drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c - manifest_repos/valens - Git at Google

 /*
  * cros_ec_sensors_core - Common function for Chrome OS EC sensor driver.
  *
  * Copyright (C) 2016 Google, Inc
  *
  * This software is licensed under the terms of the GNU General Public
  * License version 2, as published by the Free Software Foundation, and
  * may be copied, distributed, and modified under those terms.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/kfifo_buf.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/kernel.h>
 #include <linux/mfd/cros_ec.h>
 #include <linux/mfd/cros_ec_commands.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/platform_device.h>

 #include "cros_ec_sensors_core.h"

 static char *cros_ec_loc[] = {
 	[MOTIONSENSE_LOC_BASE] = "base",
 	[MOTIONSENSE_LOC_LID] = "lid",
 	[MOTIONSENSE_LOC_MAX] = "unknown",
 };

 int cros_ec_sensors_core_init(struct platform_device *pdev,
 			      struct iio_dev *indio_dev,
 			      bool physical_device)
 {
 	struct device *dev = &pdev->dev;
 	struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
 	struct cros_ec_dev *ec = dev_get_drvdata(pdev->dev.parent);
 	struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);

 	platform_set_drvdata(pdev, indio_dev);

 	state->ec = ec->ec_dev;
 	state->msg = devm_kzalloc(&pdev->dev,
 				max((u16)sizeof(struct ec_params_motion_sense),
 				state->ec->max_response), GFP_KERNEL);
 	if (!state->msg)
 		return -ENOMEM;

 	state->resp = (struct ec_response_motion_sense *)state->msg->data;

 	mutex_init(&state->cmd_lock);

 	/* Set up the host command structure. */
 	state->msg->version = 2;
 	state->msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
 	state->msg->outsize = sizeof(struct ec_params_motion_sense);

 	indio_dev->dev.parent = &pdev->dev;
 	indio_dev->name = pdev->name;

 	if (physical_device) {
 		indio_dev->modes = INDIO_DIRECT_MODE;

 		state->param.cmd = MOTIONSENSE_CMD_INFO;
 		state->param.info.sensor_num = sensor_platform->sensor_num;
 		if (cros_ec_motion_send_host_cmd(state, 0)) {
 			dev_warn(dev, "Can not access sensor info\n");
 			return -EIO;
 		}
 		state->type = state->resp->info.type;
 		state->loc = state->resp->info.location;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_init);

 int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *state,
 				 u16 opt_length)
 {
 	int ret;

 	if (opt_length)
 		state->msg->insize = min(opt_length, state->ec->max_response);
 	else
 		state->msg->insize = state->ec->max_response;

 	memcpy(state->msg->data, &state->param, sizeof(state->param));

 	ret = cros_ec_cmd_xfer_status(state->ec, state->msg);
 	if (ret < 0)
 		return -EIO;

 	if (ret &&
 	    state->resp != (struct ec_response_motion_sense *)state->msg->data)
 		memcpy(state->resp, state->msg->data, ret);

 	return 0;
 }
 EXPORT_SYMBOL_GPL(cros_ec_motion_send_host_cmd);

 static ssize_t cros_ec_sensors_calibrate(struct iio_dev *indio_dev,
 		uintptr_t private, const struct iio_chan_spec *chan,
 		const char *buf, size_t len)
 {
 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
 	int ret, i;
 	bool calibrate;

 	ret = strtobool(buf, &calibrate);
 	if (ret < 0)
 		return ret;
 	if (!calibrate)
 		return -EINVAL;

 	mutex_lock(&st->cmd_lock);
 	st->param.cmd = MOTIONSENSE_CMD_PERFORM_CALIB;
 	ret = cros_ec_motion_send_host_cmd(st, 0);
 	if (ret != 0) {
 		dev_warn(&indio_dev->dev, "Unable to calibrate sensor\n");
 	} else {
 		/* Save values */
 		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
 			st->calib[i] = st->resp->perform_calib.offset[i];
 	}
 	mutex_unlock(&st->cmd_lock);

 	return ret ? ret : len;
 }

 static ssize_t cros_ec_sensors_loc(struct iio_dev *indio_dev,
 		uintptr_t private, const struct iio_chan_spec *chan,
 		char *buf)
 {
 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);

 	return snprintf(buf, PAGE_SIZE, "%s\n", cros_ec_loc[st->loc]);
 }

 const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[] = {
 	{
 		.name = "calibrate",
 		.shared = IIO_SHARED_BY_ALL,
 		.write = cros_ec_sensors_calibrate
 	},
 	{
 		.name = "location",
 		.shared = IIO_SHARED_BY_ALL,
 		.read = cros_ec_sensors_loc
 	},
 	{ },
 };
 EXPORT_SYMBOL_GPL(cros_ec_sensors_ext_info);

