1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
4 */
5
6 #include <linux/init.h>
7 #include <linux/module.h>
8 #include <linux/kernel.h>
9 #include <linux/of.h>
10 #include <linux/platform_device.h>
11 #include <linux/reboot.h>
12 #include <linux/regmap.h>
13 #include <linux/mfd/syscon.h>
14 #include <linux/reboot-mode.h>
15
16 struct syscon_reboot_mode {
17 struct regmap *map;
18 struct reboot_mode_driver reboot;
19 u32 offset;
20 u32 mask;
21 };
22
syscon_reboot_mode_write(struct reboot_mode_driver * reboot,unsigned int magic)23 static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot,
24 unsigned int magic)
25 {
26 struct syscon_reboot_mode *syscon_rbm;
27 int ret;
28
29 syscon_rbm = container_of(reboot, struct syscon_reboot_mode, reboot);
30
31 ret = regmap_update_bits(syscon_rbm->map, syscon_rbm->offset,
32 syscon_rbm->mask, magic);
33 if (ret < 0)
34 dev_err(reboot->dev, "update reboot mode bits failed\n");
35
36 return ret;
37 }
38
syscon_reboot_mode_probe(struct platform_device * pdev)39 static int syscon_reboot_mode_probe(struct platform_device *pdev)
40 {
41 int ret;
42 struct syscon_reboot_mode *syscon_rbm;
43
44 syscon_rbm = devm_kzalloc(&pdev->dev, sizeof(*syscon_rbm), GFP_KERNEL);
45 if (!syscon_rbm)
46 return -ENOMEM;
47
48 syscon_rbm->reboot.dev = &pdev->dev;
49 syscon_rbm->reboot.write = syscon_reboot_mode_write;
50 syscon_rbm->mask = 0xffffffff;
51
52 syscon_rbm->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
53 if (IS_ERR(syscon_rbm->map))
54 return PTR_ERR(syscon_rbm->map);
55
56 if (of_property_read_u32(pdev->dev.of_node, "offset",
57 &syscon_rbm->offset))
58 return -EINVAL;
59
60 of_property_read_u32(pdev->dev.of_node, "mask", &syscon_rbm->mask);
61
62 ret = devm_reboot_mode_register(&pdev->dev, &syscon_rbm->reboot);
63 if (ret)
64 dev_err(&pdev->dev, "can't register reboot mode\n");
65
66 return ret;
67 }
68
69 static const struct of_device_id syscon_reboot_mode_of_match[] = {
70 { .compatible = "syscon-reboot-mode" },
71 {}
72 };
73 MODULE_DEVICE_TABLE(of, syscon_reboot_mode_of_match);
74
75 static struct platform_driver syscon_reboot_mode_driver = {
76 .probe = syscon_reboot_mode_probe,
77 .driver = {
78 .name = "syscon-reboot-mode",
79 .of_match_table = syscon_reboot_mode_of_match,
80 },
81 };
82 module_platform_driver(syscon_reboot_mode_driver);
83
84 MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com");
85 MODULE_DESCRIPTION("SYSCON reboot mode driver");
86 MODULE_LICENSE("GPL v2");
87