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linux/arch/arm/mach-omap2/cpuidle34xx.c
Eduardo Valentin cc1b602887 OMAP3630: PM: Erratum i583: disable coreoff if < ES1.2 
Limitation i583: Self_Refresh Exit issue after OFF mode

Issue:
When device is waking up from OFF mode, then SDRC state machine sends
inappropriate sequence violating JEDEC standards.

Impact:
OMAP3630 < ES1.2 is impacted as follows depending on the platform:
CS0: for 38.4MHz as internal sysclk, DDR content seen to be stable, while
	for all other sysclk frequencies, varied levels of instability
	seen based on varied parameters.
CS1: impacted

This patch takes option #3 as recommended by the Silicon erratum:
Avoid core power domain transitioning to OFF mode. Power consumption
impact is expected in this case.
To do this, we route core OFF requests to RET request on the impacted
revisions of silicon.

Acked-by: Jean Pihet <j-pihet@ti.com>

[nm@ti.com: rebased the code to 2.6.37-rc2- short circuit code changed a bit]
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@nokia.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
2010-12-21 14:45:53 -08:00

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/*
* 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 <plat/powerdomain.h>
#include <plat/clockdomain.h>
#include <plat/serial.h>
#include "pm.h"
#include "control.h"
#ifdef CONFIG_CPU_IDLE
#define OMAP3_MAX_STATES 7
#define OMAP3_STATE_C1 0 /* C1 - MPU WFI + Core active */
#define OMAP3_STATE_C2 1 /* C2 - MPU WFI + Core inactive */
#define OMAP3_STATE_C3 2 /* C3 - MPU CSWR + Core inactive */
#define OMAP3_STATE_C4 3 /* C4 - MPU OFF + Core iactive */
#define OMAP3_STATE_C5 4 /* C5 - MPU RET + Core RET */
#define OMAP3_STATE_C6 5 /* C6 - MPU OFF + Core RET */
#define OMAP3_STATE_C7 6 /* C7 - MPU OFF + Core OFF */
#define OMAP3_STATE_MAX OMAP3_STATE_C7
struct omap3_processor_cx {
u8 valid;
u8 type;
u32 sleep_latency;
u32 wakeup_latency;
u32 mpu_state;
u32 core_state;
u32 threshold;
u32 flags;
};
struct omap3_processor_cx omap3_power_states[OMAP3_MAX_STATES];
struct omap3_processor_cx current_cx_state;
struct powerdomain *mpu_pd, *core_pd, *per_pd;
struct powerdomain *cam_pd;
/*
* 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 */
{1, 2, 2, 5},
/* C2 */
{1, 10, 10, 30},
/* C3 */
{1, 50, 50, 300},
/* C4 */
{1, 1500, 1800, 4000},
/* C5 */
{1, 2500, 7500, 12000},
/* C6 */
{1, 3000, 8500, 15000},
/* C7 */
{1, 10000, 30000, 300000},
};
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)
{
omap2_clkdm_allow_idle(clkdm);
return 0;
}
static int _cpuidle_deny_idle(struct powerdomain *pwrdm,
struct clockdomain *clkdm)
{
omap2_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_processor_cx *cx = cpuidle_get_statedata(state);
struct timespec ts_preidle, ts_postidle, ts_idle;
u32 mpu_state = cx->mpu_state, core_state = cx->core_state;
current_cx_state = *cx;
/* 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;
if (cx->type == OMAP3_STATE_C1) {
pwrdm_for_each_clkdm(mpu_pd, _cpuidle_deny_idle);
pwrdm_for_each_clkdm(core_pd, _cpuidle_deny_idle);
}
/* Execute ARM wfi */
omap_sram_idle();
if (cx->type == OMAP3_STATE_C1) {
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 (as defined in omap3_power_states[]).
*/
static struct cpuidle_state *next_valid_state(struct cpuidle_device *dev,
struct cpuidle_state *curr)
{
struct cpuidle_state *next = NULL;
struct omap3_processor_cx *cx;
cx = (struct omap3_processor_cx *)cpuidle_get_statedata(curr);
/* Check if current state is valid */
if (cx->valid) {
return curr;
} else {
u8 idx = OMAP3_STATE_MAX;
/*
* Reach the current state starting at highest C-state
*/
for (; idx >= OMAP3_STATE_C1; 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 >= OMAP3_STATE_C1; idx--) {
struct omap3_processor_cx *cx;
cx = cpuidle_get_statedata(&dev->states[idx]);
if (cx->valid) {
next = &dev->states[idx];
break;
}
}
/*
