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 AKXXXX = 0,
208 AK8975,
209 AK8963,
210 AK09911,
211 AK09912,
212 AK09916,
213 };
214
215 enum ak_ctrl_reg_addr {
216 ST1,
217 ST2,
218 CNTL,
219 ASA_BASE,
220 MAX_REGS,
221 REGS_END,
222 };
223
224 enum ak_ctrl_reg_mask {
225 ST1_DRDY,
226 ST2_HOFL,
227 ST2_DERR,
228 CNTL_MODE,
229 MASK_END,
230 };
231
232 enum ak_ctrl_mode {
233 POWER_DOWN,
234 MODE_ONCE,
235 SELF_TEST,
236 FUSE_ROM,
237 MODE_END,
238 };
239
240 struct ak_def {
241 enum asahi_compass_chipset type;
242 long (*raw_to_gauss)(u16 data);
243 u16 range;
244 u8 ctrl_regs[REGS_END];
245 u8 ctrl_masks[MASK_END];
246 u8 ctrl_modes[MODE_END];
247 u8 data_regs[3];
248 };
249
250 static const struct ak_def ak_def_array[] = {
251 {
252 .type = AK8975,
253 .raw_to_gauss = ak8975_raw_to_gauss,
254 .range = 4096,
255 .ctrl_regs = {
256 AK8975_REG_ST1,
257 AK8975_REG_ST2,
258 AK8975_REG_CNTL,
259 AK8975_REG_ASAX,
260 AK8975_MAX_REGS},
261 .ctrl_masks = {
262 AK8975_REG_ST1_DRDY_MASK,
263 AK8975_REG_ST2_HOFL_MASK,
264 AK8975_REG_ST2_DERR_MASK,
265 AK8975_REG_CNTL_MODE_MASK},
266 .ctrl_modes = {
267 AK8975_REG_CNTL_MODE_POWER_DOWN,
268 AK8975_REG_CNTL_MODE_ONCE,
269 AK8975_REG_CNTL_MODE_SELF_TEST,
270 AK8975_REG_CNTL_MODE_FUSE_ROM},
271 .data_regs = {
272 AK8975_REG_HXL,
273 AK8975_REG_HYL,
274 AK8975_REG_HZL},
275 },
276 {
277 .type = AK8963,
278 .raw_to_gauss = ak8963_09911_raw_to_gauss,
279 .range = 8190,
280 .ctrl_regs = {
281 AK8975_REG_ST1,
282 AK8975_REG_ST2,
283 AK8975_REG_CNTL,
284 AK8975_REG_ASAX,
285 AK8975_MAX_REGS},
286 .ctrl_masks = {
287 AK8975_REG_ST1_DRDY_MASK,
288 AK8975_REG_ST2_HOFL_MASK,
289 0,
290 AK8975_REG_CNTL_MODE_MASK},
291 .ctrl_modes = {
292 AK8975_REG_CNTL_MODE_POWER_DOWN,
293 AK8975_REG_CNTL_MODE_ONCE,
294 AK8975_REG_CNTL_MODE_SELF_TEST,
295 AK8975_REG_CNTL_MODE_FUSE_ROM},
296 .data_regs = {
297 AK8975_REG_HXL,
298 AK8975_REG_HYL,
299 AK8975_REG_HZL},
300 },
301 {
302 .type = AK09911,
303 .raw_to_gauss = ak8963_09911_raw_to_gauss,
304 .range = 8192,
305 .ctrl_regs = {
306 AK09912_REG_ST1,
307 AK09912_REG_ST2,
308 AK09912_REG_CNTL2,
309 AK09912_REG_ASAX,
310 AK09912_MAX_REGS},
311 .ctrl_masks = {
312 AK09912_REG_ST1_DRDY_MASK,
313 AK09912_REG_ST2_HOFL_MASK,
314 0,
315 AK09912_REG_CNTL2_MODE_MASK},
316 .ctrl_modes = {
317 AK09912_REG_CNTL_MODE_POWER_DOWN,
318 AK09912_REG_CNTL_MODE_ONCE,
319 AK09912_REG_CNTL_MODE_SELF_TEST,
320 AK09912_REG_CNTL_MODE_FUSE_ROM},
321 .data_regs = {
322 AK09912_REG_HXL,
323 AK09912_REG_HYL,
324 AK09912_REG_HZL},
325 },
326 {
327 .type = AK09912,
