xref: /openbmc/linux/drivers/iio/adc/ti-ads1015.c (revision 6f4eaea2)
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_get_sync(dev);
327 		if (ret < 0)
328 			pm_runtime_put_noidle(dev);
329 	} else {
330 		pm_runtime_mark_last_busy(dev);
331 		ret = pm_runtime_put_autosuspend(dev);
332 	}
333 
334 	return ret < 0 ? ret : 0;
335 }
336 
337 #else /* !CONFIG_PM */
338 
339 static int ads1015_set_power_state(struct ads1015_data *data, bool on)
340 {
341 	return 0;
342 }
343 
344 #endif /* !CONFIG_PM */
345 
346 static
347 int ads1015_get_adc_result(struct ads1015_data *data, int chan, int *val)
348 {
349 	int ret, pga, dr, dr_old, conv_time;
350 	unsigned int old, mask, cfg;
351 
352 	if (chan < 0 || chan >= ADS1015_CHANNELS)
353 		return -EINVAL;
354 
355 	ret = regmap_read(data->regmap, ADS1015_CFG_REG, &old);
356 	if (ret)
357 		return ret;
358 
359 	pga = data->channel_data[chan].pga;
360 	dr = data->channel_data[chan].data_rate;
361 	mask = ADS1015_CFG_MUX_MASK | ADS1015_CFG_PGA_MASK |
362 		ADS1015_CFG_DR_MASK;
363 	cfg = chan << ADS1015_CFG_MUX_SHIFT | pga << ADS1015_CFG_PGA_SHIFT |
364 		dr << ADS1015_CFG_DR_SHIFT;
365 
366 	if (ads1015_event_channel_enabled(data)) {
367 		mask |= ADS1015_CFG_COMP_QUE_MASK | ADS1015_CFG_COMP_MODE_MASK;
368 		cfg |= data->thresh_data[chan].comp_queue <<
369 				ADS1015_CFG_COMP_QUE_SHIFT |
370 			data->comp_mode <<
371 				ADS1015_CFG_COMP_MODE_SHIFT;
372 	}
373 
374 	cfg = (old & ~mask) | (cfg & mask);
375 	if (old != cfg) {
376 		ret = regmap_write(data->regmap, ADS1015_CFG_REG, cfg);
377 		if (ret)
378 			return ret;
379 		data->conv_invalid = true;
380 	}
381 	if (data->conv_invalid) {
382 		dr_old = (old & ADS1015_CFG_DR_MASK) >> ADS1015_CFG_DR_SHIFT;
383 		conv_time = DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr_old]);
384 		conv_time += DIV_ROUND_UP(USEC_PER_SEC, data->data_rate[dr]);
385 		conv_time += conv_time / 10; /* 10% internal clock inaccuracy */
386 		usleep_range(conv_time, conv_time + 1);
387 		data->conv_invalid = false;
388 	}
389 
390 	return regmap_read(data->regmap, ADS1015_CONV_REG, val);
391 }
392 
393 static irqreturn_t ads1015_trigger_handler(int irq, void *p)
394 {
395 	struct iio_poll_func *pf = p;
396 	struct iio_dev *indio_dev = pf->indio_dev;
397 	struct ads1015_data *data = iio_priv(indio_dev);
398 	s16 buf[8]; /* 1x s16 ADC val + 3x s16 padding +  4x s16 timestamp */
399 	int chan, ret, res;
400 
401 	memset(buf, 0, sizeof(buf));
402 
403 	mutex_lock(&data->lock);
404 	chan = find_first_bit(indio_dev->active_scan_mask,
405 			      indio_dev->masklength);
406 	ret = ads1015_get_adc_result(data, chan, &res);
407 	if (ret < 0) {
408 		mutex_unlock(&data->lock);
409 		goto err;
410 	}
411 
412 	buf[0] = res;
413 	mutex_unlock(&data->lock);
414 
415 	iio_push_to_buffers_with_timestamp(indio_dev, buf,
416 					   iio_get_time_ns(indio_dev));
417 
418 err:
419 	iio_trigger_notify_done(indio_dev->trig);
420 
421 	return IRQ_HANDLED;
422 }
423 
424 static int ads1015_set_scale(struct ads1015_data *data,
425 			     struct iio_chan_spec const *chan,
426 			     int scale, int uscale)
427 {
428 	int i;
429 	int fullscale = div_s64((scale * 1000000LL + uscale) <<
430 				(chan->scan_type.realbits - 1), 1000000);
431 
