mbpfan/src/mbpfan.c

/**
 *  mbpfan.c - automatically control fan for MacBook Pro
 *  Copyright (C) 2010  Allan McRae <allan@archlinux.org>
 *  Modifications by Rafael Vega <rvega@elsoftwarehamuerto.org>
 *  Modifications (2012) by Daniel Graziotin <dgraziotin@task3.cc>
 *
 *  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 3 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.
 *
 *  2012-06-09 - v1.2
 *
 *  Notes:
 *    Assumes any number of processors and fans (max. 10)
 *    It Uses only the temperatures from the processors as input.
 *    Requires coretemp and applesmc kernel modules to be loaded.
 *    Requires root use
 *
 *  Tested models:
 *    MacBook Pro 8.1 13"  (Intel i7 - Linux 3.2)
 *    Macbook Pro 6,2 15"  (Intel i7 - Linux 3.2)
 */


#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "mbpfan.h"

/* lazy min/max... */
#define min(a,b) a < b ? a : b
#define max(a,b) a > b ? a : b

unsigned short min_fan_speed = 2000;
unsigned short max_fan_speed = 6200;

/* temperature thresholds
 * low_temp - temperature below which fan speed will be at minimum
 * high_temp - fan will increase speed when higher than this temperature
 * max_temp - fan will run at full speed above this temperature */
unsigned short low_temp = 63;   // try ranges 55-63
unsigned short high_temp = 66;  // try ranges 58-66
unsigned short max_temp = 86;   // do not set it > 90

unsigned short polling_interval = 7;


struct s_sensors {
        char* path;
        char* fan_path;
        unsigned int temperature;
        struct s_sensors *next;
};

void find_fans(t_sensors* sensors)
{
        t_sensors *tmp = sensors;

        char *path = NULL;
        const char *path_begin = "/sys/devices/platform/applesmc.768/fan";
        const char *path_end = "_min";
        int path_size = strlen(path_begin) + strlen(path_end) + 2;
        char number[1];
        sprintf(number,"%d",0);

        int counter = 0;

        for(counter = 0; counter<10; counter++) {
                path = (char*) malloc(sizeof( char ) * path_size);
                path[0] = '\0';
                sprintf(number,"%d",counter);

                strncat( path, path_begin, strlen(path_begin) );
                strncat( path, number, strlen(number) );
                strncat( path, path_end, strlen(path_begin) );

                FILE *file = fopen(path, "r");

                if(file != NULL) {
                        if (tmp->path != NULL)
                                tmp->fan_path = (char *) malloc(sizeof( char ) * path_size);
                        strcpy(tmp->fan_path, path);
                        tmp = tmp->next;
                        fclose(file);
                }
        }

        free(path);
        path = NULL;
}


t_sensors *find_sensors()
{

        t_sensors *sensors_head = NULL;
        t_sensors *s = NULL;

        char *path = NULL;
        const char *path_begin = "/sys/devices/platform/coretemp.0/temp";
        const char *path_end = "_input";

        int path_size = strlen(path_begin) + strlen(path_end) + 2;
        char number[1];
        sprintf(number,"%d",0);

        int i = 0;
        for(i = 0; i<10; i++) {
                path = (char*) malloc(sizeof( char ) * path_size);

                sprintf(number,"%d",i);
                path[0] = '\0';
                strncat( path, path_begin, strlen(path_begin) );
                strncat( path, number, strlen(number) );
                strncat( path, path_end, strlen(path_begin) );

                FILE *file = fopen(path, "r");

                if(file != NULL) {
                        s = (t_sensors *) malloc( sizeof( t_sensors ) );
                        s->path = (char *) malloc(sizeof( char ) * path_size);
                        strcpy(s->path, path);
                        int result = fscanf(file, "%d", &s->temperature);
                        if (sensors_head == NULL) {
                                sensors_head = s;
                                sensors_head->next = NULL;
                        } else {
                                t_sensors *tmp = sensors_head;
                                while (tmp->next != NULL) {
                                        tmp = tmp->next;
                                }
                                tmp->next = s;
                                tmp->next->next = NULL;
                        }
                        fclose(file);
                }
                free(path);
                path = NULL;
        }
        if(sensors_head != NULL)
                find_fans(sensors_head);
        return sensors_head;
}

t_sensors *refresh_sensors(t_sensors *sensors)
{

        t_sensors *tmp = sensors;

        while(tmp != NULL) {
                FILE *file = fopen(tmp->path, "r");

                if(file != NULL) {
                        int result = fscanf(file, "%d", &tmp->temperature);
                        fclose(file);
                }

                tmp = tmp->next;
        }
        return sensors;
}



/* Controls the speed of the fan */
void set_fan_speed(t_sensors* sensors, unsigned short speed)
{

        t_sensors *tmp = sensors;

        while(tmp != NULL) {
                FILE *file = fopen(tmp->path, "rw");

                if(file != NULL) {
                        fprintf(file, "%d", speed);
                        fclose(file);
                }

                tmp = tmp->next;
        }

}



/* Returns average CPU temp in degrees (ceiling) */
unsigned short get_temp(t_sensors* sensors)
{
        sensors = refresh_sensors(sensors);
        int sum_temp = 0;
        unsigned short temp = 0;

        t_sensors* tmp = sensors;
        while(tmp != NULL) {
                sum_temp += tmp->temperature;
                tmp = tmp->next;
        }
        temp = (unsigned short)( ceil( (float)( sum_temp ) / 2000. ) );
        return temp;
}


int main()
{
        unsigned short old_temp, new_temp, fan_speed, steps;
        short temp_change;
        float step_up, step_down;

        t_sensors* sensors = find_sensors();

        new_temp = get_temp(sensors);
        fan_speed = 2000;
        set_fan_speed(sensors, fan_speed);
        sleep(polling_interval);

        step_up = (float)( max_fan_speed - min_fan_speed ) /
                  (float)( ( max_temp - high_temp ) * ( max_temp - high_temp + 1 ) / 2 );

        step_down = (float)( max_fan_speed - min_fan_speed ) /
                    (float)( ( max_temp - low_temp ) * ( max_temp - low_temp + 1 ) / 2 );

        while(1) {
                old_temp = new_temp;
                new_temp = get_temp(sensors);

                if(new_temp >= max_temp && fan_speed != max_fan_speed) {
                        fan_speed = max_fan_speed;
                }

                if(new_temp <= low_temp && fan_speed != min_fan_speed) {
                        fan_speed = min_fan_speed;
                }

                temp_change = new_temp - old_temp;

                if(temp_change > 0 && new_temp > high_temp && new_temp < max_temp) {
                        steps = ( new_temp - high_temp ) * ( new_temp - high_temp + 1 ) / 2;
                        fan_speed = max( fan_speed, ceil(min_fan_speed + steps * step_up) );
                }

                if(temp_change < 0 && new_temp > low_temp && new_temp < max_temp) {
                        steps = ( max_temp - new_temp ) * ( max_temp - new_temp + 1 ) / 2;
                        fan_speed = min( fan_speed, floor(max_fan_speed - steps * step_down) );
                }

                set_fan_speed(sensors, fan_speed);
                sleep(polling_interval);
                printf("Old Temp %d: New Temp: %d, Fan Speed: %d\n", old_temp, new_temp, fan_speed);

        }

        return 0;
}