1 /*
2 * Driver for the Asahi Kasei EMD Corporation AK8974
3 * and Aichi Steel AMI305 magnetometer chips.
4 * Based on a patch from Samu Onkalo and the AK8975 IIO driver.
5 *
6 * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
7 * Copyright (c) 2010 NVIDIA Corporation.
8 * Copyright (C) 2016 Linaro Ltd.
9 *
10 * Author: Samu Onkalo <samu.p.onkalo@nokia.com>
11 * Author: Linus Walleij <linus.walleij@linaro.org>
12 */
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/i2c.h>
16 #include <linux/interrupt.h>
17 #include <linux/irq.h> /* For irq_get_irq_data() */
18 #include <linux/completion.h>
19 #include <linux/err.h>
20 #include <linux/mutex.h>
21 #include <linux/delay.h>
22 #include <linux/bitops.h>
23 #include <linux/random.h>
24 #include <linux/regmap.h>
25 #include <linux/regulator/consumer.h>
26 #include <linux/pm_runtime.h>
27
28 #include <linux/iio/iio.h>
29 #include <linux/iio/sysfs.h>
30 #include <linux/iio/buffer.h>
31 #include <linux/iio/trigger.h>
32 #include <linux/iio/trigger_consumer.h>
33 #include <linux/iio/triggered_buffer.h>
34
35 /*
36 * 16-bit registers are little-endian. LSB is at the address defined below
37 * and MSB is at the next higher address.
38 */
39
40 /* These registers are common for AK8974 and AMI30x */
41 #define AK8974_SELFTEST 0x0C
42 #define AK8974_SELFTEST_IDLE 0x55
43 #define AK8974_SELFTEST_OK 0xAA
44
45 #define AK8974_INFO 0x0D
46
47 #define AK8974_WHOAMI 0x0F
48 #define AK8974_WHOAMI_VALUE_AMI306 0x46
49 #define AK8974_WHOAMI_VALUE_AMI305 0x47
50 #define AK8974_WHOAMI_VALUE_AK8974 0x48
51
52 #define AK8974_DATA_X 0x10
53 #define AK8974_DATA_Y 0x12
54 #define AK8974_DATA_Z 0x14
55 #define AK8974_INT_SRC 0x16
56 #define AK8974_STATUS 0x18
57 #define AK8974_INT_CLEAR 0x1A
58 #define AK8974_CTRL1 0x1B
59 #define AK8974_CTRL2 0x1C
60 #define AK8974_CTRL3 0x1D
61 #define AK8974_INT_CTRL 0x1E
62 #define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */
63 #define AK8974_PRESET 0x30
64
65 /* AK8974-specific offsets */
66 #define AK8974_OFFSET_X 0x20
67 #define AK8974_OFFSET_Y 0x22
68 #define AK8974_OFFSET_Z 0x24
69 /* AMI305-specific offsets */
70 #define AMI305_OFFSET_X 0x6C
71 #define AMI305_OFFSET_Y 0x72
72 #define AMI305_OFFSET_Z 0x78
73
74 /* Different temperature registers */
75 #define AK8974_TEMP 0x31
76 #define AMI305_TEMP 0x60
77
78 /* AMI306-specific control register */
79 #define AMI306_CTRL4 0x5C
80
81 /* AMI306 factory calibration data */
82
83 /* fine axis sensitivity */
84 #define AMI306_FINEOUTPUT_X 0x90
85 #define AMI306_FINEOUTPUT_Y 0x92
86 #define AMI306_FINEOUTPUT_Z 0x94
87
88 /* axis sensitivity */
89 #define AMI306_SENS_X 0x96
90 #define AMI306_SENS_Y 0x98
91 #define AMI306_SENS_Z 0x9A
92
93 /* axis cross-interference */
94 #define AMI306_GAIN_PARA_XZ 0x9C
95 #define AMI306_GAIN_PARA_XY 0x9D
96 #define AMI306_GAIN_PARA_YZ 0x9E
97 #define AMI306_GAIN_PARA_YX 0x9F
98 #define AMI306_GAIN_PARA_ZY 0xA0
99 #define AMI306_GAIN_PARA_ZX 0xA1
100
101 /* offset at ZERO magnetic field */
102 #define AMI306_OFFZERO_X 0xF8
103 #define AMI306_OFFZERO_Y 0xFA
104 #define AMI306_OFFZERO_Z 0xFC
105
106
107 #define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */
108 #define AK8974_INT_Y_HIGH BIT(6)
109 #define AK8974_INT_Z_HIGH BIT(5)
110 #define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */
