From: Igor Grinberg <grinberg@compulab.co.il>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] ARMv7: OMAP: Add init function for TWL4030 GBPR1 register
Date: Sun, 04 Mar 2012 09:45:28 +0200 [thread overview]
Message-ID: <4F531D98.1050602@compulab.co.il> (raw)
In-Reply-To: <CAJCEQCLn+unnLXuEbp7F2suvx1TMti5T4W0h67an7UotGdaYkA@mail.gmail.com>
On 03/01/12 19:47, Jonathan Solnit wrote:
> Hi Igor.
>
> On Thu, Mar 1, 2012 at 12:41 AM, Igor Grinberg <grinberg at compulab.co.il <mailto:grinberg@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!
Right, but isn't this has been already fixed in kernel:
3d6271f (mfd: Turn on the twl4030-madc MADC clock)
$ git describe 3d6271f
v3.1-13-g3d6271f
>
> 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:
>
> http://e2e.ti.com/support/power_management/pmu/f/43/t/762.aspx
We would really appreciate if someone from TI (Tom?) can confirm that this is a bug in ROM code.
Nevertheless, I don't think U-Boot uses MADC feature (am I right?),
so IMO, kernel has to be fixed (I think already fixed) to not rely
on ROM/U-Boot setup of that MADC clock.
--
Regards,
Igor.
next prev parent reply other threads:[~2012-03-04 7:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-29 20:52 [U-Boot] [PATCH] ARMv7: OMAP: Add init function for TWL4030 GBPR1 register Jonathan Solnit
2012-03-01 8:41 ` Igor Grinberg
2012-03-01 17:47 ` Jonathan Solnit
2012-03-04 7:45 ` Igor Grinberg [this message]
2012-03-05 19:00 ` Jonathan Solnit
2012-03-05 19:07 ` Tom Rini
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