xref: /linux/drivers/iio/gyro/mpu3050-core.c (revision ef815d2cba782e96b9aad9483523d474ed41c62a)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * MPU3050 gyroscope driver
4  *
5  * Copyright (C) 2016 Linaro Ltd.
6  * Author: Linus Walleij <linus.walleij@linaro.org>
7  *
8  * Based on the input subsystem driver, Copyright (C) 2011 Wistron Co.Ltd
9  * Joseph Lai <joseph_lai@wistron.com> and trimmed down by
10  * Alan Cox <alan@linux.intel.com> in turn based on bma023.c.
11  * Device behaviour based on a misc driver posted by Nathan Royer in 2011.
12  *
13  * TODO: add support for setting up the low pass 3dB frequency.
14  */
15 
16 #include <linux/bitfield.h>
17 #include <linux/bitops.h>
18 #include <linux/delay.h>
19 #include <linux/err.h>
20 #include <linux/iio/buffer.h>
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/trigger.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include <linux/iio/triggered_buffer.h>
26 #include <linux/interrupt.h>
27 #include <linux/module.h>
28 #include <linux/pm_runtime.h>
29 #include <linux/property.h>
30 #include <linux/random.h>
31 #include <linux/slab.h>
32 
33 #include "mpu3050.h"
34 
35 #define MPU3050_CHIP_ID		0x68
36 #define MPU3050_CHIP_ID_MASK	0x7E
37 
38 /*
39  * Register map: anything suffixed *_H is a big-endian high byte and always
40  * followed by the corresponding low byte (*_L) even though these are not
41  * explicitly included in the register definitions.
42  */
43 #define MPU3050_CHIP_ID_REG	0x00
44 #define MPU3050_PRODUCT_ID_REG	0x01
45 #define MPU3050_XG_OFFS_TC	0x05
46 #define MPU3050_YG_OFFS_TC	0x08
47 #define MPU3050_ZG_OFFS_TC	0x0B
48 #define MPU3050_X_OFFS_USR_H	0x0C
49 #define MPU3050_Y_OFFS_USR_H	0x0E
50 #define MPU3050_Z_OFFS_USR_H	0x10
51 #define MPU3050_FIFO_EN		0x12
52 #define MPU3050_AUX_VDDIO	0x13
53 #define MPU3050_SLV_ADDR	0x14
54 #define MPU3050_SMPLRT_DIV	0x15
55 #define MPU3050_DLPF_FS_SYNC	0x16
56 #define MPU3050_INT_CFG		0x17
57 #define MPU3050_AUX_ADDR	0x18
58 #define MPU3050_INT_STATUS	0x1A
59 #define MPU3050_TEMP_H		0x1B
60 #define MPU3050_XOUT_H		0x1D
61 #define MPU3050_YOUT_H		0x1F
62 #define MPU3050_ZOUT_H		0x21
63 #define MPU3050_DMP_CFG1	0x35
64 #define MPU3050_DMP_CFG2	0x36
65 #define MPU3050_BANK_SEL	0x37
66 #define MPU3050_MEM_START_ADDR	0x38
67 #define MPU3050_MEM_R_W		0x39
68 #define MPU3050_FIFO_COUNT_H	0x3A
69 #define MPU3050_FIFO_R		0x3C
70 #define MPU3050_USR_CTRL	0x3D
71 #define MPU3050_PWR_MGM		0x3E
72 
73 /* MPU memory bank read options */
74 #define MPU3050_MEM_PRFTCH	BIT(5)
75 #define MPU3050_MEM_USER_BANK	BIT(4)
76 /* Bits 8-11 select memory bank */
77 #define MPU3050_MEM_RAM_BANK_0	0
78 #define MPU3050_MEM_RAM_BANK_1	1
79 #define MPU3050_MEM_RAM_BANK_2	2
80 #define MPU3050_MEM_RAM_BANK_3	3
81 #define MPU3050_MEM_OTP_BANK_0	4
82 
83 #define MPU3050_AXIS_REGS(axis) (MPU3050_XOUT_H + (axis * 2))
84 
85 /* Register bits */
86 
87 /* FIFO Enable */
88 #define MPU3050_FIFO_EN_FOOTER		BIT(0)
89 #define MPU3050_FIFO_EN_AUX_ZOUT	BIT(1)
90 #define MPU3050_FIFO_EN_AUX_YOUT	BIT(2)
91 #define MPU3050_FIFO_EN_AUX_XOUT	BIT(3)
92 #define MPU3050_FIFO_EN_GYRO_ZOUT	BIT(4)
93 #define MPU3050_FIFO_EN_GYRO_YOUT	BIT(5)
94 #define MPU3050_FIFO_EN_GYRO_XOUT	BIT(6)
95 #define MPU3050_FIFO_EN_TEMP_OUT	BIT(7)
96 
97 /*
98  * Digital Low Pass filter (DLPF)
99  * Full Scale (FS)
100  * and Synchronization
101  */
102 #define MPU3050_EXT_SYNC_NONE		0x00
103 #define MPU3050_EXT_SYNC_TEMP		0x20
104 #define MPU3050_EXT_SYNC_GYROX		0x40
105 #define MPU3050_EXT_SYNC_GYROY		0x60
106 #define MPU3050_EXT_SYNC_GYROZ		0x80
107 #define MPU3050_EXT_SYNC_ACCELX	0xA0
108 #define MPU3050_EXT_SYNC_ACCELY	0xC0
109 #define MPU3050_EXT_SYNC_ACCELZ	0xE0
110 #define MPU3050_EXT_SYNC_MASK		0xE0
111 #define MPU3050_EXT_SYNC_SHIFT		5
112 
113 #define MPU3050_FS_250DPS		0x00
114 #define MPU3050_FS_500DPS		0x08
115 #define MPU3050_FS_1000DPS		0x10
116 #define MPU3050_FS_2000DPS		0x18
117 #define MPU3050_FS_MASK			0x18
118 #define MPU3050_FS_SHIFT		3
119 
120 #define MPU3050_DLPF_CFG_256HZ_NOLPF2	0x00
121 #define MPU3050_DLPF_CFG_188HZ		0x01
122 #define MPU3050_DLPF_CFG_98HZ		0x02
123 #define MPU3050_DLPF_CFG_42HZ		0x03
124 #define MPU3050_DLPF_CFG_20HZ		0x04
125 #define MPU3050_DLPF_CFG_10HZ		0x05
126 #define MPU3050_DLPF_CFG_5HZ		0x06
127 #define MPU3050_DLPF_CFG_2100HZ_NOLPF	0x07
128 #define MPU3050_DLPF_CFG_MASK		0x07
129 #define MPU3050_DLPF_CFG_SHIFT		0
130 
131 /* Interrupt config */
132 #define MPU3050_INT_RAW_RDY_EN		BIT(0)
133 #define MPU3050_INT_DMP_DONE_EN		BIT(1)
