Re: [PATCH 11/13] ARM: dts: exynos: Silence SATA PHY warning in Exynos5250 Arndale

From: Marek Szyprowski <m.szyprowski@samsung.com>
To: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>, Kukjin Kim <kgene@kernel.org>,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	"linux-samsung-soc@vger.kernel.org" 
	<linux-samsung-soc@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
	Sylwester Nawrocki <snawrocki@kernel.org>
Subject: Re: [PATCH 11/13] ARM: dts: exynos: Silence SATA PHY warning in Exynos5250 Arndale
Date: Tue, 1 Sep 2020 10:36:20 +0200	[thread overview]
Message-ID: <4836dc12-df88-5936-c208-8f6ff2a6bdc1@samsung.com> (raw)
In-Reply-To: <CAJKOXPfKnzsRA3D8b3z=iG4oD6P+M7Q7YMVbrOAmLTiNgZ5mXA@mail.gmail.com>

On 01.09.2020 10:19, Krzysztof Kozlowski wrote:
> On Tue, 1 Sep 2020 at 10:17, Krzysztof Kozlowski <krzk@kernel.org> wrote:
>> On Tue, 1 Sep 2020 at 10:13, Marek Szyprowski <m.szyprowski@samsung.com> wrote:
>>> On 01.09.2020 09:54, Krzysztof Kozlowski wrote:
>>>> The SATA PHY in Exynos5250 SoCs has two interfaces and two device nodes:
>>>> 1. sata-phy@12170000
>>>> 2. i2c-9/i2c@38
>>>>
>>>> The first node represents the actual SATA PHY device with phy-cells.
>>>> The second represents additional I2C interface, needed by the driver
>>>> to communicate with the SATA PHY device.  It is not a PHY-provider in
>>>> the terms of dtschema so rename it to silence dtbs_check warning:
>>>>
>>>>     arch/arm/boot/dts/exynos5250-arndale.dt.yaml: sata-phy@38: '#phy-cells' is a required property
>>>>       From schema: lib/python3.6/site-packages/dtschema/schemas/phy/phy-provider.yaml
>>>>
>>>> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
>>>> ---
>>>>    arch/arm/boot/dts/exynos5250-arndale.dts | 2 +-
>>>>    1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/arch/arm/boot/dts/exynos5250-arndale.dts b/arch/arm/boot/dts/exynos5250-arndale.dts
>>>> index f2bcce167b2d..3c401c82905c 100644
>>>> --- a/arch/arm/boot/dts/exynos5250-arndale.dts
>>>> +++ b/arch/arm/boot/dts/exynos5250-arndale.dts
>>>> @@ -544,7 +544,7 @@
>>>>        samsung,i2c-max-bus-freq = <40000>;
>>>>        samsung,i2c-slave-addr = <0x38>;
>>>>
>>>> -     sata_phy_i2c: sata-phy@38 {
>>>> +     sata_phy_i2c: sata-phy-i2c@38 {
>>>>                compatible = "samsung,exynos-sataphy-i2c";
>>>>                reg = <0x38>;
>>>>        };
>>> I'm not against the rename, but frankly, the above node and all i2c
>>> parameters should be moved to exynos5250.dtsi. This is a SoC internal
>>> things (the same way as hdmiphy in exynos4.dtsi), so the board dts
>>> should only contain information like status = "enabled" for i2c_8 and
>>> hdmi_i2c_phy nodes. No need to duplicate it here and in smdk5250.dts.
>> Good point, the I2C bus used here is an internal part of SoC.
>>
>> I will squash these two changes into a new one. Thanks for the review!
> While at it, I wonder about the samsung,i2c-slave-addr property. Is it
> really needed? Are there multiple masters on this bus?

This might be some cargo-cult, probably copied from HDMI DDC (I'm not 
sure if it is needed there). I've removed it and SATA still works fine 
on Exynos5250 Arndale board.

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland