xref: /openbmc/linux/drivers/iio/accel/adxl372.c (revision e0d07278)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * ADXL372 3-Axis Digital Accelerometer core driver
4  *
5  * Copyright 2018 Analog Devices Inc.
6  */
7 
8 #include <linux/bitops.h>
9 #include <linux/interrupt.h>
10 #include <linux/irq.h>
11 #include <linux/module.h>
12 #include <linux/regmap.h>
13 #include <linux/spi/spi.h>
14 
15 #include <linux/iio/iio.h>
16 #include <linux/iio/sysfs.h>
17 #include <linux/iio/buffer.h>
18 #include <linux/iio/events.h>
19 #include <linux/iio/trigger.h>
20 #include <linux/iio/trigger_consumer.h>
21 #include <linux/iio/triggered_buffer.h>
22 
23 #include "adxl372.h"
24 
25 /* ADXL372 registers definition */
26 #define ADXL372_DEVID			0x00
27 #define ADXL372_DEVID_MST		0x01
28 #define ADXL372_PARTID			0x02
29 #define ADXL372_STATUS_1		0x04
30 #define ADXL372_STATUS_2		0x05
31 #define ADXL372_FIFO_ENTRIES_2		0x06
32 #define ADXL372_FIFO_ENTRIES_1		0x07
33 #define ADXL372_X_DATA_H		0x08
34 #define ADXL372_X_DATA_L		0x09
35 #define ADXL372_Y_DATA_H		0x0A
36 #define ADXL372_Y_DATA_L		0x0B
37 #define ADXL372_Z_DATA_H		0x0C
38 #define ADXL372_Z_DATA_L		0x0D
39 #define ADXL372_X_MAXPEAK_H		0x15
40 #define ADXL372_X_MAXPEAK_L		0x16
41 #define ADXL372_Y_MAXPEAK_H		0x17
42 #define ADXL372_Y_MAXPEAK_L		0x18
43 #define ADXL372_Z_MAXPEAK_H		0x19
44 #define ADXL372_Z_MAXPEAK_L		0x1A
45 #define ADXL372_OFFSET_X		0x20
46 #define ADXL372_OFFSET_Y		0x21
47 #define ADXL372_OFFSET_Z		0x22
48 #define ADXL372_X_THRESH_ACT_H		0x23
49 #define ADXL372_X_THRESH_ACT_L		0x24
50 #define ADXL372_Y_THRESH_ACT_H		0x25
51 #define ADXL372_Y_THRESH_ACT_L		0x26
52 #define ADXL372_Z_THRESH_ACT_H		0x27
53 #define ADXL372_Z_THRESH_ACT_L		0x28
54 #define ADXL372_TIME_ACT		0x29
55 #define ADXL372_X_THRESH_INACT_H	0x2A
56 #define ADXL372_X_THRESH_INACT_L	0x2B
57 #define ADXL372_Y_THRESH_INACT_H	0x2C
58 #define ADXL372_Y_THRESH_INACT_L	0x2D
59 #define ADXL372_Z_THRESH_INACT_H	0x2E
60 #define ADXL372_Z_THRESH_INACT_L	0x2F
61 #define ADXL372_TIME_INACT_H		0x30
62 #define ADXL372_TIME_INACT_L		0x31
63 #define ADXL372_X_THRESH_ACT2_H		0x32
64 #define ADXL372_X_THRESH_ACT2_L		0x33
65 #define ADXL372_Y_THRESH_ACT2_H		0x34
66 #define ADXL372_Y_THRESH_ACT2_L		0x35
67 #define ADXL372_Z_THRESH_ACT2_H		0x36
68 #define ADXL372_Z_THRESH_ACT2_L		0x37
69 #define ADXL372_HPF			0x38
70 #define ADXL372_FIFO_SAMPLES		0x39
71 #define ADXL372_FIFO_CTL		0x3A
72 #define ADXL372_INT1_MAP		0x3B
73 #define ADXL372_INT2_MAP		0x3C
74 #define ADXL372_TIMING			0x3D
75 #define ADXL372_MEASURE			0x3E
76 #define ADXL372_POWER_CTL		0x3F
77 #define ADXL372_SELF_TEST		0x40
78 #define ADXL372_RESET			0x41
79 #define ADXL372_FIFO_DATA		0x42
80 
81 #define ADXL372_DEVID_VAL		0xAD
82 #define ADXL372_PARTID_VAL		0xFA
83 #define ADXL372_RESET_CODE		0x52
84 
85 /* ADXL372_POWER_CTL */
86 #define ADXL372_POWER_CTL_MODE_MSK		GENMASK_ULL(1, 0)
87 #define ADXL372_POWER_CTL_MODE(x)		(((x) & 0x3) << 0)
88 
89 /* ADXL372_MEASURE */
90 #define ADXL372_MEASURE_LINKLOOP_MSK		GENMASK_ULL(5, 4)
91 #define ADXL372_MEASURE_LINKLOOP_MODE(x)	(((x) & 0x3) << 4)
92 #define ADXL372_MEASURE_BANDWIDTH_MSK		GENMASK_ULL(2, 0)
93 #define ADXL372_MEASURE_BANDWIDTH_MODE(x)	(((x) & 0x7) << 0)
