tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
30static 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
38static 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
46static const char ms5611_show_osr[] = "256 512 1024 2048 4096";
47
48static IIO_CONST_ATTR(oversampling_ratio_available, ms5611_show_osr);
49
50static struct attribute *ms5611_attributes[] = {
51 &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
52 NULL,
53};
54
55static const struct attribute_group ms5611_attribute_group = {
56 .attrs = ms5611_attributes,
57};
58
59static 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
85static 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(&indio_dev->dev,
92 i, &st->chip_info->prom[i]);
93 if (ret < 0) {
94 dev_err(&indio_dev->dev,
95 "failed to read prom at %d\n", i);
96 return ret;
97 }
98 }
99
100 if (!ms5611_prom_is_valid(st->chip_info->prom, MS5611_PROM_WORDS_NB)) {
101 dev_err(&indio_dev->dev, "PROM integrity check failed\n");
102 return -ENODEV;
103 }
104
105 return 0;
106}
107
108static int ms5611_read_temp_and_pressure(struct iio_dev *indio_dev,
109 s32 *temp, s32 *pressure)
110{
111 int ret;
112 struct ms5611_state *st = iio_priv(indio_dev);
113
114 ret = st->read_adc_temp_and_pressure(&indio_dev->dev, temp, pressure);
115 if (ret < 0) {
116 dev_err(&indio_dev->dev,
117 "failed to read temperature and pressure\n");
118 return ret;
119 }
120
121 return st->chip_info->temp_and_pressure_compensate(st->chip_info,
122 temp, pressure);
123}
124
125static int ms5611_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
126 s32 *temp, s32 *pressure)
127{
128 s32 t = *temp, p = *pressure;
129 s64 off, sens, dt;
130
131 dt = t - (chip_info->prom[5] << 8);
132 off = ((s64)chip_info->prom[2] << 16) + ((chip_info->prom[4] * dt) >> 7);
133 sens = ((s64)chip_info->prom[1] << 15) + ((chip_info->prom[3] * dt) >> 8);
134
135 t = 2000 + ((chip_info->prom[6] * dt) >> 23);
136 if (t < 2000) {
137 s64 off2, sens2, t2;
138
139 t2 = (dt * dt) >> 31;
140 off2 = (5 * (t - 2000) * (t - 2000)) >> 1;
141 sens2 = off2 >> 1;
142
143 if (t < -1500) {
144 s64 tmp = (t + 1500) * (t + 1500);
145
146 off2 += 7 * tmp;
147 sens2 += (11 * tmp) >> 1;
148 }
149
150 t -= t2;
151 off -= off2;
152 sens -= sens2;
153 }
154
155 *temp = t;
156 *pressure = (((p * sens) >> 21) - off) >> 15;
157
158 return 0;
159}
160
161static int ms5607_temp_and_pressure_compensate(struct ms5611_chip_info *chip_info,
162 s32 *temp, s32 *pressure)
163{
164 s32 t = *temp, p = *pressure;
165 s64 off, sens, dt;
166
167 dt = t - (chip_info->prom[5] << 8);
168 off = ((s64)chip_info->prom[2] << 17) + ((chip_info->prom[4] * dt) >> 6);
169 sens = ((s64)chip_info->prom[1] << 16) + ((chip_info->prom[3] * dt) >> 7);
170
171 t = 2000 + ((chip_info->prom[6] * dt) >> 23);
172 if (t < 2000) {
173 s64 off2, sens2, t2, tmp;
174
175 t2 = (dt * dt) >> 31;
176 tmp = (t - 2000) * (t - 2000);
177 off2 = (61 * tmp) >> 4;
178 sens2 = tmp << 1;
179
180 if (t < -1500) {
181 tmp = (t + 1500) * (t + 1500);
182 off2 += 15 * tmp;
183 sens2 += 8 * tmp;
184 }
185
186 t -= t2;
187 off -= off2;
188 sens -= sens2;
189 }
190
191 *temp = t;
192 *pressure = (((p * sens) >> 21) - off) >> 15;
193
194 return 0;
195}
196
197static int ms5611_reset(struct iio_dev *indio_dev)
