From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751188AbdAMQoT (ORCPT ); Fri, 13 Jan 2017 11:44:19 -0500 Received: from mail-wm0-f66.google.com ([74.125.82.66]:36245 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750985AbdAMQoR (ORCPT ); Fri, 13 Jan 2017 11:44:17 -0500 Subject: Re: [PATCH v1 2/2] arm: dts: mt2701: add nor flash node To: Boris Brezillon References: <1484291609-20195-1-git-send-email-guochun.mao@mediatek.com> <1484291609-20195-3-git-send-email-guochun.mao@mediatek.com> <20170113151747.6bc85245@bbrezillon> <20170113172825.75d545a3@bbrezillon> Cc: Matthias Brugger , Guochun Mao , David Woodhouse , Brian Norris , Richard Weinberger , Cyrille Pitchen , Rob Herring , Mark Rutland , Russell King , linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org From: Marek Vasut Message-ID: <86c997be-f500-eaa1-3ba5-d21cff6223b7@gmail.com> Date: Fri, 13 Jan 2017 17:44:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.4.0 MIME-Version: 1.0 In-Reply-To: <20170113172825.75d545a3@bbrezillon> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/13/2017 05:28 PM, Boris Brezillon wrote: > On Fri, 13 Jan 2017 17:13:55 +0100 > Marek Vasut wrote: > >> On 01/13/2017 04:12 PM, Matthias Brugger wrote: >>> >>> >>> On 13/01/17 15:17, Boris Brezillon wrote: >>>> On Fri, 13 Jan 2017 15:13:29 +0800 >>>> Guochun Mao wrote: >>>> >>>>> Add Mediatek nor flash node. >>>>> >>>>> Signed-off-by: Guochun Mao >>>>> --- >>>>> arch/arm/boot/dts/mt2701-evb.dts | 25 +++++++++++++++++++++++++ >>>>> arch/arm/boot/dts/mt2701.dtsi | 12 ++++++++++++ >>>>> 2 files changed, 37 insertions(+) >>>>> >>>>> diff --git a/arch/arm/boot/dts/mt2701-evb.dts >>>>> b/arch/arm/boot/dts/mt2701-evb.dts >>>>> index 082ca88..85e5ae8 100644 >>>>> --- a/arch/arm/boot/dts/mt2701-evb.dts >>>>> +++ b/arch/arm/boot/dts/mt2701-evb.dts >>>>> @@ -24,6 +24,31 @@ >>>>> }; >>>>> }; >>>>> >>>>> +&nor_flash { >>>>> + pinctrl-names = "default"; >>>>> + pinctrl-0 = <&nor_pins_default>; >>>>> + status = "okay"; >>>>> + flash@0 { >>>>> + compatible = "jedec,spi-nor"; >>>>> + reg = <0>; >>>>> + }; >>>>> +}; >>>>> + >>>>> +&pio { >>>>> + nor_pins_default: nor { >>>>> + pins1 { >>>>> + pinmux = , >>>>> + , >>>>> + , >>>>> + , >>>>> + , >>>>> + ; >>>>> + drive-strength = ; >>>>> + bias-pull-up; >>>>> + }; >>>>> + }; >>>>> +}; >>>>> + >>>>> &uart0 { >>>>> status = "okay"; >>>>> }; >>>>> diff --git a/arch/arm/boot/dts/mt2701.dtsi >>>>> b/arch/arm/boot/dts/mt2701.dtsi >>>>> index bdf8954..1eefce4 100644 >>>>> --- a/arch/arm/boot/dts/mt2701.dtsi >>>>> +++ b/arch/arm/boot/dts/mt2701.dtsi >>>>> @@ -227,6 +227,18 @@ >>>>> status = "disabled"; >>>>> }; >>>>> >>>>> + nor_flash: spi@11014000 { >>>>> + compatible = "mediatek,mt2701-nor", >>>>> + "mediatek,mt8173-nor"; >>>> >>>> Why define both here? Is "mediatek,mt8173-nor" really providing a >>>> subset of the features supported by "mediatek,mt2701-nor"? >>>> >>> >>> I think even if the ip block is the same, we should provide both >>> bindings, just in case in the future we find out that mt2701 has some >>> hidden bug, feature or bug-feature. This way even if we update the >>> driver, we stay compatible with older device tree blobs in the wild. >>> >>> We can drop the mt2701-nor in the bindings definition if you want. > > Oh, sorry, I misunderstood. What I meant is that if you want to > list/support all possible compatibles, maybe you should just put one > compatible in your DT and patch your driver (+ binding doc) to define > all of them. Uh, what ? I lost you here :-) >> This exactly. We should have a DT compat in the form: >> compatible = "vendor,-block", "vendor,-block"; >> Then if we find a problem in the future, we can match on the >> "vendor,-block" and still support the old DTs. > > Not sure it's only in term of whose IP appeared first. My understanding > is that it's a way to provide inheritance. For example: > > ",", ","; > > or > > ",",","; > > BTW, which one is the oldest between mt8173 and mt2701? :-) And that's another thing and I agree with you, but I don't think that's what we're discussing in this thread. But (!), OT, I think we should codify the rules in Documentation/ . This discussion came up multiple times recently. And my question still stands, what do we put into the DT here, IMO compatible = "mediatek,mt2701-nor", "mediatek,mt8173-nor"; and what goes into the binding document ? I guess both too ? -- Best regards, Marek Vasut From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: Re: [PATCH v1 2/2] arm: dts: mt2701: add nor flash node Date: Fri, 13 Jan 2017 17:44:12 +0100 Message-ID: <86c997be-f500-eaa1-3ba5-d21cff6223b7@gmail.com> References: <1484291609-20195-1-git-send-email-guochun.mao@mediatek.com> <1484291609-20195-3-git-send-email-guochun.mao@mediatek.com> <20170113151747.6bc85245@bbrezillon> <20170113172825.75d545a3@bbrezillon> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170113172825.75d545a3@bbrezillon> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Boris Brezillon Cc: Matthias Brugger , Guochun Mao , David Woodhouse , Brian Norris , Richard Weinberger , Cyrille Pitchen , Rob Herring , Mark Rutland , Russell King , linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 01/13/2017 05:28 PM, Boris Brezillon wrote: > On Fri, 13 Jan 2017 17:13:55 +0100 > Marek Vasut wrote: > >> On 01/13/2017 04:12 PM, Matthias Brugger wrote: >>> >>> >>> On 13/01/17 15:17, Boris Brezillon wrote: >>>> On Fri, 13 Jan 2017 15:13:29 +0800 >>>> Guochun Mao wrote: >>>> >>>>> Add Mediatek nor flash node. >>>>> >>>>> Signed-off-by: Guochun Mao >>>>> --- >>>>> arch/arm/boot/dts/mt2701-evb.dts | 25 +++++++++++++++++++++++++ >>>>> arch/arm/boot/dts/mt2701.dtsi | 12 ++++++++++++ >>>>> 2 files changed, 37 insertions(+) >>>>> >>>>> diff --git a/arch/arm/boot/dts/mt2701-evb.dts >>>>> b/arch/arm/boot/dts/mt2701-evb.dts >>>>> index 082ca88..85e5ae8 100644 >>>>> --- a/arch/arm/boot/dts/mt2701-evb.dts >>>>> +++ b/arch/arm/boot/dts/mt2701-evb.dts >>>>> @@ -24,6 +24,31 @@ >>>>> }; >>>>> }; >>>>> >>>>> +&nor_flash { >>>>> + pinctrl-names = "default"; >>>>> + pinctrl-0 = <&nor_pins_default>; >>>>> + status = "okay"; >>>>> + flash@0 { >>>>> + compatible = "jedec,spi-nor"; >>>>> + reg = <0>; >>>>> + }; >>>>> +}; >>>>> + >>>>> +&pio { >>>>> + nor_pins_default: nor { >>>>> + pins1 { >>>>> + pinmux = , >>>>> + , >>>>> + , >>>>> + , >>>>> + , >>>>> + ; >>>>> + drive-strength = ; >>>>> + bias-pull-up; >>>>> + }; >>>>> + }; >>>>> +}; >>>>> + >>>>> &uart0 { >>>>> status = "okay"; >>>>> }; >>>>> diff --git a/arch/arm/boot/dts/mt2701.dtsi >>>>> b/arch/arm/boot/dts/mt2701.dtsi >>>>> index bdf8954..1eefce4 100644 >>>>> --- a/arch/arm/boot/dts/mt2701.dtsi >>>>> +++ b/arch/arm/boot/dts/mt2701.dtsi >>>>> @@ -227,6 +227,18 @@ >>>>> status = "disabled"; >>>>> }; >>>>> >>>>> + nor_flash: spi@11014000 { >>>>> + compatible = "mediatek,mt2701-nor", >>>>> + "mediatek,mt8173-nor"; >>>> >>>> Why define both here? Is "mediatek,mt8173-nor" really providing a >>>> subset of the features supported by "mediatek,mt2701-nor"? >>>> >>> >>> I think even if the ip block is the same, we should provide both >>> bindings, just in case in the future we find out that mt2701 has some >>> hidden bug, feature or bug-feature. This way even if we update the >>> driver, we stay compatible with older device tree blobs in the wild. >>> >>> We can drop the mt2701-nor in the bindings definition if you want. > > Oh, sorry, I misunderstood. What I meant is that if you want to > list/support all possible compatibles, maybe you should just put one > compatible in your DT and patch your driver (+ binding doc) to define > all of them. Uh, what ? I lost you here :-) >> This exactly. We should have a DT compat in the form: >> compatible = "vendor,-block", "vendor,-block"; >> Then if we find a problem in the future, we can match on the >> "vendor,-block" and still support the old DTs. > > Not sure it's only in term of whose IP appeared first. My understanding > is that it's a way to provide inheritance. For example: > > ",", ","; > > or > > ",",","; > > BTW, which one is the oldest between mt8173 and mt2701? :-) And that's another thing and I agree with you, but I don't think that's what we're discussing in this thread. But (!), OT, I think we should codify the rules in Documentation/ . This discussion