treewide: Fix iomap resource size miscalculations
[linux-3.10.git] / drivers / watchdog / bcm63xx_wdt.c
1 /*
2  *  Broadcom BCM63xx SoC watchdog driver
3  *
4  *  Copyright (C) 2007, Miguel Gaio <miguel.gaio@efixo.com>
5  *  Copyright (C) 2008, Florian Fainelli <florian@openwrt.org>
6  *
7  *  This program is free software; you can redistribute it and/or
8  *  modify it under the terms of the GNU General Public License
9  *  as published by the Free Software Foundation; either version
10  *  2 of the License, or (at your option) any later version.
11  */
12
13 #include <linux/bitops.h>
14 #include <linux/errno.h>
15 #include <linux/fs.h>
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/miscdevice.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/types.h>
22 #include <linux/uaccess.h>
23 #include <linux/watchdog.h>
24 #include <linux/timer.h>
25 #include <linux/jiffies.h>
26 #include <linux/interrupt.h>
27 #include <linux/ptrace.h>
28 #include <linux/resource.h>
29 #include <linux/platform_device.h>
30
31 #include <bcm63xx_cpu.h>
32 #include <bcm63xx_io.h>
33 #include <bcm63xx_regs.h>
34 #include <bcm63xx_timer.h>
35
36 #define PFX KBUILD_MODNAME
37
38 #define WDT_HZ          50000000 /* Fclk */
39 #define WDT_DEFAULT_TIME        30      /* seconds */
40 #define WDT_MAX_TIME            256     /* seconds */
41
42 static struct {
43         void __iomem *regs;
44         struct timer_list timer;
45         int default_ticks;
46         unsigned long inuse;
47         atomic_t ticks;
48 } bcm63xx_wdt_device;
49
50 static int expect_close;
51
52 static int wdt_time = WDT_DEFAULT_TIME;
53 static int nowayout = WATCHDOG_NOWAYOUT;
54 module_param(nowayout, int, 0);
55 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
56         __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
57
58 /* HW functions */
59 static void bcm63xx_wdt_hw_start(void)
60 {
61         bcm_writel(0xfffffffe, bcm63xx_wdt_device.regs + WDT_DEFVAL_REG);
62         bcm_writel(WDT_START_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
63         bcm_writel(WDT_START_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
64 }
65
66 static void bcm63xx_wdt_hw_stop(void)
67 {
68         bcm_writel(WDT_STOP_1, bcm63xx_wdt_device.regs + WDT_CTL_REG);
69         bcm_writel(WDT_STOP_2, bcm63xx_wdt_device.regs + WDT_CTL_REG);
70 }
71
72 static void bcm63xx_wdt_isr(void *data)
73 {
74         struct pt_regs *regs = get_irq_regs();
75
76         die(PFX " fire", regs);
77 }
78
79 static void bcm63xx_timer_tick(unsigned long unused)
80 {
81         if (!atomic_dec_and_test(&bcm63xx_wdt_device.ticks)) {
82                 bcm63xx_wdt_hw_start();
83                 mod_timer(&bcm63xx_wdt_device.timer, jiffies + HZ);
84         } else
85                 printk(KERN_CRIT PFX ": watchdog will restart system\n");
86 }
87
88 static void bcm63xx_wdt_pet(void)
89 {
90         atomic_set(&bcm63xx_wdt_device.ticks, wdt_time);
91 }
92
93 static void bcm63xx_wdt_start(void)
94 {
95         bcm63xx_wdt_pet();
96         bcm63xx_timer_tick(0);
97 }
98
99 static void bcm63xx_wdt_pause(void)
100 {
101         del_timer_sync(&bcm63xx_wdt_device.timer);
102         bcm63xx_wdt_hw_stop();
103 }
104
105 static int bcm63xx_wdt_settimeout(int new_time)
106 {
107         if ((new_time <= 0) || (new_time > WDT_MAX_TIME))
108                 return -EINVAL;
109
110         wdt_time = new_time;
111
112         return 0;
113 }
114
115 static int bcm63xx_wdt_open(struct inode *inode, struct file *file)
116 {
117         if (test_and_set_bit(0, &bcm63xx_wdt_device.inuse))
118                 return -EBUSY;
119
120         bcm63xx_wdt_start();
121         return nonseekable_open(inode, file);
122 }
123
124 static int bcm63xx_wdt_release(struct inode *inode, struct file *file)
125 {
126         if (expect_close == 42)
127                 bcm63xx_wdt_pause();
128         else {
129                 printk(KERN_CRIT PFX
130                         ": Unexpected close, not stopping watchdog!\n");
131                 bcm63xx_wdt_start();
132         }
133         clear_bit(0, &bcm63xx_wdt_device.inuse);
134         expect_close = 0;
135         return 0;
136 }
137
138 static ssize_t bcm63xx_wdt_write(struct file *file, const char *data,
139                                 size_t len, loff_t *ppos)
140 {
141         if (len) {
142                 if (!nowayout) {
143                         size_t i;
144
145                         /* In case it was set long ago */
146                         expect_close = 0;
147
148                         for (i = 0; i != len; i++) {
149                                 char c;
150                                 if (get_user(c, data + i))
151                                         return -EFAULT;
152                                 if (c == 'V')
153                                         expect_close = 42;
154                         }
155                 }
156                 bcm63xx_wdt_pet();
157         }
158         return len;
159 }
160
161 static struct watchdog_info bcm63xx_wdt_info = {
162         .identity       = PFX,
163         .options        = WDIOF_SETTIMEOUT |
164                                 WDIOF_KEEPALIVEPING |
165                                 WDIOF_MAGICCLOSE,
166 };
167
168
169 static long bcm63xx_wdt_ioctl(struct file *file, unsigned int cmd,