432 	for (i = 0; i < ARRAY_SIZE(ads1015_fullscale_range); i++) {
433 		if (ads1015_fullscale_range[i] == fullscale) {
434 			data->channel_data[chan->address].pga = i;
435 			return 0;
436 		}
437 	}
438 
439 	return -EINVAL;
440 }
441 
442 static int ads1015_set_data_rate(struct ads1015_data *data, int chan, int rate)
443 {
444 	int i;
445 
446 	for (i = 0; i < ARRAY_SIZE(ads1015_data_rate); i++) {
447 		if (data->data_rate[i] == rate) {
448 			data->channel_data[chan].data_rate = i;
449 			return 0;
450 		}
451 	}
452 
453 	return -EINVAL;
454 }
455 
456 static int ads1015_read_raw(struct iio_dev *indio_dev,
457 			    struct iio_chan_spec const *chan, int *val,
458 			    int *val2, long mask)
459 {
460 	int ret, idx;
461 	struct ads1015_data *data = iio_priv(indio_dev);
462 
463 	mutex_lock(&data->lock);
464 	switch (mask) {
465 	case IIO_CHAN_INFO_RAW: {
466 		int shift = chan->scan_type.shift;
467 
468 		ret = iio_device_claim_direct_mode(indio_dev);
469 		if (ret)
470 			break;
471 
472 		if (ads1015_event_channel_enabled(data) &&
473 				data->event_channel != chan->address) {
474 			ret = -EBUSY;
475 			goto release_direct;
476 		}
477 
478 		ret = ads1015_set_power_state(data, true);
479 		if (ret < 0)
480 			goto release_direct;
481 
482 		ret = ads1015_get_adc_result(data, chan->address, val);
483 		if (ret < 0) {
484 			ads1015_set_power_state(data, false);
485 			goto release_direct;
486 		}
487 
488 		*val = sign_extend32(*val >> shift, 15 - shift);
489 
490 		ret = ads1015_set_power_state(data, false);
491 		if (ret < 0)
492 			goto release_direct;
493 
494 		ret = IIO_VAL_INT;
495 release_direct:
496 		iio_device_release_direct_mode(indio_dev);
497 		break;
498 	}
499 	case IIO_CHAN_INFO_SCALE:
500 		idx = data->channel_data[chan->address].pga;
501 		*val = ads1015_fullscale_range[idx];
502 		*val2 = chan->scan_type.realbits - 1;
503 		ret = IIO_VAL_FRACTIONAL_LOG2;
504 		break;
505 	case IIO_CHAN_INFO_SAMP_FREQ:
506 		idx = data->channel_data[chan->address].data_rate;
507 		*val = data->data_rate[idx];
508 		ret = IIO_VAL_INT;
509 		break;
510 	default:
511 		ret = -EINVAL;
512 		break;
513 	}
514 	mutex_unlock(&data->lock);
515 
516 	return ret;
517 }
518 
519 static int ads1015_write_raw(struct iio_dev *indio_dev,
520 			     struct iio_chan_spec const *chan, int val,
521 			     int val2, long mask)
522 {
523 	struct ads1015_data *data = iio_priv(indio_dev);
524 	int ret;
525 
526 	mutex_lock(&data->lock);
527 	switch (mask) {
528 	case IIO_CHAN_INFO_SCALE:
529 		ret = ads1015_set_scale(data, chan, val, val2);
530 		break;
531 	case IIO_CHAN_INFO_SAMP_FREQ:
532 		ret = ads1015_set_data_rate(data, chan->address, val);
533 		break;
534 	default:
535 		ret = -EINVAL;
536 		break;
537 	}
538 	mutex_unlock(&data->lock);
539 
540 	return ret;
541 }
542 
543 static int ads1015_read_event(struct iio_dev *indio_dev,
544 	const struct iio_chan_spec *chan, enum iio_event_type type,
545 	enum iio_event_direction dir, enum iio_event_info info, int *val,
546 	int *val2)
547 {
548 	struct ads1015_data *data = iio_priv(indio_dev);
549 	int ret;
550 	unsigned int comp_queue;
551 	int period;
552 	int dr;
553 
554 	mutex_lock(&data->lock);
555 
556 	switch (info) {
557 	case IIO_EV_INFO_VALUE:
558 		*val = (dir == IIO_EV_DIR_RISING) ?
