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authorJaecheol Lee <jc.lee@samsung.com>2011-04-13 11:11:38 +0100
committerAndy Green <andy.green@linaro.org>2011-04-13 11:11:38 +0100
commit866bef3f248f3de56c6eacb6b5df71507aa6378b (patch)
treea96d3e75ffcae4156648cbce49f6ee6ac78bae51
parent7ff3a2519e274c19b1ebe4a0acc0f5f36667868e (diff)
ARM: EXYNOS4: CPUIDLE Support
This patch supports cpuidle framework for EXYNOS4210. Currently, Only one idle state is possible to use, but more idle states can be added following by this patch. Signed-off-by: Jaecheol Lee <jc.lee@samsung.com> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com> (cherry picked from commit df7bf189d23ecd1c211c273de462b93d9e3e1fef)
-rw-r--r--arch/arm/mach-exynos4/Makefile1
-rw-r--r--arch/arm/mach-exynos4/cpuidle.c86
2 files changed, 87 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos4/Makefile b/arch/arm/mach-exynos4/Makefile
index 9be104f63c0..de197d6648a 100644
--- a/arch/arm/mach-exynos4/Makefile
+++ b/arch/arm/mach-exynos4/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_CPU_EXYNOS4210) += cpu.o init.o clock.o irq-combiner.o
obj-$(CONFIG_CPU_EXYNOS4210) += setup-i2c0.o gpiolib.o irq-eint.o dma.o
obj-$(CONFIG_PM) += pm.o sleep.o
obj-$(CONFIG_CPU_FREQ) += cpufreq.o
+obj-$(CONFIG_CPU_IDLE) += cpuidle.o
obj-$(CONFIG_SMP) += platsmp.o headsmp.o
diff --git a/arch/arm/mach-exynos4/cpuidle.c b/arch/arm/mach-exynos4/cpuidle.c
new file mode 100644
index 00000000000..bf7e96f2793
--- /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);