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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 02EDAC31E4B for ; Fri, 14 Jun 2019 13:21:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE5512133D for ; Fri, 14 Jun 2019 13:21:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560518476; bh=zSqDfvTWi/91oRnFPmD+sDE1OD8meYbhenxAA0rkJpQ=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=soIxvfI0zERmDAxV9elz+fWrEwNpBKHQ9Cce14/CGzSJk9ZR6MopqlbF+gApR21rR V7hbHziD/ZckwNNCvT/dOAiZweW4JbhfgZHWkk4f8Z/o0leJYy5NS8KaCZe1sUABCz mgGUU+AqNDPucareiJWBgSmG0Cw22wWrksxEy9FE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727737AbfFNNVM (ORCPT ); Fri, 14 Jun 2019 09:21:12 -0400 Received: from mail.kernel.org ([198.145.29.99]:57308 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727696AbfFNNVM (ORCPT ); Fri, 14 Jun 2019 09:21:12 -0400 Received: from mail-qt1-f181.google.com (mail-qt1-f181.google.com [209.85.160.181]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7F5F121537; Fri, 14 Jun 2019 13:21:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560518470; bh=zSqDfvTWi/91oRnFPmD+sDE1OD8meYbhenxAA0rkJpQ=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=R/OivYycKXCrR4qbnGPXhaeUCc8L4u/YFYrA52THSyhzc7IZ/wON5glZJ4BYkkz28 cM5y1K7zmj5znbVPQ+rM+TGktxk5HKIq8cBKMnjEirB7nBD5wAU2x7Zo2fEayOuA1b 9uyJnkaPsk0m63CXpFrWN38NQwOUSd8J1wr282ZI= Received: by mail-qt1-f181.google.com with SMTP id a15so2372779qtn.7; Fri, 14 Jun 2019 06:21:10 -0700 (PDT) X-Gm-Message-State: APjAAAWmQDFpaIyIbrVi3zBueyUJigPC0jRCM0qSLAg+bMtNqajvFrQ+ TOOBSy+JbXcLrg6VJoYjF4Tb7ZSgN944/fNT0w== X-Google-Smtp-Source: APXvYqwPY5Ii8d7b9MpE2fLLzqMQruglLqs18oegyUlcZ2uGTJsB4Rwfi7XLE6zjZcAEozwYHNHmqcKgnXfo9XquaAc= X-Received: by 2002:aed:3f10:: with SMTP id p16mr15589221qtf.110.1560518469746; Fri, 14 Jun 2019 06:21:09 -0700 (PDT) MIME-Version: 1.0 References: <20190506123456.6777-1-peter.ujfalusi@ti.com> <20190506123456.6777-10-peter.ujfalusi@ti.com> <20190613181626.GA7039@bogus> In-Reply-To: From: Rob Herring Date: Fri, 14 Jun 2019 07:20:57 -0600 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 09/16] dt-bindings: dma: ti: Add document for K3 UDMA To: Peter Ujfalusi Cc: Vinod , Nishanth Menon , Santosh Shilimkar , Dan Williams , "open list:DMA GENERIC OFFLOAD ENGINE SUBSYSTEM" , "moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE" , devicetree@vger.kernel.org, "linux-kernel@vger.kernel.org" , Grygorii Strashko , Lokesh Vutla , Tero Kristo , Tony Lindgren Content-Type: text/plain; charset="UTF-8" Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On Thu, Jun 13, 2019 at 2:33 PM Peter Ujfalusi wrote: > > Rob, > > On 13/06/2019 21.16, Rob Herring wrote: > >> +Remote PSI-L endpoint > >> + > >> +Required properties: > >> +-------------------- > >> +- ti,psil-base: PSI-L thread ID base of the endpoint > >> + > >> +Within the PSI-L endpoint node thread configuration subnodes must present with: > >> +ti,psil-configX naming convention, where X is the thread ID offset. > > > > Don't use vendor prefixes on node names. > > OK. > > >> + > >> +Configuration node Required properties: > >> +-------------------- > >> +- linux,udma-mode: Channel mode, can be: > >> + - UDMA_PKT_MODE: for Packet mode channels (peripherals) > >> + - UDMA_TR_MODE: for Third-Party mode > > > > This is hardly a common linux thing. What determines the value here. > > Unfortunately it is. No, it's a feature of your h/w and in no way is something linux defined which is the point of 'linux' prefix. > Each channel can be configured to Packet or TR mode. For some > peripherals it is true that they only support packet mode, these are the > newer PSI-L native peripherals. > For these channels a udma-mode property would be correct. > > But we have legacy peripherals as well and they are serviced by PDMA > (which is a native peripheral designed to talk to the given legacy IP). > We can use either packet or TR mode in UDMAP to talk to PDMAs, it is in > most cases clear what to use, but for example for audio (McASP) channels > Linux is using TR channel because we need cyclic DMA while for example > RTOS is using Packet mode as it fits their needs better. > > Here I need to prefix the udma-mode with linux as the mode is used by > Linux, but other OS might opt to use different channel mode. So you'd need ,udma-mode? That doesn't work... If the setting is per OS, then it belongs in the OS because the same dtb should work across OS's. > The reason why this needs to be in the DT is that when the channel is > requested we need to configure the mode and it can not be swapped > runtime easily between Packet and TR mode. So when the client makes the channel request, why doesn't it specify the mode? Rob