559 			data->thresh_data[chan->address].high_thresh :
560 			data->thresh_data[chan->address].low_thresh;
561 		ret = IIO_VAL_INT;
562 		break;
563 	case IIO_EV_INFO_PERIOD:
564 		dr = data->channel_data[chan->address].data_rate;
565 		comp_queue = data->thresh_data[chan->address].comp_queue;
566 		period = ads1015_comp_queue[comp_queue] *
567 			USEC_PER_SEC / data->data_rate[dr];
568 
569 		*val = period / USEC_PER_SEC;
570 		*val2 = period % USEC_PER_SEC;
571 		ret = IIO_VAL_INT_PLUS_MICRO;
572 		break;
573 	default:
574 		ret = -EINVAL;
575 		break;
576 	}
577 
578 	mutex_unlock(&data->lock);
579 
580 	return ret;
581 }
582 
583 static int ads1015_write_event(struct iio_dev *indio_dev,
584 	const struct iio_chan_spec *chan, enum iio_event_type type,
585 	enum iio_event_direction dir, enum iio_event_info info, int val,
586 	int val2)
587 {
588 	struct ads1015_data *data = iio_priv(indio_dev);
589 	int realbits = chan->scan_type.realbits;
590 	int ret = 0;
591 	long long period;
592 	int i;
593 	int dr;
594 
595 	mutex_lock(&data->lock);
596 
597 	switch (info) {
598 	case IIO_EV_INFO_VALUE:
599 		if (val >= 1 << (realbits - 1) || val < -1 << (realbits - 1)) {
600 			ret = -EINVAL;
601 			break;
602 		}
603 		if (dir == IIO_EV_DIR_RISING)
604 			data->thresh_data[chan->address].high_thresh = val;
605 		else
606 			data->thresh_data[chan->address].low_thresh = val;
607 		break;
608 	case IIO_EV_INFO_PERIOD:
609 		dr = data->channel_data[chan->address].data_rate;
610 		period = val * USEC_PER_SEC + val2;
611 
612 		for (i = 0; i < ARRAY_SIZE(ads1015_comp_queue) - 1; i++) {
613 			if (period <= ads1015_comp_queue[i] *
614 					USEC_PER_SEC / data->data_rate[dr])
615 				break;
616 		}
617 		data->thresh_data[chan->address].comp_queue = i;
618 		break;
619 	default:
620 		ret = -EINVAL;
621 		break;
622 	}
623 
624 	mutex_unlock(&data->lock);
625 
626 	return ret;
627 }
628 
629 static int ads1015_read_event_config(struct iio_dev *indio_dev,
630 	const struct iio_chan_spec *chan, enum iio_event_type type,
631 	enum iio_event_direction dir)
632 {
633 	struct ads1015_data *data = iio_priv(indio_dev);
634 	int ret = 0;
635 
636 	mutex_lock(&data->lock);
637 	if (data->event_channel == chan->address) {
638 		switch (dir) {
639 		case IIO_EV_DIR_RISING:
640 			ret = 1;
641 			break;
642 		case IIO_EV_DIR_EITHER:
643 			ret = (data->comp_mode == ADS1015_CFG_COMP_MODE_WINDOW);
644 			break;
645 		default:
646 			ret = -EINVAL;
647 			break;
648 		}
649 	}
