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 */
ak8975_raw_to_gauss(u16 data)173 static 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
ak8963_09911_raw_to_gauss(u16 data)187 static 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 */
ak09912_raw_to_gauss(u16 data)200 static long ak09912_raw_to_gauss(u16 data)
201 {
202 return (((long)data + 128) * 1500) / 256;
203 }
204
205 /* Compatible Asahi Kasei Compass parts */
206 enum asahi_compass_chipset {
207 AK8975,
208 AK8963,
209 AK09911,
210 AK09912,
211 AK09916,
212 };
213
214 enum ak_ctrl_reg_addr {
215 ST1,
216 ST2,
217 CNTL,
218 ASA_BASE,
219 MAX_REGS,
220 REGS_END,
221 };
222
223 enum ak_ctrl_reg_mask {
224 ST1_DRDY,
225 ST2_HOFL,
226 ST2_DERR,
227 CNTL_MODE,
228 MASK_END,
229 };
230
231 enum ak_ctrl_mode {
232 POWER_DOWN,
233 MODE_ONCE,
234 SELF_TEST,
235 FUSE_ROM,
236 MODE_END,
237 };
238
239 struct 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
249 static 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 */
380 struct 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. */
ak8975_power_on(const struct ak8975_data * data)404 static int ak8975_power_on(const struct ak8975_data *data)
405 {
406 int ret;
407
408 ret = regulator_enable(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(data->vid);
415 if (ret) {
416 dev_warn(&data->client->dev,
417 "Failed to enable specified Vid supply\n");
418 regulator_disable(data->vdd);
419 return ret;
420 }
421
422 gpiod_set_value_cansleep(data->reset_gpiod, 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(500, 1000);
430 return 0;
431 }
432
433 /* Disable attached power regulator if any. */
ak8975_power_off(const struct ak8975_data * data)434 static void ak8975_power_off(const struct ak8975_data *data)
435 {
436 gpiod_set_value_cansleep(data->reset_gpiod, 1);
437
438 regulator_disable(data->vid);
439 regulator_disable(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 */
ak8975_who_i_am(struct i2c_client * client,enum asahi_compass_chipset type)446 static 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, 2, 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 */
ak8975_set_mode(struct ak8975_data * data,enum ak_ctrl_mode mode)496 static 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(data->client,
504 data->def->ctrl_regs[CNTL], regval);
505 if (ret < 0) {
506 return ret;
507 }
508 data->cntl_cache = regval;
509 /* After mode change wait atleast 100us */
510 usleep_range(100, 500);
511
512 return 0;
513 }
514
515 /*
516 * Handle data ready irq
517 */
ak8975_irq_handler(int irq,void * data)518 static irqreturn_t ak8975_irq_handler(int irq, void *data)
519 {
520 struct ak8975_data *ak8975 = data;
521
522 set_bit(0, &ak8975->flags);
523 wake_up(&ak8975->data_ready_queue);
524
525 return IRQ_HANDLED;
526 }
527
528 /*
529 * Install data ready interrupt handler
530 */
ak8975_setup_irq(struct ak8975_data * data)531 static 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(0, &data->flags);
539 if (client->irq)
540 irq = client->irq;
541 else
542 irq = gpiod_to_irq(data->eoc_gpiod);
543
544 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,
545 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
546 dev_name(&client->dev), 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 */
ak8975_setup(struct i2c_client * client)562 static 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, 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, data->def->ctrl_regs[ASA_BASE],
578 3, 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, 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
wait_conversion_complete_gpio(struct ak8975_data * data)607 static 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(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, 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
wait_conversion_complete_polled(struct ak8975_data * data)632 static 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 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 */
wait_conversion_complete_interrupt(struct ak8975_data * data)662 static 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(0, &data->flags);
670
671 return ret > 0 ? 0 : -ETIME;
672 }
673
ak8975_start_read_axis(struct ak8975_data * data,const struct i2c_client * client)674 static 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_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 /* Return with zero if the data is ready. */
696 return !data->def->ctrl_regs[ST1_DRDY];
697 }
698
699 /* Retrieve raw flux value for one of the x, y, or z axis. */
