clocksource: Sched clock source for Versatile Express

This patch adds a trival sched clock source using free
running, 24MHz clocked counter present in the ARM Ltd.
reference platforms (Versatile, RealView, Versatile
Express) System Registers block.

This code replaces the call in the VE machine code.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 96918e1f26a3..2c27b02f0860 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -191,3 +191,14 @@ config EM_TIMER_STI
 
 config CLKSRC_QCOM
         bool
+
+config CLKSRC_VERSATILE
+        bool "ARM Versatile (Express) reference platforms clock source"
+        depends on GENERIC_SCHED_CLOCK
+        select CLKSRC_OF
+        default y if MFD_VEXPRESS_SYSREG
+        help
+          This option enables clock source based on free running
+          counter available in the "System Registers" block of
+          ARM Versatile, RealView and Versatile Express reference
+          platforms.