xref: /openbmc/linux/drivers/iio/adc/ti-ads1015.c (revision 808643ea)
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/init.h>
16 #include <linux/irq.h>
17 #include <linux/i2c.h>
18 #include <linux/property.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/iio/iio.h>
25 #include <linux/iio/types.h>
26 #include <linux/iio/sysfs.h>
27 #include <linux/iio/events.h>
28 #include <linux/iio/buffer.h>
29 #include <linux/iio/triggered_buffer.h>
30 #include <linux/iio/trigger_consumer.h>
31 
32 #define ADS1015_DRV_NAME "ads1015"
33 
34 #define ADS1015_CHANNELS 8
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 	ADSXXXX = 0,
81 	ADS1015,
82 	ADS1115,
83 };
84 
85 enum ads1015_channels {
86 	ADS1015_AIN0_AIN1 = 0,
87 	ADS1015_AIN0_AIN3,
88 	ADS1015_AIN1_AIN3,
89 	ADS1015_AIN2_AIN3,
90 	ADS1015_AIN0,
91 	ADS1015_AIN1,
92 	ADS1015_AIN2,
93 	ADS1015_AIN3,
94 	ADS1015_TIMESTAMP,
95 };
96 
97 static const unsigned int ads1015_data_rate[] = {
98 	128, 250, 490, 920, 1600, 2400, 3300, 3300
99 };
100 
101 static const unsigned int ads1115_data_rate[] = {
102 	8, 16, 32, 64, 128, 250, 475, 860
103 };
104 
105 /*
106  * Translation from PGA bits to full-scale positive and negative input voltage
107  * range in mV
108  */
109 static int ads1015_fullscale_range[] = {
110 	6144, 4096, 2048, 1024, 512, 256, 256, 256
111 };
112 
113 /*
114  * Translation from COMP_QUE field value to the number of successive readings
115  * exceed the threshold values before an interrupt is generated
116  */
117 static const int ads1015_comp_queue[] = { 1, 2, 4 };
118 
119 static const struct iio_event_spec ads1015_events[] = {
120 	{
121 		.type = IIO_EV_TYPE_THRESH,
122 		.dir = IIO_EV_DIR_RISING,
123 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
124 				BIT(IIO_EV_INFO_ENABLE),
125 	}, {
126 		.type = IIO_EV_TYPE_THRESH,
127 		.dir = IIO_EV_DIR_FALLING,
128 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
129 	}, {
130 		.type = IIO_EV_TYPE_THRESH,
131 		.dir = IIO_EV_DIR_EITHER,
132 		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
133 				BIT(IIO_EV_INFO_PERIOD),
134 	},
135 };
136 
137 #define ADS1015_V_CHAN(_chan, _addr) {				\
138 	.type = IIO_VOLTAGE,					\
139 	.indexed = 1,						\
140 	.address = _addr,					\
141 	.channel = _chan,					\
142 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
143 				BIT(IIO_CHAN_INFO_SCALE) |	\
144 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
145 	.scan_index = _addr,					\
146 	.scan_type = {						\
147 		.sign = 's',					\
148 		.realbits = 12,					\
149 		.storagebits = 16,				\
150 		.shift = 4,					\
151 		.endianness = IIO_CPU,				\
152 	},							\
153 	.event_spec = ads1015_events,				\
154 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
155 	.datasheet_name = "AIN"#_chan,				\
156 }
157 
158 #define ADS1015_V_DIFF_CHAN(_chan, _chan2, _addr) {		\
159 	.type = IIO_VOLTAGE,					\
160 	.differential = 1,					\
161 	.indexed = 1,						\
162 	.address = _addr,					\
163 	.channel = _chan,					\
164 	.channel2 = _chan2,					\
165 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
166 				BIT(IIO_CHAN_INFO_SCALE) |	\
167 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
168 	.scan_index = _addr,					\
169 	.scan_type = {						\
170 		.sign = 's',					\
171 		.realbits = 12,					\
172 		.storagebits = 16,				\
173 		.shift = 4,					\
174 		.endianness = IIO_CPU,				\
175 	},							\
176 	.event_spec = ads1015_events,				\
177 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
178 	.datasheet_name = "AIN"#_chan"-AIN"#_chan2,		\
179 }
180 
181 #define ADS1115_V_CHAN(_chan, _addr) {				\
182 	.type = IIO_VOLTAGE,					\
