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
78struct 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
94struct 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
108struct 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
116static 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 */
224int 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}
230EXPORT_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 */
249int 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}
255EXPORT_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 */
274int 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}
280EXPORT_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 */
299int 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}
311EXPORT_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 */
330int 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}
338EXPORT_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 */
357int 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}
369EXPORT_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 bytes
377 * @val:	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 */
387int mma9551_read_config_words(struct i2c_client *client, u8 app_id,
388			     u16 reg, u8 len, u16 *buf)
389{
390	int ret, i;
391	int len_words = len / sizeof(u16);
392	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS / 2];
393
394	if (len_words > ARRAY_SIZE(be_buf)) {
395		dev_err(&client->dev, "Invalid buffer size %d\n", len);
396		return -EINVAL;
397	}
398
399	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_CONFIG,
400			       reg, NULL, 0, (u8 *) be_buf, len);
401	if (ret < 0)
402		return ret;
403
404	for (i = 0; i < len_words; i++)
405		buf[i] = be16_to_cpu(be_buf[i]);
406
407	return 0;
408}
409EXPORT_SYMBOL(mma9551_read_config_words);
410
411/**
412 * mma9551_read_status_words() - read multiple status words
413 * @client:	I2C client
414 * @app_id:	Application ID
415 * @reg:	Application register
416 * @len:	Length of array to read in bytes
417 * @val:	Array of words to read
418 *
419 * Read multiple status registers (word-sized registers).
420 *
421 * Locking note: This function must be called with the device lock held.
422 * Locking is not handled inside the function. Callers should ensure they
423 * serialize access to the HW.
424 *
425 * Returns: 0 on success, negative value on failure.
426 */
427int mma9551_read_status_words(struct i2c_client *client, u8 app_id,
428			      u16 reg, u8 len, u16 *buf)
429{
430	int ret, i;
431	int len_words = len / sizeof(u16);
432	__be16 be_buf[MMA9551_MAX_MAILBOX_DATA_REGS / 2];
433
434	if (len_words > ARRAY_SIZE(be_buf)) {
435		dev_err(&client->dev, "Invalid buffer size %d\n", len);
436		return -EINVAL;
437	}
438
439	ret = mma9551_transfer(client, app_id, MMA9551_CMD_READ_STATUS,
440			       reg, NULL, 0, (u8 *) be_buf, len);
441	if (ret < 0)
442		return ret;
443
444	for (i = 0; i < len_words; i++)
445		buf[i] = be16_to_cpu(be_buf[i]);
446
447	return 0;
448}
449EXPORT_SYMBOL(mma9551_read_status_words);
450
451/**
452 * mma9551_write_config_words() - write multiple config words
453 * @client:	I2C client
454 * @app_id:	Application ID
455 * @reg:	Application register
456 * @len:	Length of array to write in bytes
457 * @val:	Array of words to write
458 *
459 * Write multiple configuration registers (word-sized registers).
460 *
461 * Locking note: This function must be called with the device lock held.
462 * Locking is not handled inside the function. Callers should ensure they
463 * serialize access to the HW.
464 *
465 * Returns: 0 on success, negative value on failure.
466 */
467int mma9551_write_config_words(struct i2c_client *client, u8 app_id,
468			       u16 reg, u8 len, u16 *buf)
469{
470	int i;
471	int len_words = len / sizeof(u16);
472	__be16 be_buf[(MMA9551_MAX_MAILBOX_DATA_REGS - 1) / 2];
473
474	if (len_words > ARRAY_SIZE(be_buf)) {
475		dev_err(&client->dev, "Invalid buffer size %d\n", len);
476		return -EINVAL;
477	}
478
479	for (i = 0; i < len_words; i++)
480		be_buf[i] = cpu_to_be16(buf[i]);
481
482	return mma9551_transfer(client, app_id, MMA9551_CMD_WRITE_CONFIG,
483				reg, (u8 *) be_buf, len, NULL, 0);
484}
485EXPORT_SYMBOL(mma9551_write_config_words);
486
487/**
488 * mma9551_update_config_bits() - update bits in register
489 * @client:	I2C client
490 * @app_id:	Application ID
491 * @reg:	Application register
492 * @mask:	Mask for the bits to update
493 * @val:	Value of the bits to update
494 *
495 * Update bits in the given register using a bit mask.
