smc.c

/*
 * Apple System Management Control (SMC) Tool
 * Copyright (C) 2006 devnull
 * Portions Copyright (C) 2013 Michael Wilber
 *
 * 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <IOKit/IOKitLib.h>
#include "smc.h"
#include <libkern/OSAtomic.h>

// Cache the keyInfo to lower the energy impact of SMCReadKey() / SMCReadKey2()
#define KEY_INFO_CACHE_SIZE 100
struct {
    UInt32 key;
    SMCKeyData_keyInfo_t keyInfo;
} g_keyInfoCache[KEY_INFO_CACHE_SIZE];

int g_keyInfoCacheCount = 0;
OSSpinLock g_keyInfoSpinLock = 0;

kern_return_t SMCCall2(int index, SMCKeyData_t *inputStructure, SMCKeyData_t *outputStructure, io_connect_t conn);

#pragma mark C Helpers

UInt32 _strtoul(char *str, int size, int base)
{
    UInt32 total = 0;
    int i;

    for (i = 0; i < size; i++)
    {
        if (base == 16)
            total += str[i] << (size - 1 - i) * 8;
        else
           total += ((unsigned char) (str[i]) << (size - 1 - i) * 8);
    }
    return total;
}

void _ultostr(char *str, UInt32 val)
{
    str[0] = '\0';
    sprintf(str, "%c%c%c%c",
            (unsigned int) val >> 24,
            (unsigned int) val >> 16,
            (unsigned int) val >> 8,
            (unsigned int) val);
}

float _strtof(unsigned char *str, int size, int e)
{
    float total = 0;
    int i;
    
    for (i = 0; i < size; i++)
    {
        if (i == (size - 1))
            total += (str[i] & 0xff) >> e;
        else
            total += str[i] << (size - 1 - i) * (8 - e);
    }
    
	total += (str[size-1] & 0x03) * 0.25;
    
    return total;
}

void printFLT(SMCVal_t val)
{
    float fval;
    memcpy(&fval,val.bytes,sizeof(float));
    printf("%.0f ", fval);
}

void printFP1F(SMCVal_t val)
{
    printf("%.5f ", ntohs(*(UInt16*)val.bytes) / 32768.0);
}

void printFP4C(SMCVal_t val)
{
    printf("%.5f ", ntohs(*(UInt16*)val.bytes) / 4096.0);
}

void printFP5B(SMCVal_t val)
{
    printf("%.5f ", ntohs(*(UInt16*)val.bytes) / 2048.0);
}

void printFP6A(SMCVal_t val)
{
    printf("%.4f ", ntohs(*(UInt16*)val.bytes) / 1024.0);
}

void printFP79(SMCVal_t val)
{
    printf("%.4f ", ntohs(*(UInt16*)val.bytes) / 512.0);
}

void printFP88(SMCVal_t val)
{
    printf("%.3f ", ntohs(*(UInt16*)val.bytes) / 256.0);
}

void printFPA6(SMCVal_t val)
{
    printf("%.2f ", ntohs(*(UInt16*)val.bytes) / 64.0);
}

void printFPC4(SMCVal_t val)
{
    printf("%.2f ", ntohs(*(UInt16*)val.bytes) / 16.0);
}

void printFPE2(SMCVal_t val)
{
    printf("%.2f ", ntohs(*(UInt16*)val.bytes) / 4.0);
}

void printUInt(SMCVal_t val)
{
    printf("%u ", (unsigned int) _strtoul((char *)val.bytes, val.dataSize, 10));
}

void printSP1E(SMCVal_t val)
{
    printf("%.5f ", ((SInt16)ntohs(*(UInt16*)val.bytes)) / 16384.0);
}

void printSP3C(SMCVal_t val)
{
    printf("%.5f ", ((SInt16)ntohs(*(UInt16*)val.bytes)) / 4096.0);
}

void printSP4B(SMCVal_t val)
{
    printf("%.4f ", ((SInt16)ntohs(*(UInt16*)val.bytes)) / 2048.0);
}

void printSP5A(SMCVal_t val)
{
    printf("%.4f ", ((SInt16)ntohs(*(UInt16*)val.bytes)) / 1024.0);
}

void printSP69(SMCVal_t val)
{
    printf("%.3f ", ((SInt16)ntohs(*(UInt16*)val.bytes)) / 512.0);
}

