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Merge tag 'block-5.11-2021-01-10' of git://git.kernel.dk/linux-block
[linux/fpc-iii.git] / drivers / iio / magnetometer / ak8975.c
blobd988b6ac3659381e75e486fdda9e257cbe730d41
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 AK09912_DEVICE_ID 0x04
82 #define AK09911_DEVICE_ID 0x05
83
84 #define AK09911_REG_INFO1 0x02
85 #define AK09911_REG_INFO2 0x03
86
87 #define AK09912_REG_ST1 0x10
88
89 #define AK09912_REG_ST1_DRDY_SHIFT 0
90 #define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT)
91
92 #define AK09912_REG_HXL 0x11
93 #define AK09912_REG_HXH 0x12
94 #define AK09912_REG_HYL 0x13
95 #define AK09912_REG_HYH 0x14
96 #define AK09912_REG_HZL 0x15
97 #define AK09912_REG_HZH 0x16
98 #define AK09912_REG_TMPS 0x17
99
100 #define AK09912_REG_ST2 0x18
101 #define AK09912_REG_ST2_HOFL_SHIFT 3
102 #define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT)
103
104 #define AK09912_REG_CNTL1 0x30
105
106 #define AK09912_REG_CNTL2 0x31
107 #define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00
108 #define AK09912_REG_CNTL_MODE_ONCE 0x01
109 #define AK09912_REG_CNTL_MODE_SELF_TEST 0x10
110 #define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F
111 #define AK09912_REG_CNTL2_MODE_SHIFT 0
112 #define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT)
113
114 #define AK09912_REG_CNTL3 0x32
115
116 #define AK09912_REG_TS1 0x33
117 #define AK09912_REG_TS2 0x34
118 #define AK09912_REG_TS3 0x35
119 #define AK09912_REG_I2CDIS 0x36
120 #define AK09912_REG_TS4 0x37
121
122 #define AK09912_REG_ASAX 0x60
123 #define AK09912_REG_ASAY 0x61
124 #define AK09912_REG_ASAZ 0x62
125
126 #define AK09912_MAX_REGS AK09912_REG_ASAZ
127
128 /*
129 * Miscellaneous values.
130 */
131 #define AK8975_MAX_CONVERSION_TIMEOUT 500
132 #define AK8975_CONVERSION_DONE_POLL_TIME 10
133 #define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000)
134
135 /*
136 * Precalculate scale factor (in Gauss units) for each axis and
137 * store in the device data.
138 *
139 * This scale factor is axis-dependent, and is derived from 3 calibration
140 * factors ASA(x), ASA(y), and ASA(z).
141 *
142 * These ASA values are read from the sensor device at start of day, and
143 * cached in the device context struct.
144 *
145 * Adjusting the flux value with the sensitivity adjustment value should be
146 * done via the following formula:
147 *
148 * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 )
149 * where H is the raw value, ASA is the sensitivity adjustment, and Hadj
150 * is the resultant adjusted value.
151 *
152 * We reduce the formula to:
153 *
154 * Hadj = H * (ASA + 128) / 256
155 *
156 * H is in the range of -4096 to 4095. The magnetometer has a range of
157 * +-1229uT. To go from the raw value to uT is:
158 *
159 * HuT = H * 1229/4096, or roughly, 3/10.
160 *
161 * Since 1uT = 0.01 gauss, our final scale factor becomes:
162 *
163 * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100
164 * Hadj = H * ((ASA + 128) * 0.003) / 256
165 *
166 * Since ASA doesn't change, we cache the resultant scale factor into the
167 * device context in ak8975_setup().
168 *
169 * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we
170 * multiply the stored scale value by 1e6.
171 */
172 static long ak8975_raw_to_gauss(u16 data)
173 {
174 return (((long)data + 128) * 3000) / 256;
175 }
176
177 /*
178 * For AK8963 and AK09911, same calculation, but the device is less sensitive:
179 *
180 * H is in the range of +-8190. The magnetometer has a range of
181 * +-4912uT. To go from the raw value to uT is:
182 *
183 * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10.
