From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Ga=c3=abtan_Carlier?= Subject: Re: Add driver for MCP45HV51 (digital potentiometer) Date: Wed, 3 Jan 2018 20:37:23 +0100 Message-ID: <13bcf912-56c7-5f18-aef7-4a5f5332e30d@gmail.com> References: <17da226a-247b-153a-6743-3e33264a1f0c@gmail.com> <20180103175628.GA31502@amd> <20180103190026.GA4564@amd> <48a0948b-daca-5526-2fa4-f82fa0074606@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: Received: from mail-wm0-f44.google.com ([74.125.82.44]:41669 "EHLO mail-wm0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750928AbeACThZ (ORCPT ); Wed, 3 Jan 2018 14:37:25 -0500 Received: by mail-wm0-f44.google.com with SMTP id g75so4567078wme.0 for ; Wed, 03 Jan 2018 11:37:25 -0800 (PST) In-Reply-To: <48a0948b-daca-5526-2fa4-f82fa0074606@gmail.com> Content-Language: en-US Sender: linux-leds-owner@vger.kernel.org List-Id: linux-leds@vger.kernel.org To: Pavel Machek Cc: linux-leds@vger.kernel.org On 01/03/2018 08:25 PM, Gaëtan Carlier wrote: > On 01/03/2018 08:00 PM, Pavel Machek wrote: >> On Wed 2018-01-03 19:38:31, Gaëtan Carlier wrote: >>> Hi Pavel, >>> On 01/03/2018 06:56 PM, Pavel Machek wrote: >>>> Hi! >>>> >>>>> I want to integrate MCP45HV51 I2C device to Linux kernel. It is a >>>>> digital >>>>> potentiometer. >>>>> I have several questions: >>>>> - Is "leds driver" the correct section ? >>>>> - On which existing I2C leds driver should I base my code to use >>>>> the most >>>>> recent API/pratice ? >>>>> - Maybe it is not needed to write a C driver and everything can be >>>>> done via >>>>> devicetree ? >>>> >>>> Umm. What makes you think that LED driver is correct section? LEDs are >>>> little lights... >>> >>> I know that, but like Led and Backlight, digital potentiometers are >>> just a >>> device that needs a 0 to 255 value... >>> So I don't know where to put it maybe in IIO driver ? >> >> Is that _output_ device? What does it control? >> >>                                     Pavel >> > > It is an output with a variable resistance (like DAC is an output with a > variable voltage).[1] > So regarding the webpage of IIO[2], digital potentiometer must be coded > on IIO API. > > Thank you taking time to answer me, > Gaëtan. > > > [1] https://en.wikipedia.org/wiki/Digital_potentiometer > [2] https://wiki.analog.com/software/linux/docs/iio/iio After a deeper search on a recent branch, potentiometer are already handled in IIO layer :D