1 /*
2 * A sensor driver for the magnetometer AK8975.
3 *
4 * Magnetic compass sensor driver for monitoring magnetic flux information.
5 *
6 * Copyright (c) 2010, NVIDIA Corporation.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful, but WITHOUT
14 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
16 * more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 */
22
23 #include <linux/module.h>
24 #include <linux/kernel.h>
25 #include <linux/slab.h>
26 #include <linux/i2c.h>
27 #include <linux/interrupt.h>
28 #include <linux/err.h>
29 #include <linux/mutex.h>
30 #include <linux/delay.h>
31 #include <linux/bitops.h>
32 #include <linux/gpio.h>
33 #include <linux/of_gpio.h>
34 #include <linux/acpi.h>
35 #include <linux/regulator/consumer.h>
36 #include <linux/pm_runtime.h>
37
38 #include <linux/iio/iio.h>
39 #include <linux/iio/sysfs.h>
40 #include <linux/iio/buffer.h>
41 #include <linux/iio/trigger.h>
42 #include <linux/iio/trigger_consumer.h>
43 #include <linux/iio/triggered_buffer.h>
44
45 #include <linux/iio/magnetometer/ak8975.h>
46
47 /*
48 * Register definitions, as well as various shifts and masks to get at the
49 * individual fields of the registers.
50 */
51 #define AK8975_REG_WIA 0x00
52 #define AK8975_DEVICE_ID 0x48
53
54 #define AK8975_REG_INFO 0x01
55
56 #define AK8975_REG_ST1 0x02
57 #define AK8975_REG_ST1_DRDY_SHIFT 0
58 #define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT)
59
60 #define AK8975_REG_HXL 0x03
61 #define AK8975_REG_HXH 0x04
62 #define AK8975_REG_HYL 0x05
63 #define AK8975_REG_HYH 0x06
64 #define AK8975_REG_HZL 0x07
65 #define AK8975_REG_HZH 0x08
66 #define AK8975_REG_ST2 0x09
67 #define AK8975_REG_ST2_DERR_SHIFT 2
68 #define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT)
69
70 #define AK8975_REG_ST2_HOFL_SHIFT 3
71 #define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT)
72
73 #define AK8975_REG_CNTL 0x0A
74 #define AK8975_REG_CNTL_MODE_SHIFT 0
75 #define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT)
76 #define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00
77 #define AK8975_REG_CNTL_MODE_ONCE 0x01
78 #define AK8975_REG_CNTL_MODE_SELF_TEST 0x08
79 #define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F
80
81 #define AK8975_REG_RSVC 0x0B
82 #define AK8975_REG_ASTC 0x0C
83 #define AK8975_REG_TS1 0x0D
84 #define AK8975_REG_TS2 0x0E
85 #define AK8975_REG_I2CDIS 0x0F
86 #define AK8975_REG_ASAX 0x10
87 #define AK8975_REG_ASAY 0x11
88 #define AK8975_REG_ASAZ 0x12
89
90 #define AK8975_MAX_REGS AK8975_REG_ASAZ
91
92 /*
93 * AK09912 Register definitions
94 */
95 #define AK09912_REG_WIA1 0x00
96 #define AK09912_REG_WIA2 0x01
97 #define AK09912_DEVICE_ID 0x04
98 #define AK09911_DEVICE_ID 0x05
99
100 #define AK09911_REG_INFO1 0x02
101 #define AK09911_REG_INFO2 0x03
102
103 #define AK09912_REG_ST1 0x10
104
105 #define AK09912_REG_ST1_DRDY_SHIFT 0
106 #define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT)
107
108 #define AK09912_REG_HXL 0x11
109 #define AK09912_REG_HXH 0x12
110 #define AK09912_REG_HYL 0x13
111 #define AK09912_REG_HYH 0x14
112 #define AK09912_REG_HZL 0x15
113 #define AK09912_REG_HZH 0x16
114 #define AK09912_REG_TMPS 0x17
115
116 #define AK09912_REG_ST2 0x18
117 #define AK09912_REG_ST2_HOFL_SHIFT 3
118 #define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT)
119
120 #define AK09912_REG_CNTL1 0x30
121
122 #define AK09912_REG_CNTL2 0x31
123 #define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00
124 #define AK09912_REG_CNTL_MODE_ONCE 0x01
125 #define AK09912_REG_CNTL_MODE_SELF_TEST 0x10
126 #define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F
127 #define AK09912_REG_CNTL2_MODE_SHIFT 0
128 #define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT)
129
130 #define AK09912_REG_CNTL3 0x32
131
132 #define AK09912_REG_TS1 0x33
133 #define AK09912_REG_TS2 0x34
134 #define AK09912_REG_TS3 0x35
135 #define AK09912_REG_I2CDIS 0x36
136 #define AK09912_REG_TS4 0x37
137
138 #define AK09912_REG_ASAX 0x60
139 #define AK09912_REG_ASAY 0x61
140 #define AK09912_REG_ASAZ 0x62
141
142 #define AK09912_MAX_REGS AK09912_REG_ASAZ
143
144 /*
145 * Miscellaneous values.
