/* 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:
* r0 = pointer to the save block
*/
ENTRY(s3c_cpu_save)
stmfd sp!, { r4 - r12, lr }
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
mrc p15, 0, r5, c3, c0, 0 @ Domain ID
mrc p15, 0, r6, c2, c0, 0 @ Translation Table BASE0
mrc p15, 0, r7, c2, c0, 1 @ Translation Table BASE1
mrc p15, 0, r8, c2, c0, 2 @ Translation Table Control
mrc p15, 0, r9, c1, c0, 0 @ Control register
mrc p15, 0, r10, c1, c0, 1 @ Auxiliary control register
mrc p15, 0, r11, c1, c0, 2 @ Co-processor access controls
stmia r0, { r4 - r13 } @ Save CP registers and SP
@@ save our state to ram
bl s3c_pm_cb_flushcache
@@ 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
.data
/* the next bit is code, but it requires easy access to the
* s3c_sleep_save_phys data before the MMU is switched on, so
* we store the code that needs this variable in the .data where
* the value can be written to (the .text segment is RO).
*/
.global s3c_sleep_save_phys
s3c_sleep_save_phys:
.word 0
/* 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
/* __v6_setup from arch/arm/mm/proc-v6.S, ensure that the caches
* are thoroughly cleaned just in case the bootloader didn't do it
* for us. */
mov r0, #0
mcr p15, 0, r0, c7, c14, 0 @ clean+invalidate D cache
mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
mcr p15, 0, r0, c7, c15, 0 @ clean+invalidate cache
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer
@@mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs
@@mcr p15, 0, r0, c7, c7, 0 @ Invalidate I + D caches
ldr r0, s3c_sleep_save_phys
ldmia r0, { r4 - r13 }
mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
mcr p15, 0, r5, c3, c0, 0 @ Domain ID
mcr p15, 0, r6, c2, c0, 0 @ Translation Table BASE0
mcr p15, 0, r7, c2, c0, 1 @ Translation Table BASE1
mcr p15, 0, r8, c2, c0, 2 @ Translation Table Control
mcr p15, 0, r10, c1, c0, 1 @ Auxiliary control register
mov r0, #0 @ restore copro access controls
mcr p15, 0, r11, c1, c0, 2 @ Co-processor access controls
mcr p15, 0, r0, c7, c5, 4
ldr r2, =resume_with_mmu
mcr p15, 0, r9, c1, c0, 0 /* turn mmu back on */
nop
mov pc, r2 /* jump back */
.end
