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 aligned_s64 ts;
200 } scan;
201 };
202
203 static const char ak8974_reg_avdd[] = "avdd";
204 static const char ak8974_reg_dvdd[] = "dvdd";
205
ak8974_get_u16_val(struct ak8974 * ak8974,u8 reg,u16 * val)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
ak8974_set_u16_val(struct ak8974 * ak8974,u8 reg,u16 val)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
ak8974_set_power(struct ak8974 * ak8974,bool mode)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
ak8974_reset(struct ak8974 * ak8974)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
ak8974_configure(struct ak8974 * ak8974)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
ak8974_trigmeas(struct ak8974 * ak8974)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_set_bits(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_FORCE);
330 }
331
ak8974_await_drdy(struct ak8974 * ak8974)332 static int ak8974_await_drdy(struct ak8974 *ak8974)
333 {
334 int timeout = 2;
335 unsigned int val;
336 int ret;
337
338 if (ak8974->drdy_irq) {
339 ret = wait_for_completion_timeout(&ak8974->drdy_complete,
340 1 + msecs_to_jiffies(1000));
341 if (!ret) {
342 dev_err(&ak8974->i2c->dev,
343 "timeout waiting for DRDY IRQ\n");
344 return -ETIMEDOUT;
345 }
346 return 0;
347 }
348
349 /* Default delay-based poll loop */
350 do {
351 msleep(AK8974_MEASTIME);
352 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
353 if (ret < 0)
354 return ret;
355 if (val & AK8974_STATUS_DRDY)
356 return 0;
357 } while (--timeout);
358
359 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n");
360 return -ETIMEDOUT;
361 }
362
ak8974_getresult(struct ak8974 * ak8974,__le16 * result)363 static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result)
364 {
365 unsigned int src;
366 int ret;
367
368 ret = ak8974_await_drdy(ak8974);
369 if (ret)
370 return ret;
371 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src);
372 if (ret < 0)
373 return ret;
374
375 /* Out of range overflow! Strong magnet close? */
376 if (src & AK8974_INT_RANGE) {
377 dev_err(&ak8974->i2c->dev,
378 "range overflow in sensor\n");
379 return -ERANGE;
380 }
381
382 return regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6);
383 }
384
ak8974_drdy_irq(int irq,void * d)385 static irqreturn_t ak8974_drdy_irq(int irq, void *d)
386 {
387 struct ak8974 *ak8974 = d;
388
389 if (!ak8974->drdy_irq)
390 return IRQ_NONE;
391
392 /* TODO: timestamp here to get good measurement stamps */
393 return IRQ_WAKE_THREAD;
394 }
395
ak8974_drdy_irq_thread(int irq,void * d)396 static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d)
397 {
398 struct ak8974 *ak8974 = d;
399 unsigned int val;
400 int ret;
401
402 /* Check if this was a DRDY from us */
403 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
404 if (ret < 0) {
405 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n");
406 return IRQ_HANDLED;
407 }
408 if (val & AK8974_STATUS_DRDY) {
409 /* Yes this was our IRQ */
410 complete(&ak8974->drdy_complete);
411 return IRQ_HANDLED;
412 }
413
414 /* We may be on a shared IRQ, let the next client check */
415 return IRQ_NONE;
416 }
417
ak8974_selftest(struct ak8974 * ak8974)418 static int ak8974_selftest(struct ak8974 *ak8974)
419 {
420 struct device *dev = &ak8974->i2c->dev;
421 unsigned int val;
422 int ret;
423
424 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
425 if (ret)
426 return ret;
427 if (val != AK8974_SELFTEST_IDLE) {
428 dev_err(dev, "selftest not idle before test\n");
429 return -EIO;
430 }
431
432 /* Trigger self-test */
433 ret = regmap_set_bits(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_SELFTEST);
434 if (ret) {
435 dev_err(dev, "could not write CTRL3\n");
436 return ret;
437 }
438
439 msleep(AK8974_SELFTEST_DELAY);
440
441 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
