1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2020 InvenSense, Inc.
4 *
5 * Driver for InvenSense ICP-1010xx barometric pressure and temperature sensor.
6 *
7 * Datasheet:
8 * http://www.invensense.com/wp-content/uploads/2018/01/DS-000186-ICP-101xx-v1.2.pdf
9 */
10
11#include <linux/device.h>
12#include <linux/module.h>
13#include <linux/mod_devicetable.h>
14#include <linux/i2c.h>
15#include <linux/pm_runtime.h>
16#include <linux/crc8.h>
17#include <linux/mutex.h>
18#include <linux/delay.h>
19#include <linux/log2.h>
20#include <linux/math64.h>
21#include <linux/regulator/consumer.h>
22#include <linux/iio/iio.h>
23
24#define ICP10100_ID_REG_GET(_reg)	((_reg) & 0x003F)
25#define ICP10100_ID_REG			0x08
26#define ICP10100_RESPONSE_WORD_LENGTH	3
27#define ICP10100_CRC8_WORD_LENGTH	2
28#define ICP10100_CRC8_POLYNOMIAL	0x31
29#define ICP10100_CRC8_INIT		0xFF
30
31enum icp10100_mode {
32	ICP10100_MODE_LP,	/* Low power mode: 1x sampling */
33	ICP10100_MODE_N,	/* Normal mode: 2x sampling */
34	ICP10100_MODE_LN,	/* Low noise mode: 4x sampling */
35	ICP10100_MODE_ULN,	/* Ultra low noise mode: 8x sampling */
36	ICP10100_MODE_NB,
37};
38
39struct icp10100_state {
40	struct mutex lock;
41	struct i2c_client *client;
42	struct regulator *vdd;
43	enum icp10100_mode mode;
44	int16_t cal[4];
45};
46
47struct icp10100_command {
48	__be16 cmd;
49	unsigned long wait_us;
50	unsigned long wait_max_us;
51	size_t response_word_nb;
52};
53
54static const struct icp10100_command icp10100_cmd_soft_reset = {
55	.cmd = cpu_to_be16(0x805D),
56	.wait_us = 170,
57	.wait_max_us = 200,
58	.response_word_nb = 0,
59};
60
61static const struct icp10100_command icp10100_cmd_read_id = {
62	.cmd = cpu_to_be16(0xEFC8),
63	.wait_us = 0,
64	.response_word_nb = 1,
65};
66
67static const struct icp10100_command icp10100_cmd_read_otp = {
68	.cmd = cpu_to_be16(0xC7F7),
69	.wait_us = 0,
70	.response_word_nb = 1,
71};
72
73static const struct icp10100_command icp10100_cmd_measure[] = {
74	[ICP10100_MODE_LP] = {
75		.cmd = cpu_to_be16(0x401A),
76		.wait_us = 1800,
77		.wait_max_us = 2000,
78		.response_word_nb = 3,
79	},
80	[ICP10100_MODE_N] = {
81		.cmd = cpu_to_be16(0x48A3),
82		.wait_us = 6300,
83		.wait_max_us = 6500,
84		.response_word_nb = 3,
85	},
86	[ICP10100_MODE_LN] = {
87		.cmd = cpu_to_be16(0x5059),
88		.wait_us = 23800,
89		.wait_max_us = 24000,
90		.response_word_nb = 3,
91	},
92	[ICP10100_MODE_ULN] = {
93		.cmd = cpu_to_be16(0x58E0),
94		.wait_us = 94500,
95		.wait_max_us = 94700,
96		.response_word_nb = 3,
97	},
98};
99
100static const uint8_t icp10100_switch_mode_otp[] =
101	{0xC5, 0x95, 0x00, 0x66, 0x9c};
102
103DECLARE_CRC8_TABLE(icp10100_crc8_table);
104
105static inline int icp10100_i2c_xfer(struct i2c_adapter *adap,
106				    struct i2c_msg *msgs, int num)
107{
108	int ret;
109
110	ret = i2c_transfer(adap, msgs, num);
111	if (ret < 0)
112		return ret;
113
114	if (ret != num)
115		return -EIO;
116
117	return 0;
118}
119
120static int icp10100_send_cmd(struct icp10100_state *st,
121			     const struct icp10100_command *cmd,
122			     __be16 *buf, size_t buf_len)
123{
124	size_t size = cmd->response_word_nb * ICP10100_RESPONSE_WORD_LENGTH;
125	uint8_t data[16];
126	uint8_t *ptr;
127	uint8_t *buf_ptr = (uint8_t *)buf;
128	struct i2c_msg msgs[2] = {
129		{
130			.addr = st->client->addr,
131			.flags = 0,
132			.len = 2,
133			.buf = (uint8_t *)&cmd->cmd,
134		}, {
135			.addr = st->client->addr,
136			.flags = I2C_M_RD,
137			.len = size,
138			.buf = data,
139		},
140	};
141	uint8_t crc;
142	unsigned int i;
143	int ret;
144
145	if (size > sizeof(data))
146		return -EINVAL;
147
148	if (cmd->response_word_nb > 0 &&
149			(buf == NULL || buf_len < (cmd->response_word_nb * 2)))
150		return -EINVAL;
151
152	dev_dbg(&st->client->dev, "sending cmd %#x\n", be16_to_cpu(cmd->cmd));
153
154	if (cmd->response_word_nb > 0 && cmd->wait_us == 0) {
155		/* direct command-response without waiting */
156		ret = icp10100_i2c_xfer(st->client->adapter, msgs,
157					ARRAY_SIZE(msgs));
158		if (ret)
159			return ret;
160	} else {
161		/* transfer command write */
162		ret = icp10100_i2c_xfer(st->client->adapter, &msgs[0], 1);
163		if (ret)
164			return ret;
165		if (cmd->wait_us > 0)
166			usleep_range(cmd->wait_us, cmd->wait_max_us);
167		/* transfer response read if needed */
168		if (cmd->response_word_nb > 0) {
169			ret = icp10100_i2c_xfer(st->client->adapter, &msgs[1], 1);
170			if (ret)
171				return ret;
172		} else {
173			return 0;
174		}
175	}
176
177	/* process read words with crc checking */
178	for (i = 0; i < cmd->response_word_nb; ++i) {
179		ptr = &data[i * ICP10100_RESPONSE_WORD_LENGTH];
180		crc = crc8(icp10100_crc8_table, ptr, ICP10100_CRC8_WORD_LENGTH,
181			   ICP10100_CRC8_INIT);
182		if (crc != ptr[ICP10100_CRC8_WORD_LENGTH]) {
183			dev_err(&st->client->dev, "crc error recv=%#x calc=%#x\n",
184				ptr[ICP10100_CRC8_WORD_LENGTH], crc);
185			return -EIO;
186		}
187		*buf_ptr++ = ptr[0];
188		*buf_ptr++ = ptr[1];
189	}
190
191	return 0;
192}
193
194static int icp10100_read_cal_otp(struct icp10100_state *st)
195{
196	__be16 val;
197	int i;
198	int ret;
199
200	/* switch into OTP read mode */
201	ret = i2c_master_send(st->client, icp10100_switch_mode_otp,
202			      ARRAY_SIZE(icp10100_switch_mode_otp));
203	if (ret < 0)
204		return ret;
205	if (ret != ARRAY_SIZE(icp10100_switch_mode_otp))
206		return -EIO;
207
208	/* read 4 calibration values */
209	for (i = 0; i < 4; ++i) {
210		ret = icp10100_send_cmd(st, &icp10100_cmd_read_otp,
211					&val, sizeof(val));
212		if (ret)
213			return ret;
214		st->cal[i] = be16_to_cpu(val);
215		dev_dbg(&st->client->dev, "cal[%d] = %d\n", i, st->cal[i]);
216	}
217
218	return 0;
219}
220
221static int icp10100_init_chip(struct icp10100_state *st)
222{
223	__be16 val;
224	uint16_t id;
225	int ret;
226
227	/* read and check id */
228	ret = icp10100_send_cmd(st, &icp10100_cmd_read_id, &val, sizeof(val));
229	if (ret)
230		return ret;
231	id = ICP10100_ID_REG_GET(be16_to_cpu(val));
