1 /*
2  * Bosch BMC150 three-axis magnetic field sensor driver
3  *
4  * Copyright (c) 2015, Intel Corporation.
5  *
6  * This code is based on bmm050_api.c authored by contact@bosch.sensortec.com:
7  *
8  * (C) Copyright 2011~2014 Bosch Sensortec GmbH All Rights Reserved
9  *
10  * This program is free software; you can redistribute it and/or modify it
11  * under the terms and conditions of the GNU General Public License,
12  * version 2, as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope it will be useful, but WITHOUT
15  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
16  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
17  * more details.
18  */
19 
20 #include <linux/module.h>
21 #include <linux/i2c.h>
22 #include <linux/interrupt.h>
23 #include <linux/delay.h>
24 #include <linux/slab.h>
25 #include <linux/acpi.h>
26 #include <linux/pm.h>
27 #include <linux/pm_runtime.h>
28 #include <linux/iio/iio.h>
29 #include <linux/iio/sysfs.h>
30 #include <linux/iio/buffer.h>
31 #include <linux/iio/events.h>
32 #include <linux/iio/trigger.h>
33 #include <linux/iio/trigger_consumer.h>
34 #include <linux/iio/triggered_buffer.h>
35 #include <linux/regmap.h>
36 
37 #include "bmc150_magn.h"
38 
39 #define BMC150_MAGN_DRV_NAME			"bmc150_magn"
40 #define BMC150_MAGN_IRQ_NAME			"bmc150_magn_event"
41 
42 #define BMC150_MAGN_REG_CHIP_ID			0x40
43 #define BMC150_MAGN_CHIP_ID_VAL			0x32
44 
45 #define BMC150_MAGN_REG_X_L			0x42
46 #define BMC150_MAGN_REG_X_M			0x43
47 #define BMC150_MAGN_REG_Y_L			0x44
48 #define BMC150_MAGN_REG_Y_M			0x45
49 #define BMC150_MAGN_SHIFT_XY_L			3
50 #define BMC150_MAGN_REG_Z_L			0x46
51 #define BMC150_MAGN_REG_Z_M			0x47
52 #define BMC150_MAGN_SHIFT_Z_L			1
53 #define BMC150_MAGN_REG_RHALL_L			0x48
54 #define BMC150_MAGN_REG_RHALL_M			0x49
55 #define BMC150_MAGN_SHIFT_RHALL_L		2
56 
57 #define BMC150_MAGN_REG_INT_STATUS		0x4A
58 
59 #define BMC150_MAGN_REG_POWER			0x4B
60 #define BMC150_MAGN_MASK_POWER_CTL		BIT(0)
61 
62 #define BMC150_MAGN_REG_OPMODE_ODR		0x4C
63 #define BMC150_MAGN_MASK_OPMODE			GENMASK(2, 1)
64 #define BMC150_MAGN_SHIFT_OPMODE		1
65 #define BMC150_MAGN_MODE_NORMAL			0x00
66 #define BMC150_MAGN_MODE_FORCED			0x01
67 #define BMC150_MAGN_MODE_SLEEP			0x03
68 #define BMC150_MAGN_MASK_ODR			GENMASK(5, 3)
69 #define BMC150_MAGN_SHIFT_ODR			3
70 
71 #define BMC150_MAGN_REG_INT			0x4D
72 
73 #define BMC150_MAGN_REG_INT_DRDY		0x4E
74 #define BMC150_MAGN_MASK_DRDY_EN		BIT(7)
75 #define BMC150_MAGN_SHIFT_DRDY_EN		7
76 #define BMC150_MAGN_MASK_DRDY_INT3		BIT(6)
77 #define BMC150_MAGN_MASK_DRDY_Z_EN		BIT(5)
78 #define BMC150_MAGN_MASK_DRDY_Y_EN		BIT(4)
79 #define BMC150_MAGN_MASK_DRDY_X_EN		BIT(3)
80 #define BMC150_MAGN_MASK_DRDY_DR_POLARITY	BIT(2)
81 #define BMC150_MAGN_MASK_DRDY_LATCHING		BIT(1)
82 #define BMC150_MAGN_MASK_DRDY_INT3_POLARITY	BIT(0)
83 
84 #define BMC150_MAGN_REG_LOW_THRESH		0x4F
85 #define BMC150_MAGN_REG_HIGH_THRESH		0x50
86 #define BMC150_MAGN_REG_REP_XY			0x51
87 #define BMC150_MAGN_REG_REP_Z			0x52
88 #define BMC150_MAGN_REG_REP_DATAMASK		GENMASK(7, 0)
89 
90 #define BMC150_MAGN_REG_TRIM_START		0x5D
91 #define BMC150_MAGN_REG_TRIM_END		0x71
92 
93 #define BMC150_MAGN_XY_OVERFLOW_VAL		-4096
94 #define BMC150_MAGN_Z_OVERFLOW_VAL		-16384
95 
96 /* Time from SUSPEND to SLEEP */
97 #define BMC150_MAGN_START_UP_TIME_MS		3
98 
99 #define BMC150_MAGN_AUTO_SUSPEND_DELAY_MS	2000
100 
101 #define BMC150_MAGN_REGVAL_TO_REPXY(regval) (((regval) * 2) + 1)
102 #define BMC150_MAGN_REGVAL_TO_REPZ(regval) ((regval) + 1)
103 #define BMC150_MAGN_REPXY_TO_REGVAL(rep) (((rep) - 1) / 2)
104 #define BMC150_MAGN_REPZ_TO_REGVAL(rep) ((rep) - 1)
105 
106 enum bmc150_magn_axis {
107 	AXIS_X,
108 	AXIS_Y,
109 	AXIS_Z,
110 	RHALL,
111 	AXIS_XYZ_MAX = RHALL,
112 	AXIS_XYZR_MAX,
113 };
114 
115 enum bmc150_magn_power_modes {
116 	BMC150_MAGN_POWER_MODE_SUSPEND,
117 	BMC150_MAGN_POWER_MODE_SLEEP,
118 	BMC150_MAGN_POWER_MODE_NORMAL,
119 };
120 
121 struct bmc150_magn_trim_regs {
122 	s8 x1;
123 	s8 y1;
124 	__le16 reserved1;
125 	u8 reserved2;
126 	__le16 z4;
127 	s8 x2;
128 	s8 y2;
129 	__le16 reserved3;
130 	__le16 z2;
131 	__le16 z1;
132 	__le16 xyz1;
133 	__le16 z3;
134 	s8 xy2;
135 	u8 xy1;
136 } __packed;
137 
138 struct bmc150_magn_data {
139 	struct device *dev;
140 	/*
141 	 * 1. Protect this structure.
