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 /* Ensure timestamp is naturally aligned */
188 struct {
189 __le16 channels[3];
190 s64 ts __aligned(8);
191 } scan;
192 };
193
194 static const char ak8974_reg_avdd[] = "avdd";
195 static const char ak8974_reg_dvdd[] = "dvdd";
196
ak8974_get_u16_val(struct ak8974 * ak8974,u8 reg,u16 * val)197 static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val)
198 {
199 int ret;
200 __le16 bulk;
201
202 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2);
203 if (ret)
204 return ret;
205 *val = le16_to_cpu(bulk);
206
207 return 0;
208 }
209
ak8974_set_u16_val(struct ak8974 * ak8974,u8 reg,u16 val)210 static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val)
211 {
212 __le16 bulk = cpu_to_le16(val);
213
214 return regmap_bulk_write(ak8974->map, reg, &bulk, 2);
215 }
216
ak8974_set_power(struct ak8974 * ak8974,bool mode)217 static int ak8974_set_power(struct ak8974 *ak8974, bool mode)
218 {
219 int ret;
220 u8 val;
221
222 val = mode ? AK8974_CTRL1_POWER : 0;
223 val |= AK8974_CTRL1_FORCE_EN;
224 ret = regmap_write(ak8974->map, AK8974_CTRL1, val);
225 if (ret < 0)
226 return ret;
227
228 if (mode)
229 msleep(AK8974_ACTIVATE_DELAY);
230
231 return 0;
232 }
233
ak8974_reset(struct ak8974 * ak8974)234 static int ak8974_reset(struct ak8974 *ak8974)
235 {
236 int ret;
237
238 /* Power on to get register access. Sets CTRL1 reg to reset state */
239 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
240 if (ret)
241 return ret;
242 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF);
243 if (ret)
244 return ret;
245 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
246 if (ret)
247 return ret;
248 ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
249 AK8974_INT_CTRL_RESDEF);
250 if (ret)
251 return ret;
252
253 /* After reset, power off is default state */
254 return ak8974_set_power(ak8974, AK8974_PWR_OFF);
255 }
256
ak8974_configure(struct ak8974 * ak8974)257 static int ak8974_configure(struct ak8974 *ak8974)
258 {
259 int ret;
260
261 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN |
262 AK8974_CTRL2_INT_EN);
263 if (ret)
264 return ret;
265 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0);
266 if (ret)
267 return ret;
268 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) {
269 /* magic from datasheet: set high-speed measurement mode */
270 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E);
271 if (ret)
272 return ret;
273 }
274 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
275 if (ret)
276 return ret;
277
278 return regmap_write(ak8974->map, AK8974_PRESET, 0);
279 }
280
ak8974_trigmeas(struct ak8974 * ak8974)281 static int ak8974_trigmeas(struct ak8974 *ak8974)
282 {
283 unsigned int clear;
284 u8 mask;
285 u8 val;
286 int ret;
287
288 /* Clear any previous measurement overflow status */
289 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear);
290 if (ret)
291 return ret;
292
293 /* If we have a DRDY IRQ line, use it */
294 if (ak8974->drdy_irq) {
295 mask = AK8974_CTRL2_INT_EN |
296 AK8974_CTRL2_DRDY_EN |
297 AK8974_CTRL2_DRDY_POL;
298 val = AK8974_CTRL2_DRDY_EN;
299
300 if (!ak8974->drdy_active_low)
301 val |= AK8974_CTRL2_DRDY_POL;
302
303 init_completion(&ak8974->drdy_complete);
304 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2,
305 mask, val);
306 if (ret)
307 return ret;
308 }
309
310 /* Force a measurement */
311 return regmap_update_bits(ak8974->map,
312 AK8974_CTRL3,
313 AK8974_CTRL3_FORCE,
314 AK8974_CTRL3_FORCE);
315 }
316
ak8974_await_drdy(struct ak8974 * ak8974)317 static int ak8974_await_drdy(struct ak8974 *ak8974)
318 {
319 int timeout = 2;
320 unsigned int val;
321 int ret;
322
323 if (ak8974->drdy_irq) {
324 ret = wait_for_completion_timeout(&ak8974->drdy_complete,
325 1 + msecs_to_jiffies(1000));
326 if (!ret) {
