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Linux 6.12-rc1
[linux-2.6-block.git] / drivers / iio / magnetometer / ak8974.c
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09c434b8 1// SPDX-License-Identifier: GPL-2.0-only
7c94a8b2
LW		 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>
2b4f0172 15#include <linux/mod_devicetable.h>
7c94a8b2
LW		 16#include <linux/kernel.h>
17#include <linux/i2c.h>
18#include <linux/interrupt.h>
19#include <linux/irq.h> /* For irq_get_irq_data() */
20#include <linux/completion.h>
21#include <linux/err.h>
22#include <linux/mutex.h>
23#include <linux/delay.h>
24#include <linux/bitops.h>
408cc6eb 25#include <linux/random.h>
7c94a8b2
LW		 26#include <linux/regmap.h>
27#include <linux/regulator/consumer.h>
28#include <linux/pm_runtime.h>
29
30#include <linux/iio/iio.h>
31#include <linux/iio/sysfs.h>
32#include <linux/iio/buffer.h>
33#include <linux/iio/trigger.h>
34#include <linux/iio/trigger_consumer.h>
35#include <linux/iio/triggered_buffer.h>
36
37/*
38 * 16-bit registers are little-endian. LSB is at the address defined below
39 * and MSB is at the next higher address.
40 */
41
21be26fc 42/* These registers are common for AK8974 and AMI30x */
7c94a8b2
LW		 43#define AK8974_SELFTEST 0x0C
44#define AK8974_SELFTEST_IDLE 0x55
45#define AK8974_SELFTEST_OK 0xAA
46
47#define AK8974_INFO 0x0D
48
49#define AK8974_WHOAMI 0x0F
21be26fc 50#define AK8974_WHOAMI_VALUE_AMI306 0x46
7c94a8b2
LW		 51#define AK8974_WHOAMI_VALUE_AMI305 0x47
52#define AK8974_WHOAMI_VALUE_AK8974 0x48
525530af 53#define AK8974_WHOAMI_VALUE_HSCDTD008A 0x49
7c94a8b2
LW		 54
55#define AK8974_DATA_X 0x10
56#define AK8974_DATA_Y 0x12
57#define AK8974_DATA_Z 0x14
58#define AK8974_INT_SRC 0x16
59#define AK8974_STATUS 0x18
60#define AK8974_INT_CLEAR 0x1A
61#define AK8974_CTRL1 0x1B
62#define AK8974_CTRL2 0x1C
63#define AK8974_CTRL3 0x1D
64#define AK8974_INT_CTRL 0x1E
65#define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */
66#define AK8974_PRESET 0x30
67
68/* AK8974-specific offsets */
69#define AK8974_OFFSET_X 0x20
70#define AK8974_OFFSET_Y 0x22
71#define AK8974_OFFSET_Z 0x24
72/* AMI305-specific offsets */
73#define AMI305_OFFSET_X 0x6C
74#define AMI305_OFFSET_Y 0x72
75#define AMI305_OFFSET_Z 0x78
76
77/* Different temperature registers */
78#define AK8974_TEMP 0x31
79#define AMI305_TEMP 0x60
80
21be26fc
MM		 81/* AMI306-specific control register */
82#define AMI306_CTRL4 0x5C
83
84/* AMI306 factory calibration data */
85
86/* fine axis sensitivity */
87#define AMI306_FINEOUTPUT_X 0x90
88#define AMI306_FINEOUTPUT_Y 0x92
89#define AMI306_FINEOUTPUT_Z 0x94
90
91/* axis sensitivity */
92#define AMI306_SENS_X 0x96
93#define AMI306_SENS_Y 0x98
94#define AMI306_SENS_Z 0x9A
95
96/* axis cross-interference */
97#define AMI306_GAIN_PARA_XZ 0x9C
98#define AMI306_GAIN_PARA_XY 0x9D
99#define AMI306_GAIN_PARA_YZ 0x9E
100#define AMI306_GAIN_PARA_YX 0x9F
101#define AMI306_GAIN_PARA_ZY 0xA0
102#define AMI306_GAIN_PARA_ZX 0xA1
103
104/* offset at ZERO magnetic field */
105#define AMI306_OFFZERO_X 0xF8
106#define AMI306_OFFZERO_Y 0xFA
107#define AMI306_OFFZERO_Z 0xFC
108
109
7c94a8b2
LW		 110#define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */
111#define AK8974_INT_Y_HIGH BIT(6)
112#define AK8974_INT_Z_HIGH BIT(5)
113#define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */
114#define AK8974_INT_Y_LOW BIT(3)
115#define AK8974_INT_Z_LOW BIT(2)
116#define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */
117
118#define AK8974_STATUS_DRDY BIT(6) /* Data ready */
119#define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */
120#define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */
121
122#define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */
123#define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */
124#define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */
125#define AK8974_CTRL1_MODE2 BIT(0) /* 0 */
126
127#define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */
128#define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */
129#define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */
130#define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL)
131
132#define AK8974_CTRL3_RESET BIT(7) /* Software reset */
133#define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */
134#define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */
135#define AK8974_CTRL3_RESDEF 0x00
136
137#define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */
138#define AK8974_INT_CTRL_YEN BIT(6)
139#define AK8974_INT_CTRL_ZEN BIT(5)
140#define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5))
141#define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */
142#define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
143#define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
144
525530af
NR		 145/* HSCDTD008A-specific control register */
146#define HSCDTD008A_CTRL4 0x1E
147#define HSCDTD008A_CTRL4_MMD BIT(7) /* must be set to 1 */
148#define HSCDTD008A_CTRL4_RANGE BIT(4) /* 0 = 14-bit output; 1 = 15-bit output */
149#define HSCDTD008A_CTRL4_RESDEF (HSCDTD008A_CTRL4_MMD | HSCDTD008A_CTRL4_RANGE)
150
7c94a8b2
LW		 151/* The AMI305 has elaborate FW version and serial number registers */
152#define AMI305_VER 0xE8
153#define AMI305_SN 0xEA
154
155#define AK8974_MAX_RANGE 2048
156
157#define AK8974_POWERON_DELAY 50
158#define AK8974_ACTIVATE_DELAY 1
159#define AK8974_SELFTEST_DELAY 1
160/*
161 * Set the autosuspend to two orders of magnitude larger than the poweron
162 * delay to make sane reasonable power tradeoff savings (5 seconds in
163 * this case).