 /**
  * cros_ec_sensors_idx_to_reg - convert index into offset in shared memory
  * @st:		pointer to state information for device
  * @idx:	sensor index (should be element of enum sensor_index)
  *
  * Return:	address to read at
  */
 static unsigned int cros_ec_sensors_idx_to_reg(
 					struct cros_ec_sensors_core_state *st,
 					unsigned int idx)
 {
 	/*
 	 * When using LPC interface, only space for 2 Accel and one Gyro.
 	 * First halfword of MOTIONSENSE_TYPE_ACCEL is used by angle.
 	 */
 	if (st->type == MOTIONSENSE_TYPE_ACCEL)
 		return EC_MEMMAP_ACC_DATA + sizeof(u16) *
 			(1 + idx + st->param.info.sensor_num *
 			 CROS_EC_SENSOR_MAX_AXIS);

 	return EC_MEMMAP_GYRO_DATA + sizeof(u16) * idx;
 }

 static int cros_ec_sensors_cmd_read_u8(struct cros_ec_device *ec,
 				       unsigned int offset, u8 *dest)
 {
 	return ec->cmd_readmem(ec, offset, 1, dest);
 }

 static int cros_ec_sensors_cmd_read_u16(struct cros_ec_device *ec,
 					 unsigned int offset, u16 *dest)
 {
 	__le16 tmp;
 	int ret = ec->cmd_readmem(ec, offset, 2, &tmp);

 	if (ret >= 0)
 		*dest = le16_to_cpu(tmp);

 	return ret;
 }

 /**
  * cros_ec_sensors_read_until_not_busy() - read until is not busy
  *
  * @st:	pointer to state information for device
  *
  * Read from EC status byte until it reads not busy.
  * Return: 8-bit status if ok, -errno on failure.
  */
 static int cros_ec_sensors_read_until_not_busy(
 					struct cros_ec_sensors_core_state *st)
 {
 	struct cros_ec_device *ec = st->ec;
 	u8 status;
 	int ret, attempts = 0;

 	ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS, &status);
 	if (ret < 0)
 		return ret;

 	while (status & EC_MEMMAP_ACC_STATUS_BUSY_BIT) {
 		/* Give up after enough attempts, return error. */
 		if (attempts++ >= 50)
 			return -EIO;

 		/* Small delay every so often. */
 		if (attempts % 5 == 0)
 			msleep(25);

 		ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
 						  &status);
 		if (ret < 0)
 			return ret;
 	}

 	return status;
 }

 /**
  * read_ec_sensors_data_unsafe() - read acceleration data from EC shared memory
  * @indio_dev:	pointer to IIO device
  * @scan_mask:	bitmap of the sensor indices to scan
  * @data:	location to store data
  *
  * This is the unsafe function for reading the EC data. It does not guarantee
  * that the EC will not modify the data as it is being read in.
  *
  * Return: 0 on success, -errno on failure.
  */
 static int cros_ec_sensors_read_data_unsafe(struct iio_dev *indio_dev,
 			 unsigned long scan_mask, s16 *data)
 {
 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
 	struct cros_ec_device *ec = st->ec;
 	unsigned int i;
 	int ret;

 	/* Read all sensors enabled in scan_mask. Each value is 2 bytes. */
 	for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
 		ret = cros_ec_sensors_cmd_read_u16(ec,
 					     cros_ec_sensors_idx_to_reg(st, i),
 					     data);
 		if (ret < 0)
 			return ret;

 		data++;
 	}

 	return 0;
 }

 int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev,
 			     unsigned long scan_mask, s16 *data)
 {
 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
 	struct cros_ec_device *ec = st->ec;
 	u8 samp_id = 0xff, status = 0;
 	int ret, attempts = 0;

