8MMINID4-EVK Shutdown feature convert into reboot (while Power is on )

[nikunj_mehta]

Hi Team,

We have Development Boards & Kits - ARM 8MMINID4-EVK , we are using Android image . 

Our requirement is when user give reboot -p  / Shutdown , Device should not going in shutdown mode its start rebooting only ( if board have power ) . so use case is if power off then and then device shutdown other wise it always in on condition . 

[igorpadykov]

Hi nikunj

on 8MMINID4-EVK schematic SPF-35104 p.12 power off and reboot are controlled

by PMIC_ON_REQ and WDOG_B signals

i.MX 8M Mini Evaluation Kit DDR4 Design Files

So one can try to change them in power drivers.

Best regards
igor
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[nikunj_mehta]

can you please elaborate more on power drivers change .

are you talking about  software change ???

[nikunj_mehta]

Hi igor ,

More clarification on this .

We don't have any control on hardware Buttons , so we have to do in software timers . as i am going through "IMX8MMRM" user manual , it shows that using below steps we can "OFF to ON, by timer

alarm" 

1. Timer alarm in SNVS is programmed by software before SoC goes OFF.
2. SoC enters OFF mode.
3. Upon timer limit, wake up alarm goes '0'. PMIC_ON_REQ goes '1'.
4. External regulator is enabled by PMIC_ON_REQ = 1.

can u have any idea regarding timer alarm or alarm_mask / wake up alarm , how they can configure in software ? 

is there any steps for doing this 

Thank you for your support 

Nikunj 

[igorpadykov]

for software changes one can consider for example

imx-snvs-poweroff.c\reset\power\drivers - linux-imx - i.MX Linux kernel 

>can u have any idea regarding timer alarm or alarm_mask / wake up alarm , how they can configure in software ?

rtcwakeup.c\mxc_rtc\test - imx-test - i.MX Driver Test Application Software 

Best regards
igor

[nikunj_mehta]

Hi Igor,

we perform changes in power drive as suggested by you below are the test  scenario we perform,

1) wrote 0x300060 into 0x30370038 register of processor

2) after implement new value in register board shutdowns 

3)  when i press ONOFF button for ~1 sec the board boots up again

logs :- 

evk_8mm:/ # devmem 0x30370038 w 0x300060
/dev/mem opened.
Memory mapped at address 0xf7467ce87000.
Value at address 0x30370038 (0xf7467ce87038): 0x300020
Written 0x300060; readback 0x300060

But our use case is device never ever gone in off state ( when system is connected to power )

Please suggest change in power drive to enable that functionality .

we need OFF to ON, by timer alarm implementation 

as per manual we can do this using LP Wake-up interrupt enable (please guide us on this )

[igorpadykov]

Hi nikunj

these changes  may be not so simple and they do not follow standard usage

of these signals. For such kind of development may be suggested to proceed with help of

Professional Engineering Services | NXP 

Best regards
igor

[nikunj_mehta]

Ok Thank you for your support