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
53 #define AK8974_DATA_X 0x10
54 #define AK8974_DATA_Y 0x12
55 #define AK8974_DATA_Z 0x14
56 #define AK8974_INT_SRC 0x16
57 #define AK8974_STATUS 0x18
58 #define AK8974_INT_CLEAR 0x1A
59 #define AK8974_CTRL1 0x1B
60 #define AK8974_CTRL2 0x1C
61 #define AK8974_CTRL3 0x1D
62 #define AK8974_INT_CTRL 0x1E
63 #define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */
64 #define AK8974_PRESET 0x30
65
66 /* AK8974-specific offsets */
67 #define AK8974_OFFSET_X 0x20
68 #define AK8974_OFFSET_Y 0x22
69 #define AK8974_OFFSET_Z 0x24
70 /* AMI305-specific offsets */
71 #define AMI305_OFFSET_X 0x6C
72 #define AMI305_OFFSET_Y 0x72
73 #define AMI305_OFFSET_Z 0x78
74
75 /* Different temperature registers */
76 #define AK8974_TEMP 0x31
77 #define AMI305_TEMP 0x60
78
79 /* AMI306-specific control register */
80 #define AMI306_CTRL4 0x5C
81
82 /* AMI306 factory calibration data */
83
84 /* fine axis sensitivity */
85 #define AMI306_FINEOUTPUT_X 0x90
86 #define AMI306_FINEOUTPUT_Y 0x92
87 #define AMI306_FINEOUTPUT_Z 0x94
88
89 /* axis sensitivity */
90 #define AMI306_SENS_X 0x96
91 #define AMI306_SENS_Y 0x98
92 #define AMI306_SENS_Z 0x9A
93
94 /* axis cross-interference */
95 #define AMI306_GAIN_PARA_XZ 0x9C
96 #define AMI306_GAIN_PARA_XY 0x9D
97 #define AMI306_GAIN_PARA_YZ 0x9E
98 #define AMI306_GAIN_PARA_YX 0x9F
99 #define AMI306_GAIN_PARA_ZY 0xA0
100 #define AMI306_GAIN_PARA_ZX 0xA1
101
102 /* offset at ZERO magnetic field */
103 #define AMI306_OFFZERO_X 0xF8
104 #define AMI306_OFFZERO_Y 0xFA
105 #define AMI306_OFFZERO_Z 0xFC
106
107
108 #define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */
109 #define AK8974_INT_Y_HIGH BIT(6)
110 #define AK8974_INT_Z_HIGH BIT(5)
111 #define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */
112 #define AK8974_INT_Y_LOW BIT(3)
113 #define AK8974_INT_Z_LOW BIT(2)
114 #define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */
115
116 #define AK8974_STATUS_DRDY BIT(6) /* Data ready */
117 #define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */
118 #define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */
119
120 #define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */
121 #define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */
122 #define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */
123 #define AK8974_CTRL1_MODE2 BIT(0) /* 0 */
124
125 #define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */
126 #define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */
127 #define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */
128 #define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL)
129
130 #define AK8974_CTRL3_RESET BIT(7) /* Software reset */
131 #define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */
132 #define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */
133 #define AK8974_CTRL3_RESDEF 0x00
134
135 #define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */
136 #define AK8974_INT_CTRL_YEN BIT(6)
137 #define AK8974_INT_CTRL_ZEN BIT(5)
138 #define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5))
139 #define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */
140 #define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
141 #define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
142
143 /* The AMI305 has elaborate FW version and serial number registers */
144 #define AMI305_VER 0xE8
145 #define AMI305_SN 0xEA
146
147 #define AK8974_MAX_RANGE 2048
148
149 #define AK8974_POWERON_DELAY 50
150 #define AK8974_ACTIVATE_DELAY 1
151 #define AK8974_SELFTEST_DELAY 1
152 /*
153 * Set the autosuspend to two orders of magnitude larger than the poweron
154 * delay to make sane reasonable power tradeoff savings (5 seconds in
155 * this case).