void printSP78(SMCVal_t val)
{
    printf("%.3f ", ((SInt16)ntohs(*(UInt16*)val.bytes)) / 256.0);
}

void printSP87(SMCVal_t val)
{
    printf("%.3f ", ((SInt16)ntohs(*(UInt16*)val.bytes)) / 128.0);
}

void printSP96(SMCVal_t val)
{
    printf("%.2f ", ((SInt16)ntohs(*(UInt16*)val.bytes)) / 64.0);
}

void printSPB4(SMCVal_t val)
{
    printf("%.2f ", ((SInt16)ntohs(*(UInt16*)val.bytes)) / 16.0);
}

void printSPF0(SMCVal_t val)
{
    printf("%.0f ", (float)ntohs(*(UInt16*)val.bytes));
}

void printSI8(SMCVal_t val)
{
    printf("%d ", (signed char)*val.bytes);
}

void printSI16(SMCVal_t val)
{
    printf("%d ", ntohs(*(SInt16*)val.bytes));
}

void printPWM(SMCVal_t val)
{
    printf("%.1f%% ", ntohs(*(UInt16*)val.bytes) * 100 / 65536.0);
}


void printBytesHex(SMCVal_t val)
{
    int i;

    printf("(bytes");
    for (i = 0; i < val.dataSize; i++)
        printf(" %02x", (unsigned char) val.bytes[i]);
    printf(")\n");
}

void printVal(SMCVal_t val)
{
    printf("  %-4s  [%-4s]  ", val.key, val.dataType);
    if (val.dataSize > 0)
    {
        if ((strcmp(val.dataType, DATATYPE_UINT8) == 0) ||
            (strcmp(val.dataType, DATATYPE_UINT16) == 0) ||
            (strcmp(val.dataType, DATATYPE_UINT32) == 0))
            printUInt(val);
        else if (strcmp(val.dataType, DATATYPE_FLT) == 0 && val.dataSize == 4)
            printFLT(val);
        else if (strcmp(val.dataType, DATATYPE_FP1F) == 0 && val.dataSize == 2)
            printFP1F(val);
        else if (strcmp(val.dataType, DATATYPE_FP4C) == 0 && val.dataSize == 2)
            printFP4C(val);
        else if (strcmp(val.dataType, DATATYPE_FP5B) == 0 && val.dataSize == 2)
            printFP5B(val);
        else if (strcmp(val.dataType, DATATYPE_FP6A) == 0 && val.dataSize == 2)
            printFP6A(val);
        else if (strcmp(val.dataType, DATATYPE_FP79) == 0 && val.dataSize == 2)
            printFP79(val);
        else if (strcmp(val.dataType, DATATYPE_FP88) == 0 && val.dataSize == 2)
            printFP88(val);
        else if (strcmp(val.dataType, DATATYPE_FPA6) == 0 && val.dataSize == 2)
            printFPA6(val);
        else if (strcmp(val.dataType, DATATYPE_FPC4) == 0 && val.dataSize == 2)
            printFPC4(val);
        else if (strcmp(val.dataType, DATATYPE_FPE2) == 0 && val.dataSize == 2)
            printFPE2(val);
		else if (strcmp(val.dataType, DATATYPE_SP1E) == 0 && val.dataSize == 2)
			printSP1E(val);
		else if (strcmp(val.dataType, DATATYPE_SP3C) == 0 && val.dataSize == 2)
			printSP3C(val);
		else if (strcmp(val.dataType, DATATYPE_SP4B) == 0 && val.dataSize == 2)
			printSP4B(val);
		else if (strcmp(val.dataType, DATATYPE_SP5A) == 0 && val.dataSize == 2)
			printSP5A(val);
		else if (strcmp(val.dataType, DATATYPE_SP69) == 0 && val.dataSize == 2)
			printSP69(val);
		else if (strcmp(val.dataType, DATATYPE_SP78) == 0 && val.dataSize == 2)
			printSP78(val);
		else if (strcmp(val.dataType, DATATYPE_SP87) == 0 && val.dataSize == 2)
			printSP87(val);
		else if (strcmp(val.dataType, DATATYPE_SP96) == 0 && val.dataSize == 2)
			printSP96(val);
		else if (strcmp(val.dataType, DATATYPE_SPB4) == 0 && val.dataSize == 2)
			printSPB4(val);
		else if (strcmp(val.dataType, DATATYPE_SPF0) == 0 && val.dataSize == 2)
			printSPF0(val);
		else if (strcmp(val.dataType, DATATYPE_SI8) == 0 && val.dataSize == 1)
			printSI8(val);
		else if (strcmp(val.dataType, DATATYPE_SI16) == 0 && val.dataSize == 2)
			printSI16(val);
		else if (strcmp(val.dataType, DATATYPE_PWM) == 0 && val.dataSize == 2)
			printPWM(val);
		else if (strcmp(val.dataType, DATATYPE_FLT) == 0 && val.dataSize == 4)
			printFLT(val);