328 .raw_to_gauss = ak09912_raw_to_gauss,
329 .range = 32752,
330 .ctrl_regs = {
331 AK09912_REG_ST1,
332 AK09912_REG_ST2,
333 AK09912_REG_CNTL2,
334 AK09912_REG_ASAX,
335 AK09912_MAX_REGS},
336 .ctrl_masks = {
337 AK09912_REG_ST1_DRDY_MASK,
338 AK09912_REG_ST2_HOFL_MASK,
339 0,
340 AK09912_REG_CNTL2_MODE_MASK},
341 .ctrl_modes = {
342 AK09912_REG_CNTL_MODE_POWER_DOWN,
343 AK09912_REG_CNTL_MODE_ONCE,
344 AK09912_REG_CNTL_MODE_SELF_TEST,
345 AK09912_REG_CNTL_MODE_FUSE_ROM},
346 .data_regs = {
347 AK09912_REG_HXL,
348 AK09912_REG_HYL,
349 AK09912_REG_HZL},
350 },
351 {
352 .type = AK09916,
353 .raw_to_gauss = ak09912_raw_to_gauss,
354 .range = 32752,
355 .ctrl_regs = {
356 AK09912_REG_ST1,
357 AK09912_REG_ST2,
358 AK09912_REG_CNTL2,
359 AK09912_REG_ASAX,
360 AK09912_MAX_REGS},
361 .ctrl_masks = {
362 AK09912_REG_ST1_DRDY_MASK,
363 AK09912_REG_ST2_HOFL_MASK,
364 0,
365 AK09912_REG_CNTL2_MODE_MASK},
366 .ctrl_modes = {
367 AK09912_REG_CNTL_MODE_POWER_DOWN,
368 AK09912_REG_CNTL_MODE_ONCE,
369 AK09912_REG_CNTL_MODE_SELF_TEST,
370 AK09912_REG_CNTL_MODE_FUSE_ROM},
371 .data_regs = {
372 AK09912_REG_HXL,
373 AK09912_REG_HYL,
374 AK09912_REG_HZL},
375 }
376 };
377
378 /*
379 * Per-instance context data for the device.
380 */
381 struct ak8975_data {
382 struct i2c_client *client;
383 const struct ak_def *def;
384 struct mutex lock;
385 u8 asa[3];
386 long raw_to_gauss[3];
387 struct gpio_desc *eoc_gpiod;
388 struct gpio_desc *reset_gpiod;
389 int eoc_irq;
390 wait_queue_head_t data_ready_queue;
391 unsigned long flags;
392 u8 cntl_cache;
393 struct iio_mount_matrix orientation;
394 struct regulator *vdd;
395 struct regulator *vid;
396
397 /* Ensure natural alignment of timestamp */
398 struct {
399 s16 channels[3];
400 s64 ts __aligned(8);
401 } scan;
402 };
403
404 /* Enable attached power regulator if any. */
ak8975_power_on(const struct ak8975_data * data)405 static int ak8975_power_on(const struct ak8975_data *data)
406 {
407 int ret;
408
409 ret = regulator_enable(data->vdd);
410 if (ret) {
411 dev_warn(&data->client->dev,
412 "Failed to enable specified Vdd supply\n");
413 return ret;
414 }
415 ret = regulator_enable(data->vid);
416 if (ret) {
417 dev_warn(&data->client->dev,
418 "Failed to enable specified Vid supply\n");
419 regulator_disable(data->vdd);
420 return ret;
421 }
422
423 gpiod_set_value_cansleep(data->reset_gpiod, 0);
424
425 /*
426 * According to the datasheet the power supply rise time is 200us
427 * and the minimum wait time before mode setting is 100us, in
428 * total 300us. Add some margin and say minimum 500us here.
