drivers/hwmon/lm75.h

Source file repositories/reference/linux-study-clean/drivers/hwmon/lm75.h

File Facts

System
Linux kernel
Corpus path
drivers/hwmon/lm75.h
Extension
.h
Size
1120 bytes
Lines
42
Domain
Driver Families
Bucket
drivers/hwmon
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/minmax.h>
#include <linux/types.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;
}

Annotation

Implementation Notes