134 #define MPU3050_INT_MPU_RDY_EN		BIT(2)
135 #define MPU3050_INT_ANYRD_2CLEAR	BIT(4)
136 #define MPU3050_INT_LATCH_EN		BIT(5)
137 #define MPU3050_INT_OPEN		BIT(6)
138 #define MPU3050_INT_ACTL		BIT(7)
139 /* Interrupt status */
140 #define MPU3050_INT_STATUS_RAW_RDY	BIT(0)
141 #define MPU3050_INT_STATUS_DMP_DONE	BIT(1)
142 #define MPU3050_INT_STATUS_MPU_RDY	BIT(2)
143 #define MPU3050_INT_STATUS_FIFO_OVFLW	BIT(7)
144 /* USR_CTRL */
145 #define MPU3050_USR_CTRL_FIFO_EN	BIT(6)
146 #define MPU3050_USR_CTRL_AUX_IF_EN	BIT(5)
147 #define MPU3050_USR_CTRL_AUX_IF_RST	BIT(3)
148 #define MPU3050_USR_CTRL_FIFO_RST	BIT(1)
149 #define MPU3050_USR_CTRL_GYRO_RST	BIT(0)
150 /* PWR_MGM */
151 #define MPU3050_PWR_MGM_PLL_X		0x01
152 #define MPU3050_PWR_MGM_PLL_Y		0x02
153 #define MPU3050_PWR_MGM_PLL_Z		0x03
154 #define MPU3050_PWR_MGM_CLKSEL_MASK	0x07
155 #define MPU3050_PWR_MGM_STBY_ZG		BIT(3)
156 #define MPU3050_PWR_MGM_STBY_YG		BIT(4)
157 #define MPU3050_PWR_MGM_STBY_XG		BIT(5)
158 #define MPU3050_PWR_MGM_SLEEP		BIT(6)
159 #define MPU3050_PWR_MGM_RESET		BIT(7)
160 #define MPU3050_PWR_MGM_MASK		0xff
161 
162 /*
163  * Fullscale precision is (for finest precision) +/- 250 deg/s, so the full
164  * scale is actually 500 deg/s. All 16 bits are then used to cover this scale,
165  * in two's complement.
166  */
167 static unsigned int mpu3050_fs_precision[] = {
168 	IIO_DEGREE_TO_RAD(250),
169 	IIO_DEGREE_TO_RAD(500),
170 	IIO_DEGREE_TO_RAD(1000),
171 	IIO_DEGREE_TO_RAD(2000)
172 };
173 
174 /*
175  * Regulator names
176  */
177 static const char mpu3050_reg_vdd[] = "vdd";
178 static const char mpu3050_reg_vlogic[] = "vlogic";
179 
180 static unsigned int mpu3050_get_freq(struct mpu3050 *mpu3050)
181 {
182 	unsigned int freq;
183 
184 	if (mpu3050->lpf == MPU3050_DLPF_CFG_256HZ_NOLPF2)
185 		freq = 8000;
186 	else
187 		freq = 1000;
188 	freq /= (mpu3050->divisor + 1);
189 
190 	return freq;
191 }
192 
193 static int mpu3050_start_sampling(struct mpu3050 *mpu3050)
194 {
195 	__be16 raw_val[3];
196 	int ret;
197 	int i;
198 
199 	/* Reset */
200 	ret = regmap_update_bits(mpu3050->map, MPU3050_PWR_MGM,
201 				 MPU3050_PWR_MGM_RESET, MPU3050_PWR_MGM_RESET);
202 	if (ret)
203 		return ret;
204 
205 	/* Turn on the Z-axis PLL */
206 	ret = regmap_update_bits(mpu3050->map, MPU3050_PWR_MGM,
207 				 MPU3050_PWR_MGM_CLKSEL_MASK,
208 				 MPU3050_PWR_MGM_PLL_Z);
209 	if (ret)
210 		return ret;
211 
212 	/* Write calibration offset registers */
213 	for (i = 0; i < 3; i++)
214 		raw_val[i] = cpu_to_be16(mpu3050->calibration[i]);
215 
216 	ret = regmap_bulk_write(mpu3050->map, MPU3050_X_OFFS_USR_H, raw_val,
217 				sizeof(raw_val));
218 	if (ret)
219 		return ret;
220 
221 	/* Set low pass filter (sample rate), sync and full scale */
222 	ret = regmap_write(mpu3050->map, MPU3050_DLPF_FS_SYNC,
223 			   MPU3050_EXT_SYNC_NONE << MPU3050_EXT_SYNC_SHIFT |
224 			   mpu3050->fullscale << MPU3050_FS_SHIFT |
225 			   mpu3050->lpf << MPU3050_DLPF_CFG_SHIFT);
226 	if (ret)
227 		return ret;
228 
229 	/* Set up sampling frequency */
230 	ret = regmap_write(mpu3050->map, MPU3050_SMPLRT_DIV, mpu3050->divisor);
231 	if (ret)
232 		return ret;
233 
234 	/*
235 	 * Max 50 ms start-up time after setting DLPF_FS_SYNC
236 	 * according to the data sheet, then wait for the next sample
237 	 * at this frequency T = 1000/f ms.
238 	 */
239 	msleep(50 + 1000 / mpu3050_get_freq(mpu3050));
240 
241 	return 0;
242 }
243 
244 static int mpu3050_set_8khz_samplerate(struct mpu3050 *mpu3050)
245 {
246 	int ret;
247 	u8 divisor;
248 	enum mpu3050_lpf lpf;
249 
250 	lpf = mpu3050->lpf;
251 	divisor = mpu3050->divisor;
252 
253 	mpu3050->lpf = LPF_256_HZ_NOLPF; /* 8 kHz base frequency */
254 	mpu3050->divisor = 0; /* Divide by 1 */
255 	ret = mpu3050_start_sampling(mpu3050);
256 
257 	mpu3050->lpf = lpf;
258 	mpu3050->divisor = divisor;
259 
260 	return ret;
261 }
262 
263 static int mpu3050_read_raw(struct iio_dev *indio_dev,
264 			    struct iio_chan_spec const *chan,
265 			    int *val, int *val2,
266 			    long mask)
267 {
268 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
269 	int ret;
270 	__be16 raw_val;
271 
272 	switch (mask) {
273 	case IIO_CHAN_INFO_OFFSET:
274 		switch (chan->type) {
275 		case IIO_TEMP:
276 			/*
277 			 * The temperature scaling is (x+23000)/280 Celsius
278 			 * for the "best fit straight line" temperature range
279 			 * of -30C..85C.  The 23000 includes room temperature
280 			 * offset of +35C, 280 is the precision scale and x is
281 			 * the 16-bit signed integer reported by hardware.
