1 /*
2 * MS5611 pressure and temperature sensor driver
3 *
4 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * Data sheet:
11 * http://www.meas-spec.com/downloads/MS5611-01BA03.pdf
12 * http://www.meas-spec.com/downloads/MS5607-02BA03.pdf
13 *
14 */
15
16 #include <linux/module.h>
17 #include <linux/iio/iio.h>
18 #include <linux/delay.h>
19 #include <linux/regulator/consumer.h>
20
21 #include <linux/iio/sysfs.h>
22 #include <linux/iio/buffer.h>
23 #include <linux/iio/triggered_buffer.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include "ms5611.h"
26
27 #define MS5611_INIT_OSR(_cmd, _conv_usec, _rate) \
28 { .cmd = _cmd, .conv_usec = _conv_usec, .rate = _rate }
29
30 static const struct ms5611_osr ms5611_avail_pressure_osr[] = {
31 MS5611_INIT_OSR(0x40, 600, 256),
32 MS5611_INIT_OSR(0x42, 1170, 512),
33 MS5611_INIT_OSR(0x44, 2280, 1024),
34 MS5611_INIT_OSR(0x46, 4540, 2048),
35 MS5611_INIT_OSR(0x48, 9040, 4096)
36 };
37
38 static const struct ms5611_osr ms5611_avail_temp_osr[] = {
39 MS5611_INIT_OSR(0x50, 600, 256),
40 MS5611_INIT_OSR(0x52, 1170, 512),
41 MS5611_INIT_OSR(0x54, 2280, 1024),
42 MS5611_INIT_OSR(0x56, 4540, 2048),
43 MS5611_INIT_OSR(0x58, 9040, 4096)
44 };
45
46 static const char ms5611_show_osr[] = "256 512 1024 2048 4096";
47
48 static IIO_CONST_ATTR(oversampling_ratio_available, ms5611_show_osr);
49
50 static struct attribute *ms5611_attributes[] = {
51 &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
52 NULL,
53 };
54
55 static const struct attribute_group ms5611_attribute_group = {
56 .attrs = ms5611_attributes,
57 };
58
ms5611_prom_is_valid(u16 * prom,size_t len)59 static bool ms5611_prom_is_valid(u16 *prom, size_t len)
60 {
61 int i, j;
62 uint16_t crc = 0, crc_orig = prom[7] & 0x000F;
63
64 prom[7] &= 0xFF00;
65
66 for (i = 0; i < len * 2; i++) {
67 if (i % 2 == 1)
68 crc ^= prom[i >> 1] & 0x00FF;
69 else
70 crc ^= prom[i >> 1] >> 8;
71
72 for (j = 0; j < 8; j++) {
73 if (crc & 0x8000)
74 crc = (crc << 1) ^ 0x3000;
75 else
76 crc <<= 1;
77 }
78 }
79
80 crc = (crc >> 12) & 0x000F;
81
82 return crc_orig != 0x0000 && crc == crc_orig;
83 }
84
ms5611_read_prom(struct iio_dev * indio_dev)85 static int ms5611_read_prom(struct iio_dev *indio_dev)
86 {
87 int ret, i;
88 struct ms5611_state *st = iio_priv(indio_dev);
89
90 for (i = 0; i < MS5611_PROM_WORDS_NB; i++) {
91 ret = st->read_prom_word(st, i, &st->prom[i]);
92 if (ret < 0) {
93 dev_err(&indio_dev->dev,
94 "failed to read prom at %d\n", i);
95 return ret;
96 }
97 }
98
99 if (!ms5611_prom_is_valid(st->prom, MS5611_PROM_WORDS_NB)) {
100 dev_err(&indio_dev->dev, "PROM integrity check failed\n");
101 return -ENODEV;
102 }
103
104 return 0;
105 }
106
ms5611_read_temp_and_pressure(struct iio_dev * indio_dev,s32 * temp,s32 * pressure)107 static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev,
108 s32 *temp, s32 *pressure)
109 {
110 int ret;
111 struct ms5611_state *st = iio_priv(indio_dev);
112
113 ret = st->read_adc_temp_and_pressure(st, temp, pressure);
114 if (ret < 0) {
115 dev_err(&indio_dev->dev,
116 "failed to read temperature and pressure\n");
117 return ret;
118 }
119
120 return st->compensate_temp_and_pressure(st, temp, pressure);
121 }
122
