1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) ST-Ericsson SA 2011-2013
4 *
5 * Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson
6 * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
7 */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/moduleparam.h>
14 #include <linux/err.h>
15 #include <linux/uaccess.h>
16 #include <linux/watchdog.h>
17 #include <linux/platform_device.h>
18
19 #include <linux/mfd/dbx500-prcmu.h>
20
21 #define WATCHDOG_TIMEOUT 600 /* 10 minutes */
22
23 #define WATCHDOG_MIN 0
24 #define WATCHDOG_MAX28 268435 /* 28 bit resolution in ms == 268435.455 s */
25
26 static unsigned int timeout = WATCHDOG_TIMEOUT;
27 module_param(timeout, uint, 0);
28 MODULE_PARM_DESC(timeout,
29 "Watchdog timeout in seconds. default="
30 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
31
32 static bool nowayout = WATCHDOG_NOWAYOUT;
33 module_param(nowayout, bool, 0);
34 MODULE_PARM_DESC(nowayout,
35 "Watchdog cannot be stopped once started (default="
36 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
37
db8500_wdt_start(struct watchdog_device * wdd)38 static int db8500_wdt_start(struct watchdog_device *wdd)
39 {
40 return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
41 }
42
db8500_wdt_stop(struct watchdog_device * wdd)43 static int db8500_wdt_stop(struct watchdog_device *wdd)
44 {
45 return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
46 }
47
db8500_wdt_keepalive(struct watchdog_device * wdd)48 static int db8500_wdt_keepalive(struct watchdog_device *wdd)
49 {
50 return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
51 }
52
db8500_wdt_set_timeout(struct watchdog_device * wdd,unsigned int timeout)53 static int db8500_wdt_set_timeout(struct watchdog_device *wdd,
54 unsigned int timeout)
55 {
56 db8500_wdt_stop(wdd);
57 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
58 db8500_wdt_start(wdd);
59
60 return 0;
61 }
62
63 static const struct watchdog_info db8500_wdt_info = {
64 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
65 .identity = "DB8500 WDT",
66 .firmware_version = 1,
67 };
68
69 static const struct watchdog_ops db8500_wdt_ops = {
70 .owner = THIS_MODULE,
71 .start = db8500_wdt_start,
72 .stop = db8500_wdt_stop,
73 .ping = db8500_wdt_keepalive,
74 .set_timeout = db8500_wdt_set_timeout,
75 };
76
77 static struct watchdog_device db8500_wdt = {
78 .info = &db8500_wdt_info,
79 .ops = &db8500_wdt_ops,
80 .min_timeout = WATCHDOG_MIN,
81 .max_timeout = WATCHDOG_MAX28,
82 };
83
db8500_wdt_probe(struct platform_device * pdev)84 static int db8500_wdt_probe(struct platform_device *pdev)
85 {
86 struct device *dev = &pdev->dev;
87 int ret;
88
89 timeout = 600; /* Default to 10 minutes */
90 db8500_wdt.parent = dev;
91 watchdog_set_nowayout(&db8500_wdt, nowayout);
92
93 /* disable auto off on sleep */
94 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
95
96 /* set HW initial value */
97 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
98
99 ret = devm_watchdog_register_device(dev, &db8500_wdt);
100 if (ret)
101 return ret;
102
103 dev_info(dev, "initialized\n");
104
105 return 0;
106 }
107
108 #ifdef CONFIG_PM
db8500_wdt_suspend(struct platform_device * pdev,pm_message_t state)109 static int db8500_wdt_suspend(struct platform_device *pdev,
110 pm_message_t state)
111 {
112 if (watchdog_active(&db8500_wdt)) {
113 db8500_wdt_stop(&db8500_wdt);
114 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);
115
116 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
117 db8500_wdt_start(&db8500_wdt);
118 }
119 return 0;
120 }
121
db8500_wdt_resume(struct platform_device * pdev)122 static int db8500_wdt_resume(struct platform_device *pdev)
123 {
124 if (watchdog_active(&db8500_wdt)) {
125 db8500_wdt_stop(&db8500_wdt);
126 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
127
128 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
129 db8500_wdt_start(&db8500_wdt);
130 }
131 return 0;
132 }
133 #else
134 #define db8500_wdt_suspend NULL
135 #define db8500_wdt_resume NULL
136 #endif
137
138 static struct platform_driver db8500_wdt_driver = {
139 .probe = db8500_wdt_probe,
140 .suspend = db8500_wdt_suspend,
141 .resume = db8500_wdt_resume,
142 .driver = {
143 .name = "db8500_wdt",
144 },
145 };
146
147 module_platform_driver(db8500_wdt_driver);
148
149 MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
150 MODULE_DESCRIPTION("DB8500 Watchdog Driver");
151 MODULE_LICENSE("GPL");
152 MODULE_ALIAS("platform:db8500_wdt");
153