1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * MS5611 pressure and temperature sensor driver
4 *
5 * Copyright (c) Tomasz Duszynski <tduszyns@gmail.com>
6 *
7 * Data sheet:
8 * http://www.meas-spec.com/downloads/MS5611-01BA03.pdf
9 * http://www.meas-spec.com/downloads/MS5607-02BA03.pdf
10 *
11 */
12
13 #include <linux/module.h>
14 #include <linux/iio/iio.h>
15 #include <linux/delay.h>
16 #include <linux/regulator/consumer.h>
17
18 #include <linux/iio/sysfs.h>
19 #include <linux/iio/buffer.h>
20 #include <linux/iio/triggered_buffer.h>
21 #include <linux/iio/trigger_consumer.h>
22 #include "ms5611.h"
23
24 #define MS5611_INIT_OSR(_cmd, _conv_usec, _rate) \
25 { .cmd = _cmd, .conv_usec = _conv_usec, .rate = _rate }
26
27 static const struct ms5611_osr ms5611_avail_pressure_osr[] = {
28 MS5611_INIT_OSR(0x40, 600, 256),
29 MS5611_INIT_OSR(0x42, 1170, 512),
30 MS5611_INIT_OSR(0x44, 2280, 1024),
31 MS5611_INIT_OSR(0x46, 4540, 2048),
32 MS5611_INIT_OSR(0x48, 9040, 4096)
33 };
34
35 static const struct ms5611_osr ms5611_avail_temp_osr[] = {
36 MS5611_INIT_OSR(0x50, 600, 256),
37 MS5611_INIT_OSR(0x52, 1170, 512),
38 MS5611_INIT_OSR(0x54, 2280, 1024),
39 MS5611_INIT_OSR(0x56, 4540, 2048),
40 MS5611_INIT_OSR(0x58, 9040, 4096)
41 };
42
43 static const char ms5611_show_osr[] = "256 512 1024 2048 4096";
44
45 static IIO_CONST_ATTR(oversampling_ratio_available, ms5611_show_osr);
46
47 static struct attribute *ms5611_attributes[] = {
48 &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
49 NULL,
50 };
51
52 static const struct attribute_group ms5611_attribute_group = {
53 .attrs = ms5611_attributes,
54 };
55
ms5611_prom_is_valid(u16 * prom,size_t len)56 static bool ms5611_prom_is_valid(u16 *prom, size_t len)
57 {
58 int i, j;
59 uint16_t crc = 0, crc_orig = prom[7] & 0x000F;
60
61 prom[7] &= 0xFF00;
62
63 for (i = 0; i < len * 2; i++) {
64 if (i % 2 == 1)
65 crc ^= prom[i >> 1] & 0x00FF;
66 else
67 crc ^= prom[i >> 1] >> 8;
68
69 for (j = 0; j < 8; j++) {
70 if (crc & 0x8000)
71 crc = (crc << 1) ^ 0x3000;
72 else
73 crc <<= 1;
74 }
75 }
76
77 crc = (crc >> 12) & 0x000F;
78
79 return crc_orig != 0x0000 && crc == crc_orig;
80 }
81
ms5611_read_prom(struct iio_dev * indio_dev)82 static int ms5611_read_prom(struct iio_dev *indio_dev)
83 {
84 int ret, i;
85 struct ms5611_state *st = iio_priv(indio_dev);
86
87 for (i = 0; i < MS5611_PROM_WORDS_NB; i++) {
88 ret = st->read_prom_word(st, i, &st->chip_info->prom[i]);
89 if (ret < 0) {
90 dev_err(&indio_dev->dev,
91 "failed to read prom at %d\n", i);
92 return ret;
93 }
94 }
95
96 if (!ms5611_prom_is_valid(st->chip_info->prom, MS5611_PROM_WORDS_NB)) {
97 dev_err(&indio_dev->dev, "PROM integrity check failed\n");
98 return -ENODEV;
99 }
100
101 return 0;
102 }
103
ms5611_read_temp_and_pressure(struct iio_dev * indio_dev,s32 * temp,s32 * pressure)104 static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev,
105 s32 *temp, s32 *pressure)
106 {
107 int ret;
108 struct ms5611_state *st = iio_priv(indio_dev);
109
110 ret = st->read_adc_temp_and_pressure(st, temp, pressure);
111 if (ret < 0) {
112 dev_err(&indio_dev->dev,
113 "failed to read temperature and pressure\n");
114 return ret;
115 }
116
117 return st->chip_info->temp_and_pressure_compensate(st->chip_info,
118 temp, pressure);
