We use the SNVS PMIC Dumb mode to control the on-module PMIC (via PWR_ON_REQ signal, using SNVS_LP Control, Bit 6 TOP Turn off System Power). This works as expected on i.MX 7Dual, however on the modules populated with the i.MX 7Solo SoC (same Mask 0N09P) we can not control that signal using the same bit.
I think the reason for that is that the i.MX 7Dual SoC's have bit 31 NPSWA_EN set in SNVS_HP Command, whereas the Solo's has that bit cleared. I also cannot set that bit on the Solo, even in U-Boot (which should be in privileged mode by default?):
Colibri iMX7 # md.l 0x30370004 1 30370004: 00000000 .... Colibri iMX7 # mw.l 0x30370004 0x80000000 Colibri iMX7 # md.l 0x30370004 1 30370004: 00000000 .... Colibri iMX7 #
How can I get access to the SNVS block on i.MX 7Solo?