1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * A sensor driver for the magnetometer AK8975.
4 *
5 * Magnetic compass sensor driver for monitoring magnetic flux information.
6 *
7 * Copyright (c) 2010, NVIDIA Corporation.
8 */
9
10 #include <linux/module.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/i2c.h>
15 #include <linux/interrupt.h>
16 #include <linux/err.h>
17 #include <linux/mutex.h>
18 #include <linux/delay.h>
19 #include <linux/bitops.h>
20 #include <linux/gpio/consumer.h>
21 #include <linux/regulator/consumer.h>
22 #include <linux/pm_runtime.h>
23
24 #include <linux/iio/iio.h>
25 #include <linux/iio/sysfs.h>
26 #include <linux/iio/buffer.h>
27 #include <linux/iio/trigger.h>
28 #include <linux/iio/trigger_consumer.h>
29 #include <linux/iio/triggered_buffer.h>
30
31 /*
32 * Register definitions, as well as various shifts and masks to get at the
33 * individual fields of the registers.
34 */
35 #define AK8975_REG_WIA 0x00
36 #define AK8975_DEVICE_ID 0x48
37
38 #define AK8975_REG_INFO 0x01
39
40 #define AK8975_REG_ST1 0x02
41 #define AK8975_REG_ST1_DRDY_SHIFT 0
42 #define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT)
43
44 #define AK8975_REG_HXL 0x03
45 #define AK8975_REG_HXH 0x04
46 #define AK8975_REG_HYL 0x05
47 #define AK8975_REG_HYH 0x06
48 #define AK8975_REG_HZL 0x07
49 #define AK8975_REG_HZH 0x08
50 #define AK8975_REG_ST2 0x09
51 #define AK8975_REG_ST2_DERR_SHIFT 2
52 #define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT)
53
54 #define AK8975_REG_ST2_HOFL_SHIFT 3
55 #define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT)
56
57 #define AK8975_REG_CNTL 0x0A
58 #define AK8975_REG_CNTL_MODE_SHIFT 0
59 #define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT)
60 #define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00
61 #define AK8975_REG_CNTL_MODE_ONCE 0x01
62 #define AK8975_REG_CNTL_MODE_SELF_TEST 0x08
63 #define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F
64
65 #define AK8975_REG_RSVC 0x0B
66 #define AK8975_REG_ASTC 0x0C
67 #define AK8975_REG_TS1 0x0D
68 #define AK8975_REG_TS2 0x0E
69 #define AK8975_REG_I2CDIS 0x0F
70 #define AK8975_REG_ASAX 0x10
71 #define AK8975_REG_ASAY 0x11
72 #define AK8975_REG_ASAZ 0x12
73
74 #define AK8975_MAX_REGS AK8975_REG_ASAZ
75
76 /*
77 * AK09912 Register definitions
78 */
79 #define AK09912_REG_WIA1 0x00
80 #define AK09912_REG_WIA2 0x01
81 #define AK09912_DEVICE_ID 0x04
82 #define AK09911_DEVICE_ID 0x05
83
84 #define AK09911_REG_INFO1 0x02
85 #define AK09911_REG_INFO2 0x03
86
87 #define AK09912_REG_ST1 0x10
88
89 #define AK09912_REG_ST1_DRDY_SHIFT 0
90 #define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT)
91
92 #define AK09912_REG_HXL 0x11
93 #define AK09912_REG_HXH 0x12
94 #define AK09912_REG_HYL 0x13
95 #define AK09912_REG_HYH 0x14
96 #define AK09912_REG_HZL 0x15
97 #define AK09912_REG_HZH 0x16
98 #define AK09912_REG_TMPS 0x17
99
100 #define AK09912_REG_ST2 0x18
101 #define AK09912_REG_ST2_HOFL_SHIFT 3
102 #define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT)
103
104 #define AK09912_REG_CNTL1 0x30
105
106 #define AK09912_REG_CNTL2 0x31
107 #define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00
108 #define AK09912_REG_CNTL_MODE_ONCE 0x01
109 #define AK09912_REG_CNTL_MODE_SELF_TEST 0x10
110 #define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F
111 #define AK09912_REG_CNTL2_MODE_SHIFT 0
112 #define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT)
113
114 #define AK09912_REG_CNTL3 0x32
115
116 #define AK09912_REG_TS1 0x33
117 #define AK09912_REG_TS2 0x34
118 #define AK09912_REG_TS3 0x35
119 #define AK09912_REG_I2CDIS 0x36
120 #define AK09912_REG_TS4 0x37
121
122 #define AK09912_REG_ASAX 0x60
123 #define AK09912_REG_ASAY 0x61
124 #define AK09912_REG_ASAZ 0x62
125
126 #define AK09912_MAX_REGS AK09912_REG_ASAZ
127
128 /*
129 * Miscellaneous values.