111 #define AK8974_INT_Y_LOW BIT(3)
112 #define AK8974_INT_Z_LOW BIT(2)
113 #define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */
114
115 #define AK8974_STATUS_DRDY BIT(6) /* Data ready */
116 #define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */
117 #define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */
118
119 #define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */
120 #define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */
121 #define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */
122 #define AK8974_CTRL1_MODE2 BIT(0) /* 0 */
123
124 #define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */
125 #define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */
126 #define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */
127 #define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL)
128
129 #define AK8974_CTRL3_RESET BIT(7) /* Software reset */
130 #define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */
131 #define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */
132 #define AK8974_CTRL3_RESDEF 0x00
133
134 #define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */
135 #define AK8974_INT_CTRL_YEN BIT(6)
136 #define AK8974_INT_CTRL_ZEN BIT(5)
137 #define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5))
138 #define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */
139 #define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
140 #define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
141
142 /* The AMI305 has elaborate FW version and serial number registers */
143 #define AMI305_VER 0xE8
144 #define AMI305_SN 0xEA
145
146 #define AK8974_MAX_RANGE 2048
147
148 #define AK8974_POWERON_DELAY 50
149 #define AK8974_ACTIVATE_DELAY 1
150 #define AK8974_SELFTEST_DELAY 1
151 /*
152 * Set the autosuspend to two orders of magnitude larger than the poweron
153 * delay to make sane reasonable power tradeoff savings (5 seconds in
154 * this case).
155 */
156 #define AK8974_AUTOSUSPEND_DELAY 5000
157
158 #define AK8974_MEASTIME 3
159
160 #define AK8974_PWR_ON 1
161 #define AK8974_PWR_OFF 0
162
163 /**
164 * struct ak8974 - state container for the AK8974 driver
165 * @i2c: parent I2C client
166 * @orientation: mounting matrix, flipped axis etc
167 * @map: regmap to access the AK8974 registers over I2C
168 * @regs: the avdd and dvdd power regulators
169 * @name: the name of the part
170 * @variant: the whoami ID value (for selecting code paths)
171 * @lock: locks the magnetometer for exclusive use during a measurement
172 * @drdy_irq: uses the DRDY IRQ line
173 * @drdy_complete: completion for DRDY
174 * @drdy_active_low: the DRDY IRQ is active low
175 */
176 struct ak8974 {
177 struct i2c_client *i2c;
178 struct iio_mount_matrix orientation;
179 struct regmap *map;
180 struct regulator_bulk_data regs[2];
181 const char *name;
182 u8 variant;
183 struct mutex lock;
184 bool drdy_irq;
185 struct completion drdy_complete;
186 bool drdy_active_low;
187 };
188
189 static const char ak8974_reg_avdd[] = "avdd";
190 static const char ak8974_reg_dvdd[] = "dvdd";
191
ak8974_get_u16_val(struct ak8974 * ak8974,u8 reg,u16 * val)192 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val)
193 {
194 int ret;
195 __le16 bulk;
196