142 	 * 2. Serialize sequences that power on/off the device and access HW.
143 	 */
144 	struct mutex mutex;
145 	struct regmap *regmap;
146 	/* 4 x 32 bits for x, y z, 4 bytes align, 64 bits timestamp */
147 	s32 buffer[6];
148 	struct iio_trigger *dready_trig;
149 	bool dready_trigger_on;
150 	int max_odr;
151 	int irq;
152 };
153 
154 static const struct {
155 	int freq;
156 	u8 reg_val;
157 } bmc150_magn_samp_freq_table[] = { {2, 0x01},
158 				    {6, 0x02},
159 				    {8, 0x03},
160 				    {10, 0x00},
161 				    {15, 0x04},
162 				    {20, 0x05},
163 				    {25, 0x06},
164 				    {30, 0x07} };
165 
166 enum bmc150_magn_presets {
167 	LOW_POWER_PRESET,
168 	REGULAR_PRESET,
169 	ENHANCED_REGULAR_PRESET,
170 	HIGH_ACCURACY_PRESET
171 };
172 
173 static const struct bmc150_magn_preset {
174 	u8 rep_xy;
175 	u8 rep_z;
176 	u8 odr;
177 } bmc150_magn_presets_table[] = {
178 	[LOW_POWER_PRESET] = {3, 3, 10},
179 	[REGULAR_PRESET] =  {9, 15, 10},
180 	[ENHANCED_REGULAR_PRESET] =  {15, 27, 10},
181 	[HIGH_ACCURACY_PRESET] =  {47, 83, 20},
182 };
183 
184 #define BMC150_MAGN_DEFAULT_PRESET REGULAR_PRESET
185 
bmc150_magn_is_writeable_reg(struct device * dev,unsigned int reg)186 static bool bmc150_magn_is_writeable_reg(struct device *dev, unsigned int reg)
187 {
188 	switch (reg) {
189 	case BMC150_MAGN_REG_POWER:
190 	case BMC150_MAGN_REG_OPMODE_ODR:
191 	case BMC150_MAGN_REG_INT:
192 	case BMC150_MAGN_REG_INT_DRDY:
193 	case BMC150_MAGN_REG_LOW_THRESH:
194 	case BMC150_MAGN_REG_HIGH_THRESH:
195 	case BMC150_MAGN_REG_REP_XY:
196 	case BMC150_MAGN_REG_REP_Z:
197 		return true;
198 	default:
199 		return false;
200 	};
201 }
202 
bmc150_magn_is_volatile_reg(struct device * dev,unsigned int reg)203 static bool bmc150_magn_is_volatile_reg(struct device *dev, unsigned int reg)
204 {
205 	switch (reg) {
206 	case BMC150_MAGN_REG_X_L:
207 	case BMC150_MAGN_REG_X_M:
208 	case BMC150_MAGN_REG_Y_L:
209 	case BMC150_MAGN_REG_Y_M:
210 	case BMC150_MAGN_REG_Z_L:
211 	case BMC150_MAGN_REG_Z_M:
212 	case BMC150_MAGN_REG_RHALL_L:
213 	case BMC150_MAGN_REG_RHALL_M:
214 	case BMC150_MAGN_REG_INT_STATUS:
215 		return true;
216 	default:
217 		return false;
218 	}
219 }
220 
221 const struct regmap_config bmc150_magn_regmap_config = {
222 	.reg_bits = 8,
223 	.val_bits = 8,
224 
225 	.max_register = BMC150_MAGN_REG_TRIM_END,
226 	.cache_type = REGCACHE_RBTREE,
227 
228 	.writeable_reg = bmc150_magn_is_writeable_reg,
229 	.volatile_reg = bmc150_magn_is_volatile_reg,
230 };
231 EXPORT_SYMBOL(bmc150_magn_regmap_config);
232 
bmc150_magn_set_power_mode(struct bmc150_magn_data * data,enum bmc150_magn_power_modes mode,bool state)233 static int bmc150_magn_set_power_mode(struct bmc150_magn_data *data,
234 				      enum bmc150_magn_power_modes mode,
235 				      bool state)
236 {
237 	int ret;
238 
239 	switch (mode) {
240 	case BMC150_MAGN_POWER_MODE_SUSPEND:
241 		ret = regmap_update_bits(data->regmap, BMC150_MAGN_REG_POWER,
242 					 BMC150_MAGN_MASK_POWER_CTL, !state);
243 		if (ret < 0)
244 			return ret;
245 		usleep_range(BMC150_MAGN_START_UP_TIME_MS * 1000, 20000);
246 		return 0;
247 	case BMC150_MAGN_POWER_MODE_SLEEP:
248 		return regmap_update_bits(data->regmap,
249 					  BMC150_MAGN_REG_OPMODE_ODR,
250 					  BMC150_MAGN_MASK_OPMODE,
251 					  BMC150_MAGN_MODE_SLEEP <<
252 					  BMC150_MAGN_SHIFT_OPMODE);
253 	case BMC150_MAGN_POWER_MODE_NORMAL:
254 		return regmap_update_bits(data->regmap,
255 					  BMC150_MAGN_REG_OPMODE_ODR,
256 					  BMC150_MAGN_MASK_OPMODE,
257 					  BMC150_MAGN_MODE_NORMAL <<
258 					  BMC150_MAGN_SHIFT_OPMODE);
259 	}
260 
261 	return -EINVAL;
262 }
263 
bmc150_magn_set_power_state(struct bmc150_magn_data * data,bool on)264 static int bmc150_magn_set_power_state(struct bmc150_magn_data *data, bool on)
