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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 | ||
14 | #include <linux/jiffies.h> | |
15 | #include <linux/of.h> | |
16 | #include <linux/of_device.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/stat.h> | |
19 | #include <linux/vexpress.h> | |
20 | ||
21 | static void vexpress_reset_do(struct device *dev, const char *what) | |
22 | { | |
23 | int err = -ENOENT; | |
24 | struct vexpress_config_func *func = | |
25 | vexpress_config_func_get_by_dev(dev); | |
26 | ||
27 | if (func) { | |
28 | unsigned long timeout; | |
29 | ||
30 | err = vexpress_config_write(func, 0, 0); | |
31 | ||
32 | timeout = jiffies + HZ; | |
33 | while (time_before(jiffies, timeout)) | |
34 | cpu_relax(); | |
35 | } | |
36 | ||
37 | dev_emerg(dev, "Unable to %s (%d)\n", what, err); | |
38 | } | |
39 | ||
40 | static struct device *vexpress_power_off_device; | |
41 | ||
42 | void vexpress_power_off(void) | |
43 | { | |
44 | vexpress_reset_do(vexpress_power_off_device, "power off"); | |
45 | } | |
46 | ||
47 | static struct device *vexpress_restart_device; | |
48 | ||
49 | void vexpress_restart(char str, const char *cmd) | |
50 | { | |
51 | vexpress_reset_do(vexpress_restart_device, "restart"); | |
52 | } | |
53 | ||
54 | static ssize_t vexpress_reset_active_show(struct device *dev, | |
55 | struct device_attribute *attr, char *buf) | |
56 | { | |
57 | return sprintf(buf, "%d\n", vexpress_restart_device == dev); | |
58 | } | |
59 | ||
60 | static ssize_t vexpress_reset_active_store(struct device *dev, | |
61 | struct device_attribute *attr, const char *buf, size_t count) | |
62 | { | |
63 | long value; | |
64 | int err = kstrtol(buf, 0, &value); | |
65 | ||
66 | if (!err && value) | |
67 | vexpress_restart_device = dev; | |
68 | ||
69 | return err ? err : count; | |
70 | } | |
71 | ||
72 | DEVICE_ATTR(active, S_IRUGO | S_IWUSR, vexpress_reset_active_show, | |
73 | vexpress_reset_active_store); | |
74 | ||
75 | ||
76 | enum vexpress_reset_func { FUNC_RESET, FUNC_SHUTDOWN, FUNC_REBOOT }; | |
77 | ||
78 | static struct of_device_id vexpress_reset_of_match[] = { | |
79 | { | |
80 | .compatible = "arm,vexpress-reset", | |
81 | .data = (void *)FUNC_RESET, | |
82 | }, { | |
83 | .compatible = "arm,vexpress-shutdown", | |
84 | .data = (void *)FUNC_SHUTDOWN | |
85 | }, { | |
86 | .compatible = "arm,vexpress-reboot", | |
87 | .data = (void *)FUNC_REBOOT | |
88 | }, | |
89 | {} | |
90 | }; | |
91 | ||
92 | static int vexpress_reset_probe(struct platform_device *pdev) | |
93 | { | |
94 | enum vexpress_reset_func func; | |
95 | const struct of_device_id *match = | |
96 | of_match_device(vexpress_reset_of_match, &pdev->dev); | |
97 | ||
98 | if (match) | |
99 | func = (enum vexpress_reset_func)match->data; | |
100 | else | |
101 | func = pdev->id_entry->driver_data; | |
102 | ||
103 | switch (func) { | |
104 | case FUNC_SHUTDOWN: | |
105 | vexpress_power_off_device = &pdev->dev; | |
106 | break; | |
107 | case FUNC_RESET: | |
108 | if (!vexpress_restart_device) | |
109 | vexpress_restart_device = &pdev->dev; | |
110 | device_create_file(&pdev->dev, &dev_attr_active); | |
111 | break; | |
112 | case FUNC_REBOOT: | |
113 | vexpress_restart_device = &pdev->dev; | |
114 | device_create_file(&pdev->dev, &dev_attr_active); | |
115 | break; | |
116 | }; | |
117 | ||
118 | return 0; | |
119 | } | |
120 | ||
121 | static const struct platform_device_id vexpress_reset_id_table[] = { | |
122 | { .name = "vexpress-reset", .driver_data = FUNC_RESET, }, | |
123 | { .name = "vexpress-shutdown", .driver_data = FUNC_SHUTDOWN, }, | |
124 | { .name = "vexpress-reboot", .driver_data = FUNC_REBOOT, }, | |
125 | {} | |
126 | }; | |
127 | ||
128 | static struct platform_driver vexpress_reset_driver = { | |
129 | .probe = vexpress_reset_probe, | |
130 | .driver = { | |
131 | .name = "vexpress-reset", | |
132 | .of_match_table = vexpress_reset_of_match, | |
133 | }, | |
134 | .id_table = vexpress_reset_id_table, | |
135 | }; | |
136 | ||
137 | static int __init vexpress_reset_init(void) | |
138 | { | |
139 | return platform_driver_register(&vexpress_reset_driver); | |
140 | } | |
141 | device_initcall(vexpress_reset_init); |