197 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2);
198 if (ret)
199 return ret;
200 *val = le16_to_cpu(bulk);
201
202 return 0;
203 }
204
ak8974_set_u16_val(struct ak8974 * ak8974,u8 reg,u16 val)205 static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val)
206 {
207 __le16 bulk = cpu_to_le16(val);
208
209 return regmap_bulk_write(ak8974->map, reg, &bulk, 2);
210 }
211
ak8974_set_power(struct ak8974 * ak8974,bool mode)212 static int ak8974_set_power(struct ak8974 *ak8974, bool mode)
213 {
214 int ret;
215 u8 val;
216
217 val = mode ? AK8974_CTRL1_POWER : 0;
218 val |= AK8974_CTRL1_FORCE_EN;
219 ret = regmap_write(ak8974->map, AK8974_CTRL1, val);
220 if (ret < 0)
221 return ret;
222
223 if (mode)
224 msleep(AK8974_ACTIVATE_DELAY);
225
226 return 0;
227 }
228
ak8974_reset(struct ak8974 * ak8974)229 static int ak8974_reset(struct ak8974 *ak8974)
230 {
231 int ret;
232
233 /* Power on to get register access. Sets CTRL1 reg to reset state */
234 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
235 if (ret)
236 return ret;
237 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF);
238 if (ret)
239 return ret;
240 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
241 if (ret)
242 return ret;
243 ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
244 AK8974_INT_CTRL_RESDEF);
245 if (ret)
246 return ret;
247
248 /* After reset, power off is default state */
249 return ak8974_set_power(ak8974, AK8974_PWR_OFF);
250 }
251
ak8974_configure(struct ak8974 * ak8974)252 static int ak8974_configure(struct ak8974 *ak8974)
253 {
254 int ret;
255
256 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN |
257 AK8974_CTRL2_INT_EN);
258 if (ret)
259 return ret;
260 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0);
261 if (ret)
262 return ret;
263 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) {
264 /* magic from datasheet: set high-speed measurement mode */
265 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E);
266 if (ret)
267 return ret;
268 }
269 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
270 if (ret)
271 return ret;
272
273 return regmap_write(ak8974->map, AK8974_PRESET, 0);
274 }
275
ak8974_trigmeas(struct ak8974 * ak8974)276 static int ak8974_trigmeas(struct ak8974 *ak8974)
277 {
278 unsigned int clear;
279 u8 mask;
280 u8 val;
281 int ret;
282
283 /* Clear any previous measurement overflow status */
284 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear);
285 if (ret)
286 return ret;
287
288 /* If we have a DRDY IRQ line, use it */
289 if (ak8974->drdy_irq) {
290 mask = AK8974_CTRL2_INT_EN |
291 AK8974_CTRL2_DRDY_EN |
292 AK8974_CTRL2_DRDY_POL;
293 val = AK8974_CTRL2_DRDY_EN;
294
295 if (!ak8974->drdy_active_low)
296 val |= AK8974_CTRL2_DRDY_POL;
297
298 init_completion(&ak8974->drdy_complete);
299 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2,
300 mask, val);
301 if (ret)
302 return ret;
303 }
304
305 /* Force a measurement */
306 return regmap_update_bits(ak8974->map,
307 AK8974_CTRL3,
308 AK8974_CTRL3_FORCE,
309 AK8974_CTRL3_FORCE);
310 }
311
ak8974_await_drdy(struct ak8974 * ak8974)312 static int ak8974_await_drdy(struct ak8974 *ak8974)
313 {
314 int timeout = 2;
315 unsigned int val;
316 int ret;
317
318 if (ak8974->drdy_irq) {
319 ret = wait_for_completion_timeout(&ak8974->drdy_complete,