183 	.indexed = 1,						\
184 	.address = _addr,					\
185 	.channel = _chan,					\
186 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
187 				BIT(IIO_CHAN_INFO_SCALE) |	\
188 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
189 	.scan_index = _addr,					\
190 	.scan_type = {						\
191 		.sign = 's',					\
192 		.realbits = 16,					\
193 		.storagebits = 16,				\
194 		.endianness = IIO_CPU,				\
195 	},							\
196 	.event_spec = ads1015_events,				\
197 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
198 	.datasheet_name = "AIN"#_chan,				\
199 }
200 
201 #define ADS1115_V_DIFF_CHAN(_chan, _chan2, _addr) {		\
202 	.type = IIO_VOLTAGE,					\
203 	.differential = 1,					\
204 	.indexed = 1,						\
205 	.address = _addr,					\
206 	.channel = _chan,					\
207 	.channel2 = _chan2,					\
208 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
209 				BIT(IIO_CHAN_INFO_SCALE) |	\
210 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
211 	.scan_index = _addr,					\
212 	.scan_type = {						\
213 		.sign = 's',					\
214 		.realbits = 16,					\
215 		.storagebits = 16,				\
216 		.endianness = IIO_CPU,				\
217 	},							\
218 	.event_spec = ads1015_events,				\
219 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
220 	.datasheet_name = "AIN"#_chan"-AIN"#_chan2,		\
221 }
222 
223 struct ads1015_channel_data {
224 	bool enabled;
225 	unsigned int pga;
226 	unsigned int data_rate;
227 };
228 
229 struct ads1015_thresh_data {
230 	unsigned int comp_queue;
231 	int high_thresh;
232 	int low_thresh;
233 };
234 
235 struct ads1015_data {
236 	struct regmap *regmap;
237 	/*
238 	 * Protects ADC ops, e.g: concurrent sysfs/buffered
239 	 * data reads, configuration updates
240 	 */
241 	struct mutex lock;
242 	struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
243 
244 	unsigned int event_channel;
245 	unsigned int comp_mode;
246 	struct ads1015_thresh_data thresh_data[ADS1015_CHANNELS];
247 
248 	unsigned int *data_rate;
249 	/*
250 	 * Set to true when the ADC is switched to the continuous-conversion
251 	 * mode and exits from a power-down state.  This flag is used to avoid
252 	 * getting the stale result from the conversion register.
253 	 */
254 	bool conv_invalid;
255 };
256 
257 static bool ads1015_event_channel_enabled(struct ads1015_data *data)
258 {
259 	return (data->event_channel != ADS1015_CHANNELS);
260 }
261 
262 static void ads1015_event_channel_enable(struct ads1015_data *data, int chan,
263 					 int comp_mode)
264 {
265 	WARN_ON(ads1015_event_channel_enabled(data));
266 
267 	data->event_channel = chan;
268 	data->comp_mode = comp_mode;
269 }
270 
271 static void ads1015_event_channel_disable(struct ads1015_data *data, int chan)
272 {
273 	data->event_channel = ADS1015_CHANNELS;
274 }
275 
276 static bool ads1015_is_writeable_reg(struct device *dev, unsigned int reg)
277 {
278 	switch (reg) {
279 	case ADS1015_CFG_REG:
280 	case ADS1015_LO_THRESH_REG:
281 	case ADS1015_HI_THRESH_REG:
282 		return true;
283 	default:
284 		return false;
285 	}
286 }
287 
288 static const struct regmap_config ads1015_regmap_config = {
289 	.reg_bits = 8,
290 	.val_bits = 16,
291 	.max_register = ADS1015_HI_THRESH_REG,
292 	.writeable_reg = ads1015_is_writeable_reg,
293 };
294 
295 static const struct iio_chan_spec ads1015_channels[] = {
296 	ADS1015_V_DIFF_CHAN(0, 1, ADS1015_AIN0_AIN1),
297 	ADS1015_V_DIFF_CHAN(0, 3, ADS1015_AIN0_AIN3),
298 	ADS1015_V_DIFF_CHAN(1, 3, ADS1015_AIN1_AIN3),
299 	ADS1015_V_DIFF_CHAN(2, 3, ADS1015_AIN2_AIN3),
300 	ADS1015_V_CHAN(0, ADS1015_AIN0),
301 	ADS1015_V_CHAN(1, ADS1015_AIN1),
302 	ADS1015_V_CHAN(2, ADS1015_AIN2),
