xref: /openbmc/linux/drivers/iio/imu/fxos8700_core.c (revision b737eecd)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * FXOS8700 - NXP IMU (accelerometer plus magnetometer)
4  *
5  * IIO core driver for FXOS8700, with support for I2C/SPI busses
6  *
7  * TODO: Buffer, trigger, and IRQ support
8  */
9 #include <linux/module.h>
10 #include <linux/regmap.h>
11 #include <linux/acpi.h>
12 #include <linux/bitops.h>
13 
14 #include <linux/iio/iio.h>
15 #include <linux/iio/sysfs.h>
16 
17 #include "fxos8700.h"
18 
19 /* Register Definitions */
20 #define FXOS8700_STATUS             0x00
21 #define FXOS8700_OUT_X_MSB          0x01
22 #define FXOS8700_OUT_X_LSB          0x02
23 #define FXOS8700_OUT_Y_MSB          0x03
24 #define FXOS8700_OUT_Y_LSB          0x04
25 #define FXOS8700_OUT_Z_MSB          0x05
26 #define FXOS8700_OUT_Z_LSB          0x06
27 #define FXOS8700_F_SETUP            0x09
28 #define FXOS8700_TRIG_CFG           0x0a
29 #define FXOS8700_SYSMOD             0x0b
30 #define FXOS8700_INT_SOURCE         0x0c
31 #define FXOS8700_WHO_AM_I           0x0d
32 #define FXOS8700_XYZ_DATA_CFG       0x0e
33 #define FXOS8700_HP_FILTER_CUTOFF   0x0f
34 #define FXOS8700_PL_STATUS          0x10
35 #define FXOS8700_PL_CFG             0x11
36 #define FXOS8700_PL_COUNT           0x12
37 #define FXOS8700_PL_BF_ZCOMP        0x13
38 #define FXOS8700_PL_THS_REG         0x14
39 #define FXOS8700_A_FFMT_CFG         0x15
40 #define FXOS8700_A_FFMT_SRC         0x16
41 #define FXOS8700_A_FFMT_THS         0x17
42 #define FXOS8700_A_FFMT_COUNT       0x18
43 #define FXOS8700_TRANSIENT_CFG      0x1d
44 #define FXOS8700_TRANSIENT_SRC      0x1e
45 #define FXOS8700_TRANSIENT_THS      0x1f
46 #define FXOS8700_TRANSIENT_COUNT    0x20
47 #define FXOS8700_PULSE_CFG          0x21
48 #define FXOS8700_PULSE_SRC          0x22
49 #define FXOS8700_PULSE_THSX         0x23
50 #define FXOS8700_PULSE_THSY         0x24
51 #define FXOS8700_PULSE_THSZ         0x25
52 #define FXOS8700_PULSE_TMLT         0x26
53 #define FXOS8700_PULSE_LTCY         0x27
54 #define FXOS8700_PULSE_WIND         0x28
55 #define FXOS8700_ASLP_COUNT         0x29
56 #define FXOS8700_CTRL_REG1          0x2a
57 #define FXOS8700_CTRL_REG2          0x2b
58 #define FXOS8700_CTRL_REG3          0x2c
59 #define FXOS8700_CTRL_REG4          0x2d
60 #define FXOS8700_CTRL_REG5          0x2e
61 #define FXOS8700_OFF_X              0x2f
62 #define FXOS8700_OFF_Y              0x30
63 #define FXOS8700_OFF_Z              0x31
64 #define FXOS8700_M_DR_STATUS        0x32
65 #define FXOS8700_M_OUT_X_MSB        0x33
66 #define FXOS8700_M_OUT_X_LSB        0x34
67 #define FXOS8700_M_OUT_Y_MSB        0x35
68 #define FXOS8700_M_OUT_Y_LSB        0x36
69 #define FXOS8700_M_OUT_Z_MSB        0x37
70 #define FXOS8700_M_OUT_Z_LSB        0x38
71 #define FXOS8700_CMP_X_MSB          0x39
72 #define FXOS8700_CMP_X_LSB          0x3a
73 #define FXOS8700_CMP_Y_MSB          0x3b
74 #define FXOS8700_CMP_Y_LSB          0x3c