        printBytesHex(val);
    }
    else
    {
            printf("no data\n");
    }
}

#pragma mark Shared SMC functions

kern_return_t SMCOpen(io_connect_t *conn)
{
    kern_return_t result;
    mach_port_t   masterPort;
    io_iterator_t iterator;
    io_object_t   device;
    
	IOMasterPort(MACH_PORT_NULL, &masterPort);
    
    CFMutableDictionaryRef matchingDictionary = IOServiceMatching("AppleSMC");
    result = IOServiceGetMatchingServices(masterPort, matchingDictionary, &iterator);
    if (result != kIOReturnSuccess)
    {
        printf("Error: IOServiceGetMatchingServices() = %08x\n", result);
        return 1;
    }
    
    device = IOIteratorNext(iterator);
    IOObjectRelease(iterator);
    if (device == 0)
    {
        printf("Error: no SMC found\n");
        return 1;
    }
    
    result = IOServiceOpen(device, mach_task_self(), 0, conn);
    IOObjectRelease(device);
    if (result != kIOReturnSuccess)
    {
        printf("Error: IOServiceOpen() = %08x\n", result);
        return 1;
    }
    
    return kIOReturnSuccess;
}

kern_return_t SMCClose(io_connect_t conn)
{
    return IOServiceClose(conn);
}

kern_return_t SMCCall2(int index, SMCKeyData_t *inputStructure, SMCKeyData_t *outputStructure,io_connect_t conn)
{
    size_t   structureInputSize;
    size_t   structureOutputSize;
    structureInputSize = sizeof(SMCKeyData_t);
    structureOutputSize = sizeof(SMCKeyData_t);
    
    return IOConnectCallStructMethod(conn, index, inputStructure, structureInputSize, outputStructure, &structureOutputSize);
}

// Provides key info, using a cache to dramatically improve the energy impact of smcFanControl
kern_return_t SMCGetKeyInfo(UInt32 key, SMCKeyData_keyInfo_t* keyInfo, io_connect_t conn)
{
    SMCKeyData_t inputStructure;
    SMCKeyData_t outputStructure;
    kern_return_t result = kIOReturnSuccess;
    int i = 0;
    
    OSSpinLockLock(&g_keyInfoSpinLock);
    
    for (; i < g_keyInfoCacheCount; ++i)
    {
        if (key == g_keyInfoCache[i].key)
        {
            *keyInfo = g_keyInfoCache[i].keyInfo;
            break;
        }
    }
    
    if (i == g_keyInfoCacheCount)
    {
        // Not in cache, must look it up.
        memset(&inputStructure, 0, sizeof(inputStructure));
        memset(&outputStructure, 0, sizeof(outputStructure));
        
        inputStructure.key = key;
        inputStructure.data8 = SMC_CMD_READ_KEYINFO;
        
        result = SMCCall2(KERNEL_INDEX_SMC, &inputStructure, &outputStructure, conn);
        if (result == kIOReturnSuccess)
        {
            *keyInfo = outputStructure.keyInfo;
            if (g_keyInfoCacheCount < KEY_INFO_CACHE_SIZE)
            {
                g_keyInfoCache[g_keyInfoCacheCount].key = key;
                g_keyInfoCache[g_keyInfoCacheCount].keyInfo = outputStructure.keyInfo;
                ++g_keyInfoCacheCount;
            }
        }
    }
    
