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Linux 5.9.7
[linux/fpc-iii.git] / drivers / iio / magnetometer / ak8974.c
blobcbb44e401c0a9e176ea76b1b437c174f2b93d631
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for the Asahi Kasei EMD Corporation AK8974
4 * and Aichi Steel AMI305 magnetometer chips.
5 * Based on a patch from Samu Onkalo and the AK8975 IIO driver.
6 *
7 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
8 * Copyright (c) 2010 NVIDIA Corporation.
9 * Copyright (C) 2016 Linaro Ltd.
10 *
11 * Author: Samu Onkalo <samu.p.onkalo@nokia.com>
12 * Author: Linus Walleij <linus.walleij@linaro.org>
13 */
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/i2c.h>
17 #include <linux/interrupt.h>
18 #include <linux/irq.h> /* For irq_get_irq_data() */
19 #include <linux/completion.h>
20 #include <linux/err.h>
21 #include <linux/mutex.h>
22 #include <linux/delay.h>
23 #include <linux/bitops.h>
24 #include <linux/random.h>
25 #include <linux/regmap.h>
26 #include <linux/regulator/consumer.h>
27 #include <linux/pm_runtime.h>
28
29 #include <linux/iio/iio.h>
30 #include <linux/iio/sysfs.h>
31 #include <linux/iio/buffer.h>
32 #include <linux/iio/trigger.h>
33 #include <linux/iio/trigger_consumer.h>
34 #include <linux/iio/triggered_buffer.h>
35
36 /*
37 * 16-bit registers are little-endian. LSB is at the address defined below
38 * and MSB is at the next higher address.
39 */
40
41 /* These registers are common for AK8974 and AMI30x */
42 #define AK8974_SELFTEST 0x0C
43 #define AK8974_SELFTEST_IDLE 0x55
44 #define AK8974_SELFTEST_OK 0xAA
45
46 #define AK8974_INFO 0x0D
47
48 #define AK8974_WHOAMI 0x0F
49 #define AK8974_WHOAMI_VALUE_AMI306 0x46
50 #define AK8974_WHOAMI_VALUE_AMI305 0x47
51 #define AK8974_WHOAMI_VALUE_AK8974 0x48
52 #define AK8974_WHOAMI_VALUE_HSCDTD008A 0x49
53
54 #define AK8974_DATA_X 0x10
55 #define AK8974_DATA_Y 0x12
56 #define AK8974_DATA_Z 0x14
57 #define AK8974_INT_SRC 0x16
58 #define AK8974_STATUS 0x18
59 #define AK8974_INT_CLEAR 0x1A
60 #define AK8974_CTRL1 0x1B
61 #define AK8974_CTRL2 0x1C
62 #define AK8974_CTRL3 0x1D
63 #define AK8974_INT_CTRL 0x1E
64 #define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */
65 #define AK8974_PRESET 0x30
66
67 /* AK8974-specific offsets */
68 #define AK8974_OFFSET_X 0x20
69 #define AK8974_OFFSET_Y 0x22
70 #define AK8974_OFFSET_Z 0x24
71 /* AMI305-specific offsets */
72 #define AMI305_OFFSET_X 0x6C
73 #define AMI305_OFFSET_Y 0x72
74 #define AMI305_OFFSET_Z 0x78
75
76 /* Different temperature registers */
77 #define AK8974_TEMP 0x31
78 #define AMI305_TEMP 0x60
79
80 /* AMI306-specific control register */
81 #define AMI306_CTRL4 0x5C
82
83 /* AMI306 factory calibration data */
84
85 /* fine axis sensitivity */
86 #define AMI306_FINEOUTPUT_X 0x90
87 #define AMI306_FINEOUTPUT_Y 0x92
88 #define AMI306_FINEOUTPUT_Z 0x94
89
90 /* axis sensitivity */
91 #define AMI306_SENS_X 0x96
92 #define AMI306_SENS_Y 0x98
93 #define AMI306_SENS_Z 0x9A
94
95 /* axis cross-interference */
96 #define AMI306_GAIN_PARA_XZ 0x9C
97 #define AMI306_GAIN_PARA_XY 0x9D
98 #define AMI306_GAIN_PARA_YZ 0x9E
99 #define AMI306_GAIN_PARA_YX 0x9F
100 #define AMI306_GAIN_PARA_ZY 0xA0
101 #define AMI306_GAIN_PARA_ZX 0xA1
102
103 /* offset at ZERO magnetic field */
104 #define AMI306_OFFZERO_X 0xF8
105 #define AMI306_OFFZERO_Y 0xFA
106 #define AMI306_OFFZERO_Z 0xFC
107
108
109 #define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */
110 #define AK8974_INT_Y_HIGH BIT(6)
111 #define AK8974_INT_Z_HIGH BIT(5)
112 #define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */
113 #define AK8974_INT_Y_LOW BIT(3)
114 #define AK8974_INT_Z_LOW BIT(2)
115 #define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */
116
117 #define AK8974_STATUS_DRDY BIT(6) /* Data ready */
118 #define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */
119 #define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */
120
121 #define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */
122 #define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */
123 #define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */
