From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Ni Subject: Re: [PATCH v3 1/4] hwmon: (lm90) split set&show temp as common codes Date: Wed, 17 Jul 2013 14:26:54 +0800 Message-ID: <51E6392E.5080906@nvidia.com> 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> <20130717051409.GA16413@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130717051409.GA16413@roeck-us.net> Sender: linux-pm-owner@vger.kernel.org To: Guenter Roeck Cc: Thierry Reding , Jean Delvare , "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 07/17/2013 01:14 PM, Guenter Roeck wrote: > 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.. Sorry, what's the "bridge" mean, does it mean we need to add a flag in the thermal_zone_device_register() to indicate if we want to register virtual hwmon device or not? Thanks. Wei. > > Guenter >