75 #define FXOS8700_CMP_Z_MSB          0x3d
76 #define FXOS8700_CMP_Z_LSB          0x3e
77 #define FXOS8700_M_OFF_X_MSB        0x3f
78 #define FXOS8700_M_OFF_X_LSB        0x40
79 #define FXOS8700_M_OFF_Y_MSB        0x41
80 #define FXOS8700_M_OFF_Y_LSB        0x42
81 #define FXOS8700_M_OFF_Z_MSB        0x43
82 #define FXOS8700_M_OFF_Z_LSB        0x44
83 #define FXOS8700_MAX_X_MSB          0x45
84 #define FXOS8700_MAX_X_LSB          0x46
85 #define FXOS8700_MAX_Y_MSB          0x47
86 #define FXOS8700_MAX_Y_LSB          0x48
87 #define FXOS8700_MAX_Z_MSB          0x49
88 #define FXOS8700_MAX_Z_LSB          0x4a
89 #define FXOS8700_MIN_X_MSB          0x4b
90 #define FXOS8700_MIN_X_LSB          0x4c
91 #define FXOS8700_MIN_Y_MSB          0x4d
92 #define FXOS8700_MIN_Y_LSB          0x4e
93 #define FXOS8700_MIN_Z_MSB          0x4f
94 #define FXOS8700_MIN_Z_LSB          0x50
95 #define FXOS8700_TEMP               0x51
96 #define FXOS8700_M_THS_CFG          0x52
97 #define FXOS8700_M_THS_SRC          0x53
98 #define FXOS8700_M_THS_X_MSB        0x54
99 #define FXOS8700_M_THS_X_LSB        0x55
100 #define FXOS8700_M_THS_Y_MSB        0x56
101 #define FXOS8700_M_THS_Y_LSB        0x57
102 #define FXOS8700_M_THS_Z_MSB        0x58
103 #define FXOS8700_M_THS_Z_LSB        0x59
104 #define FXOS8700_M_THS_COUNT        0x5a
105 #define FXOS8700_M_CTRL_REG1        0x5b
106 #define FXOS8700_M_CTRL_REG2        0x5c
107 #define FXOS8700_M_CTRL_REG3        0x5d
108 #define FXOS8700_M_INT_SRC          0x5e
109 #define FXOS8700_A_VECM_CFG         0x5f
110 #define FXOS8700_A_VECM_THS_MSB     0x60
111 #define FXOS8700_A_VECM_THS_LSB     0x61
112 #define FXOS8700_A_VECM_CNT         0x62
113 #define FXOS8700_A_VECM_INITX_MSB   0x63
114 #define FXOS8700_A_VECM_INITX_LSB   0x64
115 #define FXOS8700_A_VECM_INITY_MSB   0x65
116 #define FXOS8700_A_VECM_INITY_LSB   0x66
117 #define FXOS8700_A_VECM_INITZ_MSB   0x67
118 #define FXOS8700_A_VECM_INITZ_LSB   0x68
119 #define FXOS8700_M_VECM_CFG         0x69
120 #define FXOS8700_M_VECM_THS_MSB     0x6a
121 #define FXOS8700_M_VECM_THS_LSB     0x6b
122 #define FXOS8700_M_VECM_CNT         0x6c
123 #define FXOS8700_M_VECM_INITX_MSB   0x6d
124 #define FXOS8700_M_VECM_INITX_LSB   0x6e
125 #define FXOS8700_M_VECM_INITY_MSB   0x6f
126 #define FXOS8700_M_VECM_INITY_LSB   0x70
127 #define FXOS8700_M_VECM_INITZ_MSB   0x71
128 #define FXOS8700_M_VECM_INITZ_LSB   0x72
129 #define FXOS8700_A_FFMT_THS_X_MSB   0x73
130 #define FXOS8700_A_FFMT_THS_X_LSB   0x74
131 #define FXOS8700_A_FFMT_THS_Y_MSB   0x75
132 #define FXOS8700_A_FFMT_THS_Y_LSB   0x76
133 #define FXOS8700_A_FFMT_THS_Z_MSB   0x77
134 #define FXOS8700_A_FFMT_THS_Z_LSB   0x78
135 #define FXOS8700_A_TRAN_INIT_MSB    0x79
136 #define FXOS8700_A_TRAN_INIT_LSB_X  0x7a
137 #define FXOS8700_A_TRAN_INIT_LSB_Y  0x7b
138 #define FXOS8700_A_TRAN_INIT_LSB_Z  0x7d
139 #define FXOS8700_TM_NVM_LOCK        0x7e
140 #define FXOS8700_NVM_DATA0_35       0x80
