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Subject: Re: [PATCH 1/8] bindings: PCI: designware: Example update
To:     Kishon Vijay Abraham I <kishon@ti.com>,
        "bhelgaas@google.com" <bhelgaas@google.com>,
        "lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
        "Joao.Pinto@synopsys.com" <Joao.Pinto@synopsys.com>,
        "jingoohan1@gmail.com" <jingoohan1@gmail.com>,
        "robh+dt@kernel.org" <robh+dt@kernel.org>,
        "mark.rutland@arm.com" <mark.rutland@arm.com>
Cc:     "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>
References: <cover.1522235224.git.gustavo.pimentel@synopsys.com>
 <33aa86ee667e8b435db080b8c683cb5df1bd6544.1522235224.git.gustavo.pimentel@synopsys.com>
 <fa001440-0dfe-b84a-e5ef-9285043b5ede@ti.com>
 <36a36857-2d79-2c2d-198d-a3b65cafc768@synopsys.com>
 <c5ffa7d6-40b1-1702-c0fd-9ebb1b4197f8@ti.com>
 <170b150d-d2c6-fee8-17f7-12a3107c13ff@ti.com>
From:   Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Message-ID: <342e7438-ef13-e297-cc51-3df3a43a45d4@synopsys.com>
Date:   Tue, 3 Apr 2018 14:13:24 +0100
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Hi Kishon,

On 03/04/2018 11:53, Kishon Vijay Abraham I wrote:
> Hi,
> 
> On Tuesday 03 April 2018 04:22 PM, Kishon Vijay Abraham I wrote:
>>
>>
>> On Tuesday 03 April 2018 04:03 PM, Gustavo Pimentel wrote:
>>> Hi Kishon,
>>>
>>> On 02/04/2018 06:23, Kishon Vijay Abraham I wrote:
>>>> Hi,
>>>>
>>>> On Wednesday 28 March 2018 05:08 PM, Gustavo Pimentel wrote:
>>>>> Changes the IP registers size to accommodate the ATU unroll space.
>>>>>
>>>>> Replaces "ctrlreg" reg-name by "dbi" to be coherent with similar drivers.
>>>>>
>>>>> Replaces the pcie base address example by a real pcie base address in use.
>>>>>
>>>>> Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
>>>>> ---
>>>>>  Documentation/devicetree/bindings/pci/designware-pcie.txt | 12 ++++++------
>>>>>  1 file changed, 6 insertions(+), 6 deletions(-)
>>>>>
>>>>> diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt b/Documentation/devicetree/bindings/pci/designware-pcie.txt
>>>>> index 1da7ade..6300762 100644
>>>>> --- a/Documentation/devicetree/bindings/pci/designware-pcie.txt
>>>>> +++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt
>>>>> @@ -1,7 +1,8 @@
>>>>>  * Synopsys DesignWare PCIe interface
>>>>>  
>>>>>  Required properties:
>>>>> -- compatible: should contain "snps,dw-pcie" to identify the core.
>>>>> +- compatible:
>>>>> +	"snps,dw-pcie" for RC mode;
>>>>
>>>> I think irrespective of RC mode or EP mode, "snps,dw-pcie" can be used to
>>>> identify the pcie core?
>>>
>>> I guess so. What you suggest? I was just folling the same guideline present
>>> here: https://urldefense.proofpoint.com/v2/url?u=https-3A__lkml.org_lkml_2017_11_3_310&d=DwIC-g&c=DPL6_X_6JkXFx7AXWqB0tg&r=bkWxpLoW-f-E3EdiDCCa0_h0PicsViasSlvIpzZvPxs&m=G1MqB_DY6ZwWtvS60L9PZMHnMe6rClMnrakAyQT_hDc&s=BhQYkrcp6y3QkD23qn1I6lU882BDUfLiXjBVWQ91cmg&e=
>>
>> Okay, I think you should have
>> "snps,dw-pcie-rc", "snps,dw-pcie" for RC mode;
>>
>> and in the later patch
>> "snps,dw-pcie-ep", "snps,dw-pcie" for EP mode;
>>

Ok, I'll change it.

>>>
>>>>>  - reg: Should contain the configuration address space.
>>>>>  - reg-names: Must be "config" for the PCIe configuration space.
>>>>>      (The old way of getting the configuration address space from "ranges"
>>>>> @@ -41,11 +42,11 @@ EP mode:
>>>>>  
>>>>>  Example configuration:
>>>>>  
>>>>> -	pcie: pcie@dffff000 {
>>>>> +	pcie: pcie@dfc00000 {
>>>>>  		compatible = "snps,dw-pcie";
>>>>> -		reg = <0xdffff000 0x1000>, /* Controller registers */
>>>>> -		      <0xd0000000 0x2000>; /* PCI config space */
>>>>> -		reg-names = "ctrlreg", "config";
>>>>> +		reg = <0xdfc00000 0x302000>, /* IP registers */
>>>>
>>>> which version of synopsys IP is this. I think the ideal thing to do here is to
>>>> have a separate register space for iATU.
>>>
>>> I also agree with that. The unroll iATU was introduced on Synopsys IP version
>>> 4.80 and the kernel patch was release on 2016-08-10
>>> https://urldefense.proofpoint.com/v2/url?u=https-3A__patchwork.ozlabs.org_patch_657796_&d=DwIC-g&c=DPL6_X_6JkXFx7AXWqB0tg&r=bkWxpLoW-f-E3EdiDCCa0_h0PicsViasSlvIpzZvPxs&m=G1MqB_DY6ZwWtvS60L9PZMHnMe6rClMnrakAyQT_hDc&s=EgKKDbg4ywCxu4-lG_scYAgPMnxirsjS0uSS7SzBTeM&e=
>>> However a separate register space for iATU implies some extra code do handle it
>>> (and of course some tests) that don't fit into this patch series, in my point of
>>> view. Can this task enter in the backlog in order to be done in another patch
>>> series?
>>
>> Yes sure. I think we should also make sure existing binding doesn't break.

I'll remove the any iATU unroll reference or change from this patch to avoid any
confusion.

> 
> And IMO we should have a new compatible "snps,dw-pcie-4.80" in order to enable
> iATU unroll.
> 
> Thanks
> Kishon
>