4 files changed, 48 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h
index d7b4b38a8e86..47dfa31ad71a 100644
--- a/arch/arm64/include/asm/cpu_ops.h
+++ b/arch/arm64/include/asm/cpu_ops.h
@@ -28,6 +28,8 @@ struct device_node;
  *              enable-method property.
  * @cpu_init:   Reads any data necessary for a specific enable-method from the
  *              devicetree, for a given cpu node and proposed logical id.
+ * @cpu_init_idle: Reads any data necessary to initialize CPU idle states from
+ *              devicetree, for a given cpu node and proposed logical id.
  * @cpu_prepare: Early one-time preparation step for a cpu. If there is a
  *              mechanism for doing so, tests whether it is possible to boot
  *              the given CPU.
@@ -47,6 +49,7 @@ struct device_node;
 struct cpu_operations {
         const char      *name;
         int             (*cpu_init)(struct device_node *, unsigned int);
+        int             (*cpu_init_idle)(struct device_node *, unsigned int);
         int             (*cpu_prepare)(unsigned int);
         int             (*cpu_boot)(unsigned int);
         void            (*cpu_postboot)(void);
diff --git a/arch/arm64/include/asm/cpuidle.h b/arch/arm64/include/asm/cpuidle.h
new file mode 100644
index 000000000000..b52a9932e2b1
--- /dev/null
+++ b/arch/arm64/include/asm/cpuidle.h
@@ -0,0 +1,13 @@
+#ifndef __ASM_CPUIDLE_H
+#define __ASM_CPUIDLE_H
+
+#ifdef CONFIG_CPU_IDLE
+extern int cpu_init_idle(unsigned int cpu);
+#else
+static inline int cpu_init_idle(unsigned int cpu)
+{
+        return -EOPNOTSUPP;
+}
+#endif
+
+#endif
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
index df7ef8768fc2..6e9538c2d28a 100644
--- a/arch/arm64/kernel/Makefile
+++ b/arch/arm64/kernel/Makefile
@@ -26,6 +26,7 @@ arm64-obj-$(CONFIG_PERF_EVENTS)		+= perf_regs.o
 arm64-obj-$(CONFIG_HW_PERF_EVENTS)      += perf_event.o
 arm64-obj-$(CONFIG_HAVE_HW_BREAKPOINT)  += hw_breakpoint.o
 arm64-obj-$(CONFIG_ARM64_CPU_SUSPEND)   += sleep.o suspend.o
+arm64-obj-$(CONFIG_CPU_IDLE)            += cpuidle.o
 arm64-obj-$(CONFIG_JUMP_LABEL)          += jump_label.o
 arm64-obj-$(CONFIG_KGDB)                += kgdb.o
 arm64-obj-$(CONFIG_EFI)                 += efi.o efi-stub.o efi-entry.o
diff --git a/arch/arm64/kernel/cpuidle.c b/arch/arm64/kernel/cpuidle.c
new file mode 100644
index 000000000000..19d17f51db37
--- /dev/null
+++ b/arch/arm64/kernel/cpuidle.c
@@ -0,0 +1,31 @@
+/*
+ * ARM64 CPU idle arch support
+ *
+ * Copyright (C) 2014 ARM Ltd.
+ * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <asm/cpuidle.h>
+#include <asm/cpu_ops.h>
+
+int cpu_init_idle(unsigned int cpu)
+{
+        int ret = -EOPNOTSUPP;
+        struct device_node *cpu_node = of_cpu_device_node_get(cpu);
+
+        if (!cpu_node)
+                return -ENODEV;
+
+        if (cpu_ops[cpu] && cpu_ops[cpu]->cpu_init_idle)
+                ret = cpu_ops[cpu]->cpu_init_idle(cpu_node, cpu);
+
+        of_node_put(cpu_node);
+        return ret;
+}