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=-0.9 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 64FA9C43A1D for ; Wed, 11 Jul 2018 23:14:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1D63220C0E for ; Wed, 11 Jul 2018 23:14:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=crapouillou.net header.i=@crapouillou.net header.b="AHpNzfXC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1D63220C0E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=crapouillou.net Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390760AbeGKXUk (ORCPT ); Wed, 11 Jul 2018 19:20:40 -0400 Received: from outils.crapouillou.net ([89.234.176.41]:46398 "EHLO crapouillou.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732195AbeGKXUj (ORCPT ); Wed, 11 Jul 2018 19:20:39 -0400 Date: Thu, 12 Jul 2018 01:13:55 +0200 From: Paul Cercueil Subject: Re: [PATCH 06/14] dmaengine: dma-jz4780: Add support for the JZ4725B SoC To: Vinod Cc: Rob Herring , Mark Rutland , Ralf Baechle , Paul Burton , James Hogan , Zubair Lutfullah Kakakhel , Mathieu Malaterre , Daniel Silsby , dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@linux-mips.org Message-Id: <1531350835.2021.1@smtp.crapouillou.net> In-Reply-To: <20180711121818.GT3219@vkoul-mobl> References: <20180703123214.23090-1-paul@crapouillou.net> <20180703123214.23090-7-paul@crapouillou.net> <20180709171458.GL22377@vkoul-mobl> <1531237502.17118.3@crapouillou.net> <20180711121818.GT3219@vkoul-mobl> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1531350841; bh=3IQoraoleuUeQ63djCofqFXR2MJYkQlo2+8Sv8HIKRg=; h=Date:From:Subject:To:Cc:Message-Id:In-Reply-To:References:MIME-Version:Content-Type:Content-Transfer-Encoding; b=AHpNzfXC8Qk059jiK9VSb4qqtVv9cn4PV/OiNjjMZtH+MgFWRdRovTGD3EIgXI5RfqjWmjsEeSHeg+b7s3fgoOb49kJLnM3Iw2Q/22ADfMKPTcUvUWPSTGKTfEmuvep1GFHW3Y6HzrSLPLVVJbICtOjw/ymL4G/Q8JZedd4WmDw= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le mer. 11 juil. 2018 =E0 14:18, Vinod a =E9crit : > On 10-07-18, 17:45, Paul Cercueil wrote: >>=20 >>=20 >> Le lun. 9 juil. 2018 =E0 19:14, Vinod a =E9crit : >> > On 03-07-18, 14:32, Paul Cercueil wrote: >> > > The JZ4725B has one DMA core starring six DMA channels. >> > > As for the JZ4770, each DMA channel's clock can be enabled with >> > > a register write, the difference here being that once started,=20 >> it >> > > is not possible to turn it off. >> > >> > ok so disable for this, right.. >> > >> > > @@ -204,6 +205,8 @@ static inline void >> > > jz4780_dma_chan_enable(struct jz4780_dma_dev *jzdma, >> > > { >> > > if (jzdma->version =3D=3D ID_JZ4770) >> > > jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DCKES, BIT(chn)); >> > > + else if (jzdma->version =3D=3D ID_JZ4725B) >> > > + jz4780_dma_ctrl_writel(jzdma, JZ_DMA_REG_DCKE, BIT(chn)); >> > >> > but you are writing to a different register here.. >>=20 >> Yes. SoCs >=3D JZ4770 have the DCKE read-only register, and=20 >> DCKES/DCKEC to >> set/clear bits in DCKE. >> On JZ4725B, DCKE is read/write, but the zeros written are ignored=20 >> (at least >> that's what the >> documentation says). >=20 > and that was not documented in the log... so i though it maybe a typo. Right, I will add a comment in-code to explain that it's normal. > -- > ~Vinod Thanks, -Paul =