146 */
147 #define AK8975_MAX_CONVERSION_TIMEOUT 500
148 #define AK8975_CONVERSION_DONE_POLL_TIME 10
149 #define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000)
150
151 /*
152 * Precalculate scale factor (in Gauss units) for each axis and
153 * store in the device data.
154 *
155 * This scale factor is axis-dependent, and is derived from 3 calibration
156 * factors ASA(x), ASA(y), and ASA(z).
157 *
158 * These ASA values are read from the sensor device at start of day, and
159 * cached in the device context struct.
160 *
161 * Adjusting the flux value with the sensitivity adjustment value should be
162 * done via the following formula:
163 *
164 * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 )
165 * where H is the raw value, ASA is the sensitivity adjustment, and Hadj
166 * is the resultant adjusted value.
167 *
168 * We reduce the formula to:
169 *
170 * Hadj = H * (ASA + 128) / 256
171 *
172 * H is in the range of -4096 to 4095. The magnetometer has a range of
173 * +-1229uT. To go from the raw value to uT is:
174 *
175 * HuT = H * 1229/4096, or roughly, 3/10.
176 *
177 * Since 1uT = 0.01 gauss, our final scale factor becomes:
178 *
179 * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100
180 * Hadj = H * ((ASA + 128) * 0.003) / 256
181 *
182 * Since ASA doesn't change, we cache the resultant scale factor into the
183 * device context in ak8975_setup().
184 *
185 * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we
186 * multiply the stored scale value by 1e6.
187 */
ak8975_raw_to_gauss(u16 data)188 static long ak8975_raw_to_gauss(u16 data)
189 {
190 return (((long)data + 128) * 3000) / 256;
191 }
192
193 /*
194 * For AK8963 and AK09911, same calculation, but the device is less sensitive:
195 *
196 * H is in the range of +-8190. The magnetometer has a range of
197 * +-4912uT. To go from the raw value to uT is:
198 *
199 * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10.
200 */
201
ak8963_09911_raw_to_gauss(u16 data)202 static long ak8963_09911_raw_to_gauss(u16 data)
203 {
204 return (((long)data + 128) * 6000) / 256;
205 }
206
207 /*
208 * For AK09912, same calculation, except the device is more sensitive:
209 *
210 * H is in the range of -32752 to 32752. The magnetometer has a range of
211 * +-4912uT. To go from the raw value to uT is:
212 *
213 * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10.
214 */
ak09912_raw_to_gauss(u16 data)215 static long ak09912_raw_to_gauss(u16 data)
216 {
217 return (((long)data + 128) * 1500) / 256;
218 }
219
220 /* Compatible Asahi Kasei Compass parts */
221 enum asahi_compass_chipset {
222 AK8975,
223 AK8963,
224 AK09911,
225 AK09912,
226 AK_MAX_TYPE
227 };
228
229 enum ak_ctrl_reg_addr {
230 ST1,
231 ST2,
232 CNTL,
233 ASA_BASE,
234 MAX_REGS,
235 REGS_END,
236 };
237
238 enum ak_ctrl_reg_mask {
239 ST1_DRDY,
240 ST2_HOFL,
241 ST2_DERR,
242 CNTL_MODE,
243 MASK_END,
244 };
245
246 enum ak_ctrl_mode {
247 POWER_DOWN,
248 MODE_ONCE,
249 SELF_TEST,
250 FUSE_ROM,
251 MODE_END,
252 };
253
254 struct ak_def {
255 enum asahi_compass_chipset type;
256 long (*raw_to_gauss)(u16 data);
257 u16 range;
258 u8 ctrl_regs[REGS_END];
259 u8 ctrl_masks[MASK_END];
260 u8 ctrl_modes[MODE_END];
261 u8 data_regs[3];
262 };
263
264 static const struct ak_def ak_def_array[AK_MAX_TYPE] = {
265 {
266 .type = AK8975,
267 .raw_to_gauss = ak8975_raw_to_gauss,
268 .range = 4096,
269 .ctrl_regs = {
270 AK8975_REG_ST1,
271 AK8975_REG_ST2,
272 AK8975_REG_CNTL,