198{
199 int ret;
200 struct ms5611_state *st = iio_priv(indio_dev);
201
202 ret = st->reset(&indio_dev->dev);
203 if (ret < 0) {
204 dev_err(&indio_dev->dev, "failed to reset device\n");
205 return ret;
206 }
207
208 usleep_range(3000, 4000);
209
210 return 0;
211}
212
213static irqreturn_t ms5611_trigger_handler(int irq, void *p)
214{
215 struct iio_poll_func *pf = p;
216 struct iio_dev *indio_dev = pf->indio_dev;
217 struct ms5611_state *st = iio_priv(indio_dev);
218 s32 buf[4]; /* s32 (pressure) + s32 (temp) + 2 * s32 (timestamp) */
219 int ret;
220
221 mutex_lock(&st->lock);
222 ret = ms5611_read_temp_and_pressure(indio_dev, &buf[1], &buf[0]);
223 mutex_unlock(&st->lock);
224 if (ret < 0)
225 goto err;
226
227 iio_push_to_buffers_with_timestamp(indio_dev, buf,
228 iio_get_time_ns(indio_dev));
229
230err:
231 iio_trigger_notify_done(indio_dev->trig);
232
233 return IRQ_HANDLED;
234}
235
236static int ms5611_read_raw(struct iio_dev *indio_dev,
237 struct iio_chan_spec const *chan,
238 int *val, int *val2, long mask)
239{
240 int ret;
241 s32 temp, pressure;
242 struct ms5611_state *st = iio_priv(indio_dev);
243
244 switch (mask) {
245 case IIO_CHAN_INFO_PROCESSED:
246 mutex_lock(&st->lock);
247 ret = ms5611_read_temp_and_pressure(indio_dev,
248 &temp, &pressure);
249 mutex_unlock(&st->lock);
250 if (ret < 0)
251 return ret;
252
253 switch (chan->type) {
254 case IIO_TEMP:
255 *val = temp * 10;
256 return IIO_VAL_INT;
257 case IIO_PRESSURE:
258 *val = pressure / 1000;
259 *val2 = (pressure % 1000) * 1000;
260 return IIO_VAL_INT_PLUS_MICRO;
261 default:
262 return -EINVAL;
263 }
264 case IIO_CHAN_INFO_SCALE:
265 switch (chan->type) {
266 case IIO_TEMP:
267 *val = 10;
268 return IIO_VAL_INT;
269 case IIO_PRESSURE:
270 *val = 0;
271 *val2 = 1000;
272 return IIO_VAL_INT_PLUS_MICRO;
273 default:
274 return -EINVAL;
275 }
276 case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
277 if (chan->type != IIO_TEMP && chan->type != IIO_PRESSURE)
278 break;
279 mutex_lock(&st->lock);
280 if (chan->type == IIO_TEMP)
281 *val = (int)st->temp_osr->rate;
282 else
283 *val = (int)st->pressure_osr->rate;
284 mutex_unlock(&st->lock);
285 return IIO_VAL_INT;
286 }
287
288 return -EINVAL;
289}
290
291static const struct ms5611_osr *ms5611_find_osr(int rate,
292 const struct ms5611_osr *osr,
293 size_t count)
294{
295 unsigned int r;
296
297 for (r = 0; r < count; r++)
298 if ((unsigned short)rate == osr[r].rate)
299 break;
300 if (r >= count)
301 return NULL;
302 return &osr[r];
303}
304
305static int ms5611_write_raw(struct iio_dev *indio_dev,
306 struct iio_chan_spec const *chan,
307 int val, int val2, long mask)
308{
309 struct ms5611_state *st = iio_priv(indio_dev);
310 const struct ms5611_osr *osr = NULL;
311 int ret;
312
313 if (mask != IIO_CHAN_INFO_OVERSAMPLING_RATIO)
314 return -EINVAL;
315
316 if (chan->type == IIO_TEMP)
317 osr = ms5611_find_osr(val, ms5611_avail_temp_osr,
318 ARRAY_SIZE(ms5611_avail_temp_osr));
319 else if (chan->type == IIO_PRESSURE)
320 osr = ms5611_find_osr(val, ms5611_avail_pressure_osr,
321 ARRAY_SIZE(ms5611_avail_pressure_osr));
322 if (!osr)
323 return -EINVAL;
324
325 ret = iio_device_claim_direct_mode(indio_dev);
326 if (ret)
327 return ret;
328
329 mutex_lock(&st->lock);
