1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * cros_ec_sensors_core - Common function for Chrome OS EC sensor driver.
4  *
5  * Copyright (C) 2016 Google, Inc
6  */
7 
8 #include <linux/delay.h>
9 #include <linux/device.h>
10 #include <linux/iio/buffer.h>
11 #include <linux/iio/common/cros_ec_sensors_core.h>
12 #include <linux/iio/iio.h>
13 #include <linux/iio/kfifo_buf.h>
14 #include <linux/iio/sysfs.h>
15 #include <linux/iio/trigger_consumer.h>
16 #include <linux/iio/triggered_buffer.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/platform_data/cros_ec_commands.h>
21 #include <linux/platform_data/cros_ec_proto.h>
22 #include <linux/platform_data/cros_ec_sensorhub.h>
23 #include <linux/platform_device.h>
24 
25 /*
26  * Hard coded to the first device to support sensor fifo.  The EC has a 2048
27  * byte fifo and will trigger an interrupt when fifo is 2/3 full.
28  */
29 #define CROS_EC_FIFO_SIZE (2048 * 2 / 3)
30 
31 static char *cros_ec_loc[] = {
32 	[MOTIONSENSE_LOC_BASE] = "base",
33 	[MOTIONSENSE_LOC_LID] = "lid",
34 	[MOTIONSENSE_LOC_MAX] = "unknown",
35 };
36 
37 static int cros_ec_get_host_cmd_version_mask(struct cros_ec_device *ec_dev,
38 					     u16 cmd_offset, u16 cmd, u32 *mask)
39 {
40 	int ret;
41 	struct {
42 		struct cros_ec_command msg;
43 		union {
44 			struct ec_params_get_cmd_versions params;
45 			struct ec_response_get_cmd_versions resp;
46 		};
47 	} __packed buf = {
48 		.msg = {
49 			.command = EC_CMD_GET_CMD_VERSIONS + cmd_offset,
50 			.insize = sizeof(struct ec_response_get_cmd_versions),
51 			.outsize = sizeof(struct ec_params_get_cmd_versions)
52 			},
53 		.params = {.cmd = cmd}
54 	};
55 
56 	ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
57 	if (ret >= 0)
58 		*mask = buf.resp.version_mask;
59 	return ret;
60 }
61 
62 static void get_default_min_max_freq(enum motionsensor_type type,
63 				     u32 *min_freq,
64 				     u32 *max_freq,
65 				     u32 *max_fifo_events)
66 {
67 	/*
68 	 * We don't know fifo size, set to size previously used by older
69 	 * hardware.
70 	 */
71 	*max_fifo_events = CROS_EC_FIFO_SIZE;
72 
73 	switch (type) {
74 	case MOTIONSENSE_TYPE_ACCEL:
75 		*min_freq = 12500;
76 		*max_freq = 100000;
77 		break;
78 	case MOTIONSENSE_TYPE_GYRO:
79 		*min_freq = 25000;
80 		*max_freq = 100000;
81 		break;
82 	case MOTIONSENSE_TYPE_MAG:
83 		*min_freq = 5000;
84 		*max_freq = 25000;
85 		break;
86 	case MOTIONSENSE_TYPE_PROX:
87 	case MOTIONSENSE_TYPE_LIGHT:
88 		*min_freq = 100;
89 		*max_freq = 50000;
90 		break;
91 	case MOTIONSENSE_TYPE_BARO:
92 		*min_freq = 250;
93 		*max_freq = 20000;
94 		break;
95 	case MOTIONSENSE_TYPE_ACTIVITY:
96 	default:
97 		*min_freq = 0;
98 		*max_freq = 0;
99 		break;
100 	}
101 }
102 
103 static int cros_ec_sensor_set_ec_rate(struct cros_ec_sensors_core_state *st,
104 				      int rate)
105 {
106 	int ret;
107 
108 	if (rate > U16_MAX)
109 		rate = U16_MAX;
110 
111 	mutex_lock(&st->cmd_lock);
112 	st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
113 	st->param.ec_rate.data = rate;
114 	ret = cros_ec_motion_send_host_cmd(st, 0);
115 	mutex_unlock(&st->cmd_lock);
116 	return ret;
117 }
118 
119 static ssize_t cros_ec_sensor_set_report_latency(struct device *dev,
120 						 struct device_attribute *attr,
121 						 const char *buf, size_t len)
122 {
123 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
124 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
125 	int integer, fract, ret;
126 	int latency;
127 
128 	ret = iio_str_to_fixpoint(buf, 100000, &integer, &fract);
129 	if (ret)
130 		return ret;
131 
132 	/* EC rate is in ms. */