265 {
266 #ifdef CONFIG_PM
267 	int ret;
268 
269 	if (on) {
270 		ret = pm_runtime_get_sync(data->dev);
271 	} else {
272 		pm_runtime_mark_last_busy(data->dev);
273 		ret = pm_runtime_put_autosuspend(data->dev);
274 	}
275 
276 	if (ret < 0) {
277 		dev_err(data->dev,
278 			"failed to change power state to %d\n", on);
279 		if (on)
280 			pm_runtime_put_noidle(data->dev);
281 
282 		return ret;
283 	}
284 #endif
285 
286 	return 0;
287 }
288 
bmc150_magn_get_odr(struct bmc150_magn_data * data,int * val)289 static int bmc150_magn_get_odr(struct bmc150_magn_data *data, int *val)
290 {
291 	int ret, reg_val;
292 	u8 i, odr_val;
293 
294 	ret = regmap_read(data->regmap, BMC150_MAGN_REG_OPMODE_ODR, &reg_val);
295 	if (ret < 0)
296 		return ret;
297 	odr_val = (reg_val & BMC150_MAGN_MASK_ODR) >> BMC150_MAGN_SHIFT_ODR;
298 
299 	for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++)
300 		if (bmc150_magn_samp_freq_table[i].reg_val == odr_val) {
301 			*val = bmc150_magn_samp_freq_table[i].freq;
302 			return 0;
303 		}
304 
305 	return -EINVAL;
306 }
307 
bmc150_magn_set_odr(struct bmc150_magn_data * data,int val)308 static int bmc150_magn_set_odr(struct bmc150_magn_data *data, int val)
309 {
310 	int ret;
311 	u8 i;
312 
313 	for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++) {
314 		if (bmc150_magn_samp_freq_table[i].freq == val) {
315 			ret = regmap_update_bits(data->regmap,
316 						 BMC150_MAGN_REG_OPMODE_ODR,
317 						 BMC150_MAGN_MASK_ODR,
318 						 bmc150_magn_samp_freq_table[i].
319 						 reg_val <<
320 						 BMC150_MAGN_SHIFT_ODR);
321 			if (ret < 0)
322 				return ret;
323 			return 0;
324 		}
325 	}
326 
327 	return -EINVAL;
328 }
329 
bmc150_magn_set_max_odr(struct bmc150_magn_data * data,int rep_xy,int rep_z,int odr)330 static int bmc150_magn_set_max_odr(struct bmc150_magn_data *data, int rep_xy,
331 				   int rep_z, int odr)
332 {
333 	int ret, reg_val, max_odr;
334 
335 	if (rep_xy <= 0) {
336 		ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_XY,
337 				  &reg_val);
338 		if (ret < 0)
339 			return ret;
340 		rep_xy = BMC150_MAGN_REGVAL_TO_REPXY(reg_val);
341 	}
342 	if (rep_z <= 0) {
343 		ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_Z,
344 				  &reg_val);
345 		if (ret < 0)
346 			return ret;
347 		rep_z = BMC150_MAGN_REGVAL_TO_REPZ(reg_val);
348 	}
349 	if (odr <= 0) {
350 		ret = bmc150_magn_get_odr(data, &odr);
351 		if (ret < 0)
352 			return ret;
353 	}
354 	/* the maximum selectable read-out frequency from datasheet */
355 	max_odr = 1000000 / (145 * rep_xy + 500 * rep_z + 980);
356 	if (odr > max_odr) {
357 		dev_err(data->dev,
358 			"Can't set oversampling with sampling freq %d\n",
359 			odr);
360 		return -EINVAL;
361 	}
362 	data->max_odr = max_odr;
363 
364 	return 0;
365 }
366 
bmc150_magn_compensate_x(struct bmc150_magn_trim_regs * tregs,s16 x,u16 rhall)367 static s32 bmc150_magn_compensate_x(struct bmc150_magn_trim_regs *tregs, s16 x,
368 				    u16 rhall)
369 {
370 	s16 val;
371 	u16 xyz1 = le16_to_cpu(tregs->xyz1);
372 
373 	if (x == BMC150_MAGN_XY_OVERFLOW_VAL)
374 		return S32_MIN;
375 
376 	if (!rhall)
377 		rhall = xyz1;
378 
379 	val = ((s16)(((u16)((((s32)xyz1) << 14) / rhall)) - ((u16)0x4000)));
380 	val = ((s16)((((s32)x) * ((((((((s32)tregs->xy2) * ((((s32)val) *
381 	      ((s32)val)) >> 7)) + (((s32)val) *
382 	      ((s32)(((s16)tregs->xy1) << 7)))) >> 9) + ((s32)0x100000)) *
383 	      ((s32)(((s16)tregs->x2) + ((s16)0xA0)))) >> 12)) >> 13)) +
384 	      (((s16)tregs->x1) << 3);
385 
386 	return (s32)val;
387 }
388 
bmc150_magn_compensate_y(struct bmc150_magn_trim_regs * tregs,s16 y,u16 rhall)389 static s32 bmc150_magn_compensate_y(struct bmc150_magn_trim_regs *tregs, s16 y,