282 			 *
283 			 * Temperature value itself represents temperature of
284 			 * the sensor die.
285 			 */
286 			*val = 23000;
287 			return IIO_VAL_INT;
288 		default:
289 			return -EINVAL;
290 		}
291 	case IIO_CHAN_INFO_CALIBBIAS:
292 		switch (chan->type) {
293 		case IIO_ANGL_VEL:
294 			*val = mpu3050->calibration[chan->scan_index-1];
295 			return IIO_VAL_INT;
296 		default:
297 			return -EINVAL;
298 		}
299 	case IIO_CHAN_INFO_SAMP_FREQ:
300 		*val = mpu3050_get_freq(mpu3050);
301 		return IIO_VAL_INT;
302 	case IIO_CHAN_INFO_SCALE:
303 		switch (chan->type) {
304 		case IIO_TEMP:
305 			/* Millidegrees, see about temperature scaling above */
306 			*val = 1000;
307 			*val2 = 280;
308 			return IIO_VAL_FRACTIONAL;
309 		case IIO_ANGL_VEL:
310 			/*
311 			 * Convert to the corresponding full scale in
312 			 * radians. All 16 bits are used with sign to
313 			 * span the available scale: to account for the one
314 			 * missing value if we multiply by 1/S16_MAX, instead
315 			 * multiply with 2/U16_MAX.
316 			 */
317 			*val = mpu3050_fs_precision[mpu3050->fullscale] * 2;
318 			*val2 = U16_MAX;
319 			return IIO_VAL_FRACTIONAL;
320 		default:
321 			return -EINVAL;
322 		}
323 	case IIO_CHAN_INFO_RAW:
324 		/* Resume device */
325 		pm_runtime_get_sync(mpu3050->dev);
326 		mutex_lock(&mpu3050->lock);
327 
328 		ret = mpu3050_set_8khz_samplerate(mpu3050);
329 		if (ret)
330 			goto out_read_raw_unlock;
331 
332 		switch (chan->type) {
333 		case IIO_TEMP:
334 			ret = regmap_bulk_read(mpu3050->map, MPU3050_TEMP_H,
335 					       &raw_val, sizeof(raw_val));
336 			if (ret) {
337 				dev_err(mpu3050->dev,
338 					"error reading temperature\n");
339 				goto out_read_raw_unlock;
340 			}
341 
342 			*val = (s16)be16_to_cpu(raw_val);
343 			ret = IIO_VAL_INT;
344 
345 			goto out_read_raw_unlock;
346 		case IIO_ANGL_VEL:
347 			ret = regmap_bulk_read(mpu3050->map,
348 				       MPU3050_AXIS_REGS(chan->scan_index-1),
349 				       &raw_val,
350 				       sizeof(raw_val));
351 			if (ret) {
352 				dev_err(mpu3050->dev,
353 					"error reading axis data\n");
354 				goto out_read_raw_unlock;
355 			}
356 
357 			*val = be16_to_cpu(raw_val);
358 			ret = IIO_VAL_INT;
359 
360 			goto out_read_raw_unlock;
361 		default:
362 			ret = -EINVAL;
363 			goto out_read_raw_unlock;
364 		}
365 	default:
366 		break;
367 	}
368 
369 	return -EINVAL;
370 
371 out_read_raw_unlock:
372 	mutex_unlock(&mpu3050->lock);
373 	pm_runtime_mark_last_busy(mpu3050->dev);
374 	pm_runtime_put_autosuspend(mpu3050->dev);
375 
376 	return ret;
377 }
378 
379 static int mpu3050_write_raw(struct iio_dev *indio_dev,
380 			     const struct iio_chan_spec *chan,
381 			     int val, int val2, long mask)
382 {
383 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
384 	/*
385 	 * Couldn't figure out a way to precalculate these at compile time.
386 	 */
387 	unsigned int fs250 =
388 		DIV_ROUND_CLOSEST(mpu3050_fs_precision[0] * 1000000 * 2,
389 				  U16_MAX);
390 	unsigned int fs500 =
391 		DIV_ROUND_CLOSEST(mpu3050_fs_precision[1] * 1000000 * 2,
392 				  U16_MAX);
393 	unsigned int fs1000 =
394 		DIV_ROUND_CLOSEST(mpu3050_fs_precision[2] * 1000000 * 2,
395 				  U16_MAX);
396 	unsigned int fs2000 =
397 		DIV_ROUND_CLOSEST(mpu3050_fs_precision[3] * 1000000 * 2,
398 				  U16_MAX);
399 
400 	switch (mask) {
401 	case IIO_CHAN_INFO_CALIBBIAS:
402 		if (chan->type != IIO_ANGL_VEL)
403 			return -EINVAL;
404 		mpu3050->calibration[chan->scan_index-1] = val;
405 		return 0;
406 	case IIO_CHAN_INFO_SAMP_FREQ:
407 		/*
408 		 * The max samplerate is 8000 Hz, the minimum
409 		 * 1000 / 256 ~= 4 Hz
410 		 */
411 		if (val < 4 || val > 8000)
412 			return -EINVAL;
413 
414 		/*
415 		 * Above 1000 Hz we must turn off the digital low pass filter
416 		 * so we get a base frequency of 8kHz to the divider
417 		 */
418 		if (val > 1000) {
419 			mpu3050->lpf = LPF_256_HZ_NOLPF;
420 			mpu3050->divisor = DIV_ROUND_CLOSEST(8000, val) - 1;
421 			return 0;
422 		}
423 
424 		mpu3050->lpf = LPF_188_HZ;
425 		mpu3050->divisor = DIV_ROUND_CLOSEST(1000, val) - 1;
426 		return 0;
427 	case IIO_CHAN_INFO_SCALE:
428 		if (chan->type != IIO_ANGL_VEL)
429 			return -EINVAL;
430 		/*
431 		 * We support +/-250, +/-500, +/-1000 and +/2000 deg/s
432 		 * which means we need to round to the closest radians
433 		 * which will be roughly +/-4.3, +/-8.7, +/-17.5, +/-35
434 		 * rad/s. The scale is then for the 16 bits used to cover
435 		 * it 2/(2^16) of that.
436 		 */
437 
438 		/* Just too large, set the max range */
439 		if (val != 0) {
440 			mpu3050->fullscale = FS_2000_DPS;
441 			return 0;
442 		}
443 
444 		/*
445 		 * Now we're dealing with fractions below zero in millirad/s
446 		 * do some integer interpolation and match with the closest
447 		 * fullscale in the table.