429 */
430 usleep_range(500, 1000);
431 return 0;
432 }
433
434 /* Disable attached power regulator if any. */
ak8975_power_off(const struct ak8975_data * data)435 static void ak8975_power_off(const struct ak8975_data *data)
436 {
437 gpiod_set_value_cansleep(data->reset_gpiod, 1);
438
439 regulator_disable(data->vid);
440 regulator_disable(data->vdd);
441 }
442
443 /*
444 * Return 0 if the i2c device is the one we expect.
445 * return a negative error number otherwise
446 */
ak8975_who_i_am(struct i2c_client * client,enum asahi_compass_chipset type)447 static int ak8975_who_i_am(struct i2c_client *client,
448 enum asahi_compass_chipset type)
449 {
450 u8 wia_val[2];
451 int ret;
452
453 /*
454 * Signature for each device:
455 * Device | WIA1 | WIA2
456 * AK09916 | DEVICE_ID_| AK09916_DEVICE_ID
457 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID
458 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID
459 * AK8975 | DEVICE_ID | NA
460 * AK8963 | DEVICE_ID | NA
461 */
462 ret = i2c_smbus_read_i2c_block_data_or_emulated(
463 client, AK09912_REG_WIA1, 2, wia_val);
464 if (ret < 0) {
465 dev_err(&client->dev, "Error reading WIA\n");
466 return ret;
467 }
468
469 if (wia_val[0] != AK8975_DEVICE_ID)
470 return -ENODEV;
471
472 switch (type) {
473 case AK8975:
474 case AK8963:
475 return 0;
476 case AK09911:
477 if (wia_val[1] == AK09911_DEVICE_ID)
478 return 0;
479 break;
480 case AK09912:
481 if (wia_val[1] == AK09912_DEVICE_ID)
482 return 0;
483 break;
484 case AK09916:
485 if (wia_val[1] == AK09916_DEVICE_ID)
486 return 0;
487 break;
488 default:
489 dev_err(&client->dev, "Type %d unknown\n", type);
490 }
491 return -ENODEV;
492 }
493
494 /*
495 * Helper function to write to CNTL register.
496 */
ak8975_set_mode(struct ak8975_data * data,enum ak_ctrl_mode mode)497 static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode)
498 {
499 u8 regval;
500 int ret;
501
502 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) |
503 data->def->ctrl_modes[mode];
504 ret = i2c_smbus_write_byte_data(data->client,
505 data->def->ctrl_regs[CNTL], regval);
506 if (ret < 0) {
507 return ret;
508 }
509 data->cntl_cache = regval;
510 /* After mode change wait atleast 100us */
511 usleep_range(100, 500);
512
513 return 0;
514 }
515
516 /*
517 * Handle data ready irq
518 */
ak8975_irq_handler(int irq,void * data)519 static irqreturn_t ak8975_irq_handler(int irq, void *data)
520 {
521 struct ak8975_data *ak8975 = data;
522
523 set_bit(0, &ak8975->flags);
524 wake_up(&ak8975->data_ready_queue);
525
526 return IRQ_HANDLED;
527 }
528
529 /*
530 * Install data ready interrupt handler
531 */
ak8975_setup_irq(struct ak8975_data * data)532 static int ak8975_setup_irq(struct ak8975_data *data)
533 {
534 struct i2c_client *client = data->client;
535 int rc;
536 int irq;
537
538 init_waitqueue_head(&data->data_ready_queue);
539 clear_bit(0, &data->flags);
540 if (client->irq)
541 irq = client->irq;
542 else
543 irq = gpiod_to_irq(data->eoc_gpiod);
544
545 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,
546 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
547 dev_name(&client->dev), data);
548 if (rc < 0) {
549 dev_err(&client->dev, "irq %d request failed: %d\n", irq, rc);
550 return rc;
551 }
552
553 data->eoc_irq = irq;
554
555 return rc;
556 }
557
558
559 /*
560 * Perform some start-of-day setup, including reading the asa calibration
561 * values and caching them.
