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21
22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
24#include <linux/module.h>
25#include <linux/moduleparam.h>
26#include <linux/types.h>
27#include <linux/errno.h>
28#include <linux/miscdevice.h>
29#include <linux/fs.h>
30#include <linux/ioport.h>
31#include <linux/timer.h>
32#include <linux/completion.h>
33#include <linux/jiffies.h>
34#include <linux/io.h>
35#include <linux/uaccess.h>
36#include <linux/watchdog.h>
37
38
39
40static int verbose;
41static int port = 0x91;
42static int ticks = 10000;
43static DEFINE_SPINLOCK(cpu5wdt_lock);
44
45#define PFX "cpu5wdt: "
46
47#define CPU5WDT_EXTENT 0x0A
48
49#define CPU5WDT_STATUS_REG 0x00
50#define CPU5WDT_TIME_A_REG 0x02
51#define CPU5WDT_TIME_B_REG 0x03
52#define CPU5WDT_MODE_REG 0x04
53#define CPU5WDT_TRIGGER_REG 0x07
54#define CPU5WDT_ENABLE_REG 0x08
55#define CPU5WDT_RESET_REG 0x09
56
57#define CPU5WDT_INTERVAL (HZ/10+1)
58
59
60
61static struct {
62 struct completion stop;
63 int running;
64 struct timer_list timer;
65 int queue;
66 int default_ticks;
67 unsigned long inuse;
68} cpu5wdt_device;
69
70
71
72static void cpu5wdt_trigger(unsigned long unused)
73{
74 if (verbose > 2)
75 pr_debug("trigger at %i ticks\n", ticks);
76
77 if (cpu5wdt_device.running)
78 ticks--;
79
80 spin_lock(&cpu5wdt_lock);
81
82 outb(1, port + CPU5WDT_TRIGGER_REG);
83
84
85 if (cpu5wdt_device.queue && ticks)
86 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
87 else {
88
89 complete(&cpu5wdt_device.stop);
90 }
91 spin_unlock(&cpu5wdt_lock);
92
93}
94
95static void cpu5wdt_reset(void)
96{
97 ticks = cpu5wdt_device.default_ticks;
98
99 if (verbose)
100 pr_debug("reset (%i ticks)\n", (int) ticks);
101
102}
103
104static void cpu5wdt_start(void)
105{
106 unsigned long flags;
107
108 spin_lock_irqsave(&cpu5wdt_lock, flags);
109 if (!cpu5wdt_device.queue) {
110 cpu5wdt_device.queue = 1;
111 outb(0, port + CPU5WDT_TIME_A_REG);
112 outb(0, port + CPU5WDT_TIME_B_REG);
113 outb(1, port + CPU5WDT_MODE_REG);
114 outb(0, port + CPU5WDT_RESET_REG);
115 outb(0, port + CPU5WDT_ENABLE_REG);
116 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
117 }
118
119 cpu5wdt_device.running++;
120 spin_unlock_irqrestore(&cpu5wdt_lock, flags);
121}
122
123static int cpu5wdt_stop(void)
124{
125 unsigned long flags;
126
127 spin_lock_irqsave(&cpu5wdt_lock, flags);
128 if (cpu5wdt_device.running)
129 cpu5wdt_device.running = 0;
130 ticks = cpu5wdt_device.default_ticks;
131 spin_unlock_irqrestore(&cpu5wdt_lock, flags);
132 if (verbose)
133 pr_crit("stop not possible\n");
134 return -EIO;
135}
136
137
138
139static int cpu5wdt_open(struct inode *inode, struct file *file)
140{
141 if (test_and_set_bit(0, &cpu5wdt_device.inuse))
142 return -EBUSY;
143 return nonseekable_open(inode, file);
144}
145
146static int cpu5wdt_release(struct inode *inode, struct file *file)
147{
148 clear_bit(0, &cpu5wdt_device.inuse);
149 return 0;
150}
151
152static long cpu5wdt_ioctl(struct file *file, unsigned int cmd,
153 unsigned long arg)
154{
155 void __user *argp = (void __user *)arg;
156 int __user *p = argp;
157 unsigned int value;
158 static const struct watchdog_info ident = {
