linux-imx

/*

 * lm83.c - Part of lm_sensors, Linux kernel modules for hardware

 *          monitoring

 * Copyright (C) 2003-2009  Jean Delvare <jdelvare@suse.de>

 *

 * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is

 * a sensor chip made by National Semiconductor. It reports up to four

 * temperatures (its own plus up to three external ones) with a 1 deg

 * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained

 * from National's website at:

 *   http://www.national.com/pf/LM/LM83.html

 * Since the datasheet omits to give the chip stepping code, I give it

 * here: 0x03 (at register 0xff).

 *

 * Also supports the LM82 temp sensor, which is basically a stripped down

 * model of the LM83.  Datasheet is here:

 * http://www.national.com/pf/LM/LM82.html

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

​

#include <linux/module.h>

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/jiffies.h>

#include <linux/i2c.h>

#include <linux/hwmon-sysfs.h>

#include <linux/hwmon.h>

#include <linux/err.h>

#include <linux/mutex.h>

#include <linux/sysfs.h>

​

/*

 * Addresses to scan

 * Address is selected using 2 three-level pins, resulting in 9 possible

 * addresses.

 */

​

static const unsigned short normal_i2c[] = {

    0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };

​

enum chips { lm83, lm82 };

​

/*

 * The LM83 registers

 * Manufacturer ID is 0x01 for National Semiconductor.

 */

​

#define LM83_REG_R_MAN_ID       0xFE

#define LM83_REG_R_CHIP_ID      0xFF

#define LM83_REG_R_CONFIG       0x03

#define LM83_REG_W_CONFIG       0x09

#define LM83_REG_R_STATUS1      0x02

#define LM83_REG_R_STATUS2      0x35

#define LM83_REG_R_LOCAL_TEMP       0x00

#define LM83_REG_R_LOCAL_HIGH       0x05

#define LM83_REG_W_LOCAL_HIGH       0x0B

#define LM83_REG_R_REMOTE1_TEMP     0x30

#define LM83_REG_R_REMOTE1_HIGH     0x38

#define LM83_REG_W_REMOTE1_HIGH     0x50

#define LM83_REG_R_REMOTE2_TEMP     0x01

#define LM83_REG_R_REMOTE2_HIGH     0x07

#define LM83_REG_W_REMOTE2_HIGH     0x0D

#define LM83_REG_R_REMOTE3_TEMP     0x31

#define LM83_REG_R_REMOTE3_HIGH     0x3A

#define LM83_REG_W_REMOTE3_HIGH     0x52

#define LM83_REG_R_TCRIT        0x42

#define LM83_REG_W_TCRIT        0x5A

​

/*

 * Conversions and various macros

 * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.

 */

​

#define TEMP_FROM_REG(val)  ((val) * 1000)

#define TEMP_TO_REG(val)    ((val) <= -128000 ? -128 : \

                 (val) >= 127000 ? 127 : \

                 (val) < 0 ? ((val) - 500) / 1000 : \

                 ((val) + 500) / 1000)

​

static const u8 LM83_REG_R_TEMP[] = {

    LM83_REG_R_LOCAL_TEMP,

    LM83_REG_R_REMOTE1_TEMP,

    LM83_REG_R_REMOTE2_TEMP,