On Wed, Aug 11, 2010 at 07:49:40PM +0530, Ravi Gupta wrote: > Also, when I try to export a gpio in sysfs > > echo 9 > /sys/class/gpio/export > > It gives me an error in dmesg > gpio_request: gpio-9 (sysfs) status -22 > export_store: status -22 > > Here is a look of sysfs on my machine > > # ls /sys/class/gpio/ -la > drwxr-xr-x 4 root root 0 Jan 1 00:00 . > drwxr-xr-x 24 root root 0 Jan 1 00:00 .. > --w------- 1 root root 4096 Jan 1 00:10 export > drwxr-xr-x 3 root root 0 Jan 1 00:00 gpiochip192 > drwxr-xr-x 3 root root 0 Jan 1 00:00 gpiochip224 > --w------- 1 root root 4096 Jan 1 00:00 unexport
Your GPIO pins are numbered from 192-223 on one GPIO chip, and 224-255 on the next GPIO chip. You should be exporting GPIO pin 200 or 201 (192+8 or 192+9), depending on whether your pins are numbered from zero or one. "status -22" is -EINVAL: Invalid Argument. You're doing something which is invalid, so this makes sense. There is no "pin 9". Ira _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