141 #define FXOS8700_NVM_DATA_BNK3      0xa4
142 #define FXOS8700_NVM_DATA_BNK2      0xa5
143 #define FXOS8700_NVM_DATA_BNK1      0xa6
144 #define FXOS8700_NVM_DATA_BNK0      0xa7
145 
146 /* Bit definitions for FXOS8700_CTRL_REG1 */
147 #define FXOS8700_CTRL_ODR_MSK       0x38
148 #define FXOS8700_CTRL_ODR_MAX       0x00
149 #define FXOS8700_CTRL_ODR_MIN       GENMASK(4, 3)
150 
151 /* Bit definitions for FXOS8700_M_CTRL_REG1 */
152 #define FXOS8700_HMS_MASK           GENMASK(1, 0)
153 #define FXOS8700_OS_MASK            GENMASK(4, 2)
154 
155 /* Bit definitions for FXOS8700_M_CTRL_REG2 */
156 #define FXOS8700_MAXMIN_RST         BIT(2)
157 #define FXOS8700_MAXMIN_DIS_THS     BIT(3)
158 #define FXOS8700_MAXMIN_DIS         BIT(4)
159 
160 #define FXOS8700_ACTIVE             0x01
161 #define FXOS8700_ACTIVE_MIN_USLEEP  4000 /* from table 6 in datasheet */
162 
163 #define FXOS8700_DEVICE_ID          0xC7
164 #define FXOS8700_PRE_DEVICE_ID      0xC4
165 #define FXOS8700_DATA_BUF_SIZE      3
166 
167 struct fxos8700_data {
168 	struct regmap *regmap;
169 	struct iio_trigger *trig;
170 	__be16 buf[FXOS8700_DATA_BUF_SIZE] ____cacheline_aligned;
171 };
172 
173 /* Regmap info */
174 static const struct regmap_range read_range[] = {
175 	{
176 		.range_min = FXOS8700_STATUS,
177 		.range_max = FXOS8700_A_FFMT_COUNT,
178 	}, {
179 		.range_min = FXOS8700_TRANSIENT_CFG,
180 		.range_max = FXOS8700_A_FFMT_THS_Z_LSB,
181 	},
182 };
183 
184 static const struct regmap_range write_range[] = {
185 	{
186 		.range_min = FXOS8700_F_SETUP,
187 		.range_max = FXOS8700_TRIG_CFG,
188 	}, {
189 		.range_min = FXOS8700_XYZ_DATA_CFG,
190 		.range_max = FXOS8700_HP_FILTER_CUTOFF,
191 	}, {
192 		.range_min = FXOS8700_PL_CFG,
193 		.range_max = FXOS8700_A_FFMT_CFG,
194 	}, {
195 		.range_min = FXOS8700_A_FFMT_THS,
196 		.range_max = FXOS8700_TRANSIENT_CFG,
197 	}, {
198 		.range_min = FXOS8700_TRANSIENT_THS,
199 		.range_max = FXOS8700_PULSE_CFG,
200 	}, {
201 		.range_min = FXOS8700_PULSE_THSX,
202 		.range_max = FXOS8700_OFF_Z,
203 	}, {
204 		.range_min = FXOS8700_M_OFF_X_MSB,
205 		.range_max = FXOS8700_M_OFF_Z_LSB,
206 	}, {
207 		.range_min = FXOS8700_M_THS_CFG,
208 		.range_max = FXOS8700_M_THS_CFG,
209 	}, {
210 		.range_min = FXOS8700_M_THS_X_MSB,
211 		.range_max = FXOS8700_M_CTRL_REG3,
212 	}, {
213 		.range_min = FXOS8700_A_VECM_CFG,
214 		.range_max = FXOS8700_A_FFMT_THS_Z_LSB,
215 	},
216 };
217 
218 static const struct regmap_access_table driver_read_table = {
219 	.yes_ranges =   read_range,
220 	.n_yes_ranges = ARRAY_SIZE(read_range),
221 };
222 
223 static const struct regmap_access_table driver_write_table = {
224 	.yes_ranges =   write_range,
225 	.n_yes_ranges = ARRAY_SIZE(write_range),
226 };
227 
228 const struct regmap_config fxos8700_regmap_config = {
229 	.reg_bits = 8,
230 	.val_bits = 8,
231 	.max_register = FXOS8700_NVM_DATA_BNK0,
232 	.rd_table = &driver_read_table,
233 	.wr_table = &driver_write_table,
234 };
