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790440bc PM |
1 | /* |
2 | * This program is free software; you can redistribute it and/or modify | |
3 | * it under the terms of the GNU General Public License version 2 as | |
4 | * published by the Free Software Foundation. | |
5 | * | |
6 | * This program is distributed in the hope that it will be useful, | |
7 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
8 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
9 | * GNU General Public License for more details. | |
10 | * | |
11 | * Copyright (C) 2012 ARM Limited | |
12 | */ | |
13 | ||
d08b8037 | 14 | #include <linux/delay.h> |
46c99ac6 | 15 | #include <linux/notifier.h> |
790440bc PM |
16 | #include <linux/of.h> |
17 | #include <linux/of_device.h> | |
18 | #include <linux/platform_device.h> | |
46c99ac6 | 19 | #include <linux/reboot.h> |
790440bc PM |
20 | #include <linux/stat.h> |
21 | #include <linux/vexpress.h> | |
22 | ||
23 | static void vexpress_reset_do(struct device *dev, const char *what) | |
24 | { | |
25 | int err = -ENOENT; | |
3b9334ac | 26 | struct regmap *reg = dev_get_drvdata(dev); |
790440bc | 27 | |
3b9334ac PM |
28 | if (reg) { |
29 | err = regmap_write(reg, 0, 0); | |
d08b8037 PM |
30 | if (!err) |
31 | mdelay(1000); | |
790440bc PM |
32 | } |
33 | ||
34 | dev_emerg(dev, "Unable to %s (%d)\n", what, err); | |
35 | } | |
36 | ||
37 | static struct device *vexpress_power_off_device; | |
09bebb1a | 38 | static atomic_t vexpress_restart_nb_refcnt = ATOMIC_INIT(0); |
790440bc | 39 | |
65deb782 | 40 | static void vexpress_power_off(void) |
790440bc PM |
41 | { |
42 | vexpress_reset_do(vexpress_power_off_device, "power off"); | |
43 | } | |
44 | ||
45 | static struct device *vexpress_restart_device; | |
46 | ||
46c99ac6 GR |
47 | static int vexpress_restart(struct notifier_block *this, unsigned long mode, |
48 | void *cmd) | |
790440bc PM |
49 | { |
50 | vexpress_reset_do(vexpress_restart_device, "restart"); | |
46c99ac6 GR |
51 | |
52 | return NOTIFY_DONE; | |
790440bc PM |
53 | } |
54 | ||
46c99ac6 GR |
55 | static struct notifier_block vexpress_restart_nb = { |
56 | .notifier_call = vexpress_restart, | |
57 | .priority = 128, | |
58 | }; | |
59 | ||
790440bc PM |
60 | static ssize_t vexpress_reset_active_show(struct device *dev, |
61 | struct device_attribute *attr, char *buf) | |
62 | { | |
63 | return sprintf(buf, "%d\n", vexpress_restart_device == dev); | |
64 | } | |
65 | ||
66 | static ssize_t vexpress_reset_active_store(struct device *dev, | |
67 | struct device_attribute *attr, const char *buf, size_t count) | |
68 | { | |
69 | long value; | |
70 | int err = kstrtol(buf, 0, &value); | |
71 | ||
72 | if (!err && value) | |
73 | vexpress_restart_device = dev; | |
74 | ||
75 | return err ? err : count; | |
76 | } | |
77 | ||
0a14d280 BD |
78 | static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, vexpress_reset_active_show, |
79 | vexpress_reset_active_store); | |
790440bc PM |
80 | |
81 | ||
82 | enum vexpress_reset_func { FUNC_RESET, FUNC_SHUTDOWN, FUNC_REBOOT }; | |
83 | ||
8fb08855 | 84 | static const struct of_device_id vexpress_reset_of_match[] = { |
790440bc PM |
85 | { |
86 | .compatible = "arm,vexpress-reset", | |
87 | .data = (void *)FUNC_RESET, | |
88 | }, { | |
89 | .compatible = "arm,vexpress-shutdown", | |
90 | .data = (void *)FUNC_SHUTDOWN | |
91 | }, { | |
92 | .compatible = "arm,vexpress-reboot", | |
93 | .data = (void *)FUNC_REBOOT | |
94 | }, | |
95 | {} | |
96 | }; | |
97 | ||
46c99ac6 GR |
98 | static int _vexpress_register_restart_handler(struct device *dev) |
99 | { | |
100 | int err; | |
101 | ||
102 | vexpress_restart_device = dev; | |
09bebb1a SH |
103 | if (atomic_inc_return(&vexpress_restart_nb_refcnt) == 1) { |
104 | err = register_restart_handler(&vexpress_restart_nb); | |
105 | if (err) { | |
106 | dev_err(dev, "cannot register restart handler (err=%d)\n", err); | |
107 | atomic_dec(&vexpress_restart_nb_refcnt); | |
108 | return err; | |
109 | } | |
46c99ac6 GR |
110 | } |
111 | device_create_file(dev, &dev_attr_active); | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
790440bc PM |
116 | static int vexpress_reset_probe(struct platform_device *pdev) |
117 | { | |
790440bc PM |
118 | const struct of_device_id *match = |
119 | of_match_device(vexpress_reset_of_match, &pdev->dev); | |
3b9334ac | 120 | struct regmap *regmap; |
46c99ac6 | 121 | int ret = 0; |
790440bc | 122 | |
8f961c0a PM |
123 | if (!match) |
124 | return -EINVAL; | |
790440bc | 125 | |
3b9334ac PM |
126 | regmap = devm_regmap_init_vexpress_config(&pdev->dev); |
127 | if (IS_ERR(regmap)) | |
128 | return PTR_ERR(regmap); | |
129 | dev_set_drvdata(&pdev->dev, regmap); | |
d08b8037 | 130 | |
8f961c0a | 131 | switch ((enum vexpress_reset_func)match->data) { |
790440bc PM |
132 | case FUNC_SHUTDOWN: |
133 | vexpress_power_off_device = &pdev->dev; | |
65deb782 | 134 | pm_power_off = vexpress_power_off; |
790440bc PM |
135 | break; |
136 | case FUNC_RESET: | |
137 | if (!vexpress_restart_device) | |
46c99ac6 | 138 | ret = _vexpress_register_restart_handler(&pdev->dev); |
790440bc PM |
139 | break; |
140 | case FUNC_REBOOT: | |
46c99ac6 | 141 | ret = _vexpress_register_restart_handler(&pdev->dev); |
790440bc PM |
142 | break; |
143 | }; | |
144 | ||
46c99ac6 | 145 | return ret; |
790440bc PM |
146 | } |
147 | ||
790440bc PM |
148 | static struct platform_driver vexpress_reset_driver = { |
149 | .probe = vexpress_reset_probe, | |
150 | .driver = { | |
151 | .name = "vexpress-reset", | |
152 | .of_match_table = vexpress_reset_of_match, | |
153 | }, | |
790440bc PM |
154 | }; |
155 | ||
156 | static int __init vexpress_reset_init(void) | |
157 | { | |
158 | return platform_driver_register(&vexpress_reset_driver); | |
159 | } | |
160 | device_initcall(vexpress_reset_init); |