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1da177e4 LT |
1 | /* linux/arch/arm/mach-s3c2410/sleep.S |
2 | * | |
3 | * Copyright (c) 2004 Simtec Electronics | |
4 | * Ben Dooks <ben@simtec.co.uk> | |
5 | * | |
6 | * S3C2410 Power Manager (Suspend-To-RAM) support | |
7 | * | |
8 | * Based on PXA/SA1100 sleep code by: | |
9 | * Nicolas Pitre, (c) 2002 Monta Vista Software Inc | |
10 | * Cliff Brake, (c) 2001 | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2 of the License, or | |
15 | * (at your option) any later version. | |
16 | * | |
17 | * This program is distributed in the hope that it will be useful, | |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
20 | * GNU General Public License for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License | |
23 | * along with this program; if not, write to the Free Software | |
24 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
25 | */ | |
26 | ||
1da177e4 LT |
27 | #include <linux/linkage.h> |
28 | #include <asm/assembler.h> | |
29 | #include <asm/hardware.h> | |
30 | #include <asm/arch/map.h> | |
31 | ||
32 | #include <asm/arch/regs-gpio.h> | |
33 | #include <asm/arch/regs-clock.h> | |
34 | #include <asm/arch/regs-mem.h> | |
35 | #include <asm/arch/regs-serial.h> | |
36 | ||
37 | /* CONFIG_DEBUG_RESUME is dangerous if your bootloader does not | |
38 | * reset the UART configuration, only enable if you really need this! | |
39 | */ | |
40 | //#define CONFIG_DEBUG_RESUME | |
41 | ||
42 | .text | |
43 | ||
58095d7f | 44 | /* s3c2410_cpu_save |
1da177e4 | 45 | * |
58095d7f BD |
46 | * save enough of the CPU state to allow us to re-start |
47 | * pm.c code. as we store items like the sp/lr, we will | |
48 | * end up returning from this function when the cpu resumes | |
49 | * so the return value is set to mark this. | |
50 | * | |
51 | * This arangement means we avoid having to flush the cache | |
52 | * from this code. | |
1da177e4 LT |
53 | * |
54 | * entry: | |
58095d7f BD |
55 | * r0 = pointer to save block |
56 | * | |
57 | * exit: | |
58 | * r0 = 0 => we stored everything | |
59 | * 1 => resumed from sleep | |
1da177e4 LT |
60 | */ |
61 | ||
58095d7f | 62 | ENTRY(s3c2410_cpu_save) |
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63 | stmfd sp!, { r4 - r12, lr } |
64 | ||
65 | @@ store co-processor registers | |
66 | ||
67 | mrc p15, 0, r4, c15, c1, 0 @ CP access register | |
68 | mrc p15, 0, r5, c13, c0, 0 @ PID | |
69 | mrc p15, 0, r6, c3, c0, 0 @ Domain ID | |
70 | mrc p15, 0, r7, c2, c0, 0 @ translation table base address | |
c3fb0416 | 71 | mrc p15, 0, r8, c1, c0, 0 @ control register |
1da177e4 LT |
72 | |
73 | stmia r0, { r4 - r13 } | |
74 | ||
58095d7f BD |
75 | mov r0, #0 |
76 | ldmfd sp, { r4 - r12, pc } | |
1da177e4 | 77 | |
1da177e4 LT |
78 | @@ return to the caller, after having the MMU |
79 | @@ turned on, this restores the last bits from the | |
80 | @@ stack | |
81 | resume_with_mmu: | |
58095d7f | 82 | mov r0, #1 |
1da177e4 LT |
83 | ldmfd sp!, { r4 - r12, pc } |
84 | ||
85 | .ltorg | |
86 | ||
87 | @@ the next bits sit in the .data segment, even though they | |
88 | @@ happen to be code... the s3c2410_sleep_save_phys needs to be | |
89 | @@ accessed by the resume code before it can restore the MMU. | |
90 | @@ This means that the variable has to be close enough for the | |
91 | @@ code to read it... since the .text segment needs to be RO, | |
92 | @@ the data segment can be the only place to put this code. | |
93 | ||
94 | .data | |
95 | ||
96 | .global s3c2410_sleep_save_phys | |
97 | s3c2410_sleep_save_phys: | |
98 | .word 0 | |
99 | ||
100 | /* s3c2410_cpu_resume | |
101 | * | |
102 | * resume code entry for bootloader to call | |
103 | * | |
104 | * we must put this code here in the data segment as we have no | |
105 | * other way of restoring the stack pointer after sleep, and we | |
106 | * must not write to the code segment (code is read-only) | |
107 | */ | |
108 | ||
109 | ENTRY(s3c2410_cpu_resume) | |
801194e3 | 110 | mov r0, #PSR_I_BIT | PSR_F_BIT | SVC_MODE |
1da177e4 LT |
111 | msr cpsr_c, r0 |
112 | ||
113 | @@ load UART to allow us to print the two characters for | |
114 | @@ resume debug | |
115 | ||
0367a8d3 LCVR |
116 | mov r2, #S3C24XX_PA_UART & 0xff000000 |
117 | orr r2, r2, #S3C24XX_PA_UART & 0xff000 | |
1da177e4 LT |
118 | |
119 | #if 0 | |
120 | /* SMDK2440 LED set */ | |
0367a8d3 | 121 | mov r14, #S3C24XX_PA_GPIO |
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122 | ldr r12, [ r14, #0x54 ] |
123 | bic r12, r12, #3<<4 | |
124 | orr r12, r12, #1<<7 | |
125 | str r12, [ r14, #0x54 ] | |
126 | #endif | |
127 | ||
128 | #ifdef CONFIG_DEBUG_RESUME | |
129 | mov r3, #'L' | |
130 | strb r3, [ r2, #S3C2410_UTXH ] | |
131 | 1001: | |
132 | ldrb r14, [ r3, #S3C2410_UTRSTAT ] | |
133 | tst r14, #S3C2410_UTRSTAT_TXE | |
134 | beq 1001b | |
135 | #endif /* CONFIG_DEBUG_RESUME */ | |
136 | ||
137 | mov r1, #0 | |
138 | mcr p15, 0, r1, c8, c7, 0 @@ invalidate I & D TLBs | |
139 | mcr p15, 0, r1, c7, c7, 0 @@ invalidate I & D caches | |
140 | ||
141 | ldr r0, s3c2410_sleep_save_phys @ address of restore block | |
142 | ldmia r0, { r4 - r13 } | |
143 | ||
144 | mcr p15, 0, r4, c15, c1, 0 @ CP access register | |
145 | mcr p15, 0, r5, c13, c0, 0 @ PID | |
146 | mcr p15, 0, r6, c3, c0, 0 @ Domain ID | |
147 | mcr p15, 0, r7, c2, c0, 0 @ translation table base | |
1da177e4 LT |
148 | |
149 | #ifdef CONFIG_DEBUG_RESUME | |
150 | mov r3, #'R' | |
151 | strb r3, [ r2, #S3C2410_UTXH ] | |
152 | #endif | |
153 | ||
154 | ldr r2, =resume_with_mmu | |
c3fb0416 | 155 | mcr p15, 0, r8, c1, c0, 0 @ turn on MMU, etc |
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156 | nop @ second-to-last before mmu |
157 | mov pc, r2 @ go back to virtual address | |
158 | ||
159 | .ltorg |