1 /*
2 * Copyright (C) ST-Ericsson SA 2011-2013
3 *
4 * License Terms: GNU General Public License v2
5 *
6 * Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson
7 * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
8 */
9
10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/moduleparam.h>
15 #include <linux/miscdevice.h>
16 #include <linux/err.h>
17 #include <linux/uaccess.h>
18 #include <linux/watchdog.h>
19 #include <linux/platform_device.h>
20 #include <linux/platform_data/ux500_wdt.h>
21
22 #include <linux/mfd/dbx500-prcmu.h>
23
24 #define WATCHDOG_TIMEOUT 600 /* 10 minutes */
25
26 #define WATCHDOG_MIN 0
27 #define WATCHDOG_MAX28 268435 /* 28 bit resolution in ms == 268435.455 s */
28 #define WATCHDOG_MAX32 4294967 /* 32 bit resolution in ms == 4294967.295 s */
29
30 static unsigned int timeout = WATCHDOG_TIMEOUT;
31 module_param(timeout, uint, 0);
32 MODULE_PARM_DESC(timeout,
33 "Watchdog timeout in seconds. default="
34 __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
35
36 static bool nowayout = WATCHDOG_NOWAYOUT;
37 module_param(nowayout, bool, 0);
38 MODULE_PARM_DESC(nowayout,
39 "Watchdog cannot be stopped once started (default="
40 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
41
ux500_wdt_start(struct watchdog_device * wdd)42 static int ux500_wdt_start(struct watchdog_device *wdd)
43 {
44 return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
45 }
46
ux500_wdt_stop(struct watchdog_device * wdd)47 static int ux500_wdt_stop(struct watchdog_device *wdd)
48 {
49 return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
50 }
51
ux500_wdt_keepalive(struct watchdog_device * wdd)52 static int ux500_wdt_keepalive(struct watchdog_device *wdd)
53 {
54 return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
55 }
56
ux500_wdt_set_timeout(struct watchdog_device * wdd,unsigned int timeout)57 static int ux500_wdt_set_timeout(struct watchdog_device *wdd,
58 unsigned int timeout)
59 {
60 ux500_wdt_stop(wdd);
61 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
62 ux500_wdt_start(wdd);
63
64 return 0;
65 }
66
67 static const struct watchdog_info ux500_wdt_info = {
68 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
69 .identity = "Ux500 WDT",
70 .firmware_version = 1,
71 };
72
73 static const struct watchdog_ops ux500_wdt_ops = {
74 .owner = THIS_MODULE,
75 .start = ux500_wdt_start,
76 .stop = ux500_wdt_stop,
77 .ping = ux500_wdt_keepalive,
78 .set_timeout = ux500_wdt_set_timeout,
79 };
80
81 static struct watchdog_device ux500_wdt = {
82 .info = &ux500_wdt_info,
83 .ops = &ux500_wdt_ops,
84 .min_timeout = WATCHDOG_MIN,
85 .max_timeout = WATCHDOG_MAX32,
86 };
87
ux500_wdt_probe(struct platform_device * pdev)88 static int ux500_wdt_probe(struct platform_device *pdev)
89 {
90 int ret;
91 struct ux500_wdt_data *pdata = pdev->dev.platform_data;
92
93 if (pdata) {
94 if (pdata->timeout > 0)
95 timeout = pdata->timeout;
96 if (pdata->has_28_bits_resolution)
97 ux500_wdt.max_timeout = WATCHDOG_MAX28;
98 }
99
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 = watchdog_register_device(&ux500_wdt);
109 if (ret)
110 return ret;
111
112 dev_info(&pdev->dev, "initialized\n");
113
114 return 0;
115 }
116
ux500_wdt_remove(struct platform_device * dev)117 static int ux500_wdt_remove(struct platform_device *dev)
118 {
119 watchdog_unregister_device(&ux500_wdt);
120
121 return 0;
122 }
123
124 #ifdef CONFIG_PM
ux500_wdt_suspend(struct platform_device * pdev,pm_message_t state)125 static int ux500_wdt_suspend(struct platform_device *pdev,
126 pm_message_t state)
127 {
128 if (watchdog_active(&ux500_wdt)) {
129 ux500_wdt_stop(&ux500_wdt);
130 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);
131
132 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
133 ux500_wdt_start(&ux500_wdt);
134 }
135 return 0;
136 }
137
ux500_wdt_resume(struct platform_device * pdev)138 static int ux500_wdt_resume(struct platform_device *pdev)
139 {
140 if (watchdog_active(&ux500_wdt)) {
141 ux500_wdt_stop(&ux500_wdt);
142 prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
143
144 prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
145 ux500_wdt_start(&ux500_wdt);
146 }
147 return 0;
148 }
149 #else
150 #define ux500_wdt_suspend NULL
151 #define ux500_wdt_resume NULL
152 #endif
153
154 static struct platform_driver ux500_wdt_driver = {
155 .probe = ux500_wdt_probe,
156 .remove = ux500_wdt_remove,
157 .suspend = ux500_wdt_suspend,
158 .resume = ux500_wdt_resume,
159 .driver = {
160 .owner = THIS_MODULE,
161 .name = "ux500_wdt",
162 },
163 };
164
165 module_platform_driver(ux500_wdt_driver);
166
167 MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
168 MODULE_DESCRIPTION("Ux500 Watchdog Driver");
169 MODULE_LICENSE("GPL");
170 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
171 MODULE_ALIAS("platform:ux500_wdt");
172