linux/arch/arm/plat-s3c24xx/sleep.S
Russell King e8856a8797 ARM: pm: convert cpu_suspend() to a normal function
cpu_suspend() has a weird calling method which makes it only possible to
call from assembly code: it returns with a modified stack pointer to
finish the suspend, but on resume, it 'returns' via a provided pointer.

We can make cpu_suspend() appear to be a normal function merely by
swapping the resume pointer argument and the link register.

Do so, and update all callers to take account of this more traditional
behaviour.

Acked-by: Frank Hofmann <frank.hofmann@tomtom.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-06-24 08:48:43 +01:00

106 lines
2.5 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 <mach/hardware.h>
#include <mach/map.h>
#include <mach/regs-gpio.h>
#include <mach/regs-clock.h>
#include <mach/regs-mem.h>
#include <plat/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
/* s3c_cpu_save
*
* entry:
* r1 = v:p offset
*/
ENTRY(s3c_cpu_save)
stmfd sp!, { r4 - r12, lr }
adr r3, BSYM(s3c24xx_finish_suspend)
bl cpu_suspend
ldmfd sp!, { r4 - r12, pc }
s3c24xx_finish_suspend:
@@ jump to final code to send system to sleep
ldr r0, =pm_cpu_sleep
@@ldr pc, [ r0 ]
ldr r0, [ r0 ]
mov pc, r0
.ltorg
/* sleep magic, to allow the bootloader to check for an valid
* image to resume to. Must be the first word before the
* s3c_cpu_resume entry.
*/
.word 0x2bedf00d
/* s3c_cpu_resume
*
* resume code entry for bootloader to call
*/
ENTRY(s3c_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 */
b cpu_resume