Message-ID: <548D5CD1.10801@broadcom.com>
Date: Sun, 14 Dec 2014 10:48:01 +0100
From: Arend van Spriel <arend@broadcom.com>
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To: Arnd Bergmann <arnd@arndb.de>
CC: <linux-arm-kernel@lists.infradead.org>,
        Mark Rutland <mark.rutland@arm.com>, <devicetree@vger.kernel.org>,
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        Ray Jui <rjui@broadcom.com>, Christian Daudt <bcm@fixthebug.org>,
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        Matt Porter <mporter@linaro.org>,
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        Rob Herring <robh+dt@kernel.org>,
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        Hauke Mehrtens <hauke@hauke-m.de>, Kumar Gala <galak@codeaurora.org>,
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        Lucas Stach <l.stach@pengutronix.de>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <zajec5@gmail.com>
Subject: Re: [PATCH v2 1/4] pci: iProc: define Broadcom iProc PCIe binding
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On 12/13/14 20:46, Arnd Bergmann wrote:
> On Saturday 13 December 2014 11:05:52 Arend van Spriel wrote:
>>
>> Makes sense. I think that is what Hauke meant by "adding
>> additional support for registering to bcma". So the discovery info is a
>> piece of read-only memory in the chip. Its address is stored in the
>> chipcommon core register space. BCMA parses that memory blob resulting
>> in a list of cores which register address info. We could add DT support
>> in BCMA matching the compatible string and register a core for it.
>
> Ah, interesting idea. That would mirror what we do for drivers/amba,
> I like the idea.

+ Rafal

Let's explore this. Although I don't have the iProc hardware to verify it.

>> However, apart from the discovery info a "discoverable ARM AXI" chip has
>> a register space per core that provides common procedures like
>> enable/disable, reset, core status, which are implemented in BCMA. I am
>> not seeing that register space in the DT examples so I guess this IP
>> block is not there for iProc chips.
>
> I wouldn't draw conclusions from the absence of some node. Maybe these
> registers are present but just not used by the original BSP.

I do not intend to. We have raised the question internally to iProc chip 
designers.

Regards,
Arend
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