xref: /openbmc/linux/drivers/iio/adc/ti-ads1015.c (revision be709d48)
1 /*
2  * ADS1015 - Texas Instruments Analog-to-Digital Converter
3  *
4  * Copyright (c) 2016, Intel Corporation.
5  *
6  * This file is subject to the terms and conditions of version 2 of
7  * the GNU General Public License.  See the file COPYING in the main
8  * directory of this archive for more details.
9  *
10  * IIO driver for ADS1015 ADC 7-bit I2C slave address:
11  *	* 0x48 - ADDR connected to Ground
12  *	* 0x49 - ADDR connected to Vdd
13  *	* 0x4A - ADDR connected to SDA
14  *	* 0x4B - ADDR connected to SCL
15  */
16 
17 #include <linux/module.h>
18 #include <linux/of_device.h>
19 #include <linux/init.h>
20 #include <linux/irq.h>
21 #include <linux/i2c.h>
22 #include <linux/regmap.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/mutex.h>
25 #include <linux/delay.h>
26 
27 #include <linux/platform_data/ads1015.h>
28 
29 #include <linux/iio/iio.h>
30 #include <linux/iio/types.h>
31 #include <linux/iio/sysfs.h>
32 #include <linux/iio/events.h>
33 #include <linux/iio/buffer.h>
34 #include <linux/iio/triggered_buffer.h>
35 #include <linux/iio/trigger_consumer.h>
36 
37 #define ADS1015_DRV_NAME "ads1015"
38 
39 #define ADS1015_CONV_REG	0x00
40 #define ADS1015_CFG_REG		0x01
41 #define ADS1015_LO_THRESH_REG	0x02
42 #define ADS1015_HI_THRESH_REG	0x03
43 
44 #define ADS1015_CFG_COMP_QUE_SHIFT	0
45 #define ADS1015_CFG_COMP_LAT_SHIFT	2
46 #define ADS1015_CFG_COMP_POL_SHIFT	3
47 #define ADS1015_CFG_COMP_MODE_SHIFT	4
48 #define ADS1015_CFG_DR_SHIFT	5
49 #define ADS1015_CFG_MOD_SHIFT	8
50 #define ADS1015_CFG_PGA_SHIFT	9
51 #define ADS1015_CFG_MUX_SHIFT	12
52 
53 #define ADS1015_CFG_COMP_QUE_MASK	GENMASK(1, 0)
54 #define ADS1015_CFG_COMP_LAT_MASK	BIT(2)
55 #define ADS1015_CFG_COMP_POL_MASK	BIT(3)
56 #define ADS1015_CFG_COMP_MODE_MASK	BIT(4)
57 #define ADS1015_CFG_DR_MASK	GENMASK(7, 5)
58 #define ADS1015_CFG_MOD_MASK	BIT(8)
59 #define ADS1015_CFG_PGA_MASK	GENMASK(11, 9)
60 #define ADS1015_CFG_MUX_MASK	GENMASK(14, 12)
61 
62 /* Comparator queue and disable field */
63 #define ADS1015_CFG_COMP_DISABLE	3
64 
65 /* Comparator polarity field */
66 #define ADS1015_CFG_COMP_POL_LOW	0
67 #define ADS1015_CFG_COMP_POL_HIGH	1
68 
69 /* Comparator mode field */
70 #define ADS1015_CFG_COMP_MODE_TRAD	0
71 #define ADS1015_CFG_COMP_MODE_WINDOW	1
72 
73 /* device operating modes */
74 #define ADS1015_CONTINUOUS	0
75 #define ADS1015_SINGLESHOT	1
76 
77 #define ADS1015_SLEEP_DELAY_MS		2000
78 #define ADS1015_DEFAULT_PGA		2
79 #define ADS1015_DEFAULT_DATA_RATE	4
80 #define ADS1015_DEFAULT_CHAN		0
81 
82 enum chip_ids {
83 	ADS1015,
84 	ADS1115,
85 };
86 
87 enum ads1015_channels {
88 	ADS1015_AIN0_AIN1 = 0,
89 	ADS1015_AIN0_AIN3,
90 	ADS1015_AIN1_AIN3,
91 	ADS1015_AIN2_AIN3,
92 	ADS1015_AIN0,
93 	ADS1015_AIN1,
94 	ADS1015_AIN2,
95 	ADS1015_AIN3,
96 	ADS1015_TIMESTAMP,
97 };
98 
99 static const unsigned int ads1015_data_rate[] = {
100 	128, 250, 490, 920, 1600, 2400, 3300, 3300
101 };
102 
103 static const unsigned int ads1115_data_rate[] = {
104 	8, 16, 32, 64, 128, 250, 475, 860
105 };
106 
107 /*
108  * Translation from PGA bits to full-scale positive and negative input voltage
109  * range in mV
110  */
111 static int ads1015_fullscale_range[] = {
112 	6144, 4096, 2048, 1024, 512, 256, 256, 256
113 };
114 
115 /*
116  * Translation from COMP_QUE field value to the number of successive readings
117  * exceed the threshold values before an interrupt is generated
118  */
119 static const int ads1015_comp_queue[] = { 1, 2, 4 };
120 
121 static const struct iio_event_spec ads1015_events[] = {
122 	{
123 		.type = IIO_EV_TYPE_THRESH,
124 		.dir = IIO_EV_DIR_RISING,
125 		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
126 				BIT(IIO_EV_INFO_ENABLE),
127 	}, {
128 		.type = IIO_EV_TYPE_THRESH,
129 		.dir = IIO_EV_DIR_FALLING,
