2 * mv64x60_wdt.c - MV64X60 (Marvell Discovery) watchdog userspace interface
4 * Author: James Chapman <jchapman@katalix.com>
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.
10 * Derived from mpc8xx_wdt.c, with the following copyright.
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
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>
24 #include <linux/platform_device.h>
26 #include <asm/mv64x60.h>
27 #include <asm/uaccess.h>
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)
37 #define MV64x60_WDOG_FLAG_OPENED 0
38 #define MV64x60_WDOG_FLAG_ENABLED 1
40 static unsigned long wdt_flags;
41 static int wdt_status;
42 static void __iomem *mv64x60_regs;
43 static int mv64x60_wdt_timeout;
45 static void mv64x60_wdt_reg_write(u32 val)
47 /* Allow write only to CTL1 / CTL2 fields, retaining values in
50 u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC);
51 data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK);
53 writel(data, mv64x60_regs + MV64x60_WDT_WDC);
56 static void mv64x60_wdt_service(void)
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));
63 static void mv64x60_wdt_handler_disable(void)
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");
73 static void mv64x60_wdt_handler_enable(void)
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");
83 static int mv64x60_wdt_open(struct inode *inode, struct file *file)
85 if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
88 mv64x60_wdt_service();
89 mv64x60_wdt_handler_enable();
91 nonseekable_open(inode, file);
96 static int mv64x60_wdt_release(struct inode *inode, struct file *file)
98 mv64x60_wdt_service();
100 #if !defined(CONFIG_WATCHDOG_NOWAYOUT)
101 mv64x60_wdt_handler_disable();
104 clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);
109 static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data,
110 size_t len, loff_t * ppos)
113 mv64x60_wdt_service();
118 static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file,
119 unsigned int cmd, unsigned long arg)
122 void __user *argp = (void __user *)arg;
123 static struct watchdog_info info = {
124 .options = WDIOF_KEEPALIVEPING,
125 .firmware_version = 0,
126 .identity = "MV64x60 watchdog",
130 case WDIOC_GETSUPPORT:
131 if (copy_to_user(argp, &info, sizeof(info)))
135 case WDIOC_GETSTATUS:
136 case WDIOC_GETBOOTSTATUS:
137 if (put_user(wdt_status, (int __user *)argp))
139 wdt_status &= ~WDIOF_KEEPALIVEPING;
145 case WDIOC_SETOPTIONS:
148 case WDIOC_KEEPALIVE:
149 mv64x60_wdt_service();
150 wdt_status |= WDIOF_KEEPALIVEPING;
153 case WDIOC_SETTIMEOUT:
156 case WDIOC_GETTIMEOUT:
157 timeout = mv64x60_wdt_timeout * HZ;
158 if (put_user(timeout, (int __user *)argp))
169 static const struct file_operations mv64x60_wdt_fops = {
170 .owner = THIS_MODULE,
172 .write = mv64x60_wdt_write,
173 .ioctl = mv64x60_wdt_ioctl,
174 .open = mv64x60_wdt_open,
175 .release = mv64x60_wdt_release,
178 static struct miscdevice mv64x60_wdt_miscdev = {
179 .minor = WATCHDOG_MINOR,
181 .fops = &mv64x60_wdt_fops,
184 static int __devinit mv64x60_wdt_probe(struct platform_device *dev)
186 struct mv64x60_wdt_pdata *pdata = dev->dev.platform_data;
189 mv64x60_wdt_timeout = 10;
191 mv64x60_wdt_timeout = pdata->timeout;
192 bus_clk = pdata->bus_clk;
195 mv64x60_regs = mv64x60_get_bridge_vbase();
197 writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
198 mv64x60_regs + MV64x60_WDT_WDC);
200 return misc_register(&mv64x60_wdt_miscdev);
203 static int __devexit mv64x60_wdt_remove(struct platform_device *dev)
205 misc_deregister(&mv64x60_wdt_miscdev);
207 mv64x60_wdt_service();
208 mv64x60_wdt_handler_disable();
213 static struct platform_driver mv64x60_wdt_driver = {
214 .probe = mv64x60_wdt_probe,
215 .remove = __devexit_p(mv64x60_wdt_remove),
217 .owner = THIS_MODULE,
218 .name = MV64x60_WDT_NAME,
222 static struct platform_device *mv64x60_wdt_dev;
224 static int __init mv64x60_wdt_init(void)
228 printk(KERN_INFO "MV64x60 watchdog driver\n");
230 mv64x60_wdt_dev = platform_device_alloc(MV64x60_WDT_NAME, -1);
231 if (!mv64x60_wdt_dev) {
236 ret = platform_device_add(mv64x60_wdt_dev);
238 platform_device_put(mv64x60_wdt_dev);
242 ret = platform_driver_register(&mv64x60_wdt_driver);
244 platform_device_unregister(mv64x60_wdt_dev);
252 static void __exit mv64x60_wdt_exit(void)
254 platform_driver_unregister(&mv64x60_wdt_driver);
255 platform_device_unregister(mv64x60_wdt_dev);
258 module_init(mv64x60_wdt_init);
259 module_exit(mv64x60_wdt_exit);
261 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
262 MODULE_DESCRIPTION("MV64x60 watchdog driver");
263 MODULE_LICENSE("GPL");
264 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);