[U-Boot] [PATCH] ARMv7: OMAP: Add init function for TWL4030 GBPR1 register

Jonathan Solnit jsolnit at gmail.com
Thu Mar 1 18:47:35 CET 2012

Hi Igor.

On Thu, Mar 1, 2012 at 12:41 AM, Igor Grinberg <grinberg at compulab.co.il>wrote:

> Hi Jonathan,
> On 02/29/12 22:52, Jonathan Solnit wrote:
> > The OMAP ROM code modifies the GBPR1 register, which can cause
> s/GBPR1/GPBR1/
> > unintended consequences.
> What do you mean by this?
> Can you please elaborate, what issues do you see?
> Also, why does the OMAP ROM code needs to touch the GPBR1?
For my board, when booting the OMAP3 from MMC1, GPBR1 comes up as 0x00
instead of 0x90.  The improper clock configuration causes timeouts whenever
I try to use the MADC.  In Linux, the error looks like this:

user.err kernel: twl4030_madc twl4030_madc: conversion timeout!

As for why ROM touches GPBR1, only TI can answer that.  What I've found is
that this is a known issue and re-initializing the register at start-up is
the recommended solution:



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