https://github.com/torvalds/linux
Tip revision: d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 authored by Linus Torvalds on 27 January 2020, 00:23:03 UTC
Linux 5.5
Linux 5.5
Tip revision: d5226fa
pm.c
// SPDX-License-Identifier: GPL-2.0
//
// Copyright 2008 Openmoko, Inc.
// Copyright 2004-2008 Simtec Electronics
// Ben Dooks <ben@simtec.co.uk>
// http://armlinux.simtec.co.uk/
//
// S3C common power management (suspend to ram) support.
#include <linux/init.h>
#include <linux/suspend.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/serial_s3c.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/suspend.h>
#include <mach/map.h>
#include <mach/regs-clock.h>
#include <mach/regs-irq.h>
#include <mach/irqs.h>
#include <asm/irq.h>
#include <plat/pm.h>
#include <mach/pm-core.h>
/* for external use */
unsigned long s3c_pm_flags;
/* The IRQ ext-int code goes here, it is too small to currently bother
* with its own file. */
unsigned long s3c_irqwake_intmask = 0xffffffffL;
unsigned long s3c_irqwake_eintmask = 0xffffffffL;
int s3c_irqext_wake(struct irq_data *data, unsigned int state)
{
unsigned long bit = 1L << IRQ_EINT_BIT(data->irq);
if (!(s3c_irqwake_eintallow & bit))
return -ENOENT;
printk(KERN_INFO "wake %s for irq %d\n",
state ? "enabled" : "disabled", data->irq);
if (!state)
s3c_irqwake_eintmask |= bit;
else
s3c_irqwake_eintmask &= ~bit;
return 0;
}
void (*pm_cpu_prep)(void);
int (*pm_cpu_sleep)(unsigned long);
#define any_allowed(mask, allow) (((mask) & (allow)) != (allow))
/* s3c_pm_enter
*
* central control for sleep/resume process
*/
static int s3c_pm_enter(suspend_state_t state)
{
int ret;
/* ensure the debug is initialised (if enabled) */
s3c_pm_debug_init();
S3C_PMDBG("%s(%d)\n", __func__, state);
if (pm_cpu_prep == NULL || pm_cpu_sleep == NULL) {
printk(KERN_ERR "%s: error: no cpu sleep function\n", __func__);
return -EINVAL;
}
/* check if we have anything to wake-up with... bad things seem
* to happen if you suspend with no wakeup (system will often
* require a full power-cycle)
*/
if (!of_have_populated_dt() &&
!any_allowed(s3c_irqwake_intmask, s3c_irqwake_intallow) &&
!any_allowed(s3c_irqwake_eintmask, s3c_irqwake_eintallow)) {
printk(KERN_ERR "%s: No wake-up sources!\n", __func__);
printk(KERN_ERR "%s: Aborting sleep\n", __func__);
return -EINVAL;
}
/* save all necessary core registers not covered by the drivers */
if (!of_have_populated_dt()) {
samsung_pm_save_gpios();
samsung_pm_saved_gpios();
}
s3c_pm_save_uarts();
s3c_pm_save_core();
/* set the irq configuration for wake */
s3c_pm_configure_extint();
S3C_PMDBG("sleep: irq wakeup masks: %08lx,%08lx\n",
s3c_irqwake_intmask, s3c_irqwake_eintmask);
s3c_pm_arch_prepare_irqs();
/* call cpu specific preparation */
pm_cpu_prep();
/* flush cache back to ram */
flush_cache_all();
s3c_pm_check_store();
/* send the cpu to sleep... */
s3c_pm_arch_stop_clocks();
/* this will also act as our return point from when
* we resume as it saves its own register state and restores it
* during the resume. */
ret = cpu_suspend(0, pm_cpu_sleep);
if (ret)
return ret;
/* restore the system state */
s3c_pm_restore_core();
s3c_pm_restore_uarts();
if (!of_have_populated_dt()) {
samsung_pm_restore_gpios();
s3c_pm_restored_gpios();
}
s3c_pm_debug_init();
/* check what irq (if any) restored the system */
s3c_pm_arch_show_resume_irqs();
S3C_PMDBG("%s: post sleep, preparing to return\n", __func__);
/* LEDs should now be 1110 */
s3c_pm_debug_smdkled(1 << 1, 0);
s3c_pm_check_restore();
/* ok, let's return from sleep */
S3C_PMDBG("S3C PM Resume (post-restore)\n");
return 0;
}
static int s3c_pm_prepare(void)
{
/* prepare check area if configured */
s3c_pm_check_prepare();
return 0;
}
static void s3c_pm_finish(void)
{
s3c_pm_check_cleanup();
}
static const struct platform_suspend_ops s3c_pm_ops = {
.enter = s3c_pm_enter,
.prepare = s3c_pm_prepare,
.finish = s3c_pm_finish,
.valid = suspend_valid_only_mem,
};
/* s3c_pm_init
*
* Attach the power management functions. This should be called
* from the board specific initialisation if the board supports
* it.
*/
int __init s3c_pm_init(void)
{
printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
suspend_set_ops(&s3c_pm_ops);
return 0;
}