303 	ADS1015_V_CHAN(3, ADS1015_AIN3),
304 	IIO_CHAN_SOFT_TIMESTAMP(ADS1015_TIMESTAMP),
305 };
306 
307 static const struct iio_chan_spec ads1115_channels[] = {
308 	ADS1115_V_DIFF_CHAN(0, 1, ADS1015_AIN0_AIN1),
309 	ADS1115_V_DIFF_CHAN(0, 3, ADS1015_AIN0_AIN3),
310 	ADS1115_V_DIFF_CHAN(1, 3, ADS1015_AIN1_AIN3),
311 	ADS1115_V_DIFF_CHAN(2, 3, ADS1015_AIN2_AIN3),
312 	ADS1115_V_CHAN(0, ADS1015_AIN0),
313 	ADS1115_V_CHAN(1, ADS1015_AIN1),
314 	ADS1115_V_CHAN(2, ADS1015_AIN2),
315 	ADS1115_V_CHAN(3, ADS1015_AIN3),
316 	IIO_CHAN_SOFT_TIMESTAMP(ADS1015_TIMESTAMP),
317 };
318 
319 #ifdef CONFIG_PM
320 static int ads1015_set_power_state(struct ads1015_data *data, bool on)
321 {
322 	int ret;
323 	struct device *dev = regmap_get_device(data->regmap);
324 
325 	if (on) {
326 		ret = pm_runtime_resume_and_get(dev);
327 	} else {
328 		pm_runtime_mark_last_busy(dev);
329 		ret = pm_runtime_put_autosuspend(dev);
330 	}
331 
332 	return ret < 0 ? ret : 0;
333 }
334 
335 #else /* !CONFIG_PM */
336 
337 static int ads1015_set_power_state(struct ads1015_data *data, bool on)
338 {
339 	return 0;
340 }
341 
342 #endif /* !CONFIG_PM */
343 
344 static
345 int ads1015_get_adc_result(struct ads1015_data *data, int chan, int *val)
346 {
347 	int ret, pga, dr, dr_old, conv_time;
348 	unsigned int old, mask, cfg;
349 
350 	if (chan < 0 || chan >= ADS1015_CHANNELS)
351 		return -EINVAL;
352 
353 	ret = regmap_read(data->regmap, ADS1015_CFG_REG, &old);
354 	if (ret)
355 		return ret;
356 
357 	pga = data->channel_data[chan].pga;
358 	dr = data->channel_data[chan].data_rate;
359 	mask = ADS1015_CFG_MUX_MASK | ADS1015_CFG_PGA_MASK |
360 		ADS1015_CFG_DR_MASK;
361 	cfg = chan << ADS1015_CFG_MUX_SHIFT | pga << ADS1015_CFG_PGA_SHIFT |
362 		dr << ADS1015_CFG_DR_SHIFT;
363 
364 	if (ads1015_event_channel_enabled(data)) {
365 		mask |= ADS1015_CFG_COMP_QUE_MASK | ADS1015_CFG_COMP_MODE_MASK;
366 		cfg |= data->thresh_data[chan].comp_queue <<
367 				ADS1015_CFG_COMP_QUE_SHIFT |
368 			data->comp_mode <<
369 				ADS1015_CFG_COMP_MODE_SHIFT;
370 	}
371 
372 	cfg = (old & ~mask) | (cfg & mask);
373 	if (old != cfg) {
374 		ret = regmap_write(data->regmap, ADS1015_CFG_REG, cfg);
375 		if (ret)
376 			return ret;
377 		data->conv_invalid = true;
378 	}
379 	if (data->conv_invalid) {
380 		dr_old = (old & ADS1015_CFG_DR_MASK) >> ADS1015_CFG_DR_SHIFT;
381 		conv_time = DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr_old]);
382 		conv_time += DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr]);
383 		conv_time += conv_time / 10; /* 10% internal clock inaccuracy */
384 		usleep_range(conv_time, conv_time + 1);
385 		data->conv_invalid = false;
386 	}
387 
388 	return regmap_read(data->regmap, ADS1015_CONV_REG, val);
389 }
390 
391 static irqreturn_t ads1015_trigger_handler(int irq, void *p)
392 {
393 	struct iio_poll_func *pf = p;
394 	struct iio_dev *indio_dev = pf->indio_dev;
395 	struct ads1015_data *data = iio_priv(indio_dev);
396 	/* Ensure natural alignment of timestamp */
397 	struct {
398 		s16 chan;
399 		s64 timestamp __aligned(8);
400 	} scan;
401 	int chan, ret, res;
402 
403 	memset(&scan, 0, sizeof(scan));
404 
405 	mutex_lock(&data->lock);
406 	chan = find_first_bit(indio_dev->active_scan_mask,
407 			      indio_dev->masklength);
408 	ret = ads1015_get_adc_result(data, chan, &res);
409 	if (ret < 0) {
410 		mutex_unlock(&data->lock);
411 		goto err;
412 	}
413 
414 	scan.chan = res;
415 	mutex_unlock(&data->lock);
416 
417 	iio_push_to_buffers_with_timestamp(indio_dev, &scan,
418 					   iio_get_time_ns(indio_dev));
419 
420 err:
421 	iio_trigger_notify_done(indio_dev->trig);
