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authorAlessandro Zummo <a.zummo@towertech.it>2006-03-25 06:06:37 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-25 11:22:49 -0500
commitf52ac8fec8a13e207f675b0c16e0d5f800c1c204 (patch)
tree9e9150a6c89aa2460c8f714809494d36a5f72283 /drivers/char/watchdog
parent214fda1f6e1b8ef2a5292b0372744037fc80d318 (diff)
[PATCH] cirrus ep93xx watchdog driver
Add a driver for the on-chip watchdog on the cirrus ep93xx series of ARM CPUs. Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/char/watchdog')
-rw-r--r--drivers/char/watchdog/Kconfig10
-rw-r--r--drivers/char/watchdog/Makefile1
-rw-r--r--drivers/char/watchdog/ep93xx_wdt.c257
3 files changed, 268 insertions, 0 deletions
diff --git a/drivers/char/watchdog/Kconfig b/drivers/char/watchdog/Kconfig
index c0dfcf273f0a..16e99db2e12d 100644
--- a/drivers/char/watchdog/Kconfig
+++ b/drivers/char/watchdog/Kconfig
@@ -148,6 +148,16 @@ config MPCORE_WATCHDOG
148 To compile this driver as a module, choose M here: the 148 To compile this driver as a module, choose M here: the
149 module will be called mpcore_wdt. 149 module will be called mpcore_wdt.
150 150
151config EP93XX_WATCHDOG
152 tristate "EP93xx Watchdog"
153 depends on WATCHDOG && ARCH_EP93XX
154 help
155 Say Y here if to include support for the watchdog timer
156 embedded in the Cirrus Logic EP93xx family of devices.
157
158 To compile this driver as a module, choose M here: the
159 module will be called ep93xx_wdt.
160
151# X86 (i386 + ia64 + x86_64) Architecture 161# X86 (i386 + ia64 + x86_64) Architecture
152 162
153config ACQUIRE_WDT 163config ACQUIRE_WDT
diff --git a/drivers/char/watchdog/Makefile b/drivers/char/watchdog/Makefile
index 36c0b282b8ba..d6f27fde9905 100644
--- a/drivers/char/watchdog/Makefile
+++ b/drivers/char/watchdog/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_IXP4XX_WATCHDOG) += ixp4xx_wdt.o
30obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o 30obj-$(CONFIG_S3C2410_WATCHDOG) += s3c2410_wdt.o
31obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o 31obj-$(CONFIG_SA1100_WATCHDOG) += sa1100_wdt.o
32obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o 32obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o
33obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o
33 34
34# X86 (i386 + ia64 + x86_64) Architecture 35# X86 (i386 + ia64 + x86_64) Architecture
35obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o 36obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
diff --git a/drivers/char/watchdog/ep93xx_wdt.c b/drivers/char/watchdog/ep93xx_wdt.c
new file mode 100644
index 000000000000..9021dbb78299
--- /dev/null
+++ b/drivers/char/watchdog/ep93xx_wdt.c
@@ -0,0 +1,257 @@
1/*
2 * Watchdog driver for Cirrus Logic EP93xx family of devices.
3 *
4 * Copyright (c) 2004 Ray Lehtiniemi
5 * Copyright (c) 2006 Tower Technologies
6 * Based on ep93xx driver, bits from alim7101_wdt.c
7 *
8 * Authors: Ray Lehtiniemi <rayl@mail.com>,
9 * Alessandro Zummo <a.zummo@towertech.it>
10 *
11 * This file is licensed under the terms of the GNU General Public
12 * License version 2. This program is licensed "as is" without any
13 * warranty of any kind, whether express or implied.
14 *
15 * This watchdog fires after 250msec, which is a too short interval
16 * for us to rely on the user space daemon alone. So we ping the
17 * wdt each ~200msec and eventually stop doing it if the user space
18 * daemon dies.
