iio: cros_ec_sensors: add ChromeOS EC Contiguous Sensors driver (c14dca07) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/iio/common/cros_ec_sensors/Kconfig

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Original line number	Diff line number	Diff line
		@@ -12,3 +12,12 @@ config IIO_CROS_EC_SENSORS_CORE
		drivers.
		Define common attributes and sysfs interrupt handler.

		config IIO_CROS_EC_SENSORS
		tristate "ChromeOS EC Contiguous Sensors"
		select IIO_CROS_EC_SENSORS_CORE
		select MFD_CROSS_EC
		help
		Module to handle 3d contiguous sensors like
		Accelerometers, Gyroscope and Magnetometer that are
		presented by the ChromeOS EC Sensor hub.
		Creates an IIO device for each functions.

drivers/iio/common/cros_ec_sensors/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -3,3 +3,4 @@
		#

		obj-$(CONFIG_IIO_CROS_EC_SENSORS_CORE) += cros_ec_sensors_core.o
		obj-$(CONFIG_IIO_CROS_EC_SENSORS) += cros_ec_sensors.o

drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c

0 → 100644

+322 −0

Original line number	Diff line number	Diff line
		/*
		* cros_ec_sensors - Driver for Chrome OS Embedded Controller sensors.
		*
		* 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.
		*
		* This driver uses the cros-ec interface to communicate with the Chrome OS
		* EC about sensors data. Data access is presented through iio sysfs.
		*/

		#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/iio/triggered_buffer.h>
		#include <linux/kernel.h>
		#include <linux/mfd/cros_ec.h>
		#include <linux/mfd/cros_ec_commands.h>
		#include <linux/module.h>
		#include <linux/platform_device.h>
		#include <linux/slab.h>
		#include <linux/sysfs.h>

		#include "cros_ec_sensors_core.h"

		#define CROS_EC_SENSORS_MAX_CHANNELS 4

		/* State data for ec_sensors iio driver. */
		struct cros_ec_sensors_state {
		/* Shared by all sensors */
		struct cros_ec_sensors_core_state core;

		struct iio_chan_spec channels[CROS_EC_SENSORS_MAX_CHANNELS];
		};

		static int cros_ec_sensors_read(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		int val, int val2, long mask)
		{
		struct cros_ec_sensors_state *st = iio_priv(indio_dev);
		s16 data = 0;
		s64 val64;
		int i;
		int ret = IIO_VAL_INT;
		int idx = chan->scan_index;

		mutex_lock(&st->core.cmd_lock);

		switch (mask) {
		case IIO_CHAN_INFO_RAW:
		ret = st->core.read_ec_sensors_data(indio_dev, 1 << idx, &data);
		if (ret < 0)
		break;

		*val = data;
		break;
		case IIO_CHAN_INFO_CALIBBIAS:
		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
		st->core.param.sensor_offset.flags = 0;

		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
		if (ret < 0)
		break;

		/* Save values */
		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
		st->core.calib[i] =
		st->core.resp->sensor_offset.offset[i];

		*val = st->core.calib[idx];
		break;
		case IIO_CHAN_INFO_SCALE:
		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
		st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;

		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
		if (ret < 0)
		break;

		val64 = st->core.resp->sensor_range.ret;
		switch (st->core.type) {
		case MOTIONSENSE_TYPE_ACCEL:
		/*
		* EC returns data in g, iio exepects m/s^2.
		* Do not use IIO_G_TO_M_S_2 to avoid precision loss.
		*/
		val = div_s64(val64 980665, 10);
		*val2 = 10000 << (CROS_EC_SENSOR_BITS - 1);
		ret = IIO_VAL_FRACTIONAL;
		break;
		case MOTIONSENSE_TYPE_GYRO:
		/*
		* EC returns data in dps, iio expects rad/s.
		* Do not use IIO_DEGREE_TO_RAD to avoid precision
		* loss. Round to the nearest integer.
		*/
		val = div_s64(val64 314159 + 9000000ULL, 1000);
		*val2 = 18000 << (CROS_EC_SENSOR_BITS - 1);
		ret = IIO_VAL_FRACTIONAL;
		break;
		case MOTIONSENSE_TYPE_MAG:
		/*
		* EC returns data in 16LSB / uT,
		* iio expects Gauss
		*/
		*val = val64;
		*val2 = 100 << (CROS_EC_SENSOR_BITS - 1);
		ret = IIO_VAL_FRACTIONAL;
		break;
		default:
		ret = -EINVAL;
		}
		break;
		default:
		ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
		mask);
		break;
		}
		mutex_unlock(&st->core.cmd_lock);

		return ret;
		}

		static int cros_ec_sensors_write(struct iio_dev *indio_dev,
		struct iio_chan_spec const *chan,
		int val, int val2, long mask)
		{
		struct cros_ec_sensors_state *st = iio_priv(indio_dev);
		int i;
		int ret = 0;
		int idx = chan->scan_index;

		mutex_lock(&st->core.cmd_lock);

		switch (mask) {
		case IIO_CHAN_INFO_CALIBBIAS:
		st->core.calib[idx] = val;

