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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 unsigned int gstate;
70} mtx1_wdt_device;
71
72static void mtx1_wdt_trigger(unsigned long unused)
73{
74 spin_lock(&mtx1_wdt_device.lock);
75 if (mtx1_wdt_device.running)
76 ticks--;
77
78
79 mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
80 gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate);
81
82 if (mtx1_wdt_device.queue && ticks)
83 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
84 else
85 complete(&mtx1_wdt_device.stop);
86 spin_unlock(&mtx1_wdt_device.lock);
87}
88
89static void mtx1_wdt_reset(void)
90{
91 ticks = mtx1_wdt_device.default_ticks;
92}
93
94
95static void mtx1_wdt_start(void)
96{
97 unsigned long flags;
98
99 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
100 if (!mtx1_wdt_device.queue) {
101 mtx1_wdt_device.queue = 1;
102 mtx1_wdt_device.gstate = 1;
103 gpio_set_value(mtx1_wdt_device.gpio, 1);
104 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
105 }
106 mtx1_wdt_device.running++;
107 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
108}
109
110static int mtx1_wdt_stop(void)
111{
112 unsigned long flags;
113
114 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
115 if (mtx1_wdt_device.queue) {
116 mtx1_wdt_device.queue = 0;
117 mtx1_wdt_device.gstate = 0;
118 gpio_set_value(mtx1_wdt_device.gpio, 0);
119 }
120 ticks = mtx1_wdt_device.default_ticks;
121 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
122 return 0;
123}
124
125
126
127static int mtx1_wdt_open(struct inode *inode, struct file *file)
128{
129 if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
130 return -EBUSY;
131 return nonseekable_open(inode, file);
132}
133
134
135static int mtx1_wdt_release(struct inode *inode, struct file *file)
136{
137 clear_bit(0, &mtx1_wdt_device.inuse);
138 return 0;
139}
140
141static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
142 unsigned long arg)
143{
144 void __user *argp = (void __user *)arg;
145 int __user *p = (int __user *)argp;
146 unsigned int value;
147 static const struct watchdog_info ident = {
148 .options = WDIOF_CARDRESET,
149 .identity = "MTX-1 WDT",
150 };
151
152 switch (cmd) {
153 case WDIOC_GETSUPPORT:
154 if (copy_to_user(argp, &ident, sizeof(ident)))
155 return -EFAULT;
156 break;
157 case WDIOC_GETSTATUS:
158 case WDIOC_GETBOOTSTATUS:
159 put_user(0, p);
160 break;
161 case WDIOC_SETOPTIONS:
162 if (get_user(value, p))
163 return -EFAULT;
164 if (value & WDIOS_ENABLECARD)
165 mtx1_wdt_start();
166 else if (value & WDIOS_DISABLECARD)
167 mtx1_wdt_stop();
168 else
169 return -EINVAL;
170 return 0;
171 case WDIOC_KEEPALIVE:
172 mtx1_wdt_reset();
173 break;
174 default:
175 return -ENOTTY;
176 }
177 return 0;
178}
179
180
181static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
182 size_t count, loff_t *ppos)
183{
184 if (!count)
185 return -EIO;
186 mtx1_wdt_reset();
187 return count;
188}
189
190static const struct file_operations mtx1_wdt_fops = {
191 .owner = THIS_MODULE,
192 .llseek = no_llseek,
193 .unlocked_ioctl = mtx1_wdt_ioctl,
194 .open = mtx1_wdt_open,
195 .write = mtx1_wdt_write,
196 .release = mtx1_wdt_release,
197};
198
199
200static struct miscdevice mtx1_wdt_misc = {
201 .minor = WATCHDOG_MINOR,
202 .name = "watchdog",
203 .fops = &mtx1_wdt_fops,
204};
205
206
207static int mtx1_wdt_probe(struct platform_device *pdev)
208{
209 int ret;
210
211 mtx1_wdt_device.gpio = pdev->resource[0].start;
212 ret = gpio_request_one(mtx1_wdt_device.gpio,
213 GPIOF_OUT_INIT_HIGH, "mtx1-wdt");
214 if (ret < 0) {
215 dev_err(&pdev->dev, "failed to request gpio");
216 return ret;
217 }
218
219 spin_lock_init(&mtx1_wdt_device.lock);
220 init_completion(&mtx1_wdt_device.stop);
221 mtx1_wdt_device.queue = 0;
222 clear_bit(0, &mtx1_wdt_device.inuse);
223 setup_timer(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0L);
224 mtx1_wdt_device.default_ticks = ticks;
225
226 ret = misc_register(&mtx1_wdt_misc);
227 if (ret < 0) {
228 dev_err(&pdev->dev, "failed to register\n");
229 return ret;
230 }
231 mtx1_wdt_start();
232 dev_info(&pdev->dev, "MTX-1 Watchdog driver\n");
233 return 0;
234}
235
236static int mtx1_wdt_remove(struct platform_device *pdev)
237{
238
239 if (mtx1_wdt_device.queue) {
240 mtx1_wdt_device.queue = 0;
241 wait_for_completion(&mtx1_wdt_device.stop);
242 }
243
244 gpio_free(mtx1_wdt_device.gpio);
245 misc_deregister(&mtx1_wdt_misc);
246 return 0;
247}
248
249static struct platform_driver mtx1_wdt_driver = {
250 .probe = mtx1_wdt_probe,
251 .remove = mtx1_wdt_remove,
252 .driver.name = "mtx1-wdt",
253 .driver.owner = THIS_MODULE,
254};
255
256module_platform_driver(mtx1_wdt_driver);
257
258MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
259MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
260MODULE_LICENSE("GPL");
261MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
262MODULE_ALIAS("platform:mtx1-wdt");
263