119 }
120
ms5611_temp_and_pressure_compensate(struct ms5611_chip_info * chip_info,s32 * temp,s32 * pressure)121 static int ms5611_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
122 s32 *temp, s32 *pressure)
123 {
124 s32 t = *temp, p = *pressure;
125 s64 off, sens, dt;
126
127 dt = t - (chip_info->prom[5] << 8);
128 off = ((s64)chip_info->prom[2] << 16) + ((chip_info->prom[4] * dt) >> 7);
129 sens = ((s64)chip_info->prom[1] << 15) + ((chip_info->prom[3] * dt) >> 8);
130
131 t = 2000 + ((chip_info->prom[6] * dt) >> 23);
132 if (t < 2000) {
133 s64 off2, sens2, t2;
134
135 t2 = (dt * dt) >> 31;
136 off2 = (5 * (t - 2000) * (t - 2000)) >> 1;
137 sens2 = off2 >> 1;
138
139 if (t < -1500) {
140 s64 tmp = (t + 1500) * (t + 1500);
141
142 off2 += 7 * tmp;
143 sens2 += (11 * tmp) >> 1;
144 }
145
146 t -= t2;
147 off -= off2;
148 sens -= sens2;
149 }
150
151 *temp = t;
152 *pressure = (((p * sens) >> 21) - off) >> 15;
153
154 return 0;
155 }
156
ms5607_temp_and_pressure_compensate(struct ms5611_chip_info * chip_info,s32 * temp,s32 * pressure)157 static int ms5607_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
158 s32 *temp, s32 *pressure)
159 {
160 s32 t = *temp, p = *pressure;
161 s64 off, sens, dt;
162
163 dt = t - (chip_info->prom[5] << 8);
164 off = ((s64)chip_info->prom[2] << 17) + ((chip_info->prom[4] * dt) >> 6);
165 sens = ((s64)chip_info->prom[1] << 16) + ((chip_info->prom[3] * dt) >> 7);
166
167 t = 2000 + ((chip_info->prom[6] * dt) >> 23);
168 if (t < 2000) {
169 s64 off2, sens2, t2, tmp;
170
171 t2 = (dt * dt) >> 31;
172 tmp = (t - 2000) * (t - 2000);
173 off2 = (61 * tmp) >> 4;
174 sens2 = tmp << 1;
175
176 if (t < -1500) {
177 tmp = (t + 1500) * (t + 1500);
178 off2 += 15 * tmp;
179 sens2 += 8 * tmp;
180 }
181
182 t -= t2;
183 off -= off2;
184 sens -= sens2;
185 }
186
187 *temp = t;
188 *pressure = (((p * sens) >> 21) - off) >> 15;
189
190 return 0;
191 }
192
ms5611_reset(struct iio_dev * indio_dev)193 static int ms5611_reset(struct iio_dev *indio_dev)
194 {
195 int ret;
196 struct ms5611_state *st = iio_priv(indio_dev);
197
198 ret = st->reset(st);
199 if (ret < 0) {
200 dev_err(&indio_dev->dev, "failed to reset device\n");
201 return ret;
202 }
203
204 usleep_range(3000, 4000);
205
206 return 0;
207 }
208
ms5611_trigger_handler(int irq,void * p)209 static irqreturn_t ms5611_trigger_handler(int irq, void *p)
210 {
211 struct iio_poll_func *pf = p;
212 struct iio_dev *indio_dev = pf->indio_dev;
213 struct ms5611_state *st = iio_priv(indio_dev);
214 /* Ensure buffer elements are naturally aligned */
215 struct {
216 s32 channels[2];
217 s64 ts __aligned(8);
218 } scan;
219 int ret;
220
221 mutex_lock(&st->lock);
222 ret = ms5611_read_temp_and_pressure(indio_dev, &scan.channels[1],
223 &scan.channels[0]);
224 mutex_unlock(&st->lock);
225 if (ret < 0)
226 goto err;
227
228 iio_push_to_buffers_with_timestamp(indio_dev, &scan,
229 iio_get_time_ns(indio_dev));
230
231 err:
232 iio_trigger_notify_done(indio_dev->trig);
233
234 return IRQ_HANDLED;
235 }
236
ms5611_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)237 static int ms5611_read_raw(struct iio_dev *indio_dev,
238 struct iio_chan_spec const *chan,
239 int *val, int *val2, long mask)
240 {
241 int ret;
242 s32 temp, pressure;
