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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/init.h>
31#include <linux/ioport.h>
32#include <linux/timer.h>
33#include <linux/completion.h>
34#include <linux/jiffies.h>
35#include <linux/io.h>
36#include <linux/uaccess.h>
37#include <linux/watchdog.h>
38
39
40
41static int verbose;
42static int port = 0x91;
43static int ticks = 10000;
44static DEFINE_SPINLOCK(cpu5wdt_lock);
45
46#define PFX "cpu5wdt: "
47
48#define CPU5WDT_EXTENT 0x0A
49
50#define CPU5WDT_STATUS_REG 0x00
51#define CPU5WDT_TIME_A_REG 0x02
52#define CPU5WDT_TIME_B_REG 0x03
53#define CPU5WDT_MODE_REG 0x04
54#define CPU5WDT_TRIGGER_REG 0x07
55#define CPU5WDT_ENABLE_REG 0x08
56#define CPU5WDT_RESET_REG 0x09
57
58#define CPU5WDT_INTERVAL (HZ/10+1)
59
60
61
62static struct {
63 struct completion stop;
64 int running;
65 struct timer_list timer;
66 int queue;
67 int default_ticks;
68 unsigned long inuse;
69} cpu5wdt_device;
70
71
72
73static void cpu5wdt_trigger(unsigned long unused)
74{
75 if (verbose > 2)
76 pr_debug("trigger at %i ticks\n", ticks);
77
78 if (cpu5wdt_device.running)
79 ticks--;
80
81 spin_lock(&cpu5wdt_lock);
82
83 outb(1, port + CPU5WDT_TRIGGER_REG);
84
85
86 if (cpu5wdt_device.queue && ticks)
87 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
88 else {
89
90 complete(&cpu5wdt_device.stop);
91 }
92 spin_unlock(&cpu5wdt_lock);
93
94}
95
96static void cpu5wdt_reset(void)
97{
98 ticks = cpu5wdt_device.default_ticks;
99
100 if (verbose)
101 pr_debug("reset (%i ticks)\n", (int) ticks);
102
103}
104
105static void cpu5wdt_start(void)
106{
107 unsigned long flags;
108
109 spin_lock_irqsave(&cpu5wdt_lock, flags);
110 if (!cpu5wdt_device.queue) {
111 cpu5wdt_device.queue = 1;
112 outb(0, port + CPU5WDT_TIME_A_REG);
113 outb(0, port + CPU5WDT_TIME_B_REG);
114 outb(1, port + CPU5WDT_MODE_REG);
115 outb(0, port + CPU5WDT_RESET_REG);
116 outb(0, port + CPU5WDT_ENABLE_REG);
117 mod_timer(&cpu5wdt_device.timer, jiffies + CPU5WDT_INTERVAL);
118 }
119
120 cpu5wdt_device.running++;
121 spin_unlock_irqrestore(&cpu5wdt_lock, flags);
122}
123
124static int cpu5wdt_stop(void)
125{
126 unsigned long flags;
127
128 spin_lock_irqsave(&cpu5wdt_lock, flags);
129 if (cpu5wdt_device.running)
130 cpu5wdt_device.running = 0;
131 ticks = cpu5wdt_device.default_ticks;
132 spin_unlock_irqrestore(&cpu5wdt_lock, flags);
133 if (verbose)
134 pr_crit("stop not possible\n");
135 return -EIO;
136}
137
138
139
140static int cpu5wdt_open(struct inode *inode, struct file *file)
141{
142 if (test_and_set_bit(0, &cpu5wdt_device.inuse))
143 return -EBUSY;
144 return nonseekable_open(inode, file);
145}
146
147static int cpu5wdt_release(struct inode *inode, struct file *file)
148{
149 clear_bit(0, &cpu5wdt_device.inuse);
150 return 0;
151}
152
153static long cpu5wdt_ioctl(struct file *file, unsigned int cmd,
154 unsigned long arg)
155{
156 void __user *argp = (void __user *)arg;
157 int __user *p = argp;
158 unsigned int value;
159 static const struct watchdog_info ident = {
160 .options = WDIOF_CARDRESET,
161 .identity = "CPU5 WDT",
162 };
163
164 switch (cmd) {
165 case WDIOC_GETSUPPORT:
