linux-imx

/* Texas Instruments TMP102 SMBus temperature sensor driver

 *

 * Copyright (C) 2010 Steven King <sfking@fdwdc.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/delay.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/slab.h>

#include <linux/i2c.h>

#include <linux/hwmon.h>

#include <linux/hwmon-sysfs.h>

#include <linux/err.h>

#include <linux/mutex.h>

#include <linux/device.h>

#include <linux/jiffies.h>

#include <linux/regmap.h>

#include <linux/of.h>

​

#define DRIVER_NAME "tmp102"

​

#define TMP102_TEMP_REG         0x00

#define TMP102_CONF_REG         0x01

/* note: these bit definitions are byte swapped */

#define     TMP102_CONF_SD      0x0100

#define     TMP102_CONF_TM      0x0200

#define     TMP102_CONF_POL     0x0400

#define     TMP102_CONF_F0      0x0800

#define     TMP102_CONF_F1      0x1000

#define     TMP102_CONF_R0      0x2000

#define     TMP102_CONF_R1      0x4000

#define     TMP102_CONF_OS      0x8000

#define     TMP102_CONF_EM      0x0010

#define     TMP102_CONF_AL      0x0020

#define     TMP102_CONF_CR0     0x0040

#define     TMP102_CONF_CR1     0x0080

#define TMP102_TLOW_REG         0x02

#define TMP102_THIGH_REG        0x03

​

#define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \

                 TMP102_CONF_POL | TMP102_CONF_F0 | \

                 TMP102_CONF_F1 | TMP102_CONF_OS | \

                 TMP102_CONF_EM | TMP102_CONF_AL | \

                 TMP102_CONF_CR0 | TMP102_CONF_CR1)

​

#define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \

                 TMP102_CONF_CR0)

#define TMP102_CONFIG_SET   (TMP102_CONF_TM | TMP102_CONF_EM | \

                 TMP102_CONF_CR1)

​

#define CONVERSION_TIME_MS      35  /* in milli-seconds */

​

struct tmp102 {

    struct regmap *regmap;

    u16 config_orig;

    unsigned long ready_time;

};

​

/* convert left adjusted 13-bit TMP102 register value to milliCelsius */

static inline int tmp102_reg_to_mC(s16 val)

{

    return ((val & ~0x01) * 1000) / 128;

}

​

/* convert milliCelsius to left adjusted 13-bit TMP102 register value */

static inline u16 tmp102_mC_to_reg(int val)

{

    return (val * 128) / 1000;

}

​

static int tmp102_read(struct device *dev, enum hwmon_sensor_types type,

               u32 attr, int channel, long *temp)

{

    struct tmp102 *tmp102 = dev_get_drvdata(dev);

    unsigned int regval;

    int err, reg;

​

    switch (attr) {

    case hwmon_temp_input:

        /* Is it too early to return a conversion ? */

        if (time_before(jiffies, tmp102->ready_time)) {

            dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);