1// SPDX-License-Identifier: GPL-2.0-only
2// Copyright (C) 2013 Broadcom Corporation
3
4#include <linux/bitops.h>
5#include <linux/device.h>
6#include <linux/errno.h>
7#include <linux/init.h>
8#include <linux/io.h>
9#include <linux/jiffies.h>
10#include <linux/notifier.h>
11#include <linux/of_address.h>
12#include <linux/of_irq.h>
13#include <linux/of_platform.h>
14#include <linux/platform_device.h>
15#include <linux/printk.h>
16#include <linux/reboot.h>
17#include <linux/regmap.h>
18#include <linux/smp.h>
19#include <linux/mfd/syscon.h>
20
21#define RESET_SOURCE_ENABLE_REG 1
22#define SW_MASTER_RESET_REG 2
23
24static struct regmap *regmap;
25static u32 rst_src_en;
26static u32 sw_mstr_rst;
27
28struct reset_reg_mask {
29	u32 rst_src_en_mask;
30	u32 sw_mstr_rst_mask;
31};
32
33static const struct reset_reg_mask *reset_masks;
34
35static int brcmstb_restart_handler(struct notifier_block *this,
36				   unsigned long mode, void *cmd)
37{
38	int rc;
39	u32 tmp;
40
41	rc = regmap_write(regmap, rst_src_en, reset_masks->rst_src_en_mask);
42	if (rc) {
43		pr_err("failed to write rst_src_en (%d)\n", rc);
44		return NOTIFY_DONE;
45	}
46
47	rc = regmap_read(regmap, rst_src_en, &tmp);
48	if (rc) {
49		pr_err("failed to read rst_src_en (%d)\n", rc);
50		return NOTIFY_DONE;
51	}
52
53	rc = regmap_write(regmap, sw_mstr_rst, reset_masks->sw_mstr_rst_mask);
54	if (rc) {
55		pr_err("failed to write sw_mstr_rst (%d)\n", rc);
56		return NOTIFY_DONE;
57	}
58
59	rc = regmap_read(regmap, sw_mstr_rst, &tmp);
60	if (rc) {
61		pr_err("failed to read sw_mstr_rst (%d)\n", rc);
62		return NOTIFY_DONE;
63	}
64
65	while (1)
66		;
67
68	return NOTIFY_DONE;
69}
70
71static struct notifier_block brcmstb_restart_nb = {
72	.notifier_call = brcmstb_restart_handler,
73	.priority = 128,
74};
75
76static const struct reset_reg_mask reset_bits_40nm = {
77	.rst_src_en_mask = BIT(0),
78	.sw_mstr_rst_mask = BIT(0),
79};
80
81static const struct reset_reg_mask reset_bits_65nm = {
82	.rst_src_en_mask = BIT(3),
83	.sw_mstr_rst_mask = BIT(31),
84};
85
86static const struct of_device_id of_match[] = {
87	{ .compatible = "brcm,brcmstb-reboot", .data = &reset_bits_40nm },
88	{ .compatible = "brcm,bcm7038-reboot", .data = &reset_bits_65nm },
89	{},
90};
91
92static int brcmstb_reboot_probe(struct platform_device *pdev)
93{
94	int rc;
95	struct device_node *np = pdev->dev.of_node;
96	const struct of_device_id *of_id;
97
98	of_id = of_match_node(of_match, np);
99	if (!of_id) {
100		pr_err("failed to look up compatible string\n");
101		return -EINVAL;
102	}
103	reset_masks = of_id->data;
104
105	regmap = syscon_regmap_lookup_by_phandle(np, "syscon");
106	if (IS_ERR(regmap)) {
107		pr_err("failed to get syscon phandle\n");
108		return -EINVAL;
109	}
110
111	rc = of_property_read_u32_index(np, "syscon", RESET_SOURCE_ENABLE_REG,
112					&rst_src_en);
113	if (rc) {
114		pr_err("can't get rst_src_en offset (%d)\n", rc);
115		return -EINVAL;
116	}
117
118	rc = of_property_read_u32_index(np, "syscon", SW_MASTER_RESET_REG,
119					&sw_mstr_rst);
120	if (rc) {
121		pr_err("can't get sw_mstr_rst offset (%d)\n", rc);
122		return -EINVAL;
123	}
124
125	rc = register_restart_handler(&brcmstb_restart_nb);
126	if (rc)
127		dev_err(&pdev->dev,
128			"cannot register restart handler (err=%d)\n", rc);
129
130	return rc;
131}
132
133static struct platform_driver brcmstb_reboot_driver = {
134	.probe = brcmstb_reboot_probe,
135	.driver = {
136		.name = "brcmstb-reboot",
137		.of_match_table = of_match,
138	},
139};
140
141static int __init brcmstb_reboot_init(void)
142{
143	return platform_driver_probe(&brcmstb_reboot_driver,
144					brcmstb_reboot_probe);
145}
146subsys_initcall(brcmstb_reboot_init);
147