650 	mutex_unlock(&data->lock);
651 
652 	return ret;
653 }
654 
655 static int ads1015_enable_event_config(struct ads1015_data *data,
656 	const struct iio_chan_spec *chan, int comp_mode)
657 {
658 	int low_thresh = data->thresh_data[chan->address].low_thresh;
659 	int high_thresh = data->thresh_data[chan->address].high_thresh;
660 	int ret;
661 	unsigned int val;
662 
663 	if (ads1015_event_channel_enabled(data)) {
664 		if (data->event_channel != chan->address ||
665 			(data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD &&
666 				comp_mode == ADS1015_CFG_COMP_MODE_WINDOW))
667 			return -EBUSY;
668 
669 		return 0;
670 	}
671 
672 	if (comp_mode == ADS1015_CFG_COMP_MODE_TRAD) {
673 		low_thresh = max(-1 << (chan->scan_type.realbits - 1),
674 				high_thresh - 1);
675 	}
676 	ret = regmap_write(data->regmap, ADS1015_LO_THRESH_REG,
677 			low_thresh << chan->scan_type.shift);
678 	if (ret)
679 		return ret;
680 
681 	ret = regmap_write(data->regmap, ADS1015_HI_THRESH_REG,
682 			high_thresh << chan->scan_type.shift);
683 	if (ret)
684 		return ret;
685 
686 	ret = ads1015_set_power_state(data, true);
687 	if (ret < 0)
688 		return ret;
689 
690 	ads1015_event_channel_enable(data, chan->address, comp_mode);
691 
692 	ret = ads1015_get_adc_result(data, chan->address, &val);
693 	if (ret) {
694 		ads1015_event_channel_disable(data, chan->address);
695 		ads1015_set_power_state(data, false);
696 	}
697 
698 	return ret;
699 }
700 
701 static int ads1015_disable_event_config(struct ads1015_data *data,
702 	const struct iio_chan_spec *chan, int comp_mode)
703 {
704 	int ret;
705 
706 	if (!ads1015_event_channel_enabled(data))
707 		return 0;
708 
709 	if (data->event_channel != chan->address)
710 		return 0;
711 
712 	if (data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD &&
713 			comp_mode == ADS1015_CFG_COMP_MODE_WINDOW)
714 		return 0;
715 
716 	ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
717 				ADS1015_CFG_COMP_QUE_MASK,
718 				ADS1015_CFG_COMP_DISABLE <<
719 					ADS1015_CFG_COMP_QUE_SHIFT);
720 	if (ret)
721 		return ret;
722 
723 	ads1015_event_channel_disable(data, chan->address);
724 
725 	return ads1015_set_power_state(data, false);
726 }
727 
728 static int ads1015_write_event_config(struct iio_dev *indio_dev,
729 	const struct iio_chan_spec *chan, enum iio_event_type type,
730 	enum iio_event_direction dir, int state)
731 {
732 	struct ads1015_data *data = iio_priv(indio_dev);
733 	int ret;
734 	int comp_mode = (dir == IIO_EV_DIR_EITHER) ?