94 
95 /* ADXL372_TIMING */
96 #define ADXL372_TIMING_ODR_MSK			GENMASK_ULL(7, 5)
97 #define ADXL372_TIMING_ODR_MODE(x)		(((x) & 0x7) << 5)
98 
99 /* ADXL372_FIFO_CTL */
100 #define ADXL372_FIFO_CTL_FORMAT_MSK		GENMASK(5, 3)
101 #define ADXL372_FIFO_CTL_FORMAT_MODE(x)		(((x) & 0x7) << 3)
102 #define ADXL372_FIFO_CTL_MODE_MSK		GENMASK(2, 1)
103 #define ADXL372_FIFO_CTL_MODE_MODE(x)		(((x) & 0x3) << 1)
104 #define ADXL372_FIFO_CTL_SAMPLES_MSK		BIT(1)
105 #define ADXL372_FIFO_CTL_SAMPLES_MODE(x)	(((x) > 0xFF) ? 1 : 0)
106 
107 /* ADXL372_STATUS_1 */
108 #define ADXL372_STATUS_1_DATA_RDY(x)		(((x) >> 0) & 0x1)
109 #define ADXL372_STATUS_1_FIFO_RDY(x)		(((x) >> 1) & 0x1)
110 #define ADXL372_STATUS_1_FIFO_FULL(x)		(((x) >> 2) & 0x1)
111 #define ADXL372_STATUS_1_FIFO_OVR(x)		(((x) >> 3) & 0x1)
112 #define ADXL372_STATUS_1_USR_NVM_BUSY(x)	(((x) >> 5) & 0x1)
113 #define ADXL372_STATUS_1_AWAKE(x)		(((x) >> 6) & 0x1)
114 #define ADXL372_STATUS_1_ERR_USR_REGS(x)	(((x) >> 7) & 0x1)
115 
116 /* ADXL372_INT1_MAP */
117 #define ADXL372_INT1_MAP_DATA_RDY_MSK		BIT(0)
118 #define ADXL372_INT1_MAP_DATA_RDY_MODE(x)	(((x) & 0x1) << 0)
119 #define ADXL372_INT1_MAP_FIFO_RDY_MSK		BIT(1)
120 #define ADXL372_INT1_MAP_FIFO_RDY_MODE(x)	(((x) & 0x1) << 1)
121 #define ADXL372_INT1_MAP_FIFO_FULL_MSK		BIT(2)
122 #define ADXL372_INT1_MAP_FIFO_FULL_MODE(x)	(((x) & 0x1) << 2)
123 #define ADXL372_INT1_MAP_FIFO_OVR_MSK		BIT(3)
124 #define ADXL372_INT1_MAP_FIFO_OVR_MODE(x)	(((x) & 0x1) << 3)
125 #define ADXL372_INT1_MAP_INACT_MSK		BIT(4)
126 #define ADXL372_INT1_MAP_INACT_MODE(x)		(((x) & 0x1) << 4)
127 #define ADXL372_INT1_MAP_ACT_MSK		BIT(5)
128 #define ADXL372_INT1_MAP_ACT_MODE(x)		(((x) & 0x1) << 5)
129 #define ADXL372_INT1_MAP_AWAKE_MSK		BIT(6)
130 #define ADXL372_INT1_MAP_AWAKE_MODE(x)		(((x) & 0x1) << 6)
131 #define ADXL372_INT1_MAP_LOW_MSK		BIT(7)
132 #define ADXL372_INT1_MAP_LOW_MODE(x)		(((x) & 0x1) << 7)
133 
134 /* The ADXL372 includes a deep, 512 sample FIFO buffer */
135 #define ADXL372_FIFO_SIZE			512
136 
137 /*
138  * At +/- 200g with 12-bit resolution, scale is computed as:
139  * (200 + 200) * 9.81 / (2^12 - 1) = 0.958241
140  */
141 #define ADXL372_USCALE	958241
142 
143 enum adxl372_op_mode {
144 	ADXL372_STANDBY,
145 	ADXL372_WAKE_UP,
146 	ADXL372_INSTANT_ON,
147 	ADXL372_FULL_BW_MEASUREMENT,
148 };
149 
150 enum adxl372_act_proc_mode {
151 	ADXL372_DEFAULT,
152 	ADXL372_LINKED,
153 	ADXL372_LOOPED,
154 };
155 
156 enum adxl372_th_activity {
157 	ADXL372_ACTIVITY,
158 	ADXL372_ACTIVITY2,
159 	ADXL372_INACTIVITY,
160 };
161 
162 enum adxl372_odr {
163 	ADXL372_ODR_400HZ,
164 	ADXL372_ODR_800HZ,
165 	ADXL372_ODR_1600HZ,
166 	ADXL372_ODR_3200HZ,
167 	ADXL372_ODR_6400HZ,
168 };
169 
170 enum adxl372_bandwidth {
171 	ADXL372_BW_200HZ,
172 	ADXL372_BW_400HZ,
173 	ADXL372_BW_800HZ,
174 	ADXL372_BW_1600HZ,
175 	ADXL372_BW_3200HZ,
176 };
177 
178 static const unsigned int adxl372_th_reg_high_addr[3] = {
179 	[ADXL372_ACTIVITY] = ADXL372_X_THRESH_ACT_H,
180 	[ADXL372_ACTIVITY2] = ADXL372_X_THRESH_ACT2_H,
181 	[ADXL372_INACTIVITY] = ADXL372_X_THRESH_INACT_H,
182 };
183 
184 enum adxl372_fifo_format {
185 	ADXL372_XYZ_FIFO,
186 	ADXL372_X_FIFO,
187 	ADXL372_Y_FIFO,
188 	ADXL372_XY_FIFO,
189 	ADXL372_Z_FIFO,
