* - Switched to private locks not lock_kernel
* - Used ioremap/writew/readw
* - Added NOWAYOUT support
- *
- * 4/12 - 2002 Changes by Rob Radez <rob@osinvestor.com>
- * - Change comments
- * - Eliminate fop_llseek
- * - Change CONFIG_WATCHDOG_NOWAYOUT semantics
- * - Add KERN_* tags to printks
- * - fix possible wdt_is_open race
- * - Report proper capabilities in watchdog_info
- * - Add WDIOC_{GETSTATUS, GETBOOTSTATUS, SETTIMEOUT,
- * GETTIMEOUT, SETOPTIONS} ioctls
- * 09/8 - 2003 Changes by Wim Van Sebroeck <wim@iguana.be>
- * - cleanup of trailing spaces
- * - added extra printk's for startup problems
- * - use module_param
- * - made timeout (the emulated heartbeat) a module_param
- * - made the keepalive ping an internal subroutine
+ * 4/12 - 2002 Changes by Rob Radez <rob@osinvestor.com>
+ * - Change comments
+ * - Eliminate fop_llseek
+ * - Change CONFIG_WATCHDOG_NOWAYOUT semantics
+ * - Add KERN_* tags to printks
+ * - fix possible wdt_is_open race
+ * - Report proper capabilities in watchdog_info
+ * - Add WDIOC_{GETSTATUS, GETBOOTSTATUS, SETTIMEOUT,
+ * GETTIMEOUT, SETOPTIONS} ioctls
+ * 09/8 - 2003 Changes by Wim Van Sebroeck <wim@iguana.be>
+ * - cleanup of trailing spaces
+ * - added extra printk's for startup problems
+ * - use module_param
+ * - made timeout (the emulated heartbeat) a module_param
+ * - made the keepalive ping an internal subroutine
+ * 3/27 - 2004 Changes by Sean Young <sean@mess.org>
+ * - set MMCR_BASE to 0xfffef000
+ * - CBAR does not need to be read
+ * - removed debugging printks
*
* This WDT driver is different from most other Linux WDT
* drivers in that the driver will ping the watchdog by itself,
#include <asm/uaccess.h>
#include <asm/system.h>
+#define OUR_NAME "sc520_wdt"
+#define PFX OUR_NAME ": "
+
/*
- * The SC520 can timeout anywhere from 492us to 32.21s.
+ * The AMD Elan SC520 timeout value is 492us times a power of 2 (0-7)
+ *
+ * 0: 492us 2: 1.01s 4: 4.03s 6: 16.22s
+ * 1: 503ms 3: 2.01s 5: 8.05s 7: 32.21s
+ *
+ * We will program the SC520 watchdog for a timeout of 2.01s.
* If we reset the watchdog every ~250ms we should be safe.
*/
module_param(timeout, int, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
-/*
- * AMD Elan SC520 timeout value is 492us times a power of 2 (0-7)
- *
- * 0: 492us 2: 1.01s 4: 4.03s 6: 16.22s
- * 1: 503ms 3: 2.01s 5: 8.05s 7: 32.21s
- */
-
-#define TIMEOUT_EXPONENT ( 1 << 3 ) /* 0x08 = 2.01s */
-
-/* #define MMCR_BASE_DEFAULT 0xfffef000 */
-#define MMCR_BASE_DEFAULT ((__u16 *)0xffffe)
-#define OFFS_WDTMRCTL ((unsigned int)0xcb0)
-#define WDT_ENB 0x8000 /* [15] Watchdog Timer Enable */
-#define WDT_WRST_ENB 0x4000 /* [14] Watchdog Timer Reset Enable */
+#ifdef CONFIG_WATCHDOG_NOWAYOUT
+static int nowayout = 1;
+#else
+static int nowayout = 0;
+#endif
-#define OUR_NAME "sc520_wdt"
-#define PFX OUR_NAME ": "
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
-#define WRT_DOG(data) *wdtmrctl=data
+/*
+ * AMD Elan SC520 - Watchdog Timer Registers
+ */
+#define MMCR_BASE 0xfffef000 /* The default base address */
+#define OFFS_WDTMRCTL 0xCB0 /* Watchdog Timer Control Register */
+
+/* WDT Control Register bit definitions */
+#define WDT_EXP_SEL_01 0x0001 /* [01] Time-out = 496 us (with 33 Mhz clk). */
+#define WDT_EXP_SEL_02 0x0002 /* [02] Time-out = 508 ms (with 33 Mhz clk). */
+#define WDT_EXP_SEL_03 0x0004 /* [03] Time-out = 1.02 s (with 33 Mhz clk). */
+#define WDT_EXP_SEL_04 0x0008 /* [04] Time-out = 2.03 s (with 33 Mhz clk). */
+#define WDT_EXP_SEL_05 0x0010 /* [05] Time-out = 4.07 s (with 33 Mhz clk). */
+#define WDT_EXP_SEL_06 0x0020 /* [06] Time-out = 8.13 s (with 33 Mhz clk). */