442 if (ret)
443 return ret;
444 if (val != AK8974_SELFTEST_OK) {
445 dev_err(dev, "selftest result NOT OK (%02x)\n", val);
446 return -EIO;
447 }
448
449 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
450 if (ret)
451 return ret;
452 if (val != AK8974_SELFTEST_IDLE) {
453 dev_err(dev, "selftest not idle after test (%02x)\n", val);
454 return -EIO;
455 }
456 dev_dbg(dev, "passed self-test\n");
457
458 return 0;
459 }
460
ak8974_read_calib_data(struct ak8974 * ak8974,unsigned int reg,__le16 * tab,size_t tab_size)461 static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg,
462 __le16 *tab, size_t tab_size)
463 {
464 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size);
465 if (ret) {
466 memset(tab, 0xFF, tab_size);
467 dev_warn(&ak8974->i2c->dev,
468 "can't read calibration data (regs %u..%zu): %d\n",
469 reg, reg + tab_size - 1, ret);
470 } else {
471 add_device_randomness(tab, tab_size);
472 }
473 }
474
ak8974_detect(struct ak8974 * ak8974)475 static int ak8974_detect(struct ak8974 *ak8974)
476 {
477 unsigned int whoami;
478 const char *name;
479 int ret;
480 unsigned int fw;
481 u16 sn;
482
483 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami);
484 if (ret)
485 return ret;
486
487 name = "ami305";
488
489 switch (whoami) {
490 case AK8974_WHOAMI_VALUE_AMI306:
491 name = "ami306";
492 fallthrough;
493 case AK8974_WHOAMI_VALUE_AMI305:
494 ret = regmap_read(ak8974->map, AMI305_VER, &fw);
495 if (ret)
496 return ret;
497 fw &= 0x7f; /* only bits 0 thru 6 valid */
498 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn);
499 if (ret)
500 return ret;
501 add_device_randomness(&sn, sizeof(sn));
502 dev_info(&ak8974->i2c->dev,
503 "detected %s, FW ver %02x, S/N: %04x\n",
504 name, fw, sn);
505 break;
506 case AK8974_WHOAMI_VALUE_AK8974:
507 name = "ak8974";
508 dev_info(&ak8974->i2c->dev, "detected AK8974\n");
509 break;
510 case AK8974_WHOAMI_VALUE_HSCDTD008A:
511 name = "hscdtd008a";
512 dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n");
513 break;
514 default:
515 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
516 whoami);
517 return -ENODEV;
518 }
519
520 ak8974->name = name;
521 ak8974->variant = whoami;
522
523 if (whoami == AK8974_WHOAMI_VALUE_AMI306) {
524 __le16 fab_data1[9], fab_data2[3];
525 int i;
526
527 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X,
528 fab_data1, sizeof(fab_data1));
529 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X,
530 fab_data2, sizeof(fab_data2));
531
532 for (i = 0; i < 3; ++i) {
533 static const char axis[] = "XYZ";
534 static const char pgaxis[] = "ZYZXYX";
535 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F;
536 unsigned fine = le16_to_cpu(fab_data1[i]);
537 unsigned sens = le16_to_cpu(fab_data1[i + 3]);
538 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]);
539 unsigned pgain2 = pgain1 >> 8;
540
541 pgain1 &= 0xFF;
542
543 dev_info(&ak8974->i2c->dev,
544 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n",
545 axis[i], offz, sens, fine, pgaxis[i * 2],
546 pgain1, pgaxis[i * 2 + 1], pgain2);
547 }
548 }
549
550 return 0;
551 }
552
ak8974_measure_channel(struct ak8974 * ak8974,unsigned long address,int * val)553 static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address,
554 int *val)
555 {
556 __le16 hw_values[3];
557 int ret;
558
559 pm_runtime_get_sync(&ak8974->i2c->dev);
560 mutex_lock(&ak8974->lock);
561
562 /*
563 * We read all axes and discard all but one, for optimized
564 * reading, use the triggered buffer.
565 */
566 ret = ak8974_trigmeas(ak8974);
567 if (ret)
568 goto out_unlock;
569 ret = ak8974_getresult(ak8974, hw_values);
570 if (ret)
571 goto out_unlock;
572 /*
573 * This explicit cast to (s16) is necessary as the measurement
574 * is done in 2's complement with positive and negative values.
