/*
* 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"
#ifdef CONFIG_PM_SLEEP
static int tegra30_idle_lp2(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index);
#endif
static struct cpuidle_driver tegra_idle_driver = {
.name = "tegra_idle",
.owner = THIS_MODULE,
.en_core_tk_irqen = 1,
#ifdef CONFIG_PM_SLEEP
.state_count = 2,
#else
.state_count = 1,
#endif
.states = {
[0] = ARM_CPUIDLE_WFI_STATE_PWR(600),
#ifdef CONFIG_PM_SLEEP
[1] = {
.enter = tegra30_idle_lp2,
.exit_latency = 2000,
.target_residency = 2200,
.power_usage = 0,
.flags = CPUIDLE_FLAG_TIME_VALID,
.name = "powered-down",
.desc = "CPU power gated",
},
#endif
},
};
static DEFINE_PER_CPU(struct cpuidle_device, tegra_idle_device);
#ifdef CONFIG_PM_SLEEP
static bool tegra30_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;
/* All CPUs entering LP2 is not working.
* Don't let CPU0 enter LP2 when any secondary CPU is online.
*/
if (num_online_cpus() > 1 || !tegra_cpu_rail_off_ready()) {
cpu_do_idle();
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);
return true;
}
#ifdef CONFIG_SMP
static bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu);
smp_wmb();
save_cpu_arch_register();
cpu_suspend(0, tegra30_sleep_cpu_secondary_finish);
restore_cpu_arch_register();
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu);
return true;
}
#else
static inline bool tegra30_cpu_core_power_down(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
return true;
}
#endif
static int tegra30_idle_lp2(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;
bool last_cpu;
local_fiq_disable();
last_cpu = tegra_set_cpu_in_lp2(cpu);
cpu_pm_enter();
if (cpu == 0) {
if (last_cpu)
entered_lp2 = tegra30_cpu_cluster_power_down(dev, drv,
index);
else
cpu_do_idle();
} else {
entered_lp2 = tegra30_cpu_core_power_down(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 tegra30_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 = tegra30_tear_down_cpu;
#endif
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;
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;
}
