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[deliverable/linux.git] / drivers / iio / magnetometer / ak8975.c
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
37 #include <linux/iio/iio.h>
38 #include <linux/iio/sysfs.h>
39 #include <linux/iio/buffer.h>
40 #include <linux/iio/trigger.h>
41 #include <linux/iio/trigger_consumer.h>
42 #include <linux/iio/triggered_buffer.h>
43
44 #include <linux/iio/magnetometer/ak8975.h>
45
46 /*
47 * Register definitions, as well as various shifts and masks to get at the
48 * individual fields of the registers.
49 */
50 #define AK8975_REG_WIA 0x00
51 #define AK8975_DEVICE_ID 0x48
52
53 #define AK8975_REG_INFO 0x01
54
55 #define AK8975_REG_ST1 0x02
56 #define AK8975_REG_ST1_DRDY_SHIFT 0
57 #define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT)
58
59 #define AK8975_REG_HXL 0x03
60 #define AK8975_REG_HXH 0x04
61 #define AK8975_REG_HYL 0x05
62 #define AK8975_REG_HYH 0x06
63 #define AK8975_REG_HZL 0x07
64 #define AK8975_REG_HZH 0x08
65 #define AK8975_REG_ST2 0x09
66 #define AK8975_REG_ST2_DERR_SHIFT 2
67 #define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT)
68
69 #define AK8975_REG_ST2_HOFL_SHIFT 3
70 #define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT)
71
72 #define AK8975_REG_CNTL 0x0A
73 #define AK8975_REG_CNTL_MODE_SHIFT 0
74 #define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT)
75 #define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00
76 #define AK8975_REG_CNTL_MODE_ONCE 0x01
77 #define AK8975_REG_CNTL_MODE_SELF_TEST 0x08
78 #define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F
79
80 #define AK8975_REG_RSVC 0x0B
81 #define AK8975_REG_ASTC 0x0C
82 #define AK8975_REG_TS1 0x0D
83 #define AK8975_REG_TS2 0x0E
84 #define AK8975_REG_I2CDIS 0x0F
85 #define AK8975_REG_ASAX 0x10
86 #define AK8975_REG_ASAY 0x11
87 #define AK8975_REG_ASAZ 0x12
88
89 #define AK8975_MAX_REGS AK8975_REG_ASAZ
90
91 /*
92 * AK09912 Register definitions
93 */
94 #define AK09912_REG_WIA1 0x00
95 #define AK09912_REG_WIA2 0x01
96 #define AK09912_DEVICE_ID 0x04
97 #define AK09911_DEVICE_ID 0x05
98
99 #define AK09911_REG_INFO1 0x02
100 #define AK09911_REG_INFO2 0x03
101
102 #define AK09912_REG_ST1 0x10
103
104 #define AK09912_REG_ST1_DRDY_SHIFT 0
105 #define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT)
106
107 #define AK09912_REG_HXL 0x11
108 #define AK09912_REG_HXH 0x12
109 #define AK09912_REG_HYL 0x13
110 #define AK09912_REG_HYH 0x14
111 #define AK09912_REG_HZL 0x15
112 #define AK09912_REG_HZH 0x16
113 #define AK09912_REG_TMPS 0x17
114
115 #define AK09912_REG_ST2 0x18
116 #define AK09912_REG_ST2_HOFL_SHIFT 3
117 #define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT)
118
119 #define AK09912_REG_CNTL1 0x30
120
121 #define AK09912_REG_CNTL2 0x31
122 #define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00
123 #define AK09912_REG_CNTL_MODE_ONCE 0x01
124 #define AK09912_REG_CNTL_MODE_SELF_TEST 0x10
125 #define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F
126 #define AK09912_REG_CNTL2_MODE_SHIFT 0
127 #define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT)
128
129 #define AK09912_REG_CNTL3 0x32
130
131 #define AK09912_REG_TS1 0x33
132 #define AK09912_REG_TS2 0x34
133 #define AK09912_REG_TS3 0x35
134 #define AK09912_REG_I2CDIS 0x36
135 #define AK09912_REG_TS4 0x37
136
137 #define AK09912_REG_ASAX 0x60
138 #define AK09912_REG_ASAY 0x61
139 #define AK09912_REG_ASAZ 0x62
140
141 #define AK09912_MAX_REGS AK09912_REG_ASAZ
142
143 /*
144 * Miscellaneous values.