156 */
157 #define AK8974_AUTOSUSPEND_DELAY 5000
158
159 #define AK8974_MEASTIME 3
160
161 #define AK8974_PWR_ON 1
162 #define AK8974_PWR_OFF 0
163
164 /**
165 * struct ak8974 - state container for the AK8974 driver
166 * @i2c: parent I2C client
167 * @orientation: mounting matrix, flipped axis etc
168 * @map: regmap to access the AK8974 registers over I2C
169 * @regs: the avdd and dvdd power regulators
170 * @name: the name of the part
171 * @variant: the whoami ID value (for selecting code paths)
172 * @lock: locks the magnetometer for exclusive use during a measurement
173 * @drdy_irq: uses the DRDY IRQ line
174 * @drdy_complete: completion for DRDY
175 * @drdy_active_low: the DRDY IRQ is active low
176 */
177 struct ak8974 {
178 struct i2c_client *i2c;
179 struct iio_mount_matrix orientation;
180 struct regmap *map;
181 struct regulator_bulk_data regs[2];
182 const char *name;
183 u8 variant;
184 struct mutex lock;
185 bool drdy_irq;
186 struct completion drdy_complete;
187 bool drdy_active_low;
188 /* Ensure timestamp is naturally aligned */
189 struct {
190 __le16 channels[3];
191 s64 ts __aligned(8);
192 } scan;
193 };
194
195 static const char ak8974_reg_avdd[] = "avdd";
196 static const char ak8974_reg_dvdd[] = "dvdd";
197
ak8974_get_u16_val(struct ak8974 * ak8974,u8 reg,u16 * val)198 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val)
199 {
200 int ret;
201 __le16 bulk;
202
203 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2);
204 if (ret)
205 return ret;
206 *val = le16_to_cpu(bulk);
207
208 return 0;
209 }
210
ak8974_set_u16_val(struct ak8974 * ak8974,u8 reg,u16 val)211 static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val)
212 {
213 __le16 bulk = cpu_to_le16(val);
214
215 return regmap_bulk_write(ak8974->map, reg, &bulk, 2);
216 }
217
ak8974_set_power(struct ak8974 * ak8974,bool mode)218 static int ak8974_set_power(struct ak8974 *ak8974, bool mode)
219 {
220 int ret;
221 u8 val;
222
223 val = mode ? AK8974_CTRL1_POWER : 0;
224 val |= AK8974_CTRL1_FORCE_EN;
225 ret = regmap_write(ak8974->map, AK8974_CTRL1, val);
226 if (ret < 0)
227 return ret;
228
229 if (mode)
230 msleep(AK8974_ACTIVATE_DELAY);
231
232 return 0;
233 }
234
ak8974_reset(struct ak8974 * ak8974)235 static int ak8974_reset(struct ak8974 *ak8974)
236 {
237 int ret;
238
239 /* Power on to get register access. Sets CTRL1 reg to reset state */
240 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
241 if (ret)
242 return ret;
243 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF);
244 if (ret)
245 return ret;
246 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
247 if (ret)
248 return ret;
249 ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
250 AK8974_INT_CTRL_RESDEF);
251 if (ret)
252 return ret;
253
254 /* After reset, power off is default state */
255 return ak8974_set_power(ak8974, AK8974_PWR_OFF);
256 }
257
ak8974_configure(struct ak8974 * ak8974)258 static int ak8974_configure(struct ak8974 *ak8974)
259 {
260 int ret;
261
262 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN |
263 AK8974_CTRL2_INT_EN);
264 if (ret)
265 return ret;
266 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0);
267 if (ret)
268 return ret;
269 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) {
270 /* magic from datasheet: set high-speed measurement mode */
271 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E);
272 if (ret)
273 return ret;
274 }
275 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
276 if (ret)
277 return ret;
278
279 return regmap_write(ak8974->map, AK8974_PRESET, 0);
280 }
281
ak8974_trigmeas(struct ak8974 * ak8974)282 static int ak8974_trigmeas(struct ak8974 *ak8974)
283 {
284 unsigned int clear;
285 u8 mask;
286 u8 val;
287 int ret;
288