327 dev_err(&ak8974->i2c->dev,
328 "timeout waiting for DRDY IRQ\n");
329 return -ETIMEDOUT;
330 }
331 return 0;
332 }
333
334 /* Default delay-based poll loop */
335 do {
336 msleep(AK8974_MEASTIME);
337 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
338 if (ret < 0)
339 return ret;
340 if (val & AK8974_STATUS_DRDY)
341 return 0;
342 } while (--timeout);
343
344 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n");
345 return -ETIMEDOUT;
346 }
347
ak8974_getresult(struct ak8974 * ak8974,__le16 * result)348 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result)
349 {
350 unsigned int src;
351 int ret;
352
353 ret = ak8974_await_drdy(ak8974);
354 if (ret)
355 return ret;
356 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src);
357 if (ret < 0)
358 return ret;
359
360 /* Out of range overflow! Strong magnet close? */
361 if (src & AK8974_INT_RANGE) {
362 dev_err(&ak8974->i2c->dev,
363 "range overflow in sensor\n");
364 return -ERANGE;
365 }
366
367 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6);
368 if (ret)
369 return ret;
370
371 return ret;
372 }
373
ak8974_drdy_irq(int irq,void * d)374 static irqreturn_t ak8974_drdy_irq(int irq, void *d)
375 {
376 struct ak8974 *ak8974 = d;
377
378 if (!ak8974->drdy_irq)
379 return IRQ_NONE;
380
381 /* TODO: timestamp here to get good measurement stamps */
382 return IRQ_WAKE_THREAD;
383 }
384
ak8974_drdy_irq_thread(int irq,void * d)385 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d)
386 {
387 struct ak8974 *ak8974 = d;
388 unsigned int val;
389 int ret;
390
391 /* Check if this was a DRDY from us */
392 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
393 if (ret < 0) {
394 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n");
395 return IRQ_HANDLED;
396 }
397 if (val & AK8974_STATUS_DRDY) {
398 /* Yes this was our IRQ */
399 complete(&ak8974->drdy_complete);
400 return IRQ_HANDLED;
401 }
402
403 /* We may be on a shared IRQ, let the next client check */
404 return IRQ_NONE;
405 }
406
ak8974_selftest(struct ak8974 * ak8974)407 static int ak8974_selftest(struct ak8974 *ak8974)
408 {
409 struct device *dev = &ak8974->i2c->dev;
410 unsigned int val;
411 int ret;
412
413 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
414 if (ret)
415 return ret;
416 if (val != AK8974_SELFTEST_IDLE) {
417 dev_err(dev, "selftest not idle before test\n");
418 return -EIO;
419 }
420
421 /* Trigger self-test */
422 ret = regmap_update_bits(ak8974->map,
423 AK8974_CTRL3,
424 AK8974_CTRL3_SELFTEST,
425 AK8974_CTRL3_SELFTEST);
426 if (ret) {
427 dev_err(dev, "could not write CTRL3\n");
428 return ret;
429 }
430
431 msleep(AK8974_SELFTEST_DELAY);
432
433 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
434 if (ret)
435 return ret;
436 if (val != AK8974_SELFTEST_OK) {
437 dev_err(dev, "selftest result NOT OK (%02x)\n", val);
438 return -EIO;
439 }
440
441 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
442 if (ret)
443 return ret;
444 if (val != AK8974_SELFTEST_IDLE) {
445 dev_err(dev, "selftest not idle after test (%02x)\n", val);
446 return -EIO;
447 }
448 dev_dbg(dev, "passed self-test\n");
449
450 return 0;
451 }
452
ak8974_read_calib_data(struct ak8974 * ak8974,unsigned int reg,__le16 * tab,size_t tab_size)453 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg,
454 __le16 *tab, size_t tab_size)
455 {
456 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size);
457 if (ret) {
458 memset(tab, 0xFF, tab_size);
459 dev_warn(&ak8974->i2c->dev,
460 "can't read calibration data (regs %u..%zu): %d\n",
461 reg, reg + tab_size - 1, ret);
462 } else {
463 add_device_randomness(tab, tab_size);
464 }
465 }
466
ak8974_detect(struct ak8974 * ak8974)467 static int ak8974_detect(struct ak8974 *ak8974)
468 {
469 unsigned int whoami;
470 const char *name;
471 int ret;
472 unsigned int fw;
