On Friday 14 September 2012 01:39 PM, Arnd Bergmann wrote: > On Friday 14 September 2012, Anton Vorontsov wrote: >> Power supply subsystem's supplied_to describes not just how driver >> should notify other devices, supplied_to is more generic stuff, in terms >> that it describes power supply hierarchy. It's like a directed graph, >> e.g.: >> >> <AC power> supplied_to <main battery> and <backup battery> >> <USB power> supplied_to <main battery> and <backup battery> >> <main battery> supplied_to <system> >> <backup battery> supplied_to <system> >> <cmos battery> supplied_to <southbridge pci device> >> <mice battery> supplied_to <mice wireless hid> >> >> How things interact in linux are just implementations details. >> So, device tree is surely a perfect place to describe these things. >> >> Although, in current bindings I see this: >> >> + ab8500-fg { >> + /* Other enery management module */ >> + supplied_to = "ab8500_chargalg", "ab8500_usb"; >> + num_supplicants = <2>; >> + }; >> >> Instead of addressing supplicants by name, it's better to address >> via phandles. And, of course, num_supplicants is not needed, it can >> be derived. > > Right. that's what I thought. The other comment I made initially is > that it would be more in the spirit of the existing bindings to have > the supply property in the opposite directory, if we need it, like > (picking up your above example): > > > / { > /* power supply property in the root node is used by default */ > power-supply = <&main-battery>, <&backup-battery>; > > ac-power: power@... { > ... > }; > > usb-power: power@... { > ... > }; > > main-battery: battery@... { > power-supply = <&ac-power>, <&usb-power}; > ; > > ... > }; > > It's the same information and absolutely equivalent as far as I can tell, > but it feel more logical in the way we tend to describe things. > > Arnd > phandle'd supplied-to will looks like:
usb: ab8500-usb { }; battery : ab8500-bat-type { battery-name = "unknown|NiMH|LION|LIPO|LiFe|NiCd|LiMn"; thermistor_on_batctrl = <1>; }; chargalg: ab8500-chargalg { compatible = "stericsson,ab8500-chargalg"; interface-name = "ab8500_chargalg"; battery-info = <&ab8500-bat-type> supplied-to = <&ab8500_fg>; ... }; fuelguage: ab8500-fg { compatible = "stericsson,ab8500-fg"; interface-name = "ab8500_fg"; battery-info = <&ab8500-bat-type> supplied-to = <&ab8500_chargalg &ab8500_usb>; ... }; btemp: ab8500-btemp { compatible = "stericsson,ab8500-fg"; interface-name = "ab8500_btemp"; battery-info = <&ab8500-bat-type> supplied-to = <&ab8500_chargalg &ab8500_fg>; ... }; charger: ab8500-charger { compatible = "stericsson,ab8500-charger"; interface-name = "ab8500_charger"; battery-info = <&ab8500-bat-type> supplied-to = <&ab8500_chargalg &ab8500_fg &ab8500_btemp>; ... }; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/