273 AK8975_REG_ASAX,
274 AK8975_MAX_REGS},
275 .ctrl_masks = {
276 AK8975_REG_ST1_DRDY_MASK,
277 AK8975_REG_ST2_HOFL_MASK,
278 AK8975_REG_ST2_DERR_MASK,
279 AK8975_REG_CNTL_MODE_MASK},
280 .ctrl_modes = {
281 AK8975_REG_CNTL_MODE_POWER_DOWN,
282 AK8975_REG_CNTL_MODE_ONCE,
283 AK8975_REG_CNTL_MODE_SELF_TEST,
284 AK8975_REG_CNTL_MODE_FUSE_ROM},
285 .data_regs = {
286 AK8975_REG_HXL,
287 AK8975_REG_HYL,
288 AK8975_REG_HZL},
289 },
290 {
291 .type = AK8963,
292 .raw_to_gauss = ak8963_09911_raw_to_gauss,
293 .range = 8190,
294 .ctrl_regs = {
295 AK8975_REG_ST1,
296 AK8975_REG_ST2,
297 AK8975_REG_CNTL,
298 AK8975_REG_ASAX,
299 AK8975_MAX_REGS},
300 .ctrl_masks = {
301 AK8975_REG_ST1_DRDY_MASK,
302 AK8975_REG_ST2_HOFL_MASK,
303 0,
304 AK8975_REG_CNTL_MODE_MASK},
305 .ctrl_modes = {
306 AK8975_REG_CNTL_MODE_POWER_DOWN,
307 AK8975_REG_CNTL_MODE_ONCE,
308 AK8975_REG_CNTL_MODE_SELF_TEST,
309 AK8975_REG_CNTL_MODE_FUSE_ROM},
310 .data_regs = {
311 AK8975_REG_HXL,
312 AK8975_REG_HYL,
313 AK8975_REG_HZL},
314 },
315 {
316 .type = AK09911,
317 .raw_to_gauss = ak8963_09911_raw_to_gauss,
318 .range = 8192,
319 .ctrl_regs = {
320 AK09912_REG_ST1,
321 AK09912_REG_ST2,
322 AK09912_REG_CNTL2,
323 AK09912_REG_ASAX,
324 AK09912_MAX_REGS},
325 .ctrl_masks = {
326 AK09912_REG_ST1_DRDY_MASK,
327 AK09912_REG_ST2_HOFL_MASK,
328 0,
329 AK09912_REG_CNTL2_MODE_MASK},
330 .ctrl_modes = {
331 AK09912_REG_CNTL_MODE_POWER_DOWN,
332 AK09912_REG_CNTL_MODE_ONCE,
333 AK09912_REG_CNTL_MODE_SELF_TEST,
334 AK09912_REG_CNTL_MODE_FUSE_ROM},
335 .data_regs = {
336 AK09912_REG_HXL,
337 AK09912_REG_HYL,
338 AK09912_REG_HZL},
339 },
340 {
341 .type = AK09912,
342 .raw_to_gauss = ak09912_raw_to_gauss,
343 .range = 32752,
344 .ctrl_regs = {
345 AK09912_REG_ST1,
346 AK09912_REG_ST2,
347 AK09912_REG_CNTL2,
348 AK09912_REG_ASAX,
349 AK09912_MAX_REGS},
350 .ctrl_masks = {
351 AK09912_REG_ST1_DRDY_MASK,
352 AK09912_REG_ST2_HOFL_MASK,
353 0,
354 AK09912_REG_CNTL2_MODE_MASK},
355 .ctrl_modes = {
356 AK09912_REG_CNTL_MODE_POWER_DOWN,
357 AK09912_REG_CNTL_MODE_ONCE,
358 AK09912_REG_CNTL_MODE_SELF_TEST,
359 AK09912_REG_CNTL_MODE_FUSE_ROM},
360 .data_regs = {
361 AK09912_REG_HXL,
362 AK09912_REG_HYL,
363 AK09912_REG_HZL},
364 }
365 };
366
367 /*
368 * Per-instance context data for the device.
369 */
370 struct ak8975_data {
371 struct i2c_client *client;
372 const struct ak_def *def;
373 struct mutex lock;
374 u8 asa[3];
375 long raw_to_gauss[3];
376 int eoc_gpio;
377 int eoc_irq;
378 wait_queue_head_t data_ready_queue;
379 unsigned long flags;
380 u8 cntl_cache;
381 struct iio_mount_matrix orientation;
382 struct regulator *vdd;
383 struct regulator *vid;
384
385 /* Ensure natural alignment of timestamp */
386 struct {
387 s16 channels[3];
388 s64 ts __aligned(8);
389 } scan;
390 };
391
392 /* Enable attached power regulator if any. */
ak8975_power_on(const struct ak8975_data * data)393 static int ak8975_power_on(const struct ak8975_data *data)
394 {
395 int ret;
396
397 ret = regulator_enable(data->vdd);
398 if (ret) {
399 dev_warn(&data->client->dev,
400 "Failed to enable specified Vdd supply\n");
401 return ret;
402 }
403 ret = regulator_enable(data->vid);
404 if (ret) {
405 dev_warn(&data->client->dev,
406 "Failed to enable specified Vid supply\n");
407 return ret;
408 }
409 /*
410 * According to the datasheet the power supply rise time i 200us
411 * and the minimum wait time before mode setting is 100us, in
412 * total 300 us. Add some margin and say minimum 500us here.