390 				    u16 rhall)
391 {
392 	s16 val;
393 	u16 xyz1 = le16_to_cpu(tregs->xyz1);
394 
395 	if (y == BMC150_MAGN_XY_OVERFLOW_VAL)
396 		return S32_MIN;
397 
398 	if (!rhall)
399 		rhall = xyz1;
400 
401 	val = ((s16)(((u16)((((s32)xyz1) << 14) / rhall)) - ((u16)0x4000)));
402 	val = ((s16)((((s32)y) * ((((((((s32)tregs->xy2) * ((((s32)val) *
403 	      ((s32)val)) >> 7)) + (((s32)val) *
404 	      ((s32)(((s16)tregs->xy1) << 7)))) >> 9) + ((s32)0x100000)) *
405 	      ((s32)(((s16)tregs->y2) + ((s16)0xA0)))) >> 12)) >> 13)) +
406 	      (((s16)tregs->y1) << 3);
407 
408 	return (s32)val;
409 }
410 
bmc150_magn_compensate_z(struct bmc150_magn_trim_regs * tregs,s16 z,u16 rhall)411 static s32 bmc150_magn_compensate_z(struct bmc150_magn_trim_regs *tregs, s16 z,
412 				    u16 rhall)
413 {
414 	s32 val;
415 	u16 xyz1 = le16_to_cpu(tregs->xyz1);
416 	u16 z1 = le16_to_cpu(tregs->z1);
417 	s16 z2 = le16_to_cpu(tregs->z2);
418 	s16 z3 = le16_to_cpu(tregs->z3);
419 	s16 z4 = le16_to_cpu(tregs->z4);
420 
421 	if (z == BMC150_MAGN_Z_OVERFLOW_VAL)
422 		return S32_MIN;
423 
424 	val = (((((s32)(z - z4)) << 15) - ((((s32)z3) * ((s32)(((s16)rhall) -
425 	      ((s16)xyz1)))) >> 2)) / (z2 + ((s16)(((((s32)z1) *
426 	      ((((s16)rhall) << 1))) + (1 << 15)) >> 16))));
427 
428 	return val;
429 }
430 
bmc150_magn_read_xyz(struct bmc150_magn_data * data,s32 * buffer)431 static int bmc150_magn_read_xyz(struct bmc150_magn_data *data, s32 *buffer)
432 {
433 	int ret;
434 	__le16 values[AXIS_XYZR_MAX];
435 	s16 raw_x, raw_y, raw_z;
436 	u16 rhall;
437 	struct bmc150_magn_trim_regs tregs;
438 
439 	ret = regmap_bulk_read(data->regmap, BMC150_MAGN_REG_X_L,
440 			       values, sizeof(values));
441 	if (ret < 0)
442 		return ret;
443 
444 	raw_x = (s16)le16_to_cpu(values[AXIS_X]) >> BMC150_MAGN_SHIFT_XY_L;
445 	raw_y = (s16)le16_to_cpu(values[AXIS_Y]) >> BMC150_MAGN_SHIFT_XY_L;
446 	raw_z = (s16)le16_to_cpu(values[AXIS_Z]) >> BMC150_MAGN_SHIFT_Z_L;
447 	rhall = le16_to_cpu(values[RHALL]) >> BMC150_MAGN_SHIFT_RHALL_L;
448 
449 	ret = regmap_bulk_read(data->regmap, BMC150_MAGN_REG_TRIM_START,
450 			       &tregs, sizeof(tregs));
451 	if (ret < 0)
452 		return ret;
453 
454 	buffer[AXIS_X] = bmc150_magn_compensate_x(&tregs, raw_x, rhall);
455 	buffer[AXIS_Y] = bmc150_magn_compensate_y(&tregs, raw_y, rhall);
456 	buffer[AXIS_Z] = bmc150_magn_compensate_z(&tregs, raw_z, rhall);
457 
458 	return 0;
459 }
460 
bmc150_magn_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)461 static int bmc150_magn_read_raw(struct iio_dev *indio_dev,
462 				struct iio_chan_spec const *chan,
463 				int *val, int *val2, long mask)
464 {
465 	struct bmc150_magn_data *data = iio_priv(indio_dev);
466 	int ret, tmp;
467 	s32 values[AXIS_XYZ_MAX];
468 
469 	switch (mask) {
470 	case IIO_CHAN_INFO_RAW:
471 		if (iio_buffer_enabled(indio_dev))
472 			return -EBUSY;
473 		mutex_lock(&data->mutex);
474 
475 		ret = bmc150_magn_set_power_state(data, true);
476 		if (ret < 0) {
477 			mutex_unlock(&data->mutex);
478 			return ret;
479 		}
480 
481 		ret = bmc150_magn_read_xyz(data, values);
482 		if (ret < 0) {
483 			bmc150_magn_set_power_state(data, false);
484 			mutex_unlock(&data->mutex);
485 			return ret;
486 		}
487 		*val = values[chan->scan_index];
488 
489 		ret = bmc150_magn_set_power_state(data, false);
490 		if (ret < 0) {
491 			mutex_unlock(&data->mutex);
492 			return ret;
493 		}
494 
495 		mutex_unlock(&data->mutex);
496 		return IIO_VAL_INT;
497 	case IIO_CHAN_INFO_SCALE:
498 		/*
499 		 * The API/driver performs an off-chip temperature
500 		 * compensation and outputs x/y/z magnetic field data in
501 		 * 16 LSB/uT to the upper application layer.
