[U-Boot] twl4030_power_init cleanup proposal

Tom Tom.Rix at windriver.com
Mon Nov 30 17:17:23 CET 2009


Grazvydas Ignotas wrote:
> hi,
> 
> drivers/power/twl4030.c has a twl4030_power_init() function which is
> called by most (all?) OMAP3 boards. What it does is enabling VAUX3,
> VPLL2 and VDAC power supplies in TWL4030/TPS659x0 chip. However they
> are all very board specific and in most cases not needed at all, at
> least for booting the kernel. They also cause regulator warnings on
> latest kernels.
> 
> VAUX3: board specific, beagle doesn't have it connected at all, so it
> wastes power there.
> VPLL2: board specific, typically display related, as mainline u-boot
> shows no graphics I think it can be removed.
> VDAC: typically used to power TV-out DACs, can be removed. VDAC and
> VPLL2 is already handled by kernel by DSS2.
> 
> So I think VDAC, VPLL2 can be safely removed, probably VAUX3 too with
> whole twl4030_power_init().
> 
> Gražvydas

Please provide specifics on the kernel warnings.
These should be addressed.

The power setting should be done on board by board basis.
If you are concerned about beagle, please provide a beagle specific
patch.

Tom




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