1/*
2 * Hisilicon SoC reset code
3 *
4 * Copyright (c) 2014 Hisilicon Ltd.
5 * Copyright (c) 2014 Linaro Ltd.
6 *
7 * Author: Haojian Zhuang <haojian.zhuang@linaro.org>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 */
13
14#include <linux/delay.h>
15#include <linux/io.h>
16#include <linux/module.h>
17#include <linux/notifier.h>
18#include <linux/of_address.h>
19#include <linux/platform_device.h>
20#include <linux/reboot.h>
21
22#include <asm/proc-fns.h>
23
24static void __iomem *base;
25static u32 reboot_offset;
26
27static int hisi_restart_handler(struct notifier_block *this,
28				unsigned long mode, void *cmd)
29{
30	writel_relaxed(0xdeadbeef, base + reboot_offset);
31
32	while (1)
33		cpu_do_idle();
34
35	return NOTIFY_DONE;
36}
37
38static struct notifier_block hisi_restart_nb = {
39	.notifier_call = hisi_restart_handler,
40	.priority = 128,
41};
42
43static int hisi_reboot_probe(struct platform_device *pdev)
44{
45	struct device_node *np = pdev->dev.of_node;
46	int err;
47
48	base = of_iomap(np, 0);
49	if (!base) {
50		WARN(1, "failed to map base address");
51		return -ENODEV;
52	}
53
54	if (of_property_read_u32(np, "reboot-offset", &reboot_offset) < 0) {
55		pr_err("failed to find reboot-offset property\n");
56		return -EINVAL;
57	}
58
59	err = register_restart_handler(&hisi_restart_nb);
60	if (err)
61		dev_err(&pdev->dev, "cannot register restart handler (err=%d)\n",
62			err);
63
64	return err;
65}
66
67static const struct of_device_id hisi_reboot_of_match[] = {
68	{ .compatible = "hisilicon,sysctrl" },
69	{}
70};
71
72static struct platform_driver hisi_reboot_driver = {
73	.probe = hisi_reboot_probe,
74	.driver = {
75		.name = "hisi-reboot",
76		.of_match_table = hisi_reboot_of_match,
77	},
78};
79module_platform_driver(hisi_reboot_driver);
80