184 */
185
186 static long ak8963_09911_raw_to_gauss(u16 data)
187 {
188 return (((long)data + 128) * 6000) / 256;
189 }
190
191 /*
192 * For AK09912, same calculation, except the device is more sensitive:
193 *
194 * H is in the range of -32752 to 32752. The magnetometer has a range of
195 * +-4912uT. To go from the raw value to uT is:
196 *
197 * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10.
198 */
199 static long ak09912_raw_to_gauss(u16 data)
200 {
201 return (((long)data + 128) * 1500) / 256;
202 }
203
204 /* Compatible Asahi Kasei Compass parts */
205 enum asahi_compass_chipset {
206 AKXXXX = 0,
207 AK8975,
208 AK8963,
209 AK09911,
210 AK09912,
211 };
212
213 enum ak_ctrl_reg_addr {
214 ST1,
215 ST2,
216 CNTL,
217 ASA_BASE,
218 MAX_REGS,
219 REGS_END,
220 };
221
222 enum ak_ctrl_reg_mask {
223 ST1_DRDY,
224 ST2_HOFL,
225 ST2_DERR,
226 CNTL_MODE,
227 MASK_END,
228 };
229
230 enum ak_ctrl_mode {
231 POWER_DOWN,
232 MODE_ONCE,
233 SELF_TEST,
234 FUSE_ROM,
235 MODE_END,
236 };
237
238 struct ak_def {
239 enum asahi_compass_chipset type;
240 long (*raw_to_gauss)(u16 data);
241 u16 range;
242 u8 ctrl_regs[REGS_END];
243 u8 ctrl_masks[MASK_END];
244 u8 ctrl_modes[MODE_END];
245 u8 data_regs[3];
246 };
247
248 static const struct ak_def ak_def_array[] = {
249 {
250 .type = AK8975,
251 .raw_to_gauss = ak8975_raw_to_gauss,
252 .range = 4096,
253 .ctrl_regs = {
254 AK8975_REG_ST1,
255 AK8975_REG_ST2,
256 AK8975_REG_CNTL,
257 AK8975_REG_ASAX,
258 AK8975_MAX_REGS},
259 .ctrl_masks = {
260 AK8975_REG_ST1_DRDY_MASK,
261 AK8975_REG_ST2_HOFL_MASK,
262 AK8975_REG_ST2_DERR_MASK,
263 AK8975_REG_CNTL_MODE_MASK},
264 .ctrl_modes = {
265 AK8975_REG_CNTL_MODE_POWER_DOWN,
266 AK8975_REG_CNTL_MODE_ONCE,
267 AK8975_REG_CNTL_MODE_SELF_TEST,
268 AK8975_REG_CNTL_MODE_FUSE_ROM},
269 .data_regs = {
270 AK8975_REG_HXL,
271 AK8975_REG_HYL,
272 AK8975_REG_HZL},
273 },
274 {
275 .type = AK8963,
276 .raw_to_gauss = ak8963_09911_raw_to_gauss,
277 .range = 8190,
278 .ctrl_regs = {
279 AK8975_REG_ST1,
280 AK8975_REG_ST2,
281 AK8975_REG_CNTL,
282 AK8975_REG_ASAX,
283 AK8975_MAX_REGS},
284 .ctrl_masks = {
285 AK8975_REG_ST1_DRDY_MASK,
286 AK8975_REG_ST2_HOFL_MASK,
287 0,
288 AK8975_REG_CNTL_MODE_MASK},
289 .ctrl_modes = {
290 AK8975_REG_CNTL_MODE_POWER_DOWN,
291 AK8975_REG_CNTL_MODE_ONCE,
292 AK8975_REG_CNTL_MODE_SELF_TEST,
293 AK8975_REG_CNTL_MODE_FUSE_ROM},
294 .data_regs = {
295 AK8975_REG_HXL,
296 AK8975_REG_HYL,
297 AK8975_REG_HZL},
298 },
299 {
300 .type = AK09911,
301 .raw_to_gauss = ak8963_09911_raw_to_gauss,
302 .range = 8192,
303 .ctrl_regs = {
304 AK09912_REG_ST1,
305 AK09912_REG_ST2,
306 AK09912_REG_CNTL2,
307 AK09912_REG_ASAX,
308 AK09912_MAX_REGS},
