1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * A sensor driver for the magnetometer AK8975.
4 *
5 * Magnetic compass sensor driver for monitoring magnetic flux information.
6 *
7 * Copyright (c) 2010, NVIDIA Corporation.
8 */
9
10#include <linux/module.h>
11#include <linux/mod_devicetable.h>
12#include <linux/kernel.h>
13#include <linux/slab.h>
14#include <linux/i2c.h>
15#include <linux/interrupt.h>
16#include <linux/err.h>
17#include <linux/mutex.h>
18#include <linux/delay.h>
19#include <linux/bitops.h>
20#include <linux/gpio/consumer.h>
21#include <linux/regulator/consumer.h>
22#include <linux/pm_runtime.h>
23
24#include <linux/iio/iio.h>
25#include <linux/iio/sysfs.h>
26#include <linux/iio/buffer.h>
27#include <linux/iio/trigger.h>
28#include <linux/iio/trigger_consumer.h>
29#include <linux/iio/triggered_buffer.h>
30
31/*
32 * Register definitions, as well as various shifts and masks to get at the
33 * individual fields of the registers.
34 */
35#define AK8975_REG_WIA 0x00
36#define AK8975_DEVICE_ID 0x48
37
38#define AK8975_REG_INFO 0x01
39
40#define AK8975_REG_ST1 0x02
41#define AK8975_REG_ST1_DRDY_SHIFT 0
42#define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT)
43
44#define AK8975_REG_HXL 0x03
45#define AK8975_REG_HXH 0x04
46#define AK8975_REG_HYL 0x05
47#define AK8975_REG_HYH 0x06
48#define AK8975_REG_HZL 0x07
49#define AK8975_REG_HZH 0x08
50#define AK8975_REG_ST2 0x09
51#define AK8975_REG_ST2_DERR_SHIFT 2
52#define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT)
53
54#define AK8975_REG_ST2_HOFL_SHIFT 3
55#define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT)
56
57#define AK8975_REG_CNTL 0x0A
58#define AK8975_REG_CNTL_MODE_SHIFT 0
59#define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT)
60#define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00
61#define AK8975_REG_CNTL_MODE_ONCE 0x01
62#define AK8975_REG_CNTL_MODE_SELF_TEST 0x08
63#define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F
64
65#define AK8975_REG_RSVC 0x0B
66#define AK8975_REG_ASTC 0x0C
67#define AK8975_REG_TS1 0x0D
68#define AK8975_REG_TS2 0x0E
69#define AK8975_REG_I2CDIS 0x0F
70#define AK8975_REG_ASAX 0x10
71#define AK8975_REG_ASAY 0x11
72#define AK8975_REG_ASAZ 0x12
73
74#define AK8975_MAX_REGS AK8975_REG_ASAZ
75
76/*
77 * AK09912 Register definitions
78 */
79#define AK09912_REG_WIA1 0x00
80#define AK09912_REG_WIA2 0x01
81#define AK09916_DEVICE_ID 0x09
82#define AK09912_DEVICE_ID 0x04
83#define AK09911_DEVICE_ID 0x05
84
85#define AK09911_REG_INFO1 0x02
86#define AK09911_REG_INFO2 0x03
87
88#define AK09912_REG_ST1 0x10
89
90#define AK09912_REG_ST1_DRDY_SHIFT 0
91#define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT)
92
93#define AK09912_REG_HXL 0x11
94#define AK09912_REG_HXH 0x12
95#define AK09912_REG_HYL 0x13
96#define AK09912_REG_HYH 0x14
97#define AK09912_REG_HZL 0x15
98#define AK09912_REG_HZH 0x16
99#define AK09912_REG_TMPS 0x17
100
101#define AK09912_REG_ST2 0x18
102#define AK09912_REG_ST2_HOFL_SHIFT 3
103#define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT)
104
105#define AK09912_REG_CNTL1 0x30
106
107#define AK09912_REG_CNTL2 0x31
108#define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00
109#define AK09912_REG_CNTL_MODE_ONCE 0x01
110#define AK09912_REG_CNTL_MODE_SELF_TEST 0x10
111#define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F
112#define AK09912_REG_CNTL2_MODE_SHIFT 0
113#define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT)
114
115#define AK09912_REG_CNTL3 0x32
116
117#define AK09912_REG_TS1 0x33
118#define AK09912_REG_TS2 0x34
119#define AK09912_REG_TS3 0x35
120#define AK09912_REG_I2CDIS 0x36
121#define AK09912_REG_TS4 0x37
122
123#define AK09912_REG_ASAX 0x60
124#define AK09912_REG_ASAY 0x61
125#define AK09912_REG_ASAZ 0x62
126
127#define AK09912_MAX_REGS AK09912_REG_ASAZ
128
129/*
130 * Miscellaneous values.
