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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 D6934C4332E for ; Wed, 3 Mar 2021 19:28:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8FE6564EF0 for ; Wed, 3 Mar 2021 19:28:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1579724AbhCCSb4 convert rfc822-to-8bit (ORCPT ); Wed, 3 Mar 2021 13:31:56 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237139AbhCCOSm (ORCPT ); Wed, 3 Mar 2021 09:18:42 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A004FC061794 for ; Wed, 3 Mar 2021 06:18:01 -0800 (PST) Received: from lupine.hi.pengutronix.de ([2001:67c:670:100:3ad5:47ff:feaf:1a17] helo=lupine) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lHSK3-00014Z-9q; Wed, 03 Mar 2021 15:17:55 +0100 Received: from pza by lupine with local (Exim 4.92) (envelope-from ) id 1lHSK2-00075d-0s; Wed, 03 Mar 2021 15:17:54 +0100 Message-ID: Subject: Re: [PATCH v3 0/5] Reset driver for IMX8MQ VPU hardware block From: Philipp Zabel To: Benjamin Gaignard , robh+dt@kernel.org, shawnguo@kernel.org, s.hauer@pengutronix.de, festevam@gmail.com, ezequiel@collabora.com, mchehab@kernel.org, gregkh@linuxfoundation.org Cc: kernel@pengutronix.de, linux-imx@nxp.com, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-rockchip@lists.infradead.org, devel@driverdev.osuosl.org, kernel@collabora.com Date: Wed, 03 Mar 2021 15:17:53 +0100 In-Reply-To: <20210301151754.104749-1-benjamin.gaignard@collabora.com> References: <20210301151754.104749-1-benjamin.gaignard@collabora.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT User-Agent: Evolution 3.30.5-1.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:3ad5:47ff:feaf:1a17 X-SA-Exim-Mail-From: p.zabel@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: devicetree@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Hi Benjamin, On Mon, 2021-03-01 at 16:17 +0100, Benjamin Gaignard wrote: > The two VPUs inside IMX8MQ share the same control block which can be see > as a reset hardware block. This isn't a reset controller though. The control block also contains clock gates of some sort and a filter register for the featureset fuses. Those shouldn't be manipulated via the reset API. > In order to be able to add the second VPU (for HECV decoding) it will be > more handy if the both VPU drivers instance don't have to share the > control block registers. This lead to implement it as an independ reset > driver and to change the VPU driver to use it. Why not switch to a syscon regmap for the control block? That should also allow to keep backwards compatibility with the old binding with minimal effort. > Please note that this series break the compatibility between the DTB and > kernel. This break is limited to IMX8MQ SoC and is done when the driver > is still in staging directory. I know in this case we are pretty sure there are no users of this binding except for a staging driver, but it would still be nice to keep support for the deprecated binding, to avoid the requirement of updating kernel and DT in lock-step. regards Philipp