On Wed, Oct 28, 2015 at 7:53 AM, atull <atull@xxxxxxxxxxxxxxxxxxxxx> wrote: >> > +A Simple FPGA Bus is a bus that handles configuring an FPGA and its bridges >> > +before populating the devices below its node. All this happens when a device >> > +tree overlay is added to the live tree. This document describes that device >> > +tree overlay. >> > + >> >> This is not really true, is it? >> The driver should work without applying the overlay, e.g. the bootloader >> might have already done it. >> > > Yes it's true. I'm not clear what you are saying. If the bootloader has > programmed the FPGA, the overlay can leave out the optional properties > and the FPGA won't get reprogrammed; the child devices will still get > added and probed. So this handles both the case where you want to reprogram > the FPGA under Linux and where the FPGA was programmed by a bootloader. I think what he means is that the document explicitly calls out the overlay, when in theory it also works without an overlay. While being the most 'natural' use-case, it is not the only one ;-) Moritz -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
