STM32MP15 gpio power-off only for shutdown?

[SScar.2]

Hi there, 

I'm developing a Linux Embedded system on an STM32MP153-based custom board. 
I have a problem regarding shutdown vs low power modes. 
I have a gpio (active low) that acts as a "final switch off" for the whole system (a.k.a. when that gpio goes down, the board is no longer powered). I need this gpio to act like that only when the user asks for a shutdown. When entering any low-power mode (sleep/stop/standby), that gpio is not toggled. 
Of course, I could lower the signal of the gpio in the user space, but this would cause a dirty power off of the whole system, and that's not good (I think?). 

Is there a clean/official way to achieve that result? 

Thanks for your help!

 

[Olivier GALLIEN]

Hi @SScar.2 

 

Sorry to come late in this thread.

Did you find any solution at your end ? 

 

If you still need help providing schematics at least of your power tree with the GPIO wiring can help. 

We need to first know if you are using PMIC or discrete power solution.

 

Thanks 

 

Olivier 

 

 

[SScar.2]

Hi @Olivier GALLIEN , 

thanks for your reply. 

Yes, I still need help. We're using the STPMIC. 

For the moment my company prefers not to share schematics. 

But, I created a scheme to let you better understand the architecture, and, possibly, solve my problem.  

 

 

Here's the scheme (I also attached the PDF for higher resolution). 

The signal MPU_KEEP_ON is set to High at boot. The signal MPU_KEEP_ON_RST (reset flip flop) is the one I need to set Low only when I need to shut down the system (and keep High when I enter Cstop/Cstandby mode).

Is there a clean way to achieve that result? (avoiding to put the signal Low in userspace .-.)

Thanks a lot!!