145 */
146 #define AK8975_MAX_CONVERSION_TIMEOUT 500
147 #define AK8975_CONVERSION_DONE_POLL_TIME 10
148 #define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000)
149
150 /*
151 * Precalculate scale factor (in Gauss units) for each axis and
152 * store in the device data.
153 *
154 * This scale factor is axis-dependent, and is derived from 3 calibration
155 * factors ASA(x), ASA(y), and ASA(z).
156 *
157 * These ASA values are read from the sensor device at start of day, and
158 * cached in the device context struct.
159 *
160 * Adjusting the flux value with the sensitivity adjustment value should be
161 * done via the following formula:
162 *
163 * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 )
164 * where H is the raw value, ASA is the sensitivity adjustment, and Hadj
165 * is the resultant adjusted value.
166 *
167 * We reduce the formula to:
168 *
169 * Hadj = H * (ASA + 128) / 256
170 *
171 * H is in the range of -4096 to 4095. The magnetometer has a range of
172 * +-1229uT. To go from the raw value to uT is:
173 *
174 * HuT = H * 1229/4096, or roughly, 3/10.
175 *
176 * Since 1uT = 0.01 gauss, our final scale factor becomes:
177 *
178 * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100
179 * Hadj = H * ((ASA + 128) * 0.003) / 256
180 *
181 * Since ASA doesn't change, we cache the resultant scale factor into the
182 * device context in ak8975_setup().
183 *
184 * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we
185 * multiply the stored scale value by 1e6.
186 */
187 static long ak8975_raw_to_gauss(u16 data)
188 {
189 return (((long)data + 128) * 3000) / 256;
190 }
191
192 /*
193 * For AK8963 and AK09911, same calculation, but the device is less sensitive:
194 *
195 * H is in the range of +-8190. The magnetometer has a range of
196 * +-4912uT. To go from the raw value to uT is:
197 *
198 * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10.
199 */
200
201 static long ak8963_09911_raw_to_gauss(u16 data)
202 {
203 return (((long)data + 128) * 6000) / 256;
204 }
205
206 /*
207 * For AK09912, same calculation, except the device is more sensitive:
208 *
209 * H is in the range of -32752 to 32752. The magnetometer has a range of
210 * +-4912uT. To go from the raw value to uT is:
211 *
212 * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10.
213 */
214 static long ak09912_raw_to_gauss(u16 data)
215 {
216 return (((long)data + 128) * 1500) / 256;
217 }
218
219 /* Compatible Asahi Kasei Compass parts */
220 enum asahi_compass_chipset {
221 AK8975,
222 AK8963,
223 AK09911,
224 AK09912,
225 AK_MAX_TYPE
226 };
227
228 enum ak_ctrl_reg_addr {
229 ST1,
230 ST2,
231 CNTL,
232 ASA_BASE,
233 MAX_REGS,
234 REGS_END,
235 };
236
237 enum ak_ctrl_reg_mask {
238 ST1_DRDY,
239 ST2_HOFL,
240 ST2_DERR,
241 CNTL_MODE,
242 MASK_END,
243 };
244
245 enum ak_ctrl_mode {
