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* OMAP4 Power Management Routines
* Copyright (C) 2010-2011 Texas Instruments, Inc.
* Rajendra Nayak <>
* Santosh Shilimkar <>
* 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/pm.h>
#include <linux/suspend.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <asm/system_misc.h>
#include "common.h"
#include "clockdomain.h"
#include "powerdomain.h"
#include "pm.h"
struct power_state {
struct powerdomain *pwrdm;
u32 next_state;
u32 saved_state;
u32 saved_logic_state;
struct list_head node;
static LIST_HEAD(pwrst_list);
static int omap4_pm_suspend(void)
struct power_state *pwrst;
int state, ret = 0;
u32 cpu_id = smp_processor_id();
/* Save current powerdomain state */
list_for_each_entry(pwrst, &pwrst_list, node) {
pwrst->saved_state = pwrdm_read_next_pwrst(pwrst->pwrdm);
pwrst->saved_logic_state = pwrdm_read_logic_retst(pwrst->pwrdm);
/* Set targeted power domain states by suspend */
list_for_each_entry(pwrst, &pwrst_list, node) {
omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
pwrdm_set_logic_retst(pwrst->pwrdm, PWRDM_POWER_OFF);
* For MPUSS to hit power domain retention(CSWR or OSWR),
* CPU0 and CPU1 power domains need to be in OFF or DORMANT state,
* since CPU power domain CSWR is not supported by hardware
* Only master CPU follows suspend path. All other CPUs follow
* CPU hotplug path in system wide suspend. On OMAP4, CPU power
* domain CSWR is not supported by hardware.
* More details can be found in OMAP4430 TRM section
omap4_enter_lowpower(cpu_id, PWRDM_POWER_OFF);
/* Restore next powerdomain state */
list_for_each_entry(pwrst, &pwrst_list, node) {
state = pwrdm_read_prev_pwrst(pwrst->pwrdm);
if (state > pwrst->next_state) {
pr_info("Powerdomain (%s) didn't enter "
"target state %d\n",
pwrst->pwrdm->name, pwrst->next_state);
ret = -1;
omap_set_pwrdm_state(pwrst->pwrdm, pwrst->saved_state);
pwrdm_set_logic_retst(pwrst->pwrdm, pwrst->saved_logic_state);
if (ret)
pr_crit("Could not enter target state in pm_suspend\n");
pr_info("Successfully put all powerdomains to target state\n");
return 0;
#endif /* CONFIG_SUSPEND */
static int __init pwrdms_setup(struct powerdomain *pwrdm, void *unused)
struct power_state *pwrst;
if (!pwrdm->pwrsts)
return 0;
* Skip CPU0 and CPU1 power domains. CPU1 is programmed
* through hotplug path and CPU0 explicitly programmed
* further down in the code path
if (!strncmp(pwrdm->name, "cpu", 3))
return 0;
* FIXME: Remove this check when core retention is supported
* Only MPUSS power domain is added in the list.
if (strcmp(pwrdm->name, "mpu_pwrdm"))
return 0;
pwrst = kmalloc(sizeof(struct power_state), GFP_ATOMIC);
if (!pwrst)
return -ENOMEM;
pwrst->pwrdm = pwrdm;
pwrst->next_state = PWRDM_POWER_RET;
list_add(&pwrst->node, &pwrst_list);
return omap_set_pwrdm_state(pwrst->pwrdm, pwrst->next_state);
* omap_default_idle - OMAP4 default ilde routine.'
* Implements OMAP4 memory, IO ordering requirements which can't be addressed
* with default cpu_do_idle() hook. Used by all CPUs with !CONFIG_CPUIDLE and
* by secondary CPU with CONFIG_CPUIDLE.
static void omap_default_idle(void)
* omap4_pm_init - Init routine for OMAP4 PM
* Initializes all powerdomain and clockdomain target states
* and all PRCM settings.
int __init omap4_pm_init(void)
int ret;
struct clockdomain *emif_clkdm, *mpuss_clkdm, *l3_1_clkdm, *l4wkup;
struct clockdomain *ducati_clkdm, *l3_2_clkdm, *l4_per_clkdm;
if (omap_rev() == OMAP4430_REV_ES1_0) {
WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
return -ENODEV;
pr_err("Power Management for TI OMAP4.\n");
ret = pwrdm_for_each(pwrdms_setup, NULL);
if (ret) {
pr_err("Failed to setup powerdomains\n");
goto err2;
* The dynamic dependency between MPUSS -> MEMIF and
* MPUSS -> L4_PER/L3_* and DUCATI -> L3_* doesn't work as
* expected. The hardware recommendation is to enable static
* dependencies for these to avoid system lock ups or random crashes.
* The L4 wakeup depedency is added to workaround the OCP sync hardware
* BUG with 32K synctimer which lead to incorrect timer value read
* from the 32K counter. The BUG applies for GPTIMER1 and WDT2 which
* are part of L4 wakeup clockdomain.
mpuss_clkdm = clkdm_lookup("mpuss_clkdm");
emif_clkdm = clkdm_lookup("l3_emif_clkdm");
l3_1_clkdm = clkdm_lookup("l3_1_clkdm");
l3_2_clkdm = clkdm_lookup("l3_2_clkdm");
l4_per_clkdm = clkdm_lookup("l4_per_clkdm");
l4wkup = clkdm_lookup("l4_wkup_clkdm");
ducati_clkdm = clkdm_lookup("ducati_clkdm");
if ((!mpuss_clkdm) || (!emif_clkdm) || (!l3_1_clkdm) || (!l4wkup) ||
(!l3_2_clkdm) || (!ducati_clkdm) || (!l4_per_clkdm))
goto err2;
ret = clkdm_add_wkdep(mpuss_clkdm, emif_clkdm);
ret |= clkdm_add_wkdep(mpuss_clkdm, l3_1_clkdm);
ret |= clkdm_add_wkdep(mpuss_clkdm, l3_2_clkdm);
ret |= clkdm_add_wkdep(mpuss_clkdm, l4_per_clkdm);
ret |= clkdm_add_wkdep(mpuss_clkdm, l4wkup);
ret |= clkdm_add_wkdep(ducati_clkdm, l3_1_clkdm);
ret |= clkdm_add_wkdep(ducati_clkdm, l3_2_clkdm);
if (ret) {
pr_err("Failed to add MPUSS -> L3/EMIF/L4PER, DUCATI -> L3 "
"wakeup dependency\n");
goto err2;
ret = omap4_mpuss_init();
if (ret) {
pr_err("Failed to initialise OMAP4 MPUSS\n");
goto err2;
(void) clkdm_for_each(omap_pm_clkdms_setup, NULL);
omap_pm_suspend = omap4_pm_suspend;
/* Overwrite the default cpu_do_idle() */
arm_pm_idle = omap_default_idle;
return ret;