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James Chapman3be10212005-08-17 09:01:33 +02001/*
2 * mv64x60_wdt.c - MV64X60 (Marvell Discovery) watchdog userspace interface
3 *
4 * Author: James Chapman <jchapman@katalix.com>
5 *
6 * Platform-specific setup code should configure the dog to generate
7 * interrupt or reset as required. This code only enables/disables
8 * and services the watchdog.
9 *
10 * Derived from mpc8xx_wdt.c, with the following copyright.
11 *
12 * 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
13 * the terms of the GNU General Public License version 2. This program
14 * is licensed "as is" without any warranty of any kind, whether express
15 * or implied.
16 */
17
James Chapman3be10212005-08-17 09:01:33 +020018#include <linux/fs.h>
19#include <linux/init.h>
20#include <linux/kernel.h>
21#include <linux/miscdevice.h>
22#include <linux/module.h>
23#include <linux/watchdog.h>
Russell Kingd052d1b2005-10-29 19:07:23 +010024#include <linux/platform_device.h>
25
James Chapman3be10212005-08-17 09:01:33 +020026#include <asm/mv64x60.h>
27#include <asm/uaccess.h>
28#include <asm/io.h>
29
30/* MV64x60 WDC (config) register access definitions */
31#define MV64x60_WDC_CTL1_MASK (3 << 24)
32#define MV64x60_WDC_CTL1(val) ((val & 3) << 24)
33#define MV64x60_WDC_CTL2_MASK (3 << 26)
34#define MV64x60_WDC_CTL2(val) ((val & 3) << 26)
35
36/* Flags bits */
37#define MV64x60_WDOG_FLAG_OPENED 0
38#define MV64x60_WDOG_FLAG_ENABLED 1
39
40static unsigned long wdt_flags;
41static int wdt_status;
42static void __iomem *mv64x60_regs;
43static int mv64x60_wdt_timeout;
44
45static void mv64x60_wdt_reg_write(u32 val)
46{
47 /* Allow write only to CTL1 / CTL2 fields, retaining values in
48 * other fields.
49 */
50 u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC);
51 data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK);
52 data |= val;
53 writel(data, mv64x60_regs + MV64x60_WDT_WDC);
54}
55
56static void mv64x60_wdt_service(void)
57{
58 /* Write 01 followed by 10 to CTL2 */
59 mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01));
60 mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02));
61}
62
63static void mv64x60_wdt_handler_disable(void)
64{
65 if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
66 /* Write 01 followed by 10 to CTL1 */
67 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
68 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
69 printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n");
70 }
71}
72
73static void mv64x60_wdt_handler_enable(void)
74{
75 if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
76 /* Write 01 followed by 10 to CTL1 */
77 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
78 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
79 printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
80 }
81}
82
83static int mv64x60_wdt_open(struct inode *inode, struct file *file)
84{
85 if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
86 return -EBUSY;
87
88 mv64x60_wdt_service();
89 mv64x60_wdt_handler_enable();
90
Al Virob2846df2005-09-29 00:42:27 +010091 nonseekable_open(inode, file);
92
James Chapman3be10212005-08-17 09:01:33 +020093 return 0;
94}
95
96static int mv64x60_wdt_release(struct inode *inode, struct file *file)
97{
98 mv64x60_wdt_service();
99
100#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
101 mv64x60_wdt_handler_disable();
102#endif
103
104 clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);
105
106 return 0;
107}
108
Al Virob2846df2005-09-29 00:42:27 +0100109static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data,
James Chapman3be10212005-08-17 09:01:33 +0200110 size_t len, loff_t * ppos)
111{
James Chapman3be10212005-08-17 09:01:33 +0200112 if (len)
113 mv64x60_wdt_service();
114
115 return len;
116}
117
118static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file,
119 unsigned int cmd, unsigned long arg)
120{
121 int timeout;
Al Virob2846df2005-09-29 00:42:27 +0100122 void __user *argp = (void __user *)arg;
James Chapman3be10212005-08-17 09:01:33 +0200123 static struct watchdog_info info = {
124 .options = WDIOF_KEEPALIVEPING,
125 .firmware_version = 0,
126 .identity = "MV64x60 watchdog",
127 };
128
129 switch (cmd) {
130 case WDIOC_GETSUPPORT:
