summaryrefslogtreecommitdiffstats
path: root/drivers/iio/pressure/ms5611_core.c
blob: 76578b07bb6e6e67734cbcf0236131c612cec92c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
/*
 * MS5611 pressure and temperature sensor driver
 *
 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Data sheet:
 *  http://www.meas-spec.com/downloads/MS5611-01BA03.pdf
 *  http://www.meas-spec.com/downloads/MS5607-02BA03.pdf
 *
 */

#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/delay.h>
#include <linux/regulator/consumer.h>

#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include "ms5611.h"

#define MS5611_INIT_OSR(_cmd, _conv_usec, _rate) \
	{ .cmd = _cmd, .conv_usec = _conv_usec, .rate = _rate }

static const struct ms5611_osr ms5611_avail_pressure_osr[] = {
	MS5611_INIT_OSR(0x40, 600,  256),
	MS5611_INIT_OSR(0x42, 1170, 512),
	MS5611_INIT_OSR(0x44, 2280, 1024),
	MS5611_INIT_OSR(0x46, 4540, 2048),
	MS5611_INIT_OSR(0x48, 9040, 4096)
};

static const struct ms5611_osr ms5611_avail_temp_osr[] = {
	MS5611_INIT_OSR(0x50, 600,  256),
	MS5611_INIT_OSR(0x52, 1170, 512),
	MS5611_INIT_OSR(0x54, 2280, 1024),
	MS5611_INIT_OSR(0x56, 4540, 2048),
	MS5611_INIT_OSR(0x58, 9040, 4096)
};

static const char ms5611_show_osr[] = "256 512 1024 2048 4096";

static IIO_CONST_ATTR(oversampling_ratio_available, ms5611_show_osr);

static struct attribute *ms5611_attributes[] = {
	&iio_const_attr_oversampling_ratio_available.dev_attr.attr,
	NULL,
};

static const struct attribute_group ms5611_attribute_group = {
	.attrs = ms5611_attributes,
};

static bool ms5611_prom_is_valid(u16 *prom, size_t len)
{
	int i, j;
	uint16_t crc = 0, crc_orig = prom[7] & 0x000F;

	prom[7] &= 0xFF00;

	for (i = 0; i < len * 2; i++) {
		if (i % 2 == 1)
			crc ^= prom[i >> 1] & 0x00FF;
		else
			crc ^= prom[i >> 1] >> 8;

		for (j = 0; j < 8; j++) {
			if (crc & 0x8000)
				crc = (crc << 1) ^ 0x3000;
			else
				crc <<= 1;
		}
	}

	crc = (crc >> 12) & 0x000F;

	return crc_orig != 0x0000 && crc == crc_orig;
}

static int ms5611_read_prom(struct iio_dev *indio_dev)
{
	int ret, i;
	struct ms5611_state *st = iio_priv(indio_dev);

	for (i = 0; i < MS5611_PROM_WORDS_NB; i++) {
		ret = st->read_prom_word(&indio_dev->dev,
					 i, &st->chip_info->prom[i]);
		if (ret < 0) {
			dev_err(&indio_dev->dev,
				"failed to read prom at %d\n", i);
			return ret;
		}
	}

	if (!ms5611_prom_is_valid(st->chip_info->prom, MS5611_PROM_WORDS_NB)) {
		dev_err(&indio_dev->dev, "PROM integrity check failed\n");
		return -ENODEV;
	}

	return 0;
}

static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev,
					 s32 *temp, s32 *pressure)
{
	int ret;
	struct ms5611_state *st = iio_priv(indio_dev);

	ret = st->read_adc_temp_and_pressure(&indio_dev->dev, temp, pressure);
	if (ret < 0) {
		dev_err(&indio_dev->dev,
			"failed to read temperature and pressure\n");
		return ret;
	}

	return st->chip_info->temp_and_pressure_compensate(st->chip_info,
							   temp, pressure);
}

static int ms5611_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
					       s32 *temp, s32 *pressure)
{
	s32 t = *temp, p = *pressure;
	s64 off, sens, dt;

	dt = t - (chip_info->prom[5] << 8);
	off = ((s64)chip_info->prom[2] << 16) + ((chip_info->prom[4] * dt) >> 7);
	sens = ((s64)chip_info->prom[1] << 15) + ((chip_info->prom[3] * dt) >> 8);

	t = 2000 + ((chip_info->prom[6] * dt) >> 23);
	if (t < 2000) {
		s64 off2, sens2, t2;

		t2 = (dt * dt) >> 31;
		off2 = (5 * (t - 2000) * (t - 2000)) >> 1;
		sens2 = off2 >> 1;

		if (t < -1500) {
			s64 tmp = (t + 1500) * (t + 1500);