166 if (copy_to_user(argp, &ident, sizeof(ident)))
167 return -EFAULT;
168 break;
169 case WDIOC_GETSTATUS:
170 value = inb(port + CPU5WDT_STATUS_REG);
171 value = (value >> 2) & 1;
172 return put_user(value, p);
173 case WDIOC_GETBOOTSTATUS:
174 return put_user(0, p);
175 case WDIOC_SETOPTIONS:
176 if (get_user(value, p))
177 return -EFAULT;
178 if (value & WDIOS_ENABLECARD)
179 cpu5wdt_start();
180 if (value & WDIOS_DISABLECARD)
181 cpu5wdt_stop();
182 break;
183 case WDIOC_KEEPALIVE:
184 cpu5wdt_reset();
185 break;
186 default:
187 return -ENOTTY;
188 }
189 return 0;
190}
191
192static ssize_t cpu5wdt_write(struct file *file, const char __user *buf,
193 size_t count, loff_t *ppos)
194{
195 if (!count)
196 return -EIO;
197 cpu5wdt_reset();
198 return count;
199}
200
201static const struct file_operations cpu5wdt_fops = {
202 .owner = THIS_MODULE,
203 .llseek = no_llseek,
204 .unlocked_ioctl = cpu5wdt_ioctl,
205 .open = cpu5wdt_open,
206 .write = cpu5wdt_write,
207 .release = cpu5wdt_release,
208};
209
210static struct miscdevice cpu5wdt_misc = {
211 .minor = WATCHDOG_MINOR,
212 .name = "watchdog",
213 .fops = &cpu5wdt_fops,
214};
215
216
217
218static int cpu5wdt_init(void)
219{
220 unsigned int val;
221 int err;
222
223 if (verbose)
224 pr_debug("port=0x%x, verbose=%i\n", port, verbose);
225
226 init_completion(&cpu5wdt_device.stop);
227 cpu5wdt_device.queue = 0;
228 setup_timer(&cpu5wdt_device.timer, cpu5wdt_trigger, 0);
229 cpu5wdt_device.default_ticks = ticks;
230
231 if (!request_region(port, CPU5WDT_EXTENT, PFX)) {
232 pr_err("request_region failed\n");
233 err = -EBUSY;
234 goto no_port;
235 }
236
237
238 val = inb(port + CPU5WDT_STATUS_REG);
239 val = (val >> 2) & 1;
240 if (!val)
241 pr_info("sorry, was my fault\n");
242
243 err = misc_register(&cpu5wdt_misc);
244 if (err < 0) {
245 pr_err("misc_register failed\n");
246 goto no_misc;
247 }
248
249
250 pr_info("init success\n");
251 return 0;
252
253no_misc:
254 release_region(port, CPU5WDT_EXTENT);
255no_port:
256 return err;
257}
258
259static int cpu5wdt_init_module(void)
260{
261 return cpu5wdt_init();
262}
263
264static void cpu5wdt_exit(void)
265{
266 if (cpu5wdt_device.queue) {
267 cpu5wdt_device.queue = 0;
268 wait_for_completion(&cpu5wdt_device.stop);
269 del_timer(&cpu5wdt_device.timer);
270 }
271
272 misc_deregister(&cpu5wdt_misc);
273
274 release_region(port, CPU5WDT_EXTENT);
275
276}
277
278static void cpu5wdt_exit_module(void)
279{
280 cpu5wdt_exit();
281}
282
283
284
285module_init(cpu5wdt_init_module);
286module_exit(cpu5wdt_exit_module);
287
288MODULE_AUTHOR("Heiko Ronsdorf <hero@ihg.uni-duisburg.de>");
289MODULE_DESCRIPTION("sma cpu5 watchdog driver");
290MODULE_SUPPORTED_DEVICE("sma cpu5 watchdog");
291MODULE_LICENSE("GPL");
292MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
293
294module_param(port, int, 0);
295MODULE_PARM_DESC(port, "base address of watchdog card, default is 0x91");
296
297module_param(verbose, int, 0);
298MODULE_PARM_DESC(verbose, "be verbose, default is 0 (no)");
299
300module_param(ticks, int, 0);
301MODULE_PARM_DESC(ticks, "count down ticks, default is 10000");
302
