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/mod_devicetable.h>
13#include <linux/watchdog.h>
14#include <linux/platform_device.h>
15#include <linux/mfd/twl.h>
16
17#define TWL4030_WATCHDOG_CFG_REG_OFFS	0x3
18
19static bool nowayout = WATCHDOG_NOWAYOUT;
20module_param(nowayout, bool, 0);
21MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
22	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
23
24static int twl4030_wdt_write(unsigned char val)
25{
26	return twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, val,
27					TWL4030_WATCHDOG_CFG_REG_OFFS);
28}
29
30static int twl4030_wdt_start(struct watchdog_device *wdt)
31{
32	return twl4030_wdt_write(wdt->timeout + 1);
33}
34
35static int twl4030_wdt_stop(struct watchdog_device *wdt)
36{
37	return twl4030_wdt_write(0);
38}
39
40static int twl4030_wdt_set_timeout(struct watchdog_device *wdt,
41				   unsigned int timeout)
42{
43	wdt->timeout = timeout;
44	return 0;
45}
46
47static const struct watchdog_info twl4030_wdt_info = {
48	.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
49	.identity = "TWL4030 Watchdog",
50};
51
52static const struct watchdog_ops twl4030_wdt_ops = {
53	.owner		= THIS_MODULE,
54	.start		= twl4030_wdt_start,
55	.stop		= twl4030_wdt_stop,
56	.set_timeout	= twl4030_wdt_set_timeout,
57};
58
59static int twl4030_wdt_probe(struct platform_device *pdev)
60{
61	struct device *dev = &pdev->dev;
62	struct watchdog_device *wdt;
63
64	wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
65	if (!wdt)
66		return -ENOMEM;
67
68	wdt->info		= &twl4030_wdt_info;
69	wdt->ops		= &twl4030_wdt_ops;
70	wdt->status		= 0;
71	wdt->timeout		= 30;
72	wdt->min_timeout	= 1;
73	wdt->max_timeout	= 30;
74	wdt->parent = dev;
75
76	watchdog_set_nowayout(wdt, nowayout);
77	platform_set_drvdata(pdev, wdt);
78
79	twl4030_wdt_stop(wdt);
80
81	return devm_watchdog_register_device(dev, wdt);
82}
83
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
102static const struct of_device_id twl_wdt_of_match[] = {
103	{ .compatible = "ti,twl4030-wdt", },
104	{ },
105};
106MODULE_DEVICE_TABLE(of, twl_wdt_of_match);
107
108static struct platform_driver twl4030_wdt_driver = {
109	.probe		= twl4030_wdt_probe,
110	.suspend	= pm_ptr(twl4030_wdt_suspend),
111	.resume		= pm_ptr(twl4030_wdt_resume),
112	.driver		= {
113		.name		= "twl4030_wdt",
114		.of_match_table	= twl_wdt_of_match,
115	},
116};
117
118module_platform_driver(twl4030_wdt_driver);
119
120MODULE_AUTHOR("Nokia Corporation");
121MODULE_LICENSE("GPL");
122MODULE_ALIAS("platform:twl4030_wdt");
123
124