502 		 */
503 		*val = 0;
504 		*val2 = 625;
505 		return IIO_VAL_INT_PLUS_MICRO;
506 	case IIO_CHAN_INFO_SAMP_FREQ:
507 		ret = bmc150_magn_get_odr(data, val);
508 		if (ret < 0)
509 			return ret;
510 		return IIO_VAL_INT;
511 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
512 		switch (chan->channel2) {
513 		case IIO_MOD_X:
514 		case IIO_MOD_Y:
515 			ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_XY,
516 					  &tmp);
517 			if (ret < 0)
518 				return ret;
519 			*val = BMC150_MAGN_REGVAL_TO_REPXY(tmp);
520 			return IIO_VAL_INT;
521 		case IIO_MOD_Z:
522 			ret = regmap_read(data->regmap, BMC150_MAGN_REG_REP_Z,
523 					  &tmp);
524 			if (ret < 0)
525 				return ret;
526 			*val = BMC150_MAGN_REGVAL_TO_REPZ(tmp);
527 			return IIO_VAL_INT;
528 		default:
529 			return -EINVAL;
530 		}
531 	default:
532 		return -EINVAL;
533 	}
534 }
535 
bmc150_magn_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)536 static int bmc150_magn_write_raw(struct iio_dev *indio_dev,
537 				 struct iio_chan_spec const *chan,
538 				 int val, int val2, long mask)
539 {
540 	struct bmc150_magn_data *data = iio_priv(indio_dev);
541 	int ret;
542 
543 	switch (mask) {
544 	case IIO_CHAN_INFO_SAMP_FREQ:
545 		if (val > data->max_odr)
546 			return -EINVAL;
547 		mutex_lock(&data->mutex);
548 		ret = bmc150_magn_set_odr(data, val);
549 		mutex_unlock(&data->mutex);
550 		return ret;
551 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
552 		switch (chan->channel2) {
553 		case IIO_MOD_X:
554 		case IIO_MOD_Y:
555 			if (val < 1 || val > 511)
556 				return -EINVAL;
557 			mutex_lock(&data->mutex);
558 			ret = bmc150_magn_set_max_odr(data, val, 0, 0);
559 			if (ret < 0) {
560 				mutex_unlock(&data->mutex);
561 				return ret;
562 			}
563 			ret = regmap_update_bits(data->regmap,
564 						 BMC150_MAGN_REG_REP_XY,
565 						 BMC150_MAGN_REG_REP_DATAMASK,
566 						 BMC150_MAGN_REPXY_TO_REGVAL
567 						 (val));
568 			mutex_unlock(&data->mutex);
569 			return ret;
570 		case IIO_MOD_Z:
571 			if (val < 1 || val > 256)
572 				return -EINVAL;
573 			mutex_lock(&data->mutex);
574 			ret = bmc150_magn_set_max_odr(data, 0, val, 0);
575 			if (ret < 0) {
576 				mutex_unlock(&data->mutex);
577 				return ret;
578 			}
579 			ret = regmap_update_bits(data->regmap,
580 						 BMC150_MAGN_REG_REP_Z,
581 						 BMC150_MAGN_REG_REP_DATAMASK,
582 						 BMC150_MAGN_REPZ_TO_REGVAL
583 						 (val));
584 			mutex_unlock(&data->mutex);
585 			return ret;
586 		default:
587 			return -EINVAL;
588 		}
589 	default:
590 		return -EINVAL;
591 	}
592 }
593 
bmc150_magn_show_samp_freq_avail(struct device * dev,struct device_attribute * attr,char * buf)594 static ssize_t bmc150_magn_show_samp_freq_avail(struct device *dev,
595 						struct device_attribute *attr,
596 						char *buf)
597 {
598 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
599 	struct bmc150_magn_data *data = iio_priv(indio_dev);
600 	size_t len = 0;
601 	u8 i;
602 
603 	for (i = 0; i < ARRAY_SIZE(bmc150_magn_samp_freq_table); i++) {
604 		if (bmc150_magn_samp_freq_table[i].freq > data->max_odr)
605 			break;
606 		len += scnprintf(buf + len, PAGE_SIZE - len, "%d ",
607 				 bmc150_magn_samp_freq_table[i].freq);
608 	}
609 	/* replace last space with a newline */
610 	buf[len - 1] = '\n';
611 
612 	return len;
613 }
614 
615 static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(bmc150_magn_show_samp_freq_avail);
616 
617 static struct attribute *bmc150_magn_attributes[] = {
618 	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
619 	NULL,
620 };
621 
622 static const struct attribute_group bmc150_magn_attrs_group = {
623 	.attrs = bmc150_magn_attributes,
624 };
625 
626 #define BMC150_MAGN_CHANNEL(_axis) {					\
627 	.type = IIO_MAGN,						\
628 	.modified = 1,							\
629 	.channel2 = IIO_MOD_##_axis,					\