131 */
132#define AK8975_MAX_CONVERSION_TIMEOUT 500
133#define AK8975_CONVERSION_DONE_POLL_TIME 10
134#define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000)
135
136/*
137 * Precalculate scale factor (in Gauss units) for each axis and
138 * store in the device data.
139 *
140 * This scale factor is axis-dependent, and is derived from 3 calibration
141 * factors ASA(x), ASA(y), and ASA(z).
142 *
143 * These ASA values are read from the sensor device at start of day, and
144 * cached in the device context struct.
145 *
146 * Adjusting the flux value with the sensitivity adjustment value should be
147 * done via the following formula:
148 *
149 * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 )
150 * where H is the raw value, ASA is the sensitivity adjustment, and Hadj
151 * is the resultant adjusted value.
152 *
153 * We reduce the formula to:
154 *
155 * Hadj = H * (ASA + 128) / 256
156 *
157 * H is in the range of -4096 to 4095. The magnetometer has a range of
158 * +-1229uT. To go from the raw value to uT is:
159 *
160 * HuT = H * 1229/4096, or roughly, 3/10.
161 *
162 * Since 1uT = 0.01 gauss, our final scale factor becomes:
163 *
164 * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100
165 * Hadj = H * ((ASA + 128) * 0.003) / 256
166 *
167 * Since ASA doesn't change, we cache the resultant scale factor into the
168 * device context in ak8975_setup().
169 *
170 * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we
171 * multiply the stored scale value by 1e6.
172 */
173static long ak8975_raw_to_gauss(u16 data)
174{
175 return (((long)data + 128) * 3000) / 256;
176}
177
178/*
179 * For AK8963 and AK09911, same calculation, but the device is less sensitive:
180 *
181 * H is in the range of +-8190. The magnetometer has a range of
182 * +-4912uT. To go from the raw value to uT is:
183 *
184 * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10.
185 */
186
187static long ak8963_09911_raw_to_gauss(u16 data)
188{
189 return (((long)data + 128) * 6000) / 256;
190}
191
192/*
193 * For AK09912, same calculation, except the device is more sensitive:
194 *
195 * H is in the range of -32752 to 32752. The magnetometer has a range of
196 * +-4912uT. To go from the raw value to uT is:
197 *
198 * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10.
199 */
200static long ak09912_raw_to_gauss(u16 data)
201{
202 return (((long)data + 128) * 1500) / 256;
203}
204
205/* Compatible Asahi Kasei Compass parts */
206enum asahi_compass_chipset {
207 AK8975,
208 AK8963,
209 AK09911,
210 AK09912,
211 AK09916,
212};
213
214enum ak_ctrl_reg_addr {
215 ST1,
216 ST2,
217 CNTL,
218 ASA_BASE,
219 MAX_REGS,
220 REGS_END,
221};
222
223enum ak_ctrl_reg_mask {
224 ST1_DRDY,
225 ST2_HOFL,
226 ST2_DERR,
227 CNTL_MODE,
228 MASK_END,
229};
230
231enum ak_ctrl_mode {
232 POWER_DOWN,
233 MODE_ONCE,
234 SELF_TEST,
235 FUSE_ROM,
236 MODE_END,
237};
238
239struct ak_def {
240 enum asahi_compass_chipset type;
241 long (*raw_to_gauss)(u16 data);
242 u16 range;
243 u8 ctrl_regs[REGS_END];
244 u8 ctrl_masks[MASK_END];
245 u8 ctrl_modes[MODE_END];
246 u8 data_regs[3];
247};
248
