1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) Nokia Corporation
4 *
5 * Written by Timo Kokkonen <timo.t.kokkonen at nokia.com>
6 */
7
8#include <linux/module.h>
9#include <linux/types.h>
10#include <linux/slab.h>
11#include <linux/kernel.h>
12#include <linux/watchdog.h>
13#include <linux/platform_device.h>
14#include <linux/mfd/twl.h>
15
16#define TWL4030_WATCHDOG_CFG_REG_OFFS	0x3
17
18static bool nowayout = WATCHDOG_NOWAYOUT;
19module_param(nowayout, bool, 0);
20MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
21	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
22
23static int twl4030_wdt_write(unsigned char val)
24{
25	return twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, val,
26					TWL4030_WATCHDOG_CFG_REG_OFFS);
27}
28
29static int twl4030_wdt_start(struct watchdog_device *wdt)
30{
31	return twl4030_wdt_write(wdt->timeout + 1);
32}
33
34static int twl4030_wdt_stop(struct watchdog_device *wdt)
35{
36	return twl4030_wdt_write(0);
37}
38
39static int twl4030_wdt_set_timeout(struct watchdog_device *wdt,
40				   unsigned int timeout)
41{
42	wdt->timeout = timeout;
43	return 0;
44}
45
46static const struct watchdog_info twl4030_wdt_info = {
47	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
48	.identity = "TWL4030 Watchdog",
49};
50
51static const struct watchdog_ops twl4030_wdt_ops = {
52	.owner		= THIS_MODULE,
53	.start		= twl4030_wdt_start,
54	.stop		= twl4030_wdt_stop,
55	.set_timeout	= twl4030_wdt_set_timeout,
56};
57
58static int twl4030_wdt_probe(struct platform_device *pdev)
59{
60	struct device *dev = &pdev->dev;
61	struct watchdog_device *wdt;
62
63	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
64	if (!wdt)
65		return -ENOMEM;
66
67	wdt->info		= &twl4030_wdt_info;
68	wdt->ops		= &twl4030_wdt_ops;
69	wdt->status		= 0;
70	wdt->timeout		= 30;
71	wdt->min_timeout	= 1;
72	wdt->max_timeout	= 30;
73	wdt->parent = dev;
74
75	watchdog_set_nowayout(wdt, nowayout);
76	platform_set_drvdata(pdev, wdt);
77
78	twl4030_wdt_stop(wdt);
79
80	return devm_watchdog_register_device(dev, wdt);
81}
82
83#ifdef CONFIG_PM
84static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
85{
86	struct watchdog_device *wdt = platform_get_drvdata(pdev);
87	if (watchdog_active(wdt))
88		return twl4030_wdt_stop(wdt);
89
90	return 0;
91}
92
93static int twl4030_wdt_resume(struct platform_device *pdev)
94{
95	struct watchdog_device *wdt = platform_get_drvdata(pdev);
96	if (watchdog_active(wdt))
97		return twl4030_wdt_start(wdt);
98
99	return 0;
100}
101#else
102#define twl4030_wdt_suspend        NULL
103#define twl4030_wdt_resume         NULL
104#endif
105
106static const struct of_device_id twl_wdt_of_match[] = {
107	{ .compatible = "ti,twl4030-wdt", },
108	{ },
109};
110MODULE_DEVICE_TABLE(of, twl_wdt_of_match);
111
112static struct platform_driver twl4030_wdt_driver = {
113	.probe		= twl4030_wdt_probe,
114	.suspend	= twl4030_wdt_suspend,
115	.resume		= twl4030_wdt_resume,
116	.driver		= {
117		.name		= "twl4030_wdt",
118		.of_match_table	= twl_wdt_of_match,
119	},
120};
121
122module_platform_driver(twl4030_wdt_driver);
123
124MODULE_AUTHOR("Nokia Corporation");
125MODULE_LICENSE("GPL");
126MODULE_ALIAS("platform:twl4030_wdt");
127
128