* C1 and C2 are 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
*
* Used for C states with CPUIDLE_FLAG_CHECK_BM flag set. 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_processor_cx *cx;
int ret;
if ((state->flags & CPUIDLE_FLAG_CHECK_BM) && 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 managment 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 upto and including this for mpu domain
* @core_deepest_state: Enable states upto 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 = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
struct omap3_processor_cx *cx = &omap3_power_states[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 = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
cpuidle_params_table[i].valid =
cpuidle_board_params[i].valid;
cpuidle_params_table[i].sleep_latency =
cpuidle_board_params[i].sleep_latency;
cpuidle_params_table[i].wake_latency =
cpuidle_board_params[i].wake_latency;
cpuidle_params_table[i].threshold =
cpuidle_board_params[i].threshold;
}
return;
}
/* omap3_init_power_states - Initialises the OMAP3 specific C states.
*
* Below is the desciption of each C state.
* C1 . MPU WFI + Core active
* C2 . MPU WFI + Core inactive
* C3 . MPU CSWR + Core inactive
* C4 . MPU OFF + Core inactive
* C5 . MPU CSWR + Core CSWR
* C6 . MPU OFF + Core CSWR
* C7 . MPU OFF + Core OFF
*/
void omap_init_power_states(void)
{
/* C1 . MPU WFI + Core active */
omap3_power_states[OMAP3_STATE_C1].valid =
cpuidle_params_table[OMAP3_STATE_C1].valid;
omap3_power_states[OMAP3_STATE_C1].type = OMAP3_STATE_C1;
omap3_power_states[OMAP3_STATE_C1].sleep_latency =
cpuidle_params_table[OMAP3_STATE_C1].sleep_latency;
omap3_power_states[OMAP3_STATE_C1].wakeup_latency =
cpuidle_params_table[OMAP3_STATE_C1].wake_latency;
omap3_power_states[OMAP3_STATE_C1].threshold =
cpuidle_params_table[OMAP3_STATE_C1].threshold;
omap3_power_states[OMAP3_STATE_C1].mpu_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C1].core_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C1].flags = CPUIDLE_FLAG_TIME_VALID;
/* C2 . MPU WFI + Core inactive */
omap3_power_states[OMAP3_STATE_C2].valid =
cpuidle_params_table[OMAP3_STATE_C2].valid;
omap3_power_states[OMAP3_STATE_C2].type = OMAP3_STATE_C2;
omap3_power_states[OMAP3_STATE_C2].sleep_latency =
cpuidle_params_table[OMAP3_STATE_C2].sleep_latency;
omap3_power_states[OMAP3_STATE_C2].wakeup_latency =
cpuidle_params_table[OMAP3_STATE_C2].wake_latency;
omap3_power_states[OMAP3_STATE_C2].threshold =
cpuidle_params_table[OMAP3_STATE_C2].threshold;
omap3_power_states[OMAP3_STATE_C2].mpu_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C2].core_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C2].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
/* C3 . MPU CSWR + Core inactive */
omap3_power_states[OMAP3_STATE_C3].valid =
cpuidle_params_table[OMAP3_STATE_C3].valid;
omap3_power_states[OMAP3_STATE_C3].type = OMAP3_STATE_C3;
omap3_power_states[OMAP3_STATE_C3].sleep_latency =
cpuidle_params_table[OMAP3_STATE_C3].sleep_latency;
omap3_power_states[OMAP3_STATE_C3].wakeup_latency =
cpuidle_params_table[OMAP3_STATE_C3].wake_latency;
omap3_power_states[OMAP3_STATE_C3].threshold =
cpuidle_params_table[OMAP3_STATE_C3].threshold;
omap3_power_states[OMAP3_STATE_C3].mpu_state = PWRDM_POWER_RET;
omap3_power_states[OMAP3_STATE_C3].core_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C3].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
/* C4 . MPU OFF + Core inactive */
omap3_power_states[OMAP3_STATE_C4].valid =
cpuidle_params_table[OMAP3_STATE_C4].valid;
omap3_power_states[OMAP3_STATE_C4].type = OMAP3_STATE_C4;
omap3_power_states[OMAP3_STATE_C4].sleep_latency =
cpuidle_params_table[OMAP3_STATE_C4].sleep_latency;
omap3_power_states[OMAP3_STATE_C4].wakeup_latency =
cpuidle_params_table[OMAP3_STATE_C4].wake_latency;
omap3_power_states[OMAP3_STATE_C4].threshold =
cpuidle_params_table[OMAP3_STATE_C4].threshold;
