2 messages, 2 authors, 2006-09-29 · open the first message on its own page
From: Jean-Baptiste Maneyrol <hidden>
Date: 2006-09-29 08:15:59
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. Signed-off-by: Jean-Baptiste Maneyrol [off-list ref] Jean-Baptiste Maneyrol Teamlog - France
From: Eugene Surovegin <hidden>
Date: 2006-09-29 16:42:48
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