1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2014 Linaro Ltd.
4 *
5 * Author: Linus Walleij <linus.walleij@linaro.org>
6 */
7#include <linux/init.h>
8#include <linux/mfd/syscon.h>
9#include <linux/reboot.h>
10#include <linux/regmap.h>
11#include <linux/of.h>
12
13#define INTEGRATOR_HDR_CTRL_OFFSET	0x0C
14#define INTEGRATOR_HDR_LOCK_OFFSET	0x14
15#define INTEGRATOR_CM_CTRL_RESET	(1 << 3)
16
17#define VERSATILE_SYS_LOCK_OFFSET	0x20
18#define VERSATILE_SYS_RESETCTL_OFFSET	0x40
19
20/* Magic unlocking token used on all Versatile boards */
21#define VERSATILE_LOCK_VAL		0xA05F
22
23/*
24 * We detect the different syscon types from the compatible strings.
25 */
26enum versatile_reboot {
27	INTEGRATOR_REBOOT_CM,
28	VERSATILE_REBOOT_CM,
29	REALVIEW_REBOOT_EB,
30	REALVIEW_REBOOT_PB1176,
31	REALVIEW_REBOOT_PB11MP,
32	REALVIEW_REBOOT_PBA8,
33	REALVIEW_REBOOT_PBX,
34};
35
36/* Pointer to the system controller */
37static struct regmap *syscon_regmap;
38static enum versatile_reboot versatile_reboot_type;
39
40static const struct of_device_id versatile_reboot_of_match[] = {
41	{
42		.compatible = "arm,core-module-integrator",
43		.data = (void *)INTEGRATOR_REBOOT_CM
44	},
45	{
46		.compatible = "arm,core-module-versatile",
47		.data = (void *)VERSATILE_REBOOT_CM,
48	},
49	{
50		.compatible = "arm,realview-eb-syscon",
51		.data = (void *)REALVIEW_REBOOT_EB,
52	},
53	{
54		.compatible = "arm,realview-pb1176-syscon",
55		.data = (void *)REALVIEW_REBOOT_PB1176,
56	},
57	{
58		.compatible = "arm,realview-pb11mp-syscon",
59		.data = (void *)REALVIEW_REBOOT_PB11MP,
60	},
61	{
62		.compatible = "arm,realview-pba8-syscon",
63		.data = (void *)REALVIEW_REBOOT_PBA8,
64	},
65	{
66		.compatible = "arm,realview-pbx-syscon",
67		.data = (void *)REALVIEW_REBOOT_PBX,
68	},
69	{},
70};
71
72static int versatile_reboot(struct notifier_block *this, unsigned long mode,
73			    void *cmd)
74{
75	/* Unlock the reset register */
76	/* Then hit reset on the different machines */
77	switch (versatile_reboot_type) {
78	case INTEGRATOR_REBOOT_CM:
79		regmap_write(syscon_regmap, INTEGRATOR_HDR_LOCK_OFFSET,
80			     VERSATILE_LOCK_VAL);
81		regmap_update_bits(syscon_regmap,
82				   INTEGRATOR_HDR_CTRL_OFFSET,
83				   INTEGRATOR_CM_CTRL_RESET,
84				   INTEGRATOR_CM_CTRL_RESET);
85		break;
86	case VERSATILE_REBOOT_CM:
87		regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
88			     VERSATILE_LOCK_VAL);
89		regmap_update_bits(syscon_regmap,
90				   VERSATILE_SYS_RESETCTL_OFFSET,
91				   0x0107,
92				   0x0105);
93		regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
94			     0);
95		break;
96	case REALVIEW_REBOOT_EB:
97		regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
98			     VERSATILE_LOCK_VAL);
99		regmap_write(syscon_regmap,
100			     VERSATILE_SYS_RESETCTL_OFFSET, 0x0008);
101		break;
102	case REALVIEW_REBOOT_PB1176:
103		regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
104			     VERSATILE_LOCK_VAL);
105		regmap_write(syscon_regmap,
106			     VERSATILE_SYS_RESETCTL_OFFSET, 0x0100);
107		break;
108	case REALVIEW_REBOOT_PB11MP:
109	case REALVIEW_REBOOT_PBA8:
110		regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
111			     VERSATILE_LOCK_VAL);
112		regmap_write(syscon_regmap, VERSATILE_SYS_RESETCTL_OFFSET,
113			     0x0000);
114		regmap_write(syscon_regmap, VERSATILE_SYS_RESETCTL_OFFSET,
115			     0x0004);
116		break;
117	case REALVIEW_REBOOT_PBX:
118		regmap_write(syscon_regmap, VERSATILE_SYS_LOCK_OFFSET,
119			     VERSATILE_LOCK_VAL);
120		regmap_write(syscon_regmap, VERSATILE_SYS_RESETCTL_OFFSET,
121			     0x00f0);
122		regmap_write(syscon_regmap, VERSATILE_SYS_RESETCTL_OFFSET,
123			     0x00f4);
124		break;
125	}
126	dsb();
127
128	return NOTIFY_DONE;
129}
130
131static struct notifier_block versatile_reboot_nb = {
132	.notifier_call = versatile_reboot,
133	.priority = 192,
134};
135
136static int __init versatile_reboot_probe(void)
137{
138	const struct of_device_id *reboot_id;
139	struct device_node *np;
140	int err;
141
142	np = of_find_matching_node_and_match(NULL, versatile_reboot_of_match,
143						 &reboot_id);
144	if (!np)
145		return -ENODEV;
146	versatile_reboot_type = (enum versatile_reboot)reboot_id->data;
147
148	syscon_regmap = syscon_node_to_regmap(np);
149	of_node_put(np);
150	if (IS_ERR(syscon_regmap))
151		return PTR_ERR(syscon_regmap);
152
153	err = register_restart_handler(&versatile_reboot_nb);
154	if (err)
155		return err;
156
157	pr_info("versatile reboot driver registered\n");
158	return 0;
159}
160device_initcall(versatile_reboot_probe);
161