413 */
414 usleep_range(500, 1000);
415 return 0;
416 }
417
418 /* Disable attached power regulator if any. */
ak8975_power_off(const struct ak8975_data * data)419 static void ak8975_power_off(const struct ak8975_data *data)
420 {
421 regulator_disable(data->vid);
422 regulator_disable(data->vdd);
423 }
424
425 /*
426 * Return 0 if the i2c device is the one we expect.
427 * return a negative error number otherwise
428 */
ak8975_who_i_am(struct i2c_client * client,enum asahi_compass_chipset type)429 static int ak8975_who_i_am(struct i2c_client *client,
430 enum asahi_compass_chipset type)
431 {
432 u8 wia_val[2];
433 int ret;
434
435 /*
436 * Signature for each device:
437 * Device | WIA1 | WIA2
438 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID
439 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID
440 * AK8975 | DEVICE_ID | NA
441 * AK8963 | DEVICE_ID | NA
442 */
443 ret = i2c_smbus_read_i2c_block_data_or_emulated(
444 client, AK09912_REG_WIA1, 2, wia_val);
445 if (ret < 0) {
446 dev_err(&client->dev, "Error reading WIA\n");
447 return ret;
448 }
449
450 if (wia_val[0] != AK8975_DEVICE_ID)
451 return -ENODEV;
452
453 switch (type) {
454 case AK8975:
455 case AK8963:
456 return 0;
457 case AK09911:
458 if (wia_val[1] == AK09911_DEVICE_ID)
459 return 0;
460 break;
461 case AK09912:
462 if (wia_val[1] == AK09912_DEVICE_ID)
463 return 0;
464 break;
465 default:
466 dev_err(&client->dev, "Type %d unknown\n", type);
467 }
468 return -ENODEV;
469 }
470
471 /*
472 * Helper function to write to CNTL register.
473 */
ak8975_set_mode(struct ak8975_data * data,enum ak_ctrl_mode mode)474 static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode)
475 {
476 u8 regval;
477 int ret;
478
479 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) |
480 data->def->ctrl_modes[mode];
481 ret = i2c_smbus_write_byte_data(data->client,
482 data->def->ctrl_regs[CNTL], regval);
483 if (ret < 0) {
484 return ret;
485 }
486 data->cntl_cache = regval;
487 /* After mode change wait atleast 100us */
488 usleep_range(100, 500);
489
490 return 0;
491 }
492
493 /*
494 * Handle data ready irq
495 */
ak8975_irq_handler(int irq,void * data)496 static irqreturn_t ak8975_irq_handler(int irq, void *data)
497 {
498 struct ak8975_data *ak8975 = data;
499
500 set_bit(0, &ak8975->flags);
501 wake_up(&ak8975->data_ready_queue);
502
503 return IRQ_HANDLED;
504 }
505
506 /*
507 * Install data ready interrupt handler
508 */
ak8975_setup_irq(struct ak8975_data * data)509 static int ak8975_setup_irq(struct ak8975_data *data)
510 {
511 struct i2c_client *client = data->client;
512 int rc;
513 int irq;
514
515 init_waitqueue_head(&data->data_ready_queue);
516 clear_bit(0, &data->flags);
517 if (client->irq)
518 irq = client->irq;
519 else
520 irq = gpio_to_irq(data->eoc_gpio);
521
522 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,
523 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
524 dev_name(&client->dev), data);
525 if (rc < 0) {
526 dev_err(&client->dev,
527 "irq %d request failed, (gpio %d): %d\n",
528 irq, data->eoc_gpio, rc);
529 return rc;
530 }
531
532 data->eoc_irq = irq;
533
534 return rc;
535 }
536
537
538 /*
539 * Perform some start-of-day setup, including reading the asa calibration
540 * values and caching them.