630 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |			\
631 			      BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
632 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SAMP_FREQ) |	\
633 				    BIT(IIO_CHAN_INFO_SCALE),		\
634 	.scan_index = AXIS_##_axis,					\
635 	.scan_type = {							\
636 		.sign = 's',						\
637 		.realbits = 32,						\
638 		.storagebits = 32,					\
639 		.endianness = IIO_LE					\
640 	},								\
641 }
642 
643 static const struct iio_chan_spec bmc150_magn_channels[] = {
644 	BMC150_MAGN_CHANNEL(X),
645 	BMC150_MAGN_CHANNEL(Y),
646 	BMC150_MAGN_CHANNEL(Z),
647 	IIO_CHAN_SOFT_TIMESTAMP(3),
648 };
649 
650 static const struct iio_info bmc150_magn_info = {
651 	.attrs = &bmc150_magn_attrs_group,
652 	.read_raw = bmc150_magn_read_raw,
653 	.write_raw = bmc150_magn_write_raw,
654 };
655 
656 static const unsigned long bmc150_magn_scan_masks[] = {
657 					BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
658 					0};
659 
bmc150_magn_trigger_handler(int irq,void * p)660 static irqreturn_t bmc150_magn_trigger_handler(int irq, void *p)
661 {
662 	struct iio_poll_func *pf = p;
663 	struct iio_dev *indio_dev = pf->indio_dev;
664 	struct bmc150_magn_data *data = iio_priv(indio_dev);
665 	int ret;
666 
667 	mutex_lock(&data->mutex);
668 	ret = bmc150_magn_read_xyz(data, data->buffer);
669 	if (ret < 0)
670 		goto err;
671 
672 	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
673 					   pf->timestamp);
674 
675 err:
676 	mutex_unlock(&data->mutex);
677 	iio_trigger_notify_done(indio_dev->trig);
678 
679 	return IRQ_HANDLED;
680 }
681 
bmc150_magn_init(struct bmc150_magn_data * data)682 static int bmc150_magn_init(struct bmc150_magn_data *data)
683 {
684 	int ret, chip_id;
685 	struct bmc150_magn_preset preset;
686 
687 	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND,
688 					 false);
689 	if (ret < 0) {
690 		dev_err(data->dev,
691 			"Failed to bring up device from suspend mode\n");
692 		return ret;
693 	}
694 
695 	ret = regmap_read(data->regmap, BMC150_MAGN_REG_CHIP_ID, &chip_id);
696 	if (ret < 0) {
697 		dev_err(data->dev, "Failed reading chip id\n");
698 		goto err_poweroff;
699 	}
700 	if (chip_id != BMC150_MAGN_CHIP_ID_VAL) {
701 		dev_err(data->dev, "Invalid chip id 0x%x\n", chip_id);
702 		ret = -ENODEV;
703 		goto err_poweroff;
704 	}
705 	dev_dbg(data->dev, "Chip id %x\n", chip_id);
706 
707 	preset = bmc150_magn_presets_table[BMC150_MAGN_DEFAULT_PRESET];
708 	ret = bmc150_magn_set_odr(data, preset.odr);
709 	if (ret < 0) {
710 		dev_err(data->dev, "Failed to set ODR to %d\n",
711 			preset.odr);
712 		goto err_poweroff;
713 	}
714 
715 	ret = regmap_write(data->regmap, BMC150_MAGN_REG_REP_XY,
716 			   BMC150_MAGN_REPXY_TO_REGVAL(preset.rep_xy));
717 	if (ret < 0) {
718 		dev_err(data->dev, "Failed to set REP XY to %d\n",
719 			preset.rep_xy);
720 		goto err_poweroff;
721 	}
722 
723 	ret = regmap_write(data->regmap, BMC150_MAGN_REG_REP_Z,
724 			   BMC150_MAGN_REPZ_TO_REGVAL(preset.rep_z));
725 	if (ret < 0) {
726 		dev_err(data->dev, "Failed to set REP Z to %d\n",
727 			preset.rep_z);
728 		goto err_poweroff;
729 	}
730 
731 	ret = bmc150_magn_set_max_odr(data, preset.rep_xy, preset.rep_z,
732 				      preset.odr);
733 	if (ret < 0)
734 		goto err_poweroff;
735 
736 	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
737 					 true);
738 	if (ret < 0) {
739 		dev_err(data->dev, "Failed to power on device\n");
740 		goto err_poweroff;
741 	}
742 
743 	return 0;
744 
745 err_poweroff:
746 	bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
747 	return ret;
748 }
749 
bmc150_magn_reset_intr(struct bmc150_magn_data * data)750 static int bmc150_magn_reset_intr(struct bmc150_magn_data *data)
751 {
752 	int tmp;
753 
754 	/*
755 	 * Data Ready (DRDY) is always cleared after
756 	 * readout of data registers ends.
