Power off i.MX6

danielmattsson — Tue, 04 Feb 2014 11:10:22 GMT

Hi,

We have developed a custom board with i.MX6DL and MMPF0100 PMIC running android 4.2. We have problems powering off the board from SW.

We have followed the instructions in:

Result:

- The function pm_power_off is assigned in board file (pm_power_off = mx6_snvs_poweroff;)

- The function mx6_snvs_poweroff writes bits TOP & DP_EN to register SNVS_LPCR.

- We have verified that mx6_snvs_poweroff is called when powering off from android GUI (long press power button and accept the popup box).

- The systems hangs when writing bits TOP & DP_EN to register SNVS_LPCR.

The following have also been tried:

* Calling linux command 'reboot' from adb shell with various flags including -p.

Result: Hangs the system (seems to call pm_power_off)

* Calling busybox poweroff.

Result: Nothing happens

* Power off by calling the 'reboot' system call from a c program (http://man7.org/linux/man-pages/man2/reboot.2.html).

Result: Hangs the system

* Enter PMIC 'OFF' state by setting:

- All SWxOMODE bits=0

- PWRON_CFG = 0

- PWRONRSTEN = 1

- Finally trigger PWRON by setting various bit combinations in WDOGx_WCR.

Result: Hangs the system (or in some cases => reboots the system).

Any input is appreciated!

Re: Power off i.MX6

MarekVasut — Wed, 05 Feb 2014 02:56:34 GMT

"The system hangs when writing bits" usually means "Clock to domain *FOO* aren't enabled" . Try checking the clock please.

danielmattsson — Fri, 07 Feb 2014 06:44:36 GMT

Hi,

We have done some further investigations and it looks like it was a HW problem, but thanks for your input.