 	/*
 	 * Continually read all data from EC until the status byte after
 	 * all reads reflects that the EC is not busy and the sample id
 	 * matches the sample id from before all reads. This guarantees
 	 * that data read in was not modified by the EC while reading.
 	 */
 	while ((status & (EC_MEMMAP_ACC_STATUS_BUSY_BIT |
 			  EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK)) != samp_id) {
 		/* If we have tried to read too many times, return error. */
 		if (attempts++ >= 5)
 			return -EIO;

 		/* Read status byte until EC is not busy. */
 		ret = cros_ec_sensors_read_until_not_busy(st);
 		if (ret < 0)
 			return ret;

 		/*
 		 * Store the current sample id so that we can compare to the
 		 * sample id after reading the data.
 		 */
 		samp_id = ret & EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK;

 		/* Read all EC data, format it, and store it into data. */
 		ret = cros_ec_sensors_read_data_unsafe(indio_dev, scan_mask,
 						       data);
 		if (ret < 0)
 			return ret;

 		/* Read status byte. */
 		ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
 						  &status);
 		if (ret < 0)
 			return ret;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_read_lpc);

 int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev,
 			     unsigned long scan_mask, s16 *data)
 {
 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
 	int ret;
 	unsigned int i;

 	/* Read all sensor data through a command. */
 	st->param.cmd = MOTIONSENSE_CMD_DATA;
 	ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->data));
 	if (ret != 0) {
 		dev_warn(&indio_dev->dev, "Unable to read sensor data\n");
 		return ret;
 	}

 	for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
 		*data = st->resp->data.data[i];
 		data++;
 	}

 	return 0;
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_read_cmd);

 irqreturn_t cros_ec_sensors_capture(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
 	int ret;

 	mutex_lock(&st->cmd_lock);

 	/* Clear capture data. */
 	memset(st->samples, 0, indio_dev->scan_bytes);

 	/* Read data based on which channels are enabled in scan mask. */
 	ret = st->read_ec_sensors_data(indio_dev,
 				       *(indio_dev->active_scan_mask),
 				       (s16 *)st->samples);
 	if (ret < 0)
 		goto done;

 	iio_push_to_buffers_with_timestamp(indio_dev, st->samples,
 					   iio_get_time_ns(indio_dev));

 done:
 	/*
 	 * Tell the core we are done with this trigger and ready for the
 	 * next one.
 	 */
 	iio_trigger_notify_done(indio_dev->trig);

 	mutex_unlock(&st->cmd_lock);

 	return IRQ_HANDLED;
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_capture);

 int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
 			  struct iio_chan_spec const *chan,
 			  int *val, int *val2, long mask)
 {
 	int ret = IIO_VAL_INT;

 	switch (mask) {
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
 		st->param.ec_rate.data =
 			EC_MOTION_SENSE_NO_VALUE;

 		if (cros_ec_motion_send_host_cmd(st, 0))
 			ret = -EIO;
 		else
 			*val = st->resp->ec_rate.ret;
 		break;
 	case IIO_CHAN_INFO_FREQUENCY:
 		st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
 		st->param.sensor_odr.data =
 			EC_MOTION_SENSE_NO_VALUE;

 		if (cros_ec_motion_send_host_cmd(st, 0))
 			ret = -EIO;
 		else
 			*val = st->resp->sensor_odr.ret;
 		break;
 	default:
 		break;
 	}

 	return ret;
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read);

 int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
 			       struct iio_chan_spec const *chan,
 			       int val, int val2, long mask)
 {
 	int ret = 0;

 	switch (mask) {
 	case IIO_CHAN_INFO_FREQUENCY:
 		st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
 		st->param.sensor_odr.data = val;

 		/* Always roundup, so caller gets at least what it asks for. */
 		st->param.sensor_odr.roundup = 1;

 		if (cros_ec_motion_send_host_cmd(st, 0))
 			ret = -EIO;
 		break;
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
 		st->param.ec_rate.data = val;

 		if (cros_ec_motion_send_host_cmd(st, 0))
 			ret = -EIO;
 		else
 			st->curr_sampl_freq = val;
 		break;
 	default:
 		ret = -EINVAL;
 		break;
 	}
 	return ret;
 }
 EXPORT_SYMBOL_GPL(cros_ec_sensors_core_write);