330
331 if (chan->type == IIO_TEMP)
332 st->temp_osr = osr;
333 else
334 st->pressure_osr = osr;
335
336 mutex_unlock(&st->lock);
337 iio_device_release_direct_mode(indio_dev);
338
339 return 0;
340}
341
342static const unsigned long ms5611_scan_masks[] = {0x3, 0};
343
344static struct ms5611_chip_info chip_info_tbl[] = {
345 [MS5611] = {
346 .temp_and_pressure_compensate = ms5611_temp_and_pressure_compensate,
347 },
348 [MS5607] = {
349 .temp_and_pressure_compensate = ms5607_temp_and_pressure_compensate,
350 }
351};
352
353static const struct iio_chan_spec ms5611_channels[] = {
354 {
355 .type = IIO_PRESSURE,
356 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
357 BIT(IIO_CHAN_INFO_SCALE) |
358 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
359 .scan_index = 0,
360 .scan_type = {
361 .sign = 's',
362 .realbits = 32,
363 .storagebits = 32,
364 .endianness = IIO_CPU,
365 },
366 },
367 {
368 .type = IIO_TEMP,
369 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
370 BIT(IIO_CHAN_INFO_SCALE) |
371 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
372 .scan_index = 1,
373 .scan_type = {
374 .sign = 's',
375 .realbits = 32,
376 .storagebits = 32,
377 .endianness = IIO_CPU,
378 },
379 },
380 IIO_CHAN_SOFT_TIMESTAMP(2),
381};
382
383static const struct iio_info ms5611_info = {
384 .read_raw = &ms5611_read_raw,
385 .write_raw = &ms5611_write_raw,
386 .attrs = &ms5611_attribute_group,
387};
388
389static int ms5611_init(struct iio_dev *indio_dev)
390{
391 int ret;
392 struct ms5611_state *st = iio_priv(indio_dev);
393
394 /* Enable attached regulator if any. */
395 st->vdd = devm_regulator_get(indio_dev->dev.parent, "vdd");
396 if (IS_ERR(st->vdd))
397 return PTR_ERR(st->vdd);
398
399 ret = regulator_enable(st->vdd);
400 if (ret) {
401 dev_err(indio_dev->dev.parent,
402 "failed to enable Vdd supply: %d\n", ret);
403 return ret;
404 }
405
406 ret = ms5611_reset(indio_dev);
407 if (ret < 0)
408 goto err_regulator_disable;
409
410 ret = ms5611_read_prom(indio_dev);
411 if (ret < 0)
412 goto err_regulator_disable;
413
414 return 0;
415
416err_regulator_disable:
417 regulator_disable(st->vdd);
418 return ret;
419}
420
421static void ms5611_fini(const struct iio_dev *indio_dev)
422{
423 const struct ms5611_state *st = iio_priv(indio_dev);
424
425 regulator_disable(st->vdd);
426}
427
428int ms5611_probe(struct iio_dev *indio_dev, struct device *dev,
429 const char *name, int type)
430{
431 int ret;
432 struct ms5611_state *st = iio_priv(indio_dev);
433
434 mutex_init(&st->lock);
435 st->chip_info = &chip_info_tbl[type];
436 st->temp_osr =
437 &ms5611_avail_temp_osr[ARRAY_SIZE(ms5611_avail_temp_osr) - 1];
438 st->pressure_osr =
439 &ms5611_avail_pressure_osr[ARRAY_SIZE(ms5611_avail_pressure_osr)
440 - 1];
441 indio_dev->dev.parent = dev;
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
468err_buffer_cleanup:
469 iio_triggered_buffer_cleanup(indio_dev);
470err_fini:
471 ms5611_fini(indio_dev);
472 return ret;
473}
474EXPORT_SYMBOL(ms5611_probe);
475
476int 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 return 0;
483}
484EXPORT_SYMBOL(ms5611_remove);
485
486MODULE_AUTHOR("Tomasz Duszynski <tduszyns@gmail.com>");
487MODULE_DESCRIPTION("MS5611 core driver");
488MODULE_LICENSE("GPL v2");