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    SubjectRe: [PATCH] devicetree - document using aliases to set spi bus number.
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    On 05/24/2016 07:20 PM, Mark Brown wrote:
    >> Not having used devicetree that much it was surprisingly hard to
    >> figure out how to assign a stable bus number to a spi bus. Add
    >> a simple example that shows how to do that.
    >
    > I'm not sure this is something we want to support at all, I can't
    > immediately see anything that does this deliberately in the SPI
    > code and obviously the "bus number" is something of a Linux
    > specific concept which would need some explanation if we were going
    > to document it. It's something I'm struggling a bit to see a
    > robust use case for that isn't better served by parsing sysfs,
    > what's the goal here?

    Well, that's how it works right now:

    commit bb29785e0d6d150181704be2efcc3141044625e2
    Author: Grant Likely <grant.likely@secretlab.ca>
    Date: Fri Dec 21 19:32:09 2012 +0000

    spi/of: Use DT aliases for assigning bus number

    > + if ((master->bus_num < 0) && master->dev.of_node) +
    > master->bus_num = of_alias_get_id(master->dev.of_node, "spi");

    If this isn't something that should be in the Documentation/devicetree
    because it's not generig enough, where should Linux-specific
    interpretations such as this be documented?

    /Christer

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