 MODULE_DESCRIPTION("ChromeOS EC sensor hub core functions");
 MODULE_LICENSE("GPL v2");
	/*
	* cros_ec_sensors_core - Common function for Chrome OS EC sensor driver.
	*
	* Copyright (C) 2016 Google, Inc
	*
	* This software is licensed under the terms of the GNU General Public
	* License version 2, as published by the Free Software Foundation, and
	* may be copied, distributed, and modified under those terms.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	#include <linux/delay.h>
	#include <linux/device.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/kfifo_buf.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/kernel.h>
	#include <linux/mfd/cros_ec.h>
	#include <linux/mfd/cros_ec_commands.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/sysfs.h>
	#include <linux/platform_device.h>

	#include "cros_ec_sensors_core.h"

	static char *cros_ec_loc[] = {
	[MOTIONSENSE_LOC_BASE] = "base",
	[MOTIONSENSE_LOC_LID] = "lid",
	[MOTIONSENSE_LOC_MAX] = "unknown",
	};

	int cros_ec_sensors_core_init(struct platform_device *pdev,
	struct iio_dev *indio_dev,
	bool physical_device)
	{
	struct device *dev = &pdev->dev;
	struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
	struct cros_ec_dev *ec = dev_get_drvdata(pdev->dev.parent);
	struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);

	platform_set_drvdata(pdev, indio_dev);

	state->ec = ec->ec_dev;
	state->msg = devm_kzalloc(&pdev->dev,
	max((u16)sizeof(struct ec_params_motion_sense),
	state->ec->max_response), GFP_KERNEL);
	if (!state->msg)
	return -ENOMEM;

	state->resp = (struct ec_response_motion_sense *)state->msg->data;

	mutex_init(&state->cmd_lock);

	/* Set up the host command structure. */
	state->msg->version = 2;
	state->msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
	state->msg->outsize = sizeof(struct ec_params_motion_sense);

	indio_dev->dev.parent = &pdev->dev;
	indio_dev->name = pdev->name;

	if (physical_device) {
	indio_dev->modes = INDIO_DIRECT_MODE;

	state->param.cmd = MOTIONSENSE_CMD_INFO;
	state->param.info.sensor_num = sensor_platform->sensor_num;
	if (cros_ec_motion_send_host_cmd(state, 0)) {
	dev_warn(dev, "Can not access sensor info\n");
	return -EIO;
	}
	state->type = state->resp->info.type;
	state->loc = state->resp->info.location;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(cros_ec_sensors_core_init);

	int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *state,
	u16 opt_length)
	{
	int ret;

	if (opt_length)
	state->msg->insize = min(opt_length, state->ec->max_response);
	else
	state->msg->insize = state->ec->max_response;

	memcpy(state->msg->data, &state->param, sizeof(state->param));

	ret = cros_ec_cmd_xfer_status(state->ec, state->msg);
	if (ret < 0)
	return -EIO;

	if (ret &&
	state->resp != (struct ec_response_motion_sense *)state->msg->data)
	memcpy(state->resp, state->msg->data, ret);

	return 0;
	}
	EXPORT_SYMBOL_GPL(cros_ec_motion_send_host_cmd);

	static ssize_t cros_ec_sensors_calibrate(struct iio_dev *indio_dev,
	uintptr_t private, const struct iio_chan_spec *chan,
	const char *buf, size_t len)
	{
	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
	int ret, i;
	bool calibrate;

	ret = strtobool(buf, &calibrate);
	if (ret < 0)
	return ret;
	if (!calibrate)
	return -EINVAL;

	mutex_lock(&st->cmd_lock);
	st->param.cmd = MOTIONSENSE_CMD_PERFORM_CALIB;
	ret = cros_ec_motion_send_host_cmd(st, 0);
	if (ret != 0) {
	dev_warn(&indio_dev->dev, "Unable to calibrate sensor\n");
	} else {
	/* Save values */
	for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
	st->calib[i] = st->resp->perform_calib.offset[i];
	}
	mutex_unlock(&st->cmd_lock);

