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, int16_t *temp)
17{
18 struct device *dev = regmap_get_device(map: 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, enable: true, NULL);
26 if (ret)
27 goto exit;
28
29 raw = (__be16 *)&st->buffer[0];
30 ret = regmap_bulk_read(map: st->map, INV_ICM42600_REG_TEMP_DATA, val: raw, val_count: sizeof(*raw));
31 if (ret)
32 goto exit;
33
34 *temp = (int16_t)be16_to_cpup(p: raw);
35 if (*temp == INV_ICM42600_DATA_INVALID)
36 ret = -EINVAL;
37
38exit:
39 mutex_unlock(lock: &st->lock);
40 pm_runtime_mark_last_busy(dev);
41 pm_runtime_put_autosuspend(dev);
42
43 return ret;
44}
45
46int inv_icm42600_temp_read_raw(struct iio_dev *indio_dev,
47 struct iio_chan_spec const *chan,
48 int *val, int *val2, long mask)
49{
50 struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
51 int16_t temp;
52 int ret;
53
54 if (chan->type != IIO_TEMP)
55 return -EINVAL;
56
57 switch (mask) {
58 case IIO_CHAN_INFO_RAW:
59 ret = iio_device_claim_direct_mode(indio_dev);
60 if (ret)
61 return ret;
62 ret = inv_icm42600_temp_read(st, temp: &temp);
63 iio_device_release_direct_mode(indio_dev);
64 if (ret)
65 return ret;
66 *val = temp;
67 return IIO_VAL_INT;
68 /*
69 * T°C = (temp / 132.48) + 25
70 * Tm°C = 1000 * ((temp * 100 / 13248) + 25)
71 * scale: 100000 / 13248 ~= 7.548309
72 * offset: 25000
73 */
74 case IIO_CHAN_INFO_SCALE:
75 *val = 7;
76 *val2 = 548309;
77 return IIO_VAL_INT_PLUS_MICRO;
78 case IIO_CHAN_INFO_OFFSET:
79 *val = 25000;
80 return IIO_VAL_INT;
81 default:
82 return -EINVAL;
83 }
84}
85

source code of linux/drivers/iio/imu/inv_icm42600/inv_icm42600_temp.c