>> Scott> #size-cells is zero on i2c, so it should just be reg = <68>. >> >> Scott> You'll probably need to add #address-cells and #size-cells to >> the >> Scott> controller node, as well. > > Uh.. yes.. i2c interfaces should really always have #a and #s.
More generally, every node that defines a bus needs it (unless the defaults of 2 resp. 1 are correct for this bus, but even then you might want it because it makes things more explicit). >> [EMAIL PROTECTED] { >> + #address-cells = <1>; >> + #size-cells = <0>; >> device_type = "i2c"; > > Hrm... we probably want an "i2c" device_type class, but I don't think > we've actually defined one, which is a problem By defining new device_type's, or new semantics for device_type, you open the door to (accidentally) becoming incompatible with "real" OF. And you don't need to: "real" OF has a mechanism for specifying the "generic device class" already, if you use the "generic names" recommended practice (and you do, for both this node and the rtc node): it's the generic name itself! >> + [EMAIL PROTECTED] { >> + device_type = "rtc"; >> + compatible = "dallas,ds1339"; >> + reg = <68>; >> + }; > > I think we want to think a bit more carefully about how to do bindings > for RTC devices. No "rtc" device_type is defined, but again we might > want to. Actually, "device_type" = "rtc" _is_ defined (in the "device support extensions" recommended practice), and there is no useful way a flat device tree can implement it (it merely defines get-time and set-time methods). > The fact that NVRAM+RTC chips are so common is a bit of an issue from > the point of view of defining a device class binding - a device can't > have type "rtc" and "nvram". You should match OS drivers on "compatible" only anyway. Those cases where OS drivers don't nicely 1-1 match device nodes are a bit of a headache; for RTC/NVRAM devices, these problems are nicely side-stepped by handling this from platform code. Segher _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev