 
53 #define ADS1119_CM_SINGLE	0
54 #define ADS1119_CM_CONTINUOUS	1
55 
56 #define ADS1119_DR_20_SPS	0
57 #define ADS1119_DR_90_SPS	1
58 #define ADS1119_DR_330_SPS	2
59 #define ADS1119_DR_1000_SPS	3
60 
61 #define ADS1119_GAIN_1	0
62 #define ADS1119_GAIN_4	1
63 
64 #define ADS1119_MUX_AIN0_AIN1	0
65 #define ADS1119_MUX_AIN2_AIN3	1
66 #define ADS1119_MUX_AIN1_AIN2	2
67 #define ADS1119_MUX_AIN0	3
68 #define ADS1119_MUX_AIN1	4
69 #define ADS1119_MUX_AIN2	5
70 #define ADS1119_MUX_AIN3	6
71 #define ADS1119_MUX_SHORTED	7
72 
73 /* Status register */
74 #define ADS1119_REG_STATUS	0x01
75 #define ADS1119_STATUS_DRDY_FIELD	BIT(7)
76 
77 #define ADS1119_DEFAULT_GAIN		1
78 #define ADS1119_DEFAULT_DATARATE	20
79 
80 #define ADS1119_SUSPEND_DELAY		2000
81 
82 /* Timeout based on the minimum sample rate of 20 SPS (50000us) */
83 #define ADS1119_MAX_DRDY_TIMEOUT	85000
84 
85 #define ADS1119_MAX_CHANNELS		7
86 #define ADS1119_MAX_SINGLE_CHANNELS	4
87 
88 struct ads1119_channel_config {
89 	int gain;
90 	int datarate;
91 	int mux;
92 };
93 
94 struct ads1119_state {
95 	struct completion completion;
96 	struct i2c_client *client;
97 	struct gpio_desc *reset_gpio;
98 	struct iio_trigger *trig;
99 	struct ads1119_channel_config *channels_cfg;
100 	unsigned int num_channels_cfg;
101 	unsigned int cached_config;
102 	int vref_uV;
103 };
104 
105 static const char * const ads1119_power_supplies[] = {
106 	"avdd", "dvdd"
107 };
108 
109 static const int ads1119_available_datarates[] = {
110 	20, 90, 330, 1000,
111 };
112 
113 static const int ads1119_available_gains[] = {
114 	1, 1,
115 	1, 4,
116 };
117 
118 static int ads1119_upd_cfg_reg(struct ads1119_state *st, unsigned int fields,
119 			       unsigned int val)
120 {
121 	unsigned int config = st->cached_config;
122 	int ret;
123 
124 	config &= ~fields;
125 	config |= val;
126 
127 	ret = i2c_smbus_write_byte_data(st->client, ADS1119_CMD_WREG, config);
128 	if (ret)
129 		return ret;
130 
131 	st->cached_config = config;
132 
133 	return 0;
134 }
135 
136 static bool ads1119_data_ready(struct ads1119_state *st)
137 {
138 	int status;
139 
140 	status = i2c_smbus_read_byte_data(st->client, ADS1119_CMD_RREG_STATUS);
141 	if (status < 0)
142 		return false;
143 
144 	return FIELD_GET(ADS1119_STATUS_DRDY_FIELD, status);
145 }
146 
147 static int ads1119_reset(struct ads1119_state *st)
148 {
149 	st->cached_config = 0;
150 
151 	if (!st->reset_gpio)
152 		return i2c_smbus_write_byte(st->client, ADS1119_CMD_RESET);
153 
154 	gpiod_set_value_cansleep(st->reset_gpio, 1);
155 	udelay(1);
156 	gpiod_set_value_cansleep(st->reset_gpio, 0);
157 	udelay(1);
158 
159 	return 0;
160 }
161 
162 static int ads1119_set_conv_mode(struct ads1119_state *st, bool continuous)
163 {
164 	unsigned int mode;
165 
166 	if (continuous)
167 		mode = ADS1119_CM_CONTINUOUS;
168 	else
169 		mode = ADS1119_CM_SINGLE;
170 
171 	return ads1119_upd_cfg_reg(st, ADS1119_CONFIG_CM_FIELD,
172 				   FIELD_PREP(ADS1119_CONFIG_CM_FIELD, mode));
173 }
174 
175 static int ads1119_get_hw_gain(int gain)
176 {
177 	if (gain == 4)
178 		return ADS1119_GAIN_4;
179 	else
180 		return ADS1119_GAIN_1;
181 }