164 */
165#define AK8974_AUTOSUSPEND_DELAY 5000
166
167#define AK8974_MEASTIME 3
168
169#define AK8974_PWR_ON 1
170#define AK8974_PWR_OFF 0
171
172/**
173 * struct ak8974 - state container for the AK8974 driver
174 * @i2c: parent I2C client
175 * @orientation: mounting matrix, flipped axis etc
176 * @map: regmap to access the AK8974 registers over I2C
177 * @regs: the avdd and dvdd power regulators
178 * @name: the name of the part
179 * @variant: the whoami ID value (for selecting code paths)
180 * @lock: locks the magnetometer for exclusive use during a measurement
181 * @drdy_irq: uses the DRDY IRQ line
182 * @drdy_complete: completion for DRDY
183 * @drdy_active_low: the DRDY IRQ is active low
5497523e 184 * @scan: timestamps
7c94a8b2
LW		 185 */
186struct ak8974 {
187 struct i2c_client *i2c;
188 struct iio_mount_matrix orientation;
189 struct regmap *map;
190 struct regulator_bulk_data regs[2];
191 const char *name;
192 u8 variant;
193 struct mutex lock;
194 bool drdy_irq;
195 struct completion drdy_complete;
196 bool drdy_active_low;
838e00b1
JC		 197 /* Ensure timestamp is naturally aligned */
198 struct {
199 __le16 channels[3];
200 s64 ts __aligned(8);
201 } scan;
7c94a8b2
LW		 202};
203
204static const char ak8974_reg_avdd[] = "avdd";
205static const char ak8974_reg_dvdd[] = "dvdd";
206
21be26fc
MM		 207static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val)
208{
209 int ret;
210 __le16 bulk;
211
212 ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2);
213 if (ret)
214 return ret;
215 *val = le16_to_cpu(bulk);
216
217 return 0;
218}
219
220static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val)
221{
222 __le16 bulk = cpu_to_le16(val);
223
224 return regmap_bulk_write(ak8974->map, reg, &bulk, 2);
225}
226
7c94a8b2
LW		 227static int ak8974_set_power(struct ak8974 *ak8974, bool mode)
228{
229 int ret;
230 u8 val;
231
232 val = mode ? AK8974_CTRL1_POWER : 0;
233 val |= AK8974_CTRL1_FORCE_EN;
234 ret = regmap_write(ak8974->map, AK8974_CTRL1, val);
235 if (ret < 0)
236 return ret;
237
238 if (mode)
239 msleep(AK8974_ACTIVATE_DELAY);
240
241 return 0;
242}
243
244static int ak8974_reset(struct ak8974 *ak8974)
245{
246 int ret;
247
248 /* Power on to get register access. Sets CTRL1 reg to reset state */
249 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
250 if (ret)
251 return ret;
252 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF);
253 if (ret)
254 return ret;
255 ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
256 if (ret)
257 return ret;
525530af
NR		 258 if (ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A) {
259 ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
260 AK8974_INT_CTRL_RESDEF);
261 if (ret)
262 return ret;
263 } else {
264 ret = regmap_write(ak8974->map, HSCDTD008A_CTRL4,
265 HSCDTD008A_CTRL4_RESDEF);
266 if (ret)
267 return ret;
268 }
7c94a8b2
LW		 269
270 /* After reset, power off is default state */
271 return ak8974_set_power(ak8974, AK8974_PWR_OFF);
272}
273
274static int ak8974_configure(struct ak8974 *ak8974)
275{
276 int ret;
277
278 ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN |
279 AK8974_CTRL2_INT_EN);
280 if (ret)
281 return ret;
282 ret = regmap_write(ak8974->map, AK8974_CTRL3, 0);
283 if (ret)
284 return ret;
21be26fc
MM		 285 if (ak8974->variant == AK8974_WHOAMI_VALUE_AMI306) {
286 /* magic from datasheet: set high-speed measurement mode */
287 ret = ak8974_set_u16_val(ak8974, AMI306_CTRL4, 0xA07E);
288 if (ret)
289 return ret;
290 }
525530af
NR		 291 if (ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A)
292 return 0;
7c94a8b2
LW		 293 ret = regmap_write(ak8974->map, AK8974_INT_CTRL, AK8974_INT_CTRL_POL);