562 */
ak8975_setup(struct i2c_client * client)563 static int ak8975_setup(struct i2c_client *client)
564 {
565 struct iio_dev *indio_dev = i2c_get_clientdata(client);
566 struct ak8975_data *data = iio_priv(indio_dev);
567 int ret;
568
569 /* Write the fused rom access mode. */
570 ret = ak8975_set_mode(data, FUSE_ROM);
571 if (ret < 0) {
572 dev_err(&client->dev, "Error in setting fuse access mode\n");
573 return ret;
574 }
575
576 /* Get asa data and store in the device data. */
577 ret = i2c_smbus_read_i2c_block_data_or_emulated(
578 client, data->def->ctrl_regs[ASA_BASE],
579 3, data->asa);
580 if (ret < 0) {
581 dev_err(&client->dev, "Not able to read asa data\n");
582 return ret;
583 }
584
585 /* After reading fuse ROM data set power-down mode */
586 ret = ak8975_set_mode(data, POWER_DOWN);
587 if (ret < 0) {
588 dev_err(&client->dev, "Error in setting power-down mode\n");
589 return ret;
590 }
591
592 if (data->eoc_gpiod || client->irq > 0) {
593 ret = ak8975_setup_irq(data);
594 if (ret < 0) {
595 dev_err(&client->dev,
596 "Error setting data ready interrupt\n");
597 return ret;
598 }
599 }
600
601 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]);
602 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]);
603 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]);
604
605 return 0;
606 }
607
wait_conversion_complete_gpio(struct ak8975_data * data)608 static int wait_conversion_complete_gpio(struct ak8975_data *data)
609 {
610 struct i2c_client *client = data->client;
611 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
612 int ret;
613
614 /* Wait for the conversion to complete. */
615 while (timeout_ms) {
616 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
617 if (gpiod_get_value(data->eoc_gpiod))
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 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]);
627 if (ret < 0)
628 dev_err(&client->dev, "Error in reading ST1\n");
629
630 return ret;
631 }
632
wait_conversion_complete_polled(struct ak8975_data * data)633 static int wait_conversion_complete_polled(struct ak8975_data *data)
634 {
635 struct i2c_client *client = data->client;
636 u8 read_status;
637 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
638 int ret;
639
640 /* Wait for the conversion to complete. */
641 while (timeout_ms) {
642 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
643 ret = i2c_smbus_read_byte_data(client,
644 data->def->ctrl_regs[ST1]);
645 if (ret < 0) {
646 dev_err(&client->dev, "Error in reading ST1\n");
647 return ret;
648 }
649 read_status = ret;
650 if (read_status)
651 break;
652 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
653 }
654 if (!timeout_ms) {
655 dev_err(&client->dev, "Conversion timeout happened\n");
656 return -EINVAL;
657 }
658
659 return read_status;
660 }
661
662 /* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */
wait_conversion_complete_interrupt(struct ak8975_data * data)663 static int wait_conversion_complete_interrupt(struct ak8975_data *data)
664 {
665 int ret;
666
667 ret = wait_event_timeout(data->data_ready_queue,
668 test_bit(0, &data->flags),
669 AK8975_DATA_READY_TIMEOUT);
670 clear_bit(0, &data->flags);
671
672 return ret > 0 ? 0 : -ETIME;
673 }
674
ak8975_start_read_axis(struct ak8975_data * data,const struct i2c_client * client)675 static int ak8975_start_read_axis(struct ak8975_data *data,