246 POWER_DOWN,
247 MODE_ONCE,
248 SELF_TEST,
249 FUSE_ROM,
250 MODE_END,
251 };
252
253 struct ak_def {
254 enum asahi_compass_chipset type;
255 long (*raw_to_gauss)(u16 data);
256 u16 range;
257 u8 ctrl_regs[REGS_END];
258 u8 ctrl_masks[MASK_END];
259 u8 ctrl_modes[MODE_END];
260 u8 data_regs[3];
261 };
262
263 static const struct ak_def ak_def_array[AK_MAX_TYPE] = {
264 {
265 .type = AK8975,
266 .raw_to_gauss = ak8975_raw_to_gauss,
267 .range = 4096,
268 .ctrl_regs = {
269 AK8975_REG_ST1,
270 AK8975_REG_ST2,
271 AK8975_REG_CNTL,
272 AK8975_REG_ASAX,
273 AK8975_MAX_REGS},
274 .ctrl_masks = {
275 AK8975_REG_ST1_DRDY_MASK,
276 AK8975_REG_ST2_HOFL_MASK,
277 AK8975_REG_ST2_DERR_MASK,
278 AK8975_REG_CNTL_MODE_MASK},
279 .ctrl_modes = {
280 AK8975_REG_CNTL_MODE_POWER_DOWN,
281 AK8975_REG_CNTL_MODE_ONCE,
282 AK8975_REG_CNTL_MODE_SELF_TEST,
283 AK8975_REG_CNTL_MODE_FUSE_ROM},
284 .data_regs = {
285 AK8975_REG_HXL,
286 AK8975_REG_HYL,
287 AK8975_REG_HZL},
288 },
289 {
290 .type = AK8963,
291 .raw_to_gauss = ak8963_09911_raw_to_gauss,
292 .range = 8190,
293 .ctrl_regs = {
294 AK8975_REG_ST1,
295 AK8975_REG_ST2,
296 AK8975_REG_CNTL,
297 AK8975_REG_ASAX,
298 AK8975_MAX_REGS},
299 .ctrl_masks = {
300 AK8975_REG_ST1_DRDY_MASK,
301 AK8975_REG_ST2_HOFL_MASK,
302 0,
303 AK8975_REG_CNTL_MODE_MASK},
304 .ctrl_modes = {
305 AK8975_REG_CNTL_MODE_POWER_DOWN,
306 AK8975_REG_CNTL_MODE_ONCE,
307 AK8975_REG_CNTL_MODE_SELF_TEST,
308 AK8975_REG_CNTL_MODE_FUSE_ROM},
309 .data_regs = {
310 AK8975_REG_HXL,
311 AK8975_REG_HYL,
312 AK8975_REG_HZL},
313 },
314 {
315 .type = AK09911,
316 .raw_to_gauss = ak8963_09911_raw_to_gauss,
317 .range = 8192,
318 .ctrl_regs = {
319 AK09912_REG_ST1,
320 AK09912_REG_ST2,
321 AK09912_REG_CNTL2,
322 AK09912_REG_ASAX,
323 AK09912_MAX_REGS},
324 .ctrl_masks = {
325 AK09912_REG_ST1_DRDY_MASK,
326 AK09912_REG_ST2_HOFL_MASK,
327 0,
328 AK09912_REG_CNTL2_MODE_MASK},
329 .ctrl_modes = {
330 AK09912_REG_CNTL_MODE_POWER_DOWN,
331 AK09912_REG_CNTL_MODE_ONCE,
332 AK09912_REG_CNTL_MODE_SELF_TEST,
333 AK09912_REG_CNTL_MODE_FUSE_ROM},
334 .data_regs = {
335 AK09912_REG_HXL,
336 AK09912_REG_HYL,
337 AK09912_REG_HZL},
338 },
339 {
340 .type = AK09912,
341 .raw_to_gauss = ak09912_raw_to_gauss,
342 .range = 32752,
343 .ctrl_regs = {
344 AK09912_REG_ST1,
345 AK09912_REG_ST2,
346 AK09912_REG_CNTL2,
347 AK09912_REG_ASAX,
348 AK09912_MAX_REGS},
349 .ctrl_masks = {
350 AK09912_REG_ST1_DRDY_MASK,
351 AK09912_REG_ST2_HOFL_MASK,
352 0,
353 AK09912_REG_CNTL2_MODE_MASK},
354 .ctrl_modes = {
355 AK09912_REG_CNTL_MODE_POWER_DOWN,
356 AK09912_REG_CNTL_MODE_ONCE,
357 AK09912_REG_CNTL_MODE_SELF_TEST,
358 AK09912_REG_CNTL_MODE_FUSE_ROM},
359 .data_regs = {
360 AK09912_REG_HXL,
361 AK09912_REG_HYL,
362 AK09912_REG_HZL},
363 }
364 };
365
366 /*
367 * Per-instance context data for the device.