294 if (ret)
295 return ret;
296
297 return regmap_write(ak8974->map, AK8974_PRESET, 0);
298}
299
300static int ak8974_trigmeas(struct ak8974 *ak8974)
301{
302 unsigned int clear;
303 u8 mask;
304 u8 val;
305 int ret;
306
307 /* Clear any previous measurement overflow status */
308 ret = regmap_read(ak8974->map, AK8974_INT_CLEAR, &clear);
309 if (ret)
310 return ret;
311
312 /* If we have a DRDY IRQ line, use it */
313 if (ak8974->drdy_irq) {
314 mask = AK8974_CTRL2_INT_EN |
315 AK8974_CTRL2_DRDY_EN |
316 AK8974_CTRL2_DRDY_POL;
317 val = AK8974_CTRL2_DRDY_EN;
318
319 if (!ak8974->drdy_active_low)
320 val |= AK8974_CTRL2_DRDY_POL;
321
322 init_completion(&ak8974->drdy_complete);
323 ret = regmap_update_bits(ak8974->map, AK8974_CTRL2,
324 mask, val);
325 if (ret)
326 return ret;
327 }
328
329 /* Force a measurement */
e93bd172 330 return regmap_set_bits(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_FORCE);
7c94a8b2
LW		 331}
332
333static int ak8974_await_drdy(struct ak8974 *ak8974)
334{
335 int timeout = 2;
336 unsigned int val;
337 int ret;
338
339 if (ak8974->drdy_irq) {
340 ret = wait_for_completion_timeout(&ak8974->drdy_complete,
341 1 + msecs_to_jiffies(1000));
342 if (!ret) {
343 dev_err(&ak8974->i2c->dev,
344 "timeout waiting for DRDY IRQ\n");
345 return -ETIMEDOUT;
346 }
347 return 0;
348 }
349
350 /* Default delay-based poll loop */
351 do {
352 msleep(AK8974_MEASTIME);
353 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
354 if (ret < 0)
355 return ret;
356 if (val & AK8974_STATUS_DRDY)
357 return 0;
358 } while (--timeout);
7c94a8b2 359
e2eb179c
CIK		 360 dev_err(&ak8974->i2c->dev, "timeout waiting for DRDY\n");
361 return -ETIMEDOUT;
7c94a8b2
LW		 362}
363
7f709dcd 364static int ak8974_getresult(struct ak8974 *ak8974, __le16 *result)
7c94a8b2
LW		 365{
366 unsigned int src;
367 int ret;
368
369 ret = ak8974_await_drdy(ak8974);
370 if (ret)
371 return ret;
372 ret = regmap_read(ak8974->map, AK8974_INT_SRC, &src);
373 if (ret < 0)
374 return ret;
375
376 /* Out of range overflow! Strong magnet close? */
377 if (src & AK8974_INT_RANGE) {
378 dev_err(&ak8974->i2c->dev,
379 "range overflow in sensor\n");
380 return -ERANGE;
381 }
382
383 ret = regmap_bulk_read(ak8974->map, AK8974_DATA_X, result, 6);
384 if (ret)
385 return ret;
386
387 return ret;
388}
389
390static irqreturn_t ak8974_drdy_irq(int irq, void *d)
391{
392 struct ak8974 *ak8974 = d;
393
394 if (!ak8974->drdy_irq)
395 return IRQ_NONE;
396
397 /* TODO: timestamp here to get good measurement stamps */
398 return IRQ_WAKE_THREAD;
399}
400
401static irqreturn_t ak8974_drdy_irq_thread(int irq, void *d)
402{
403 struct ak8974 *ak8974 = d;
404 unsigned int val;
405 int ret;
406
407 /* Check if this was a DRDY from us */
408 ret = regmap_read(ak8974->map, AK8974_STATUS, &val);
409 if (ret < 0) {
410 dev_err(&ak8974->i2c->dev, "error reading DRDY status\n");
411 return IRQ_HANDLED;
412 }
413 if (val & AK8974_STATUS_DRDY) {
414 /* Yes this was our IRQ */
415 complete(&ak8974->drdy_complete);
416 return IRQ_HANDLED;
417 }
418
419 /* We may be on a shared IRQ, let the next client check */
420 return IRQ_NONE;
421}
422
423static int ak8974_selftest(struct ak8974 *ak8974)
424{
425 struct device *dev = &ak8974->i2c->dev;
426 unsigned int val;
427 int ret;
428
429 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
430 if (ret)
431 return ret;
432 if (val != AK8974_SELFTEST_IDLE) {
433 dev_err(dev, "selftest not idle before test\n");
434 return -EIO;
435 }
436
437 /* Trigger self-test */
e93bd172 438 ret = regmap_set_bits(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_SELFTEST);
7c94a8b2
LW		 439 if (ret) {
