xref: /openbmc/linux/drivers/iio/accel/mma9551_core.c (revision 293d5b43)
1 /*
2  * Common code for Freescale MMA955x Intelligent Sensor Platform drivers
3  * Copyright (c) 2014, Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  */
14 
15 #include <linux/module.h>
16 #include <linux/i2c.h>
17 #include <linux/delay.h>
18 #include <linux/iio/iio.h>
19 #include <linux/pm_runtime.h>
20 #include "mma9551_core.h"
21 
22 /* Command masks for mailbox write command */
23 #define MMA9551_CMD_READ_VERSION_INFO	0x00
24 #define MMA9551_CMD_READ_CONFIG		0x10
25 #define MMA9551_CMD_WRITE_CONFIG	0x20
26 #define MMA9551_CMD_READ_STATUS		0x30
27 
28 /* Mailbox read command */
29 #define MMA9551_RESPONSE_COCO		BIT(7)
30 
31 /* Error-Status codes returned in mailbox read command */
32 #define MMA9551_MCI_ERROR_NONE			0x00
33 #define MMA9551_MCI_ERROR_PARAM			0x04
34 #define MMA9551_MCI_INVALID_COUNT		0x19
35 #define MMA9551_MCI_ERROR_COMMAND		0x1C
36 #define MMA9551_MCI_ERROR_INVALID_LENGTH	0x21
37 #define MMA9551_MCI_ERROR_FIFO_BUSY		0x22
38 #define MMA9551_MCI_ERROR_FIFO_ALLOCATED	0x23
39 #define MMA9551_MCI_ERROR_FIFO_OVERSIZE		0x24
40 
41 /* GPIO Application */
42 #define MMA9551_GPIO_POL_MSB		0x08
43 #define MMA9551_GPIO_POL_LSB		0x09
44 
45 /* Sleep/Wake application */
46 #define MMA9551_SLEEP_CFG		0x06
47 #define MMA9551_SLEEP_CFG_SNCEN		BIT(0)
48 #define MMA9551_SLEEP_CFG_FLEEN		BIT(1)
49 #define MMA9551_SLEEP_CFG_SCHEN		BIT(2)
50 
51 /* AFE application */
52 #define MMA9551_AFE_X_ACCEL_REG		0x00
53 #define MMA9551_AFE_Y_ACCEL_REG		0x02
54 #define MMA9551_AFE_Z_ACCEL_REG		0x04
55 
56 /* Reset/Suspend/Clear application */
57 #define MMA9551_RSC_RESET		0x00
58 #define MMA9551_RSC_OFFSET(mask)	(3 - (ffs(mask) - 1) / 8)
59 #define MMA9551_RSC_VAL(mask)		(mask >> (((ffs(mask) - 1) / 8) * 8))
60 
61 /*
62  * A response is composed of:
63  * - control registers: MB0-3
64  * - data registers: MB4-31
65  *
66  * A request is composed of:
67  * - mbox to write to (always 0)
68  * - control registers: MB1-4
69  * - data registers: MB5-31
70  */
71 #define MMA9551_MAILBOX_CTRL_REGS	4
72 #define MMA9551_MAX_MAILBOX_DATA_REGS	28
73 #define MMA9551_MAILBOX_REGS		32
74 
75 #define MMA9551_I2C_READ_RETRIES	5
76 #define MMA9551_I2C_READ_DELAY	50	/* us */
77 
78 struct mma9551_mbox_request {
79 	u8 start_mbox;		/* Always 0. */
80 	u8 app_id;
81 	/*
82 	 * See Section 5.3.1 of the MMA955xL Software Reference Manual.
83 	 *
84 	 * Bit 7: reserved, always 0
85 	 * Bits 6-4: command
86 	 * Bits 3-0: upper bits of register offset
87 	 */
88 	u8 cmd_off;
89 	u8 lower_off;
90 	u8 nbytes;
91 	u8 buf[MMA9551_MAX_MAILBOX_DATA_REGS - 1];
92 } __packed;
93 
94 struct mma9551_mbox_response {
95 	u8 app_id;
96 	/*
97 	 * See Section 5.3.3 of the MMA955xL Software Reference Manual.
98 	 *
99 	 * Bit 7: COCO
100 	 * Bits 6-0: Error code.
