On Tue, Jul 30, 2013 at 1:18 PM, Alexander Shiyan <shc_work@xxxxxxx> wrote: > +++ b/Documentation/devicetree/bindings/gpio/gpio-generic.txt > @@ -0,0 +1,25 @@ > +Generic memory-mapped GPIO controller > + > +Required properties: > +- compatible: Should be "basic-mmio-gpio" or "basic-mmio-gpio-be". > +- reg: Physical base GPIO controller registers location and length. > +- reg-names: Should be the names of reg resources. Each register uses > + its own reg name, so there should be as many reg names as referenced > + registers: > + "dat" : Input/output register (Required), > + "set" : Register for set output bits (Optional), > + "clr" : Register for clear output bits (Optional), > + "dirout" : Register for setup direction as output (Optional), > + "dirin" : Register for setup direction as input (Optional). > +- gpio-controller: Marks the device node as a gpio controller. > +- #gpio-cells: Should be two. This appears to make a *lot* of implicit assumptions about these registers. You absolutely *have* to define every assumption in clear text for this. Example of implicit assumptions: - Registers in "basic-mmio-gpio" are these assumed to be little endian? Or target-CPU-endian? - Does "-be" mean that the CPU or the bus is big endian? (I assume the bus...) - Is is assumed that 0 in a dat bit is low line and 1is a high line? - Is it assumed that setting a bit to 1 in set drives the line high and setting it to 1 in clr clears the line? - Same question for dirout/dirin? - What happens if you set the same bit in both dirin and dirout? - Is it assumed that the first GPIO line is bit 0, second GPIO line is bit 1 (etc) up to bit ....N? - How many bits are there in a register after all? 8? 16? 32? 64? Or the bus size of the architecture maybe? This really need some very details definition before it can be considered for merging. Yours, Linus Walleij -- 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
