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
19static void __iomem *cpu_reset_base;
20static size_t cpu_reset_size;
21
22#define CPU_RESET_OFFSET(cpu) (cpu * 0x8)
23#define CPU_RESET_ASSERT      BIT(0)
24
25int mvebu_cpu_reset_deassert(int cpu)
26{
27	u32 reg;
28
29	if (!cpu_reset_base)
30		return -ENODEV;
31
32	if (CPU_RESET_OFFSET(cpu) >= cpu_reset_size)
33		return -EINVAL;
34
35	reg = readl(cpu_reset_base + CPU_RESET_OFFSET(cpu));
36	reg &= ~CPU_RESET_ASSERT;
37	writel(reg, cpu_reset_base + CPU_RESET_OFFSET(cpu));
38
39	return 0;
40}
41
42static int mvebu_cpu_reset_map(struct device_node *np, int res_idx)
43{
44	struct resource res;
45
46	if (of_address_to_resource(np, res_idx, &res)) {
47		pr_err("unable to get resource\n");
48		return -ENOENT;
49	}
50
51	if (!request_mem_region(res.start, resource_size(&res),
52				np->full_name)) {
53		pr_err("unable to request region\n");
54		return -EBUSY;
55	}
56
57	cpu_reset_base = ioremap(res.start, resource_size(&res));
58	if (!cpu_reset_base) {
59		pr_err("unable to map registers\n");
60		release_mem_region(res.start, resource_size(&res));
61		return -ENOMEM;
62	}
63
64	cpu_reset_size = resource_size(&res);
65
66	return 0;
67}
68
69static int __init mvebu_cpu_reset_init(void)
70{
71	struct device_node *np;
72	int res_idx;
73	int ret;
74
75	np = of_find_compatible_node(NULL, NULL,
76				     "marvell,armada-370-cpu-reset");
77	if (np) {
78		res_idx = 0;
79	} else {
80		/*
81		 * This code is kept for backward compatibility with
82		 * old Device Trees.
83		 */
84		np = of_find_compatible_node(NULL, NULL,
85					     "marvell,armada-370-xp-pmsu");
86		if (np) {
87			pr_warn(FW_WARN "deprecated pmsu binding\n");
88			res_idx = 1;
89		}
90	}
91
92	/* No reset node found */
93	if (!np)
94		return -ENODEV;
95
96	ret = mvebu_cpu_reset_map(np, res_idx);
97	of_node_put(np);
98
99	return ret;
100}
101
102early_initcall(mvebu_cpu_reset_init);
103