linux-stable/drivers/iio/imu/inv_icm42600/inv_icm42600_temp.c
Jean-Baptiste Maneyrol bc3eb0207f iio: imu: inv_icm42600: add temperature sensor support
Add temperature channel in gyroscope and accelerometer devices.

Temperature is available in full 16 bits resolution when reading
register and in low 8 bits resolution in the FIFO. Return full
precision raw temperature with corresponding scale and offset.

Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-06-27 14:20:16 +01:00

84 lines
1.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2020 Invensense, Inc.
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include "inv_icm42600.h"
#include "inv_icm42600_temp.h"
static int inv_icm42600_temp_read(struct inv_icm42600_state *st, int16_t *temp)
{
struct device *dev = regmap_get_device(st->map);
__be16 *raw;
int ret;
pm_runtime_get_sync(dev);
mutex_lock(&st->lock);
ret = inv_icm42600_set_temp_conf(st, true, NULL);
if (ret)
goto exit;
raw = (__be16 *)&st->buffer[0];
ret = regmap_bulk_read(st->map, INV_ICM42600_REG_TEMP_DATA, raw, sizeof(*raw));
if (ret)
goto exit;
*temp = (int16_t)be16_to_cpup(raw);
if (*temp == INV_ICM42600_DATA_INVALID)
ret = -EINVAL;
exit:
mutex_unlock(&st->lock);
pm_runtime_mark_last_busy(dev);
pm_runtime_put_autosuspend(dev);
return ret;
}
int inv_icm42600_temp_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
int16_t temp;
int ret;
if (chan->type != IIO_TEMP)
return -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
ret = inv_icm42600_temp_read(st, &temp);
iio_device_release_direct_mode(indio_dev);
if (ret)
return ret;
*val = temp;
return IIO_VAL_INT;
/*
* T°C = (temp / 132.48) + 25
* Tm°C = 1000 * ((temp * 100 / 13248) + 25)
* scale: 100000 / 13248 ~= 7.548309
* offset: 25000
*/
case IIO_CHAN_INFO_SCALE:
*val = 7;
*val2 = 548309;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_OFFSET:
*val = 25000;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}