676 const struct i2c_client *client)
677 {
678 /* Set up the device for taking a sample. */
679 int ret = ak8975_set_mode(data, MODE_ONCE);
680
681 if (ret < 0) {
682 dev_err(&client->dev, "Error in setting operating mode\n");
683 return ret;
684 }
685
686 /* Wait for the conversion to complete. */
687 if (data->eoc_irq)
688 ret = wait_conversion_complete_interrupt(data);
689 else if (data->eoc_gpiod)
690 ret = wait_conversion_complete_gpio(data);
691 else
692 ret = wait_conversion_complete_polled(data);
693 if (ret < 0)
694 return ret;
695
696 /* This will be executed only for non-interrupt based waiting case */
697 if (ret & data->def->ctrl_masks[ST1_DRDY]) {
698 ret = i2c_smbus_read_byte_data(client,
699 data->def->ctrl_regs[ST2]);
700 if (ret < 0) {
701 dev_err(&client->dev, "Error in reading ST2\n");
702 return ret;
703 }
704 if (ret & (data->def->ctrl_masks[ST2_DERR] |
705 data->def->ctrl_masks[ST2_HOFL])) {
706 dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
707 return -EINVAL;
708 }
709 }
710
711 return 0;
712 }
713
714 /* 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)715 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
716 {
717 struct ak8975_data *data = iio_priv(indio_dev);
718 const struct i2c_client *client = data->client;
719 const struct ak_def *def = data->def;
720 __le16 rval;
721 u16 buff;
722 int ret;
723
724 pm_runtime_get_sync(&data->client->dev);
725
726 mutex_lock(&data->lock);
727
728 ret = ak8975_start_read_axis(data, client);
729 if (ret)
730 goto exit;
731
732 ret = i2c_smbus_read_i2c_block_data_or_emulated(
733 client, def->data_regs[index],
734 sizeof(rval), (u8*)&rval);
735 if (ret < 0)
736 goto exit;
737
738 mutex_unlock(&data->lock);
739
740 pm_runtime_mark_last_busy(&data->client->dev);
741 pm_runtime_put_autosuspend(&data->client->dev);
742
743 /* Swap bytes and convert to valid range. */
744 buff = le16_to_cpu(rval);
745 *val = clamp_t(s16, buff, -def->range, def->range);
746 return IIO_VAL_INT;
747
748 exit:
749 mutex_unlock(&data->lock);
750 dev_err(&client->dev, "Error in reading axis\n");
751 return ret;
752 }
753
ak8975_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)754 static int ak8975_read_raw(struct iio_dev *indio_dev,
755 struct iio_chan_spec const *chan,
756 int *val, int *val2,
757 long mask)
758 {
759 struct ak8975_data *data = iio_priv(indio_dev);
760
761 switch (mask) {
762 case IIO_CHAN_INFO_RAW:
763 return ak8975_read_axis(indio_dev, chan->address, val);
764 case IIO_CHAN_INFO_SCALE:
765 *val = 0;
766 *val2 = data->raw_to_gauss[chan->address];
767 return IIO_VAL_INT_PLUS_MICRO;
768 }
769 return -EINVAL;
770 }
771
772 static const struct iio_mount_matrix *
ak8975_get_mount_matrix(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)773 ak8975_get_mount_matrix(const struct iio_dev *indio_dev,
774 const struct iio_chan_spec *chan)
775 {
776 struct ak8975_data *data = iio_priv(indio_dev);
777
778 return &data->orientation;
779 }
780
781 static const struct iio_chan_spec_ext_info ak8975_ext_info[] = {
782 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix),
783 { }
784 };
785
786 #define AK8975_CHANNEL(axis, index) \
787 { \
788 .type = IIO_MAGN, \
789 .modified = 1, \
790 .channel2 = IIO_MOD_##axis, \
791 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
792 BIT(IIO_CHAN_INFO_SCALE), \
793 .address = index, \
