diff options
| -rw-r--r-- | arch/x86/kernel/x86_init.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c index 18a799c8fa28..ce89430a7f80 100644 --- a/arch/x86/kernel/x86_init.c +++ b/arch/x86/kernel/x86_init.c @@ -31,6 +31,28 @@ static int __init iommu_init_noop(void) { return 0; } static void iommu_shutdown_noop(void) { } bool __init bool_x86_init_noop(void) { return false; } void x86_op_int_noop(int cpu) { } +static __init int set_rtc_noop(const struct timespec64 *now) { return -EINVAL; } +static __init void get_rtc_noop(struct timespec64 *now) { } + +static __initconst const struct of_device_id of_cmos_match[] = { + { .compatible = "motorola,mc146818" }, + {} +}; + +/* + * Allow devicetree configured systems to disable the RTC by setting the + * corresponding DT node's status property to disabled. Code is optimized + * out for CONFIG_OF=n builds. + */ +static __init void x86_wallclock_init(void) +{ + struct device_node *node = of_find_matching_node(NULL, of_cmos_match); + + if (node && !of_device_is_available(node)) { + x86_platform.get_wallclock = get_rtc_noop; + x86_platform.set_wallclock = set_rtc_noop; + } +} /* * The platform setup functions are preset with the default functions @@ -73,7 +95,7 @@ struct x86_init_ops x86_init __initdata = { .timers = { .setup_percpu_clockev = setup_boot_APIC_clock, .timer_init = hpet_time_init, - .wallclock_init = x86_init_noop, + .wallclock_init = x86_wallclock_init, }, .iommu = { |