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
 18static void __iomem *cpu_reset_base;
 19static size_t cpu_reset_size;
 20
 21#define CPU_RESET_OFFSET(cpu) (cpu * 0x8)
 22#define CPU_RESET_ASSERT      BIT(0)
 23
 24int 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
 41static 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
 68static 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
101early_initcall(mvebu_cpu_reset_init);