clocksource/drivers/arm_arch_timer: Enable and verify MMIO access

So far, we have been blindly assuming that having access to a
memory-mapped timer frame implies that the individual elements of that
frame frame are already enabled. Whilst it's the firmware's job to give
us non-secure access to frames in the first place, we should not rely
on implementations always being generous enough to also configure CNTACR
for those non-secure frames (e.g. [1]).

Explicitly enable feature-level access per-frame, and verify that the
access we want is really implemented before trying to make use of it.

[1]:https://github.com/ARM-software/tf-issues/issues/170

Acked-by: Mark Rutland <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Tested-by: Stephen Boyd <[email protected]>
Acked-by: Marc Zyngier <[email protected]>
Signed-off-by: Robin Murphy <[email protected]>
Signed-off-by: Daniel Lezcano <[email protected]>

0 files changed, 0 insertions, 0 deletions