// SPDX-License-Identifier: GPL-2.0
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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 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/device.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/common/cros_ec_sensors_core.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/module.h>
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#include <linux/platform_data/cros_ec_commands.h>
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#include <linux/platform_data/cros_ec_proto.h>
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#include <linux/platform_device.h>
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#include <linux/slab.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;
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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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ret = IIO_VAL_INT;
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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].offset =
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st->core.resp->sensor_offset.offset[i];
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ret = IIO_VAL_INT;
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*val = st->core.calib[idx].offset;
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break;
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case IIO_CHAN_INFO_CALIBSCALE:
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st->core.param.cmd = MOTIONSENSE_CMD_SENSOR_SCALE;
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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 == -EPROTO || ret == -EOPNOTSUPP) {
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/* Reading calibscale is not supported on older EC. */
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*val = 1;
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*val2 = 0;
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ret = IIO_VAL_INT_PLUS_MICRO;
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break;
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} else if (ret) {
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break;
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}
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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].scale =
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st->core.resp->sensor_scale.scale[i];
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*val = st->core.calib[idx].scale >> 15;
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*val2 = ((st->core.calib[idx].scale & 0x7FFF) * 1000000LL) /
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MOTION_SENSE_DEFAULT_SCALE;
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ret = IIO_VAL_INT_PLUS_MICRO;
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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 = 0;
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*val2 = div_s64(val64 * 3141592653ULL,
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180 << (CROS_EC_SENSOR_BITS - 1));
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ret = IIO_VAL_INT_PLUS_NANO;
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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;
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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].offset = 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].offset;
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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_CALIBSCALE:
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st->core.calib[idx].scale = 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_SCALE;
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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_scale.scale[i] =
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st->core.calib[i].scale;
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st->core.param.sensor_scale.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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if (ret == 0) {
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st->core.range_updated = true;
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st->core.curr_range = val;
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}
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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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.read_avail = &cros_ec_sensors_core_read_avail,
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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 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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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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cros_ec_sensors_capture,
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cros_ec_sensors_push_data,
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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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BIT(IIO_CHAN_INFO_CALIBSCALE);
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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_SAMP_FREQ);
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channel->info_mask_shared_by_all_available =
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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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return devm_iio_device_register(dev, indio_dev);
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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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.pm = &cros_ec_sensors_pm_ops,
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},
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.probe = cros_ec_sensors_probe,
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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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