    OSSpinLockUnlock(&g_keyInfoSpinLock);
    
    return result;
}

kern_return_t SMCReadKey2(UInt32Char_t key, SMCVal_t *val,io_connect_t conn)
{
    kern_return_t result;
    SMCKeyData_t  inputStructure;
    SMCKeyData_t  outputStructure;
    
    memset(&inputStructure, 0, sizeof(SMCKeyData_t));
    memset(&outputStructure, 0, sizeof(SMCKeyData_t));
    memset(val, 0, sizeof(SMCVal_t));
    
    inputStructure.key = _strtoul(key, 4, 16);
    sprintf(val->key, key);
    
    result = SMCGetKeyInfo(inputStructure.key, &outputStructure.keyInfo, conn);
    if (result != kIOReturnSuccess)
    {
        return result;
    }
    
    val->dataSize = outputStructure.keyInfo.dataSize;
    _ultostr(val->dataType, outputStructure.keyInfo.dataType);
    inputStructure.keyInfo.dataSize = val->dataSize;
    inputStructure.data8 = SMC_CMD_READ_BYTES;
    
    result = SMCCall2(KERNEL_INDEX_SMC, &inputStructure, &outputStructure,conn);
    if (result != kIOReturnSuccess)
    {
        return result;
    }
    
    memcpy(val->bytes, outputStructure.bytes, sizeof(outputStructure.bytes));
    
    return kIOReturnSuccess;
}

#pragma mark Command line only
// Exclude command-line only code from smcFanControl UI
#ifdef CMD_TOOL_BUILD

io_connect_t g_conn = 0;

void smc_init(){
	SMCOpen(&g_conn);
}

void smc_close(){
	SMCClose(g_conn);
}

kern_return_t SMCCall(int index, SMCKeyData_t *inputStructure, SMCKeyData_t *outputStructure)
{
    return SMCCall2(index, inputStructure, outputStructure, g_conn);
}

kern_return_t SMCReadKey(UInt32Char_t key, SMCVal_t *val)
{
    return SMCReadKey2(key, val, g_conn);
}

kern_return_t SMCWriteKey2(SMCVal_t writeVal, io_connect_t conn)
{
    kern_return_t result;
    SMCKeyData_t  inputStructure;
    SMCKeyData_t  outputStructure;
    
    SMCVal_t      readVal;
    
    result = SMCReadKey2(writeVal.key, &readVal,conn);
    if (result != kIOReturnSuccess)
        return result;
    
    if (readVal.dataSize != writeVal.dataSize)
        return kIOReturnError;
    
    memset(&inputStructure, 0, sizeof(SMCKeyData_t));
    memset(&outputStructure, 0, sizeof(SMCKeyData_t));
    
    inputStructure.key = _strtoul(writeVal.key, 4, 16);
    inputStructure.data8 = SMC_CMD_WRITE_BYTES;
    inputStructure.keyInfo.dataSize = writeVal.dataSize;
    memcpy(inputStructure.bytes, writeVal.bytes, sizeof(writeVal.bytes));
    result = SMCCall2(KERNEL_INDEX_SMC, &inputStructure, &outputStructure,conn);
    
    if (result != kIOReturnSuccess)
        return result;
    return kIOReturnSuccess;
}

kern_return_t SMCWriteKey(SMCVal_t writeVal)
{
    return SMCWriteKey2(writeVal, g_conn);
}

UInt32 SMCReadIndexCount(void)
{
    SMCVal_t val;
    
    SMCReadKey("#KEY", &val);
    return _strtoul((char *)val.bytes, val.dataSize, 10);
}

kern_return_t SMCPrintAll(void)
{
    kern_return_t result;
    SMCKeyData_t  inputStructure;
    SMCKeyData_t  outputStructure;
    
    int           totalKeys, i;
    UInt32Char_t  key;
    SMCVal_t      val;
    
    totalKeys = SMCReadIndexCount();
    for (i = 0; i < totalKeys; i++)
    {
        memset(&inputStructure, 0, sizeof(SMCKeyData_t));
        memset(&outputStructure, 0, sizeof(SMCKeyData_t));
        memset(&val, 0, sizeof(SMCVal_t));
        
        inputStructure.data8 = SMC_CMD_READ_INDEX;
        inputStructure.data32 = i;
        
        result = SMCCall(KERNEL_INDEX_SMC, &inputStructure, &outputStructure);
        if (result != kIOReturnSuccess)
            continue;
        
        _ultostr(key, outputStructure.key);
        
