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
18 static bool nowayout = WATCHDOG_NOWAYOUT;
19 module_param(nowayout, bool, 0);
20 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
21 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
22
twl4030_wdt_write(unsigned char val)23 static 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
twl4030_wdt_start(struct watchdog_device * wdt)29 static int twl4030_wdt_start(struct watchdog_device *wdt)
30 {
31 return twl4030_wdt_write(wdt->timeout + 1);
32 }
33
twl4030_wdt_stop(struct watchdog_device * wdt)34 static int twl4030_wdt_stop(struct watchdog_device *wdt)
35 {
36 return twl4030_wdt_write(0);
37 }
38
twl4030_wdt_set_timeout(struct watchdog_device * wdt,unsigned int timeout)39 static int twl4030_wdt_set_timeout(struct watchdog_device *wdt,
40 unsigned int timeout)
41 {
42 wdt->timeout = timeout;
43 return 0;
44 }
45
46 static const struct watchdog_info twl4030_wdt_info = {
47 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
48 .identity = "TWL4030 Watchdog",
49 };
50
51 static 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
twl4030_wdt_probe(struct platform_device * pdev)58 static 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
twl4030_wdt_suspend(struct platform_device * pdev,pm_message_t state)84 static 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
twl4030_wdt_resume(struct platform_device * pdev)93 static 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
106 static const struct of_device_id twl_wdt_of_match[] = {
107 { .compatible = "ti,twl4030-wdt", },
108 { },
109 };
110 MODULE_DEVICE_TABLE(of, twl_wdt_of_match);
111
112 static 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
122 module_platform_driver(twl4030_wdt_driver);
123
124 MODULE_AUTHOR("Nokia Corporation");
125 MODULE_LICENSE("GPL");
126 MODULE_ALIAS("platform:twl4030_wdt");
127
128