On Thu, Jun 22, 2017 at 12:50:47PM +0800, Ziping Chen wrote: > 2017-06-22 4:35 GMT+08:00 Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>: > > > On Tue, Jun 20, 2017 at 09:44:43PM +0800, Ziping Chen wrote: > > > From: Ziping Chen <techping.chan@xxxxxxxxx> > > > > > > Allwinner A83T SoC has a low res adc like the one > > > in Allwinner A10 SoC, however, the A10 SoC's vref > > > of lradc internally is divided by 2/3 and the A83T > > > SoC's isn't, thus add a hardware variant for it to > > > be compatible with various devices. > > > > Where did you get that info from? > > > > Judging from the user manual, the threshold is actually set to 3/4, > > and not 2/3, but there's still one. > > > > In the top of page 266 of the A10 User Manual V1.50, it said "2/3 ADC_REF > (Level A)" which mean Level A is 2/3 of the vref. > > In the bottom of page 230 of the A83T User Manual V1.5.1, it said "1.35V > (Level A)" meaning that Level A is 1.35V. Oh, it's my fault... It's 3/4 of > the vref (A83T's ADC_REF is fixed at 1.8V). > > So... i will change r_lradc_variant_a83t.divisor_numerator to 3 > and r_lradc_variant_a83t.divisor_denominator to 4... > > Is there any other problems? I don't see any :) Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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