130 */
131 #define AK8975_MAX_CONVERSION_TIMEOUT 500
132 #define AK8975_CONVERSION_DONE_POLL_TIME 10
133 #define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000)
134
135 /*
136 * Precalculate scale factor (in Gauss units) for each axis and
137 * store in the device data.
138 *
139 * This scale factor is axis-dependent, and is derived from 3 calibration
140 * factors ASA(x), ASA(y), and ASA(z).
141 *
142 * These ASA values are read from the sensor device at start of day, and
143 * cached in the device context struct.
144 *
145 * Adjusting the flux value with the sensitivity adjustment value should be
146 * done via the following formula:
147 *
148 * Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 )
149 * where H is the raw value, ASA is the sensitivity adjustment, and Hadj
150 * is the resultant adjusted value.
151 *
152 * We reduce the formula to:
153 *
154 * Hadj = H * (ASA + 128) / 256
155 *
156 * H is in the range of -4096 to 4095. The magnetometer has a range of
157 * +-1229uT. To go from the raw value to uT is:
158 *
159 * HuT = H * 1229/4096, or roughly, 3/10.
160 *
161 * Since 1uT = 0.01 gauss, our final scale factor becomes:
162 *
163 * Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100
164 * Hadj = H * ((ASA + 128) * 0.003) / 256
165 *
166 * Since ASA doesn't change, we cache the resultant scale factor into the
167 * device context in ak8975_setup().
168 *
169 * Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we
170 * multiply the stored scale value by 1e6.
171 */
ak8975_raw_to_gauss(u16 data)172 static long ak8975_raw_to_gauss(u16 data)
173 {
174 return (((long)data + 128) * 3000) / 256;
175 }
176
177 /*
178 * For AK8963 and AK09911, same calculation, but the device is less sensitive:
179 *
180 * H is in the range of +-8190. The magnetometer has a range of
181 * +-4912uT. To go from the raw value to uT is:
182 *
183 * HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10.
184 */
185
ak8963_09911_raw_to_gauss(u16 data)186 static long ak8963_09911_raw_to_gauss(u16 data)
187 {
188 return (((long)data + 128) * 6000) / 256;
189 }
190
191 /*
192 * For AK09912, same calculation, except the device is more sensitive:
193 *
194 * H is in the range of -32752 to 32752. The magnetometer has a range of
195 * +-4912uT. To go from the raw value to uT is:
196 *
197 * HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10.
198 */
ak09912_raw_to_gauss(u16 data)199 static long ak09912_raw_to_gauss(u16 data)
200 {
201 return (((long)data + 128) * 1500) / 256;
202 }
203
204 /* Compatible Asahi Kasei Compass parts */
205 enum asahi_compass_chipset {
206 AKXXXX = 0,
207 AK8975,
208 AK8963,
209 AK09911,
210 AK09912,
211 };
212
213 enum ak_ctrl_reg_addr {
214 ST1,
215 ST2,
216 CNTL,
217 ASA_BASE,
218 MAX_REGS,
219 REGS_END,
220 };
221
222 enum ak_ctrl_reg_mask {
223 ST1_DRDY,
224 ST2_HOFL,
225 ST2_DERR,
226 CNTL_MODE,
227 MASK_END,
228 };
229
230 enum ak_ctrl_mode {
231 POWER_DOWN,
232 MODE_ONCE,
233 SELF_TEST,
234 FUSE_ROM,
235 MODE_END,
236 };
237
238 struct ak_def {
239 enum asahi_compass_chipset type;
240 long (*raw_to_gauss)(u16 data);
241 u16 range;
242 u8 ctrl_regs[REGS_END];
243 u8 ctrl_masks[MASK_END];
244 u8 ctrl_modes[MODE_END];
245 u8 data_regs[3];
246 };
247
248 static const struct ak_def ak_def_array[] = {
249 {
250 .type = AK8975,
251 .raw_to_gauss = ak8975_raw_to_gauss,
252 .range = 4096,
253 .ctrl_regs = {
254 AK8975_REG_ST1,
255 AK8975_REG_ST2,
256 AK8975_REG_CNTL,
257 AK8975_REG_ASAX,
258 AK8975_MAX_REGS},
259 .ctrl_masks = {
260 AK8975_REG_ST1_DRDY_MASK,
261 AK8975_REG_ST2_HOFL_MASK,
262 AK8975_REG_ST2_DERR_MASK,
263 AK8975_REG_CNTL_MODE_MASK},
264 .ctrl_modes = {
265 AK8975_REG_CNTL_MODE_POWER_DOWN,
266 AK8975_REG_CNTL_MODE_ONCE,
267 AK8975_REG_CNTL_MODE_SELF_TEST,
