linux/arch/arm/mach-s3c64xx/sleep.S

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/* linux/arch/arm/plat-s3c64xx/sleep.S
*
* Copyright 2008 Openmoko, Inc.
* Copyright 2008 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
* http://armlinux.simtec.co.uk/
*
* S3C64XX CPU sleep code
*
* 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/linkage.h>
#include <asm/assembler.h>
#include <mach/map.h>
#undef S3C64XX_VA_GPIO
#define S3C64XX_VA_GPIO (0x0)
#include <mach/regs-gpio.h>
#include <mach/gpio-bank-n.h>
#define LL_UART (S3C_PA_UART + (0x400 * CONFIG_S3C_LOWLEVEL_UART_PORT))
.text
/* s3c_cpu_save
*
* Save enough processor state to allow the restart of the pm.c
* code after resume.
*
* entry:
* r1 = v:p offset
*/
ENTRY(s3c_cpu_save)
stmfd sp!, { r4 - r12, lr }
ldr r3, =resume_with_mmu
bl cpu_suspend
@@ call final suspend code
ldr r0, =pm_cpu_sleep
ldr pc, [r0]
@@ return to the caller, after the MMU is turned on.
@@ restore the last bits of the stack and return.
resume_with_mmu:
ldmfd sp!, { r4 - r12, pc } @ return, from sp from s3c_cpu_save
/* Sleep magic, the word before the resume entry point so that the
* bootloader can check for a resumeable image. */
.word 0x2bedf00d
/* s3c_cpu_reusme
*
* This is the entry point, stored by whatever method the bootloader
* requires to get the kernel runnign again. This code expects to be
* entered with no caches live and the MMU disabled. It will then
* restore the MMU and other basic CP registers saved and restart
* the kernel C code to finish the resume code.
*/
ENTRY(s3c_cpu_resume)
msr cpsr_c, #PSR_I_BIT | PSR_F_BIT | SVC_MODE
ldr r2, =LL_UART /* for debug */
#ifdef CONFIG_S3C_PM_DEBUG_LED_SMDK
/* Initialise the GPIO state if we are debugging via the SMDK LEDs,
* as the uboot version supplied resets these to inputs during the
* resume checks.
*/
ldr r3, =S3C64XX_PA_GPIO
ldr r0, [ r3, #S3C64XX_GPNCON ]
bic r0, r0, #(S3C64XX_GPN_CONMASK(12) | S3C64XX_GPN_CONMASK(13) | \
S3C64XX_GPN_CONMASK(14) | S3C64XX_GPN_CONMASK(15))
orr r0, r0, #(S3C64XX_GPN_OUTPUT(12) | S3C64XX_GPN_OUTPUT(13) | \
S3C64XX_GPN_OUTPUT(14) | S3C64XX_GPN_OUTPUT(15))
str r0, [ r3, #S3C64XX_GPNCON ]
ldr r0, [ r3, #S3C64XX_GPNDAT ]
bic r0, r0, #0xf << 12 @ GPN12..15
orr r0, r0, #1 << 15 @ GPN15
str r0, [ r3, #S3C64XX_GPNDAT ]
#endif
b cpu_resume