496 *
497 * Locking note: This function must be called with the device lock held.
498 * Locking is not handled inside the function. Callers should ensure they
499 * serialize access to the HW.
500 *
501 * Returns: 0 on success, negative value on failure.
502 */
503int mma9551_update_config_bits(struct i2c_client *client, u8 app_id,
504			       u16 reg, u8 mask, u8 val)
505{
506	int ret;
507	u8 tmp, orig;
508
509	ret = mma9551_read_config_byte(client, app_id, reg, &orig);
510	if (ret < 0)
511		return ret;
512
513	tmp = orig & ~mask;
514	tmp |= val & mask;
515
516	if (tmp == orig)
517		return 0;
518
519	return mma9551_write_config_byte(client, app_id, reg, tmp);
520}
521EXPORT_SYMBOL(mma9551_update_config_bits);
522
523/**
524 * mma9551_gpio_config() - configure gpio
525 * @client:	I2C client
526 * @pin:	GPIO pin to configure
527 * @app_id:	Application ID
528 * @bitnum:	Bit number of status register being assigned to the GPIO pin.
529 * @polarity:	The polarity parameter is described in section 6.2.2, page 66,
530 *		of the Software Reference Manual.  Basically, polarity=0 means
531 *		the interrupt line has the same value as the selected bit,
532 *		while polarity=1 means the line is inverted.
533 *
534 * Assign a bit from an application’s status register to a specific GPIO pin.
535 *
536 * Locking note: This function must be called with the device lock held.
537 * Locking is not handled inside the function. Callers should ensure they
538 * serialize access to the HW.
539 *
540 * Returns: 0 on success, negative value on failure.
541 */
542int mma9551_gpio_config(struct i2c_client *client, enum mma9551_gpio_pin pin,
543			u8 app_id, u8 bitnum, int polarity)
544{
545	u8 reg, pol_mask, pol_val;
546	int ret;
547
548	if (pin > mma9551_gpio_max) {
549		dev_err(&client->dev, "bad GPIO pin\n");
550		return -EINVAL;
551	}
552
553	/*
554	 * Pin 6 is configured by regs 0x00 and 0x01, pin 7 by 0x02 and
555	 * 0x03, and so on.
556	 */
557	reg = pin * 2;
558
559	ret = mma9551_write_config_byte(client, MMA9551_APPID_GPIO,
560					reg, app_id);
561	if (ret < 0) {
562		dev_err(&client->dev, "error setting GPIO app_id\n");
563		return ret;
564	}
565
566	ret = mma9551_write_config_byte(client, MMA9551_APPID_GPIO,
567					reg + 1, bitnum);
568	if (ret < 0) {
569		dev_err(&client->dev, "error setting GPIO bit number\n");
570		return ret;
571	}
572
573	switch (pin) {
574	case mma9551_gpio6:
575		reg = MMA9551_GPIO_POL_LSB;
576		pol_mask = 1 << 6;
577		break;
578	case mma9551_gpio7:
579		reg = MMA9551_GPIO_POL_LSB;
580		pol_mask = 1 << 7;
581		break;
582	case mma9551_gpio8:
583		reg = MMA9551_GPIO_POL_MSB;
584		pol_mask = 1 << 0;
585		break;
586	case mma9551_gpio9:
587		reg = MMA9551_GPIO_POL_MSB;
588		pol_mask = 1 << 1;
589		break;
590	}
591	pol_val = polarity ? pol_mask : 0;
592
593	ret = mma9551_update_config_bits(client, MMA9551_APPID_GPIO, reg,
594					 pol_mask, pol_val);
595	if (ret < 0)
596		dev_err(&client->dev, "error setting GPIO polarity\n");
597
598	return ret;
599}
600EXPORT_SYMBOL(mma9551_gpio_config);
601
602/**
603 * mma9551_read_version() - read device version information
604 * @client:	I2C client
605 *
606 * Read version information and print device id and firmware version.