575 * The following assignment to *val will then convert the signed
576 * s16 value to a signed int value.
577 */
578 *val = (s16)le16_to_cpu(hw_values[address]);
579 out_unlock:
580 mutex_unlock(&ak8974->lock);
581 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
582
583 return ret;
584 }
585
ak8974_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)586 static int ak8974_read_raw(struct iio_dev *indio_dev,
587 struct iio_chan_spec const *chan,
588 int *val, int *val2,
589 long mask)
590 {
591 struct ak8974 *ak8974 = iio_priv(indio_dev);
592 int ret;
593
594 switch (mask) {
595 case IIO_CHAN_INFO_RAW:
596 if (chan->address > 2) {
597 dev_err(&ak8974->i2c->dev, "faulty channel address\n");
598 return -EIO;
599 }
600 ret = ak8974_measure_channel(ak8974, chan->address, val);
601 if (ret)
602 return ret;
603 return IIO_VAL_INT;
604 case IIO_CHAN_INFO_SCALE:
605 switch (ak8974->variant) {
606 case AK8974_WHOAMI_VALUE_AMI306:
607 case AK8974_WHOAMI_VALUE_AMI305:
608 /*
609 * The datasheet for AMI305 and AMI306, page 6
610 * specifies the range of the sensor to be
611 * +/- 12 Gauss.
612 */
613 *val = 12;
614 /*
615 * 12 bits are used, +/- 2^11
616 * [ -2048 .. 2047 ] (manual page 20)
617 * [ 0xf800 .. 0x07ff ]
618 */
619 *val2 = 11;
620 return IIO_VAL_FRACTIONAL_LOG2;
621 case AK8974_WHOAMI_VALUE_HSCDTD008A:
622 /*
623 * The datasheet for HSCDTF008A, page 3 specifies the
624 * range of the sensor as +/- 2.4 mT per axis, which
625 * corresponds to +/- 2400 uT = +/- 24 Gauss.
626 */
627 *val = 24;
628 /*
629 * 15 bits are used (set up in CTRL4), +/- 2^14
630 * [ -16384 .. 16383 ] (manual page 24)
631 * [ 0xc000 .. 0x3fff ]
632 */
633 *val2 = 14;
634 return IIO_VAL_FRACTIONAL_LOG2;
635 default:
636 /* GUESSING +/- 12 Gauss */
637 *val = 12;
638 /* GUESSING 12 bits ADC +/- 2^11 */
639 *val2 = 11;
640 return IIO_VAL_FRACTIONAL_LOG2;
641 }
642 break;
643 default:
644 /* Unknown request */
645 break;
646 }
647
648 return -EINVAL;
649 }
650
ak8974_fill_buffer(struct iio_dev * indio_dev)651 static void ak8974_fill_buffer(struct iio_dev *indio_dev)
652 {
653 struct ak8974 *ak8974 = iio_priv(indio_dev);
654 int ret;
655
656 pm_runtime_get_sync(&ak8974->i2c->dev);
657 mutex_lock(&ak8974->lock);
658
659 ret = ak8974_trigmeas(ak8974);
660 if (ret) {
661 dev_err(&ak8974->i2c->dev, "error triggering measure\n");
662 goto out_unlock;
663 }
664 ret = ak8974_getresult(ak8974, ak8974->scan.channels);
665 if (ret) {
666 dev_err(&ak8974->i2c->dev, "error getting measures\n");
667 goto out_unlock;
668 }
669
670 iio_push_to_buffers_with_ts(indio_dev, &ak8974->scan, sizeof(ak8974->scan),
671 iio_get_time_ns(indio_dev));
672
673 out_unlock:
674 mutex_unlock(&ak8974->lock);
675 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
676 }
677
ak8974_handle_trigger(int irq,void * p)678 static irqreturn_t ak8974_handle_trigger(int irq, void *p)
679 {
680 const struct iio_poll_func *pf = p;
681 struct iio_dev *indio_dev = pf->indio_dev;
682
683 ak8974_fill_buffer(indio_dev);
684 iio_trigger_notify_done(indio_dev->trig);
685
686 return IRQ_HANDLED;
687 }
688
689 static const struct iio_mount_matrix *
ak8974_get_mount_matrix(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)690 ak8974_get_mount_matrix(const struct iio_dev *indio_dev,
691 const struct iio_chan_spec *chan)
692 {
693 struct ak8974 *ak8974 = iio_priv(indio_dev);
694
695 return &ak8974->orientation;
696 }
697
698 static const struct iio_chan_spec_ext_info ak8974_ext_info[] = {
699 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix),
700 { }
701 };
702
703 #define AK8974_AXIS_CHANNEL(axis, index, bits) \
704 { \
705 .type = IIO_MAGN, \
706 .modified = 1, \
707 .channel2 = IIO_MOD_##axis, \
708 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
709 BIT(IIO_CHAN_INFO_SCALE), \
710 .ext_info = ak8974_ext_info, \
711 .address = index, \
712 .scan_index = index, \
713 .scan_type = { \
714 .sign = 's', \
715 .realbits = bits, \
716 .storagebits = 16, \
717 .endianness = IIO_LE \
718 }, \
719 }
720
721 /*
722 * We have no datasheet for the AK8974 but we guess that its
723 * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit
724 * ADC.