448 		 */
449 		if (val2 <= fs250 ||
450 		    val2 < ((fs500 + fs250) / 2))
451 			mpu3050->fullscale = FS_250_DPS;
452 		else if (val2 <= fs500 ||
453 			 val2 < ((fs1000 + fs500) / 2))
454 			mpu3050->fullscale = FS_500_DPS;
455 		else if (val2 <= fs1000 ||
456 			 val2 < ((fs2000 + fs1000) / 2))
457 			mpu3050->fullscale = FS_1000_DPS;
458 		else
459 			/* Catch-all */
460 			mpu3050->fullscale = FS_2000_DPS;
461 		return 0;
462 	default:
463 		break;
464 	}
465 
466 	return -EINVAL;
467 }
468 
469 static irqreturn_t mpu3050_trigger_handler(int irq, void *p)
470 {
471 	const struct iio_poll_func *pf = p;
472 	struct iio_dev *indio_dev = pf->indio_dev;
473 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
474 	int ret;
475 	struct {
476 		__be16 chans[4];
477 		s64 timestamp __aligned(8);
478 	} scan;
479 	s64 timestamp;
480 	unsigned int datums_from_fifo = 0;
481 
482 	/*
483 	 * If we're using the hardware trigger, get the precise timestamp from
484 	 * the top half of the threaded IRQ handler. Otherwise get the
485 	 * timestamp here so it will be close in time to the actual values
486 	 * read from the registers.
487 	 */
488 	if (iio_trigger_using_own(indio_dev))
489 		timestamp = mpu3050->hw_timestamp;
490 	else
491 		timestamp = iio_get_time_ns(indio_dev);
492 
493 	mutex_lock(&mpu3050->lock);
494 
495 	/* Using the hardware IRQ trigger? Check the buffer then. */
496 	if (mpu3050->hw_irq_trigger) {
497 		__be16 raw_fifocnt;
498 		u16 fifocnt;
499 		/* X, Y, Z + temperature */
500 		unsigned int bytes_per_datum = 8;
501 		bool fifo_overflow = false;
502 
503 		ret = regmap_bulk_read(mpu3050->map,
504 				       MPU3050_FIFO_COUNT_H,
505 				       &raw_fifocnt,
506 				       sizeof(raw_fifocnt));
507 		if (ret)
508 			goto out_trigger_unlock;
509 		fifocnt = be16_to_cpu(raw_fifocnt);
510 
511 		if (fifocnt == 512) {
512 			dev_info(mpu3050->dev,
513 				 "FIFO overflow! Emptying and resetting FIFO\n");
514 			fifo_overflow = true;
515 			/* Reset and enable the FIFO */
516 			ret = regmap_update_bits(mpu3050->map,
517 						 MPU3050_USR_CTRL,
518 						 MPU3050_USR_CTRL_FIFO_EN |
519 						 MPU3050_USR_CTRL_FIFO_RST,
520 						 MPU3050_USR_CTRL_FIFO_EN |
521 						 MPU3050_USR_CTRL_FIFO_RST);
522 			if (ret) {
523 				dev_info(mpu3050->dev, "error resetting FIFO\n");
524 				goto out_trigger_unlock;
525 			}
526 			mpu3050->pending_fifo_footer = false;
527 		}
528 
529 		if (fifocnt)
530 			dev_dbg(mpu3050->dev,
531 				"%d bytes in the FIFO\n",
532 				fifocnt);
533 
534 		while (!fifo_overflow && fifocnt > bytes_per_datum) {
535 			unsigned int toread;
536 			unsigned int offset;
537 			__be16 fifo_values[5];
538 
539 			/*
540 			 * If there is a FIFO footer in the pipe, first clear
541 			 * that out. This follows the complex algorithm in the
542 			 * datasheet that states that you may never leave the
543 			 * FIFO empty after the first reading: you have to
544 			 * always leave two footer bytes in it. The footer is
545 			 * in practice just two zero bytes.
546 			 */
547 			if (mpu3050->pending_fifo_footer) {
548 				toread = bytes_per_datum + 2;
549 				offset = 0;
550 			} else {
551 				toread = bytes_per_datum;
552 				offset = 1;
553 				/* Put in some dummy value */
554 				fifo_values[0] = cpu_to_be16(0xAAAA);
555 			}
556 
557 			ret = regmap_bulk_read(mpu3050->map,
558 					       MPU3050_FIFO_R,
559 					       &fifo_values[offset],
560 					       toread);
561 			if (ret)
562 				goto out_trigger_unlock;
563 
564 			dev_dbg(mpu3050->dev,
565 				"%04x %04x %04x %04x %04x\n",
566 				fifo_values[0],
567 				fifo_values[1],
568 				fifo_values[2],
569 				fifo_values[3],
570 				fifo_values[4]);
571 
572 			/* Index past the footer (fifo_values[0]) and push */
573 			iio_push_to_buffers_with_ts_unaligned(indio_dev,
574 							      &fifo_values[1],
575 							      sizeof(__be16) * 4,
576 							      timestamp);
577 
578 			fifocnt -= toread;
579 			datums_from_fifo++;
580 			mpu3050->pending_fifo_footer = true;
581 
582 			/*
583 			 * If we're emptying the FIFO, just make sure to
584 			 * check if something new appeared.
585 			 */
586 			if (fifocnt < bytes_per_datum) {
587 				ret = regmap_bulk_read(mpu3050->map,
588 						       MPU3050_FIFO_COUNT_H,
589 						       &raw_fifocnt,
590 						       sizeof(raw_fifocnt));
591 				if (ret)
592 					goto out_trigger_unlock;
593 				fifocnt = be16_to_cpu(raw_fifocnt);
594 			}
595 
596 			if (fifocnt < bytes_per_datum)
597 				dev_dbg(mpu3050->dev,
598 					"%d bytes left in the FIFO\n",
599 					fifocnt);
600 
601 			/*
602 			 * At this point, the timestamp that triggered the
603 			 * hardware interrupt is no longer valid for what
604 			 * we are reading (the interrupt likely fired for
605 			 * the value on the top of the FIFO), so set the
606 			 * timestamp to zero and let userspace deal with it.
607 			 */
608 			timestamp = 0;
609 		}
610 	}
611 
612 	/*
613 	 * If we picked some datums from the FIFO that's enough, else
614 	 * fall through and just read from the current value registers.
615 	 * This happens in two cases:
616 	 *
617 	 * - We are using some other trigger (external, like an HRTimer)
618 	 *   than the sensor's own sample generator. In this case the
619 	 *   sensor is just set to the max sampling frequency and we give
620 	 *   the trigger a copy of the latest value every time we get here.