757 	 */
758 	return regmap_read(data->regmap, BMC150_MAGN_REG_X_L, &tmp);
759 }
760 
bmc150_magn_trig_try_reen(struct iio_trigger * trig)761 static int bmc150_magn_trig_try_reen(struct iio_trigger *trig)
762 {
763 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
764 	struct bmc150_magn_data *data = iio_priv(indio_dev);
765 	int ret;
766 
767 	if (!data->dready_trigger_on)
768 		return 0;
769 
770 	mutex_lock(&data->mutex);
771 	ret = bmc150_magn_reset_intr(data);
772 	mutex_unlock(&data->mutex);
773 
774 	return ret;
775 }
776 
bmc150_magn_data_rdy_trigger_set_state(struct iio_trigger * trig,bool state)777 static int bmc150_magn_data_rdy_trigger_set_state(struct iio_trigger *trig,
778 						  bool state)
779 {
780 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
781 	struct bmc150_magn_data *data = iio_priv(indio_dev);
782 	int ret = 0;
783 
784 	mutex_lock(&data->mutex);
785 	if (state == data->dready_trigger_on)
786 		goto err_unlock;
787 
788 	ret = regmap_update_bits(data->regmap, BMC150_MAGN_REG_INT_DRDY,
789 				 BMC150_MAGN_MASK_DRDY_EN,
790 				 state << BMC150_MAGN_SHIFT_DRDY_EN);
791 	if (ret < 0)
792 		goto err_unlock;
793 
794 	data->dready_trigger_on = state;
795 
796 	if (state) {
797 		ret = bmc150_magn_reset_intr(data);
798 		if (ret < 0)
799 			goto err_unlock;
800 	}
801 	mutex_unlock(&data->mutex);
802 
803 	return 0;
804 
805 err_unlock:
806 	mutex_unlock(&data->mutex);
807 	return ret;
808 }
809 
810 static const struct iio_trigger_ops bmc150_magn_trigger_ops = {
811 	.set_trigger_state = bmc150_magn_data_rdy_trigger_set_state,
812 	.try_reenable = bmc150_magn_trig_try_reen,
813 };
814 
bmc150_magn_buffer_preenable(struct iio_dev * indio_dev)815 static int bmc150_magn_buffer_preenable(struct iio_dev *indio_dev)
816 {
817 	struct bmc150_magn_data *data = iio_priv(indio_dev);
818 
819 	return bmc150_magn_set_power_state(data, true);
820 }
821 
bmc150_magn_buffer_postdisable(struct iio_dev * indio_dev)822 static int bmc150_magn_buffer_postdisable(struct iio_dev *indio_dev)
823 {
824 	struct bmc150_magn_data *data = iio_priv(indio_dev);
825 
826 	return bmc150_magn_set_power_state(data, false);
827 }
828 
829 static const struct iio_buffer_setup_ops bmc150_magn_buffer_setup_ops = {
830 	.preenable = bmc150_magn_buffer_preenable,
831 	.postenable = iio_triggered_buffer_postenable,
832 	.predisable = iio_triggered_buffer_predisable,
833 	.postdisable = bmc150_magn_buffer_postdisable,
834 };
835 
bmc150_magn_match_acpi_device(struct device * dev)836 static const char *bmc150_magn_match_acpi_device(struct device *dev)
837 {
838 	const struct acpi_device_id *id;
839 
840 	id = acpi_match_device(dev->driver->acpi_match_table, dev);
841 	if (!id)
842 		return NULL;
843 
844 	return dev_name(dev);
845 }
846 
bmc150_magn_probe(struct device * dev,struct regmap * regmap,int irq,const char * name)847 int bmc150_magn_probe(struct device *dev, struct regmap *regmap,
848 		      int irq, const char *name)
849 {
850 	struct bmc150_magn_data *data;
851 	struct iio_dev *indio_dev;
852 	int ret;
853 
854 	indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
855 	if (!indio_dev)
856 		return -ENOMEM;
857 
858 	data = iio_priv(indio_dev);
859 	dev_set_drvdata(dev, indio_dev);
860 	data->regmap = regmap;
861 	data->irq = irq;
862 	data->dev = dev;
863 
864 	if (!name && ACPI_HANDLE(dev))
865 		name = bmc150_magn_match_acpi_device(dev);
866 
867 	mutex_init(&data->mutex);
868 
869 	ret = bmc150_magn_init(data);
870 	if (ret < 0)
871 		return ret;
872 
873 	indio_dev->dev.parent = dev;
874 	indio_dev->channels = bmc150_magn_channels;
875 	indio_dev->num_channels = ARRAY_SIZE(bmc150_magn_channels);
876 	indio_dev->available_scan_masks = bmc150_magn_scan_masks;
877 	indio_dev->name = name;
878 	indio_dev->modes = INDIO_DIRECT_MODE;
879 	indio_dev->info = &bmc150_magn_info;
880 
881 	if (irq > 0) {
882 		data->dready_trig = devm_iio_trigger_alloc(dev,
883 							   "%s-dev%d",
884 							   indio_dev->name,
885 							   indio_dev->id);
886 		if (!data->dready_trig) {
887 			ret = -ENOMEM;
888 			dev_err(dev, "iio trigger alloc failed\n");
889 			goto err_poweroff;
890 		}
891 
892 		data->dready_trig->dev.parent = dev;
893 		data->dready_trig->ops = &bmc150_magn_trigger_ops;
894 		iio_trigger_set_drvdata(data->dready_trig, indio_dev);
895 		ret = iio_trigger_register(data->dready_trig);
896 		if (ret) {
897 			dev_err(dev, "iio trigger register failed\n");
898 			goto err_poweroff;
899 		}
900 
901 		ret = request_threaded_irq(irq,