133 	latency = integer * 1000 + fract / 1000;
134 	ret = cros_ec_sensor_set_ec_rate(st, latency);
135 	if (ret < 0)
136 		return ret;
137 
138 	return len;
139 }
140 
141 static ssize_t cros_ec_sensor_get_report_latency(struct device *dev,
142 						 struct device_attribute *attr,
143 						 char *buf)
144 {
145 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
146 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
147 	int latency, ret;
148 
149 	mutex_lock(&st->cmd_lock);
150 	st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
151 	st->param.ec_rate.data = EC_MOTION_SENSE_NO_VALUE;
152 
153 	ret = cros_ec_motion_send_host_cmd(st, 0);
154 	latency = st->resp->ec_rate.ret;
155 	mutex_unlock(&st->cmd_lock);
156 	if (ret < 0)
157 		return ret;
158 
159 	return sprintf(buf, "%d.%06u\n",
160 		       latency / 1000,
161 		       (latency % 1000) * 1000);
162 }
163 
164 static IIO_DEVICE_ATTR(hwfifo_timeout, 0644,
165 		       cros_ec_sensor_get_report_latency,
166 		       cros_ec_sensor_set_report_latency, 0);
167 
168 static ssize_t hwfifo_watermark_max_show(struct device *dev,
169 					 struct device_attribute *attr,
170 					 char *buf)
171 {
172 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
173 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
174 
175 	return sprintf(buf, "%d\n", st->fifo_max_event_count);
176 }
177 
178 static IIO_DEVICE_ATTR_RO(hwfifo_watermark_max, 0);
179 
180 static const struct attribute *cros_ec_sensor_fifo_attributes[] = {
181 	&iio_dev_attr_hwfifo_timeout.dev_attr.attr,
182 	&iio_dev_attr_hwfifo_watermark_max.dev_attr.attr,
183 	NULL,
184 };
185 
186 int cros_ec_sensors_push_data(struct iio_dev *indio_dev,
187 			      s16 *data,
188 			      s64 timestamp)
189 {
190 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
191 	s16 *out;
192 	s64 delta;
193 	unsigned int i;
194 
195 	/*
196 	 * Ignore samples if the buffer is not set: it is needed if the ODR is
197 	 * set but the buffer is not enabled yet.
198 	 */
199 	if (!iio_buffer_enabled(indio_dev))
200 		return 0;
201 
202 	out = (s16 *)st->samples;
203 	for_each_set_bit(i,
204 			 indio_dev->active_scan_mask,
205 			 indio_dev->masklength) {
206 		*out = data[i];
207 		out++;
208 	}
209 
210 	if (iio_device_get_clock(indio_dev) != CLOCK_BOOTTIME)
211 		delta = iio_get_time_ns(indio_dev) - cros_ec_get_time_ns();
212 	else
213 		delta = 0;
214 
215 	iio_push_to_buffers_with_timestamp(indio_dev, st->samples,
216 					   timestamp + delta);
217 
218 	return 0;
219 }
220 EXPORT_SYMBOL_GPL(cros_ec_sensors_push_data);
221 
222 static void cros_ec_sensors_core_clean(void *arg)
223 {
224 	struct platform_device *pdev = (struct platform_device *)arg;
225 	struct cros_ec_sensorhub *sensor_hub =
226 		dev_get_drvdata(pdev->dev.parent);
227 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
228 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
229 	u8 sensor_num = st->param.info.sensor_num;
230 
231 	cros_ec_sensorhub_unregister_push_data(sensor_hub, sensor_num);
232 }
233 
234 /**
235  * cros_ec_sensors_core_init() - basic initialization of the core structure
236  * @pdev:		platform device created for the sensors
237  * @indio_dev:		iio device structure of the device
238  * @physical_device:	true if the device refers to a physical device
239  * @trigger_capture:    function pointer to call buffer is triggered,
240  *    for backward compatibility.
241  * @push_data:          function to call when cros_ec_sensorhub receives
242  *    a sample for that sensor.
243  * @has_hw_fifo:	Set true if this device has/uses a HW FIFO
244  *
245  * Return: 0 on success, -errno on failure.