			off2 += 7 * tmp;
			sens2 += (11 * tmp) >> 1;
		}

		t -= t2;
		off -= off2;
		sens -= sens2;
	}

	*temp = t;
	*pressure = (((p * sens) >> 21) - off) >> 15;

	return 0;
}

static int ms5607_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
					       s32 *temp, s32 *pressure)
{
	s32 t = *temp, p = *pressure;
	s64 off, sens, dt;

	dt = t - (chip_info->prom[5] << 8);
	off = ((s64)chip_info->prom[2] << 17) + ((chip_info->prom[4] * dt) >> 6);
	sens = ((s64)chip_info->prom[1] << 16) + ((chip_info->prom[3] * dt) >> 7);

	t = 2000 + ((chip_info->prom[6] * dt) >> 23);
	if (t < 2000) {
		s64 off2, sens2, t2, tmp;

		t2 = (dt * dt) >> 31;
		tmp = (t - 2000) * (t - 2000);
		off2 = (61 * tmp) >> 4;
		sens2 = tmp << 1;

		if (t < -1500) {
			tmp = (t + 1500) * (t + 1500);
			off2 += 15 * tmp;
			sens2 += 8 * tmp;
		}

		t -= t2;
		off -= off2;
		sens -= sens2;
	}

	*temp = t;
	*pressure = (((p * sens) >> 21) - off) >> 15;

	return 0;
}

static int ms5611_reset(struct iio_dev *indio_dev)
{
	int ret;
	struct ms5611_state *st = iio_priv(indio_dev);

	ret = st->reset(&indio_dev->dev);
	if (ret < 0) {
		dev_err(&indio_dev->dev, "failed to reset device\n");
		return ret;
	}

	usleep_range(3000, 4000);

	return 0;
}

static irqreturn_t ms5611_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct ms5611_state *st = iio_priv(indio_dev);
	s32 buf[4]; /* s32 (pressure) + s32 (temp) + 2 * s32 (timestamp) */
	int ret;

	mutex_lock(&st->lock);
	ret = ms5611_read_temp_and_pressure(indio_dev, &buf[1], &buf[0]);
	mutex_unlock(&st->lock);
	if (ret < 0)
		goto err;

	iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());

err:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static int ms5611_read_raw(struct iio_dev *indio_dev,
			   struct iio_chan_spec const *chan,
			   int *val, int *val2, long mask)
{
	int ret;
	s32 temp, pressure;
	struct ms5611_state *st = iio_priv(indio_dev);

	switch (mask) {
	case IIO_CHAN_INFO_PROCESSED:
		mutex_lock(&st->lock);
		ret = ms5611_read_temp_and_pressure(indio_dev,
						    &temp, &pressure);
		mutex_unlock(&st->lock);
		if (ret < 0)
			return ret;

		switch (chan->type) {
		case IIO_TEMP:
			*val = temp * 10;
			return IIO_VAL_INT;
		case IIO_PRESSURE:
			*val = pressure / 1000;
			*val2 = (pressure % 1000) * 1000;
			return IIO_VAL_INT_PLUS_MICRO;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_TEMP:
			*val = 10;
			return IIO_VAL_INT;
		case IIO_PRESSURE:
			*val = 0;
			*val2 = 1000;
			return IIO_VAL_INT_PLUS_MICRO;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
		if (chan->type != IIO_TEMP && chan->type != IIO_PRESSURE)
			break;
		mutex_lock(&st->lock);
		if (chan->type == IIO_TEMP)
			*val = (int)st->temp_osr->rate;
		else
			*val = (int)st->pressure_osr->rate;
		mutex_unlock(&st->lock);
		return IIO_VAL_INT;
	}

	return -EINVAL;
}

static const struct ms5611_osr *ms5611_find_osr(int rate,
						const struct ms5611_osr *osr,
						size_t count)
{
	unsigned int r;

	for (r = 0; r < count; r++)
		if ((unsigned short)rate == osr[r].rate)
			break;
	if (r >= count)
		return NULL;
	return &osr[r];
}

static int ms5611_write_raw(struct iio_dev *indio_dev,
			    struct iio_chan_spec const *chan,
			    int val, int val2, long mask)
{
	struct ms5611_state *st = iio_priv(indio_dev);
	const struct ms5611_osr *osr = NULL;

	if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
		return -EINVAL;

	if (chan->type == IIO_TEMP)
		osr = ms5611_find_osr(val, ms5611_avail_temp_osr,
				      ARRAY_SIZE(ms5611_avail_temp_osr));
	else if (chan->type == IIO_PRESSURE)
		osr = ms5611_find_osr(val, ms5611_avail_pressure_osr,
				      ARRAY_SIZE(ms5611_avail_pressure_osr));
	if (!osr)
		return -EINVAL;

