/*
* CPU idle driver for Tegra CPUs
*
* Copyright (c) 2010-2012, NVIDIA Corporation.
* Copyright (c) 2011 Google, Inc.
* Author: Colin Cross <ccross@android.com>
* Gary King <gking@nvidia.com>
*
* Rework for 3.3 by Peter De Schrijver <pdeschrijver@nvidia.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/cpuidle.h>
#include <linux/cpu_pm.h>
#include <linux/clockchips.h>
#include <linux/clk/tegra.h>
#include <asm/cpuidle.h>
#include <asm/proc-fns.h>
#include <asm/suspend.h>
#include <asm/smp_plat.h>
#include "pm.h"
#include "sleep.h"
#include "iomap.h"
#include "irq.h"
#include "flowctrl.h"
#ifdef CONFIG_PM_SLEEP
static bool abort_flag;
static atomic_t abort_barrier;
static int tegra20_idle_lp2_coupled(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index);
#endif
static struct cpuidle_state tegra_idle_states[] = {
[0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
#ifdef CONFIG_PM_SLEEP
[1] = {
.enter = tegra20_idle_lp2_coupled,
.exit_latency = 5000,
.target_residency = 10000,
.power_usage = 0,
.flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_COUPLED,
.name = "powered-down",
.desc = "CPU power gated",
},
#endif
};
static struct cpuidle_driver tegra_idle_driver = {
.name = "tegra_idle",
.owner = THIS_MODULE,
.en_core_tk_irqen = 1,
};
static DEFINE_PER_CPU(struct cpuidle_device, tegra_idle_device);
#ifdef CONFIG_PM_SLEEP
#ifdef CONFIG_SMP
static void __iomem *pmc = IO_ADDRESS(TEGRA_PMC_BASE);
static int tegra20_reset_sleeping_cpu_1(void)
{
int ret = 0;
tegra_pen_lock();
if (readl(pmc + PMC_SCRATCH41) == CPU_RESETTABLE)
tegra20_cpu_shutdown(1);
else
ret = -EINVAL;
tegra_pen_unlock();
return ret;
}
static void tegra20_wake_cpu1_from_reset(void)
{
tegra_pen_lock();
tegra20_cpu_clear_resettable();
/* enable cpu clock on cpu */
tegra_enable_cpu_clock(1);
/* take the CPU out of reset */
tegra_cpu_out_of_reset(1);
/* unhalt the cpu */
flowctrl_write_cpu_halt(1, 0);
tegra_pen_unlock();
}
static int tegra20_reset_cpu_1(void)
{
if (!cpu_online(1) || !tegra20_reset_sleeping_cpu_1())
return 0;
tegra20_wake_cpu1_from_reset();
return -EBUSY;
}
#else
static inline void tegra20_wake_cpu1_from_reset(void)
{
}
static inline int tegra20_reset_cpu_1(void)
{
return 0;
}
#endif
static bool tegra20_cpu_cluster_power_down(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
struct cpuidle_state *state = &drv->states[index];
u32 cpu_on_time = state->exit_latency;
u32 cpu_off_time = state->target_residency - state->exit_latency;
while (tegra20_cpu_is_resettable_soon())
cpu_relax();
if (tegra20_reset_cpu_1() || !tegra_cpu_rail_off_ready())
return false;
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
tegra_idle_lp2_last(cpu_on_time, cpu_off_time);
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
if (cpu_online(1))
tegra20_wake_cpu1_from_reset();
return true;
}
#ifdef CONFIG_SMP
static bool tegra20_idle_enter_lp2_cpu_1(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
cpu_suspend(0, tegra20_sleep_cpu_secondary_finish);
tegra20_cpu_clear_resettable();
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
return true;
}
#else
static inline bool tegra20_idle_enter_lp2_cpu_1(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
return true;
}
#endif
static int tegra20_idle_lp2_coupled(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
u32 cpu = is_smp() ? cpu_logical_map(dev->cpu) : dev->cpu;
bool entered_lp2 = false;
if (tegra_pending_sgi())
ACCESS_ONCE(abort_flag) = true;
cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
if (abort_flag) {
cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
abort_flag = false; /* clean flag for next coming */
return -EINTR;
}
local_fiq_disable();
tegra_set_cpu_in_lp2(cpu);
cpu_pm_enter();
if (cpu == 0)
entered_lp2 = tegra20_cpu_cluster_power_down(dev, drv, index);
else
entered_lp2 = tegra20_idle_enter_lp2_cpu_1(dev, drv, index);
cpu_pm_exit();
tegra_clear_cpu_in_lp2(cpu);
local_fiq_enable();
smp_rmb();
return entered_lp2 ? index : 0;
}
#endif
int __init tegra20_cpuidle_init(void)
{
int ret;
unsigned int cpu;
struct cpuidle_device *dev;
struct cpuidle_driver *drv = &tegra_idle_driver;
#ifdef CONFIG_PM_SLEEP
tegra_tear_down_cpu = tegra20_tear_down_cpu;
#endif
drv->state_count = ARRAY_SIZE(tegra_idle_states);
memcpy(drv->states, tegra_idle_states,
drv->state_count * sizeof(drv->states[0]));
ret = cpuidle_register_driver(&tegra_idle_driver);
if (ret) {
pr_err("CPUidle driver registration failed\n");
return ret;
}
for_each_possible_cpu(cpu) {
dev = &per_cpu(tegra_idle_device, cpu);
dev->cpu = cpu;
#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
dev->coupled_cpus = *cpu_possible_mask;
#endif
dev->state_count = drv->state_count;
ret = cpuidle_register_device(dev);
if (ret) {
pr_err("CPU%u: CPUidle device registration failed\n",
cpu);
return ret;
}
}
return 0;
}