320 1 + msecs_to_jiffies(1000));
321 if (!ret) {
322 dev_err(&ak8974->i2c->dev,
323 "timeout waiting for DRDY IRQ\n");
324 return -ETIMEDOUT;
325 }
326 return 0;
327 }
328
329 /* Default delay-based poll loop */
330 do {
331 msleep(AK8974_MEASTIME);
332 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
333 if (ret < 0)
334 return ret;
335 if (val & AK8974_STATUS_DRDY)
336 return 0;
337 } while (--timeout);
338
339 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n");
340 return -ETIMEDOUT;
341 }
342
ak8974_getresult(struct ak8974 * ak8974,__le16 * result)343 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result)
344 {
345 unsigned int src;
346 int ret;
347
348 ret = ak8974_await_drdy(ak8974);
349 if (ret)
350 return ret;
351 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src);
352 if (ret < 0)
353 return ret;
354
355 /* Out of range overflow! Strong magnet close? */
356 if (src & AK8974_INT_RANGE) {
357 dev_err(&ak8974->i2c->dev,
358 "range overflow in sensor\n");
359 return -ERANGE;
360 }
361
362 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6);
363 if (ret)
364 return ret;
365
366 return ret;
367 }
368
ak8974_drdy_irq(int irq,void * d)369 static irqreturn_t ak8974_drdy_irq(int irq, void *d)
370 {
371 struct ak8974 *ak8974 = d;
372
373 if (!ak8974->drdy_irq)
374 return IRQ_NONE;
375
376 /* TODO: timestamp here to get good measurement stamps */
377 return IRQ_WAKE_THREAD;
378 }
379
ak8974_drdy_irq_thread(int irq,void * d)380 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d)
381 {
382 struct ak8974 *ak8974 = d;
383 unsigned int val;
384 int ret;
385
386 /* Check if this was a DRDY from us */
387 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
388 if (ret < 0) {
389 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n");
390 return IRQ_HANDLED;
391 }
392 if (val & AK8974_STATUS_DRDY) {
393 /* Yes this was our IRQ */
394 complete(&ak8974->drdy_complete);
395 return IRQ_HANDLED;
396 }
397
398 /* We may be on a shared IRQ, let the next client check */
399 return IRQ_NONE;
400 }
401
ak8974_selftest(struct ak8974 * ak8974)402 static int ak8974_selftest(struct ak8974 *ak8974)
403 {
404 struct device *dev = &ak8974->i2c->dev;
405 unsigned int val;
406 int ret;
407
408 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
409 if (ret)
410 return ret;
411 if (val != AK8974_SELFTEST_IDLE) {
412 dev_err(dev, "selftest not idle before test\n");
413 return -EIO;
414 }
415
416 /* Trigger self-test */
417 ret = regmap_update_bits(ak8974->map,
418 AK8974_CTRL3,
419 AK8974_CTRL3_SELFTEST,
420 AK8974_CTRL3_SELFTEST);
421 if (ret) {
422 dev_err(dev, "could not write CTRL3\n");
423 return ret;
424 }
425
426 msleep(AK8974_SELFTEST_DELAY);
427
428 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
429 if (ret)
430 return ret;
431 if (val != AK8974_SELFTEST_OK) {
432 dev_err(dev, "selftest result NOT OK (%02x)\n", val);
433 return -EIO;
434 }
435
436 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
437 if (ret)
438 return ret;
439 if (val != AK8974_SELFTEST_IDLE) {
440 dev_err(dev, "selftest not idle after test (%02x)\n", val);
441 return -EIO;
442 }
443 dev_dbg(dev, "passed self-test\n");
444
445 return 0;
446 }
447