		SMCReadKey(key, &val);
        printVal(val);
    }
    
    return kIOReturnSuccess;
}


//Fix me with other types
float getFloatFromVal(SMCVal_t val)
{
    float fval = -1.0f;

    if (val.dataSize > 0)
    {
        if (strcmp(val.dataType, DATATYPE_FLT) == 0 && val.dataSize == 4) {
	         memcpy(&fval,val.bytes,sizeof(float));
        }
        else if (strcmp(val.dataType, DATATYPE_FPE2) == 0 && val.dataSize == 2) {
    	     fval = _strtof(val.bytes, val.dataSize, 2);
        }
        else if (strcmp(val.dataType, DATATYPE_UINT16) == 0 && val.dataSize == 2) {
    	     fval = (float)_strtoul((char *)val.bytes, val.dataSize, 10);
        }
        else if (strcmp(val.dataType, DATATYPE_UINT8) == 0 && val.dataSize == 1) {
    	     fval = (float)_strtoul((char *)val.bytes, val.dataSize, 10);
        }
    }

    return fval;
}

kern_return_t SMCPrintFans(void)
{
    kern_return_t result;
    SMCVal_t      val;
    UInt32Char_t  key;
    int           totalFans, i;
    
    result = SMCReadKey("FNum", &val);
    if (result != kIOReturnSuccess)
        return kIOReturnError;
    
    totalFans = _strtoul((char *)val.bytes, val.dataSize, 10);
    printf("Total fans in system: %d\n", totalFans);
    
    for (i = 0; i < totalFans; i++)
    {
        printf("\nFan #%d:\n", i);
        sprintf(key, "F%cID", fannum[i]);
        SMCReadKey(key, &val);
        if(val.dataSize > 0) {
            printf("    Fan ID       : %s\n", val.bytes+4);
        }
        sprintf(key, "F%cAc", fannum[i]);
        SMCReadKey(key, &val);
        printf("    Current speed : %.0f\n", getFloatFromVal(val));
        sprintf(key, "F%cMn", fannum[i]);
        SMCReadKey(key, &val);
        printf("    Minimum speed: %.0f\n", getFloatFromVal(val));
        sprintf(key, "F%cMx", fannum[i]);
        SMCReadKey(key, &val);
        printf("    Maximum speed: %.0f\n", getFloatFromVal(val));
        sprintf(key, "F%cSf", fannum[i]);
        SMCReadKey(key, &val);
        printf("    Safe speed   : %.0f\n", getFloatFromVal(val));
        sprintf(key, "F%cTg", fannum[i]);
        SMCReadKey(key, &val);
        printf("    Target speed : %.0f\n", getFloatFromVal(val));
        SMCReadKey("FS! ", &val);
        if(val.dataSize > 0) {
            if ((_strtoul((char *)val.bytes, 2, 16) & (1 << i)) == 0)
                printf("    Mode         : auto\n");
            else
                printf("    Mode         : forced\n");
        }
        else {
            sprintf(key, "F%dMd", i);
            SMCReadKey(key, &val);
            if (getFloatFromVal(val))
                printf("    Mode         : forced\n");
            else
                printf("    Mode         : auto\n");
        }
    }
    
    return kIOReturnSuccess;
}

kern_return_t SMCPrintTemps(void)
{
    kern_return_t result;
    SMCKeyData_t  inputStructure;
    SMCKeyData_t  outputStructure;

    int           totalKeys, i;
    UInt32Char_t  key;
    SMCVal_t      val;

    totalKeys = SMCReadIndexCount();
    for (i = 0; i < totalKeys; i++)
    {
        memset(&inputStructure, 0, sizeof(SMCKeyData_t));
        memset(&outputStructure, 0, sizeof(SMCKeyData_t));
        memset(&val, 0, sizeof(SMCVal_t));

        inputStructure.data8 = SMC_CMD_READ_INDEX;
        inputStructure.data32 = i;

        result = SMCCall(KERNEL_INDEX_SMC, &inputStructure, &outputStructure);
        if (result != kIOReturnSuccess)
            continue;

        _ultostr(key, outputStructure.key);
        if ( key[0] != 'T' )
            continue;