289 /* Clear any previous measurement overflow status */
290 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear);
291 if (ret)
292 return ret;
293
294 /* If we have a DRDY IRQ line, use it */
295 if (ak8974->drdy_irq) {
296 mask = AK8974_CTRL2_INT_EN |
297 AK8974_CTRL2_DRDY_EN |
298 AK8974_CTRL2_DRDY_POL;
299 val = AK8974_CTRL2_DRDY_EN;
300
301 if (!ak8974->drdy_active_low)
302 val |= AK8974_CTRL2_DRDY_POL;
303
304 init_completion(&ak8974->drdy_complete);
305 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2,
306 mask, val);
307 if (ret)
308 return ret;
309 }
310
311 /* Force a measurement */
312 return regmap_update_bits(ak8974->map,
313 AK8974_CTRL3,
314 AK8974_CTRL3_FORCE,
315 AK8974_CTRL3_FORCE);
316 }
317
ak8974_await_drdy(struct ak8974 * ak8974)318 static int ak8974_await_drdy(struct ak8974 *ak8974)
319 {
320 int timeout = 2;
321 unsigned int val;
322 int ret;
323
324 if (ak8974->drdy_irq) {
325 ret = wait_for_completion_timeout(&ak8974->drdy_complete,
326 1 + msecs_to_jiffies(1000));
327 if (!ret) {
328 dev_err(&ak8974->i2c->dev,
329 "timeout waiting for DRDY IRQ\n");
330 return -ETIMEDOUT;
331 }
332 return 0;
333 }
334
335 /* Default delay-based poll loop */
336 do {
337 msleep(AK8974_MEASTIME);
338 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
339 if (ret < 0)
340 return ret;
341 if (val & AK8974_STATUS_DRDY)
342 return 0;
343 } while (--timeout);
344
345 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n");
346 return -ETIMEDOUT;
347 }
348
ak8974_getresult(struct ak8974 * ak8974,__le16 * result)349 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result)
350 {
351 unsigned int src;
352 int ret;
353
354 ret = ak8974_await_drdy(ak8974);
355 if (ret)
356 return ret;
357 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src);
358 if (ret < 0)
359 return ret;
360
361 /* Out of range overflow! Strong magnet close? */
362 if (src & AK8974_INT_RANGE) {
363 dev_err(&ak8974->i2c->dev,
364 "range overflow in sensor\n");
365 return -ERANGE;
366 }
367
368 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6);
369 if (ret)
370 return ret;
371
372 return ret;
373 }
374
ak8974_drdy_irq(int irq,void * d)375 static irqreturn_t ak8974_drdy_irq(int irq, void *d)
376 {
377 struct ak8974 *ak8974 = d;
378
379 if (!ak8974->drdy_irq)
380 return IRQ_NONE;
381
382 /* TODO: timestamp here to get good measurement stamps */
383 return IRQ_WAKE_THREAD;
384 }
385
ak8974_drdy_irq_thread(int irq,void * d)386 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d)
387 {
388 struct ak8974 *ak8974 = d;
389 unsigned int val;
390 int ret;
391
392 /* Check if this was a DRDY from us */
393 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
394 if (ret < 0) {
395 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n");
396 return IRQ_HANDLED;
397 }
398 if (val & AK8974_STATUS_DRDY) {
399 /* Yes this was our IRQ */
400 complete(&ak8974->drdy_complete);
401 return IRQ_HANDLED;
402 }
403
404 /* We may be on a shared IRQ, let the next client check */
405 return IRQ_NONE;
406 }
407
ak8974_selftest(struct ak8974 * ak8974)408 static int ak8974_selftest(struct ak8974 *ak8974)
409 {
410 struct device *dev = &ak8974->i2c->dev;
411 unsigned int val;
412 int ret;
413
414 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
415 if (ret)
416 return ret;
417 if (val != AK8974_SELFTEST_IDLE) {
418 dev_err(dev, "selftest not idle before test\n");
419 return -EIO;
420 }
421
422 /* Trigger self-test */
423 ret = regmap_update_bits(ak8974->map,
424 AK8974_CTRL3,
425 AK8974_CTRL3_SELFTEST,
426 AK8974_CTRL3_SELFTEST);
427 if (ret) {
428 dev_err(dev, "could not write CTRL3\n");
429 return ret;
430 }
431
432 msleep(AK8974_SELFTEST_DELAY);
433
434 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
435 if (ret)
436 return ret;
