Re: [PATCH v4 3/6] mfd: ti_am335x_tscadc: Remove unwanted reg_se_cache save

From: Richard Cochran
Date: Fri Nov 21 2014 - 16:40:23 EST


On Fri, Nov 21, 2014 at 07:17:18PM +0100, Johannes Pointner wrote:
> Before the patches were also jumps but I thought it is something
> Vignesh should know. Maybe there is some fix for that too?
> As Richard also noted, it would be nice if ti could let us know how to
> get the delay values right. By trial and error is IMHO not the best
> way.

That is not only an opinion, it is a matter of fact. TI really dropped
the ball on this one. I thought the patch series was a sign they
finally were going to properly address this issue. Wrong again.

The data sheet for the TI part used to have a reference to an app-note
for the touch controller.

spruh73f page 1154

The Pen IRQ can only occur if the correct Pen Ctrl bits are high
(AFE Pen Ctrl bits 6:5 in the TSC_ADC control register) and if
the correct ground transistor biasing is set in the StepConfig
[N] Register. Refer to the application notes for the correct
settings.

I searched high and low for this application note. Then, the data
sheet got revised.

Thanks,
Richard
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