On Wed, Oct 28, 2015 at 12:59:16PM -0500, Josh Cartwright wrote: > On Wed, Oct 28, 2015 at 12:03:41PM -0500, atull wrote: > > On Wed, 28 Oct 2015, Moritz Fischer wrote: > > > > > On Wed, Oct 28, 2015 at 9:18 AM, Josh Cartwright <joshc@xxxxxx> wrote: > > > > On Wed, Oct 28, 2015 at 08:37:51AM -0700, Moritz Fischer wrote: > > > >> On Wed, Oct 28, 2015 at 3:07 AM, Josh Cartwright <joshc@xxxxxx> wrote: > > > >> > On Tue, Oct 27, 2015 at 05:09:12PM -0500, atull@xxxxxxxxxxxxxxxxxxxxx wrote: > > > >> >> From: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx> > > > >> >> > > > >> >> The Simple FPGA bus uses the FPGA Manager Framework and the > > > >> >> FPGA Bridge Framework to provide a manufactorer-agnostic > > > >> >> interface for reprogramming FPGAs that is Device Tree > > > >> >> Overlays-based. > > > >> > > > > >> > Do you intend the "simple-fpga-bus" to be used on Zynq as well? The > > > >> > whole concept of the socfpga's "FPGA Bridge" doesn't map to the Zynq at > > > >> > all, from what I can tell. > > > >> > > > >> For Zynq the zynq-fpga driver takes care of the level shifters on full > > > >> reconfiguration, > > > >> and doesn't for partial reconfiguration. Now depending on which parts > > > >> of the fabric > > > >> are partial reconfigured (say AXI masters), one might run into issues > > > >> with a setup like that. > > > >> > > > >> My first plan was to counter that by using zynq-reset to hold the > > > >> reset high during > > > >> reconfiguration of that part of the FPGA. > > > >> > > > >> I'm happy to rethink that part and maybe redo the level shifters and > > > >> resets together in a bridge > > > >> driver under devicetree control gives finer grained control. > > > > > > > > There is already a framework which is used to describe and manipulate > > > > level shifting/other IO properties, and that is pinctrl, and if we > > > > wanted to use an appropriate abstraction, I think pinctrl would be the > > > > best bet. > > > > > > Alright, I'll investigate that. Again, for the non-partial reconfig > > > case I'm happy > > > with the behavior as implemented, for the partial reconfig I just > > > haven't run into > > > issues with not dealing with the level shifters. > > > > Are you suggesting pinctrl instead of introducing a FPGA Bridge Framework? > > I'm suggesting that for the set of operations/configuration states that > need to be managed _for the Zynq[1]_ during reprogramming, I think > pinctrl might be a good fit. > > But the pinctrl state activation would happen in the context of the zynq > fpga_mgr_ops write *grr*... in the context of the zynq's write_init(), and write_complete() callbacks. Josh -- 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