came up multiple times recently. And my question still stands, what do we put into the DT here, IMO compatible = "mediatek,mt2701-nor", "mediatek,mt8173-nor"; and what goes into the binding document ? I guess both too ? -- Best regards, Marek Vasut -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: marek.vasut@gmail.com (Marek Vasut) Date: Fri, 13 Jan 2017 17:44:12 +0100 Subject: [PATCH v1 2/2] arm: dts: mt2701: add nor flash node In-Reply-To: <20170113172825.75d545a3@bbrezillon> References: <1484291609-20195-1-git-send-email-guochun.mao@mediatek.com> <1484291609-20195-3-git-send-email-guochun.mao@mediatek.com> <20170113151747.6bc85245@bbrezillon> <20170113172825.75d545a3@bbrezillon> Message-ID: <86c997be-f500-eaa1-3ba5-d21cff6223b7@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 01/13/2017 05:28 PM, Boris Brezillon wrote: > On Fri, 13 Jan 2017 17:13:55 +0100 > Marek Vasut wrote: > >> On 01/13/2017 04:12 PM, Matthias Brugger wrote: >>> >>> >>> On 13/01/17 15:17, Boris Brezillon wrote: >>>> On Fri, 13 Jan 2017 15:13:29 +0800 >>>> Guochun Mao wrote: >>>> >>>>> Add Mediatek nor flash node. >>>>> >>>>> Signed-off-by: Guochun Mao >>>>> --- >>>>> arch/arm/boot/dts/mt2701-evb.dts | 25 +++++++++++++++++++++++++ >>>>> arch/arm/boot/dts/mt2701.dtsi | 12 ++++++++++++ >>>>> 2 files changed, 37 insertions(+) >>>>> >>>>> diff --git a/arch/arm/boot/dts/mt2701-evb.dts >>>>> b/arch/arm/boot/dts/mt2701-evb.dts >>>>> index 082ca88..85e5ae8 100644 >>>>> --- a/arch/arm/boot/dts/mt2701-evb.dts >>>>> +++ b/arch/arm/boot/dts/mt2701-evb.dts >>>>> @@ -24,6 +24,31 @@ >>>>> }; >>>>> }; >>>>> >>>>> +&nor_flash { >>>>> + pinctrl-names = "default"; >>>>> + pinctrl-0 = <&nor_pins_default>; >>>>> + status = "okay"; >>>>> + flash at 0 { >>>>> + compatible = "jedec,spi-nor"; >>>>> + reg = <0>; >>>>> + }; >>>>> +}; >>>>> + >>>>> +&pio { >>>>> + nor_pins_default: nor { >>>>> + pins1 { >>>>> + pinmux = , >>>>> + , >>>>> + , >>>>> + , >>>>> + , >>>>> + ; >>>>> + drive-strength = ; >>>>> + bias-pull-up; >>>>> + }; >>>>> + }; >>>>> +}; >>>>> + >>>>> &uart0 { >>>>> status = "okay"; >>>>> }; >>>>> diff --git a/arch/arm/boot/dts/mt2701.dtsi >>>>> b/arch/arm/boot/dts/mt2701.dtsi >>>>> index bdf8954..1eefce4 100644 >>>>> --- a/arch/arm/boot/dts/mt2701.dtsi >>>>> +++ b/arch/arm/boot/dts/mt2701.dtsi >>>>> @@ -227,6 +227,18 @@ >>>>> status = "disabled"; >>>>> }; >>>>> >>>>> + nor_flash: spi at 11014000 { >>>>> + compatible = "mediatek,mt2701-nor", >>>>> + "mediatek,mt8173-nor"; >>>> >>>> Why define both here? Is "mediatek,mt8173-nor" really providing a >>>> subset of the features supported by "mediatek,mt2701-nor"? >>>> >>> >>> I think even if the ip block is the same, we should provide both >>> bindings, just in case in the future we find out that mt2701 has some >>> hidden bug, feature or bug-feature. This way even if we update the >>> driver, we stay compatible with older device tree blobs in the wild. >>> >>> We can drop the mt2701-nor in the bindings definition if you want. > > Oh, sorry, I misunderstood. What I meant is that if you want to > list/support all possible compatibles, maybe you should just put one > compatible in your DT and patch your driver (+ binding doc) to define > all of them. Uh, what ? I lost you here :-) >> This exactly. We should have a DT compat in the form: >> compatible = "vendor,-block", "vendor,-block"; >> Then if we find a problem in the future, we can match on the >> "vendor,-block" and still support the old DTs. > > Not sure it's only in term of whose IP appeared first. My understanding > is that it's a way to provide inheritance. For example: > > ",", ","; > > or > > ",",","; > > BTW, which one is the oldest between mt8173 and mt2701? :-) And that's another thing and I agree with you, but I don't think that's what we're discussing in this thread. But (!), OT, I think we should codify the rules in Documentation/ . This discussion came up multiple times recently. And my question still stands, what do we put into the DT here, IMO compatible = "mediatek,mt2701-nor", "mediatek,mt8173-nor"; and what goes into the binding document ? I guess both too ? -- Best regards, Marek Vasut