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Diffstat (limited to 'arch/arm/kernel/smp_scu.c')
-rw-r--r--arch/arm/kernel/smp_scu.c23
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm/kernel/smp_scu.c b/arch/arm/kernel/smp_scu.c
index 9ab4149bd983..a1e757c3439b 100644
--- a/arch/arm/kernel/smp_scu.c
+++ b/arch/arm/kernel/smp_scu.c
@@ -50,3 +50,26 @@ void __init scu_enable(void __iomem *scu_base)
*/
flush_cache_all();
}
+
+/*
+ * Set the executing CPUs power mode as defined. This will be in
+ * preparation for it executing a WFI instruction.
+ *
+ * This function must be called with preemption disabled, and as it
+ * has the side effect of disabling coherency, caches must have been
+ * flushed. Interrupts must also have been disabled.
+ */
+int scu_power_mode(void __iomem *scu_base, unsigned int mode)
+{
+ unsigned int val;
+ int cpu = smp_processor_id();
+
+ if (mode > 3 || mode == 1 || cpu > 3)
+ return -EINVAL;
+
+ val = __raw_readb(scu_base + SCU_CPU_STATUS + cpu) & ~0x03;
+ val |= mode;
+ __raw_writeb(val, scu_base + SCU_CPU_STATUS + cpu);
+
+ return 0;
+}