170                                 unsigned long arg)
171 {
172         void __user *argp = (void __user *)arg;
173         int __user *p = argp;
174         int new_value, retval = -EINVAL;
175
176         switch (cmd) {
177         case WDIOC_GETSUPPORT:
178                 return copy_to_user(argp, &bcm63xx_wdt_info,
179                         sizeof(bcm63xx_wdt_info)) ? -EFAULT : 0;
180
181         case WDIOC_GETSTATUS:
182         case WDIOC_GETBOOTSTATUS:
183                 return put_user(0, p);
184
185         case WDIOC_SETOPTIONS:
186                 if (get_user(new_value, p))
187                         return -EFAULT;
188
189                 if (new_value & WDIOS_DISABLECARD) {
190                         bcm63xx_wdt_pause();
191                         retval = 0;
192                 }
193                 if (new_value & WDIOS_ENABLECARD) {
194                         bcm63xx_wdt_start();
195                         retval = 0;
196                 }
197
198                 return retval;
199
200         case WDIOC_KEEPALIVE:
201                 bcm63xx_wdt_pet();
202                 return 0;
203
204         case WDIOC_SETTIMEOUT:
205                 if (get_user(new_value, p))
206                         return -EFAULT;
207
208                 if (bcm63xx_wdt_settimeout(new_value))
209                         return -EINVAL;
210
211                 bcm63xx_wdt_pet();
212
213         case WDIOC_GETTIMEOUT:
214                 return put_user(wdt_time, p);
215
216         default:
217                 return -ENOTTY;
218
219         }
220 }
221
222 static const struct file_operations bcm63xx_wdt_fops = {
223         .owner          = THIS_MODULE,
224         .llseek         = no_llseek,
225         .write          = bcm63xx_wdt_write,
226         .unlocked_ioctl = bcm63xx_wdt_ioctl,
227         .open           = bcm63xx_wdt_open,
228         .release        = bcm63xx_wdt_release,
229 };
230
231 static struct miscdevice bcm63xx_wdt_miscdev = {
232         .minor  = WATCHDOG_MINOR,
233         .name   = "watchdog",
234         .fops   = &bcm63xx_wdt_fops,
235 };
236
237
238 static int __devinit bcm63xx_wdt_probe(struct platform_device *pdev)
239 {
240         int ret;
241         struct resource *r;
242
243         setup_timer(&bcm63xx_wdt_device.timer, bcm63xx_timer_tick, 0L);
244
245         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
246         if (!r) {
247                 dev_err(&pdev->dev, "failed to get resources\n");
248                 return -ENODEV;
249         }
250
251         bcm63xx_wdt_device.regs = ioremap_nocache(r->start, resource_size(r));
252         if (!bcm63xx_wdt_device.regs) {
253                 dev_err(&pdev->dev, "failed to remap I/O resources\n");
254                 return -ENXIO;
255         }
256
257         ret = bcm63xx_timer_register(TIMER_WDT_ID, bcm63xx_wdt_isr, NULL);
258         if (ret < 0) {
259                 dev_err(&pdev->dev, "failed to register wdt timer isr\n");
260                 goto unmap;
261         }
262
263         if (bcm63xx_wdt_settimeout(wdt_time)) {
264                 bcm63xx_wdt_settimeout(WDT_DEFAULT_TIME);
265                 dev_info(&pdev->dev,
266                         ": wdt_time value must be 1 <= wdt_time <= 256, using %d\n",
267                         wdt_time);
268         }
269
270         ret = misc_register(&bcm63xx_wdt_miscdev);
271         if (ret < 0) {
272                 dev_err(&pdev->dev, "failed to register watchdog device\n");
273                 goto unregister_timer;
274         }
275
276         dev_info(&pdev->dev, " started, timer margin: %d sec\n",
277                                                 WDT_DEFAULT_TIME);
278
279         return 0;
280
281 unregister_timer:
282         bcm63xx_timer_unregister(TIMER_WDT_ID);
283 unmap:
284         iounmap(bcm63xx_wdt_device.regs);
285         return ret;
286 }
287
288 static int __devexit bcm63xx_wdt_remove(struct platform_device *pdev)
289 {
290         if (!nowayout)
291                 bcm63xx_wdt_pause();
292
293         misc_deregister(&bcm63xx_wdt_miscdev);
294         bcm63xx_timer_unregister(TIMER_WDT_ID);
295         iounmap(bcm63xx_wdt_device.regs);
296         return 0;
297 }
298
299 static void bcm63xx_wdt_shutdown(struct platform_device *pdev)
300 {
301         bcm63xx_wdt_pause();
302 }
303
304 static struct platform_driver bcm63xx_wdt = {
305         .probe  = bcm63xx_wdt_probe,
306         .remove = __devexit_p(bcm63xx_wdt_remove),
307         .shutdown = bcm63xx_wdt_shutdown,
308         .driver = {
309                 .owner = THIS_MODULE,
310                 .name = "bcm63xx-wdt",
311         }
312 };
313
314 static int __init bcm63xx_wdt_init(void)
315 {
316         return platform_driver_register(&bcm63xx_wdt);
317 }
318
319 static void __exit bcm63xx_wdt_exit(void)
320 {
321         platform_driver_unregister(&bcm63xx_wdt);
322 }
323
324 module_init(bcm63xx_wdt_init);
325 module_exit(bcm63xx_wdt_exit);
326
327 MODULE_AUTHOR("Miguel Gaio <miguel.gaio@efixo.com>");
328 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
329 MODULE_DESCRIPTION("Driver for the Broadcom BCM63xx SoC watchdog");
330 MODULE_LICENSE("GPL");
331 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
332 MODULE_ALIAS("platform:bcm63xx-wdt");