621 	 *
622 	 * - The hardware trigger is active but unused and we actually use
623 	 *   another trigger which calls here with a frequency higher
624 	 *   than what the device provides data. We will then just read
625 	 *   duplicate values directly from the hardware registers.
626 	 */
627 	if (datums_from_fifo) {
628 		dev_dbg(mpu3050->dev,
629 			"read %d datums from the FIFO\n",
630 			datums_from_fifo);
631 		goto out_trigger_unlock;
632 	}
633 
634 	ret = regmap_bulk_read(mpu3050->map, MPU3050_TEMP_H, scan.chans,
635 			       sizeof(scan.chans));
636 	if (ret) {
637 		dev_err(mpu3050->dev,
638 			"error reading axis data\n");
639 		goto out_trigger_unlock;
640 	}
641 
642 	iio_push_to_buffers_with_timestamp(indio_dev, &scan, timestamp);
643 
644 out_trigger_unlock:
645 	mutex_unlock(&mpu3050->lock);
646 	iio_trigger_notify_done(indio_dev->trig);
647 
648 	return IRQ_HANDLED;
649 }
650 
651 static int mpu3050_buffer_preenable(struct iio_dev *indio_dev)
652 {
653 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
654 
655 	pm_runtime_get_sync(mpu3050->dev);
656 
657 	/* Unless we have OUR trigger active, run at full speed */
658 	if (!mpu3050->hw_irq_trigger)
659 		return mpu3050_set_8khz_samplerate(mpu3050);
660 
661 	return 0;
662 }
663 
664 static int mpu3050_buffer_postdisable(struct iio_dev *indio_dev)
665 {
666 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
667 
668 	pm_runtime_mark_last_busy(mpu3050->dev);
669 	pm_runtime_put_autosuspend(mpu3050->dev);
670 
671 	return 0;
672 }
673 
674 static const struct iio_buffer_setup_ops mpu3050_buffer_setup_ops = {
675 	.preenable = mpu3050_buffer_preenable,
676 	.postdisable = mpu3050_buffer_postdisable,
677 };
678 
679 static const struct iio_mount_matrix *
680 mpu3050_get_mount_matrix(const struct iio_dev *indio_dev,
681 			 const struct iio_chan_spec *chan)
682 {
683 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
684 
685 	return &mpu3050->orientation;
686 }
687 
688 static const struct iio_chan_spec_ext_info mpu3050_ext_info[] = {
689 	IIO_MOUNT_MATRIX(IIO_SHARED_BY_TYPE, mpu3050_get_mount_matrix),
690 	{ },
691 };
692 
693 #define MPU3050_AXIS_CHANNEL(axis, index)				\
694 	{								\
695 		.type = IIO_ANGL_VEL,					\
696 		.modified = 1,						\
697 		.channel2 = IIO_MOD_##axis,				\
698 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
699 			BIT(IIO_CHAN_INFO_CALIBBIAS),			\
700 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
701 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),\
702 		.ext_info = mpu3050_ext_info,				\
703 		.scan_index = index,					\
704 		.scan_type = {						\
705 			.sign = 's',					\
706 			.realbits = 16,					\
707 			.storagebits = 16,				\
708 			.endianness = IIO_BE,				\
709 		},							\
710 	}
711 
712 static const struct iio_chan_spec mpu3050_channels[] = {
713 	{
714 		.type = IIO_TEMP,
715 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
716 				      BIT(IIO_CHAN_INFO_SCALE) |
717 				      BIT(IIO_CHAN_INFO_OFFSET),
718 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
719 		.scan_index = 0,
720 		.scan_type = {
721 			.sign = 's',
722 			.realbits = 16,
723 			.storagebits = 16,
724 			.endianness = IIO_BE,
725 		},
726 	},
727 	MPU3050_AXIS_CHANNEL(X, 1),
728 	MPU3050_AXIS_CHANNEL(Y, 2),
729 	MPU3050_AXIS_CHANNEL(Z, 3),
730 	IIO_CHAN_SOFT_TIMESTAMP(4),
731 };
732 
733 /* Four channels apart from timestamp, scan mask = 0x0f */
734 static const unsigned long mpu3050_scan_masks[] = { 0xf, 0 };
735 
736 /*
737  * These are just the hardcoded factors resulting from the more elaborate
738  * calculations done with fractions in the scale raw get/set functions.
739  */
740 static IIO_CONST_ATTR(anglevel_scale_available,
741 		      "0.000122070 "
742 		      "0.000274658 "
743 		      "0.000518798 "
744 		      "0.001068115");
745 
746 static struct attribute *mpu3050_attributes[] = {
747 	&iio_const_attr_anglevel_scale_available.dev_attr.attr,
748 	NULL,
749 };
750 
751 static const struct attribute_group mpu3050_attribute_group = {
752 	.attrs = mpu3050_attributes,
753 };
754 
755 static const struct iio_info mpu3050_info = {
756 	.read_raw = mpu3050_read_raw,
757 	.write_raw = mpu3050_write_raw,
758 	.attrs = &mpu3050_attribute_group,
759 };
760 
761 /**
762  * mpu3050_read_mem() - read MPU-3050 internal memory
763  * @mpu3050: device to read from
764  * @bank: target bank
765  * @addr: target address
766  * @len: number of bytes
767  * @buf: the buffer to store the read bytes in
768  */
769 static int mpu3050_read_mem(struct mpu3050 *mpu3050,
770 			    u8 bank,
771 			    u8 addr,
772 			    u8 len,
773 			    u8 *buf)
774 {
775 	int ret;
776 
777 	ret = regmap_write(mpu3050->map,
778 			   MPU3050_BANK_SEL,
779 			   bank);
780 	if (ret)
781 		return ret;
782 
783 	ret = regmap_write(mpu3050->map,
784 			   MPU3050_MEM_START_ADDR,
785 			   addr);
786 	if (ret)
787 		return ret;
788 
789 	return regmap_bulk_read(mpu3050->map,
790 				MPU3050_MEM_R_W,
791 				buf,
792 				len);
793 }
794 
795 static int mpu3050_hw_init(struct mpu3050 *mpu3050)
796 {
797 	int ret;
798 	__le64 otp_le;
799 	u64 otp;
800 
801 	/* Reset */
802 	ret = regmap_update_bits(mpu3050->map,
803 				 MPU3050_PWR_MGM,
804 				 MPU3050_PWR_MGM_RESET,
805 				 MPU3050_PWR_MGM_RESET);
806 	if (ret)
807 		return ret;
808 
809 	/* Turn on the PLL */
810 	ret = regmap_update_bits(mpu3050->map,
811 				 MPU3050_PWR_MGM,
812 				 MPU3050_PWR_MGM_CLKSEL_MASK,
813 				 MPU3050_PWR_MGM_PLL_Z);
814 	if (ret)
815 		return ret;
816 
817 	/* Disable IRQs */
818 	ret = regmap_write(mpu3050->map,
819 			   MPU3050_INT_CFG,
820 			   0);
821 	if (ret)
822 		return ret;
823 
824 	/* Read out the 8 bytes of OTP (one-time-programmable) memory */
825 	ret = mpu3050_read_mem(mpu3050,
826 			       (MPU3050_MEM_PRFTCH |
827 				MPU3050_MEM_USER_BANK |
828 				MPU3050_MEM_OTP_BANK_0),
829 			       0,
830 			       sizeof(otp_le),
831 			       (u8 *)&otp_le);
832 	if (ret)
833 		return ret;
834 
835 	/* This is device-unique data so it goes into the entropy pool */
836 	add_device_randomness(&otp_le, sizeof(otp_le));
837 
838 	otp = le64_to_cpu(otp_le);
839 
840 	dev_info(mpu3050->dev,
841 		 "die ID: %04llX, wafer ID: %02llX, A lot ID: %04llX, "
842 		 "W lot ID: %03llX, WP ID: %01llX, rev ID: %02llX\n",
843 		 /* Die ID, bits 0-12 */
844 		 FIELD_GET(GENMASK_ULL(12, 0), otp),
845 		 /* Wafer ID, bits 13-17 */
846 		 FIELD_GET(GENMASK_ULL(17, 13), otp),
847 		 /* A lot ID, bits 18-33 */
848 		 FIELD_GET(GENMASK_ULL(33, 18), otp),
849 		 /* W lot ID, bits 34-45 */
850 		 FIELD_GET(GENMASK_ULL(45, 34), otp),
851 		 /* WP ID, bits 47-49 */
852 		 FIELD_GET(GENMASK_ULL(49, 47), otp),
853 		 /* rev ID, bits 50-55 */
854 		 FIELD_GET(GENMASK_ULL(55, 50), otp));
855 
856 	return 0;
857 }
858 
859 static int mpu3050_power_up(struct mpu3050 *mpu3050)
860 {
861 	int ret;
862 
863 	ret = regulator_bulk_enable(ARRAY_SIZE(mpu3050->regs), mpu3050->regs);
864 	if (ret) {
865 		dev_err(mpu3050->dev, "cannot enable regulators\n");
866 		return ret;
867 	}
868 	/*
869 	 * 20-100 ms start-up time for register read/write according to
870 	 * the datasheet, be on the safe side and wait 200 ms.
871 	 */
872 	msleep(200);
873 
874 	/* Take device out of sleep mode */
875 	ret = regmap_update_bits(mpu3050->map, MPU3050_PWR_MGM,
876 				 MPU3050_PWR_MGM_SLEEP, 0);
877 	if (ret) {
878 		regulator_bulk_disable(ARRAY_SIZE(mpu3050->regs), mpu3050->regs);
879 		dev_err(mpu3050->dev, "error setting power mode\n");
880 		return ret;
881 	}
882 	usleep_range(10000, 20000);
883 
884 	return 0;
885 }
886 
887 static int mpu3050_power_down(struct mpu3050 *mpu3050)
888 {
889 	int ret;
890 
891 	/*
892 	 * Put MPU-3050 into sleep mode before cutting regulators.
893 	 * This is important, because we may not be the sole user
894 	 * of the regulator so the power may stay on after this, and
895 	 * then we would be wasting power unless we go to sleep mode
896 	 * first.
897 	 */
898 	ret = regmap_update_bits(mpu3050->map, MPU3050_PWR_MGM,
899 				 MPU3050_PWR_MGM_SLEEP, MPU3050_PWR_MGM_SLEEP);
900 	if (ret)
901 		dev_err(mpu3050->dev, "error putting to sleep\n");
902 
903 	ret = regulator_bulk_disable(ARRAY_SIZE(mpu3050->regs), mpu3050->regs);
904 	if (ret)
905 		dev_err(mpu3050->dev, "error disabling regulators\n");
906 
907 	return 0;
908 }
909 
910 static irqreturn_t mpu3050_irq_handler(int irq, void *p)
911 {
912 	struct iio_trigger *trig = p;
913 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
914 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
915 
916 	if (!mpu3050->hw_irq_trigger)
917 		return IRQ_NONE;
918 
919 	/* Get the time stamp as close in time as possible */
920 	mpu3050->hw_timestamp = iio_get_time_ns(indio_dev);
921 
922 	return IRQ_WAKE_THREAD;
923 }
924 
925 static irqreturn_t mpu3050_irq_thread(int irq, void *p)
926 {
927 	struct iio_trigger *trig = p;
928 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
929 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
930 	unsigned int val;
931 	int ret;
932 
933 	/* ACK IRQ and check if it was from us */
934 	ret = regmap_read(mpu3050->map, MPU3050_INT_STATUS, &val);
935 	if (ret) {
936 		dev_err(mpu3050->dev, "error reading IRQ status\n");
937 		return IRQ_HANDLED;
938 	}
939 	if (!(val & MPU3050_INT_STATUS_RAW_RDY))
940 		return IRQ_NONE;
941 
942 	iio_trigger_poll_nested(p);
943 
944 	return IRQ_HANDLED;
945 }
946 
947 /**
948  * mpu3050_drdy_trigger_set_state() - set data ready interrupt state
