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 #include <linux/platform_data/ux500_wdt.h>
19
20 #include <linux/mfd/dbx500-prcmu.h>
21
22 #define WATCHDOG_TIMEOUT 600 /* 10 minutes */
23
24 #define WATCHDOG_MIN 0
25 #define WATCHDOG_MAX28 268435 /* 28 bit resolution in ms == 268435.455 s */
26 #define WATCHDOG_MAX32 4294967 /* 32 bit resolution in ms == 4294967.295 s */
27
28 static unsigned int timeout = WATCHDOG_TIMEOUT;
29 module_param(timeout, uint, 0);
30 MODULE_PARM_DESC(timeout,
31 "Watchdog timeout in seconds. default="
32 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
33
34 static bool nowayout = WATCHDOG_NOWAYOUT;
35 module_param(nowayout, bool, 0);
36 MODULE_PARM_DESC(nowayout,
37 "Watchdog cannot be stopped once started (default="
38 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
39
ux500_wdt_start(struct watchdog_device * wdd)40 static int ux500_wdt_start(struct watchdog_device *wdd)
41 {
42 return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
43 }
44
ux500_wdt_stop(struct watchdog_device * wdd)45 static int ux500_wdt_stop(struct watchdog_device *wdd)
46 {
47 return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
48 }
49
ux500_wdt_keepalive(struct watchdog_device * wdd)50 static int ux500_wdt_keepalive(struct watchdog_device *wdd)
51 {
52 return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
53 }
54
ux500_wdt_set_timeout(struct watchdog_device * wdd,unsigned int timeout)55 static int ux500_wdt_set_timeout(struct watchdog_device *wdd,
56 unsigned int timeout)
57 {
58 ux500_wdt_stop(wdd);
59 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
60 ux500_wdt_start(wdd);
61
62 return 0;
63 }
64
65 static const struct watchdog_info ux500_wdt_info = {
66 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
67 .identity = "Ux500 WDT",
68 .firmware_version = 1,
69 };
70
71 static const struct watchdog_ops ux500_wdt_ops = {
72 .owner = THIS_MODULE,
73 .start = ux500_wdt_start,
74 .stop = ux500_wdt_stop,
75 .ping = ux500_wdt_keepalive,
76 .set_timeout = ux500_wdt_set_timeout,
77 };
78
79 static struct watchdog_device ux500_wdt = {
80 .info = &ux500_wdt_info,
81 .ops = &ux500_wdt_ops,
82 .min_timeout = WATCHDOG_MIN,
83 .max_timeout = WATCHDOG_MAX32,
84 };
85
ux500_wdt_probe(struct platform_device * pdev)86 static int ux500_wdt_probe(struct platform_device *pdev)
87 {
88 struct device *dev = &pdev->dev;
89 int ret;
90 struct ux500_wdt_data *pdata = dev_get_platdata(dev);
91
92 if (pdata) {
93 if (pdata->timeout > 0)
94 timeout = pdata->timeout;
95 if (pdata->has_28_bits_resolution)
96 ux500_wdt.max_timeout = WATCHDOG_MAX28;
97 }
98
99 ux500_wdt.parent = dev;
100 watchdog_set_nowayout(&ux500_wdt, nowayout);
101
102 /* disable auto off on sleep */
103 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
104
105 /* set HW initial value */
106 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
107
108 ret = devm_watchdog_register_device(dev, &ux500_wdt);
109 if (ret)
110 return ret;
111
112 dev_info(dev, "initialized\n");
113
114 return 0;
115 }
116
117 #ifdef CONFIG_PM
ux500_wdt_suspend(struct platform_device * pdev,pm_message_t state)118 static int ux500_wdt_suspend(struct platform_device *pdev,
119 pm_message_t state)
120 {
121 if (watchdog_active(&ux500_wdt)) {
122 ux500_wdt_stop(&ux500_wdt);
123 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);
124
125 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
126 ux500_wdt_start(&ux500_wdt);
127 }
128 return 0;
129 }
130
ux500_wdt_resume(struct platform_device * pdev)131 static int ux500_wdt_resume(struct platform_device *pdev)
132 {
133 if (watchdog_active(&ux500_wdt)) {
134 ux500_wdt_stop(&ux500_wdt);
135 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
136
137 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
138 ux500_wdt_start(&ux500_wdt);
139 }
140 return 0;
141 }
142 #else
143 #define ux500_wdt_suspend NULL
144 #define ux500_wdt_resume NULL
145 #endif
146
147 static struct platform_driver ux500_wdt_driver = {
148 .probe = ux500_wdt_probe,
149 .suspend = ux500_wdt_suspend,
150 .resume = ux500_wdt_resume,
151 .driver = {
152 .name = "ux500_wdt",
153 },
154 };
155
156 module_platform_driver(ux500_wdt_driver);
157
158 MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
159 MODULE_DESCRIPTION("Ux500 Watchdog Driver");
160 MODULE_LICENSE("GPL");
161 MODULE_ALIAS("platform:ux500_wdt");
162