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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 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
102 if (!mtx1_wdt_device.queue) {
103 mtx1_wdt_device.queue = 1;
104 gpio_set_value(mtx1_wdt_device.gpio, 1);
105 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
106 }
107 mtx1_wdt_device.running++;
108 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
109}
110
111static int mtx1_wdt_stop(void)
112{
113 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
114 if (mtx1_wdt_device.queue) {
115 mtx1_wdt_device.queue = 0;
116 gpio_set_value(mtx1_wdt_device.gpio, 0);
117 }
118 ticks = mtx1_wdt_device.default_ticks;
119 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
120 return 0;
121}
122
123
124
125static int mtx1_wdt_open(struct inode *inode, struct file *file)
126{
127 if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
128 return -EBUSY;
129 return nonseekable_open(inode, file);
130}
131
132
133static int mtx1_wdt_release(struct inode *inode, struct file *file)
134{
135 clear_bit(0, &mtx1_wdt_device.inuse);
136 return 0;
137}
138
139static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
140 unsigned long arg)
141{
142 void __user *argp = (void __user *)arg;
143 int __user *p = (int __user *)argp;
144 unsigned int value;
145 static const struct watchdog_info ident = {
146 .options = WDIOF_CARDRESET,
147 .identity = "MTX-1 WDT",
148 };
149
150 switch (cmd) {
151 case WDIOC_GETSUPPORT:
152 if (copy_to_user(argp, &ident, sizeof(ident)))
153 return -EFAULT;
154 break;
155 case WDIOC_GETSTATUS:
156 case WDIOC_GETBOOTSTATUS:
157 put_user(0, p);
158 break;
159 case WDIOC_SETOPTIONS:
160 if (get_user(value, p))
161 return -EFAULT;
162 if (value & WDIOS_ENABLECARD)
163 mtx1_wdt_start();
164 else if (value & WDIOS_DISABLECARD)
165 mtx1_wdt_stop();
166 else
167 return -EINVAL;
168 return 0;
169 case WDIOC_KEEPALIVE:
170 mtx1_wdt_reset();
171 break;
172 default:
173 return -ENOTTY;
174 }
175 return 0;
176}
177
178
179static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
180 size_t count, loff_t *ppos)
181{
182 if (!count)
183 return -EIO;
184 mtx1_wdt_reset();
185 return count;
186}
187
188static const struct file_operations mtx1_wdt_fops = {
189 .owner = THIS_MODULE,
190 .llseek = no_llseek,
191 .unlocked_ioctl = mtx1_wdt_ioctl,
192 .open = mtx1_wdt_open,
193 .write = mtx1_wdt_write,
194 .release = mtx1_wdt_release,
195};
196
197
198static struct miscdevice mtx1_wdt_misc = {
199 .minor = WATCHDOG_MINOR,
200 .name = "watchdog",
201 .fops = &mtx1_wdt_fops,
202};
203
204
205static int mtx1_wdt_probe(struct platform_device *pdev)
206{
207 int ret;
208
209 mtx1_wdt_device.gpio = pdev->resource[0].start;
210
211 spin_lock_init(&mtx1_wdt_device.lock);
212 init_completion(&mtx1_wdt_device.stop);
213 mtx1_wdt_device.queue = 0;
214 clear_bit(0, &mtx1_wdt_device.inuse);
215 setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
216 mtx1_wdt_device.default_ticks = ticks;
217
218 ret = misc_register(&mtx1_wdt_misc);
219 if (ret < 0) {
220 printk(KERN_ERR " mtx-1_wdt : failed to register\n");
221 return ret;
222 }
223 mtx1_wdt_start();
224 printk(KERN_INFO "MTX-1 Watchdog driver\n");
225 return 0;
226}
227
228static int mtx1_wdt_remove(struct platform_device *pdev)
229{
230
231 if (mtx1_wdt_device.queue) {
232 mtx1_wdt_device.queue = 0;
233 wait_for_completion(&mtx1_wdt_device.stop);
234 }
235 misc_deregister(&mtx1_wdt_misc);
236 return 0;
237}
238
239static struct platform_driver mtx1_wdt = {
240 .probe = mtx1_wdt_probe,
241 .remove = mtx1_wdt_remove,
242 .driver.name = "mtx1-wdt",
243 .driver.owner = THIS_MODULE,
244};
245
246static int __init mtx1_wdt_init(void)
247{
248 return platform_driver_register(&mtx1_wdt);
249}
250
251static void __exit mtx1_wdt_exit(void)
252{
253 platform_driver_unregister(&mtx1_wdt);
254}
255
256module_init(mtx1_wdt_init);
257module_exit(mtx1_wdt_exit);
258
259MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
260MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
261MODULE_LICENSE("GPL");
262MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
263MODULE_ALIAS("platform:mtx1-wdt");
264
