[mirror_ubuntu-hirsute-kernel.git] / drivers / hwmon / lm75.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
    lm75.h - Part of lm_sensors, Linux kernel modules for hardware
	      monitoring
    Copyright (c) 2003 Mark M. Hoffman <mhoffman@lightlink.com>

*/

/*
    This file contains common code for encoding/decoding LM75 type
    temperature readings, which are emulated by many of the chips
    we support.  As the user is unlikely to load more than one driver
    which contains this code, we don't worry about the wasted space.
*/

#include <linux/kernel.h>

/* straight from the datasheet */
#define LM75_TEMP_MIN (-55000)
#define LM75_TEMP_MAX 125000
#define LM75_SHUTDOWN 0x01

/* TEMP: 0.001C/bit (-55C to +125C)
   REG: (0.5C/bit, two's complement) << 7 */
static inline u16 LM75_TEMP_TO_REG(long temp)
{
	int ntemp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
	ntemp += (ntemp < 0 ? -250 : 250);
	return (u16)((ntemp / 500) << 7);
}

static inline int LM75_TEMP_FROM_REG(u16 reg)
{
	/* use integer division instead of equivalent right shift to
	   guarantee arithmetic shift and preserve the sign */
	return ((s16)reg / 128) * 500;
}
Commit	Line	Data
74ba9207	1	/* SPDX-License-Identifier: GPL-2.0-or-later */
1da177e4 LT	2	/*
1da177e4 LT	3	lm75.h - Part of lm_sensors, Linux kernel modules for hardware
a01a6847	4	monitoring
1da177e4 LT	5	Copyright (c) 2003 Mark M. Hoffman <mhoffman@lightlink.com>
1da177e4 LT	6
1da177e4 LT	7	*/
	8
	9	/*
	10	This file contains common code for encoding/decoding LM75 type
	11	temperature readings, which are emulated by many of the chips
	12	we support. As the user is unlikely to load more than one driver
	13	which contains this code, we don't worry about the wasted space.
	14	*/
	15
5a4c0601	16	#include <linux/kernel.h>
1da177e4 LT	17
	18	/* straight from the datasheet */
	19	#define LM75_TEMP_MIN (-55000)
	20	#define LM75_TEMP_MAX 125000
9914518e	21	#define LM75_SHUTDOWN 0x01
1da177e4 LT	22
	23	/* TEMP: 0.001C/bit (-55C to +125C)
	24	REG: (0.5C/bit, two's complement) << 7 */
5bfedac0	25	static inline u16 LM75_TEMP_TO_REG(long temp)
1da177e4	26	{
2a844c14	27	int ntemp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
a01a6847	28	ntemp += (ntemp < 0 ? -250 : 250);
1da177e4 LT	29	return (u16)((ntemp / 500) << 7);
	30	}
	31
	32	static inline int LM75_TEMP_FROM_REG(u16 reg)
	33	{
	34	/* use integer division instead of equivalent right shift to
	35	guarantee arithmetic shift and preserve the sign */
	36	return ((s16)reg / 128) * 500;
	37	}