diff options
| -rw-r--r-- | Documentation/devicetree/bindings/arm/arch_timer.txt | 8 | ||||
| -rw-r--r-- | drivers/clocksource/arm_arch_timer.c | 8 |
2 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/arch_timer.txt b/Documentation/devicetree/bindings/arm/arch_timer.txt index 37b2caf..256b4d8 100644 --- a/Documentation/devicetree/bindings/arm/arch_timer.txt +++ b/Documentation/devicetree/bindings/arm/arch_timer.txt @@ -22,6 +22,14 @@ to deliver its interrupts via SPIs. - always-on : a boolean property. If present, the timer is powered through an always-on power domain, therefore it never loses context. +** Optional properties: + +- arm,cpu-registers-not-fw-configured : Firmware does not initialize + any of the generic timer CPU registers, which contain their + architecturally-defined reset values. Only supported for 32-bit + systems which follow the ARMv7 architected reset values. + + Example: timer { diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 55256e4..6967cb0 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -705,6 +705,14 @@ static void __init arch_timer_init(struct device_node *np) arch_timer_detect_rate(NULL, np); /* + * If we cannot rely on firmware initializing the timer registers then + * we should use the physical timers instead. + */ + if (IS_ENABLED(CONFIG_ARM) && + of_property_read_bool(np, "arm,cpu-registers-not-fw-configured")) + arch_timer_use_virtual = false; + + /* * If HYP mode is available, we know that the physical timer * has been configured to be accessible from PL1. Use it, so * that a guest can use the virtual timer instead. |
