OSD32MP157C-512M-IAA energy modes

[Daniel Yebana]

Hello,

 

We are using OSD32MP157C-512M-IAA and we need to use energy modes of the OpenSTLinux distribution. To be more concrete, we would like to use the LPLV-Stop and Standby modes as described in ST wiki, see link below:

https://wiki.st.com/stm32mpu/wiki/Power_overview#On_STM32MP15x_lines_2

 

It supposed that LPLV-Stop and Standby modes can be entered any time and leaved through a GPIO, in case of standby only through wakeup capables pins but in LPLV-Stop it is supposed to be through any GPIO.

We have made a lot of testing and doc review but we have not been able to achieve the following points:

1. In case of LPLV mode, we haven’t been able to configure and enable a GPIO as a wakeup source, enter to LPLV and leave it by means of this GPIO, for example PF10.

2. In case of standby mode, we are able to enter the energy mode and leave it by means of a wakeup pin but we don’t know how to enable/disable a wakeup pin as a wakeup source from the set of declared in the devicetree, i.e., we have configured in the device tree the pins PI8 and PI11 as wakeup pins but we don’t know how to disable one of them during runtime, just for being able to select which wakeup pin has to be a wakeup source under differente conditions.

Someone have been able to do that? Some real example and functional, at least in the DK2 kit? We really appreciate if someone could share it, we have seen doc through web but none seems to be functional.

 

Best,

Daniel

[Neeraj Dantu]

Daniel,

 

For #1, https://community.st.com/s/question/0D53W00000cxRieSAE/wakeup-on-gpio-in-linux-on-stm32mp1 seems to have relevant information.

I have not tired this, but libgpiod can be of help for user space GPIO event detection: https://github.com/starnight/libgpiod-example/blob/master/libgpiod-event/main.c#L33

For #2, I believe you can enable/disable any wake up source via sysfs. For example, to disable a wake up source, “echo disabled > /sys/devices/platform/soc/<peripheral directory>/power/wakeup”

Best,

Neeraj

 

 

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