[U-Boot] [PATCH] ARM: tegra: rm Jetson TK1 PMIC GPIO programming

From: Tom Warren <TWarren@nvidia.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH] ARM: tegra: rm Jetson TK1 PMIC GPIO programming
Date: Thu, 28 Jan 2016 17:30:11 +0000	[thread overview]
Message-ID: <5936d18a16ed440484771300eb7d6dc4@HQMAIL104.nvidia.com> (raw)
In-Reply-To: <56AA4BA6.4040406@wwwdotorg.org>

OK. I was waiting to see if Simon's dm display driver changes would go in via the Tegra repo (they apply / build OK now, but I've had no time for testing).

With the merge window closing, I'll send a PR with just this fix. Thanks.

Tom

> -----Original Message-----
> From: Stephen Warren [mailto:swarren at wwwdotorg.org]
> Sent: Thursday, January 28, 2016 10:11 AM
> To: Tom Warren <TWarren@nvidia.com>
> Cc: u-boot at lists.denx.de; Simon Glass <sjg@chromium.org>; Stephen Warren
> <swarren@nvidia.com>; Thierry Reding <treding@nvidia.com>
> Subject: Re: [PATCH] ARM: tegra: rm Jetson TK1 PMIC GPIO programming
> 
> On 01/18/2016 12:16 PM, Tom Warren wrote:
> > Stephen Warren wrotea tMonday, January 18, 2016 11:23 AM:
> >> The PMIC is configured such that its GPIOs have the correct
> >> configuration at power-up, so no programming is required.
> >>
> >> In fact, the current programming is actively wrong, since:
> >>
> >> (a) the AS3722 driver configures the GPIO to be an output before
> >> setting its output value, which causes a 0v glitch on the output.
> >>
> >> (b) the AS3722 driver configures the GPIO to drive a high voltage
> >> from its VSUP_GPIO power source rather than its VDD_GPIO_LV power
> >> source, so the pin drives 5V not 1.8V as desired.
> >>
> >> Solve these problems by removing the code which configures the PMIC
> GPIOs.
> >>
> >> Note that this patch was tested directly on top of v2016.01; since
> >> then, commit
> >> 96350f729c42 "dm: tegra: net: Convert tegra boards to driver model
> >> for Ethernet" prevents PCIe from being initialized. Alternatively,
> >> simply revert that commit to get PCIe Ethernet working again, then apply
> this patch to test.
> >>
> > Acked-by: Tom Warren <twarren@nvidia.com> I'll apply this to
> > u-boot-tegra/next ASAP.
> 
> I don't see this patch there yet. It'd be good to get it pulled upstream ASAP
> since the merge window for v2016.03 closes this weekend.
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