182 
183 static int ads1119_get_hw_datarate(int datarate)
184 {
185 	switch (datarate) {
186 	case 90:
187 		return ADS1119_DR_90_SPS;
188 	case 330:
189 		return ADS1119_DR_330_SPS;
190 	case 1000:
191 		return ADS1119_DR_1000_SPS;
192 	case 20:
193 	default:
194 		return ADS1119_DR_20_SPS;
195 	}
196 }
197 
198 static int ads1119_configure_channel(struct ads1119_state *st, int mux,
199 				     int gain, int datarate)
200 {
201 	int ret;
202 
203 	ret = ads1119_upd_cfg_reg(st, ADS1119_CONFIG_MUX_FIELD,
204 				  FIELD_PREP(ADS1119_CONFIG_MUX_FIELD, mux));
205 	if (ret)
206 		return ret;
207 
208 	ret = ads1119_upd_cfg_reg(st, ADS1119_CONFIG_GAIN_FIELD,
209 				  FIELD_PREP(ADS1119_CONFIG_GAIN_FIELD,
210 					     ads1119_get_hw_gain(gain)));
211 	if (ret)
212 		return ret;
213 
214 	return ads1119_upd_cfg_reg(st, ADS1119_CONFIG_DR_FIELD,
215 				   FIELD_PREP(ADS1119_CONFIG_DR_FIELD,
216 					      ads1119_get_hw_datarate(datarate)));
217 }
218 
219 static int ads1119_poll_data_ready(struct ads1119_state *st,
220 				   struct iio_chan_spec const *chan)
221 {
222 	unsigned int datarate = st->channels_cfg[chan->address].datarate;
223 	unsigned long wait_time;
224 	bool data_ready;
225 
226 	/* Poll 5 times more than the data rate */
227 	wait_time = DIV_ROUND_CLOSEST(MICRO, 5 * datarate);
228 
229 	return read_poll_timeout(ads1119_data_ready, data_ready,
230 				 data_ready, wait_time,
231 				 ADS1119_MAX_DRDY_TIMEOUT, false, st);
232 }
233 
234 static int ads1119_read_data(struct ads1119_state *st,
235 			     struct iio_chan_spec const *chan,
236 			     unsigned int *val)
237 {
238 	unsigned int timeout;
239 	int ret = 0;
240 
241 	timeout = msecs_to_jiffies(ADS1119_MAX_DRDY_TIMEOUT);
242 
243 	if (!st->client->irq) {
244 		ret = ads1119_poll_data_ready(st, chan);
245 		if (ret)
246 			return ret;
247 	} else if (!wait_for_completion_timeout(&st->completion, timeout)) {
248 		return -ETIMEDOUT;
249 	}
250 
251 	ret = i2c_smbus_read_word_swapped(st->client, ADS1119_CMD_RDATA);
252 	if (ret < 0)
253 		return ret;
254 
255 	*val = ret;
256 
257 	return 0;
258 }
259 
260 static int ads1119_single_conversion(struct ads1119_state *st,
261 				     struct iio_chan_spec const *chan,
262 				     int *val,
263 				     bool calib_offset)
264 {
265 	struct device *dev = &st->client->dev;
266 	int mux = st->channels_cfg[chan->address].mux;
267 	int gain = st->channels_cfg[chan->address].gain;
268 	int datarate = st->channels_cfg[chan->address].datarate;
269 	unsigned int sample;
270 	int ret;
271 
272 	if (calib_offset)
273 		mux = ADS1119_MUX_SHORTED;
274 
275 	ret = pm_runtime_resume_and_get(dev);
276 	if (ret)
277 		goto pdown;
278 
279 	ret = ads1119_configure_channel(st, mux, gain, datarate);
280 	if (ret)
281 		goto pdown;
282 
283 	ret = i2c_smbus_write_byte(st->client, ADS1119_CMD_START_SYNC);
284 	if (ret)
285 		goto pdown;
286 
287 	ret = ads1119_read_data(st, chan, &sample);
288 	if (ret)
289 		goto pdown;
290 
291 	*val = sign_extend32(sample, chan->scan_type.realbits - 1);
292 	ret = IIO_VAL_INT;
293 pdown:
294 	pm_runtime_mark_last_busy(dev);
295 	pm_runtime_put_autosuspend(dev);