422 
423 	return IRQ_HANDLED;
424 }
425 
426 static int ads1015_set_scale(struct ads1015_data *data,
427 			     struct iio_chan_spec const *chan,
428 			     int scale, int uscale)
429 {
430 	int i;
431 	int fullscale = div_s64((scale * 1000000LL + uscale) <<
432 				(chan->scan_type.realbits - 1), 1000000);
433 
434 	for (i = 0; i < ARRAY_SIZE(ads1015_fullscale_range); i++) {
435 		if (ads1015_fullscale_range[i] == fullscale) {
436 			data->channel_data[chan->address].pga = i;
437 			return 0;
438 		}
439 	}
440 
441 	return -EINVAL;
442 }
443 
444 static int ads1015_set_data_rate(struct ads1015_data *data, int chan, int rate)
445 {
446 	int i;
447 
448 	for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++) {
449 		if (data->data_rate[i] == rate) {
450 			data->channel_data[chan].data_rate = i;
451 			return 0;
452 		}
453 	}
454 
455 	return -EINVAL;
456 }
457 
458 static int ads1015_read_raw(struct iio_dev *indio_dev,
459 			    struct iio_chan_spec const *chan, int *val,
460 			    int *val2, long mask)
461 {
462 	int ret, idx;
463 	struct ads1015_data *data = iio_priv(indio_dev);
464 
465 	mutex_lock(&data->lock);
466 	switch (mask) {
467 	case IIO_CHAN_INFO_RAW: {
468 		int shift = chan->scan_type.shift;
469 
470 		ret = iio_device_claim_direct_mode(indio_dev);
471 		if (ret)
472 			break;
473 
474 		if (ads1015_event_channel_enabled(data) &&
475 				data->event_channel != chan->address) {
476 			ret = -EBUSY;
477 			goto release_direct;
478 		}
479 
480 		ret = ads1015_set_power_state(data, true);
481 		if (ret < 0)
482 			goto release_direct;
483 
484 		ret = ads1015_get_adc_result(data, chan->address, val);
485 		if (ret < 0) {
486 			ads1015_set_power_state(data, false);
487 			goto release_direct;
488 		}
489 
490 		*val = sign_extend32(*val >> shift, 15 - shift);
491 
492 		ret = ads1015_set_power_state(data, false);
493 		if (ret < 0)
494 			goto release_direct;
495 
496 		ret = IIO_VAL_INT;
497 release_direct:
498 		iio_device_release_direct_mode(indio_dev);
499 		break;
500 	}
501 	case IIO_CHAN_INFO_SCALE:
502 		idx = data->channel_data[chan->address].pga;
503 		*val = ads1015_fullscale_range[idx];
504 		*val2 = chan->scan_type.realbits - 1;
505 		ret = IIO_VAL_FRACTIONAL_LOG2;
506 		break;
507 	case IIO_CHAN_INFO_SAMP_FREQ:
508 		idx = data->channel_data[chan->address].data_rate;
509 		*val = data->data_rate[idx];
510 		ret = IIO_VAL_INT;
511 		break;
512 	default:
513 		ret = -EINVAL;
514 		break;
515 	}
516 	mutex_unlock(&data->lock);
517 
518 	return ret;
519 }
520 
521 static int ads1015_write_raw(struct iio_dev *indio_dev,
522 			     struct iio_chan_spec const *chan, int val,
523 			     int val2, long mask)
524 {
525 	struct ads1015_data *data = iio_priv(indio_dev);
526 	int ret;
527 
528 	mutex_lock(&data->lock);
529 	switch (mask) {
530 	case IIO_CHAN_INFO_SCALE:
531 		ret = ads1015_set_scale(data, chan, val, val2);
532 		break;
533 	case IIO_CHAN_INFO_SAMP_FREQ:
534 		ret = ads1015_set_data_rate(data, chan->address, val);
535 		break;
536 	default:
537 		ret = -EINVAL;
538 		break;
539 	}
540 	mutex_unlock(&data->lock);
541 
542 	return ret;
543 }
544 
545 static int ads1015_read_event(struct iio_dev *indio_dev,
546 	const struct iio_chan_spec *chan, enum iio_event_type type,
547 	enum iio_event_direction dir, enum iio_event_info info, int *val,
548 	int *val2)
549 {
550 	struct ads1015_data *data = iio_priv(indio_dev);
551 	int ret;
552 	unsigned int comp_queue;
553 	int period;
554 	int dr;
555 
556 	mutex_lock(&data->lock);
557 
558 	switch (info) {
559 	case IIO_EV_INFO_VALUE:
560 		*val = (dir == IIO_EV_DIR_RISING) ?