249static const struct ak_def ak_def_array[] = {
250 [AK8975] = {
251 .type = AK8975,
252 .raw_to_gauss = ak8975_raw_to_gauss,
253 .range = 4096,
254 .ctrl_regs = {
255 AK8975_REG_ST1,
256 AK8975_REG_ST2,
257 AK8975_REG_CNTL,
258 AK8975_REG_ASAX,
259 AK8975_MAX_REGS},
260 .ctrl_masks = {
261 AK8975_REG_ST1_DRDY_MASK,
262 AK8975_REG_ST2_HOFL_MASK,
263 AK8975_REG_ST2_DERR_MASK,
264 AK8975_REG_CNTL_MODE_MASK},
265 .ctrl_modes = {
266 AK8975_REG_CNTL_MODE_POWER_DOWN,
267 AK8975_REG_CNTL_MODE_ONCE,
268 AK8975_REG_CNTL_MODE_SELF_TEST,
269 AK8975_REG_CNTL_MODE_FUSE_ROM},
270 .data_regs = {
271 AK8975_REG_HXL,
272 AK8975_REG_HYL,
273 AK8975_REG_HZL},
274 },
275 [AK8963] = {
276 .type = AK8963,
277 .raw_to_gauss = ak8963_09911_raw_to_gauss,
278 .range = 8190,
279 .ctrl_regs = {
280 AK8975_REG_ST1,
281 AK8975_REG_ST2,
282 AK8975_REG_CNTL,
283 AK8975_REG_ASAX,
284 AK8975_MAX_REGS},
285 .ctrl_masks = {
286 AK8975_REG_ST1_DRDY_MASK,
287 AK8975_REG_ST2_HOFL_MASK,
288 0,
289 AK8975_REG_CNTL_MODE_MASK},
290 .ctrl_modes = {
291 AK8975_REG_CNTL_MODE_POWER_DOWN,
292 AK8975_REG_CNTL_MODE_ONCE,
293 AK8975_REG_CNTL_MODE_SELF_TEST,
294 AK8975_REG_CNTL_MODE_FUSE_ROM},
295 .data_regs = {
296 AK8975_REG_HXL,
297 AK8975_REG_HYL,
298 AK8975_REG_HZL},
299 },
300 [AK09911] = {
301 .type = AK09911,
302 .raw_to_gauss = ak8963_09911_raw_to_gauss,
303 .range = 8192,
304 .ctrl_regs = {
305 AK09912_REG_ST1,
306 AK09912_REG_ST2,
307 AK09912_REG_CNTL2,
308 AK09912_REG_ASAX,
309 AK09912_MAX_REGS},
310 .ctrl_masks = {
311 AK09912_REG_ST1_DRDY_MASK,
312 AK09912_REG_ST2_HOFL_MASK,
313 0,
314 AK09912_REG_CNTL2_MODE_MASK},
315 .ctrl_modes = {
316 AK09912_REG_CNTL_MODE_POWER_DOWN,
317 AK09912_REG_CNTL_MODE_ONCE,
318 AK09912_REG_CNTL_MODE_SELF_TEST,
319 AK09912_REG_CNTL_MODE_FUSE_ROM},
320 .data_regs = {
321 AK09912_REG_HXL,
322 AK09912_REG_HYL,
323 AK09912_REG_HZL},
324 },
325 [AK09912] = {
326 .type = AK09912,
327 .raw_to_gauss = ak09912_raw_to_gauss,
328 .range = 32752,
329 .ctrl_regs = {
330 AK09912_REG_ST1,
331 AK09912_REG_ST2,
332 AK09912_REG_CNTL2,
333 AK09912_REG_ASAX,
334 AK09912_MAX_REGS},
335 .ctrl_masks = {
336 AK09912_REG_ST1_DRDY_MASK,
337 AK09912_REG_ST2_HOFL_MASK,
338 0,
339 AK09912_REG_CNTL2_MODE_MASK},
340 .ctrl_modes = {
341 AK09912_REG_CNTL_MODE_POWER_DOWN,
342 AK09912_REG_CNTL_MODE_ONCE,
343 AK09912_REG_CNTL_MODE_SELF_TEST,
344 AK09912_REG_CNTL_MODE_FUSE_ROM},
345 .data_regs = {
346 AK09912_REG_HXL,
347 AK09912_REG_HYL,
348 AK09912_REG_HZL},
349 },
350 [AK09916] = {
351 .type = AK09916,
352 .raw_to_gauss = ak09912_raw_to_gauss,
353 .range = 32752,
354 .ctrl_regs = {
355 AK09912_REG_ST1,
356 AK09912_REG_ST2,
357 AK09912_REG_CNTL2,
358 AK09912_REG_ASAX,
359 AK09912_MAX_REGS},
360 .ctrl_masks = {
361 AK09912_REG_ST1_DRDY_MASK,
362 AK09912_REG_ST2_HOFL_MASK,
363 0,
364 AK09912_REG_CNTL2_MODE_MASK},
365 .ctrl_modes = {
366 AK09912_REG_CNTL_MODE_POWER_DOWN,
367 AK09912_REG_CNTL_MODE_ONCE,
368 AK09912_REG_CNTL_MODE_SELF_TEST,
369 AK09912_REG_CNTL_MODE_FUSE_ROM},
370 .data_regs = {
371 AK09912_REG_HXL,
372 AK09912_REG_HYL,
373 AK09912_REG_HZL},
374 }
375};
376
377/*
378 * Per-instance context data for the device.