794 .scan_index = index, \
795 .scan_type = { \
796 .sign = 's', \
797 .realbits = 16, \
798 .storagebits = 16, \
799 .endianness = IIO_CPU \
800 }, \
801 .ext_info = ak8975_ext_info, \
802 }
803
804 static const struct iio_chan_spec ak8975_channels[] = {
805 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
806 IIO_CHAN_SOFT_TIMESTAMP(3),
807 };
808
809 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
810
811 static const struct iio_info ak8975_info = {
812 .read_raw = &ak8975_read_raw,
813 };
814
815 static const struct acpi_device_id ak_acpi_match[] = {
816 {"AK8975", AK8975},
817 {"AK8963", AK8963},
818 {"INVN6500", AK8963},
819 {"AK009911", AK09911},
820 {"AK09911", AK09911},
821 {"AKM9911", AK09911},
822 {"AK09912", AK09912},
823 { }
824 };
825 MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
826
ak8975_fill_buffer(struct iio_dev * indio_dev)827 static void ak8975_fill_buffer(struct iio_dev *indio_dev)
828 {
829 struct ak8975_data *data = iio_priv(indio_dev);
830 const struct i2c_client *client = data->client;
831 const struct ak_def *def = data->def;
832 int ret;
833 __le16 fval[3];
834
835 mutex_lock(&data->lock);
836
837 ret = ak8975_start_read_axis(data, client);
838 if (ret)
839 goto unlock;
840
841 /*
842 * For each axis, read the flux value from the appropriate register
843 * (the register is specified in the iio device attributes).
844 */
845 ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
846 def->data_regs[0],
847 3 * sizeof(fval[0]),
848 (u8 *)fval);
849 if (ret < 0)
850 goto unlock;
851
852 mutex_unlock(&data->lock);
853
854 /* Clamp to valid range. */
855 data->scan.channels[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range);
856 data->scan.channels[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range);
857 data->scan.channels[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range);
858
859 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
860 iio_get_time_ns(indio_dev));
861
862 return;
863
864 unlock:
865 mutex_unlock(&data->lock);
866 dev_err(&client->dev, "Error in reading axes block\n");
867 }
868
ak8975_handle_trigger(int irq,void * p)869 static irqreturn_t ak8975_handle_trigger(int irq, void *p)
870 {
871 const struct iio_poll_func *pf = p;
872 struct iio_dev *indio_dev = pf->indio_dev;
873
874 ak8975_fill_buffer(indio_dev);
875 iio_trigger_notify_done(indio_dev->trig);
876 return IRQ_HANDLED;
877 }
878
ak8975_probe(struct i2c_client * client)879 static int ak8975_probe(struct i2c_client *client)
880 {
881 const struct i2c_device_id *id = i2c_client_get_device_id(client);
882 struct ak8975_data *data;
883 struct iio_dev *indio_dev;
884 struct gpio_desc *eoc_gpiod;
885 struct gpio_desc *reset_gpiod;
886 const void *match;
887 unsigned int i;
888 int err;
889 enum asahi_compass_chipset chipset;
890 const char *name = NULL;
891
892 /*
893 * Grab and set up the supplied GPIO.
894 * We may not have a GPIO based IRQ to scan, that is fine, we will
895 * poll if so.
896 */
897 eoc_gpiod = devm_gpiod_get_optional(&client->dev, NULL, GPIOD_IN);
898 if (IS_ERR(eoc_gpiod))
899 return PTR_ERR(eoc_gpiod);
900 if (eoc_gpiod)
901 gpiod_set_consumer_name(eoc_gpiod, "ak_8975");
902
903 /*
904 * According to AK09911 datasheet, if reset GPIO is provided then
905 * deassert reset on ak8975_power_on() and assert reset on
906 * ak8975_power_off().
