blob: f1b9cf89f153ab727d357435437c0f6fc54dea73 [file] [log] [blame]
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
18#include <linux/config.h>
19#include <linux/fs.h>
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/miscdevice.h>
23#include <linux/module.h>
24#include <linux/watchdog.h>
Russell Kingd052d1b2005-10-29 19:07:23 +010025#include <linux/platform_device.h>
26
James Chapman3be10212005-08-17 09:01:33 +020027#include <asm/mv64x60.h>
28#include <asm/uaccess.h>
29#include <asm/io.h>
30
31/* MV64x60 WDC (config) register access definitions */
32#define MV64x60_WDC_CTL1_MASK (3 << 24)
33#define MV64x60_WDC_CTL1(val) ((val & 3) << 24)
34#define MV64x60_WDC_CTL2_MASK (3 << 26)
35#define MV64x60_WDC_CTL2(val) ((val & 3) << 26)
36
37/* Flags bits */
38#define MV64x60_WDOG_FLAG_OPENED 0
39#define MV64x60_WDOG_FLAG_ENABLED 1
40
41static unsigned long wdt_flags;
42static int wdt_status;
43static void __iomem *mv64x60_regs;
44static int mv64x60_wdt_timeout;
45
46static void mv64x60_wdt_reg_write(u32 val)
47{
48 /* Allow write only to CTL1 / CTL2 fields, retaining values in
49 * other fields.
50 */
51 u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC);
52 data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK);
53 data |= val;
54 writel(data, mv64x60_regs + MV64x60_WDT_WDC);
55}
56
57static void mv64x60_wdt_service(void)
58{
59 /* Write 01 followed by 10 to CTL2 */
60 mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01));
61 mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02));
62}
63
64static void mv64x60_wdt_handler_disable(void)
65{
66 if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
67 /* Write 01 followed by 10 to CTL1 */
68 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
69 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
70 printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n");
71 }
72}
73
74static void mv64x60_wdt_handler_enable(void)
75{
76 if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
77 /* Write 01 followed by 10 to CTL1 */
78 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
79 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
80 printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
81 }
82}
83
84static int mv64x60_wdt_open(struct inode *inode, struct file *file)
85{
86 if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
87 return -EBUSY;
88
89 mv64x60_wdt_service();
90 mv64x60_wdt_handler_enable();
91
Al Virob2846df2005-09-29 00:42:27 +010092 nonseekable_open(inode, file);
93
James Chapman3be10212005-08-17 09:01:33 +020094 return 0;
95}
96
97static int mv64x60_wdt_release(struct inode *inode, struct file *file)
98{
99 mv64x60_wdt_service();
100
101#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
102 mv64x60_wdt_handler_disable();
103#endif
104
105 clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);
106
107 return 0;
108}
109
Al Virob2846df2005-09-29 00:42:27 +0100110static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data,
James Chapman3be10212005-08-17 09:01:33 +0200111 size_t len, loff_t * ppos)
112{
James Chapman3be10212005-08-17 09:01:33 +0200113 if (len)
114 mv64x60_wdt_service();
115
116 return len;
117}
118
119static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file,
120 unsigned int cmd, unsigned long arg)
121{
122 int timeout;
Al Virob2846df2005-09-29 00:42:27 +0100123 void __user *argp = (void __user *)arg;
James Chapman3be10212005-08-17 09:01:33 +0200124 static struct watchdog_info info = {
125 .options = WDIOF_KEEPALIVEPING,
126 .firmware_version = 0,
127 .identity = "MV64x60 watchdog",
128 };
129
130 switch (cmd) {
131 case WDIOC_GETSUPPORT:
Al Virob2846df2005-09-29 00:42:27 +0100132 if (copy_to_user(argp, &info, sizeof(info)))
James Chapman3be10212005-08-17 09:01:33 +0200133 return -EFAULT;
134 break;
135
136 case WDIOC_GETSTATUS:
137 case WDIOC_GETBOOTSTATUS:
Al Virob2846df2005-09-29 00:42:27 +0100138 if (put_user(wdt_status, (int __user *)argp))
James Chapman3be10212005-08-17 09:01:33 +0200139 return -EFAULT;
140 wdt_status &= ~WDIOF_KEEPALIVEPING;
141 break;
142
143 case WDIOC_GETTEMP:
144 return -EOPNOTSUPP;
145
146 case WDIOC_SETOPTIONS:
147 return -EOPNOTSUPP;
148
149 case WDIOC_KEEPALIVE:
150 mv64x60_wdt_service();
151 wdt_status |= WDIOF_KEEPALIVEPING;
152 break;
153
154 case WDIOC_SETTIMEOUT:
155 return -EOPNOTSUPP;
156
157 case WDIOC_GETTIMEOUT:
158 timeout = mv64x60_wdt_timeout * HZ;
Al Virob2846df2005-09-29 00:42:27 +0100159 if (put_user(timeout, (int __user *)argp))
James Chapman3be10212005-08-17 09:01:33 +0200160 return -EFAULT;
161 break;
162
163 default:
164 return -ENOIOCTLCMD;
165 }
166
167 return 0;
168}
169
170static struct file_operations mv64x60_wdt_fops = {
171 .owner = THIS_MODULE,
172 .llseek = no_llseek,
173 .write = mv64x60_wdt_write,
174 .ioctl = mv64x60_wdt_ioctl,
175 .open = mv64x60_wdt_open,
176 .release = mv64x60_wdt_release,
177};
178
179static struct miscdevice mv64x60_wdt_miscdev = {
180 .minor = WATCHDOG_MINOR,
181 .name = "watchdog",
182 .fops = &mv64x60_wdt_fops,
183};
184
Russell King3ae5eae2005-11-09 22:32:44 +0000185static int __devinit mv64x60_wdt_probe(struct platform_device *dev)
James Chapman3be10212005-08-17 09:01:33 +0200186{
Russell King3ae5eae2005-11-09 22:32:44 +0000187 struct mv64x60_wdt_pdata *pdata = dev->dev.platform_data;
James Chapman3be10212005-08-17 09:01:33 +0200188 int bus_clk = 133;
189
190 mv64x60_wdt_timeout = 10;
191 if (pdata) {
192 mv64x60_wdt_timeout = pdata->timeout;
193 bus_clk = pdata->bus_clk;
194 }
195
196 mv64x60_regs = mv64x60_get_bridge_vbase();
197
198 writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
199 mv64x60_regs + MV64x60_WDT_WDC);
200
201 return misc_register(&mv64x60_wdt_miscdev);
202}
203
Russell King3ae5eae2005-11-09 22:32:44 +0000204static int __devexit mv64x60_wdt_remove(struct platform_device *dev)
James Chapman3be10212005-08-17 09:01:33 +0200205{
206 misc_deregister(&mv64x60_wdt_miscdev);
207
208 mv64x60_wdt_service();
209 mv64x60_wdt_handler_disable();
210
211 return 0;
212}
213
Russell King3ae5eae2005-11-09 22:32:44 +0000214static struct platform_driver mv64x60_wdt_driver = {
James Chapman3be10212005-08-17 09:01:33 +0200215 .probe = mv64x60_wdt_probe,
216 .remove = __devexit_p(mv64x60_wdt_remove),
Russell King3ae5eae2005-11-09 22:32:44 +0000217 .driver = {
218 .owner = THIS_MODULE,
219 .name = MV64x60_WDT_NAME,
220 },
James Chapman3be10212005-08-17 09:01:33 +0200221};
222
223static struct platform_device *mv64x60_wdt_dev;
224
225static int __init mv64x60_wdt_init(void)
226{
227 int ret;
228
229 printk(KERN_INFO "MV64x60 watchdog driver\n");
230
Dmitry Torokhoveee8ab72006-03-22 00:07:54 -0800231 mv64x60_wdt_dev = platform_device_alloc(MV64x60_WDT_NAME, -1);
232 if (!mv64x60_wdt_dev) {
233 ret = -ENOMEM;
234 goto out;
235 }
236
237 ret = platform_device_add(mv64x60_wdt_dev);
238 if (ret) {
239 platform_device_put(mv64x60_wdt_dev);
James Chapman3be10212005-08-17 09:01:33 +0200240 goto out;
241 }
242
Russell King3ae5eae2005-11-09 22:32:44 +0000243 ret = platform_driver_register(&mv64x60_wdt_driver);
Dmitry Torokhoveee8ab72006-03-22 00:07:54 -0800244 if (ret) {
245 platform_device_unregister(mv64x60_wdt_dev);
246 goto out;
247 }
248
249 out:
James Chapman3be10212005-08-17 09:01:33 +0200250 return ret;
251}
252
253static void __exit mv64x60_wdt_exit(void)
254{
Russell King3ae5eae2005-11-09 22:32:44 +0000255 platform_driver_unregister(&mv64x60_wdt_driver);
James Chapman3be10212005-08-17 09:01:33 +0200256 platform_device_unregister(mv64x60_wdt_dev);
257}
258
259module_init(mv64x60_wdt_init);
260module_exit(mv64x60_wdt_exit);
261
262MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
263MODULE_DESCRIPTION("MV64x60 watchdog driver");
264MODULE_LICENSE("GPL");
265MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);