368 */
369 struct ak8975_data {
370 struct i2c_client *client;
371 const struct ak_def *def;
372 struct mutex lock;
373 u8 asa[3];
374 long raw_to_gauss[3];
375 int eoc_gpio;
376 int eoc_irq;
377 wait_queue_head_t data_ready_queue;
378 unsigned long flags;
379 u8 cntl_cache;
380 struct iio_mount_matrix orientation;
381 struct regulator *vdd;
382 };
383
384 /* Enable attached power regulator if any. */
385 static int ak8975_power_on(struct i2c_client *client)
386 {
387 const struct iio_dev *indio_dev = i2c_get_clientdata(client);
388 struct ak8975_data *data = iio_priv(indio_dev);
389 int ret;
390
391 data->vdd = devm_regulator_get(&client->dev, "vdd");
392 if (IS_ERR_OR_NULL(data->vdd)) {
393 ret = PTR_ERR(data->vdd);
394 if (ret == -ENODEV)
395 ret = 0;
396 } else {
397 ret = regulator_enable(data->vdd);
398 }
399
400 if (ret)
401 dev_err(&client->dev, "failed to enable Vdd supply: %d\n", ret);
402 return ret;
403 }
404
405 /* Disable attached power regulator if any. */
406 static void ak8975_power_off(const struct i2c_client *client)
407 {
408 const struct iio_dev *indio_dev = i2c_get_clientdata(client);
409 const struct ak8975_data *data = iio_priv(indio_dev);
410
411 if (!IS_ERR_OR_NULL(data->vdd))
412 regulator_disable(data->vdd);
413 }
414
415 /*
416 * Return 0 if the i2c device is the one we expect.
417 * return a negative error number otherwise
418 */
419 static int ak8975_who_i_am(struct i2c_client *client,
420 enum asahi_compass_chipset type)
421 {
422 u8 wia_val[2];
423 int ret;
424
425 /*
426 * Signature for each device:
427 * Device | WIA1 | WIA2
428 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID
429 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID
430 * AK8975 | DEVICE_ID | NA
431 * AK8963 | DEVICE_ID | NA
432 */
433 ret = i2c_smbus_read_i2c_block_data(client, AK09912_REG_WIA1,
434 2, wia_val);
435 if (ret < 0) {
436 dev_err(&client->dev, "Error reading WIA\n");
437 return ret;
438 }
439
440 if (wia_val[0] != AK8975_DEVICE_ID)
441 return -ENODEV;
442
443 switch (type) {
444 case AK8975:
445 case AK8963:
446 return 0;
447 case AK09911:
448 if (wia_val[1] == AK09911_DEVICE_ID)
449 return 0;
450 break;
451 case AK09912:
452 if (wia_val[1] == AK09912_DEVICE_ID)
453 return 0;
454 break;
455 default:
456 dev_err(&client->dev, "Type %d unknown\n", type);
457 }
458 return -ENODEV;
459 }
460
461 /*
462 * Helper function to write to CNTL register.
463 */
464 static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode)
465 {
466 u8 regval;
467 int ret;
468
469 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) |
470 data->def->ctrl_modes[mode];
471 ret = i2c_smbus_write_byte_data(data->client,
472 data->def->ctrl_regs[CNTL], regval);
473 if (ret < 0) {
474 return ret;
475 }
476 data->cntl_cache = regval;
477 /* After mode change wait atleast 100us */
478 usleep_range(100, 500);
479
480 return 0;
481 }
482
483 /*
484 * Handle data ready irq
485 */
486 static irqreturn_t ak8975_irq_handler(int irq, void *data)
487 {
488 struct ak8975_data *ak8975 = data;
489
490 set_bit(0, &ak8975->flags);
491 wake_up(&ak8975->data_ready_queue);
492
493 return IRQ_HANDLED;
494 }
495
496 /*
497 * Install data ready interrupt handler
498 */
499 static int ak8975_setup_irq(struct ak8975_data *data)
500 {
501 struct i2c_client *client = data->client;
502 int rc;
503 int irq;
504
505 init_waitqueue_head(&data->data_ready_queue);
506 clear_bit(0, &data->flags);
507 if (client->irq)
508 irq = client->irq;
509 else
510 irq = gpio_to_irq(data->eoc_gpio);
511
512 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,
513 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
514 dev_name(&client->dev), data);
515 if (rc < 0) {
516 dev_err(&client->dev,
517 "irq %d request failed, (gpio %d): %d\n",
518 irq, data->eoc_gpio, rc);
519 return rc;
520 }
521
522 data->eoc_irq = irq;
523
524 return rc;
525 }
526
527
528 /*
529 * Perform some start-of-day setup, including reading the asa calibration
530 * values and caching them.