ak8974_read_calib_data(struct ak8974 * ak8974,unsigned int reg,__le16 * tab,size_t tab_size)448 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg,
449 __le16 *tab, size_t tab_size)
450 {
451 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size);
452 if (ret) {
453 memset(tab, 0xFF, tab_size);
454 dev_warn(&ak8974->i2c->dev,
455 "can't read calibration data (regs %u..%zu): %d\n",
456 reg, reg + tab_size - 1, ret);
457 } else {
458 add_device_randomness(tab, tab_size);
459 }
460 }
461
ak8974_detect(struct ak8974 * ak8974)462 static int ak8974_detect(struct ak8974 *ak8974)
463 {
464 unsigned int whoami;
465 const char *name;
466 int ret;
467 unsigned int fw;
468 u16 sn;
469
470 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami);
471 if (ret)
472 return ret;
473
474 name = "ami305";
475
476 switch (whoami) {
477 case AK8974_WHOAMI_VALUE_AMI306:
478 name = "ami306";
479 /* fall-through */
480 case AK8974_WHOAMI_VALUE_AMI305:
481 ret = regmap_read(ak8974->map, AMI305_VER, &fw);
482 if (ret)
483 return ret;
484 fw &= 0x7f; /* only bits 0 thru 6 valid */
485 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn);
486 if (ret)
487 return ret;
488 add_device_randomness(&sn, sizeof(sn));
489 dev_info(&ak8974->i2c->dev,
490 "detected %s, FW ver %02x, S/N: %04x\n",
491 name, fw, sn);
492 break;
493 case AK8974_WHOAMI_VALUE_AK8974:
494 name = "ak8974";
495 dev_info(&ak8974->i2c->dev, "detected AK8974\n");
496 break;
497 default:
498 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
499 whoami);
500 return -ENODEV;
501 }
502
503 ak8974->name = name;
504 ak8974->variant = whoami;
505
506 if (whoami == AK8974_WHOAMI_VALUE_AMI306) {
507 __le16 fab_data1[9], fab_data2[3];
508 int i;
509
510 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X,
511 fab_data1, sizeof(fab_data1));
512 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X,
513 fab_data2, sizeof(fab_data2));
514
515 for (i = 0; i < 3; ++i) {
516 static const char axis[3] = "XYZ";
517 static const char pgaxis[6] = "ZYZXYX";
518 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F;
519 unsigned fine = le16_to_cpu(fab_data1[i]);
520 unsigned sens = le16_to_cpu(fab_data1[i + 3]);
521 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]);
522 unsigned pgain2 = pgain1 >> 8;
523
524 pgain1 &= 0xFF;
525
526 dev_info(&ak8974->i2c->dev,
527 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n",
528 axis[i], offz, sens, fine, pgaxis[i * 2],
529 pgain1, pgaxis[i * 2 + 1], pgain2);
530 }
531 }
532
533 return 0;
534 }
535
ak8974_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)536 static int ak8974_read_raw(struct iio_dev *indio_dev,
537 struct iio_chan_spec const *chan,
538 int *val, int *val2,
539 long mask)
540 {
541 struct ak8974 *ak8974 = iio_priv(indio_dev);
542 __le16 hw_values[3];
543 int ret = -EINVAL;
544
545 pm_runtime_get_sync(&ak8974->i2c->dev);
546 mutex_lock(&ak8974->lock);
547
548 switch (mask) {
549 case IIO_CHAN_INFO_RAW:
550 if (chan->address > 2) {
551 dev_err(&ak8974->i2c->dev, "faulty channel address\n");
552 ret = -EIO;
553 goto out_unlock;
554 }
555 ret = ak8974_trigmeas(ak8974);
556 if (ret)
557 goto out_unlock;
558 ret = ak8974_getresult(ak8974, hw_values);
559 if (ret)
560 goto out_unlock;
561
562 /*
563 * We read all axes and discard all but one, for optimized
564 * reading, use the triggered buffer.
