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[209.132.180.67]) by mx.google.com with ESMTP id r28-v6si16027162pfb.65.2018.07.09.10.05.08; Mon, 09 Jul 2018 10:05:23 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=AzexXNFj; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933617AbeGIREK (ORCPT + 99 others); Mon, 9 Jul 2018 13:04:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:52258 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933287AbeGIREI (ORCPT ); Mon, 9 Jul 2018 13:04:08 -0400 Received: from localhost (unknown [106.201.46.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 08BEA208A2; Mon, 9 Jul 2018 17:04:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1531155847; bh=FWVzE+ZhWgS1LzSatExJjSjS4NiclU90mwFI0yMlPF8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=AzexXNFjFQlUVcS9nREVhyu5mm2Qy8vc6/AI6y1j2JuKddFdXZGvMSJdLPPfLq6bH FR4G/VRmyTXnT8A9bdQsZ2010n3DmFVCpeo9lQga16jyZqIuGJJvTPu0Fd8O70VYKi 9vDy4fwhH1bmeAFMRwDmlx0roSuSodwunD1tZMWE= Date: Mon, 9 Jul 2018 22:33:59 +0530 From: Vinod To: Paul Cercueil 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 Subject: Re: [PATCH 02/14] dmaengine: dma-jz4780: Separate chan/ctrl registers Message-ID: <20180709170359.GI22377@vkoul-mobl> References: <20180703123214.23090-1-paul@crapouillou.net> <20180703123214.23090-3-paul@crapouillou.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180703123214.23090-3-paul@crapouillou.net> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03-07-18, 14:32, Paul Cercueil wrote: > The register area of the JZ4780 DMA core can be split into different > sections for different purposes: > > * one set of registers is used to perform actions at the DMA core level, > that will generally affect all channels; > > * one set of registers per DMA channel, to perform actions at the DMA > channel level, that will only affect the channel in question. > > The problem rises when trying to support new versions of the JZ47xx > Ingenic SoC. For instance, the JZ4770 has two DMA cores, each one > with six DMA channels, and the register sets are interleaved: > > > By using one memory resource for the channel-specific registers and > one memory resource for the core-specific registers, we can support > the JZ4770, by initializing the driver once per DMA core with different > addresses. > > Signed-off-by: Paul Cercueil > --- > .../devicetree/bindings/dma/jz4780-dma.txt | 6 +- Pls move to separate patch. > drivers/dma/dma-jz4780.c | 106 +++++++++++------- > 2 files changed, 69 insertions(+), 43 deletions(-) > > diff --git a/Documentation/devicetree/bindings/dma/jz4780-dma.txt b/Documentation/devicetree/bindings/dma/jz4780-dma.txt > index f25feee62b15..f9b1864f5b77 100644 > --- a/Documentation/devicetree/bindings/dma/jz4780-dma.txt > +++ b/Documentation/devicetree/bindings/dma/jz4780-dma.txt > @@ -3,7 +3,8 @@ > Required properties: > > - compatible: Should be "ingenic,jz4780-dma" > -- reg: Should contain the DMA controller registers location and length. > +- reg: Should contain the DMA channel registers location and length, followed > + by the DMA controller registers location and length. > - interrupts: Should contain the interrupt specifier of the DMA controller. > - interrupt-parent: Should be the phandle of the interrupt controller that > - clocks: Should contain a clock specifier for the JZ4780 PDMA clock. > @@ -22,7 +23,8 @@ Example: > > dma: dma@13420000 { > compatible = "ingenic,jz4780-dma"; > - reg = <0x13420000 0x10000>; > + reg = <0x13420000 0x400 > + 0x13421000 0x40>; Second should be optional or we break platform which may not have updated DT.. > - jzdma->base = devm_ioremap_resource(dev, res); > - if (IS_ERR(jzdma->base)) > - return PTR_ERR(jzdma->base); > + jzdma->chn_base = devm_ioremap_resource(dev, res); > + if (IS_ERR(jzdma->chn_base)) > + return PTR_ERR(jzdma->chn_base); > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); > + if (!res) { > + dev_err(dev, "failed to get I/O memory\n"); > + return -EINVAL; > + } okay and this breaks if you happen to get probed on older DT. I think DT is treated as ABI so you need to continue support older method while finding if DT has split resources -- ~Vinod