531 */
532 static int ak8975_setup(struct i2c_client *client)
533 {
534 struct iio_dev *indio_dev = i2c_get_clientdata(client);
535 struct ak8975_data *data = iio_priv(indio_dev);
536 int ret;
537
538 /* Write the fused rom access mode. */
539 ret = ak8975_set_mode(data, FUSE_ROM);
540 if (ret < 0) {
541 dev_err(&client->dev, "Error in setting fuse access mode\n");
542 return ret;
543 }
544
545 /* Get asa data and store in the device data. */
546 ret = i2c_smbus_read_i2c_block_data(client,
547 data->def->ctrl_regs[ASA_BASE],
548 3, data->asa);
549 if (ret < 0) {
550 dev_err(&client->dev, "Not able to read asa data\n");
551 return ret;
552 }
553
554 /* After reading fuse ROM data set power-down mode */
555 ret = ak8975_set_mode(data, POWER_DOWN);
556 if (ret < 0) {
557 dev_err(&client->dev, "Error in setting power-down mode\n");
558 return ret;
559 }
560
561 if (data->eoc_gpio > 0 || client->irq > 0) {
562 ret = ak8975_setup_irq(data);
563 if (ret < 0) {
564 dev_err(&client->dev,
565 "Error setting data ready interrupt\n");
566 return ret;
567 }
568 }
569
570 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]);
571 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]);
572 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]);
573
574 return 0;
575 }
576
577 static int wait_conversion_complete_gpio(struct ak8975_data *data)
578 {
579 struct i2c_client *client = data->client;
580 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
581 int ret;
582
583 /* Wait for the conversion to complete. */
584 while (timeout_ms) {
585 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
586 if (gpio_get_value(data->eoc_gpio))
587 break;
588 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
589 }
590 if (!timeout_ms) {
591 dev_err(&client->dev, "Conversion timeout happened\n");
592 return -EINVAL;
593 }
594
595 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]);
596 if (ret < 0)
597 dev_err(&client->dev, "Error in reading ST1\n");
598
599 return ret;
600 }
601
602 static int wait_conversion_complete_polled(struct ak8975_data *data)
603 {
604 struct i2c_client *client = data->client;
605 u8 read_status;
606 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
607 int ret;
608
609 /* Wait for the conversion to complete. */
610 while (timeout_ms) {
611 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
612 ret = i2c_smbus_read_byte_data(client,
613 data->def->ctrl_regs[ST1]);
614 if (ret < 0) {
615 dev_err(&client->dev, "Error in reading ST1\n");
616 return ret;
617 }
618 read_status = ret;
619 if (read_status)
620 break;
621 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
622 }
623 if (!timeout_ms) {
624 dev_err(&client->dev, "Conversion timeout happened\n");
625 return -EINVAL;
626 }
627
628 return read_status;
629 }
630
631 /* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */
632 static int wait_conversion_complete_interrupt(struct ak8975_data *data)
633 {
634 int ret;
635
636 ret = wait_event_timeout(data->data_ready_queue,
637 test_bit(0, &data->flags),
638 AK8975_DATA_READY_TIMEOUT);
639 clear_bit(0, &data->flags);
640
641 return ret > 0 ? 0 : -ETIME;
642 }
643
644 static int ak8975_start_read_axis(struct ak8975_data *data,
645 const struct i2c_client *client)
646 {
647 /* Set up the device for taking a sample. */
648 int ret = ak8975_set_mode(data, MODE_ONCE);
649
650 if (ret < 0) {
651 dev_err(&client->dev, "Error in setting operating mode\n");
652 return ret;
653 }
654
655 /* Wait for the conversion to complete. */
656 if (data->eoc_irq)
657 ret = wait_conversion_complete_interrupt(data);
658 else if (gpio_is_valid(data->eoc_gpio))
659 ret = wait_conversion_complete_gpio(data);
660 else
661 ret = wait_conversion_complete_polled(data);
662 if (ret < 0)
663 return ret;
664
665 /* This will be executed only for non-interrupt based waiting case */
666 if (ret & data->def->ctrl_masks[ST1_DRDY]) {
667 ret = i2c_smbus_read_byte_data(client,
