inv_icm42600_temp.c

 1// SPDX-License-Identifier: GPL-2.0-or-later
 2/*
 3 * Copyright (C) 2020 Invensense, Inc.
 4 */
 5
 6#include <linux/kernel.h>
 7#include <linux/device.h>
 8#include <linux/mutex.h>
 9#include <linux/pm_runtime.h>
10#include <linux/regmap.h>
11#include <linux/iio/iio.h>
12
13#include "inv_icm42600.h"
14#include "inv_icm42600_temp.h"
15
16static int inv_icm42600_temp_read(struct inv_icm42600_state *st, s16 *temp)
17{
18	struct device *dev = regmap_get_device(st->map);
19	__be16 *raw;
20	int ret;
21
22	pm_runtime_get_sync(dev);
23	mutex_lock(&st->lock);
24
25	ret = inv_icm42600_set_temp_conf(st, true, NULL);
26	if (ret)
27		goto exit;
28
29	raw = (__be16 *)&st->buffer[0];
30	ret = regmap_bulk_read(st->map, INV_ICM42600_REG_TEMP_DATA, raw, sizeof(*raw));
31	if (ret)
32		goto exit;
33
34	*temp = (s16)be16_to_cpup(raw);
35	/*
36	 * Temperature data is invalid if both accel and gyro are off.
37	 * Return -EBUSY in this case.
38	 */
39	if (*temp == INV_ICM42600_DATA_INVALID)
40		ret = -EBUSY;
41
42exit:
43	mutex_unlock(&st->lock);
44	pm_runtime_put_autosuspend(dev);
45
46	return ret;
47}
48
49int inv_icm42600_temp_read_raw(struct iio_dev *indio_dev,
50			       struct iio_chan_spec const *chan,
51			       int *val, int *val2, long mask)
52{
53	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
54	s16 temp;
55	int ret;
56
57	if (chan->type != IIO_TEMP)
58		return -EINVAL;
59
60	switch (mask) {
61	case IIO_CHAN_INFO_RAW:
62		if (!iio_device_claim_direct(indio_dev))
63			return -EBUSY;
64		ret = inv_icm42600_temp_read(st, &temp);
65		iio_device_release_direct(indio_dev);
66		if (ret)
67			return ret;
68		*val = temp;
69		return IIO_VAL_INT;
70	/*
71	 * T°C = (temp / 132.48) + 25
72	 * Tm°C = 1000 * ((temp / 132.48) + 25)
73	 * Tm°C = 7.548309 * temp + 25000
74	 * Tm°C = (temp + 3312) * 7.548309
75	 * scale: 100000 / 13248 ~= 7.548309
76	 * offset: 3312
77	 */
78	case IIO_CHAN_INFO_SCALE:
79		*val = 7;
80		*val2 = 548309;
81		return IIO_VAL_INT_PLUS_MICRO;
82	case IIO_CHAN_INFO_OFFSET:
83		*val = 3312;
84		return IIO_VAL_INT;
85	default:
86		return -EINVAL;
87	}
88}