Re: [PATCH 2/3] ARM: tegra: Add PMC thermtrip programming to Jetson TK1 device tree

From: Thierry Reding
Date: Wed Aug 13 2014 - 04:03:40 EST


On Wed, Aug 13, 2014 at 10:52:18AM +0300, Mikko Perttunen wrote:
> On 13/08/14 10:37, Thierry Reding wrote:
> >* PGP Signed by an unknown key
> >
> >On Tue, Aug 05, 2014 at 11:12:59AM +0300, Mikko Perttunen wrote:
> >>This adds the required information to reset the board during an overheating
> >>situation to the Jetson TK1 device tree. The thermal reset is handled by the
> >>PMC by sending an I2C message to the PMIC. The entries specify the I2C
> >>message to be sent.
> >>
> >>Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
> >>---
> >> arch/arm/boot/dts/tegra124-jetson-tk1.dts | 5 +++++
> >> 1 file changed, 5 insertions(+)
> >>
> >>diff --git a/arch/arm/boot/dts/tegra124-jetson-tk1.dts b/arch/arm/boot/dts/tegra124-jetson-tk1.dts
> >>index 624b0fb..ee178c4 100644
> >>--- a/arch/arm/boot/dts/tegra124-jetson-tk1.dts
> >>+++ b/arch/arm/boot/dts/tegra124-jetson-tk1.dts
> >>@@ -1617,6 +1617,11 @@
> >> nvidia,core-pwr-off-time = <61036>;
> >> nvidia,core-power-req-active-high;
> >> nvidia,sys-clock-req-active-high;
> >>+
> >>+ nvidia,thermtrip-pmu-i2c-addr = <0x40>;
> >>+ nvidia,thermtrip-i2c-controller = <4>;
> >>+ nvidia,thermtrip-reg-addr = <0x36>;
> >>+ nvidia,thermtrip-reg-data = <0x2>;
> >
> >Given the number of properties that this can potentially have, I wonder
> >if perhaps it would be a good idea to put this into a subnode, like
> >this:
> >
> > thermtrip {
> > pmu-i2c-addr = <0x40>;
> > i2c-controller = <4>;
> > ...
> > };
>
> I guess that'd look a bit nicer.

Mind you, this may be somewhat on the edge of what's considered good
practice for DT content, so maybe wait for a second opinion before going
ahead with this.

I don't have any objections to a set of nvidia,thermtrip-* properties, I
just think it's fairly redundant to keep repeating that prefix (and it
causes ugliness in drivers, too).

Thierry

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