linux/arch/arm/mach-omap2/cpuidle34xx.c
Jean Pihet badc303a86 OMAP3: cpuidle: re-organize the C-states data
The current implementation defines an internal structure and a
C-states array. Using those structures is redundant to the
structs used by the cpuidle framework.

This patch provides a clean-up of the internal struct, removes the
internal C-states array, stores the data using the existing cpuidle
per C-state struct and registers the mach specific data to cpuidle
C-state driver_data (accessed using cpuidle_[gs]et_statedata).
Also removes unused macros, fields and code and compacts the repeating
code using an inline helper function.

The result is more compact and more readable code as well as
reduced data RAM usage.

Also retain C1 as the only always valid C-state and system safe state.

Signed-off-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
2011-05-20 17:15:53 +02:00

430 lines
11 KiB
C

/*
* linux/arch/arm/mach-omap2/cpuidle34xx.c
*
* OMAP3 CPU IDLE Routines
*
* Copyright (C) 2008 Texas Instruments, Inc.
* Rajendra Nayak <rnayak@ti.com>
*
* Copyright (C) 2007 Texas Instruments, Inc.
* Karthik Dasu <karthik-dp@ti.com>
*
* Copyright (C) 2006 Nokia Corporation
* Tony Lindgren <tony@atomide.com>
*
* Copyright (C) 2005 Texas Instruments, Inc.
* Richard Woodruff <r-woodruff2@ti.com>
*
* Based on pm.c for omap2
*
* 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 <plat/prcm.h>
#include <plat/irqs.h>
#include "powerdomain.h"
#include "clockdomain.h"
#include <plat/serial.h>
#include "pm.h"
#include "control.h"
#ifdef CONFIG_CPU_IDLE
/*
* The latencies/thresholds for various C states have
* to be configured from the respective board files.
* These are some default values (which might not provide
* the best power savings) used on boards which do not
* pass these details from the board file.
*/
static struct cpuidle_params cpuidle_params_table[] = {
/* C1 */
{2 + 2, 5, 1},
/* C2 */
{10 + 10, 30, 1},
/* C3 */
{50 + 50, 300, 1},
/* C4 */
{1500 + 1800, 4000, 1},
/* C5 */
{2500 + 7500, 12000, 1},
/* C6 */
{3000 + 8500, 15000, 1},
/* C7 */
{10000 + 30000, 300000, 1},
};
#define OMAP3_NUM_STATES ARRAY_SIZE(cpuidle_params_table)
/* Mach specific information to be recorded in the C-state driver_data */
struct omap3_idle_statedata {
u32 mpu_state;
u32 core_state;
u8 valid;
};
struct omap3_idle_statedata omap3_idle_data[OMAP3_NUM_STATES];
struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
static int omap3_idle_bm_check(void)
{
if (!omap3_can_sleep())
return 1;
return 0;
}
static int _cpuidle_allow_idle(struct powerdomain *pwrdm,
struct clockdomain *clkdm)
{
clkdm_allow_idle(clkdm);
return 0;
}
static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
struct clockdomain *clkdm)
{
clkdm_deny_idle(clkdm);
return 0;
}
/**
* omap3_enter_idle - Programs OMAP3 to enter the specified state
* @dev: cpuidle device
* @state: The target state to be programmed
*
* Called from the CPUidle framework to program the device to the
* specified target state selected by the governor.
*/
static int omap3_enter_idle(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
struct omap3_idle_statedata *cx = cpuidle_get_statedata(state);
struct timespec ts_preidle, ts_postidle, ts_idle;
u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
/* Used to keep track of the total time in idle */
getnstimeofday(&ts_preidle);
local_irq_disable();
local_fiq_disable();
pwrdm_set_next_pwrst(mpu_pd, mpu_state);
pwrdm_set_next_pwrst(core_pd, core_state);
if (omap_irq_pending() || need_resched())
goto return_sleep_time;
/* Deny idle for C1 */
if (state == &dev->states[0]) {
pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
}
/* Execute ARM wfi */
omap_sram_idle();
