[PATCH 0/3] Introduce atomic MMIO register clear-set

From: Ezequiel Garcia
Date: Sat Aug 10 2013 - 08:43:50 EST


Following a suggestion from Sebastian Hesselbarth and Russell King
here's some work to introduce a generic thread-safe clear-set register
access.

The original motivation for this comes from the need to access the same
register from a clocksource driver and a watchdog driver as we find
in Kirkwood, Armada 370/XP SoCs.

Since this sort of design is expected to appear in other platforms,
instead of exporting platform-specific {mvebu,orion}_clear_set() functions
for the thread-safe access, this patchset implements a system-wide API.

Although this is placed in arm/kernel/io.c, there's nothing
ARM-specific in the API and should probably me moved somewhere else.

Suggestions on where to put it are appreciated.

Using this API it's possible -for instance- to add support for Armada 370/XP
in the orion_wdt driver. That work is ready, and it's been hold until we
decide a proper solution for shared-register access.

Based in v3.11-rc4.

Ezequiel Garcia (3):
ARM: Introduce atomic MMIO clear/set
clocksource: orion: Use atomic access for shared registers
watchdog: orion: Use atomic access for shared registers

arch/arm/include/asm/io.h | 5 +++++
arch/arm/kernel/io.c | 24 ++++++++++++++++++++++++
drivers/clocksource/time-orion.c | 9 ++-------
drivers/watchdog/orion_wdt.c | 8 ++------
4 files changed, 33 insertions(+), 13 deletions(-)

--
1.8.1.5

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