arm: arch_timer: move core to drivers/clocksource

The core functionality of the arch_timer driver is not directly tied to
anything under arch/arm, and can be split out.

This patch factors out the core of the arch_timer driver, so it can be
shared with other architectures. A couple of functions are added so
that architecture-specific code can interact with the driver without
needing to touch its internals.

The ARM_ARCH_TIMER config variable is moved out to
drivers/clocksource/Kconfig, existing uses in arch/arm are replaced with
HAVE_ARM_ARCH_TIMER, which selects it.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 7fdcbd3f4da5..dbb085ac64d4 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -58,3 +58,6 @@ config CLKSRC_ARM_GENERIC
         def_bool y if ARM64
         help
           This option enables support for the ARM generic timer.
+
+config ARM_ARCH_TIMER
+        bool