xref: /openbmc/linux/drivers/iio/adc/ti-ads1015.c (revision a44e4f3a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * ADS1015 - Texas Instruments Analog-to-Digital Converter
4  *
5  * Copyright (c) 2016, Intel Corporation.
6  *
7  * IIO driver for ADS1015 ADC 7-bit I2C slave address:
8  *	* 0x48 - ADDR connected to Ground
9  *	* 0x49 - ADDR connected to Vdd
10  *	* 0x4A - ADDR connected to SDA
11  *	* 0x4B - ADDR connected to SCL
12  */
13 
14 #include <linux/module.h>
15 #include <linux/of_device.h>
16 #include <linux/init.h>
17 #include <linux/irq.h>
18 #include <linux/i2c.h>
19 #include <linux/regmap.h>
20 #include <linux/pm_runtime.h>
21 #include <linux/mutex.h>
22 #include <linux/delay.h>
23 
24 #include <linux/platform_data/ads1015.h>
25 
26 #include <linux/iio/iio.h>
27 #include <linux/iio/types.h>
28 #include <linux/iio/sysfs.h>
29 #include <linux/iio/events.h>
30 #include <linux/iio/buffer.h>
31 #include <linux/iio/triggered_buffer.h>
32 #include <linux/iio/trigger_consumer.h>
33 
34 #define ADS1015_DRV_NAME "ads1015"
35 
36 #define ADS1015_CONV_REG	0x00
37 #define ADS1015_CFG_REG		0x01
38 #define ADS1015_LO_THRESH_REG	0x02
39 #define ADS1015_HI_THRESH_REG	0x03
40 
41 #define ADS1015_CFG_COMP_QUE_SHIFT	0
42 #define ADS1015_CFG_COMP_LAT_SHIFT	2
43 #define ADS1015_CFG_COMP_POL_SHIFT	3
44 #define ADS1015_CFG_COMP_MODE_SHIFT	4
45 #define ADS1015_CFG_DR_SHIFT	5
46 #define ADS1015_CFG_MOD_SHIFT	8
47 #define ADS1015_CFG_PGA_SHIFT	9
48 #define ADS1015_CFG_MUX_SHIFT	12
49 
50 #define ADS1015_CFG_COMP_QUE_MASK	GENMASK(1, 0)
51 #define ADS1015_CFG_COMP_LAT_MASK	BIT(2)
52 #define ADS1015_CFG_COMP_POL_MASK	BIT(3)
53 #define ADS1015_CFG_COMP_MODE_MASK	BIT(4)
54 #define ADS1015_CFG_DR_MASK	GENMASK(7, 5)
55 #define ADS1015_CFG_MOD_MASK	BIT(8)
56 #define ADS1015_CFG_PGA_MASK	GENMASK(11, 9)
57 #define ADS1015_CFG_MUX_MASK	GENMASK(14, 12)
58 
59 /* Comparator queue and disable field */
60 #define ADS1015_CFG_COMP_DISABLE	3
61 
62 /* Comparator polarity field */
63 #define ADS1015_CFG_COMP_POL_LOW	0
64 #define ADS1015_CFG_COMP_POL_HIGH	1
65 
66 /* Comparator mode field */
67 #define ADS1015_CFG_COMP_MODE_TRAD	0
68 #define ADS1015_CFG_COMP_MODE_WINDOW	1
69 
70 /* device operating modes */
71 #define ADS1015_CONTINUOUS	0
72 #define ADS1015_SINGLESHOT	1
73 
74 #define ADS1015_SLEEP_DELAY_MS		2000
75 #define ADS1015_DEFAULT_PGA		2
76 #define ADS1015_DEFAULT_DATA_RATE	4
77 #define ADS1015_DEFAULT_CHAN		0
78 
79 enum chip_ids {
80 	ADS1015,
81 	ADS1115,
82 };
83 
84 enum ads1015_channels {
85 	ADS1015_AIN0_AIN1 = 0,
86 	ADS1015_AIN0_AIN3,
87 	ADS1015_AIN1_AIN3,
88 	ADS1015_AIN2_AIN3,
89 	ADS1015_AIN0,
90 	ADS1015_AIN1,
91 	ADS1015_AIN2,
92 	ADS1015_AIN3,
93 	ADS1015_TIMESTAMP,
94 };
95 
96 static const unsigned int ads1015_data_rate[] = {
97 	128, 250, 490, 920, 1600, 2400, 3300, 3300
98 };
99 
100 static const unsigned int ads1115_data_rate[] = {
101 	8, 16, 32, 64, 128, 250, 475, 860
102 };
103 
104 /*
105  * Translation from PGA bits to full-scale positive and negative input voltage
106  * range in mV
107  */
108 static int ads1015_fullscale_range[] = {
109 	6144, 4096, 2048, 1024, 512, 256, 256, 256
110 };
111 
112 /*
113  * Translation from COMP_QUE field value to the number of successive readings
114  * exceed the threshold values before an interrupt is generated
115  */
116 static const int ads1015_comp_queue[] = { 1, 2, 4 };
117 
118 static const struct iio_event_spec ads1015_events[] = {
119 	{
120 		.type = IIO_EV_TYPE_THRESH,
121 		.dir = IIO_EV_DIR_RISING,
122 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
123 				BIT(IIO_EV_INFO_ENABLE),
124 	}, {
125 		.type = IIO_EV_TYPE_THRESH,
126 		.dir = IIO_EV_DIR_FALLING,
127 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
128 	}, {