437 if (val != AK8974_SELFTEST_OK) {
438 dev_err(dev, "selftest result NOT OK (%02x)\n", val);
439 return -EIO;
440 }
441
442 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
443 if (ret)
444 return ret;
445 if (val != AK8974_SELFTEST_IDLE) {
446 dev_err(dev, "selftest not idle after test (%02x)\n", val);
447 return -EIO;
448 }
449 dev_dbg(dev, "passed self-test\n");
450
451 return 0;
452 }
453
ak8974_read_calib_data(struct ak8974 * ak8974,unsigned int reg,__le16 * tab,size_t tab_size)454 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg,
455 __le16 *tab, size_t tab_size)
456 {
457 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size);
458 if (ret) {
459 memset(tab, 0xFF, tab_size);
460 dev_warn(&ak8974->i2c->dev,
461 "can't read calibration data (regs %u..%zu): %d\n",
462 reg, reg + tab_size - 1, ret);
463 } else {
464 add_device_randomness(tab, tab_size);
465 }
466 }
467
ak8974_detect(struct ak8974 * ak8974)468 static int ak8974_detect(struct ak8974 *ak8974)
469 {
470 unsigned int whoami;
471 const char *name;
472 int ret;
473 unsigned int fw;
474 u16 sn;
475
476 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami);
477 if (ret)
478 return ret;
479
480 name = "ami305";
481
482 switch (whoami) {
483 case AK8974_WHOAMI_VALUE_AMI306:
484 name = "ami306";
485 /* fall-through */
486 case AK8974_WHOAMI_VALUE_AMI305:
487 ret = regmap_read(ak8974->map, AMI305_VER, &fw);
488 if (ret)
489 return ret;
490 fw &= 0x7f; /* only bits 0 thru 6 valid */
491 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn);
492 if (ret)
493 return ret;
494 add_device_randomness(&sn, sizeof(sn));
495 dev_info(&ak8974->i2c->dev,
496 "detected %s, FW ver %02x, S/N: %04x\n",
497 name, fw, sn);
498 break;
499 case AK8974_WHOAMI_VALUE_AK8974:
500 name = "ak8974";
501 dev_info(&ak8974->i2c->dev, "detected AK8974\n");
502 break;
503 default:
504 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
505 whoami);
506 return -ENODEV;
507 }
508
509 ak8974->name = name;
510 ak8974->variant = whoami;
511
512 if (whoami == AK8974_WHOAMI_VALUE_AMI306) {
513 __le16 fab_data1[9], fab_data2[3];
514 int i;
515
516 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X,
517 fab_data1, sizeof(fab_data1));
518 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X,
519 fab_data2, sizeof(fab_data2));
520
521 for (i = 0; i < 3; ++i) {
522 static const char axis[3] = "XYZ";
523 static const char pgaxis[6] = "ZYZXYX";
524 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F;
525 unsigned fine = le16_to_cpu(fab_data1[i]);
526 unsigned sens = le16_to_cpu(fab_data1[i + 3]);
527 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]);
528 unsigned pgain2 = pgain1 >> 8;
529
530 pgain1 &= 0xFF;
531
532 dev_info(&ak8974->i2c->dev,
533 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n",
534 axis[i], offz, sens, fine, pgaxis[i * 2],
535 pgain1, pgaxis[i * 2 + 1], pgain2);
536 }
537 }
538
539 return 0;
540 }
541
ak8974_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)542 static int ak8974_read_raw(struct iio_dev *indio_dev,
543 struct iio_chan_spec const *chan,
544 int *val, int *val2,
545 long mask)
546 {
547 struct ak8974 *ak8974 = iio_priv(indio_dev);
548 __le16 hw_values[3];
549 int ret = -EINVAL;
550
551 pm_runtime_get_sync(&ak8974->i2c->dev);
552 mutex_lock(&ak8974->lock);
553
554 switch (mask) {
555 case IIO_CHAN_INFO_RAW:
556 if (chan->address > 2) {
557 dev_err(&ak8974->i2c->dev, "faulty channel address\n");
558 ret = -EIO;
559 goto out_unlock;
560 }
561 ret = ak8974_trigmeas(ak8974);
562 if (ret)
563 goto out_unlock;
564 ret = ak8974_getresult(ak8974, hw_values);
565 if (ret)
566 goto out_unlock;
567
568 /*
569 * We read all axes and discard all but one, for optimized
570 * reading, use the triggered buffer.
