Message-ID: <51F96B48.10209@cogentembedded.com>
Date: Wed, 31 Jul 2013 23:53:44 +0400
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Organization: Cogent Embedded
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To: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
CC: Tuomas Tynkkynen <ttynkkynen@nvidia.com>, swarren@wwwdotorg.org,
        linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-usb@vger.kernel.org, Mikko Perttunen <mperttunen@nvidia.com>
Subject: Re: [PATCH 2/2] ARM: dts: USB for Tegra114 Dalmore
References: <1375292543-7896-1-git-send-email-ttynkkynen@nvidia.com> <1375292543-7896-3-git-send-email-ttynkkynen@nvidia.com> <51F9550F.3080503@cogentembedded.com> <51F9660C.6090604@iki.fi>
In-Reply-To: <51F9660C.6090604@iki.fi>
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Hello.

On 07/31/2013 11:31 PM, Tuomas Tynkkynen wrote:

>>> From: Mikko Perttunen <mperttunen@nvidia.com>

>>> Device tree entries for the three EHCI controllers on Tegra114.
>>> Enables the the third controller (USB host) on Dalmore.

>>     I would have done the board patch separately from the SoC one.

>>> Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
>> [...]
>>
>>> diff --git a/arch/arm/boot/dts/tegra114.dtsi
>>> b/arch/arm/boot/dts/tegra114.dtsi
>>> index abf6c40..2905145 100644
>>> --- a/arch/arm/boot/dts/tegra114.dtsi
>>> +++ b/arch/arm/boot/dts/tegra114.dtsi
>>> @@ -430,6 +430,68 @@
>>>           status = "disable";
>>>       };
>>>
>>> +    usb@7d000000 {
>>> +        compatible = "nvidia,tegra30-ehci", "usb-ehci";
>>> +        reg = <0x7d000000 0x4000>;
>>> +        interrupts = <GIC_SPI 20 IRQ_TYPE_LEVEL_HIGH>;
>>> +        phy_type = "utmi";
>>> +        clocks = <&tegra_car TEGRA114_CLK_USBD>;
>>> +        nvidia,phy = <&phy1>;
>>> +        status = "disabled";
>>> +    };
>>> +
>>> +    phy1: usb-phy@7d000000 {

>>     At the same address as the previous node?

> Yes. The first node is for the EHCI driver and the second for the PHY driver.
> There is some overlap in the exact registers used, so both drives map the
> whole USB controller block.

    That's really horrible design.

>>> +        compatible = "nvidia,tegra30-usb-phy";
>>> +        reg = <0x7d000000 0x4000 0x7d000000 0x4000>;

>>     Hm, there must be some mistake: two similar register ranges.

> The second range is used to configure the UTMI pad registers. All the UTMI pad
> registers are located in the first USB controller's range.

    Which second range? This is one and the same range.

>>> +    usb@7d008000 {
>>> +        compatible = "nvidia,tegra30-ehci", "usb-ehci";
>>> +        reg = <0x7d008000 0x4000>;
>>> +        interrupts = <GIC_SPI 97 IRQ_TYPE_LEVEL_HIGH>;
>>> +        phy_type = "utmi";
>>> +        clocks = <&tegra_car TEGRA114_CLK_USB3>;
>>> +        nvidia,phy = <&phy3>;
>>> +        status = "disabled";
>>> +    };
>>> +
>>> +    phy3: usb-phy@7d008000 {

>>     Again at the same address as previous node?

>>> +        compatible = "nvidia,tegra30-usb-phy";
>>> +        reg = <0x7d008000 0x4000 0x7d000000 0x4000>;

>>     Second range conflicts with previous nodes.

    Are you sure it's valid? Are you sure it shouldn't be 0x7d008000?

>> WBR, Sergei

> All these entries mapping the same address are expected. See
> arch/arm/boot/dts/tegra20.dtsi for an existing example of Tegra USB bindings.

    Don't they cause numerous resource conflicts while device nodes being 
instantiated as the platform devices?

WBR, Sergei

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