735 		ADS1015_CFG_COMP_MODE_WINDOW : ADS1015_CFG_COMP_MODE_TRAD;
736 
737 	mutex_lock(&data->lock);
738 
739 	/* Prevent from enabling both buffer and event at a time */
740 	ret = iio_device_claim_direct_mode(indio_dev);
741 	if (ret) {
742 		mutex_unlock(&data->lock);
743 		return ret;
744 	}
745 
746 	if (state)
747 		ret = ads1015_enable_event_config(data, chan, comp_mode);
748 	else
749 		ret = ads1015_disable_event_config(data, chan, comp_mode);
750 
751 	iio_device_release_direct_mode(indio_dev);
752 	mutex_unlock(&data->lock);
753 
754 	return ret;
755 }
756 
757 static irqreturn_t ads1015_event_handler(int irq, void *priv)
758 {
759 	struct iio_dev *indio_dev = priv;
760 	struct ads1015_data *data = iio_priv(indio_dev);
761 	int val;
762 	int ret;
763 
764 	/* Clear the latched ALERT/RDY pin */
765 	ret = regmap_read(data->regmap, ADS1015_CONV_REG, &val);
766 	if (ret)
767 		return IRQ_HANDLED;
768 
769 	if (ads1015_event_channel_enabled(data)) {
770 		enum iio_event_direction dir;
771 		u64 code;
772 
773 		dir = data->comp_mode == ADS1015_CFG_COMP_MODE_TRAD ?
774 					IIO_EV_DIR_RISING : IIO_EV_DIR_EITHER;
775 		code = IIO_UNMOD_EVENT_CODE(IIO_VOLTAGE, data->event_channel,
776 					IIO_EV_TYPE_THRESH, dir);
777 		iio_push_event(indio_dev, code, iio_get_time_ns(indio_dev));
778 	}
779 
780 	return IRQ_HANDLED;
781 }
782 
783 static int ads1015_buffer_preenable(struct iio_dev *indio_dev)
784 {
785 	struct ads1015_data *data = iio_priv(indio_dev);
786 
787 	/* Prevent from enabling both buffer and event at a time */
788 	if (ads1015_event_channel_enabled(data))
789 		return -EBUSY;
790 
791 	return ads1015_set_power_state(iio_priv(indio_dev), true);
792 }
793 
794 static int ads1015_buffer_postdisable(struct iio_dev *indio_dev)
795 {
796 	return ads1015_set_power_state(iio_priv(indio_dev), false);
797 }
798 
799 static const struct iio_buffer_setup_ops ads1015_buffer_setup_ops = {
800 	.preenable	= ads1015_buffer_preenable,
801 	.postdisable	= ads1015_buffer_postdisable,
802 	.validate_scan_mask = &iio_validate_scan_mask_onehot,
803 };
804 
805 static IIO_CONST_ATTR_NAMED(ads1015_scale_available, scale_available,
806 	"3 2 1 0.5 0.25 0.125");
807 static IIO_CONST_ATTR_NAMED(ads1115_scale_available, scale_available,
808 	"0.1875 0.125 0.0625 0.03125 0.015625 0.007813");
809 
810 static IIO_CONST_ATTR_NAMED(ads1015_sampling_frequency_available,
811 	sampling_frequency_available, "128 250 490 920 1600 2400 3300");
812 static IIO_CONST_ATTR_NAMED(ads1115_sampling_frequency_available,
813 	sampling_frequency_available, "8 16 32 64 128 250 475 860");
814 
815 static struct attribute *ads1015_attributes[] = {
816 	&iio_const_attr_ads1015_scale_available.dev_attr.attr,
817 	&iio_const_attr_ads1015_sampling_frequency_available.dev_attr.attr,
818 	NULL,
819 };
820 
821 static const struct attribute_group ads1015_attribute_group = {
822 	.attrs = ads1015_attributes,
823 };
824 
825 static struct attribute *ads1115_attributes[] = {
826 	&iio_const_attr_ads1115_scale_available.dev_attr.attr,
827 	&iio_const_attr_ads1115_sampling_frequency_available.dev_attr.attr,
828 	NULL,
