Date: Sat, 13 Nov 2010 18:01:36 +0100
From: Jean Delvare <khali@linux-fr.org>
To: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Phil Pokorny <ppokorny@penguincomputing.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Alan Cox <alan@lxorguk.ukuu.org.uk>,
        "lm-sensors@lm-sensors.org" <lm-sensors@lm-sensors.org>
Subject: Re: [lm-sensors] Location for thermal drivers
Message-ID: <20101113180136.2743fb2d@endymion.delvare>
In-Reply-To: <20101113144021.GA29753@ericsson.com>
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On Sat, 13 Nov 2010 06:40:21 -0800, Guenter Roeck wrote:
> On Sat, Nov 13, 2010 at 02:21:58AM -0500, Phil Pokorny wrote:
> > Reading the thermal sysfs-api and code, it's seems clear that it is a
> > very ACPI centric kind of thing.  It's involved in the coordination of
> > temperatures and the ways (fans, throttle algorithms, etc.) to keep
> > them in check.  It makes regular calls into the ACPI parser to
> > evaluate values.
> > 
> > But this driver that Alan has written seems to be a hwmon driver.
> > It's poking at registers, setting up A2D channels and dealing with
> > thermistors and perhaps voltages?  Those are very hwmon like things
> > for a driver to do.
> > 
> > It appears to be very similar to the coretemp and k10temp drivers that
> > read temperatures from the internals of the CPU.
>
> If the driver would use the hwmon framework, yes. However, it uses the thermal
> framework, in which hwmon support is optional.
> 
> The thermal framework itself is acpi independent. There is no single
> acpi call in the thermal framework code. acpi use may be true for the 
> drivers currently registering with the thermal framework, but that
> doesn't mean that the thermal framework itself in any way depends on 
> or is only supposed to be used with ACPI devices. ACPI is only referenced
> in the documentation as example.
> 
> If the thermal framework were to be used for acpi devices only, it would
> presumably reside in drivers/acpi and not be independent.
> 
> So your reasoning isn't really correct. Putting thermal drivers into 
> the hwmon directory doesn't really make sense. hwmon functionality
> is an optional subset of thermal drivers, but that does not mean
> that thermal drivers _are_ hwmon drivers.

+1

-- 
Jean Delvare
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