440 dev_err(dev, "could not write CTRL3\n");
441 return ret;
442 }
443
444 msleep(AK8974_SELFTEST_DELAY);
445
446 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
447 if (ret)
448 return ret;
449 if (val != AK8974_SELFTEST_OK) {
450 dev_err(dev, "selftest result NOT OK (%02x)\n", val);
451 return -EIO;
452 }
453
454 ret = regmap_read(ak8974->map, AK8974_SELFTEST, &val);
455 if (ret)
456 return ret;
457 if (val != AK8974_SELFTEST_IDLE) {
458 dev_err(dev, "selftest not idle after test (%02x)\n", val);
459 return -EIO;
460 }
461 dev_dbg(dev, "passed self-test\n");
462
463 return 0;
464}
465
0a60340f
MM		 466static void ak8974_read_calib_data(struct ak8974 *ak8974, unsigned int reg,
467 __le16 *tab, size_t tab_size)
468{
469 int ret = regmap_bulk_read(ak8974->map, reg, tab, tab_size);
470 if (ret) {
471 memset(tab, 0xFF, tab_size);
472 dev_warn(&ak8974->i2c->dev,
473 "can't read calibration data (regs %u..%zu): %d\n",
474 reg, reg + tab_size - 1, ret);
475 } else {
476 add_device_randomness(tab, tab_size);
477 }
478}
479
7c94a8b2
LW		 480static int ak8974_detect(struct ak8974 *ak8974)
481{
482 unsigned int whoami;
483 const char *name;
484 int ret;
485 unsigned int fw;
486 u16 sn;
487
488 ret = regmap_read(ak8974->map, AK8974_WHOAMI, &whoami);
489 if (ret)
490 return ret;
491
21be26fc
MM		 492 name = "ami305";
493
7c94a8b2 494 switch (whoami) {
21be26fc
MM		 495 case AK8974_WHOAMI_VALUE_AMI306:
496 name = "ami306";
df561f66 497 fallthrough;
7c94a8b2 498 case AK8974_WHOAMI_VALUE_AMI305:
7c94a8b2
LW		 499 ret = regmap_read(ak8974->map, AMI305_VER, &fw);
500 if (ret)
501 return ret;
502 fw &= 0x7f; /* only bits 0 thru 6 valid */
503 ret = ak8974_get_u16_val(ak8974, AMI305_SN, &sn);
504 if (ret)
505 return ret;
408cc6eb 506 add_device_randomness(&sn, sizeof(sn));
7c94a8b2
LW		 507 dev_info(&ak8974->i2c->dev,
508 "detected %s, FW ver %02x, S/N: %04x\n",
509 name, fw, sn);
510 break;
511 case AK8974_WHOAMI_VALUE_AK8974:
512 name = "ak8974";
513 dev_info(&ak8974->i2c->dev, "detected AK8974\n");
514 break;
525530af
NR		 515 case AK8974_WHOAMI_VALUE_HSCDTD008A:
516 name = "hscdtd008a";
517 dev_info(&ak8974->i2c->dev, "detected hscdtd008a\n");
518 break;
7c94a8b2
LW		 519 default:
520 dev_err(&ak8974->i2c->dev, "unsupported device (%02x) ",
521 whoami);
522 return -ENODEV;
523 }
524
525 ak8974->name = name;
526 ak8974->variant = whoami;
527
0a60340f
MM		 528 if (whoami == AK8974_WHOAMI_VALUE_AMI306) {
529 __le16 fab_data1[9], fab_data2[3];
530 int i;
531
532 ak8974_read_calib_data(ak8974, AMI306_FINEOUTPUT_X,
533 fab_data1, sizeof(fab_data1));
534 ak8974_read_calib_data(ak8974, AMI306_OFFZERO_X,
535 fab_data2, sizeof(fab_data2));
536
537 for (i = 0; i < 3; ++i) {
538 static const char axis[3] = "XYZ";
539 static const char pgaxis[6] = "ZYZXYX";
540 unsigned offz = le16_to_cpu(fab_data2[i]) & 0x7F;
541 unsigned fine = le16_to_cpu(fab_data1[i]);
542 unsigned sens = le16_to_cpu(fab_data1[i + 3]);
543 unsigned pgain1 = le16_to_cpu(fab_data1[i + 6]);
544 unsigned pgain2 = pgain1 >> 8;
545
546 pgain1 &= 0xFF;
547
548 dev_info(&ak8974->i2c->dev,
549 "factory calibration for axis %c: offz=%u sens=%u fine=%u pga%c=%u pga%c=%u\n",
550 axis[i], offz, sens, fine, pgaxis[i * 2],
551 pgain1, pgaxis[i * 2 + 1], pgain2);
552 }
553 }
554
7c94a8b2
LW		 555 return 0;
556}
557
55ecaf17
LW		 558static int ak8974_measure_channel(struct ak8974 *ak8974, unsigned long address,
559 int *val)
560{
561 __le16 hw_values[3];
562 int ret;
563
564 pm_runtime_get_sync(&ak8974->i2c->dev);
565 mutex_lock(&ak8974->lock);
566
567 /*
568 * We read all axes and discard all but one, for optimized
569 * reading, use the triggered buffer.