268 AK8975_REG_CNTL_MODE_FUSE_ROM},
269 .data_regs = {
270 AK8975_REG_HXL,
271 AK8975_REG_HYL,
272 AK8975_REG_HZL},
273 },
274 {
275 .type = AK8963,
276 .raw_to_gauss = ak8963_09911_raw_to_gauss,
277 .range = 8190,
278 .ctrl_regs = {
279 AK8975_REG_ST1,
280 AK8975_REG_ST2,
281 AK8975_REG_CNTL,
282 AK8975_REG_ASAX,
283 AK8975_MAX_REGS},
284 .ctrl_masks = {
285 AK8975_REG_ST1_DRDY_MASK,
286 AK8975_REG_ST2_HOFL_MASK,
287 0,
288 AK8975_REG_CNTL_MODE_MASK},
289 .ctrl_modes = {
290 AK8975_REG_CNTL_MODE_POWER_DOWN,
291 AK8975_REG_CNTL_MODE_ONCE,
292 AK8975_REG_CNTL_MODE_SELF_TEST,
293 AK8975_REG_CNTL_MODE_FUSE_ROM},
294 .data_regs = {
295 AK8975_REG_HXL,
296 AK8975_REG_HYL,
297 AK8975_REG_HZL},
298 },
299 {
300 .type = AK09911,
301 .raw_to_gauss = ak8963_09911_raw_to_gauss,
302 .range = 8192,
303 .ctrl_regs = {
304 AK09912_REG_ST1,
305 AK09912_REG_ST2,
306 AK09912_REG_CNTL2,
307 AK09912_REG_ASAX,
308 AK09912_MAX_REGS},
309 .ctrl_masks = {
310 AK09912_REG_ST1_DRDY_MASK,
311 AK09912_REG_ST2_HOFL_MASK,
312 0,
313 AK09912_REG_CNTL2_MODE_MASK},
314 .ctrl_modes = {
315 AK09912_REG_CNTL_MODE_POWER_DOWN,
316 AK09912_REG_CNTL_MODE_ONCE,
317 AK09912_REG_CNTL_MODE_SELF_TEST,
318 AK09912_REG_CNTL_MODE_FUSE_ROM},
319 .data_regs = {
320 AK09912_REG_HXL,
321 AK09912_REG_HYL,
322 AK09912_REG_HZL},
323 },
324 {
325 .type = AK09912,
326 .raw_to_gauss = ak09912_raw_to_gauss,
327 .range = 32752,
328 .ctrl_regs = {
329 AK09912_REG_ST1,
330 AK09912_REG_ST2,
331 AK09912_REG_CNTL2,
332 AK09912_REG_ASAX,
333 AK09912_MAX_REGS},
334 .ctrl_masks = {
335 AK09912_REG_ST1_DRDY_MASK,
336 AK09912_REG_ST2_HOFL_MASK,
337 0,
338 AK09912_REG_CNTL2_MODE_MASK},
339 .ctrl_modes = {
340 AK09912_REG_CNTL_MODE_POWER_DOWN,
341 AK09912_REG_CNTL_MODE_ONCE,
342 AK09912_REG_CNTL_MODE_SELF_TEST,
343 AK09912_REG_CNTL_MODE_FUSE_ROM},
344 .data_regs = {
345 AK09912_REG_HXL,
346 AK09912_REG_HYL,
347 AK09912_REG_HZL},
348 }
349 };
350
351 /*
352 * Per-instance context data for the device.
353 */
354 struct ak8975_data {
355 struct i2c_client *client;
356 const struct ak_def *def;
357 struct mutex lock;
358 u8 asa[3];
359 long raw_to_gauss[3];
360 struct gpio_desc *eoc_gpiod;
361 struct gpio_desc *reset_gpiod;
362 int eoc_irq;
363 wait_queue_head_t data_ready_queue;
364 unsigned long flags;
365 u8 cntl_cache;
366 struct iio_mount_matrix orientation;
367 struct regulator *vdd;
368 struct regulator *vid;
369
370 /* Ensure natural alignment of timestamp */
371 struct {
372 s16 channels[3];
373 s64 ts __aligned(8);
374 } scan;
375 };
376
377 /* Enable attached power regulator if any. */
ak8975_power_on(const struct ak8975_data * data)378 static int ak8975_power_on(const struct ak8975_data *data)
379 {
380 int ret;
381
382 ret = regulator_enable(data->vdd);
383 if (ret) {
384 dev_warn(&data->client->dev,
385 "Failed to enable specified Vdd supply\n");
386 return ret;
387 }
388 ret = regulator_enable(data->vid);
389 if (ret) {
390 dev_warn(&data->client->dev,
391 "Failed to enable specified Vid supply\n");
392 regulator_disable(data->vdd);
393 return ret;
394 }
395
396 gpiod_set_value_cansleep(data->reset_gpiod, 0);
397
398 /*
399 * According to the datasheet the power supply rise time is 200us
400 * and the minimum wait time before mode setting is 100us, in
401 * total 300us. Add some margin and say minimum 500us here.
402 */
403 usleep_range(500, 1000);
404 return 0;
405 }
406
407 /* Disable attached power regulator if any. */
ak8975_power_off(const struct ak8975_data * data)408 static void ak8975_power_off(const struct ak8975_data *data)
409 {
410 gpiod_set_value_cansleep(data->reset_gpiod, 1);
411
412 regulator_disable(data->vid);
413 regulator_disable(data->vdd);
414 }
415
416 /*
417 * Return 0 if the i2c device is the one we expect.
