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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD735C43460 for ; Thu, 6 May 2021 11:35:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8391F613DD for ; Thu, 6 May 2021 11:35:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234836AbhEFLgG (ORCPT ); Thu, 6 May 2021 07:36:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:44348 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234832AbhEFLgF (ORCPT ); Thu, 6 May 2021 07:36:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id E1CC261157; Thu, 6 May 2021 11:35:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620300907; bh=DiqP12Vg8J2d6hM0eOvFLpV7oR3nT9I8QI77NtuOz9A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DzArdHvKrANtpFIwPYJDBmAFfGoRcp3HXsVYohZdJW1sYatBvZivS1N/6gjrIGxYy DNK+II3OnJnRM0NxGbPFAkXvmCPnjYZ/WSHaxXAS2ZsT/XyartQlTs793Sc0SyFTWC 6HxipSahBNGnsq87JuX2Y8bZnCbMmX+f7aLjPKLLiS36+blklvW5yX5Cw4ZUuLFgtZ jJrU+fUrIO2oM6WAXa+1smjC/A1EIbynbpwOT57IGQthckZM8La+bdU9t+14DONP9h +FhKqcEj8cjEDOQVO4ZFK5lESvyplYorWyXBQX8Q6YUj7RgtpCOchx8ePYyXY7gegJ IKPQvlS3jO7EA== Date: Thu, 6 May 2021 12:34:30 +0100 From: Mark Brown To: Andy Shevchenko Cc: Linus Walleij , Jay Fang , "linux-spi@vger.kernel.org" , "linux-gpio@vger.kernel.org" , "linuxarm@huawei.com" , "huangdaode@huawei.com" , "tangzihao1@hisilicon.com" Subject: Re: [PATCH 0/2] spi: Correct CS GPIOs polarity when using GPIO descriptors Message-ID: <20210506113430.GB4642@sirena.org.uk> References: <1620270017-52643-1-git-send-email-f.fangjian@huawei.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="24zk1gE8NUlDmwG9" Content-Disposition: inline In-Reply-To: X-Cookie: If it ain't baroque, don't phiques it. User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org --24zk1gE8NUlDmwG9 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, May 06, 2021 at 02:24:17PM +0300, Andy Shevchenko wrote: > On Thursday, May 6, 2021, Linus Walleij wrote: > > Curious that ACPI has SPI CS as always active high, > Here I didn=E2=80=99t get what exactly you are pointing out. GPIOs are ac= tive high, > due to historical reasons. Otherwise SPI CS depends on the actual hardware > and may be (most of the cases?) active low. SPI chip selects are almost always active low - the signal is often written nCS or /CS for that reason. --24zk1gE8NUlDmwG9 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmCT1EYACgkQJNaLcl1U h9BtRwf8CmSo0LBbA+fnpHRVtFy4gGNTPypwY9UMtIsBN1Egb/9HtWlfewD3TcDF K/x3Qx6M1SdZHkCkpxN/QWVsuJxKxZm2YbGzCG4WidQ4js9aufOX+QrKEepcmPCP hW+4H49yn6HRCU7MD0qOEI6/OwDhiYq7TDpFWnJSZ0+hDhp0SWkU8yjkOcwJvTfz Rf0f0tFmv5i+C2H7x6+T/2DydlrUBE7CXreNgR6fY5wbBMftnTDN7C2znLusm6mN t1Xzh7BIMkmVwtwZ8daUem6Pfy+3PhWd+4/pDpg9yR10m9CcjRBwfaSBh8iggVhx DDDnRebtd3kg7nnBEl/9pCdwuro6Gw== =Z+no -----END PGP SIGNATURE----- --24zk1gE8NUlDmwG9--