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1 | /* |
2 | * Low-level power-management support for Alpine platform. | |
3 | * | |
4 | * Copyright (C) 2015 Annapurna Labs Ltd. | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | */ | |
16 | ||
17 | #include <linux/io.h> | |
18 | #include <linux/of.h> | |
19 | #include <linux/of_address.h> | |
20 | #include <linux/regmap.h> | |
21 | #include <linux/mfd/syscon.h> | |
22 | ||
23 | #include "alpine_cpu_pm.h" | |
24 | #include "alpine_cpu_resume.h" | |
25 | ||
26 | /* NB registers */ | |
27 | #define AL_SYSFAB_POWER_CONTROL(cpu) (0x2000 + (cpu)*0x100 + 0x20) | |
28 | ||
29 | static struct regmap *al_sysfabric; | |
30 | static struct al_cpu_resume_regs __iomem *al_cpu_resume_regs; | |
31 | static int wakeup_supported; | |
32 | ||
33 | int alpine_cpu_wakeup(unsigned int phys_cpu, uint32_t phys_resume_addr) | |
34 | { | |
35 | if (!wakeup_supported) | |
36 | return -ENOSYS; | |
37 | ||
38 | /* | |
39 | * Set CPU resume address - | |
40 | * secure firmware running on boot will jump to this address | |
41 | * after setting proper CPU mode, and initialiing e.g. secure | |
42 | * regs (the same mode all CPUs are booted to - usually HYP) | |
43 | */ | |
44 | writel(phys_resume_addr, | |
45 | &al_cpu_resume_regs->per_cpu[phys_cpu].resume_addr); | |
46 | ||
47 | /* Power-up the CPU */ | |
48 | regmap_write(al_sysfabric, AL_SYSFAB_POWER_CONTROL(phys_cpu), 0); | |
49 | ||
50 | return 0; | |
51 | } | |
52 | ||
53 | void __init alpine_cpu_pm_init(void) | |
54 | { | |
55 | struct device_node *np; | |
56 | uint32_t watermark; | |
57 | ||
58 | al_sysfabric = syscon_regmap_lookup_by_compatible("al,alpine-sysfabric-service"); | |
59 | ||
60 | np = of_find_compatible_node(NULL, NULL, "al,alpine-cpu-resume"); | |
61 | al_cpu_resume_regs = of_iomap(np, 0); | |
62 | ||
63 | wakeup_supported = !IS_ERR(al_sysfabric) && al_cpu_resume_regs; | |
64 | ||
65 | if (wakeup_supported) { | |
66 | watermark = readl(&al_cpu_resume_regs->watermark); | |
67 | wakeup_supported = (watermark & AL_CPU_RESUME_MAGIC_NUM_MASK) | |
68 | == AL_CPU_RESUME_MAGIC_NUM; | |
69 | } | |
70 | } |