418 * return a negative error number otherwise
419 */
ak8975_who_i_am(struct i2c_client * client,enum asahi_compass_chipset type)420 static int ak8975_who_i_am(struct i2c_client *client,
421 enum asahi_compass_chipset type)
422 {
423 u8 wia_val[2];
424 int ret;
425
426 /*
427 * Signature for each device:
428 * Device | WIA1 | WIA2
429 * AK09912 | DEVICE_ID | AK09912_DEVICE_ID
430 * AK09911 | DEVICE_ID | AK09911_DEVICE_ID
431 * AK8975 | DEVICE_ID | NA
432 * AK8963 | DEVICE_ID | NA
433 */
434 ret = i2c_smbus_read_i2c_block_data_or_emulated(
435 client, AK09912_REG_WIA1, 2, wia_val);
436 if (ret < 0) {
437 dev_err(&client->dev, "Error reading WIA\n");
438 return ret;
439 }
440
441 if (wia_val[0] != AK8975_DEVICE_ID)
442 return -ENODEV;
443
444 switch (type) {
445 case AK8975:
446 case AK8963:
447 return 0;
448 case AK09911:
449 if (wia_val[1] == AK09911_DEVICE_ID)
450 return 0;
451 break;
452 case AK09912:
453 if (wia_val[1] == AK09912_DEVICE_ID)
454 return 0;
455 break;
456 default:
457 dev_err(&client->dev, "Type %d unknown\n", type);
458 }
459 return -ENODEV;
460 }
461
462 /*
463 * Helper function to write to CNTL register.
464 */
ak8975_set_mode(struct ak8975_data * data,enum ak_ctrl_mode mode)465 static int ak8975_set_mode(struct ak8975_data *data, enum ak_ctrl_mode mode)
466 {
467 u8 regval;
468 int ret;
469
470 regval = (data->cntl_cache & ~data->def->ctrl_masks[CNTL_MODE]) |
471 data->def->ctrl_modes[mode];
472 ret = i2c_smbus_write_byte_data(data->client,
473 data->def->ctrl_regs[CNTL], regval);
474 if (ret < 0) {
475 return ret;
476 }
477 data->cntl_cache = regval;
478 /* After mode change wait atleast 100us */
479 usleep_range(100, 500);
480
481 return 0;
482 }
483
484 /*
485 * Handle data ready irq
486 */
ak8975_irq_handler(int irq,void * data)487 static irqreturn_t ak8975_irq_handler(int irq, void *data)
488 {
489 struct ak8975_data *ak8975 = data;
490
491 set_bit(0, &ak8975->flags);
492 wake_up(&ak8975->data_ready_queue);
493
494 return IRQ_HANDLED;
495 }
496
497 /*
498 * Install data ready interrupt handler
499 */
ak8975_setup_irq(struct ak8975_data * data)500 static int ak8975_setup_irq(struct ak8975_data *data)
501 {
502 struct i2c_client *client = data->client;
503 int rc;
504 int irq;
505
506 init_waitqueue_head(&data->data_ready_queue);
507 clear_bit(0, &data->flags);
508 if (client->irq)
509 irq = client->irq;
510 else
511 irq = gpiod_to_irq(data->eoc_gpiod);
512
513 rc = devm_request_irq(&client->dev, irq, ak8975_irq_handler,
514 IRQF_TRIGGER_RISING | IRQF_ONESHOT,
515 dev_name(&client->dev), data);
516 if (rc < 0) {
517 dev_err(&client->dev, "irq %d request failed: %d\n", irq, rc);
518 return rc;
519 }
520
521 data->eoc_irq = irq;
522
523 return rc;
524 }
525
526
527 /*
528 * Perform some start-of-day setup, including reading the asa calibration
529 * values and caching them.