101 	 */
102 	u8 coco_err;
103 	u8 nbytes;
104 	u8 req_bytes;
105 	u8 buf[MMA9551_MAX_MAILBOX_DATA_REGS];
106 } __packed;
107 
108 struct mma9551_version_info {
109 	__be32 device_id;
110 	u8 rom_version[2];
111 	u8 fw_version[2];
112 	u8 hw_version[2];
113 	u8 fw_build[2];
114 };
115 
116 static int mma9551_transfer(struct i2c_client *client,
117 			    u8 app_id, u8 command, u16 offset,
118 			    u8 *inbytes, int num_inbytes,
119 			    u8 *outbytes, int num_outbytes)
120 {
121 	struct mma9551_mbox_request req;
122 	struct mma9551_mbox_response rsp;
123 	struct i2c_msg in, out;
124 	u8 req_len, err_code;
125 	int ret, retries;
126 
127 	if (offset >= 1 << 12) {
128 		dev_err(&client->dev, "register offset too large\n");
129 		return -EINVAL;
130 	}
131 
132 	req_len = 1 + MMA9551_MAILBOX_CTRL_REGS + num_inbytes;
133 	req.start_mbox = 0;
134 	req.app_id = app_id;
135 	req.cmd_off = command | (offset >> 8);
136 	req.lower_off = offset;
137 
138 	if (command == MMA9551_CMD_WRITE_CONFIG)
139 		req.nbytes = num_inbytes;
140 	else
141 		req.nbytes = num_outbytes;
142 	if (num_inbytes)
143 		memcpy(req.buf, inbytes, num_inbytes);
144 
145 	out.addr = client->addr;
146 	out.flags = 0;
147 	out.len = req_len;
148 	out.buf = (u8 *)&req;
149 
150 	ret = i2c_transfer(client->adapter, &out, 1);
151 	if (ret < 0) {
152 		dev_err(&client->dev, "i2c write failed\n");
153 		return ret;
154 	}
155 
156 	retries = MMA9551_I2C_READ_RETRIES;
157 	do {
158 		udelay(MMA9551_I2C_READ_DELAY);
159 
160 		in.addr = client->addr;
161 		in.flags = I2C_M_RD;
162 		in.len = sizeof(rsp);
163 		in.buf = (u8 *)&rsp;
164 
165 		ret = i2c_transfer(client->adapter, &in, 1);
166 		if (ret < 0) {
167 			dev_err(&client->dev, "i2c read failed\n");
168 			return ret;
169 		}
170 
171 		if (rsp.coco_err & MMA9551_RESPONSE_COCO)
172 			break;
173 	} while (--retries > 0);
174 
175 	if (retries == 0) {
176 		dev_err(&client->dev,
177 			"timed out while waiting for command response\n");
178 		return -ETIMEDOUT;
179 	}
180 
181 	if (rsp.app_id != app_id) {
182 		dev_err(&client->dev,
183 			"app_id mismatch in response got %02x expected %02x\n",
184 			rsp.app_id, app_id);
185 		return -EINVAL;
186 	}
187 
188 	err_code = rsp.coco_err & ~MMA9551_RESPONSE_COCO;
189 	if (err_code != MMA9551_MCI_ERROR_NONE) {
190 		dev_err(&client->dev, "read returned error %x\n", err_code);
191 		return -EINVAL;
192 	}
193 
194 	if (rsp.nbytes != rsp.req_bytes) {
195 		dev_err(&client->dev,
196 			"output length mismatch got %d expected %d\n",
197 			rsp.nbytes, rsp.req_bytes);
198 		return -EINVAL;
199 	}
200 
201 	if (num_outbytes)
202 		memcpy(outbytes, rsp.buf, num_outbytes);
203 
204 	return 0;
205 }
206 
207 /**
208  * mma9551_read_config_byte() - read 1 configuration byte
209  * @client:	I2C client
210  * @app_id:	Application ID
211  * @reg:	Application register
212  * @val:	Pointer to store value read
213  *
214  * Read one configuration byte from the device using MMA955xL command format.
215  * Commands to the MMA955xL platform consist of a write followed
216  * by one or more reads.
217  *
218  * Locking note: This function must be called with the device lock held.
219  * Locking is not handled inside the function. Callers should ensure they
220  * serialize access to the HW.
221  *
222  * Returns: 0 on success, negative value on failure.