309 .ctrl_masks = {
310 AK09912_REG_ST1_DRDY_MASK,
311 AK09912_REG_ST2_HOFL_MASK,
312 0,
313 AK09912_REG_CNTL2_MODE_MASK},
314 .ctrl_modes = {
315 AK09912_REG_CNTL_MODE_POWER_DOWN,
316 AK09912_REG_CNTL_MODE_ONCE,
317 AK09912_REG_CNTL_MODE_SELF_TEST,
318 AK09912_REG_CNTL_MODE_FUSE_ROM},
319 .data_regs = {
320 AK09912_REG_HXL,
321 AK09912_REG_HYL,
322 AK09912_REG_HZL},
323 },
324 {
325 .type = AK09912,
326 .raw_to_gauss = ak09912_raw_to_gauss,
327 .range = 32752,
328 .ctrl_regs = {
329 AK09912_REG_ST1,
330 AK09912_REG_ST2,
331 AK09912_REG_CNTL2,
332 AK09912_REG_ASAX,
333 AK09912_MAX_REGS},
334 .ctrl_masks = {
335 AK09912_REG_ST1_DRDY_MASK,
336 AK09912_REG_ST2_HOFL_MASK,
337 0,
338 AK09912_REG_CNTL2_MODE_MASK},
339 .ctrl_modes = {
340 AK09912_REG_CNTL_MODE_POWER_DOWN,
341 AK09912_REG_CNTL_MODE_ONCE,
342 AK09912_REG_CNTL_MODE_SELF_TEST,
343 AK09912_REG_CNTL_MODE_FUSE_ROM},
344 .data_regs = {
345 AK09912_REG_HXL,
346 AK09912_REG_HYL,
347 AK09912_REG_HZL},
348 }
349 };
350
351 /*
352 * Per-instance context data for the device.
353 */
354 struct ak8975_data {
355 struct i2c_client *client;
356 const struct ak_def *def;
357 struct mutex lock;
358 u8 asa[3];
359 long raw_to_gauss[3];
360 struct gpio_desc *eoc_gpiod;
361 struct gpio_desc *reset_gpiod;
362 int eoc_irq;
363 wait_queue_head_t data_ready_queue;
364 unsigned long flags;
365 u8 cntl_cache;
366 struct iio_mount_matrix orientation;
367 struct regulator *vdd;
368 struct regulator *vid;
369
370 /* Ensure natural alignment of timestamp */
371 struct {
372 s16 channels[3];
373 s64 ts __aligned(8);
374 } scan;
375 };
376
377 /* Enable attached power regulator if any. */
378 static int ak8975_power_on(const struct ak8975_data *data)
379 {
380 int ret;
381
382 ret = regulator_enable(data->vdd);
383 if (ret) {
384 dev_warn(&data->client->dev,
385 "Failed to enable specified Vdd supply\n");
386 return ret;
387 }
388 ret = regulator_enable(data->vid);
389 if (ret) {
390 dev_warn(&data->client->dev,
391 "Failed to enable specified Vid supply\n");
392 return ret;
393 }
394
395 gpiod_set_value_cansleep(data->reset_gpiod, 0);
396
397 /*
398 * According to the datasheet the power supply rise time is 200us
399 * and the minimum wait time before mode setting is 100us, in
400 * total 300us. Add some margin and say minimum 500us here.
401 */
402 usleep_range(500, 1000);
403 return 0;
404 }
405
406 /* Disable attached power regulator if any. */
407 static void ak8975_power_off(const struct ak8975_data *data)
408 {
409 gpiod_set_value_cansleep(data->reset_gpiod, 1);
410
411 regulator_disable(data->vid);
412 regulator_disable(data->vdd);
413 }
414
415 /*
416 * Return 0 if the i2c device is the one we expect.
