forked from Minki/linux
iio: cros_ec_sensors: add ChromeOS EC Contiguous Sensors driver
Handle 3d contiguous sensors like Accelerometers, Gyroscope and Magnetometer that are presented by the ChromeOS EC Sensor hub. Signed-off-by: Guenter Roeck <groeck@chromium.org> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Enric Balletbo i Serra
Jonathan Cameron
parent
974e6f02e2
commit
c14dca07a3
@ -12,3 +12,12 @@ config IIO_CROS_EC_SENSORS_CORE
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drivers.
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Define common attributes and sysfs interrupt handler.
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config IIO_CROS_EC_SENSORS
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tristate "ChromeOS EC Contiguous Sensors"
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select IIO_CROS_EC_SENSORS_CORE
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select MFD_CROSS_EC
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help
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Module to handle 3d contiguous sensors like
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Accelerometers, Gyroscope and Magnetometer that are
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presented by the ChromeOS EC Sensor hub.
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Creates an IIO device for each functions.
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@ -3,3 +3,4 @@
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#
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obj-$(CONFIG_IIO_CROS_EC_SENSORS_CORE) += cros_ec_sensors_core.o
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obj-$(CONFIG_IIO_CROS_EC_SENSORS) += cros_ec_sensors.o
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322
drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
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322
drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
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@ -0,0 +1,322 @@
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/*
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* cros_ec_sensors - Driver for Chrome OS Embedded Controller sensors.
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*
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* Copyright (C) 2016 Google, Inc
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* This driver uses the cros-ec interface to communicate with the Chrome OS
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* EC about sensors data. Data access is presented through iio sysfs.
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*/
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/kfifo_buf.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/triggered_buffer.h>
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#include <linux/kernel.h>
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#include <linux/mfd/cros_ec.h>
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#include <linux/mfd/cros_ec_commands.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/sysfs.h>
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#include "cros_ec_sensors_core.h"
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#define CROS_EC_SENSORS_MAX_CHANNELS 4
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/* State data for ec_sensors iio driver. */
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struct cros_ec_sensors_state {
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/* Shared by all sensors */
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struct cros_ec_sensors_core_state core;
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struct iio_chan_spec channels[CROS_EC_SENSORS_MAX_CHANNELS];
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};
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static int cros_ec_sensors_read(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct cros_ec_sensors_state *st = iio_priv(indio_dev);
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s16 data = 0;
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s64 val64;
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int i;
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int ret = IIO_VAL_INT;
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int idx = chan->scan_index;
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mutex_lock(&st->core.cmd_lock);
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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ret = st->core.read_ec_sensors_data(indio_dev, 1 << idx, &data);
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if (ret < 0)
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break;
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*val = data;
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break;
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case IIO_CHAN_INFO_CALIBBIAS:
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st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
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st->core.param.sensor_offset.flags = 0;
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ret = cros_ec_motion_send_host_cmd(&st->core, 0);
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if (ret < 0)
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break;
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/* Save values */
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for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
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st->core.calib[i] =
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st->core.resp->sensor_offset.offset[i];
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*val = st->core.calib[idx];
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break;
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case IIO_CHAN_INFO_SCALE:
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st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
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st->core.param.sensor_range.data = EC_MOTION_SENSE_NO_VALUE;
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ret = cros_ec_motion_send_host_cmd(&st->core, 0);
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if (ret < 0)
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break;
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val64 = st->core.resp->sensor_range.ret;
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switch (st->core.type) {
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case MOTIONSENSE_TYPE_ACCEL:
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/*
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* EC returns data in g, iio exepects m/s^2.
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* Do not use IIO_G_TO_M_S_2 to avoid precision loss.
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*/
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*val = div_s64(val64 * 980665, 10);
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*val2 = 10000 << (CROS_EC_SENSOR_BITS - 1);
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ret = IIO_VAL_FRACTIONAL;
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break;
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case MOTIONSENSE_TYPE_GYRO:
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/*
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* EC returns data in dps, iio expects rad/s.
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* Do not use IIO_DEGREE_TO_RAD to avoid precision
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* loss. Round to the nearest integer.
