From 3d73998558beac1e56efaaf7c5bf3469ee4c6ba2 Mon Sep 17 00:00:00 2001 From: Jaecheol Lee Date: Wed, 16 Mar 2011 07:28:23 +0900 Subject: 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 Signed-off-by: Kukjin Kim --- arch/arm/mach-exynos4/cpuidle.c | 86 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 arch/arm/mach-exynos4/cpuidle.c (limited to 'arch/arm/mach-exynos4/cpuidle.c') 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 +#include +#include +#include + +#include + +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); -- cgit v1.2.3