ak8975_read_axis(struct iio_dev * indio_dev,int index,int * val)700 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
701 {
702 struct ak8975_data *data = iio_priv(indio_dev);
703 const struct i2c_client *client = data->client;
704 const struct ak_def *def = data->def;
705 __le16 rval;
706 u16 buff;
707 int ret;
708
709 pm_runtime_get_sync(&data->client->dev);
710
711 mutex_lock(&data->lock);
712
713 ret = ak8975_start_read_axis(data, client);
714 if (ret)
715 goto exit;
716
717 ret = i2c_smbus_read_i2c_block_data_or_emulated(
718 client, def->data_regs[index],
719 sizeof(rval), (u8*)&rval);
720 if (ret < 0)
721 goto exit;
722
723 /* Read out ST2 for release lock on measurment data. */
724 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST2]);
725 if (ret < 0) {
726 dev_err(&client->dev, "Error in reading ST2\n");
727 goto exit;
728 }
729
730 if (ret & (data->def->ctrl_masks[ST2_DERR] |
731 data->def->ctrl_masks[ST2_HOFL])) {
732 dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
733 ret = -EINVAL;
734 goto exit;
735 }
736
737 mutex_unlock(&data->lock);
738
739 pm_runtime_mark_last_busy(&data->client->dev);
740 pm_runtime_put_autosuspend(&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
747 exit:
748 mutex_unlock(&data->lock);
749 dev_err(&client->dev, "Error in reading axis\n");
750 return ret;
751 }
752
ak8975_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)753 static 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, 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
771 static const struct iio_mount_matrix *
ak8975_get_mount_matrix(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)772 ak8975_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
780 static 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
803 static 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
808 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
809
810 static const struct iio_info ak8975_info = {
811 .read_raw = &ak8975_read_raw,
812 };
813
814 static const struct acpi_device_id ak_acpi_match[] = {
815 {"AK8975", (kernel_ulong_t)&ak_def_array[AK8975] },
816 {"AK8963", (kernel_ulong_t)&ak_def_array[AK8963] },
817 {"INVN6500", (kernel_ulong_t)&ak_def_array[AK8963] },
818 {"AK009911", (kernel_ulong_t)&ak_def_array[AK09911] },
819 {"AK09911", (kernel_ulong_t)&ak_def_array[AK09911] },
820 {"AKM9911", (kernel_ulong_t)&ak_def_array[AK09911] },
821 {"AK09912", (kernel_ulong_t)&ak_def_array[AK09912] },
822 { }
823 };
824 MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
825
ak8975_fill_buffer(struct iio_dev * indio_dev)826 static void ak8975_fill_buffer(struct iio_dev *indio_dev)
827 {
828 struct ak8975_data *data = iio_priv(indio_dev);
829 const struct i2c_client *client = data->client;
830 const struct ak_def *def = data->def;
831 int ret;
832 __le16 fval[3];
833
834 mutex_lock(&data->lock);
835
836 ret = ak8975_start_read_axis(data, client);
837 if (ret)
838 goto unlock;
839
840 /*
841 * For each axis, read the flux value from the appropriate register
842 * (the register is specified in the iio device attributes).
843 */
844 ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
845 def->data_regs[0],
846 3 * sizeof(fval[0]),
847 (u8 *)fval);
848 if (ret < 0)
849 goto unlock;
850
851 mutex_unlock(&data->lock);
852
853 /* Clamp to valid range. */
854 data->scan.channels[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range);
855 data->scan.channels[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range);
856 data->scan.channels[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range);
857
858 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
859 iio_get_time_ns(indio_dev));
860
861 return;
862
863 unlock:
864 mutex_unlock(&data->lock);
865 dev_err(&client->dev, "Error in reading axes block\n");
866 }
867
ak8975_handle_trigger(int irq,void * p)868 static irqreturn_t ak8975_handle_trigger(int irq, void *p)
869 {
870 const struct iio_poll_func *pf = p;
871 struct iio_dev *indio_dev = pf->indio_dev;
872
873 ak8975_fill_buffer(indio_dev);
874 iio_trigger_notify_done(indio_dev->trig);
875 return IRQ_HANDLED;
876 }
877
ak8975_probe(struct i2c_client * client)878 static int ak8975_probe(struct i2c_client *client)
879 {
880 const struct i2c_device_id *id = i2c_client_get_device_id(client);
881 struct ak8975_data *data;
882 struct iio_dev *indio_dev;
883 struct gpio_desc *eoc_gpiod;
884 struct gpio_desc *reset_gpiod;
885 int err;
886 const char *name = NULL;
887
888 /*
889 * Grab and set up the supplied GPIO.
