AXP313 vs AXP313A: is there a difference?

In a boot log from an OrangePi Zero3 (Allwinner H618) you'll see the PMIC named two different ways:

• U-Boot SPL prints AXP313 read 40 / set 60
• Linux prints axp20x-i2c 0-0036: AXP20x variant AXP313a found

There is only one chip. The shipping part is the AXP313A: the "A" is part of the product name, not a die-revision suffix distinguishing a variant from a plain "AXP313." The public X-Powers datasheet is titled *AXP313A*. SPL just abbreviates the name in its terser boot output.

Board pairing is board-specific, not fixed by SoC family:

• OrangePi Zero3 (Allwinner H618) → AXP313A
• OrangePi Zero 2W (H618) → AXP313A
• OrangePi Zero2 (Allwinner H616) → AXP305 (different PMIC entirely)

So if you're staring at an H616 board expecting AXP313A, or an H618 board expecting AXP305, check the board revision: the SoC alone doesn't tell you which PMIC you have.

Kernel-side support for AXP313A in the axp20x MFD driver landed in Linux 6.5. Older kernels won't identify the chip and will fail to bring up any regulator it owns.