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 <linux/mv643xx.h>
27 #include <asm/uaccess.h>
30 #define MV64x60_WDT_WDC_OFFSET 0
32 /* MV64x60 WDC (config) register access definitions */
33 #define MV64x60_WDC_CTL1_MASK (3 << 24)
34 #define MV64x60_WDC_CTL1(val) ((val & 3) << 24)
35 #define MV64x60_WDC_CTL2_MASK (3 << 26)
36 #define MV64x60_WDC_CTL2(val) ((val & 3) << 26)
39 #define MV64x60_WDOG_FLAG_OPENED 0
40 #define MV64x60_WDOG_FLAG_ENABLED 1
42 static unsigned long wdt_flags;
43 static int wdt_status;
44 static void __iomem *mv64x60_wdt_regs;
45 static int mv64x60_wdt_timeout;
47 static void mv64x60_wdt_reg_write(u32 val)
49 /* Allow write only to CTL1 / CTL2 fields, retaining values in
52 u32 data = readl(mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
53 data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK);
55 writel(data, mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
58 static void mv64x60_wdt_service(void)
60 /* Write 01 followed by 10 to CTL2 */
61 mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01));
62 mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02));
65 static void mv64x60_wdt_handler_disable(void)
67 if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
68 /* Write 01 followed by 10 to CTL1 */
69 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
70 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
71 printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n");
75 static void mv64x60_wdt_handler_enable(void)
77 if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
78 /* Write 01 followed by 10 to CTL1 */
79 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
80 mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
81 printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
85 static int mv64x60_wdt_open(struct inode *inode, struct file *file)
87 if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
90 mv64x60_wdt_service();
91 mv64x60_wdt_handler_enable();
93 return 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;
190 mv64x60_wdt_timeout = 10;
192 mv64x60_wdt_timeout = pdata->timeout;
193 bus_clk = pdata->bus_clk;
196 r = platform_get_resource(dev, IORESOURCE_MEM, 0);
200 mv64x60_wdt_regs = ioremap(r->start, r->end - r->start + 1);
201 if (mv64x60_wdt_regs == NULL)
204 writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
205 mv64x60_wdt_regs + MV64x60_WDT_WDC_OFFSET);
207 return misc_register(&mv64x60_wdt_miscdev);
210 static int __devexit mv64x60_wdt_remove(struct platform_device *dev)
212 misc_deregister(&mv64x60_wdt_miscdev);
214 mv64x60_wdt_service();
215 mv64x60_wdt_handler_disable();
217 iounmap(mv64x60_wdt_regs);
222 static struct platform_driver mv64x60_wdt_driver = {
223 .probe = mv64x60_wdt_probe,
224 .remove = __devexit_p(mv64x60_wdt_remove),
226 .owner = THIS_MODULE,
227 .name = MV64x60_WDT_NAME,
231 static int __init mv64x60_wdt_init(void)
233 printk(KERN_INFO "MV64x60 watchdog driver\n");
235 return platform_driver_register(&mv64x60_wdt_driver);
238 static void __exit mv64x60_wdt_exit(void)
240 platform_driver_unregister(&mv64x60_wdt_driver);
243 module_init(mv64x60_wdt_init);
244 module_exit(mv64x60_wdt_exit);
246 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
247 MODULE_DESCRIPTION("MV64x60 watchdog driver");
248 MODULE_LICENSE("GPL");
249 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);