379 */
380struct ak8975_data {
381 struct i2c_client *client;
382 const struct ak_def *def;
383 struct mutex lock;
384 u8 asa[3];
385 long raw_to_gauss[3];
386 struct gpio_desc *eoc_gpiod;
387 struct gpio_desc *reset_gpiod;
388 int eoc_irq;
389 wait_queue_head_t data_ready_queue;
390 unsigned long flags;
391 u8 cntl_cache;
392 struct iio_mount_matrix orientation;
393 struct regulator *vdd;
394 struct regulator *vid;
395
396 /* Ensure natural alignment of timestamp */
397 struct {
398 s16 channels[3];
399 s64 ts __aligned(8);
400 } scan;
401};
402
403/* Enable attached power regulator if any. */
404static int ak8975_power_on(const struct ak8975_data *data)
405{
406 int ret;
407
408 ret = regulator_enable(regulator: data->vdd);
409 if (ret) {
410 dev_warn(&data->client->dev,
411 "Failed to enable specified Vdd supply\n");
412 return ret;
413 }
414 ret = regulator_enable(regulator: data->vid);
415 if (ret) {
416 dev_warn(&data->client->dev,
417 "Failed to enable specified Vid supply\n");
418 regulator_disable(regulator: data->vdd);
419 return ret;
420 }
421
422 gpiod_set_value_cansleep(desc: data->reset_gpiod, value: 0);
423
424 /*
425 * According to the datasheet the power supply rise time is 200us
426 * and the minimum wait time before mode setting is 100us, in
427 * total 300us. Add some margin and say minimum 500us here.
428 */
429 usleep_range(min: 500, max: 1000);
430 return 0;
431}
432
433/* Disable attached power regulator if any. */
434static void ak8975_power_off(const struct ak8975_data *data)
435{
436 gpiod_set_value_cansleep(desc: data->reset_gpiod, value: 1);
437
438 regulator_disable(regulator: data->vid);
439 regulator_disable(regulator: data->vdd);
440}
441
442/*
443 * Return 0 if the i2c device is the one we expect.
444 * return a negative error number otherwise
445 */
446static int ak8975_who_i_am(struct i2c_client *client,
447 enum asahi_compass_chipset type)
448{
449 u8 wia_val[2];
450 int ret;
451
452 /*
453 * Signature for each device:
454 * Device | WIA1 | WIA2
455 * AK09916 | DEVICE_ID_| AK09916_DEVICE_ID
456 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID
457 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID
458 * AK8975 | DEVICE_ID | NA
459 * AK8963 | DEVICE_ID | NA
460 */
461 ret = i2c_smbus_read_i2c_block_data_or_emulated(
462 client, AK09912_REG_WIA1, length: 2, values: wia_val);
463 if (ret < 0) {
464 dev_err(&client->dev, "Error reading WIA\n");
465 return ret;
466 }
467
468 if (wia_val[0] != AK8975_DEVICE_ID)
469 return -ENODEV;
470
471 switch (type) {
472 case AK8975:
473 case AK8963:
474 return 0;
475 case AK09911:
476 if (wia_val[1] == AK09911_DEVICE_ID)
477 return 0;
478 break;
479 case AK09912:
480 if (wia_val[1] == AK09912_DEVICE_ID)
481 return 0;
482 break;
483 case AK09916:
484 if (wia_val[1] == AK09916_DEVICE_ID)
485 return 0;
486 break;
487 default:
488 dev_err(&client->dev, "Type %d unknown\n", type);
489 }
490 return -ENODEV;
491}
492
493/*
494 * Helper function to write to CNTL register.
495 */
496static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode)
497{
498 u8 regval;
499 int ret;
500
501 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) |
502 data->def->ctrl_modes[mode];
503 ret = i2c_smbus_write_byte_data(client: data->client,
504 command: data->def->ctrl_regs[CNTL], value: regval);
505 if (ret < 0) {
506 return ret;
507 }
508 data->cntl_cache = regval;
509 /* After mode change wait atleast 100us */
510 usleep_range(min: 100, max: 500);
511
512 return 0;
513}
514
515/*
516 * Handle data ready irq
517 */
518static irqreturn_t ak8975_irq_handler(int irq, void *data)
519{
520 struct ak8975_data *ak8975 = data;
521
522 set_bit(nr: 0, addr: &ak8975->flags);
523 wake_up(&ak8975->data_ready_queue);
524
525 return IRQ_HANDLED;
526}
527
528/*
529 * Install data ready interrupt handler
530 */
531static int ak8975_setup_irq(struct ak8975_data *data)
532{
533 struct i2c_client *client = data->client;
534 int rc;
535 int irq;
536
537 init_waitqueue_head(&data->data_ready_queue);
538 clear_bit(nr: 0, addr: &data->flags);
539 if (client->irq)
540 irq = client->irq;
541 else
542 irq = gpiod_to_irq(desc: data->eoc_gpiod);
543
544 rc = devm_request_irq(dev: &client->dev, irq, handler: ak8975_irq_handler,
545 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
546 devname: dev_name(dev: &client->dev), dev_id: data);
547 if (rc < 0) {
548 dev_err(&client->dev, "irq %d request failed: %d\n", irq, rc);
549 return rc;
550 }
551
552 data->eoc_irq = irq;
553
554 return rc;
555}
556
557
558/*
559 * Perform some start-of-day setup, including reading the asa calibration
560 * values and caching them.
