ARM: at91: Implement clocksource selection

Allow selecting and unselecting the PIT clocksource driver so it doesn't
have to be compiled when unused.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/arch/arm/mach-at91/Kconfig b/arch/arm/mach-at91/Kconfig
index 903f23c309df..da1d97a06c53 100644
--- a/arch/arm/mach-at91/Kconfig
+++ b/arch/arm/mach-at91/Kconfig
@@ -107,6 +107,29 @@ config SOC_AT91SAM9
             AT91SAM9X35
             AT91SAM9XE
 
+comment "Clocksource driver selection"
+
+config ATMEL_CLOCKSOURCE_PIT
+        bool "Periodic Interval Timer (PIT) support"
+        depends on SOC_AT91SAM9 || SOC_SAMA5
+        default SOC_AT91SAM9 || SOC_SAMA5
+        select ATMEL_PIT
+        help
+          Select this to get a clocksource based on the Atmel Periodic Interval
+          Timer. It has a relatively low resolution and the TC Block clocksource
+          should be preferred.
+
+config ATMEL_CLOCKSOURCE_TCB
+        bool "Timer Counter Blocks (TCB) support"
+        default SOC_AT91RM9200 || SOC_AT91SAM9 || SOC_SAMA5
+        select ATMEL_TCB_CLKSRC
+        help
+          Select this to get a high precision clocksource based on a
+          TC block with a 5+ MHz base clock rate.
+          On platforms with 16-bit counters, two timer channels are combined
+          to make a single 32-bit timer.
+          It can also be used as a clock event device supporting oneshot mode.
+
 config HAVE_AT91_UTMI
         bool