243 struct ms5611_state *st = iio_priv(indio_dev);
244
245 switch (mask) {
246 case IIO_CHAN_INFO_PROCESSED:
247 mutex_lock(&st->lock);
248 ret = ms5611_read_temp_and_pressure(indio_dev,
249 &temp, &pressure);
250 mutex_unlock(&st->lock);
251 if (ret < 0)
252 return ret;
253
254 switch (chan->type) {
255 case IIO_TEMP:
256 *val = temp * 10;
257 return IIO_VAL_INT;
258 case IIO_PRESSURE:
259 *val = pressure / 1000;
260 *val2 = (pressure % 1000) * 1000;
261 return IIO_VAL_INT_PLUS_MICRO;
262 default:
263 return -EINVAL;
264 }
265 case IIO_CHAN_INFO_SCALE:
266 switch (chan->type) {
267 case IIO_TEMP:
268 *val = 10;
269 return IIO_VAL_INT;
270 case IIO_PRESSURE:
271 *val = 0;
272 *val2 = 1000;
273 return IIO_VAL_INT_PLUS_MICRO;
274 default:
275 return -EINVAL;
276 }
277 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
278 if (chan->type != IIO_TEMP && chan->type != IIO_PRESSURE)
279 break;
280 mutex_lock(&st->lock);
281 if (chan->type == IIO_TEMP)
282 *val = (int)st->temp_osr->rate;
283 else
284 *val = (int)st->pressure_osr->rate;
285 mutex_unlock(&st->lock);
286 return IIO_VAL_INT;
287 }
288
289 return -EINVAL;
290 }
291
ms5611_find_osr(int rate,const struct ms5611_osr * osr,size_t count)292 static const struct ms5611_osr *ms5611_find_osr(int rate,
293 const struct ms5611_osr *osr,
294 size_t count)
295 {
296 unsigned int r;
297
298 for (r = 0; r < count; r++)
299 if ((unsigned short)rate == osr[r].rate)
300 break;
301 if (r >= count)
302 return NULL;
303 return &osr[r];
304 }
305
ms5611_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)306 static int ms5611_write_raw(struct iio_dev *indio_dev,
307 struct iio_chan_spec const *chan,
308 int val, int val2, long mask)
309 {
310 struct ms5611_state *st = iio_priv(indio_dev);
311 const struct ms5611_osr *osr = NULL;
312 int ret;
313
314 if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
315 return -EINVAL;
316
317 if (chan->type == IIO_TEMP)
318 osr = ms5611_find_osr(val, ms5611_avail_temp_osr,
319 ARRAY_SIZE(ms5611_avail_temp_osr));
320 else if (chan->type == IIO_PRESSURE)
321 osr = ms5611_find_osr(val, ms5611_avail_pressure_osr,
322 ARRAY_SIZE(ms5611_avail_pressure_osr));
323 if (!osr)
324 return -EINVAL;
325
326 ret = iio_device_claim_direct_mode(indio_dev);
327 if (ret)
328 return ret;
329
330 mutex_lock(&st->lock);
331
332 if (chan->type == IIO_TEMP)
333 st->temp_osr = osr;
334 else
335 st->pressure_osr = osr;
336
337 mutex_unlock(&st->lock);
338 iio_device_release_direct_mode(indio_dev);
339
340 return 0;
341 }
342
343 static const unsigned long ms5611_scan_masks[] = {0x3, 0};
344
345 static struct ms5611_chip_info chip_info_tbl[] = {
346 [MS5611] = {
347 .temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate,
348 },
349 [MS5607] = {
350 .temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate,
351 }
352 };
353
354 static const struct iio_chan_spec ms5611_channels[] = {
355 {
356 .type = IIO_PRESSURE,
357 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
358 BIT(IIO_CHAN_INFO_SCALE) |
359 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
360 .scan_index = 0,
361 .scan_type = {
362 .sign = 's',
363 .realbits = 32,
364 .storagebits = 32,
365 .endianness = IIO_CPU,
366 },
367 },
368 {
369 .type = IIO_TEMP,
370 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