	mutex_lock(&st->lock);

	if (iio_buffer_enabled(indio_dev)) {
		mutex_unlock(&st->lock);
		return -EBUSY;
	}

	if (chan->type == IIO_TEMP)
		st->temp_osr = osr;
	else
		st->pressure_osr = osr;

	mutex_unlock(&st->lock);
	return 0;
}

static const unsigned long ms5611_scan_masks[] = {0x3, 0};

static struct ms5611_chip_info chip_info_tbl[] = {
	[MS5611] = {
		.temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate,
	},
	[MS5607] = {
		.temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate,
	}
};

static const struct iio_chan_spec ms5611_channels[] = {
	{
		.type = IIO_PRESSURE,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
			BIT(IIO_CHAN_INFO_SCALE) |
			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
		.scan_index = 0,
		.scan_type = {
			.sign = 's',
			.realbits = 32,
			.storagebits = 32,
			.endianness = IIO_CPU,
		},
	},
	{
		.type = IIO_TEMP,
		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
			BIT(IIO_CHAN_INFO_SCALE) |
			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
		.scan_index = 1,
		.scan_type = {
			.sign = 's',
			.realbits = 32,
			.storagebits = 32,
			.endianness = IIO_CPU,
		},
	},
	IIO_CHAN_SOFT_TIMESTAMP(2),
};

static const struct iio_info ms5611_info = {
	.read_raw = &ms5611_read_raw,
	.write_raw = &ms5611_write_raw,
	.attrs = &ms5611_attribute_group,
	.driver_module = THIS_MODULE,
};

static int ms5611_init(struct iio_dev *indio_dev)
{
	int ret;
	struct ms5611_state *st = iio_priv(indio_dev);

	/* Enable attached regulator if any. */
	st->vdd = devm_regulator_get(indio_dev->dev.parent, "vdd");
	if (!IS_ERR(st->vdd)) {
		ret = regulator_enable(st->vdd);
		if (ret) {
			dev_err(indio_dev->dev.parent,
				"failed to enable Vdd supply: %d\n", ret);
			return ret;
		}
	} else {
		ret = PTR_ERR(st->vdd);
		if (ret != -ENODEV)
			return ret;
	}

	ret = ms5611_reset(indio_dev);
	if (ret < 0)
		goto err_regulator_disable;

	ret = ms5611_read_prom(indio_dev);
	if (ret < 0)
		goto err_regulator_disable;

	return 0;

err_regulator_disable:
	if (!IS_ERR_OR_NULL(st->vdd))
		regulator_disable(st->vdd);
	return ret;
}

static void ms5611_fini(const struct iio_dev *indio_dev)
{
	const struct ms5611_state *st = iio_priv(indio_dev);

	if (!IS_ERR_OR_NULL(st->vdd))
		regulator_disable(st->vdd);
}

int ms5611_probe(struct iio_dev *indio_dev, struct device *dev,
		 const char *name, int type)
{
	int ret;
	struct ms5611_state *st = iio_priv(indio_dev);

	mutex_init(&st->lock);
	st->chip_info = &chip_info_tbl[type];
	st->temp_osr =
		&ms5611_avail_temp_osr[ARRAY_SIZE(ms5611_avail_temp_osr) - 1];
	st->pressure_osr =
		&ms5611_avail_pressure_osr[ARRAY_SIZE(ms5611_avail_pressure_osr)
					   - 1];
	indio_dev->dev.parent = dev;
	indio_dev->name = name;
	indio_dev->info = &ms5611_info;
	indio_dev->channels = ms5611_channels;
	indio_dev->num_channels = ARRAY_SIZE(ms5611_channels);
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->available_scan_masks = ms5611_scan_masks;

	ret = ms5611_init(indio_dev);
	if (ret < 0)
		return ret;

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
					 ms5611_trigger_handler, NULL);
	if (ret < 0) {
		dev_err(dev, "iio triggered buffer setup failed\n");
		goto err_fini;
	}

	ret = iio_device_register(indio_dev);
	if (ret < 0) {
		dev_err(dev, "unable to register iio device\n");
		goto err_buffer_cleanup;
	}

	return 0;

err_buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);
err_fini:
	ms5611_fini(indio_dev);
	return ret;
}
EXPORT_SYMBOL(ms5611_probe);

int ms5611_remove(struct iio_dev *indio_dev)
{
	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);
	ms5611_fini(indio_dev);

	return 0;
}
EXPORT_SYMBOL(ms5611_remove);

MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
MODULE_DESCRIPTION("MS5611 core driver");
MODULE_LICENSE("GPL v2");
OpenPOWER on IntegriCloud