On Wed, 08 May 2019, Marek Vasut wrote: > On 5/8/19 4:48 AM, [email protected] wrote: > > Hi Jones, > > > >> "Lee Jones" <[email protected]> > >> 2019/05/07 下午 08:58 > >> > >> To > >> > >> "Marek Vasut" <[email protected]>, > >> > >> cc > >> > >> "Rob Herring" <[email protected]>, "Mason Yang" > >> <[email protected]>, [email protected], linux- > >> [email protected], [email protected], > >> [email protected], [email protected], "Geert > >> Uytterhoeven" <[email protected]>, > >> [email protected], [email protected], > >> [email protected], [email protected], "Simon Horman" > >> <[email protected]>, [email protected] > >> > >> Subject > >> > >> Re: [PATCH v12 3/3] dt-bindings: mfd: Document Renesas R-Car Gen3 > >> RPC-IF MFD bindings > >> > >> On Wed, 24 Apr 2019, Marek Vasut wrote: > >> > >> > On 4/24/19 11:23 PM, Rob Herring wrote: > >> > > On Wed, Apr 24, 2019 at 03:55:36PM +0800, Mason Yang wrote: > >> > >> Document the bindings used by the Renesas R-Car Gen3 RPC-IF MFD. > >> > >> > >> > >> Signed-off-by: Mason Yang <[email protected]> > >> > >> --- > >> > >> .../devicetree/bindings/mfd/mfd-renesas-rpc.txt | 40 ++++++ > >> ++++++++++++++++ > >> > >> 1 file changed, 40 insertions(+) > >> > >> create mode 100644 Documentation/devicetree/bindings/mfd/mfd- > >> renesas-rpc.txt > >> > >> > >> > >> diff --git a/Documentation/devicetree/bindings/mfd/mfd-renesas- > >> rpc.txt b/Documentation/devicetree/bindings/mfd/mfd-renesas-rpc.txt > >> > >> new file mode 100644 > >> > >> index 0000000..668b822 > >> > >> --- /dev/null > >> > >> +++ b/Documentation/devicetree/bindings/mfd/mfd-renesas-rpc.txt > >> > >> @@ -0,0 +1,40 @@ > >> > >> +Renesas R-Car Gen3 RPC-IF MFD Device Tree Bindings > >> > >> +-------------------------------------------------- > >> > > > >> > > Looks like a SPI flash controller from the example. What makes it an > >> > > MFD? > >> > > >> > It supports both SPI NOR and HyperFlash (CFI-compliant flash with > >> > different bus interface). > >> > >> Looks like you're registering one OR the other. > >> > >> Why don't you just do this from DT? > >> > >> No reason for this to be an MFD IMHO. > > > > > > okay, I will patch it back to SPI mode only. > > I don't think that's what Lee meant . The controller supports _both_ > modes , hence it would have the same compatible string. You just need to > extract the mode of operation from the DT.
HiSilicon attempted to upstream something similar, only their controller provided NAND and NOR functionality. They used different compatible strings to differentiate between the varying technologies. They too tried to use MFD as a means to select between them (which was also NACKed). Not sure what they ended up doing, but the original submission and (half of) the conversation can be found at [0]. Some more of the thread continues at [1]. Hope that helps. [0] https://groups.google.com/forum/#!topic/fa.linux.kernel/F6i9o8sfOIw [1] https://marc.info/?l=devicetree&m=147669165104431&w=2 -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