235 EXPORT_SYMBOL(fxos8700_regmap_config);
236 
237 #define FXOS8700_CHANNEL(_type, _axis) {			\
238 	.type = _type,						\
239 	.modified = 1,						\
240 	.channel2 = IIO_MOD_##_axis,				\
241 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
242 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |  \
243 		BIT(IIO_CHAN_INFO_SAMP_FREQ),			\
244 }
245 
246 enum fxos8700_accel_scale_bits {
247 	MODE_2G = 0,
248 	MODE_4G,
249 	MODE_8G,
250 };
251 
252 /* scan indexes follow DATA register order */
253 enum fxos8700_scan_axis {
254 	FXOS8700_SCAN_ACCEL_X = 0,
255 	FXOS8700_SCAN_ACCEL_Y,
256 	FXOS8700_SCAN_ACCEL_Z,
257 	FXOS8700_SCAN_MAGN_X,
258 	FXOS8700_SCAN_MAGN_Y,
259 	FXOS8700_SCAN_MAGN_Z,
260 	FXOS8700_SCAN_RHALL,
261 	FXOS8700_SCAN_TIMESTAMP,
262 };
263 
264 enum fxos8700_sensor {
265 	FXOS8700_ACCEL	= 0,
266 	FXOS8700_MAGN,
267 	FXOS8700_NUM_SENSORS /* must be last */
268 };
269 
270 enum fxos8700_int_pin {
271 	FXOS8700_PIN_INT1,
272 	FXOS8700_PIN_INT2
273 };
274 
275 struct fxos8700_scale {
276 	u8 bits;
277 	int uscale;
278 };
279 
280 struct fxos8700_odr {
281 	u8 bits;
282 	int odr;
283 	int uodr;
284 };
285 
286 static const struct fxos8700_scale fxos8700_accel_scale[] = {
287 	{ MODE_2G, 244},
288 	{ MODE_4G, 488},
289 	{ MODE_8G, 976},
290 };
291 
292 /*
293  * Accellerometer and magnetometer have the same ODR options, set in the
294  * CTRL_REG1 register. ODR is halved when using both sensors at once in
295  * hybrid mode.
296  */
297 static const struct fxos8700_odr fxos8700_odr[] = {
298 	{0x00, 800, 0},
299 	{0x01, 400, 0},
300 	{0x02, 200, 0},
301 	{0x03, 100, 0},
302 	{0x04, 50, 0},
303 	{0x05, 12, 500000},
304 	{0x06, 6, 250000},
305 	{0x07, 1, 562500},
306 };
307 
308 static const struct iio_chan_spec fxos8700_channels[] = {
309 	FXOS8700_CHANNEL(IIO_ACCEL, X),
310 	FXOS8700_CHANNEL(IIO_ACCEL, Y),
311 	FXOS8700_CHANNEL(IIO_ACCEL, Z),
312 	FXOS8700_CHANNEL(IIO_MAGN, X),
313 	FXOS8700_CHANNEL(IIO_MAGN, Y),
314 	FXOS8700_CHANNEL(IIO_MAGN, Z),
315 	IIO_CHAN_SOFT_TIMESTAMP(FXOS8700_SCAN_TIMESTAMP),
316 };
317 
318 static enum fxos8700_sensor fxos8700_to_sensor(enum iio_chan_type iio_type)
319 {
320 	switch (iio_type) {
321 	case IIO_ACCEL:
322 		return FXOS8700_ACCEL;
323 	case IIO_ANGL_VEL:
324 		return FXOS8700_MAGN;
325 	default:
326 		return -EINVAL;
327 	}
328 }
329 
330 static int fxos8700_set_active_mode(struct fxos8700_data *data,
331 				    enum fxos8700_sensor t, bool mode)
332 {
333 	int ret;
334 
335 	ret = regmap_write(data->regmap, FXOS8700_CTRL_REG1, mode);
336 	if (ret)
337 		return ret;
338 
339 	usleep_range(FXOS8700_ACTIVE_MIN_USLEEP,
340 		     FXOS8700_ACTIVE_MIN_USLEEP + 1000);
341 
342 	return 0;
343 }
344 
345 static int fxos8700_set_scale(struct fxos8700_data *data,
346 			      enum fxos8700_sensor t, int uscale)
347 {
348 	int i;
349 	static const int scale_num = ARRAY_SIZE(fxos8700_accel_scale);
350 	struct device *dev = regmap_get_device(data->regmap);
351 