668 data->def->ctrl_regs[ST2]);
669 if (ret < 0) {
670 dev_err(&client->dev, "Error in reading ST2\n");
671 return ret;
672 }
673 if (ret & (data->def->ctrl_masks[ST2_DERR] |
674 data->def->ctrl_masks[ST2_HOFL])) {
675 dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
676 return -EINVAL;
677 }
678 }
679
680 return 0;
681 }
682
683 /* Retrieve raw flux value for one of the x, y, or z axis. */
684 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
685 {
686 struct ak8975_data *data = iio_priv(indio_dev);
687 const struct i2c_client *client = data->client;
688 const struct ak_def *def = data->def;
689 int ret;
690
691 mutex_lock(&data->lock);
692
693 ret = ak8975_start_read_axis(data, client);
694 if (ret)
695 goto exit;
696
697 ret = i2c_smbus_read_word_data(client, def->data_regs[index]);
698 if (ret < 0)
699 goto exit;
700
701 mutex_unlock(&data->lock);
702
703 /* Clamp to valid range. */
704 *val = clamp_t(s16, ret, -def->range, def->range);
705 return IIO_VAL_INT;
706
707 exit:
708 mutex_unlock(&data->lock);
709 dev_err(&client->dev, "Error in reading axis\n");
710 return ret;
711 }
712
713 static int ak8975_read_raw(struct iio_dev *indio_dev,
714 struct iio_chan_spec const *chan,
715 int *val, int *val2,
716 long mask)
717 {
718 struct ak8975_data *data = iio_priv(indio_dev);
719
720 switch (mask) {
721 case IIO_CHAN_INFO_RAW:
722 return ak8975_read_axis(indio_dev, chan->address, val);
723 case IIO_CHAN_INFO_SCALE:
724 *val = 0;
725 *val2 = data->raw_to_gauss[chan->address];
726 return IIO_VAL_INT_PLUS_MICRO;
727 }
728 return -EINVAL;
729 }
730
731 static const struct iio_mount_matrix *
732 ak8975_get_mount_matrix(const struct iio_dev *indio_dev,
733 const struct iio_chan_spec *chan)
734 {
735 return &((struct ak8975_data *)iio_priv(indio_dev))->orientation;
736 }
737
738 static const struct iio_chan_spec_ext_info ak8975_ext_info[] = {
739 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix),
740 { },
741 };
742
743 #define AK8975_CHANNEL(axis, index) \
744 { \
745 .type = IIO_MAGN, \
746 .modified = 1, \
747 .channel2 = IIO_MOD_##axis, \
748 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
749 BIT(IIO_CHAN_INFO_SCALE), \
750 .address = index, \
751 .scan_index = index, \
752 .scan_type = { \
753 .sign = 's', \
754 .realbits = 16, \
755 .storagebits = 16, \
756 .endianness = IIO_CPU \
757 }, \
758 .ext_info = ak8975_ext_info, \
759 }
760
761 static const struct iio_chan_spec ak8975_channels[] = {
762 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
763 IIO_CHAN_SOFT_TIMESTAMP(3),
764 };
765
766 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
767
768 static const struct iio_info ak8975_info = {
769 .read_raw = &ak8975_read_raw,
770 .driver_module = THIS_MODULE,
771 };
772
773 static const struct acpi_device_id ak_acpi_match[] = {
774 {"AK8975", AK8975},
775 {"AK8963", AK8963},
776 {"INVN6500", AK8963},
777 {"AK09911", AK09911},
778 {"AK09912", AK09912},
779 { },
780 };
781 MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
782
783 static const char *ak8975_match_acpi_device(struct device *dev,
784 enum asahi_compass_chipset *chipset)
785 {
786 const struct acpi_device_id *id;
787
788 id = acpi_match_device(dev->driver->acpi_match_table, dev);
789 if (!id)
790 return NULL;
791 *chipset = (int)id->driver_data;
792
793 return dev_name(dev);
794 }
795
796 static void ak8975_fill_buffer(struct iio_dev *indio_dev)
797 {
798 struct ak8975_data *data = iio_priv(indio_dev);
799 const struct i2c_client *client = data->client;
800 const struct ak_def *def = data->def;
801 int ret;
802 s16 buff[8]; /* 3 x 16 bits axis values + 1 aligned 64 bits timestamp */
803
804 mutex_lock(&data->lock);
805
806 ret = ak8975_start_read_axis(data, client);
807 if (ret)
808 goto unlock;
809
810 /*
811 * For each axis, read the flux value from the appropriate register
812 * (the register is specified in the iio device attributes).
