[PATCH V5 9/9] ARM: dts: tegra: add the PM configurations of PMC

Joseph Lo josephl at nvidia.com
Wed Apr 3 03:11:17 EDT 2013


On Wed, 2013-04-03 at 15:04 +0800, Thierry Reding wrote:
> * PGP Signed by an unknown key
> 
> On Wed, Apr 03, 2013 at 02:34:25PM +0800, Joseph Lo wrote:
> > On Wed, 2013-04-03 at 13:59 +0800, Thierry Reding wrote:
> > > > Old Signed by an unknown key
> > > 
> > > On Tue, Apr 02, 2013 at 02:00:55PM -0600, Stephen Warren wrote:
> > > > On 04/02/2013 05:20 AM, Joseph Lo wrote:
> > > > > Adding the PM configuration of PMC when the platform support suspend
> > > > > function.
> > > > 
> > > > For this patch, some more boards could be supported, but I think we'll
> > > > have to rely on other people (Lucas, Thierry) to send patches for them,
> > > > since they know the details of the board. It's fine to leave suspend
> > > > disabled on those boards until later.
> > > 
> > > I'm not sure what would be the best way to get the Tamonten devices out
> > > of suspend again. For Plutux and TEC we have a power button that could
> > > possibly be reused. There's a WAKEUP pin on the Tamonten connector which
> > > goes to GPIO PV2, but the mechanism to trigger it is carrier-board
> > > dependent.
> > > 
> > > For the Medcom-Wide we don't have a power button, but it could possibly
> > > use the WAKEUP pin if that's connected. It seems like in all designs it
> > > goes to the CPLD, but I need to check with engineering if there's a way
> > > to manipulate it.
> > > 
> > > So yes, I think for now we can leave suspend disabled on Tamonten and I
> > > can send patches to enable it once I've clarified with engineering.
> > > 
> > Hi Thierry,
> > 
> > I just recall I still need at least "nvidia,cpu-pwr-good-time" and
> > "nvidia,cpu-pwr-off-time" two properties to make CPU idle power-down
> > mode (same with LP2) work normally after this series.
> > 
> > So can you provide me that or point me out where is your downstream
> > kernel source? There data would be come from DT after this series.
> 
> We don't have suspend support in downstream kernels either. However
> since the Tamonten was derived from the Harmony reference design I
> suppose the same values can be reused.
> 
OK. That's enough.

> That said, the binding document says that those values are only required
> if nvidia,suspend-mode is set. So if we don't add it for the Tamonten
> boards why would you need the cpu-pwr-good-time and cpu-pwr-off-time
> values. Or maybe the binding document is wrong?

Actually, when you support CPU idle power-down mode (LP2), you already
support suspend function (at least LP2 mode). Just no wake up source
define in DT for your boards.

May I add these properties to your boards (same as Harmony)? Then you
can figure out your wake up source later, at least the RTC can wake up
your device I believe.

Thanks,
Joseph





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