omap3_power_states[OMAP3_STATE_C4].mpu_state = PWRDM_POWER_OFF;
omap3_power_states[OMAP3_STATE_C4].core_state = PWRDM_POWER_ON;
omap3_power_states[OMAP3_STATE_C4].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
/* C5 . MPU CSWR + Core CSWR*/
omap3_power_states[OMAP3_STATE_C5].valid =
cpuidle_params_table[OMAP3_STATE_C5].valid;
omap3_power_states[OMAP3_STATE_C5].type = OMAP3_STATE_C5;
omap3_power_states[OMAP3_STATE_C5].sleep_latency =
cpuidle_params_table[OMAP3_STATE_C5].sleep_latency;
omap3_power_states[OMAP3_STATE_C5].wakeup_latency =
cpuidle_params_table[OMAP3_STATE_C5].wake_latency;
omap3_power_states[OMAP3_STATE_C5].threshold =
cpuidle_params_table[OMAP3_STATE_C5].threshold;
omap3_power_states[OMAP3_STATE_C5].mpu_state = PWRDM_POWER_RET;
omap3_power_states[OMAP3_STATE_C5].core_state = PWRDM_POWER_RET;
omap3_power_states[OMAP3_STATE_C5].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
/* C6 . MPU OFF + Core CSWR */
omap3_power_states[OMAP3_STATE_C6].valid =
cpuidle_params_table[OMAP3_STATE_C6].valid;
omap3_power_states[OMAP3_STATE_C6].type = OMAP3_STATE_C6;
omap3_power_states[OMAP3_STATE_C6].sleep_latency =
cpuidle_params_table[OMAP3_STATE_C6].sleep_latency;
omap3_power_states[OMAP3_STATE_C6].wakeup_latency =
cpuidle_params_table[OMAP3_STATE_C6].wake_latency;
omap3_power_states[OMAP3_STATE_C6].threshold =
cpuidle_params_table[OMAP3_STATE_C6].threshold;
omap3_power_states[OMAP3_STATE_C6].mpu_state = PWRDM_POWER_OFF;
omap3_power_states[OMAP3_STATE_C6].core_state = PWRDM_POWER_RET;
omap3_power_states[OMAP3_STATE_C6].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
/* C7 . MPU OFF + Core OFF */
omap3_power_states[OMAP3_STATE_C7].valid =
cpuidle_params_table[OMAP3_STATE_C7].valid;
omap3_power_states[OMAP3_STATE_C7].type = OMAP3_STATE_C7;
omap3_power_states[OMAP3_STATE_C7].sleep_latency =
cpuidle_params_table[OMAP3_STATE_C7].sleep_latency;
omap3_power_states[OMAP3_STATE_C7].wakeup_latency =
cpuidle_params_table[OMAP3_STATE_C7].wake_latency;
omap3_power_states[OMAP3_STATE_C7].threshold =
cpuidle_params_table[OMAP3_STATE_C7].threshold;
omap3_power_states[OMAP3_STATE_C7].mpu_state = PWRDM_POWER_OFF;
omap3_power_states[OMAP3_STATE_C7].core_state = PWRDM_POWER_OFF;
omap3_power_states[OMAP3_STATE_C7].flags = CPUIDLE_FLAG_TIME_VALID |
CPUIDLE_FLAG_CHECK_BM;
/*
* 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)) {
omap3_power_states[OMAP3_STATE_C7].valid = 0;
cpuidle_params_table[OMAP3_STATE_C7].valid = 0;
WARN_ONCE(1, "%s: core off state C7 disabled due to i583\n",
__func__);
}
}
struct cpuidle_driver omap3_idle_driver = {
.name = "omap3_idle",
.owner = THIS_MODULE,
};
/**
* omap3_idle_init - Init routine for OMAP3 idle
*
* Registers the OMAP3 specific cpuidle driver with the cpuidle
* framework with the valid set of states.
*/
int __init omap3_idle_init(void)
{
int i, count = 0;
struct omap3_processor_cx *cx;
struct cpuidle_state *state;
struct cpuidle_device *dev;
mpu_pd = pwrdm_lookup("mpu_pwrdm");
core_pd = pwrdm_lookup("core_pwrdm");
per_pd = pwrdm_lookup("per_pwrdm");
cam_pd = pwrdm_lookup("cam_pwrdm");
omap_init_power_states();
cpuidle_register_driver(&omap3_idle_driver);
dev = &per_cpu(omap3_idle_dev, smp_processor_id());
for (i = OMAP3_STATE_C1; i < OMAP3_MAX_STATES; i++) {
cx = &omap3_power_states[i];
state = &dev->states[count];
if (!cx->valid)
continue;
cpuidle_set_statedata(state, cx);
state->exit_latency = cx->sleep_latency + cx->wakeup_latency;
state->target_residency = cx->threshold;
state->flags = cx->flags;
state->enter = (state->flags & CPUIDLE_FLAG_CHECK_BM) ?
omap3_enter_idle_bm : omap3_enter_idle;
if (cx->type == OMAP3_STATE_C1)
dev->safe_state = state;
sprintf(state->name, "C%d", count+1);
count++;
}
if (!count)
return -EINVAL;
dev->state_count = count;
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);
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 */
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