130 		.mask_separate = BIT(IIO_EV_INFO_VALUE),
131 	}, {
132 		.type = IIO_EV_TYPE_THRESH,
133 		.dir = IIO_EV_DIR_EITHER,
134 		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
135 				BIT(IIO_EV_INFO_PERIOD),
136 	},
137 };
138 
139 #define ADS1015_V_CHAN(_chan, _addr) {				\
140 	.type = IIO_VOLTAGE,					\
141 	.indexed = 1,						\
142 	.address = _addr,					\
143 	.channel = _chan,					\
144 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
145 				BIT(IIO_CHAN_INFO_SCALE) |	\
146 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
147 	.scan_index = _addr,					\
148 	.scan_type = {						\
149 		.sign = 's',					\
150 		.realbits = 12,					\
151 		.storagebits = 16,				\
152 		.shift = 4,					\
153 		.endianness = IIO_CPU,				\
154 	},							\
155 	.event_spec = ads1015_events,				\
156 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
157 	.datasheet_name = "AIN"#_chan,				\
158 }
159 
160 #define ADS1015_V_DIFF_CHAN(_chan, _chan2, _addr) {		\
161 	.type = IIO_VOLTAGE,					\
162 	.differential = 1,					\
163 	.indexed = 1,						\
164 	.address = _addr,					\
165 	.channel = _chan,					\
166 	.channel2 = _chan2,					\
167 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
168 				BIT(IIO_CHAN_INFO_SCALE) |	\
169 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
170 	.scan_index = _addr,					\
171 	.scan_type = {						\
172 		.sign = 's',					\
173 		.realbits = 12,					\
174 		.storagebits = 16,				\
175 		.shift = 4,					\
176 		.endianness = IIO_CPU,				\
177 	},							\
178 	.event_spec = ads1015_events,				\
179 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
180 	.datasheet_name = "AIN"#_chan"-AIN"#_chan2,		\
181 }
182 
183 #define ADS1115_V_CHAN(_chan, _addr) {				\
184 	.type = IIO_VOLTAGE,					\
185 	.indexed = 1,						\
186 	.address = _addr,					\
187 	.channel = _chan,					\
188 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
189 				BIT(IIO_CHAN_INFO_SCALE) |	\
190 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
191 	.scan_index = _addr,					\
192 	.scan_type = {						\
193 		.sign = 's',					\
194 		.realbits = 16,					\
195 		.storagebits = 16,				\
196 		.endianness = IIO_CPU,				\
197 	},							\
198 	.event_spec = ads1015_events,				\
199 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
200 	.datasheet_name = "AIN"#_chan,				\
201 }
202 
203 #define ADS1115_V_DIFF_CHAN(_chan, _chan2, _addr) {		\
204 	.type = IIO_VOLTAGE,					\
205 	.differential = 1,					\
206 	.indexed = 1,						\
207 	.address = _addr,					\
208 	.channel = _chan,					\
209 	.channel2 = _chan2,					\
210 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
211 				BIT(IIO_CHAN_INFO_SCALE) |	\
212 				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
213 	.scan_index = _addr,					\
214 	.scan_type = {						\
215 		.sign = 's',					\
216 		.realbits = 16,					\
217 		.storagebits = 16,				\
218 		.endianness = IIO_CPU,				\
219 	},							\
220 	.event_spec = ads1015_events,				\
221 	.num_event_specs = ARRAY_SIZE(ads1015_events),		\
222 	.datasheet_name = "AIN"#_chan"-AIN"#_chan2,		\
223 }
224 
225 struct ads1015_thresh_data {
226 	unsigned int comp_queue;
227 	int high_thresh;
228 	int low_thresh;
229 };
230 
231 struct ads1015_data {
232 	struct regmap *regmap;
233 	/*
234 	 * Protects ADC ops, e.g: concurrent sysfs/buffered
235 	 * data reads, configuration updates
236 	 */
237 	struct mutex lock;
238 	struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
239 
240 	unsigned int event_channel;
241 	unsigned int comp_mode;
242 	struct ads1015_thresh_data thresh_data[ADS1015_CHANNELS];
243 
244 	unsigned int *data_rate;
245 	/*
246 	 * Set to true when the ADC is switched to the continuous-conversion
247 	 * mode and exits from a power-down state.  This flag is used to avoid
248 	 * getting the stale result from the conversion register.