541 */
ak8975_setup(struct i2c_client * client)542 static int ak8975_setup(struct i2c_client *client)
543 {
544 struct iio_dev *indio_dev = i2c_get_clientdata(client);
545 struct ak8975_data *data = iio_priv(indio_dev);
546 int ret;
547
548 /* Write the fused rom access mode. */
549 ret = ak8975_set_mode(data, FUSE_ROM);
550 if (ret < 0) {
551 dev_err(&client->dev, "Error in setting fuse access mode\n");
552 return ret;
553 }
554
555 /* Get asa data and store in the device data. */
556 ret = i2c_smbus_read_i2c_block_data_or_emulated(
557 client, data->def->ctrl_regs[ASA_BASE],
558 3, data->asa);
559 if (ret < 0) {
560 dev_err(&client->dev, "Not able to read asa data\n");
561 return ret;
562 }
563
564 /* After reading fuse ROM data set power-down mode */
565 ret = ak8975_set_mode(data, POWER_DOWN);
566 if (ret < 0) {
567 dev_err(&client->dev, "Error in setting power-down mode\n");
568 return ret;
569 }
570
571 if (data->eoc_gpio > 0 || client->irq > 0) {
572 ret = ak8975_setup_irq(data);
573 if (ret < 0) {
574 dev_err(&client->dev,
575 "Error setting data ready interrupt\n");
576 return ret;
577 }
578 }
579
580 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]);
581 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]);
582 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]);
583
584 return 0;
585 }
586
wait_conversion_complete_gpio(struct ak8975_data * data)587 static int wait_conversion_complete_gpio(struct ak8975_data *data)
588 {
589 struct i2c_client *client = data->client;
590 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
591 int ret;
592
593 /* Wait for the conversion to complete. */
594 while (timeout_ms) {
595 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
596 if (gpio_get_value(data->eoc_gpio))
597 break;
598 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
599 }
600 if (!timeout_ms) {
601 dev_err(&client->dev, "Conversion timeout happened\n");
602 return -EINVAL;
603 }
604
605 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]);
606 if (ret < 0)
607 dev_err(&client->dev, "Error in reading ST1\n");
608
609 return ret;
610 }
611
wait_conversion_complete_polled(struct ak8975_data * data)612 static int wait_conversion_complete_polled(struct ak8975_data *data)
613 {
614 struct i2c_client *client = data->client;
615 u8 read_status;
616 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
617 int ret;
618
619 /* Wait for the conversion to complete. */
620 while (timeout_ms) {
621 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
622 ret = i2c_smbus_read_byte_data(client,
623 data->def->ctrl_regs[ST1]);
624 if (ret < 0) {
625 dev_err(&client->dev, "Error in reading ST1\n");
626 return ret;
627 }
628 read_status = ret;
629 if (read_status)
630 break;
631 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
632 }
633 if (!timeout_ms) {
634 dev_err(&client->dev, "Conversion timeout happened\n");
635 return -EINVAL;
636 }
637
638 return read_status;
639 }
640
641 /* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */
wait_conversion_complete_interrupt(struct ak8975_data * data)642 static int wait_conversion_complete_interrupt(struct ak8975_data *data)
643 {
644 int ret;
645
646 ret = wait_event_timeout(data->data_ready_queue,
647 test_bit(0, &data->flags),
648 AK8975_DATA_READY_TIMEOUT);
649 clear_bit(0, &data->flags);
650
651 return ret > 0 ? 0 : -ETIME;
652 }
653
ak8975_start_read_axis(struct ak8975_data * data,const struct i2c_client * client)654 static int ak8975_start_read_axis(struct ak8975_data *data,
655 const struct i2c_client *client)
656 {
657 /* Set up the device for taking a sample. */
658 int ret = ak8975_set_mode(data, MODE_ONCE);
659
660 if (ret < 0) {
661 dev_err(&client->dev, "Error in setting operating mode\n");
662 return ret;
663 }
664
665 /* Wait for the conversion to complete. */
666 if (data->eoc_irq)
667 ret = wait_conversion_complete_interrupt(data);
668 else if (gpio_is_valid(data->eoc_gpio))
669 ret = wait_conversion_complete_gpio(data);
670 else
671 ret = wait_conversion_complete_polled(data);
672 if (ret < 0)
673 return ret;
674
675 /* This will be executed only for non-interrupt based waiting case */
676 if (ret & data->def->ctrl_masks[ST1_DRDY]) {
677 ret = i2c_smbus_read_byte_data(client,
678 data->def->ctrl_regs[ST2]);
679 if (ret < 0) {
680 dev_err(&client->dev, "Error in reading ST2\n");
