1/*
2 * Copyright (C) 2013 Broadcom Corporation
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation version 2.
7 *
8 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9 * kind, whether express or implied; without even the implied warranty
10 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * GNU General Public License for more details.
12 */
13
14#include <linux/bitops.h>
15#include <linux/device.h>
16#include <linux/errno.h>
17#include <linux/init.h>
18#include <linux/io.h>
19#include <linux/jiffies.h>
20#include <linux/notifier.h>
21#include <linux/of_address.h>
22#include <linux/of_irq.h>
23#include <linux/of_platform.h>
24#include <linux/platform_device.h>
25#include <linux/printk.h>
26#include <linux/reboot.h>
27#include <linux/regmap.h>
28#include <linux/smp.h>
29#include <linux/mfd/syscon.h>
30
31#define RESET_SOURCE_ENABLE_REG 1
32#define SW_MASTER_RESET_REG 2
33
34static struct regmap *regmap;
35static u32 rst_src_en;
36static u32 sw_mstr_rst;
37
38struct reset_reg_mask {
39	u32 rst_src_en_mask;
40	u32 sw_mstr_rst_mask;
41};
42
43static const struct reset_reg_mask *reset_masks;
44
45static int brcmstb_restart_handler(struct notifier_block *this,
46				   unsigned long mode, void *cmd)
47{
48	int rc;
49	u32 tmp;
50
51	rc = regmap_write(regmap, rst_src_en, reset_masks->rst_src_en_mask);
52	if (rc) {
53		pr_err("failed to write rst_src_en (%d)\n", rc);
54		return NOTIFY_DONE;
55	}
56
57	rc = regmap_read(regmap, rst_src_en, &tmp);
58	if (rc) {
59		pr_err("failed to read rst_src_en (%d)\n", rc);
60		return NOTIFY_DONE;
61	}
62
63	rc = regmap_write(regmap, sw_mstr_rst, reset_masks->sw_mstr_rst_mask);
64	if (rc) {
65		pr_err("failed to write sw_mstr_rst (%d)\n", rc);
66		return NOTIFY_DONE;
67	}
68
69	rc = regmap_read(regmap, sw_mstr_rst, &tmp);
70	if (rc) {
71		pr_err("failed to read sw_mstr_rst (%d)\n", rc);
72		return NOTIFY_DONE;
73	}
74
75	while (1)
76		;
77
78	return NOTIFY_DONE;
79}
80
81static struct notifier_block brcmstb_restart_nb = {
82	.notifier_call = brcmstb_restart_handler,
83	.priority = 128,
84};
85
86static const struct reset_reg_mask reset_bits_40nm = {
87	.rst_src_en_mask = BIT(0),
88	.sw_mstr_rst_mask = BIT(0),
89};
90
91static const struct reset_reg_mask reset_bits_65nm = {
92	.rst_src_en_mask = BIT(3),
93	.sw_mstr_rst_mask = BIT(31),
94};
95
96static const struct of_device_id of_match[] = {
97	{ .compatible = "brcm,brcmstb-reboot", .data = &reset_bits_40nm },
98	{ .compatible = "brcm,bcm7038-reboot", .data = &reset_bits_65nm },
99	{},
100};
101
102static int brcmstb_reboot_probe(struct platform_device *pdev)
103{
104	int rc;
105	struct device_node *np = pdev->dev.of_node;
106	const struct of_device_id *of_id;
107
108	of_id = of_match_node(of_match, np);
109	if (!of_id) {
110		pr_err("failed to look up compatible string\n");
111		return -EINVAL;
112	}
113	reset_masks = of_id->data;
114
115	regmap = syscon_regmap_lookup_by_phandle(np, "syscon");
116	if (IS_ERR(regmap)) {
117		pr_err("failed to get syscon phandle\n");
118		return -EINVAL;
119	}
120
121	rc = of_property_read_u32_index(np, "syscon", RESET_SOURCE_ENABLE_REG,
122					&rst_src_en);
123	if (rc) {
124		pr_err("can't get rst_src_en offset (%d)\n", rc);
125		return -EINVAL;
126	}
127
128	rc = of_property_read_u32_index(np, "syscon", SW_MASTER_RESET_REG,
129					&sw_mstr_rst);
130	if (rc) {
131		pr_err("can't get sw_mstr_rst offset (%d)\n", rc);
132		return -EINVAL;
133	}
134
135	rc = register_restart_handler(&brcmstb_restart_nb);
136	if (rc)
137		dev_err(&pdev->dev,
138			"cannot register restart handler (err=%d)\n", rc);
139
140	return rc;
141}
142
143static struct platform_driver brcmstb_reboot_driver = {
144	.probe = brcmstb_reboot_probe,
145	.driver = {
146		.name = "brcmstb-reboot",
147		.of_match_table = of_match,
148	},
149};
150
151static int __init brcmstb_reboot_init(void)
152{
153	return platform_driver_probe(&brcmstb_reboot_driver,
154					brcmstb_reboot_probe);
155}
156subsys_initcall(brcmstb_reboot_init);
157