129 		.type = IIO_EV_TYPE_THRESH,
130 		.dir = IIO_EV_DIR_EITHER,
131 		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
132 				BIT(IIO_EV_INFO_PERIOD),
133 	},
134 };
135 
136 #define ADS1015_V_CHAN(_chan, _addr) {				\
137 	.type = IIO_VOLTAGE,					\
138 	.indexed = 1,						\
139 	.address = _addr,					\
140 	.channel = _chan,					\
141 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
142 				BIT(IIO_CHAN_INFO_SCALE) |	\
143 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
144 	.scan_index = _addr,					\
145 	.scan_type = {						\
146 		.sign = 's',					\
147 		.realbits = 12,					\
148 		.storagebits = 16,				\
149 		.shift = 4,					\
150 		.endianness = IIO_CPU,				\
151 	},							\
152 	.event_spec = ads1015_events,				\
153 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
154 	.datasheet_name = "AIN"#_chan,				\
155 }
156 
157 #define ADS1015_V_DIFF_CHAN(_chan, _chan2, _addr) {		\
158 	.type = IIO_VOLTAGE,					\
159 	.differential = 1,					\
160 	.indexed = 1,						\
161 	.address = _addr,					\
162 	.channel = _chan,					\
163 	.channel2 = _chan2,					\
164 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
165 				BIT(IIO_CHAN_INFO_SCALE) |	\
166 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
167 	.scan_index = _addr,					\
168 	.scan_type = {						\
169 		.sign = 's',					\
170 		.realbits = 12,					\
171 		.storagebits = 16,				\
172 		.shift = 4,					\
173 		.endianness = IIO_CPU,				\
174 	},							\
175 	.event_spec = ads1015_events,				\
176 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
177 	.datasheet_name = "AIN"#_chan"-AIN"#_chan2,		\
178 }
179 
180 #define ADS1115_V_CHAN(_chan, _addr) {				\
181 	.type = IIO_VOLTAGE,					\
182 	.indexed = 1,						\
183 	.address = _addr,					\
184 	.channel = _chan,					\
185 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
186 				BIT(IIO_CHAN_INFO_SCALE) |	\
187 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
188 	.scan_index = _addr,					\
189 	.scan_type = {						\
190 		.sign = 's',					\
191 		.realbits = 16,					\
192 		.storagebits = 16,				\
193 		.endianness = IIO_CPU,				\
194 	},							\
195 	.event_spec = ads1015_events,				\
196 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
197 	.datasheet_name = "AIN"#_chan,				\
198 }
199 
200 #define ADS1115_V_DIFF_CHAN(_chan, _chan2, _addr) {		\
201 	.type = IIO_VOLTAGE,					\
202 	.differential = 1,					\
203 	.indexed = 1,						\
204 	.address = _addr,					\
205 	.channel = _chan,					\
206 	.channel2 = _chan2,					\
207 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
208 				BIT(IIO_CHAN_INFO_SCALE) |	\
209 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
210 	.scan_index = _addr,					\
211 	.scan_type = {						\
212 		.sign = 's',					\
213 		.realbits = 16,					\
214 		.storagebits = 16,				\
215 		.endianness = IIO_CPU,				\
216 	},							\
217 	.event_spec = ads1015_events,				\
218 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
219 	.datasheet_name = "AIN"#_chan"-AIN"#_chan2,		\
220 }
221 
222 struct ads1015_thresh_data {
223 	unsigned int comp_queue;
224 	int high_thresh;
225 	int low_thresh;
226 };
227 
228 struct ads1015_data {
229 	struct regmap *regmap;
230 	/*
231 	 * Protects ADC ops, e.g: concurrent sysfs/buffered
232 	 * data reads, configuration updates
233 	 */
234 	struct mutex lock;
235 	struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
236 
237 	unsigned int event_channel;
238 	unsigned int comp_mode;
239 	struct ads1015_thresh_data thresh_data[ADS1015_CHANNELS];
240 
241 	unsigned int *data_rate;
242 	/*
243 	 * Set to true when the ADC is switched to the continuous-conversion
244 	 * mode and exits from a power-down state.  This flag is used to avoid
245 	 * getting the stale result from the conversion register.