571 */
572 *val = (s16)le16_to_cpu(hw_values[chan->address]);
573
574 ret = IIO_VAL_INT;
575 }
576
577 out_unlock:
578 mutex_unlock(&ak8974->lock);
579 pm_runtime_mark_last_busy(&ak8974->i2c->dev);
580 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
581
582 return ret;
583 }
584
ak8974_fill_buffer(struct iio_dev * indio_dev)585 static void ak8974_fill_buffer(struct iio_dev *indio_dev)
586 {
587 struct ak8974 *ak8974 = iio_priv(indio_dev);
588 int ret;
589
590 pm_runtime_get_sync(&ak8974->i2c->dev);
591 mutex_lock(&ak8974->lock);
592
593 ret = ak8974_trigmeas(ak8974);
594 if (ret) {
595 dev_err(&ak8974->i2c->dev, "error triggering measure\n");
596 goto out_unlock;
597 }
598 ret = ak8974_getresult(ak8974, ak8974->scan.channels);
599 if (ret) {
600 dev_err(&ak8974->i2c->dev, "error getting measures\n");
601 goto out_unlock;
602 }
603
604 iio_push_to_buffers_with_timestamp(indio_dev, &ak8974->scan,
605 iio_get_time_ns(indio_dev));
606
607 out_unlock:
608 mutex_unlock(&ak8974->lock);
609 pm_runtime_mark_last_busy(&ak8974->i2c->dev);
610 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
611 }
612
ak8974_handle_trigger(int irq,void * p)613 static irqreturn_t ak8974_handle_trigger(int irq, void *p)
614 {
615 const struct iio_poll_func *pf = p;
616 struct iio_dev *indio_dev = pf->indio_dev;
617
618 ak8974_fill_buffer(indio_dev);
619 iio_trigger_notify_done(indio_dev->trig);
620
621 return IRQ_HANDLED;
622 }
623
624 static const struct iio_mount_matrix *
ak8974_get_mount_matrix(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)625 ak8974_get_mount_matrix(const struct iio_dev *indio_dev,
626 const struct iio_chan_spec *chan)
627 {
628 struct ak8974 *ak8974 = iio_priv(indio_dev);
629
630 return &ak8974->orientation;
631 }
632
633 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = {
634 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix),
635 { },
636 };
637
638 #define AK8974_AXIS_CHANNEL(axis, index) \
639 { \
640 .type = IIO_MAGN, \
641 .modified = 1, \
642 .channel2 = IIO_MOD_##axis, \
643 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
644 .ext_info = ak8974_ext_info, \
645 .address = index, \
646 .scan_index = index, \
647 .scan_type = { \
648 .sign = 's', \
649 .realbits = 16, \
650 .storagebits = 16, \
651 .endianness = IIO_LE \
652 }, \
653 }
654
655 static const struct iio_chan_spec ak8974_channels[] = {
656 AK8974_AXIS_CHANNEL(X, 0),
657 AK8974_AXIS_CHANNEL(Y, 1),
658 AK8974_AXIS_CHANNEL(Z, 2),
659 IIO_CHAN_SOFT_TIMESTAMP(3),
660 };
661
662 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
663
664 static const struct iio_info ak8974_info = {
665 .read_raw = &ak8974_read_raw,
666 };
667
ak8974_writeable_reg(struct device * dev,unsigned int reg)668 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
669 {
670 struct i2c_client *i2c = to_i2c_client(dev);
671 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
672 struct ak8974 *ak8974 = iio_priv(indio_dev);
673
674 switch (reg) {
675 case AK8974_CTRL1:
676 case AK8974_CTRL2:
677 case AK8974_CTRL3:
678 case AK8974_INT_CTRL:
679 case AK8974_INT_THRES:
680 case AK8974_INT_THRES + 1:
681 case AK8974_PRESET:
682 case AK8974_PRESET + 1:
683 return true;
684 case AK8974_OFFSET_X:
685 case AK8974_OFFSET_X + 1:
686 case AK8974_OFFSET_Y:
687 case AK8974_OFFSET_Y + 1:
688 case AK8974_OFFSET_Z:
689 case AK8974_OFFSET_Z + 1:
690 if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974)
691 return true;
692 return false;
693 case AMI305_OFFSET_X:
694 case AMI305_OFFSET_X + 1:
695 case AMI305_OFFSET_Y:
696 case AMI305_OFFSET_Y + 1:
697 case AMI305_OFFSET_Z:
698 case AMI305_OFFSET_Z + 1:
699 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 ||