530 */
ak8975_setup(struct i2c_client * client)531 static int ak8975_setup(struct i2c_client *client)
532 {
533 struct iio_dev *indio_dev = i2c_get_clientdata(client);
534 struct ak8975_data *data = iio_priv(indio_dev);
535 int ret;
536
537 /* Write the fused rom access mode. */
538 ret = ak8975_set_mode(data, FUSE_ROM);
539 if (ret < 0) {
540 dev_err(&client->dev, "Error in setting fuse access mode\n");
541 return ret;
542 }
543
544 /* Get asa data and store in the device data. */
545 ret = i2c_smbus_read_i2c_block_data_or_emulated(
546 client, data->def->ctrl_regs[ASA_BASE],
547 3, data->asa);
548 if (ret < 0) {
549 dev_err(&client->dev, "Not able to read asa data\n");
550 return ret;
551 }
552
553 /* After reading fuse ROM data set power-down mode */
554 ret = ak8975_set_mode(data, POWER_DOWN);
555 if (ret < 0) {
556 dev_err(&client->dev, "Error in setting power-down mode\n");
557 return ret;
558 }
559
560 if (data->eoc_gpiod || client->irq > 0) {
561 ret = ak8975_setup_irq(data);
562 if (ret < 0) {
563 dev_err(&client->dev,
564 "Error setting data ready interrupt\n");
565 return ret;
566 }
567 }
568
569 data->raw_to_gauss[0] = data->def->raw_to_gauss(data->asa[0]);
570 data->raw_to_gauss[1] = data->def->raw_to_gauss(data->asa[1]);
571 data->raw_to_gauss[2] = data->def->raw_to_gauss(data->asa[2]);
572
573 return 0;
574 }
575
wait_conversion_complete_gpio(struct ak8975_data * data)576 static int wait_conversion_complete_gpio(struct ak8975_data *data)
577 {
578 struct i2c_client *client = data->client;
579 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
580 int ret;
581
582 /* Wait for the conversion to complete. */
583 while (timeout_ms) {
584 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
585 if (gpiod_get_value(data->eoc_gpiod))
586 break;
587 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
588 }
589 if (!timeout_ms) {
590 dev_err(&client->dev, "Conversion timeout happened\n");
591 return -EINVAL;
592 }
593
594 ret = i2c_smbus_read_byte_data(client, data->def->ctrl_regs[ST1]);
595 if (ret < 0)
596 dev_err(&client->dev, "Error in reading ST1\n");
597
598 return ret;
599 }
600
wait_conversion_complete_polled(struct ak8975_data * data)601 static int wait_conversion_complete_polled(struct ak8975_data *data)
602 {
603 struct i2c_client *client = data->client;
604 u8 read_status;
605 u32 timeout_ms = AK8975_MAX_CONVERSION_TIMEOUT;
606 int ret;
607
608 /* Wait for the conversion to complete. */
609 while (timeout_ms) {
610 msleep(AK8975_CONVERSION_DONE_POLL_TIME);
611 ret = i2c_smbus_read_byte_data(client,
612 data->def->ctrl_regs[ST1]);
613 if (ret < 0) {
614 dev_err(&client->dev, "Error in reading ST1\n");
615 return ret;
616 }
617 read_status = ret;
618 if (read_status)
619 break;
620 timeout_ms -= AK8975_CONVERSION_DONE_POLL_TIME;
621 }
622 if (!timeout_ms) {
623 dev_err(&client->dev, "Conversion timeout happened\n");
624 return -EINVAL;
625 }
626
627 return read_status;
628 }
629
630 /* Returns 0 if the end of conversion interrupt occured or -ETIME otherwise */
wait_conversion_complete_interrupt(struct ak8975_data * data)631 static int wait_conversion_complete_interrupt(struct ak8975_data *data)
632 {
633 int ret;
634
635 ret = wait_event_timeout(data->data_ready_queue,
636 test_bit(0, &data->flags),
637 AK8975_DATA_READY_TIMEOUT);
638 clear_bit(0, &data->flags);
639
640 return ret > 0 ? 0 : -ETIME;
641 }
642
ak8975_start_read_axis(struct ak8975_data * data,const struct i2c_client * client)643 static int ak8975_start_read_axis(struct ak8975_data *data,
644 const struct i2c_client *client)
645 {
646 /* Set up the device for taking a sample. */
647 int ret = ak8975_set_mode(data, MODE_ONCE);
648
649 if (ret < 0) {
650 dev_err(&client->dev, "Error in setting operating mode\n");
651 return ret;
652 }
653
654 /* Wait for the conversion to complete. */
655 if (data->eoc_irq)
656 ret = wait_conversion_complete_interrupt(data);
657 else if (data->eoc_gpiod)
658 ret = wait_conversion_complete_gpio(data);
659 else
660 ret = wait_conversion_complete_polled(data);
661 if (ret < 0)
662 return ret;
663
664 /* This will be executed only for non-interrupt based waiting case */
