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
18 static void __iomem *cpu_reset_base;
19 static size_t cpu_reset_size;
20
21 #define CPU_RESET_OFFSET(cpu) (cpu * 0x8)
22 #define CPU_RESET_ASSERT BIT(0)
23
24 int 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
41 static 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
68 static 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
101 early_initcall(mvebu_cpu_reset_init);
102
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