561 			data->thresh_data[chan->address].high_thresh :
562 			data->thresh_data[chan->address].low_thresh;
563 		ret = IIO_VAL_INT;
564 		break;
565 	case IIO_EV_INFO_PERIOD:
566 		dr = data->channel_data[chan->address].data_rate;
567 		comp_queue = data->thresh_data[chan->address].comp_queue;
568 		period = ads1015_comp_queue[comp_queue] *
569 			USEC_PER_SEC / data->data_rate[dr];
570 
571 		*val = period / USEC_PER_SEC;
572 		*val2 = period % USEC_PER_SEC;
573 		ret = IIO_VAL_INT_PLUS_MICRO;
574 		break;
575 	default:
576 		ret = -EINVAL;
577 		break;
578 	}
579 
580 	mutex_unlock(&data->lock);
581 
582 	return ret;
583 }
584 
585 static int ads1015_write_event(struct iio_dev *indio_dev,
586 	const struct iio_chan_spec *chan, enum iio_event_type type,
587 	enum iio_event_direction dir, enum iio_event_info info, int val,
588 	int val2)
589 {
590 	struct ads1015_data *data = iio_priv(indio_dev);
591 	int realbits = chan->scan_type.realbits;
592 	int ret = 0;
593 	long long period;
594 	int i;
595 	int dr;
596 
597 	mutex_lock(&data->lock);
598 
599 	switch (info) {
600 	case IIO_EV_INFO_VALUE:
601 		if (val >= 1 << (realbits - 1) || val < -1 << (realbits - 1)) {
602 			ret = -EINVAL;
603 			break;
604 		}
605 		if (dir == IIO_EV_DIR_RISING)
606 			data->thresh_data[chan->address].high_thresh = val;
607 		else
608 			data->thresh_data[chan->address].low_thresh = val;
609 		break;
610 	case IIO_EV_INFO_PERIOD:
611 		dr = data->channel_data[chan->address].data_rate;
612 		period = val * USEC_PER_SEC + val2;
613 
614 		for (i = 0; i < ARRAY_SIZE(ads1015_comp_queue) - 1; i++) {
615 			if (period <= ads1015_comp_queue[i] *
616 					USEC_PER_SEC / data->data_rate[dr])
617 				break;
618 		}
619 		data->thresh_data[chan->address].comp_queue = i;
620 		break;
621 	default:
622 		ret = -EINVAL;
623 		break;
624 	}
625 
626 	mutex_unlock(&data->lock);
627 
628 	return ret;
629 }
630 
631 static int ads1015_read_event_config(struct iio_dev *indio_dev,
632 	const struct iio_chan_spec *chan, enum iio_event_type type,
633 	enum iio_event_direction dir)
634 {
635 	struct ads1015_data *data = iio_priv(indio_dev);
636 	int ret = 0;
637 
638 	mutex_lock(&data->lock);
639 	if (data->event_channel == chan->address) {
640 		switch (dir) {
641 		case IIO_EV_DIR_RISING:
642 			ret = 1;
643 			break;
644 		case IIO_EV_DIR_EITHER:
645 			ret = (data->comp_mode == ADS1015_CFG_COMP_MODE_WINDOW);
646 			break;
647 		default:
648 			ret = -EINVAL;
649 			break;
650 		}
651 	}
652 	mutex_unlock(&data->lock);
653 
654 	return ret;
655 }
656 
657 static int ads1015_enable_event_config(struct ads1015_data *data,
658 	const struct iio_chan_spec *chan, int comp_mode)
659 {
660 	int low_thresh = data->thresh_data[chan->address].low_thresh;
661 	int high_thresh = data->thresh_data[chan->address].high_thresh;
662 	int ret;
663 	unsigned int val;
664 
665 	if (ads1015_event_channel_enabled(data)) {
666 		if (data->event_channel != chan->address ||
667 			(data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD &&
668 				comp_mode == ADS1015_CFG_COMP_MODE_WINDOW))
669 			return -EBUSY;
670 
671 		return 0;
672 	}
673 
674 	if (comp_mode == ADS1015_CFG_COMP_MODE_TRAD) {
675 		low_thresh = max(-1 << (chan->scan_type.realbits - 1),
676 				high_thresh - 1);
677 	}
678 	ret = regmap_write(data->regmap, ADS1015_LO_THRESH_REG,
679 			low_thresh << chan->scan_type.shift);
680 	if (ret)
681 		return ret;
682 
683 	ret = regmap_write(data->regmap, ADS1015_HI_THRESH_REG,
684 			high_thresh << chan->scan_type.shift);
685 	if (ret)
686 		return ret;
687 
688 	ret = ads1015_set_power_state(data, true);
689 	if (ret < 0)
690 		return ret;
691 
692 	ads1015_event_channel_enable(data, chan->address, comp_mode);
693 
694 	ret = ads1015_get_adc_result(data, chan->address, &val);
695 	if (ret) {
696 		ads1015_event_channel_disable(data, chan->address);
697 		ads1015_set_power_state(data, false);
698 	}
699 
700 	return ret;
701 }
702 
703 static int ads1015_disable_event_config(struct ads1015_data *data,
704 	const struct iio_chan_spec *chan, int comp_mode)
705 {
706 	int ret;
707 
708 	if (!ads1015_event_channel_enabled(data))
709 		return 0;
710 
711 	if (data->event_channel != chan->address)
712 		return 0;
713 
714 	if (data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD &&
715 			comp_mode == ADS1015_CFG_COMP_MODE_WINDOW)
716 		return 0;
717 
718 	ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
719 				ADS1015_CFG_COMP_QUE_MASK,
720 				ADS1015_CFG_COMP_DISABLE <<
721 					ADS1015_CFG_COMP_QUE_SHIFT);
722 	if (ret)
723 		return ret;
724 
725 	ads1015_event_channel_disable(data, chan->address);
726 
727 	return ads1015_set_power_state(data, false);
728 }
729 
730 static int ads1015_write_event_config(struct iio_dev *indio_dev,
731 	const struct iio_chan_spec *chan, enum iio_event_type type,
732 	enum iio_event_direction dir, int state)
733 {
734 	struct ads1015_data *data = iio_priv(indio_dev);
735 	int ret;
736 	int comp_mode = (dir == IIO_EV_DIR_EITHER) ?