417 * return a negative error number otherwise
418 */
419 static int ak8975_who_i_am(struct i2c_client *client,
420 enum asahi_compass_chipset type)
421 {
422 u8 wia_val[2];
423 int ret;
424
425 /*
426 * Signature for each device:
427 * Device | WIA1 | WIA2
428 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID
429 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID
430 * AK8975 | DEVICE_ID | NA
431 * AK8963 | DEVICE_ID | NA
432 */
433 ret = i2c_smbus_read_i2c_block_data_or_emulated(
434 client, AK09912_REG_WIA1, 2, wia_val);
435 if (ret < 0) {
436 dev_err(&client->dev, "Error reading WIA\n");
437 return ret;
438 }
439
440 if (wia_val[0] != AK8975_DEVICE_ID)
441 return -ENODEV;
442
443 switch (type) {
444 case AK8975:
445 case AK8963:
446 return 0;
447 case AK09911:
448 if (wia_val[1] == AK09911_DEVICE_ID)
449 return 0;
450 break;
451 case AK09912:
452 if (wia_val[1] == AK09912_DEVICE_ID)
453 return 0;
454 break;
455 default:
456 dev_err(&client->dev, "Type %d unknown\n", type);
457 }
458 return -ENODEV;
459 }
460
461 /*
462 * Helper function to write to CNTL register.
463 */
464 static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode)
465 {
466 u8 regval;
467 int ret;
468
469 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) |
470 data->def->ctrl_modes[mode];
471 ret = i2c_smbus_write_byte_data(data->client,
472 data->def->ctrl_regs[CNTL], regval);
473 if (ret < 0) {
474 return ret;
475 }
476 data->cntl_cache = regval;
477 /* After mode change wait atleast 100us */
478 usleep_range(100, 500);
479
480 return 0;
481 }
482
483 /*
484 * Handle data ready irq
485 */
486 static irqreturn_t ak8975_irq_handler(int irq, void *data)
487 {
488 struct ak8975_data *ak8975 = data;
489
490 set_bit(0, &ak8975->flags);
491 wake_up(&ak8975->data_ready_queue);
492
493 return IRQ_HANDLED;
494 }
495
496 /*
497 * Install data ready interrupt handler
498 */
499 static int ak8975_setup_irq(struct ak8975_data *data)
500 {
501 struct i2c_client *client = data->client;
502 int rc;
503 int irq;
504
505 init_waitqueue_head(&data->data_ready_queue);
506 clear_bit(0, &data->flags);
507 if (client->irq)
508 irq = client->irq;
509 else
510 irq = gpiod_to_irq(data->eoc_gpiod);
511
512 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,
513 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
514 dev_name(&client->dev), data);
515 if (rc < 0) {
516 dev_err(&client->dev, "irq %d request failed: %d\n", irq, rc);
517 return rc;
518 }
519
520 data->eoc_irq = irq;
521
522 return rc;
523 }
524
525
526 /*
527 * Perform some start-of-day setup, including reading the asa calibration
528 * values and caching them.
529 */
530 static int ak8975_setup(struct i2c_client *client)
531 {
532 struct iio_dev *indio_dev = i2c_get_clientdata(client);
533 struct ak8975_data *data = iio_priv(indio_dev);
534 int ret;
535
536 /* Write the fused rom access mode. */
537 ret = ak8975_set_mode(data, FUSE_ROM);
538 if (ret < 0) {
539 dev_err(&client->dev, "Error in setting fuse access mode\n");
540 return ret;
541 }
542
543 /* Get asa data and store in the device data. */
544 ret = i2c_smbus_read_i2c_block_data_or_emulated(
545 client, data->def->ctrl_regs[ASA_BASE],
546 3, data->asa);
547 if (ret < 0) {
548 dev_err(&client->dev, "Not able to read asa data\n");
549 return ret;
550 }
551
552 /* After reading fuse ROM data set power-down mode */
553 ret = ak8975_set_mode(data, POWER_DOWN);
554 if (ret < 0) {
555 dev_err(&client->dev, "Error in setting power-down mode\n");
556 return ret;
557 }
558
559 if (data->eoc_gpiod || client->irq > 0) {
560 ret = ak8975_setup_irq(data);
561 if (ret < 0) {
562 dev_err(&client->dev,
563 "Error setting data ready interrupt\n");
564 return ret;
565 }
566 }
567
568 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]);
569 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]);
570 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]);
571
572 return 0;
573 }
574