473 u16 sn;
474
475 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami);
476 if (ret)
477 return ret;
478
479 name = "ami305";
480
481 switch (whoami) {
482 case AK8974_WHOAMI_VALUE_AMI306:
483 name = "ami306";
484 /* fall-through */
485 case AK8974_WHOAMI_VALUE_AMI305:
486 ret = regmap_read(ak8974->map, AMI305_VER, &fw);
487 if (ret)
488 return ret;
489 fw &= 0x7f; /* only bits 0 thru 6 valid */
490 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn);
491 if (ret)
492 return ret;
493 add_device_randomness(&sn, sizeof(sn));
494 dev_info(&ak8974->i2c->dev,
495 "detected %s, FW ver %02x, S/N: %04x\n",
496 name, fw, sn);
497 break;
498 case AK8974_WHOAMI_VALUE_AK8974:
499 name = "ak8974";
500 dev_info(&ak8974->i2c->dev, "detected AK8974\n");
501 break;
502 default:
503 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
504 whoami);
505 return -ENODEV;
506 }
507
508 ak8974->name = name;
509 ak8974->variant = whoami;
510
511 if (whoami == AK8974_WHOAMI_VALUE_AMI306) {
512 __le16 fab_data1[9], fab_data2[3];
513 int i;
514
515 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X,
516 fab_data1, sizeof(fab_data1));
517 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X,
518 fab_data2, sizeof(fab_data2));
519
520 for (i = 0; i < 3; ++i) {
521 static const char axis[3] = "XYZ";
522 static const char pgaxis[6] = "ZYZXYX";
523 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F;
524 unsigned fine = le16_to_cpu(fab_data1[i]);
525 unsigned sens = le16_to_cpu(fab_data1[i + 3]);
526 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]);
527 unsigned pgain2 = pgain1 >> 8;
528
529 pgain1 &= 0xFF;
530
531 dev_info(&ak8974->i2c->dev,
532 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n",
533 axis[i], offz, sens, fine, pgaxis[i * 2],
534 pgain1, pgaxis[i * 2 + 1], pgain2);
535 }
536 }
537
538 return 0;
539 }
540
ak8974_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)541 static int ak8974_read_raw(struct iio_dev *indio_dev,
542 struct iio_chan_spec const *chan,
543 int *val, int *val2,
544 long mask)
545 {
546 struct ak8974 *ak8974 = iio_priv(indio_dev);
547 __le16 hw_values[3];
548 int ret = -EINVAL;
549
550 pm_runtime_get_sync(&ak8974->i2c->dev);
551 mutex_lock(&ak8974->lock);
552
553 switch (mask) {
554 case IIO_CHAN_INFO_RAW:
555 if (chan->address > 2) {
556 dev_err(&ak8974->i2c->dev, "faulty channel address\n");
557 ret = -EIO;
558 goto out_unlock;
559 }
560 ret = ak8974_trigmeas(ak8974);
561 if (ret)
562 goto out_unlock;
563 ret = ak8974_getresult(ak8974, hw_values);
564 if (ret)
565 goto out_unlock;
566
567 /*
568 * We read all axes and discard all but one, for optimized
569 * reading, use the triggered buffer.
570 */
571 *val = (s16)le16_to_cpu(hw_values[chan->address]);
572
573 ret = IIO_VAL_INT;
574 }
575
576 out_unlock:
577 mutex_unlock(&ak8974->lock);
578 pm_runtime_mark_last_busy(&ak8974->i2c->dev);
579 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
580
581 return ret;
582 }
583
ak8974_fill_buffer(struct iio_dev * indio_dev)584 static void ak8974_fill_buffer(struct iio_dev *indio_dev)
585 {
586 struct ak8974 *ak8974 = iio_priv(indio_dev);
587 int ret;
588
589 pm_runtime_get_sync(&ak8974->i2c->dev);
590 mutex_lock(&ak8974->lock);
591
592 ret = ak8974_trigmeas(ak8974);
593 if (ret) {
594 dev_err(&ak8974->i2c->dev, "error triggering measure\n");
595 goto out_unlock;
596 }
597 ret = ak8974_getresult(ak8974, ak8974->scan.channels);
598 if (ret) {
599 dev_err(&ak8974->i2c->dev, "error getting measures\n");
600 goto out_unlock;
601 }
602
603 iio_push_to_buffers_with_timestamp(indio_dev, &ak8974->scan,
604 iio_get_time_ns(indio_dev));
605
606 out_unlock:
607 mutex_unlock(&ak8974->lock);
608 pm_runtime_mark_last_busy(&ak8974->i2c->dev);
609 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
610 }
611