352 	if (t == FXOS8700_MAGN) {
353 		dev_err(dev, "Magnetometer scale is locked at 1200uT\n");
354 		return -EINVAL;
355 	}
356 
357 	for (i = 0; i < scale_num; i++)
358 		if (fxos8700_accel_scale[i].uscale == uscale)
359 			break;
360 
361 	if (i == scale_num)
362 		return -EINVAL;
363 
364 	return regmap_write(data->regmap, FXOS8700_XYZ_DATA_CFG,
365 			    fxos8700_accel_scale[i].bits);
366 }
367 
368 static int fxos8700_get_scale(struct fxos8700_data *data,
369 			      enum fxos8700_sensor t, int *uscale)
370 {
371 	int i, ret, val;
372 	static const int scale_num = ARRAY_SIZE(fxos8700_accel_scale);
373 
374 	if (t == FXOS8700_MAGN) {
375 		*uscale = 1200; /* Magnetometer is locked at 1200uT */
376 		return 0;
377 	}
378 
379 	ret = regmap_read(data->regmap, FXOS8700_XYZ_DATA_CFG, &val);
380 	if (ret)
381 		return ret;
382 
383 	for (i = 0; i < scale_num; i++) {
384 		if (fxos8700_accel_scale[i].bits == (val & 0x3)) {
385 			*uscale = fxos8700_accel_scale[i].uscale;
386 			return 0;
387 		}
388 	}
389 
390 	return -EINVAL;
391 }
392 
393 static int fxos8700_get_data(struct fxos8700_data *data, int chan_type,
394 			     int axis, int *val)
395 {
396 	u8 base, reg;
397 	int ret;
398 	enum fxos8700_sensor type = fxos8700_to_sensor(chan_type);
399 
400 	base = type ? FXOS8700_OUT_X_MSB : FXOS8700_M_OUT_X_MSB;
401 
402 	/* Block read 6 bytes of device output registers to avoid data loss */
403 	ret = regmap_bulk_read(data->regmap, base, data->buf,
404 			       FXOS8700_DATA_BUF_SIZE);
405 	if (ret)
406 		return ret;
407 
408 	/* Convert axis to buffer index */
409 	reg = axis - IIO_MOD_X;
410 
411 	/* Convert to native endianness */
412 	*val = sign_extend32(be16_to_cpu(data->buf[reg]), 15);
413 
414 	return 0;
415 }
416 
417 static int fxos8700_set_odr(struct fxos8700_data *data, enum fxos8700_sensor t,
418 			    int odr, int uodr)
419 {
420 	int i, ret, val;
421 	bool active_mode;
422 	static const int odr_num = ARRAY_SIZE(fxos8700_odr);
423 
424 	ret = regmap_read(data->regmap, FXOS8700_CTRL_REG1, &val);
425 	if (ret)
426 		return ret;
427 
428 	active_mode = val & FXOS8700_ACTIVE;
429 
430 	if (active_mode) {
431 		/*
432 		 * The device must be in standby mode to change any of the
433 		 * other fields within CTRL_REG1
434 		 */
435 		ret = regmap_write(data->regmap, FXOS8700_CTRL_REG1,
436 				   val & ~FXOS8700_ACTIVE);
437 		if (ret)
438 			return ret;
439 	}
440 
441 	for (i = 0; i < odr_num; i++)
442 		if (fxos8700_odr[i].odr == odr && fxos8700_odr[i].uodr == uodr)
443 			break;
444 
445 	if (i >= odr_num)
446 		return -EINVAL;
447 
448 	return regmap_update_bits(data->regmap,
449 				  FXOS8700_CTRL_REG1,
450 				  FXOS8700_CTRL_ODR_MSK + FXOS8700_ACTIVE,
451 				  fxos8700_odr[i].bits << 3 | active_mode);
452 }
453 
454 static int fxos8700_get_odr(struct fxos8700_data *data, enum fxos8700_sensor t,
455 			    int *odr, int *uodr)
456 {
457 	int i, val, ret;
458 	static const int odr_num = ARRAY_SIZE(fxos8700_odr);