725 */
726 static const struct iio_chan_spec ak8974_12_bits_channels[] = {
727 AK8974_AXIS_CHANNEL(X, 0, 12),
728 AK8974_AXIS_CHANNEL(Y, 1, 12),
729 AK8974_AXIS_CHANNEL(Z, 2, 12),
730 IIO_CHAN_SOFT_TIMESTAMP(3),
731 };
732
733 /*
734 * The HSCDTD008A has 15 bits resolution the way we set it up
735 * in CTRL4.
736 */
737 static const struct iio_chan_spec ak8974_15_bits_channels[] = {
738 AK8974_AXIS_CHANNEL(X, 0, 15),
739 AK8974_AXIS_CHANNEL(Y, 1, 15),
740 AK8974_AXIS_CHANNEL(Z, 2, 15),
741 IIO_CHAN_SOFT_TIMESTAMP(3),
742 };
743
744 static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
745
746 static const struct iio_info ak8974_info = {
747 .read_raw = &ak8974_read_raw,
748 };
749
ak8974_writeable_reg(struct device * dev,unsigned int reg)750 static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
751 {
752 struct i2c_client *i2c = to_i2c_client(dev);
753 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
754 struct ak8974 *ak8974 = iio_priv(indio_dev);
755
756 switch (reg) {
757 case AK8974_CTRL1:
758 case AK8974_CTRL2:
759 case AK8974_CTRL3:
760 case AK8974_INT_CTRL:
761 case AK8974_INT_THRES:
762 case AK8974_INT_THRES + 1:
763 return true;
764 case AK8974_PRESET:
765 case AK8974_PRESET + 1:
766 return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A;
767 case AK8974_OFFSET_X:
768 case AK8974_OFFSET_X + 1:
769 case AK8974_OFFSET_Y:
770 case AK8974_OFFSET_Y + 1:
771 case AK8974_OFFSET_Z:
772 case AK8974_OFFSET_Z + 1:
773 return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 ||
774 ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A;
775 case AMI305_OFFSET_X:
776 case AMI305_OFFSET_X + 1:
777 case AMI305_OFFSET_Y:
778 case AMI305_OFFSET_Y + 1:
779 case AMI305_OFFSET_Z:
780 case AMI305_OFFSET_Z + 1:
781 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 ||
782 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
783 case AMI306_CTRL4:
784 case AMI306_CTRL4 + 1:
785 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
786 default:
787 return false;
788 }
789 }
790
ak8974_precious_reg(struct device * dev,unsigned int reg)791 static bool ak8974_precious_reg(struct device *dev, unsigned int reg)
792 {
793 return reg == AK8974_INT_CLEAR;
794 }
795
796 static const struct regmap_config ak8974_regmap_config = {
797 .reg_bits = 8,
798 .val_bits = 8,
799 .max_register = 0xff,
800 .writeable_reg = ak8974_writeable_reg,
801 .precious_reg = ak8974_precious_reg,
802 };
803
ak8974_probe(struct i2c_client * i2c)804 static int ak8974_probe(struct i2c_client *i2c)
805 {
806 struct iio_dev *indio_dev;
807 struct ak8974 *ak8974;
808 unsigned long irq_trig;
809 int irq = i2c->irq;
810 int ret;
811
812 /* Register with IIO */
813 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974));
814 if (indio_dev == NULL)
815 return -ENOMEM;
816
817 ak8974 = iio_priv(indio_dev);
818 i2c_set_clientdata(i2c, indio_dev);
819 ak8974->i2c = i2c;
820 mutex_init(&ak8974->lock);
821
822 ret = iio_read_mount_matrix(&i2c->dev, &ak8974->orientation);
823 if (ret)
824 return ret;
825
826 ak8974->regs[0].supply = ak8974_reg_avdd;
