/*
* 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"
#ifdef CONFIG_CPU_IDLE
/* Machine specific information to be recorded in the C-state driver_data */
struct omap4_idle_statedata {
u32 cpu_state;
u32 mpu_logic_state;
u32 mpu_state;
u8 valid;
};
static struct cpuidle_params cpuidle_params_table[] = {
/* C1 - CPU0 ON + CPU1 ON + MPU ON */
{.exit_latency = 2 + 2 , .target_residency = 5, .valid = 1},
/* C2- CPU0 OFF + CPU1 OFF + MPU CSWR */
{.exit_latency = 328 + 440 , .target_residency = 960, .valid = 1},
/* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
{.exit_latency = 460 + 518 , .target_residency = 1100, .valid = 1},
};
#define OMAP4_NUM_STATES ARRAY_SIZE(cpuidle_params_table)
struct omap4_idle_statedata omap4_idle_data[OMAP4_NUM_STATES];
static struct powerdomain *mpu_pd, *cpu0_pd, *cpu1_pd;
/**
* omap4_enter_idle - Programs OMAP4 to enter the specified state
* @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(struct cpuidle_device *dev,
struct cpuidle_driver *drv,
int index)
{
struct omap4_idle_statedata *cx =
cpuidle_get_statedata(&dev->states_usage[index]);
struct timespec ts_preidle, ts_postidle, ts_idle;
u32 cpu1_state;
int idle_time;
int cpu_id = smp_processor_id();
/* Used to keep track of the total time in idle */
getnstimeofday(&ts_preidle);
local_irq_disable();
local_fiq_disable();
/*
* CPU0 has to stay ON (i.e in C1) 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.
* Update dev->last_state so that governor stats reflects right
* data.
*/
cpu1_state = pwrdm_read_pwrst(cpu1_pd);
if (cpu1_state != PWRDM_POWER_OFF) {
index = drv->safe_state_index;
cx = cpuidle_get_statedata(&dev->states_usage[index]);
}
if (index > 0)
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.
*/
if (cx->cpu_state == PWRDM_POWER_OFF)
cpu_pm_enter();
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);
/*
* Call idle CPU PM exit notifier chain to restore
* VFP and per CPU IRQ context. Only CPU0 state is
* considered since CPU1 is managed by CPU hotplug.
*/
if (pwrdm_read_prev_pwrst(cpu0_pd) == PWRDM_POWER_OFF)
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();
if (index > 0)
clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu_id);
getnstimeofday(&ts_postidle);
ts_idle = timespec_sub(ts_postidle, ts_preidle);
local_irq_enable();
local_fiq_enable();
idle_time = ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * \
USEC_PER_SEC;
/* Update cpuidle counters */
dev->last_residency = idle_time;
return index;
}
DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);
struct cpuidle_driver omap4_idle_driver = {
.name = "omap4_idle",
.owner = THIS_MODULE,
};
static inline void _fill_cstate(struct cpuidle_driver *drv,
int idx, const char *descr)
{
struct cpuidle_state *state = &drv->states[idx];
state->exit_latency = cpuidle_params_table[idx].exit_latency;
state->target_residency = cpuidle_params_table[idx].target_residency;
state->flags = CPUIDLE_FLAG_TIME_VALID;
state->enter = omap4_enter_idle;
sprintf(state->name, "C%d", idx + 1);
strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
}
static inline struct omap4_idle_statedata *_fill_cstate_usage(
struct cpuidle_device *dev,
int idx)
{
struct omap4_idle_statedata *cx = &omap4_idle_data[idx];
struct cpuidle_state_usage *state_usage = &dev->states_usage[idx];
cx->valid = cpuidle_params_table[idx].valid;
cpuidle_set_statedata(state_usage, cx);
return cx;
}
/**
* 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 omap4_idle_statedata *cx;
struct cpuidle_device *dev;
struct cpuidle_driver *drv = &omap4_idle_driver;
unsigned int cpu_id = 0;
mpu_pd = pwrdm_lookup("mpu_pwrdm");
cpu0_pd = pwrdm_lookup("cpu0_pwrdm");
cpu1_pd = pwrdm_lookup("cpu1_pwrdm");
if ((!mpu_pd) || (!cpu0_pd) || (!cpu1_pd))
return -ENODEV;
drv->safe_state_index = -1;
dev = &per_cpu(omap4_idle_dev, cpu_id);
dev->cpu = cpu_id;
/* C1 - CPU0 ON + CPU1 ON + MPU ON */
_fill_cstate(drv, 0, "MPUSS ON");
drv->safe_state_index = 0;
cx = _fill_cstate_usage(dev, 0);
cx->valid = 1; /* C1 is always valid */
cx->cpu_state = PWRDM_POWER_ON;
cx->mpu_state = PWRDM_POWER_ON;
cx->mpu_logic_state = PWRDM_POWER_RET;
/* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
_fill_cstate(drv, 1, "MPUSS CSWR");
cx = _fill_cstate_usage(dev, 1);
cx->cpu_state = PWRDM_POWER_OFF;
cx->mpu_state = PWRDM_POWER_RET;
cx->mpu_logic_state = PWRDM_POWER_RET;
/* C3 - CPU0 OFF + CPU1 OFF + MPU OSWR */
_fill_cstate(drv, 2, "MPUSS OSWR");
cx = _fill_cstate_usage(dev, 2);
cx->cpu_state = PWRDM_POWER_OFF;
cx->mpu_state = PWRDM_POWER_RET;
cx->mpu_logic_state = PWRDM_POWER_OFF;
drv->state_count = OMAP4_NUM_STATES;
cpuidle_register_driver(&omap4_idle_driver);
dev->state_count = OMAP4_NUM_STATES;
if (cpuidle_register_device(dev)) {
pr_err("%s: CPUidle register device failed\n", __func__);
return -EIO;
}
return 0;
}
#else
int __init omap4_idle_init(void)
{
return 0;
}
#endif /* CONFIG_CPU_IDLE */