890 * We may not have a GPIO based IRQ to scan, that is fine, we will
891 * poll if so.
892 */
893 eoc_gpiod = devm_gpiod_get_optional(&client->dev, NULL, GPIOD_IN);
894 if (IS_ERR(eoc_gpiod))
895 return PTR_ERR(eoc_gpiod);
896 if (eoc_gpiod)
897 gpiod_set_consumer_name(eoc_gpiod, "ak_8975");
898
899 /*
900 * According to AK09911 datasheet, if reset GPIO is provided then
901 * deassert reset on ak8975_power_on() and assert reset on
902 * ak8975_power_off().
903 */
904 reset_gpiod = devm_gpiod_get_optional(&client->dev,
905 "reset", GPIOD_OUT_HIGH);
906 if (IS_ERR(reset_gpiod))
907 return PTR_ERR(reset_gpiod);
908
909 /* Register with IIO */
910 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
911 if (indio_dev == NULL)
912 return -ENOMEM;
913
914 data = iio_priv(indio_dev);
915 i2c_set_clientdata(client, indio_dev);
916
917 data->client = client;
918 data->eoc_gpiod = eoc_gpiod;
919 data->reset_gpiod = reset_gpiod;
920 data->eoc_irq = 0;
921
922 err = iio_read_mount_matrix(&client->dev, &data->orientation);
923 if (err)
924 return err;
925
926 /* id will be NULL when enumerated via ACPI */
927 data->def = i2c_get_match_data(client);
928 if (!data->def)
929 return -ENODEV;
930
931 /* If enumerated via firmware node, fix the ABI */
932 if (dev_fwnode(&client->dev))
933 name = dev_name(&client->dev);
934 else
935 name = id->name;
936
937 /* Fetch the regulators */
938 data->vdd = devm_regulator_get(&client->dev, "vdd");
939 if (IS_ERR(data->vdd))
940 return PTR_ERR(data->vdd);
941 data->vid = devm_regulator_get(&client->dev, "vid");
942 if (IS_ERR(data->vid))
943 return PTR_ERR(data->vid);
944
945 err = ak8975_power_on(data);
946 if (err)
947 return err;
948
949 err = ak8975_who_i_am(client, data->def->type);
950 if (err < 0) {
951 dev_err(&client->dev, "Unexpected device\n");
952 goto power_off;
953 }
954 dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
955
956 /* Perform some basic start-of-day setup of the device. */
957 err = ak8975_setup(client);
958 if (err < 0) {
959 dev_err(&client->dev, "%s initialization fails\n", name);
960 goto power_off;
961 }
962
963 mutex_init(&data->lock);
964 indio_dev->channels = ak8975_channels;
965 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
966 indio_dev->info = &ak8975_info;
967 indio_dev->available_scan_masks = ak8975_scan_masks;
968 indio_dev->modes = INDIO_DIRECT_MODE;
969 indio_dev->name = name;
970
971 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
972 NULL);
973 if (err) {
974 dev_err(&client->dev, "triggered buffer setup failed\n");
975 goto power_off;
976 }
977
978 err = iio_device_register(indio_dev);
979 if (err) {
980 dev_err(&client->dev, "device register failed\n");
981 goto cleanup_buffer;
982 }
983
984 /* Enable runtime PM */
985 pm_runtime_get_noresume(&client->dev);
986 pm_runtime_set_active(&client->dev);
987 pm_runtime_enable(&client->dev);
988 /*
989 * The device comes online in 500us, so add two orders of magnitude
990 * of delay before autosuspending: 50 ms.
