linux-imx

/*

 * Driver for Linear Technology LTC4260 I2C Positive Voltage Hot Swap Controller

 *

 * Copyright (c) 2014 Guenter Roeck

 *

 * 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/kernel.h>

#include <linux/module.h>

#include <linux/err.h>

#include <linux/slab.h>

#include <linux/i2c.h>

#include <linux/hwmon.h>

#include <linux/hwmon-sysfs.h>

#include <linux/jiffies.h>

#include <linux/regmap.h>

​

/* chip registers */

#define LTC4260_CONTROL 0x00

#define LTC4260_ALERT   0x01

#define LTC4260_STATUS  0x02

#define LTC4260_FAULT   0x03

#define LTC4260_SENSE   0x04

#define LTC4260_SOURCE  0x05

#define LTC4260_ADIN    0x06

​

/*

 * Fault register bits

 */

#define FAULT_OV    (1 << 0)

#define FAULT_UV    (1 << 1)

#define FAULT_OC    (1 << 2)

#define FAULT_POWER_BAD (1 << 3)

#define FAULT_FET_SHORT (1 << 5)

​

/* Return the voltage from the given register in mV or mA */

static int ltc4260_get_value(struct device *dev, u8 reg)

{

    struct regmap *regmap = dev_get_drvdata(dev);

    unsigned int val;

    int ret;

​

    ret = regmap_read(regmap, reg, &val);

    if (ret < 0)

        return ret;

​

    switch (reg) {

    case LTC4260_ADIN:

        /* 10 mV resolution. Convert to mV. */

        val = val * 10;

        break;

    case LTC4260_SOURCE:

        /* 400 mV resolution. Convert to mV. */

        val = val * 400;