RE: [PATCH] thermal: qoriq: add multiple sensors support
From: Andy Tang
Date: Tue Oct 23 2018 - 22:49:03 EST
Hi Daniel,
> -----Original Message-----
> From: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> Sent: 2018å10æ16æ 19:21
> To: Andy Tang <andy.tang@xxxxxxx>; rui.zhang@xxxxxxxxx
> Cc: edubezval@xxxxxxxxx; linux-pm@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; Rob Herring <robh+dt@xxxxxxxxxx>
> Subject: Re: [PATCH] thermal: qoriq: add multiple sensors support
>
> >>>> The current code is reading the DT in order to get the sensor id
> >>>> and initialize it. IOW, the DT gives the sensors to use.
> >>>>
> >>>> IMO, it would be more self contained if the driver initializes all
> >>>> the sensors without taking care of the DT and let the of- code to
> >>>> do the binding when the thermal zone, no ?
> >>> [Andy] could you please explain more about this way? I am not sure
> >>> how
> >> to implement it.
> >>> But one thing is for sure: we must get the sensor IDs explicitly so
> >>> that we can enable them by the following command:
> tmu_write(qdata,
> >>> sites | TMR_ME | TMR_ALPF, &qdata->regs->tmr);
> >>
> >> What I meant is about code separation between the driver itself and
> >> the of-thermal code.
> >>
> >> The code above re-inspect the DT to find out the sensor ids in order
> >> to enable them and somehow this is not wrong but breaks the self
> >> encapsulation of the driver. I was suggesting if it isn't possible to
> >> enable all the sensors without taking care of digging into the DT.
> >
> > [Andy] I don't want to re-parse the DT here too. But I have to.
> > This driver will be used by all our SOCs with different sensor IDs and
> number.
> > For example: there are 2 sensors on ls1088a platform with ID 0 and 1.
> > While on ls1043a there are 6 sensors with ID 0, 1, 2, 3, 4, 5.
> > If we don't scan the DT we would not know how many sensors it is and
> > what are the sensor's IDs, unless we hardcode it in driver.
>
> Yes, you are not the only one in this situation IMO and the drivers
> supporting multiple sensors are increasing, so this will repeat again and
> again.
>
> That could be hardcoded in the driver by using the compatible string but it
> will be nicer if we can fix that in the DT.
>
> [Cc'ing Rob]
>
> What is missing is a description of the sensors id in the temperature
> device node. We have the <thermal-sensor-cells> with 0 or 1 telling if
> there is one or several sensors but we can't specify which sensor ids we
> have. The only alternative is to parse the thermal zones to found out which
> sensors are in use and use them to initialize the driver, an approach which
> breaks the self-encapsulation: the of-thermal framework is the one in
> charge of doing the link between the thermal zone and a sensor id.
>
> Is it acceptable to add the list of the sensors id in the temp device node, so
> the driver can initialize these sensors without parsing the thermal zone in
> the DT ?
>
Have you got any conclusion yet?
When can I send the next version of this patch?
BR,
Andy
>
>
>
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