829 };
830 
831 static const struct attribute_group ads1115_attribute_group = {
832 	.attrs = ads1115_attributes,
833 };
834 
835 static const struct iio_info ads1015_info = {
836 	.read_raw	= ads1015_read_raw,
837 	.write_raw	= ads1015_write_raw,
838 	.read_event_value = ads1015_read_event,
839 	.write_event_value = ads1015_write_event,
840 	.read_event_config = ads1015_read_event_config,
841 	.write_event_config = ads1015_write_event_config,
842 	.attrs          = &ads1015_attribute_group,
843 };
844 
845 static const struct iio_info ads1115_info = {
846 	.read_raw	= ads1015_read_raw,
847 	.write_raw	= ads1015_write_raw,
848 	.read_event_value = ads1015_read_event,
849 	.write_event_value = ads1015_write_event,
850 	.read_event_config = ads1015_read_event_config,
851 	.write_event_config = ads1015_write_event_config,
852 	.attrs          = &ads1115_attribute_group,
853 };
854 
855 static int ads1015_client_get_channels_config(struct i2c_client *client)
856 {
857 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
858 	struct ads1015_data *data = iio_priv(indio_dev);
859 	struct device *dev = &client->dev;
860 	struct fwnode_handle *node;
861 	int i = -1;
862 
863 	device_for_each_child_node(dev, node) {
864 		u32 pval;
865 		unsigned int channel;
866 		unsigned int pga = ADS1015_DEFAULT_PGA;
867 		unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
868 
869 		if (fwnode_property_read_u32(node, "reg", &pval)) {
870 			dev_err(dev, "invalid reg on %pfw\n", node);
871 			continue;
872 		}
873 
874 		channel = pval;
875 		if (channel >= ADS1015_CHANNELS) {
876 			dev_err(dev, "invalid channel index %d on %pfw\n",
877 				channel, node);
878 			continue;
879 		}
880 
881 		if (!fwnode_property_read_u32(node, "ti,gain", &pval)) {
882 			pga = pval;
883 			if (pga > 6) {
884 				dev_err(dev, "invalid gain on %pfw\n", node);
885 				fwnode_handle_put(node);
886 				return -EINVAL;
887 			}
888 		}
889 
890 		if (!fwnode_property_read_u32(node, "ti,datarate", &pval)) {
891 			data_rate = pval;
892 			if (data_rate > 7) {
893 				dev_err(dev, "invalid data_rate on %pfw\n", node);
894 				fwnode_handle_put(node);
895 				return -EINVAL;
896 			}
897 		}
898 
899 		data->channel_data[channel].pga = pga;
900 		data->channel_data[channel].data_rate = data_rate;
901 
902 		i++;
903 	}
904 
905 	return i < 0 ? -EINVAL : 0;
906 }
907 
908 static void ads1015_get_channels_config(struct i2c_client *client)
909 {
910 	unsigned int k;
911 
912 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
913 	struct ads1015_data *data = iio_priv(indio_dev);
914 
915 	if (!ads1015_client_get_channels_config(client))
916 		return;
917 
918 	/* fallback on default configuration */
919 	for (k = 0; k < ADS1015_CHANNELS; ++k) {
920 		data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
921 		data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
922 	}
923 }
924 
925 static int ads1015_set_conv_mode(struct ads1015_data *data, int mode)
926 {
927 	return regmap_update_bits(data->regmap, ADS1015_CFG_REG,
928 				  ADS1015_CFG_MOD_MASK,
929 				  mode << ADS1015_CFG_MOD_SHIFT);
930 }
