forked from Minki/linux
6c729af9f0
Add a magic number before the resume code so that a bootloader can check that there is an image to resume to. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
166 lines
4.4 KiB
ArmAsm
166 lines
4.4 KiB
ArmAsm
/* linux/arch/arm/plat-s3c24xx/sleep.S
|
|
*
|
|
* Copyright (c) 2004 Simtec Electronics
|
|
* Ben Dooks <ben@simtec.co.uk>
|
|
*
|
|
* S3C2410 Power Manager (Suspend-To-RAM) support
|
|
*
|
|
* Based on PXA/SA1100 sleep code by:
|
|
* Nicolas Pitre, (c) 2002 Monta Vista Software Inc
|
|
* Cliff Brake, (c) 2001
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
#include <asm/hardware.h>
|
|
#include <asm/arch/map.h>
|
|
|
|
#include <asm/arch/regs-gpio.h>
|
|
#include <asm/arch/regs-clock.h>
|
|
#include <asm/arch/regs-mem.h>
|
|
#include <asm/plat-s3c/regs-serial.h>
|
|
|
|
/* CONFIG_DEBUG_RESUME is dangerous if your bootloader does not
|
|
* reset the UART configuration, only enable if you really need this!
|
|
*/
|
|
//#define CONFIG_DEBUG_RESUME
|
|
|
|
.text
|
|
|
|
/* s3c2410_cpu_save
|
|
*
|
|
* save enough of the CPU state to allow us to re-start
|
|
* pm.c code. as we store items like the sp/lr, we will
|
|
* end up returning from this function when the cpu resumes
|
|
* so the return value is set to mark this.
|
|
*
|
|
* This arangement means we avoid having to flush the cache
|
|
* from this code.
|
|
*
|
|
* entry:
|
|
* r0 = pointer to save block
|
|
*
|
|
* exit:
|
|
* r0 = 0 => we stored everything
|
|
* 1 => resumed from sleep
|
|
*/
|
|
|
|
ENTRY(s3c2410_cpu_save)
|
|
stmfd sp!, { r4 - r12, lr }
|
|
|
|
@@ store co-processor registers
|
|
|
|
mrc p15, 0, r4, c13, c0, 0 @ PID
|
|
mrc p15, 0, r5, c3, c0, 0 @ Domain ID
|
|
mrc p15, 0, r6, c2, c0, 0 @ translation table base address
|
|
mrc p15, 0, r7, c1, c0, 0 @ control register
|
|
|
|
stmia r0, { r4 - r13 }
|
|
|
|
mov r0, #0
|
|
ldmfd sp, { r4 - r12, pc }
|
|
|
|
@@ return to the caller, after having the MMU
|
|
@@ turned on, this restores the last bits from the
|
|
@@ stack
|
|
resume_with_mmu:
|
|
mov r0, #1
|
|
ldmfd sp!, { r4 - r12, pc }
|
|
|
|
.ltorg
|
|
|
|
@@ the next bits sit in the .data segment, even though they
|
|
@@ happen to be code... the s3c2410_sleep_save_phys needs to be
|
|
@@ accessed by the resume code before it can restore the MMU.
|
|
@@ This means that the variable has to be close enough for the
|
|
@@ code to read it... since the .text segment needs to be RO,
|
|
@@ the data segment can be the only place to put this code.
|
|
|
|
.data
|
|
|
|
.global s3c2410_sleep_save_phys
|
|
s3c2410_sleep_save_phys:
|
|
.word 0
|
|
|
|
|
|
/* sleep magic, to allow the bootloader to check for an valid
|
|
* image to resume to. Must be the first word before the
|
|
* s3c2410_cpu_resume entry.
|
|
*/
|
|
|
|
.word 0x2bedf00d
|
|
|
|
/* s3c2410_cpu_resume
|
|
*
|
|
* resume code entry for bootloader to call
|
|
*
|
|
* we must put this code here in the data segment as we have no
|
|
* other way of restoring the stack pointer after sleep, and we
|
|
* must not write to the code segment (code is read-only)
|
|
*/
|
|
|
|
ENTRY(s3c2410_cpu_resume)
|
|
mov r0, #PSR_I_BIT | PSR_F_BIT | SVC_MODE
|
|
msr cpsr_c, r0
|
|
|
|
@@ load UART to allow us to print the two characters for
|
|
@@ resume debug
|
|
|
|
mov r2, #S3C24XX_PA_UART & 0xff000000
|
|
orr r2, r2, #S3C24XX_PA_UART & 0xff000
|
|
|
|
#if 0
|
|
/* SMDK2440 LED set */
|
|
mov r14, #S3C24XX_PA_GPIO
|
|
ldr r12, [ r14, #0x54 ]
|
|
bic r12, r12, #3<<4
|
|
orr r12, r12, #1<<7
|
|
str r12, [ r14, #0x54 ]
|
|
#endif
|
|
|
|
#ifdef CONFIG_DEBUG_RESUME
|
|
mov r3, #'L'
|
|
strb r3, [ r2, #S3C2410_UTXH ]
|
|
1001:
|
|
ldrb r14, [ r3, #S3C2410_UTRSTAT ]
|
|
tst r14, #S3C2410_UTRSTAT_TXE
|
|
beq 1001b
|
|
#endif /* CONFIG_DEBUG_RESUME */
|
|
|
|
mov r1, #0
|
|
mcr p15, 0, r1, c8, c7, 0 @@ invalidate I & D TLBs
|
|
mcr p15, 0, r1, c7, c7, 0 @@ invalidate I & D caches
|
|
|
|
ldr r0, s3c2410_sleep_save_phys @ address of restore block
|
|
ldmia r0, { r4 - r13 }
|
|
|
|
mcr p15, 0, r4, c13, c0, 0 @ PID
|
|
mcr p15, 0, r5, c3, c0, 0 @ Domain ID
|
|
mcr p15, 0, r6, c2, c0, 0 @ translation table base
|
|
|
|
#ifdef CONFIG_DEBUG_RESUME
|
|
mov r3, #'R'
|
|
strb r3, [ r2, #S3C2410_UTXH ]
|
|
#endif
|
|
|
|
ldr r2, =resume_with_mmu
|
|
mcr p15, 0, r7, c1, c0, 0 @ turn on MMU, etc
|
|
nop @ second-to-last before mmu
|
|
mov pc, r2 @ go back to virtual address
|
|
|
|
.ltorg
|