570 */
571 ret = ak8974_trigmeas(ak8974);
572 if (ret)
573 goto out_unlock;
574 ret = ak8974_getresult(ak8974, hw_values);
575 if (ret)
576 goto out_unlock;
577 /*
578 * This explicit cast to (s16) is necessary as the measurement
579 * is done in 2's complement with positive and negative values.
580 * The follwing assignment to *val will then convert the signed
581 * s16 value to a signed int value.
582 */
583 *val = (s16)le16_to_cpu(hw_values[address]);
584out_unlock:
585 mutex_unlock(&ak8974->lock);
586 pm_runtime_mark_last_busy(&ak8974->i2c->dev);
587 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
588
589 return ret;
590}
591
7c94a8b2
LW		 592static int ak8974_read_raw(struct iio_dev *indio_dev,
593 struct iio_chan_spec const *chan,
594 int *val, int *val2,
595 long mask)
596{
597 struct ak8974 *ak8974 = iio_priv(indio_dev);
55ecaf17 598 int ret;
7c94a8b2
LW		 599
600 switch (mask) {
601 case IIO_CHAN_INFO_RAW:
602 if (chan->address > 2) {
603 dev_err(&ak8974->i2c->dev, "faulty channel address\n");
55ecaf17 604 return -EIO;
7c94a8b2 605 }
55ecaf17 606 ret = ak8974_measure_channel(ak8974, chan->address, val);
7c94a8b2 607 if (ret)
55ecaf17
LW		 608 return ret;
609 return IIO_VAL_INT;
16636527
LW		 610 case IIO_CHAN_INFO_SCALE:
611 switch (ak8974->variant) {
612 case AK8974_WHOAMI_VALUE_AMI306:
613 case AK8974_WHOAMI_VALUE_AMI305:
614 /*
615 * The datasheet for AMI305 and AMI306, page 6
616 * specifies the range of the sensor to be
617 * +/- 12 Gauss.
618 */
619 *val = 12;
620 /*
621 * 12 bits are used, +/- 2^11
622 * [ -2048 .. 2047 ] (manual page 20)
623 * [ 0xf800 .. 0x07ff ]
624 */
625 *val2 = 11;
626 return IIO_VAL_FRACTIONAL_LOG2;
627 case AK8974_WHOAMI_VALUE_HSCDTD008A:
628 /*
629 * The datasheet for HSCDTF008A, page 3 specifies the
630 * range of the sensor as +/- 2.4 mT per axis, which
631 * corresponds to +/- 2400 uT = +/- 24 Gauss.
632 */
633 *val = 24;
634 /*
635 * 15 bits are used (set up in CTRL4), +/- 2^14
636 * [ -16384 .. 16383 ] (manual page 24)
637 * [ 0xc000 .. 0x3fff ]
638 */
639 *val2 = 14;
640 return IIO_VAL_FRACTIONAL_LOG2;
641 default:
642 /* GUESSING +/- 12 Gauss */
643 *val = 12;
644 /* GUESSING 12 bits ADC +/- 2^11 */
645 *val2 = 11;
646 return IIO_VAL_FRACTIONAL_LOG2;
647 }
648 break;
649 default:
650 /* Unknown request */
651 break;
7c94a8b2
LW		 652 }
653
55ecaf17 654 return -EINVAL;
7c94a8b2
LW		 655}
656
657static void ak8974_fill_buffer(struct iio_dev *indio_dev)
658{
659 struct ak8974 *ak8974 = iio_priv(indio_dev);
660 int ret;
7c94a8b2
LW		 661
662 pm_runtime_get_sync(&ak8974->i2c->dev);
663 mutex_lock(&ak8974->lock);
664
665 ret = ak8974_trigmeas(ak8974);
666 if (ret) {
667 dev_err(&ak8974->i2c->dev, "error triggering measure\n");
668 goto out_unlock;
669 }
838e00b1 670 ret = ak8974_getresult(ak8974, ak8974->scan.channels);
7c94a8b2
LW		 671 if (ret) {
672 dev_err(&ak8974->i2c->dev, "error getting measures\n");
673 goto out_unlock;
674 }
675
838e00b1 676 iio_push_to_buffers_with_timestamp(indio_dev, &ak8974->scan,
7c94a8b2
LW		 677 iio_get_time_ns(indio_dev));
678
679 out_unlock:
680 mutex_unlock(&ak8974->lock);
681 pm_runtime_mark_last_busy(&ak8974->i2c->dev);
682 pm_runtime_put_autosuspend(&ak8974->i2c->dev);
683}
684
685static irqreturn_t ak8974_handle_trigger(int irq, void *p)
686{
687 const struct iio_poll_func *pf = p;
688 struct iio_dev *indio_dev = pf->indio_dev;
689
690 ak8974_fill_buffer(indio_dev);
691 iio_trigger_notify_done(indio_dev->trig);
692
693 return IRQ_HANDLED;
694}
695
696static const struct iio_mount_matrix *
697ak8974_get_mount_matrix(const struct iio_dev *indio_dev,