232	if (id != ICP10100_ID_REG) {
233		dev_err(&st->client->dev, "invalid id %#x\n", id);
234		return -ENODEV;
235	}
236
237	/* read calibration data from OTP */
238	ret = icp10100_read_cal_otp(st);
239	if (ret)
240		return ret;
241
242	/* reset chip */
243	return icp10100_send_cmd(st, &icp10100_cmd_soft_reset, NULL, 0);
244}
245
246static int icp10100_get_measures(struct icp10100_state *st,
247				uint32_t *pressure, uint16_t *temperature)
248{
249	const struct icp10100_command *cmd;
250	__be16 measures[3];
251	int ret;
252
253	ret = pm_runtime_resume_and_get(&st->client->dev);
254	if (ret < 0)
255		return ret;
256
257	mutex_lock(&st->lock);
258	cmd = &icp10100_cmd_measure[st->mode];
259	ret = icp10100_send_cmd(st, cmd, measures, sizeof(measures));
260	mutex_unlock(&st->lock);
261	if (ret)
262		goto error_measure;
263
264	*pressure = (be16_to_cpu(measures[0]) << 8) |
265			(be16_to_cpu(measures[1]) >> 8);
266	*temperature = be16_to_cpu(measures[2]);
267
268	pm_runtime_mark_last_busy(&st->client->dev);
269error_measure:
270	pm_runtime_put_autosuspend(&st->client->dev);
271	return ret;
272}
273
274static uint32_t icp10100_get_pressure(struct icp10100_state *st,
275				      uint32_t raw_pressure, uint16_t raw_temp)
276{
277	static int32_t p_calib[] = {45000, 80000, 105000};
278	static int32_t lut_lower = 3670016;
279	static int32_t lut_upper = 12058624;
280	static int32_t inv_quadr_factor = 16777216;
281	static int32_t offset_factor = 2048;
282	int64_t val1, val2;
283	int32_t p_lut[3];
284	int32_t t, t_square;
285	int64_t a, b, c;
286	uint32_t pressure_mPa;
287
288	dev_dbg(&st->client->dev, "raw: pressure = %u, temp = %u\n",
289		raw_pressure, raw_temp);
290
291	/* compute p_lut values */
292	t = (int32_t)raw_temp - 32768;
293	t_square = t * t;
294	val1 = (int64_t)st->cal[0] * (int64_t)t_square;
295	p_lut[0] = lut_lower + (int32_t)div_s64(val1, inv_quadr_factor);
296	val1 = (int64_t)st->cal[1] * (int64_t)t_square;
297	p_lut[1] = offset_factor * st->cal[3] +
298			(int32_t)div_s64(val1, inv_quadr_factor);
299	val1 = (int64_t)st->cal[2] * (int64_t)t_square;
300	p_lut[2] = lut_upper + (int32_t)div_s64(val1, inv_quadr_factor);
301	dev_dbg(&st->client->dev, "p_lut = [%d, %d, %d]\n",
302		p_lut[0], p_lut[1], p_lut[2]);
303
304	/* compute a, b, c factors */
305	val1 = (int64_t)p_lut[0] * (int64_t)p_lut[1] *
306			(int64_t)(p_calib[0] - p_calib[1]) +
307		(int64_t)p_lut[1] * (int64_t)p_lut[2] *
308			(int64_t)(p_calib[1] - p_calib[2]) +
309		(int64_t)p_lut[2] * (int64_t)p_lut[0] *
310			(int64_t)(p_calib[2] - p_calib[0]);
311	val2 = (int64_t)p_lut[2] * (int64_t)(p_calib[0] - p_calib[1]) +
312		(int64_t)p_lut[0] * (int64_t)(p_calib[1] - p_calib[2]) +
313		(int64_t)p_lut[1] * (int64_t)(p_calib[2] - p_calib[0]);
314	c = div64_s64(val1, val2);
315	dev_dbg(&st->client->dev, "val1 = %lld, val2 = %lld, c = %lld\n",
316		val1, val2, c);
317	val1 = (int64_t)p_calib[0] * (int64_t)p_lut[0] -
318		(int64_t)p_calib[1] * (int64_t)p_lut[1] -
319		(int64_t)(p_calib[1] - p_calib[0]) * c;
