From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751333AbbCJJYn (ORCPT ); Tue, 10 Mar 2015 05:24:43 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:59931 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751279AbbCJJYk (ORCPT ); Tue, 10 Mar 2015 05:24:40 -0400 Message-ID: <1425979443.6226.4.camel@pengutronix.de> Subject: Re: [PATCH 1/5] soc: mediatek: Add SMI driver From: Lucas Stach To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, Mark Rutland , devicetree@vger.kernel.org, linux-mediatek@lists.infradead.org, srv_heupstream@mediatek.com, Catalin Marinas , Joerg Roedel , Will Deacon , linux-kernel@vger.kernel.org, Tomasz Figa , iommu@lists.linux-foundation.org, Rob Herring , Daniel Kurtz , Sasha Hauer , Matthias Brugger , Yingjoe Chen , Robin Murphy , yong.wu@mediatek.com Date: Tue, 10 Mar 2015 10:24:03 +0100 In-Reply-To: <2583132.xxsZocsQta@wuerfel> References: <1425638900-24989-1-git-send-email-yong.wu@mediatek.com> <1425638900-24989-2-git-send-email-yong.wu@mediatek.com> <1425871612.4871.10.camel@mtksdaap41> <2583132.xxsZocsQta@wuerfel> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.12.9-1+b1 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-SA-Exim-Connect-IP: 2001:67c:670:100:fa0f:41ff:fe58:4010 X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Arnd, Am Montag, den 09.03.2015, 22:56 +0100 schrieb Arnd Bergmann: > On Monday 09 March 2015 11:26:52 Yingjoe Chen wrote: > > On Fri, 2015-03-06 at 18:48 +0800, yong.wu@mediatek.com wrote: > > > From: Yong Wu > > > > > > This patch add SMI(Smart Multimedia Interface) driver. This driver is > > > responsible to enable/disable iommu and control the clocks of each > > > local arbiter. > > > > > > Signed-off-by: Yong Wu > > > --- > > > drivers/soc/mediatek/Kconfig | 7 ++ > > > drivers/soc/mediatek/Makefile | 1 + > > > drivers/soc/mediatek/mt8173-smi.c | 143 ++++++++++++++++++++++++++++++++++++++ > > > include/linux/mtk-smi.h | 40 +++++++++++ > > > 4 files changed, 191 insertions(+) > > > create mode 100644 drivers/soc/mediatek/mt8173-smi.c > > > create mode 100644 include/linux/mtk-smi.h > > > > > > > Hi Arnd, Matthias, > > > > For the SMI driver, we can't find a better place, so we put it in > > drivers/soc/mediatek now. Please let us know if you have any suggestion > > or concern. Thanks > > From what I understand from your description, I think it would better > fit in drivers/iommu. Another option is drivers/memory, which I think > is where the respective Tegra driver ended up. > Note that this is not the IOMMU driver. M4U is the IOMMU unit. The SMI unit is more of a bridge control for the internal buses where you can control various properties for the masters on the bus. One notable property (and why this driver is part of the IOMMU series) is the control weather a master should go through the M4U unit for translation or bypass it and talk directly to external memory controller. Regards, Lucas -- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ |