1/* SPDX-License-Identifier: GPL-2.0-or-later */
 2/*
 3 * lm75.h - Part of lm_sensors, Linux kernel modules for hardware monitoring
 4 * Copyright (c) 2003 Mark M. Hoffman <mhoffman@lightlink.com>
 5 */
 6
 7/*
 8 * This file contains common code for encoding/decoding LM75 type
 9 * temperature readings, which are emulated by many of the chips
10 * we support.  As the user is unlikely to load more than one driver
11 * which contains this code, we don't worry about the wasted space.
12 */
13
14#include <linux/kernel.h>
15
16/* straight from the datasheet */
17#define LM75_TEMP_MIN (-55000)
18#define LM75_TEMP_MAX 125000
19#define LM75_SHUTDOWN 0x01
20
21/*
22 * TEMP: 0.001C/bit (-55C to +125C)
23 * REG: (0.5C/bit, two's complement) << 7
24 */
25static inline u16 LM75_TEMP_TO_REG(long temp)
26{
27	int ntemp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
28
29	ntemp += (ntemp < 0 ? -250 : 250);
30	return (u16)((ntemp / 500) << 7);
31}
32
33static inline int LM75_TEMP_FROM_REG(u16 reg)
34{
35	/*
36	 * use integer division instead of equivalent right shift to
37	 * guarantee arithmetic shift and preserve the sign
38	 */
39	return ((s16)reg / 128) * 500;
40}

 1/* SPDX-License-Identifier: GPL-2.0-or-later */
 2/*
 3 * lm75.h - Part of lm_sensors, Linux kernel modules for hardware monitoring
 4 * Copyright (c) 2003 Mark M. Hoffman <mhoffman@lightlink.com>
 5 */
 6
 7/*
 8 * This file contains common code for encoding/decoding LM75 type
 9 * temperature readings, which are emulated by many of the chips
10 * we support.  As the user is unlikely to load more than one driver
11 * which contains this code, we don't worry about the wasted space.
12 */
13
14#include <linux/kernel.h>
15
16/* straight from the datasheet */
17#define LM75_TEMP_MIN (-55000)
18#define LM75_TEMP_MAX 125000
19#define LM75_SHUTDOWN 0x01
20
21/*
22 * TEMP: 0.001C/bit (-55C to +125C)
23 * REG: (0.5C/bit, two's complement) << 7
24 */
25static inline u16 LM75_TEMP_TO_REG(long temp)
26{
27	int ntemp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
28
29	ntemp += (ntemp < 0 ? -250 : 250);
30	return (u16)((ntemp / 500) << 7);
31}
32
33static inline int LM75_TEMP_FROM_REG(u16 reg)
34{
35	/*
36	 * use integer division instead of equivalent right shift to
37	 * guarantee arithmetic shift and preserve the sign
38	 */
39	return ((s16)reg / 128) * 500;
40}