diff options
Diffstat (limited to 'arch/arm/mach-exynos/cpuidle.c')
-rw-r--r-- | arch/arm/mach-exynos/cpuidle.c | 90 |
1 files changed, 90 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c new file mode 100644 index 000000000000..35f6502144ae --- /dev/null +++ b/arch/arm/mach-exynos/cpuidle.c @@ -0,0 +1,90 @@ +/* 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_driver *drv, + int index); + +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_driver *drv, + int index) +{ + 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); + + dev->last_residency = idle_time; + return index; +} + +static int __init exynos4_init_cpuidle(void) +{ + int i, max_cpuidle_state, cpu_id; + struct cpuidle_device *device; + struct cpuidle_driver *drv = &exynos4_idle_driver; + + /* Setup cpuidle driver */ + drv->state_count = (sizeof(exynos4_cpuidle_set) / + sizeof(struct cpuidle_state)); + max_cpuidle_state = drv->state_count; + for (i = 0; i < max_cpuidle_state; i++) { + memcpy(&drv->states[i], &exynos4_cpuidle_set[i], + sizeof(struct cpuidle_state)); + } + 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 = drv->state_count; + + if (cpuidle_register_device(device)) { + printk(KERN_ERR "CPUidle register device failed\n,"); + return -EIO; + } + } + return 0; +} +device_initcall(exynos4_init_cpuidle); |