linux-imx

/*

 *  MEN 14F021P00 Board Management Controller (BMC) hwmon driver.

 *

 *  This is the core hwmon driver of the MEN 14F021P00 BMC.

 *  The BMC monitors the board voltages which can be access with this

 *  driver through sysfs.

 *

 *  Copyright (C) 2014 MEN Mikro Elektronik Nuernberg GmbH

 *

 *  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.

 */

​

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/platform_device.h>

#include <linux/hwmon.h>

#include <linux/hwmon-sysfs.h>

#include <linux/jiffies.h>

#include <linux/slab.h>

#include <linux/i2c.h>

#include <linux/err.h>

​

#define DRV_NAME  "menf21bmc_hwmon"

​

#define BMC_VOLT_COUNT  5

#define MENF21BMC_V33   0

#define MENF21BMC_V5    1

#define MENF21BMC_V12   2

#define MENF21BMC_V5_SB 3

#define MENF21BMC_VBAT  4

​

#define IDX_TO_VOLT_MIN_CMD(idx) (0x40 + idx)

#define IDX_TO_VOLT_MAX_CMD(idx) (0x50 + idx)

#define IDX_TO_VOLT_INP_CMD(idx) (0x60 + idx)

​

struct menf21bmc_hwmon {

    bool valid;

    struct i2c_client *i2c_client;

    unsigned long last_update;

    int in_val[BMC_VOLT_COUNT];

    int in_min[BMC_VOLT_COUNT];

    int in_max[BMC_VOLT_COUNT];

};

​

static const char *const input_names[] = {

    [MENF21BMC_V33]     = "MON_3_3V",

    [MENF21BMC_V5]      = "MON_5V",

    [MENF21BMC_V12]     = "MON_12V",

    [MENF21BMC_V5_SB]   = "5V_STANDBY",

    [MENF21BMC_VBAT]    = "VBAT"

};

​

static struct menf21bmc_hwmon *menf21bmc_hwmon_update(struct device *dev)

{

    int i;

    int val;

    struct menf21bmc_hwmon *drv_data = dev_get_drvdata(dev);

    struct menf21bmc_hwmon *data_ret = drv_data;

​

    if (time_after(jiffies, drv_data->last_update + HZ)

        || !drv_data->valid) {

        for (i = 0; i < BMC_VOLT_COUNT; i++) {

            val = i2c_smbus_read_word_data(drv_data->i2c_client,

                               IDX_TO_VOLT_INP_CMD(i));

            if (val < 0) {

                data_ret = ERR_PTR(val);

                goto abort;

            }

            drv_data->in_val[i] = val;

        }

        drv_data->last_update = jiffies;

        drv_data->valid = true;

    }

abort:

    return data_ret;

}

​

static int menf21bmc_hwmon_get_volt_limits(struct menf21bmc_hwmon *drv_data)

{

    int i, val;

​

    for (i = 0; i < BMC_VOLT_COUNT; i++) {

        val = i2c_smbus_read_word_data(drv_data->i2c_client,

                           IDX_TO_VOLT_MIN_CMD(i));

        if (val < 0)

            return val;

​

        drv_data->in_min[i] = val;

​