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