Hi10 pro speaker enabler

spken.c

#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <dirent.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/utsname.h>
#include <fcntl.h>

int gpio_offset() {
    struct utsname ver;
    int major, minor;

    uname(&ver);

    sscanf(ver.release, "%d.%d.", &major, &minor);

    if (major == 4) {
        // until 4.15
        if (minor < 16)
            return 21;
    }

    // 4.16 +
    return 27;
}


void die_usage(const char *prog) {
    printf( "spken (c) 2018 Taeyeon Mori\n"
            "CHUWI Hi10 Pro speaker enabler\n"
            "\n"
            "Usage: %s [enable:0/1]\n"
            "\n"
            "If omitted, speakers are enabled\n",
            prog);
    exit(1);
}

void die(const char *msg) {
    perror(msg);
    exit(errno);
}


int main(int argc, const char**argv) {
    char pathbuf[256];
    int enable = 1;
    int fd, gpio;
    DIR *dir;
    struct dirent *ent;

    // Check argv
    if (argc > 2)
        die_usage(argv[0]);
    else if (argc == 2) {
        if (argv[1][0] == '1')
            ;
        else if (argv[1][0] == '0')
            enable = 0;
        else
            die_usage(argv[0]);
        if (argv[1][1] != 0)
            die_usage(argv[0]);
    }

    // find chip
    dir = opendir("/sys/devices/platform/INT33FF:01/gpio");
    if (!dir) 
        die("Could not open INT33FF:01/gpio in sysfs");
    while (1) {
        ent = readdir(dir);
        if (!ent) {
            if (errno)
                die("Could not list INT33FF:01/gpio in sysfs");
            else {
                puts("No gpiochip in INT33FF:01!");
                exit(2);
            }
        }
        if (!strncmp(ent->d_name, "gpiochip", 8))
            break;
    }
    //printf("Found gpiochip: %s\n", ent->d_name);
    closedir(dir);

    // find number
    gpio = atoi(ent->d_name + 8) + gpio_offset();
    printf("Using gpio %d\n", gpio);

    if (snprintf(pathbuf, 255, "/sys/class/gpio/gpio%d/value", gpio) < 0)
        die("Could not build path name");

    // Export
    if (access(pathbuf, F_OK)) {
        fd = open("/sys/class/gpio/export", O_WRONLY);
        if (fd < 0)
            die("Could not open /sys/class/gpio/export");
        if(dprintf(fd, "%d", gpio) < 0)
            die("Could not export GPIO");
        close(fd);
    }

    // Open
    fd = open(pathbuf, O_WRONLY);
    if (fd < 0)
        die("Could not open gpio pin");
    if (dprintf(fd, "%d", enable) < 0)
        die("Could not write gpio pin");
    close(fd);

    return 0;
}

For some reason the pin offset changed. Code is updated to work with 4.16

Hardcoding numbers is a hack in the first place, so it's not all too surprising it broke. Unfortunately I'm not aware of a userspace solution to properly extract the pin number from the DSDT AND map it to the linux subsystem numbers...

Thank you so much for the update. I am not very deep in this pin number thing but how do you currently find it out maybe I could then try to find a way to get it from userspace. Maybe something like this could work (if you can find the correct PIN number in the output)?

Extract ACPI tables (as root)

# cat /sys/firmware/acpi/tables/DSDT > dsdt.dat

Decompile

# iasl -d dsdt.dat

Maybe the needed info is in the dsdt.dsl??

Info taken from Arch Wiki (DSDT).

Well yes, but you'll still have to somehow map it to the numbering system linux uses. I originally found out by writing a patch to the kernel driver, since driver code can get the info pretty easily; see the earlier discussion in danielotero/linux-on-hi10#8