1 files changed, 95 insertions, 0 deletions
diff --git a/arch/arm/mach-imx/cpuidle-imx6q.c b/arch/arm/mach-imx/cpuidle-imx6q.c
new file mode 100644
index 00000000000..d533e2695f0
--- /dev/null
+++ b/arch/arm/mach-imx/cpuidle-imx6q.c
@@ -0,0 +1,95 @@
+/*
+ * 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/clockchips.h>
+#include <linux/cpuidle.h>
+#include <linux/module.h>
+#include <asm/cpuidle.h>
+#include <asm/proc-fns.h>
+
+#include "common.h"
+#include "cpuidle.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)
+{
+	int cpu = dev->cpu;
+
+	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
+
+	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);
+	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
+
+	return index;
+}
+
+/*
+ * For each cpu, setup the broadcast timer because local timer
+ * stops for the states other than WFI.
+ */
+static void imx6q_setup_broadcast_timer(void *arg)
+{
+	int cpu = smp_processor_id();
+
+	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &cpu);
+}
+
+static struct cpuidle_driver imx6q_cpuidle_driver = {
+	.name = "imx6q_cpuidle",
+	.owner = THIS_MODULE,
+	.en_core_tk_irqen = 1,
+	.states = {
+		/* WFI */
+		ARM_CPUIDLE_WFI_STATE,
+		/* WAIT */
+		{
+			.exit_latency = 50,
+			.target_residency = 75,
+			.flags = CPUIDLE_FLAG_TIME_VALID,
+			.enter = imx6q_enter_wait,
+			.name = "WAIT",
+			.desc = "Clock off",
+		},
+	},
+	.state_count = 2,
+	.safe_state_index = 0,
+};
+
+int __init imx6q_cpuidle_init(void)
+{
+	/* Need to enable SCU standby for entering WAIT modes */
+	imx_scu_standby_enable();
+
+	/* Set chicken bit to get a reliable WAIT mode support */
+	imx6q_set_chicken_bit();
+
+	/* Configure the broadcast timer on each cpu */
+	on_each_cpu(imx6q_setup_broadcast_timer, NULL, 1);
+
+	return imx_cpuidle_init(&imx6q_cpuidle_driver);
+}