Argh! I must confess that shot myself in the foot.
Starting with a clean reboot, GPIO devices are all existent as they should
be:
debian@beaglebone:~/stepper/beaglebone$ ls /sys/class/gpio/
export gpio112 gpio117 gpio19 gpio26 gpio32 gpio37 gpio45 gpio5
gpio62 gpio68 gpio72 gpio77 gpio81 gpio9 unexport
gpio10 gpio113 gpio12 gpio2 gpio27 gpio33 gpio38 gpio46 gpio50
gpio63 gpio69 gpio73 gpio78 gpio86 gpiochip0
gpio11 gpio114 gpio13 gpio20 gpio3 gpio34 gpio39 gpio47 gpio51
gpio65 gpio7 gpio74 gpio79 gpio87 gpiochip32
gpio110 gpio115 gpio14 gpio22 gpio30 gpio35 gpio4 gpio48 gpio60
gpio66 gpio70 gpio75 gpio8 gpio88 gpiochip64
gpio111 gpio116 gpio15 gpio23 gpio31 gpio36 gpio44 gpio49 gpio61
gpio67 gpio71 gpio76 gpio80 gpio89 gpiochip96
Then I ran this snippet of code:
#define SYSFS_GPIO_DIR "/sys/class/gpio"
#define MAX_BUF 64
int gpio_export(unsigned int gpio)
{
int fd, len;
char buf[MAX_BUF];
fd = open(SYSFS_GPIO_DIR "/export", O_WRONLY);
if (fd < 0) {
perror("gpio/export");
return fd;
}
len = snprintf(buf, sizeof(buf), "%d", gpio);
write(fd, buf, len);
close(fd);
return 0;
}
int main(int argc, char *argv[]){
gpio_export(26);
return 0;
}
and *poof* gpio26 disappears:
debian@beaglebone:~/stepper/beaglebone$ ls /sys/class/gpio/
export gpio112 gpio117 gpio19 gpio27 gpio33 gpio38 gpio46 gpio50
gpio63 gpio69 gpio73 gpio78 gpio86 gpiochip0
gpio10 gpio113 gpio12 gpio2 gpio3 gpio34 gpio39 gpio47 gpio51
gpio65 gpio7 gpio74 gpio79 gpio87 gpiochip32
gpio11 gpio114 gpio13 gpio20 gpio30 gpio35 gpio4 gpio48 gpio60
gpio66 gpio70 gpio75 gpio8 gpio88 gpiochip64
gpio110 gpio115 gpio14 gpio22 gpio31 gpio36 gpio44 gpio49 gpio61
gpio67 gpio71 gpio76 gpio80 gpio89 gpiochip96
gpio111 gpio116 gpio15 gpio23 gpio32 gpio37 gpio45 gpio5 gpio62
gpio68 gpio72 gpio77 gpio81 gpio9 unexport
Sorry for the distraction.
--
For more options, visit http://beagleboard.org/discuss
---
You received this message because you are subscribed to the Google Groups
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To view this discussion on the web visit
https://groups.google.com/d/msgid/beagleboard/1f0054f2-e3f7-4323-8c92-ee7cc633fd89%40googlegroups.com.
