From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH v3 1/4] hwmon: (lm90) split set&show temp as common codes Date: Tue, 16 Jul 2013 22:14:09 -0700 Message-ID: <20130717051409.GA16413@roeck-us.net> References: <1373615287-18502-1-git-send-email-wni@nvidia.com> <1373615287-18502-2-git-send-email-wni@nvidia.com> <20130712152615.23464a6b@endymion.delvare> <20130712135000.GA3386@roeck-us.net> <20130712163034.1fc1cd66@endymion.delvare> <20130712144011.GC3629@roeck-us.net> <51E395D9.6070000@nvidia.com> <20130715092415.6d082aa2@endymion.delvare> <20130717042618.GA11359@mithrandir> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20130717042618.GA11359@mithrandir> Sender: linux-pm-owner@vger.kernel.org To: Thierry Reding Cc: Jean Delvare , Wei Ni , rui.zhang@intel.com, lm-sensors@lm-sensors.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org List-Id: linux-tegra@vger.kernel.org On Wed, Jul 17, 2013 at 06:26:20AM +0200, Thierry Reding wrote: > On Mon, Jul 15, 2013 at 09:24:15AM +0200, Jean Delvare wrote: > > On Mon, 15 Jul 2013 14:25:29 +0800, Wei Ni wrote: > > > On 07/12/2013 10:40 PM, Guenter Roeck wrote: > > > > On Fri, Jul 12, 2013 at 04:30:34PM +0200, Jean Delvare wrote: > > > >> If that means that for example the ACPI thermal zone is no longer > > > >> displayed by "sensors", then I strongly object - unless it is > > > >> explicitly registered as a separate hwmon device from now on, of course. > > > > > > > > If I recall correctly that was the idea. Of course, in practice that will mean > > > > that devices will _not_ get exposed as hwmon devices, as implementers won't > > > > bother doing both. > > > > > > > >> My idea was to make the bridge optional - you decide when you register > > > >> a thermal device if it should be exposed as hwmon or not. > > > > > > > > Yes, that would be a much better solution. > > > > > > I think we can decide it in the DT, we can add a dt property in the lm90 > > > device node, such as: > > > sys-interface = SYS_HWMON; > > > or > > > sys-interface = SYS_THERMAL; > > > So we register it as the hwmon or thermal device > > > > This is an option, but please keep in mind that DT is not the only way > > to instantiate LM90-like devices, and we should not expose duplicate > > inputs by default. It is fine with me if the default is to create only a > > HWMON device (as the lm90 driver was doing so far), and only > > DT-instantiated devices have the choice. > > I don't think this information belongs in the device tree. Whether the > device is exposed as hwmon or thermal device (or both) is entirely a > software issue whereas DT is a means to describe the hardware. > Correct; this is exactly the type of information which does _not_ belong int devicetree. > It seems to me that the earlier proposal of communicating to the bridge > whether or not a device should be exposed as hwmon device is the right > thing to do here. > Agreed.. Guenter