813 */
814 ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
815 def->data_regs[0],
816 3 * sizeof(buff[0]),
817 (u8 *)buff);
818 if (ret < 0)
819 goto unlock;
820
821 mutex_unlock(&data->lock);
822
823 /* Clamp to valid range. */
824 buff[0] = clamp_t(s16, le16_to_cpu(buff[0]), -def->range, def->range);
825 buff[1] = clamp_t(s16, le16_to_cpu(buff[1]), -def->range, def->range);
826 buff[2] = clamp_t(s16, le16_to_cpu(buff[2]), -def->range, def->range);
827
828 iio_push_to_buffers_with_timestamp(indio_dev, buff, iio_get_time_ns());
829 return;
830
831 unlock:
832 mutex_unlock(&data->lock);
833 dev_err(&client->dev, "Error in reading axes block\n");
834 }
835
836 static irqreturn_t ak8975_handle_trigger(int irq, void *p)
837 {
838 const struct iio_poll_func *pf = p;
839 struct iio_dev *indio_dev = pf->indio_dev;
840
841 ak8975_fill_buffer(indio_dev);
842 iio_trigger_notify_done(indio_dev->trig);
843 return IRQ_HANDLED;
844 }
845
846 static int ak8975_probe(struct i2c_client *client,
847 const struct i2c_device_id *id)
848 {
849 struct ak8975_data *data;
850 struct iio_dev *indio_dev;
851 int eoc_gpio;
852 int err;
853 const char *name = NULL;
854 enum asahi_compass_chipset chipset = AK_MAX_TYPE;
855 const struct ak8975_platform_data *pdata =
856 dev_get_platdata(&client->dev);
857
858 /* Grab and set up the supplied GPIO. */
859 if (pdata)
860 eoc_gpio = pdata->eoc_gpio;
861 else if (client->dev.of_node)
862 eoc_gpio = of_get_gpio(client->dev.of_node, 0);
863 else
864 eoc_gpio = -1;
865
866 if (eoc_gpio == -EPROBE_DEFER)
867 return -EPROBE_DEFER;
868
869 /* We may not have a GPIO based IRQ to scan, that is fine, we will
870 poll if so */
871 if (gpio_is_valid(eoc_gpio)) {
872 err = devm_gpio_request_one(&client->dev, eoc_gpio,
873 GPIOF_IN, "ak_8975");
874 if (err < 0) {
875 dev_err(&client->dev,
876 "failed to request GPIO %d, error %d\n",
877 eoc_gpio, err);
878 return err;
879 }
880 }
881
882 /* Register with IIO */
883 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
884 if (indio_dev == NULL)
885 return -ENOMEM;
886
887 data = iio_priv(indio_dev);
888 i2c_set_clientdata(client, indio_dev);
889
890 data->client = client;
891 data->eoc_gpio = eoc_gpio;
892 data->eoc_irq = 0;
893
894 if (!pdata) {
895 err = of_iio_read_mount_matrix(&client->dev,
896 "mount-matrix",
897 &data->orientation);
898 if (err)
899 return err;
900 } else
901 data->orientation = pdata->orientation;
902
903 /* id will be NULL when enumerated via ACPI */
904 if (id) {
905 chipset = (enum asahi_compass_chipset)(id->driver_data);
906 name = id->name;
907 } else if (ACPI_HANDLE(&client->dev)) {
908 name = ak8975_match_acpi_device(&client->dev, &chipset);
909 if (!name)
910 return -ENODEV;
911 } else
912 return -ENOSYS;
913
914 if (chipset >= AK_MAX_TYPE) {
915 dev_err(&client->dev, "AKM device type unsupported: %d\n",
916 chipset);
917 return -ENODEV;