907 */
908 reset_gpiod = devm_gpiod_get_optional(&client->dev,
909 "reset", GPIOD_OUT_HIGH);
910 if (IS_ERR(reset_gpiod))
911 return PTR_ERR(reset_gpiod);
912
913 /* Register with IIO */
914 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
915 if (indio_dev == NULL)
916 return -ENOMEM;
917
918 data = iio_priv(indio_dev);
919 i2c_set_clientdata(client, indio_dev);
920
921 data->client = client;
922 data->eoc_gpiod = eoc_gpiod;
923 data->reset_gpiod = reset_gpiod;
924 data->eoc_irq = 0;
925
926 err = iio_read_mount_matrix(&client->dev, &data->orientation);
927 if (err)
928 return err;
929
930 /* id will be NULL when enumerated via ACPI */
931 match = device_get_match_data(&client->dev);
932 if (match) {
933 chipset = (uintptr_t)match;
934 name = dev_name(&client->dev);
935 } else if (id) {
936 chipset = (enum asahi_compass_chipset)(id->driver_data);
937 name = id->name;
938 } else
939 return -ENOSYS;
940
941 for (i = 0; i < ARRAY_SIZE(ak_def_array); i++)
942 if (ak_def_array[i].type == chipset)
943 break;
944
945 if (i == ARRAY_SIZE(ak_def_array)) {
946 dev_err(&client->dev, "AKM device type unsupported: %d\n",
947 chipset);
948 return -ENODEV;
949 }
950
951 data->def = &ak_def_array[i];
952
953 /* Fetch the regulators */
954 data->vdd = devm_regulator_get(&client->dev, "vdd");
955 if (IS_ERR(data->vdd))
956 return PTR_ERR(data->vdd);
957 data->vid = devm_regulator_get(&client->dev, "vid");
958 if (IS_ERR(data->vid))
959 return PTR_ERR(data->vid);
960
961 err = ak8975_power_on(data);
962 if (err)
963 return err;
964
965 err = ak8975_who_i_am(client, data->def->type);
966 if (err < 0) {
967 dev_err(&client->dev, "Unexpected device\n");
968 goto power_off;
969 }
970 dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
971
972 /* Perform some basic start-of-day setup of the device. */
973 err = ak8975_setup(client);
974 if (err < 0) {
975 dev_err(&client->dev, "%s initialization fails\n", name);
976 goto power_off;
977 }
978
979 mutex_init(&data->lock);
980 indio_dev->channels = ak8975_channels;
981 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
982 indio_dev->info = &ak8975_info;
983 indio_dev->available_scan_masks = ak8975_scan_masks;
984 indio_dev->modes = INDIO_DIRECT_MODE;
985 indio_dev->name = name;
986
987 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
988 NULL);
989 if (err) {
990 dev_err(&client->dev, "triggered buffer setup failed\n");
991 goto power_off;
992 }
993
994 err = iio_device_register(indio_dev);
995 if (err) {
996 dev_err(&client->dev, "device register failed\n");
997 goto cleanup_buffer;
998 }
999
1000 /* Enable runtime PM */
1001 pm_runtime_get_noresume(&client->dev);
1002 pm_runtime_set_active(&client->dev);
1003 pm_runtime_enable(&client->dev);
1004 /*
1005 * The device comes online in 500us, so add two orders of magnitude
1006 * of delay before autosuspending: 50 ms.
