We On Thu, 18 Dec 2014, Arnd Bergmann wrote: > On Thursday 18 December 2014 08:13:34 Lee Jones wrote: > > On Wed, 17 Dec 2014, Arnd Bergmann wrote: > > > > > On Wednesday 17 December 2014 16:45:24 Lee Jones wrote: > > > > +- compatible : Must be one of: "st,stih407-lpc" "st,stih416-lpc" > > > > + "st,stih415-lpc" "st,stid127-lpc" > > > > +- reg : LPC registers base address + size > > > > +- interrupts : LPC interrupt line number and associated flags > > > > +- clocks : Clock used by LPC device (See: ../clock/clock-bindings.txt) > > > > +- st,lpc-mode : The LPC can run either one of two modes ST_LPC_MODE_RTC [0] or > > > > + ST_LPC_MODE_WDT [1]. One (and only one) mode must be > > > > + selected. > > > > > > > > > > I'm glad you got it to work with two drivers for the same device. > > > > > > With this binding, I'm still a bit unhappy about the st,lpc-mode property, > > > in particular since you rely on a shared include file for something that > > > can only be set in one way or another and always has to be present. > > > > > > Why not just use a boolean property that enforces one mode when present > > > and another mode when absent? > > > > There is nothing stopping me from doing that, and it was a > > consideration. I concluded that this method would be more explicit > > however. Both when describing our choices in DT and at a functional > > level within each of the drivers. > > > > Let me know if you fundamentally disagree and I can fix-up. > > I generally don't like header files that define interfaces between C code > and DT nodes. There are cases where it's the least ugly solution, but I don't > think this is one of them. > > If you want to be more explicit about the modes, how about having one > boolean property per mode? That would also allow devices that could be > driven in either mode, e.g. if you have only one instance of this device. Isn't this was you suggested above? Making a decision on the absence is a property is what I'm calling not-explicit. If it's accidentally left off the driver(s) won't issue a warning, it'll just assume that the lack of this boolean property was intentional and go follow the Watchdog path for instance. But as I briefly mentioned to you elsewhere, there are actually 3 devices (Watchdog, RTC and Global Timer). How would you like to handle that with a Boolean property when we introduce this new driver? -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- 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
