/* linux/arch/arm/plat-s3c/pm.c
*
* Copyright 2008 Openmoko, Inc.
* Copyright 2004,2006,2008 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
* http://armlinux.simtec.co.uk/
*
* S3C common power management (suspend to ram) support.
*
* 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/init.h>
#include <linux/suspend.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/serial_core.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <mach/hardware.h>
#include <plat/regs-serial.h>
#include <mach/regs-clock.h>
#include <mach/regs-gpio.h>
#include <mach/regs-mem.h>
#include <mach/regs-irq.h>
#include <plat/pm.h>
#include <plat/pm-core.h>
/* for external use */
unsigned long s3c_pm_flags;
/* Debug code:
*
* This code supports debug output to the low level UARTs for use on
* resume before the console layer is available.
*/
#ifdef CONFIG_S3C2410_PM_DEBUG
extern void printascii(const char *);
void s3c_pm_dbg(const char *fmt, ...)
{
va_list va;
char buff[256];
va_start(va, fmt);
vsprintf(buff, fmt, va);
va_end(va);
printascii(buff);
}
static inline void s3c_pm_debug_init(void)
{
/* restart uart clocks so we can use them to output */
s3c_pm_debug_init_uart();
}
#else
#define s3c_pm_debug_init() do { } while(0)
#endif /* CONFIG_S3C2410_PM_DEBUG */
/* Save the UART configurations if we are configured for debug. */
#ifdef CONFIG_S3C2410_PM_DEBUG
#define SAVE_UART(va) \
SAVE_ITEM((va) + S3C2410_ULCON), \
SAVE_ITEM((va) + S3C2410_UCON), \
SAVE_ITEM((va) + S3C2410_UFCON), \
SAVE_ITEM((va) + S3C2410_UMCON), \
SAVE_ITEM((va) + S3C2410_UBRDIV)
static struct sleep_save uart_save[] = {
SAVE_UART(S3C_VA_UART0),
SAVE_UART(S3C_VA_UART1),
#ifndef CONFIG_CPU_S3C2400
SAVE_UART(S3C_VA_UART2),
#endif
};
static void s3c_pm_save_uart(void)
{
s3c_pm_do_save(uart_save, ARRAY_SIZE(uart_save));
}
static void s3c_pm_restore_uart(void)
{
s3c_pm_do_restore(uart_save, ARRAY_SIZE(uart_save));
}
#else
static void s3c_pm_save_uart(void) { }
static void s3c_pm_restore_uart(void) { }
#endif
/* helper functions to save and restore register state */
/**
* s3c_pm_do_save() - save a set of registers for restoration on resume.
* @ptr: Pointer to an array of registers.
* @count: Size of the ptr array.
*
* Run through the list of registers given, saving their contents in the
* array for later restoration when we wakeup.
*/
void s3c_pm_do_save(struct sleep_save *ptr, int count)
{
for (; count > 0; count--, ptr++) {
ptr->val = __raw_readl(ptr->reg);
S3C_PMDBG("saved %p value %08lx\n", ptr->reg, ptr->val);
}
}
/**
* s3c_pm_do_restore() - restore register values from the save list.
* @ptr: Pointer to an array of registers.
* @count: Size of the ptr array.
*
* Restore the register values saved from s3c_pm_do_save().
*
* Note, we do not use S3C_PMDBG() in here, as the system may not have
* restore the UARTs state yet
*/
void s3c_pm_do_restore(struct sleep_save *ptr, int count)
{
for (; count > 0; count--, ptr++) {
printk(KERN_DEBUG "restore %p (restore %08lx, was %08x)\n",
ptr->reg, ptr->val, __raw_readl(ptr->reg));
__raw_writel(ptr->val, ptr->reg);
}
}
/**
* s3c_pm_do_restore_core() - early restore register values from save list.
*
* This is similar to s3c_pm_do_restore() except we try and minimise the
* side effects of the function in case registers that hardware might need
* to work has been restored.
*
* WARNING: Do not put any debug in here that may effect memory or use
* peripherals, as things may be changing!
*/
void s3c_pm_do_restore_core(struct sleep_save *ptr, int count)
{
for (; count > 0; count--, ptr++)
__raw_writel(ptr->val, ptr->reg);
}
/* s3c2410_pm_show_resume_irqs
*
* print any IRQs asserted at resume time (ie, we woke from)
*/
static void s3c_pm_show_resume_irqs(int start, unsigned long which,
unsigned long mask)
{
int i;
which &= ~mask;
for (i = 0; i <= 31; i++) {
if (which & (1L<<i)) {
S3C_PMDBG("IRQ %d asserted at resume\n", start+i);
}
}
}
void (*pm_cpu_prep)(void);
void (*pm_cpu_sleep)(void);
#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)
{
unsigned long regs_save[16];
/* 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 (!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;
}
/* prepare check area if configured */
s3c_pm_check_prepare();
/* store the physical address of the register recovery block */
s3c_sleep_save_phys = virt_to_phys(regs_save);
S3C_PMDBG("s3c_sleep_save_phys=0x%08lx\n", s3c_sleep_save_phys);
/* save all necessary core registers not covered by the drivers */
s3c_pm_save_gpios();
s3c_pm_save_uart();
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();
/* s3c2410_cpu_save will also act as our return point from when
* we resume as it saves its own register state, so use the return
* code to differentiate return from save and return from sleep */
if (s3c2410_cpu_save(regs_save) == 0) {
flush_cache_all();
pm_cpu_sleep();
}
/* restore the cpu state using the kernel's cpu init code. */
cpu_init();
/* restore the system state */
s3c_pm_restore_core();
s3c_pm_restore_uart();
s3c_pm_restore_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__);
s3c_pm_check_restore();
/* ok, let's return from sleep */
S3C_PMDBG("S3C PM Resume (post-restore)\n");
return 0;
}
static struct platform_suspend_ops s3c_pm_ops = {
.enter = s3c_pm_enter,
.valid = suspend_valid_only_mem,
};
/* s3c2410_pm_init
*
* Attach the power management functions. This should be called
* from the board specific initialisation if the board supports
* it.
*/
int __init s3c2410_pm_init(void)
{
printk("S3C Power Management, Copyright 2004 Simtec Electronics\n");
suspend_set_ops(&s3c_pm_ops);
return 0;
}