+#define WDT_EXP_SEL_07 0x0040 /* [07] Time-out = 16.27s (with 33 Mhz clk). */
+#define WDT_EXP_SEL_08 0x0080 /* [08] Time-out = 32.54s (with 33 Mhz clk). */
+#define WDT_IRQ_FLG 0x1000 /* [12] Interrupt Request Flag */
+#define WDT_WRST_ENB 0x4000 /* [14] Watchdog Timer Reset Enable */
+#define WDT_ENB 0x8000 /* [15] Watchdog Timer Enable */
static __u16 *wdtmrctl;
static char wdt_expect_close;
static spinlock_t wdt_spinlock;
-#ifdef CONFIG_WATCHDOG_NOWAYOUT
-static int nowayout = 1;
-#else
-static int nowayout = 0;
-#endif
-
-module_param(nowayout, int, 0);
-MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)");
-
/*
* Whack the dog
*/
}
/*
- * Utility routines
+ * Utility routines
*/
static void wdt_config(int writeval)
/* buy some time (ping) */
spin_lock_irqsave(&wdt_spinlock, flags);
- dummy=readw(wdtmrctl); /* ensure write synchronization */
+ dummy=readw(wdtmrctl); /* ensure write synchronization */
writew(0xAAAA, wdtmrctl);
writew(0x5555, wdtmrctl);
- /* make WDT configuration register writable one time */
+ /* unlock WDT = make WDT configuration register writable one time */
writew(0x3333, wdtmrctl);
writew(0xCCCC, wdtmrctl);
/* write WDT configuration register */
spin_unlock_irqrestore(&wdt_spinlock, flags);
}
-static void wdt_startup(void)
+static int wdt_startup(void)
{
next_heartbeat = jiffies + (timeout * HZ);
timer.expires = jiffies + WDT_INTERVAL;
add_timer(&timer);
- wdt_config(WDT_ENB | WDT_WRST_ENB | TIMEOUT_EXPONENT);
+ /* Start the watchdog */
+ wdt_config(WDT_ENB | WDT_WRST_ENB | WDT_EXP_SEL_04);
+
printk(KERN_INFO PFX "Watchdog timer is now enabled.\n");
+ return 0;
}
-static void wdt_turnoff(void)
+static int wdt_turnoff(void)
{
- if (!nowayout) {
- /* Stop the timer */
- del_timer(&timer);
- wdt_config(0);
- printk(KERN_INFO PFX "Watchdog timer is now disabled...\n");
- }
+ /* Stop the timer */
+ del_timer(&timer);
+
+ /* Stop the watchdog */
+ wdt_config(0);
+
+ printk(KERN_INFO PFX "Watchdog timer is now disabled...\n");
+ return 0;
}
-static void wdt_keepalive(void)
+static int wdt_keepalive(void)
{
/* user land ping */
next_heartbeat = jiffies + (timeout * HZ);
+ return 0;
+}
+
+static int wdt_set_heartbeat(int t)
+{
+ if ((t < 1) || (t > 3600)) /* arbitrary upper limit */
+ return -EINVAL;
+
+ timeout = t;
+ return 0;
}
/*
- * /dev/watchdog handling
+ * /dev/watchdog handling
*/
static ssize_t fop_write(struct file * file, const char * buf, size_t count, loff_t * ppos)
return -ESPIPE;
/* See if we got the magic character 'V' and reload the timer */
- if(count)
- {
- if (!nowayout)
- {
+ if(count) {
+ if (!nowayout) {
size_t ofs;
/* note: just in case someone wrote the magic character
static int fop_close(struct inode * inode, struct file * file)
{
- if(wdt_expect_close == 42)
+ if(wdt_expect_close == 42) {
wdt_turnoff();
- else {
- del_timer(&timer);
- printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n");
+ } else {
+ printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n");
+ wdt_keepalive();
}
clear_bit(0, &wdt_is_open);
wdt_expect_close = 0;
static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
- static struct watchdog_info ident=
- {
+ static struct watchdog_info ident = {
.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
.firmware_version = 1,
.identity = "SC520",
if(get_user(new_timeout, (int *)arg))
return -EFAULT;
- if(new_timeout < 1 || new_timeout > 3600) /* arbitrary upper limit */
+ if(wdt_set_heartbeat(new_timeout))
return -EINVAL;
- timeout = new_timeout;
wdt_keepalive();
/* Fall through */
}
* turn the timebomb registers off.