1007 */
1008 pm_runtime_set_autosuspend_delay(&client->dev, 50);
1009 pm_runtime_use_autosuspend(&client->dev);
1010 pm_runtime_put(&client->dev);
1011
1012 return 0;
1013
1014 cleanup_buffer:
1015 iio_triggered_buffer_cleanup(indio_dev);
1016 power_off:
1017 ak8975_power_off(data);
1018 return err;
1019 }
1020
ak8975_remove(struct i2c_client * client)1021 static void ak8975_remove(struct i2c_client *client)
1022 {
1023 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1024 struct ak8975_data *data = iio_priv(indio_dev);
1025
1026 pm_runtime_get_sync(&client->dev);
1027 pm_runtime_put_noidle(&client->dev);
1028 pm_runtime_disable(&client->dev);
1029 iio_device_unregister(indio_dev);
1030 iio_triggered_buffer_cleanup(indio_dev);
1031 ak8975_set_mode(data, POWER_DOWN);
1032 ak8975_power_off(data);
1033 }
1034
ak8975_runtime_suspend(struct device * dev)1035 static int ak8975_runtime_suspend(struct device *dev)
1036 {
1037 struct i2c_client *client = to_i2c_client(dev);
1038 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1039 struct ak8975_data *data = iio_priv(indio_dev);
1040 int ret;
1041
1042 /* Set the device in power down if it wasn't already */
1043 ret = ak8975_set_mode(data, POWER_DOWN);
1044 if (ret < 0) {
1045 dev_err(&client->dev, "Error in setting power-down mode\n");
1046 return ret;
1047 }
1048 /* Next cut the regulators */
1049 ak8975_power_off(data);
1050
1051 return 0;
1052 }
1053
ak8975_runtime_resume(struct device * dev)1054 static int ak8975_runtime_resume(struct device *dev)
1055 {
1056 struct i2c_client *client = to_i2c_client(dev);
1057 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1058 struct ak8975_data *data = iio_priv(indio_dev);
1059 int ret;
1060
1061 /* Take up the regulators */
1062 ak8975_power_on(data);
1063 /*
1064 * We come up in powered down mode, the reading routines will
1065 * put us in the mode to read values later.
1066 */
1067 ret = ak8975_set_mode(data, POWER_DOWN);
1068 if (ret < 0) {
1069 dev_err(&client->dev, "Error in setting power-down mode\n");
1070 return ret;
1071 }
1072
1073 return 0;
1074 }
1075
1076 static DEFINE_RUNTIME_DEV_PM_OPS(ak8975_dev_pm_ops, ak8975_runtime_suspend,
1077 ak8975_runtime_resume, NULL);
1078
1079 static const struct i2c_device_id ak8975_id[] = {
1080 {"ak8975", AK8975},
1081 {"ak8963", AK8963},
1082 {"AK8963", AK8963},
1083 {"ak09911", AK09911},
1084 {"ak09912", AK09912},
1085 {"ak09916", AK09916},
1086 {}
1087 };
1088
1089 MODULE_DEVICE_TABLE(i2c, ak8975_id);
1090
1091 static const struct of_device_id ak8975_of_match[] = {
1092 { .compatible = "asahi-kasei,ak8975", },
1093 { .compatible = "ak8975", },
1094 { .compatible = "asahi-kasei,ak8963", },
1095 { .compatible = "ak8963", },
1096 { .compatible = "asahi-kasei,ak09911", },
1097 { .compatible = "ak09911", },
1098 { .compatible = "asahi-kasei,ak09912", },
1099 { .compatible = "ak09912", },
1100 { .compatible = "asahi-kasei,ak09916", },
1101 { .compatible = "ak09916", },
1102 {}
1103 };
1104 MODULE_DEVICE_TABLE(of, ak8975_of_match);
1105
1106 static struct i2c_driver ak8975_driver = {
1107 .driver = {
1108 .name = "ak8975",
1109 .pm = pm_ptr(&ak8975_dev_pm_ops),
1110 .of_match_table = ak8975_of_match,
1111 .acpi_match_table = ak_acpi_match,
1112 },
1113 .probe = ak8975_probe,
1114 .remove = ak8975_remove,
1115 .id_table = ak8975_id,
1116 };
1117 module_i2c_driver(ak8975_driver);
1118
1119 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1120 MODULE_DESCRIPTION("AK8975 magnetometer driver");
1121 MODULE_LICENSE("GPL");
1122