827 ak8974->regs[1].supply = ak8974_reg_dvdd;
828
829 ret = devm_regulator_bulk_get(&i2c->dev,
830 ARRAY_SIZE(ak8974->regs),
831 ak8974->regs);
832 if (ret < 0)
833 return dev_err_probe(&i2c->dev, ret, "cannot get regulators\n");
834
835 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
836 if (ret < 0) {
837 dev_err(&i2c->dev, "cannot enable regulators\n");
838 return ret;
839 }
840
841 /* Take runtime PM online */
842 pm_runtime_get_noresume(&i2c->dev);
843 pm_runtime_set_active(&i2c->dev);
844 pm_runtime_enable(&i2c->dev);
845
846 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config);
847 if (IS_ERR(ak8974->map)) {
848 dev_err(&i2c->dev, "failed to allocate register map\n");
849 pm_runtime_put_noidle(&i2c->dev);
850 pm_runtime_disable(&i2c->dev);
851 return PTR_ERR(ak8974->map);
852 }
853
854 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
855 if (ret) {
856 dev_err(&i2c->dev, "could not power on\n");
857 goto disable_pm;
858 }
859
860 ret = ak8974_detect(ak8974);
861 if (ret) {
862 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n");
863 goto disable_pm;
864 }
865
866 ret = ak8974_selftest(ak8974);
867 if (ret)
868 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n");
869
870 ret = ak8974_reset(ak8974);
871 if (ret) {
872 dev_err(&i2c->dev, "AK8974 reset failed\n");
873 goto disable_pm;
874 }
875
876 switch (ak8974->variant) {
877 case AK8974_WHOAMI_VALUE_AMI306:
878 case AK8974_WHOAMI_VALUE_AMI305:
879 indio_dev->channels = ak8974_12_bits_channels;
880 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels);
881 break;
882 case AK8974_WHOAMI_VALUE_HSCDTD008A:
883 indio_dev->channels = ak8974_15_bits_channels;
884 indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels);
885 break;
886 default:
887 indio_dev->channels = ak8974_12_bits_channels;
888 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels);
889 break;
890 }
891 indio_dev->info = &ak8974_info;
892 indio_dev->available_scan_masks = ak8974_scan_masks;
893 indio_dev->modes = INDIO_DIRECT_MODE;
894 indio_dev->name = ak8974->name;
895
896 ret = iio_triggered_buffer_setup(indio_dev, NULL,
897 ak8974_handle_trigger,
898 NULL);
899 if (ret) {
900 dev_err(&i2c->dev, "triggered buffer setup failed\n");
901 goto disable_pm;
902 }
903
904 /* If we have a valid DRDY IRQ, make use of it */
905 if (irq > 0) {
906 irq_trig = irq_get_trigger_type(irq);
907 if (irq_trig == IRQF_TRIGGER_RISING) {
908 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n");
909 } else if (irq_trig == IRQF_TRIGGER_FALLING) {
910 ak8974->drdy_active_low = true;
911 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n");
912 } else {
913 irq_trig = IRQF_TRIGGER_RISING;
914 }
915 irq_trig |= IRQF_ONESHOT;
916 irq_trig |= IRQF_SHARED;
917
918 ret = devm_request_threaded_irq(&i2c->dev,
919 irq,
920 ak8974_drdy_irq,
921 ak8974_drdy_irq_thread,
922 irq_trig,
923 ak8974->name,
924 ak8974);
925 if (ret)
926 goto no_irq;
927 ak8974->drdy_irq = true;
928 }
929
930 no_irq:
931 ret = iio_device_register(indio_dev);
932 if (ret) {
933 dev_err(&i2c->dev, "device register failed\n");
934 goto cleanup_buffer;
935 }