223  */
224 int mma9551_read_config_byte(struct i2c_client *client, u8 app_id,
225 			     u16 reg, u8 *val)
226 {
227 	return mma9551_transfer(client, app_id, MMA9551_CMD_READ_CONFIG,
228 				reg, NULL, 0, val, 1);
229 }
230 EXPORT_SYMBOL(mma9551_read_config_byte);
231 
232 /**
233  * mma9551_write_config_byte() - write 1 configuration byte
234  * @client:	I2C client
235  * @app_id:	Application ID
236  * @reg:	Application register
237  * @val:	Value to write
238  *
239  * Write one configuration byte from the device using MMA955xL command format.
240  * Commands to the MMA955xL platform consist of a write followed by one or
241  * more reads.
242  *
243  * Locking note: This function must be called with the device lock held.
244  * Locking is not handled inside the function. Callers should ensure they
245  * serialize access to the HW.
246  *
247  * Returns: 0 on success, negative value on failure.
248  */
249 int mma9551_write_config_byte(struct i2c_client *client, u8 app_id,
250 			      u16 reg, u8 val)
251 {
252 	return mma9551_transfer(client, app_id, MMA9551_CMD_WRITE_CONFIG, reg,
253 				&val, 1, NULL, 0);
254 }
255 EXPORT_SYMBOL(mma9551_write_config_byte);
256 
257 /**
258  * mma9551_read_status_byte() - read 1 status byte
259  * @client:	I2C client
260  * @app_id:	Application ID
261  * @reg:	Application register
262  * @val:	Pointer to store value read
263  *
264  * Read one status byte from the device using MMA955xL command format.
265  * Commands to the MMA955xL platform consist of a write followed by one or
266  * more reads.
267  *
268  * Locking note: This function must be called with the device lock held.
269  * Locking is not handled inside the function. Callers should ensure they
270  * serialize access to the HW.
271  *
272  * Returns: 0 on success, negative value on failure.
273  */
274 int mma9551_read_status_byte(struct i2c_client *client, u8 app_id,
275 			     u16 reg, u8 *val)
276 {
277 	return mma9551_transfer(client, app_id, MMA9551_CMD_READ_STATUS,
278 				reg, NULL, 0, val, 1);
279 }
280 EXPORT_SYMBOL(mma9551_read_status_byte);
281 
282 /**
283  * mma9551_read_config_word() - read 1 config word
284  * @client:	I2C client
285  * @app_id:	Application ID
286  * @reg:	Application register
287  * @val:	Pointer to store value read
288  *
289  * Read one configuration word from the device using MMA955xL command format.
290  * Commands to the MMA955xL platform consist of a write followed by one or
291  * more reads.
292  *
293  * Locking note: This function must be called with the device lock held.
294  * Locking is not handled inside the function. Callers should ensure they
295  * serialize access to the HW.
296  *
297  * Returns: 0 on success, negative value on failure.
298  */
299 int mma9551_read_config_word(struct i2c_client *client, u8 app_id,
300 			     u16 reg, u16 *val)
301 {
302 	int ret;
303 	__be16 v;
304 
305 	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_CONFIG,
306 			       reg, NULL, 0, (u8 *)&v, 2);
307 	*val = be16_to_cpu(v);
308 
309 	return ret;
310 }
311 EXPORT_SYMBOL(mma9551_read_config_word);
312 
313 /**
314  * mma9551_write_config_word() - write 1 config word
315  * @client:	I2C client
316  * @app_id:	Application ID
317  * @reg:	Application register
318  * @val:	Value to write
319  *
320  * Write one configuration word from the device using MMA955xL command format.
321  * Commands to the MMA955xL platform consist of a write followed by one or
322  * more reads.
323  *
324  * Locking note: This function must be called with the device lock held.
325  * Locking is not handled inside the function. Callers should ensure they
326  * serialize access to the HW.
327  *
328  * Returns: 0 on success, negative value on failure.