607 *
608 * Locking note: This function must be called with the device lock held.
609 * Locking is not handled inside the function. Callers should ensure they
610 * serialize access to the HW.
611 *
612 * Returns: 0 on success, negative value on failure.
613 */
614int mma9551_read_version(struct i2c_client *client)
615{
616	struct mma9551_version_info info;
617	int ret;
618
619	ret = mma9551_transfer(client, MMA9551_APPID_VERSION, 0x00, 0x00,
620			       NULL, 0, (u8 *)&info, sizeof(info));
621	if (ret < 0)
622		return ret;
623
624	dev_info(&client->dev, "device ID 0x%x, firmware version %02x.%02x\n",
625		 be32_to_cpu(info.device_id), info.fw_version[0],
626		 info.fw_version[1]);
627
628	return 0;
629}
630EXPORT_SYMBOL(mma9551_read_version);
631
632/**
633 * mma9551_set_device_state() - sets HW power mode
634 * @client:	I2C client
635 * @enable:	Use true to power on device, false to cause the device
636 *		to enter sleep.
637 *
638 * Set power on/off for device using the Sleep/Wake Application.
639 * When enable is true, power on chip and enable doze mode.
640 * When enable is false, enter sleep mode (device remains in the
641 * lowest-power mode).
642 *
643 * Locking note: This function must be called with the device lock held.
644 * Locking is not handled inside the function. Callers should ensure they
645 * serialize access to the HW.
646 *
647 * Returns: 0 on success, negative value on failure.
648 */
649int mma9551_set_device_state(struct i2c_client *client, bool enable)
650{
651	return mma9551_update_config_bits(client, MMA9551_APPID_SLEEP_WAKE,
652					  MMA9551_SLEEP_CFG,
653					  MMA9551_SLEEP_CFG_SNCEN |
654					  MMA9551_SLEEP_CFG_FLEEN |
655					  MMA9551_SLEEP_CFG_SCHEN,
656					  enable ? MMA9551_SLEEP_CFG_SCHEN |
657					  MMA9551_SLEEP_CFG_FLEEN :
658					  MMA9551_SLEEP_CFG_SNCEN);
659}
660EXPORT_SYMBOL(mma9551_set_device_state);
661
662/**
663 * mma9551_set_power_state() - sets runtime PM state
664 * @client:	I2C client
665 * @on:		Use true to power on device, false to power off
666 *
667 * Resume or suspend the device using Runtime PM.
668 * The device will suspend after the autosuspend delay.
669 *
670 * Returns: 0 on success, negative value on failure.
671 */
672int mma9551_set_power_state(struct i2c_client *client, bool on)
673{
674#ifdef CONFIG_PM
675	int ret;
676
677	if (on)
678		ret = pm_runtime_get_sync(&client->dev);
679	else {
680		pm_runtime_mark_last_busy(&client->dev);
681		ret = pm_runtime_put_autosuspend(&client->dev);
682	}
683
684	if (ret < 0) {
685		dev_err(&client->dev,
686			"failed to change power state to %d\n", on);
687		if (on)
688			pm_runtime_put_noidle(&client->dev);
689
690		return ret;
691	}
692#endif
693
694	return 0;
695}
696EXPORT_SYMBOL(mma9551_set_power_state);
697
698/**
699 * mma9551_sleep() - sleep
700 * @freq:	Application frequency
701 *
702 * Firmware applications run at a certain frequency on the
703 * device. Sleep for one application cycle to make sure the
704 * application had time to run once and initialize set values.