/* Re-allow idle for C1 */
if (state == &dev->states[0]) {
pwrdm_for_each_clkdm(mpu_pd, _cpuidle_allow_idle);
pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle);
}
return_sleep_time:
getnstimeofday(&ts_postidle);
ts_idle = timespec_sub(ts_postidle, ts_preidle);
local_irq_enable();
local_fiq_enable();
return ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * USEC_PER_SEC;
}
/**
* next_valid_state - Find next valid c-state
* @dev: cpuidle device
* @state: Currently selected c-state
*
* If the current state is valid, it is returned back to the caller.
* Else, this function searches for a lower c-state which is still
* valid.
*/
static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
struct cpuidle_state *curr)
{
struct cpuidle_state *next = NULL;
struct omap3_idle_statedata *cx;
cx = cpuidle_get_statedata(curr);
/* Check if current state is valid */
if (cx->valid) {
return curr;
} else {
int idx = OMAP3_NUM_STATES - 1;
/*
* Reach the current state starting at highest C-state
*/
for (; idx >= 0; idx--) {
if (&dev->states[idx] == curr) {
next = &dev->states[idx];
break;
}
}
/*
* Should never hit this condition.
*/
WARN_ON(next == NULL);
/*
* Drop to next valid state.
* Start search from the next (lower) state.
*/
idx--;
for (; idx >= 0; idx--) {
cx = cpuidle_get_statedata(&dev->states[idx]);
if (cx->valid) {
next = &dev->states[idx];
break;
}
}
/*
* C1 is always valid.
* So, no need to check for 'next==NULL' outside this loop.
*/
}
return next;
}
/**
* omap3_enter_idle_bm - Checks for any bus activity
* @dev: cpuidle device
* @state: The target state to be programmed
*
* This function checks for any pending activity and then programs
* the device to the specified or a safer state.
*/
static int omap3_enter_idle_bm(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
struct cpuidle_state *new_state = next_valid_state(dev, state);
u32 core_next_state, per_next_state = 0, per_saved_state = 0;
u32 cam_state;
struct omap3_idle_statedata *cx;
int ret;
if (omap3_idle_bm_check()) {
BUG_ON(!dev->safe_state);
new_state = dev->safe_state;
goto select_state;
}
cx = cpuidle_get_statedata(state);
core_next_state = cx->core_state;
/*
* FIXME: we currently manage device-specific idle states
* for PER and CORE in combination with CPU-specific
* idle states. This is wrong, and device-specific
* idle management needs to be separated out into
* its own code.
*/
/*
* Prevent idle completely if CAM is active.
* CAM does not have wakeup capability in OMAP3.
*/
cam_state = pwrdm_read_pwrst(cam_pd);
if (cam_state == PWRDM_POWER_ON) {
new_state = dev->safe_state;
goto select_state;
}
/*
* Prevent PER off if CORE is not in retention or off as this
* would disable PER wakeups completely.
*/
per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd);
if ((per_next_state == PWRDM_POWER_OFF) &&
(core_next_state > PWRDM_POWER_RET))
per_next_state = PWRDM_POWER_RET;
/* Are we changing PER target state? */
if (per_next_state != per_saved_state)
pwrdm_set_next_pwrst(per_pd, per_next_state);
select_state:
dev->last_state = new_state;
ret = omap3_enter_idle(dev, new_state);
/* Restore original PER state if it was modified */
if (per_next_state != per_saved_state)
pwrdm_set_next_pwrst(per_pd, per_saved_state);
return ret;
}
DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
/**
* omap3_cpuidle_update_states() - Update the cpuidle states
* @mpu_deepest_state: Enable states up to and including this for mpu domain
* @core_deepest_state: Enable states up to and including this for core domain
*
* This goes through the list of states available and enables and disables the
* validity of C states based on deepest state that can be achieved for the
* variable domain
*/