159 .options = WDIOF_CARDRESET,
160 .identity = "CPU5 WDT",
161 };
162
163 switch (cmd) {
164 case WDIOC_GETSUPPORT:
165 if (copy_to_user(argp, &ident, sizeof(ident)))
166 return -EFAULT;
167 break;
168 case WDIOC_GETSTATUS:
169 value = inb(port + CPU5WDT_STATUS_REG);
170 value = (value >> 2) & 1;
171 return put_user(value, p);
172 case WDIOC_GETBOOTSTATUS:
173 return put_user(0, p);
174 case WDIOC_SETOPTIONS:
175 if (get_user(value, p))
176 return -EFAULT;
177 if (value & WDIOS_ENABLECARD)
178 cpu5wdt_start();
179 if (value & WDIOS_DISABLECARD)
180 cpu5wdt_stop();
181 break;
182 case WDIOC_KEEPALIVE:
183 cpu5wdt_reset();
184 break;
185 default:
186 return -ENOTTY;
187 }
188 return 0;
189}
190
191static ssize_t cpu5wdt_write(struct file *file, const char __user *buf,
192 size_t count, loff_t *ppos)
193{
194 if (!count)
195 return -EIO;
196 cpu5wdt_reset();
197 return count;
198}
199
200static const struct file_operations cpu5wdt_fops = {
201 .owner = THIS_MODULE,
202 .llseek = no_llseek,
203 .unlocked_ioctl = cpu5wdt_ioctl,
204 .open = cpu5wdt_open,
205 .write = cpu5wdt_write,
206 .release = cpu5wdt_release,
207};
208
209static struct miscdevice cpu5wdt_misc = {
210 .minor = WATCHDOG_MINOR,
211 .name = "watchdog",
212 .fops = &cpu5wdt_fops,
213};
214
215
216
217static int cpu5wdt_init(void)
218{
219 unsigned int val;
220 int err;
221
222 if (verbose)
223 pr_debug("port=0x%x, verbose=%i\n", port, verbose);
224
225 init_completion(&cpu5wdt_device.stop);
226 cpu5wdt_device.queue = 0;
227 setup_timer(&cpu5wdt_device.timer, cpu5wdt_trigger, 0);
228 cpu5wdt_device.default_ticks = ticks;
229
230 if (!request_region(port, CPU5WDT_EXTENT, PFX)) {
231 pr_err("request_region failed\n");
232 err = -EBUSY;
233 goto no_port;
234 }
235
236
237 val = inb(port + CPU5WDT_STATUS_REG);
238 val = (val >> 2) & 1;
239 if (!val)
240 pr_info("sorry, was my fault\n");
241
242 err = misc_register(&cpu5wdt_misc);
243 if (err < 0) {
244 pr_err("misc_register failed\n");
245 goto no_misc;
246 }
247
248
249 pr_info("init success\n");
250 return 0;
251
252no_misc:
253 release_region(port, CPU5WDT_EXTENT);
254no_port:
255 return err;
256}
257
258static int cpu5wdt_init_module(void)
259{
260 return cpu5wdt_init();
261}
262
263static void cpu5wdt_exit(void)
264{
265 if (cpu5wdt_device.queue) {
266 cpu5wdt_device.queue = 0;
267 wait_for_completion(&cpu5wdt_device.stop);
268 del_timer(&cpu5wdt_device.timer);
269 }
270
271 misc_deregister(&cpu5wdt_misc);
272
273 release_region(port, CPU5WDT_EXTENT);
274
275}
276
277static void cpu5wdt_exit_module(void)
278{
279 cpu5wdt_exit();
280}
281
282
283
284module_init(cpu5wdt_init_module);
285module_exit(cpu5wdt_exit_module);
286
287MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
288MODULE_DESCRIPTION("sma cpu5 watchdog driver");
289MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
290MODULE_LICENSE("GPL");
291
292module_param(port, int, 0);
293MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
294
295module_param(verbose, int, 0);
296MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
297
298module_param(ticks, int, 0);
299MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");
300