320	val2 = (int64_t)p_lut[0] - (int64_t)p_lut[1];
321	a = div64_s64(val1, val2);
322	dev_dbg(&st->client->dev, "val1 = %lld, val2 = %lld, a = %lld\n",
323		val1, val2, a);
324	b = ((int64_t)p_calib[0] - a) * ((int64_t)p_lut[0] + c);
325	dev_dbg(&st->client->dev, "b = %lld\n", b);
326
327	/*
328	 * pressure_Pa = a + (b / (c + raw_pressure))
329	 * pressure_mPa = 1000 * pressure_Pa
330	 */
331	pressure_mPa = 1000LL * a + div64_s64(1000LL * b, c + raw_pressure);
332
333	return pressure_mPa;
334}
335
336static int icp10100_read_raw_measures(struct iio_dev *indio_dev,
337				      struct iio_chan_spec const *chan,
338				      int *val, int *val2)
339{
340	struct icp10100_state *st = iio_priv(indio_dev);
341	uint32_t raw_pressure;
342	uint16_t raw_temp;
343	uint32_t pressure_mPa;
344	int ret;
345
346	ret = iio_device_claim_direct_mode(indio_dev);
347	if (ret)
348		return ret;
349
350	ret = icp10100_get_measures(st, &raw_pressure, &raw_temp);
351	if (ret)
352		goto error_release;
353
354	switch (chan->type) {
355	case IIO_PRESSURE:
356		pressure_mPa = icp10100_get_pressure(st, raw_pressure,
357						     raw_temp);
358		/* mPa to kPa */
359		*val = pressure_mPa / 1000000;
360		*val2 = pressure_mPa % 1000000;
361		ret = IIO_VAL_INT_PLUS_MICRO;
362		break;
363	case IIO_TEMP:
364		*val = raw_temp;
365		ret = IIO_VAL_INT;
366		break;
367	default:
368		ret = -EINVAL;
369		break;
370	}
371
372error_release:
373	iio_device_release_direct_mode(indio_dev);
374	return ret;
375}
376
377static int icp10100_read_raw(struct iio_dev *indio_dev,
378			     struct iio_chan_spec const *chan,
379			     int *val, int *val2, long mask)
380{
381	struct icp10100_state *st = iio_priv(indio_dev);
382
383	switch (mask) {
384	case IIO_CHAN_INFO_RAW:
385	case IIO_CHAN_INFO_PROCESSED:
386		return icp10100_read_raw_measures(indio_dev, chan, val, val2);
387	case IIO_CHAN_INFO_SCALE:
388		switch (chan->type) {
389		case IIO_TEMP:
390			/* 1000 * 175��C / 65536 in m��C */
391			*val = 2;
392			*val2 = 670288;
393			return IIO_VAL_INT_PLUS_MICRO;
394		default:
395			return -EINVAL;
396		}
397		break;
398	case IIO_CHAN_INFO_OFFSET:
399		switch (chan->type) {
400		case IIO_TEMP:
401			/* 1000 * -45��C in m��C */
402			*val = -45000;
403			return IIO_VAL_INT;
404		default:
405			return -EINVAL;
406		}
407		break;
408	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
409		mutex_lock(&st->lock);
410		*val = 1 << st->mode;
411		mutex_unlock(&st->lock);
412		return IIO_VAL_INT;
413	default:
414		return -EINVAL;
415	}
416}
417
418static int icp10100_read_avail(struct iio_dev *indio_dev,
419			       struct iio_chan_spec const *chan,
420			       const int **vals, int *type, int *length,
421			       long mask)
422{
423	static int oversamplings[] = {1, 2, 4, 8};
424
425	switch (mask) {
426	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
427		*vals = oversamplings;
428		*type = IIO_VAL_INT;
429		*length = ARRAY_SIZE(oversamplings);
430		return IIO_AVAIL_LIST;
431	default:
432		return -EINVAL;
