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28#include <linux/module.h>
29#include <linux/moduleparam.h>
30#include <linux/types.h>
31#include <linux/errno.h>
32#include <linux/miscdevice.h>
33#include <linux/fs.h>
34#include <linux/ioport.h>
35#include <linux/timer.h>
36#include <linux/completion.h>
37#include <linux/jiffies.h>
38#include <linux/watchdog.h>
39#include <linux/platform_device.h>
40#include <linux/io.h>
41#include <linux/uaccess.h>
42#include <linux/gpio.h>
43
44#include <asm/mach-au1x00/au1000.h>
45
46#define MTX1_WDT_INTERVAL (5 * HZ)
47
48static int ticks = 100 * HZ;
49
50static struct {
51 struct completion stop;
52 spinlock_t lock;
53 int running;
54 struct timer_list timer;
55 int queue;
56 int default_ticks;
57 unsigned long inuse;
58 unsigned gpio;
59 unsigned int gstate;
60} mtx1_wdt_device;
61
62static void mtx1_wdt_trigger(struct timer_list *unused)
63{
64 spin_lock(&mtx1_wdt_device.lock);
65 if (mtx1_wdt_device.running)
66 ticks--;
67
68
69 mtx1_wdt_device.gstate = !mtx1_wdt_device.gstate;
70 gpio_set_value(mtx1_wdt_device.gpio, mtx1_wdt_device.gstate);
71
72 if (mtx1_wdt_device.queue && ticks)
73 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
74 else
75 complete(&mtx1_wdt_device.stop);
76 spin_unlock(&mtx1_wdt_device.lock);
77}
78
79static void mtx1_wdt_reset(void)
80{
81 ticks = mtx1_wdt_device.default_ticks;
82}
83
84
85static void mtx1_wdt_start(void)
86{
87 unsigned long flags;
88
89 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
90 if (!mtx1_wdt_device.queue) {
91 mtx1_wdt_device.queue = 1;
92 mtx1_wdt_device.gstate = 1;
93 gpio_set_value(mtx1_wdt_device.gpio, 1);
94 mod_timer(&mtx1_wdt_device.timer, jiffies + MTX1_WDT_INTERVAL);
95 }
96 mtx1_wdt_device.running++;
97 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
98}
99
100static int mtx1_wdt_stop(void)
101{
102 unsigned long flags;
103
104 spin_lock_irqsave(&mtx1_wdt_device.lock, flags);
105 if (mtx1_wdt_device.queue) {
106 mtx1_wdt_device.queue = 0;
107 mtx1_wdt_device.gstate = 0;
108 gpio_set_value(mtx1_wdt_device.gpio, 0);
109 }
110 ticks = mtx1_wdt_device.default_ticks;
111 spin_unlock_irqrestore(&mtx1_wdt_device.lock, flags);
112 return 0;
113}
114
115
116
117static int mtx1_wdt_open(struct inode *inode, struct file *file)
118{
119 if (test_and_set_bit(0, &mtx1_wdt_device.inuse))
120 return -EBUSY;
121 return nonseekable_open(inode, file);
122}
123
124
125static int mtx1_wdt_release(struct inode *inode, struct file *file)
126{
127 clear_bit(0, &mtx1_wdt_device.inuse);
128 return 0;
129}
130
131static long mtx1_wdt_ioctl(struct file *file, unsigned int cmd,
132 unsigned long arg)
133{
134 void __user *argp = (void __user *)arg;
135 int __user *p = (int __user *)argp;
136 unsigned int value;
137 static const struct watchdog_info ident = {
138 .options = WDIOF_CARDRESET,
139 .identity = "MTX-1 WDT",
140 };
141
142 switch (cmd) {
143 case WDIOC_GETSUPPORT:
144 if (copy_to_user(argp, &ident, sizeof(ident)))
145 return -EFAULT;
146 break;
147 case WDIOC_GETSTATUS:
148 case WDIOC_GETBOOTSTATUS:
149 put_user(0, p);
150 break;
151 case WDIOC_SETOPTIONS:
152 if (get_user(value, p))
153 return -EFAULT;
154 if (value & WDIOS_ENABLECARD)
155 mtx1_wdt_start();
156 else if (value & WDIOS_DISABLECARD)
157 mtx1_wdt_stop();
158 else
159 return -EINVAL;
160 return 0;
161 case WDIOC_KEEPALIVE:
162 mtx1_wdt_reset();
163 break;
164 default:
165 return -ENOTTY;
166 }
167 return 0;
168}
169
170
171static ssize_t mtx1_wdt_write(struct file *file, const char *buf,
172 size_t count, loff_t *ppos)
173{
174 if (!count)
175 return -EIO;
176 mtx1_wdt_reset();
177 return count;
178}
179
180static const struct file_operations mtx1_wdt_fops = {
181 .owner = THIS_MODULE,
182 .llseek = no_llseek,
183 .unlocked_ioctl = mtx1_wdt_ioctl,
184 .open = mtx1_wdt_open,
185 .write = mtx1_wdt_write,
186 .release = mtx1_wdt_release,
187};
188
189
190static struct miscdevice mtx1_wdt_misc = {
191 .minor = WATCHDOG_MINOR,
192 .name = "watchdog",
193 .fops = &mtx1_wdt_fops,
194};
195
196
197static int mtx1_wdt_probe(struct platform_device *pdev)
198{
199 int ret;
200
201 mtx1_wdt_device.gpio = pdev->resource[0].start;
202 ret = devm_gpio_request_one(&pdev->dev, mtx1_wdt_device.gpio,
203 GPIOF_OUT_INIT_HIGH, "mtx1-wdt");
204 if (ret < 0) {
205 dev_err(&pdev->dev, "failed to request gpio");
206 return ret;
207 }
208
209 spin_lock_init(&mtx1_wdt_device.lock);
210 init_completion(&mtx1_wdt_device.stop);
211 mtx1_wdt_device.queue = 0;
212 clear_bit(0, &mtx1_wdt_device.inuse);
213 timer_setup(&mtx1_wdt_device.timer, mtx1_wdt_trigger, 0);
214 mtx1_wdt_device.default_ticks = ticks;
215
216 ret = misc_register(&mtx1_wdt_misc);
217 if (ret < 0) {
218 dev_err(&pdev->dev, "failed to register\n");
219 return ret;
220 }
221 mtx1_wdt_start();
222 dev_info(&pdev->dev, "MTX-1 Watchdog driver\n");
223 return 0;
224}
225
226static int mtx1_wdt_remove(struct platform_device *pdev)
227{
228
229 if (mtx1_wdt_device.queue) {
230 mtx1_wdt_device.queue = 0;
231 wait_for_completion(&mtx1_wdt_device.stop);
232 }
233
234 misc_deregister(&mtx1_wdt_misc);
235 return 0;
236}
237
238static struct platform_driver mtx1_wdt_driver = {
239 .probe = mtx1_wdt_probe,
240 .remove = mtx1_wdt_remove,
241 .driver.name = "mtx1-wdt",
242 .driver.owner = THIS_MODULE,
243};
244
245module_platform_driver(mtx1_wdt_driver);
246
247MODULE_AUTHOR("Michael Stickel, Florian Fainelli");
248MODULE_DESCRIPTION("Driver for the MTX-1 watchdog");
249MODULE_LICENSE("GPL");
250MODULE_ALIAS("platform:mtx1-wdt");
251
