summaryrefslogtreecommitdiff
path: root/arch/arm/mach-exynos4/cpuidle.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-exynos4/cpuidle.c')
-rw-r--r--arch/arm/mach-exynos4/cpuidle.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos4/cpuidle.c b/arch/arm/mach-exynos4/cpuidle.c
new file mode 100644
index 000000000000..bf7e96f2793a
--- /dev/null
+++ b/arch/arm/mach-exynos4/cpuidle.c
@@ -0,0 +1,86 @@
+/* linux/arch/arm/mach-exynos4/cpuidle.c
+ *
+ * Copyright (c) 2011 Samsung Electronics Co., Ltd.
+ * http://www.samsung.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/kernel.h>
+#include <linux/init.h>
+#include <linux/cpuidle.h>
+#include <linux/io.h>
+
+#include <asm/proc-fns.h>
+
+static int exynos4_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_state *state);
+
+static struct cpuidle_state exynos4_cpuidle_set[] = {
+ [0] = {
+ .enter = exynos4_enter_idle,
+ .exit_latency = 1,
+ .target_residency = 100000,
+ .flags = CPUIDLE_FLAG_TIME_VALID,
+ .name = "IDLE",
+ .desc = "ARM clock gating(WFI)",
+ },
+};
+
+static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device);
+
+static struct cpuidle_driver exynos4_idle_driver = {
+ .name = "exynos4_idle",
+ .owner = THIS_MODULE,
+};
+
+static int exynos4_enter_idle(struct cpuidle_device *dev,
+ struct cpuidle_state *state)
+{
+ struct timeval before, after;
+ int idle_time;
+
+ local_irq_disable();
+ do_gettimeofday(&before);
+
+ cpu_do_idle();
+
+ do_gettimeofday(&after);
+ local_irq_enable();
+ idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC +
+ (after.tv_usec - before.tv_usec);
+
+ return idle_time;
+}
+
+static int __init exynos4_init_cpuidle(void)
+{
+ int i, max_cpuidle_state, cpu_id;
+ struct cpuidle_device *device;
+
+ cpuidle_register_driver(&exynos4_idle_driver);
+
+ for_each_cpu(cpu_id, cpu_online_mask) {
+ device = &per_cpu(exynos4_cpuidle_device, cpu_id);
+ device->cpu = cpu_id;
+
+ device->state_count = (sizeof(exynos4_cpuidle_set) /
+ sizeof(struct cpuidle_state));
+
+ max_cpuidle_state = device->state_count;
+
+ for (i = 0; i < max_cpuidle_state; i++) {
+ memcpy(&device->states[i], &exynos4_cpuidle_set[i],
+ sizeof(struct cpuidle_state));
+ }
+
+ if (cpuidle_register_device(device)) {
+ printk(KERN_ERR "CPUidle register device failed\n,");
+ return -EIO;
+ }
+ }
+ return 0;
+}
+device_initcall(exynos4_init_cpuidle);