433	}
434}
435
436static int icp10100_write_raw(struct iio_dev *indio_dev,
437			      struct iio_chan_spec const *chan,
438			      int val, int val2, long mask)
439{
440	struct icp10100_state *st = iio_priv(indio_dev);
441	unsigned int mode;
442	int ret;
443
444	switch (mask) {
445	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
446		/* oversampling is always positive and a power of 2 */
447		if (val <= 0 || !is_power_of_2(val))
448			return -EINVAL;
449		mode = ilog2(val);
450		if (mode >= ICP10100_MODE_NB)
451			return -EINVAL;
452		ret = iio_device_claim_direct_mode(indio_dev);
453		if (ret)
454			return ret;
455		mutex_lock(&st->lock);
456		st->mode = mode;
457		mutex_unlock(&st->lock);
458		iio_device_release_direct_mode(indio_dev);
459		return 0;
460	default:
461		return -EINVAL;
462	}
463}
464
465static int icp10100_write_raw_get_fmt(struct iio_dev *indio_dev,
466				      struct iio_chan_spec const *chan,
467				      long mask)
468{
469	switch (mask) {
470	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
471		return IIO_VAL_INT;
472	default:
473		return -EINVAL;
474	}
475}
476
477static const struct iio_info icp10100_info = {
478	.read_raw = icp10100_read_raw,
479	.read_avail = icp10100_read_avail,
480	.write_raw = icp10100_write_raw,
481	.write_raw_get_fmt = icp10100_write_raw_get_fmt,
482};
483
484static const struct iio_chan_spec icp10100_channels[] = {
485	{
486		.type = IIO_PRESSURE,
487		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
488		.info_mask_shared_by_all =
489			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
490		.info_mask_shared_by_all_available =
491			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
492	}, {
493		.type = IIO_TEMP,
494		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
495			BIT(IIO_CHAN_INFO_SCALE) |
496			BIT(IIO_CHAN_INFO_OFFSET),
497		.info_mask_shared_by_all =
498			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
499		.info_mask_shared_by_all_available =
500			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
501	},
502};
503
504static int icp10100_enable_regulator(struct icp10100_state *st)
505{
506	int ret;
507
508	ret = regulator_enable(st->vdd);
509	if (ret)
510		return ret;
511	msleep(100);
512
513	return 0;
514}
515
516static void icp10100_disable_regulator_action(void *data)
517{
518	struct icp10100_state *st = data;
519	int ret;
520
521	ret = regulator_disable(st->vdd);
522	if (ret)
523		dev_err(&st->client->dev, "error %d disabling vdd\n", ret);
524}
525
526static void icp10100_pm_disable(void *data)
527{
528	struct device *dev = data;
529
530	pm_runtime_disable(dev);
531}
532
533static int icp10100_probe(struct i2c_client *client)
534{
535	struct iio_dev *indio_dev;
536	struct icp10100_state *st;
537	int ret;
538
539	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
540		dev_err(&client->dev, "plain i2c transactions not supported\n");
541		return -ENODEV;
542	}
543
544	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
545	if (!indio_dev)
