71 lines
2.0 KiB
C
71 lines
2.0 KiB
C
/*
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* Low-level power-management support for Alpine platform.
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*
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* Copyright (C) 2015 Annapurna Labs Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/regmap.h>
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#include <linux/mfd/syscon.h>
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#include "alpine_cpu_pm.h"
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#include "alpine_cpu_resume.h"
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/* NB registers */
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#define AL_SYSFAB_POWER_CONTROL(cpu) (0x2000 + (cpu)*0x100 + 0x20)
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static struct regmap *al_sysfabric;
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static struct al_cpu_resume_regs __iomem *al_cpu_resume_regs;
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static int wakeup_supported;
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int alpine_cpu_wakeup(unsigned int phys_cpu, uint32_t phys_resume_addr)
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{
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if (!wakeup_supported)
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return -ENOSYS;
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/*
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* Set CPU resume address -
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* secure firmware running on boot will jump to this address
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* after setting proper CPU mode, and initialiing e.g. secure
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* regs (the same mode all CPUs are booted to - usually HYP)
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*/
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writel(phys_resume_addr,
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&al_cpu_resume_regs->per_cpu[phys_cpu].resume_addr);
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/* Power-up the CPU */
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regmap_write(al_sysfabric, AL_SYSFAB_POWER_CONTROL(phys_cpu), 0);
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return 0;
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}
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void __init alpine_cpu_pm_init(void)
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{
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struct device_node *np;
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uint32_t watermark;
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al_sysfabric = syscon_regmap_lookup_by_compatible("al,alpine-sysfabric-service");
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np = of_find_compatible_node(NULL, NULL, "al,alpine-cpu-resume");
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al_cpu_resume_regs = of_iomap(np, 0);
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wakeup_supported = !IS_ERR(al_sysfabric) && al_cpu_resume_regs;
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if (wakeup_supported) {
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watermark = readl(&al_cpu_resume_regs->watermark);
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wakeup_supported = (watermark & AL_CPU_RESUME_MAGIC_NUM_MASK)
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== AL_CPU_RESUME_MAGIC_NUM;
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}
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}
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