1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Low-level power-management support for Alpine platform. 4 * 5 * Copyright (C) 2015 Annapurna Labs Ltd. 6 */ 7 8 #include <linux/io.h> 9 #include <linux/of.h> 10 #include <linux/of_address.h> 11 #include <linux/regmap.h> 12 #include <linux/mfd/syscon.h> 13 14 #include "alpine_cpu_pm.h" 15 #include "alpine_cpu_resume.h" 16 17 /* NB registers */ 18 #define AL_SYSFAB_POWER_CONTROL(cpu) (0x2000 + (cpu)*0x100 + 0x20) 19 20 static struct regmap *al_sysfabric; 21 static struct al_cpu_resume_regs __iomem *al_cpu_resume_regs; 22 static int wakeup_supported; 23 24 int alpine_cpu_wakeup(unsigned int phys_cpu, uint32_t phys_resume_addr) 25 { 26 if (!wakeup_supported) 27 return -ENOSYS; 28 29 /* 30 * Set CPU resume address - 31 * secure firmware running on boot will jump to this address 32 * after setting proper CPU mode, and initialiing e.g. secure 33 * regs (the same mode all CPUs are booted to - usually HYP) 34 */ 35 writel(phys_resume_addr, 36 &al_cpu_resume_regs->per_cpu[phys_cpu].resume_addr); 37 38 /* Power-up the CPU */ 39 regmap_write(al_sysfabric, AL_SYSFAB_POWER_CONTROL(phys_cpu), 0); 40 41 return 0; 42 } 43 44 void __init alpine_cpu_pm_init(void) 45 { 46 struct device_node *np; 47 uint32_t watermark; 48 49 al_sysfabric = syscon_regmap_lookup_by_compatible("al,alpine-sysfabric-service"); 50 51 np = of_find_compatible_node(NULL, NULL, "al,alpine-cpu-resume"); 52 al_cpu_resume_regs = of_iomap(np, 0); 53 54 wakeup_supported = !IS_ERR(al_sysfabric) && al_cpu_resume_regs; 55 56 if (wakeup_supported) { 57 watermark = readl(&al_cpu_resume_regs->watermark); 58 wakeup_supported = (watermark & AL_CPU_RESUME_MAGIC_NUM_MASK) 59 == AL_CPU_RESUME_MAGIC_NUM; 60 } 61 } 62