/* 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);