124 #define AK8974_CTRL1_MODE2 BIT(0) /* 0 */
125
126 #define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */
127 #define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */
128 #define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */
129 #define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL)
130
131 #define AK8974_CTRL3_RESET BIT(7) /* Software reset */
132 #define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */
133 #define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */
134 #define AK8974_CTRL3_RESDEF 0x00
135
136 #define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */
137 #define AK8974_INT_CTRL_YEN BIT(6)
138 #define AK8974_INT_CTRL_ZEN BIT(5)
139 #define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5))
140 #define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */
141 #define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
142 #define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
143
144 /* HSCDTD008A-specific control register */
145 #define HSCDTD008A_CTRL4 0x1E
146 #define HSCDTD008A_CTRL4_MMD BIT(7) /* must be set to 1 */
147 #define HSCDTD008A_CTRL4_RANGE BIT(4) /* 0 = 14-bit output; 1 = 15-bit output */
148 #define HSCDTD008A_CTRL4_RESDEF (HSCDTD008A_CTRL4_MMD | HSCDTD008A_CTRL4_RANGE)
149
150 /* The AMI305 has elaborate FW version and serial number registers */
151 #define AMI305_VER 0xE8
152 #define AMI305_SN 0xEA
153
154 #define AK8974_MAX_RANGE 2048
155
156 #define AK8974_POWERON_DELAY 50
157 #define AK8974_ACTIVATE_DELAY 1
158 #define AK8974_SELFTEST_DELAY 1
159 /*
160 * Set the autosuspend to two orders of magnitude larger than the poweron
161 * delay to make sane reasonable power tradeoff savings (5 seconds in
162 * this case).
163 */
164 #define AK8974_AUTOSUSPEND_DELAY 5000
165
166 #define AK8974_MEASTIME 3
167
168 #define AK8974_PWR_ON 1
169 #define AK8974_PWR_OFF 0
170
171 /**
172 * struct ak8974 - state container for the AK8974 driver
173 * @i2c: parent I2C client
174 * @orientation: mounting matrix, flipped axis etc
175 * @map: regmap to access the AK8974 registers over I2C
176 * @regs: the avdd and dvdd power regulators
177 * @name: the name of the part
178 * @variant: the whoami ID value (for selecting code paths)
179 * @lock: locks the magnetometer for exclusive use during a measurement
180 * @drdy_irq: uses the DRDY IRQ line
181 * @drdy_complete: completion for DRDY
182 * @drdy_active_low: the DRDY IRQ is active low
183 * @scan: timestamps
184 */
185 struct ak8974 {
186 struct i2c_client *i2c;
187 struct iio_mount_matrix orientation;
188 struct regmap *map;
189 struct regulator_bulk_data regs[2];
190 const char *name;
191 u8 variant;
192 struct mutex lock;
193 bool drdy_irq;
194 struct completion drdy_complete;
195 bool drdy_active_low;
196 /* Ensure timestamp is naturally aligned */
197 struct {
198 __le16 channels[3];
199 s64 ts __aligned(8);
200 } scan;
201 };
202
203 static const char ak8974_reg_avdd[] = "avdd";
204 static const char ak8974_reg_dvdd[] = "dvdd";
205
206 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val)
207 {
208 int ret;
209 __le16 bulk;
210
211 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2);
212 if (ret)
213 return ret;
214 *val = le16_to_cpu(bulk);
215
216 return 0;
217 }
218
219 static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val)
220 {
221 __le16 bulk = cpu_to_le16(val);
222
223 return regmap_bulk_write(ak8974->map, reg, &bulk, 2);
224 }
225
226 static int ak8974_set_power(struct ak8974 *ak8974, bool mode)
227 {
228 int ret;
229 u8 val;
230
231 val = mode ? AK8974_CTRL1_POWER : 0;
232 val |= AK8974_CTRL1_FORCE_EN;
233 ret = regmap_write(ak8974->map, AK8974_CTRL1, val);
234 if (ret < 0)
235 return ret;
236
237 if (mode)
238 msleep(AK8974_ACTIVATE_DELAY);
239
240 return 0;
241 }
242
243 static int ak8974_reset(struct ak8974 *ak8974)
244 {
245 int ret;
246
247 /* Power on to get register access. Sets CTRL1 reg to reset state */
248 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
249 if (ret)
250 return ret;
251 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF);
252 if (ret)