246 	 */
247 	bool conv_invalid;
248 };
249 
250 static bool ads1015_event_channel_enabled(struct ads1015_data *data)
251 {
252 	return (data->event_channel != ADS1015_CHANNELS);
253 }
254 
255 static void ads1015_event_channel_enable(struct ads1015_data *data, int chan,
256 					 int comp_mode)
257 {
258 	WARN_ON(ads1015_event_channel_enabled(data));
259 
260 	data->event_channel = chan;
261 	data->comp_mode = comp_mode;
262 }
263 
264 static void ads1015_event_channel_disable(struct ads1015_data *data, int chan)
265 {
266 	data->event_channel = ADS1015_CHANNELS;
267 }
268 
269 static bool ads1015_is_writeable_reg(struct device *dev, unsigned int reg)
270 {
271 	switch (reg) {
272 	case ADS1015_CFG_REG:
273 	case ADS1015_LO_THRESH_REG:
274 	case ADS1015_HI_THRESH_REG:
275 		return true;
276 	default:
277 		return false;
278 	}
279 }
280 
281 static const struct regmap_config ads1015_regmap_config = {
282 	.reg_bits = 8,
283 	.val_bits = 16,
284 	.max_register = ADS1015_HI_THRESH_REG,
285 	.writeable_reg = ads1015_is_writeable_reg,
286 };
287 
288 static const struct iio_chan_spec ads1015_channels[] = {
289 	ADS1015_V_DIFF_CHAN(0, 1, ADS1015_AIN0_AIN1),
290 	ADS1015_V_DIFF_CHAN(0, 3, ADS1015_AIN0_AIN3),
291 	ADS1015_V_DIFF_CHAN(1, 3, ADS1015_AIN1_AIN3),
292 	ADS1015_V_DIFF_CHAN(2, 3, ADS1015_AIN2_AIN3),
293 	ADS1015_V_CHAN(0, ADS1015_AIN0),
294 	ADS1015_V_CHAN(1, ADS1015_AIN1),
295 	ADS1015_V_CHAN(2, ADS1015_AIN2),
296 	ADS1015_V_CHAN(3, ADS1015_AIN3),
297 	IIO_CHAN_SOFT_TIMESTAMP(ADS1015_TIMESTAMP),
298 };
299 
300 static const struct iio_chan_spec ads1115_channels[] = {
301 	ADS1115_V_DIFF_CHAN(0, 1, ADS1015_AIN0_AIN1),
302 	ADS1115_V_DIFF_CHAN(0, 3, ADS1015_AIN0_AIN3),
303 	ADS1115_V_DIFF_CHAN(1, 3, ADS1015_AIN1_AIN3),
304 	ADS1115_V_DIFF_CHAN(2, 3, ADS1015_AIN2_AIN3),
305 	ADS1115_V_CHAN(0, ADS1015_AIN0),
306 	ADS1115_V_CHAN(1, ADS1015_AIN1),
307 	ADS1115_V_CHAN(2, ADS1015_AIN2),
308 	ADS1115_V_CHAN(3, ADS1015_AIN3),
309 	IIO_CHAN_SOFT_TIMESTAMP(ADS1015_TIMESTAMP),
310 };
311 
312 static int ads1015_set_power_state(struct ads1015_data *data, bool on)
313 {
314 	int ret;
315 	struct device *dev = regmap_get_device(data->regmap);
316 
317 	if (on) {
318 		ret = pm_runtime_get_sync(dev);
319 		if (ret < 0)
320 			pm_runtime_put_noidle(dev);
321 	} else {
322 		pm_runtime_mark_last_busy(dev);
323 		ret = pm_runtime_put_autosuspend(dev);
324 	}
325 
326 	return ret < 0 ? ret : 0;
327 }
328 
329 static
330 int ads1015_get_adc_result(struct ads1015_data *data, int chan, int *val)
331 {
332 	int ret, pga, dr, dr_old, conv_time;
333 	unsigned int old, mask, cfg;
334 
335 	if (chan < 0 || chan >= ADS1015_CHANNELS)
336 		return -EINVAL;
337 
338 	ret = regmap_read(data->regmap, ADS1015_CFG_REG, &old);
339 	if (ret)
340 		return ret;
341 
342 	pga = data->channel_data[chan].pga;
343 	dr = data->channel_data[chan].data_rate;
344 	mask = ADS1015_CFG_MUX_MASK | ADS1015_CFG_PGA_MASK |
345 		ADS1015_CFG_DR_MASK;
346 	cfg = chan << ADS1015_CFG_MUX_SHIFT | pga << ADS1015_CFG_PGA_SHIFT |
347 		dr << ADS1015_CFG_DR_SHIFT;
348 
349 	if (ads1015_event_channel_enabled(data)) {
350 		mask |= ADS1015_CFG_COMP_QUE_MASK | ADS1015_CFG_COMP_MODE_MASK;
351 		cfg |= data->thresh_data[chan].comp_queue <<
352 				ADS1015_CFG_COMP_QUE_SHIFT |
353 			data->comp_mode <<
354 				ADS1015_CFG_COMP_MODE_SHIFT;
355 	}
356 
357 	cfg = (old & ~mask) | (cfg & mask);
358 	if (old != cfg) {
359 		ret = regmap_write(data->regmap, ADS1015_CFG_REG, cfg);
360 		if (ret)
361 			return ret;
362 		data->conv_invalid = true;
363 	}
364 	if (data->conv_invalid) {
365 		dr_old = (old & ADS1015_CFG_DR_MASK) >> ADS1015_CFG_DR_SHIFT;
366 		conv_time = DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr_old]);
367 		conv_time += DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr]);
368 		conv_time += conv_time / 10; /* 10% internal clock inaccuracy */
369 		usleep_range(conv_time, conv_time + 1);
370 		data->conv_invalid = false;
371 	}
372 
373 	return regmap_read(data->regmap, ADS1015_CONV_REG, val);
374 }
375 
376 static irqreturn_t ads1015_trigger_handler(int irq, void *p)
377 {
378 	struct iio_poll_func *pf = p;
379 	struct iio_dev *indio_dev = pf->indio_dev;
380 	struct ads1015_data *data = iio_priv(indio_dev);
