On 07/15/2013 07:10 PM, Laurent Pinchart wrote: > On Friday 12 July 2013 08:42:41 Stephen Warren wrote: ... >> I think the values for any common system-wide flags should be defined >> once in some system-wide place, and the values for any HW-specific >> values should be defined only in the documentation for that specific HW. >> You could try and avoid conflicts by either: >> >> a) Allocating system-wide flags from bit 0 up, and HW-specific flags >> from bit 31 down. >> >> or: >> >> b) Using 1 cell for standard flags, and a separate cell for any >> HW-specific flags. Drivers can quite easily adapt to adding extra cells >> to #pwm-cells, thus making adding a HW-specific cell later >> backwards-compatible. > > I wasn't referring to HW-specific flags, but rather to system-wide flags that > might not be supported by all drivers. If we later add new system-wide flags I > think the individual DT bindings should explicitly document which flags they > support. Shouldn't all system-wide flags be supported by all HW, perhaps being implemented by the core subsystem rather than individual drivers to ensure that? Consider the case of the GPIO active-low flag which is actually implemented in SW, hence can work with any GPIO controller. Perhaps that's not possible in all cases, in which case, yes, it does make sense to define which of the common flags a particular HW module supports. But then there's a problem where people assume that the common flags are always available, and somewhere they aren't... Care is needed in the choice of which common flags to define and/or how they're used. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