ms5611_temp_and_pressure_compensate(struct ms5611_state * st,s32 * temp,s32 * pressure)123 static int ms5611_temp_and_pressure_compensate(struct ms5611_state *st,
124 s32 *temp, s32 *pressure)
125 {
126 s32 t = *temp, p = *pressure;
127 s64 off, sens, dt;
128
129 dt = t - (st->prom[5] << 8);
130 off = ((s64)st->prom[2] << 16) + ((st->prom[4] * dt) >> 7);
131 sens = ((s64)st->prom[1] << 15) + ((st->prom[3] * dt) >> 8);
132
133 t = 2000 + ((st->prom[6] * dt) >> 23);
134 if (t < 2000) {
135 s64 off2, sens2, t2;
136
137 t2 = (dt * dt) >> 31;
138 off2 = (5 * (t - 2000) * (t - 2000)) >> 1;
139 sens2 = off2 >> 1;
140
141 if (t < -1500) {
142 s64 tmp = (t + 1500) * (t + 1500);
143
144 off2 += 7 * tmp;
145 sens2 += (11 * tmp) >> 1;
146 }
147
148 t -= t2;
149 off -= off2;
150 sens -= sens2;
151 }
152
153 *temp = t;
154 *pressure = (((p * sens) >> 21) - off) >> 15;
155
156 return 0;
157 }
158
ms5607_temp_and_pressure_compensate(struct ms5611_state * st,s32 * temp,s32 * pressure)159 static int ms5607_temp_and_pressure_compensate(struct ms5611_state *st,
160 s32 *temp, s32 *pressure)
161 {
162 s32 t = *temp, p = *pressure;
163 s64 off, sens, dt;
164
165 dt = t - (st->prom[5] << 8);
166 off = ((s64)st->prom[2] << 17) + ((st->prom[4] * dt) >> 6);
167 sens = ((s64)st->prom[1] << 16) + ((st->prom[3] * dt) >> 7);
168
169 t = 2000 + ((st->prom[6] * dt) >> 23);
170 if (t < 2000) {
171 s64 off2, sens2, t2, tmp;
172
173 t2 = (dt * dt) >> 31;
174 tmp = (t - 2000) * (t - 2000);
175 off2 = (61 * tmp) >> 4;
176 sens2 = tmp << 1;
177
178 if (t < -1500) {
179 tmp = (t + 1500) * (t + 1500);
180 off2 += 15 * tmp;
181 sens2 += 8 * tmp;
182 }
183
184 t -= t2;
185 off -= off2;
186 sens -= sens2;
187 }
188
189 *temp = t;
190 *pressure = (((p * sens) >> 21) - off) >> 15;
191
192 return 0;
193 }
194
ms5611_reset(struct iio_dev * indio_dev)195 static int ms5611_reset(struct iio_dev *indio_dev)
196 {
197 int ret;
198 struct ms5611_state *st = iio_priv(indio_dev);
199
200 ret = st->reset(st);
201 if (ret < 0) {
202 dev_err(&indio_dev->dev, "failed to reset device\n");
203 return ret;
204 }
205
206 usleep_range(3000, 4000);
207
208 return 0;
209 }
210
ms5611_trigger_handler(int irq,void * p)211 static irqreturn_t ms5611_trigger_handler(int irq, void *p)
212 {
213 struct iio_poll_func *pf = p;
214 struct iio_dev *indio_dev = pf->indio_dev;
215 struct ms5611_state *st = iio_priv(indio_dev);
216 /* Ensure buffer elements are naturally aligned */
217 struct {
218 s32 channels[2];
219 s64 ts __aligned(8);
220 } scan;
221 int ret;
222
223 mutex_lock(&st->lock);
224 ret = ms5611_read_temp_and_pressure(indio_dev, &scan.channels[1],
225 &scan.channels[0]);
226 mutex_unlock(&st->lock);
227 if (ret < 0)
228 goto err;
229
230 iio_push_to_buffers_with_timestamp(indio_dev, &scan,
231 iio_get_time_ns(indio_dev));
232
233 err:
234 iio_trigger_notify_done(indio_dev->trig);
235
236 return IRQ_HANDLED;
237 }
238
ms5611_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)239 static int ms5611_read_raw(struct iio_dev *indio_dev,
240 struct iio_chan_spec const *chan,
241 int *val, int *val2, long mask)
242 {
243 int ret;
244 s32 temp, pressure;
245 struct ms5611_state *st = iio_priv(indio_dev);
246
247 switch (mask) {
248 case IIO_CHAN_INFO_PROCESSED:
