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From: Christopher Bostic <christopher.lee.bostic@gmail.com>
Date: Wed, 1 Feb 2017 11:09:38 -0600
Message-ID: <CAA0LjjVMh4DNH7BoF_pgQHWowS0d4_LBue_VP20GkydHSgcLow@mail.gmail.com>
Subject: Re: [PATCH v2 15/18] drivers/fsi: Add documentation for GPIO based
 FSI master
To: Jeremy Kerr <jk@ozlabs.org>
Cc: Rob Herring <robh@kernel.org>, Mark Rutland <mark.rutland@arm.com>,
        linux@armlinux.org.uk, Greg KH <gregkh@linuxfoundation.org>,
        Michael Turquette <mturquette@baylibre.com>, geert+renesas@glider.be,
        Open List OF Flattened dev tree bindings 
        <devicetree@vger.kernel.org>,
        "Moderated list: ARM PORT" <linux-arm-kernel@lists.infradead.org>,
        Joel Stanley <joel@jms.id.au>,
        Linux open list <linux-kernel@vger.kernel.org>,
        Andrew Jeffery <andrew@aj.id.au>,
        Alistair Popple <alistair@popple.id.au>,
        Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Chris Bostic <cbostic@us.ibm.com>
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On Wed, Jan 18, 2017 at 8:11 PM, Jeremy Kerr <jk@ozlabs.org> wrote:
> Hi Chris,
>
> From this:
>
>>> +
>>> +The standard FSI master node
>>> +----------------------------
>>> +This node describes a FSI master implmemented fully in hardware
>>> +with dedicated input/output pins required for its function (i.e.
>>> +not using generic GPIO pins).
>>> +Required property:
>>> +    compatible = "ibm,fsi-master"
>
> and this:
>
>>> +Example:
>>> +
>>> +fsi-master {
>>> +    compatible = "ibm,fsi-master-gpio", "ibm,fsi-master";
>>
>> From the description, these should be mutually exclusive.
>
> I agree with Rob here. The intention is for "ibm,fsi-master" to be an
> abstract master -- simply indicating that this node describes a master,
> with no specific implementation, and "ibm,fsi-master-gpio" to be a
> GPIO-based implementation. A hardware-based FSI master would have a
> different compatible value, based on the hardware.
>
> We should remove references to implementations in the "The standard FSI
> master node" section, because this is independent of implementation.
>

Hi,

OK will make that change for version 4.

>>> +    clk-gpios = <&gpio 0>, <&gpio 6>;
>>> +    data-gpios = <&gpio 1>, <&gpio 7>;
>>> +    enable-gpios = <&gpio 2>, <&gpio 8>;
>>> +    trans-gpios = <&gpio 3>, <&gpio 9>;
>>> +    mux-gpios = <&gpio 4>, <&gpio 10>;
>
> Do we support multiple-link masters? This example implies a 2-link
> master.
>

Should we start with a single link in this case?  To start off with
only one link is supported by the master.

Thanks

> Cheers,
>
>
> Jeremy