eswin reset driver

[br]

Summary

Add eswin reset driver

Test Plan

Works on SiFive Premier P550

[jrtc27]

sys/riscv/eswin/eswin_reset.c

170

Why not just use IDs from 0 through N? You can then do >> 5 to get the word number and & 31 to get the bit offset. That's really how the FDT should have represented it too, probably... logically it's just a big bit vector.

[br]

store both reg and bit in the hwreset *id

[jrtc27]

sys/riscv/eswin/eswin_reset.c

166

<< 5 but & 0xff is inconsistent and not what I said (which was & 31 ie 0x1f). Also is cells[1] the bit number or bit mask? Because it's being encoded as if it's the former, but used in the other functions as if it's the latter (no 1u << bit).

[br]

Right, sorry:)

[mhorne]

sys/riscv/eswin/eswin_reset.c

51

Unused?