On Tue, Apr 8, 2014 at 11:02 AM, delicious quinoa <delicious.qui...@gmail.com> wrote: > On Tue, Apr 8, 2014 at 9:33 AM, Steffen Trumtrar > <s.trumt...@pengutronix.de> wrote: >> On Tue, Apr 08, 2014 at 09:29:50AM -0500, Thor Thayer wrote: >>> On Tue, 2014-04-08 at 15:38 +0200, Steffen Trumtrar wrote: >>> > Hi! >>> > >>> > On Mon, Apr 07, 2014 at 04:54:07PM -0500, ttha...@altera.com wrote: >>> > > From: Thor Thayer <ttha...@altera.com> >>> > > >>> > > Addition of the Altera SDRAM controller bindings and device >>> > > tree changes to the Altera SoC project. >>> > > >>> [snip] >>> > > + >>> > > +Required properties: >>> > > +- compatible : "altr,sdr-ctl", "syscon"; >>> > > + Note that syscon is invoked for this device to support >>> > > the FPGA >>> > > + bridge driver, EDAC driver and other devices that share the >>> > > + registers. >>> > > +- reg : Should contain 1 register ranges(address and length) >>> > >>> > I haven't really thought this through, but why would the FPGA bridge >>> > driver >>> > access the sdram controller? For releasing the resets in fpgaportrst ? Or >>> > is >>> > there more? >>> >>> Hi Steffan. No, not for resets. We need to enable the FPGA to SDRAM >>> path. Our SDRAM controller allows FPGA master access to the SDRAM. >>> >> >> Yes. But what you have to do to enable the path is let the FPGA port you use >> out of reset. And that is it as far as I can see. The rest happens in the >> bitstream. Or is there more to enable the path? >> The FPGA2SDRAM bridge is the one I didn't use as of yet, so if I miss >> something >> please elaborate. > > Hi Steffen, > > The sdram controller is used by two drivers. That's why we want to > specify "syscon" here. The other driver is the FPGA bridge driver. > Its functionality is very separate from what this driver is doing (we > are not enabling the bridge in this driver; we are enabling the > monitoring and resetting the interrupt bit of the EDAC). We wanted to > specify "syscon" her so that we don't have to have to change it for > the other driver.
But are there actually overlapping registers which are accessed by both drivers and need the protection of regmap? Perhaps MFD is more appropriate than syscon? Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