249 	 */
250 	bool conv_invalid;
251 };
252 
253 static bool ads1015_event_channel_enabled(struct ads1015_data *data)
254 {
255 	return (data->event_channel != ADS1015_CHANNELS);
256 }
257 
258 static void ads1015_event_channel_enable(struct ads1015_data *data, int chan,
259 					 int comp_mode)
260 {
261 	WARN_ON(ads1015_event_channel_enabled(data));
262 
263 	data->event_channel = chan;
264 	data->comp_mode = comp_mode;
265 }
266 
267 static void ads1015_event_channel_disable(struct ads1015_data *data, int chan)
268 {
269 	data->event_channel = ADS1015_CHANNELS;
270 }
271 
272 static bool ads1015_is_writeable_reg(struct device *dev, unsigned int reg)
273 {
274 	switch (reg) {
275 	case ADS1015_CFG_REG:
276 	case ADS1015_LO_THRESH_REG:
277 	case ADS1015_HI_THRESH_REG:
278 		return true;
279 	default:
280 		return false;
281 	}
282 }
283 
284 static const struct regmap_config ads1015_regmap_config = {
285 	.reg_bits = 8,
286 	.val_bits = 16,
287 	.max_register = ADS1015_HI_THRESH_REG,
288 	.writeable_reg = ads1015_is_writeable_reg,
289 };
290 
291 static const struct iio_chan_spec ads1015_channels[] = {
292 	ADS1015_V_DIFF_CHAN(0, 1, ADS1015_AIN0_AIN1),
293 	ADS1015_V_DIFF_CHAN(0, 3, ADS1015_AIN0_AIN3),
294 	ADS1015_V_DIFF_CHAN(1, 3, ADS1015_AIN1_AIN3),
295 	ADS1015_V_DIFF_CHAN(2, 3, ADS1015_AIN2_AIN3),
296 	ADS1015_V_CHAN(0, ADS1015_AIN0),
297 	ADS1015_V_CHAN(1, ADS1015_AIN1),
298 	ADS1015_V_CHAN(2, ADS1015_AIN2),
299 	ADS1015_V_CHAN(3, ADS1015_AIN3),
300 	IIO_CHAN_SOFT_TIMESTAMP(ADS1015_TIMESTAMP),
301 };
302 
303 static const struct iio_chan_spec ads1115_channels[] = {
304 	ADS1115_V_DIFF_CHAN(0, 1, ADS1015_AIN0_AIN1),
305 	ADS1115_V_DIFF_CHAN(0, 3, ADS1015_AIN0_AIN3),
306 	ADS1115_V_DIFF_CHAN(1, 3, ADS1015_AIN1_AIN3),
307 	ADS1115_V_DIFF_CHAN(2, 3, ADS1015_AIN2_AIN3),
308 	ADS1115_V_CHAN(0, ADS1015_AIN0),
309 	ADS1115_V_CHAN(1, ADS1015_AIN1),
310 	ADS1115_V_CHAN(2, ADS1015_AIN2),
311 	ADS1115_V_CHAN(3, ADS1015_AIN3),
312 	IIO_CHAN_SOFT_TIMESTAMP(ADS1015_TIMESTAMP),
313 };
314 
315 static int ads1015_set_power_state(struct ads1015_data *data, bool on)
316 {
317 	int ret;
318 	struct device *dev = regmap_get_device(data->regmap);
319 
320 	if (on) {
321 		ret = pm_runtime_get_sync(dev);
322 		if (ret < 0)
323 			pm_runtime_put_noidle(dev);
324 	} else {
325 		pm_runtime_mark_last_busy(dev);
326 		ret = pm_runtime_put_autosuspend(dev);
327 	}
328 
329 	return ret < 0 ? ret : 0;
330 }
331 
332 static
333 int ads1015_get_adc_result(struct ads1015_data *data, int chan, int *val)
334 {
335 	int ret, pga, dr, dr_old, conv_time;
336 	unsigned int old, mask, cfg;
337 
338 	if (chan < 0 || chan >= ADS1015_CHANNELS)
339 		return -EINVAL;
340 
341 	ret = regmap_read(data->regmap, ADS1015_CFG_REG, &old);
342 	if (ret)
343 		return ret;
344 
345 	pga = data->channel_data[chan].pga;
346 	dr = data->channel_data[chan].data_rate;
347 	mask = ADS1015_CFG_MUX_MASK | ADS1015_CFG_PGA_MASK |
348 		ADS1015_CFG_DR_MASK;
349 	cfg = chan << ADS1015_CFG_MUX_SHIFT | pga << ADS1015_CFG_PGA_SHIFT |
350 		dr << ADS1015_CFG_DR_SHIFT;
351 
352 	if (ads1015_event_channel_enabled(data)) {
353 		mask |= ADS1015_CFG_COMP_QUE_MASK | ADS1015_CFG_COMP_MODE_MASK;
354 		cfg |= data->thresh_data[chan].comp_queue <<
355 				ADS1015_CFG_COMP_QUE_SHIFT |
356 			data->comp_mode <<
357 				ADS1015_CFG_COMP_MODE_SHIFT;
358 	}
359 
360 	cfg = (old & ~mask) | (cfg & mask);
361 	if (old != cfg) {
362 		ret = regmap_write(data->regmap, ADS1015_CFG_REG, cfg);
363 		if (ret)
364 			return ret;
365 		data->conv_invalid = true;
366 	}
367 	if (data->conv_invalid) {
368 		dr_old = (old & ADS1015_CFG_DR_MASK) >> ADS1015_CFG_DR_SHIFT;
369 		conv_time = DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr_old]);
370 		conv_time += DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr]);
371 		conv_time += conv_time / 10; /* 10% internal clock inaccuracy */
372 		usleep_range(conv_time, conv_time + 1);
373 		data->conv_invalid = false;
374 	}
375 
376 	return regmap_read(data->regmap, ADS1015_CONV_REG, val);
377 }
378 
379 static irqreturn_t ads1015_trigger_handler(int irq, void *p)
380 {
381 	struct iio_poll_func *pf = p;
382 	struct iio_dev *indio_dev = pf->indio_dev;
383 	struct ads1015_data *data = iio_priv(indio_dev);