575 static int wait_conversion_complete_gpio(struct ak8975_data *data)
576 {
577 struct i2c_client *client = data->client;
578 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
579 int ret;
580
581 /* Wait for the conversion to complete. */
582 while (timeout_ms) {
583 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
584 if (gpiod_get_value(data->eoc_gpiod))
585 break;
586 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
587 }
588 if (!timeout_ms) {
589 dev_err(&client->dev, "Conversion timeout happened\n");
590 return -EINVAL;
591 }
592
593 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]);
594 if (ret < 0)
595 dev_err(&client->dev, "Error in reading ST1\n");
596
597 return ret;
598 }
599
600 static int wait_conversion_complete_polled(struct ak8975_data *data)
601 {
602 struct i2c_client *client = data->client;
603 u8 read_status;
604 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
605 int ret;
606
607 /* Wait for the conversion to complete. */
608 while (timeout_ms) {
609 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
610 ret = i2c_smbus_read_byte_data(client,
611 data->def->ctrl_regs[ST1]);
612 if (ret < 0) {
613 dev_err(&client->dev, "Error in reading ST1\n");
614 return ret;
615 }
616 read_status = ret;
617 if (read_status)
618 break;
619 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
620 }
621 if (!timeout_ms) {
622 dev_err(&client->dev, "Conversion timeout happened\n");
623 return -EINVAL;
624 }
625
626 return read_status;
627 }
628
629 /* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */
630 static int wait_conversion_complete_interrupt(struct ak8975_data *data)
631 {
632 int ret;
633
634 ret = wait_event_timeout(data->data_ready_queue,
635 test_bit(0, &data->flags),
636 AK8975_DATA_READY_TIMEOUT);
637 clear_bit(0, &data->flags);
638
639 return ret > 0 ? 0 : -ETIME;
640 }
641
642 static int ak8975_start_read_axis(struct ak8975_data *data,
643 const struct i2c_client *client)
644 {
645 /* Set up the device for taking a sample. */
646 int ret = ak8975_set_mode(data, MODE_ONCE);
647
648 if (ret < 0) {
649 dev_err(&client->dev, "Error in setting operating mode\n");
650 return ret;
651 }
652
653 /* Wait for the conversion to complete. */
654 if (data->eoc_irq)
655 ret = wait_conversion_complete_interrupt(data);
656 else if (data->eoc_gpiod)
657 ret = wait_conversion_complete_gpio(data);
658 else
659 ret = wait_conversion_complete_polled(data);
660 if (ret < 0)
661 return ret;
662
663 /* This will be executed only for non-interrupt based waiting case */
664 if (ret & data->def->ctrl_masks[ST1_DRDY]) {
665 ret = i2c_smbus_read_byte_data(client,
666 data->def->ctrl_regs[ST2]);
667 if (ret < 0) {
668 dev_err(&client->dev, "Error in reading ST2\n");
669 return ret;
670 }
671 if (ret & (data->def->ctrl_masks[ST2_DERR] |
672 data->def->ctrl_masks[ST2_HOFL])) {
673 dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
674 return -EINVAL;
675 }
676 }
677
678 return 0;
679 }
680
681 /* Retrieve raw flux value for one of the x, y, or z axis. */
682 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
683 {
684 struct ak8975_data *data = iio_priv(indio_dev);
685 const struct i2c_client *client = data->client;
686 const struct ak_def *def = data->def;
687 __le16 rval;
688 u16 buff;
689 int ret;
690
691 pm_runtime_get_sync(&data->client->dev);
692
693 mutex_lock(&data->lock);
694
695 ret = ak8975_start_read_axis(data, client);
696 if (ret)
697 goto exit;
698
699 ret = i2c_smbus_read_i2c_block_data_or_emulated(
700 client, def->data_regs[index],
701 sizeof(rval), (u8*)&rval);
702 if (ret < 0)
703 goto exit;
704
705 mutex_unlock(&data->lock);
706
707 pm_runtime_mark_last_busy(&data->client->dev);
708 pm_runtime_put_autosuspend(&data->client->dev);
709
710 /* Swap bytes and convert to valid range. */
711 buff = le16_to_cpu(rval);
712 *val = clamp_t(s16, buff, -def->range, def->range);
713 return IIO_VAL_INT;
714
715 exit:
716 mutex_unlock(&data->lock);
717 dev_err(&client->dev, "Error in reading axis\n");
718 return ret;
719 }
720
721 static int ak8975_read_raw(struct iio_dev *indio_dev,
722 struct iio_chan_spec const *chan,
723 int *val, int *val2,
724 long mask)
725 {
726 struct ak8975_data *data = iio_priv(indio_dev);
727
728 switch (mask) {
729 case IIO_CHAN_INFO_RAW:
730 return ak8975_read_axis(indio_dev, chan->address, val);
731 case IIO_CHAN_INFO_SCALE:
732 *val = 0;
733 *val2 = data->raw_to_gauss[chan->address];
734 return IIO_VAL_INT_PLUS_MICRO;
735 }
736 return -EINVAL;
737 }
738
739 static const struct iio_mount_matrix *
740 ak8975_get_mount_matrix(const struct iio_dev *indio_dev,
741 const struct iio_chan_spec *chan)
742 {
743 struct ak8975_data *data = iio_priv(indio_dev);
744
745 return &data->orientation;
746 }
747
748 static const struct iio_chan_spec_ext_info ak8975_ext_info[] = {
749 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix),
750 { }
751 };
752
753 #define AK8975_CHANNEL(axis, index) \
754 { \
755 .type = IIO_MAGN, \
756 .modified = 1, \
757 .channel2 = IIO_MOD_##axis, \
758 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
759 BIT(IIO_CHAN_INFO_SCALE), \
760 .address = index, \
761 .scan_index = index, \
762 .scan_type = { \
763 .sign = 's', \
764 .realbits = 16, \
765 .storagebits = 16, \
766 .endianness = IIO_CPU \
767 }, \
768 .ext_info = ak8975_ext_info, \
769 }
770
771 static const struct iio_chan_spec ak8975_channels[] = {
772 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
773 IIO_CHAN_SOFT_TIMESTAMP(3),
774 };
775
776 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
777
778 static const struct iio_info ak8975_info = {
779 .read_raw = &ak8975_read_raw,
780 };
781
782 static const struct acpi_device_id ak_acpi_match[] = {
783 {"AK8975", AK8975},
784 {"AK8963", AK8963},
785 {"INVN6500", AK8963},
786 {"AK009911", AK09911},
787 {"AK09911", AK09911},
788 {"AKM9911", AK09911},
789 {"AK09912", AK09912},
790 { }
791 };
792 MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
793
794 static void ak8975_fill_buffer(struct iio_dev *indio_dev)
795 {
796 struct ak8975_data *data = iio_priv(indio_dev);
797 const struct i2c_client *client = data->client;
798 const struct ak_def *def = data->def;
799 int ret;
800 __le16 fval[3];
801
802 mutex_lock(&data->lock);
803
804 ret = ak8975_start_read_axis(data, client);
805 if (ret)
806 goto unlock;
807
808 /*
809 * For each axis, read the flux value from the appropriate register
810 * (the register is specified in the iio device attributes).
811 */
812 ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
813 def->data_regs[0],
814 3 * sizeof(fval[0]),
815 (u8 *)fval);
816 if (ret < 0)
817 goto unlock;
818
819 mutex_unlock(&data->lock);
820
821 /* Clamp to valid range. */
822 data->scan.channels[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range);
823 data->scan.channels[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range);
824 data->scan.channels[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range);
825
826 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
827 iio_get_time_ns(indio_dev));
828
829 return;
830
831 unlock:
832 mutex_unlock(&data->lock);
833 dev_err(&client->dev, "Error in reading axes block\n");
834 }
835
836 static irqreturn_t ak8975_handle_trigger(int irq, void *p)
837 {
838 const struct iio_poll_func *pf = p;
839 struct iio_dev *indio_dev = pf->indio_dev;
840
841 ak8975_fill_buffer(indio_dev);
842 iio_trigger_notify_done(indio_dev->trig);
843 return IRQ_HANDLED;
844 }
845
846 static int ak8975_probe(struct i2c_client *client,
847 const struct i2c_device_id *id)
848 {
849 struct ak8975_data *data;
850 struct iio_dev *indio_dev;
851 struct gpio_desc *eoc_gpiod;
852 struct gpio_desc *reset_gpiod;
853 const void *match;
854 unsigned int i;
855 int err;
856 enum asahi_compass_chipset chipset;
857 const char *name = NULL;
858
859 /*
860 * Grab and set up the supplied GPIO.