253 return ret;
254 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
255 if (ret)
256 return ret;
257 if (ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A) {
258 ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
259 AK8974_INT_CTRL_RESDEF);
260 if (ret)
261 return ret;
262 } else {
263 ret = regmap_write(ak8974->map, HSCDTD008A_CTRL4,
264 HSCDTD008A_CTRL4_RESDEF);
265 if (ret)
266 return ret;
267 }
268
269 /* After reset, power off is default state */
270 return ak8974_set_power(ak8974, AK8974_PWR_OFF);
271 }
272
273 static int ak8974_configure(struct ak8974 *ak8974)
274 {
275 int ret;
276
277 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN |
278 AK8974_CTRL2_INT_EN);
279 if (ret)
280 return ret;
281 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0);
282 if (ret)
283 return ret;
284 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) {
285 /* magic from datasheet: set high-speed measurement mode */
286 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E);
287 if (ret)
288 return ret;
289 }
290 if (ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A)
291 return 0;
292 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
293 if (ret)
294 return ret;
295
296 return regmap_write(ak8974->map, AK8974_PRESET, 0);
297 }
298
299 static int ak8974_trigmeas(struct ak8974 *ak8974)
300 {
301 unsigned int clear;
302 u8 mask;
303 u8 val;
304 int ret;
305
306 /* Clear any previous measurement overflow status */
307 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear);
308 if (ret)
309 return ret;
310
311 /* If we have a DRDY IRQ line, use it */
312 if (ak8974->drdy_irq) {
313 mask = AK8974_CTRL2_INT_EN |
314 AK8974_CTRL2_DRDY_EN |
315 AK8974_CTRL2_DRDY_POL;
316 val = AK8974_CTRL2_DRDY_EN;
317
318 if (!ak8974->drdy_active_low)
319 val |= AK8974_CTRL2_DRDY_POL;
320
321 init_completion(&ak8974->drdy_complete);
322 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2,
323 mask, val);
324 if (ret)
325 return ret;
326 }
327
328 /* Force a measurement */
329 return regmap_update_bits(ak8974->map,
330 AK8974_CTRL3,
331 AK8974_CTRL3_FORCE,
332 AK8974_CTRL3_FORCE);
333 }
334
335 static int ak8974_await_drdy(struct ak8974 *ak8974)
336 {
337 int timeout = 2;
338 unsigned int val;
339 int ret;
340
341 if (ak8974->drdy_irq) {
342 ret = wait_for_completion_timeout(&ak8974->drdy_complete,
343 1 + msecs_to_jiffies(1000));
344 if (!ret) {
345 dev_err(&ak8974->i2c->dev,
346 "timeout waiting for DRDY IRQ\n");
347 return -ETIMEDOUT;
348 }
349 return 0;
350 }
351
352 /* Default delay-based poll loop */
353 do {
354 msleep(AK8974_MEASTIME);
355 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
356 if (ret < 0)
357 return ret;
358 if (val & AK8974_STATUS_DRDY)
359 return 0;
360 } while (--timeout);
361
362 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n");
363 return -ETIMEDOUT;
364 }
365
366 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result)
367 {
368 unsigned int src;
369 int ret;
370
371 ret = ak8974_await_drdy(ak8974);
372 if (ret)
373 return ret;
374 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src);
375 if (ret < 0)
376 return ret;
377
378 /* Out of range overflow! Strong magnet close? */
379 if (src & AK8974_INT_RANGE) {
380 dev_err(&ak8974->i2c->dev,
381 "range overflow in sensor\n");
382 return -ERANGE;
383 }
384
385 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6);
386 if (ret)
387 return ret;
388
389 return ret;
390 }
391
392 static irqreturn_t ak8974_drdy_irq(int irq, void *d)
393 {
394 struct ak8974 *ak8974 = d;
395
396 if (!ak8974->drdy_irq)
397 return IRQ_NONE;
398
399 /* TODO: timestamp here to get good measurement stamps */
400 return IRQ_WAKE_THREAD;
401 }
402
403 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d)
404 {
405 struct ak8974 *ak8974 = d;
406 unsigned int val;
407 int ret;
408
409 /* Check if this was a DRDY from us */
410 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
411 if (ret < 0) {
412 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n");
413 return IRQ_HANDLED;
414 }
415 if (val & AK8974_STATUS_DRDY) {
416 /* Yes this was our IRQ */