        SMCReadKey(key, &val);
        //printVal(val);
        if (strcmp(val.dataType, DATATYPE_SP78) == 0 && val.dataSize == 2) {
          printf("%-4s ", val.key);
          printSP78(val);
          printf("\n");
        }
    }

    return kIOReturnSuccess;
}

void usage(char* prog)
{
    printf("Apple System Management Control (SMC) tool %s\n", VERSION);
    printf("Usage:\n");
    printf("%s [options]\n", prog);
    printf("    -f         : fan info decoded\n");
    printf("    -t         : list all temperatures\n");
    printf("    -h         : help\n");
    printf("    -k <key>   : key to manipulate\n");
    printf("    -l         : list all keys and values\n");
    printf("    -r         : read the value of a key\n");
    printf("    -w <value> : write the specified value to a key\n");
    printf("    -v         : version\n");
    printf("\n");
}

kern_return_t SMCWriteSimple(UInt32Char_t key, char *wvalue, io_connect_t conn)
{
    kern_return_t result;
    SMCVal_t   val;
    int i;
    char c[3];
    for (i = 0; i < strlen(wvalue); i++)
    {
        sprintf(c, "%c%c", wvalue[i * 2], wvalue[(i * 2) + 1]);
        val.bytes[i] = (int) strtol(c, NULL, 16);
    }
    val.dataSize = i / 2;
    sprintf(val.key, key);
    result = SMCWriteKey2(val, conn);
    if (result != kIOReturnSuccess)
        printf("Error: SMCWriteKey() = %08x\n", result);
	
    
    return result;
}

int main(int argc, char *argv[])
{
    int c;
    extern char   *optarg;
    
    kern_return_t result;
    int           op = OP_NONE;
    UInt32Char_t  key = { 0 };
    SMCVal_t      val;
    
    while ((c = getopt(argc, argv, "fthk:lrw:v")) != -1)
    {
        switch(c)
        {
            case 'f':
                op = OP_READ_FAN;
                break;
            case 't':
                op = OP_READ_TEMPS;
                break;
            case 'k':
                strncpy(key, optarg, sizeof(key));   //fix for buffer overflow
                key[sizeof(key) - 1] = '\0';
                break;
            case 'l':
                op = OP_LIST;
                break;
            case 'r':
                op = OP_READ;
                break;
            case 'v':
                printf("%s\n", VERSION);
                return 0;
                break;
            case 'w':
                op = OP_WRITE;
            {
                int i;
                char c[3];
                for (i = 0; i < strlen(optarg); i++)
                {
                    sprintf(c, "%c%c", optarg[i * 2], optarg[(i * 2) + 1]);
                    val.bytes[i] = (int) strtol(c, NULL, 16);
                }
                val.dataSize = i / 2;
                if ((val.dataSize * 2) != strlen(optarg))
                {
                    printf("Error: value is not valid\n");
                    return 1;
                }
            }
                break;
            case 'h':
            case '?':
                op = OP_NONE;
                break;
        }
    }
    
    if (op == OP_NONE)
    {
        usage(argv[0]);
        return 1;
    }
    
    smc_init();
    
    switch(op)
    {
        case OP_LIST:
            result = SMCPrintAll();
            if (result != kIOReturnSuccess)
                printf("Error: SMCPrintAll() = %08x\n", result);
            break;
        case OP_READ:
            if (strlen(key) > 0)
            {
                result = SMCReadKey(key, &val);
                if (result != kIOReturnSuccess)
                    printf("Error: SMCReadKey() = %08x\n", result);
                else
                    printVal(val);
            }
            else
            {
                printf("Error: specify a key to read\n");
            }
            break;
        case OP_READ_FAN:
            result = SMCPrintFans();
            if (result != kIOReturnSuccess)
                printf("Error: SMCPrintFans() = %08x\n", result);
            break;
        case OP_READ_TEMPS:
            result = SMCPrintTemps();
            if (result != kIOReturnSuccess)
                printf("Error: SMCPrintFans() = %08x\n", result);
            break;
        case OP_WRITE:
            if (strlen(key) > 0)
            {
                sprintf(val.key, key);
                result = SMCWriteKey(val);
                if (result != kIOReturnSuccess)
                    printf("Error: SMCWriteKey() = %08x\n", result);
            }
            else
            {
                printf("Error: specify a key to write\n");
            }
            break;
    }
    
    smc_close();
    return 0;
}
#endif //#ifdef CMD_TOOL