329  */
330 int mma9551_write_config_word(struct i2c_client *client, u8 app_id,
331 			      u16 reg, u16 val)
332 {
333 	__be16 v = cpu_to_be16(val);
334 
335 	return mma9551_transfer(client, app_id, MMA9551_CMD_WRITE_CONFIG, reg,
336 				(u8 *)&v, 2, NULL, 0);
337 }
338 EXPORT_SYMBOL(mma9551_write_config_word);
339 
340 /**
341  * mma9551_read_status_word() - read 1 status word
342  * @client:	I2C client
343  * @app_id:	Application ID
344  * @reg:	Application register
345  * @val:	Pointer to store value read
346  *
347  * Read one status word from the device using MMA955xL command format.
348  * Commands to the MMA955xL platform consist of a write followed by one or
349  * more reads.
350  *
351  * Locking note: This function must be called with the device lock held.
352  * Locking is not handled inside the function. Callers should ensure they
353  * serialize access to the HW.
354  *
355  * Returns: 0 on success, negative value on failure.
356  */
357 int mma9551_read_status_word(struct i2c_client *client, u8 app_id,
358 			     u16 reg, u16 *val)
359 {
360 	int ret;
361 	__be16 v;
362 
363 	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_STATUS,
364 			       reg, NULL, 0, (u8 *)&v, 2);
365 	*val = be16_to_cpu(v);
366 
367 	return ret;
368 }
369 EXPORT_SYMBOL(mma9551_read_status_word);
370 
371 /**
372  * mma9551_read_config_words() - read multiple config words
373  * @client:	I2C client
374  * @app_id:	Application ID
375  * @reg:	Application register
376  * @len:	Length of array to read (in words)
377  * @buf:	Array of words to read
378  *
379  * Read multiple configuration registers (word-sized registers).
380  *
381  * Locking note: This function must be called with the device lock held.
382  * Locking is not handled inside the function. Callers should ensure they
383  * serialize access to the HW.
384  *
385  * Returns: 0 on success, negative value on failure.
386  */
387 int mma9551_read_config_words(struct i2c_client *client, u8 app_id,
388 			      u16 reg, u8 len, u16 *buf)
389 {
390 	int ret, i;
391 	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS / 2];
392 
393 	if (len > ARRAY_SIZE(be_buf)) {
394 		dev_err(&client->dev, "Invalid buffer size %d\n", len);
395 		return -EINVAL;
396 	}
397 
398 	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_CONFIG,
399 			       reg, NULL, 0, (u8 *)be_buf, len * sizeof(u16));
400 	if (ret < 0)
401 		return ret;
402 
403 	for (i = 0; i < len; i++)
404 		buf[i] = be16_to_cpu(be_buf[i]);
405 
406 	return 0;
407 }
408 EXPORT_SYMBOL(mma9551_read_config_words);
409 
410 /**
411  * mma9551_read_status_words() - read multiple status words
412  * @client:	I2C client
413  * @app_id:	Application ID
414  * @reg:	Application register
415  * @len:	Length of array to read (in words)
416  * @buf:	Array of words to read
417  *
418  * Read multiple status registers (word-sized registers).
419  *
420  * Locking note: This function must be called with the device lock held.
421  * Locking is not handled inside the function. Callers should ensure they
422  * serialize access to the HW.
423  *
424  * Returns: 0 on success, negative value on failure.
425  */
426 int mma9551_read_status_words(struct i2c_client *client, u8 app_id,
427 			      u16 reg, u8 len, u16 *buf)
428 {
429 	int ret, i;
430 	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS / 2];
431 
432 	if (len > ARRAY_SIZE(be_buf)) {
433 		dev_err(&client->dev, "Invalid buffer size %d\n", len);
434 		return -EINVAL;
435 	}
436 
437 	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_STATUS,
438 			       reg, NULL, 0, (u8 *)be_buf, len * sizeof(u16));
439 	if (ret < 0)
440 		return ret;
441 
442 	for (i = 0; i < len; i++)
443 		buf[i] = be16_to_cpu(be_buf[i]);
444 
445 	return 0;
446 }
447 EXPORT_SYMBOL(mma9551_read_status_words);
448 
449 /**
450  * mma9551_write_config_words() - write multiple config words
451  * @client:	I2C client
452  * @app_id:	Application ID
453  * @reg:	Application register
454  * @len:	Length of array to write (in words)
455  * @buf:	Array of words to write
456  *
457  * Write multiple configuration registers (word-sized registers).
458  *
459  * Locking note: This function must be called with the device lock held.
460  * Locking is not handled inside the function. Callers should ensure they
461  * serialize access to the HW.
