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=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 3544BC4338F for ; Wed, 28 Jul 2021 11:05:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0DE9060F46 for ; Wed, 28 Jul 2021 11:05:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235963AbhG1LFQ (ORCPT ); Wed, 28 Jul 2021 07:05:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:58120 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235781AbhG1LFO (ORCPT ); Wed, 28 Jul 2021 07:05:14 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4D9D760F46; Wed, 28 Jul 2021 11:05:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627470313; bh=mFVcar/DSTt8tbbW79iYEF1zXXU/0XiVA1P3oMx5bXQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=DAe+8a6JljBbypytw+Fw7gTxuu9D9Go7TAoUdt9kTrBWbeibEGRsSQKRgaEHWQ5hF Jj6qFAnlrhwoGkkkrKS1Sg8LBndJ9RPacupMrLflze78vO+6rRfTI9j6pjPK9savEk HDKUwmPo9Sss61Vw75mAHMuJvODupeHf4jnUnkxmTOveaD4JA47P4b+CQtZW3lCPCd 8iaNDzqpJNW78hbH/iO0dPaeSkIW3DfCvZLtTiJF39bijl+42Ktt+ls5EyoocZDt51 y3rbaIP6xPgFtkBlDqiFKd3SfAJ6l9dFQdnXTIgQYTYffmSTaVGE/6dmQeX+G6he0H WDWzkuUArEUbw== Date: Wed, 28 Jul 2021 16:35:07 +0530 From: Vinod Koul To: Biju Das Cc: Prabhakar Mahadev Lad , Chris Paterson , Geert Uytterhoeven , "dmaengine@vger.kernel.org" , Chris Brandt , "linux-renesas-soc@vger.kernel.org" Subject: Re: [PATCH v4 2/4] drivers: dma: sh: Add DMAC driver for RZ/G2L SoC Message-ID: References: <20210719092535.4474-1-biju.das.jz@bp.renesas.com> <20210719092535.4474-3-biju.das.jz@bp.renesas.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org Hi Biju, On 28-07-21, 07:00, Biju Das wrote: > > > > Sorry I dont like passing numbers like this :( > > > > Can you explain what is meant by each of the above values and looks like > > some (if not all) can be derived (slave config as well as transaction > > properties) > > > 0x11228 (Tx) > 0x11220 (Rx) > > BIT 22:- TM :- Transfer Mode What are the values, here it seems 0 > Bits 16->19 :- DDS(Destination Data Size) --> 0x0001 (16 bits) > Bits 12->15 :- SDS(Source Data size)--> 0x0001 (16 bits) use src_addr_width/dst_addr_width ..? > Bit 11 :- Reserved > Bits 8->10 :- Ack mode --> 0x010 (Bus cycle mode) What does this mean? > Bit 7 :- Reserved > Bit 6:- LVL --> Level -->0 (DMA request based on edge of thesignal) > Bit 5:- HIEN --> High Enable --> 1 (Detects a DMA request on rising edge of the signal) > Bit 4:- LOEN --> Low Enable -->0 (Does not DMA request on falling edge of the signal) > Bit 3:- REQD --> Request Direction ->1 (DMAREQ is Destination) how and what decides these values It is now hardcoded in the client driver, can we do that in dma driver instead? While deriving most of the values? -- ~Vinod