546		return -ENOMEM;
547
548	i2c_set_clientdata(client, indio_dev);
549	indio_dev->name = client->name;
550	indio_dev->modes = INDIO_DIRECT_MODE;
551	indio_dev->channels = icp10100_channels;
552	indio_dev->num_channels = ARRAY_SIZE(icp10100_channels);
553	indio_dev->info = &icp10100_info;
554
555	st = iio_priv(indio_dev);
556	mutex_init(&st->lock);
557	st->client = client;
558	st->mode = ICP10100_MODE_N;
559
560	st->vdd = devm_regulator_get(&client->dev, "vdd");
561	if (IS_ERR(st->vdd))
562		return PTR_ERR(st->vdd);
563
564	ret = icp10100_enable_regulator(st);
565	if (ret)
566		return ret;
567
568	ret = devm_add_action_or_reset(&client->dev,
569				       icp10100_disable_regulator_action, st);
570	if (ret)
571		return ret;
572
573	/* has to be done before the first i2c communication */
574	crc8_populate_msb(icp10100_crc8_table, ICP10100_CRC8_POLYNOMIAL);
575
576	ret = icp10100_init_chip(st);
577	if (ret) {
578		dev_err(&client->dev, "init chip error %d\n", ret);
579		return ret;
580	}
581
582	/* enable runtime pm with autosuspend delay of 2s */
583	pm_runtime_get_noresume(&client->dev);
584	pm_runtime_set_active(&client->dev);
585	pm_runtime_enable(&client->dev);
586	pm_runtime_set_autosuspend_delay(&client->dev, 2000);
587	pm_runtime_use_autosuspend(&client->dev);
588	pm_runtime_put(&client->dev);
589	ret = devm_add_action_or_reset(&client->dev, icp10100_pm_disable,
590				       &client->dev);
591	if (ret)
592		return ret;
593
594	return devm_iio_device_register(&client->dev, indio_dev);
595}
596
597static int icp10100_suspend(struct device *dev)
598{
599	struct icp10100_state *st = iio_priv(dev_get_drvdata(dev));
600	int ret;
601
602	mutex_lock(&st->lock);
603	ret = regulator_disable(st->vdd);
604	mutex_unlock(&st->lock);
605
606	return ret;
607}
608
609static int icp10100_resume(struct device *dev)
610{
611	struct icp10100_state *st = iio_priv(dev_get_drvdata(dev));
612	int ret;
613
614	mutex_lock(&st->lock);
615
616	ret = icp10100_enable_regulator(st);
617	if (ret)
618		goto out_unlock;
619
620	/* reset chip */
621	ret = icp10100_send_cmd(st, &icp10100_cmd_soft_reset, NULL, 0);
622
623out_unlock:
624	mutex_unlock(&st->lock);
625	return ret;
626}
627
628static DEFINE_RUNTIME_DEV_PM_OPS(icp10100_pm, icp10100_suspend, icp10100_resume,
629				 NULL);
630
631static const struct of_device_id icp10100_of_match[] = {
632	{
633		.compatible = "invensense,icp10100",
634	},
635	{ }
636};
637MODULE_DEVICE_TABLE(of, icp10100_of_match);
638
639static const struct i2c_device_id icp10100_id[] = {
640	{ "icp10100", 0 },
641	{ }
642};
643MODULE_DEVICE_TABLE(i2c, icp10100_id);
644
645static struct i2c_driver icp10100_driver = {
646	.driver = {
647		.name = "icp10100",
648		.pm = pm_ptr(&icp10100_pm),
649		.of_match_table = icp10100_of_match,
650	},
651	.probe = icp10100_probe,
652	.id_table = icp10100_id,
653};
654module_i2c_driver(icp10100_driver);
655
656MODULE_AUTHOR("InvenSense, Inc.");
657MODULE_DESCRIPTION("InvenSense icp10100 driver");
658MODULE_LICENSE("GPL");
659