Al Virob2846df2005-09-29 00:42:27 +0100131 if (copy_to_user(argp, &info, sizeof(info)))
James Chapman3be10212005-08-17 09:01:33 +0200132 return -EFAULT;
133 break;
134
135 case WDIOC_GETSTATUS:
136 case WDIOC_GETBOOTSTATUS:
Al Virob2846df2005-09-29 00:42:27 +0100137 if (put_user(wdt_status, (int __user *)argp))
James Chapman3be10212005-08-17 09:01:33 +0200138 return -EFAULT;
139 wdt_status &= ~WDIOF_KEEPALIVEPING;
140 break;
141
142 case WDIOC_GETTEMP:
143 return -EOPNOTSUPP;
144
145 case WDIOC_SETOPTIONS:
146 return -EOPNOTSUPP;
147
148 case WDIOC_KEEPALIVE:
149 mv64x60_wdt_service();
150 wdt_status |= WDIOF_KEEPALIVEPING;
151 break;
152
153 case WDIOC_SETTIMEOUT:
154 return -EOPNOTSUPP;
155
156 case WDIOC_GETTIMEOUT:
157 timeout = mv64x60_wdt_timeout * HZ;
Al Virob2846df2005-09-29 00:42:27 +0100158 if (put_user(timeout, (int __user *)argp))
James Chapman3be10212005-08-17 09:01:33 +0200159 return -EFAULT;
160 break;
161
162 default:
Samuel Tardieu795b89d2006-09-09 17:34:31 +0200163 return -ENOTTY;
James Chapman3be10212005-08-17 09:01:33 +0200164 }
165
166 return 0;
167}
168
Arjan van de Ven62322d22006-07-03 00:24:21 -0700169static const struct file_operations mv64x60_wdt_fops = {
James Chapman3be10212005-08-17 09:01:33 +0200170 .owner = THIS_MODULE,
171 .llseek = no_llseek,
172 .write = mv64x60_wdt_write,
173 .ioctl = mv64x60_wdt_ioctl,
174 .open = mv64x60_wdt_open,
175 .release = mv64x60_wdt_release,
176};
177
178static struct miscdevice mv64x60_wdt_miscdev = {
179 .minor = WATCHDOG_MINOR,
180 .name = "watchdog",
181 .fops = &mv64x60_wdt_fops,
182};
183
Russell King3ae5eae2005-11-09 22:32:44 +0000184static int __devinit mv64x60_wdt_probe(struct platform_device *dev)
James Chapman3be10212005-08-17 09:01:33 +0200185{
Russell King3ae5eae2005-11-09 22:32:44 +0000186 struct mv64x60_wdt_pdata *pdata = dev->dev.platform_data;
James Chapman3be10212005-08-17 09:01:33 +0200187 int bus_clk = 133;
188
189 mv64x60_wdt_timeout = 10;
190 if (pdata) {
191 mv64x60_wdt_timeout = pdata->timeout;
192 bus_clk = pdata->bus_clk;
193 }
194
195 mv64x60_regs = mv64x60_get_bridge_vbase();
196
197 writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
198 mv64x60_regs + MV64x60_WDT_WDC);
199
200 return misc_register(&mv64x60_wdt_miscdev);
201}
202
Russell King3ae5eae2005-11-09 22:32:44 +0000203static int __devexit mv64x60_wdt_remove(struct platform_device *dev)
James Chapman3be10212005-08-17 09:01:33 +0200204{
205 misc_deregister(&mv64x60_wdt_miscdev);
206
207 mv64x60_wdt_service();
208 mv64x60_wdt_handler_disable();
209
210 return 0;
211}
212
Russell King3ae5eae2005-11-09 22:32:44 +0000213static struct platform_driver mv64x60_wdt_driver = {
James Chapman3be10212005-08-17 09:01:33 +0200214 .probe = mv64x60_wdt_probe,
215 .remove = __devexit_p(mv64x60_wdt_remove),
Russell King3ae5eae2005-11-09 22:32:44 +0000216 .driver = {
217 .owner = THIS_MODULE,
218 .name = MV64x60_WDT_NAME,
219 },
James Chapman3be10212005-08-17 09:01:33 +0200220};
221
222static struct platform_device *mv64x60_wdt_dev;
223
224static int __init mv64x60_wdt_init(void)
225{
226 int ret;
227
228 printk(KERN_INFO "MV64x60 watchdog driver\n");
229
Dmitry Torokhoveee8ab72006-03-22 00:07:54 -0800230 mv64x60_wdt_dev = platform_device_alloc(MV64x60_WDT_NAME, -1);
231 if (!mv64x60_wdt_dev) {
232 ret = -ENOMEM;
233 goto out;
234 }
235
236 ret = platform_device_add(mv64x60_wdt_dev);
237 if (ret) {
238 platform_device_put(mv64x60_wdt_dev);
James Chapman3be10212005-08-17 09:01:33 +0200239 goto out;
240 }
241
Russell King3ae5eae2005-11-09 22:32:44 +0000242 ret = platform_driver_register(&mv64x60_wdt_driver);
Dmitry Torokhoveee8ab72006-03-22 00:07:54 -0800243 if (ret) {
244 platform_device_unregister(mv64x60_wdt_dev);
245 goto out;
246 }
247
248 out:
James Chapman3be10212005-08-17 09:01:33 +0200249 return ret;
250}
251
252static void __exit mv64x60_wdt_exit(void)
253{
Russell King3ae5eae2005-11-09 22:32:44 +0000254 platform_driver_unregister(&mv64x60_wdt_driver);
James Chapman3be10212005-08-17 09:01:33 +0200255 platform_device_unregister(mv64x60_wdt_dev);
256}
257
258module_init(mv64x60_wdt_init);
259module_exit(mv64x60_wdt_exit);
260
261MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
262MODULE_DESCRIPTION("MV64x60 watchdog driver");
263MODULE_LICENSE("GPL");
264MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);