	return ret ? ret : len;
	}

	static ssize_t cros_ec_sensors_loc(struct iio_dev *indio_dev,
	uintptr_t private, const struct iio_chan_spec *chan,
	char *buf)
	{
	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);

	return snprintf(buf, PAGE_SIZE, "%s\n", cros_ec_loc[st->loc]);
	}

	const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[] = {
	{
	.name = "calibrate",
	.shared = IIO_SHARED_BY_ALL,
	.write = cros_ec_sensors_calibrate
	},
	{
	.name = "location",
	.shared = IIO_SHARED_BY_ALL,
	.read = cros_ec_sensors_loc
	},
	{ },
	};
	EXPORT_SYMBOL_GPL(cros_ec_sensors_ext_info);

	/**
	* cros_ec_sensors_idx_to_reg - convert index into offset in shared memory
	* @st: pointer to state information for device
	* @idx: sensor index (should be element of enum sensor_index)
	*
	* Return: address to read at
	*/
	static unsigned int cros_ec_sensors_idx_to_reg(
	struct cros_ec_sensors_core_state *st,
	unsigned int idx)
	{
	/*
	* When using LPC interface, only space for 2 Accel and one Gyro.
	* First halfword of MOTIONSENSE_TYPE_ACCEL is used by angle.
	*/
	if (st->type == MOTIONSENSE_TYPE_ACCEL)
	return EC_MEMMAP_ACC_DATA + sizeof(u16) *
	(1 + idx + st->param.info.sensor_num *
	CROS_EC_SENSOR_MAX_AXIS);

	return EC_MEMMAP_GYRO_DATA + sizeof(u16) * idx;
	}

	static int cros_ec_sensors_cmd_read_u8(struct cros_ec_device *ec,
	unsigned int offset, u8 *dest)
	{
	return ec->cmd_readmem(ec, offset, 1, dest);
	}

	static int cros_ec_sensors_cmd_read_u16(struct cros_ec_device *ec,
	unsigned int offset, u16 *dest)
	{
	__le16 tmp;
	int ret = ec->cmd_readmem(ec, offset, 2, &tmp);

	if (ret >= 0)
	*dest = le16_to_cpu(tmp);

	return ret;
	}

	/**
	* cros_ec_sensors_read_until_not_busy() - read until is not busy
	*
	* @st: pointer to state information for device
	*
	* Read from EC status byte until it reads not busy.
	* Return: 8-bit status if ok, -errno on failure.
	*/
	static int cros_ec_sensors_read_until_not_busy(
	struct cros_ec_sensors_core_state *st)
	{
	struct cros_ec_device *ec = st->ec;
	u8 status;
	int ret, attempts = 0;

	ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS, &status);
	if (ret < 0)
	return ret;

	while (status & EC_MEMMAP_ACC_STATUS_BUSY_BIT) {
	/* Give up after enough attempts, return error. */
	if (attempts++ >= 50)
	return -EIO;

	/* Small delay every so often. */
	if (attempts % 5 == 0)
	msleep(25);

	ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
	&status);
	if (ret < 0)
	return ret;
	}

	return status;
	}

	/**
	* read_ec_sensors_data_unsafe() - read acceleration data from EC shared memory
	* @indio_dev: pointer to IIO device
	* @scan_mask: bitmap of the sensor indices to scan
	* @data: location to store data
	*
	* This is the unsafe function for reading the EC data. It does not guarantee
	* that the EC will not modify the data as it is being read in.
	*
	* Return: 0 on success, -errno on failure.
	*/
	static int cros_ec_sensors_read_data_unsafe(struct iio_dev *indio_dev,
	unsigned long scan_mask, s16 *data)
	{
	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
	struct cros_ec_device *ec = st->ec;
	unsigned int i;
	int ret;

	/* Read all sensors enabled in scan_mask. Each value is 2 bytes. */
	for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
	ret = cros_ec_sensors_cmd_read_u16(ec,
	cros_ec_sensors_idx_to_reg(st, i),
	data);
	if (ret < 0)
	return ret;

	data++;
	}

	return 0;
	}

	int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev,
	unsigned long scan_mask, s16 *data)
	{
	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
	struct cros_ec_device *ec = st->ec;
	u8 samp_id = 0xff, status = 0;
	int ret, attempts = 0;