		/* Send to EC for each axis, even if not complete */
		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
		st->core.param.sensor_offset.flags =
		MOTION_SENSE_SET_OFFSET;
		for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
		st->core.param.sensor_offset.offset[i] =
		st->core.calib[i];
		st->core.param.sensor_offset.temp =
		EC_MOTION_SENSE_INVALID_CALIB_TEMP;

		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
		break;
		case IIO_CHAN_INFO_SCALE:
		if (st->core.type == MOTIONSENSE_TYPE_MAG) {
		ret = -EINVAL;
		break;
		}
		st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
		st->core.param.sensor_range.data = val;

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

		ret = cros_ec_motion_send_host_cmd(&st->core, 0);
		break;
		default:
		ret = cros_ec_sensors_core_write(
		&st->core, chan, val, val2, mask);
		break;
		}

		mutex_unlock(&st->core.cmd_lock);

		return ret;
		}

		static const struct iio_info ec_sensors_info = {
		.read_raw = &cros_ec_sensors_read,
		.write_raw = &cros_ec_sensors_write,
		.driver_module = THIS_MODULE,
		};

		static int cros_ec_sensors_probe(struct platform_device *pdev)
		{
		struct device *dev = &pdev->dev;
		struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
		struct cros_ec_device *ec_device;
		struct iio_dev *indio_dev;
		struct cros_ec_sensors_state *state;
		struct iio_chan_spec *channel;
		int ret, i;

		if (!ec_dev \|\| !ec_dev->ec_dev) {
		dev_warn(&pdev->dev, "No CROS EC device found.\n");
		return -EINVAL;
		}
		ec_device = ec_dev->ec_dev;

		indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*state));
		if (!indio_dev)
		return -ENOMEM;

		ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
		if (ret)
		return ret;

		indio_dev->info = &ec_sensors_info;
		state = iio_priv(indio_dev);
		for (channel = state->channels, i = CROS_EC_SENSOR_X;
		i < CROS_EC_SENSOR_MAX_AXIS; i++, channel++) {
		/* Common part */
		channel->info_mask_separate =
		BIT(IIO_CHAN_INFO_RAW) \|
		BIT(IIO_CHAN_INFO_CALIBBIAS);
		channel->info_mask_shared_by_all =
		BIT(IIO_CHAN_INFO_SCALE) \|
		BIT(IIO_CHAN_INFO_FREQUENCY) \|
		BIT(IIO_CHAN_INFO_SAMP_FREQ);
		channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
		channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
		channel->scan_index = i;
		channel->ext_info = cros_ec_sensors_ext_info;
		channel->modified = 1;
		channel->channel2 = IIO_MOD_X + i;
		channel->scan_type.sign = 's';

		/* Sensor specific */
		switch (state->core.type) {
		case MOTIONSENSE_TYPE_ACCEL:
		channel->type = IIO_ACCEL;
		break;
		case MOTIONSENSE_TYPE_GYRO:
		channel->type = IIO_ANGL_VEL;
		break;
		case MOTIONSENSE_TYPE_MAG:
		channel->type = IIO_MAGN;
		break;
		default:
		dev_err(&pdev->dev, "Unknown motion sensor\n");
		return -EINVAL;
		}
		}

		/* Timestamp */
		channel->type = IIO_TIMESTAMP;
		channel->channel = -1;
		channel->scan_index = CROS_EC_SENSOR_MAX_AXIS;
		channel->scan_type.sign = 's';
		channel->scan_type.realbits = 64;
		channel->scan_type.storagebits = 64;

		indio_dev->channels = state->channels;
		indio_dev->num_channels = CROS_EC_SENSORS_MAX_CHANNELS;

		/* There is only enough room for accel and gyro in the io space */
		if ((state->core.ec->cmd_readmem != NULL) &&
		(state->core.type != MOTIONSENSE_TYPE_MAG))
		state->core.read_ec_sensors_data = cros_ec_sensors_read_lpc;
		else
		state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;

		ret = iio_triggered_buffer_setup(indio_dev, NULL,
		cros_ec_sensors_capture, NULL);
		if (ret)
		return ret;

		ret = iio_device_register(indio_dev);
		if (ret)
		goto error_uninit_buffer;

		return 0;

		error_uninit_buffer:
		iio_triggered_buffer_cleanup(indio_dev);

		return ret;
		}

		static int cros_ec_sensors_remove(struct platform_device *pdev)
		{
		struct iio_dev *indio_dev = platform_get_drvdata(pdev);

		iio_device_unregister(indio_dev);
		iio_triggered_buffer_cleanup(indio_dev);

		return 0;
		}

		static const struct platform_device_id cros_ec_sensors_ids[] = {
		{
		.name = "cros-ec-accel",
		},
		{
		.name = "cros-ec-gyro",
		},
		{
		.name = "cros-ec-mag",
		},
		{ /* sentinel */ }
		};
		MODULE_DEVICE_TABLE(platform, cros_ec_sensors_ids);

		static struct platform_driver cros_ec_sensors_platform_driver = {
		.driver = {
		.name = "cros-ec-sensors",
		},
		.probe = cros_ec_sensors_probe,
		.remove = cros_ec_sensors_remove,
		.id_table = cros_ec_sensors_ids,
		};
		module_platform_driver(cros_ec_sensors_platform_driver);

		MODULE_DESCRIPTION("ChromeOS EC 3-axis sensors driver");
		MODULE_LICENSE("GPL v2");