1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2021 Emil Renner Berthing
4 */
5
6 #include <linux/mfd/tps65086.h>
7 #include <linux/mod_devicetable.h>
8 #include <linux/module.h>
9 #include <linux/platform_device.h>
10 #include <linux/reboot.h>
11
12 struct tps65086_restart {
13 struct notifier_block handler;
14 struct device *dev;
15 };
16
tps65086_restart_notify(struct notifier_block * this,unsigned long mode,void * cmd)17 static int tps65086_restart_notify(struct notifier_block *this,
18 unsigned long mode, void *cmd)
19 {
20 struct tps65086_restart *tps65086_restart =
21 container_of(this, struct tps65086_restart, handler);
22 struct tps65086 *tps65086 = dev_get_drvdata(tps65086_restart->dev->parent);
23 int ret;
24
25 ret = regmap_write(tps65086->regmap, TPS65086_FORCESHUTDN, 1);
26 if (ret) {
27 dev_err(tps65086_restart->dev, "%s: error writing to tps65086 pmic: %d\n",
28 __func__, ret);
29 return NOTIFY_DONE;
30 }
31
32 /* give it a little time */
33 mdelay(200);
34
35 WARN_ON(1);
36
37 return NOTIFY_DONE;
38 }
39
tps65086_restart_probe(struct platform_device * pdev)40 static int tps65086_restart_probe(struct platform_device *pdev)
41 {
42 struct tps65086_restart *tps65086_restart;
43 int ret;
44
45 tps65086_restart = devm_kzalloc(&pdev->dev, sizeof(*tps65086_restart), GFP_KERNEL);
46 if (!tps65086_restart)
47 return -ENOMEM;
48
49 platform_set_drvdata(pdev, tps65086_restart);
50
51 tps65086_restart->handler.notifier_call = tps65086_restart_notify;
52 tps65086_restart->handler.priority = 192;
53 tps65086_restart->dev = &pdev->dev;
54
55 ret = register_restart_handler(&tps65086_restart->handler);
56 if (ret) {
57 dev_err(&pdev->dev, "%s: cannot register restart handler: %d\n",
58 __func__, ret);
59 return -ENODEV;
60 }
61
62 return 0;
63 }
64
tps65086_restart_remove(struct platform_device * pdev)65 static int tps65086_restart_remove(struct platform_device *pdev)
66 {
67 struct tps65086_restart *tps65086_restart = platform_get_drvdata(pdev);
68 int ret;
69
70 ret = unregister_restart_handler(&tps65086_restart->handler);
71 if (ret) {
72 dev_err(&pdev->dev, "%s: cannot unregister restart handler: %d\n",
73 __func__, ret);
74 return -ENODEV;
75 }
76
77 return 0;
78 }
79
80 static const struct platform_device_id tps65086_restart_id_table[] = {
81 { "tps65086-reset", },
82 { /* sentinel */ }
83 };
84 MODULE_DEVICE_TABLE(platform, tps65086_restart_id_table);
85
86 static struct platform_driver tps65086_restart_driver = {
87 .driver = {
88 .name = "tps65086-restart",
89 },
90 .probe = tps65086_restart_probe,
91 .remove = tps65086_restart_remove,
92 .id_table = tps65086_restart_id_table,
93 };
94 module_platform_driver(tps65086_restart_driver);
95
96 MODULE_AUTHOR("Emil Renner Berthing <kernel@esmil.dk>");
97 MODULE_DESCRIPTION("TPS65086 restart driver");
98 MODULE_LICENSE("GPL v2");
99