296 	return ret;
297 }
298 
299 static int ads1119_validate_datarate(struct ads1119_state *st, int datarate)
300 {
301 	switch (datarate) {
302 	case 20:
303 	case 90:
304 	case 330:
305 	case 1000:
306 		return datarate;
307 	default:
308 		return -EINVAL;
309 	}
310 }
311 
312 static int ads1119_read_avail(struct iio_dev *indio_dev,
313 			      struct iio_chan_spec const *chan,
314 			      const int **vals, int *type, int *length,
315 			      long mask)
316 {
317 	switch (mask) {
318 	case IIO_CHAN_INFO_SCALE:
319 		*type = IIO_VAL_FRACTIONAL;
320 		*vals = ads1119_available_gains;
321 		*length = ARRAY_SIZE(ads1119_available_gains);
322 		return IIO_AVAIL_LIST;
323 	case IIO_CHAN_INFO_SAMP_FREQ:
324 		*type = IIO_VAL_INT;
325 		*vals = ads1119_available_datarates;
326 		*length = ARRAY_SIZE(ads1119_available_datarates);
327 		return IIO_AVAIL_LIST;
328 	default:
329 		return -EINVAL;
330 	}
331 }
332 
333 static int ads1119_read_raw(struct iio_dev *indio_dev,
334 			    struct iio_chan_spec const *chan, int *val,
335 			    int *val2, long mask)
336 {
337 	struct ads1119_state *st = iio_priv(indio_dev);
338 	unsigned int index = chan->address;
339 	int ret;
340 
341 	if (index >= st->num_channels_cfg)
342 		return -EINVAL;
343 
344 	switch (mask) {
345 	case IIO_CHAN_INFO_RAW:
346 		if (!iio_device_claim_direct(indio_dev))
347 			return -EBUSY;
348 		ret = ads1119_single_conversion(st, chan, val, false);
349 		iio_device_release_direct(indio_dev);
350 		return ret;
351 	case IIO_CHAN_INFO_OFFSET:
352 		if (!iio_device_claim_direct(indio_dev))
353 			return -EBUSY;
354 		ret = ads1119_single_conversion(st, chan, val, true);
355 		iio_device_release_direct(indio_dev);
356 		return ret;
357 	case IIO_CHAN_INFO_SCALE:
358 		*val = st->vref_uV / 1000;
359 		*val /= st->channels_cfg[index].gain;
360 		*val2 = chan->scan_type.realbits - 1;
361 		return IIO_VAL_FRACTIONAL_LOG2;
362 	case IIO_CHAN_INFO_SAMP_FREQ:
363 		*val = st->channels_cfg[index].datarate;
364 		return IIO_VAL_INT;
365 	default:
366 		return -EINVAL;
367 	}
368 }
369 
370 static int ads1119_write_raw(struct iio_dev *indio_dev,
371 			     struct iio_chan_spec const *chan, int val,
372 			     int val2, long mask)
373 {
374 	struct ads1119_state *st = iio_priv(indio_dev);
375 	unsigned int index = chan->address;
376 	int ret;
377 
378 	if (index >= st->num_channels_cfg)
379 		return -EINVAL;
380 
381 	switch (mask) {
382 	case IIO_CHAN_INFO_SCALE:
383 		ret = MICRO / ((val * MICRO) + val2);
384 		if (ret != 1 && ret != 4)
385 			return -EINVAL;
386 
387 		st->channels_cfg[index].gain = ret;
388 		return 0;
389 	case IIO_CHAN_INFO_SAMP_FREQ:
390 		ret = ads1119_validate_datarate(st, val);
391 		if (ret < 0)
392 			return ret;
393 
394 		st->channels_cfg[index].datarate = ret;
395 		return 0;
396 	default:
397 		return -EINVAL;
398 	}
399 }
400 
401 static int ads1119_debugfs_reg_access(struct iio_dev *indio_dev,
402 				      unsigned int reg, unsigned int writeval,
403 				      unsigned int *readval)
404 {
405 	struct ads1119_state *st = iio_priv(indio_dev);
406 	int ret;
407 
408 	if (reg > ADS1119_REG_STATUS)
