/*
* OMAP MPUSS low power code
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Santosh Shilimkar <santosh.shilimkar@ti.com>
*
* OMAP4430 MPUSS mainly consists of dual Cortex-A9 with per-CPU
* Local timer and Watchdog, GIC, SCU, PL310 L2 cache controller,
* CPU0 and CPU1 LPRM modules.
* CPU0, CPU1 and MPUSS each have there own power domain and
* hence multiple low power combinations of MPUSS are possible.
*
* The CPU0 and CPU1 can't support Closed switch Retention (CSWR)
* because the mode is not supported by hw constraints of dormant
* mode. While waking up from the dormant mode, a reset signal
* to the Cortex-A9 processor must be asserted by the external
* power controller.
*
* With architectural inputs and hardware recommendations, only
* below modes are supported from power gain vs latency point of view.
*
* CPU0 CPU1 MPUSS
* ----------------------------------------------
* ON ON ON
* ON(Inactive) OFF ON(Inactive)
* OFF OFF CSWR
* OFF OFF OSWR (*TBD)
* OFF OFF OFF* (*TBD)
* ----------------------------------------------
*
* Note: CPU0 is the master core and it is the last CPU to go down
* and first to wake-up when MPUSS low power states are excercised
*
*
* 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/kernel.h>
#include <linux/io.h>
#include <linux/errno.h>
#include <linux/linkage.h>
#include <linux/smp.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/smp_scu.h>
#include <asm/system.h>
#include <asm/pgalloc.h>
#include <asm/suspend.h>
#include <plat/omap44xx.h>
#include "common.h"
#include "omap4-sar-layout.h"
#include "pm.h"
#include "powerdomain.h"
#ifdef CONFIG_SMP
struct omap4_cpu_pm_info {
struct powerdomain *pwrdm;
void __iomem *scu_sar_addr;
void __iomem *wkup_sar_addr;
};
static DEFINE_PER_CPU(struct omap4_cpu_pm_info, omap4_pm_info);
/*
* Program the wakeup routine address for the CPU0 and CPU1
* used for OFF or DORMANT wakeup.
*/
static inline void set_cpu_wakeup_addr(unsigned int cpu_id, u32 addr)
{
struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
__raw_writel(addr, pm_info->wkup_sar_addr);
}
/*
* Set the CPUx powerdomain's previous power state
*/
static inline void set_cpu_next_pwrst(unsigned int cpu_id,
unsigned int power_state)
{
struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
pwrdm_set_next_pwrst(pm_info->pwrdm, power_state);
}
/*
* Read CPU's previous power state
*/
static inline unsigned int read_cpu_prev_pwrst(unsigned int cpu_id)
{
struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
return pwrdm_read_prev_pwrst(pm_info->pwrdm);
}
/*
* Clear the CPUx powerdomain's previous power state
*/
static inline void clear_cpu_prev_pwrst(unsigned int cpu_id)
{
struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
}
/*
* Store the SCU power status value to scratchpad memory
*/
static void scu_pwrst_prepare(unsigned int cpu_id, unsigned int cpu_state)
{
struct omap4_cpu_pm_info *pm_info = &per_cpu(omap4_pm_info, cpu_id);
u32 scu_pwr_st;
switch (cpu_state) {
case PWRDM_POWER_RET:
scu_pwr_st = SCU_PM_DORMANT;
break;
case PWRDM_POWER_OFF:
scu_pwr_st = SCU_PM_POWEROFF;
break;
case PWRDM_POWER_ON:
case PWRDM_POWER_INACTIVE:
default:
scu_pwr_st = SCU_PM_NORMAL;
break;
}
__raw_writel(scu_pwr_st, pm_info->scu_sar_addr);
}
/**
* omap4_enter_lowpower: OMAP4 MPUSS Low Power Entry Function
* The purpose of this function is to manage low power programming
* of OMAP4 MPUSS subsystem
* @cpu : CPU ID
* @power_state: Low power state.
*/
int omap4_enter_lowpower(unsigned int cpu, unsigned int power_state)
{
unsigned int save_state = 0;
unsigned int wakeup_cpu;
if (omap_rev() == OMAP4430_REV_ES1_0)
return -ENXIO;
switch (power_state) {
case PWRDM_POWER_ON:
case PWRDM_POWER_INACTIVE:
save_state = 0;
break;
case PWRDM_POWER_OFF:
save_state = 1;
break;
case PWRDM_POWER_RET:
default:
/*
* CPUx CSWR is invalid hardware state. Also CPUx OSWR
* doesn't make much scense, since logic is lost and $L1
* needs to be cleaned because of coherency. This makes
* CPUx OSWR equivalent to CPUX OFF and hence not supported
*/
WARN_ON(1);
return -ENXIO;
}
clear_cpu_prev_pwrst(cpu);
set_cpu_next_pwrst(cpu, power_state);
set_cpu_wakeup_addr(cpu, virt_to_phys(omap4_cpu_resume));
scu_pwrst_prepare(cpu, power_state);
/*
* Call low level function with targeted low power state.
*/
cpu_suspend(save_state, omap4_finish_suspend);
/*
* Restore the CPUx power state to ON otherwise CPUx
* power domain can transitions to programmed low power
* state while doing WFI outside the low powe code. On
* secure devices, CPUx does WFI which can result in
* domain transition
*/
wakeup_cpu = smp_processor_id();
set_cpu_next_pwrst(wakeup_cpu, PWRDM_POWER_ON);
return 0;
}
/*
* Initialise OMAP4 MPUSS
*/
int __init omap4_mpuss_init(void)
{
struct omap4_cpu_pm_info *pm_info;
void __iomem *sar_base = omap4_get_sar_ram_base();
if (omap_rev() == OMAP4430_REV_ES1_0) {
WARN(1, "Power Management not supported on OMAP4430 ES1.0\n");
return -ENODEV;
}
/* Initilaise per CPU PM information */
pm_info = &per_cpu(omap4_pm_info, 0x0);
pm_info->scu_sar_addr = sar_base + SCU_OFFSET0;
pm_info->wkup_sar_addr = sar_base + CPU0_WAKEUP_NS_PA_ADDR_OFFSET;
pm_info->pwrdm = pwrdm_lookup("cpu0_pwrdm");
if (!pm_info->pwrdm) {
pr_err("Lookup failed for CPU0 pwrdm\n");
return -ENODEV;
}
/* Clear CPU previous power domain state */
pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
/* Initialise CPU0 power domain state to ON */
pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);
pm_info = &per_cpu(omap4_pm_info, 0x1);
pm_info->scu_sar_addr = sar_base + SCU_OFFSET1;
pm_info->wkup_sar_addr = sar_base + CPU1_WAKEUP_NS_PA_ADDR_OFFSET;
pm_info->pwrdm = pwrdm_lookup("cpu1_pwrdm");
if (!pm_info->pwrdm) {
pr_err("Lookup failed for CPU1 pwrdm\n");
return -ENODEV;
}
/* Clear CPU previous power domain state */
pwrdm_clear_all_prev_pwrst(pm_info->pwrdm);
/* Initialise CPU1 power domain state to ON */
pwrdm_set_next_pwrst(pm_info->pwrdm, PWRDM_POWER_ON);
/* Save device type on scratchpad for low level code to use */
if (omap_type() != OMAP2_DEVICE_TYPE_GP)
__raw_writel(1, sar_base + OMAP_TYPE_OFFSET);
else
__raw_writel(0, sar_base + OMAP_TYPE_OFFSET);
return 0;
}
#endif
