Add a watchdog driver for rdc321x (needs testing) and try to detect the rdc cpu
[openwrt/svn-archive/archive.git] / target / linux / rdc-2.6 / files / arch / i386 / mach-rdc / wdt.c
1 /*
2 * RDC321x watchdog driver
3 *
4 * Copyright (C) 2007 Florian Fainelli <florian@openwrt.org>
5 *
6 * This driver is highly inspired from the rdc321x_wdt driver
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 *
22 */
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/platform_device.h>
36 #include <linux/watchdog.h>
37
38 #include <asm/io.h>
39 #include <asm/uaccess.h>
40
41 #include <asm/mach-rdc/rdc321x_defs.h>
42
43 #define RDC_WDT_MASK 0x80000000 /* Mask */
44 #define RDC_WDT_EN 0x00800000 /* Enable bit */
45 #define RDC_WDT_WTI 0x00200000 /* Generate a CPU reset/NMI/WDT irq when WDT timeout is reached */
46 #define RDC_WDT_RST 0x00100000 /* Reset bit */
47 #define RDC_WDT_WIF 0x00040000 /* WDT IRQ Flag */
48 #define RDC_WDT_IRT 0x00000100 /* IRQ Routing table */
49 #define RDC_WDT_CNT 0x00000001 /* WDT count */
50
51 #define RDC_CLS_TMR 0x80003844 /* Clear timer */
52
53 #define RDC_WDT_INTERVAL (HZ/10+1)
54
55 int nowayout = WATCHDOG_NOWAYOUT;
56 module_param(nowayout, int, 0);
57 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
58
59 static int ticks = 1000;
60
61 /* some device data */
62
63 static struct {
64 struct completion stop;
65 volatile int running;
66 struct timer_list timer;
67 volatile int queue;
68 int default_ticks;
69 unsigned long inuse;
70 } rdc321x_wdt_device;
71
72 /* generic helper functions */
73
74 static void rdc321x_wdt_trigger(unsigned long unused)
75 {
76 if( rdc321x_wdt_device.running )
77 ticks--;
78
79 /* keep watchdog alive */
80 outl(RDC_WDT_EN|inl(RDC3210_CFGREG_DATA), RDC3210_CFGREG_DATA);
81
82 /* requeue?? */
83 if (rdc321x_wdt_device.queue && ticks)
84 mod_timer(&rdc321x_wdt_device.timer, jiffies + RDC_WDT_INTERVAL);
85 else {
86 /* ticks doesn't matter anyway */
87 complete(&rdc321x_wdt_device.stop);
88 }
89
90 }
91
92 static void rdc321x_wdt_reset(void)
93 {
94 ticks = rdc321x_wdt_device.default_ticks;
95 }
96
97 static void rdc321x_wdt_start(void)
98 {
99 if (!rdc321x_wdt_device.queue) {
100 rdc321x_wdt_device.queue = 1;
101
102 /* Clear the timer */
103 outl(RDC_CLS_TMR, RDC3210_CFGREG_ADDR);
104
105 /* Enable watchdog and set the timeout to 81.92 us */
106 outl(RDC_WDT_EN|RDC_WDT_CNT, RDC3210_CFGREG_DATA);
107
108 mod_timer(&rdc321x_wdt_device.timer, jiffies + RDC_WDT_INTERVAL);
109 }
110
111 /* if process dies, counter is not decremented */
112 rdc321x_wdt_device.running++;
113 }
114
115 static int rdc321x_wdt_stop(void)
116 {
117 if (rdc321x_wdt_device.running)
118 rdc321x_wdt_device.running = 0;
119
120 ticks = rdc321x_wdt_device.default_ticks;
121
122 return -EIO;
123 }
124
125 /* filesystem operations */
126
127 static int rdc321x_wdt_open(struct inode *inode, struct file *file)
128 {
129 if (test_and_set_bit(0, &rdc321x_wdt_device.inuse))
130 return -EBUSY;
131
132 return nonseekable_open(inode, file);
133 }
134
135 static int rdc321x_wdt_release(struct inode *inode, struct file *file)
136 {
137 clear_bit(0, &rdc321x_wdt_device.inuse);
138 return 0;
139 }
140
