On 12/20/2018 3:22 AM, Trent Piepho wrote: > On Wed, 2018-12-19 at 16:47 -0800, Andrey Smirnov wrote: >>>> This series initially added explicit offsets but I suggested a single >>>> "controller-id" because: >>>> * There are multiple bit and byte offsets >>>> * Other imx8 SOCs also have 2x pcie with other bit/byte offsets >>>> >>>> Hiding this behind a compatible string and single "controller-id" seem >>>> preferable to elaborating register maps in dt bindings. It also makes >>>> upgrades simpler: if features are added which use other bits there is no >>>> need to describe them in DT and deal with compatibility headaches. >>> >>> You already have an id for the controllers: the address. Use that if >>> you don't want to put the register offsets in DT. >> >> Lucas, are you on board with this? > > Does address here mean the address from the controller's reg property? > > How do you map that address to the controller's index? I guess you could have a constant for the address of the first controller and then substract. But hardcoding any sort of physical address feels wrong with DT. > The situation here is that some registers for these controllers are > interleaved, right? I.e., there's one register somewhere where bit 0 > means enable controller 0 and bit 1 means enable controller 1 and so > on. > > Isn't cell-index already the standard device tree property for this > kind of setup? Look at how this cell-index property is documented in other bindings it seems to be an excellent fit: just rename controller-id to cell-index.