561 */
562static int ak8975_setup(struct i2c_client *client)
563{
564 struct iio_dev *indio_dev = i2c_get_clientdata(client);
565 struct ak8975_data *data = iio_priv(indio_dev);
566 int ret;
567
568 /* Write the fused rom access mode. */
569 ret = ak8975_set_mode(data, mode: FUSE_ROM);
570 if (ret < 0) {
571 dev_err(&client->dev, "Error in setting fuse access mode\n");
572 return ret;
573 }
574
575 /* Get asa data and store in the device data. */
576 ret = i2c_smbus_read_i2c_block_data_or_emulated(
577 client, command: data->def->ctrl_regs[ASA_BASE],
578 length: 3, values: data->asa);
579 if (ret < 0) {
580 dev_err(&client->dev, "Not able to read asa data\n");
581 return ret;
582 }
583
584 /* After reading fuse ROM data set power-down mode */
585 ret = ak8975_set_mode(data, mode: POWER_DOWN);
586 if (ret < 0) {
587 dev_err(&client->dev, "Error in setting power-down mode\n");
588 return ret;
589 }
590
591 if (data->eoc_gpiod || client->irq > 0) {
592 ret = ak8975_setup_irq(data);
593 if (ret < 0) {
594 dev_err(&client->dev,
595 "Error setting data ready interrupt\n");
596 return ret;
597 }
598 }
599
600 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]);
601 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]);
602 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]);
603
604 return 0;
605}
606
607static int wait_conversion_complete_gpio(struct ak8975_data *data)
608{
609 struct i2c_client *client = data->client;
610 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
611 int ret;
612
613 /* Wait for the conversion to complete. */
614 while (timeout_ms) {
615 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
616 if (gpiod_get_value(desc: data->eoc_gpiod))
617 break;
618 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
619 }
620 if (!timeout_ms) {
621 dev_err(&client->dev, "Conversion timeout happened\n");
622 return -EINVAL;
623 }
624
625 ret = i2c_smbus_read_byte_data(client, command: data->def->ctrl_regs[ST1]);
626 if (ret < 0)
627 dev_err(&client->dev, "Error in reading ST1\n");
628
629 return ret;
630}
631
632static int wait_conversion_complete_polled(struct ak8975_data *data)
633{
634 struct i2c_client *client = data->client;
635 u8 read_status;
636 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
637 int ret;
638
639 /* Wait for the conversion to complete. */
640 while (timeout_ms) {
641 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
642 ret = i2c_smbus_read_byte_data(client,
643 command: data->def->ctrl_regs[ST1]);
644 if (ret < 0) {
645 dev_err(&client->dev, "Error in reading ST1\n");
646 return ret;
647 }
648 read_status = ret;
649 if (read_status)
650 break;
651 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
652 }
653 if (!timeout_ms) {
654 dev_err(&client->dev, "Conversion timeout happened\n");
655 return -EINVAL;
656 }
657
658 return read_status;
659}
660
661/* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */
662static int wait_conversion_complete_interrupt(struct ak8975_data *data)
663{
664 int ret;
665
666 ret = wait_event_timeout(data->data_ready_queue,
667 test_bit(0, &data->flags),
668 AK8975_DATA_READY_TIMEOUT);
669 clear_bit(nr: 0, addr: &data->flags);
670
671 return ret > 0 ? 0 : -ETIME;
672}
673
674static int ak8975_start_read_axis(struct ak8975_data *data,
675 const struct i2c_client *client)
676{
677 /* Set up the device for taking a sample. */
678 int ret = ak8975_set_mode(data, mode: MODE_ONCE);
679
680 if (ret < 0) {
681 dev_err(&client->dev, "Error in setting operating mode\n");
682 return ret;
683 }
684
685 /* Wait for the conversion to complete. */
686 if (data->eoc_irq)
687 ret = wait_conversion_complete_interrupt(data);
688 else if (data->eoc_gpiod)
689 ret = wait_conversion_complete_gpio(data);
690 else
691 ret = wait_conversion_complete_polled(data);
692 if (ret < 0)
693 return ret;
694
695 /* This will be executed only for non-interrupt based waiting case */
696 if (ret & data->def->ctrl_masks[ST1_DRDY]) {
697 ret = i2c_smbus_read_byte_data(client,
698 command: data->def->ctrl_regs[ST2]);
699 if (ret < 0) {
700 dev_err(&client->dev, "Error in reading ST2\n");
701 return ret;
702 }
703 if (ret & (data->def->ctrl_masks[ST2_DERR] |
704 data->def->ctrl_masks[ST2_HOFL])) {
705 dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
706 return -EINVAL;
707 }
708 }
709
710 return 0;
711}
712
713/* Retrieve raw flux value for one of the x, y, or z axis. */
714static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
715{