409 		return -EINVAL;
410 
411 	if (readval) {
412 		ret = i2c_smbus_read_byte_data(st->client,
413 					       ADS1119_CMD_RREG(reg));
414 		if (ret < 0)
415 			return ret;
416 
417 		*readval = ret;
418 		return 0;
419 	}
420 
421 	if (reg > ADS1119_REG_CONFIG)
422 		return -EINVAL;
423 
424 	return i2c_smbus_write_byte_data(st->client, ADS1119_CMD_WREG,
425 					 writeval);
426 }
427 
428 static const struct iio_info ads1119_info = {
429 	.read_avail = ads1119_read_avail,
430 	.read_raw = ads1119_read_raw,
431 	.write_raw = ads1119_write_raw,
432 	.debugfs_reg_access = ads1119_debugfs_reg_access,
433 };
434 
435 static int ads1119_triggered_buffer_preenable(struct iio_dev *indio_dev)
436 {
437 	struct ads1119_state *st = iio_priv(indio_dev);
438 	struct device *dev = &st->client->dev;
439 	unsigned int index;
440 	int ret;
441 
442 	index = find_first_bit(indio_dev->active_scan_mask,
443 			       iio_get_masklength(indio_dev));
444 
445 	ret = ads1119_set_conv_mode(st, true);
446 	if (ret)
447 		return ret;
448 
449 	ret = ads1119_configure_channel(st,
450 					st->channels_cfg[index].mux,
451 					st->channels_cfg[index].gain,
452 					st->channels_cfg[index].datarate);
453 	if (ret)
454 		return ret;
455 
456 	ret = pm_runtime_resume_and_get(dev);
457 	if (ret)
458 		return ret;
459 
460 	return i2c_smbus_write_byte(st->client, ADS1119_CMD_START_SYNC);
461 }
462 
463 static int ads1119_triggered_buffer_postdisable(struct iio_dev *indio_dev)
464 {
465 	struct ads1119_state *st = iio_priv(indio_dev);
466 	struct device *dev = &st->client->dev;
467 	int ret;
468 
469 	ret = ads1119_set_conv_mode(st, false);
470 	if (ret)
471 		return ret;
472 
473 	pm_runtime_mark_last_busy(dev);
474 	pm_runtime_put_autosuspend(dev);
475 
476 	return 0;
477 }
478 
479 static const struct iio_buffer_setup_ops ads1119_buffer_setup_ops = {
480 	.preenable = ads1119_triggered_buffer_preenable,
481 	.postdisable = ads1119_triggered_buffer_postdisable,
482 	.validate_scan_mask = &iio_validate_scan_mask_onehot,
483 };
484 
485 static const struct iio_trigger_ops ads1119_trigger_ops = {
486 	.validate_device = &iio_trigger_validate_own_device,
487 };
488 
489 static irqreturn_t ads1119_irq_handler(int irq, void *dev_id)
490 {
491 	struct iio_dev *indio_dev = dev_id;
492 	struct ads1119_state *st = iio_priv(indio_dev);
493 
494 	if (iio_buffer_enabled(indio_dev) && iio_trigger_using_own(indio_dev))
495 		iio_trigger_poll(indio_dev->trig);
496 	else
497 		complete(&st->completion);
498 
499 	return IRQ_HANDLED;
500 }
501 
502 static irqreturn_t ads1119_trigger_handler(int irq, void *private)
503 {
504 	struct iio_poll_func *pf = private;
505 	struct iio_dev *indio_dev = pf->indio_dev;
506 	struct ads1119_state *st = iio_priv(indio_dev);
507 	struct {
508 		s16 sample;
509 		aligned_s64 timestamp;
510 	} scan;
511 	unsigned int index;
512 	int ret;
513 
514 	memset(&scan, 0, sizeof(scan));
515 
516 	if (!iio_trigger_using_own(indio_dev)) {
517 		index = find_first_bit(indio_dev->active_scan_mask,
518 				       iio_get_masklength(indio_dev));
519 
520 		ret = ads1119_poll_data_ready(st, &indio_dev->channels[index]);