698 const struct iio_chan_spec *chan)
699{
700 struct ak8974 *ak8974 = iio_priv(indio_dev);
701
702 return &ak8974->orientation;
703}
704
705static const struct iio_chan_spec_ext_info ak8974_ext_info[] = {
706 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8974_get_mount_matrix),
707 { },
708};
709
b67959eb 710#define AK8974_AXIS_CHANNEL(axis, index, bits) \
7c94a8b2
LW		 711 { \
712 .type = IIO_MAGN, \
713 .modified = 1, \
714 .channel2 = IIO_MOD_##axis, \
16636527
LW		 715 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
716 BIT(IIO_CHAN_INFO_SCALE), \
7c94a8b2
LW		 717 .ext_info = ak8974_ext_info, \
718 .address = index, \
719 .scan_index = index, \
720 .scan_type = { \
721 .sign = 's', \
b67959eb 722 .realbits = bits, \
7c94a8b2
LW		 723 .storagebits = 16, \
724 .endianness = IIO_LE \
725 }, \
726 }
727
b67959eb
LW		 728/*
729 * We have no datasheet for the AK8974 but we guess that its
730 * ADC is 12 bits. The AMI305 and AMI306 certainly has 12bit
731 * ADC.
732 */
733static const struct iio_chan_spec ak8974_12_bits_channels[] = {
734 AK8974_AXIS_CHANNEL(X, 0, 12),
735 AK8974_AXIS_CHANNEL(Y, 1, 12),
736 AK8974_AXIS_CHANNEL(Z, 2, 12),
737 IIO_CHAN_SOFT_TIMESTAMP(3),
738};
739
740/*
741 * The HSCDTD008A has 15 bits resolution the way we set it up
742 * in CTRL4.
743 */
744static const struct iio_chan_spec ak8974_15_bits_channels[] = {
745 AK8974_AXIS_CHANNEL(X, 0, 15),
746 AK8974_AXIS_CHANNEL(Y, 1, 15),
747 AK8974_AXIS_CHANNEL(Z, 2, 15),
7c94a8b2
LW		 748 IIO_CHAN_SOFT_TIMESTAMP(3),
749};
750
751static const unsigned long ak8974_scan_masks[] = { 0x7, 0 };
752
753static const struct iio_info ak8974_info = {
754 .read_raw = &ak8974_read_raw,
7c94a8b2
LW		 755};
756
757static bool ak8974_writeable_reg(struct device *dev, unsigned int reg)
758{
759 struct i2c_client *i2c = to_i2c_client(dev);
760 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
761 struct ak8974 *ak8974 = iio_priv(indio_dev);
762
763 switch (reg) {
764 case AK8974_CTRL1:
765 case AK8974_CTRL2:
766 case AK8974_CTRL3:
767 case AK8974_INT_CTRL:
768 case AK8974_INT_THRES:
769 case AK8974_INT_THRES + 1:
525530af 770 return true;
7c94a8b2
LW		 771 case AK8974_PRESET:
772 case AK8974_PRESET + 1:
525530af 773 return ak8974->variant != AK8974_WHOAMI_VALUE_HSCDTD008A;
7c94a8b2
LW		 774 case AK8974_OFFSET_X:
775 case AK8974_OFFSET_X + 1:
776 case AK8974_OFFSET_Y:
777 case AK8974_OFFSET_Y + 1:
778 case AK8974_OFFSET_Z:
779 case AK8974_OFFSET_Z + 1:
525530af
NR		 780 return ak8974->variant == AK8974_WHOAMI_VALUE_AK8974 ||
781 ak8974->variant == AK8974_WHOAMI_VALUE_HSCDTD008A;
7c94a8b2
LW		 782 case AMI305_OFFSET_X:
783 case AMI305_OFFSET_X + 1:
784 case AMI305_OFFSET_Y:
785 case AMI305_OFFSET_Y + 1:
786 case AMI305_OFFSET_Z:
787 case AMI305_OFFSET_Z + 1:
21be26fc
MM		 788 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI305 ||
789 ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
790 case AMI306_CTRL4:
791 case AMI306_CTRL4 + 1:
792 return ak8974->variant == AK8974_WHOAMI_VALUE_AMI306;
7c94a8b2
LW		 793 default:
794 return false;
795 }
796}
797
9991f99e
MM		 798static bool ak8974_precious_reg(struct device *dev, unsigned int reg)
799{
800 return reg == AK8974_INT_CLEAR;
801}
802
7c94a8b2
LW		 803static const struct regmap_config ak8974_regmap_config = {
804 .reg_bits = 8,
805 .val_bits = 8,
806 .max_register = 0xff,
807 .writeable_reg = ak8974_writeable_reg,
9991f99e 808 .precious_reg = ak8974_precious_reg,
7c94a8b2
LW		 809};
810
149a5043 811static int ak8974_probe(struct i2c_client *i2c)
7c94a8b2
LW		 812{
813 struct iio_dev *indio_dev;
814 struct ak8974 *ak8974;