861 * We may not have a GPIO based IRQ to scan, that is fine, we will
862 * poll if so.
863 */
864 eoc_gpiod = devm_gpiod_get_optional(&client->dev, NULL, GPIOD_IN);
865 if (IS_ERR(eoc_gpiod))
866 return PTR_ERR(eoc_gpiod);
867 if (eoc_gpiod)
868 gpiod_set_consumer_name(eoc_gpiod, "ak_8975");
869
870 /*
871 * According to AK09911 datasheet, if reset GPIO is provided then
872 * deassert reset on ak8975_power_on() and assert reset on
873 * ak8975_power_off().
874 */
875 reset_gpiod = devm_gpiod_get_optional(&client->dev,
876 "reset", GPIOD_OUT_HIGH);
877 if (IS_ERR(reset_gpiod))
878 return PTR_ERR(reset_gpiod);
879
880 /* Register with IIO */
881 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
882 if (indio_dev == NULL)
883 return -ENOMEM;
884
885 data = iio_priv(indio_dev);
886 i2c_set_clientdata(client, indio_dev);
887
888 data->client = client;
889 data->eoc_gpiod = eoc_gpiod;
890 data->reset_gpiod = reset_gpiod;
891 data->eoc_irq = 0;
892
893 err = iio_read_mount_matrix(&client->dev, "mount-matrix", &data->orientation);
894 if (err)
895 return err;
896
897 /* id will be NULL when enumerated via ACPI */
898 match = device_get_match_data(&client->dev);
899 if (match) {
900 chipset = (enum asahi_compass_chipset)(match);
901 name = dev_name(&client->dev);
902 } else if (id) {
903 chipset = (enum asahi_compass_chipset)(id->driver_data);
904 name = id->name;
905 } else
906 return -ENOSYS;
907
908 for (i = 0; i < ARRAY_SIZE(ak_def_array); i++)
909 if (ak_def_array[i].type == chipset)
910 break;
911
912 if (i == ARRAY_SIZE(ak_def_array)) {
913 dev_err(&client->dev, "AKM device type unsupported: %d\n",
914 chipset);
915 return -ENODEV;
916 }
917
918 data->def = &ak_def_array[i];
919
920 /* Fetch the regulators */
921 data->vdd = devm_regulator_get(&client->dev, "vdd");
922 if (IS_ERR(data->vdd))
923 return PTR_ERR(data->vdd);
924 data->vid = devm_regulator_get(&client->dev, "vid");
925 if (IS_ERR(data->vid))
926 return PTR_ERR(data->vid);
927
928 err = ak8975_power_on(data);
929 if (err)
930 return err;
931
932 err = ak8975_who_i_am(client, data->def->type);
933 if (err < 0) {
934 dev_err(&client->dev, "Unexpected device\n");
935 goto power_off;
936 }
937 dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
938
939 /* Perform some basic start-of-day setup of the device. */
940 err = ak8975_setup(client);
941 if (err < 0) {
942 dev_err(&client->dev, "%s initialization fails\n", name);
943 goto power_off;
944 }
945
946 mutex_init(&data->lock);
947 indio_dev->channels = ak8975_channels;
948 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
949 indio_dev->info = &ak8975_info;
950 indio_dev->available_scan_masks = ak8975_scan_masks;
951 indio_dev->modes = INDIO_DIRECT_MODE;
952 indio_dev->name = name;
953
954 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
955 NULL);
956 if (err) {
957 dev_err(&client->dev, "triggered buffer setup failed\n");
958 goto power_off;
959 }
960
961 err = iio_device_register(indio_dev);
962 if (err) {
963 dev_err(&client->dev, "device register failed\n");
964 goto cleanup_buffer;
965 }
966
967 /* Enable runtime PM */
968 pm_runtime_get_noresume(&client->dev);
969 pm_runtime_set_active(&client->dev);
970 pm_runtime_enable(&client->dev);
971 /*
972 * The device comes online in 500us, so add two orders of magnitude
973 * of delay before autosuspending: 50 ms.