681 return ret;
682 }
683 if (ret & (data->def->ctrl_masks[ST2_DERR] |
684 data->def->ctrl_masks[ST2_HOFL])) {
685 dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
686 return -EINVAL;
687 }
688 }
689
690 return 0;
691 }
692
693 /* 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)694 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
695 {
696 struct ak8975_data *data = iio_priv(indio_dev);
697 const struct i2c_client *client = data->client;
698 const struct ak_def *def = data->def;
699 __le16 rval;
700 u16 buff;
701 int ret;
702
703 pm_runtime_get_sync(&data->client->dev);
704
705 mutex_lock(&data->lock);
706
707 ret = ak8975_start_read_axis(data, client);
708 if (ret)
709 goto exit;
710
711 ret = i2c_smbus_read_i2c_block_data_or_emulated(
712 client, def->data_regs[index],
713 sizeof(rval), (u8*)&rval);
714 if (ret < 0)
715 goto exit;
716
717 mutex_unlock(&data->lock);
718
719 pm_runtime_mark_last_busy(&data->client->dev);
720 pm_runtime_put_autosuspend(&data->client->dev);
721
722 /* Swap bytes and convert to valid range. */
723 buff = le16_to_cpu(rval);
724 *val = clamp_t(s16, buff, -def->range, def->range);
725 return IIO_VAL_INT;
726
727 exit:
728 mutex_unlock(&data->lock);
729 dev_err(&client->dev, "Error in reading axis\n");
730 return ret;
731 }
732
ak8975_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)733 static int ak8975_read_raw(struct iio_dev *indio_dev,
734 struct iio_chan_spec const *chan,
735 int *val, int *val2,
736 long mask)
737 {
738 struct ak8975_data *data = iio_priv(indio_dev);
739
740 switch (mask) {
741 case IIO_CHAN_INFO_RAW:
742 return ak8975_read_axis(indio_dev, chan->address, val);
743 case IIO_CHAN_INFO_SCALE:
744 *val = 0;
745 *val2 = data->raw_to_gauss[chan->address];
746 return IIO_VAL_INT_PLUS_MICRO;
747 }
748 return -EINVAL;
749 }
750
751 static const struct iio_mount_matrix *
ak8975_get_mount_matrix(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)752 ak8975_get_mount_matrix(const struct iio_dev *indio_dev,
753 const struct iio_chan_spec *chan)
754 {
755 return &((struct ak8975_data *)iio_priv(indio_dev))->orientation;
756 }
757
758 static const struct iio_chan_spec_ext_info ak8975_ext_info[] = {
759 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix),
760 { },
761 };
762
763 #define AK8975_CHANNEL(axis, index) \
764 { \
765 .type = IIO_MAGN, \
766 .modified = 1, \
767 .channel2 = IIO_MOD_##axis, \
768 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
769 BIT(IIO_CHAN_INFO_SCALE), \
770 .address = index, \
771 .scan_index = index, \
772 .scan_type = { \
773 .sign = 's', \
774 .realbits = 16, \
775 .storagebits = 16, \
776 .endianness = IIO_CPU \
777 }, \
778 .ext_info = ak8975_ext_info, \
779 }
780
781 static const struct iio_chan_spec ak8975_channels[] = {
782 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
783 IIO_CHAN_SOFT_TIMESTAMP(3),
784 };
785
786 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
787
788 static const struct iio_info ak8975_info = {
789 .read_raw = &ak8975_read_raw,
790 };
791
792 #ifdef CONFIG_ACPI
793 static const struct acpi_device_id ak_acpi_match[] = {
794 {"AK8975", AK8975},
795 {"AK8963", AK8963},
796 {"INVN6500", AK8963},
797 {"AK009911", AK09911},
798 {"AK09911", AK09911},
799 {"AK09912", AK09912},
800 { },
801 };
802 MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
803 #endif
804
ak8975_match_acpi_device(struct device * dev,enum asahi_compass_chipset * chipset)805 static const char *ak8975_match_acpi_device(struct device *dev,
806 enum asahi_compass_chipset *chipset)
807 {
808 const struct acpi_device_id *id;
809
810 id = acpi_match_device(dev->driver->acpi_match_table, dev);
811 if (!id)
812 return NULL;
813 *chipset = (int)id->driver_data;
814
815 return dev_name(dev);
816 }
817
ak8975_fill_buffer(struct iio_dev * indio_dev)818 static void ak8975_fill_buffer(struct iio_dev *indio_dev)
819 {
820 struct ak8975_data *data = iio_priv(indio_dev);
821 const struct i2c_client *client = data->client;
822 const struct ak_def *def = data->def;
823 int ret;
824 __le16 fval[3];
825
826 mutex_lock(&data->lock);
827
828 ret = ak8975_start_read_axis(data, client);
829 if (ret)
830 goto unlock;
831
832 /*
833 * For each axis, read the flux value from the appropriate register
834 * (the register is specified in the iio device attributes).