141 static int rdc321x_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
142 {
143 void __user *argp = (void __user *)arg;
144 unsigned int value;
145 static struct watchdog_info ident =
146 {
147 .options = WDIOF_CARDRESET,
148 .identity = "RDC321x WDT",
149 };
150
151 switch(cmd) {
152 case WDIOC_KEEPALIVE:
153 rdc321x_wdt_reset();
154 break;
155 case WDIOC_GETSTATUS:
156 /* Read the value from the DATA register */
157 value = inl(RDC3210_CFGREG_DATA);
158 if ( copy_to_user(argp, &value, sizeof(int)) )
159 return -EFAULT;
160 break;
161 case WDIOC_GETSUPPORT:
162 if ( copy_to_user(argp, &ident, sizeof(ident)) )
163 return -EFAULT;
164 break;
165 case WDIOC_SETOPTIONS:
166 if ( copy_from_user(&value, argp, sizeof(int)) )
167 return -EFAULT;
168 switch(value) {
169 case WDIOS_ENABLECARD:
170 rdc321x_wdt_start();
171 break;
172 case WDIOS_DISABLECARD:
173 return rdc321x_wdt_stop();
174 default:
175 return -EINVAL;
176 }
177 break;
178 default:
179 return -ENOTTY;
180 }
181 return 0;
182 }
183
184 static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
185 {
186 if ( !count )
187 return -EIO;
188
189 rdc321x_wdt_reset();
190
191 return count;
192 }
193
194 static const struct file_operations rdc321x_wdt_fops = {
195 .owner = THIS_MODULE,
196 .llseek = no_llseek,
197 .ioctl = rdc321x_wdt_ioctl,
198 .open = rdc321x_wdt_open,
199 .write = rdc321x_wdt_write,
200 .release = rdc321x_wdt_release,
201 };
202
203 static struct miscdevice rdc321x_wdt_misc = {
204 .minor = WATCHDOG_MINOR,
205 .name = "watchdog",
206 .fops = &rdc321x_wdt_fops,
207 };
208
209 static int __devinit rdc321x_wdt_probe(struct platform_device *pdev)
210 {
211 int err;
212
213 if ( (err = misc_register(&rdc321x_wdt_misc)) < 0 ) {
214 printk(KERN_ERR PFX "misc_register failed\n");
215 goto no_misc;
216 }
217
218 /* Reset the watchdog */
219 outl(RDC_WDT_RST, RDC3210_CFGREG_DATA);
220
221 init_completion(&rdc321x_wdt_device.stop);
222 rdc321x_wdt_device.queue = 0;
223
224 clear_bit(0, &rdc321x_wdt_device.inuse);
225
226 setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
227
228 rdc321x_wdt_device.default_ticks = ticks;
229
230 printk(KERN_INFO PFX "init success\n");
231
232 return 0;
233
234 no_misc:
235 return err;
236 }
237
238 static int rdc321x_wdt_remove(struct platform_device *pdev)
239 {
240 if (rdc321x_wdt_device.queue) {
241 rdc321x_wdt_device.queue = 0;
242 wait_for_completion(&rdc321x_wdt_device.stop);
243 }
244
245 misc_deregister(&rdc321x_wdt_misc);
246
247 return 0;
248 }
249
250 static struct platform_driver rdc321x_wdt_driver = {
251 .probe = rdc321x_wdt_probe,
252 .remove = rdc321x_wdt_remove,
253 .driver = {
254 .owner = THIS_MODULE,
255 .name = "rdc321x_wdt",
256 },
257 };
258
259 static int __init rdc321x_wdt_init(void)
260 {
261 return platform_driver_register(&rdc321x_wdt_driver);
262 }
263
264 static void __exit rdc321x_wdt_exit(void)
265 {
266 platform_driver_unregister(&rdc321x_wdt_driver);
267 }
268
269 module_init(rdc321x_wdt_init);
270 module_exit(rdc321x_wdt_exit);
271
272 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
273 MODULE_DESCRIPTION("RDC321x watchdog driver");
274 MODULE_LICENSE("GPL");
275 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);