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
26static unsigned int timeout = WATCHDOG_TIMEOUT;
27module_param(timeout, uint, 0);
28MODULE_PARM_DESC(timeout,
29 "Watchdog timeout in seconds. default="
30 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
31
32static bool nowayout = WATCHDOG_NOWAYOUT;
33module_param(nowayout, bool, 0);
34MODULE_PARM_DESC(nowayout,
35 "Watchdog cannot be stopped once started (default="
36 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
37
38static int db8500_wdt_start(struct watchdog_device *wdd)
39{
40 return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
41}
42
43static int db8500_wdt_stop(struct watchdog_device *wdd)
44{
45 return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
46}
47
48static int db8500_wdt_keepalive(struct watchdog_device *wdd)
49{
50 return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
51}
52
53static 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
63static 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
69static 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
77static 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
84static 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(wdd: &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
108static int db8500_wdt_suspend(struct platform_device *pdev,
109 pm_message_t state)
110{
111 if (watchdog_active(wdd: &db8500_wdt)) {
112 db8500_wdt_stop(wdd: &db8500_wdt);
113 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);
114
115 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
116 db8500_wdt_start(wdd: &db8500_wdt);
117 }
118 return 0;
119}
120
121static int db8500_wdt_resume(struct platform_device *pdev)
122{
123 if (watchdog_active(wdd: &db8500_wdt)) {
124 db8500_wdt_stop(wdd: &db8500_wdt);
125 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
126
127 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
128 db8500_wdt_start(wdd: &db8500_wdt);
129 }
130 return 0;
131}
132
133static struct platform_driver db8500_wdt_driver = {
134 .probe = db8500_wdt_probe,
135 .suspend = pm_ptr(db8500_wdt_suspend),
136 .resume = pm_ptr(db8500_wdt_resume),
137 .driver = {
138 .name = "db8500_wdt",
139 },
140};
141
142module_platform_driver(db8500_wdt_driver);
143
144MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
145MODULE_DESCRIPTION("DB8500 Watchdog Driver");
146MODULE_LICENSE("GPL");
147MODULE_ALIAS("platform:db8500_wdt");
148

source code of linux/drivers/watchdog/db8500_wdt.c