665 if (ret & data->def->ctrl_masks[ST1_DRDY]) {
666 ret = i2c_smbus_read_byte_data(client,
667 data->def->ctrl_regs[ST2]);
668 if (ret < 0) {
669 dev_err(&client->dev, "Error in reading ST2\n");
670 return ret;
671 }
672 if (ret & (data->def->ctrl_masks[ST2_DERR] |
673 data->def->ctrl_masks[ST2_HOFL])) {
674 dev_err(&client->dev, "ST2 status error 0x%x\n", ret);
675 return -EINVAL;
676 }
677 }
678
679 return 0;
680 }
681
682 /* 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)683 static int ak8975_read_axis(struct iio_dev *indio_dev, int index, int *val)
684 {
685 struct ak8975_data *data = iio_priv(indio_dev);
686 const struct i2c_client *client = data->client;
687 const struct ak_def *def = data->def;
688 __le16 rval;
689 u16 buff;
690 int ret;
691
692 pm_runtime_get_sync(&data->client->dev);
693
694 mutex_lock(&data->lock);
695
696 ret = ak8975_start_read_axis(data, client);
697 if (ret)
698 goto exit;
699
700 ret = i2c_smbus_read_i2c_block_data_or_emulated(
701 client, def->data_regs[index],
702 sizeof(rval), (u8*)&rval);
703 if (ret < 0)
704 goto exit;
705
706 mutex_unlock(&data->lock);
707
708 pm_runtime_mark_last_busy(&data->client->dev);
709 pm_runtime_put_autosuspend(&data->client->dev);
710
711 /* Swap bytes and convert to valid range. */
712 buff = le16_to_cpu(rval);
713 *val = clamp_t(s16, buff, -def->range, def->range);
714 return IIO_VAL_INT;
715
716 exit:
717 mutex_unlock(&data->lock);
718 dev_err(&client->dev, "Error in reading axis\n");
719 return ret;
720 }
721
ak8975_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)722 static int ak8975_read_raw(struct iio_dev *indio_dev,
723 struct iio_chan_spec const *chan,
724 int *val, int *val2,
725 long mask)
726 {
727 struct ak8975_data *data = iio_priv(indio_dev);
728
729 switch (mask) {
730 case IIO_CHAN_INFO_RAW:
731 return ak8975_read_axis(indio_dev, chan->address, val);
732 case IIO_CHAN_INFO_SCALE:
733 *val = 0;
734 *val2 = data->raw_to_gauss[chan->address];
735 return IIO_VAL_INT_PLUS_MICRO;
736 }
737 return -EINVAL;
738 }
739
740 static const struct iio_mount_matrix *
ak8975_get_mount_matrix(const struct iio_dev * indio_dev,const struct iio_chan_spec * chan)741 ak8975_get_mount_matrix(const struct iio_dev *indio_dev,
742 const struct iio_chan_spec *chan)
743 {
744 struct ak8975_data *data = iio_priv(indio_dev);
745
746 return &data->orientation;
747 }
748
749 static const struct iio_chan_spec_ext_info ak8975_ext_info[] = {
750 IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, ak8975_get_mount_matrix),
751 { }
752 };
753
754 #define AK8975_CHANNEL(axis, index) \
755 { \
756 .type = IIO_MAGN, \
757 .modified = 1, \
758 .channel2 = IIO_MOD_##axis, \
759 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
760 BIT(IIO_CHAN_INFO_SCALE), \
761 .address = index, \
762 .scan_index = index, \
763 .scan_type = { \
764 .sign = 's', \
765 .realbits = 16, \
766 .storagebits = 16, \
767 .endianness = IIO_CPU \
768 }, \
769 .ext_info = ak8975_ext_info, \
770 }
771
772 static const struct iio_chan_spec ak8975_channels[] = {
773 AK8975_CHANNEL(X, 0), AK8975_CHANNEL(Y, 1), AK8975_CHANNEL(Z, 2),
774 IIO_CHAN_SOFT_TIMESTAMP(3),
775 };
776
777 static const unsigned long ak8975_scan_masks[] = { 0x7, 0 };
778
779 static const struct iio_info ak8975_info = {
780 .read_raw = &ak8975_read_raw,
781 };
782
783 static const struct acpi_device_id ak_acpi_match[] = {
784 {"AK8975", AK8975},
785 {"AK8963", AK8963},
786 {"INVN6500", AK8963},
787 {"AK009911", AK09911},
788 {"AK09911", AK09911},
789 {"AKM9911", AK09911},
790 {"AK09912", AK09912},
791 { }
792 };
793 MODULE_DEVICE_TABLE(acpi, ak_acpi_match);
794
ak8975_fill_buffer(struct iio_dev * indio_dev)795 static void ak8975_fill_buffer(struct iio_dev *indio_dev)
796 {
797 struct ak8975_data *data = iio_priv(indio_dev);
798 const struct i2c_client *client = data->client;
799 const struct ak_def *def = data->def;
800 int ret;
801 __le16 fval[3];
802
803 mutex_lock(&data->lock);
804
805 ret = ak8975_start_read_axis(data, client);
806 if (ret)
807 goto unlock;
808
809 /*
810 * For each axis, read the flux value from the appropriate register
811 * (the register is specified in the iio device attributes).