521 		if (ret) {
522 			dev_err(&st->client->dev,
523 				"Failed to poll data on trigger (%d)\n", ret);
524 			goto done;
525 		}
526 	}
527 
528 	ret = i2c_smbus_read_word_swapped(st->client, ADS1119_CMD_RDATA);
529 	if (ret < 0) {
530 		dev_err(&st->client->dev,
531 			"Failed to read data on trigger (%d)\n", ret);
532 		goto done;
533 	}
534 
535 	scan.sample = ret;
536 
537 	iio_push_to_buffers_with_ts(indio_dev, &scan, sizeof(scan),
538 				    iio_get_time_ns(indio_dev));
539 done:
540 	iio_trigger_notify_done(indio_dev->trig);
541 	return IRQ_HANDLED;
542 }
543 
544 static int ads1119_init(struct ads1119_state *st, bool vref_external)
545 {
546 	int ret;
547 
548 	ret = ads1119_reset(st);
549 	if (ret)
550 		return ret;
551 
552 	if (vref_external)
553 		return ads1119_upd_cfg_reg(st,
554 					   ADS1119_CONFIG_VREF_FIELD,
555 					   FIELD_PREP(ADS1119_CONFIG_VREF_FIELD,
556 						      ADS1119_VREF_EXTERNAL));
557 	return 0;
558 }
559 
560 static int ads1119_map_analog_inputs_mux(int ain_pos, int ain_neg,
561 					 bool differential)
562 {
563 	if (ain_pos >= ADS1119_MAX_SINGLE_CHANNELS)
564 		return -EINVAL;
565 
566 	if (!differential)
567 		return ADS1119_MUX_AIN0 + ain_pos;
568 
569 	if (ain_pos == 0 && ain_neg == 1)
570 		return ADS1119_MUX_AIN0_AIN1;
571 	else if (ain_pos == 1 && ain_neg == 2)
572 		return ADS1119_MUX_AIN1_AIN2;
573 	else if (ain_pos == 2 && ain_neg == 3)
574 		return ADS1119_MUX_AIN2_AIN3;
575 
576 	return -EINVAL;
577 }
578 
579 static int ads1119_alloc_and_config_channels(struct iio_dev *indio_dev)
580 {
581 	const struct iio_chan_spec ads1119_channel =
582 		(const struct iio_chan_spec) {
583 		.type = IIO_VOLTAGE,
584 		.indexed = 1,
585 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
586 		BIT(IIO_CHAN_INFO_SCALE) |
587 		BIT(IIO_CHAN_INFO_OFFSET) |
588 		BIT(IIO_CHAN_INFO_SAMP_FREQ),
589 		.info_mask_shared_by_all_available =
590 		BIT(IIO_CHAN_INFO_SCALE) |
591 		BIT(IIO_CHAN_INFO_SAMP_FREQ),
592 		.scan_type = {
593 			.sign = 's',
594 			.realbits = 16,
595 			.storagebits = 16,
596 			.endianness = IIO_CPU,
597 		},
598 	};
599 	const struct iio_chan_spec ads1119_ts = IIO_CHAN_SOFT_TIMESTAMP(0);
600 	struct ads1119_state *st = iio_priv(indio_dev);
601 	struct iio_chan_spec *iio_channels, *chan;
602 	struct device *dev = &st->client->dev;
603 	unsigned int num_channels, i;
604 	bool differential;
605 	u32 ain[2];
606 	int ret;
607 
608 	st->num_channels_cfg = device_get_child_node_count(dev);
609 	if (st->num_channels_cfg > ADS1119_MAX_CHANNELS)
610 		return dev_err_probe(dev, -EINVAL,
611 				     "Too many channels %d, max is %d\n",
612 				     st->num_channels_cfg,
613 				     ADS1119_MAX_CHANNELS);
614 
615 	st->channels_cfg = devm_kcalloc(dev, st->num_channels_cfg,
616 					sizeof(*st->channels_cfg), GFP_KERNEL);
617 	if (!st->channels_cfg)
618 		return -ENOMEM;
619 
620 	/* Allocate one more iio channel for the timestamp */
621 	num_channels = st->num_channels_cfg + 1;
622 	iio_channels = devm_kcalloc(dev, num_channels, sizeof(*iio_channels),
623 				    GFP_KERNEL);
624 	if (!iio_channels)
625 		return -ENOMEM;
626 
627 	i = 0;
628 