246  */
247 int cros_ec_sensors_core_init(struct platform_device *pdev,
248 			      struct iio_dev *indio_dev,
249 			      bool physical_device,
250 			      cros_ec_sensors_capture_t trigger_capture,
251 			      cros_ec_sensorhub_push_data_cb_t push_data,
252 			      bool has_hw_fifo)
253 {
254 	struct device *dev = &pdev->dev;
255 	struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
256 	struct cros_ec_sensorhub *sensor_hub = dev_get_drvdata(dev->parent);
257 	struct cros_ec_dev *ec = sensor_hub->ec;
258 	struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
259 	u32 ver_mask, temp;
260 	int frequencies[ARRAY_SIZE(state->frequencies) / 2] = { 0 };
261 	int ret, i;
262 
263 	platform_set_drvdata(pdev, indio_dev);
264 
265 	state->ec = ec->ec_dev;
266 	state->msg = devm_kzalloc(&pdev->dev,
267 				max((u16)sizeof(struct ec_params_motion_sense),
268 				state->ec->max_response), GFP_KERNEL);
269 	if (!state->msg)
270 		return -ENOMEM;
271 
272 	state->resp = (struct ec_response_motion_sense *)state->msg->data;
273 
274 	mutex_init(&state->cmd_lock);
275 
276 	ret = cros_ec_get_host_cmd_version_mask(state->ec,
277 						ec->cmd_offset,
278 						EC_CMD_MOTION_SENSE_CMD,
279 						&ver_mask);
280 	if (ret < 0)
281 		return ret;
282 
283 	/* Set up the host command structure. */
284 	state->msg->version = fls(ver_mask) - 1;
285 	state->msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
286 	state->msg->outsize = sizeof(struct ec_params_motion_sense);
287 
288 	indio_dev->name = pdev->name;
289 
290 	if (physical_device) {
291 		state->param.cmd = MOTIONSENSE_CMD_INFO;
292 		state->param.info.sensor_num = sensor_platform->sensor_num;
293 		ret = cros_ec_motion_send_host_cmd(state, 0);
294 		if (ret) {
295 			dev_warn(dev, "Can not access sensor info\n");
296 			return ret;
297 		}
298 		state->type = state->resp->info.type;
299 		state->loc = state->resp->info.location;
300 
301 		/* Set sign vector, only used for backward compatibility. */
302 		memset(state->sign, 1, CROS_EC_SENSOR_MAX_AXIS);
303 
304 		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
305 			state->calib[i].scale = MOTION_SENSE_DEFAULT_SCALE;
306 
307 		/* 0 is a correct value used to stop the device */
308 		if (state->msg->version < 3) {
309 			get_default_min_max_freq(state->resp->info.type,
310 						 &frequencies[1],
311 						 &frequencies[2],
312 						 &state->fifo_max_event_count);
313 		} else {
314 			if (state->resp->info_3.max_frequency == 0) {
315 				get_default_min_max_freq(state->resp->info.type,
316 							 &frequencies[1],
317 							 &frequencies[2],
318 							 &temp);
319 			} else {
320 				frequencies[1] = state->resp->info_3.min_frequency;
321 				frequencies[2] = state->resp->info_3.max_frequency;
322 			}
323 			state->fifo_max_event_count = state->resp->info_3.fifo_max_event_count;
324 		}
325 		for (i = 0; i < ARRAY_SIZE(frequencies); i++) {
326 			state->frequencies[2 * i] = frequencies[i] / 1000;
327 			state->frequencies[2 * i + 1] =
328 				(frequencies[i] % 1000) * 1000;
329 		}
330 
331 		if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
332 			/*
333 			 * Create a software buffer, feed by the EC FIFO.
334 			 * We can not use trigger here, as events are generated
335 			 * as soon as sample_frequency is set.