417 complete(&ak8974->drdy_complete);
418 return IRQ_HANDLED;
419 }
420
421 /* We may be on a shared IRQ, let the next client check */
422 return IRQ_NONE;
423 }
424
425 static int ak8974_selftest(struct ak8974 *ak8974)
426 {
427 struct device *dev = &ak8974->i2c->dev;
428 unsigned int val;
429 int ret;
430
431 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
432 if (ret)
433 return ret;
434 if (val != AK8974_SELFTEST_IDLE) {
435 dev_err(dev, "selftest not idle before test\n");
436 return -EIO;
437 }
438
439 /* Trigger self-test */
440 ret = regmap_update_bits(ak8974->map,
441 AK8974_CTRL3,
442 AK8974_CTRL3_SELFTEST,
443 AK8974_CTRL3_SELFTEST);
444 if (ret) {
445 dev_err(dev, "could not write CTRL3\n");
446 return ret;
447 }
448
449 msleep(AK8974_SELFTEST_DELAY);
450
451 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
452 if (ret)
453 return ret;
454 if (val != AK8974_SELFTEST_OK) {
455 dev_err(dev, "selftest result NOT OK (%02x)\n", val);
456 return -EIO;
457 }
458
459 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
460 if (ret)
461 return ret;
462 if (val != AK8974_SELFTEST_IDLE) {
463 dev_err(dev, "selftest not idle after test (%02x)\n", val);
464 return -EIO;
465 }
466 dev_dbg(dev, "passed self-test\n");
467
468 return 0;
469 }
470
471 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg,
472 __le16 *tab, size_t tab_size)
473 {
474 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size);
475 if (ret) {
476 memset(tab, 0xFF, tab_size);
477 dev_warn(&ak8974->i2c->dev,
478 "can't read calibration data (regs %u..%zu): %d\n",
479 reg, reg + tab_size - 1, ret);
480 } else {
481 add_device_randomness(tab, tab_size);
482 }
483 }
484
485 static int ak8974_detect(struct ak8974 *ak8974)
486 {
487 unsigned int whoami;
488 const char *name;
489 int ret;
490 unsigned int fw;
491 u16 sn;
492
493 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami);
494 if (ret)
495 return ret;
496
497 name = "ami305";
498
499 switch (whoami) {
500 case AK8974_WHOAMI_VALUE_AMI306:
501 name = "ami306";
502 fallthrough;
503 case AK8974_WHOAMI_VALUE_AMI305:
504 ret = regmap_read(ak8974->map, AMI305_VER, &fw);
505 if (ret)
506 return ret;
507 fw &= 0x7f; /* only bits 0 thru 6 valid */
508 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn);
509 if (ret)
510 return ret;
511 add_device_randomness(&sn, sizeof(sn));
512 dev_info(&ak8974->i2c->dev,
513 "detected %s, FW ver %02x, S/N: %04x\n",
514 name, fw, sn);
515 break;
516 case AK8974_WHOAMI_VALUE_AK8974:
517 name = "ak8974";
518 dev_info(&ak8974->i2c->dev, "detected AK8974\n");
519 break;
520 case AK8974_WHOAMI_VALUE_HSCDTD008A:
521 name = "hscdtd008a";
522 dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n");
523 break;
524 default:
525 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
526 whoami);
527 return -ENODEV;
528 }
529
530 ak8974->name = name;
531 ak8974->variant = whoami;
532
533 if (whoami == AK8974_WHOAMI_VALUE_AMI306) {
534 __le16 fab_data1[9], fab_data2[3];
535 int i;
536
537 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X,
538 fab_data1, sizeof(fab_data1));
539 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X,
540 fab_data2, sizeof(fab_data2));
541
542 for (i = 0; i < 3; ++i) {
543 static const char axis[3] = "XYZ";
544 static const char pgaxis[6] = "ZYZXYX";
545 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F;
546 unsigned fine = le16_to_cpu(fab_data1[i]);
547 unsigned sens = le16_to_cpu(fab_data1[i + 3]);
548 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]);
549 unsigned pgain2 = pgain1 >> 8;
550
551 pgain1 &= 0xFF;
552
553 dev_info(&ak8974->i2c->dev,
554 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n",
555 axis[i], offz, sens, fine, pgaxis[i * 2],
556 pgain1, pgaxis[i * 2 + 1], pgain2);
557 }
558 }
559
560 return 0;
561 }
562
563 static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address,
564 int *val)
565 {
566 __le16 hw_values[3];
567 int ret;
568
569 pm_runtime_get_sync(&ak8974->i2c->dev);
570 mutex_lock(&ak8974->lock);
571
572 /*
573 * We read all axes and discard all but one, for optimized
574 * reading, use the triggered buffer.
