gpio: palmas: fix compilation failures
[linux-2.6.git] / drivers / watchdog / ep93xx_wdt.c
1 /*
2  * Watchdog driver for Cirrus Logic EP93xx family of devices.
3  *
4  * Copyright (c) 2004 Ray Lehtiniemi
5  * Copyright (c) 2006 Tower Technologies
6  * Based on ep93xx driver, bits from alim7101_wdt.c
7  *
8  * Authors: Ray Lehtiniemi <rayl@mail.com>,
9  *      Alessandro Zummo <a.zummo@towertech.it>
10  *
11  * Copyright (c) 2012 H Hartley Sweeten <hsweeten@visionengravers.com>
12  *      Convert to a platform device and use the watchdog framework API
13  *
14  * This file is licensed under the terms of the GNU General Public
15  * License version 2. This program is licensed "as is" without any
16  * warranty of any kind, whether express or implied.
17  *
18  * This watchdog fires after 250msec, which is a too short interval
19  * for us to rely on the user space daemon alone. So we ping the
20  * wdt each ~200msec and eventually stop doing it if the user space
21  * daemon dies.
22  *
23  * TODO:
24  *
25  *      - Test last reset from watchdog status
26  *      - Add a few missing ioctls
27  */
28
29 #include <linux/platform_device.h>
30 #include <linux/module.h>
31 #include <linux/miscdevice.h>
32 #include <linux/watchdog.h>
33 #include <linux/timer.h>
34 #include <linux/io.h>
35
36 #define WDT_VERSION     "0.4"
37
38 /* default timeout (secs) */
39 #define WDT_TIMEOUT 30
40
41 static bool nowayout = WATCHDOG_NOWAYOUT;
42 module_param(nowayout, bool, 0);
43 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
44
45 static unsigned int timeout = WDT_TIMEOUT;
46 module_param(timeout, uint, 0);
47 MODULE_PARM_DESC(timeout,
48         "Watchdog timeout in seconds. (1<=timeout<=3600, default="
49                                 __MODULE_STRING(WDT_TIMEOUT) ")");
50
51 static void __iomem *mmio_base;
52 static struct timer_list timer;
53 static unsigned long next_heartbeat;
54
55 #define EP93XX_WATCHDOG         0x00
56 #define EP93XX_WDSTATUS         0x04
57
58 /* reset the wdt every ~200ms - the heartbeat of the device is 0.250 seconds*/
59 #define WDT_INTERVAL (HZ/5)
60
61 static void ep93xx_wdt_timer_ping(unsigned long data)
62 {
63         if (time_before(jiffies, next_heartbeat))
64                 writel(0x5555, mmio_base + EP93XX_WATCHDOG);
65
66         /* Re-set the timer interval */
67         mod_timer(&timer, jiffies + WDT_INTERVAL);
68 }
69
70 static int ep93xx_wdt_start(struct watchdog_device *wdd)
71 {
72         next_heartbeat = jiffies + (timeout * HZ);
73
74         writel(0xaaaa, mmio_base + EP93XX_WATCHDOG);
75         mod_timer(&timer, jiffies + WDT_INTERVAL);
76
77         return 0;
78 }
79
80 static int ep93xx_wdt_stop(struct watchdog_device *wdd)
81 {
82         del_timer_sync(&timer);
83         writel(0xaa55, mmio_base + EP93XX_WATCHDOG);
84
85         return 0;
86 }
87
88 static int ep93xx_wdt_keepalive(struct watchdog_device *wdd)
89 {
90         /* user land ping */
91         next_heartbeat = jiffies + (timeout * HZ);
92
93         return 0;
94 }
95
96 static const struct watchdog_info ep93xx_wdt_ident = {
97         .options        = WDIOF_CARDRESET |
98                           WDIOF_MAGICCLOSE |
99                           WDIOF_KEEPALIVEPING,
100         .identity       = "EP93xx Watchdog",
101 };
102
103 static struct watchdog_ops ep93xx_wdt_ops = {
104         .owner          = THIS_MODULE,
105         .start          = ep93xx_wdt_start,
106         .stop           = ep93xx_wdt_stop,
107         .ping           = ep93xx_wdt_keepalive,
108 };
109
110 static struct watchdog_device ep93xx_wdt_wdd = {
111         .info           = &ep93xx_wdt_ident,
112         .ops            = &ep93xx_wdt_ops,
113 };
114
115 static int __devinit ep93xx_wdt_probe(struct platform_device *pdev)
116 {
117         struct resource *res;
118         unsigned long val;
119         int err;
120
121         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
122         if (!res)
123                 return -ENXIO;
124
125         if (!devm_request_mem_region(&pdev->dev, res->start,
126                                      resource_size(res), pdev->name))
127                 return -EBUSY;
128
129         mmio_base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
130         if (!mmio_base)
131                 return -ENXIO;
132
133         if (timeout < 1 || timeout > 3600) {
134                 timeout = WDT_TIMEOUT;
135                 dev_warn(&pdev->dev,
136                         "timeout value must be 1<=x<=3600, using %d\n",
137                         timeout);
138         }
139
140         val = readl(mmio_base + EP93XX_WATCHDOG);
141         ep93xx_wdt_wdd.bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0;
142         ep93xx_wdt_wdd.timeout = timeout;
143
144         watchdog_set_nowayout(&ep93xx_wdt_wdd, nowayout);
145
146         setup_timer(&timer, ep93xx_wdt_timer_ping, 1);
147
148         err = watchdog_register_device(&ep93xx_wdt_wdd);
149         if (err)
150                 return err;
151
152         dev_info(&pdev->dev,
153                 "EP93XX watchdog, driver version " WDT_VERSION "%s\n",
154                 (val & 0x08) ? " (nCS1 disable detected)" : "");
155
156         return 0;
157 }
158
159 static int __devexit ep93xx_wdt_remove(struct platform_device *pdev)
160 {
161         watchdog_unregister_device(&ep93xx_wdt_wdd);
162         return 0;
163 }
164
165 static struct platform_driver ep93xx_wdt_driver = {
166         .driver         = {
167                 .owner  = THIS_MODULE,
168                 .name   = "ep93xx-wdt",
169         },
170         .probe          = ep93xx_wdt_probe,
171         .remove         = __devexit_p(ep93xx_wdt_remove),
172 };
173
174 module_platform_driver(ep93xx_wdt_driver);
175
176 MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>,"
177                 "Alessandro Zummo <a.zummo@towertech.it>,"
178                 "H Hartley Sweeten <hsweeten@visionengravers.com>");
179 MODULE_DESCRIPTION("EP93xx Watchdog");
180 MODULE_LICENSE("GPL");
181 MODULE_VERSION(WDT_VERSION);
182 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);