> Date: Mon, 01 Aug 2005 20:47:39 -0700 > From: david-b@xxxxxxxxxxx > > > We decided in Ottawa to create a completely seperate hierarchy for power > ^^^^^^^^^ > Hierarchy normally implies tree; power relations can be directed > acyclic graphs (DAGs). A device on some particular data bus > could need three power supplies, switched using devices on two > different busses; and also use two additional control or data > busses. I wouldn't want to model that as a tree, and might not > need to model quite everything in software anyway! The device I was thinking about is actually more complex than that. It's a multifunction chip, TSC2101: - Audio i/o chip, using audio power supplies; - Touchscreen sensor x/y/pressure; - Temperature, Voltage, Battery, and other sensors; - Two GPIO lines; - SPI/MicroWire control bus; - ... more Chips like this one don't seem to fit neatly into the driver model quite yet, starting with lack of SPI support. :) - Dave