462  *
463  * Returns: 0 on success, negative value on failure.
464  */
465 int mma9551_write_config_words(struct i2c_client *client, u8 app_id,
466 			       u16 reg, u8 len, u16 *buf)
467 {
468 	int i;
469 	__be16 be_buf[(MMA9551_MAX_MAILBOX_DATA_REGS - 1) / 2];
470 
471 	if (len > ARRAY_SIZE(be_buf)) {
472 		dev_err(&client->dev, "Invalid buffer size %d\n", len);
473 		return -EINVAL;
474 	}
475 
476 	for (i = 0; i < len; i++)
477 		be_buf[i] = cpu_to_be16(buf[i]);
478 
479 	return mma9551_transfer(client, app_id, MMA9551_CMD_WRITE_CONFIG,
480 				reg, (u8 *)be_buf, len * sizeof(u16), NULL, 0);
481 }
482 EXPORT_SYMBOL(mma9551_write_config_words);
483 
484 /**
485  * mma9551_update_config_bits() - update bits in register
486  * @client:	I2C client
487  * @app_id:	Application ID
488  * @reg:	Application register
489  * @mask:	Mask for the bits to update
490  * @val:	Value of the bits to update
491  *
492  * Update bits in the given register using a bit mask.
493  *
494  * Locking note: This function must be called with the device lock held.
495  * Locking is not handled inside the function. Callers should ensure they
496  * serialize access to the HW.
497  *
498  * Returns: 0 on success, negative value on failure.
499  */
500 int mma9551_update_config_bits(struct i2c_client *client, u8 app_id,
501 			       u16 reg, u8 mask, u8 val)
502 {
503 	int ret;
504 	u8 tmp, orig;
505 
506 	ret = mma9551_read_config_byte(client, app_id, reg, &orig);
507 	if (ret < 0)
508 		return ret;
509 
510 	tmp = orig & ~mask;
511 	tmp |= val & mask;
512 
513 	if (tmp == orig)
514 		return 0;
515 
516 	return mma9551_write_config_byte(client, app_id, reg, tmp);
517 }
518 EXPORT_SYMBOL(mma9551_update_config_bits);
519 
520 /**
521  * mma9551_gpio_config() - configure gpio
522  * @client:	I2C client
523  * @pin:	GPIO pin to configure
524  * @app_id:	Application ID
525  * @bitnum:	Bit number of status register being assigned to the GPIO pin.
526  * @polarity:	The polarity parameter is described in section 6.2.2, page 66,
527  *		of the Software Reference Manual.  Basically, polarity=0 means
528  *		the interrupt line has the same value as the selected bit,
529  *		while polarity=1 means the line is inverted.
530  *
531  * Assign a bit from an application’s status register to a specific GPIO pin.
532  *
533  * Locking note: This function must be called with the device lock held.
534  * Locking is not handled inside the function. Callers should ensure they
535  * serialize access to the HW.
536  *
537  * Returns: 0 on success, negative value on failure.
538  */
539 int mma9551_gpio_config(struct i2c_client *client, enum mma9551_gpio_pin pin,
540 			u8 app_id, u8 bitnum, int polarity)
541 {
542 	u8 reg, pol_mask, pol_val;
543 	int ret;
544 
545 	if (pin > mma9551_gpio_max) {
546 		dev_err(&client->dev, "bad GPIO pin\n");
547 		return -EINVAL;
548 	}
549 
550 	/*
551 	 * Pin 6 is configured by regs 0x00 and 0x01, pin 7 by 0x02 and
552 	 * 0x03, and so on.