190 	ADXL372_XZ_FIFO,
191 	ADXL372_YZ_FIFO,
192 	ADXL372_XYZ_PEAK_FIFO,
193 };
194 
195 enum adxl372_fifo_mode {
196 	ADXL372_FIFO_BYPASSED,
197 	ADXL372_FIFO_STREAMED,
198 	ADXL372_FIFO_TRIGGERED,
199 	ADXL372_FIFO_OLD_SAVED
200 };
201 
202 static const int adxl372_samp_freq_tbl[5] = {
203 	400, 800, 1600, 3200, 6400,
204 };
205 
206 static const int adxl372_bw_freq_tbl[5] = {
207 	200, 400, 800, 1600, 3200,
208 };
209 
210 struct adxl372_axis_lookup {
211 	unsigned int bits;
212 	enum adxl372_fifo_format fifo_format;
213 };
214 
215 static const struct adxl372_axis_lookup adxl372_axis_lookup_table[] = {
216 	{ BIT(0), ADXL372_X_FIFO },
217 	{ BIT(1), ADXL372_Y_FIFO },
218 	{ BIT(2), ADXL372_Z_FIFO },
219 	{ BIT(0) | BIT(1), ADXL372_XY_FIFO },
220 	{ BIT(0) | BIT(2), ADXL372_XZ_FIFO },
221 	{ BIT(1) | BIT(2), ADXL372_YZ_FIFO },
222 	{ BIT(0) | BIT(1) | BIT(2), ADXL372_XYZ_FIFO },
223 };
224 
225 #define ADXL372_ACCEL_CHANNEL(index, reg, axis) {			\
226 	.type = IIO_ACCEL,						\
227 	.address = reg,							\
228 	.modified = 1,							\
229 	.channel2 = IIO_MOD_##axis,					\
230 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
231 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |		\
232 				    BIT(IIO_CHAN_INFO_SAMP_FREQ) |	\
233 		BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY),	\
234 	.scan_index = index,						\
235 	.scan_type = {							\
236 		.sign = 's',						\
237 		.realbits = 12,						\
238 		.storagebits = 16,					\
239 		.shift = 4,						\
240 		.endianness = IIO_BE,					\
241 	},								\
242 }
243 
244 static const struct iio_chan_spec adxl372_channels[] = {
245 	ADXL372_ACCEL_CHANNEL(0, ADXL372_X_DATA_H, X),
246 	ADXL372_ACCEL_CHANNEL(1, ADXL372_Y_DATA_H, Y),
247 	ADXL372_ACCEL_CHANNEL(2, ADXL372_Z_DATA_H, Z),
248 };
249 
250 struct adxl372_state {
251 	int				irq;
252 	struct device			*dev;
253 	struct regmap			*regmap;
254 	struct iio_trigger		*dready_trig;
255 	enum adxl372_fifo_mode		fifo_mode;
256 	enum adxl372_fifo_format	fifo_format;
257 	enum adxl372_op_mode		op_mode;
258 	enum adxl372_act_proc_mode	act_proc_mode;
259 	enum adxl372_odr		odr;
260 	enum adxl372_bandwidth		bw;
261 	u32				act_time_ms;
262 	u32				inact_time_ms;
263 	u8				fifo_set_size;
264 	u8				int1_bitmask;
265 	u8				int2_bitmask;
266 	u16				watermark;
267 	__be16				fifo_buf[ADXL372_FIFO_SIZE];
268 };
269 
270 static const unsigned long adxl372_channel_masks[] = {
271 	BIT(0), BIT(1), BIT(2),
272 	BIT(0) | BIT(1),
273 	BIT(0) | BIT(2),
274 	BIT(1) | BIT(2),
275 	BIT(0) | BIT(1) | BIT(2),
276 	0
277 };
278 
279 static int adxl372_read_axis(struct adxl372_state *st, u8 addr)
280 {
281 	__be16 regval;
282 	int ret;
283 
284 	ret = regmap_bulk_read(st->regmap, addr, &regval, sizeof(regval));
285 	if (ret < 0)
286 		return ret;
287 
288 	return be16_to_cpu(regval);
289 }
290 
291 static int adxl372_set_op_mode(struct adxl372_state *st,
292 			       enum adxl372_op_mode op_mode)
293 {
294 	int ret;
295 
296 	ret = regmap_update_bits(st->regmap, ADXL372_POWER_CTL,
297 				 ADXL372_POWER_CTL_MODE_MSK,
298 				 ADXL372_POWER_CTL_MODE(op_mode));
299 	if (ret < 0)
300 		return ret;
301 
302 	st->op_mode = op_mode;
303 
304 	return ret;
305 }
306 
307 static int adxl372_set_odr(struct adxl372_state *st,
