d9af93458df3f264df82d9bb8ad622a0a8552d07
[sfrench/cifs-2.6.git] / drivers / watchdog / ux500_wdt.c
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
42 static int ux500_wdt_start(struct watchdog_device *wdd)
43 {
44         return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
45 }
46
47 static int ux500_wdt_stop(struct watchdog_device *wdd)
48 {
49         return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
50 }
51
52 static int ux500_wdt_keepalive(struct watchdog_device *wdd)
53 {
54         return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
55 }
56
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
88 static int ux500_wdt_probe(struct platform_device *pdev)
89 {
90         int ret;
91         struct ux500_wdt_data *pdata = dev_get_platdata(&pdev->dev);
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
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
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
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");