553 	 */
554 	reg = pin * 2;
555 
556 	ret = mma9551_write_config_byte(client, MMA9551_APPID_GPIO,
557 					reg, app_id);
558 	if (ret < 0) {
559 		dev_err(&client->dev, "error setting GPIO app_id\n");
560 		return ret;
561 	}
562 
563 	ret = mma9551_write_config_byte(client, MMA9551_APPID_GPIO,
564 					reg + 1, bitnum);
565 	if (ret < 0) {
566 		dev_err(&client->dev, "error setting GPIO bit number\n");
567 		return ret;
568 	}
569 
570 	switch (pin) {
571 	case mma9551_gpio6:
572 		reg = MMA9551_GPIO_POL_LSB;
573 		pol_mask = 1 << 6;
574 		break;
575 	case mma9551_gpio7:
576 		reg = MMA9551_GPIO_POL_LSB;
577 		pol_mask = 1 << 7;
578 		break;
579 	case mma9551_gpio8:
580 		reg = MMA9551_GPIO_POL_MSB;
581 		pol_mask = 1 << 0;
582 		break;
583 	case mma9551_gpio9:
584 		reg = MMA9551_GPIO_POL_MSB;
585 		pol_mask = 1 << 1;
586 		break;
587 	}
588 	pol_val = polarity ? pol_mask : 0;
589 
590 	ret = mma9551_update_config_bits(client, MMA9551_APPID_GPIO, reg,
591 					 pol_mask, pol_val);
592 	if (ret < 0)
593 		dev_err(&client->dev, "error setting GPIO polarity\n");
594 
595 	return ret;
596 }
597 EXPORT_SYMBOL(mma9551_gpio_config);
598 
599 /**
600  * mma9551_read_version() - read device version information
601  * @client:	I2C client
602  *
603  * Read version information and print device id and firmware version.
604  *
605  * Locking note: This function must be called with the device lock held.
606  * Locking is not handled inside the function. Callers should ensure they
607  * serialize access to the HW.
608  *
609  * Returns: 0 on success, negative value on failure.
610  */
611 int mma9551_read_version(struct i2c_client *client)
612 {
613 	struct mma9551_version_info info;
614 	int ret;
615 
616 	ret = mma9551_transfer(client, MMA9551_APPID_VERSION, 0x00, 0x00,
617 			       NULL, 0, (u8 *)&info, sizeof(info));
618 	if (ret < 0)
619 		return ret;
620 
621 	dev_info(&client->dev, "device ID 0x%x, firmware version %02x.%02x\n",
622 		 be32_to_cpu(info.device_id), info.fw_version[0],
623 		 info.fw_version[1]);
624 
625 	return 0;
626 }
627 EXPORT_SYMBOL(mma9551_read_version);
628 
629 /**
630  * mma9551_set_device_state() - sets HW power mode
631  * @client:	I2C client
632  * @enable:	Use true to power on device, false to cause the device
633  *		to enter sleep.
634  *
635  * Set power on/off for device using the Sleep/Wake Application.
636  * When enable is true, power on chip and enable doze mode.
637  * When enable is false, enter sleep mode (device remains in the
638  * lowest-power mode).
639  *
640  * Locking note: This function must be called with the device lock held.
641  * Locking is not handled inside the function. Callers should ensure they
642  * serialize access to the HW.
643  *
644  * Returns: 0 on success, negative value on failure.
645  */
646 int mma9551_set_device_state(struct i2c_client *client, bool enable)
647 {
648 	return mma9551_update_config_bits(client, MMA9551_APPID_SLEEP_WAKE,
649 					  MMA9551_SLEEP_CFG,
650 					  MMA9551_SLEEP_CFG_SNCEN |
651 					  MMA9551_SLEEP_CFG_FLEEN |
652 					  MMA9551_SLEEP_CFG_SCHEN,
653 					  enable ? MMA9551_SLEEP_CFG_SCHEN |
654 					  MMA9551_SLEEP_CFG_FLEEN :
655 					  MMA9551_SLEEP_CFG_SNCEN);
656 }
657 EXPORT_SYMBOL(mma9551_set_device_state);
658 
659 /**
660  * mma9551_set_power_state() - sets runtime PM state
661  * @client:	I2C client
662  * @on:		Use true to power on device, false to power off
663  *
664  * Resume or suspend the device using Runtime PM.
665  * The device will suspend after the autosuspend delay.
666  *
667  * Returns: 0 on success, negative value on failure.
668  */
669 int mma9551_set_power_state(struct i2c_client *client, bool on)
670 {
671 #ifdef CONFIG_PM
672 	int ret;
673 
674 	if (on)
675 		ret = pm_runtime_get_sync(&client->dev);
676 	else {
677 		pm_runtime_mark_last_busy(&client->dev);
678 		ret = pm_runtime_put_autosuspend(&client->dev);
679 	}
680 
681 	if (ret < 0) {
682 		dev_err(&client->dev,
683 			"failed to change power state to %d\n", on);
684 		if (on)
685 			pm_runtime_put_noidle(&client->dev);
686 
687 		return ret;
688 	}
689 #endif
690 
691 	return 0;
692 }
693 EXPORT_SYMBOL(mma9551_set_power_state);
694 
695 /**
696  * mma9551_sleep() - sleep
697  * @freq:	Application frequency
698  *
699  * Firmware applications run at a certain frequency on the
700  * device. Sleep for one application cycle to make sure the
701  * application had time to run once and initialize set values.
