From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756708AbbLQQE6 (ORCPT ); Thu, 17 Dec 2015 11:04:58 -0500 Received: from unicorn.mansr.com ([81.2.72.234]:46015 "EHLO unicorn.mansr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755010AbbLQQE5 convert rfc822-to-8bit (ORCPT ); Thu, 17 Dec 2015 11:04:57 -0500 From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Andy Shevchenko Cc: Tejun Heo , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] ata: sata_dwc_460ex: use "dmas" DT property to find dma channel References: <1450221935-6034-1-git-send-email-mans@mansr.com> <1450364395.30729.136.camel@linux.intel.com> <1450367702.30729.146.camel@linux.intel.com> Date: Thu, 17 Dec 2015 16:04:56 +0000 In-Reply-To: <1450367702.30729.146.camel@linux.intel.com> (Andy Shevchenko's message of "Thu, 17 Dec 2015 17:55:02 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andy Shevchenko writes: > On Thu, 2015-12-17 at 15:13 +0000, Måns Rullgård wrote: >> Andy Shevchenko writes: >> >> > On Tue, 2015-12-15 at 23:34 +0000, Måns Rullgård wrote: >> > > Mans Rullgard writes: >> > > >> > > > Currently this driver only works with a DesignWare DMA engine >> > > > which it registers manually using the second "reg" address >> > > > range and interrupt number from the DT node. >> > > > >> > > > This patch makes the driver instead use the "dmas" property if >> > > > present, otherwise optionally falling back on the old way so >> > > > existing device trees can continue to work. >> > > > >> > > > With this change, there is no longer any reason to depend on >> > > > the 460EX machine type so drop that from Kconfig. >> > > > >> > > > Signed-off-by: Mans Rullgard >> > > > --- >> > > >  drivers/ata/Kconfig          |  10 ++- >> > > >  drivers/ata/sata_dwc_460ex.c | 192 >> > > > +++++++++++++++++++++++++++-- >> > > > -------------- >> > > >  2 files changed, 131 insertions(+), 71 deletions(-) >> > > >> > > The corresponding patch for the canyonlands devicetree looks >> > > something >> > > like this.  I don't have any such hardware or even a manual, so I >> > > don't >> > > know what values to use for the various required DT properties of >> > > the >> > > DMA controller node, nor can I test it.  The SATA driver works >> > > with a >> > > different DMA controller on a Sigma Designs chip. >> > > >> > > diff --git a/arch/powerpc/boot/dts/canyonlands.dts >> > > b/arch/powerpc/boot/dts/canyonlands.dts >> > > index 3dc75de..959f36e 100644 >> > > --- a/arch/powerpc/boot/dts/canyonlands.dts >> > > +++ b/arch/powerpc/boot/dts/canyonlands.dts >> > > @@ -190,12 +190,22 @@ >> > >    /* DMA */ 0x2 &UIC0 0xc >> > > 0x4>; >> > >   }; >> > >   >> > > + DMA0: dma@bffd0800 { >> > > + compatible = "snps,dma-spear1340"; >> > > + reg = <4 0xbffd0800 0x400>; >> > > + interrupt-parent = <&UIC3>; >> > > + interrupts = <0x5 0x4>; >> > > + #dma-cells = <3>; >> > > + /* required properties here */ >> > >> > You have to move the master assignments and other custom dw_dmac >> > properties. Maybe at some point I will fix that in dw/platform.c. >> > >> > > + }; >> >> The current sata_dwc driver calls dw_dma_probe() with null pdata >> which causes the dw_dma driver to auto-detect most parameters.  It >> looks like simply omitting those properties here results in the same >> thing, although in this case dw_dma_parse_dt() leaves a >> devm-allocated pdata struct adrift.  Deferring the allocation of that >> and changing the DT binding doc to make these properties optional for >> auto-detect-capable hardware should just work. > > Yeah, I would like to allow autoconfiguration in case of DT as well and > translate it to use unified device property API. > >> Something like this: > > If it works for you, please, submit as a patch. Thanks. I can't test it since I have no such hardware. -- Måns Rullgård