Re: [PATCH 1/3] thermal: hisilicon: add new hisilicon thermal sensor driver

[kongxinwei]

On 03/23/2015 12:46 PM, Leo Yan wrote:
> On Fri, Mar 20, 2015 at 03:55:27PM +0000, Mark Rutland wrote:
> > > > That may be the case in the code as it stands today, but per the binding
> > > > the trip points are the temperatures at which an action is to be taken.
> > > >
> > > > The thermal-zone has poilling-delay and polling-delay-passive, but
> > > > there's no reason you couldn't also use the interrupt to handle the
> > > > "hot" trip-point, adn the reset at the "critical" trip-point. All that's
> > > > missing is the plumbing in order to do so.
> > > >
> > > > So please co-ordinate with the thermal framework to do that.
> > > Let's dig further more for this point, so that we can get more specific
> > > gudiance and have a good preparation for next version's patch set.
> > >
> > > After i reviewed the thermal framework code, currently have one smooth
> > > way to co-ordinate the trip points w/t thermal framework: use the function
> > > *thermal_zone_device_register()* to register sensor, and can use the
> > > callback function .get_trip_temp to tell thermal framework for the
> > > trip points' temperature.
> > >
> > > For hisi thermal case, now the driver is using the function
> > > *thermal_zone_of_sensor_register* to register sensor, but use this way
> > > i have not found there have standard APIs which can be used by sensor
> > > driver to get the trip points info from thermal framework.
> > >
> > > I may miss something for thermal framework, so if have existed APIs to
> > > get the trip points, could pls point out?
> > I am only familiar with the binding, not the Linux implementation -- The
> > latter can change to accomodate your hardware without requiring binding
> > changes. Please co-ordinate with the thermal maintainers.
> Found the functions of_thermal_get_trip_points(tz) and of_thermal_get_ntrips(tz)
> will help for this.
>
> > > > > > > +       if (of_property_read_bool(np, "hisilicon,tsensor-bind-irq")) {
> > > > > > > +
> > > > > > > +               if (data->irq_bind_sensor != -1)
> > > > > > > +                       dev_warn(&pdev->dev, "irq has bound to index %d\n",
> > > > > > > +                                data->irq_bind_sensor);
> > > > > > > +
> > > > > > > +               /* bind irq to this sensor */
> > > > > > > +               data->irq_bind_sensor = index;
> > > > > > > +       }
> > > > > > I don't see why this should be specified in the DT. Why do you believe
> > > > > > it should?
> > > > > The thermal sensor module has four sensors, but have only one
> > > > > interrupt signal; This interrupt can only be used by one sensor;
> > > > > So want to use dts to bind the interrupt with one selected sensor.
> > > > That's not all that great, though I'm not exactly sure how the kernel
> > > > would select the best sensor to measure with. It would be good if you
> > > > could talk to the thermal maintainers w.r.t. this.
> > > This will be decided by the silicon, right? Every soc has different
> > > combination with cpu/gpu/vpu, so which part is hottest, this maybe
> > > highly dependent on individual SoC.
> > >
> > > S/W just need provide the flexibility so that later can choose
> > > the interrupt to bind with the sensor within the hottest part.
> > Then the property you care about is which sensor is closest to what is
> > likely to be the hottest component. Given that, the kernel can decide
> > how to use the interrupt.
> Will modify the driver to dynamically bind the interrupt to hottest
> sensor; Appreciate for good suggestion.
>
> Thanks,
> Leo Yan

Hi mark:
   Thank you for your comments,please wait the next version to slove your
presenting problem.

Thanks.
Xinwei

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