308 			   enum adxl372_odr odr)
309 {
310 	int ret;
311 
312 	ret = regmap_update_bits(st->regmap, ADXL372_TIMING,
313 				 ADXL372_TIMING_ODR_MSK,
314 				 ADXL372_TIMING_ODR_MODE(odr));
315 	if (ret < 0)
316 		return ret;
317 
318 	st->odr = odr;
319 
320 	return ret;
321 }
322 
323 static int adxl372_find_closest_match(const int *array,
324 				      unsigned int size, int val)
325 {
326 	int i;
327 
328 	for (i = 0; i < size; i++) {
329 		if (val <= array[i])
330 			return i;
331 	}
332 
333 	return size - 1;
334 }
335 
336 static int adxl372_set_bandwidth(struct adxl372_state *st,
337 				 enum adxl372_bandwidth bw)
338 {
339 	int ret;
340 
341 	ret = regmap_update_bits(st->regmap, ADXL372_MEASURE,
342 				 ADXL372_MEASURE_BANDWIDTH_MSK,
343 				 ADXL372_MEASURE_BANDWIDTH_MODE(bw));
344 	if (ret < 0)
345 		return ret;
346 
347 	st->bw = bw;
348 
349 	return ret;
350 }
351 
352 static int adxl372_set_act_proc_mode(struct adxl372_state *st,
353 				     enum adxl372_act_proc_mode mode)
354 {
355 	int ret;
356 
357 	ret = regmap_update_bits(st->regmap,
358 				 ADXL372_MEASURE,
359 				 ADXL372_MEASURE_LINKLOOP_MSK,
360 				 ADXL372_MEASURE_LINKLOOP_MODE(mode));
361 	if (ret < 0)
362 		return ret;
363 
364 	st->act_proc_mode = mode;
365 
366 	return ret;
367 }
368 
369 static int adxl372_set_activity_threshold(struct adxl372_state *st,
370 					  enum adxl372_th_activity act,
371 					  bool ref_en, bool enable,
372 					  unsigned int threshold)
373 {
374 	unsigned char buf[6];
375 	unsigned char th_reg_high_val, th_reg_low_val, th_reg_high_addr;
376 
377 	/* scale factor is 100 mg/code */
378 	th_reg_high_val = (threshold / 100) >> 3;
379 	th_reg_low_val = ((threshold / 100) << 5) | (ref_en << 1) | enable;
380 	th_reg_high_addr = adxl372_th_reg_high_addr[act];
381 
382 	buf[0] = th_reg_high_val;
383 	buf[1] = th_reg_low_val;
384 	buf[2] = th_reg_high_val;
385 	buf[3] = th_reg_low_val;
386 	buf[4] = th_reg_high_val;
387 	buf[5] = th_reg_low_val;
388 
389 	return regmap_bulk_write(st->regmap, th_reg_high_addr,
390 				 buf, ARRAY_SIZE(buf));
391 }
392 
393 static int adxl372_set_activity_time_ms(struct adxl372_state *st,
394 					unsigned int act_time_ms)
395 {
396 	unsigned int reg_val, scale_factor;
397 	int ret;
398 
399 	/*
400 	 * 3.3 ms per code is the scale factor of the TIME_ACT register for
401 	 * ODR = 6400 Hz. It is 6.6 ms per code for ODR = 3200 Hz and below.
402 	 */
403 	if (st->odr == ADXL372_ODR_6400HZ)
404 		scale_factor = 3300;
405 	else
406 		scale_factor = 6600;
407 
408 	reg_val = DIV_ROUND_CLOSEST(act_time_ms * 1000, scale_factor);
409 
410 	/* TIME_ACT register is 8 bits wide */
411 	if (reg_val > 0xFF)
412 		reg_val = 0xFF;
413 
414 	ret = regmap_write(st->regmap, ADXL372_TIME_ACT, reg_val);
415 	if (ret < 0)
416 		return ret;
417 
418 	st->act_time_ms = act_time_ms;
419 
420 	return ret;
421 }
422 
423 static int adxl372_set_inactivity_time_ms(struct adxl372_state *st,
424 					  unsigned int inact_time_ms)
425 {
426 	unsigned int reg_val_h, reg_val_l, res, scale_factor;
427 	int ret;
428 
429 	/*
430 	 * 13 ms per code is the scale factor of the TIME_INACT register for
431 	 * ODR = 6400 Hz. It is 26 ms per code for ODR = 3200 Hz and below.