716 struct ak8975_data *data = iio_priv(indio_dev);
717 const struct i2c_client *client = data->client;
718 const struct ak_def *def = data->def;
719 __le16 rval;
720 u16 buff;
721 int ret;
722
723 pm_runtime_get_sync(dev: &data->client->dev);
724
725 mutex_lock(&data->lock);
726
727 ret = ak8975_start_read_axis(data, client);
728 if (ret)
729 goto exit;
730
731 ret = i2c_smbus_read_i2c_block_data_or_emulated(
732 client, command: def->data_regs[index],
733 length: sizeof(rval), values: (u8*)&rval);
734 if (ret < 0)
735 goto exit;
736
737 mutex_unlock(lock: &data->lock);
738
739 pm_runtime_mark_last_busy(dev: &data->client->dev);
740 pm_runtime_put_autosuspend(dev: &data->client->dev);
741
742 /* Swap bytes and convert to valid range. */
743 buff = le16_to_cpu(rval);
744 *val = clamp_t(s16, buff, -def->range, def->range);
745 return IIO_VAL_INT;
746
747exit:
748 mutex_unlock(lock: &data->lock);
749 dev_err(&client->dev, "Error in reading axis\n");
750 return ret;
751}
752
753static int ak8975_read_raw(struct iio_dev *indio_dev,
754 struct iio_chan_spec const *chan,
755 int *val, int *val2,
756 long mask)
757{
758 struct ak8975_data *data = iio_priv(indio_dev);
759
760 switch (mask) {
761 case IIO_CHAN_INFO_RAW:
762 return ak8975_read_axis(indio_dev, index: chan->address, val);
763 case IIO_CHAN_INFO_SCALE:
764 *val = 0;
765 *val2 = data->raw_to_gauss[chan->address];
766 return IIO_VAL_INT_PLUS_MICRO;
767 }
768 return -EINVAL;
769}
770
771static const struct iio_mount_matrix *
772ak8975_get_mount_matrix(const struct iio_dev *indio_dev,
773 const struct iio_chan_spec *chan)
774{
775 struct ak8975_data *data = iio_priv(indio_dev);
776
777 return &data->orientation;
778}
779
780static const struct iio_chan_spec_ext_info ak8975_ext_info[] = {
781 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix),
782 { }
783};
784
785#define AK8975_CHANNEL(axis, index) \
786 { \
787 .type = IIO_MAGN, \
788 .modified = 1, \
789 .channel2 = IIO_MOD_##axis, \
790 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
791 BIT(IIO_CHAN_INFO_SCALE), \
792 .address = index, \
793 .scan_index = index, \
794 .scan_type = { \
795 .sign = 's', \
796 .realbits = 16, \
797 .storagebits = 16, \
798 .endianness = IIO_CPU \
799 }, \
800 .ext_info = ak8975_ext_info, \
801 }
802
803static const struct iio_chan_spec ak8975_channels[] = {
804 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
805 IIO_CHAN_SOFT_TIMESTAMP(3),
806};
807
808static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
809
810static const struct iio_info ak8975_info = {
811 .read_raw = &ak8975_read_raw,
812};
813
814static void ak8975_fill_buffer(struct iio_dev *indio_dev)
815{
816 struct ak8975_data *data = iio_priv(indio_dev);
817 const struct i2c_client *client = data->client;
818 const struct ak_def *def = data->def;
819 int ret;
820 __le16 fval[3];
821
822 mutex_lock(&data->lock);
823
824 ret = ak8975_start_read_axis(data, client);
825 if (ret)
826 goto unlock;
827
828 /*
829 * For each axis, read the flux value from the appropriate register
830 * (the register is specified in the iio device attributes).
831 */
832 ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
833 command: def->data_regs[0],
834 length: 3 * sizeof(fval[0]),
835 values: (u8 *)fval);
836 if (ret < 0)
837 goto unlock;
838
839 mutex_unlock(lock: &data->lock);
840
841 /* Clamp to valid range. */
842 data->scan.channels[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range);
843 data->scan.channels[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range);
844 data->scan.channels[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range);
845
846 iio_push_to_buffers_with_timestamp(indio_dev, data: &data->scan,
847 timestamp: iio_get_time_ns(indio_dev));
848
849 return;
850
851unlock:
852 mutex_unlock(lock: &data->lock);
853 dev_err(&client->dev, "Error in reading axes block\n");
854}
855
856static irqreturn_t ak8975_handle_trigger(int irq, void *p)
857{
858 const struct iio_poll_func *pf = p;
859 struct iio_dev *indio_dev = pf->indio_dev;
860
861 ak8975_fill_buffer(indio_dev);
862 iio_trigger_notify_done(trig: indio_dev->trig);
863 return IRQ_HANDLED;
864}
865
866static int ak8975_probe(struct i2c_client *client)
867{
868 const struct i2c_device_id *id = i2c_client_get_device_id(client);
869 struct ak8975_data *data;
870 struct iio_dev *indio_dev;
871 struct gpio_desc *eoc_gpiod;
872 struct gpio_desc *reset_gpiod;
873 int err;
874 const char *name = NULL;
875
876 /*
877 * Grab and set up the supplied GPIO.