835 */
836 ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
837 def->data_regs[0],
838 3 * sizeof(fval[0]),
839 (u8 *)fval);
840 if (ret < 0)
841 goto unlock;
842
843 mutex_unlock(&data->lock);
844
845 /* Clamp to valid range. */
846 data->scan.channels[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range);
847 data->scan.channels[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range);
848 data->scan.channels[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range);
849
850 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
851 iio_get_time_ns(indio_dev));
852
853 return;
854
855 unlock:
856 mutex_unlock(&data->lock);
857 dev_err(&client->dev, "Error in reading axes block\n");
858 }
859
ak8975_handle_trigger(int irq,void * p)860 static irqreturn_t ak8975_handle_trigger(int irq, void *p)
861 {
862 const struct iio_poll_func *pf = p;
863 struct iio_dev *indio_dev = pf->indio_dev;
864
865 ak8975_fill_buffer(indio_dev);
866 iio_trigger_notify_done(indio_dev->trig);
867 return IRQ_HANDLED;
868 }
869
ak8975_probe(struct i2c_client * client,const struct i2c_device_id * id)870 static int ak8975_probe(struct i2c_client *client,
871 const struct i2c_device_id *id)
872 {
873 struct ak8975_data *data;
874 struct iio_dev *indio_dev;
875 int eoc_gpio;
876 int err;
877 const char *name = NULL;
878 enum asahi_compass_chipset chipset = AK_MAX_TYPE;
879 const struct ak8975_platform_data *pdata =
880 dev_get_platdata(&client->dev);
881
882 /* Grab and set up the supplied GPIO. */
883 if (pdata)
884 eoc_gpio = pdata->eoc_gpio;
885 else if (client->dev.of_node)
886 eoc_gpio = of_get_gpio(client->dev.of_node, 0);
887 else
888 eoc_gpio = -1;
889
890 if (eoc_gpio == -EPROBE_DEFER)
891 return -EPROBE_DEFER;
892
893 /* We may not have a GPIO based IRQ to scan, that is fine, we will
894 poll if so */
895 if (gpio_is_valid(eoc_gpio)) {
896 err = devm_gpio_request_one(&client->dev, eoc_gpio,
897 GPIOF_IN, "ak_8975");
898 if (err < 0) {
899 dev_err(&client->dev,
900 "failed to request GPIO %d, error %d\n",
901 eoc_gpio, err);
902 return err;
903 }
904 }
905
906 /* Register with IIO */
907 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
908 if (indio_dev == NULL)
909 return -ENOMEM;
910
911 data = iio_priv(indio_dev);
912 i2c_set_clientdata(client, indio_dev);
913
914 data->client = client;
915 data->eoc_gpio = eoc_gpio;
916 data->eoc_irq = 0;
917
918 if (!pdata) {
919 err = of_iio_read_mount_matrix(&client->dev,
920 "mount-matrix",
921 &data->orientation);
922 if (err)
923 return err;
924 } else
925 data->orientation = pdata->orientation;
926
927 /* id will be NULL when enumerated via ACPI */
928 if (id) {
929 chipset = (enum asahi_compass_chipset)(id->driver_data);
930 name = id->name;
931 } else if (ACPI_HANDLE(&client->dev)) {
932 name = ak8975_match_acpi_device(&client->dev, &chipset);
933 if (!name)
934 return -ENODEV;
935 } else
936 return -ENOSYS;
937
938 if (chipset >= AK_MAX_TYPE) {
939 dev_err(&client->dev, "AKM device type unsupported: %d\n",
940 chipset);
941 return -ENODEV;
942 }
943
944 data->def = &ak_def_array[chipset];
945
946 /* Fetch the regulators */
947 data->vdd = devm_regulator_get(&client->dev, "vdd");
948 if (IS_ERR(data->vdd))
949 return PTR_ERR(data->vdd);
950 data->vid = devm_regulator_get(&client->dev, "vid");
951 if (IS_ERR(data->vid))
952 return PTR_ERR(data->vid);
953
954 err = ak8975_power_on(data);
955 if (err)
956 return err;
957
958 err = ak8975_who_i_am(client, data->def->type);
959 if (err < 0) {
960 dev_err(&client->dev, "Unexpected device\n");
961 goto power_off;
962 }
963 dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
964
965 /* Perform some basic start-of-day setup of the device. */
966 err = ak8975_setup(client);
967 if (err < 0) {
968 dev_err(&client->dev, "%s initialization fails\n", name);
969 goto power_off;
970 }
971
972 mutex_init(&data->lock);
973 indio_dev->dev.parent = &client->dev;
974 indio_dev->channels = ak8975_channels;
975 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
976 indio_dev->info = &ak8975_info;
977 indio_dev->available_scan_masks = ak8975_scan_masks;
978 indio_dev->modes = INDIO_DIRECT_MODE;
979 indio_dev->name = name;
980
981 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
982 NULL);
983 if (err) {
984 dev_err(&client->dev, "triggered buffer setup failed\n");
985 goto power_off;
986 }
987
988 err = iio_device_register(indio_dev);
989 if (err) {
990 dev_err(&client->dev, "device register failed\n");
991 goto cleanup_buffer;
992 }
993
994 /* Enable runtime PM */
995 pm_runtime_get_noresume(&client->dev);
996 pm_runtime_set_active(&client->dev);
997 pm_runtime_enable(&client->dev);
998 /*
999 * The device comes online in 500us, so add two orders of magnitude
1000 * of delay before autosuspending: 50 ms.
