xref: /OK3568_Linux_fs/kernel/arch/arm/mach-s3c/sleep-s3c24xx.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0+ */
2*4882a593Smuzhiyun/*
3*4882a593Smuzhiyun * Copyright (c) 2004 Simtec Electronics
4*4882a593Smuzhiyun *	Ben Dooks <ben@simtec.co.uk>
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * S3C2410 Power Manager (Suspend-To-RAM) support
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * Based on PXA/SA1100 sleep code by:
9*4882a593Smuzhiyun *	Nicolas Pitre, (c) 2002 Monta Vista Software Inc
10*4882a593Smuzhiyun *	Cliff Brake, (c) 2001
11*4882a593Smuzhiyun */
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun#include <linux/linkage.h>
14*4882a593Smuzhiyun#include <linux/serial_s3c.h>
15*4882a593Smuzhiyun#include <asm/assembler.h>
16*4882a593Smuzhiyun#include "map.h"
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun#include "regs-gpio.h"
19*4882a593Smuzhiyun#include "regs-clock.h"
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun/*
22*4882a593Smuzhiyun * S3C24XX_DEBUG_RESUME is dangerous if your bootloader does not
23*4882a593Smuzhiyun * reset the UART configuration, only enable if you really need this!
24*4882a593Smuzhiyun */
25*4882a593Smuzhiyun//#define S3C24XX_DEBUG_RESUME
26*4882a593Smuzhiyun
27*4882a593Smuzhiyun	.text
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun	/* sleep magic, to allow the bootloader to check for an valid
30*4882a593Smuzhiyun	 * image to resume to. Must be the first word before the
31*4882a593Smuzhiyun	 * s3c_cpu_resume entry.
32*4882a593Smuzhiyun	*/
33*4882a593Smuzhiyun
34*4882a593Smuzhiyun	.word	0x2bedf00d
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun	/* s3c_cpu_resume
37*4882a593Smuzhiyun	 *
38*4882a593Smuzhiyun	 * resume code entry for bootloader to call
39*4882a593Smuzhiyun	*/
40*4882a593Smuzhiyun
41*4882a593SmuzhiyunENTRY(s3c_cpu_resume)
42*4882a593Smuzhiyun	mov	r0, #PSR_I_BIT | PSR_F_BIT | SVC_MODE
43*4882a593Smuzhiyun	msr	cpsr_c, r0
44*4882a593Smuzhiyun
45*4882a593Smuzhiyun	@@ load UART to allow us to print the two characters for
46*4882a593Smuzhiyun	@@ resume debug
47*4882a593Smuzhiyun
48*4882a593Smuzhiyun	mov	r2, #S3C24XX_PA_UART & 0xff000000
49*4882a593Smuzhiyun	orr	r2, r2, #S3C24XX_PA_UART & 0xff000
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun#if 0
52*4882a593Smuzhiyun	/* SMDK2440 LED set */
53*4882a593Smuzhiyun	mov	r14, #S3C24XX_PA_GPIO
54*4882a593Smuzhiyun	ldr	r12, [ r14, #0x54 ]
55*4882a593Smuzhiyun	bic	r12, r12, #3<<4
56*4882a593Smuzhiyun	orr	r12, r12, #1<<7
57*4882a593Smuzhiyun	str	r12, [ r14, #0x54 ]
58*4882a593Smuzhiyun#endif
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun#ifdef S3C24XX_DEBUG_RESUME
61*4882a593Smuzhiyun	mov	r3, #'L'
62*4882a593Smuzhiyun	strb	r3, [ r2, #S3C2410_UTXH ]
63*4882a593Smuzhiyun1001:
64*4882a593Smuzhiyun	ldrb	r14, [ r3, #S3C2410_UTRSTAT ]
65*4882a593Smuzhiyun	tst	r14, #S3C2410_UTRSTAT_TXE
66*4882a593Smuzhiyun	beq	1001b
67*4882a593Smuzhiyun#endif /* S3C24XX_DEBUG_RESUME */
68*4882a593Smuzhiyun
69*4882a593Smuzhiyun	b	cpu_resume
70