700 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
701 case AMI306_CTRL4:
702 case AMI306_CTRL4 + 1:
703 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
704 default:
705 return false;
706 }
707 }
708
ak8974_precious_reg(struct device * dev,unsigned int reg)709 static bool ak8974_precious_reg(struct device *dev, unsigned int reg)
710 {
711 return reg == AK8974_INT_CLEAR;
712 }
713
714 static const struct regmap_config ak8974_regmap_config = {
715 .reg_bits = 8,
716 .val_bits = 8,
717 .max_register = 0xff,
718 .writeable_reg = ak8974_writeable_reg,
719 .precious_reg = ak8974_precious_reg,
720 };
721
ak8974_probe(struct i2c_client * i2c,const struct i2c_device_id * id)722 static int ak8974_probe(struct i2c_client *i2c,
723 const struct i2c_device_id *id)
724 {
725 struct iio_dev *indio_dev;
726 struct ak8974 *ak8974;
727 unsigned long irq_trig;
728 int irq = i2c->irq;
729 int ret;
730
731 /* Register with IIO */
732 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974));
733 if (indio_dev == NULL)
734 return -ENOMEM;
735
736 ak8974 = iio_priv(indio_dev);
737 i2c_set_clientdata(i2c, indio_dev);
738 ak8974->i2c = i2c;
739 mutex_init(&ak8974->lock);
740
741 ret = iio_read_mount_matrix(&i2c->dev, "mount-matrix",
742 &ak8974->orientation);
743 if (ret)
744 return ret;
745
746 ak8974->regs[0].supply = ak8974_reg_avdd;
747 ak8974->regs[1].supply = ak8974_reg_dvdd;
748
749 ret = devm_regulator_bulk_get(&i2c->dev,
750 ARRAY_SIZE(ak8974->regs),
751 ak8974->regs);
752 if (ret < 0) {
753 dev_err(&i2c->dev, "cannot get regulators\n");
754 return ret;
755 }
756
757 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
758 if (ret < 0) {
759 dev_err(&i2c->dev, "cannot enable regulators\n");
760 return ret;
761 }
762
763 /* Take runtime PM online */
764 pm_runtime_get_noresume(&i2c->dev);
765 pm_runtime_set_active(&i2c->dev);
766 pm_runtime_enable(&i2c->dev);
767
768 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config);
769 if (IS_ERR(ak8974->map)) {
770 dev_err(&i2c->dev, "failed to allocate register map\n");
771 pm_runtime_put_noidle(&i2c->dev);
772 pm_runtime_disable(&i2c->dev);
773 return PTR_ERR(ak8974->map);
774 }
775
776 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
777 if (ret) {
778 dev_err(&i2c->dev, "could not power on\n");
779 goto disable_pm;
780 }
781
782 ret = ak8974_detect(ak8974);
783 if (ret) {
784 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n");
785 goto disable_pm;
786 }
787
788 ret = ak8974_selftest(ak8974);
789 if (ret)
790 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n");
791
792 ret = ak8974_reset(ak8974);
793 if (ret) {
794 dev_err(&i2c->dev, "AK8974 reset failed\n");
795 goto disable_pm;
796 }
797
798 indio_dev->dev.parent = &i2c->dev;
799 indio_dev->channels = ak8974_channels;
800 indio_dev->num_channels = ARRAY_SIZE(ak8974_channels);
801 indio_dev->info = &ak8974_info;
802 indio_dev->available_scan_masks = ak8974_scan_masks;
803 indio_dev->modes = INDIO_DIRECT_MODE;
804 indio_dev->name = ak8974->name;
805
806 ret = iio_triggered_buffer_setup(indio_dev, NULL,
807 ak8974_handle_trigger,
808 NULL);
809 if (ret) {
810 dev_err(&i2c->dev, "triggered buffer setup failed\n");
811 goto disable_pm;
812 }
813
814 /* If we have a valid DRDY IRQ, make use of it */
815 if (irq > 0) {
816 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
817 if (irq_trig == IRQF_TRIGGER_RISING) {
818 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n");
819 } else if (irq_trig == IRQF_TRIGGER_FALLING) {
820 ak8974->drdy_active_low = true;
821 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n");
822 } else {
823 irq_trig = IRQF_TRIGGER_RISING;