void omap3_cpuidle_update_states(u32 mpu_deepest_state, u32 core_deepest_state)
{
int i;
for (i = 0; i < OMAP3_NUM_STATES; i++) {
struct omap3_idle_statedata *cx = &omap3_idle_data[i];
if ((cx->mpu_state >= mpu_deepest_state) &&
(cx->core_state >= core_deepest_state)) {
cx->valid = 1;
} else {
cx->valid = 0;
}
}
}
void omap3_pm_init_cpuidle(struct cpuidle_params *cpuidle_board_params)
{
int i;
if (!cpuidle_board_params)
return;
for (i = 0; i < OMAP3_NUM_STATES; i++) {
cpuidle_params_table[i].valid = cpuidle_board_params[i].valid;
cpuidle_params_table[i].exit_latency =
cpuidle_board_params[i].exit_latency;
cpuidle_params_table[i].target_residency =
cpuidle_board_params[i].target_residency;
}
return;
}
struct cpuidle_driver omap3_idle_driver = {
.name = "omap3_idle",
.owner = THIS_MODULE,
};
/* Fill in the state data from the mach tables and register the driver_data */
static inline struct omap3_idle_statedata *_fill_cstate(
struct cpuidle_device *dev,
int idx, const char *descr)
{
struct omap3_idle_statedata *cx = &omap3_idle_data[idx];
struct cpuidle_state *state = &dev->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 = omap3_enter_idle_bm;
cx->valid = cpuidle_params_table[idx].valid;
sprintf(state->name, "C%d", idx + 1);
strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
cpuidle_set_statedata(state, cx);
return cx;
}
/**
* omap3_idle_init - Init routine for OMAP3 idle
*
* Registers the OMAP3 specific cpuidle driver to the cpuidle
* framework with the valid set of states.
*/
int __init omap3_idle_init(void)
{
struct cpuidle_device *dev;
struct omap3_idle_statedata *cx;
mpu_pd = pwrdm_lookup("mpu_pwrdm");
core_pd = pwrdm_lookup("core_pwrdm");
per_pd = pwrdm_lookup("per_pwrdm");
cam_pd = pwrdm_lookup("cam_pwrdm");
cpuidle_register_driver(&omap3_idle_driver);
dev = &per_cpu(omap3_idle_dev, smp_processor_id());
/* C1 . MPU WFI + Core active */
cx = _fill_cstate(dev, 0, "MPU ON + CORE ON");
(&dev->states[0])->enter = omap3_enter_idle;
dev->safe_state = &dev->states[0];
cx->valid = 1; /* C1 is always valid */
cx->mpu_state = PWRDM_POWER_ON;
cx->core_state = PWRDM_POWER_ON;
/* C2 . MPU WFI + Core inactive */
cx = _fill_cstate(dev, 1, "MPU ON + CORE ON");
cx->mpu_state = PWRDM_POWER_ON;
cx->core_state = PWRDM_POWER_ON;
/* C3 . MPU CSWR + Core inactive */
cx = _fill_cstate(dev, 2, "MPU RET + CORE ON");
cx->mpu_state = PWRDM_POWER_RET;
cx->core_state = PWRDM_POWER_ON;
/* C4 . MPU OFF + Core inactive */
cx = _fill_cstate(dev, 3, "MPU OFF + CORE ON");
cx->mpu_state = PWRDM_POWER_OFF;
cx->core_state = PWRDM_POWER_ON;
/* C5 . MPU RET + Core RET */
cx = _fill_cstate(dev, 4, "MPU RET + CORE RET");
cx->mpu_state = PWRDM_POWER_RET;
cx->core_state = PWRDM_POWER_RET;
/* C6 . MPU OFF + Core RET */
cx = _fill_cstate(dev, 5, "MPU OFF + CORE RET");
cx->mpu_state = PWRDM_POWER_OFF;
cx->core_state = PWRDM_POWER_RET;
/* C7 . MPU OFF + Core OFF */
cx = _fill_cstate(dev, 6, "MPU OFF + CORE OFF");
/*
* Erratum i583: implementation for ES rev < Es1.2 on 3630. We cannot
* enable OFF mode in a stable form for previous revisions.
* We disable C7 state as a result.
*/
if (IS_PM34XX_ERRATUM(PM_SDRC_WAKEUP_ERRATUM_i583)) {
cx->valid = 0;
pr_warn("%s: core off state C7 disabled due to i583\n",
__func__);
}
cx->mpu_state = PWRDM_POWER_OFF;
cx->core_state = PWRDM_POWER_OFF;
if (enable_off_mode)
omap3_cpuidle_update_states(PWRDM_POWER_OFF, PWRDM_POWER_OFF);
else
omap3_cpuidle_update_states(PWRDM_POWER_RET, PWRDM_POWER_RET);
dev->state_count = OMAP3_NUM_STATES;
if (cpuidle_register_device(dev)) {
printk(KERN_ERR "%s: CPUidle register device failed\n",
__func__);
return -EIO;
}
return 0;
}
#else
int __init omap3_idle_init(void)
{
return 0;
}
#endif /* CONFIG_CPU_IDLE */