1001 */
1002 pm_runtime_set_autosuspend_delay(&client->dev, 50);
1003 pm_runtime_use_autosuspend(&client->dev);
1004 pm_runtime_put(&client->dev);
1005
1006 return 0;
1007
1008 cleanup_buffer:
1009 iio_triggered_buffer_cleanup(indio_dev);
1010 power_off:
1011 ak8975_power_off(data);
1012 return err;
1013 }
1014
ak8975_remove(struct i2c_client * client)1015 static int ak8975_remove(struct i2c_client *client)
1016 {
1017 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1018 struct ak8975_data *data = iio_priv(indio_dev);
1019
1020 pm_runtime_get_sync(&client->dev);
1021 pm_runtime_put_noidle(&client->dev);
1022 pm_runtime_disable(&client->dev);
1023 iio_device_unregister(indio_dev);
1024 iio_triggered_buffer_cleanup(indio_dev);
1025 ak8975_set_mode(data, POWER_DOWN);
1026 ak8975_power_off(data);
1027
1028 return 0;
1029 }
1030
1031 #ifdef CONFIG_PM
ak8975_runtime_suspend(struct device * dev)1032 static int ak8975_runtime_suspend(struct device *dev)
1033 {
1034 struct i2c_client *client = to_i2c_client(dev);
1035 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1036 struct ak8975_data *data = iio_priv(indio_dev);
1037 int ret;
1038
1039 /* Set the device in power down if it wasn't already */
1040 ret = ak8975_set_mode(data, POWER_DOWN);
1041 if (ret < 0) {
1042 dev_err(&client->dev, "Error in setting power-down mode\n");
1043 return ret;
1044 }
1045 /* Next cut the regulators */
1046 ak8975_power_off(data);
1047
1048 return 0;
1049 }
1050
ak8975_runtime_resume(struct device * dev)1051 static int ak8975_runtime_resume(struct device *dev)
1052 {
1053 struct i2c_client *client = to_i2c_client(dev);
1054 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1055 struct ak8975_data *data = iio_priv(indio_dev);
1056 int ret;
1057
1058 /* Take up the regulators */
1059 ak8975_power_on(data);
1060 /*
1061 * We come up in powered down mode, the reading routines will
1062 * put us in the mode to read values later.
1063 */
1064 ret = ak8975_set_mode(data, POWER_DOWN);
1065 if (ret < 0) {
1066 dev_err(&client->dev, "Error in setting power-down mode\n");
1067 return ret;
1068 }
1069
1070 return 0;
1071 }
1072 #endif /* CONFIG_PM */
1073
1074 static const struct dev_pm_ops ak8975_dev_pm_ops = {
1075 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1076 pm_runtime_force_resume)
1077 SET_RUNTIME_PM_OPS(ak8975_runtime_suspend,
1078 ak8975_runtime_resume, NULL)
1079 };
1080
1081 static const struct i2c_device_id ak8975_id[] = {
1082 {"ak8975", AK8975},
1083 {"ak8963", AK8963},
1084 {"AK8963", AK8963},
1085 {"ak09911", AK09911},
1086 {"ak09912", AK09912},
1087 {}
1088 };
1089
1090 MODULE_DEVICE_TABLE(i2c, ak8975_id);
1091
1092 static const struct of_device_id ak8975_of_match[] = {
1093 { .compatible = "asahi-kasei,ak8975", },
1094 { .compatible = "ak8975", },
1095 { .compatible = "asahi-kasei,ak8963", },
1096 { .compatible = "ak8963", },
1097 { .compatible = "asahi-kasei,ak09911", },
1098 { .compatible = "ak09911", },
1099 { .compatible = "asahi-kasei,ak09912", },
1100 { .compatible = "ak09912", },
1101 {}
1102 };
1103 MODULE_DEVICE_TABLE(of, ak8975_of_match);
1104
1105 static struct i2c_driver ak8975_driver = {
1106 .driver = {
1107 .name = "ak8975",
1108 .pm = &ak8975_dev_pm_ops,
1109 .of_match_table = of_match_ptr(ak8975_of_match),
1110 .acpi_match_table = ACPI_PTR(ak_acpi_match),
1111 },
1112 .probe = ak8975_probe,
1113 .remove = ak8975_remove,
1114 .id_table = ak8975_id,
1115 };
1116 module_i2c_driver(ak8975_driver);
1117
1118 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1119 MODULE_DESCRIPTION("AK8975 magnetometer driver");
1120 MODULE_LICENSE("GPL");
1121