max8688.c

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/*
 * Hardware monitoring driver for Maxim MAX8688
 *
 * Copyright (c) 2011 Ericsson AB.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include "pmbus.h"

#define MAX8688_MFR_VOUT_PEAK       0xd4
#define MAX8688_MFR_IOUT_PEAK       0xd5
#define MAX8688_MFR_TEMPERATURE_PEAK    0xd6
#define MAX8688_MFG_STATUS      0xd8

#define MAX8688_STATUS_OC_FAULT     (1 << 4)
#define MAX8688_STATUS_OV_FAULT     (1 << 5)
#define MAX8688_STATUS_OV_WARNING   (1 << 8)
#define MAX8688_STATUS_UV_FAULT     (1 << 9)
#define MAX8688_STATUS_UV_WARNING   (1 << 10)
#define MAX8688_STATUS_UC_FAULT     (1 << 11)
#define MAX8688_STATUS_OC_WARNING   (1 << 12)
#define MAX8688_STATUS_OT_FAULT     (1 << 13)
#define MAX8688_STATUS_OT_WARNING   (1 << 14)

static int max8688_read_word_data(struct i2c_client *client, int page, int reg)
{
    int ret;

    if (page)
        return -ENXIO;

    switch (reg) {
    case PMBUS_VIRT_READ_VOUT_MAX:
        ret = pmbus_read_word_data(client, 0, MAX8688_MFR_VOUT_PEAK);
        break;
    case PMBUS_VIRT_READ_IOUT_MAX:
        ret = pmbus_read_word_data(client, 0, MAX8688_MFR_IOUT_PEAK);
        break;
    case PMBUS_VIRT_READ_TEMP_MAX:
        ret = pmbus_read_word_data(client, 0,
                       MAX8688_MFR_TEMPERATURE_PEAK);
        break;
    case PMBUS_VIRT_RESET_VOUT_HISTORY:
    case PMBUS_VIRT_RESET_IOUT_HISTORY:
    case PMBUS_VIRT_RESET_TEMP_HISTORY:
        ret = 0;
        break;
    default:
        ret = -ENODATA;
        break;
    }
    return ret;
}

static int max8688_write_word_data(struct i2c_client *client, int page, int reg,
                   u16 word)
{
    int ret;

    switch (reg) {
    case PMBUS_VIRT_RESET_VOUT_HISTORY:
        ret = pmbus_write_word_data(client, 0, MAX8688_MFR_VOUT_PEAK,
                        0);
        break;
    case PMBUS_VIRT_RESET_IOUT_HISTORY:
        ret = pmbus_write_word_data(client, 0, MAX8688_MFR_IOUT_PEAK,
                        0);
        break;
    case PMBUS_VIRT_RESET_TEMP_HISTORY:
        ret = pmbus_write_word_data(client, 0,
                        MAX8688_MFR_TEMPERATURE_PEAK,
                        0xffff);
        break;
    default:
        ret = -ENODATA;
        break;
    }
    return ret;
}

static int max8688_read_byte_data(struct i2c_client *client, int page, int reg)
{
    int ret = 0;
    int mfg_status;

    if (page > 0)
        return -ENXIO;

    switch (reg) {
    case PMBUS_STATUS_VOUT:
        mfg_status = pmbus_read_word_data(client, 0,
                          MAX8688_MFG_STATUS);
        if (mfg_status < 0)
            return mfg_status;
        if (mfg_status & MAX8688_STATUS_UV_WARNING)
            ret |= PB_VOLTAGE_UV_WARNING;
        if (mfg_status & MAX8688_STATUS_UV_FAULT)
            ret |= PB_VOLTAGE_UV_FAULT;
        if (mfg_status & MAX8688_STATUS_OV_WARNING)
            ret |= PB_VOLTAGE_OV_WARNING;
        if (mfg_status & MAX8688_STATUS_OV_FAULT)
            ret |= PB_VOLTAGE_OV_FAULT;
        break;
    case PMBUS_STATUS_IOUT:
        mfg_status = pmbus_read_word_data(client, 0,
                          MAX8688_MFG_STATUS);
        if (mfg_status < 0)
            return mfg_status;
        if (mfg_status & MAX8688_STATUS_UC_FAULT)
            ret |= PB_IOUT_UC_FAULT;
        if (mfg_status & MAX8688_STATUS_OC_WARNING)
            ret |= PB_IOUT_OC_WARNING;
        if (mfg_status & MAX8688_STATUS_OC_FAULT)
            ret |= PB_IOUT_OC_FAULT;
        break;
    case PMBUS_STATUS_TEMPERATURE:
        mfg_status = pmbus_read_word_data(client, 0,
                          MAX8688_MFG_STATUS);
        if (mfg_status < 0)
            return mfg_status;
        if (mfg_status & MAX8688_STATUS_OT_WARNING)
            ret |= PB_TEMP_OT_WARNING;
        if (mfg_status & MAX8688_STATUS_OT_FAULT)
            ret |= PB_TEMP_OT_FAULT;
        break;
    default:
        ret = -ENODATA;
        break;
    }
    return ret;
}

static struct pmbus_driver_info max8688_info = {
    .pages = 1,
    .format[PSC_VOLTAGE_IN] = direct,
    .format[PSC_VOLTAGE_OUT] = direct,
    .format[PSC_TEMPERATURE] = direct,
    .format[PSC_CURRENT_OUT] = direct,
    .m[PSC_VOLTAGE_IN] = 19995,
    .b[PSC_VOLTAGE_IN] = 0,
    .R[PSC_VOLTAGE_IN] = -1,
    .m[PSC_VOLTAGE_OUT] = 19995,
    .b[PSC_VOLTAGE_OUT] = 0,
    .R[PSC_VOLTAGE_OUT] = -1,
    .m[PSC_CURRENT_OUT] = 23109,
    .b[PSC_CURRENT_OUT] = 0,
    .R[PSC_CURRENT_OUT] = -2,
    .m[PSC_TEMPERATURE] = -7612,
    .b[PSC_TEMPERATURE] = 335,
    .R[PSC_TEMPERATURE] = -3,
    .func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP
        | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT
        | PMBUS_HAVE_STATUS_TEMP,
    .read_byte_data = max8688_read_byte_data,
    .read_word_data = max8688_read_word_data,
    .write_word_data = max8688_write_word_data,
};

static int max8688_probe(struct i2c_client *client,
             const struct i2c_device_id *id)
{
    return pmbus_do_probe(client, id, &max8688_info);
}

static const struct i2c_device_id max8688_id[] = {
    {"max8688", 0},
    { }
};

MODULE_DEVICE_TABLE(i2c, max8688_id);

/* This is the driver that will be inserted */
static struct i2c_driver max8688_driver = {
    .driver = {
           .name = "max8688",
           },
    .probe = max8688_probe,
    .remove = pmbus_do_remove,
    .id_table = max8688_id,
};

module_i2c_driver(max8688_driver);

MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus driver for Maxim MAX8688");
MODULE_LICENSE("GPL");