249 mutex_lock(&st->lock);
250 ret = ms5611_read_temp_and_pressure(indio_dev,
251 &temp, &pressure);
252 mutex_unlock(&st->lock);
253 if (ret < 0)
254 return ret;
255
256 switch (chan->type) {
257 case IIO_TEMP:
258 *val = temp * 10;
259 return IIO_VAL_INT;
260 case IIO_PRESSURE:
261 *val = pressure / 1000;
262 *val2 = (pressure % 1000) * 1000;
263 return IIO_VAL_INT_PLUS_MICRO;
264 default:
265 return -EINVAL;
266 }
267 case IIO_CHAN_INFO_SCALE:
268 switch (chan->type) {
269 case IIO_TEMP:
270 *val = 10;
271 return IIO_VAL_INT;
272 case IIO_PRESSURE:
273 *val = 0;
274 *val2 = 1000;
275 return IIO_VAL_INT_PLUS_MICRO;
276 default:
277 return -EINVAL;
278 }
279 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
280 if (chan->type != IIO_TEMP && chan->type != IIO_PRESSURE)
281 break;
282 mutex_lock(&st->lock);
283 if (chan->type == IIO_TEMP)
284 *val = (int)st->temp_osr->rate;
285 else
286 *val = (int)st->pressure_osr->rate;
287 mutex_unlock(&st->lock);
288 return IIO_VAL_INT;
289 }
290
291 return -EINVAL;
292 }
293
ms5611_find_osr(int rate,const struct ms5611_osr * osr,size_t count)294 static const struct ms5611_osr *ms5611_find_osr(int rate,
295 const struct ms5611_osr *osr,
296 size_t count)
297 {
298 unsigned int r;
299
300 for (r = 0; r < count; r++)
301 if ((unsigned short)rate == osr[r].rate)
302 break;
303 if (r >= count)
304 return NULL;
305 return &osr[r];
306 }
307
ms5611_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)308 static int ms5611_write_raw(struct iio_dev *indio_dev,
309 struct iio_chan_spec const *chan,
310 int val, int val2, long mask)
311 {
312 struct ms5611_state *st = iio_priv(indio_dev);
313 const struct ms5611_osr *osr = NULL;
314 int ret;
315
316 if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
317 return -EINVAL;
318
319 if (chan->type == IIO_TEMP)
320 osr = ms5611_find_osr(val, ms5611_avail_temp_osr,
321 ARRAY_SIZE(ms5611_avail_temp_osr));
322 else if (chan->type == IIO_PRESSURE)
323 osr = ms5611_find_osr(val, ms5611_avail_pressure_osr,
324 ARRAY_SIZE(ms5611_avail_pressure_osr));
325 if (!osr)
326 return -EINVAL;
327
328 ret = iio_device_claim_direct_mode(indio_dev);
329 if (ret)
330 return ret;
331
332 mutex_lock(&st->lock);
333
334 if (chan->type == IIO_TEMP)
335 st->temp_osr = osr;
336 else
337 st->pressure_osr = osr;
338
339 mutex_unlock(&st->lock);
340 iio_device_release_direct_mode(indio_dev);
341
342 return 0;
343 }
344
345 static const unsigned long ms5611_scan_masks[] = {0x3, 0};
346
347 static const struct iio_chan_spec ms5611_channels[] = {
348 {
349 .type = IIO_PRESSURE,
350 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
351 BIT(IIO_CHAN_INFO_SCALE) |
352 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
353 .scan_index = 0,
354 .scan_type = {
355 .sign = 's',
356 .realbits = 32,
357 .storagebits = 32,
358 .endianness = IIO_CPU,
359 },
360 },
361 {
362 .type = IIO_TEMP,
363 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
364 BIT(IIO_CHAN_INFO_SCALE) |
365 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
366 .scan_index = 1,
367 .scan_type = {
368 .sign = 's',
369 .realbits = 32,
370 .storagebits = 32,
371 .endianness = IIO_CPU,
372 },
373 },
374 IIO_CHAN_SOFT_TIMESTAMP(2),
375 };
376
