toggle fan boost for acer predator helios 300 2019 edition, tested on PH315-52-78VL

fanBoostToggle.c

/**
 * @author Wagyourtail
 * @version 1.1
 * @date 2022-01-13
 * @license MIT
 *
 * Toggles the fan boost bit
 */
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>


int main(int argc, const char * argv[]) {
    if (getuid() != 0) {
        printf("You must be root to run this program\n");
        return 1;
    }


    // if /sys/kernel/debug/ec/ec0/io doesn't exist, tell the user to run the following command
    // modprobe -r ec_sys
    // modprobe ec_sys write_support=1

    if (access("/sys/kernel/debug/ec/ec0/io", F_OK) == -1) {
        printf("You must run the following commands to enable writing to the EC:\n");
        printf("modprobe -r ec_sys\n");
        printf("modprobe ec_sys write_support=1\n");
        return 1;
    }


    // open /sys/kernel/debug/ec/ec0/io to read/write the fan boost bit

    int fd = open("/sys/kernel/debug/ec/ec0/io", O_RDWR);
    if (fd < 0) {
        perror("open");
        return 1;
    }

    // read the current value of the fan boost bit (0x40 bit of the 0xF5 byte)
    char buf[1];
    pread(fd, buf, 1, 0xF5);
    if (buf[0] & 0x40) {
        printf("Fan boost is currently on (0x%02x)\n", buf[0]);
    } else {
        printf("Fan boost is currently off (0x%02x)\n", buf[0]);
    }

    printf("Toggling fan boost...\n");

    // toggle the fan boost bit
    buf[0] ^= 0x40;
    pwrite(fd, buf, 1, 0xF5);

    // read the current value of the fan boost bit (0x40 bit of the 0xF5 byte)
    pread(fd, buf, 1, 0xF5);
    if (buf[0] & 0x40) {
        printf("Fan boost is now on (0x%02x)\n", buf[0]);
    } else {
        printf("Fan boost is now off (0x%02x)\n", buf[0]);
    }

    close(fd);

    return 0;
}