diff options
Diffstat (limited to 'arch/arm/mach-exynos/cpuidle.c')
-rw-r--r-- | arch/arm/mach-exynos/cpuidle.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/arch/arm/mach-exynos/cpuidle.c b/arch/arm/mach-exynos/cpuidle.c new file mode 100644 index 00000000..33ab4e75 --- /dev/null +++ b/arch/arm/mach-exynos/cpuidle.c @@ -0,0 +1,235 @@ +/* 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/cpu_pm.h> +#include <linux/io.h> +#include <linux/export.h> +#include <linux/time.h> + +#include <asm/proc-fns.h> +#include <asm/smp_scu.h> +#include <asm/suspend.h> +#include <asm/unified.h> +#include <mach/regs-pmu.h> +#include <mach/pmu.h> + +#include <plat/cpu.h> + +#define REG_DIRECTGO_ADDR (samsung_rev() == EXYNOS4210_REV_1_1 ? \ + S5P_INFORM7 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \ + (S5P_VA_SYSRAM + 0x24) : S5P_INFORM0)) +#define REG_DIRECTGO_FLAG (samsung_rev() == EXYNOS4210_REV_1_1 ? \ + S5P_INFORM6 : (samsung_rev() == EXYNOS4210_REV_1_0 ? \ + (S5P_VA_SYSRAM + 0x20) : S5P_INFORM1)) + +#define S5P_CHECK_AFTR 0xFCBA0D10 + +static int exynos4_enter_idle(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index); +static int exynos4_enter_lowpower(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index); + +static struct cpuidle_state exynos4_cpuidle_set[] __initdata = { + [0] = { + .enter = exynos4_enter_idle, + .exit_latency = 1, + .target_residency = 100000, + .flags = CPUIDLE_FLAG_TIME_VALID, + .name = "C0", + .desc = "ARM clock gating(WFI)", + }, + [1] = { + .enter = exynos4_enter_lowpower, + .exit_latency = 300, + .target_residency = 100000, + .flags = CPUIDLE_FLAG_TIME_VALID, + .name = "C1", + .desc = "ARM power down", + }, +}; + +static DEFINE_PER_CPU(struct cpuidle_device, exynos4_cpuidle_device); + +static struct cpuidle_driver exynos4_idle_driver = { + .name = "exynos4_idle", + .owner = THIS_MODULE, +}; + +/* Ext-GIC nIRQ/nFIQ is the only wakeup source in AFTR */ +static void exynos4_set_wakeupmask(void) +{ + __raw_writel(0x0000ff3e, S5P_WAKEUP_MASK); +} + +static unsigned int g_pwr_ctrl, g_diag_reg; + +static void save_cpu_arch_register(void) +{ + /*read power control register*/ + asm("mrc p15, 0, %0, c15, c0, 0" : "=r"(g_pwr_ctrl) : : "cc"); + /*read diagnostic register*/ + asm("mrc p15, 0, %0, c15, c0, 1" : "=r"(g_diag_reg) : : "cc"); + return; +} + +static void restore_cpu_arch_register(void) +{ + /*write power control register*/ + asm("mcr p15, 0, %0, c15, c0, 0" : : "r"(g_pwr_ctrl) : "cc"); + /*write diagnostic register*/ + asm("mcr p15, 0, %0, c15, c0, 1" : : "r"(g_diag_reg) : "cc"); + return; +} + +static int idle_finisher(unsigned long flags) +{ + cpu_do_idle(); + return 1; +} + +static int exynos4_enter_core0_aftr(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + struct timeval before, after; + int idle_time; + unsigned long tmp; + + local_irq_disable(); + do_gettimeofday(&before); + + exynos4_set_wakeupmask(); + + /* Set value of power down register for aftr mode */ + exynos4_sys_powerdown_conf(SYS_AFTR); + + __raw_writel(virt_to_phys(s3c_cpu_resume), REG_DIRECTGO_ADDR); + __raw_writel(S5P_CHECK_AFTR, REG_DIRECTGO_FLAG); + + save_cpu_arch_register(); + + /* Setting Central Sequence Register for power down mode */ + tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION); + tmp &= ~S5P_CENTRAL_LOWPWR_CFG; + __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION); + + cpu_pm_enter(); + cpu_suspend(0, idle_finisher); + +#ifdef CONFIG_SMP + scu_enable(S5P_VA_SCU); +#endif + cpu_pm_exit(); + + restore_cpu_arch_register(); + + /* + * If PMU failed while entering sleep mode, WFI will be + * ignored by PMU and then exiting cpu_do_idle(). + * S5P_CENTRAL_LOWPWR_CFG bit will not be set automatically + * in this situation. + */ + tmp = __raw_readl(S5P_CENTRAL_SEQ_CONFIGURATION); + if (!(tmp & S5P_CENTRAL_LOWPWR_CFG)) { + tmp |= S5P_CENTRAL_LOWPWR_CFG; + __raw_writel(tmp, S5P_CENTRAL_SEQ_CONFIGURATION); + } + + /* Clear wakeup state register */ + __raw_writel(0x0, S5P_WAKEUP_STAT); + + 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 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 exynos4_enter_lowpower(struct cpuidle_device *dev, + struct cpuidle_driver *drv, + int index) +{ + int new_index = index; + + /* This mode only can be entered when other core's are offline */ + if (num_online_cpus() > 1) + new_index = drv->safe_state_index; + + if (new_index == 0) + return exynos4_enter_idle(dev, drv, new_index); + else + return exynos4_enter_core0_aftr(dev, drv, new_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)); + } + drv->safe_state_index = 0; + 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; + + if (cpu_id == 0) + device->state_count = (sizeof(exynos4_cpuidle_set) / + sizeof(struct cpuidle_state)); + else + device->state_count = 1; /* Support IDLE only */ + + if (cpuidle_register_device(device)) { + printk(KERN_ERR "CPUidle register device failed\n,"); + return -EIO; + } + } + + return 0; +} +device_initcall(exynos4_init_cpuidle); |