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Date: Mon, 13 Jun 2011 12:00:23 -0700
Message-ID: <BANLkTi=_gHea17gcFWaNfzZjUUGEcXTJyA@mail.gmail.com>
From: Garrett Cooper <yanegomi@gmail.com>
To: freebsd-hackers@freebsd.org
Content-Type: text/plain; charset=ISO-8859-1
Subject: Opening a character device from a helper driver?
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Hi,
    Just to confirm whether or not this is the best way, say I had a
module foo(4) that pokes at /dev/bar0, which is attached to bar(4).
Should I setup the foo(4) driver with the same class as bar(4) and use
KPIs like device_get_parent(9) to get the device_t structure and pass
it along to bar(4)'s helper/ioctl functions, or is there a better way
to skin the proverbial cat?
    I'm basing this observation off what I see in /sys/dev/uart_bus_puc.c .
Thanks!
-Garrett