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(mod_no: 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(val: wdt->timeout + 1);
33}
34
35static int twl4030_wdt_stop(struct watchdog_device *wdt)
36{
37 return twl4030_wdt_write(val: 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, size: 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(wdd: wdt, nowayout);
77 platform_set_drvdata(pdev, data: 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(wdd: 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(wdd: 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_DESCRIPTION("TWL4030 Watchdog");
122MODULE_LICENSE("GPL");
123MODULE_ALIAS("platform:twl4030_wdt");
124
125

source code of linux/drivers/watchdog/twl4030_wdt.c