Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758180Ab2EOObM (ORCPT ); Tue, 15 May 2012 10:31:12 -0400 Received: from ppsw-41.csi.cam.ac.uk ([131.111.8.141]:56161 "EHLO ppsw-41.csi.cam.ac.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758106Ab2EOObK (ORCPT ); Tue, 15 May 2012 10:31:10 -0400 X-Cam-AntiVirus: no malware found X-Cam-SpamDetails: not scanned X-Cam-ScannerInfo: http://www.cam.ac.uk/cs/email/scanner/ Message-ID: <4FB268A9.5040007@cam.ac.uk> Date: Tue, 15 May 2012 15:31:05 +0100 From: Jonathan Cameron User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: Lars-Peter Clausen CC: Guenter Roeck , "R, Durgadoss" , "Tc, Jenny" , "linux-kernel@vger.kernel.org" , "lm-sensors@lm-sensors.org" , Jonathan Cameron Subject: Re: [lm-sensors] [PATCH] hwmon: Generic ADC support for hwmon References: <1337092008-31263-1-git-send-email-jenny.tc@intel.com> <20120515121339.GA21600@ericsson.com> <4D68720C2E767A4AA6A8796D42C8EB59124E22@BGSMSX101.gar.corp.intel.com> <20120515134257.GA21933@ericsson.com> <4FB265C1.7060306@metafoo.de> In-Reply-To: <4FB265C1.7060306@metafoo.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2645 Lines: 62 On 5/15/2012 3:18 PM, Lars-Peter Clausen wrote: > On 05/15/2012 03:42 PM, Guenter Roeck wrote: >> On Tue, May 15, 2012 at 08:42:57AM -0400, R, Durgadoss wrote: >>> Hi Guenter, >>> >>> Thanks for a quick reply. >>> >>>> On Tue, May 15, 2012 at 10:26:48AM -0400, Jenny TC wrote: >>>>> Currently drivers are using custom APIs to communicate with ADC driver. >>>>> So it make sense to have generic APIs to commnicate with ADC drivers. >>>>> This patch introduces generic APIs to communicate with ADC drivers. >>>>> >>>>> Signed-off-by: Jenny TC >>>> >>>> Hi Jenny, >>>> >>>> Do you have a practical use case ? >>> >>> We have some platform specific component drivers, thermal drivers, >>> battery drivers using this General purpose ADC in the platform. >>> That's why we thought of doing something like this. >>> >>>> >>>> Also, shouldn't those generic ADCs rather be supported through the IO >>>> subsystem ? >>>> After all, hwmon is all about hardware monitoring, not to provide generic ADC >>>> access. >>> >>> In this case, can we try this in iio or mfd subsystem ? >>> Kindly advise. >>> >> I meant iio (more specifically staging/iio/adc). >> >> I suspect it might make more sense to have a hwmon client, in parallel to the other >> users/clients (battery control, thermal etc), if the values reported by the ADC reflect >> information relevant for hardware monitoring. >> > > So there is already an experimental IIO to hwmon bridge in > drivers/staging/iio/, which you can use to expose a IIO ADC driver as an > hwmon device. Thanks Lars-Peter. That bridge is currently limited to voltage reading but that's more because my test part didn't do anything else. Trivial to add other bits and bobs as needed. In the short term, the interrupt driven side of things is still under review (so you are limited to polling devices - though this is typically fine for hwmon etc). I'll be submitting a patch to move the existing hwmon bridge driver into drivers/hwmon in the next cycle (after the IIO core is out of staging). Longer term plans involve reducing the connection between the IIO userspace front end and the backend to give cleaner support when people don't want generic userspace interfaces. This means making absolutely everything under the sun available through generic in kernel interfaces which will be 'interesting' for some more interesting devices... Jonathan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/