565 */
566 *val = le16_to_cpu(hw_values[chan->address]);
567
568 ret = IIO_VAL_INT;
569 }
570
571 out_unlock:
572 mutex_unlock(&ak8974->lock);
573 pm_runtime_mark_last_busy(&ak8974->i2c->dev);
574 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
575
576 return ret;
577 }
578
ak8974_fill_buffer(struct iio_dev * indio_dev)579 static void ak8974_fill_buffer(struct iio_dev *indio_dev)
580 {
581 struct ak8974 *ak8974 = iio_priv(indio_dev);
582 int ret;
583 __le16 hw_values[8]; /* Three axes + 64bit padding */
584
585 pm_runtime_get_sync(&ak8974->i2c->dev);
586 mutex_lock(&ak8974->lock);
587
588 ret = ak8974_trigmeas(ak8974);
589 if (ret) {
590 dev_err(&ak8974->i2c->dev, "error triggering measure\n");
591 goto out_unlock;
592 }
593 ret = ak8974_getresult(ak8974, hw_values);
594 if (ret) {
595 dev_err(&ak8974->i2c->dev, "error getting measures\n");
596 goto out_unlock;
597 }
598
599 iio_push_to_buffers_with_timestamp(indio_dev, hw_values,
600 iio_get_time_ns(indio_dev));
601
602 out_unlock:
603 mutex_unlock(&ak8974->lock);
604 pm_runtime_mark_last_busy(&ak8974->i2c->dev);
605 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
606 }
607
ak8974_handle_trigger(int irq,void * p)608 static irqreturn_t ak8974_handle_trigger(int irq, void *p)
609 {
610 const struct iio_poll_func *pf = p;
611 struct iio_dev *indio_dev = pf->indio_dev;
612
613 ak8974_fill_buffer(indio_dev);
614 iio_trigger_notify_done(indio_dev->trig);
615
616 return IRQ_HANDLED;
617 }
618
619 static const struct iio_mount_matrix *
ak8974_get_mount_matrix(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)620 ak8974_get_mount_matrix(const struct iio_dev *indio_dev,
621 const struct iio_chan_spec *chan)
622 {
623 struct ak8974 *ak8974 = iio_priv(indio_dev);
624
625 return &ak8974->orientation;
626 }
627
628 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = {
629 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix),
630 { },
631 };
632
633 #define AK8974_AXIS_CHANNEL(axis, index) \
634 { \
635 .type = IIO_MAGN, \
636 .modified = 1, \
637 .channel2 = IIO_MOD_##axis, \
638 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
639 .ext_info = ak8974_ext_info, \
640 .address = index, \
641 .scan_index = index, \
642 .scan_type = { \
643 .sign = 's', \
644 .realbits = 16, \
645 .storagebits = 16, \
646 .endianness = IIO_LE \
647 }, \
648 }
649
650 static const struct iio_chan_spec ak8974_channels[] = {
651 AK8974_AXIS_CHANNEL(X, 0),
652 AK8974_AXIS_CHANNEL(Y, 1),
653 AK8974_AXIS_CHANNEL(Z, 2),
654 IIO_CHAN_SOFT_TIMESTAMP(3),
655 };
656
657 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
658
659 static const struct iio_info ak8974_info = {
660 .read_raw = &ak8974_read_raw,
661 };
662
ak8974_writeable_reg(struct device * dev,unsigned int reg)663 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
664 {
665 struct i2c_client *i2c = to_i2c_client(dev);
666 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
667 struct ak8974 *ak8974 = iio_priv(indio_dev);
668
669 switch (reg) {
670 case AK8974_CTRL1:
671 case AK8974_CTRL2:
672 case AK8974_CTRL3:
673 case AK8974_INT_CTRL:
674 case AK8974_INT_THRES:
675 case AK8974_INT_THRES + 1:
676 case AK8974_PRESET:
677 case AK8974_PRESET + 1:
678 return true;
679 case AK8974_OFFSET_X:
680 case AK8974_OFFSET_X + 1:
681 case AK8974_OFFSET_Y:
682 case AK8974_OFFSET_Y + 1:
683 case AK8974_OFFSET_Z:
684 case AK8974_OFFSET_Z + 1:
685 if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974)
686 return true;
687 return false;
688 case AMI305_OFFSET_X:
689 case AMI305_OFFSET_X + 1:
690 case AMI305_OFFSET_Y:
691 case AMI305_OFFSET_Y + 1:
692 case AMI305_OFFSET_Z:
693 case AMI305_OFFSET_Z + 1:
694 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 ||
695 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
696 case AMI306_CTRL4:
697 case AMI306_CTRL4 + 1:
698 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
699 default:
700 return false;
701 }
702 }
703
ak8974_precious_reg(struct device * dev,unsigned int reg)704 static bool ak8974_precious_reg(struct device *dev, unsigned int reg)
705 {
706 return reg == AK8974_INT_CLEAR;
707 }
708
709 static const struct regmap_config ak8974_regmap_config = {
710 .reg_bits = 8,
711 .val_bits = 8,
712 .max_register = 0xff,
713 .writeable_reg = ak8974_writeable_reg,
714 .precious_reg = ak8974_precious_reg,
715 };
716
ak8974_probe(struct i2c_client * i2c,const struct i2c_device_id * id)717 static int ak8974_probe(struct i2c_client *i2c,
718 const struct i2c_device_id *id)
719 {
720 struct iio_dev *indio_dev;
721 struct ak8974 *ak8974;
722 unsigned long irq_trig;
723 int irq = i2c->irq;
724 int ret;
725
726 /* Register with IIO */
727 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974));
728 if (indio_dev == NULL)
729 return -ENOMEM;
730
731 ak8974 = iio_priv(indio_dev);
732 i2c_set_clientdata(i2c, indio_dev);
733 ak8974->i2c = i2c;
734 mutex_init(&ak8974->lock);
735
736 ret = of_iio_read_mount_matrix(&i2c->dev,
737 "mount-matrix",
738 &ak8974->orientation);
739 if (ret)
740 return ret;
741
742 ak8974->regs[0].supply = ak8974_reg_avdd;
743 ak8974->regs[1].supply = ak8974_reg_dvdd;
744
745 ret = devm_regulator_bulk_get(&i2c->dev,
746 ARRAY_SIZE(ak8974->regs),
747 ak8974->regs);
748 if (ret < 0) {
749 dev_err(&i2c->dev, "cannot get regulators\n");
750 return ret;
751 }
752
753 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
754 if (ret < 0) {
755 dev_err(&i2c->dev, "cannot enable regulators\n");
756 return ret;
757 }
758
759 /* Take runtime PM online */
760 pm_runtime_get_noresume(&i2c->dev);
761 pm_runtime_set_active(&i2c->dev);
762 pm_runtime_enable(&i2c->dev);
763
764 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config);
765 if (IS_ERR(ak8974->map)) {
766 dev_err(&i2c->dev, "failed to allocate register map\n");
767 return PTR_ERR(ak8974->map);
768 }
769
770 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
771 if (ret) {
772 dev_err(&i2c->dev, "could not power on\n");
773 goto power_off;
774 }
775
776 ret = ak8974_detect(ak8974);
777 if (ret) {
778 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n");
779 goto power_off;
780 }
781
782 ret = ak8974_selftest(ak8974);
783 if (ret)
784 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n");
785
786 ret = ak8974_reset(ak8974);
787 if (ret) {
788 dev_err(&i2c->dev, "AK8974 reset failed\n");
789 goto power_off;
790 }
791
792 pm_runtime_set_autosuspend_delay(&i2c->dev,
793 AK8974_AUTOSUSPEND_DELAY);
794 pm_runtime_use_autosuspend(&i2c->dev);
795 pm_runtime_put(&i2c->dev);
796
797 indio_dev->dev.parent = &i2c->dev;
798 indio_dev->channels = ak8974_channels;
799 indio_dev->num_channels = ARRAY_SIZE(ak8974_channels);
800 indio_dev->info = &ak8974_info;
801 indio_dev->available_scan_masks = ak8974_scan_masks;
802 indio_dev->modes = INDIO_DIRECT_MODE;
803 indio_dev->name = ak8974->name;
804
805 ret = iio_triggered_buffer_setup(indio_dev, NULL,
806 ak8974_handle_trigger,
807 NULL);
808 if (ret) {
809 dev_err(&i2c->dev, "triggered buffer setup failed\n");
810 goto disable_pm;
811 }
812
813 /* If we have a valid DRDY IRQ, make use of it */
814 if (irq > 0) {
815 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
816 if (irq_trig == IRQF_TRIGGER_RISING) {
817 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n");
818 } else if (irq_trig == IRQF_TRIGGER_FALLING) {
