From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BF69C433F5 for ; Thu, 21 Apr 2022 11:57:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1382554AbiDUL7t (ORCPT ); Thu, 21 Apr 2022 07:59:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43142 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240811AbiDUL7p (ORCPT ); Thu, 21 Apr 2022 07:59:45 -0400 Received: from ssl.serverraum.org (ssl.serverraum.org [IPv6:2a01:4f8:151:8464::1:2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D490727B3D; Thu, 21 Apr 2022 04:56:55 -0700 (PDT) Received: from ssl.serverraum.org (web.serverraum.org [172.16.0.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id D9B9B221D4; Thu, 21 Apr 2022 13:56:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1650542214; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AOeQgoECQEhyta1L5h2/I133FzGSSN8MIFX4Atj/rK0=; b=OHied78EstkaA4YcA9JI+ooNCI3q92EHUJ00a//CVYwrxG3C4g5BIktr4SSSyLRIjAu9KZ wLcKD0OpA856uJHZ/K/ECpGH3pGSTJUi1U3syzpFMQ8ueDs/ZR48axWH2NtYrGWZsXerVa PG1+GXrxqomkuqCmweDnniLgdjCKixA= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 21 Apr 2022 13:56:53 +0200 From: Michael Walle To: Krzysztof Kozlowski Cc: broonie@kernel.org, devicetree@vger.kernel.org, jerry.huang@nxp.com, krzysztof.kozlowski+dt@linaro.org, leoyang.li@nxp.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, robh+dt@kernel.org, shawnguo@kernel.org, Vladimir Oltean Subject: Re: [EXT] Re: [PATCH 1/2 v4] dt-bindings: dspi: added for semtech sx1301 In-Reply-To: <663d9e81-9036-6986-f52a-3846b4b5c673@linaro.org> References: <20220421094421.288672-1-michael@walle.cc> <663d9e81-9036-6986-f52a-3846b4b5c673@linaro.org> User-Agent: Roundcube Webmail/1.4.13 Message-ID: <20ef94a4ae0928deaadb52eccfd6e882@walle.cc> X-Sender: michael@walle.cc Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 2022-04-21 13:08, schrieb Krzysztof Kozlowski: >> But there *could* be a sane default which then could be replaced in >> an DT overlay. Like "mirkobus-socket" or similar, which might expose >> spidev. Actually it is more than just SPI, there is GPIO and resets >> and >> I2C. Maybe it should be an MFD? I don't know. But that is something >> for >> the DT maintainers to decide if they'll allow such "generic" devices. > > I think if you have DT overlay, you can add device node and there is no > need for placeholder, right? Yes, that is certainly correct. I was thinking of the user experience. Sometimes you have eval board with that connector to tinker around with different modules. Therefore I thought it would be nice to have an userspace spi device by default for first steps and tinkering. There is UART which you can use by just opening the tty. There is I2C which you can use by the i2ctools. There are GPIOs and PWM which can also be used either by sysfs or the gpio-utils. But there is no SPI device which can be used by the spi-tools. But as I said, that is something up to you to decide :) -michael