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 EE77AC3F2CD for ; Wed, 4 Mar 2020 12:03:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C091B2146E for ; Wed, 4 Mar 2020 12:03:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1583323405; bh=ngZGyk6qLBiIKqhNyOYfQtSNN1Zuio5UyG02XlxIspc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ZkSkzdozhBGqbsUTfIOSHUBFkZmIHXIBbXBgCdqWUnJRyOF3FsLjfk48zap65hVRo urJSYYAYDqjE84Q8NrlWzC0PwaNc5ztIrvUJB37hmomihXB4H3KG0MCsolMo20xAIR 6rFnj5dHbbEZxefsuJl5ff3s5sTDXYK+hSaD8eRM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387950AbgCDMDY (ORCPT ); Wed, 4 Mar 2020 07:03:24 -0500 Received: from foss.arm.com ([217.140.110.172]:33380 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728953AbgCDMDY (ORCPT ); Wed, 4 Mar 2020 07:03:24 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 95AE831B; Wed, 4 Mar 2020 04:03:23 -0800 (PST) Received: from localhost (unknown [10.37.6.21]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 1947D3F534; Wed, 4 Mar 2020 04:03:22 -0800 (PST) Date: Wed, 4 Mar 2020 12:03:21 +0000 From: Mark Brown To: Lars =?iso-8859-1?Q?M=F6llendorf?= Cc: linux-kernel@vger.kernel.org Subject: Re: Question about regmap_range_cfg and regmap_mmio Message-ID: <20200304120321.GA5646@sirena.org.uk> References: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="XsQoSWH+UP9D9v3l" Content-Disposition: inline In-Reply-To: X-Cookie: Tomorrow, you can be anywhere. 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 --XsQoSWH+UP9D9v3l Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Mar 04, 2020 at 12:25:09PM +0100, Lars M=F6llendorf wrote: > this mail is copied from internal issue written in markdown - I hope > this is still readable as mail. Not really frankly. I *think* you are saying that paging doesn't work due to relying on having register read and write operations? > My assumption is that paging is not a common use case for Memory-mapped > I/O and thus has not been implemented for this case. > - Are my assumptions correct? > - If so, what would you recommend me to do: > - Continue using `regmap-mmio` and implement my custom paging > functions on top of that? This will obviously work. > - Enhance the current `regmap-mmio` implementation so it does paging > and submit a patch? That's not really possible since MMIO never writes the register address to the bus. > - Write my own `better-regmap-mmio` implementation? It's not clear what that would mean. You could also look into making the paging code not rely on explicit register read and write operations. --XsQoSWH+UP9D9v3l Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAl5fmQYACgkQJNaLcl1U h9D3yQf/UKX+tbsv4ndgOEtwq4K+LBy2wvNpprCJ4eStbWILTnSqxHW4Va0aJG/6 z4w2M11jzUjyrqXa3dDKTTFjeRo/n27XmGhu2x1IQJq+kMHKMRywIrhEPMcfljeX cZX/J0GmELaRISFqzAKuSZ7v7ct2wdpdjRTJQQb1D9pvxUlE+SlCQTyHRY64T8JC BQW12Dg7YasFxRcpp3+Le0Er6ez7GYslXKGNdR9JEMQnI+e6KBXpI2s9pql+p7eA EnAejaDidYxptqlsw94VOAa50VtXd0/oGxkOcXuZLQu5fbWb3qwHQgNOVy+D3vYZ zBjvE6GPIxSUwNZ577VOAdHu3ni7GA== =91IF -----END PGP SIGNATURE----- --XsQoSWH+UP9D9v3l--