1/*
  2 * Copyright (C) 2014 Marvell
  3 *
  4 * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
  5 *
  6 * This file is licensed under the terms of the GNU General Public
  7 * License version 2.  This program is licensed "as is" without any
  8 * warranty of any kind, whether express or implied.
  9 */
 10
 11#define pr_fmt(fmt) "mvebu-cpureset: " fmt
 12
 13#include <linux/kernel.h>
 14#include <linux/init.h>
 15#include <linux/of_address.h>
 16#include <linux/io.h>
 17#include <linux/resource.h>
 18
 19#include "common.h"
 20
 21static void __iomem *cpu_reset_base;
 22static size_t cpu_reset_size;
 23
 24#define CPU_RESET_OFFSET(cpu) (cpu * 0x8)
 25#define CPU_RESET_ASSERT      BIT(0)
 26
 27int mvebu_cpu_reset_deassert(int cpu)
 28{
 29	u32 reg;
 30
 31	if (!cpu_reset_base)
 32		return -ENODEV;
 33
 34	if (CPU_RESET_OFFSET(cpu) >= cpu_reset_size)
 35		return -EINVAL;
 36
 37	reg = readl(cpu_reset_base + CPU_RESET_OFFSET(cpu));
 38	reg &= ~CPU_RESET_ASSERT;
 39	writel(reg, cpu_reset_base + CPU_RESET_OFFSET(cpu));
 40
 41	return 0;
 42}
 43
 44static int mvebu_cpu_reset_map(struct device_node *np, int res_idx)
 45{
 46	struct resource res;
 47
 48	if (of_address_to_resource(np, res_idx, &res)) {
 49		pr_err("unable to get resource\n");
 50		return -ENOENT;
 51	}
 52
 53	if (!request_mem_region(res.start, resource_size(&res),
 54				np->full_name)) {
 55		pr_err("unable to request region\n");
 56		return -EBUSY;
 57	}
 58
 59	cpu_reset_base = ioremap(res.start, resource_size(&res));
 60	if (!cpu_reset_base) {
 61		pr_err("unable to map registers\n");
 62		release_mem_region(res.start, resource_size(&res));
 63		return -ENOMEM;
 64	}
 65
 66	cpu_reset_size = resource_size(&res);
 67
 68	return 0;
 69}
 70
 71static int __init mvebu_cpu_reset_init(void)
 72{
 73	struct device_node *np;
 74	int res_idx;
 75	int ret;
 76
 77	np = of_find_compatible_node(NULL, NULL,
 78				     "marvell,armada-370-cpu-reset");
 79	if (np) {
 80		res_idx = 0;
 81	} else {
 82		/*
 83		 * This code is kept for backward compatibility with
 84		 * old Device Trees.
 85		 */
 86		np = of_find_compatible_node(NULL, NULL,
 87					     "marvell,armada-370-xp-pmsu");
 88		if (np) {
 89			pr_warn(FW_WARN "deprecated pmsu binding\n");
 90			res_idx = 1;
 91		}
 92	}
 93
 94	/* No reset node found */
 95	if (!np)
 96		return -ENODEV;
 97
 98	ret = mvebu_cpu_reset_map(np, res_idx);
 99	of_node_put(np);
100
101	return ret;
102}
103
104early_initcall(mvebu_cpu_reset_init);