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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BEB5BE7716E for ; Thu, 5 Dec 2024 18:13:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:CC:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=0JnhlkT+86La11TTNlcsIBnITx15puWkRfuAEfVFs/I=; b=x9vFTqPJC1dg9i6EQXSl/piokB +lqus1SibDgzSxzXDhdYJXQehNhv7XodV5OpW9zbuWXX5DHVcQ8XBYsv9qrTqNxQPYL5M111RlbAI LU5dXZhymdidiO/h7Y7D9WQAjnQpW86mas/MKzkAuUSHVh0L/cDkWsjZ6GGBugt2i8lUxgfpeJeHp 8hcu15oHjmN7SyEwwYIz6NqjAYvxDhz98E7GdJ6zNEM29pr47LeKtoGyNizL0+SRsLQfrkFfvIG5q 0NM8fAgWZqJ3PgLOBxJnK8Ccdhjpueo+5+wdLgpWzTeC6HHFjIFf9zm3CFBSd723kLVCrbLzX6J9L 6xp/Yp/Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tJGLr-0000000H5Kv-2iIq; Thu, 05 Dec 2024 18:13:23 +0000 Received: from mx08-00178001.pphosted.com ([91.207.212.93] helo=mx07-00178001.pphosted.com) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tJGFY-0000000H43K-0k2b for linux-arm-kernel@lists.infradead.org; Thu, 05 Dec 2024 18:06:53 +0000 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4B5G4HBk019839; Thu, 5 Dec 2024 19:06:41 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=selector1; bh= 0JnhlkT+86La11TTNlcsIBnITx15puWkRfuAEfVFs/I=; b=G5nZotVwCco3qDt6 3Cfl9zzcdOOU/Uml9SI6+Fw7T1PoD+tUBhguTxQqOSCFrZl4j6YaIKRFFUSUsiU6 Z6iGESJ+JSmq9RTT1t3VA0DFwQJ/Tm6hJnSkA69uFFtZMyJqrtuK7FELR3ZTBTrK S3s21nK0xDo+JIR2VMGa8d3iOmV8DY445J5iDbsysAGTRpdMXryOLz5RnGT76Ar8 6seG7FYjzqNSVuXp9r0ifTCCPcdi+nC9M07N/9QOT0Rzif4ecraID5m2AoIhGBS1 14KhdkgN7fTr44dxms2+AewXh3kKtod4nNUch5Ho3mf5FBvTX1vRFu9/CPIl0cGW ZAkXGQ== Received: from beta.dmz-ap.st.com (beta.dmz-ap.st.com [138.198.100.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 437rq9gssg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 05 Dec 2024 19:06:40 +0100 (CET) Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-ap.st.com (STMicroelectronics) with ESMTP id 69D6840049; Thu, 5 Dec 2024 19:05:36 +0100 (CET) Received: from Webmail-eu.st.com (shfdag1node3.st.com [10.75.129.71]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id 52D9D267F27; Thu, 5 Dec 2024 19:04:41 +0100 (CET) Received: from [10.252.15.31] (10.252.15.31) by SHFDAG1NODE3.st.com (10.75.129.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.37; Thu, 5 Dec 2024 19:04:40 +0100 Message-ID: Date: Thu, 5 Dec 2024 19:04:39 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v1] dt-bindings: dma: st-stm32-dmamux: Add description for dma-cell values To: Krzysztof Kozlowski , Ken Sloat CC: , , , , , , , , , , References: <28d1bb46-ab18-42da-9ca2-ff498c888d66@kernel.org> Content-Language: en-US From: Amelie Delaunay In-Reply-To: <28d1bb46-ab18-42da-9ca2-ff498c888d66@kernel.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.252.15.31] X-ClientProxiedBy: EQNCAS1NODE4.st.com (10.75.129.82) To SHFDAG1NODE3.st.com (10.75.129.71) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241205_100652_664222_B5996737 X-CRM114-Status: GOOD ( 14.37 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 12/5/24 17:09, Krzysztof Kozlowski wrote: > On 05/12/2024 17:07, Ken Sloat wrote: >>>> + 1. The mux input number/line for the request >>>> + 2. Bitfield representing DMA channel configuration that is passed >>>> + to the real DMA controller >>>> + 3. Bitfield representing device dependent DMA features passed to >>>> + the real DMA controller >>>> + >>>> + For bitfield definitions of cells 2 and 3, see the associated >>>> + bindings doc for the actual DMA controller the mux is connected >>> >>> This does not sound right. This is the binding for DMA controller, so >>> you are saying "please look at itself". I suggest to drop this as well. >>> >> >> While logically it is the DMA controller, this doc is specifically for >> the mux - the DMA controller has its own driver and binding docs in >> Documentation/devicetree/bindings/dma/stm32/st,stm32-dma.yaml >> >> I can reference st,stm32-dma.yaml directly, but I was unsure if this >> mux IP was used with another DMA controller from ST on a different >> SoC. >> >> What do you suggest here? > > Thanks for explanation, I think it is fine. > > Best regards, > Krzysztof This description was lost when STM32 DMAMUX binding txt file was converted to yaml: 0b7c446fa9f7 ("dt-bindings: dma: Convert stm32 DMAMUX bindings to json-schema") -- #dma-cells: Should be set to <3>. - First parameter is request line number. - Second is DMA channel configuration - Third is Fifo threshold - For more details about the three cells, please see - stm32-dma.txt documentation binding file stm32-dmamux exclusively muxes stm32-dma channels. It is not used with other ST DMA controllers (STM32 MDMA, STM32 DMA3). So it is fine to refer to st,stm32-dma.yaml. Regards, Amelie