This patch supports cpuidle framework for samsung S5PV310. Currently, Only one idle state is possible to use, but more idle states can be added followed by this patch.
Signed-off-by: Jaecheol Lee jc.lee@samsung.com Signed-off-by: Amit Daniel Kachhap amit.kachhap@linaro.org --- Rebasing the 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-s5pv310/Makefile | 1 + arch/arm/mach-s5pv310/cpuidle.c | 87 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 88 insertions(+), 0 deletions(-) create mode 100644 arch/arm/mach-s5pv310/cpuidle.c
diff --git a/arch/arm/mach-s5pv310/Makefile b/arch/arm/mach-s5pv310/Makefile index 036fb38..c5db0fa 100644 --- a/arch/arm/mach-s5pv310/Makefile +++ b/arch/arm/mach-s5pv310/Makefile @@ -15,6 +15,7 @@ obj- := obj-$(CONFIG_CPU_S5PV310) += cpu.o init.o clock.o irq-combiner.o obj-$(CONFIG_CPU_S5PV310) += setup-i2c0.o time.o gpiolib.o irq-eint.o dma.o obj-$(CONFIG_CPU_FREQ) += cpufreq.o +obj-$(CONFIG_CPU_IDLE) += cpuidle.o
obj-$(CONFIG_SMP) += platsmp.o headsmp.o obj-$(CONFIG_LOCAL_TIMERS) += localtimer.o diff --git a/arch/arm/mach-s5pv310/cpuidle.c b/arch/arm/mach-s5pv310/cpuidle.c new file mode 100644 index 0000000..f35b537 --- /dev/null +++ b/arch/arm/mach-s5pv310/cpuidle.c @@ -0,0 +1,87 @@ +/* linux/arch/arm/mach-s5pv310/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 s5pv310_enter_idle(struct cpuidle_device *dev, + struct cpuidle_state *state); + +static struct cpuidle_state s5pv310_cpuidle_set[] = { + [0] = { + .enter = s5pv310_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, s5pv310_cpuidle_device); + +static struct cpuidle_driver s5pv310_idle_driver = { + .name = "s5pv310_idle", + .owner = THIS_MODULE, +}; + +static int s5pv310_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 s5pv310_init_cpuidle(void) +{ + int i, max_cpuidle_state, cpu_id; + struct cpuidle_device *device; + + cpuidle_register_driver(&s5pv310_idle_driver); + + for_each_cpu(cpu_id, cpu_online_mask) { + device = &per_cpu(s5pv310_cpuidle_device, cpu_id); + device->cpu = cpu_id; + + device->state_count = (sizeof(s5pv310_cpuidle_set) / + sizeof(struct cpuidle_state)); + + max_cpuidle_state = device->state_count; + + for (i = 0; i < max_cpuidle_state; i++) { + memcpy(&device->states[i], &s5pv310_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(s5pv310_init_cpuidle);