[PATCH RFC] uio: allow use on nommu systems

From: Rich Felker
Date: Thu Jul 14 2016 - 20:53:31 EST


mmap of uio devices does not seem to work without further
nommu-specific support, but interrupt handling already works, and
userspace drivers for nommu systems can simply use physical mmio
addresses from userspace directly anyway without mmap.

Signed-off-by: Rich Felker <dalias@xxxxxxxx>
---

I don't particularly expect this to be accepted upstream as-is, but
since we're actually trying to use the UIO subsystem on nommu (J2),
I'd like to start a discussion of what an acceptable patch would
entail.

The uio_pdrv_genirq driver was tested on J2 with this patch and
interrupt handling works as expected.

drivers/uio/Kconfig | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
index 52c98ce..387b2bb 100644
--- a/drivers/uio/Kconfig
+++ b/drivers/uio/Kconfig
@@ -1,6 +1,5 @@
menuconfig UIO
tristate "Userspace I/O drivers"
- depends on MMU
help
Enable this to allow the userspace driver core code to be
built. This code allows userspace programs easy access to
--
2.8.1