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 000000000000..d533e2695f0e
--- /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);
+}