From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-path: Date: Wed, 28 Jun 2017 19:02:29 +0200 From: Tom Levens To: Guenter Roeck CC: Tom Levens , Mike Looijmans , , , , , , Subject: Re: [PATCH v2 3/3] hwmon: ltc2990: support all measurement modes In-Reply-To: <20170628160048.GA8915@roeck-us.net> Message-ID: References: <1479384616-12479-1-git-send-email-tom.levens@cern.ch> <1479384616-12479-3-git-send-email-tom.levens@cern.ch> <410de6c9-a13e-51f7-4d66-6f4e2537c574@roeck-us.net> <97eb089f-e0e2-1146-6e17-8f9f790433d8@topic.nl> <20170628150130.GC30968@roeck-us.net> <20170628160048.GA8915@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII"; format=flowed List-ID: On Wed, 28 Jun 2017, Guenter Roeck wrote: > On Wed, Jun 28, 2017 at 05:29:38PM +0200, Tom Levens wrote: >> > [ ... ] > >>> >>>> Whatever happened to this patch though? It didn't make it to mainline, >>>> otherwise I'd have found it sooner... >>>> >>> I'll have to look it up, but I guess I didn't get an updated version. >> >> As far as I remember I had a working V3 of this patch, but it is entirely >> possible that it was never submitted as I have been busy with other projects >> recently. I'll dig it out and check that it is complete. >> > FWIW, I don't see it at > https://patchwork.kernel.org/project/linux-hwmon/list/?submitter=171225&state=* > > Maybe you were waiting for a reply from Rob. Either case, it might make > sense to only provide valid modes, ie to abstract the mode bits from the > hardware, such as > > 0 - internal temp only > 1 - Tr1 > 2 - V1 > 3 - V1-V2 > 4 - Tr2 > 5 - V3 > 6 - V3-V4 > 7 to 14 - per bit 0..2 > > Guenter > You are right, there was still an open question about how best to handle the mode selection in DT. In the latest version of my patch I have it implemented as an array for setting the two values, for example: lltc,meas-mode = <7 3>; This sets bits [2..0] = 7 and [4..3] = 3. Of course these could be split into two DT properties, but I was unsure what to name them as both fields are called "mode" in the datasheet and "mode-43"/"mode-20" (or similar) is ugly. With regards to your proposal, it is not clear to me whether the modes which have the same result are exactly equivalent. Does disabling a measurement with the mode[4..3] bits really leaves the part in a safe state for all possible HW connections? With this doubt in my head, I would prefer to keep the option available to the user to select any specific mode. But I am open to suggestions. Mike, if you would like to test it, the latest version of my code is here: https://github.com/levens/ltc2990/blob/dev/drivers/hwmon/ltc2990.c Cheers,