384 	s16 buf[8]; /* 1x s16 ADC val + 3x s16 padding +  4x s16 timestamp */
385 	int chan, ret, res;
386 
387 	memset(buf, 0, sizeof(buf));
388 
389 	mutex_lock(&data->lock);
390 	chan = find_first_bit(indio_dev->active_scan_mask,
391 			      indio_dev->masklength);
392 	ret = ads1015_get_adc_result(data, chan, &res);
393 	if (ret < 0) {
394 		mutex_unlock(&data->lock);
395 		goto err;
396 	}
397 
398 	buf[0] = res;
399 	mutex_unlock(&data->lock);
400 
401 	iio_push_to_buffers_with_timestamp(indio_dev, buf,
402 					   iio_get_time_ns(indio_dev));
403 
404 err:
405 	iio_trigger_notify_done(indio_dev->trig);
406 
407 	return IRQ_HANDLED;
408 }
409 
410 static int ads1015_set_scale(struct ads1015_data *data,
411 			     struct iio_chan_spec const *chan,
412 			     int scale, int uscale)
413 {
414 	int i;
415 	int fullscale = div_s64((scale * 1000000LL + uscale) <<
416 				(chan->scan_type.realbits - 1), 1000000);
417 
418 	for (i = 0; i < ARRAY_SIZE(ads1015_fullscale_range); i++) {
419 		if (ads1015_fullscale_range[i] == fullscale) {
420 			data->channel_data[chan->address].pga = i;
421 			return 0;
422 		}
423 	}
424 
425 	return -EINVAL;
426 }
427 
428 static int ads1015_set_data_rate(struct ads1015_data *data, int chan, int rate)
429 {
430 	int i;
431 
432 	for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++) {
433 		if (data->data_rate[i] == rate) {
434 			data->channel_data[chan].data_rate = i;
435 			return 0;
436 		}
437 	}
438 
439 	return -EINVAL;
440 }
441 
442 static int ads1015_read_raw(struct iio_dev *indio_dev,
443 			    struct iio_chan_spec const *chan, int *val,
444 			    int *val2, long mask)
445 {
446 	int ret, idx;
447 	struct ads1015_data *data = iio_priv(indio_dev);
448 
449 	mutex_lock(&data->lock);
450 	switch (mask) {
451 	case IIO_CHAN_INFO_RAW: {
452 		int shift = chan->scan_type.shift;
453 
454 		ret = iio_device_claim_direct_mode(indio_dev);
455 		if (ret)
456 			break;
457 
458 		if (ads1015_event_channel_enabled(data) &&
459 				data->event_channel != chan->address) {
460 			ret = -EBUSY;
461 			goto release_direct;
462 		}
463 
464 		ret = ads1015_set_power_state(data, true);
465 		if (ret < 0)
466 			goto release_direct;
467 
468 		ret = ads1015_get_adc_result(data, chan->address, val);
469 		if (ret < 0) {
470 			ads1015_set_power_state(data, false);
471 			goto release_direct;
472 		}
473 
474 		*val = sign_extend32(*val >> shift, 15 - shift);
475 
476 		ret = ads1015_set_power_state(data, false);
477 		if (ret < 0)
478 			goto release_direct;
479 
480 		ret = IIO_VAL_INT;
481 release_direct:
482 		iio_device_release_direct_mode(indio_dev);
483 		break;
484 	}
485 	case IIO_CHAN_INFO_SCALE:
486 		idx = data->channel_data[chan->address].pga;
487 		*val = ads1015_fullscale_range[idx];
488 		*val2 = chan->scan_type.realbits - 1;
489 		ret = IIO_VAL_FRACTIONAL_LOG2;
490 		break;
491 	case IIO_CHAN_INFO_SAMP_FREQ:
492 		idx = data->channel_data[chan->address].data_rate;
493 		*val = data->data_rate[idx];
494 		ret = IIO_VAL_INT;
495 		break;
496 	default:
497 		ret = -EINVAL;
498 		break;
499 	}
500 	mutex_unlock(&data->lock);
501 
502 	return ret;
503 }
504 
505 static int ads1015_write_raw(struct iio_dev *indio_dev,
506 			     struct iio_chan_spec const *chan, int val,
507 			     int val2, long mask)
508 {
509 	struct ads1015_data *data = iio_priv(indio_dev);
510 	int ret;
511 
512 	mutex_lock(&data->lock);
513 	switch (mask) {
514 	case IIO_CHAN_INFO_SCALE:
515 		ret = ads1015_set_scale(data, chan, val, val2);
516 		break;
517 	case IIO_CHAN_INFO_SAMP_FREQ:
518 		ret = ads1015_set_data_rate(data, chan->address, val);
519 		break;
520 	default:
521 		ret = -EINVAL;
522 		break;
523 	}
524 	mutex_unlock(&data->lock);
525 
526 	return ret;
527 }
528 
529 static int ads1015_read_event(struct iio_dev *indio_dev,
530 	const struct iio_chan_spec *chan, enum iio_event_type type,
531 	enum iio_event_direction dir, enum iio_event_info info, int *val,
532 	int *val2)
533 {
534 	struct ads1015_data *data = iio_priv(indio_dev);
535 	int ret;
536 	unsigned int comp_queue;
537 	int period;
538 	int dr;
539 
540 	mutex_lock(&data->lock);
541 
542 	switch (info) {
543 	case IIO_EV_INFO_VALUE:
544 		*val = (dir == IIO_EV_DIR_RISING) ?
