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. > Implementing the FPGA Bridge interface in the Zynq driver because it's > what the core expects is just backwards. It's an abstraction inversion. Yeah, you're probably right. Thanks, 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