432 	 */
433 	if (st->odr == ADXL372_ODR_6400HZ)
434 		scale_factor = 13;
435 	else
436 		scale_factor = 26;
437 
438 	res = DIV_ROUND_CLOSEST(inact_time_ms, scale_factor);
439 	reg_val_h = (res >> 8) & 0xFF;
440 	reg_val_l = res & 0xFF;
441 
442 	ret = regmap_write(st->regmap, ADXL372_TIME_INACT_H, reg_val_h);
443 	if (ret < 0)
444 		return ret;
445 
446 	ret = regmap_write(st->regmap, ADXL372_TIME_INACT_L, reg_val_l);
447 	if (ret < 0)
448 		return ret;
449 
450 	st->inact_time_ms = inact_time_ms;
451 
452 	return ret;
453 }
454 
455 static int adxl372_set_interrupts(struct adxl372_state *st,
456 				  unsigned char int1_bitmask,
457 				  unsigned char int2_bitmask)
458 {
459 	int ret;
460 
461 	ret = regmap_write(st->regmap, ADXL372_INT1_MAP, int1_bitmask);
462 	if (ret < 0)
463 		return ret;
464 
465 	return regmap_write(st->regmap, ADXL372_INT2_MAP, int2_bitmask);
466 }
467 
468 static int adxl372_configure_fifo(struct adxl372_state *st)
469 {
470 	unsigned int fifo_samples, fifo_ctl;
471 	int ret;
472 
473 	/* FIFO must be configured while in standby mode */
474 	ret = adxl372_set_op_mode(st, ADXL372_STANDBY);
475 	if (ret < 0)
476 		return ret;
477 
478 	/*
479 	 * watermark stores the number of sets; we need to write the FIFO
480 	 * registers with the number of samples
481 	 */
482 	fifo_samples = (st->watermark * st->fifo_set_size);
483 	fifo_ctl = ADXL372_FIFO_CTL_FORMAT_MODE(st->fifo_format) |
484 		   ADXL372_FIFO_CTL_MODE_MODE(st->fifo_mode) |
485 		   ADXL372_FIFO_CTL_SAMPLES_MODE(fifo_samples);
486 
487 	ret = regmap_write(st->regmap,
488 			   ADXL372_FIFO_SAMPLES, fifo_samples & 0xFF);
489 	if (ret < 0)
490 		return ret;
491 
492 	ret = regmap_write(st->regmap, ADXL372_FIFO_CTL, fifo_ctl);
493 	if (ret < 0)
494 		return ret;
495 
496 	return adxl372_set_op_mode(st, ADXL372_FULL_BW_MEASUREMENT);
497 }
498 
499 static int adxl372_get_status(struct adxl372_state *st,
500 			      u8 *status1, u8 *status2,
501 			      u16 *fifo_entries)
502 {
503 	__be32 buf;
504 	u32 val;
505 	int ret;
506 
507 	/* STATUS1, STATUS2, FIFO_ENTRIES2 and FIFO_ENTRIES are adjacent regs */
508 	ret = regmap_bulk_read(st->regmap, ADXL372_STATUS_1,
509 			       &buf, sizeof(buf));
510 	if (ret < 0)
511 		return ret;
512 
513 	val = be32_to_cpu(buf);
514 
515 	*status1 = (val >> 24) & 0x0F;
516 	*status2 = (val >> 16) & 0x0F;
517 	/*
518 	 * FIFO_ENTRIES contains the least significant byte, and FIFO_ENTRIES2
519 	 * contains the two most significant bits
520 	 */
521 	*fifo_entries = val & 0x3FF;
522 
523 	return ret;
524 }
525 
526 static irqreturn_t adxl372_trigger_handler(int irq, void  *p)
527 {
528 	struct iio_poll_func *pf = p;
529 	struct iio_dev *indio_dev = pf->indio_dev;
530 	struct adxl372_state *st = iio_priv(indio_dev);
531 	u8 status1, status2;
532 	u16 fifo_entries;
533 	int i, ret;
534 
535 	ret = adxl372_get_status(st, &status1, &status2, &fifo_entries);
536 	if (ret < 0)
537 		goto err;
538 
539 	if (st->fifo_mode != ADXL372_FIFO_BYPASSED &&
540 	    ADXL372_STATUS_1_FIFO_FULL(status1)) {
541 		/*
542 		 * When reading data from multiple axes from the FIFO,
543 		 * to ensure that data is not overwritten and stored out
544 		 * of order at least one sample set must be left in the
545 		 * FIFO after every read.
546 		 */
547 		fifo_entries -= st->fifo_set_size;
548 
549 		/* Read data from the FIFO */
550 		ret = regmap_noinc_read(st->regmap, ADXL372_FIFO_DATA,
551 					st->fifo_buf,
552 					fifo_entries * sizeof(u16));
553 		if (ret < 0)
554 			goto err;
555 
556 		/* Each sample is 2 bytes */
557 		for (i = 0; i < fifo_entries; i += st->fifo_set_size)
558 			iio_push_to_buffers(indio_dev, &st->fifo_buf[i]);
559 	}
560 err:
561 	iio_trigger_notify_done(indio_dev->trig);
562 	return IRQ_HANDLED;
563 }
564 
565 static int adxl372_setup(struct adxl372_state *st)
566 {
567 	unsigned int regval;
568 	int ret;
569 
570 	ret = regmap_read(st->regmap, ADXL372_DEVID, &regval);
571 	if (ret < 0)
572 		return ret;
573 
574 	if (regval != ADXL372_DEVID_VAL) {
575 		dev_err(st->dev, "Invalid chip id %x\n", regval);
576 		return -ENODEV;
577 	}
578 
579 	/*
580 	 * Perform a software reset to make sure the device is in a consistent
581 	 * state after start up.