545 			data->thresh_data[chan->address].high_thresh :
546 			data->thresh_data[chan->address].low_thresh;
547 		ret = IIO_VAL_INT;
548 		break;
549 	case IIO_EV_INFO_PERIOD:
550 		dr = data->channel_data[chan->address].data_rate;
551 		comp_queue = data->thresh_data[chan->address].comp_queue;
552 		period = ads1015_comp_queue[comp_queue] *
553 			USEC_PER_SEC / data->data_rate[dr];
554 
555 		*val = period / USEC_PER_SEC;
556 		*val2 = period % USEC_PER_SEC;
557 		ret = IIO_VAL_INT_PLUS_MICRO;
558 		break;
559 	default:
560 		ret = -EINVAL;
561 		break;
562 	}
563 
564 	mutex_unlock(&data->lock);
565 
566 	return ret;
567 }
568 
569 static int ads1015_write_event(struct iio_dev *indio_dev,
570 	const struct iio_chan_spec *chan, enum iio_event_type type,
571 	enum iio_event_direction dir, enum iio_event_info info, int val,
572 	int val2)
573 {
574 	struct ads1015_data *data = iio_priv(indio_dev);
575 	int realbits = chan->scan_type.realbits;
576 	int ret = 0;
577 	long long period;
578 	int i;
579 	int dr;
580 
581 	mutex_lock(&data->lock);
582 
583 	switch (info) {
584 	case IIO_EV_INFO_VALUE:
585 		if (val >= 1 << (realbits - 1) || val < -1 << (realbits - 1)) {
586 			ret = -EINVAL;
587 			break;
588 		}
589 		if (dir == IIO_EV_DIR_RISING)
590 			data->thresh_data[chan->address].high_thresh = val;
591 		else
592 			data->thresh_data[chan->address].low_thresh = val;
593 		break;
594 	case IIO_EV_INFO_PERIOD:
595 		dr = data->channel_data[chan->address].data_rate;
596 		period = val * USEC_PER_SEC + val2;
597 
598 		for (i = 0; i < ARRAY_SIZE(ads1015_comp_queue) - 1; i++) {
599 			if (period <= ads1015_comp_queue[i] *
600 					USEC_PER_SEC / data->data_rate[dr])
601 				break;
602 		}
603 		data->thresh_data[chan->address].comp_queue = i;
604 		break;
605 	default:
606 		ret = -EINVAL;
607 		break;
608 	}
609 
610 	mutex_unlock(&data->lock);
611 
612 	return ret;
613 }
614 
615 static int ads1015_read_event_config(struct iio_dev *indio_dev,
616 	const struct iio_chan_spec *chan, enum iio_event_type type,
617 	enum iio_event_direction dir)
618 {
619 	struct ads1015_data *data = iio_priv(indio_dev);
620 	int ret = 0;
621 
622 	mutex_lock(&data->lock);
623 	if (data->event_channel == chan->address) {
624 		switch (dir) {
625 		case IIO_EV_DIR_RISING:
626 			ret = 1;
627 			break;
628 		case IIO_EV_DIR_EITHER:
629 			ret = (data->comp_mode == ADS1015_CFG_COMP_MODE_WINDOW);
630 			break;
631 		default:
632 			ret = -EINVAL;
633 			break;
634 		}
635 	}
636 	mutex_unlock(&data->lock);
637 
638 	return ret;
639 }
640 
641 static int ads1015_enable_event_config(struct ads1015_data *data,
642 	const struct iio_chan_spec *chan, int comp_mode)
643 {
644 	int low_thresh = data->thresh_data[chan->address].low_thresh;
645 	int high_thresh = data->thresh_data[chan->address].high_thresh;
646 	int ret;
647 	unsigned int val;
648 
649 	if (ads1015_event_channel_enabled(data)) {
650 		if (data->event_channel != chan->address ||
651 			(data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD &&
652 				comp_mode == ADS1015_CFG_COMP_MODE_WINDOW))
653 			return -EBUSY;
654 
655 		return 0;
656 	}
657 
658 	if (comp_mode == ADS1015_CFG_COMP_MODE_TRAD) {
659 		low_thresh = max(-1 << (chan->scan_type.realbits - 1),
660 				high_thresh - 1);
661 	}
662 	ret = regmap_write(data->regmap, ADS1015_LO_THRESH_REG,
663 			low_thresh << chan->scan_type.shift);
664 	if (ret)
665 		return ret;
666 
667 	ret = regmap_write(data->regmap, ADS1015_HI_THRESH_REG,
668 			high_thresh << chan->scan_type.shift);
669 	if (ret)
670 		return ret;
671 
672 	ret = ads1015_set_power_state(data, true);
673 	if (ret < 0)
674 		return ret;
675 
676 	ads1015_event_channel_enable(data, chan->address, comp_mode);
677 
678 	ret = ads1015_get_adc_result(data, chan->address, &val);
679 	if (ret) {
680 		ads1015_event_channel_disable(data, chan->address);
681 		ads1015_set_power_state(data, false);
682 	}
683 
684 	return ret;
685 }
686 
687 static int ads1015_disable_event_config(struct ads1015_data *data,
688 	const struct iio_chan_spec *chan, int comp_mode)
689 {
690 	int ret;
691 
692 	if (!ads1015_event_channel_enabled(data))
693 		return 0;
694 
695 	if (data->event_channel != chan->address)
696 		return 0;
697 
698 	if (data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD &&
699 			comp_mode == ADS1015_CFG_COMP_MODE_WINDOW)
700 		return 0;
701 
702 	ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
703 				ADS1015_CFG_COMP_QUE_MASK,
704 				ADS1015_CFG_COMP_DISABLE <<
705 					ADS1015_CFG_COMP_QUE_SHIFT);
706 	if (ret)
707 		return ret;
708 
709 	ads1015_event_channel_disable(data, chan->address);
710 
711 	return ads1015_set_power_state(data, false);
712 }
713 
714 static int ads1015_write_event_config(struct iio_dev *indio_dev,
715 	const struct iio_chan_spec *chan, enum iio_event_type type,
716 	enum iio_event_direction dir, int state)
717 {
718 	struct ads1015_data *data = iio_priv(indio_dev);
719 	int ret;
720 	int comp_mode = (dir == IIO_EV_DIR_EITHER) ?