931 
932 static int ads1015_probe(struct i2c_client *client,
933 			 const struct i2c_device_id *id)
934 {
935 	struct iio_dev *indio_dev;
936 	struct ads1015_data *data;
937 	int ret;
938 	enum chip_ids chip;
939 	int i;
940 
941 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
942 	if (!indio_dev)
943 		return -ENOMEM;
944 
945 	data = iio_priv(indio_dev);
946 	i2c_set_clientdata(client, indio_dev);
947 
948 	mutex_init(&data->lock);
949 
950 	indio_dev->name = ADS1015_DRV_NAME;
951 	indio_dev->modes = INDIO_DIRECT_MODE;
952 
953 	chip = (enum chip_ids)device_get_match_data(&client->dev);
954 	if (chip == ADSXXXX)
955 		chip = id->driver_data;
956 	switch (chip) {
957 	case ADS1015:
958 		indio_dev->channels = ads1015_channels;
959 		indio_dev->num_channels = ARRAY_SIZE(ads1015_channels);
960 		indio_dev->info = &ads1015_info;
961 		data->data_rate = (unsigned int *) &ads1015_data_rate;
962 		break;
963 	case ADS1115:
964 		indio_dev->channels = ads1115_channels;
965 		indio_dev->num_channels = ARRAY_SIZE(ads1115_channels);
966 		indio_dev->info = &ads1115_info;
967 		data->data_rate = (unsigned int *) &ads1115_data_rate;
968 		break;
969 	default:
970 		dev_err(&client->dev, "Unknown chip %d\n", chip);
971 		return -EINVAL;
972 	}
973 
974 	data->event_channel = ADS1015_CHANNELS;
975 	/*
976 	 * Set default lower and upper threshold to min and max value
977 	 * respectively.
978 	 */
979 	for (i = 0; i < ADS1015_CHANNELS; i++) {
980 		int realbits = indio_dev->channels[i].scan_type.realbits;
981 
982 		data->thresh_data[i].low_thresh = -1 << (realbits - 1);
983 		data->thresh_data[i].high_thresh = (1 << (realbits - 1)) - 1;
984 	}
985 
986 	/* we need to keep this ABI the same as used by hwmon ADS1015 driver */
987 	ads1015_get_channels_config(client);
988 
989 	data->regmap = devm_regmap_init_i2c(client, &ads1015_regmap_config);
990 	if (IS_ERR(data->regmap)) {
991 		dev_err(&client->dev, "Failed to allocate register map\n");
992 		return PTR_ERR(data->regmap);
993 	}
994 
995 	ret = devm_iio_triggered_buffer_setup(&client->dev, indio_dev, NULL,
996 					      ads1015_trigger_handler,
997 					      &ads1015_buffer_setup_ops);
998 	if (ret < 0) {
999 		dev_err(&client->dev, "iio triggered buffer setup failed\n");
1000 		return ret;
1001 	}
1002 
1003 	if (client->irq) {
1004 		unsigned long irq_trig =
1005 			irqd_get_trigger_type(irq_get_irq_data(client->irq));
1006 		unsigned int cfg_comp_mask = ADS1015_CFG_COMP_QUE_MASK |
1007 			ADS1015_CFG_COMP_LAT_MASK | ADS1015_CFG_COMP_POL_MASK;
1008 		unsigned int cfg_comp =
1009 			ADS1015_CFG_COMP_DISABLE << ADS1015_CFG_COMP_QUE_SHIFT |
1010 			1 << ADS1015_CFG_COMP_LAT_SHIFT;
1011 
1012 		switch (irq_trig) {
1013 		case IRQF_TRIGGER_LOW:
1014 			cfg_comp |= ADS1015_CFG_COMP_POL_LOW <<
1015 					ADS1015_CFG_COMP_POL_SHIFT;
1016 			break;
1017 		case IRQF_TRIGGER_HIGH:
1018 			cfg_comp |= ADS1015_CFG_COMP_POL_HIGH <<
1019 					ADS1015_CFG_COMP_POL_SHIFT;
1020 			break;
1021 		default:
1022 			return -EINVAL;
1023 		}
1024 
1025 		ret = regmap_update_bits(data->regmap, ADS1015_CFG_REG,
1026 					cfg_comp_mask, cfg_comp);