371 BIT(IIO_CHAN_INFO_SCALE) |
372 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
373 .scan_index = 1,
374 .scan_type = {
375 .sign = 's',
376 .realbits = 32,
377 .storagebits = 32,
378 .endianness = IIO_CPU,
379 },
380 },
381 IIO_CHAN_SOFT_TIMESTAMP(2),
382 };
383
384 static const struct iio_info ms5611_info = {
385 .read_raw = &ms5611_read_raw,
386 .write_raw = &ms5611_write_raw,
387 .attrs = &ms5611_attribute_group,
388 };
389
ms5611_init(struct iio_dev * indio_dev)390 static int ms5611_init(struct iio_dev *indio_dev)
391 {
392 int ret;
393 struct ms5611_state *st = iio_priv(indio_dev);
394
395 /* Enable attached regulator if any. */
396 st->vdd = devm_regulator_get(indio_dev->dev.parent, "vdd");
397 if (IS_ERR(st->vdd))
398 return PTR_ERR(st->vdd);
399
400 ret = regulator_enable(st->vdd);
401 if (ret) {
402 dev_err(indio_dev->dev.parent,
403 "failed to enable Vdd supply: %d\n", ret);
404 return ret;
405 }
406
407 ret = ms5611_reset(indio_dev);
408 if (ret < 0)
409 goto err_regulator_disable;
410
411 ret = ms5611_read_prom(indio_dev);
412 if (ret < 0)
413 goto err_regulator_disable;
414
415 return 0;
416
417 err_regulator_disable:
418 regulator_disable(st->vdd);
419 return ret;
420 }
421
ms5611_fini(const struct iio_dev * indio_dev)422 static void ms5611_fini(const struct iio_dev *indio_dev)
423 {
424 const struct ms5611_state *st = iio_priv(indio_dev);
425
426 regulator_disable(st->vdd);
427 }
428
ms5611_probe(struct iio_dev * indio_dev,struct device * dev,const char * name,int type)429 int ms5611_probe(struct iio_dev *indio_dev, struct device *dev,
430 const char *name, int type)
431 {
432 int ret;
433 struct ms5611_state *st = iio_priv(indio_dev);
434
435 mutex_init(&st->lock);
436 st->chip_info = &chip_info_tbl[type];
437 st->temp_osr =
438 &ms5611_avail_temp_osr[ARRAY_SIZE(ms5611_avail_temp_osr) - 1];
439 st->pressure_osr =
440 &ms5611_avail_pressure_osr[ARRAY_SIZE(ms5611_avail_pressure_osr)
441 - 1];
442 indio_dev->name = name;
443 indio_dev->info = &ms5611_info;
444 indio_dev->channels = ms5611_channels;
445 indio_dev->num_channels = ARRAY_SIZE(ms5611_channels);
446 indio_dev->modes = INDIO_DIRECT_MODE;
447 indio_dev->available_scan_masks = ms5611_scan_masks;
448
449 ret = ms5611_init(indio_dev);
450 if (ret < 0)
451 return ret;
452
453 ret = iio_triggered_buffer_setup(indio_dev, NULL,
454 ms5611_trigger_handler, NULL);
455 if (ret < 0) {
456 dev_err(dev, "iio triggered buffer setup failed\n");
457 goto err_fini;
458 }
459
460 ret = iio_device_register(indio_dev);
461 if (ret < 0) {
462 dev_err(dev, "unable to register iio device\n");
463 goto err_buffer_cleanup;
464 }
465
466 return 0;
467
468 err_buffer_cleanup:
469 iio_triggered_buffer_cleanup(indio_dev);
470 err_fini:
471 ms5611_fini(indio_dev);
472 return ret;
473 }
474 EXPORT_SYMBOL_NS(ms5611_probe, IIO_MS5611);
475
ms5611_remove(struct iio_dev * indio_dev)476 void ms5611_remove(struct iio_dev *indio_dev)
477 {
478 iio_device_unregister(indio_dev);
479 iio_triggered_buffer_cleanup(indio_dev);
480 ms5611_fini(indio_dev);
481 }
482 EXPORT_SYMBOL_NS(ms5611_remove, IIO_MS5611);
483
484 MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
485 MODULE_DESCRIPTION("MS5611 core driver");
486 MODULE_LICENSE("GPL v2");
487