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There are SoCs where attempting to enter a low power state is ignored, and the CPU continues executing instructions with all state preserved. It is over-complex at that point to disable the MMU just to call the resume path. Instead, allow the suspend finisher to return error codes to abort suspend in this circumstance, where the cpu_suspend internals will then unwind the saved state on the stack. Also omit the tlb flush as no changes to the page tables will have happened. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
82 lines
1.9 KiB
C
82 lines
1.9 KiB
C
/* linux/arch/arm/mach-s3c2416/pm.c
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*
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* Copyright (c) 2010 Samsung Electronics Co., Ltd.
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* http://www.samsung.com
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*
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* S3C2416 - PM support (Based on Ben Dooks' S3C2412 PM support)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/sysdev.h>
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#include <linux/syscore_ops.h>
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#include <linux/io.h>
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#include <asm/cacheflush.h>
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#include <mach/regs-power.h>
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#include <mach/regs-s3c2443-clock.h>
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#include <plat/cpu.h>
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#include <plat/pm.h>
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extern void s3c2412_sleep_enter(void);
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static int s3c2416_cpu_suspend(unsigned long arg)
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{
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/* enable wakeup sources regardless of battery state */
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__raw_writel(S3C2443_PWRCFG_SLEEP, S3C2443_PWRCFG);
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/* set the mode as sleep, 2BED represents "Go to BED" */
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__raw_writel(0x2BED, S3C2443_PWRMODE);
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s3c2412_sleep_enter();
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panic("sleep resumed to originator?");
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}
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static void s3c2416_pm_prepare(void)
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{
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/*
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* write the magic value u-boot uses to check for resume into
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* the INFORM0 register, and ensure INFORM1 is set to the
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* correct address to resume from.
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*/
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__raw_writel(0x2BED, S3C2412_INFORM0);
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__raw_writel(virt_to_phys(s3c_cpu_resume), S3C2412_INFORM1);
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}
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static int s3c2416_pm_add(struct sys_device *sysdev)
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{
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pm_cpu_prep = s3c2416_pm_prepare;
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pm_cpu_sleep = s3c2416_cpu_suspend;
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return 0;
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}
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static struct sysdev_driver s3c2416_pm_driver = {
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.add = s3c2416_pm_add,
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};
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static __init int s3c2416_pm_init(void)
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{
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return sysdev_driver_register(&s3c2416_sysclass, &s3c2416_pm_driver);
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}
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arch_initcall(s3c2416_pm_init);
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static void s3c2416_pm_resume(void)
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{
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/* unset the return-from-sleep amd inform flags */
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__raw_writel(0x0, S3C2443_PWRMODE);
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__raw_writel(0x0, S3C2412_INFORM0);
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__raw_writel(0x0, S3C2412_INFORM1);
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}
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struct syscore_ops s3c2416_pm_syscore_ops = {
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.resume = s3c2416_pm_resume,
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};
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