629 	device_for_each_child_node_scoped(dev, child) {
630 		chan = &iio_channels[i];
631 
632 		differential = fwnode_property_present(child, "diff-channels");
633 		if (differential)
634 			ret = fwnode_property_read_u32_array(child,
635 							     "diff-channels",
636 							     ain, 2);
637 		else
638 			ret = fwnode_property_read_u32(child, "single-channel",
639 						       &ain[0]);
640 
641 		if (ret)
642 			return dev_err_probe(dev, ret,
643 					     "Failed to get channel property\n");
644 
645 		ret = ads1119_map_analog_inputs_mux(ain[0], ain[1],
646 						    differential);
647 		if (ret < 0)
648 			return dev_err_probe(dev, ret,
649 					     "Invalid channel value\n");
650 
651 		st->channels_cfg[i].mux = ret;
652 		st->channels_cfg[i].gain = ADS1119_DEFAULT_GAIN;
653 		st->channels_cfg[i].datarate = ADS1119_DEFAULT_DATARATE;
654 
655 		*chan = ads1119_channel;
656 		chan->channel = ain[0];
657 		chan->address = i;
658 		chan->scan_index = i;
659 
660 		if (differential) {
661 			chan->channel2 = ain[1];
662 			chan->differential = 1;
663 		}
664 
665 		dev_dbg(dev, "channel: index %d, mux %d\n", i,
666 			st->channels_cfg[i].mux);
667 
668 		i++;
669 	}
670 
671 	iio_channels[i] = ads1119_ts;
672 	iio_channels[i].address = i;
673 	iio_channels[i].scan_index = i;
674 
675 	indio_dev->channels = iio_channels;
676 	indio_dev->num_channels = num_channels;
677 
678 	return 0;
679 }
680 
681 static void ads1119_powerdown(void *data)
682 {
683 	struct ads1119_state *st = data;
684 
685 	i2c_smbus_write_byte(st->client, ADS1119_CMD_POWERDOWN);
686 }
687 
688 static int ads1119_probe(struct i2c_client *client)
689 {
690 	struct iio_dev *indio_dev;
691 	struct ads1119_state *st;
692 	struct device *dev = &client->dev;
693 	bool vref_external = true;
694 	int ret;
695 
696 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
697 	if (!indio_dev)
698 		return dev_err_probe(dev, -ENOMEM,
699 				     "Failed to allocate IIO device\n");
700 
701 	st = iio_priv(indio_dev);
702 	st->client = client;
703 
704 	indio_dev->name = "ads1119";
705 	indio_dev->info = &ads1119_info;
706 	indio_dev->modes = INDIO_DIRECT_MODE;
707 
708 	i2c_set_clientdata(client, indio_dev);
709 
710 	ret = devm_regulator_bulk_get_enable(dev,
711 					     ARRAY_SIZE(ads1119_power_supplies),
712 					     ads1119_power_supplies);
713 	if (ret)
714 		return dev_err_probe(dev, ret,
715 				     "Failed to get and enable supplies\n");
716 
717 	st->vref_uV = devm_regulator_get_enable_read_voltage(dev, "vref");
718 	if (st->vref_uV == -ENODEV) {
719 		vref_external = false;
720 		st->vref_uV = ADS1119_VREF_INTERNAL_VAL;
721 	} else if (st->vref_uV < 0) {
722 		return dev_err_probe(dev, st->vref_uV, "Failed to get vref\n");
723 	}
724 
725 	st->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
726 	if (IS_ERR(st->reset_gpio))
727 		return dev_err_probe(dev, PTR_ERR(st->reset_gpio),
728 				     "Failed to get reset gpio\n");
729 
730 	ret = ads1119_alloc_and_config_channels(indio_dev);
731 	if (ret)
732 		return ret;
733 
734 	init_completion(&st->completion);
735 
736 	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
