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b3e1b276 | 1 | // SPDX-License-Identifier: GPL-2.0 |
fa0f8d67 GU |
2 | /* |
3 | * Renesas R-Mobile Reset Driver | |
4 | * | |
5 | * Copyright (C) 2014 Glider bvba | |
fa0f8d67 GU |
6 | */ |
7 | ||
8 | #include <linux/io.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/notifier.h> | |
11 | #include <linux/of_address.h> | |
12 | #include <linux/platform_device.h> | |
13 | #include <linux/printk.h> | |
14 | #include <linux/reboot.h> | |
15 | ||
16 | /* SYSC Register Bank 2 */ | |
17 | #define RESCNT2 0x20 /* Reset Control Register 2 */ | |
18 | ||
19 | /* Reset Control Register 2 */ | |
20 | #define RESCNT2_PRES 0x80000000 /* Soft power-on reset */ | |
21 | ||
22 | static void __iomem *sysc_base2; | |
23 | ||
24 | static int rmobile_reset_handler(struct notifier_block *this, | |
25 | unsigned long mode, void *cmd) | |
26 | { | |
27 | pr_debug("%s %lu\n", __func__, mode); | |
28 | ||
29 | /* Let's assume we have acquired the HPB semaphore */ | |
30 | writel(RESCNT2_PRES, sysc_base2 + RESCNT2); | |
31 | ||
32 | return NOTIFY_DONE; | |
33 | } | |
34 | ||
35 | static struct notifier_block rmobile_reset_nb = { | |
36 | .notifier_call = rmobile_reset_handler, | |
37 | .priority = 192, | |
38 | }; | |
39 | ||
40 | static int rmobile_reset_probe(struct platform_device *pdev) | |
41 | { | |
42 | int error; | |
43 | ||
44 | sysc_base2 = of_iomap(pdev->dev.of_node, 1); | |
45 | if (!sysc_base2) | |
46 | return -ENODEV; | |
47 | ||
48 | error = register_restart_handler(&rmobile_reset_nb); | |
49 | if (error) { | |
50 | dev_err(&pdev->dev, | |
51 | "cannot register restart handler (err=%d)\n", error); | |
52 | goto fail_unmap; | |
53 | } | |
54 | ||
55 | return 0; | |
56 | ||
57 | fail_unmap: | |
58 | iounmap(sysc_base2); | |
59 | return error; | |
60 | } | |
61 | ||
62 | static int rmobile_reset_remove(struct platform_device *pdev) | |
63 | { | |
64 | unregister_restart_handler(&rmobile_reset_nb); | |
65 | iounmap(sysc_base2); | |
66 | return 0; | |
67 | } | |
68 | ||
69 | static const struct of_device_id rmobile_reset_of_match[] = { | |
70 | { .compatible = "renesas,sysc-rmobile", }, | |
71 | { /* sentinel */ } | |
72 | }; | |
73 | MODULE_DEVICE_TABLE(of, rmobile_reset_of_match); | |
74 | ||
75 | static struct platform_driver rmobile_reset_driver = { | |
76 | .probe = rmobile_reset_probe, | |
77 | .remove = rmobile_reset_remove, | |
78 | .driver = { | |
79 | .name = "rmobile_reset", | |
80 | .of_match_table = rmobile_reset_of_match, | |
81 | }, | |
82 | }; | |
83 | ||
84 | module_platform_driver(rmobile_reset_driver); | |
85 | ||
86 | MODULE_DESCRIPTION("Renesas R-Mobile Reset Driver"); | |
87 | MODULE_AUTHOR("Geert Uytterhoeven <geert+renesas@glider.be>"); | |
88 | MODULE_LICENSE("GPL v2"); |