ak8974_handle_trigger(int irq,void * p)612 static irqreturn_t ak8974_handle_trigger(int irq, void *p)
613 {
614 const struct iio_poll_func *pf = p;
615 struct iio_dev *indio_dev = pf->indio_dev;
616
617 ak8974_fill_buffer(indio_dev);
618 iio_trigger_notify_done(indio_dev->trig);
619
620 return IRQ_HANDLED;
621 }
622
623 static const struct iio_mount_matrix *
ak8974_get_mount_matrix(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)624 ak8974_get_mount_matrix(const struct iio_dev *indio_dev,
625 const struct iio_chan_spec *chan)
626 {
627 struct ak8974 *ak8974 = iio_priv(indio_dev);
628
629 return &ak8974->orientation;
630 }
631
632 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = {
633 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix),
634 { },
635 };
636
637 #define AK8974_AXIS_CHANNEL(axis, index) \
638 { \
639 .type = IIO_MAGN, \
640 .modified = 1, \
641 .channel2 = IIO_MOD_##axis, \
642 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
643 .ext_info = ak8974_ext_info, \
644 .address = index, \
645 .scan_index = index, \
646 .scan_type = { \
647 .sign = 's', \
648 .realbits = 16, \
649 .storagebits = 16, \
650 .endianness = IIO_LE \
651 }, \
652 }
653
654 static const struct iio_chan_spec ak8974_channels[] = {
655 AK8974_AXIS_CHANNEL(X, 0),
656 AK8974_AXIS_CHANNEL(Y, 1),
657 AK8974_AXIS_CHANNEL(Z, 2),
658 IIO_CHAN_SOFT_TIMESTAMP(3),
659 };
660
661 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
662
663 static const struct iio_info ak8974_info = {
664 .read_raw = &ak8974_read_raw,
665 };
666
ak8974_writeable_reg(struct device * dev,unsigned int reg)667 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
668 {
669 struct i2c_client *i2c = to_i2c_client(dev);
670 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
671 struct ak8974 *ak8974 = iio_priv(indio_dev);
672
673 switch (reg) {
674 case AK8974_CTRL1:
675 case AK8974_CTRL2:
676 case AK8974_CTRL3:
677 case AK8974_INT_CTRL:
678 case AK8974_INT_THRES:
679 case AK8974_INT_THRES + 1:
680 case AK8974_PRESET:
681 case AK8974_PRESET + 1:
682 return true;
683 case AK8974_OFFSET_X:
684 case AK8974_OFFSET_X + 1:
685 case AK8974_OFFSET_Y:
686 case AK8974_OFFSET_Y + 1:
687 case AK8974_OFFSET_Z:
688 case AK8974_OFFSET_Z + 1:
689 if (ak8974->variant == AK8974_WHOAMI_VALUE_AK8974)
690 return true;
691 return false;
692 case AMI305_OFFSET_X:
693 case AMI305_OFFSET_X + 1:
694 case AMI305_OFFSET_Y:
695 case AMI305_OFFSET_Y + 1:
696 case AMI305_OFFSET_Z:
697 case AMI305_OFFSET_Z + 1:
698 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 ||
699 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
700 case AMI306_CTRL4:
701 case AMI306_CTRL4 + 1:
702 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
703 default:
704 return false;
705 }
706 }
707
ak8974_precious_reg(struct device * dev,unsigned int reg)708 static bool ak8974_precious_reg(struct device *dev, unsigned int reg)
709 {
710 return reg == AK8974_INT_CLEAR;
711 }
712
713 static const struct regmap_config ak8974_regmap_config = {
714 .reg_bits = 8,
715 .val_bits = 8,
716 .max_register = 0xff,
717 .writeable_reg = ak8974_writeable_reg,
718 .precious_reg = ak8974_precious_reg,
719 };
720
ak8974_probe(struct i2c_client * i2c,const struct i2c_device_id * id)721 static int ak8974_probe(struct i2c_client *i2c,
722 const struct i2c_device_id *id)
723 {
724 struct iio_dev *indio_dev;
725 struct ak8974 *ak8974;
726 unsigned long irq_trig;
727 int irq = i2c->irq;
728 int ret;
729
730 /* Register with IIO */
731 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974));
732 if (indio_dev == NULL)
733 return -ENOMEM;
734
735 ak8974 = iio_priv(indio_dev);
736 i2c_set_clientdata(i2c, indio_dev);
737 ak8974->i2c = i2c;
738 mutex_init(&ak8974->lock);
739
740 ret = of_iio_read_mount_matrix(&i2c->dev,
741 "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