// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2014 Marvell
 *
 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
 */

#define pr_fmt(fmt) "mvebu-cpureset: " fmt

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of_address.h>
#include <linux/io.h>
#include <linux/resource.h>

#include "common.h"

static void __iomem *cpu_reset_base;
static size_t cpu_reset_size;

#define CPU_RESET_OFFSET(cpu) (cpu * 0x8)
#define CPU_RESET_ASSERT      BIT(0)

int mvebu_cpu_reset_deassert(int cpu)
{
        u32 reg;

        if (!cpu_reset_base)
                return -ENODEV;

        if (CPU_RESET_OFFSET(cpu) >= cpu_reset_size)
                return -EINVAL;

        reg = readl(cpu_reset_base + CPU_RESET_OFFSET(cpu));
        reg &= ~CPU_RESET_ASSERT;
        writel(reg, cpu_reset_base + CPU_RESET_OFFSET(cpu));

        return 0;
}

static int mvebu_cpu_reset_map(struct device_node *np, int res_idx)
{
        struct resource res;

        if (of_address_to_resource(np, res_idx, &res)) {
                pr_err("unable to get resource\n");
                return -ENOENT;
        }

        if (!request_mem_region(res.start, resource_size(&res),
                                np->full_name)) {
                pr_err("unable to request region\n");
                return -EBUSY;
        }

        cpu_reset_base = ioremap(res.start, resource_size(&res));
        if (!cpu_reset_base) {
                pr_err("unable to map registers\n");
                release_mem_region(res.start, resource_size(&res));
                return -ENOMEM;
        }

        cpu_reset_size = resource_size(&res);

        return 0;
}

static int __init mvebu_cpu_reset_init(void)
{
        struct device_node *np;
        int res_idx;
        int ret;

        np = of_find_compatible_node(NULL, NULL,
                                     "marvell,armada-370-cpu-reset");
        if (np) {
                res_idx = 0;
        } else {
                /*
                 * This code is kept for backward compatibility with
                 * old Device Trees.
                 */
                np = of_find_compatible_node(NULL, NULL,
                                             "marvell,armada-370-xp-pmsu");
                if (np) {
                        pr_warn(FW_WARN "deprecated pmsu binding\n");
                        res_idx = 1;
                }
        }

        /* No reset node found */
        if (!np)
                return -ENODEV;

        ret = mvebu_cpu_reset_map(np, res_idx);
        of_node_put(np);

        return ret;
}

early_initcall(mvebu_cpu_reset_init);