381 	s16 buf[8]; /* 1x s16 ADC val + 3x s16 padding +  4x s16 timestamp */
382 	int chan, ret, res;
383 
384 	memset(buf, 0, sizeof(buf));
385 
386 	mutex_lock(&data->lock);
387 	chan = find_first_bit(indio_dev->active_scan_mask,
388 			      indio_dev->masklength);
389 	ret = ads1015_get_adc_result(data, chan, &res);
390 	if (ret < 0) {
391 		mutex_unlock(&data->lock);
392 		goto err;
393 	}
394 
395 	buf[0] = res;
396 	mutex_unlock(&data->lock);
397 
398 	iio_push_to_buffers_with_timestamp(indio_dev, buf,
399 					   iio_get_time_ns(indio_dev));
400 
401 err:
402 	iio_trigger_notify_done(indio_dev->trig);
403 
404 	return IRQ_HANDLED;
405 }
406 
407 static int ads1015_set_scale(struct ads1015_data *data,
408 			     struct iio_chan_spec const *chan,
409 			     int scale, int uscale)
410 {
411 	int i;
412 	int fullscale = div_s64((scale * 1000000LL + uscale) <<
413 				(chan->scan_type.realbits - 1), 1000000);
414 
415 	for (i = 0; i < ARRAY_SIZE(ads1015_fullscale_range); i++) {
416 		if (ads1015_fullscale_range[i] == fullscale) {
417 			data->channel_data[chan->address].pga = i;
418 			return 0;
419 		}
420 	}
421 
422 	return -EINVAL;
423 }
424 
425 static int ads1015_set_data_rate(struct ads1015_data *data, int chan, int rate)
426 {
427 	int i;
428 
429 	for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++) {
430 		if (data->data_rate[i] == rate) {
431 			data->channel_data[chan].data_rate = i;
432 			return 0;
433 		}
434 	}
435 
436 	return -EINVAL;
437 }
438 
439 static int ads1015_read_raw(struct iio_dev *indio_dev,
440 			    struct iio_chan_spec const *chan, int *val,
441 			    int *val2, long mask)
442 {
443 	int ret, idx;
444 	struct ads1015_data *data = iio_priv(indio_dev);
445 
446 	mutex_lock(&data->lock);
447 	switch (mask) {
448 	case IIO_CHAN_INFO_RAW: {
449 		int shift = chan->scan_type.shift;
450 
451 		ret = iio_device_claim_direct_mode(indio_dev);
452 		if (ret)
453 			break;
454 
455 		if (ads1015_event_channel_enabled(data) &&
456 				data->event_channel != chan->address) {
457 			ret = -EBUSY;
458 			goto release_direct;
459 		}
460 
461 		ret = ads1015_set_power_state(data, true);
462 		if (ret < 0)
463 			goto release_direct;
464 
465 		ret = ads1015_get_adc_result(data, chan->address, val);
466 		if (ret < 0) {
467 			ads1015_set_power_state(data, false);
468 			goto release_direct;
469 		}
470 
471 		*val = sign_extend32(*val >> shift, 15 - shift);
472 
473 		ret = ads1015_set_power_state(data, false);
474 		if (ret < 0)
475 			goto release_direct;
476 
477 		ret = IIO_VAL_INT;
478 release_direct:
479 		iio_device_release_direct_mode(indio_dev);
480 		break;
481 	}
482 	case IIO_CHAN_INFO_SCALE:
483 		idx = data->channel_data[chan->address].pga;
484 		*val = ads1015_fullscale_range[idx];
485 		*val2 = chan->scan_type.realbits - 1;
486 		ret = IIO_VAL_FRACTIONAL_LOG2;
487 		break;
488 	case IIO_CHAN_INFO_SAMP_FREQ:
489 		idx = data->channel_data[chan->address].data_rate;
490 		*val = data->data_rate[idx];
491 		ret = IIO_VAL_INT;
492 		break;
493 	default:
494 		ret = -EINVAL;
495 		break;
496 	}
497 	mutex_unlock(&data->lock);
498 
499 	return ret;
500 }
501 
502 static int ads1015_write_raw(struct iio_dev *indio_dev,
503 			     struct iio_chan_spec const *chan, int val,
504 			     int val2, long mask)
505 {
506 	struct ads1015_data *data = iio_priv(indio_dev);
507 	int ret;
508 
509 	mutex_lock(&data->lock);
510 	switch (mask) {
511 	case IIO_CHAN_INFO_SCALE:
512 		ret = ads1015_set_scale(data, chan, val, val2);
513 		break;
514 	case IIO_CHAN_INFO_SAMP_FREQ:
515 		ret = ads1015_set_data_rate(data, chan->address, val);
516 		break;
517 	default:
518 		ret = -EINVAL;
519 		break;
520 	}
521 	mutex_unlock(&data->lock);
522 
523 	return ret;
524 }
525 
526 static int ads1015_read_event(struct iio_dev *indio_dev,
527 	const struct iio_chan_spec *chan, enum iio_event_type type,
528 	enum iio_event_direction dir, enum iio_event_info info, int *val,
529 	int *val2)
530 {
531 	struct ads1015_data *data = iio_priv(indio_dev);
532 	int ret;
533 	unsigned int comp_queue;
534 	int period;
535 	int dr;
536 
537 	mutex_lock(&data->lock);
538 
539 	switch (info) {
540 	case IIO_EV_INFO_VALUE:
541 		*val = (dir == IIO_EV_DIR_RISING) ?
