1 files changed, 44 insertions, 0 deletions
diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c
index 17a9cbb8b3df..995ad9e69ded 100644
--- a/arch/mips/kernel/cevt-r4k.c
+++ b/arch/mips/kernel/cevt-r4k.c
@@ -8,6 +8,7 @@
  */
 #include <linux/clockchips.h>
 #include <linux/interrupt.h>
+#include <linux/cpufreq.h>
 #include <linux/percpu.h>
 #include <linux/smp.h>
 #include <linux/irq.h>
@@ -250,6 +251,49 @@ unsigned int __weak get_c0_compare_int(void)
 	return MIPS_CPU_IRQ_BASE + cp0_compare_irq;
 }
 
+#ifdef CONFIG_CPU_FREQ
+
+static unsigned long mips_ref_freq;
+
+static int r4k_cpufreq_callback(struct notifier_block *nb,
+				unsigned long val, void *data)
+{
+	struct cpufreq_freqs *freq = data;
+	struct clock_event_device *cd;
+	unsigned long rate;
+	int cpu;
+
+	if (!mips_ref_freq)
+		mips_ref_freq = freq->old;
+
+	if (val == CPUFREQ_POSTCHANGE) {
+		rate = cpufreq_scale(mips_hpt_frequency, mips_ref_freq,
+				     freq->new);
+
+		for_each_cpu(cpu, freq->policy->cpus) {
+			cd = &per_cpu(mips_clockevent_device, cpu);
+
+			clockevents_update_freq(cd, rate);
+		}
+	}
+
+	return 0;
+}
+
+static struct notifier_block r4k_cpufreq_notifier = {
+	.notifier_call  = r4k_cpufreq_callback,
+};
+
+static int __init r4k_register_cpufreq_notifier(void)
+{
+	return cpufreq_register_notifier(&r4k_cpufreq_notifier,
+					 CPUFREQ_TRANSITION_NOTIFIER);
+
+}
+core_initcall(r4k_register_cpufreq_notifier);
+
+#endif /* !CONFIG_CPU_FREQ */
+
 int r4k_clockevent_init(void)
 {
 	unsigned long flags = IRQF_PERCPU | IRQF_TIMER | IRQF_SHARED;