336 			 */
337 			struct iio_buffer *buffer;
338 
339 			buffer = devm_iio_kfifo_allocate(dev);
340 			if (!buffer)
341 				return -ENOMEM;
342 
343 			iio_device_attach_buffer(indio_dev, buffer);
344 			indio_dev->modes = INDIO_BUFFER_SOFTWARE;
345 
346 			ret = cros_ec_sensorhub_register_push_data(
347 					sensor_hub, sensor_platform->sensor_num,
348 					indio_dev, push_data);
349 			if (ret)
350 				return ret;
351 
352 			ret = devm_add_action_or_reset(
353 					dev, cros_ec_sensors_core_clean, pdev);
354 			if (ret)
355 				return ret;
356 
357 			/* Timestamp coming from FIFO are in ns since boot. */
358 			ret = iio_device_set_clock(indio_dev, CLOCK_BOOTTIME);
359 			if (ret)
360 				return ret;
361 		} else {
362 			const struct attribute **fifo_attrs;
363 
364 			if (has_hw_fifo)
365 				fifo_attrs = cros_ec_sensor_fifo_attributes;
366 			else
367 				fifo_attrs = NULL;
368 
369 			/*
370 			 * The only way to get samples in buffer is to set a
371 			 * software trigger (systrig, hrtimer).
372 			 */
373 			ret = devm_iio_triggered_buffer_setup_ext(
374 					dev, indio_dev, NULL, trigger_capture,
375 					NULL, fifo_attrs);
376 			if (ret)
377 				return ret;
378 		}
379 	}
380 
381 	return 0;
382 }
383 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_init);
384 
385 /**
386  * cros_ec_motion_send_host_cmd() - send motion sense host command
387  * @state:		pointer to state information for device
388  * @opt_length:	optional length to reduce the response size, useful on the data
389  *		path. Otherwise, the maximal allowed response size is used
390  *
391  * When called, the sub-command is assumed to be set in param->cmd.
392  *
393  * Return: 0 on success, -errno on failure.
394  */
395 int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *state,
396 				 u16 opt_length)
397 {
398 	int ret;
399 
400 	if (opt_length)
401 		state->msg->insize = min(opt_length, state->ec->max_response);
402 	else
403 		state->msg->insize = state->ec->max_response;
404 
405 	memcpy(state->msg->data, &state->param, sizeof(state->param));
406 
407 	ret = cros_ec_cmd_xfer_status(state->ec, state->msg);
408 	if (ret < 0)
409 		return ret;
410 
411 	if (ret &&
412 	    state->resp != (struct ec_response_motion_sense *)state->msg->data)
413 		memcpy(state->resp, state->msg->data, ret);
414 
415 	return 0;
416 }
417 EXPORT_SYMBOL_GPL(cros_ec_motion_send_host_cmd);
418 
419 static ssize_t cros_ec_sensors_calibrate(struct iio_dev *indio_dev,
420 		uintptr_t private, const struct iio_chan_spec *chan,
421 		const char *buf, size_t len)
422 {
423 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
424 	int ret, i;
425 	bool calibrate;
426 
427 	ret = strtobool(buf, &calibrate);
428 	if (ret < 0)
429 		return ret;
430 	if (!calibrate)
431 		return -EINVAL;
432 
433 	mutex_lock(&st->cmd_lock);
434 	st->param.cmd = MOTIONSENSE_CMD_PERFORM_CALIB;
435 	ret = cros_ec_motion_send_host_cmd(st, 0);
436 	if (ret != 0) {
437 		dev_warn(&indio_dev->dev, "Unable to calibrate sensor\n");
438 	} else {
439 		/* Save values */
440 		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
441 			st->calib[i].offset = st->resp->perform_calib.offset[i];
442 	}
443 	mutex_unlock(&st->cmd_lock);
444 
445 	return ret ? ret : len;
446 }
447 
448 static ssize_t cros_ec_sensors_id(struct iio_dev *indio_dev,
449 				  uintptr_t private,
450 				  const struct iio_chan_spec *chan, char *buf)
451 {
452 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
453 
454 	return snprintf(buf, PAGE_SIZE, "%d\n", st->param.info.sensor_num);
455 }
456 
457 static ssize_t cros_ec_sensors_loc(struct iio_dev *indio_dev,
458 		uintptr_t private, const struct iio_chan_spec *chan,
459 		char *buf)
460 {
461 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
462 
463 	return snprintf(buf, PAGE_SIZE, "%s\n", cros_ec_loc[st->loc]);
464 }
465 
466 const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[] = {
467 	{
468 		.name = "calibrate",
469 		.shared = IIO_SHARED_BY_ALL,
470 		.write = cros_ec_sensors_calibrate
471 	},
472 	{
473 		.name = "id",
474 		.shared = IIO_SHARED_BY_ALL,
475 		.read = cros_ec_sensors_id
476 	},
477 	{
478 		.name = "location",
479 		.shared = IIO_SHARED_BY_ALL,
480 		.read = cros_ec_sensors_loc
481 	},
482 	{ },
483 };
484 EXPORT_SYMBOL_GPL(cros_ec_sensors_ext_info);
485 
486 /**
487  * cros_ec_sensors_idx_to_reg - convert index into offset in shared memory
488  * @st:		pointer to state information for device
489  * @idx:	sensor index (should be element of enum sensor_index)
490  *
491  * Return:	address to read at
492  */
493 static unsigned int cros_ec_sensors_idx_to_reg(
494 					struct cros_ec_sensors_core_state *st,
495 					unsigned int idx)
496 {
497 	/*
498 	 * When using LPC interface, only space for 2 Accel and one Gyro.