815 unsigned long irq_trig;
816 int irq = i2c->irq;
817 int ret;
818
819 /* Register with IIO */
820 indio_dev = devm_iio_device_alloc(&i2c->dev, sizeof(*ak8974));
821 if (indio_dev == NULL)
822 return -ENOMEM;
823
824 ak8974 = iio_priv(indio_dev);
825 i2c_set_clientdata(i2c, indio_dev);
826 ak8974->i2c = i2c;
827 mutex_init(&ak8974->lock);
828
b892770a 829 ret = iio_read_mount_matrix(&i2c->dev, &ak8974->orientation);
7c94a8b2
LW		 830 if (ret)
831 return ret;
832
833 ak8974->regs[0].supply = ak8974_reg_avdd;
834 ak8974->regs[1].supply = ak8974_reg_dvdd;
835
836 ret = devm_regulator_bulk_get(&i2c->dev,
837 ARRAY_SIZE(ak8974->regs),
838 ak8974->regs);
5d2180ce
KK		 839 if (ret < 0)
840 return dev_err_probe(&i2c->dev, ret, "cannot get regulators\n");
7c94a8b2
LW		 841
842 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
843 if (ret < 0) {
844 dev_err(&i2c->dev, "cannot enable regulators\n");
845 return ret;
846 }
847
848 /* Take runtime PM online */
849 pm_runtime_get_noresume(&i2c->dev);
850 pm_runtime_set_active(&i2c->dev);
851 pm_runtime_enable(&i2c->dev);
852
853 ak8974->map = devm_regmap_init_i2c(i2c, &ak8974_regmap_config);
854 if (IS_ERR(ak8974->map)) {
855 dev_err(&i2c->dev, "failed to allocate register map\n");
0187294d
DL		 856 pm_runtime_put_noidle(&i2c->dev);
857 pm_runtime_disable(&i2c->dev);
7c94a8b2
LW		 858 return PTR_ERR(ak8974->map);
859 }
860
861 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
862 if (ret) {
863 dev_err(&i2c->dev, "could not power on\n");
0187294d 864 goto disable_pm;
7c94a8b2
LW		 865 }
866
867 ret = ak8974_detect(ak8974);
868 if (ret) {
21be26fc 869 dev_err(&i2c->dev, "neither AK8974 nor AMI30x found\n");
0187294d 870 goto disable_pm;
7c94a8b2
LW		 871 }
872
873 ret = ak8974_selftest(ak8974);
874 if (ret)
875 dev_err(&i2c->dev, "selftest failed (continuing anyway)\n");
876
877 ret = ak8974_reset(ak8974);
878 if (ret) {
879 dev_err(&i2c->dev, "AK8974 reset failed\n");
0187294d 880 goto disable_pm;
7c94a8b2
LW		 881 }
882
b67959eb
LW		 883 switch (ak8974->variant) {
884 case AK8974_WHOAMI_VALUE_AMI306:
885 case AK8974_WHOAMI_VALUE_AMI305:
886 indio_dev->channels = ak8974_12_bits_channels;
887 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels);
888 break;
889 case AK8974_WHOAMI_VALUE_HSCDTD008A:
890 indio_dev->channels = ak8974_15_bits_channels;
891 indio_dev->num_channels = ARRAY_SIZE(ak8974_15_bits_channels);
892 break;
893 default:
894 indio_dev->channels = ak8974_12_bits_channels;
895 indio_dev->num_channels = ARRAY_SIZE(ak8974_12_bits_channels);
896 break;
897 }
7c94a8b2
LW		 898 indio_dev->info = &ak8974_info;
899 indio_dev->available_scan_masks = ak8974_scan_masks;
900 indio_dev->modes = INDIO_DIRECT_MODE;
901 indio_dev->name = ak8974->name;
902
903 ret = iio_triggered_buffer_setup(indio_dev, NULL,
904 ak8974_handle_trigger,
905 NULL);
906 if (ret) {
907 dev_err(&i2c->dev, "triggered buffer setup failed\n");
908 goto disable_pm;
909 }
910
911 /* If we have a valid DRDY IRQ, make use of it */
912 if (irq > 0) {
913 irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
914 if (irq_trig == IRQF_TRIGGER_RISING) {
915 dev_info(&i2c->dev, "enable rising edge DRDY IRQ\n");
916 } else if (irq_trig == IRQF_TRIGGER_FALLING) {
917 ak8974->drdy_active_low = true;
918 dev_info(&i2c->dev, "enable falling edge DRDY IRQ\n");
919 } else {
920 irq_trig = IRQF_TRIGGER_RISING;
921 }
922 irq_trig |= IRQF_ONESHOT;
923 irq_trig |= IRQF_SHARED;
924
925 ret = devm_request_threaded_irq(&i2c->dev,
926 irq,
927 ak8974_drdy_irq,
928 ak8974_drdy_irq_thread,
929 irq_trig,
930 ak8974->name,
931 ak8974);
