Thanks， I will check ARM Versatile Express codes. Why move the folder
to /sys/kernel/debug/.

On Tue, Sep 24, 2013 at 7:46 PM, Botao Sun <email address hidden> wrote:
> on ARM Versatile Express A9 board with Linaro Android image:
>
> https://android-build.linaro.org/builds/~linaro-android/vexpress-
> linaro-13.09-release/#build=6
>
> For files under path "/sys/class", it shows as:
>
> root@vexpress:/sys/class # ls -la
> drwxr-xr-x root     root              2013-09-24 11:39 bdi
> drwxr-xr-x root     root              2013-09-24 11:39 block
> drwxr-xr-x root     root              2013-09-24 11:39 bsg
> drwxr-xr-x root     root              2013-09-24 11:39 firmware
> drwxr-xr-x root     root              2013-09-24 11:39 graphics
> drwxr-xr-x root     root              2013-09-24 11:39 hwmon
> drwxr-xr-x root     root              2013-09-24 11:39 input
> drwxr-xr-x root     root              2013-09-24 11:39 leds
> drwxr-xr-x root     root              2013-09-24 11:39 mdio_bus
> drwxr-xr-x root     root              2013-09-24 11:39 mem
> drwxr-xr-x root     root              2013-09-24 11:39 misc
> drwxr-xr-x root     root              2013-09-24 11:39 mmc_host
> drwxr-xr-x root     root              2013-09-24 11:39 mtd
> drwxr-xr-x root     root              2013-09-24 11:39 net
> drwxr-xr-x root     root              2013-09-24 11:39 power_supply
> drwxr-xr-x root     root              2013-09-24 11:39 regulator
> drwxr-xr-x root     root              2013-09-24 11:39 rtc
> drwxr-xr-x root     root              2013-09-24 11:39 scsi_device
> drwxr-xr-x root     root              2013-09-24 11:39 scsi_disk
> drwxr-xr-x root     root              2013-09-24 11:39 scsi_host
> drwxr-xr-x root     root              2013-09-24 11:39 sound
> drwxr-xr-x root     root              2013-09-24 11:39 switch
> drwxr-xr-x root     root              2013-09-24 11:39 timed_output
> drwxr-xr-x root     root              2013-09-24 11:39 tty
> drwxr-xr-x root     root              2013-09-24 11:39 vc
> drwxr-xr-x root     root              2013-09-24 11:39 vtconsole
> root@vexpress:/sys/class #
>
> There is no "gpio" directory there. However, I found file "gpio" under
> the path "/sys/kernel/debug"
>
> /sys/kernel/debug/gpio
>
> And the content of this file shows:
>
> GPIOs 0-10, platform/10000000.sysreg, vexpress-sysreg:
>  gpio-0   (mmci-pl18x (cd)     ) in  hi
>  gpio-1   (mmci-pl18x (wp)     ) in  lo
>  gpio-3   (v2m:green:user1     ) out lo
>  gpio-4   (v2m:green:user2     ) out lo
>  gpio-5   (v2m:green:user3     ) out lo
>  gpio-6   (v2m:green:user4     ) out lo
>  gpio-7   (v2m:green:user5     ) out lo
>  gpio-8   (v2m:green:user6     ) out hi
>  gpio-9   (v2m:green:user7     ) out lo
>  gpio-10  (v2m:green:user8     ) out lo
>
> --
> You received this bug notification because you are a bug assignee.
> https://bugs.launchpad.net/bugs/1229658
>
> Title:
>   Information is unavailable on "Clocks" & "Gpio" pages in powerdebug
>   0.7.1
>
> Status in Powerdebug - a tool to help ARM developers:
>   New
>
> Bug description:
>   On ARM Versatile Express A9 board with Linaro Android image:
>
>   https://android-build.linaro.org/builds/~linaro-android/vexpress-
>   linaro-13.09-release/#build=6
>
>   Information is unavailable on "Clocks" & "Gpio" after launched
>   powerdebug version 0.7.1, error output shows as below:
>
>   root@vexpress:/ # powerdebug
>   failed to initialize clock details (check debugfs)
>   error: unable to open directory /sys/class/gpio
>   failed to initialize gpios
>   root@vexpress:/ #
>
>   Please refer to attachment to get snapshot pictures.
>
>   Note: Please run powerdebug in ADB shell, which the output is well
>   formated, however the failure is same as run in serial console.
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/linaro-powerdebug/+bug/1229658/+subscriptions