819 ak8974->drdy_active_low = true;
820 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n");
821 } else {
822 irq_trig = IRQF_TRIGGER_RISING;
823 }
824 irq_trig |= IRQF_ONESHOT;
825 irq_trig |= IRQF_SHARED;
826
827 ret = devm_request_threaded_irq(&i2c->dev,
828 irq,
829 ak8974_drdy_irq,
830 ak8974_drdy_irq_thread,
831 irq_trig,
832 ak8974->name,
833 ak8974);
834 if (ret) {
835 dev_err(&i2c->dev, "unable to request DRDY IRQ "
836 "- proceeding without IRQ\n");
837 goto no_irq;
838 }
839 ak8974->drdy_irq = true;
840 }
841
842 no_irq:
843 ret = iio_device_register(indio_dev);
844 if (ret) {
845 dev_err(&i2c->dev, "device register failed\n");
846 goto cleanup_buffer;
847 }
848
849 return 0;
850
851 cleanup_buffer:
852 iio_triggered_buffer_cleanup(indio_dev);
853 disable_pm:
854 pm_runtime_put_noidle(&i2c->dev);
855 pm_runtime_disable(&i2c->dev);
856 ak8974_set_power(ak8974, AK8974_PWR_OFF);
857 power_off:
858 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
859
860 return ret;
861 }
862
ak8974_remove(struct i2c_client * i2c)863 static int ak8974_remove(struct i2c_client *i2c)
864 {
865 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
866 struct ak8974 *ak8974 = iio_priv(indio_dev);
867
868 iio_device_unregister(indio_dev);
869 iio_triggered_buffer_cleanup(indio_dev);
870 pm_runtime_get_sync(&i2c->dev);
871 pm_runtime_put_noidle(&i2c->dev);
872 pm_runtime_disable(&i2c->dev);
873 ak8974_set_power(ak8974, AK8974_PWR_OFF);
874 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
875
876 return 0;
877 }
878
ak8974_runtime_suspend(struct device * dev)879 static int __maybe_unused ak8974_runtime_suspend(struct device *dev)
880 {
881 struct ak8974 *ak8974 =
882 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
883
884 ak8974_set_power(ak8974, AK8974_PWR_OFF);
885 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
886
887 return 0;
888 }
889
ak8974_runtime_resume(struct device * dev)890 static int __maybe_unused ak8974_runtime_resume(struct device *dev)
891 {
892 struct ak8974 *ak8974 =
893 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
894 int ret;
895
896 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
897 if (ret)
898 return ret;
899 msleep(AK8974_POWERON_DELAY);
900 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
901 if (ret)
902 goto out_regulator_disable;
903
904 ret = ak8974_configure(ak8974);
905 if (ret)
906 goto out_disable_power;
907
908 return 0;
909
910 out_disable_power:
911 ak8974_set_power(ak8974, AK8974_PWR_OFF);
912 out_regulator_disable:
913 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
914
915 return ret;
916 }
917
918 static const struct dev_pm_ops ak8974_dev_pm_ops = {
919 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
920 pm_runtime_force_resume)
921 SET_RUNTIME_PM_OPS(ak8974_runtime_suspend,
922 ak8974_runtime_resume, NULL)
923 };
924
925 static const struct i2c_device_id ak8974_id[] = {
926 {"ami305", 0 },
927 {"ami306", 0 },
928 {"ak8974", 0 },
929 {}
930 };
931 MODULE_DEVICE_TABLE(i2c, ak8974_id);
932
933 static const struct of_device_id ak8974_of_match[] = {
934 { .compatible = "asahi-kasei,ak8974", },
935 {}
936 };
937 MODULE_DEVICE_TABLE(of, ak8974_of_match);
938
939 static struct i2c_driver ak8974_driver = {
940 .driver = {
941 .name = "ak8974",
942 .pm = &ak8974_dev_pm_ops,
943 .of_match_table = of_match_ptr(ak8974_of_match),
944 },
945 .probe = ak8974_probe,
946 .remove = ak8974_remove,
947 .id_table = ak8974_id,
948 };
949 module_i2c_driver(ak8974_driver);
950
951 MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver");
952 MODULE_AUTHOR("Samu Onkalo");
953 MODULE_AUTHOR("Linus Walleij");
954 MODULE_LICENSE("GPL v2");
955