582 	 */
583 	ret = regmap_write(st->regmap, ADXL372_RESET, ADXL372_RESET_CODE);
584 	if (ret < 0)
585 		return ret;
586 
587 	ret = adxl372_set_op_mode(st, ADXL372_STANDBY);
588 	if (ret < 0)
589 		return ret;
590 
591 	/* Set threshold for activity detection to 1g */
592 	ret = adxl372_set_activity_threshold(st, ADXL372_ACTIVITY,
593 					     true, true, 1000);
594 	if (ret < 0)
595 		return ret;
596 
597 	/* Set threshold for inactivity detection to 100mg */
598 	ret = adxl372_set_activity_threshold(st, ADXL372_INACTIVITY,
599 					     true, true, 100);
600 	if (ret < 0)
601 		return ret;
602 
603 	/* Set activity processing in Looped mode */
604 	ret = adxl372_set_act_proc_mode(st, ADXL372_LOOPED);
605 	if (ret < 0)
606 		return ret;
607 
608 	ret = adxl372_set_odr(st, ADXL372_ODR_6400HZ);
609 	if (ret < 0)
610 		return ret;
611 
612 	ret = adxl372_set_bandwidth(st, ADXL372_BW_3200HZ);
613 	if (ret < 0)
614 		return ret;
615 
616 	/* Set activity timer to 1ms */
617 	ret = adxl372_set_activity_time_ms(st, 1);
618 	if (ret < 0)
619 		return ret;
620 
621 	/* Set inactivity timer to 10s */
622 	ret = adxl372_set_inactivity_time_ms(st, 10000);
623 	if (ret < 0)
624 		return ret;
625 
626 	/* Set the mode of operation to full bandwidth measurement mode */
627 	return adxl372_set_op_mode(st, ADXL372_FULL_BW_MEASUREMENT);
628 }
629 
630 static int adxl372_reg_access(struct iio_dev *indio_dev,
631 			      unsigned int reg,
632 			      unsigned int writeval,
633 			      unsigned int *readval)
634 {
635 	struct adxl372_state *st = iio_priv(indio_dev);
636 
637 	if (readval)
638 		return regmap_read(st->regmap, reg, readval);
639 	else
640 		return regmap_write(st->regmap, reg, writeval);
641 }
642 
643 static int adxl372_read_raw(struct iio_dev *indio_dev,
644 			    struct iio_chan_spec const *chan,
645 			    int *val, int *val2, long info)
646 {
647 	struct adxl372_state *st = iio_priv(indio_dev);
648 	int ret;
649 
650 	switch (info) {
651 	case IIO_CHAN_INFO_RAW:
652 		ret = iio_device_claim_direct_mode(indio_dev);
653 		if (ret)
654 			return ret;
655 
656 		ret = adxl372_read_axis(st, chan->address);
657 		iio_device_release_direct_mode(indio_dev);
658 		if (ret < 0)
659 			return ret;
660 
661 		*val = sign_extend32(ret >> chan->scan_type.shift,
662 				     chan->scan_type.realbits - 1);
663 		return IIO_VAL_INT;
664 	case IIO_CHAN_INFO_SCALE:
665 		*val = 0;
666 		*val2 = ADXL372_USCALE;
667 		return IIO_VAL_INT_PLUS_MICRO;
668 	case IIO_CHAN_INFO_SAMP_FREQ:
669 		*val = adxl372_samp_freq_tbl[st->odr];
670 		return IIO_VAL_INT;
671 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
672 		*val = adxl372_bw_freq_tbl[st->bw];
673 		return IIO_VAL_INT;
674 	}
675 
676 	return -EINVAL;
677 }
678 
679 static int adxl372_write_raw(struct iio_dev *indio_dev,
680 			     struct iio_chan_spec const *chan,
681 			     int val, int val2, long info)
682 {
683 	struct adxl372_state *st = iio_priv(indio_dev);
684 	int odr_index, bw_index, ret;
685 
686 	switch (info) {
687 	case IIO_CHAN_INFO_SAMP_FREQ:
688 		odr_index = adxl372_find_closest_match(adxl372_samp_freq_tbl,
689 					ARRAY_SIZE(adxl372_samp_freq_tbl),
690 					val);
691 		ret = adxl372_set_odr(st, odr_index);
692 		if (ret < 0)
693 			return ret;
694 		/*
695 		 * The timer period depends on the ODR selected.
696 		 * At 3200 Hz and below, it is 6.6 ms; at 6400 Hz, it is 3.3 ms
697 		 */
698 		ret = adxl372_set_activity_time_ms(st, st->act_time_ms);
699 		if (ret < 0)
700 			return ret;
701 		/*
702 		 * The timer period depends on the ODR selected.