575 */
576 ret = ak8974_trigmeas(ak8974);
577 if (ret)
578 goto out_unlock;
579 ret = ak8974_getresult(ak8974, hw_values);
580 if (ret)
581 goto out_unlock;
582 /*
583 * This explicit cast to (s16) is necessary as the measurement
584 * is done in 2's complement with positive and negative values.
585 * The follwing assignment to *val will then convert the signed
586 * s16 value to a signed int value.
587 */
588 *val = (s16)le16_to_cpu(hw_values[address]);
589 out_unlock:
590 mutex_unlock(&ak8974->lock);
591 pm_runtime_mark_last_busy(&ak8974->i2c->dev);
592 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
593
594 return ret;
595 }
596
597 static int ak8974_read_raw(struct iio_dev *indio_dev,
598 struct iio_chan_spec const *chan,
599 int *val, int *val2,
600 long mask)
601 {
602 struct ak8974 *ak8974 = iio_priv(indio_dev);
603 int ret;
604
605 switch (mask) {
606 case IIO_CHAN_INFO_RAW:
607 if (chan->address > 2) {
608 dev_err(&ak8974->i2c->dev, "faulty channel address\n");
609 return -EIO;
610 }
611 ret = ak8974_measure_channel(ak8974, chan->address, val);
612 if (ret)
613 return ret;
614 return IIO_VAL_INT;
615 case IIO_CHAN_INFO_SCALE:
616 switch (ak8974->variant) {
617 case AK8974_WHOAMI_VALUE_AMI306:
618 case AK8974_WHOAMI_VALUE_AMI305:
619 /*
620 * The datasheet for AMI305 and AMI306, page 6
621 * specifies the range of the sensor to be
622 * +/- 12 Gauss.
623 */
624 *val = 12;
625 /*
626 * 12 bits are used, +/- 2^11
627 * [ -2048 .. 2047 ] (manual page 20)
628 * [ 0xf800 .. 0x07ff ]
629 */
630 *val2 = 11;
631 return IIO_VAL_FRACTIONAL_LOG2;
632 case AK8974_WHOAMI_VALUE_HSCDTD008A:
633 /*
634 * The datasheet for HSCDTF008A, page 3 specifies the
635 * range of the sensor as +/- 2.4 mT per axis, which
636 * corresponds to +/- 2400 uT = +/- 24 Gauss.