949  * @trig: trigger instance
950  * @enable: true if trigger should be enabled, false to disable
951  */
952 static int mpu3050_drdy_trigger_set_state(struct iio_trigger *trig,
953 					  bool enable)
954 {
955 	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trig);
956 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
957 	unsigned int val;
958 	int ret;
959 
960 	/* Disabling trigger: disable interrupt and return */
961 	if (!enable) {
962 		/* Disable all interrupts */
963 		ret = regmap_write(mpu3050->map,
964 				   MPU3050_INT_CFG,
965 				   0);
966 		if (ret)
967 			dev_err(mpu3050->dev, "error disabling IRQ\n");
968 
969 		/* Clear IRQ flag */
970 		ret = regmap_read(mpu3050->map, MPU3050_INT_STATUS, &val);
971 		if (ret)
972 			dev_err(mpu3050->dev, "error clearing IRQ status\n");
973 
974 		/* Disable all things in the FIFO and reset it */
975 		ret = regmap_write(mpu3050->map, MPU3050_FIFO_EN, 0);
976 		if (ret)
977 			dev_err(mpu3050->dev, "error disabling FIFO\n");
978 
979 		ret = regmap_write(mpu3050->map, MPU3050_USR_CTRL,
980 				   MPU3050_USR_CTRL_FIFO_RST);
981 		if (ret)
982 			dev_err(mpu3050->dev, "error resetting FIFO\n");
983 
984 		pm_runtime_mark_last_busy(mpu3050->dev);
985 		pm_runtime_put_autosuspend(mpu3050->dev);
986 		mpu3050->hw_irq_trigger = false;
987 
988 		return 0;
989 	} else {
990 		/* Else we're enabling the trigger from this point */
991 		pm_runtime_get_sync(mpu3050->dev);
992 		mpu3050->hw_irq_trigger = true;
993 
994 		/* Disable all things in the FIFO */
995 		ret = regmap_write(mpu3050->map, MPU3050_FIFO_EN, 0);
996 		if (ret)
997 			return ret;
998 
999 		/* Reset and enable the FIFO */
1000 		ret = regmap_update_bits(mpu3050->map, MPU3050_USR_CTRL,
1001 					 MPU3050_USR_CTRL_FIFO_EN |
1002 					 MPU3050_USR_CTRL_FIFO_RST,
1003 					 MPU3050_USR_CTRL_FIFO_EN |
1004 					 MPU3050_USR_CTRL_FIFO_RST);
1005 		if (ret)
1006 			return ret;
1007 
1008 		mpu3050->pending_fifo_footer = false;
1009 
1010 		/* Turn on the FIFO for temp+X+Y+Z */
1011 		ret = regmap_write(mpu3050->map, MPU3050_FIFO_EN,
1012 				   MPU3050_FIFO_EN_TEMP_OUT |
1013 				   MPU3050_FIFO_EN_GYRO_XOUT |
1014 				   MPU3050_FIFO_EN_GYRO_YOUT |
1015 				   MPU3050_FIFO_EN_GYRO_ZOUT |
1016 				   MPU3050_FIFO_EN_FOOTER);
1017 		if (ret)
1018 			return ret;
1019 
1020 		/* Configure the sample engine */
1021 		ret = mpu3050_start_sampling(mpu3050);
1022 		if (ret)
1023 			return ret;
1024 
1025 		/* Clear IRQ flag */
1026 		ret = regmap_read(mpu3050->map, MPU3050_INT_STATUS, &val);
1027 		if (ret)
1028 			dev_err(mpu3050->dev, "error clearing IRQ status\n");
1029 
1030 		/* Give us interrupts whenever there is new data ready */
1031 		val = MPU3050_INT_RAW_RDY_EN;
1032 
1033 		if (mpu3050->irq_actl)
1034 			val |= MPU3050_INT_ACTL;
1035 		if (mpu3050->irq_latch)
1036 			val |= MPU3050_INT_LATCH_EN;
1037 		if (mpu3050->irq_opendrain)
1038 			val |= MPU3050_INT_OPEN;
1039 
1040 		ret = regmap_write(mpu3050->map, MPU3050_INT_CFG, val);
1041 		if (ret)
1042 			return ret;
1043 	}
1044 
1045 	return 0;
1046 }
1047 
1048 static const struct iio_trigger_ops mpu3050_trigger_ops = {
1049 	.set_trigger_state = mpu3050_drdy_trigger_set_state,
1050 };
1051 
1052 static int mpu3050_trigger_probe(struct iio_dev *indio_dev, int irq)
1053 {
1054 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
1055 	struct device *dev = mpu3050->dev;
1056 	unsigned long irq_trig;
1057 	int ret;
1058 
1059 	mpu3050->trig = devm_iio_trigger_alloc(&indio_dev->dev,
1060 					       "%s-dev%d",
1061 					       indio_dev->name,
1062 					       iio_device_id(indio_dev));
1063 	if (!mpu3050->trig)
1064 		return -ENOMEM;
1065 
1066 	/* Check if IRQ is open drain */
1067 	mpu3050->irq_opendrain = device_property_read_bool(dev, "drive-open-drain");
1068 
1069 	irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
1070 	/*
1071 	 * Configure the interrupt generator hardware to supply whatever
1072 	 * the interrupt is configured for, edges low/high level low/high,
1073 	 * we can provide it all.
1074 	 */
1075 	switch (irq_trig) {
1076 	case IRQF_TRIGGER_RISING:
1077 		dev_info(&indio_dev->dev,
1078 			 "pulse interrupts on the rising edge\n");
1079 		break;
1080 	case IRQF_TRIGGER_FALLING:
1081 		mpu3050->irq_actl = true;
1082 		dev_info(&indio_dev->dev,
1083 			 "pulse interrupts on the falling edge\n");
1084 		break;
1085 	case IRQF_TRIGGER_HIGH:
1086 		mpu3050->irq_latch = true;
1087 		dev_info(&indio_dev->dev,
1088 			 "interrupts active high level\n");
1089 		/*
1090 		 * With level IRQs, we mask the IRQ until it is processed,
1091 		 * but with edge IRQs (pulses) we can queue several interrupts
1092 		 * in the top half.