499 	 * First halfword of MOTIONSENSE_TYPE_ACCEL is used by angle.
500 	 */
501 	if (st->type == MOTIONSENSE_TYPE_ACCEL)
502 		return EC_MEMMAP_ACC_DATA + sizeof(u16) *
503 			(1 + idx + st->param.info.sensor_num *
504 			 CROS_EC_SENSOR_MAX_AXIS);
505 
506 	return EC_MEMMAP_GYRO_DATA + sizeof(u16) * idx;
507 }
508 
509 static int cros_ec_sensors_cmd_read_u8(struct cros_ec_device *ec,
510 				       unsigned int offset, u8 *dest)
511 {
512 	return ec->cmd_readmem(ec, offset, 1, dest);
513 }
514 
515 static int cros_ec_sensors_cmd_read_u16(struct cros_ec_device *ec,
516 					 unsigned int offset, u16 *dest)
517 {
518 	__le16 tmp;
519 	int ret = ec->cmd_readmem(ec, offset, 2, &tmp);
520 
521 	if (ret >= 0)
522 		*dest = le16_to_cpu(tmp);
523 
524 	return ret;
525 }
526 
527 /**
528  * cros_ec_sensors_read_until_not_busy() - read until is not busy
529  *
530  * @st:	pointer to state information for device
531  *
532  * Read from EC status byte until it reads not busy.
533  * Return: 8-bit status if ok, -errno on failure.
534  */
535 static int cros_ec_sensors_read_until_not_busy(
536 					struct cros_ec_sensors_core_state *st)
537 {
538 	struct cros_ec_device *ec = st->ec;
539 	u8 status;
540 	int ret, attempts = 0;
541 
542 	ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS, &status);
543 	if (ret < 0)
544 		return ret;
545 
546 	while (status & EC_MEMMAP_ACC_STATUS_BUSY_BIT) {
547 		/* Give up after enough attempts, return error. */
548 		if (attempts++ >= 50)
549 			return -EIO;
550 
551 		/* Small delay every so often. */
552 		if (attempts % 5 == 0)
553 			msleep(25);
554 
555 		ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
556 						  &status);
557 		if (ret < 0)
558 			return ret;
559 	}
560 
561 	return status;
562 }
563 
564 /**
565  * read_ec_sensors_data_unsafe() - read acceleration data from EC shared memory
566  * @indio_dev:	pointer to IIO device
567  * @scan_mask:	bitmap of the sensor indices to scan
568  * @data:	location to store data
569  *
570  * This is the unsafe function for reading the EC data. It does not guarantee
571  * that the EC will not modify the data as it is being read in.
572  *
573  * Return: 0 on success, -errno on failure.
574  */
575 static int cros_ec_sensors_read_data_unsafe(struct iio_dev *indio_dev,
576 			 unsigned long scan_mask, s16 *data)
577 {
578 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
579 	struct cros_ec_device *ec = st->ec;
580 	unsigned int i;
581 	int ret;
582 
583 	/* Read all sensors enabled in scan_mask. Each value is 2 bytes. */
584 	for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
585 		ret = cros_ec_sensors_cmd_read_u16(ec,
586 					     cros_ec_sensors_idx_to_reg(st, i),
587 					     data);
588 		if (ret < 0)
589 			return ret;
590 
591 		*data *= st->sign[i];
592 		data++;
593 	}
594 
595 	return 0;
596 }
597 
598 /**
599  * cros_ec_sensors_read_lpc() - read acceleration data from EC shared memory.
600  * @indio_dev: pointer to IIO device.
601  * @scan_mask: bitmap of the sensor indices to scan.
602  * @data: location to store data.
603  *
604  * Note: this is the safe function for reading the EC data. It guarantees
605  * that the data sampled was not modified by the EC while being read.
