1 /*
2 * ZTE zx296702 SoC reset code
3 *
4 * Copyright (c) 2015 Linaro Ltd.
5 *
6 * Author: Jun Nie <jun.nie@linaro.org>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/delay.h>
14 #include <linux/io.h>
15 #include <linux/module.h>
16 #include <linux/notifier.h>
17 #include <linux/of_address.h>
18 #include <linux/platform_device.h>
19 #include <linux/reboot.h>
20
21 static void __iomem *base;
22 static void __iomem *pcu_base;
23
zx_restart_handler(struct notifier_block * this,unsigned long mode,void * cmd)24 static int zx_restart_handler(struct notifier_block *this,
25 unsigned long mode, void *cmd)
26 {
27 writel_relaxed(1, base + 0xb0);
28 writel_relaxed(1, pcu_base + 0x34);
29
30 mdelay(50);
31 pr_emerg("Unable to restart system\n");
32
33 return NOTIFY_DONE;
34 }
35
36 static struct notifier_block zx_restart_nb = {
37 .notifier_call = zx_restart_handler,
38 .priority = 128,
39 };
40
zx_reboot_probe(struct platform_device * pdev)41 static int zx_reboot_probe(struct platform_device *pdev)
42 {
43 struct device_node *np = pdev->dev.of_node;
44 int err;
45
46 base = of_iomap(np, 0);
47 if (!base) {
48 WARN(1, "failed to map base address");
49 return -ENODEV;
50 }
51
52 np = of_find_compatible_node(NULL, NULL, "zte,zx296702-pcu");
53 pcu_base = of_iomap(np, 0);
54 if (!pcu_base) {
55 iounmap(base);
56 WARN(1, "failed to map pcu_base address");
57 return -ENODEV;
58 }
59
60 err = register_restart_handler(&zx_restart_nb);
61 if (err)
62 dev_err(&pdev->dev, "Register restart handler failed(err=%d)\n",
63 err);
64
65 return err;
66 }
67
68 static const struct of_device_id zx_reboot_of_match[] = {
69 { .compatible = "zte,sysctrl" },
70 {}
71 };
72
73 static struct platform_driver zx_reboot_driver = {
74 .probe = zx_reboot_probe,
75 .driver = {
76 .name = "zx-reboot",
77 .of_match_table = zx_reboot_of_match,
78 },
79 };
80 module_platform_driver(zx_reboot_driver);
81
82 MODULE_DESCRIPTION("ZTE SoCs reset driver");
83 MODULE_AUTHOR("Jun Nie <jun.nie@linaro.org>");
84 MODULE_LICENSE("GPL v2");
85