721 		ADS1015_CFG_COMP_MODE_WINDOW : ADS1015_CFG_COMP_MODE_TRAD;
722 
723 	mutex_lock(&data->lock);
724 
725 	/* Prevent from enabling both buffer and event at a time */
726 	ret = iio_device_claim_direct_mode(indio_dev);
727 	if (ret) {
728 		mutex_unlock(&data->lock);
729 		return ret;
730 	}
731 
732 	if (state)
733 		ret = ads1015_enable_event_config(data, chan, comp_mode);
734 	else
735 		ret = ads1015_disable_event_config(data, chan, comp_mode);
736 
737 	iio_device_release_direct_mode(indio_dev);
738 	mutex_unlock(&data->lock);
739 
740 	return ret;
741 }
742 
743 static irqreturn_t ads1015_event_handler(int irq, void *priv)
744 {
745 	struct iio_dev *indio_dev = priv;
746 	struct ads1015_data *data = iio_priv(indio_dev);
747 	int val;
748 	int ret;
749 
750 	/* Clear the latched ALERT/RDY pin */
751 	ret = regmap_read(data->regmap, ADS1015_CONV_REG, &val);
752 	if (ret)
753 		return IRQ_HANDLED;
754 
755 	if (ads1015_event_channel_enabled(data)) {
756 		enum iio_event_direction dir;
757 		u64 code;
758 
759 		dir = data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD ?
760 					IIO_EV_DIR_RISING : IIO_EV_DIR_EITHER;
761 		code = IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, data->event_channel,
762 					IIO_EV_TYPE_THRESH, dir);
763 		iio_push_event(indio_dev, code, iio_get_time_ns(indio_dev));
764 	}
765 
766 	return IRQ_HANDLED;
767 }
768 
769 static int ads1015_buffer_preenable(struct iio_dev *indio_dev)
770 {
771 	struct ads1015_data *data = iio_priv(indio_dev);
772 
773 	/* Prevent from enabling both buffer and event at a time */
774 	if (ads1015_event_channel_enabled(data))
775 		return -EBUSY;
776 
777 	return ads1015_set_power_state(iio_priv(indio_dev), true);
778 }
779 
780 static int ads1015_buffer_postdisable(struct iio_dev *indio_dev)
781 {
782 	return ads1015_set_power_state(iio_priv(indio_dev), false);
783 }
784 
785 static const struct iio_buffer_setup_ops ads1015_buffer_setup_ops = {
786 	.preenable	= ads1015_buffer_preenable,
787 	.postenable	= iio_triggered_buffer_postenable,
788 	.predisable	= iio_triggered_buffer_predisable,
789 	.postdisable	= ads1015_buffer_postdisable,
790 	.validate_scan_mask = &iio_validate_scan_mask_onehot,
791 };
792 
793 static IIO_CONST_ATTR_NAMED(ads1015_scale_available, scale_available,
794 	"3 2 1 0.5 0.25 0.125");
795 static IIO_CONST_ATTR_NAMED(ads1115_scale_available, scale_available,
796 	"0.1875 0.125 0.0625 0.03125 0.015625 0.007813");
797 
798 static IIO_CONST_ATTR_NAMED(ads1015_sampling_frequency_available,
799 	sampling_frequency_available, "128 250 490 920 1600 2400 3300");
800 static IIO_CONST_ATTR_NAMED(ads1115_sampling_frequency_available,
801 	sampling_frequency_available, "8 16 32 64 128 250 475 860");
802 
803 static struct attribute *ads1015_attributes[] = {
804 	&iio_const_attr_ads1015_scale_available.dev_attr.attr,
805 	&iio_const_attr_ads1015_sampling_frequency_available.dev_attr.attr,
806 	NULL,
807 };
808 
809 static const struct attribute_group ads1015_attribute_group = {
810 	.attrs = ads1015_attributes,
811 };
812 
813 static struct attribute *ads1115_attributes[] = {
814 	&iio_const_attr_ads1115_scale_available.dev_attr.attr,
815 	&iio_const_attr_ads1115_sampling_frequency_available.dev_attr.attr,
816 	NULL,
817 };
818 
819 static const struct attribute_group ads1115_attribute_group = {
820 	.attrs = ads1115_attributes,
821 };
822 
823 static const struct iio_info ads1015_info = {
824 	.read_raw	= ads1015_read_raw,
825 	.write_raw	= ads1015_write_raw,
826 	.read_event_value = ads1015_read_event,
827 	.write_event_value = ads1015_write_event,
828 	.read_event_config = ads1015_read_event_config,
829 	.write_event_config = ads1015_write_event_config,
830 	.attrs          = &ads1015_attribute_group,
831 };
832 
833 static const struct iio_info ads1115_info = {
834 	.read_raw	= ads1015_read_raw,
835 	.write_raw	= ads1015_write_raw,
836 	.read_event_value = ads1015_read_event,
837 	.write_event_value = ads1015_write_event,
838 	.read_event_config = ads1015_read_event_config,
839 	.write_event_config = ads1015_write_event_config,
