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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 7F020C47257 for ; Fri, 8 May 2020 10:22:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5BAE420A8B for ; Fri, 8 May 2020 10:22:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588933334; bh=0zdzBynO1wxpltbyCDGMW3LJkzChWsD2F3DXAG0KVvs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=R6ZYFADtRVUR27Envp554HNJLFWB7CZeDFTrZzw5N+MqfAFEb6DDQeIp+9sxQHiks mQ/PJFDTz/+OqZdL+NELfEXE+6G9+fFCFiAeYbDpfVflgulROWTIBgdpKYzSOEhnUF xWoHf4E8GRAfB45njaPYVROv6c6YYcmdUnyjzJ2A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726815AbgEHKWN (ORCPT ); Fri, 8 May 2020 06:22:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:37256 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725815AbgEHKWN (ORCPT ); Fri, 8 May 2020 06:22:13 -0400 Received: from localhost (fw-tnat.cambridge.arm.com [217.140.96.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D2DBA208D6; Fri, 8 May 2020 10:22:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588933332; bh=0zdzBynO1wxpltbyCDGMW3LJkzChWsD2F3DXAG0KVvs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=1LorngV4QwrEbOgNnfaULvNuCzhPnLImq+CL9GgvYjaScTv/v1pQTz7r67TRzncGC wnJoT6sRoiyLNpqXUsZhDchHJZhmOrP9iYVSr4QGjPFiXMC9pKtsJLpWVNmXG/oO6d mOSP6xhcQ5fR9Zdxi+tbEjHDtt1EygyINhUb5aEo= Date: Fri, 8 May 2020 11:22:10 +0100 From: Mark Brown To: Serge Semin Cc: Andy Shevchenko , Ramil Zaripov , Alexey Malahov , Thomas Bogendoerfer , Paul Burton , Ralf Baechle , Lee Jones , Miquel Raynal , Arnd Bergmann , Rob Herring , linux-mips@vger.kernel.org, devicetree , John Garry , Chuanhong Guo , Eddie James , Geert Uytterhoeven , Chris Packham , Tomer Maimon , Masahisa Kojima , Krzysztof Kozlowski , Florian Fainelli , Jassi Brar , Linux Kernel Mailing List , linux-spi Subject: Re: [PATCH 2/2] spi: Add Baikal-T1 System Boot SPI Controller driver Message-ID: <20200508102210.GC4820@sirena.org.uk> References: <20200508093621.31619-1-Sergey.Semin@baikalelectronics.ru> <20200508093621.31619-3-Sergey.Semin@baikalelectronics.ru> <20200508101541.e3yxaocuilaiyutg@mobilestation> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="+nBD6E3TurpgldQp" Content-Disposition: inline In-Reply-To: <20200508101541.e3yxaocuilaiyutg@mobilestation> X-Cookie: Give him an evasive answer. User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --+nBD6E3TurpgldQp Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, May 08, 2020 at 01:15:41PM +0300, Serge Semin wrote: > On Fri, May 08, 2020 at 01:03:11PM +0300, Andy Shevchenko wrote: > > > slave device. Taking into account the peculiarities of the controller > > > registers and physically mapped SPI flash access, very limited resources > > > and seeing the normal usecase of the controller is to access an external > > > SPI-nor flash, we decided to create a dedicated SPI driver for it. > > It seems a lot of code. > > Why can't you use spi-dw-mmio.c et al.? > I said above why. Even though the registers set is similar It's too specific > to be integrated into the generic DW SSI driver. Can you be more specific about the issues? From what you wrote it sounded like the main thing was chip select handling. > > > The driver provides callbacks for native messages-based SPI interface, > > > SPI-memory and direct mapping read operations. Due to not having any > > > asynchronous signaling interface provided by the core we have no choice What do you mean by "asynchronous signaling interface provided by the core" here? --+nBD6E3TurpgldQp Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl61MtEACgkQJNaLcl1U h9BbBAf+Jl9EnhQJquSLhnymjo26KCwHkpt/NEN6OKsKTLYfqL6Emy6SUPmqzpdM AUxNE0209CAMHG/ThduAVeKtICEoc5aek/HHkit5GcPze80sUzY2xRTLvNtVFp2S DcYhPtO+n422dQo/pp4T7LOBp+9o/oLkw3laGi8PL2zqGu7JOMOaEt8Zxsr1V5OV UrtTzdDW6ztfatRY/p1Re4Uy+pDS6fPEgfHKxImaZSeoLSbhLc07y3R6QOtChd+p Kk3L9eoLS90IjB9xTHjgASfmLKE+15kuoRfH0w3bU3ldRRUVlfckYXxKklZBVRO4 KnZnpFoa6wjOYpoPbHLv5cpFOXKpPw== =5r9D -----END PGP SIGNATURE----- --+nBD6E3TurpgldQp--