878 * We may not have a GPIO based IRQ to scan, that is fine, we will
879 * poll if so.
880 */
881 eoc_gpiod = devm_gpiod_get_optional(dev: &client->dev, NULL, flags: GPIOD_IN);
882 if (IS_ERR(ptr: eoc_gpiod))
883 return PTR_ERR(ptr: eoc_gpiod);
884 if (eoc_gpiod)
885 gpiod_set_consumer_name(desc: eoc_gpiod, name: "ak_8975");
886
887 /*
888 * According to AK09911 datasheet, if reset GPIO is provided then
889 * deassert reset on ak8975_power_on() and assert reset on
890 * ak8975_power_off().
891 */
892 reset_gpiod = devm_gpiod_get_optional(dev: &client->dev,
893 con_id: "reset", flags: GPIOD_OUT_HIGH);
894 if (IS_ERR(ptr: reset_gpiod))
895 return PTR_ERR(ptr: reset_gpiod);
896
897 /* Register with IIO */
898 indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*data));
899 if (indio_dev == NULL)
900 return -ENOMEM;
901
902 data = iio_priv(indio_dev);
903 i2c_set_clientdata(client, data: indio_dev);
904
905 data->client = client;
906 data->eoc_gpiod = eoc_gpiod;
907 data->reset_gpiod = reset_gpiod;
908 data->eoc_irq = 0;
909
910 err = iio_read_mount_matrix(dev: &client->dev, matrix: &data->orientation);
911 if (err)
912 return err;
913
914 /* id will be NULL when enumerated via ACPI */
915 data->def = i2c_get_match_data(client);
916 if (!data->def)
917 return -ENODEV;
918
919 /* If enumerated via firmware node, fix the ABI */
920 if (dev_fwnode(&client->dev))
921 name = dev_name(dev: &client->dev);
922 else
923 name = id->name;
924
925 /* Fetch the regulators */
926 data->vdd = devm_regulator_get(dev: &client->dev, id: "vdd");
927 if (IS_ERR(ptr: data->vdd))
928 return PTR_ERR(ptr: data->vdd);
929 data->vid = devm_regulator_get(dev: &client->dev, id: "vid");
930 if (IS_ERR(ptr: data->vid))
931 return PTR_ERR(ptr: data->vid);
932
933 err = ak8975_power_on(data);
934 if (err)
935 return err;
936
937 err = ak8975_who_i_am(client, type: data->def->type);
938 if (err < 0) {
939 dev_err(&client->dev, "Unexpected device\n");
940 goto power_off;
941 }
942 dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
943
944 /* Perform some basic start-of-day setup of the device. */
945 err = ak8975_setup(client);
946 if (err < 0) {
947 dev_err(&client->dev, "%s initialization fails\n", name);
948 goto power_off;
949 }
950
951 mutex_init(&data->lock);
952 indio_dev->channels = ak8975_channels;
953 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
954 indio_dev->info = &ak8975_info;
955 indio_dev->available_scan_masks = ak8975_scan_masks;
956 indio_dev->modes = INDIO_DIRECT_MODE;
957 indio_dev->name = name;
958
959 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
960 NULL);
961 if (err) {
962 dev_err(&client->dev, "triggered buffer setup failed\n");
963 goto power_off;
964 }
965
966 err = iio_device_register(indio_dev);
967 if (err) {
968 dev_err(&client->dev, "device register failed\n");
969 goto cleanup_buffer;
970 }
971
972 /* Enable runtime PM */
973 pm_runtime_get_noresume(dev: &client->dev);
974 pm_runtime_set_active(dev: &client->dev);
975 pm_runtime_enable(dev: &client->dev);
976 /*
977 * The device comes online in 500us, so add two orders of magnitude
978 * of delay before autosuspending: 50 ms.