840 	.attrs          = &ads1115_attribute_group,
841 };
842 
843 #ifdef CONFIG_OF
844 static int ads1015_get_channels_config_of(struct i2c_client *client)
845 {
846 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
847 	struct ads1015_data *data = iio_priv(indio_dev);
848 	struct device_node *node;
849 
850 	if (!client->dev.of_node ||
851 	    !of_get_next_child(client->dev.of_node, NULL))
852 		return -EINVAL;
853 
854 	for_each_child_of_node(client->dev.of_node, node) {
855 		u32 pval;
856 		unsigned int channel;
857 		unsigned int pga = ADS1015_DEFAULT_PGA;
858 		unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
859 
860 		if (of_property_read_u32(node, "reg", &pval)) {
861 			dev_err(&client->dev, "invalid reg on %pOF\n",
862 				node);
863 			continue;
864 		}
865 
866 		channel = pval;
867 		if (channel >= ADS1015_CHANNELS) {
868 			dev_err(&client->dev,
869 				"invalid channel index %d on %pOF\n",
870 				channel, node);
871 			continue;
872 		}
873 
874 		if (!of_property_read_u32(node, "ti,gain", &pval)) {
875 			pga = pval;
876 			if (pga > 6) {
877 				dev_err(&client->dev, "invalid gain on %pOF\n",
878 					node);
879 				of_node_put(node);
880 				return -EINVAL;
881 			}
882 		}
883 
884 		if (!of_property_read_u32(node, "ti,datarate", &pval)) {
885 			data_rate = pval;
886 			if (data_rate > 7) {
887 				dev_err(&client->dev,
888 					"invalid data_rate on %pOF\n",
889 					node);
890 				of_node_put(node);
891 				return -EINVAL;
892 			}
893 		}
894 
895 		data->channel_data[channel].pga = pga;
896 		data->channel_data[channel].data_rate = data_rate;
897 	}
898 
899 	return 0;
900 }
901 #endif
902 
903 static void ads1015_get_channels_config(struct i2c_client *client)
904 {
905 	unsigned int k;
906 
907 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
908 	struct ads1015_data *data = iio_priv(indio_dev);
909 	struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
910 
911 	/* prefer platform data */
912 	if (pdata) {
913 		memcpy(data->channel_data, pdata->channel_data,
914 		       sizeof(data->channel_data));
915 		return;
916 	}
917 
918 #ifdef CONFIG_OF
919 	if (!ads1015_get_channels_config_of(client))
920 		return;
921 #endif
922 	/* fallback on default configuration */
923 	for (k = 0; k < ADS1015_CHANNELS; ++k) {
924 		data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
925 		data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
926 	}
927 }
928 
929 static int ads1015_set_conv_mode(struct ads1015_data *data, int mode)
930 {
931 	return regmap_update_bits(data->regmap, ADS1015_CFG_REG,
932 				  ADS1015_CFG_MOD_MASK,
933 				  mode << ADS1015_CFG_MOD_SHIFT);
934 }
935 
936 static int ads1015_probe(struct i2c_client *client,
937 			 const struct i2c_device_id *id)
938 {
939 	struct iio_dev *indio_dev;
940 	struct ads1015_data *data;
941 	int ret;
942 	enum chip_ids chip;
943 	int i;
944 
945 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
946 	if (!indio_dev)
947 		return -ENOMEM;
948 
949 	data = iio_priv(indio_dev);
950 	i2c_set_clientdata(client, indio_dev);
951 
952 	mutex_init(&data->lock);
953 
954 	indio_dev->dev.parent = &client->dev;
955 	indio_dev->dev.of_node = client->dev.of_node;
956 	indio_dev->name = ADS1015_DRV_NAME;
957 	indio_dev->modes = INDIO_DIRECT_MODE;
958 
959 	if (client->dev.of_node)
960 		chip = (enum chip_ids)of_device_get_match_data(&client->dev);
961 	else
962 		chip = id->driver_data;
963 	switch (chip) {
964 	case ADS1015:
965 		indio_dev->channels = ads1015_channels;
966 		indio_dev->num_channels = ARRAY_SIZE(ads1015_channels);
967 		indio_dev->info = &ads1015_info;
968 		data->data_rate = (unsigned int *) &ads1015_data_rate;
969 		break;
970 	case ADS1115:
971 		indio_dev->channels = ads1115_channels;
972 		indio_dev->num_channels = ARRAY_SIZE(ads1115_channels);
973 		indio_dev->info = &ads1115_info;
974 		data->data_rate = (unsigned int *) &ads1115_data_rate;
975 		break;
976 	}
977 
978 	data->event_channel = ADS1015_CHANNELS;
979 	/*
980 	 * Set default lower and upper threshold to min and max value
981 	 * respectively.
