On 18 March 2011 08:51, Amit Daniel Kachhap
<amit.kachhap@linaro.org> wrote:
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: Amit Daniel Kachhap <amit.kachhap@linaro.org>
---
FIX: Fixed the merging issue reported by Nicolas Pitre <nicolas.pitre@linaro.org>
Sending the rebased patch for linaro 2.6.38 kernel. This patch adds basic cpuidle
infrastructure and fixes the launchpad bug(bug id: 723543). This patch is
under review in samsung mailing list.
http://www.spinics.net/lists/linux-samsung-soc/msg04268.html
arch/arm/mach-exynos4/Makefile | 1 +
arch/arm/mach-exynos4/cpuidle.c | 87 +++++++++++++++++++++++++++++++++++++++
2 files changed, 88 insertions(+), 0 deletions(-)
create mode 100644 arch/arm/mach-exynos4/cpuidle.c
diff --git a/arch/arm/mach-exynos4/Makefile b/arch/arm/mach-exynos4/Makefile
index b8f0e7d..f8a3a74 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 0000000..a543a18
--- /dev/null
+++ b/arch/arm/mach-exynos4/cpuidle.c
@@ -0,0 +1,87 @@
+/* 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);
--
1.7.1