PM8916 PON (SPMI SID0, base 0x800) reason registers, read-only via /sys/kernel/debug/regmap/0-00/registers (9 B/line, offset reg*9).
Bit names per Qualcomm downstream drivers/input/misc/qpnp-power-on.c tables (not verified against a PM8916 datasheet):
 0x808 PON_REASON1: b0 Hard Reset, b1 SMPL, b2 RTC alarm, b3 DC charger, b4 USB charger insertion, b5 PON1, b6 CBL, b7 KPD (power key)
 0x80A WARM_RESET_REASON1 / 0x80C POFF_REASON1: b0 SOFT, b1 PS_HOLD, b2 PMIC_WD, b3 GP1, b4 GP2, b5 KPDPWR_AND_RESIN, b6 RESIN_N, b7 KPDPWR_N
 0x80D POFF_REASON2: b3 CHARGER, b4 TFT (thermal fault), b5 UVLO (under-voltage lock-out), b6 OTST3 (over-temperature), b7 STAGE3
2026-09-30 22:30 (boot after the 22:26:10 spontaneous reset): 0808=10 (USB charger insertion), 080a=02 (PS_HOLD, likely stale), 080c=00, 080d=20 (UVLO).
