From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f173.google.com ([209.85.223.173]:36453 "EHLO mail-io0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757437AbbIVB1Q (ORCPT ); Mon, 21 Sep 2015 21:27:16 -0400 Received: by ioii196 with SMTP id i196so2099820ioi.3 for ; Mon, 21 Sep 2015 18:27:15 -0700 (PDT) Date: Mon, 21 Sep 2015 20:27:07 -0500 From: Michael Welling To: Guenter Roeck Cc: lm-sensors@lm-sensors.org, linux-iio@vger.kernel.org, Jonathan Cameron Subject: Re: ADS1018 ADC driver Message-ID: <20150922012707.GA20799@deathstar> References: <20150921220648.GA12569@deathstar> <5600A924.1090303@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <5600A924.1090303@roeck-us.net> Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On Mon, Sep 21, 2015 at 06:04:36PM -0700, Guenter Roeck wrote: > Hi Michael, > > On 09/21/2015 03:06 PM, Michael Welling wrote: > >I am in the process of starting a new device driver for the ADS1018 ADC. > >Before starting I did some research as whether similar drivers exist in the kernel. > > > >It appears that ADC drivers are in both hwmon and iio/adc. The closest drivers to > >the device mentioned are in hwmon. > > > >Where is the best place for this new ADC driver? > > Your call. You could add support for the chip to hwmon/ads1015.c, or you could write > a new driver in iio/adc. If you do the latter, maybe you can also include support > for ads1015 and ads1115, so we can ultimately remove the ads1015 driver from hwmon. Guenter, Though the iio route may be more work I have a feeling the driver will be better off there. The use of regmap support should allow for both the SPI and I2C version to coexist. I will try my best to implement the driver in a way that can cover these other I2C devices mentioned. > > >Shouldn't ADCs all be in the same subsystem? > >Has there been any effort to unify or distiguish where drivers should go? > > > In general, ADCs primarily used for the purpose of ADC measurements would go > into iio, and ADCs used primarily for hardware monitoring would go into hwmon. > > There are no strict rules, though, and this is not always black-and-white. > I am sure there are some drivers in hwmon which would be better suited for iio. > Primarily that would be the case because the iio subsystem is relatively new, > and such drivers did not have a home other than hwmon until a couple of years ago. > If you find any drivers in hwmon which you think should be moved, please feel free > to do the conversion. Has anyone considered an alternative implementation for generic ADCs? I was thinking about an implementation similar to gpiolib whereas ADCs can be resources for other drivers. For instance, ADC lines could be registered to a joystick driver and used to provide analog stick or pressure sensitive button. Another example could be registering analog lines for an analog accelerometer driver. Is this a bad idea? -Michael > > Guenter >