812 */
813 ret = i2c_smbus_read_i2c_block_data_or_emulated(client,
814 def->data_regs[0],
815 3 * sizeof(fval[0]),
816 (u8 *)fval);
817 if (ret < 0)
818 goto unlock;
819
820 mutex_unlock(&data->lock);
821
822 /* Clamp to valid range. */
823 data->scan.channels[0] = clamp_t(s16, le16_to_cpu(fval[0]), -def->range, def->range);
824 data->scan.channels[1] = clamp_t(s16, le16_to_cpu(fval[1]), -def->range, def->range);
825 data->scan.channels[2] = clamp_t(s16, le16_to_cpu(fval[2]), -def->range, def->range);
826
827 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
828 iio_get_time_ns(indio_dev));
829
830 return;
831
832 unlock:
833 mutex_unlock(&data->lock);
834 dev_err(&client->dev, "Error in reading axes block\n");
835 }
836
ak8975_handle_trigger(int irq,void * p)837 static irqreturn_t ak8975_handle_trigger(int irq, void *p)
838 {
839 const struct iio_poll_func *pf = p;
840 struct iio_dev *indio_dev = pf->indio_dev;
841
842 ak8975_fill_buffer(indio_dev);
843 iio_trigger_notify_done(indio_dev->trig);
844 return IRQ_HANDLED;
845 }
846
ak8975_probe(struct i2c_client * client,const struct i2c_device_id * id)847 static int ak8975_probe(struct i2c_client *client,
848 const struct i2c_device_id *id)
849 {
850 struct ak8975_data *data;
851 struct iio_dev *indio_dev;
852 struct gpio_desc *eoc_gpiod;
853 struct gpio_desc *reset_gpiod;
854 const void *match;
855 unsigned int i;
856 int err;
857 enum asahi_compass_chipset chipset;
858 const char *name = NULL;
859
860 /*
861 * Grab and set up the supplied GPIO.
862 * We may not have a GPIO based IRQ to scan, that is fine, we will
863 * poll if so.
864 */
865 eoc_gpiod = devm_gpiod_get_optional(&client->dev, NULL, GPIOD_IN);
866 if (IS_ERR(eoc_gpiod))
867 return PTR_ERR(eoc_gpiod);
868 if (eoc_gpiod)
869 gpiod_set_consumer_name(eoc_gpiod, "ak_8975");
870
871 /*
872 * According to AK09911 datasheet, if reset GPIO is provided then
873 * deassert reset on ak8975_power_on() and assert reset on
874 * ak8975_power_off().
875 */
876 reset_gpiod = devm_gpiod_get_optional(&client->dev,
877 "reset", GPIOD_OUT_HIGH);
878 if (IS_ERR(reset_gpiod))
879 return PTR_ERR(reset_gpiod);
880
881 /* Register with IIO */
882 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
883 if (indio_dev == NULL)
884 return -ENOMEM;
885
886 data = iio_priv(indio_dev);
887 i2c_set_clientdata(client, indio_dev);
888
889 data->client = client;
890 data->eoc_gpiod = eoc_gpiod;
891 data->reset_gpiod = reset_gpiod;
892 data->eoc_irq = 0;
893
894 err = iio_read_mount_matrix(&client->dev, &data->orientation);
895 if (err)
896 return err;
897
898 /* id will be NULL when enumerated via ACPI */
899 match = device_get_match_data(&client->dev);
900 if (match) {
901 chipset = (enum asahi_compass_chipset)(match);
902 name = dev_name(&client->dev);
903 } else if (id) {
904 chipset = (enum asahi_compass_chipset)(id->driver_data);
905 name = id->name;
906 } else
907 return -ENOSYS;
908
909 for (i = 0; i < ARRAY_SIZE(ak_def_array); i++)
910 if (ak_def_array[i].type == chipset)
911 break;
912
913 if (i == ARRAY_SIZE(ak_def_array)) {
914 dev_err(&client->dev, "AKM device type unsupported: %d\n",
915 chipset);
916 return -ENODEV;
917 }
918
919 data->def = &ak_def_array[i];
920
921 /* Fetch the regulators */
922 data->vdd = devm_regulator_get(&client->dev, "vdd");
923 if (IS_ERR(data->vdd))
924 return PTR_ERR(data->vdd);
925 data->vid = devm_regulator_get(&client->dev, "vid");
926 if (IS_ERR(data->vid))
927 return PTR_ERR(data->vid);
928
929 err = ak8975_power_on(data);
930 if (err)
931 return err;
932
933 err = ak8975_who_i_am(client, data->def->type);
934 if (err < 0) {
935 dev_err(&client->dev, "Unexpected device\n");
936 goto power_off;
937 }
938 dev_dbg(&client->dev, "Asahi compass chip %s\n", name);
939
940 /* Perform some basic start-of-day setup of the device. */
941 err = ak8975_setup(client);
942 if (err < 0) {
943 dev_err(&client->dev, "%s initialization fails\n", name);
944 goto power_off;
945 }
946
947 mutex_init(&data->lock);
948 indio_dev->channels = ak8975_channels;
949 indio_dev->num_channels = ARRAY_SIZE(ak8975_channels);
950 indio_dev->info = &ak8975_info;
951 indio_dev->available_scan_masks = ak8975_scan_masks;
952 indio_dev->modes = INDIO_DIRECT_MODE;
953 indio_dev->name = name;
954
955 err = iio_triggered_buffer_setup(indio_dev, NULL, ak8975_handle_trigger,
956 NULL);
957 if (err) {
958 dev_err(&client->dev, "triggered buffer setup failed\n");
959 goto power_off;
960 }
961
962 err = iio_device_register(indio_dev);
963 if (err) {
964 dev_err(&client->dev, "device register failed\n");
965 goto cleanup_buffer;
966 }
967
968 /* Enable runtime PM */
969 pm_runtime_get_noresume(&client->dev);
970 pm_runtime_set_active(&client->dev);
971 pm_runtime_enable(&client->dev);
972 /*
973 * The device comes online in 500us, so add two orders of magnitude
974 * of delay before autosuspending: 50 ms.
