On 22 June 2016 at 21:24, Alistair Francis <alistair.fran...@xilinx.com> wrote: > Add GPIO functionality to the register API. This allows association > and automatic connection of GPIOs to bits in registers. GPIO inputs > will attach to handlers that automatically set read-only bits in > registers. GPIO outputs will be updated to reflect their field value > when their respective registers are written (or reset). Supports > active low GPIOs. > > This is particularly effective for implementing system level > controllers, where heterogenous collections of control signals are > placed is a SoC specific peripheral then propagated all over the > system.
I still don't think this is a good idea. GPIOs are device-level, not register-level. Most devices don't really have very many GPIOs. It should be easy to wire up "change GPIO state based on new register value" from a register post-write hook. This API can't handle the absolute most common case, which is "GPIO state is based on a bit being set in (raw-state-register AND mask-register)." Basically I don't think GPIOs belong in this API, and I don't think there's a good case that adding them makes a significant class of devices much easier to write. thanks -- PMM