542 			data->thresh_data[chan->address].high_thresh :
543 			data->thresh_data[chan->address].low_thresh;
544 		ret = IIO_VAL_INT;
545 		break;
546 	case IIO_EV_INFO_PERIOD:
547 		dr = data->channel_data[chan->address].data_rate;
548 		comp_queue = data->thresh_data[chan->address].comp_queue;
549 		period = ads1015_comp_queue[comp_queue] *
550 			USEC_PER_SEC / data->data_rate[dr];
551 
552 		*val = period / USEC_PER_SEC;
553 		*val2 = period % USEC_PER_SEC;
554 		ret = IIO_VAL_INT_PLUS_MICRO;
555 		break;
556 	default:
557 		ret = -EINVAL;
558 		break;
559 	}
560 
561 	mutex_unlock(&data->lock);
562 
563 	return ret;
564 }
565 
566 static int ads1015_write_event(struct iio_dev *indio_dev,
567 	const struct iio_chan_spec *chan, enum iio_event_type type,
568 	enum iio_event_direction dir, enum iio_event_info info, int val,
569 	int val2)
570 {
571 	struct ads1015_data *data = iio_priv(indio_dev);
572 	int realbits = chan->scan_type.realbits;
573 	int ret = 0;
574 	long long period;
575 	int i;
576 	int dr;
577 
578 	mutex_lock(&data->lock);
579 
580 	switch (info) {
581 	case IIO_EV_INFO_VALUE:
582 		if (val >= 1 << (realbits - 1) || val < -1 << (realbits - 1)) {
583 			ret = -EINVAL;
584 			break;
585 		}
586 		if (dir == IIO_EV_DIR_RISING)
587 			data->thresh_data[chan->address].high_thresh = val;
588 		else
589 			data->thresh_data[chan->address].low_thresh = val;
590 		break;
591 	case IIO_EV_INFO_PERIOD:
592 		dr = data->channel_data[chan->address].data_rate;
593 		period = val * USEC_PER_SEC + val2;
594 
595 		for (i = 0; i < ARRAY_SIZE(ads1015_comp_queue) - 1; i++) {
596 			if (period <= ads1015_comp_queue[i] *
597 					USEC_PER_SEC / data->data_rate[dr])
598 				break;
599 		}
600 		data->thresh_data[chan->address].comp_queue = i;
601 		break;
602 	default:
603 		ret = -EINVAL;
604 		break;
605 	}
606 
607 	mutex_unlock(&data->lock);
608 
609 	return ret;
610 }
611 
612 static int ads1015_read_event_config(struct iio_dev *indio_dev,
613 	const struct iio_chan_spec *chan, enum iio_event_type type,
614 	enum iio_event_direction dir)
615 {
616 	struct ads1015_data *data = iio_priv(indio_dev);
617 	int ret = 0;
618 
619 	mutex_lock(&data->lock);
620 	if (data->event_channel == chan->address) {
621 		switch (dir) {
622 		case IIO_EV_DIR_RISING:
623 			ret = 1;
624 			break;
625 		case IIO_EV_DIR_EITHER:
626 			ret = (data->comp_mode == ADS1015_CFG_COMP_MODE_WINDOW);
627 			break;
628 		default:
629 			ret = -EINVAL;
630 			break;
631 		}
632 	}
633 	mutex_unlock(&data->lock);
634 
635 	return ret;
636 }
637 
638 static int ads1015_enable_event_config(struct ads1015_data *data,
639 	const struct iio_chan_spec *chan, int comp_mode)
640 {
641 	int low_thresh = data->thresh_data[chan->address].low_thresh;
642 	int high_thresh = data->thresh_data[chan->address].high_thresh;
643 	int ret;
644 	unsigned int val;
645 
646 	if (ads1015_event_channel_enabled(data)) {
647 		if (data->event_channel != chan->address ||
648 			(data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD &&
649 				comp_mode == ADS1015_CFG_COMP_MODE_WINDOW))
650 			return -EBUSY;
651 
652 		return 0;
653 	}
654 
655 	if (comp_mode == ADS1015_CFG_COMP_MODE_TRAD) {
656 		low_thresh = max(-1 << (chan->scan_type.realbits - 1),
657 				high_thresh - 1);
658 	}
659 	ret = regmap_write(data->regmap, ADS1015_LO_THRESH_REG,
660 			low_thresh << chan->scan_type.shift);
661 	if (ret)
662 		return ret;
663 
664 	ret = regmap_write(data->regmap, ADS1015_HI_THRESH_REG,
665 			high_thresh << chan->scan_type.shift);
666 	if (ret)
667 		return ret;
668 
669 	ret = ads1015_set_power_state(data, true);
670 	if (ret < 0)
671 		return ret;
672 
673 	ads1015_event_channel_enable(data, chan->address, comp_mode);
674 
675 	ret = ads1015_get_adc_result(data, chan->address, &val);
676 	if (ret) {
677 		ads1015_event_channel_disable(data, chan->address);
678 		ads1015_set_power_state(data, false);
679 	}
680 
681 	return ret;
682 }
683 
684 static int ads1015_disable_event_config(struct ads1015_data *data,
685 	const struct iio_chan_spec *chan, int comp_mode)
686 {
687 	int ret;
688 
689 	if (!ads1015_event_channel_enabled(data))
690 		return 0;
691 
692 	if (data->event_channel != chan->address)
693 		return 0;
694 
695 	if (data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD &&
696 			comp_mode == ADS1015_CFG_COMP_MODE_WINDOW)
697 		return 0;
698 
699 	ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
700 				ADS1015_CFG_COMP_QUE_MASK,
701 				ADS1015_CFG_COMP_DISABLE <<
702 					ADS1015_CFG_COMP_QUE_SHIFT);
703 	if (ret)
704 		return ret;
705 
706 	ads1015_event_channel_disable(data, chan->address);
707 
708 	return ads1015_set_power_state(data, false);
709 }
710 
711 static int ads1015_write_event_config(struct iio_dev *indio_dev,
712 	const struct iio_chan_spec *chan, enum iio_event_type type,
713 	enum iio_event_direction dir, int state)
714 {
715 	struct ads1015_data *data = iio_priv(indio_dev);
716 	int ret;
717 	int comp_mode = (dir == IIO_EV_DIR_EITHER) ?
