Gets continuous pulses on SNVS_PMIC_ON_REQ after applying the RTC wakeup from power off

[lalabhaidesai]

Hello,

I am using I.MX6UL processor and i want to wakeup the device from power off state. I did the changes as per the patches available. Added rtc_write_sync_lp(data) function in rtc-snvs.c file and also added regmap_update_bits(map, offset, mask, mask); in syscon-poweroff.c file.

I am giving the command "echo +30 > /sys/class/rtc/rtc0/wakealarm && shutdown -h now" so after this, device gets power off and also gets wakeup after 30 seconds but our problem is that we want to poweroff the the device in some of the scenarios from the u-boot so we are using mx6_snvs_poweroff() function, devices gets turn off and automatically wakeup again and this process is executing continuously so what should we have to do to turn off the device from bootloader. I have tried to clear the some bits of SNVS_LPCR and SNVS_LPSR registers related to rtc alarm but still device gets wakeup after calling the mx6_snvs_poweroff() function from the boot loader, we observed the signal on SNVS_PMIC_ON_REQ and gets continuous pluses at certain time periods so what is reason behind this and how can we removes these pulses from the  SNVS_PMIC_ON_REQ line.So please help me ASAP.

Thanks in advance. 

Waiting for your reply.

Regards,

Lalabhai

[igorpadykov]

Hi Lalabhai

examples of SW control PMIC_ON_REQ can be found on

Q&A: How is mx6 PMIC_ON_REQ under SW control? 

Reason for continuous device turn off and power up again

may be that nxp reference boards turn on automatically after applying power.

So one can consider some circuit, similar to spf-27392 p.19 "OPTIONAL:
PMIC Power On Circuit", so processor does not power-up automatically after

applying power to board.

Schematics (1)
i.MX6_SABRE_SDP_DESIGNFILES
SABRE Platform for Smart Devices|NXP 

Best regards
igor
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