From mboxrd@z Thu Jan 1 00:00:00 1970 From: arno@natisbad.org (Arnaud Ebalard) Subject: Re: [PATCHv0] hwmon: Add support for GMT G751 Temp. Sensor and Thermal Watchdog Date: Sat, 09 Nov 2013 18:28:46 +0100 Message-ID: <87fvr5h4c1.fsf@natisbad.org> References: <87ob5uv5bv.fsf@natisbad.org> <527D9286.4080009@roeck-us.net> <87siv5bmcp.fsf@natisbad.org> <527E6908.2000703@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <527E6908.2000703@roeck-us.net> (Guenter Roeck's message of "Sat, 09 Nov 2013 08:55:36 -0800") Sender: linux-doc-owner@vger.kernel.org To: Guenter Roeck Cc: Jean Delvare , Rob Herring , Pawel Moll , Mark Rutland , Stephen Warren , Ian Campbell , Rob Landley , Grant Likely , Linus Walleij , Arnd Bergmann , devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, lm-sensors@lm-sensors.org List-Id: devicetree@vger.kernel.org Hi Guenter, Guenter Roeck writes: >> Sadly (for me), you are not: I compared the GMT G751 datasheet to an >> original (1996) National semiconductor LM75 datasheet and they are >> identical. I mean both the structure and full content (text, diagrams, >> etc) is the same. Lesson learned: next time I start a driver, I will ask >> if it ressembles an existing supported chip beforehand. >> > > Hi Arnaud, > > that is interesting; I thought it is Yet Another Clone, not really exactly > the same chip. If you want to compare: http://www.ieap.uni-kiel.de/surface/ag-berndt/lehre/fpmc/ns/lm75.pdf http://natisbad.org/NAS4/refs/GMT_G751.pdf >>> Please use the lm75 driver and add the g751 parameters to it. >> >> I will test if the driver does indeed work as expected to drive the G751 >> and will send a patch to document compatibility w/ GMT G751 (Kconfig, >> i2c_device_id struct and lm75_detect function). While I am at it, if you >> see something in the patch I pushed which could be useful for current >> lm75 driver (doc, sysfs, of_ part for polarity, ...), just tell me. >> > > Depends on what you need. The fault_queue and mode sysfs attributes are neither > necessary nor acceptable - hwmon has well defined attributes, and new ones > are only added after discussion. If you _need_ to configure polarity, > interrupt mode, or fault queue depth in your application to anything but > the default, we might discuss adding those as devicetree properties. > However, you would have to make sure that it does not negatively affect > the other chips supported by the driver, and we should then discuss > if other properties should be supported as well. Overall, I strongly suspect > that the HW is happy with the default configuration. If so, we should just leave > it alone. Let's keep lm75 in I2C trivial devices list. > Power control (the shutdown attribute) should be handled through the PM > subsystem; see CONFIG_PM / CONFIG_PM_SLEEP in other drivers. If your hardware > can sleep (which may be somewhat unlikely for a NAS), lm75 driver does have #ifdef CONFIG_PM (or am I missing something?), but you are right, I don't think the NAS can take advantage of it ATM. I just finished the a first version of a patch for lm75 to reference g751. I'll send it in a separate email. Anyway, thanks for the quick feedback. Cheers, a+