718 		ADS1015_CFG_COMP_MODE_WINDOW : ADS1015_CFG_COMP_MODE_TRAD;
719 
720 	mutex_lock(&data->lock);
721 
722 	/* Prevent from enabling both buffer and event at a time */
723 	ret = iio_device_claim_direct_mode(indio_dev);
724 	if (ret) {
725 		mutex_unlock(&data->lock);
726 		return ret;
727 	}
728 
729 	if (state)
730 		ret = ads1015_enable_event_config(data, chan, comp_mode);
731 	else
732 		ret = ads1015_disable_event_config(data, chan, comp_mode);
733 
734 	iio_device_release_direct_mode(indio_dev);
735 	mutex_unlock(&data->lock);
736 
737 	return ret;
738 }
739 
740 static irqreturn_t ads1015_event_handler(int irq, void *priv)
741 {
742 	struct iio_dev *indio_dev = priv;
743 	struct ads1015_data *data = iio_priv(indio_dev);
744 	int val;
745 	int ret;
746 
747 	/* Clear the latched ALERT/RDY pin */
748 	ret = regmap_read(data->regmap, ADS1015_CONV_REG, &val);
749 	if (ret)
750 		return IRQ_HANDLED;
751 
752 	if (ads1015_event_channel_enabled(data)) {
753 		enum iio_event_direction dir;
754 		u64 code;
755 
756 		dir = data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD ?
757 					IIO_EV_DIR_RISING : IIO_EV_DIR_EITHER;
758 		code = IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, data->event_channel,
759 					IIO_EV_TYPE_THRESH, dir);
760 		iio_push_event(indio_dev, code, iio_get_time_ns(indio_dev));
761 	}
762 
763 	return IRQ_HANDLED;
764 }
765 
766 static int ads1015_buffer_preenable(struct iio_dev *indio_dev)
767 {
768 	struct ads1015_data *data = iio_priv(indio_dev);
769 
770 	/* Prevent from enabling both buffer and event at a time */
771 	if (ads1015_event_channel_enabled(data))
772 		return -EBUSY;
773 
774 	return ads1015_set_power_state(iio_priv(indio_dev), true);
775 }
776 
777 static int ads1015_buffer_postdisable(struct iio_dev *indio_dev)
778 {
779 	return ads1015_set_power_state(iio_priv(indio_dev), false);
780 }
781 
782 static const struct iio_buffer_setup_ops ads1015_buffer_setup_ops = {
783 	.preenable	= ads1015_buffer_preenable,
784 	.postenable	= iio_triggered_buffer_postenable,
785 	.predisable	= iio_triggered_buffer_predisable,
786 	.postdisable	= ads1015_buffer_postdisable,
787 	.validate_scan_mask = &iio_validate_scan_mask_onehot,
788 };
789 
790 static IIO_CONST_ATTR_NAMED(ads1015_scale_available, scale_available,
791 	"3 2 1 0.5 0.25 0.125");
792 static IIO_CONST_ATTR_NAMED(ads1115_scale_available, scale_available,
793 	"0.1875 0.125 0.0625 0.03125 0.015625 0.007813");
794 
795 static IIO_CONST_ATTR_NAMED(ads1015_sampling_frequency_available,
796 	sampling_frequency_available, "128 250 490 920 1600 2400 3300");
797 static IIO_CONST_ATTR_NAMED(ads1115_sampling_frequency_available,
798 	sampling_frequency_available, "8 16 32 64 128 250 475 860");
799 
800 static struct attribute *ads1015_attributes[] = {
801 	&iio_const_attr_ads1015_scale_available.dev_attr.attr,
802 	&iio_const_attr_ads1015_sampling_frequency_available.dev_attr.attr,
803 	NULL,
804 };
805 
806 static const struct attribute_group ads1015_attribute_group = {
807 	.attrs = ads1015_attributes,
808 };
809 
810 static struct attribute *ads1115_attributes[] = {
811 	&iio_const_attr_ads1115_scale_available.dev_attr.attr,
812 	&iio_const_attr_ads1115_sampling_frequency_available.dev_attr.attr,
813 	NULL,
814 };
815 
816 static const struct attribute_group ads1115_attribute_group = {
817 	.attrs = ads1115_attributes,
818 };
819 
820 static const struct iio_info ads1015_info = {
821 	.read_raw	= ads1015_read_raw,
822 	.write_raw	= ads1015_write_raw,
823 	.read_event_value = ads1015_read_event,
824 	.write_event_value = ads1015_write_event,
825 	.read_event_config = ads1015_read_event_config,
826 	.write_event_config = ads1015_write_event_config,
827 	.attrs          = &ads1015_attribute_group,
828 };
829 
830 static const struct iio_info ads1115_info = {
831 	.read_raw	= ads1015_read_raw,
832 	.write_raw	= ads1015_write_raw,
833 	.read_event_value = ads1015_read_event,
834 	.write_event_value = ads1015_write_event,
835 	.read_event_config = ads1015_read_event_config,
836 	.write_event_config = ads1015_write_event_config,