702  */
703 void mma9551_sleep(int freq)
704 {
705 	int sleep_val = 1000 / freq;
706 
707 	if (sleep_val < 20)
708 		usleep_range(sleep_val * 1000, 20000);
709 	else
710 		msleep_interruptible(sleep_val);
711 }
712 EXPORT_SYMBOL(mma9551_sleep);
713 
714 /**
715  * mma9551_read_accel_chan() - read accelerometer channel
716  * @client:	I2C client
717  * @chan:	IIO channel
718  * @val:	Pointer to the accelerometer value read
719  * @val2:	Unused
720  *
721  * Read accelerometer value for the specified channel.
722  *
723  * Locking note: This function must be called with the device lock held.
724  * Locking is not handled inside the function. Callers should ensure they
725  * serialize access to the HW.
726  *
727  * Returns: IIO_VAL_INT on success, negative value on failure.
728  */
729 int mma9551_read_accel_chan(struct i2c_client *client,
730 			    const struct iio_chan_spec *chan,
731 			    int *val, int *val2)
732 {
733 	u16 reg_addr;
734 	s16 raw_accel;
735 	int ret;
736 
737 	switch (chan->channel2) {
738 	case IIO_MOD_X:
739 		reg_addr = MMA9551_AFE_X_ACCEL_REG;
740 		break;
741 	case IIO_MOD_Y:
742 		reg_addr = MMA9551_AFE_Y_ACCEL_REG;
743 		break;
744 	case IIO_MOD_Z:
745 		reg_addr = MMA9551_AFE_Z_ACCEL_REG;
746 		break;
747 	default:
748 		return -EINVAL;
749 	}
750 
751 	ret = mma9551_set_power_state(client, true);
752 	if (ret < 0)
753 		return ret;
754 
755 	ret = mma9551_read_status_word(client, MMA9551_APPID_AFE,
756 				       reg_addr, &raw_accel);
757 	if (ret < 0)
758 		goto out_poweroff;
759 
760 	*val = raw_accel;
761 
762 	ret = IIO_VAL_INT;
763 
764 out_poweroff:
765 	mma9551_set_power_state(client, false);
766 	return ret;
767 }
768 EXPORT_SYMBOL(mma9551_read_accel_chan);
769 
770 /**
771  * mma9551_read_accel_scale() - read accelerometer scale
772  * @val:	Pointer to the accelerometer scale (int value)
773  * @val2:	Pointer to the accelerometer scale (micro value)
774  *
775  * Read accelerometer scale.
776  *
777  * Returns: IIO_VAL_INT_PLUS_MICRO.
778  */
779 int mma9551_read_accel_scale(int *val, int *val2)
780 {
781 	*val = 0;
782 	*val2 = 2440;
783 
784 	return IIO_VAL_INT_PLUS_MICRO;
785 }
786 EXPORT_SYMBOL(mma9551_read_accel_scale);
787 
788 /**
789  * mma9551_app_reset() - reset application
790  * @client:	I2C client
791  * @app_mask:	Application to reset
792  *
793  * Reset the given application (using the Reset/Suspend/Clear
794  * Control Application)
795  *
796  * Returns: 0 on success, negative value on failure.
797  */
798 int mma9551_app_reset(struct i2c_client *client, u32 app_mask)
799 {
800 	return mma9551_write_config_byte(client, MMA9551_APPID_RSC,
801 					 MMA9551_RSC_RESET +
802 					 MMA9551_RSC_OFFSET(app_mask),
803 					 MMA9551_RSC_VAL(app_mask));
804 }
805 EXPORT_SYMBOL(mma9551_app_reset);
806 
807 MODULE_AUTHOR("Irina Tirdea <irina.tirdea@intel.com>");
808 MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
809 MODULE_LICENSE("GPL v2");
810 MODULE_DESCRIPTION("MMA955xL sensors core");
811