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37#include <linux/module.h>
38#include <linux/moduleparam.h>
39#include <linux/types.h>
40#include <linux/errno.h>
41#include <linux/miscdevice.h>
42#include <linux/fs.h>
43#include <linux/init.h>
44#include <linux/ioport.h>
45#include <linux/timer.h>
46#include <linux/completion.h>
47#include <linux/jiffies.h>
48#include <linux/watchdog.h>
49#include <linux/platform_device.h>
50#include <linux/io.h>
51#include <linux/uaccess.h>
52#include <linux/gpio.h>
53
54#include <asm/mach-au1x00/au1000.h>
55
56#define MTX1_WDT_INTERVAL (5 * HZ)
57
58static int ticks = 100 * HZ;
59
60static struct {
61 struct completion stop;
62 spinlock_t lock;
63 int running;
64 struct timer_list timer;
65 int queue;
66 int default_ticks;
67 unsigned long inuse;
68 unsigned gpio;
69} mtx1_wdt_device;
70
71static void mtx1_wdt_trigger(unsigned long unused)
72{
73 u32 tmp;
74
75 spin_lock(&mtx1_wdt_device.lock);
76 if (mtx1_wdt_device.running)
77 ticks--;
78
79
80
81 tmp = au_readl(GPIO2_DIR);
82 tmp = (tmp & ~(1 << mtx1_wdt_device.gpio)) |
83 ((~tmp) & (1 << mtx1_wdt_device.gpio));
84 au_writel(tmp, GPIO2_DIR);
85
86 if (mtx1_wdt_device.queue && ticks)
87 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
88 else
89 complete(&mtx1_wdt_device.stop);
90 spin_unlock(&mtx1_wdt_device.lock);
91}
92
93static void mtx1_wdt_reset(void)
94{
95 ticks = mtx1_wdt_device.default_ticks;
96}
97
98
99static void mtx1_wdt_start(void)
100{
101 unsigned long flags;
102
103 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
104 if (!mtx1_wdt_device.queue) {
105 mtx1_wdt_device.queue = 1;
106 gpio_set_value(mtx1_wdt_device.gpio, 1);
107 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
108 }
109 mtx1_wdt_device.running++;
110 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
111}
112
113static int mtx1_wdt_stop(void)
114{
115 unsigned long flags;
116
117 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
118 if (mtx1_wdt_device.queue) {
119 mtx1_wdt_device.queue = 0;
120 gpio_set_value(mtx1_wdt_device.gpio, 0);
121 }
122 ticks = mtx1_wdt_device.default_ticks;
123 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
124 return 0;
125}
126
127
128
129static int mtx1_wdt_open(struct inode *inode, struct file *file)
130{
131 if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
132 return -EBUSY;
133 return nonseekable_open(inode, file);
134}
135
136
137static int mtx1_wdt_release(struct inode *inode, struct file *file)
138{
139 clear_bit(0, &mtx1_wdt_device.inuse);
140 return 0;
141}
142
143static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
144 unsigned long arg)
145{
146 void __user *argp = (void __user *)arg;
147 int __user *p = (int __user *)argp;
148 unsigned int value;
149 static const struct watchdog_info ident = {
150 .options = WDIOF_CARDRESET,
151 .identity = "MTX-1 WDT",
152 };
153
154 switch (cmd) {
155 case WDIOC_GETSUPPORT:
156 if (copy_to_user(argp, &ident, sizeof(ident)))
157 return -EFAULT;
158 break;
159 case WDIOC_GETSTATUS:
160 case WDIOC_GETBOOTSTATUS:
161 put_user(0, p);
162 break;
163 case WDIOC_SETOPTIONS:
164 if (get_user(value, p))
165 return -EFAULT;
166 if (value & WDIOS_ENABLECARD)
167 mtx1_wdt_start();
168 else if (value & WDIOS_DISABLECARD)
169 mtx1_wdt_stop();
170 else
171 return -EINVAL;
172 return 0;
173 case WDIOC_KEEPALIVE:
174 mtx1_wdt_reset();
175 break;
176 default:
177 return -ENOTTY;
178 }
179 return 0;
180}
181
182
183static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
184 size_t count, loff_t *ppos)
185{
186 if (!count)
187 return -EIO;
188 mtx1_wdt_reset();
189 return count;
190}
191
192static const struct file_operations mtx1_wdt_fops = {
193 .owner = THIS_MODULE,
194 .llseek = no_llseek,
195 .unlocked_ioctl = mtx1_wdt_ioctl,
196 .open = mtx1_wdt_open,
197 .write = mtx1_wdt_write,
198 .release = mtx1_wdt_release,
199};
200
201
202static struct miscdevice mtx1_wdt_misc = {
203 .minor = WATCHDOG_MINOR,
204 .name = "watchdog",
205 .fops = &mtx1_wdt_fops,
206};
207
208
209static int __devinit mtx1_wdt_probe(struct platform_device *pdev)
210{
211 int ret;
212
213 mtx1_wdt_device.gpio = pdev->resource[0].start;
214
215 spin_lock_init(&mtx1_wdt_device.lock);
216 init_completion(&mtx1_wdt_device.stop);
217 mtx1_wdt_device.queue = 0;
218 clear_bit(0, &mtx1_wdt_device.inuse);
219 setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
220 mtx1_wdt_device.default_ticks = ticks;
221
222 ret = misc_register(&mtx1_wdt_misc);
223 if (ret < 0) {
224 printk(KERN_ERR " mtx-1_wdt : failed to register\n");
225 return ret;
226 }
227 mtx1_wdt_start();
228 printk(KERN_INFO "MTX-1 Watchdog driver\n");
229 return 0;
230}
231
232static int __devexit mtx1_wdt_remove(struct platform_device *pdev)
233{
234
235 if (mtx1_wdt_device.queue) {
236 mtx1_wdt_device.queue = 0;
237 wait_for_completion(&mtx1_wdt_device.stop);
238 }
239 misc_deregister(&mtx1_wdt_misc);
240 return 0;
241}
242
243static struct platform_driver mtx1_wdt = {
244 .probe = mtx1_wdt_probe,
245 .remove = __devexit_p(mtx1_wdt_remove),
246 .driver.name = "mtx1-wdt",
247 .driver.owner = THIS_MODULE,
248};
249
250static int __init mtx1_wdt_init(void)
251{
252 return platform_driver_register(&mtx1_wdt);
253}
254
255static void __exit mtx1_wdt_exit(void)
256{
257 platform_driver_unregister(&mtx1_wdt);
258}
259
260module_init(mtx1_wdt_init);
261module_exit(mtx1_wdt_exit);
262
263MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
264MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
265MODULE_LICENSE("GPL");
266MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
267MODULE_ALIAS("platform:mtx1-wdt");
268
