From mboxrd@z Thu Jan  1 00:00:00 1970
From: leilk.liu@mediatek.com (leilk liu)
Date: Fri, 15 May 2015 15:38:42 +0800
Subject: [PATCH 2/3] spi: mediatek: Add spi bus for Mediatek MT8173
In-Reply-To: <20150512160540.GB3066@sirena.org.uk>
References: <1431075343-7887-1-git-send-email-leilk.liu@mediatek.com>
 <1431075343-7887-3-git-send-email-leilk.liu@mediatek.com>
 <20150508175306.GG2761@sirena.org.uk> <1431434356.2128.9.camel@mhfsdcap03>
 <20150512160540.GB3066@sirena.org.uk>
Message-ID: <1431675522.2128.13.camel@mhfsdcap03>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Dear Mark,

Thanks for your reply.

On Tue, 2015-05-12 at 17:05 +0100, Mark Brown wrote:
> On Tue, May 12, 2015 at 08:39:16PM +0800, leilk liu wrote:
> > On Fri, 2015-05-08 at 18:53 +0100, Mark Brown wrote:
> > > On Fri, May 08, 2015 at 04:55:42PM +0800, leilk.liu at mediatek.com wrote:
> 
> > Could you tell me more details about "You should also be using the core
> > helpers for DMA mapping"?
> 
> Implement can_dma() - look for drivers providing that for examples.
> 

MTK spi hardware uses the dmaengine in spi controller. According to
datasheet, spi driver just need to enable dma register bit and write a
physical address to relevant dma address register, so I think it may be
complex while the driver supports can_dma.

> > > > +static const struct of_device_id mtk_spi_of_match[] = {
> > > > +	{ .compatible = "mediatek,mt6589-spi", .data = (void *)COMPAT_MT6589},
> > > > +	{ .compatible = "mediatek,mt8173-spi", .data = (void *)COMPAT_MT8173},
> > > > +	{}
> > > > +};
> > > > +MODULE_DEVICE_TABLE(of, mtk_spi_of_match);
> 
> > > There were three compatible strings listed in the DT binding but only
> > > two here.
> 
> > MT6589 and MT8135 is compatible; 
> > For MT8135 IC, it can use the follow way in dts to probe:
> >   compatible = "mediatek,mt8135-spi", 
> > 	       "mediatek,mt6589-spi";
> 
> > And I test it's ok on MT8135 platform. So I add struct of_device_id
> > mtk_spi_of_match like this in spi driver code.
> 
> You should list all the compatibles documented in the binding here, if
> some of them are the same just have them map to a single constant.