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
19 static bool nowayout = WATCHDOG_NOWAYOUT;
20 module_param(nowayout, bool, 0);
21 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
22 "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
23
twl4030_wdt_write(unsigned char val)24 static 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
twl4030_wdt_start(struct watchdog_device * wdt)30 static int twl4030_wdt_start(struct watchdog_device *wdt)
31 {
32 return twl4030_wdt_write(wdt->timeout + 1);
33 }
34
twl4030_wdt_stop(struct watchdog_device * wdt)35 static int twl4030_wdt_stop(struct watchdog_device *wdt)
36 {
37 return twl4030_wdt_write(0);
38 }
39
twl4030_wdt_set_timeout(struct watchdog_device * wdt,unsigned int timeout)40 static int twl4030_wdt_set_timeout(struct watchdog_device *wdt,
41 unsigned int timeout)
42 {
43 wdt->timeout = timeout;
44 return 0;
45 }
46
47 static const struct watchdog_info twl4030_wdt_info = {
48 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
49 .identity = "TWL4030 Watchdog",
50 };
51
52 static 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
twl4030_wdt_probe(struct platform_device * pdev)59 static 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
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
102 static const struct of_device_id twl_wdt_of_match[] = {
103 { .compatible = "ti,twl4030-wdt", },
104 { },
105 };
106 MODULE_DEVICE_TABLE(of, twl_wdt_of_match);
107
108 static 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
118 module_platform_driver(twl4030_wdt_driver);
119
120 MODULE_AUTHOR("Nokia Corporation");
121 MODULE_DESCRIPTION("TWL4030 Watchdog");
122 MODULE_LICENSE("GPL");
123 MODULE_ALIAS("platform:twl4030_wdt");
124
125