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);
105