377 static const struct iio_info ms5611_info = {
378 .read_raw = &ms5611_read_raw,
379 .write_raw = &ms5611_write_raw,
380 .attrs = &ms5611_attribute_group,
381 };
382
ms5611_init(struct iio_dev * indio_dev)383 static int ms5611_init(struct iio_dev *indio_dev)
384 {
385 int ret;
386 struct ms5611_state *st = iio_priv(indio_dev);
387
388 /* Enable attached regulator if any. */
389 st->vdd = devm_regulator_get(indio_dev->dev.parent, "vdd");
390 if (IS_ERR(st->vdd))
391 return PTR_ERR(st->vdd);
392
393 ret = regulator_enable(st->vdd);
394 if (ret) {
395 dev_err(indio_dev->dev.parent,
396 "failed to enable Vdd supply: %d\n", ret);
397 return ret;
398 }
399
400 ret = ms5611_reset(indio_dev);
401 if (ret < 0)
402 goto err_regulator_disable;
403
404 ret = ms5611_read_prom(indio_dev);
405 if (ret < 0)
406 goto err_regulator_disable;
407
408 return 0;
409
410 err_regulator_disable:
411 regulator_disable(st->vdd);
412 return ret;
413 }
414
ms5611_fini(const struct iio_dev * indio_dev)415 static void ms5611_fini(const struct iio_dev *indio_dev)
416 {
417 const struct ms5611_state *st = iio_priv(indio_dev);
418
419 regulator_disable(st->vdd);
420 }
421
ms5611_probe(struct iio_dev * indio_dev,struct device * dev,const char * name,int type)422 int ms5611_probe(struct iio_dev *indio_dev, struct device *dev,
423 const char *name, int type)
424 {
425 int ret;
426 struct ms5611_state *st = iio_priv(indio_dev);
427
428 mutex_init(&st->lock);
429
430 switch (type) {
431 case MS5611:
432 st->compensate_temp_and_pressure =
433 ms5611_temp_and_pressure_compensate;
434 break;
435 case MS5607:
436 st->compensate_temp_and_pressure =
437 ms5607_temp_and_pressure_compensate;
438 break;
439 default:
440 return -EINVAL;
441 }
442
443 st->temp_osr =
444 &ms5611_avail_temp_osr[ARRAY_SIZE(ms5611_avail_temp_osr) - 1];
445 st->pressure_osr =
446 &ms5611_avail_pressure_osr[ARRAY_SIZE(ms5611_avail_pressure_osr)
447 - 1];
448 indio_dev->dev.parent = dev;
449 indio_dev->name = name;
450 indio_dev->info = &ms5611_info;
451 indio_dev->channels = ms5611_channels;
452 indio_dev->num_channels = ARRAY_SIZE(ms5611_channels);
453 indio_dev->modes = INDIO_DIRECT_MODE;
454 indio_dev->available_scan_masks = ms5611_scan_masks;
455
456 ret = ms5611_init(indio_dev);
457 if (ret < 0)
458 return ret;
459
460 ret = iio_triggered_buffer_setup(indio_dev, NULL,
461 ms5611_trigger_handler, NULL);
462 if (ret < 0) {
463 dev_err(dev, "iio triggered buffer setup failed\n");
464 goto err_fini;
465 }
466
467 ret = iio_device_register(indio_dev);
468 if (ret < 0) {
469 dev_err(dev, "unable to register iio device\n");
470 goto err_buffer_cleanup;
471 }
472
473 return 0;
474
475 err_buffer_cleanup:
476 iio_triggered_buffer_cleanup(indio_dev);
477 err_fini:
478 ms5611_fini(indio_dev);
479 return ret;
480 }
481 EXPORT_SYMBOL(ms5611_probe);
482
ms5611_remove(struct iio_dev * indio_dev)483 int ms5611_remove(struct iio_dev *indio_dev)
484 {
485 iio_device_unregister(indio_dev);
486 iio_triggered_buffer_cleanup(indio_dev);
487 ms5611_fini(indio_dev);
488
489 return 0;
490 }
491 EXPORT_SYMBOL(ms5611_remove);
492
493 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
494 MODULE_DESCRIPTION("MS5611 core driver");
495 MODULE_LICENSE("GPL v2");
496