737 		ADS1015_CFG_COMP_MODE_WINDOW : ADS1015_CFG_COMP_MODE_TRAD;
738 
739 	mutex_lock(&data->lock);
740 
741 	/* Prevent from enabling both buffer and event at a time */
742 	ret = iio_device_claim_direct_mode(indio_dev);
743 	if (ret) {
744 		mutex_unlock(&data->lock);
745 		return ret;
746 	}
747 
748 	if (state)
749 		ret = ads1015_enable_event_config(data, chan, comp_mode);
750 	else
751 		ret = ads1015_disable_event_config(data, chan, comp_mode);
752 
753 	iio_device_release_direct_mode(indio_dev);
754 	mutex_unlock(&data->lock);
755 
756 	return ret;
757 }
758 
759 static irqreturn_t ads1015_event_handler(int irq, void *priv)
760 {
761 	struct iio_dev *indio_dev = priv;
762 	struct ads1015_data *data = iio_priv(indio_dev);
763 	int val;
764 	int ret;
765 
766 	/* Clear the latched ALERT/RDY pin */
767 	ret = regmap_read(data->regmap, ADS1015_CONV_REG, &val);
768 	if (ret)
769 		return IRQ_HANDLED;
770 
771 	if (ads1015_event_channel_enabled(data)) {
772 		enum iio_event_direction dir;
773 		u64 code;
774 
775 		dir = data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD ?
776 					IIO_EV_DIR_RISING : IIO_EV_DIR_EITHER;
777 		code = IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, data->event_channel,
778 					IIO_EV_TYPE_THRESH, dir);
779 		iio_push_event(indio_dev, code, iio_get_time_ns(indio_dev));
780 	}
781 
782 	return IRQ_HANDLED;
783 }
784 
785 static int ads1015_buffer_preenable(struct iio_dev *indio_dev)
786 {
787 	struct ads1015_data *data = iio_priv(indio_dev);
788 
789 	/* Prevent from enabling both buffer and event at a time */
790 	if (ads1015_event_channel_enabled(data))
791 		return -EBUSY;
792 
793 	return ads1015_set_power_state(iio_priv(indio_dev), true);
794 }
795 
796 static int ads1015_buffer_postdisable(struct iio_dev *indio_dev)
797 {
798 	return ads1015_set_power_state(iio_priv(indio_dev), false);
799 }
800 
801 static const struct iio_buffer_setup_ops ads1015_buffer_setup_ops = {
802 	.preenable	= ads1015_buffer_preenable,
803 	.postdisable	= ads1015_buffer_postdisable,
804 	.validate_scan_mask = &iio_validate_scan_mask_onehot,
805 };
806 
807 static IIO_CONST_ATTR_NAMED(ads1015_scale_available, scale_available,
808 	"3 2 1 0.5 0.25 0.125");
809 static IIO_CONST_ATTR_NAMED(ads1115_scale_available, scale_available,
810 	"0.1875 0.125 0.0625 0.03125 0.015625 0.007813");
811 
812 static IIO_CONST_ATTR_NAMED(ads1015_sampling_frequency_available,
813 	sampling_frequency_available, "128 250 490 920 1600 2400 3300");
814 static IIO_CONST_ATTR_NAMED(ads1115_sampling_frequency_available,
815 	sampling_frequency_available, "8 16 32 64 128 250 475 860");
816 
817 static struct attribute *ads1015_attributes[] = {
818 	&iio_const_attr_ads1015_scale_available.dev_attr.attr,
819 	&iio_const_attr_ads1015_sampling_frequency_available.dev_attr.attr,
820 	NULL,
821 };
822 
823 static const struct attribute_group ads1015_attribute_group = {
824 	.attrs = ads1015_attributes,
825 };
826 
827 static struct attribute *ads1115_attributes[] = {
828 	&iio_const_attr_ads1115_scale_available.dev_attr.attr,
829 	&iio_const_attr_ads1115_sampling_frequency_available.dev_attr.attr,
830 	NULL,
831 };
832 
833 static const struct attribute_group ads1115_attribute_group = {
834 	.attrs = ads1115_attributes,
835 };
836 
837 static const struct iio_info ads1015_info = {
838 	.read_raw	= ads1015_read_raw,
839 	.write_raw	= ads1015_write_raw,
840 	.read_event_value = ads1015_read_event,
841 	.write_event_value = ads1015_write_event,
842 	.read_event_config = ads1015_read_event_config,
843 	.write_event_config = ads1015_write_event_config,
844 	.attrs          = &ads1015_attribute_group,
845 };
846 
847 static const struct iio_info ads1115_info = {
848 	.read_raw	= ads1015_read_raw,
849 	.write_raw	= ads1015_write_raw,
850 	.read_event_value = ads1015_read_event,
