Subject: Re: [PATCH] Documentation: dt-binding: net: wireless: add
 bcm43430-fmac
To: Rob Herring <robh@kernel.org>, Antony Antony <antony@phenome.org>
Cc: Chen-Yu Tsai <wens@csie.org>, Kalle Valo <kvalo@codeaurora.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Icenowy Zheng <icenowy@aosc.io>,
        devicetree <devicetree@vger.kernel.org>,
        Hans de Goede <hdegoede@redhat.com>,
        linux-wireless <linux-wireless@vger.kernel.org>,
        Maxime Ripard <maxime.ripard@free-electrons.com>
References: <20170829214309.34466-1-antony@phenome.org>
 <CAGb2v66=JvS9wHkUNBwd+vHwx4NAQsaWyhx1OyEokSZizo+7-g@mail.gmail.com>
 <20170830120218.ms3xuhp4qsibistv@AntonyAntony.local>
 <20170901164911.aiu5ej5u546z5kow@rob-hp-laptop>
From: Arend van Spriel <arend.vanspriel@broadcom.com>
Message-ID: <bb53a79e-8045-3c9b-8c98-8d4815c3b57a@broadcom.com> (sfid-20170901_211047_487358_F6B6E407)
Date: Fri, 1 Sep 2017 21:10:41 +0200
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Sender: linux-wireless-owner@vger.kernel.org

On 01-09-17 18:49, Rob Herring wrote:
> On Wed, Aug 30, 2017 at 02:02:18PM +0200, Antony Antony wrote:
>> hi,
>>
>> On Wed, Aug 30, 2017 at 10:28:20AM +0800, Chen-Yu Tsai wrote:
>>> On Wed, Aug 30, 2017 at 5:43 AM, Antony Antony <antony@phenome.org> wrote:
>>
>>>> a/Documentation/devicetree/bindings/net/wireless/brcm,bcm43xx-fmac.txt
>>>> +++ b/Documentation/devicetree/bindings/net/wireless/brcm,bcm43xx-fmac.txt
>>>> @@ -6,7 +6,9 @@ connects the device to the system.
>>>>
>>>>   Required properties:
>>>>
>>>> - - compatible : Should be "brcm,bcm4329-fmac".
>>>> + - compatible : should be one of the following:
>>>> +       * "brcm,bcm4329-fmac"
>>>> +       * "brcm,bcm43430-fmac"
>>>
>>> You updated the bindings, but not the driver. So it's not actually
>>> going to work. More specifically, OOB interrupts won't work.
>>>
>>
>> understood, ignore this patch for now. Thanks Chen-Yu.
>>
>>> IIRC, The compatible string for this particular case, as it was
>>> originally proposed, only serves as a placeholder for the driver
>>> to check against. None of the instances in sunxi device trees
>>> match the actual chip model. Actual model matching is done
>>> through SDIO, as you've already seen.
>>
>> yes it seems SDIO driveer code is smarter, once it initialize
>> brcm,bcm4329-fmac it ignore the DT info and read the chip details to locate
>> firmware file.
>>
>> I also noticed other boards using bcm4329-fmac in similar situations.
>> https://patchwork.kernel.org/patch/9739181/
>>
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/amlogic/meson-gxbb-nanopi-k2.dts?h=v4.13-rc7
>>
>> I will resend "NanoPi NEO Plus2" dts with "brcm,bcm4329-fmac" and see where
>> it goes.
> 
> Adding the compatible or instead of? The former would be better. You
> should still have the actual chip in case you do have some difference to
> handle.

Hi Rob,

Actually the Broadcom wifi chips themselves are discoverable. So once 
the driver has access to the register space of the device it can 
determine the actual chip, its revision, and exactly what cores (and 
their revision) are present in the chip. Hence there is a single 
compatible string as there is no need to convey the same information 
through device tree data.

Regards,
Arend