637 */
638 *val = 24;
639 /*
640 * 15 bits are used (set up in CTRL4), +/- 2^14
641 * [ -16384 .. 16383 ] (manual page 24)
642 * [ 0xc000 .. 0x3fff ]
643 */
644 *val2 = 14;
645 return IIO_VAL_FRACTIONAL_LOG2;
646 default:
647 /* GUESSING +/- 12 Gauss */
648 *val = 12;
649 /* GUESSING 12 bits ADC +/- 2^11 */
650 *val2 = 11;
651 return IIO_VAL_FRACTIONAL_LOG2;
652 }
653 break;
654 default:
655 /* Unknown request */
656 break;
657 }
658
659 return -EINVAL;
660 }
661
662 static void ak8974_fill_buffer(struct iio_dev *indio_dev)
663 {
664 struct ak8974 *ak8974 = iio_priv(indio_dev);
665 int ret;
666
667 pm_runtime_get_sync(&ak8974->i2c->dev);
668 mutex_lock(&ak8974->lock);
669
670 ret = ak8974_trigmeas(ak8974);
671 if (ret) {
672 dev_err(&ak8974->i2c->dev, "error triggering measure\n");
673 goto out_unlock;
674 }
675 ret = ak8974_getresult(ak8974, ak8974->scan.channels);
676 if (ret) {
677 dev_err(&ak8974->i2c->dev, "error getting measures\n");
678 goto out_unlock;
679 }
680
681 iio_push_to_buffers_with_timestamp(indio_dev, &ak8974->scan,
682 iio_get_time_ns(indio_dev));
683
684 out_unlock:
685 mutex_unlock(&ak8974->lock);
686 pm_runtime_mark_last_busy(&ak8974->i2c->dev);
687 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
688 }
689
690 static irqreturn_t ak8974_handle_trigger(int irq, void *p)
691 {
692 const struct iio_poll_func *pf = p;
693 struct iio_dev *indio_dev = pf->indio_dev;
694
695 ak8974_fill_buffer(indio_dev);
696 iio_trigger_notify_done(indio_dev->trig);
697
698 return IRQ_HANDLED;
699 }
700
701 static const struct iio_mount_matrix *
702 ak8974_get_mount_matrix(const struct iio_dev *indio_dev,
703 const struct iio_chan_spec *chan)
704 {
705 struct ak8974 *ak8974 = iio_priv(indio_dev);
706
707 return &ak8974->orientation;
708 }
709
710 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = {
711 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix),
712 { },
713 };
714
715 #define AK8974_AXIS_CHANNEL(axis, index, bits) \
716 { \
717 .type = IIO_MAGN, \
718 .modified = 1, \
719 .channel2 = IIO_MOD_##axis, \
720 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
721 BIT(IIO_CHAN_INFO_SCALE), \
722 .ext_info = ak8974_ext_info, \
723 .address = index, \
724 .scan_index = index, \
725 .scan_type = { \
726 .sign = 's', \
727 .realbits = bits, \
728 .storagebits = 16, \
729 .endianness = IIO_LE \
730 }, \
731 }
732
733 /*
734 * We have no datasheet for the AK8974 but we guess that its
735 * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit
736 * ADC.
737 */
738 static const struct iio_chan_spec ak8974_12_bits_channels[] = {
739 AK8974_AXIS_CHANNEL(X, 0, 12),
740 AK8974_AXIS_CHANNEL(Y, 1, 12),
741 AK8974_AXIS_CHANNEL(Z, 2, 12),
742 IIO_CHAN_SOFT_TIMESTAMP(3),
743 };
744
745 /*
746 * The HSCDTD008A has 15 bits resolution the way we set it up
747 * in CTRL4.
748 */
749 static const struct iio_chan_spec ak8974_15_bits_channels[] = {
750 AK8974_AXIS_CHANNEL(X, 0, 15),
751 AK8974_AXIS_CHANNEL(Y, 1, 15),
752 AK8974_AXIS_CHANNEL(Z, 2, 15),
753 IIO_CHAN_SOFT_TIMESTAMP(3),
754 };
755
756 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
757
758 static const struct iio_info ak8974_info = {
759 .read_raw = &ak8974_read_raw,
760 };
761
762 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
763 {
764 struct i2c_client *i2c = to_i2c_client(dev);
765 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
766 struct ak8974 *ak8974 = iio_priv(indio_dev);
767
768 switch (reg) {
769 case AK8974_CTRL1:
770 case AK8974_CTRL2:
771 case AK8974_CTRL3:
772 case AK8974_INT_CTRL:
773 case AK8974_INT_THRES:
774 case AK8974_INT_THRES + 1:
775 return true;
776 case AK8974_PRESET:
777 case AK8974_PRESET + 1:
778 return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A;
779 case AK8974_OFFSET_X:
780 case AK8974_OFFSET_X + 1:
781 case AK8974_OFFSET_Y:
782 case AK8974_OFFSET_Y + 1:
783 case AK8974_OFFSET_Z:
784 case AK8974_OFFSET_Z + 1:
785 return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 ||
786 ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A;
