Re: GPIO interrupt on QEMU

[Peter Maydell]

On Fri, 4 Aug 2023 at 10:25, Swedha R <swedhar10@gmail.com> wrote:
>
> Hi team,
> I have arm64 up and  running in Qemu, And I built kernel image, rootfs 
> everything via buildroot open source I cloned from git.
> And I customized via make - menuconfig like enabling gpio support, libgpiod 
> module and in device drivers gpio chip named pl061 .
> After that, I able to see gpiochip in the /dev directory inside arm running 
> in qemu.
> I want to know , how to trigger the gpio line ( that is function for 
> poweroff) and it have to cach and service it in this case.
> The gpiochip has 7 lines in it. How to find which line is a poweroff key , 
> the qemu-virt board has )

If your guest is Linux it in theory [*] should have already
found the power-off key GPIO by looking in the device tree that
QEMU passed it (the information is in the /gpio-keys/poweroff
node).

You can trigger the power-down button by using the
"system_powerdown" command at the QEMU monitor (HMP)
prompt.

[*] The guest I have didn't power down in response
to the system_powerdown command, but I might well have
not compiled in all the necessary kernel options for
it to work. QEMU definitely does raise the GPIO line
when you use the system_powerdown command.

thanks
-- PMM