From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Brugger Subject: Re: [RESEND PATCH v3 1/2] dt-bindings: i2c: Add Mediatek MT2701 i2c binding Date: Wed, 10 May 2017 12:35:42 +0200 Message-ID: <4111ffc2-0a25-0811-fbd3-401649431315@gmail.com> References: <1489029185-21447-1-git-send-email-jun.gao@mediatek.com> <1489029185-21447-2-git-send-email-jun.gao@mediatek.com> <20170322090543.sxacnddn2o7stjnq@ninjato> <1490694612.18582.11.camel@mhfsdcap03> <20170328192258.GA4525@katana> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170328192258.GA4525@katana> Content-Language: en-US Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wolfram Sang , Jun Gao Cc: robh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, srv_heupstream-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, yingjoe.chen-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org List-Id: linux-i2c@vger.kernel.org On 28/03/17 21:22, Wolfram Sang wrote: > On Tue, Mar 28, 2017 at 05:50:12PM +0800, Jun Gao wrote: >> On Wed, 2017-03-22 at 10:05 +0100, Wolfram Sang wrote: >>> On Thu, Mar 09, 2017 at 11:13:04AM +0800, Jun Gao wrote: >>>> From: Jun Gao >>>> >>>> Add MT2701 i2c binding to i2c-mt6577.txt and there is no need to >>>> modify i2c driver. >>>> >>>> Signed-off-by: Jun Gao >>> >>> There is still the issue which Matthias Brugger pointed out on January, >>> 24th: you need to describe the fallback compatibles. >>> >> >> IMHO the value under compatible are just inputs which can be accepted. >> It's little strange to add fallback information in binding. Some other >> bindings do not describe so detailedly. >> Is it OK to make binding as minimum standard? >> If we describe it very detailedly, we will have to modify binding if >> there are some changes for mt2701. > > My reading of the below is that I could simply use "mediatek,mt2701-i2c" > as compatible and things will work. But it won't, we don't have that in > the driver IIRC. So, we need a fallback for that to work. > >> Rob, could you give some suggestions? Thanks! > > Would be welcome, yes. I lost track what the preferred solution is. > We will need to define the fallback binding for each SoC. As example take the rockchip mmc: http://elixir.free-electrons.com/linux/latest/source/Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt Regards, Matthias >> >>>> --- >>>> .../devicetree/bindings/i2c/i2c-mt6577.txt | 11 ++++++----- >>>> 1 file changed, 6 insertions(+), 5 deletions(-) >>>> >>>> diff --git a/Documentation/devicetree/bindings/i2c/i2c-mt6577.txt b/Documentation/devicetree/bindings/i2c/i2c-mt6577.txt >>>> index 0ce6fa3..27dbbf9 100644 >>>> --- a/Documentation/devicetree/bindings/i2c/i2c-mt6577.txt >>>> +++ b/Documentation/devicetree/bindings/i2c/i2c-mt6577.txt >>>> @@ -4,11 +4,12 @@ The Mediatek's I2C controller is used to interface with I2C devices. >>>> >>>> Required properties: >>>> - compatible: value should be either of the following. >>>> - (a) "mediatek,mt6577-i2c", for i2c compatible with mt6577 i2c. >>>> - (b) "mediatek,mt6589-i2c", for i2c compatible with mt6589 i2c. >>>> - (c) "mediatek,mt8127-i2c", for i2c compatible with mt8127 i2c. >>>> - (d) "mediatek,mt8135-i2c", for i2c compatible with mt8135 i2c. >>>> - (e) "mediatek,mt8173-i2c", for i2c compatible with mt8173 i2c. >>>> + "mediatek,mt2701-i2c" >>>> + "mediatek,mt6577-i2c" >>>> + "mediatek,mt6589-i2c" >>>> + "mediatek,mt8127-i2c" >>>> + "mediatek,mt8135-i2c" >>>> + "mediatek,mt8173-i2c" >>>> - reg: physical base address of the controller and dma base, length of memory >>>> mapped region. >>>> - interrupts: interrupt number to the cpu. >>>> -- >>>> 1.7.9.5 >>>> >> >> -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html