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Florian Fainellib3e8f2c2008-02-25 12:59:26 +01001/*
2 * RDC321x watchdog driver
3 *
Florian Fainelli842102f2010-03-22 22:56:24 -04004 * Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org>
Florian Fainellib3e8f2c2008-02-25 12:59:26 +01005 *
6 * This driver is highly inspired from the cpu5_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#include <linux/io.h>
38#include <linux/uaccess.h>
Florian Fainelli842102f2010-03-22 22:56:24 -040039#include <linux/mfd/rdc321x.h>
Florian Fainellib3e8f2c2008-02-25 12:59:26 +010040
41#define RDC_WDT_MASK 0x80000000 /* Mask */
42#define RDC_WDT_EN 0x00800000 /* Enable bit */
43#define RDC_WDT_WTI 0x00200000 /* Generate CPU reset/NMI/WDT on timeout */
44#define RDC_WDT_RST 0x00100000 /* Reset bit */
45#define RDC_WDT_WIF 0x00040000 /* WDT IRQ Flag */
46#define RDC_WDT_IRT 0x00000100 /* IRQ Routing table */
47#define RDC_WDT_CNT 0x00000001 /* WDT count */
48
49#define RDC_CLS_TMR 0x80003844 /* Clear timer */
50
51#define RDC_WDT_INTERVAL (HZ/10+1)
52
53static int ticks = 1000;
54
55/* some device data */
56
57static struct {
58 struct completion stop;
59 int running;
60 struct timer_list timer;
61 int queue;
62 int default_ticks;
63 unsigned long inuse;
64 spinlock_t lock;
Florian Fainelli842102f2010-03-22 22:56:24 -040065 struct pci_dev *sb_pdev;
66 int base_reg;
Florian Fainellib3e8f2c2008-02-25 12:59:26 +010067} rdc321x_wdt_device;
68
69/* generic helper functions */
70
71static void rdc321x_wdt_trigger(unsigned long unused)
72{
73 unsigned long flags;
Florian Fainelli842102f2010-03-22 22:56:24 -040074 u32 val;
Florian Fainellib3e8f2c2008-02-25 12:59:26 +010075
76 if (rdc321x_wdt_device.running)
77 ticks--;
78
79 /* keep watchdog alive */
80 spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
Florian Fainelli842102f2010-03-22 22:56:24 -040081 pci_read_config_dword(rdc321x_wdt_device.sb_pdev,
82 rdc321x_wdt_device.base_reg, &val);
83 val |= RDC_WDT_EN;
84 pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
85 rdc321x_wdt_device.base_reg, val);
Florian Fainellib3e8f2c2008-02-25 12:59:26 +010086 spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
87
88 /* requeue?? */
89 if (rdc321x_wdt_device.queue && ticks)
90 mod_timer(&rdc321x_wdt_device.timer,
91 jiffies + RDC_WDT_INTERVAL);
92 else {
93 /* ticks doesn't matter anyway */
94 complete(&rdc321x_wdt_device.stop);
95 }
96
97}
98
99static void rdc321x_wdt_reset(void)
100{
101 ticks = rdc321x_wdt_device.default_ticks;
102}
103
104static void rdc321x_wdt_start(void)
105{
106 unsigned long flags;
107
108 if (!rdc321x_wdt_device.queue) {
109 rdc321x_wdt_device.queue = 1;
110
111 /* Clear the timer */
112 spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
Florian Fainelli842102f2010-03-22 22:56:24 -0400113 pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
114 rdc321x_wdt_device.base_reg, RDC_CLS_TMR);
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100115
116 /* Enable watchdog and set the timeout to 81.92 us */
Florian Fainelli842102f2010-03-22 22:56:24 -0400117 pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
118 rdc321x_wdt_device.base_reg,
119 RDC_WDT_EN | RDC_WDT_CNT);
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100120 spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
121
122 mod_timer(&rdc321x_wdt_device.timer,
123 jiffies + RDC_WDT_INTERVAL);
124 }
125
126 /* if process dies, counter is not decremented */
127 rdc321x_wdt_device.running++;
128}
129
130static int rdc321x_wdt_stop(void)
131{
132 if (rdc321x_wdt_device.running)
133 rdc321x_wdt_device.running = 0;
134
135 ticks = rdc321x_wdt_device.default_ticks;
136
137 return -EIO;
138}
139
140/* filesystem operations */
141static int rdc321x_wdt_open(struct inode *inode, struct file *file)
142{
143 if (test_and_set_bit(0, &rdc321x_wdt_device.inuse))
144 return -EBUSY;
145
146 return nonseekable_open(inode, file);
147}
148
149static int rdc321x_wdt_release(struct inode *inode, struct file *file)
150{
151 clear_bit(0, &rdc321x_wdt_device.inuse);
152 return 0;
153}
154
Wim Van Sebroeck7275fc82008-09-18 12:26:15 +0000155static long rdc321x_wdt_ioctl(struct file *file, unsigned int cmd,
156 unsigned long arg)
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100157{
158 void __user *argp = (void __user *)arg;
Florian Fainelli842102f2010-03-22 22:56:24 -0400159 u32 value;
Wim Van Sebroeck42747d72009-12-26 18:55:22 +0000160 static const struct watchdog_info ident = {
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100161 .options = WDIOF_CARDRESET,
162 .identity = "RDC321x WDT",
163 };
164 unsigned long flags;
165
166 switch (cmd) {
167 case WDIOC_KEEPALIVE:
168 rdc321x_wdt_reset();