787 case AMI305_OFFSET_X:
788 case AMI305_OFFSET_X + 1:
789 case AMI305_OFFSET_Y:
790 case AMI305_OFFSET_Y + 1:
791 case AMI305_OFFSET_Z:
792 case AMI305_OFFSET_Z + 1:
793 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 ||
794 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
795 case AMI306_CTRL4:
796 case AMI306_CTRL4 + 1:
797 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
798 default:
799 return false;
800 }
801 }
802
803 static bool ak8974_precious_reg(struct device *dev, unsigned int reg)
804 {
805 return reg == AK8974_INT_CLEAR;
806 }
807
808 static const struct regmap_config ak8974_regmap_config = {
809 .reg_bits = 8,
810 .val_bits = 8,
811 .max_register = 0xff,
812 .writeable_reg = ak8974_writeable_reg,
813 .precious_reg = ak8974_precious_reg,
814 };
815
816 static int ak8974_probe(struct i2c_client *i2c,
817 const struct i2c_device_id *id)
818 {
819 struct iio_dev *indio_dev;
820 struct ak8974 *ak8974;
821 unsigned long irq_trig;
822 int irq = i2c->irq;
823 int ret;
824
825 /* Register with IIO */
826 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974));
827 if (indio_dev == NULL)
828 return -ENOMEM;
829
830 ak8974 = iio_priv(indio_dev);
831 i2c_set_clientdata(i2c, indio_dev);
832 ak8974->i2c = i2c;
833 mutex_init(&ak8974->lock);
834
835 ret = iio_read_mount_matrix(&i2c->dev, "mount-matrix",
836 &ak8974->orientation);
837 if (ret)
838 return ret;
839
840 ak8974->regs[0].supply = ak8974_reg_avdd;
841 ak8974->regs[1].supply = ak8974_reg_dvdd;
842
843 ret = devm_regulator_bulk_get(&i2c->dev,
844 ARRAY_SIZE(ak8974->regs),
845 ak8974->regs);
846 if (ret < 0) {
847 if (ret != -EPROBE_DEFER)
848 dev_err(&i2c->dev, "cannot get regulators: %d\n", ret);
849 else
850 dev_dbg(&i2c->dev,
851 "regulators unavailable, deferring probe\n");
852
853 return ret;
854 }
855
856 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
857 if (ret < 0) {
858 dev_err(&i2c->dev, "cannot enable regulators\n");
859 return ret;
860 }
861
862 /* Take runtime PM online */
863 pm_runtime_get_noresume(&i2c->dev);
864 pm_runtime_set_active(&i2c->dev);
865 pm_runtime_enable(&i2c->dev);
866
867 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config);
868 if (IS_ERR(ak8974->map)) {
869 dev_err(&i2c->dev, "failed to allocate register map\n");
870 pm_runtime_put_noidle(&i2c->dev);
871 pm_runtime_disable(&i2c->dev);
872 return PTR_ERR(ak8974->map);
873 }
874
875 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
876 if (ret) {
877 dev_err(&i2c->dev, "could not power on\n");
878 goto disable_pm;
879 }
880
881 ret = ak8974_detect(ak8974);
882 if (ret) {
883 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n");
884 goto disable_pm;
885 }
886
887 ret = ak8974_selftest(ak8974);
888 if (ret)
889 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n");
890
891 ret = ak8974_reset(ak8974);
892 if (ret) {
893 dev_err(&i2c->dev, "AK8974 reset failed\n");
894 goto disable_pm;
895 }
896
897 switch (ak8974->variant) {
898 case AK8974_WHOAMI_VALUE_AMI306:
899 case AK8974_WHOAMI_VALUE_AMI305:
900 indio_dev->channels = ak8974_12_bits_channels;
901 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels);
902 break;
903 case AK8974_WHOAMI_VALUE_HSCDTD008A:
904 indio_dev->channels = ak8974_15_bits_channels;
905 indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels);
906 break;
907 default:
908 indio_dev->channels = ak8974_12_bits_channels;
909 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels);
910 break;
911 }
912 indio_dev->info = &ak8974_info;
913 indio_dev->available_scan_masks = ak8974_scan_masks;
914 indio_dev->modes = INDIO_DIRECT_MODE;
915 indio_dev->name = ak8974->name;
916
917 ret = iio_triggered_buffer_setup(indio_dev, NULL,
918 ak8974_handle_trigger,
919 NULL);
920 if (ret) {
921 dev_err(&i2c->dev, "triggered buffer setup failed\n");
922 goto disable_pm;
923 }
924
925 /* If we have a valid DRDY IRQ, make use of it */
926 if (irq > 0) {
927 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