851 	.write_event_value = ads1015_write_event,
852 	.read_event_config = ads1015_read_event_config,
853 	.write_event_config = ads1015_write_event_config,
854 	.attrs          = &ads1115_attribute_group,
855 };
856 
857 static int ads1015_client_get_channels_config(struct i2c_client *client)
858 {
859 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
860 	struct ads1015_data *data = iio_priv(indio_dev);
861 	struct device *dev = &client->dev;
862 	struct fwnode_handle *node;
863 	int i = -1;
864 
865 	device_for_each_child_node(dev, node) {
866 		u32 pval;
867 		unsigned int channel;
868 		unsigned int pga = ADS1015_DEFAULT_PGA;
869 		unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
870 
871 		if (fwnode_property_read_u32(node, "reg", &pval)) {
872 			dev_err(dev, "invalid reg on %pfw\n", node);
873 			continue;
874 		}
875 
876 		channel = pval;
877 		if (channel >= ADS1015_CHANNELS) {
878 			dev_err(dev, "invalid channel index %d on %pfw\n",
879 				channel, node);
880 			continue;
881 		}
882 
883 		if (!fwnode_property_read_u32(node, "ti,gain", &pval)) {
884 			pga = pval;
885 			if (pga > 6) {
886 				dev_err(dev, "invalid gain on %pfw\n", node);
887 				fwnode_handle_put(node);
888 				return -EINVAL;
889 			}
890 		}
891 
892 		if (!fwnode_property_read_u32(node, "ti,datarate", &pval)) {
893 			data_rate = pval;
894 			if (data_rate > 7) {
895 				dev_err(dev, "invalid data_rate on %pfw\n", node);
896 				fwnode_handle_put(node);
897 				return -EINVAL;
898 			}
899 		}
900 
901 		data->channel_data[channel].pga = pga;
902 		data->channel_data[channel].data_rate = data_rate;
903 
904 		i++;
905 	}
906 
907 	return i < 0 ? -EINVAL : 0;
908 }
909 
910 static void ads1015_get_channels_config(struct i2c_client *client)
911 {
912 	unsigned int k;
913 
914 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
915 	struct ads1015_data *data = iio_priv(indio_dev);
916 
917 	if (!ads1015_client_get_channels_config(client))
918 		return;
919 
920 	/* fallback on default configuration */
921 	for (k = 0; k < ADS1015_CHANNELS; ++k) {
922 		data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
923 		data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
924 	}
925 }
926 
927 static int ads1015_set_conv_mode(struct ads1015_data *data, int mode)
928 {
929 	return regmap_update_bits(data->regmap, ADS1015_CFG_REG,
930 				  ADS1015_CFG_MOD_MASK,
931 				  mode << ADS1015_CFG_MOD_SHIFT);
932 }
933 
934 static int ads1015_probe(struct i2c_client *client,
935 			 const struct i2c_device_id *id)
936 {
937 	struct iio_dev *indio_dev;
938 	struct ads1015_data *data;
939 	int ret;
940 	enum chip_ids chip;
941 	int i;
942 
943 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
944 	if (!indio_dev)
945 		return -ENOMEM;
946 
947 	data = iio_priv(indio_dev);
948 	i2c_set_clientdata(client, indio_dev);
949 
950 	mutex_init(&data->lock);
951 
952 	indio_dev->name = ADS1015_DRV_NAME;
953 	indio_dev->modes = INDIO_DIRECT_MODE;
954 
955 	chip = (enum chip_ids)device_get_match_data(&client->dev);
956 	if (chip == ADSXXXX)
957 		chip = id->driver_data;
958 	switch (chip) {
959 	case ADS1015:
960 		indio_dev->channels = ads1015_channels;
961 		indio_dev->num_channels = ARRAY_SIZE(ads1015_channels);
962 		indio_dev->info = &ads1015_info;
963 		data->data_rate = (unsigned int *) &ads1015_data_rate;
964 		break;
965 	case ADS1115:
966 		indio_dev->channels = ads1115_channels;
967 		indio_dev->num_channels = ARRAY_SIZE(ads1115_channels);
968 		indio_dev->info = &ads1115_info;
969 		data->data_rate = (unsigned int *) &ads1115_data_rate;
970 		break;
971 	default:
972 		dev_err(&client->dev, "Unknown chip %d\n", chip);
973 		return -EINVAL;
974 	}
975 
976 	data->event_channel = ADS1015_CHANNELS;
977 	/*
978 	 * Set default lower and upper threshold to min and max value
979 	 * respectively.
