drivers: clocksource: add support for ARM architected timer event stream

[~andy/linux] / drivers / clocksource / Kconfig

diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index b7b9b040a89ba807e36062c2029feedfceee8016..559d80335446ffcdfe7a9bcf86ee939f0be5fb96 100644 (file)
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -74,6 +74,21 @@ config ARM_ARCH_TIMER
        bool
        select CLKSRC_OF if OF
 
+config ARM_ARCH_TIMER_EVTSTREAM
+       bool "Support for ARM architected timer event stream generation"
+       default y if ARM_ARCH_TIMER
+       help
+         This option enables support for event stream generation based on
+         the ARM architected timer. It is used for waking up CPUs executing
+         the wfe instruction at a frequency represented as a power-of-2
+         divisor of the clock rate.
+         The main use of the event stream is wfe-based timeouts of userspace
+         locking implementations. It might also be useful for imposing timeout
+         on wfe to safeguard against any programming errors in case an expected
+         event is not generated.
+         This must be disabled for hardware validation purposes to detect any
+         hardware anomalies of missing events.
+
 config ARM_GLOBAL_TIMER
        bool
        select CLKSRC_OF if OF
@@ -99,7 +114,6 @@ config CLKSRC_EXYNOS_MCT
 
 config CLKSRC_SAMSUNG_PWM
        bool
-       select CLKSRC_MMIO
        help
          This is a new clocksource driver for the PWM timer found in
          Samsung S3C, S5P and Exynos SoCs, replacing an earlier driver