837 	.attrs          = &ads1115_attribute_group,
838 };
839 
840 #ifdef CONFIG_OF
841 static int ads1015_get_channels_config_of(struct i2c_client *client)
842 {
843 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
844 	struct ads1015_data *data = iio_priv(indio_dev);
845 	struct device_node *node;
846 
847 	if (!client->dev.of_node ||
848 	    !of_get_next_child(client->dev.of_node, NULL))
849 		return -EINVAL;
850 
851 	for_each_child_of_node(client->dev.of_node, node) {
852 		u32 pval;
853 		unsigned int channel;
854 		unsigned int pga = ADS1015_DEFAULT_PGA;
855 		unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
856 
857 		if (of_property_read_u32(node, "reg", &pval)) {
858 			dev_err(&client->dev, "invalid reg on %pOF\n",
859 				node);
860 			continue;
861 		}
862 
863 		channel = pval;
864 		if (channel >= ADS1015_CHANNELS) {
865 			dev_err(&client->dev,
866 				"invalid channel index %d on %pOF\n",
867 				channel, node);
868 			continue;
869 		}
870 
871 		if (!of_property_read_u32(node, "ti,gain", &pval)) {
872 			pga = pval;
873 			if (pga > 6) {
874 				dev_err(&client->dev, "invalid gain on %pOF\n",
875 					node);
876 				of_node_put(node);
877 				return -EINVAL;
878 			}
879 		}
880 
881 		if (!of_property_read_u32(node, "ti,datarate", &pval)) {
882 			data_rate = pval;
883 			if (data_rate > 7) {
884 				dev_err(&client->dev,
885 					"invalid data_rate on %pOF\n",
886 					node);
887 				of_node_put(node);
888 				return -EINVAL;
889 			}
890 		}
891 
892 		data->channel_data[channel].pga = pga;
893 		data->channel_data[channel].data_rate = data_rate;
894 	}
895 
896 	return 0;
897 }
898 #endif
899 
900 static void ads1015_get_channels_config(struct i2c_client *client)
901 {
902 	unsigned int k;
903 
904 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
905 	struct ads1015_data *data = iio_priv(indio_dev);
906 	struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
907 
908 	/* prefer platform data */
909 	if (pdata) {
910 		memcpy(data->channel_data, pdata->channel_data,
911 		       sizeof(data->channel_data));
912 		return;
913 	}
914 
915 #ifdef CONFIG_OF
916 	if (!ads1015_get_channels_config_of(client))
917 		return;
918 #endif
919 	/* fallback on default configuration */
920 	for (k = 0; k < ADS1015_CHANNELS; ++k) {
921 		data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
922 		data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
923 	}
924 }
925 
926 static int ads1015_set_conv_mode(struct ads1015_data *data, int mode)
927 {
928 	return regmap_update_bits(data->regmap, ADS1015_CFG_REG,
929 				  ADS1015_CFG_MOD_MASK,
930 				  mode << ADS1015_CFG_MOD_SHIFT);
931 }
932 
933 static int ads1015_probe(struct i2c_client *client,
934 			 const struct i2c_device_id *id)
935 {
936 	struct iio_dev *indio_dev;
937 	struct ads1015_data *data;
938 	int ret;
939 	enum chip_ids chip;
940 	int i;
941 
942 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
943 	if (!indio_dev)
944 		return -ENOMEM;
945 
946 	data = iio_priv(indio_dev);
947 	i2c_set_clientdata(client, indio_dev);
948 
949 	mutex_init(&data->lock);
950 
951 	indio_dev->dev.parent = &client->dev;
952 	indio_dev->dev.of_node = client->dev.of_node;
953 	indio_dev->name = ADS1015_DRV_NAME;
954 	indio_dev->modes = INDIO_DIRECT_MODE;
955 
956 	if (client->dev.of_node)
957 		chip = (enum chip_ids)of_device_get_match_data(&client->dev);
958 	else
959 		chip = id->driver_data;
960 	switch (chip) {
961 	case ADS1015:
962 		indio_dev->channels = ads1015_channels;
963 		indio_dev->num_channels = ARRAY_SIZE(ads1015_channels);
964 		indio_dev->info = &ads1015_info;
965 		data->data_rate = (unsigned int *) &ads1015_data_rate;
966 		break;
967 	case ADS1115:
968 		indio_dev->channels = ads1115_channels;
969 		indio_dev->num_channels = ARRAY_SIZE(ads1115_channels);
970 		indio_dev->info = &ads1115_info;
971 		data->data_rate = (unsigned int *) &ads1115_data_rate;
972 		break;
973 	}
974 
975 	data->event_channel = ADS1015_CHANNELS;
976 	/*
977 	 * Set default lower and upper threshold to min and max value
978 	 * respectively.