459 
460 	ret = regmap_read(data->regmap, FXOS8700_CTRL_REG1, &val);
461 	if (ret)
462 		return ret;
463 
464 	val &= FXOS8700_CTRL_ODR_MSK;
465 
466 	for (i = 0; i < odr_num; i++)
467 		if (val == fxos8700_odr[i].bits)
468 			break;
469 
470 	if (i >= odr_num)
471 		return -EINVAL;
472 
473 	*odr = fxos8700_odr[i].odr;
474 	*uodr = fxos8700_odr[i].uodr;
475 
476 	return 0;
477 }
478 
479 static int fxos8700_read_raw(struct iio_dev *indio_dev,
480 			     struct iio_chan_spec const *chan,
481 			     int *val, int *val2, long mask)
482 {
483 	int ret;
484 	struct fxos8700_data *data = iio_priv(indio_dev);
485 
486 	switch (mask) {
487 	case IIO_CHAN_INFO_RAW:
488 		ret = fxos8700_get_data(data, chan->type, chan->channel2, val);
489 		if (ret)
490 			return ret;
491 		return IIO_VAL_INT;
492 	case IIO_CHAN_INFO_SCALE:
493 		*val = 0;
494 		ret = fxos8700_get_scale(data, fxos8700_to_sensor(chan->type),
495 					 val2);
496 		return ret ? ret : IIO_VAL_INT_PLUS_MICRO;
497 	case IIO_CHAN_INFO_SAMP_FREQ:
498 		ret = fxos8700_get_odr(data, fxos8700_to_sensor(chan->type),
499 				       val, val2);
500 		return ret ? ret : IIO_VAL_INT_PLUS_MICRO;
501 	default:
502 		return -EINVAL;
503 	}
504 }
505 
506 static int fxos8700_write_raw(struct iio_dev *indio_dev,
507 			      struct iio_chan_spec const *chan,
508 			      int val, int val2, long mask)
509 {
510 	struct fxos8700_data *data = iio_priv(indio_dev);
511 
512 	switch (mask) {
513 	case IIO_CHAN_INFO_SCALE:
514 		return fxos8700_set_scale(data, fxos8700_to_sensor(chan->type),
515 					  val2);
516 	case IIO_CHAN_INFO_SAMP_FREQ:
517 		return fxos8700_set_odr(data, fxos8700_to_sensor(chan->type),
518 					val, val2);
519 	default:
520 		return -EINVAL;
521 	}
522 }
523 
524 static IIO_CONST_ATTR(in_accel_sampling_frequency_available,
525 		      "1.5625 6.25 12.5 50 100 200 400 800");
526 static IIO_CONST_ATTR(in_magn_sampling_frequency_available,
527 		      "1.5625 6.25 12.5 50 100 200 400 800");
528 static IIO_CONST_ATTR(in_accel_scale_available, "0.000244 0.000488 0.000976");
529 static IIO_CONST_ATTR(in_magn_scale_available, "0.000001200");
530 
531 static struct attribute *fxos8700_attrs[] = {
532 	&iio_const_attr_in_accel_sampling_frequency_available.dev_attr.attr,
533 	&iio_const_attr_in_magn_sampling_frequency_available.dev_attr.attr,
534 	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
535 	&iio_const_attr_in_magn_scale_available.dev_attr.attr,
536 	NULL,
537 };
538 
539 static const struct attribute_group fxos8700_attrs_group = {
540 	.attrs = fxos8700_attrs,
541 };
542 
543 static const struct iio_info fxos8700_info = {
544 	.read_raw = fxos8700_read_raw,
545 	.write_raw = fxos8700_write_raw,
546 	.attrs = &fxos8700_attrs_group,
547 };
548 
549 static int fxos8700_chip_init(struct fxos8700_data *data, bool use_spi)
550 {
551 	int ret;
552 	unsigned int val;
553 	struct device *dev = regmap_get_device(data->regmap);
554 