1027 		if (ret)
1028 			return ret;
1029 
1030 		ret = devm_request_threaded_irq(&client->dev, client->irq,
1031 						NULL, ads1015_event_handler,
1032 						irq_trig | IRQF_ONESHOT,
1033 						client->name, indio_dev);
1034 		if (ret)
1035 			return ret;
1036 	}
1037 
1038 	ret = ads1015_set_conv_mode(data, ADS1015_CONTINUOUS);
1039 	if (ret)
1040 		return ret;
1041 
1042 	data->conv_invalid = true;
1043 
1044 	ret = pm_runtime_set_active(&client->dev);
1045 	if (ret)
1046 		return ret;
1047 	pm_runtime_set_autosuspend_delay(&client->dev, ADS1015_SLEEP_DELAY_MS);
1048 	pm_runtime_use_autosuspend(&client->dev);
1049 	pm_runtime_enable(&client->dev);
1050 
1051 	ret = iio_device_register(indio_dev);
1052 	if (ret < 0) {
1053 		dev_err(&client->dev, "Failed to register IIO device\n");
1054 		return ret;
1055 	}
1056 
1057 	return 0;
1058 }
1059 
1060 static int ads1015_remove(struct i2c_client *client)
1061 {
1062 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
1063 	struct ads1015_data *data = iio_priv(indio_dev);
1064 
1065 	iio_device_unregister(indio_dev);
1066 
1067 	pm_runtime_disable(&client->dev);
1068 	pm_runtime_set_suspended(&client->dev);
1069 	pm_runtime_put_noidle(&client->dev);
1070 
1071 	/* power down single shot mode */
1072 	return ads1015_set_conv_mode(data, ADS1015_SINGLESHOT);
1073 }
1074 
1075 #ifdef CONFIG_PM
1076 static int ads1015_runtime_suspend(struct device *dev)
1077 {
1078 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
1079 	struct ads1015_data *data = iio_priv(indio_dev);
1080 
1081 	return ads1015_set_conv_mode(data, ADS1015_SINGLESHOT);
1082 }
1083 
1084 static int ads1015_runtime_resume(struct device *dev)
1085 {
1086 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
1087 	struct ads1015_data *data = iio_priv(indio_dev);
1088 	int ret;
1089 
1090 	ret = ads1015_set_conv_mode(data, ADS1015_CONTINUOUS);
1091 	if (!ret)
1092 		data->conv_invalid = true;
1093 
1094 	return ret;
1095 }
1096 #endif
1097 
1098 static const struct dev_pm_ops ads1015_pm_ops = {
1099 	SET_RUNTIME_PM_OPS(ads1015_runtime_suspend,
1100 			   ads1015_runtime_resume, NULL)
1101 };
1102 
1103 static const struct i2c_device_id ads1015_id[] = {
1104 	{"ads1015", ADS1015},
1105 	{"ads1115", ADS1115},
1106 	{}
1107 };
1108 MODULE_DEVICE_TABLE(i2c, ads1015_id);
1109 
1110 static const struct of_device_id ads1015_of_match[] = {
1111 	{
1112 		.compatible = "ti,ads1015",
1113 		.data = (void *)ADS1015
1114 	},
1115 	{
1116 		.compatible = "ti,ads1115",
1117 		.data = (void *)ADS1115
1118 	},
1119 	{}
1120 };
1121 MODULE_DEVICE_TABLE(of, ads1015_of_match);
1122 
1123 static struct i2c_driver ads1015_driver = {
1124 	.driver = {
1125 		.name = ADS1015_DRV_NAME,
1126 		.of_match_table = ads1015_of_match,
1127 		.pm = &ads1015_pm_ops,
1128 	},
1129 	.probe		= ads1015_probe,
1130 	.remove		= ads1015_remove,
1131 	.id_table	= ads1015_id,
1132 };
1133 
1134 module_i2c_driver(ads1015_driver);
1135 
1136 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com>");
1137 MODULE_DESCRIPTION("Texas Instruments ADS1015 ADC driver");
1138 MODULE_LICENSE("GPL v2");
1139