703 		 * At 3200 Hz and below, it is 26 ms; at 6400 Hz, it is 13 ms
704 		 */
705 		ret = adxl372_set_inactivity_time_ms(st, st->inact_time_ms);
706 		if (ret < 0)
707 			return ret;
708 		/*
709 		 * The maximum bandwidth is constrained to at most half of
710 		 * the ODR to ensure that the Nyquist criteria is not violated
711 		 */
712 		if (st->bw > odr_index)
713 			ret = adxl372_set_bandwidth(st, odr_index);
714 
715 		return ret;
716 	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
717 		bw_index = adxl372_find_closest_match(adxl372_bw_freq_tbl,
718 					ARRAY_SIZE(adxl372_bw_freq_tbl),
719 					val);
720 		return adxl372_set_bandwidth(st, bw_index);
721 	default:
722 		return -EINVAL;
723 	}
724 }
725 
726 static ssize_t adxl372_show_filter_freq_avail(struct device *dev,
727 					      struct device_attribute *attr,
728 					      char *buf)
729 {
730 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
731 	struct adxl372_state *st = iio_priv(indio_dev);
732 	int i;
733 	size_t len = 0;
734 
735 	for (i = 0; i <= st->odr; i++)
736 		len += scnprintf(buf + len, PAGE_SIZE - len,
737 				 "%d ", adxl372_bw_freq_tbl[i]);
738 
739 	buf[len - 1] = '\n';
740 
741 	return len;
742 }
743 
744 static ssize_t adxl372_get_fifo_enabled(struct device *dev,
745 					  struct device_attribute *attr,
746 					  char *buf)
747 {
748 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
749 	struct adxl372_state *st = iio_priv(indio_dev);
750 
751 	return sprintf(buf, "%d\n", st->fifo_mode);
752 }
753 
754 static ssize_t adxl372_get_fifo_watermark(struct device *dev,
755 					  struct device_attribute *attr,
756 					  char *buf)
757 {
758 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
759 	struct adxl372_state *st = iio_priv(indio_dev);
760 
761 	return sprintf(buf, "%d\n", st->watermark);
762 }
763 
764 static IIO_CONST_ATTR(hwfifo_watermark_min, "1");
765 static IIO_CONST_ATTR(hwfifo_watermark_max,
766 		      __stringify(ADXL372_FIFO_SIZE));
767 static IIO_DEVICE_ATTR(hwfifo_watermark, 0444,
768 		       adxl372_get_fifo_watermark, NULL, 0);
769 static IIO_DEVICE_ATTR(hwfifo_enabled, 0444,
770 		       adxl372_get_fifo_enabled, NULL, 0);
771 
772 static const struct attribute *adxl372_fifo_attributes[] = {
773 	&iio_const_attr_hwfifo_watermark_min.dev_attr.attr,
774 	&iio_const_attr_hwfifo_watermark_max.dev_attr.attr,
775 	&iio_dev_attr_hwfifo_watermark.dev_attr.attr,
776 	&iio_dev_attr_hwfifo_enabled.dev_attr.attr,
777 	NULL,
778 };
779 
780 static int adxl372_set_watermark(struct iio_dev *indio_dev, unsigned int val)
781 {
782 	struct adxl372_state *st  = iio_priv(indio_dev);
783 
784 	if (val > ADXL372_FIFO_SIZE)
785 		val = ADXL372_FIFO_SIZE;
786 
787 	st->watermark = val;
788 
789 	return 0;
790 }
791 
792 static int adxl372_buffer_postenable(struct iio_dev *indio_dev)
793 {
794 	struct adxl372_state *st = iio_priv(indio_dev);
795 	unsigned int mask;
796 	int i, ret;
797 
798 	ret = adxl372_set_interrupts(st, ADXL372_INT1_MAP_FIFO_FULL_MSK, 0);
799 	if (ret < 0)
800 		return ret;
801 
802 	mask = *indio_dev->active_scan_mask;
803 
804 	for (i = 0; i < ARRAY_SIZE(adxl372_axis_lookup_table); i++) {
805 		if (mask == adxl372_axis_lookup_table[i].bits)
806 			break;
807 	}
808 
809 	if (i == ARRAY_SIZE(adxl372_axis_lookup_table))
810 		return -EINVAL;
811 
812 	st->fifo_format = adxl372_axis_lookup_table[i].fifo_format;
813 	st->fifo_set_size = bitmap_weight(indio_dev->active_scan_mask,
814 					  indio_dev->masklength);
815 	/*
816 	 * The 512 FIFO samples can be allotted in several ways, such as:
817 	 * 170 sample sets of concurrent 3-axis data
818 	 * 256 sample sets of concurrent 2-axis data (user selectable)
819 	 * 512 sample sets of single-axis data
820 	 */
821 	if ((st->watermark * st->fifo_set_size) > ADXL372_FIFO_SIZE)
822 		st->watermark = (ADXL372_FIFO_SIZE  / st->fifo_set_size);
823 
824 	st->fifo_mode = ADXL372_FIFO_STREAMED;
825 
826 	ret = adxl372_configure_fifo(st);
827 	if (ret < 0) {
828 		st->fifo_mode = ADXL372_FIFO_BYPASSED;
829 		adxl372_set_interrupts(st, 0, 0);
830 		return ret;
831 	}
832 
833 	return 0;
834 }
835 
836 static int adxl372_buffer_predisable(struct iio_dev *indio_dev)
837 {
838 	struct adxl372_state *st = iio_priv(indio_dev);
839 
840 	adxl372_set_interrupts(st, 0, 0);
841 	st->fifo_mode = ADXL372_FIFO_BYPASSED;
