From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail02.prevas.se ([62.95.78.10]:15620 "EHLO mail02.prevas.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754906AbcA1HkY (ORCPT ); Thu, 28 Jan 2016 02:40:24 -0500 Subject: Re: [PATCH] iio:dac:ad5755 fixed SPI_MODE To: Lars-Peter Clausen , , Jonathan Cameron References: <1453905547-27938-1-git-send-email-sean.nyekjaer@prevas.dk> <56A8D800.3030804@metafoo.de> <56A8E344.8070803@prevas.dk> <56A8E606.2030708@metafoo.de> From: =?UTF-8?Q?Sean_Nyekj=c3=a6r?= Message-ID: <56A9C375.70501@prevas.dk> Date: Thu, 28 Jan 2016 08:29:57 +0100 MIME-Version: 1.0 In-Reply-To: <56A8E606.2030708@metafoo.de> Content-Type: text/plain; charset="windows-1252"; format=flowed Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 2016-01-27 16:45, Lars-Peter Clausen wrote: > On 01/27/2016 04:33 PM, Sean Nyekjær wrote: >> On 2016-01-27 15:45, Lars-Peter Clausen wrote: >>> On 01/27/2016 03:39 PM, Sean Nyekjaer wrote: >>>> According to datasheet data is latched on the falling edge of the SCK. >>>> >>>> I agree it works in SPI_MODE_0 on the eval kit, but in other configurations >>>> with optic isolators (that adds a small delay). We are falling out of spec. >>>> >>>> Signed-off-by: Sean Nyekjaer >>> Hi, >>> >>> The SPI mode is usually specified in the spi_board_info struct or devicetree >>> rather than hardcoding it in the driver. >>> >>> - Lars >> Hi >> I know :-) >> But, all devices in this family have only support for SPI_MODE_1. So why >> leave it up to the spi_board_info or devicetree when only one mode is allowed? > As far as I can see they should work with either SPI_MODE_1 or SPI_MODE_2. > But it would certainly be nice if the SPI framework had support for > auto-configuration, based on the support modes of the SPI controller and the > device, in case no mode was explicit specified. > >> If you don't like this patch I think we should create some documentation for >> the device, so other people don't have to use hours in debugging :-D > https://wiki.analog.com/resources/tools-software/linux-drivers/iio-dac/ad5755?&#example_platform_device_initialization Ops the gmail app on android is not very good answering text only emails :-) Is there a reason why this documentation is not in the kernel? It's also missing the options and examples for devicetree bindings... Should I create the devicetree documentation instead of this patch? I still think this patch is a better solution to prevent future problems with the driver. /Sean