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 | |
24 | static 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 | |
30 | static int twl4030_wdt_start(struct watchdog_device *wdt) |
31 | { |
32 | return twl4030_wdt_write(val: wdt->timeout + 1); |
33 | } |
34 | |
35 | static int twl4030_wdt_stop(struct watchdog_device *wdt) |
36 | { |
37 | return twl4030_wdt_write(val: 0); |
38 | } |
39 | |
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 | |
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, 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 | |
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(wdd: wdt)) |
88 | return twl4030_wdt_stop(wdt); |
89 | |
90 | return 0; |
91 | } |
92 | |
93 | static 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 | |
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_LICENSE("GPL" ); |
122 | MODULE_ALIAS("platform:twl4030_wdt" ); |
123 | |
124 | |