979 	 */
980 	for (i = 0; i < ADS1015_CHANNELS; i++) {
981 		int realbits = indio_dev->channels[i].scan_type.realbits;
982 
983 		data->thresh_data[i].low_thresh = -1 << (realbits - 1);
984 		data->thresh_data[i].high_thresh = (1 << (realbits - 1)) - 1;
985 	}
986 
987 	/* we need to keep this ABI the same as used by hwmon ADS1015 driver */
988 	ads1015_get_channels_config(client);
989 
990 	data->regmap = devm_regmap_init_i2c(client, &ads1015_regmap_config);
991 	if (IS_ERR(data->regmap)) {
992 		dev_err(&client->dev, "Failed to allocate register map\n");
993 		return PTR_ERR(data->regmap);
994 	}
995 
996 	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
997 					      ads1015_trigger_handler,
998 					      &ads1015_buffer_setup_ops);
999 	if (ret < 0) {
1000 		dev_err(&client->dev, "iio triggered buffer setup failed\n");
1001 		return ret;
1002 	}
1003 
1004 	if (client->irq) {
1005 		unsigned long irq_trig =
1006 			irqd_get_trigger_type(irq_get_irq_data(client->irq));
1007 		unsigned int cfg_comp_mask = ADS1015_CFG_COMP_QUE_MASK |
1008 			ADS1015_CFG_COMP_LAT_MASK | ADS1015_CFG_COMP_POL_MASK;
1009 		unsigned int cfg_comp =
1010 			ADS1015_CFG_COMP_DISABLE << ADS1015_CFG_COMP_QUE_SHIFT |
1011 			1 << ADS1015_CFG_COMP_LAT_SHIFT;
1012 
1013 		switch (irq_trig) {
1014 		case IRQF_TRIGGER_LOW:
1015 			cfg_comp |= ADS1015_CFG_COMP_POL_LOW <<
1016 					ADS1015_CFG_COMP_POL_SHIFT;
1017 			break;
1018 		case IRQF_TRIGGER_HIGH:
1019 			cfg_comp |= ADS1015_CFG_COMP_POL_HIGH <<
1020 					ADS1015_CFG_COMP_POL_SHIFT;
1021 			break;
1022 		default:
1023 			return -EINVAL;
1024 		}
1025 
1026 		ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
1027 					cfg_comp_mask, cfg_comp);
1028 		if (ret)
1029 			return ret;
1030 
1031 		ret = devm_request_threaded_irq(&client->dev, client->irq,
1032 						NULL, ads1015_event_handler,
1033 						irq_trig | IRQF_ONESHOT,
1034 						client->name, indio_dev);
1035 		if (ret)
1036 			return ret;
1037 	}
1038 
1039 	ret = ads1015_set_conv_mode(data, ADS1015_CONTINUOUS);
1040 	if (ret)
1041 		return ret;
1042 
1043 	data->conv_invalid = true;
1044 
1045 	ret = pm_runtime_set_active(&client->dev);
1046 	if (ret)
1047 		return ret;
1048 	pm_runtime_set_autosuspend_delay(&client->dev, ADS1015_SLEEP_DELAY_MS);
1049 	pm_runtime_use_autosuspend(&client->dev);
1050 	pm_runtime_enable(&client->dev);
1051 
1052 	ret = iio_device_register(indio_dev);
1053 	if (ret < 0) {
1054 		dev_err(&client->dev, "Failed to register IIO device\n");
1055 		return ret;
1056 	}
1057 
1058 	return 0;
1059 }
1060 
1061 static int ads1015_remove(struct i2c_client *client)
1062 {
1063 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
1064 	struct ads1015_data *data = iio_priv(indio_dev);
1065 
1066 	iio_device_unregister(indio_dev);
1067 
1068 	pm_runtime_disable(&client->dev);
1069 	pm_runtime_set_suspended(&client->dev);
1070 	pm_runtime_put_noidle(&client->dev);
1071 
1072 	/* power down single shot mode */
1073 	return ads1015_set_conv_mode(data, ADS1015_SINGLESHOT);
1074 }
1075 
1076 #ifdef CONFIG_PM
1077 static int ads1015_runtime_suspend(struct device *dev)
1078 {
1079 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
1080 	struct ads1015_data *data = iio_priv(indio_dev);
1081 
1082 	return ads1015_set_conv_mode(data, ADS1015_SINGLESHOT);
1083 }
1084 
1085 static int ads1015_runtime_resume(struct device *dev)
1086 {
1087 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
1088 	struct ads1015_data *data = iio_priv(indio_dev);
1089 	int ret;
1090 
1091 	ret = ads1015_set_conv_mode(data, ADS1015_CONTINUOUS);
1092 	if (!ret)
1093 		data->conv_invalid = true;
1094 
1095 	return ret;
1096 }
1097 #endif
1098 
1099 static const struct dev_pm_ops ads1015_pm_ops = {
1100 	SET_RUNTIME_PM_OPS(ads1015_runtime_suspend,
1101 			   ads1015_runtime_resume, NULL)
1102 };
1103 
1104 static const struct i2c_device_id ads1015_id[] = {
1105 	{"ads1015", ADS1015},
1106 	{"ads1115", ADS1115},
1107 	{}
1108 };
1109 MODULE_DEVICE_TABLE(i2c, ads1015_id);
1110 
1111 static const struct of_device_id ads1015_of_match[] = {
1112 	{
1113 		.compatible = "ti,ads1015",
1114 		.data = (void *)ADS1015
1115 	},
1116 	{
1117 		.compatible = "ti,ads1115",
1118 		.data = (void *)ADS1115
1119 	},
1120 	{}
1121 };
1122 MODULE_DEVICE_TABLE(of, ads1015_of_match);
1123 
1124 static struct i2c_driver ads1015_driver = {
1125 	.driver = {
1126 		.name = ADS1015_DRV_NAME,
1127 		.of_match_table = ads1015_of_match,
1128 		.pm = &ads1015_pm_ops,
1129 	},
1130 	.probe		= ads1015_probe,
1131 	.remove		= ads1015_remove,
1132 	.id_table	= ads1015_id,
1133 };
1134 
1135 module_i2c_driver(ads1015_driver);
1136 
1137 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
1138 MODULE_DESCRIPTION("Texas Instruments ADS1015 ADC driver");
1139 MODULE_LICENSE("GPL v2");
1140