1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Low-level power-management support for Alpine platform.
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright (C) 2015 Annapurna Labs Ltd.
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun #include <linux/io.h>
9*4882a593Smuzhiyun #include <linux/of.h>
10*4882a593Smuzhiyun #include <linux/of_address.h>
11*4882a593Smuzhiyun #include <linux/regmap.h>
12*4882a593Smuzhiyun #include <linux/mfd/syscon.h>
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun #include "alpine_cpu_pm.h"
15*4882a593Smuzhiyun #include "alpine_cpu_resume.h"
16*4882a593Smuzhiyun
17*4882a593Smuzhiyun /* NB registers */
18*4882a593Smuzhiyun #define AL_SYSFAB_POWER_CONTROL(cpu) (0x2000 + (cpu)*0x100 + 0x20)
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun static struct regmap *al_sysfabric;
21*4882a593Smuzhiyun static struct al_cpu_resume_regs __iomem *al_cpu_resume_regs;
22*4882a593Smuzhiyun static int wakeup_supported;
23*4882a593Smuzhiyun
alpine_cpu_wakeup(unsigned int phys_cpu,uint32_t phys_resume_addr)24*4882a593Smuzhiyun int alpine_cpu_wakeup(unsigned int phys_cpu, uint32_t phys_resume_addr)
25*4882a593Smuzhiyun {
26*4882a593Smuzhiyun if (!wakeup_supported)
27*4882a593Smuzhiyun return -ENOSYS;
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun /*
30*4882a593Smuzhiyun * Set CPU resume address -
31*4882a593Smuzhiyun * secure firmware running on boot will jump to this address
32*4882a593Smuzhiyun * after setting proper CPU mode, and initialiing e.g. secure
33*4882a593Smuzhiyun * regs (the same mode all CPUs are booted to - usually HYP)
34*4882a593Smuzhiyun */
35*4882a593Smuzhiyun writel(phys_resume_addr,
36*4882a593Smuzhiyun &al_cpu_resume_regs->per_cpu[phys_cpu].resume_addr);
37*4882a593Smuzhiyun
38*4882a593Smuzhiyun /* Power-up the CPU */
39*4882a593Smuzhiyun regmap_write(al_sysfabric, AL_SYSFAB_POWER_CONTROL(phys_cpu), 0);
40*4882a593Smuzhiyun
41*4882a593Smuzhiyun return 0;
42*4882a593Smuzhiyun }
43*4882a593Smuzhiyun
alpine_cpu_pm_init(void)44*4882a593Smuzhiyun void __init alpine_cpu_pm_init(void)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun struct device_node *np;
47*4882a593Smuzhiyun uint32_t watermark;
48*4882a593Smuzhiyun
49*4882a593Smuzhiyun al_sysfabric = syscon_regmap_lookup_by_compatible("al,alpine-sysfabric-service");
50*4882a593Smuzhiyun
51*4882a593Smuzhiyun np = of_find_compatible_node(NULL, NULL, "al,alpine-cpu-resume");
52*4882a593Smuzhiyun al_cpu_resume_regs = of_iomap(np, 0);
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun wakeup_supported = !IS_ERR(al_sysfabric) && al_cpu_resume_regs;
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun if (wakeup_supported) {
57*4882a593Smuzhiyun watermark = readl(&al_cpu_resume_regs->watermark);
58*4882a593Smuzhiyun wakeup_supported = (watermark & AL_CPU_RESUME_MAGIC_NUM_MASK)
59*4882a593Smuzhiyun == AL_CPU_RESUME_MAGIC_NUM;
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun }
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