975 */
976 pm_runtime_set_autosuspend_delay(&client->dev, 50);
977 pm_runtime_use_autosuspend(&client->dev);
978 pm_runtime_put(&client->dev);
979
980 return 0;
981
982 cleanup_buffer:
983 iio_triggered_buffer_cleanup(indio_dev);
984 power_off:
985 ak8975_power_off(data);
986 return err;
987 }
988
ak8975_remove(struct i2c_client * client)989 static int ak8975_remove(struct i2c_client *client)
990 {
991 struct iio_dev *indio_dev = i2c_get_clientdata(client);
992 struct ak8975_data *data = iio_priv(indio_dev);
993
994 pm_runtime_get_sync(&client->dev);
995 pm_runtime_put_noidle(&client->dev);
996 pm_runtime_disable(&client->dev);
997 iio_device_unregister(indio_dev);
998 iio_triggered_buffer_cleanup(indio_dev);
999 ak8975_set_mode(data, POWER_DOWN);
1000 ak8975_power_off(data);
1001
1002 return 0;
1003 }
1004
1005 #ifdef CONFIG_PM
ak8975_runtime_suspend(struct device * dev)1006 static int ak8975_runtime_suspend(struct device *dev)
1007 {
1008 struct i2c_client *client = to_i2c_client(dev);
1009 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1010 struct ak8975_data *data = iio_priv(indio_dev);
1011 int ret;
1012
1013 /* Set the device in power down if it wasn't already */
1014 ret = ak8975_set_mode(data, POWER_DOWN);
1015 if (ret < 0) {
1016 dev_err(&client->dev, "Error in setting power-down mode\n");
1017 return ret;
1018 }
1019 /* Next cut the regulators */
1020 ak8975_power_off(data);
1021
1022 return 0;
1023 }
1024
ak8975_runtime_resume(struct device * dev)1025 static int ak8975_runtime_resume(struct device *dev)
1026 {
1027 struct i2c_client *client = to_i2c_client(dev);
1028 struct iio_dev *indio_dev = i2c_get_clientdata(client);
1029 struct ak8975_data *data = iio_priv(indio_dev);
1030 int ret;
1031
1032 /* Take up the regulators */
1033 ak8975_power_on(data);
1034 /*
1035 * We come up in powered down mode, the reading routines will
1036 * put us in the mode to read values later.
1037 */
1038 ret = ak8975_set_mode(data, POWER_DOWN);
1039 if (ret < 0) {
1040 dev_err(&client->dev, "Error in setting power-down mode\n");
1041 return ret;
1042 }
1043
1044 return 0;
1045 }
1046 #endif /* CONFIG_PM */
1047
1048 static const struct dev_pm_ops ak8975_dev_pm_ops = {
1049 SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
1050 pm_runtime_force_resume)
1051 SET_RUNTIME_PM_OPS(ak8975_runtime_suspend,
1052 ak8975_runtime_resume, NULL)
1053 };
1054
1055 static const struct i2c_device_id ak8975_id[] = {
1056 {"ak8975", AK8975},
1057 {"ak8963", AK8963},
1058 {"AK8963", AK8963},
1059 {"ak09911", AK09911},
1060 {"ak09912", AK09912},
1061 {}
1062 };
1063
1064 MODULE_DEVICE_TABLE(i2c, ak8975_id);
1065
1066 static const struct of_device_id ak8975_of_match[] = {
1067 { .compatible = "asahi-kasei,ak8975", },
1068 { .compatible = "ak8975", },
1069 { .compatible = "asahi-kasei,ak8963", },
1070 { .compatible = "ak8963", },
1071 { .compatible = "asahi-kasei,ak09911", },
1072 { .compatible = "ak09911", },
1073 { .compatible = "asahi-kasei,ak09912", },
1074 { .compatible = "ak09912", },
1075 {}
1076 };
1077 MODULE_DEVICE_TABLE(of, ak8975_of_match);
1078
1079 static struct i2c_driver ak8975_driver = {
1080 .driver = {
1081 .name = "ak8975",
1082 .pm = &ak8975_dev_pm_ops,
1083 .of_match_table = ak8975_of_match,
1084 .acpi_match_table = ak_acpi_match,
1085 },
1086 .probe = ak8975_probe,
1087 .remove = ak8975_remove,
1088 .id_table = ak8975_id,
1089 };
1090 module_i2c_driver(ak8975_driver);
1091
1092 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
1093 MODULE_DESCRIPTION("AK8975 magnetometer driver");
1094 MODULE_LICENSE("GPL");
1095