169 break;
170 case WDIOC_GETSTATUS:
171 /* Read the value from the DATA register */
172 spin_lock_irqsave(&rdc321x_wdt_device.lock, flags);
Florian Fainelli842102f2010-03-22 22:56:24 -0400173 pci_read_config_dword(rdc321x_wdt_device.sb_pdev,
174 rdc321x_wdt_device.base_reg, &value);
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100175 spin_unlock_irqrestore(&rdc321x_wdt_device.lock, flags);
Florian Fainelli842102f2010-03-22 22:56:24 -0400176 if (copy_to_user(argp, &value, sizeof(u32)))
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100177 return -EFAULT;
178 break;
179 case WDIOC_GETSUPPORT:
180 if (copy_to_user(argp, &ident, sizeof(ident)))
181 return -EFAULT;
182 break;
183 case WDIOC_SETOPTIONS:
184 if (copy_from_user(&value, argp, sizeof(int)))
185 return -EFAULT;
186 switch (value) {
187 case WDIOS_ENABLECARD:
188 rdc321x_wdt_start();
189 break;
190 case WDIOS_DISABLECARD:
191 return rdc321x_wdt_stop();
192 default:
193 return -EINVAL;
194 }
195 break;
196 default:
197 return -ENOTTY;
198 }
199 return 0;
200}
201
202static ssize_t rdc321x_wdt_write(struct file *file, const char __user *buf,
203 size_t count, loff_t *ppos)
204{
205 if (!count)
206 return -EIO;
207
208 rdc321x_wdt_reset();
209
210 return count;
211}
212
213static const struct file_operations rdc321x_wdt_fops = {
214 .owner = THIS_MODULE,
215 .llseek = no_llseek,
Wim Van Sebroeck7275fc82008-09-18 12:26:15 +0000216 .unlocked_ioctl = rdc321x_wdt_ioctl,
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100217 .open = rdc321x_wdt_open,
218 .write = rdc321x_wdt_write,
219 .release = rdc321x_wdt_release,
220};
221
222static struct miscdevice rdc321x_wdt_misc = {
223 .minor = WATCHDOG_MINOR,
224 .name = "watchdog",
225 .fops = &rdc321x_wdt_fops,
226};
227
228static int __devinit rdc321x_wdt_probe(struct platform_device *pdev)
229{
230 int err;
Florian Fainelli842102f2010-03-22 22:56:24 -0400231 struct resource *r;
232 struct rdc321x_wdt_pdata *pdata;
233
234 pdata = pdev->dev.platform_data;
235 if (!pdata) {
236 dev_err(&pdev->dev, "no platform data supplied\n");
237 return -ENODEV;
238 }
239
Florian Fainelli8deca39e2010-05-15 22:58:27 +0200240 r = platform_get_resource_byname(pdev, IORESOURCE_IO, "wdt-reg");
Florian Fainelli842102f2010-03-22 22:56:24 -0400241 if (!r) {
242 dev_err(&pdev->dev, "failed to get wdt-reg resource\n");
243 return -ENODEV;
244 }
245
246 rdc321x_wdt_device.sb_pdev = pdata->sb_pdev;
247 rdc321x_wdt_device.base_reg = r->start;
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100248
249 err = misc_register(&rdc321x_wdt_misc);
250 if (err < 0) {
Florian Fainelli842102f2010-03-22 22:56:24 -0400251 dev_err(&pdev->dev, "misc_register failed\n");
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100252 return err;
253 }
254
255 spin_lock_init(&rdc321x_wdt_device.lock);
256
257 /* Reset the watchdog */
Florian Fainelli842102f2010-03-22 22:56:24 -0400258 pci_write_config_dword(rdc321x_wdt_device.sb_pdev,
259 rdc321x_wdt_device.base_reg, RDC_WDT_RST);
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100260
261 init_completion(&rdc321x_wdt_device.stop);
262 rdc321x_wdt_device.queue = 0;
263
264 clear_bit(0, &rdc321x_wdt_device.inuse);
265
266 setup_timer(&rdc321x_wdt_device.timer, rdc321x_wdt_trigger, 0);
267
268 rdc321x_wdt_device.default_ticks = ticks;
269
Florian Fainelli842102f2010-03-22 22:56:24 -0400270 dev_info(&pdev->dev, "watchdog init success\n");
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100271
272 return 0;
273}
274
Wim Van Sebroeckb6bf2912009-04-14 20:30:55 +0000275static int __devexit rdc321x_wdt_remove(struct platform_device *pdev)
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100276{
277 if (rdc321x_wdt_device.queue) {
278 rdc321x_wdt_device.queue = 0;
279 wait_for_completion(&rdc321x_wdt_device.stop);
280 }
281
282 misc_deregister(&rdc321x_wdt_misc);
283
284 return 0;
285}
286
287static struct platform_driver rdc321x_wdt_driver = {
288 .probe = rdc321x_wdt_probe,
Wim Van Sebroeckb6bf2912009-04-14 20:30:55 +0000289 .remove = __devexit_p(rdc321x_wdt_remove),
Florian Fainellib3e8f2c2008-02-25 12:59:26 +0100290 .driver = {
291 .owner = THIS_MODULE,
292 .name = "rdc321x-wdt",
293 },
294};
295
296static int __init rdc321x_wdt_init(void)
297{
298 return platform_driver_register(&rdc321x_wdt_driver);
299}
300
301static void __exit rdc321x_wdt_exit(void)
302{
303 platform_driver_unregister(&rdc321x_wdt_driver);
304}
305
306module_init(rdc321x_wdt_init);
307module_exit(rdc321x_wdt_exit);
308
309MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
310MODULE_DESCRIPTION("RDC321x watchdog driver");
311MODULE_LICENSE("GPL");
312MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);