932 if (ret) {
933 dev_err(&i2c->dev, "unable to request DRDY IRQ "
934 "- proceeding without IRQ\n");
935 goto no_irq;
936 }
937 ak8974->drdy_irq = true;
938 }
939
940no_irq:
941 ret = iio_device_register(indio_dev);
942 if (ret) {
943 dev_err(&i2c->dev, "device register failed\n");
944 goto cleanup_buffer;
945 }
946
0187294d
DL		 947 pm_runtime_set_autosuspend_delay(&i2c->dev,
948 AK8974_AUTOSUSPEND_DELAY);
949 pm_runtime_use_autosuspend(&i2c->dev);
950 pm_runtime_put(&i2c->dev);
951
7c94a8b2
LW		 952 return 0;
953
954cleanup_buffer:
955 iio_triggered_buffer_cleanup(indio_dev);
956disable_pm:
957 pm_runtime_put_noidle(&i2c->dev);
958 pm_runtime_disable(&i2c->dev);
959 ak8974_set_power(ak8974, AK8974_PWR_OFF);
7c94a8b2
LW		 960 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
961
962 return ret;
963}
964
ed5c2f5f 965static void ak8974_remove(struct i2c_client *i2c)
7c94a8b2
LW		 966{
967 struct iio_dev *indio_dev = i2c_get_clientdata(i2c);
968 struct ak8974 *ak8974 = iio_priv(indio_dev);
969
970 iio_device_unregister(indio_dev);
971 iio_triggered_buffer_cleanup(indio_dev);
972 pm_runtime_get_sync(&i2c->dev);
973 pm_runtime_put_noidle(&i2c->dev);
974 pm_runtime_disable(&i2c->dev);
975 ak8974_set_power(ak8974, AK8974_PWR_OFF);
976 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
7c94a8b2
LW		 977}
978
74f4595a 979static int ak8974_runtime_suspend(struct device *dev)
7c94a8b2
LW		 980{
981 struct ak8974 *ak8974 =
982 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
983
984 ak8974_set_power(ak8974, AK8974_PWR_OFF);
985 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
986
987 return 0;
988}
989
74f4595a 990static int ak8974_runtime_resume(struct device *dev)
7c94a8b2
LW		 991{
992 struct ak8974 *ak8974 =
993 iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
994 int ret;
995
996 ret = regulator_bulk_enable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
997 if (ret)
998 return ret;
999 msleep(AK8974_POWERON_DELAY);
1000 ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
1001 if (ret)
1002 goto out_regulator_disable;
1003
1004 ret = ak8974_configure(ak8974);
1005 if (ret)
1006 goto out_disable_power;
1007
1008 return 0;
1009
1010out_disable_power:
1011 ak8974_set_power(ak8974, AK8974_PWR_OFF);
1012out_regulator_disable:
1013 regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs);
1014
1015 return ret;
1016}
7c94a8b2 1017
74f4595a
JC		 1018static DEFINE_RUNTIME_DEV_PM_OPS(ak8974_dev_pm_ops, ak8974_runtime_suspend,
1019 ak8974_runtime_resume, NULL);
7c94a8b2
LW		 1020
1021static const struct i2c_device_id ak8974_id[] = {
4391affa
UKK		 1022 { "ami305" },
1023 { "ami306" },
1024 { "ak8974" },
1025 { "hscdtd008a" },
7c94a8b2
LW		 1026 {}
1027};
1028MODULE_DEVICE_TABLE(i2c, ak8974_id);
1029
1030static const struct of_device_id ak8974_of_match[] = {
1031 { .compatible = "asahi-kasei,ak8974", },
525530af 1032 { .compatible = "alps,hscdtd008a", },
7c94a8b2
LW		 1033 {}
1034};
1035MODULE_DEVICE_TABLE(of, ak8974_of_match);
1036
1037static struct i2c_driver ak8974_driver = {
1038 .driver = {
1039 .name = "ak8974",
74f4595a 1040 .pm = pm_ptr(&ak8974_dev_pm_ops),
2b4f0172 1041 .of_match_table = ak8974_of_match,
7c94a8b2 1042 },
7cf15f42 1043 .probe = ak8974_probe,
3ff861f5 1044 .remove = ak8974_remove,
7c94a8b2
LW		 1045 .id_table = ak8974_id,
1046};
1047module_i2c_driver(ak8974_driver);
1048
21be26fc 1049MODULE_DESCRIPTION("AK8974 and AMI30x 3-axis magnetometer driver");
7c94a8b2
LW		 1050MODULE_AUTHOR("Samu Onkalo");
1051MODULE_AUTHOR("Linus Walleij");
1052MODULE_LICENSE("GPL v2");
Linux 6.x block layer and io_uring tree(s)