From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751778Ab3JEJjF (ORCPT ); Sat, 5 Oct 2013 05:39:05 -0400 Received: from pegase1.c-s.fr ([93.17.236.30]:47292 "EHLO mailhub1.si.c-s.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751408Ab3JEJjD (ORCPT ); Sat, 5 Oct 2013 05:39:03 -0400 Message-ID: <524FDE35.3050008@c-s.fr> Date: Sat, 05 Oct 2013 11:39:01 +0200 From: leroy christophe User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Lars-Peter Clausen CC: Jonathan Cameron , linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org, patrick.vasseur@c-s.fr Subject: Re: [PATCH] IIO AD7923 iio_consumer support References: <201310050821.r958LBqP012933@localhost.localdomain> <524FD0AB.7020209@metafoo.de> <524FD976.9060708@c-s.fr> <524FDD4F.7080406@metafoo.de> In-Reply-To: <524FDD4F.7080406@metafoo.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 05/10/2013 11:35, Lars-Peter Clausen a écrit : > On 10/05/2013 11:18 AM, leroy christophe wrote: >> Le 05/10/2013 10:41, Lars-Peter Clausen a écrit : >>> On 10/05/2013 10:21 AM, Christophe Leroy wrote: >>>> + .consumer_channel = "channel_0", >>>> + .adc_channel_label = "0", >>>> + }, >>>> + { >>>> + .consumer_dev_name = AD7923_NAME, >>>> + .consumer_channel = "channel_1", >>>> + .adc_channel_label = "1", >>>> + }, >>>> + { >>>> + .consumer_dev_name = AD7923_NAME, >>>> + .consumer_channel = "channel_2", >>>> + .adc_channel_label = "2", >>>> + }, >>>> + { >>>> + .consumer_dev_name = AD7923_NAME, >>>> + .consumer_channel = "channel_3", >>>> + .adc_channel_label = "3", >>>> + }, >>>> + { } >>>> +}; >>> This is a mapping between channel names of the provider between the channel >>> names of the consumer. So it is specific to a certain combination of >>> consumer and provider and usually depend on how things are physically wired >>> on your board. As such there can be no generic mapping and this needs to go >>> into your machine/board driver. The mapping is usually passed to the IIO >>> driver via its platform data. >>> >>> So e.g. imagine you have a provider like this driver and you have a consumer >>> that has a "voltage" channel. And on your board channel 3 of the ADC is what >>> you want to route to that consumer. Then your mapping would look like this: >>> >>> { >>> .consumer_dev_name = "your_consumer_device.1", >>> .consumer_channel = "voltage", >>> .adc_channel_label = "AIN3", >>> } >>> >>> And in your consumer driver you'd do: >>> >>> channel = iio_channel_get(dev, "voltage"); >>> >>> >> Thanks for the explanation. >> >> Can the mapping be retrieved via of_platform ? >> >> Indeed, the only exemple I found was in the lp8788_adc driver, which >> includes iio/machine.h and declares a default mapping, but it is based on >> platform_data, not of_platform. >> > If you are using device tree you can specify the mapping inside the > devicetree. Have a look at > Documentation/devicetree/bindings/iio/iio-bindings.txt > > Yes, I saw that. Is there anything that shall be done in the driver to support it, or is it automatic ? Christophe