[PATCH] IBM GPIO driver for PowerPC 4xx is back from the dead
Eugene Surovegin
ebs at ebshome.net
Sat Sep 30 02:42:45 EST 2006
On Fri, Sep 29, 2006 at 09:46:04AM +0200, Jean-Baptiste Maneyrol wrote:
> Here is a patch for linux 2.6.18 that makes come back the old ibm gpio
> driver from 2.6.10.
>
> It is mainly useful for compatibility with old linux 2.4 from Montavista
> I think, because direct memory access seems the new way to go.
In my opinion it should stay dead. And no, direct memory access isn't
a way to go - how are you gonna provide synchronization in this case?
Think about different processes mucking with GPIO registers.
I think such low-level functionality should never be exported to the
user-space in the first place. If your user-space needs such access
make it explicit through procfs/sysfs (e.g.
/proc/sys/dev/my_board/reset_that_device for GPIO pin wired to some
chip reset) or just make a specific driver for your hardware.
--
Eugene
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