606  *
607  * Return: 0 on success, -errno on failure.
608  */
609 int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev,
610 			     unsigned long scan_mask, s16 *data)
611 {
612 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
613 	struct cros_ec_device *ec = st->ec;
614 	u8 samp_id = 0xff, status = 0;
615 	int ret, attempts = 0;
616 
617 	/*
618 	 * Continually read all data from EC until the status byte after
619 	 * all reads reflects that the EC is not busy and the sample id
620 	 * matches the sample id from before all reads. This guarantees
621 	 * that data read in was not modified by the EC while reading.
622 	 */
623 	while ((status & (EC_MEMMAP_ACC_STATUS_BUSY_BIT |
624 			  EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK)) != samp_id) {
625 		/* If we have tried to read too many times, return error. */
626 		if (attempts++ >= 5)
627 			return -EIO;
628 
629 		/* Read status byte until EC is not busy. */
630 		ret = cros_ec_sensors_read_until_not_busy(st);
631 		if (ret < 0)
632 			return ret;
633 
634 		/*
635 		 * Store the current sample id so that we can compare to the
636 		 * sample id after reading the data.
637 		 */
638 		samp_id = ret & EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK;
639 
640 		/* Read all EC data, format it, and store it into data. */
641 		ret = cros_ec_sensors_read_data_unsafe(indio_dev, scan_mask,
642 						       data);
643 		if (ret < 0)
644 			return ret;
645 
646 		/* Read status byte. */
647 		ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
648 						  &status);
649 		if (ret < 0)
650 			return ret;
651 	}
652 
653 	return 0;
654 }
655 EXPORT_SYMBOL_GPL(cros_ec_sensors_read_lpc);
656 
657 /**
658  * cros_ec_sensors_read_cmd() - retrieve data using the EC command protocol
659  * @indio_dev:	pointer to IIO device
660  * @scan_mask:	bitmap of the sensor indices to scan
661  * @data:	location to store data
662  *
663  * Return: 0 on success, -errno on failure.
664  */
665 int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev,
666 			     unsigned long scan_mask, s16 *data)
667 {
668 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
669 	int ret;
670 	unsigned int i;
671 
672 	/* Read all sensor data through a command. */
673 	st->param.cmd = MOTIONSENSE_CMD_DATA;
674 	ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->data));
675 	if (ret != 0) {
676 		dev_warn(&indio_dev->dev, "Unable to read sensor data\n");
677 		return ret;
678 	}
679 
680 	for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
681 		*data = st->resp->data.data[i];
682 		data++;
683 	}
684 
685 	return 0;
686 }
687 EXPORT_SYMBOL_GPL(cros_ec_sensors_read_cmd);
688 
689 /**
690  * cros_ec_sensors_capture() - the trigger handler function
691  * @irq:	the interrupt number.
692  * @p:		a pointer to the poll function.
693  *
694  * On a trigger event occurring, if the pollfunc is attached then this
695  * handler is called as a threaded interrupt (and hence may sleep). It
696  * is responsible for grabbing data from the device and pushing it into
697  * the associated buffer.
698  *
699  * Return: IRQ_HANDLED
700  */
701 irqreturn_t cros_ec_sensors_capture(int irq, void *p)
702 {
703 	struct iio_poll_func *pf = p;
704 	struct iio_dev *indio_dev = pf->indio_dev;
705 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
706 	int ret;
707 
708 	mutex_lock(&st->cmd_lock);
709 
710 	/* Clear capture data. */
711 	memset(st->samples, 0, indio_dev->scan_bytes);
712 
713 	/* Read data based on which channels are enabled in scan mask. */
714 	ret = st->read_ec_sensors_data(indio_dev,
715 				       *(indio_dev->active_scan_mask),
716 				       (s16 *)st->samples);
717 	if (ret < 0)
718 		goto done;
719 
720 	iio_push_to_buffers_with_timestamp(indio_dev, st->samples,
721 					   iio_get_time_ns(indio_dev));
722 
723 done:
724 	/*
725 	 * Tell the core we are done with this trigger and ready for the
726 	 * next one.
