1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2014 Marvell 4 * 5 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com> 6 */ 7 8 #define pr_fmt(fmt) "mvebu-cpureset: " fmt 9 10 #include <linux/kernel.h> 11 #include <linux/init.h> 12 #include <linux/of_address.h> 13 #include <linux/io.h> 14 #include <linux/resource.h> 15 16 #include "common.h" 17 18 static void __iomem *cpu_reset_base; 19 static size_t cpu_reset_size; 20 21 #define CPU_RESET_OFFSET(cpu) (cpu * 0x8) 22 #define CPU_RESET_ASSERT BIT(0) 23 24 int mvebu_cpu_reset_deassert(int cpu) 25 { 26 u32 reg; 27 28 if (!cpu_reset_base) 29 return -ENODEV; 30 31 if (CPU_RESET_OFFSET(cpu) >= cpu_reset_size) 32 return -EINVAL; 33 34 reg = readl(cpu_reset_base + CPU_RESET_OFFSET(cpu)); 35 reg &= ~CPU_RESET_ASSERT; 36 writel(reg, cpu_reset_base + CPU_RESET_OFFSET(cpu)); 37 38 return 0; 39 } 40 41 static int mvebu_cpu_reset_map(struct device_node *np, int res_idx) 42 { 43 struct resource res; 44 45 if (of_address_to_resource(np, res_idx, &res)) { 46 pr_err("unable to get resource\n"); 47 return -ENOENT; 48 } 49 50 if (!request_mem_region(res.start, resource_size(&res), 51 np->full_name)) { 52 pr_err("unable to request region\n"); 53 return -EBUSY; 54 } 55 56 cpu_reset_base = ioremap(res.start, resource_size(&res)); 57 if (!cpu_reset_base) { 58 pr_err("unable to map registers\n"); 59 release_mem_region(res.start, resource_size(&res)); 60 return -ENOMEM; 61 } 62 63 cpu_reset_size = resource_size(&res); 64 65 return 0; 66 } 67 68 static int __init mvebu_cpu_reset_init(void) 69 { 70 struct device_node *np; 71 int res_idx; 72 int ret; 73 74 np = of_find_compatible_node(NULL, NULL, 75 "marvell,armada-370-cpu-reset"); 76 if (np) { 77 res_idx = 0; 78 } else { 79 /* 80 * This code is kept for backward compatibility with 81 * old Device Trees. 82 */ 83 np = of_find_compatible_node(NULL, NULL, 84 "marvell,armada-370-xp-pmsu"); 85 if (np) { 86 pr_warn(FW_WARN "deprecated pmsu binding\n"); 87 res_idx = 1; 88 } 89 } 90 91 /* No reset node found */ 92 if (!np) 93 return -ENODEV; 94 95 ret = mvebu_cpu_reset_map(np, res_idx); 96 of_node_put(np); 97 98 return ret; 99 } 100 101 early_initcall(mvebu_cpu_reset_init); 102