991 */
992 pm_runtime_set_autosuspend_delay(&client->dev, 50);
993 pm_runtime_use_autosuspend(&client->dev);
994 pm_runtime_put(&client->dev);
995
996 return 0;
997
998 cleanup_buffer:
999 iio_triggered_buffer_cleanup(indio_dev);
1000 power_off:
1001 ak8975_power_off(data);
1002 return err;
1003 }
1004
ak8975_remove(struct i2c_client * client)1005 static void ak8975_remove(struct i2c_client *client)
1006 {
1007 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1008 struct ak8975_data *data = iio_priv(indio_dev);
1009
1010 pm_runtime_get_sync(&client->dev);
1011 pm_runtime_put_noidle(&client->dev);
1012 pm_runtime_disable(&client->dev);
1013 iio_device_unregister(indio_dev);
1014 iio_triggered_buffer_cleanup(indio_dev);
1015 ak8975_set_mode(data, POWER_DOWN);
1016 ak8975_power_off(data);
1017 }
1018
ak8975_runtime_suspend(struct device * dev)1019 static int ak8975_runtime_suspend(struct device *dev)
1020 {
1021 struct i2c_client *client = to_i2c_client(dev);
1022 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1023 struct ak8975_data *data = iio_priv(indio_dev);
1024 int ret;
1025
1026 /* Set the device in power down if it wasn't already */
1027 ret = ak8975_set_mode(data, POWER_DOWN);
1028 if (ret < 0) {
1029 dev_err(&client->dev, "Error in setting power-down mode\n");
1030 return ret;
1031 }
1032 /* Next cut the regulators */
1033 ak8975_power_off(data);
1034
1035 return 0;
1036 }
1037
ak8975_runtime_resume(struct device * dev)1038 static int ak8975_runtime_resume(struct device *dev)
1039 {
1040 struct i2c_client *client = to_i2c_client(dev);
1041 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1042 struct ak8975_data *data = iio_priv(indio_dev);
1043 int ret;
1044
1045 /* Take up the regulators */
1046 ak8975_power_on(data);
1047 /*
1048 * We come up in powered down mode, the reading routines will
1049 * put us in the mode to read values later.
1050 */
1051 ret = ak8975_set_mode(data, POWER_DOWN);
1052 if (ret < 0) {
1053 dev_err(&client->dev, "Error in setting power-down mode\n");
1054 return ret;
1055 }
1056
1057 return 0;
1058 }
1059
1060 static DEFINE_RUNTIME_DEV_PM_OPS(ak8975_dev_pm_ops, ak8975_runtime_suspend,
1061 ak8975_runtime_resume, NULL);
1062
1063 static const struct i2c_device_id ak8975_id[] = {
1064 {"ak8975", (kernel_ulong_t)&ak_def_array[AK8975] },
1065 {"ak8963", (kernel_ulong_t)&ak_def_array[AK8963] },
1066 {"AK8963", (kernel_ulong_t)&ak_def_array[AK8963] },
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 };
1072
1073 MODULE_DEVICE_TABLE(i2c, ak8975_id);
1074
1075 static const struct of_device_id ak8975_of_match[] = {
1076 { .compatible = "asahi-kasei,ak8975", .data = &ak_def_array[AK8975] },
1077 { .compatible = "ak8975", .data = &ak_def_array[AK8975] },
1078 { .compatible = "asahi-kasei,ak8963", .data = &ak_def_array[AK8963] },
1079 { .compatible = "ak8963", .data = &ak_def_array[AK8963] },
1080 { .compatible = "asahi-kasei,ak09911", .data = &ak_def_array[AK09911] },
1081 { .compatible = "ak09911", .data = &ak_def_array[AK09911] },
1082 { .compatible = "asahi-kasei,ak09912", .data = &ak_def_array[AK09912] },
1083 { .compatible = "ak09912", .data = &ak_def_array[AK09912] },
1084 { .compatible = "asahi-kasei,ak09916", .data = &ak_def_array[AK09916] },
1085 {}
1086 };
1087 MODULE_DEVICE_TABLE(of, ak8975_of_match);
1088
1089 static 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 };
1100 module_i2c_driver(ak8975_driver);
1101
1102 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1103 MODULE_DESCRIPTION("AK8975 magnetometer driver");
1104 MODULE_LICENSE("GPL");
1105