842 	adxl372_configure_fifo(st);
843 
844 	return 0;
845 }
846 
847 static const struct iio_buffer_setup_ops adxl372_buffer_ops = {
848 	.postenable = adxl372_buffer_postenable,
849 	.predisable = adxl372_buffer_predisable,
850 };
851 
852 static int adxl372_dready_trig_set_state(struct iio_trigger *trig,
853 					 bool state)
854 {
855 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
856 	struct adxl372_state *st = iio_priv(indio_dev);
857 	unsigned long int mask = 0;
858 
859 	if (state)
860 		mask = ADXL372_INT1_MAP_FIFO_FULL_MSK;
861 
862 	return adxl372_set_interrupts(st, mask, 0);
863 }
864 
865 static int adxl372_validate_trigger(struct iio_dev *indio_dev,
866 				    struct iio_trigger *trig)
867 {
868 	struct adxl372_state *st = iio_priv(indio_dev);
869 
870 	if (st->dready_trig != trig)
871 		return -EINVAL;
872 
873 	return 0;
874 }
875 
876 static const struct iio_trigger_ops adxl372_trigger_ops = {
877 	.validate_device = &iio_trigger_validate_own_device,
878 	.set_trigger_state = adxl372_dready_trig_set_state,
879 };
880 
881 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("400 800 1600 3200 6400");
882 static IIO_DEVICE_ATTR(in_accel_filter_low_pass_3db_frequency_available,
883 		       0444, adxl372_show_filter_freq_avail, NULL, 0);
884 
885 static struct attribute *adxl372_attributes[] = {
886 	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
887 	&iio_dev_attr_in_accel_filter_low_pass_3db_frequency_available.dev_attr.attr,
888 	NULL,
889 };
890 
891 static const struct attribute_group adxl372_attrs_group = {
892 	.attrs = adxl372_attributes,
893 };
894 
895 static const struct iio_info adxl372_info = {
896 	.validate_trigger = &adxl372_validate_trigger,
897 	.attrs = &adxl372_attrs_group,
898 	.read_raw = adxl372_read_raw,
899 	.write_raw = adxl372_write_raw,
900 	.debugfs_reg_access = &adxl372_reg_access,
901 	.hwfifo_set_watermark = adxl372_set_watermark,
902 };
903 
904 bool adxl372_readable_noinc_reg(struct device *dev, unsigned int reg)
905 {
906 	return (reg == ADXL372_FIFO_DATA);
907 }
908 EXPORT_SYMBOL_GPL(adxl372_readable_noinc_reg);
909 
910 int adxl372_probe(struct device *dev, struct regmap *regmap,
911 		  int irq, const char *name)
912 {
913 	struct iio_dev *indio_dev;
914 	struct adxl372_state *st;
915 	int ret;
916 
917 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
918 	if (!indio_dev)
919 		return -ENOMEM;
920 
921 	st = iio_priv(indio_dev);
922 	dev_set_drvdata(dev, indio_dev);
923 
924 	st->dev = dev;
925 	st->regmap = regmap;
926 	st->irq = irq;
927 
928 	indio_dev->channels = adxl372_channels;
929 	indio_dev->num_channels = ARRAY_SIZE(adxl372_channels);
930 	indio_dev->available_scan_masks = adxl372_channel_masks;
931 	indio_dev->name = name;
932 	indio_dev->info = &adxl372_info;
933 	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
934 
935 	ret = adxl372_setup(st);
936 	if (ret < 0) {
937 		dev_err(dev, "ADXL372 setup failed\n");
938 		return ret;
939 	}
940 
941 	ret = devm_iio_triggered_buffer_setup(dev,
942 					      indio_dev, NULL,
943 					      adxl372_trigger_handler,
944 					      &adxl372_buffer_ops);
945 	if (ret < 0)
946 		return ret;
947 
948 	iio_buffer_set_attrs(indio_dev->buffer, adxl372_fifo_attributes);
949 
950 	if (st->irq) {
951 		st->dready_trig = devm_iio_trigger_alloc(dev,
952 							 "%s-dev%d",
953 							 indio_dev->name,
954 							 indio_dev->id);
955 		if (st->dready_trig == NULL)
956 			return -ENOMEM;
957 
958 		st->dready_trig->ops = &adxl372_trigger_ops;
959 		st->dready_trig->dev.parent = dev;
960 		iio_trigger_set_drvdata(st->dready_trig, indio_dev);
961 		ret = devm_iio_trigger_register(dev, st->dready_trig);
962 		if (ret < 0)
963 			return ret;
964 
965 		indio_dev->trig = iio_trigger_get(st->dready_trig);
966 
967 		ret = devm_request_threaded_irq(dev, st->irq,
968 					iio_trigger_generic_data_rdy_poll,
969 					NULL,
970 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
971 					indio_dev->name, st->dready_trig);
972 		if (ret < 0)
973 			return ret;
974 	}
975 
976 	return devm_iio_device_register(dev, indio_dev);
977 }
978 EXPORT_SYMBOL_GPL(adxl372_probe);
979 
980 MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
981 MODULE_DESCRIPTION("Analog Devices ADXL372 3-axis accelerometer driver");
982 MODULE_LICENSE("GPL");
983