902 					   iio_trigger_generic_data_rdy_poll,
903 					   NULL,
904 					   IRQF_TRIGGER_RISING | IRQF_ONESHOT,
905 					   BMC150_MAGN_IRQ_NAME,
906 					   data->dready_trig);
907 		if (ret < 0) {
908 			dev_err(dev, "request irq %d failed\n", irq);
909 			goto err_trigger_unregister;
910 		}
911 	}
912 
913 	ret = iio_triggered_buffer_setup(indio_dev,
914 					 iio_pollfunc_store_time,
915 					 bmc150_magn_trigger_handler,
916 					 &bmc150_magn_buffer_setup_ops);
917 	if (ret < 0) {
918 		dev_err(dev, "iio triggered buffer setup failed\n");
919 		goto err_free_irq;
920 	}
921 
922 	ret = pm_runtime_set_active(dev);
923 	if (ret)
924 		goto err_buffer_cleanup;
925 
926 	pm_runtime_enable(dev);
927 	pm_runtime_set_autosuspend_delay(dev,
928 					 BMC150_MAGN_AUTO_SUSPEND_DELAY_MS);
929 	pm_runtime_use_autosuspend(dev);
930 
931 	ret = iio_device_register(indio_dev);
932 	if (ret < 0) {
933 		dev_err(dev, "unable to register iio device\n");
934 		goto err_buffer_cleanup;
935 	}
936 
937 	dev_dbg(dev, "Registered device %s\n", name);
938 	return 0;
939 
940 err_buffer_cleanup:
941 	iio_triggered_buffer_cleanup(indio_dev);
942 err_free_irq:
943 	if (irq > 0)
944 		free_irq(irq, data->dready_trig);
945 err_trigger_unregister:
946 	if (data->dready_trig)
947 		iio_trigger_unregister(data->dready_trig);
948 err_poweroff:
949 	bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
950 	return ret;
951 }
952 EXPORT_SYMBOL(bmc150_magn_probe);
953 
bmc150_magn_remove(struct device * dev)954 int bmc150_magn_remove(struct device *dev)
955 {
956 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
957 	struct bmc150_magn_data *data = iio_priv(indio_dev);
958 
959 	iio_device_unregister(indio_dev);
960 
961 	pm_runtime_disable(dev);
962 	pm_runtime_set_suspended(dev);
963 	pm_runtime_put_noidle(dev);
964 
965 	iio_triggered_buffer_cleanup(indio_dev);
966 
967 	if (data->irq > 0)
968 		free_irq(data->irq, data->dready_trig);
969 
970 	if (data->dready_trig)
971 		iio_trigger_unregister(data->dready_trig);
972 
973 	mutex_lock(&data->mutex);
974 	bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SUSPEND, true);
975 	mutex_unlock(&data->mutex);
976 
977 	return 0;
978 }
979 EXPORT_SYMBOL(bmc150_magn_remove);
980 
981 #ifdef CONFIG_PM
bmc150_magn_runtime_suspend(struct device * dev)982 static int bmc150_magn_runtime_suspend(struct device *dev)
983 {
984 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
985 	struct bmc150_magn_data *data = iio_priv(indio_dev);
986 	int ret;
987 
988 	mutex_lock(&data->mutex);
989 	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
990 					 true);
991 	mutex_unlock(&data->mutex);
992 	if (ret < 0) {
993 		dev_err(dev, "powering off device failed\n");
994 		return ret;
995 	}
996 	return 0;
997 }
998 
999 /*
1000  * Should be called with data->mutex held.
1001  */
bmc150_magn_runtime_resume(struct device * dev)1002 static int bmc150_magn_runtime_resume(struct device *dev)
1003 {
1004 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
1005 	struct bmc150_magn_data *data = iio_priv(indio_dev);
1006 
1007 	return bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
1008 					  true);
1009 }
1010 #endif
1011 
1012 #ifdef CONFIG_PM_SLEEP
bmc150_magn_suspend(struct device * dev)1013 static int bmc150_magn_suspend(struct device *dev)
1014 {
1015 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
1016 	struct bmc150_magn_data *data = iio_priv(indio_dev);
1017 	int ret;
1018 
1019 	mutex_lock(&data->mutex);
1020 	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_SLEEP,
1021 					 true);
1022 	mutex_unlock(&data->mutex);
1023 
1024 	return ret;
1025 }
1026 
bmc150_magn_resume(struct device * dev)1027 static int bmc150_magn_resume(struct device *dev)
1028 {
1029 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
1030 	struct bmc150_magn_data *data = iio_priv(indio_dev);
1031 	int ret;
1032 
1033 	mutex_lock(&data->mutex);
1034 	ret = bmc150_magn_set_power_mode(data, BMC150_MAGN_POWER_MODE_NORMAL,
1035 					 true);
1036 	mutex_unlock(&data->mutex);
1037 
1038 	return ret;
1039 }
1040 #endif
1041 
1042 const struct dev_pm_ops bmc150_magn_pm_ops = {
1043 	SET_SYSTEM_SLEEP_PM_OPS(bmc150_magn_suspend, bmc150_magn_resume)
1044 	SET_RUNTIME_PM_OPS(bmc150_magn_runtime_suspend,
1045 			   bmc150_magn_runtime_resume, NULL)
1046 };
1047 EXPORT_SYMBOL(bmc150_magn_pm_ops);
1048 
1049 MODULE_AUTHOR("Irina Tirdea <irina.tirdea@intel.com>");
1050 MODULE_LICENSE("GPL v2");
1051 MODULE_DESCRIPTION("BMC150 magnetometer core driver");
1052