RE: How to use the generic thermal sysfs.

[Wei Ni <wni@nvidia.com>]

On Fri, 2012-07-13 at 15:41 +0800, Zhang Rui wrote:
> On 五, 2012-07-13 at 15:30 +0800, Wei Ni wrote:
> > 
> > Our tegra thermal framework also will use the generic thermal layer. It
> > will register the cooling device, and run the throttling in this generic
> > framework.
> > But we have a special mechanism, when the temp is below the trip temp,
> > we will set different cpu capability for different temp range. For
> > example, set the low/high temp as 20C/30C to the sensor, and set the cpu
> > to the max capability, it mean the cpu can run up to the max freq and
> > voltage in this temp range. if the temp is out that range, the sensor
> > will have irq/alert to notify the tegra framework, then we will set to
> > another temperature range and cpu capability.
> > I think we can try to add this mechanism to the generic framework as a
> > new policy, right?
> > 
> I think you can make use of the upper&lower limit in my patch set.
> Say, here is your thermal policy
> 20C - 30C, P0
> 30C - 40C, P1 - P2
> 40C - 60C, P3 - P5
> 60C+, P6 ~ Pn
> 
> you can register to the thermal layer 4 passive trip points,
> 20C, 30C, 40C, 60C, and then
> 1) for trip 0 (20C), upper limit 0, lower limit 0
> 2) for trip 1 (30C), upper limit 2, lower limit 1
> 3) for trip 2 (40C), upper limit 5, lower limit 3
> 4) for trip 3 (60C), upper limit n, lower limit 6
> 
> you can program your own sensor to get interrupt when the temperature
> hits 20C/30C/40C/60C, and the generic thermal layer will put the
> processors to proper frequency for each trip point.
> 
> what do you think?

Hi, Rui
I'm trying your upper/lower codes on our tegra platform.
Since we want to set limit value to the sensor to get interrupt, and
many sensor drivers can support the limit alert property, could we add a
new callback .set_limits() for the thermal zone device, so that we can
program it in the generic layer. when the temperature hits the
trip_temp, we can try to set to the next limit range.
I can try to add these codes base on your patches.

Thanks.
Wei.

> 
> BTW, the upper and lower limit is introduced in the patch set I'm
> testing, so maybe you were not aware of it.
> 
> thanks,
> rui