xref: /linux/arch/arm/mach-exynos/sleep.S (revision e0bf6c5ca2d3281f231c5f0c9bf145e9513644de)
1/*
2 * Copyright (c) 2013 Samsung Electronics Co., Ltd.
3 *		http://www.samsung.com
4 *
5 * Exynos low-level resume code
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 */
17
18#include <linux/linkage.h>
19#include <asm/asm-offsets.h>
20#include <asm/hardware/cache-l2x0.h>
21#include "smc.h"
22
23#define CPU_MASK	0xff0ffff0
24#define CPU_CORTEX_A9	0x410fc090
25
26	/*
27	 * The following code is located into the .data section. This is to
28	 * allow l2x0_regs_phys to be accessed with a relative load while we
29	 * can't rely on any MMU translation. We could have put l2x0_regs_phys
30	 * in the .text section as well, but some setups might insist on it to
31	 * be truly read-only. (Reference from: arch/arm/kernel/sleep.S)
32	 */
33	.data
34	.align
35
36	/*
37	 * sleep magic, to allow the bootloader to check for an valid
38	 * image to resume to. Must be the first word before the
39	 * exynos_cpu_resume entry.
40	 */
41
42	.word	0x2bedf00d
43
44	/*
45	 * exynos_cpu_resume
46	 *
47	 * resume code entry for bootloader to call
48	 */
49
50ENTRY(exynos_cpu_resume)
51#ifdef CONFIG_CACHE_L2X0
52	mrc	p15, 0, r0, c0, c0, 0
53	ldr	r1, =CPU_MASK
54	and	r0, r0, r1
55	ldr	r1, =CPU_CORTEX_A9
56	cmp	r0, r1
57	bleq	l2c310_early_resume
58#endif
59	b	cpu_resume
60ENDPROC(exynos_cpu_resume)
61
62	.align
63
64ENTRY(exynos_cpu_resume_ns)
65	mrc	p15, 0, r0, c0, c0, 0
66	ldr	r1, =CPU_MASK
67	and	r0, r0, r1
68	ldr	r1, =CPU_CORTEX_A9
69	cmp	r0, r1
70	bne	skip_cp15
71
72	adr	r0, cp15_save_power
73	ldr	r1, [r0]
74	adr	r0, cp15_save_diag
75	ldr	r2, [r0]
76	mov	r0, #SMC_CMD_C15RESUME
77	dsb
78	smc	#0
79#ifdef CONFIG_CACHE_L2X0
80	adr	r0, 1f
81	ldr	r2, [r0]
82	add	r0, r2, r0
83
84	/* Check that the address has been initialised. */
85	ldr	r1, [r0, #L2X0_R_PHY_BASE]
86	teq	r1, #0
87	beq	skip_l2x0
88
89	/* Check if controller has been enabled. */
90	ldr	r2, [r1, #L2X0_CTRL]
91	tst	r2, #0x1
92	bne	skip_l2x0
93
94	ldr	r1, [r0, #L2X0_R_TAG_LATENCY]
95	ldr	r2, [r0, #L2X0_R_DATA_LATENCY]
96	ldr	r3, [r0, #L2X0_R_PREFETCH_CTRL]
97	mov	r0, #SMC_CMD_L2X0SETUP1
98	smc	#0
99
100	/* Reload saved regs pointer because smc corrupts registers. */
101	adr	r0, 1f
102	ldr	r2, [r0]
103	add	r0, r2, r0
104
105	ldr	r1, [r0, #L2X0_R_PWR_CTRL]
106	ldr	r2, [r0, #L2X0_R_AUX_CTRL]
107	mov	r0, #SMC_CMD_L2X0SETUP2
108	smc	#0
109
110	mov	r0, #SMC_CMD_L2X0INVALL
111	smc	#0
112
113	mov	r1, #1
114	mov	r0, #SMC_CMD_L2X0CTRL
115	smc	#0
116skip_l2x0:
117#endif /* CONFIG_CACHE_L2X0 */
118skip_cp15:
119	b	cpu_resume
120ENDPROC(exynos_cpu_resume_ns)
121	.globl cp15_save_diag
122cp15_save_diag:
123	.long	0	@ cp15 diagnostic
124	.globl cp15_save_power
125cp15_save_power:
126	.long	0	@ cp15 power control
127
128#ifdef CONFIG_CACHE_L2X0
129	.align
1301:	.long	l2x0_saved_regs - .
131#endif /* CONFIG_CACHE_L2X0 */
132