974 */
975 pm_runtime_set_autosuspend_delay(&client->dev, 50);
976 pm_runtime_use_autosuspend(&client->dev);
977 pm_runtime_put(&client->dev);
978
979 return 0;
980
981 cleanup_buffer:
982 iio_triggered_buffer_cleanup(indio_dev);
983 power_off:
984 ak8975_power_off(data);
985 return err;
986 }
987
988 static int ak8975_remove(struct i2c_client *client)
989 {
990 struct iio_dev *indio_dev = i2c_get_clientdata(client);
991 struct ak8975_data *data = iio_priv(indio_dev);
992
993 pm_runtime_get_sync(&client->dev);
994 pm_runtime_put_noidle(&client->dev);
995 pm_runtime_disable(&client->dev);
996 iio_device_unregister(indio_dev);
997 iio_triggered_buffer_cleanup(indio_dev);
998 ak8975_set_mode(data, POWER_DOWN);
999 ak8975_power_off(data);
1000
1001 return 0;
1002 }
1003
1004 #ifdef CONFIG_PM
1005 static int ak8975_runtime_suspend(struct device *dev)
1006 {
1007 struct i2c_client *client = to_i2c_client(dev);
1008 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1009 struct ak8975_data *data = iio_priv(indio_dev);
1010 int ret;
1011
1012 /* Set the device in power down if it wasn't already */
1013 ret = ak8975_set_mode(data, POWER_DOWN);
1014 if (ret < 0) {
1015 dev_err(&client->dev, "Error in setting power-down mode\n");
1016 return ret;
1017 }
1018 /* Next cut the regulators */
1019 ak8975_power_off(data);
1020
1021 return 0;
1022 }
1023
1024 static int ak8975_runtime_resume(struct device *dev)
1025 {
1026 struct i2c_client *client = to_i2c_client(dev);
1027 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1028 struct ak8975_data *data = iio_priv(indio_dev);
1029 int ret;
1030
1031 /* Take up the regulators */
1032 ak8975_power_on(data);
1033 /*
1034 * We come up in powered down mode, the reading routines will
1035 * put us in the mode to read values later.
1036 */
1037 ret = ak8975_set_mode(data, POWER_DOWN);
1038 if (ret < 0) {
1039 dev_err(&client->dev, "Error in setting power-down mode\n");
1040 return ret;
1041 }
1042
1043 return 0;
1044 }
1045 #endif /* CONFIG_PM */
1046
1047 static const struct dev_pm_ops ak8975_dev_pm_ops = {
1048 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1049 pm_runtime_force_resume)
1050 SET_RUNTIME_PM_OPS(ak8975_runtime_suspend,
1051 ak8975_runtime_resume, NULL)
1052 };
1053
1054 static const struct i2c_device_id ak8975_id[] = {
1055 {"ak8975", AK8975},
1056 {"ak8963", AK8963},
1057 {"AK8963", AK8963},
1058 {"ak09911", AK09911},
1059 {"ak09912", AK09912},
1060 {}
1061 };
1062
1063 MODULE_DEVICE_TABLE(i2c, ak8975_id);
1064
1065 static const struct of_device_id ak8975_of_match[] = {
1066 { .compatible = "asahi-kasei,ak8975", },
1067 { .compatible = "ak8975", },
1068 { .compatible = "asahi-kasei,ak8963", },
1069 { .compatible = "ak8963", },
1070 { .compatible = "asahi-kasei,ak09911", },
1071 { .compatible = "ak09911", },
1072 { .compatible = "asahi-kasei,ak09912", },
1073 { .compatible = "ak09912", },
1074 {}
1075 };
1076 MODULE_DEVICE_TABLE(of, ak8975_of_match);
1077
1078 static struct i2c_driver ak8975_driver = {
1079 .driver = {
1080 .name = "ak8975",
1081 .pm = &ak8975_dev_pm_ops,
1082 .of_match_table = ak8975_of_match,
1083 .acpi_match_table = ak_acpi_match,
1084 },
1085 .probe = ak8975_probe,
1086 .remove = ak8975_remove,
1087 .id_table = ak8975_id,
1088 };
1089 module_i2c_driver(ak8975_driver);
1090
1091 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1092 MODULE_DESCRIPTION("AK8975 magnetometer driver");
1093 MODULE_LICENSE("GPL");
Linux with added FPC-III support