928 if (irq_trig == IRQF_TRIGGER_RISING) {
929 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n");
930 } else if (irq_trig == IRQF_TRIGGER_FALLING) {
931 ak8974->drdy_active_low = true;
932 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n");
933 } else {
934 irq_trig = IRQF_TRIGGER_RISING;
935 }
936 irq_trig |= IRQF_ONESHOT;
937 irq_trig |= IRQF_SHARED;
938
939 ret = devm_request_threaded_irq(&i2c->dev,
940 irq,
941 ak8974_drdy_irq,
942 ak8974_drdy_irq_thread,
943 irq_trig,
944 ak8974->name,
945 ak8974);
946 if (ret) {
947 dev_err(&i2c->dev, "unable to request DRDY IRQ "
948 "- proceeding without IRQ\n");
949 goto no_irq;
950 }
951 ak8974->drdy_irq = true;
952 }
953
954 no_irq:
955 ret = iio_device_register(indio_dev);
956 if (ret) {
957 dev_err(&i2c->dev, "device register failed\n");
958 goto cleanup_buffer;
959 }
960
961 pm_runtime_set_autosuspend_delay(&i2c->dev,
962 AK8974_AUTOSUSPEND_DELAY);
963 pm_runtime_use_autosuspend(&i2c->dev);
964 pm_runtime_put(&i2c->dev);
965
966 return 0;
967
968 cleanup_buffer:
969 iio_triggered_buffer_cleanup(indio_dev);
970 disable_pm:
971 pm_runtime_put_noidle(&i2c->dev);
972 pm_runtime_disable(&i2c->dev);
973 ak8974_set_power(ak8974, AK8974_PWR_OFF);
974 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
975
976 return ret;
977 }
978
979 static int ak8974_remove(struct i2c_client *i2c)
980 {
981 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
982 struct ak8974 *ak8974 = iio_priv(indio_dev);
983
984 iio_device_unregister(indio_dev);
985 iio_triggered_buffer_cleanup(indio_dev);
986 pm_runtime_get_sync(&i2c->dev);
987 pm_runtime_put_noidle(&i2c->dev);
988 pm_runtime_disable(&i2c->dev);
989 ak8974_set_power(ak8974, AK8974_PWR_OFF);
990 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
991
992 return 0;
993 }
994
995 static int __maybe_unused ak8974_runtime_suspend(struct device *dev)
996 {
997 struct ak8974 *ak8974 =
998 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
999
1000 ak8974_set_power(ak8974, AK8974_PWR_OFF);
1001 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
1002
1003 return 0;
1004 }
1005
1006 static int __maybe_unused ak8974_runtime_resume(struct device *dev)
1007 {
1008 struct ak8974 *ak8974 =
1009 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
1010 int ret;
1011
1012 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
1013 if (ret)
1014 return ret;
1015 msleep(AK8974_POWERON_DELAY);
1016 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
1017 if (ret)
1018 goto out_regulator_disable;
1019
1020 ret = ak8974_configure(ak8974);
1021 if (ret)
1022 goto out_disable_power;
1023
1024 return 0;
1025
1026 out_disable_power:
1027 ak8974_set_power(ak8974, AK8974_PWR_OFF);
1028 out_regulator_disable:
1029 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
1030
1031 return ret;
1032 }
1033
1034 static const struct dev_pm_ops ak8974_dev_pm_ops = {
1035 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1036 pm_runtime_force_resume)
1037 SET_RUNTIME_PM_OPS(ak8974_runtime_suspend,
1038 ak8974_runtime_resume, NULL)
1039 };
1040
1041 static const struct i2c_device_id ak8974_id[] = {
1042 {"ami305", 0 },
1043 {"ami306", 0 },
1044 {"ak8974", 0 },
1045 {"hscdtd008a", 0 },
1046 {}
1047 };
1048 MODULE_DEVICE_TABLE(i2c, ak8974_id);
1049
1050 static const struct of_device_id ak8974_of_match[] = {
1051 { .compatible = "asahi-kasei,ak8974", },
1052 { .compatible = "alps,hscdtd008a", },
1053 {}
1054 };
1055 MODULE_DEVICE_TABLE(of, ak8974_of_match);
1056
1057 static struct i2c_driver ak8974_driver = {
1058 .driver = {
1059 .name = "ak8974",
1060 .pm = &ak8974_dev_pm_ops,
1061 .of_match_table = of_match_ptr(ak8974_of_match),
1062 },
1063 .probe = ak8974_probe,
1064 .remove = ak8974_remove,
1065 .id_table = ak8974_id,
1066 };
1067 module_i2c_driver(ak8974_driver);
1068
1069 MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver");
1070 MODULE_AUTHOR("Samu Onkalo");
1071 MODULE_AUTHOR("Linus Walleij");
1072 MODULE_LICENSE("GPL v2");
Linux with added FPC-III support