Tsahee Zidenberg | e9e06f2 | 2015-03-12 13:53:06 +0200 | [diff] [blame] | 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 | } |