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Diffstat (limited to 'kernel/arch/arm/mach-imx/cpuidle-imx6q.c')
-rw-r--r--kernel/arch/arm/mach-imx/cpuidle-imx6q.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/kernel/arch/arm/mach-imx/cpuidle-imx6q.c b/kernel/arch/arm/mach-imx/cpuidle-imx6q.c
new file mode 100644
index 000000000..8e21ccc1e
--- /dev/null
+++ b/kernel/arch/arm/mach-imx/cpuidle-imx6q.c
@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2012 Freescale Semiconductor, Inc.
+ *
+ * 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/cpuidle.h>
+#include <linux/module.h>
+#include <asm/cpuidle.h>
+
+#include "common.h"
+#include "cpuidle.h"
+#include "hardware.h"
+
+static atomic_t master = ATOMIC_INIT(0);
+static DEFINE_SPINLOCK(master_lock);
+
+static int imx6q_enter_wait(struct cpuidle_device *dev,
+ struct cpuidle_driver *drv, int index)
+{
+ if (atomic_inc_return(&master) == num_online_cpus()) {
+ /*
+ * With this lock, we prevent other cpu to exit and enter
+ * this function again and become the master.
+ */
+ if (!spin_trylock(&master_lock))
+ goto idle;
+ imx6q_set_lpm(WAIT_UNCLOCKED);
+ cpu_do_idle();
+ imx6q_set_lpm(WAIT_CLOCKED);
+ spin_unlock(&master_lock);
+ goto done;
+ }
+
+idle:
+ cpu_do_idle();
+done:
+ atomic_dec(&master);
+
+ return index;
+}
+
+static struct cpuidle_driver imx6q_cpuidle_driver = {
+ .name = "imx6q_cpuidle",
+ .owner = THIS_MODULE,
+ .states = {
+ /* WFI */
+ ARM_CPUIDLE_WFI_STATE,
+ /* WAIT */
+ {
+ .exit_latency = 50,
+ .target_residency = 75,
+ .flags = CPUIDLE_FLAG_TIMER_STOP,
+ .enter = imx6q_enter_wait,
+ .name = "WAIT",
+ .desc = "Clock off",
+ },
+ },
+ .state_count = 2,
+ .safe_state_index = 0,
+};
+
+int __init imx6q_cpuidle_init(void)
+{
+ /* Set INT_MEM_CLK_LPM bit to get a reliable WAIT mode support */
+ imx6q_set_int_mem_clk_lpm(true);
+
+ return cpuidle_register(&imx6q_cpuidle_driver, NULL);
+}