1093 		 */
1094 		irq_trig |= IRQF_ONESHOT;
1095 		break;
1096 	case IRQF_TRIGGER_LOW:
1097 		mpu3050->irq_latch = true;
1098 		mpu3050->irq_actl = true;
1099 		irq_trig |= IRQF_ONESHOT;
1100 		dev_info(&indio_dev->dev,
1101 			 "interrupts active low level\n");
1102 		break;
1103 	default:
1104 		/* This is the most preferred mode, if possible */
1105 		dev_err(&indio_dev->dev,
1106 			"unsupported IRQ trigger specified (%lx), enforce "
1107 			"rising edge\n", irq_trig);
1108 		irq_trig = IRQF_TRIGGER_RISING;
1109 		break;
1110 	}
1111 
1112 	/* An open drain line can be shared with several devices */
1113 	if (mpu3050->irq_opendrain)
1114 		irq_trig |= IRQF_SHARED;
1115 
1116 	ret = request_threaded_irq(irq,
1117 				   mpu3050_irq_handler,
1118 				   mpu3050_irq_thread,
1119 				   irq_trig,
1120 				   mpu3050->trig->name,
1121 				   mpu3050->trig);
1122 	if (ret) {
1123 		dev_err(dev, "can't get IRQ %d, error %d\n", irq, ret);
1124 		return ret;
1125 	}
1126 
1127 	mpu3050->irq = irq;
1128 	mpu3050->trig->dev.parent = dev;
1129 	mpu3050->trig->ops = &mpu3050_trigger_ops;
1130 	iio_trigger_set_drvdata(mpu3050->trig, indio_dev);
1131 
1132 	ret = iio_trigger_register(mpu3050->trig);
1133 	if (ret)
1134 		return ret;
1135 
1136 	indio_dev->trig = iio_trigger_get(mpu3050->trig);
1137 
1138 	return 0;
1139 }
1140 
1141 int mpu3050_common_probe(struct device *dev,
1142 			 struct regmap *map,
1143 			 int irq,
1144 			 const char *name)
1145 {
1146 	struct iio_dev *indio_dev;
1147 	struct mpu3050 *mpu3050;
1148 	unsigned int val;
1149 	int ret;
1150 
1151 	indio_dev = devm_iio_device_alloc(dev, sizeof(*mpu3050));
1152 	if (!indio_dev)
1153 		return -ENOMEM;
1154 	mpu3050 = iio_priv(indio_dev);
1155 
1156 	mpu3050->dev = dev;
1157 	mpu3050->map = map;
1158 	mutex_init(&mpu3050->lock);
1159 	/* Default fullscale: 2000 degrees per second */
1160 	mpu3050->fullscale = FS_2000_DPS;
1161 	/* 1 kHz, divide by 100, default frequency = 10 Hz */
1162 	mpu3050->lpf = MPU3050_DLPF_CFG_188HZ;
1163 	mpu3050->divisor = 99;
1164 
1165 	/* Read the mounting matrix, if present */
1166 	ret = iio_read_mount_matrix(dev, &mpu3050->orientation);
1167 	if (ret)
1168 		return ret;
1169 
1170 	/* Fetch and turn on regulators */
1171 	mpu3050->regs[0].supply = mpu3050_reg_vdd;
1172 	mpu3050->regs[1].supply = mpu3050_reg_vlogic;
1173 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(mpu3050->regs),
1174 				      mpu3050->regs);
1175 	if (ret) {
1176 		dev_err(dev, "Cannot get regulators\n");
1177 		return ret;
1178 	}
1179 
1180 	ret = mpu3050_power_up(mpu3050);
1181 	if (ret)
1182 		return ret;
1183 
1184 	ret = regmap_read(map, MPU3050_CHIP_ID_REG, &val);
1185 	if (ret) {
1186 		dev_err(dev, "could not read device ID\n");
1187 		ret = -ENODEV;
1188 
1189 		goto err_power_down;
1190 	}
1191 
1192 	if ((val & MPU3050_CHIP_ID_MASK) != MPU3050_CHIP_ID) {
1193 		dev_err(dev, "unsupported chip id %02x\n",
1194 				(u8)(val & MPU3050_CHIP_ID_MASK));
1195 		ret = -ENODEV;
1196 		goto err_power_down;
1197 	}
1198 
1199 	ret = regmap_read(map, MPU3050_PRODUCT_ID_REG, &val);
1200 	if (ret) {
1201 		dev_err(dev, "could not read device ID\n");
1202 		ret = -ENODEV;
1203 
1204 		goto err_power_down;
1205 	}
1206 	dev_info(dev, "found MPU-3050 part no: %d, version: %d\n",
1207 		 ((val >> 4) & 0xf), (val & 0xf));
1208 
1209 	ret = mpu3050_hw_init(mpu3050);
1210 	if (ret)
1211 		goto err_power_down;
1212 
1213 	indio_dev->channels = mpu3050_channels;
1214 	indio_dev->num_channels = ARRAY_SIZE(mpu3050_channels);
1215 	indio_dev->info = &mpu3050_info;
1216 	indio_dev->available_scan_masks = mpu3050_scan_masks;
1217 	indio_dev->modes = INDIO_DIRECT_MODE;
1218 	indio_dev->name = name;
1219 
1220 	ret = iio_triggered_buffer_setup(indio_dev, iio_pollfunc_store_time,
1221 					 mpu3050_trigger_handler,
1222 					 &mpu3050_buffer_setup_ops);
1223 	if (ret) {
1224 		dev_err(dev, "triggered buffer setup failed\n");
1225 		goto err_power_down;
1226 	}
1227 
1228 	ret = iio_device_register(indio_dev);
1229 	if (ret) {
1230 		dev_err(dev, "device register failed\n");
1231 		goto err_cleanup_buffer;
1232 	}
1233 
1234 	dev_set_drvdata(dev, indio_dev);
1235 
1236 	/* Check if we have an assigned IRQ to use as trigger */
1237 	if (irq) {
1238 		ret = mpu3050_trigger_probe(indio_dev, irq);
1239 		if (ret)
1240 			dev_err(dev, "failed to register trigger\n");
1241 	}
1242 
1243 	/* Enable runtime PM */
1244 	pm_runtime_get_noresume(dev);
1245 	pm_runtime_set_active(dev);
1246 	pm_runtime_enable(dev);
1247 	/*
1248 	 * Set autosuspend to two orders of magnitude larger than the
1249 	 * start-up time. 100ms start-up time means 10000ms autosuspend,
1250 	 * i.e. 10 seconds.
1251 	 */
1252 	pm_runtime_set_autosuspend_delay(dev, 10000);
1253 	pm_runtime_use_autosuspend(dev);
1254 	pm_runtime_put(dev);
1255 
1256 	return 0;
1257 
1258 err_cleanup_buffer:
1259 	iio_triggered_buffer_cleanup(indio_dev);
1260 err_power_down:
1261 	mpu3050_power_down(mpu3050);
1262 
1263 	return ret;
1264 }
1265 
1266 void mpu3050_common_remove(struct device *dev)
1267 {
1268 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
1269 	struct mpu3050 *mpu3050 = iio_priv(indio_dev);
1270 
1271 	pm_runtime_get_sync(dev);
1272 	pm_runtime_put_noidle(dev);
1273 	pm_runtime_disable(dev);
1274 	iio_triggered_buffer_cleanup(indio_dev);
1275 	if (mpu3050->irq)
1276 		free_irq(mpu3050->irq, mpu3050);
1277 	iio_device_unregister(indio_dev);
1278 	mpu3050_power_down(mpu3050);
1279 }
1280 
1281 static int mpu3050_runtime_suspend(struct device *dev)
1282 {
1283 	return mpu3050_power_down(iio_priv(dev_get_drvdata(dev)));
1284 }
1285 
1286 static int mpu3050_runtime_resume(struct device *dev)
1287 {
1288 	return mpu3050_power_up(iio_priv(dev_get_drvdata(dev)));
1289 }
1290 
1291 DEFINE_RUNTIME_DEV_PM_OPS(mpu3050_dev_pm_ops, mpu3050_runtime_suspend,
1292 			  mpu3050_runtime_resume, NULL);
1293 MODULE_AUTHOR("Linus Walleij");
1294 MODULE_DESCRIPTION("MPU3050 gyroscope driver");
1295 MODULE_LICENSE("GPL");
1296