824 }
825 irq_trig |= IRQF_ONESHOT;
826 irq_trig |= IRQF_SHARED;
827
828 ret = devm_request_threaded_irq(&i2c->dev,
829 irq,
830 ak8974_drdy_irq,
831 ak8974_drdy_irq_thread,
832 irq_trig,
833 ak8974->name,
834 ak8974);
835 if (ret) {
836 dev_err(&i2c->dev, "unable to request DRDY IRQ "
837 "- proceeding without IRQ\n");
838 goto no_irq;
839 }
840 ak8974->drdy_irq = true;
841 }
842
843 no_irq:
844 ret = iio_device_register(indio_dev);
845 if (ret) {
846 dev_err(&i2c->dev, "device register failed\n");
847 goto cleanup_buffer;
848 }
849
850 pm_runtime_set_autosuspend_delay(&i2c->dev,
851 AK8974_AUTOSUSPEND_DELAY);
852 pm_runtime_use_autosuspend(&i2c->dev);
853 pm_runtime_put(&i2c->dev);
854
855 return 0;
856
857 cleanup_buffer:
858 iio_triggered_buffer_cleanup(indio_dev);
859 disable_pm:
860 pm_runtime_put_noidle(&i2c->dev);
861 pm_runtime_disable(&i2c->dev);
862 ak8974_set_power(ak8974, AK8974_PWR_OFF);
863 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
864
865 return ret;
866 }
867
ak8974_remove(struct i2c_client * i2c)868 static int ak8974_remove(struct i2c_client *i2c)
869 {
870 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
871 struct ak8974 *ak8974 = iio_priv(indio_dev);
872
873 iio_device_unregister(indio_dev);
874 iio_triggered_buffer_cleanup(indio_dev);
875 pm_runtime_get_sync(&i2c->dev);
876 pm_runtime_put_noidle(&i2c->dev);
877 pm_runtime_disable(&i2c->dev);
878 ak8974_set_power(ak8974, AK8974_PWR_OFF);
879 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
880
881 return 0;
882 }
883
ak8974_runtime_suspend(struct device * dev)884 static int __maybe_unused ak8974_runtime_suspend(struct device *dev)
885 {
886 struct ak8974 *ak8974 =
887 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
888
889 ak8974_set_power(ak8974, AK8974_PWR_OFF);
890 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
891
892 return 0;
893 }
894
ak8974_runtime_resume(struct device * dev)895 static int __maybe_unused ak8974_runtime_resume(struct device *dev)
896 {
897 struct ak8974 *ak8974 =
898 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
899 int ret;
900
901 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
902 if (ret)
903 return ret;
904 msleep(AK8974_POWERON_DELAY);
905 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
906 if (ret)
907 goto out_regulator_disable;
908
909 ret = ak8974_configure(ak8974);
910 if (ret)
911 goto out_disable_power;
912
913 return 0;
914
915 out_disable_power:
916 ak8974_set_power(ak8974, AK8974_PWR_OFF);
917 out_regulator_disable:
918 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
919
920 return ret;
921 }
922
923 static const struct dev_pm_ops ak8974_dev_pm_ops = {
924 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
925 pm_runtime_force_resume)
926 SET_RUNTIME_PM_OPS(ak8974_runtime_suspend,
927 ak8974_runtime_resume, NULL)
928 };
929
930 static const struct i2c_device_id ak8974_id[] = {
931 {"ami305", 0 },
932 {"ami306", 0 },
933 {"ak8974", 0 },
934 {}
935 };
936 MODULE_DEVICE_TABLE(i2c, ak8974_id);
937
938 static const struct of_device_id ak8974_of_match[] = {
939 { .compatible = "asahi-kasei,ak8974", },
940 {}
941 };
942 MODULE_DEVICE_TABLE(of, ak8974_of_match);
943
944 static struct i2c_driver ak8974_driver = {
945 .driver = {
946 .name = "ak8974",
947 .pm = &ak8974_dev_pm_ops,
948 .of_match_table = of_match_ptr(ak8974_of_match),
949 },
950 .probe = ak8974_probe,
951 .remove = ak8974_remove,
952 .id_table = ak8974_id,
953 };
954 module_i2c_driver(ak8974_driver);
955
956 MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver");
957 MODULE_AUTHOR("Samu Onkalo");
958 MODULE_AUTHOR("Linus Walleij");
959 MODULE_LICENSE("GPL v2");
960