918 }
919
920 data->def = &ak_def_array[chipset];
921
922 err = ak8975_power_on(client);
923 if (err)
924 return err;
925
926 err = ak8975_who_i_am(client, data->def->type);
927 if (err < 0) {
928 dev_err(&client->dev, "Unexpected device\n");
929 goto power_off;
930 }
931 dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
932
933 /* Perform some basic start-of-day setup of the device. */
934 err = ak8975_setup(client);
935 if (err < 0) {
936 dev_err(&client->dev, "%s initialization fails\n", name);
937 goto power_off;
938 }
939
940 mutex_init(&data->lock);
941 indio_dev->dev.parent = &client->dev;
942 indio_dev->channels = ak8975_channels;
943 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
944 indio_dev->info = &ak8975_info;
945 indio_dev->available_scan_masks = ak8975_scan_masks;
946 indio_dev->modes = INDIO_DIRECT_MODE;
947 indio_dev->name = name;
948
949 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
950 NULL);
951 if (err) {
952 dev_err(&client->dev, "triggered buffer setup failed\n");
953 goto power_off;
954 }
955
956 err = iio_device_register(indio_dev);
957 if (err) {
958 dev_err(&client->dev, "device register failed\n");
959 goto cleanup_buffer;
960 }
961
962 return 0;
963
964 cleanup_buffer:
965 iio_triggered_buffer_cleanup(indio_dev);
966 power_off:
967 ak8975_power_off(client);
968 return err;
969 }
970
971 static int ak8975_remove(struct i2c_client *client)
972 {
973 struct iio_dev *indio_dev = i2c_get_clientdata(client);
974
975 iio_device_unregister(indio_dev);
976 iio_triggered_buffer_cleanup(indio_dev);
977 ak8975_power_off(client);
978
979 return 0;
980 }
981
982 static const struct i2c_device_id ak8975_id[] = {
983 {"ak8975", AK8975},
984 {"ak8963", AK8963},
985 {"AK8963", AK8963},
986 {"ak09911", AK09911},
987 {"ak09912", AK09912},
988 {}
989 };
990
991 MODULE_DEVICE_TABLE(i2c, ak8975_id);
992
993 static const struct of_device_id ak8975_of_match[] = {
994 { .compatible = "asahi-kasei,ak8975", },
995 { .compatible = "ak8975", },
996 { .compatible = "asahi-kasei,ak8963", },
997 { .compatible = "ak8963", },
998 { .compatible = "asahi-kasei,ak09911", },
999 { .compatible = "ak09911", },
1000 { .compatible = "asahi-kasei,ak09912", },
1001 { .compatible = "ak09912", },
1002 {}
1003 };
1004 MODULE_DEVICE_TABLE(of, ak8975_of_match);
1005
1006 static struct i2c_driver ak8975_driver = {
1007 .driver = {
1008 .name = "ak8975",
1009 .of_match_table = of_match_ptr(ak8975_of_match),
1010 .acpi_match_table = ACPI_PTR(ak_acpi_match),
1011 },
1012 .probe = ak8975_probe,
1013 .remove = ak8975_remove,
1014 .id_table = ak8975_id,
1015 };
1016 module_i2c_driver(ak8975_driver);
1017
1018 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1019 MODULE_DESCRIPTION("AK8975 magnetometer driver");
1020 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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