980 	 */
981 	for (i = 0; i < ADS1015_CHANNELS; i++) {
982 		int realbits = indio_dev->channels[i].scan_type.realbits;
983 
984 		data->thresh_data[i].low_thresh = -1 << (realbits - 1);
985 		data->thresh_data[i].high_thresh = (1 << (realbits - 1)) - 1;
986 	}
987 
988 	/* we need to keep this ABI the same as used by hwmon ADS1015 driver */
989 	ads1015_get_channels_config(client);
990 
991 	data->regmap = devm_regmap_init_i2c(client, &ads1015_regmap_config);
992 	if (IS_ERR(data->regmap)) {
993 		dev_err(&client->dev, "Failed to allocate register map\n");
994 		return PTR_ERR(data->regmap);
995 	}
996 
997 	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
998 					      ads1015_trigger_handler,
999 					      &ads1015_buffer_setup_ops);
1000 	if (ret < 0) {
1001 		dev_err(&client->dev, "iio triggered buffer setup failed\n");
1002 		return ret;
1003 	}
1004 
1005 	if (client->irq) {
1006 		unsigned long irq_trig =
1007 			irqd_get_trigger_type(irq_get_irq_data(client->irq));
1008 		unsigned int cfg_comp_mask = ADS1015_CFG_COMP_QUE_MASK |
1009 			ADS1015_CFG_COMP_LAT_MASK | ADS1015_CFG_COMP_POL_MASK;
1010 		unsigned int cfg_comp =
1011 			ADS1015_CFG_COMP_DISABLE << ADS1015_CFG_COMP_QUE_SHIFT |
1012 			1 << ADS1015_CFG_COMP_LAT_SHIFT;
1013 
1014 		switch (irq_trig) {
1015 		case IRQF_TRIGGER_LOW:
1016 			cfg_comp |= ADS1015_CFG_COMP_POL_LOW <<
1017 					ADS1015_CFG_COMP_POL_SHIFT;
1018 			break;
1019 		case IRQF_TRIGGER_HIGH:
1020 			cfg_comp |= ADS1015_CFG_COMP_POL_HIGH <<
1021 					ADS1015_CFG_COMP_POL_SHIFT;
1022 			break;
1023 		default:
1024 			return -EINVAL;
1025 		}
1026 
1027 		ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
1028 					cfg_comp_mask, cfg_comp);
1029 		if (ret)
1030 			return ret;
1031 
1032 		ret = devm_request_threaded_irq(&client->dev, client->irq,
1033 						NULL, ads1015_event_handler,
1034 						irq_trig | IRQF_ONESHOT,
1035 						client->name, indio_dev);
1036 		if (ret)
1037 			return ret;
1038 	}
1039 
1040 	ret = ads1015_set_conv_mode(data, ADS1015_CONTINUOUS);
1041 	if (ret)
1042 		return ret;
1043 
1044 	data->conv_invalid = true;
1045 
1046 	ret = pm_runtime_set_active(&client->dev);
1047 	if (ret)
1048 		return ret;
1049 	pm_runtime_set_autosuspend_delay(&client->dev, ADS1015_SLEEP_DELAY_MS);
1050 	pm_runtime_use_autosuspend(&client->dev);
1051 	pm_runtime_enable(&client->dev);
1052 
1053 	ret = iio_device_register(indio_dev);
1054 	if (ret < 0) {
1055 		dev_err(&client->dev, "Failed to register IIO device\n");
1056 		return ret;
1057 	}
1058 
1059 	return 0;
1060 }
1061 
1062 static int ads1015_remove(struct i2c_client *client)
1063 {
1064 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
1065 	struct ads1015_data *data = iio_priv(indio_dev);
1066 
1067 	iio_device_unregister(indio_dev);
1068 
1069 	pm_runtime_disable(&client->dev);
1070 	pm_runtime_set_suspended(&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