Merge tag 'mfd-for-linus-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd
[deliverable/linux.git] / arch / arm / mach-mvebu / cpu-reset.c
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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#include "armada-370-xp.h"
19
20static void __iomem *cpu_reset_base;
21static size_t cpu_reset_size;
22
23#define CPU_RESET_OFFSET(cpu) (cpu * 0x8)
24#define CPU_RESET_ASSERT BIT(0)
25
26int mvebu_cpu_reset_deassert(int cpu)
27{
28 u32 reg;
29
30 if (!cpu_reset_base)
31 return -ENODEV;
32
33 if (CPU_RESET_OFFSET(cpu) >= cpu_reset_size)
34 return -EINVAL;
35
36 reg = readl(cpu_reset_base + CPU_RESET_OFFSET(cpu));
37 reg &= ~CPU_RESET_ASSERT;
38 writel(reg, cpu_reset_base + CPU_RESET_OFFSET(cpu));
39
40 return 0;
41}
42
49754ffe 43static int mvebu_cpu_reset_map(struct device_node *np, int res_idx)
3f20fb11 44{
3f20fb11 45 struct resource res;
3f20fb11 46
49754ffe 47 if (of_address_to_resource(np, res_idx, &res)) {
3f20fb11 48 pr_err("unable to get resource\n");
49754ffe 49 return -ENOENT;
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50 }
51
52 if (!request_mem_region(res.start, resource_size(&res),
53 np->full_name)) {
54 pr_err("unable to request region\n");
49754ffe 55 return -EBUSY;
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56 }
57
58 cpu_reset_base = ioremap(res.start, resource_size(&res));
59 if (!cpu_reset_base) {
60 pr_err("unable to map registers\n");
61 release_mem_region(res.start, resource_size(&res));
49754ffe 62 return -ENOMEM;
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63 }
64
65 cpu_reset_size = resource_size(&res);
66
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67 return 0;
68}
69
70int __init mvebu_cpu_reset_init(void)
71{
72 struct device_node *np;
73 int res_idx;
74 int ret;
75
76 np = of_find_compatible_node(NULL, NULL,
77 "marvell,armada-370-cpu-reset");
78 if (np) {
79 res_idx = 0;
80 } else {
81 /*
82 * This code is kept for backward compatibility with
83 * old Device Trees.
84 */
85 np = of_find_compatible_node(NULL, NULL,
86 "marvell,armada-370-xp-pmsu");
87 if (np) {
88 pr_warn(FW_WARN "deprecated pmsu binding\n");
89 res_idx = 1;
90 }
91 }
92
93 /* No reset node found */
94 if (!np)
95 return -ENODEV;
96
97 ret = mvebu_cpu_reset_map(np, res_idx);
3f20fb11 98 of_node_put(np);
49754ffe 99
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100 return ret;
101}
102
103early_initcall(mvebu_cpu_reset_init);
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