	/*
	* Continually read all data from EC until the status byte after
	* all reads reflects that the EC is not busy and the sample id
	* matches the sample id from before all reads. This guarantees
	* that data read in was not modified by the EC while reading.
	*/
	while ((status & (EC_MEMMAP_ACC_STATUS_BUSY_BIT \|
	EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK)) != samp_id) {
	/* If we have tried to read too many times, return error. */
	if (attempts++ >= 5)
	return -EIO;

	/* Read status byte until EC is not busy. */
	ret = cros_ec_sensors_read_until_not_busy(st);
	if (ret < 0)
	return ret;

	/*
	* Store the current sample id so that we can compare to the
	* sample id after reading the data.
	*/
	samp_id = ret & EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK;

	/* Read all EC data, format it, and store it into data. */
	ret = cros_ec_sensors_read_data_unsafe(indio_dev, scan_mask,
	data);
	if (ret < 0)
	return ret;

	/* Read status byte. */
	ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
	&status);
	if (ret < 0)
	return ret;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(cros_ec_sensors_read_lpc);

	int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev,
	unsigned long scan_mask, s16 *data)
	{
	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
	int ret;
	unsigned int i;

	/* Read all sensor data through a command. */
	st->param.cmd = MOTIONSENSE_CMD_DATA;
	ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->data));
	if (ret != 0) {
	dev_warn(&indio_dev->dev, "Unable to read sensor data\n");
	return ret;
	}

	for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
	*data = st->resp->data.data[i];
	data++;
	}

	return 0;
	}
	EXPORT_SYMBOL_GPL(cros_ec_sensors_read_cmd);

	irqreturn_t cros_ec_sensors_capture(int irq, void *p)
	{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
	int ret;

	mutex_lock(&st->cmd_lock);

	/* Clear capture data. */
	memset(st->samples, 0, indio_dev->scan_bytes);

	/* Read data based on which channels are enabled in scan mask. */
	ret = st->read_ec_sensors_data(indio_dev,
	*(indio_dev->active_scan_mask),
	(s16 *)st->samples);
	if (ret < 0)
	goto done;

	iio_push_to_buffers_with_timestamp(indio_dev, st->samples,
	iio_get_time_ns(indio_dev));

	done:
	/*
	* Tell the core we are done with this trigger and ready for the
	* next one.
	*/
	iio_trigger_notify_done(indio_dev->trig);

	mutex_unlock(&st->cmd_lock);

	return IRQ_HANDLED;
	}
	EXPORT_SYMBOL_GPL(cros_ec_sensors_capture);

	int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	int ret = IIO_VAL_INT;

	switch (mask) {
	case IIO_CHAN_INFO_SAMP_FREQ:
	st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
	st->param.ec_rate.data =
	EC_MOTION_SENSE_NO_VALUE;

	if (cros_ec_motion_send_host_cmd(st, 0))
	ret = -EIO;
	else
	*val = st->resp->ec_rate.ret;
	break;
	case IIO_CHAN_INFO_FREQUENCY:
	st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
	st->param.sensor_odr.data =
	EC_MOTION_SENSE_NO_VALUE;

	if (cros_ec_motion_send_host_cmd(st, 0))
	ret = -EIO;
	else
	*val = st->resp->sensor_odr.ret;
	break;
	default:
	break;
	}

	return ret;
	}
	EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read);

	int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	int ret = 0;

	switch (mask) {
	case IIO_CHAN_INFO_FREQUENCY:
	st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
	st->param.sensor_odr.data = val;

	/* Always roundup, so caller gets at least what it asks for. */
	st->param.sensor_odr.roundup = 1;

	if (cros_ec_motion_send_host_cmd(st, 0))
	ret = -EIO;
	break;
	case IIO_CHAN_INFO_SAMP_FREQ:
	st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
	st->param.ec_rate.data = val;

	if (cros_ec_motion_send_host_cmd(st, 0))
	ret = -EIO;
	else
	st->curr_sampl_freq = val;
	break;
	default:
	ret = -EINVAL;
	break;
	}
	return ret;
	}
	EXPORT_SYMBOL_GPL(cros_ec_sensors_core_write);

	MODULE_DESCRIPTION("ChromeOS EC sensor hub core functions");
	MODULE_LICENSE("GPL v2");