linux-imx

/*

 * Driver for Texas Instruments / National Semiconductor LM95234

 *

 * Copyright (c) 2013, 2014 Guenter Roeck <linux@roeck-us.net>

 *

 * Derived from lm95241.c

 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>

 *

 * 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.h>

#include <linux/hwmon-sysfs.h>

#include <linux/err.h>

#include <linux/mutex.h>

#include <linux/sysfs.h>

​

#define DRVNAME "lm95234"

​

enum chips { lm95233, lm95234 };

​

static const unsigned short normal_i2c[] = {

    0x18, 0x2a, 0x2b, 0x4d, 0x4e, I2C_CLIENT_END };

​

/* LM95234 registers */

#define LM95234_REG_MAN_ID      0xFE

#define LM95234_REG_CHIP_ID     0xFF

#define LM95234_REG_STATUS      0x02

#define LM95234_REG_CONFIG      0x03

#define LM95234_REG_CONVRATE        0x04

#define LM95234_REG_STS_FAULT       0x07

#define LM95234_REG_STS_TCRIT1      0x08

#define LM95234_REG_STS_TCRIT2      0x09

#define LM95234_REG_TEMPH(x)        ((x) + 0x10)

#define LM95234_REG_TEMPL(x)        ((x) + 0x20)

#define LM95234_REG_UTEMPH(x)       ((x) + 0x19)    /* Remote only */

#define LM95234_REG_UTEMPL(x)       ((x) + 0x29)

#define LM95234_REG_REM_MODEL       0x30

#define LM95234_REG_REM_MODEL_STS   0x38

#define LM95234_REG_OFFSET(x)       ((x) + 0x31)    /* Remote only */

#define LM95234_REG_TCRIT1(x)       ((x) + 0x40)

#define LM95234_REG_TCRIT2(x)       ((x) + 0x49)    /* Remote channel 1,2 */

#define LM95234_REG_TCRIT_HYST      0x5a

​

#define NATSEMI_MAN_ID          0x01

#define LM95233_CHIP_ID         0x89

#define LM95234_CHIP_ID         0x79

​

/* Client data (each client gets its own) */

struct lm95234_data {

    struct i2c_client *client;

    const struct attribute_group *groups[3];

    struct mutex update_lock;

    unsigned long last_updated, interval;   /* in jiffies */

    bool valid;     /* false until following fields are valid */

    /* registers values */

    int temp[5];        /* temperature (signed) */

    u32 status;     /* fault/alarm status */

    u8 tcrit1[5];       /* critical temperature limit */

    u8 tcrit2[2];       /* high temperature limit */

    s8 toffset[4];      /* remote temperature offset */

    u8 thyst;       /* common hysteresis */

​

    u8 sensor_type;     /* temperature sensor type */

};

​

static int lm95234_read_temp(struct i2c_client *client, int index, int *t)

{

    int val;

    u16 temp = 0;

​

    if (index) {

        val = i2c_smbus_read_byte_data(client,

                           LM95234_REG_UTEMPH(index - 1));

        if (val < 0)

            return val;

        temp = val << 8;

        val = i2c_smbus_read_byte_data(client,

                           LM95234_REG_UTEMPL(index - 1));