737 					      ads1119_trigger_handler,
738 					      &ads1119_buffer_setup_ops);
739 	if (ret)
740 		return dev_err_probe(dev, ret, "Failed to setup IIO buffer\n");
741 
742 	if (client->irq > 0) {
743 		ret = devm_request_threaded_irq(dev, client->irq,
744 						ads1119_irq_handler,
745 						NULL, IRQF_ONESHOT,
746 						"ads1119", indio_dev);
747 		if (ret)
748 			return dev_err_probe(dev, ret,
749 					     "Failed to allocate irq\n");
750 
751 		st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
752 						  indio_dev->name,
753 						  iio_device_id(indio_dev));
754 		if (!st->trig)
755 			return dev_err_probe(dev, -ENOMEM,
756 					     "Failed to allocate IIO trigger\n");
757 
758 		st->trig->ops = &ads1119_trigger_ops;
759 		iio_trigger_set_drvdata(st->trig, indio_dev);
760 
761 		ret = devm_iio_trigger_register(dev, st->trig);
762 		if (ret)
763 			return dev_err_probe(dev, ret,
764 					     "Failed to register IIO trigger\n");
765 	}
766 
767 	ret = ads1119_init(st, vref_external);
768 	if (ret)
769 		return dev_err_probe(dev, ret,
770 				     "Failed to initialize device\n");
771 
772 	pm_runtime_set_autosuspend_delay(dev, ADS1119_SUSPEND_DELAY);
773 	pm_runtime_use_autosuspend(dev);
774 	pm_runtime_mark_last_busy(dev);
775 	pm_runtime_set_active(dev);
776 
777 	ret = devm_pm_runtime_enable(dev);
778 	if (ret)
779 		return dev_err_probe(dev, ret, "Failed to enable pm runtime\n");
780 
781 	ret = devm_add_action_or_reset(dev, ads1119_powerdown, st);
782 	if (ret)
783 		return dev_err_probe(dev, ret,
784 				     "Failed to add powerdown action\n");
785 
786 	return devm_iio_device_register(dev, indio_dev);
787 }
788 
789 static int ads1119_runtime_suspend(struct device *dev)
790 {
791 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
792 	struct ads1119_state *st = iio_priv(indio_dev);
793 
794 	return i2c_smbus_write_byte(st->client, ADS1119_CMD_POWERDOWN);
795 }
796 
797 /*
798  * The ADS1119 does not require a resume function because it automatically
799  * powers on after a reset.
800  * After a power down command, the ADS1119 can still communicate but turns off
801  * its analog parts. To resume from power down, the device will power up again
802  * upon receiving a start/sync command.
803  */
804 static DEFINE_RUNTIME_DEV_PM_OPS(ads1119_pm_ops, ads1119_runtime_suspend,
805 				 NULL, NULL);
806 
807 static const struct of_device_id __maybe_unused ads1119_of_match[] = {
808 	{ .compatible = "ti,ads1119" },
809 	{ }
810 };
811 MODULE_DEVICE_TABLE(of, ads1119_of_match);
812 
813 static const struct i2c_device_id ads1119_id[] = {
814 	{ "ads1119" },
815 	{ }
816 };
817 MODULE_DEVICE_TABLE(i2c, ads1119_id);
818 
819 static struct i2c_driver ads1119_driver = {
820 	.driver = {
821 		.name = "ads1119",
822 		.of_match_table = ads1119_of_match,
823 		.pm = pm_ptr(&ads1119_pm_ops),
824 	},
825 	.probe = ads1119_probe,
826 	.id_table = ads1119_id,
827 };
828 module_i2c_driver(ads1119_driver);
829 
830 MODULE_AUTHOR("João Paulo Gonçalves <joao.goncalves@toradex.com>");
831 MODULE_DESCRIPTION("Texas Instruments ADS1119 ADC Driver");
832 MODULE_LICENSE("GPL");
833