555 	ret = regmap_read(data->regmap, FXOS8700_WHO_AM_I, &val);
556 	if (ret) {
557 		dev_err(dev, "Error reading chip id\n");
558 		return ret;
559 	}
560 	if (val != FXOS8700_DEVICE_ID && val != FXOS8700_PRE_DEVICE_ID) {
561 		dev_err(dev, "Wrong chip id, got %x expected %x or %x\n",
562 			val, FXOS8700_DEVICE_ID, FXOS8700_PRE_DEVICE_ID);
563 		return -ENODEV;
564 	}
565 
566 	ret = fxos8700_set_active_mode(data, FXOS8700_ACCEL, true);
567 	if (ret)
568 		return ret;
569 
570 	ret = fxos8700_set_active_mode(data, FXOS8700_MAGN, true);
571 	if (ret)
572 		return ret;
573 
574 	/*
575 	 * The device must be in standby mode to change any of the other fields
576 	 * within CTRL_REG1
577 	 */
578 	ret = regmap_write(data->regmap, FXOS8700_CTRL_REG1, 0x00);
579 	if (ret)
580 		return ret;
581 
582 	/* Set max oversample ratio (OSR) and both devices active */
583 	ret = regmap_write(data->regmap, FXOS8700_M_CTRL_REG1,
584 			   FXOS8700_HMS_MASK | FXOS8700_OS_MASK);
585 	if (ret)
586 		return ret;
587 
588 	/* Disable and rst min/max measurements & threshold */
589 	ret = regmap_write(data->regmap, FXOS8700_M_CTRL_REG2,
590 			   FXOS8700_MAXMIN_RST | FXOS8700_MAXMIN_DIS_THS |
591 			   FXOS8700_MAXMIN_DIS);
592 	if (ret)
593 		return ret;
594 
595 	/* Max ODR (800Hz individual or 400Hz hybrid), active mode */
596 	ret = regmap_write(data->regmap, FXOS8700_CTRL_REG1,
597 			   FXOS8700_CTRL_ODR_MAX | FXOS8700_ACTIVE);
598 	if (ret)
599 		return ret;
600 
601 	/* Set for max full-scale range (+/-8G) */
602 	return regmap_write(data->regmap, FXOS8700_XYZ_DATA_CFG, MODE_8G);
603 }
604 
605 static void fxos8700_chip_uninit(void *data)
606 {
607 	struct fxos8700_data *fxos8700_data = data;
608 
609 	fxos8700_set_active_mode(fxos8700_data, FXOS8700_ACCEL, false);
610 	fxos8700_set_active_mode(fxos8700_data, FXOS8700_MAGN, false);
611 }
612 
613 int fxos8700_core_probe(struct device *dev, struct regmap *regmap,
614 			const char *name, bool use_spi)
615 {
616 	struct iio_dev *indio_dev;
617 	struct fxos8700_data *data;
618 	int ret;
619 
620 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
621 	if (!indio_dev)
622 		return -ENOMEM;
623 
624 	data = iio_priv(indio_dev);
625 	dev_set_drvdata(dev, indio_dev);
626 	data->regmap = regmap;
627 
628 	ret = fxos8700_chip_init(data, use_spi);
629 	if (ret)
630 		return ret;
631 
632 	ret = devm_add_action_or_reset(dev, fxos8700_chip_uninit, data);
633 	if (ret)
634 		return ret;
635 
636 	indio_dev->channels = fxos8700_channels;
637 	indio_dev->num_channels = ARRAY_SIZE(fxos8700_channels);
638 	indio_dev->name = name ? name : "fxos8700";
639 	indio_dev->modes = INDIO_DIRECT_MODE;
640 	indio_dev->info = &fxos8700_info;
641 
642 	return devm_iio_device_register(dev, indio_dev);
643 }
644 EXPORT_SYMBOL_GPL(fxos8700_core_probe);
645 
646 MODULE_AUTHOR("Robert Jones <rjones@gateworks.com>");
647 MODULE_DESCRIPTION("FXOS8700 6-Axis Acc and Mag Combo Sensor driver");
648 MODULE_LICENSE("GPL v2");
649