*/
-static struct notifier_block wdt_notifier=
-{
+static struct notifier_block wdt_notifier = {
.notifier_call = wdt_notify_sys,
};
static void __exit sc520_wdt_unload(void)
{
- wdt_turnoff();
+ if (!nowayout)
+ wdt_turnoff();
/* Deregister */
misc_deregister(&wdt_miscdev);
- iounmap(wdtmrctl);
unregister_reboot_notifier(&wdt_notifier);
+ iounmap(wdtmrctl);
}
static int __init sc520_wdt_init(void)
{
int rc = -EBUSY;
- unsigned long cbar;
spin_lock_init(&wdt_spinlock);
- if(timeout < 1 || timeout > 3600) /* arbitrary upper limit */
- {
- timeout = WATCHDOG_TIMEOUT;
- printk(KERN_INFO PFX "timeout value must be 1<=x<=3600, using %d\n",
- timeout);
- }
-
init_timer(&timer);
timer.function = wdt_timer_ping;
timer.data = 0;
- rc = misc_register(&wdt_miscdev);
- if (rc)
- {
- printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
- wdt_miscdev.minor, rc);
+ /* Check that the timeout value is within it's range ; if not reset to the default */
+ if (wdt_set_heartbeat(timeout)) {
+ wdt_set_heartbeat(WATCHDOG_TIMEOUT);
+ printk(KERN_INFO PFX "timeout value must be 1<=timeout<=3600, using %d\n",
+ WATCHDOG_TIMEOUT);
+ }
+
+ wdtmrctl = ioremap((unsigned long)(MMCR_BASE + OFFS_WDTMRCTL), 2);
+ if (!wdtmrctl) {
+ printk(KERN_ERR PFX "Unable to remap memory\n");
+ rc = -ENOMEM;
goto err_out_region2;
}
rc = register_reboot_notifier(&wdt_notifier);
- if (rc)
- {
+ if (rc) {
printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n",
rc);
- goto err_out_miscdev;
+ goto err_out_ioremap;
}
- /* get the Base Address Register */
- cbar = inl_p(0xfffc);
- printk(KERN_INFO PFX "CBAR: 0x%08lx\n", cbar);
- /* check if MMCR aliasing bit is set */
- if (cbar & 0x80000000) {
- printk(KERN_INFO PFX "MMCR Aliasing enabled.\n");
- wdtmrctl = (__u16 *)(cbar & 0x3fffffff);
- } else {
- printk(KERN_INFO PFX "!!! WARNING !!!\n"
- "\t MMCR Aliasing found NOT enabled!\n"
- "\t Using default value of: %p\n"
- "\t This has not been tested!\n"
- "\t Please email Scott Jennings <smj@oro.net>\n"
- "\t and Bill Jennings <bj@oro.net> if it works!\n"
- , MMCR_BASE_DEFAULT
- );
- wdtmrctl = MMCR_BASE_DEFAULT;
- }
-
- wdtmrctl = (__u16 *)((char *)wdtmrctl + OFFS_WDTMRCTL);
- wdtmrctl = ioremap((unsigned long)wdtmrctl, 2);
- if (!wdtmrctl) {
- printk (KERN_ERR PFX "Unable to remap memory.\n");
- rc = -ENOMEM;
+ rc = misc_register(&wdt_miscdev);
+ if (rc) {
+ printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n",
+ WATCHDOG_MINOR, rc);
goto err_out_notifier;
}
+
printk(KERN_INFO PFX "WDT driver for SC520 initialised. timeout=%d sec (nowayout=%d)\n",
timeout,nowayout);
err_out_notifier:
unregister_reboot_notifier(&wdt_notifier);
-err_out_miscdev:
- misc_deregister(&wdt_miscdev);
+err_out_ioremap:
+ iounmap(wdtmrctl);
err_out_region2:
return rc;
}
git://git.onelab.eu / linux-2.6.git / blobdiff