727 	 */
728 	iio_trigger_notify_done(indio_dev->trig);
729 
730 	mutex_unlock(&st->cmd_lock);
731 
732 	return IRQ_HANDLED;
733 }
734 EXPORT_SYMBOL_GPL(cros_ec_sensors_capture);
735 
736 /**
737  * cros_ec_sensors_core_read() - function to request a value from the sensor
738  * @st:		pointer to state information for device
739  * @chan:	channel specification structure table
740  * @val:	will contain one element making up the returned value
741  * @val2:	will contain another element making up the returned value
742  * @mask:	specifies which values to be requested
743  *
744  * Return:	the type of value returned by the device
745  */
746 int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
747 			  struct iio_chan_spec const *chan,
748 			  int *val, int *val2, long mask)
749 {
750 	int ret, frequency;
751 
752 	switch (mask) {
753 	case IIO_CHAN_INFO_SAMP_FREQ:
754 		st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
755 		st->param.sensor_odr.data =
756 			EC_MOTION_SENSE_NO_VALUE;
757 
758 		ret = cros_ec_motion_send_host_cmd(st, 0);
759 		if (ret)
760 			break;
761 
762 		frequency = st->resp->sensor_odr.ret;
763 		*val = frequency / 1000;
764 		*val2 = (frequency % 1000) * 1000;
765 		ret = IIO_VAL_INT_PLUS_MICRO;
766 		break;
767 	default:
768 		ret = -EINVAL;
769 		break;
770 	}
771 
772 	return ret;
773 }
774 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read);
775 
776 /**
777  * cros_ec_sensors_core_read_avail() - get available values
778  * @indio_dev:		pointer to state information for device
779  * @chan:	channel specification structure table
780  * @vals:	list of available values
781  * @type:	type of data returned
782  * @length:	number of data returned in the array
783  * @mask:	specifies which values to be requested
784  *
785  * Return:	an error code, IIO_AVAIL_RANGE or IIO_AVAIL_LIST
786  */
787 int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev,
788 				    struct iio_chan_spec const *chan,
789 				    const int **vals,
790 				    int *type,
791 				    int *length,
792 				    long mask)
793 {
794 	struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
795 
796 	switch (mask) {
797 	case IIO_CHAN_INFO_SAMP_FREQ:
798 		*length = ARRAY_SIZE(state->frequencies);
799 		*vals = (const int *)&state->frequencies;
800 		*type = IIO_VAL_INT_PLUS_MICRO;
801 		return IIO_AVAIL_LIST;
802 	}
803 
804 	return -EINVAL;
805 }
806 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read_avail);
807 
808 /**
809  * cros_ec_sensors_core_write() - function to write a value to the sensor
810  * @st:		pointer to state information for device
811  * @chan:	channel specification structure table
812  * @val:	first part of value to write
813  * @val2:	second part of value to write
814  * @mask:	specifies which values to write
815  *
816  * Return:	the type of value returned by the device
817  */
818 int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
819 			       struct iio_chan_spec const *chan,
820 			       int val, int val2, long mask)
821 {
822 	int ret, frequency;
823 
824 	switch (mask) {
825 	case IIO_CHAN_INFO_SAMP_FREQ:
826 		frequency = val * 1000 + val2 / 1000;
827 		st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
828 		st->param.sensor_odr.data = frequency;
829 
830 		/* Always roundup, so caller gets at least what it asks for. */
831 		st->param.sensor_odr.roundup = 1;
832 
833 		ret = cros_ec_motion_send_host_cmd(st, 0);
834 		break;
835 	default:
836 		ret = -EINVAL;
837 		break;
838 	}
839 	return ret;
840 }
841 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_write);
842 
843 static int __maybe_unused cros_ec_sensors_resume(struct device *dev)
844 {
845 	struct platform_device *pdev = to_platform_device(dev);
846 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
847 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
848 	int ret = 0;
849 
850 	if (st->range_updated) {
851 		mutex_lock(&st->cmd_lock);
852 		st->param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
853 		st->param.sensor_range.data = st->curr_range;
854 		st->param.sensor_range.roundup = 1;
855 		ret = cros_ec_motion_send_host_cmd(st, 0);
856 		mutex_unlock(&st->cmd_lock);
857 	}
858 	return ret;
859 }
860 
861 SIMPLE_DEV_PM_OPS(cros_ec_sensors_pm_ops, NULL, cros_ec_sensors_resume);
862 EXPORT_SYMBOL_GPL(cros_ec_sensors_pm_ops);
863 
864 MODULE_DESCRIPTION("ChromeOS EC sensor hub core functions");
865 MODULE_LICENSE("GPL v2");
866