982 	 */
983 	for (i = 0; i < ADS1015_CHANNELS; i++) {
984 		int realbits = indio_dev->channels[i].scan_type.realbits;
985 
986 		data->thresh_data[i].low_thresh = -1 << (realbits - 1);
987 		data->thresh_data[i].high_thresh = (1 << (realbits - 1)) - 1;
988 	}
989 
990 	/* we need to keep this ABI the same as used by hwmon ADS1015 driver */
991 	ads1015_get_channels_config(client);
992 
993 	data->regmap = devm_regmap_init_i2c(client, &ads1015_regmap_config);
994 	if (IS_ERR(data->regmap)) {
995 		dev_err(&client->dev, "Failed to allocate register map\n");
996 		return PTR_ERR(data->regmap);
997 	}
998 
999 	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
1000 					      ads1015_trigger_handler,
1001 					      &ads1015_buffer_setup_ops);
1002 	if (ret < 0) {
1003 		dev_err(&client->dev, "iio triggered buffer setup failed\n");
1004 		return ret;
1005 	}
1006 
1007 	if (client->irq) {
1008 		unsigned long irq_trig =
1009 			irqd_get_trigger_type(irq_get_irq_data(client->irq));
1010 		unsigned int cfg_comp_mask = ADS1015_CFG_COMP_QUE_MASK |
1011 			ADS1015_CFG_COMP_LAT_MASK | ADS1015_CFG_COMP_POL_MASK;
1012 		unsigned int cfg_comp =
1013 			ADS1015_CFG_COMP_DISABLE << ADS1015_CFG_COMP_QUE_SHIFT |
1014 			1 << ADS1015_CFG_COMP_LAT_SHIFT;
1015 
1016 		switch (irq_trig) {
1017 		case IRQF_TRIGGER_LOW:
1018 			cfg_comp |= ADS1015_CFG_COMP_POL_LOW <<
1019 					ADS1015_CFG_COMP_POL_SHIFT;
1020 			break;
1021 		case IRQF_TRIGGER_HIGH:
1022 			cfg_comp |= ADS1015_CFG_COMP_POL_HIGH <<
1023 					ADS1015_CFG_COMP_POL_SHIFT;
1024 			break;
1025 		default:
1026 			return -EINVAL;
1027 		}
1028 
1029 		ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
1030 					cfg_comp_mask, cfg_comp);
1031 		if (ret)
1032 			return ret;
1033 
1034 		ret = devm_request_threaded_irq(&client->dev, client->irq,
1035 						NULL, ads1015_event_handler,
1036 						irq_trig | IRQF_ONESHOT,
1037 						client->name, indio_dev);
1038 		if (ret)
1039 			return ret;
1040 	}
1041 
1042 	ret = ads1015_set_conv_mode(data, ADS1015_CONTINUOUS);
1043 	if (ret)
1044 		return ret;
1045 
1046 	data->conv_invalid = true;
1047 
1048 	ret = pm_runtime_set_active(&client->dev);
1049 	if (ret)
1050 		return ret;
1051 	pm_runtime_set_autosuspend_delay(&client->dev, ADS1015_SLEEP_DELAY_MS);
1052 	pm_runtime_use_autosuspend(&client->dev);
1053 	pm_runtime_enable(&client->dev);
1054 
1055 	ret = iio_device_register(indio_dev);
1056 	if (ret < 0) {
1057 		dev_err(&client->dev, "Failed to register IIO device\n");
1058 		return ret;
1059 	}
1060 
1061 	return 0;
1062 }
1063 
1064 static int ads1015_remove(struct i2c_client *client)
1065 {
1066 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
1067 	struct ads1015_data *data = iio_priv(indio_dev);
1068 
1069 	iio_device_unregister(indio_dev);
1070 
1071 	pm_runtime_disable(&client->dev);
1072 	pm_runtime_set_suspended(&client->dev);
1073 	pm_runtime_put_noidle(&client->dev);
1074 
1075 	/* power down single shot mode */
1076 	return ads1015_set_conv_mode(data, ADS1015_SINGLESHOT);
1077 }
1078 
1079 #ifdef CONFIG_PM
1080 static int ads1015_runtime_suspend(struct device *dev)
1081 {
1082 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
1083 	struct ads1015_data *data = iio_priv(indio_dev);
1084 
1085 	return ads1015_set_conv_mode(data, ADS1015_SINGLESHOT);
1086 }
1087 
1088 static int ads1015_runtime_resume(struct device *dev)
1089 {
1090 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
1091 	struct ads1015_data *data = iio_priv(indio_dev);
1092 	int ret;
1093 
1094 	ret = ads1015_set_conv_mode(data, ADS1015_CONTINUOUS);
1095 	if (!ret)
1096 		data->conv_invalid = true;
1097 
1098 	return ret;
1099 }
1100 #endif
1101 
1102 static const struct dev_pm_ops ads1015_pm_ops = {
1103 	SET_RUNTIME_PM_OPS(ads1015_runtime_suspend,
1104 			   ads1015_runtime_resume, NULL)
1105 };
1106 
1107 static const struct i2c_device_id ads1015_id[] = {
1108 	{"ads1015", ADS1015},
1109 	{"ads1115", ADS1115},
1110 	{}
1111 };
1112 MODULE_DEVICE_TABLE(i2c, ads1015_id);
1113 
1114 static const struct of_device_id ads1015_of_match[] = {
1115 	{
1116 		.compatible = "ti,ads1015",
1117 		.data = (void *)ADS1015
1118 	},
1119 	{
1120 		.compatible = "ti,ads1115",
1121 		.data = (void *)ADS1115
1122 	},
1123 	{}
1124 };
1125 MODULE_DEVICE_TABLE(of, ads1015_of_match);
1126 
1127 static struct i2c_driver ads1015_driver = {
1128 	.driver = {
1129 		.name = ADS1015_DRV_NAME,
1130 		.of_match_table = ads1015_of_match,
1131 		.pm = &ads1015_pm_ops,
1132 	},
1133 	.probe		= ads1015_probe,
1134 	.remove		= ads1015_remove,
1135 	.id_table	= ads1015_id,
1136 };
1137 
1138 module_i2c_driver(ads1015_driver);
1139 
1140 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
1141 MODULE_DESCRIPTION("Texas Instruments ADS1015 ADC driver");
1142 MODULE_LICENSE("GPL v2");
1143