h616 clocks

I’m trying to add support for allwinner H616 ccu
I downloaded H616 user manual and i mostly can figure out differences from allwinner H6 but i have a question
how is the CCU_GATE clock parent assigned to a specifc ccu gate - there is no indication in the manual
for example 
CCU_GATE(CLK_BUS_DE, "bus-de", "psi-ahb1-ahb2", 0x60c, 0)
the manual says that
0x060C DE Bus Gating Reset Register (Default Value: 0x0000_0000) has bit 0 as DE_GATING and bit 16 as DE_RST
but why is psi-ahb1-ahb2 chosen as parent ? (can’t find any reference in the manual)