Messages in this thread | | | Date | Mon, 20 Apr 2009 11:38:49 -0400 | From | James Kosin <> | Subject | Re: [RFD] voltage/current regulator consumer interface |
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Mike Rapoport wrote: > Hi, > > Recently there was a brief discussion on linux-arm-kernel list [1] about > controlling voltage regulator state in cases when there is no consumer device > for a particular regulator. > > I have some thoughts but I'd like to know people opinion before I start > implementation. > > Problem > ------- > The regulator framework API provides ability to control the state of > voltage/current regulators from within the kernel. Usually the regulator > supplies power to a device and device driver or some hooks to the platform code > from the device driver manipulate the regulator state. However, the regulator > framework does not have userspace ABI that allows regulator state modifications. > Lack of this ABI prevents fine-grained control for power consumption of devices > such as GPS trancievers and GSM modems. Moreover, in SoC based systems it is > possible to switch on/off power to entire subsystem when it is not used. >
I'd also ask the question, Why? If exposing to user space it leaves the possibility of damaging hardware or completely frying a board.
James
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