From: "Enrico Weigelt, metux IT consult" <lkml@metux.net>
To: Sven Van Asbroeck <thesven73@gmail.com>,
"Enrico Weigelt, metux IT consult" <info@metux.net>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>,
Frank Rowand <frowand.list@gmail.com>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
devicetree <devicetree@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [Q] devicetree overlays
Date: Wed, 12 Aug 2020 15:27:47 +0200 [thread overview]
Message-ID: <1acc987a-d844-fca7-77eb-cf1d466f35c1@metux.net> (raw)
In-Reply-To: <CAGngYiVokqYkEiQTcqAMnvif3qEWkPOb1cAk+4rvwgxBKZ5Ukw@mail.gmail.com>
On 07.08.20 16:17, Sven Van Asbroeck wrote:
Hi,
> I believe you're asking: "how do I associate device tree nodes to
> devices on a dynamically discoverable bus such as USB or PCI" right ?
>
> I believe that already exists. You can describe the _expected_ pci or
> usb topology in the
> devicetree. If a device gets detected in a spot on the bus described
> in the tree, that
> snippet will be automatically associated with this device.
>
> How to for usb:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/usb/usb-device.txt?h=v5.8
>
> How to for pci:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/pci/pci.txt?h=v5.8
Thanks, that looks good.
But I've still got another problem: how can I use DT along w/ ACPI ?
The scenario goes like this:
* machine boots and probes normally w/ ACPI
* device is detected via USB, PCI, DMI, etc -> driver gets active
* driver loads (or carries) a DT snippet
* devices on the bus are instantiated via this DT snippet
(driver could also be some udev vodoo)
Example a:
* generic usb i2c dongle w/ some i2c devices attached behind it
* config (or DT snippet) somewhere in the FS
Example b:
* x86 board driver (eg. apu2/3/4), probed via DMI
* just instantiates a bunch of generic drivers and wires up
devices (gpio, leds, keys, ...)
Do you think we can already do that ?
Otherwise, what has to be done to achieve that ?
--mtx
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Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
info@metux.net -- +49-151-27565287
next prev parent reply other threads:[~2020-08-12 13:28 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-16 14:46 [Q] devicetree overlays Sven Van Asbroeck
2020-04-27 20:26 ` Frank Rowand
2020-04-28 12:20 ` Sven Van Asbroeck
2020-08-07 11:25 ` Enrico Weigelt, metux IT consult
2020-08-07 14:17 ` Sven Van Asbroeck
2020-08-12 13:27 ` Enrico Weigelt, metux IT consult [this message]
2020-08-12 14:43 ` Sven Van Asbroeck
2020-08-12 15:13 ` Frank Rowand
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