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Power Management on i.MX8QM

Question asked by vinothkumar s on Mar 3, 2020
Latest reply on Apr 13, 2020 by vinothkumar s

Hi All,

 

I am working on IMX8QM-MEK with Android 9 Automotive. I checked some functionality, Power OFF/ ON and Reset by using switches (button).

 

And I checked the possible in software (only suspend is there) and only two functionality (mem, freeze) is there on the software side.

 

mek_8q:/ # cat /sys/power/state
freeze mem

 

And I checked the possible by using the hardware switch 

2.15. User interface buttons

There are two user interface buttons on the MEK board.

 

2.15.1.ON/OFF Button (SW3)

The chip supports the use of a button input signal to request main SoC power state changes (i.e. ON or
OFF) from the PMU.
In the ON state, if ON/OFF button is held longer than the 5 s, the power-off interrupt is generated. In the
OFF state, if ON/OFF button is held longer than the 0.5 s, the state will transit from OFF to ON.

 

2.15.2. Reset button (SW1)

In the ON state, holding the RESET button (SW1) will force to reset the power rails except the
VDD_SNVS on the i.MX 8QuadXPlus MEK board. The reset signal from SW1 is connected to the WDI
pin of the PMIC. Once the button is pressed, the PMIC will turn off the powers and generate a POR
signal to the processor and the peripherals. The i.MX 8QuadXPlus applications processor will be
immediately turned off and reinitiate a boot cycle from the OFF state.

 

I need to, how to test available functionality  (SUSPEND, RESUME) for power management for iMX8QM-MEQ.

 

 

Reference: https://www.nxp.com/downloads/en/schematics/SPF-29420_C4.pdf 

SW1 - Reset
SW2 - Boot configuration
SW3 - ON/OFF
SW4 - SCU_DBG_SEL (not sure what is this)

 

 

I need to know how to test the suspend and resume mode?

 

Is there any power management demo available for the imx8qm device?

 

 

 

Thank You,

Vinoth S,

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