979 */
980 pm_runtime_set_autosuspend_delay(dev: &client->dev, delay: 50);
981 pm_runtime_use_autosuspend(dev: &client->dev);
982 pm_runtime_put(dev: &client->dev);
983
984 return 0;
985
986cleanup_buffer:
987 iio_triggered_buffer_cleanup(indio_dev);
988power_off:
989 ak8975_power_off(data);
990 return err;
991}
992
993static void ak8975_remove(struct i2c_client *client)
994{
995 struct iio_dev *indio_dev = i2c_get_clientdata(client);
996 struct ak8975_data *data = iio_priv(indio_dev);
997
998 pm_runtime_get_sync(dev: &client->dev);
999 pm_runtime_put_noidle(dev: &client->dev);
1000 pm_runtime_disable(dev: &client->dev);
1001 iio_device_unregister(indio_dev);
1002 iio_triggered_buffer_cleanup(indio_dev);
1003 ak8975_set_mode(data, mode: POWER_DOWN);
1004 ak8975_power_off(data);
1005}
1006
1007static int ak8975_runtime_suspend(struct device *dev)
1008{
1009 struct i2c_client *client = to_i2c_client(dev);
1010 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1011 struct ak8975_data *data = iio_priv(indio_dev);
1012 int ret;
1013
1014 /* Set the device in power down if it wasn't already */
1015 ret = ak8975_set_mode(data, mode: POWER_DOWN);
1016 if (ret < 0) {
1017 dev_err(&client->dev, "Error in setting power-down mode\n");
1018 return ret;
1019 }
1020 /* Next cut the regulators */
1021 ak8975_power_off(data);
1022
1023 return 0;
1024}
1025
1026static int ak8975_runtime_resume(struct device *dev)
1027{
1028 struct i2c_client *client = to_i2c_client(dev);
1029 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1030 struct ak8975_data *data = iio_priv(indio_dev);
1031 int ret;
1032
1033 /* Take up the regulators */
1034 ak8975_power_on(data);
1035 /*
1036 * We come up in powered down mode, the reading routines will
1037 * put us in the mode to read values later.
1038 */
1039 ret = ak8975_set_mode(data, mode: POWER_DOWN);
1040 if (ret < 0) {
1041 dev_err(&client->dev, "Error in setting power-down mode\n");
1042 return ret;
1043 }
1044
1045 return 0;
1046}
1047
1048static DEFINE_RUNTIME_DEV_PM_OPS(ak8975_dev_pm_ops, ak8975_runtime_suspend,
1049 ak8975_runtime_resume, NULL);
1050
1051static const struct acpi_device_id ak_acpi_match[] = {
1052 {"AK8963", (kernel_ulong_t)&ak_def_array[AK8963] },
1053 {"AK8975", (kernel_ulong_t)&ak_def_array[AK8975] },
1054 {"AK009911", (kernel_ulong_t)&ak_def_array[AK09911] },
1055 {"AK09911", (kernel_ulong_t)&ak_def_array[AK09911] },
1056 {"AK09912", (kernel_ulong_t)&ak_def_array[AK09912] },
1057 {"AKM9911", (kernel_ulong_t)&ak_def_array[AK09911] },
1058 {"INVN6500", (kernel_ulong_t)&ak_def_array[AK8963] },
1059 { }
1060};
1061MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
1062
1063static const struct i2c_device_id ak8975_id[] = {
1064 {"AK8963", (kernel_ulong_t)&ak_def_array[AK8963] },
1065 {"ak8963", (kernel_ulong_t)&ak_def_array[AK8963] },
1066 {"ak8975", (kernel_ulong_t)&ak_def_array[AK8975] },
1067 {"ak09911", (kernel_ulong_t)&ak_def_array[AK09911] },
1068 {"ak09912", (kernel_ulong_t)&ak_def_array[AK09912] },
1069 {"ak09916", (kernel_ulong_t)&ak_def_array[AK09916] },
1070 {}
1071};
1072MODULE_DEVICE_TABLE(i2c, ak8975_id);
1073
1074static const struct of_device_id ak8975_of_match[] = {
1075 { .compatible = "asahi-kasei,ak8975", .data = &ak_def_array[AK8975] },
1076 { .compatible = "ak8975", .data = &ak_def_array[AK8975] },
1077 { .compatible = "asahi-kasei,ak8963", .data = &ak_def_array[AK8963] },
1078 { .compatible = "ak8963", .data = &ak_def_array[AK8963] },
1079 { .compatible = "asahi-kasei,ak09911", .data = &ak_def_array[AK09911] },
1080 { .compatible = "ak09911", .data = &ak_def_array[AK09911] },
1081 { .compatible = "asahi-kasei,ak09912", .data = &ak_def_array[AK09912] },
1082 { .compatible = "ak09912", .data = &ak_def_array[AK09912] },
1083 { .compatible = "asahi-kasei,ak09916", .data = &ak_def_array[AK09916] },
1084 { .compatible = "ak09916", .data = &ak_def_array[AK09916] },
1085 {}
1086};
1087MODULE_DEVICE_TABLE(of, ak8975_of_match);
1088
1089static struct i2c_driver ak8975_driver = {
1090 .driver = {
1091 .name = "ak8975",
1092 .pm = pm_ptr(&ak8975_dev_pm_ops),
1093 .of_match_table = ak8975_of_match,
1094 .acpi_match_table = ak_acpi_match,
1095 },
1096 .probe = ak8975_probe,
1097 .remove = ak8975_remove,
1098 .id_table = ak8975_id,
1099};
1100module_i2c_driver(ak8975_driver);
1101
1102MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1103MODULE_DESCRIPTION("AK8975 magnetometer driver");
1104MODULE_LICENSE("GPL");
1105

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source code of linux/drivers/iio/magnetometer/ak8975.c