705 */
706void mma9551_sleep(int freq)
707{
708	int sleep_val = 1000 / freq;
709
710	if (sleep_val < 20)
711		usleep_range(sleep_val * 1000, 20000);
712	else
713		msleep_interruptible(sleep_val);
714}
715EXPORT_SYMBOL(mma9551_sleep);
716
717/**
718 * mma9551_read_accel_chan() - read accelerometer channel
719 * @client:	I2C client
720 * @chan:	IIO channel
721 * @val:	Pointer to the accelerometer value read
722 * @val2:	Unused
723 *
724 * Read accelerometer value for the specified channel.
725 *
726 * Locking note: This function must be called with the device lock held.
727 * Locking is not handled inside the function. Callers should ensure they
728 * serialize access to the HW.
729 *
730 * Returns: IIO_VAL_INT on success, negative value on failure.
731 */
732int mma9551_read_accel_chan(struct i2c_client *client,
733			    const struct iio_chan_spec *chan,
734			    int *val, int *val2)
735{
736	u16 reg_addr;
737	s16 raw_accel;
738	int ret;
739
740	switch (chan->channel2) {
741	case IIO_MOD_X:
742		reg_addr = MMA9551_AFE_X_ACCEL_REG;
743		break;
744	case IIO_MOD_Y:
745		reg_addr = MMA9551_AFE_Y_ACCEL_REG;
746		break;
747	case IIO_MOD_Z:
748		reg_addr = MMA9551_AFE_Z_ACCEL_REG;
749		break;
750	default:
751		return -EINVAL;
752	}
753
754	ret = mma9551_set_power_state(client, true);
755	if (ret < 0)
756		return ret;
757
758	ret = mma9551_read_status_word(client, MMA9551_APPID_AFE,
759				       reg_addr, &raw_accel);
760	if (ret < 0)
761		goto out_poweroff;
762
763	*val = raw_accel;
764
765	ret = IIO_VAL_INT;
766
767out_poweroff:
768	mma9551_set_power_state(client, false);
769	return ret;
770}
771EXPORT_SYMBOL(mma9551_read_accel_chan);
772
773/**
774 * mma9551_read_accel_scale() - read accelerometer scale
775 * @val:	Pointer to the accelerometer scale (int value)
776 * @val2:	Pointer to the accelerometer scale (micro value)
777 *
778 * Read accelerometer scale.
779 *
780 * Returns: IIO_VAL_INT_PLUS_MICRO.
781 */
782int mma9551_read_accel_scale(int *val, int *val2)
783{
784	*val = 0;
785	*val2 = 2440;
786
787	return IIO_VAL_INT_PLUS_MICRO;
788}
789EXPORT_SYMBOL(mma9551_read_accel_scale);
790
791/**
792 * mma9551_app_reset() - reset application
793 * @client:	I2C client
794 * @app_mask:	Application to reset
795 *
796 * Reset the given application (using the Reset/Suspend/Clear
797 * Control Application)
798 *
799 * Returns: 0 on success, negative value on failure.
800 */
801int mma9551_app_reset(struct i2c_client *client, u32 app_mask)
802{
803	return mma9551_write_config_byte(client, MMA9551_APPID_RCS,
804					 MMA9551_RSC_RESET +
805					 MMA9551_RSC_OFFSET(app_mask),
806					 MMA9551_RSC_VAL(app_mask));
807}
808EXPORT_SYMBOL(mma9551_app_reset);
809
810MODULE_AUTHOR("Irina Tirdea <irina.tirdea@intel.com>");
811MODULE_AUTHOR("Vlad Dogaru <vlad.dogaru@intel.com>");
812MODULE_LICENSE("GPL v2");
813MODULE_DESCRIPTION("MMA955xL sensors core");
814