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
18 #include <linux/config.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>
25 #include <linux/platform_device.h>
27 #include <asm/mv64x60.h>
28 #include <asm/uaccess.h>
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)
38 #define MV64x60_WDOG_FLAG_OPENED 0
39 #define MV64x60_WDOG_FLAG_ENABLED 1
41 static unsigned long wdt_flags
;
42 static int wdt_status
;
43 static void __iomem
*mv64x60_regs
;
44 static int mv64x60_wdt_timeout
;
46 static void mv64x60_wdt_reg_write(u32 val
)
48 /* Allow write only to CTL1 / CTL2 fields, retaining values in
51 u32 data
= readl(mv64x60_regs
+ MV64x60_WDT_WDC
);
52 data
&= ~(MV64x60_WDC_CTL1_MASK
| MV64x60_WDC_CTL2_MASK
);
54 writel(data
, mv64x60_regs
+ MV64x60_WDT_WDC
);
57 static void mv64x60_wdt_service(void)
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));
64 static void mv64x60_wdt_handler_disable(void)
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");
74 static void mv64x60_wdt_handler_enable(void)
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");
84 static int mv64x60_wdt_open(struct inode
*inode
, struct file
*file
)
86 if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED
, &wdt_flags
))
89 mv64x60_wdt_service();
90 mv64x60_wdt_handler_enable();
92 nonseekable_open(inode
, file
);
97 static int mv64x60_wdt_release(struct inode
*inode
, struct file
*file
)
99 mv64x60_wdt_service();
101 #if !defined(CONFIG_WATCHDOG_NOWAYOUT)
102 mv64x60_wdt_handler_disable();
105 clear_bit(MV64x60_WDOG_FLAG_OPENED
, &wdt_flags
);
110 static ssize_t
mv64x60_wdt_write(struct file
*file
, const char __user
*data
,
111 size_t len
, loff_t
* ppos
)
114 mv64x60_wdt_service();
119 static int mv64x60_wdt_ioctl(struct inode
*inode
, struct file
*file
,
120 unsigned int cmd
, unsigned long arg
)
123 void __user
*argp
= (void __user
*)arg
;
124 static struct watchdog_info info
= {
125 .options
= WDIOF_KEEPALIVEPING
,
126 .firmware_version
= 0,
127 .identity
= "MV64x60 watchdog",
131 case WDIOC_GETSUPPORT
:
132 if (copy_to_user(argp
, &info
, sizeof(info
)))
136 case WDIOC_GETSTATUS
:
137 case WDIOC_GETBOOTSTATUS
:
138 if (put_user(wdt_status
, (int __user
*)argp
))
140 wdt_status
&= ~WDIOF_KEEPALIVEPING
;
146 case WDIOC_SETOPTIONS
:
149 case WDIOC_KEEPALIVE
:
150 mv64x60_wdt_service();
151 wdt_status
|= WDIOF_KEEPALIVEPING
;
154 case WDIOC_SETTIMEOUT
:
157 case WDIOC_GETTIMEOUT
:
158 timeout
= mv64x60_wdt_timeout
* HZ
;
159 if (put_user(timeout
, (int __user
*)argp
))
170 static struct file_operations mv64x60_wdt_fops
= {
171 .owner
= THIS_MODULE
,
173 .write
= mv64x60_wdt_write
,
174 .ioctl
= mv64x60_wdt_ioctl
,
175 .open
= mv64x60_wdt_open
,
176 .release
= mv64x60_wdt_release
,
179 static struct miscdevice mv64x60_wdt_miscdev
= {
180 .minor
= WATCHDOG_MINOR
,
182 .fops
= &mv64x60_wdt_fops
,
185 static int __devinit
mv64x60_wdt_probe(struct device
*dev
)
187 struct platform_device
*pd
= to_platform_device(dev
);
188 struct mv64x60_wdt_pdata
*pdata
= pd
->dev
.platform_data
;
191 mv64x60_wdt_timeout
= 10;
193 mv64x60_wdt_timeout
= pdata
->timeout
;
194 bus_clk
= pdata
->bus_clk
;
197 mv64x60_regs
= mv64x60_get_bridge_vbase();
199 writel((mv64x60_wdt_timeout
* (bus_clk
* 1000000)) >> 8,
200 mv64x60_regs
+ MV64x60_WDT_WDC
);
202 return misc_register(&mv64x60_wdt_miscdev
);
205 static int __devexit
mv64x60_wdt_remove(struct device
*dev
)
207 misc_deregister(&mv64x60_wdt_miscdev
);
209 mv64x60_wdt_service();
210 mv64x60_wdt_handler_disable();
215 static struct device_driver mv64x60_wdt_driver
= {
216 .name
= MV64x60_WDT_NAME
,
217 .bus
= &platform_bus_type
,
218 .probe
= mv64x60_wdt_probe
,
219 .remove
= __devexit_p(mv64x60_wdt_remove
),
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_register_simple(MV64x60_WDT_NAME
,
232 if (IS_ERR(mv64x60_wdt_dev
)) {
233 ret
= PTR_ERR(mv64x60_wdt_dev
);
237 ret
= driver_register(&mv64x60_wdt_driver
);
242 static void __exit
mv64x60_wdt_exit(void)
244 driver_unregister(&mv64x60_wdt_driver
);
245 platform_device_unregister(mv64x60_wdt_dev
);
248 module_init(mv64x60_wdt_init
);
249 module_exit(mv64x60_wdt_exit
);
251 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
252 MODULE_DESCRIPTION("MV64x60 watchdog driver");
253 MODULE_LICENSE("GPL");
254 MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR
);