936
937 pm_runtime_set_autosuspend_delay(&i2c->dev,
938 AK8974_AUTOSUSPEND_DELAY);
939 pm_runtime_use_autosuspend(&i2c->dev);
940 pm_runtime_put(&i2c->dev);
941
942 return 0;
943
944 cleanup_buffer:
945 iio_triggered_buffer_cleanup(indio_dev);
946 disable_pm:
947 pm_runtime_put_noidle(&i2c->dev);
948 pm_runtime_disable(&i2c->dev);
949 ak8974_set_power(ak8974, AK8974_PWR_OFF);
950 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
951
952 return ret;
953 }
954
ak8974_remove(struct i2c_client * i2c)955 static void ak8974_remove(struct i2c_client *i2c)
956 {
957 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
958 struct ak8974 *ak8974 = iio_priv(indio_dev);
959
960 iio_device_unregister(indio_dev);
961 iio_triggered_buffer_cleanup(indio_dev);
962 pm_runtime_get_sync(&i2c->dev);
963 pm_runtime_put_noidle(&i2c->dev);
964 pm_runtime_disable(&i2c->dev);
965 ak8974_set_power(ak8974, AK8974_PWR_OFF);
966 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
967 }
968
ak8974_runtime_suspend(struct device * dev)969 static int ak8974_runtime_suspend(struct device *dev)
970 {
971 struct ak8974 *ak8974 =
972 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
973
974 ak8974_set_power(ak8974, AK8974_PWR_OFF);
975 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
976
977 return 0;
978 }
979
ak8974_runtime_resume(struct device * dev)980 static int ak8974_runtime_resume(struct device *dev)
981 {
982 struct ak8974 *ak8974 =
983 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
984 int ret;
985
986 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
987 if (ret)
988 return ret;
989 msleep(AK8974_POWERON_DELAY);
990 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
991 if (ret)
992 goto out_regulator_disable;
993
994 ret = ak8974_configure(ak8974);
995 if (ret)
996 goto out_disable_power;
997
998 return 0;
999
1000 out_disable_power:
1001 ak8974_set_power(ak8974, AK8974_PWR_OFF);
1002 out_regulator_disable:
1003 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
1004
1005 return ret;
1006 }
1007
1008 static DEFINE_RUNTIME_DEV_PM_OPS(ak8974_dev_pm_ops, ak8974_runtime_suspend,
1009 ak8974_runtime_resume, NULL);
1010
1011 static const struct i2c_device_id ak8974_id[] = {
1012 { .name = "ami305" },
1013 { .name = "ami306" },
1014 { .name = "ak8974" },
1015 { .name = "hscdtd008a" },
1016 { }
1017 };
1018 MODULE_DEVICE_TABLE(i2c, ak8974_id);
1019
1020 static const struct of_device_id ak8974_of_match[] = {
1021 { .compatible = "asahi-kasei,ak8974", },
1022 { .compatible = "alps,hscdtd008a", },
1023 { }
1024 };
1025 MODULE_DEVICE_TABLE(of, ak8974_of_match);
1026
1027 static struct i2c_driver ak8974_driver = {
1028 .driver = {
1029 .name = "ak8974",
1030 .pm = pm_ptr(&ak8974_dev_pm_ops),
1031 .of_match_table = ak8974_of_match,
1032 },
1033 .probe = ak8974_probe,
1034 .remove = ak8974_remove,
1035 .id_table = ak8974_id,
1036 };
1037 module_i2c_driver(ak8974_driver);
1038
1039 MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver");
1040 MODULE_AUTHOR("Samu Onkalo");
1041 MODULE_AUTHOR("Linus Walleij");
1042 MODULE_LICENSE("GPL v2");
1043