19 *
20 * TODO:
21 *
22 * - Test last reset from watchdog status
23 * - Add a few missing ioctls
24 */
25
26#include <linux/module.h>
27#include <linux/fs.h>
28#include <linux/miscdevice.h>
29#include <linux/watchdog.h>
30#include <linux/timer.h>
31
32#include <asm/hardware.h>
33#include <asm/uaccess.h>
34
35#define WDT_VERSION "0.3"
36#define PFX "ep93xx_wdt: "
37
38/* default timeout (secs) */
39#define WDT_TIMEOUT 30
40
41static int nowayout = WATCHDOG_NOWAYOUT;
42static int timeout = WDT_TIMEOUT;
43
44static struct timer_list timer;
45static unsigned long next_heartbeat;
46static unsigned long wdt_status;
47static unsigned long boot_status;
48
49#define WDT_IN_USE 0
50#define WDT_OK_TO_CLOSE 1
51
52#define EP93XX_WDT_REG(x) (EP93XX_WATCHDOG_BASE + (x))
53#define EP93XX_WDT_WATCHDOG EP93XX_WDT_REG(0x00)
54#define EP93XX_WDT_WDSTATUS EP93XX_WDT_REG(0x04)
55
56/* reset the wdt every ~200ms */
57#define WDT_INTERVAL (HZ/5)
58
59static void wdt_enable(void)
60{
61 __raw_writew(0xaaaa, EP93XX_WDT_WATCHDOG);
62}
63
64static void wdt_disable(void)
65{
66 __raw_writew(0xaa55, EP93XX_WDT_WATCHDOG);
67}
68
69static inline void wdt_ping(void)
70{
71 __raw_writew(0x5555, EP93XX_WDT_WATCHDOG);
72}
73
74static void wdt_startup(void)
75{
76 next_heartbeat = jiffies + (timeout * HZ);
77
78 wdt_enable();
79 mod_timer(&timer, jiffies + WDT_INTERVAL);
80}
81
82static void wdt_shutdown(void)
83{
84 del_timer_sync(&timer);
85 wdt_disable();
86}
87
88static void wdt_keepalive(void)
89{
90 /* user land ping */
91 next_heartbeat = jiffies + (timeout * HZ);
92}
93
94static int ep93xx_wdt_open(struct inode *inode, struct file *file)
95{
96 if (test_and_set_bit(WDT_IN_USE, &wdt_status))
97 return -EBUSY;
98
99 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
100
101 wdt_startup();
102
103 return nonseekable_open(inode, file);
104}
105
106static ssize_t
107ep93xx_wdt_write(struct file *file, const char __user *data, size_t len,
108 loff_t *ppos)
109{
110 /* Can't seek (pwrite) on this device */
111 if (*ppos != file->f_pos)
112 return -ESPIPE;
113
114 if (len) {
115 if (!nowayout) {
116 size_t i;
117
118 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
119
120 for (i = 0; i != len; i++) {
121 char c;
122
123 if (get_user(c, data + i))
124 return -EFAULT;
125
126 if (c == 'V')
127 set_bit(WDT_OK_TO_CLOSE, &wdt_status);
128 else
129 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
130 }
131 }
132 wdt_keepalive();
133 }
134
135 return len;
136}
137
138static struct watchdog_info ident = {
139 .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE,
140 .identity = "EP93xx Watchdog",
141};
142
143static int
144ep93xx_wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
145 unsigned long arg)
146{
147 int ret = -ENOIOCTLCMD;
148
149 switch (cmd) {
150 case WDIOC_GETSUPPORT:
151 ret = copy_to_user((struct watchdog_info __user *)arg, &ident,
152 sizeof(ident)) ? -EFAULT : 0;
153 break;
154
155 case WDIOC_GETSTATUS:
156 ret = put_user(0, (int __user *)arg);
157 break;
158
159 case WDIOC_GETBOOTSTATUS:
160 ret = put_user(boot_status, (int __user *)arg);
161 break;
162
163 case WDIOC_GETTIMEOUT:
164 /* actually, it is 0.250 seconds.... */
165 ret = put_user(1, (int __user *)arg);
166 break;
167
168 case WDIOC_KEEPALIVE:
169 wdt_keepalive();
170 ret = 0;
171 break;
172 }
173 return ret;
174}
175
176static int ep93xx_wdt_release(struct inode *inode, struct file *file)
177{
178 if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
179 wdt_shutdown();
180 else
181 printk(KERN_CRIT PFX "Device closed unexpectedly - "
182 "timer will not stop\n");
183
184 clear_bit(WDT_IN_USE, &wdt_status);
185 clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
186
187 return 0;
188}
189
190static struct file_operations ep93xx_wdt_fops = {
191 .owner = THIS_MODULE,
192 .write = ep93xx_wdt_write,
193 .ioctl = ep93xx_wdt_ioctl,
194 .open = ep93xx_wdt_open,
195 .release = ep93xx_wdt_release,
196};
197
198static struct miscdevice ep93xx_wdt_miscdev = {
199 .minor = WATCHDOG_MINOR,
200 .name = "watchdog",
201 .fops = &ep93xx_wdt_fops,
202};
203
204static void ep93xx_timer_ping(unsigned long data)
205{
206 if (time_before(jiffies, next_heartbeat))
207 wdt_ping();
208
209 /* Re-set the timer interval */
210 mod_timer(&timer, jiffies + WDT_INTERVAL);
211}
212
213static int __init ep93xx_wdt_init(void)
214{
215 int err;
216
217 err = misc_register(&ep93xx_wdt_miscdev);
218
219 boot_status = __raw_readl(EP93XX_WDT_WATCHDOG) & 0x01 ? 1 : 0;
220
221 printk(KERN_INFO PFX "EP93XX watchdog, driver version "
222 WDT_VERSION "%s\n",
223 (__raw_readl(EP93XX_WDT_WATCHDOG) & 0x08)
224 ? " (nCS1 disable detected)" : "");
225
226 if (timeout < 1 || timeout > 3600) {
227 timeout = WDT_TIMEOUT;
228 printk(KERN_INFO PFX
229 "timeout value must be 1<=x<=3600, using %d\n",
230 timeout);
231 }
232
233 setup_timer(&timer, ep93xx_timer_ping, 1);
234 return err;
235}
236
237static void __exit ep93xx_wdt_exit(void)
238{
239 wdt_shutdown();
240 misc_deregister(&ep93xx_wdt_miscdev);
241}
242
243module_init(ep93xx_wdt_init);
244module_exit(ep93xx_wdt_exit);
245
246module_param(nowayout, int, 0);
247MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started");
248
249module_param(timeout, int, 0);
250MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
251
252MODULE_AUTHOR("Ray Lehtiniemi <rayl@mail.com>,"
253 "Alessandro Zummo <a.zummo@towertech.it>");
254MODULE_DESCRIPTION("EP93xx Watchdog");
255MODULE_LICENSE("GPL");
256MODULE_VERSION(WDT_VERSION);
257MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);