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*/
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*val = div_s64(val64 * 314159 + 9000000ULL, 1000);
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*val2 = 18000 << (CROS_EC_SENSOR_BITS - 1);
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ret = IIO_VAL_FRACTIONAL;
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break;
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case MOTIONSENSE_TYPE_MAG:
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/*
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* EC returns data in 16LSB / uT,
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* iio expects Gauss
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*/
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*val = val64;
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*val2 = 100 << (CROS_EC_SENSOR_BITS - 1);
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ret = IIO_VAL_FRACTIONAL;
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break;
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default:
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ret = -EINVAL;
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}
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break;
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default:
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ret = cros_ec_sensors_core_read(&st->core, chan, val, val2,
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mask);
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break;
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}
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mutex_unlock(&st->core.cmd_lock);
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return ret;
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}
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static int cros_ec_sensors_write(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int val, int val2, long mask)
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{
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struct cros_ec_sensors_state *st = iio_priv(indio_dev);
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int i;
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int ret = 0;
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int idx = chan->scan_index;
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mutex_lock(&st->core.cmd_lock);
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switch (mask) {
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case IIO_CHAN_INFO_CALIBBIAS:
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st->core.calib[idx] = val;
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/* Send to EC for each axis, even if not complete */
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st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_OFFSET;
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st->core.param.sensor_offset.flags =
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MOTION_SENSE_SET_OFFSET;
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for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
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st->core.param.sensor_offset.offset[i] =
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st->core.calib[i];
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st->core.param.sensor_offset.temp =
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EC_MOTION_SENSE_INVALID_CALIB_TEMP;
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ret = cros_ec_motion_send_host_cmd(&st->core, 0);
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break;
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case IIO_CHAN_INFO_SCALE:
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if (st->core.type == MOTIONSENSE_TYPE_MAG) {
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ret = -EINVAL;
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break;
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}
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st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_RANGE;
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st->core.param.sensor_range.data = val;
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/* Always roundup, so caller gets at least what it asks for. */
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st->core.param.sensor_range.roundup = 1;
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ret = cros_ec_motion_send_host_cmd(&st->core, 0);
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break;
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default:
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ret = cros_ec_sensors_core_write(
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&st->core, chan, val, val2, mask);
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break;
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}
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mutex_unlock(&st->core.cmd_lock);
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return ret;
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}
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static const struct iio_info ec_sensors_info = {
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.read_raw = &cros_ec_sensors_read,
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.write_raw = &cros_ec_sensors_write,
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.driver_module = THIS_MODULE,
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};
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static int cros_ec_sensors_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
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struct cros_ec_device *ec_device;
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struct iio_dev *indio_dev;
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struct cros_ec_sensors_state *state;
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struct iio_chan_spec *channel;
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int ret, i;
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if (!ec_dev || !ec_dev->ec_dev) {
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dev_warn(&pdev->dev, "No CROS EC device found.\n");
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return -EINVAL;
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}
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ec_device = ec_dev->ec_dev;
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indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*state));
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if (!indio_dev)
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return -ENOMEM;
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ret = cros_ec_sensors_core_init(pdev, indio_dev, true);
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if (ret)
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return ret;
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indio_dev->info = &ec_sensors_info;
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state = iio_priv(indio_dev);
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for (channel = state->channels, i = CROS_EC_SENSOR_X;
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i < CROS_EC_SENSOR_MAX_AXIS; i++, channel++) {
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/* Common part */
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channel->info_mask_separate =
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BIT(IIO_CHAN_INFO_RAW) |
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BIT(IIO_CHAN_INFO_CALIBBIAS);
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channel->info_mask_shared_by_all =
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BIT(IIO_CHAN_INFO_SCALE) |
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BIT(IIO_CHAN_INFO_FREQUENCY) |
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BIT(IIO_CHAN_INFO_SAMP_FREQ);
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channel->scan_type.realbits = CROS_EC_SENSOR_BITS;
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channel->scan_type.storagebits = CROS_EC_SENSOR_BITS;
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channel->scan_index = i;
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channel->ext_info = cros_ec_sensors_ext_info;
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channel->modified = 1;
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channel->channel2 = IIO_MOD_X + i;
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channel->scan_type.sign = 's';
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/* Sensor specific */
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switch (state->core.type) {
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case MOTIONSENSE_TYPE_ACCEL:
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channel->type = IIO_ACCEL;
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break;
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case MOTIONSENSE_TYPE_GYRO:
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channel->type = IIO_ANGL_VEL;
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break;
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case MOTIONSENSE_TYPE_MAG:
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channel->type = IIO_MAGN;
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break;
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default:
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dev_err(&pdev->dev, "Unknown motion sensor\n");
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return -EINVAL;
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}
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}
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/* Timestamp */
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channel->type = IIO_TIMESTAMP;
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channel->channel = -1;
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channel->scan_index = CROS_EC_SENSOR_MAX_AXIS;
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channel->scan_type.sign = 's';
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channel->scan_type.realbits = 64;
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channel->scan_type.storagebits = 64;
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indio_dev->channels = state->channels;
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indio_dev->num_channels = CROS_EC_SENSORS_MAX_CHANNELS;
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/* There is only enough room for accel and gyro in the io space */
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if ((state->core.ec->cmd_readmem != NULL) &&
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(state->core.type != MOTIONSENSE_TYPE_MAG))
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state->core.read_ec_sensors_data = cros_ec_sensors_read_lpc;
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else
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state->core.read_ec_sensors_data = cros_ec_sensors_read_cmd;
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ret = iio_triggered_buffer_setup(indio_dev, NULL,
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cros_ec_sensors_capture, NULL);
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if (ret)
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return ret;
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ret = iio_device_register(indio_dev);
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if (ret)
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goto error_uninit_buffer;
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return 0;
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error_uninit_buffer:
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iio_triggered_buffer_cleanup(indio_dev);
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return ret;
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}
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static int cros_ec_sensors_remove(struct platform_device *pdev)
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{
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struct iio_dev *indio_dev = platform_get_drvdata(pdev);
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iio_device_unregister(indio_dev);
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iio_triggered_buffer_cleanup(indio_dev);
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return 0;
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}
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static const struct platform_device_id cros_ec_sensors_ids[] = {
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{
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.name = "cros-ec-accel",
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},
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{
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.name = "cros-ec-gyro",
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},
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{
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.name = "cros-ec-mag",
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},
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(platform, cros_ec_sensors_ids);
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static struct platform_driver cros_ec_sensors_platform_driver = {
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.driver = {
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.name = "cros-ec-sensors",
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},
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.probe = cros_ec_sensors_probe,
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.remove = cros_ec_sensors_remove,
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.id_table = cros_ec_sensors_ids,
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};
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module_platform_driver(cros_ec_sensors_platform_driver);
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MODULE_DESCRIPTION("ChromeOS EC 3-axis sensors driver");
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MODULE_LICENSE("GPL v2");
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