/*
* OMAP4 CPU idle Routines
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Santosh Shilimkar <santosh.shilimkar@ti.com>
* Rajendra Nayak <rnayak@ti.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/sched.h>
#include <linux/cpuidle.h>
#include <linux/cpu_pm.h>
#include <linux/export.h>
#include <linux/clockchips.h>
#include <asm/proc-fns.h>
#include "common.h"
#include "pm.h"
#include "prm.h"
#include "clockdomain.h"
/* Machine specific information */
struct omap4_idle_statedata {
u32 cpu_state;
u32 mpu_logic_state;
u32 mpu_state;
};
static struct omap4_idle_statedata omap4_idle_data[] = {
{
.cpu_state = PWRDM_POWER_ON,
.mpu_state = PWRDM_POWER_ON,
.mpu_logic_state = PWRDM_POWER_RET,
},
{
.cpu_state = PWRDM_POWER_OFF,
.mpu_state = PWRDM_POWER_RET,
.mpu_logic_state = PWRDM_POWER_RET,
},
{
.cpu_state = PWRDM_POWER_OFF,
.mpu_state = PWRDM_POWER_RET,
.mpu_logic_state = PWRDM_POWER_OFF,
},
};
static struct powerdomain *mpu_pd, *cpu_pd[NR_CPUS];
static struct clockdomain *cpu_clkdm[NR_CPUS];
static atomic_t abort_barrier;
static bool cpu_done[NR_CPUS];
/* Private functions */
/**
* omap4_enter_idle_coupled_[simple/coupled] - OMAP4 cpuidle entry functions
* @dev: cpuidle device
* @drv: cpuidle driver
* @index: the index of state to be entered
*
* Called from the CPUidle framework to program the device to the
* specified low power state selected by the governor.
* Returns the amount of time spent in the low power state.
*/
static int omap4_enter_idle_simple(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
omap_do_wfi();
return index;
}
static int omap4_enter_idle_coupled(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
struct omap4_idle_statedata *cx = &omap4_idle_data[index];
int cpu_id = smp_processor_id();
/*
* CPU0 has to wait and stay ON until CPU1 is OFF state.
* This is necessary to honour hardware recommondation
* of triggeing all the possible low power modes once CPU1 is
* out of coherency and in OFF mode.
*/
if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
while (pwrdm_read_pwrst(cpu_pd[1]) != PWRDM_POWER_OFF) {
cpu_relax();
/*
* CPU1 could have already entered & exited idle
* without hitting off because of a wakeup
* or a failed attempt to hit off mode. Check for
* that here, otherwise we could spin forever
* waiting for CPU1 off.
*/
if (cpu_done[1])
goto fail;
}
}
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu_id);
/*
* Call idle CPU PM enter notifier chain so that
* VFP and per CPU interrupt context is saved.
*/
cpu_pm_enter();
if (dev->cpu == 0) {
pwrdm_set_logic_retst(mpu_pd, cx->mpu_logic_state);
omap_set_pwrdm_state(mpu_pd, cx->mpu_state);
/*
* Call idle CPU cluster PM enter notifier chain
* to save GIC and wakeupgen context.
*/
if ((cx->mpu_state == PWRDM_POWER_RET) &&
(cx->mpu_logic_state == PWRDM_POWER_OFF))
cpu_cluster_pm_enter();
}
omap4_enter_lowpower(dev->cpu, cx->cpu_state);
cpu_done[dev->cpu] = true;
/* Wakeup CPU1 only if it is not offlined */
if (dev->cpu == 0 && cpumask_test_cpu(1, cpu_online_mask)) {
clkdm_wakeup(cpu_clkdm[1]);
clkdm_allow_idle(cpu_clkdm[1]);
}
/*
* Call idle CPU PM exit notifier chain to restore
* VFP and per CPU IRQ context.
*/
cpu_pm_exit();
/*
* Call idle CPU cluster PM exit notifier chain
* to restore GIC and wakeupgen context.
*/
if (omap4_mpuss_read_prev_context_state())
cpu_cluster_pm_exit();
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);
fail:
cpuidle_coupled_parallel_barrier(dev, &abort_barrier);
cpu_done[dev->cpu] = false;
return index;
}
/*
* For each cpu, setup the broadcast timer because local timers
* stops for the states above C1.
*/
static void omap_setup_broadcast_timer(void *arg)
{
int cpu = smp_processor_id();
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &cpu);
}
static DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);
static struct cpuidle_driver omap4_idle_driver = {
.name = "omap4_idle",
.owner = THIS_MODULE,
.en_core_tk_irqen = 1,
.states = {
{
/* C1 - CPU0 ON + CPU1 ON + MPU ON */
.exit_latency = 2 + 2,
.target_residency = 5,
.flags = CPUIDLE_FLAG_TIME_VALID,
.enter = omap4_enter_idle_simple,
.name = "C1",
.desc = "MPUSS ON"
},
{
/* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
.exit_latency = 328 + 440,
.target_residency = 960,
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
.enter = omap4_enter_idle_coupled,
.name = "C2",
.desc = "MPUSS CSWR",
},
{
/* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
.exit_latency = 460 + 518,
.target_residency = 1100,
.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
.enter = omap4_enter_idle_coupled,
.name = "C3",
.desc = "MPUSS OSWR",
},
},
.state_count = ARRAY_SIZE(omap4_idle_data),
.safe_state_index = 0,
};
/* Public functions */
/**
* omap4_idle_init - Init routine for OMAP4 idle
*
* Registers the OMAP4 specific cpuidle driver to the cpuidle
* framework with the valid set of states.
*/
int __init omap4_idle_init(void)
{
struct cpuidle_device *dev;
unsigned int cpu_id = 0;
mpu_pd = pwrdm_lookup("mpu_pwrdm");
cpu_pd[0] = pwrdm_lookup("cpu0_pwrdm");
cpu_pd[1] = pwrdm_lookup("cpu1_pwrdm");
if ((!mpu_pd) || (!cpu_pd[0]) || (!cpu_pd[1]))
return -ENODEV;
cpu_clkdm[0] = clkdm_lookup("mpu0_clkdm");
cpu_clkdm[1] = clkdm_lookup("mpu1_clkdm");
if (!cpu_clkdm[0] || !cpu_clkdm[1])
return -ENODEV;
/* Configure the broadcast timer on each cpu */
on_each_cpu(omap_setup_broadcast_timer, NULL, 1);
for_each_cpu(cpu_id, cpu_online_mask) {
dev = &per_cpu(omap4_idle_dev, cpu_id);
dev->cpu = cpu_id;
#ifdef CONFIG_ARCH_NEEDS_CPU_IDLE_COUPLED
dev->coupled_cpus = *cpu_online_mask;
#endif
cpuidle_register_driver(&omap4_idle_driver);
if (cpuidle_register_device(dev)) {
pr_err("%s: CPUidle register failed\n", __func__);
return -EIO;
}
}
return 0;
}
