This commit was manufactured by cvs2svn to create branch 'vserver'.

[linux-2.6.git] / drivers / char / watchdog / booke_wdt.c

diff --git a/drivers/char/watchdog/booke_wdt.c b/drivers/char/watchdog/booke_wdt.c
new file mode 100644 (file)
index 0000000..b664060
--- /dev/null
+++ b/drivers/char/watchdog/booke_wdt.c
@@ -0,0 +1,193 @@
+/*
+ * drivers/char/watchdog/booke_wdt.c
+ *
+ * Watchdog timer for PowerPC Book-E systems
+ *
+ * Author: Matthew McClintock
+ * Maintainer: Kumar Gala <galak@kernel.crashing.org>
+ *
+ * Copyright 2005 Freescale Semiconductor Inc.
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/notifier.h>
+#include <linux/watchdog.h>
+
+#include <asm/reg_booke.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+
+/* If the kernel parameter wdt_enable=1, the watchdog will be enabled at boot.
+ * Also, the wdt_period sets the watchdog timer period timeout.
+ * For E500 cpus the wdt_period sets which bit changing from 0->1 will
+ * trigger a watchog timeout. This watchdog timeout will occur 3 times, the
+ * first time nothing will happen, the second time a watchdog exception will
+ * occur, and the final time the board will reset.
+ */
+
+#ifdef CONFIG_FSL_BOOKE
+#define WDT_PERIOD_DEFAULT 63  /* Ex. wdt_period=28 bus=333Mhz , reset=~40sec */
+#else
+#define WDT_PERIOD_DEFAULT 4   /* Refer to the PPC40x and PPC4xx manuals */
+#endif                         /* for timing information */
+
+u32 booke_wdt_enabled = 0;
+u32 booke_wdt_period = WDT_PERIOD_DEFAULT;
+
+#ifdef CONFIG_FSL_BOOKE
+#define WDTP(x)                ((((63-x)&0x3)<<30)|(((63-x)&0x3c)<<15))
+#else
+#define WDTP(x)                (TCR_WP(x))
+#endif
+
+/*
+ * booke_wdt_enable:
+ */
+static __inline__ void booke_wdt_enable(void)
+{
+       u32 val;
+
+       val = mfspr(SPRN_TCR);
+       val |= (TCR_WIE|TCR_WRC(WRC_CHIP)|WDTP(booke_wdt_period));
+
+       mtspr(SPRN_TCR, val);
+}
+
+/*
+ * booke_wdt_ping:
+ */
+static __inline__ void booke_wdt_ping(void)
+{
+       mtspr(SPRN_TSR, TSR_ENW|TSR_WIS);
+}
+
+/*
+ * booke_wdt_write:
+ */
+static ssize_t booke_wdt_write (struct file *file, const char __user *buf,
+                               size_t count, loff_t *ppos)
+{
+       booke_wdt_ping();
+       return count;
+}
+
+static struct watchdog_info ident = {
+  .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+  .firmware_version = 0,
+  .identity = "PowerPC Book-E Watchdog",
+};
+
+/*
+ * booke_wdt_ioctl:
+ */
+static int booke_wdt_ioctl (struct inode *inode, struct file *file,
+                           unsigned int cmd, unsigned long arg)
+{
+       u32 tmp = 0;
+       u32 __user *p = (u32 __user *)arg;
+
+       switch (cmd) {
+       case WDIOC_GETSUPPORT:
+               if (copy_to_user ((struct watchdog_info __user *) arg, &ident,
+                               sizeof(struct watchdog_info)))
+                       return -EFAULT;
+       case WDIOC_GETSTATUS:
+               return put_user(ident.options, p);
+       case WDIOC_GETBOOTSTATUS:
+               /* XXX: something is clearing TSR */
+               tmp = mfspr(SPRN_TSR) & TSR_WRS(3);
+               /* returns 1 if last reset was caused by the WDT */
+               return (tmp ? 1 : 0);
+       case WDIOC_KEEPALIVE:
+               booke_wdt_ping();
+               return 0;
+       case WDIOC_SETTIMEOUT:
+               if (get_user(booke_wdt_period, p))
+                       return -EFAULT;
+               mtspr(SPRN_TCR, (mfspr(SPRN_TCR)&~WDTP(0))|WDTP(booke_wdt_period));
+               return 0;
+       case WDIOC_GETTIMEOUT:
+               return put_user(booke_wdt_period, p);
+       case WDIOC_SETOPTIONS:
+               if (get_user(tmp, p))
+                       return -EINVAL;
+               if (tmp == WDIOS_ENABLECARD) {
+                       booke_wdt_ping();
+                       break;
+               } else
+                       return -EINVAL;
+               return 0;
+       default:
+               return -ENOIOCTLCMD;
+       }
+
+       return 0;
+}
+/*
+ * booke_wdt_open:
+ */
+static int booke_wdt_open (struct inode *inode, struct file *file)
+{
+       if (booke_wdt_enabled == 0) {
+               booke_wdt_enabled = 1;
+               booke_wdt_enable();
+               printk (KERN_INFO "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
+                               booke_wdt_period);
+       }
+
+       return 0;
+}
+
+static struct file_operations booke_wdt_fops = {
+  .owner = THIS_MODULE,
+  .llseek = no_llseek,
+  .write = booke_wdt_write,
+  .ioctl = booke_wdt_ioctl,
+  .open = booke_wdt_open,
+};
+
+static struct miscdevice booke_wdt_miscdev = {
+  .minor = WATCHDOG_MINOR,
+  .name = "watchdog",
+  .fops = &booke_wdt_fops,
+};
+
+static void __exit booke_wdt_exit(void)
+{
+       misc_deregister(&booke_wdt_miscdev);
+}
+
+/*
+ * booke_wdt_init:
+ */
+static int __init booke_wdt_init(void)
+{
+       int ret = 0;
+
+       printk (KERN_INFO "PowerPC Book-E Watchdog Timer Loaded\n");
+       ident.firmware_version = cur_cpu_spec->pvr_value;
+
+       ret = misc_register(&booke_wdt_miscdev);
+       if (ret) {
+               printk (KERN_CRIT "Cannot register miscdev on minor=%d (err=%d)\n",
+                               WATCHDOG_MINOR, ret);
+               return ret;
+       }
+
+       if (booke_wdt_enabled == 1) {
+               printk (KERN_INFO "PowerPC Book-E Watchdog Timer Enabled (wdt_period=%d)\n",
+                               booke_wdt_period);
+               booke_wdt_enable();
+       }
+
+       return ret;
+}
+device_initcall(booke_wdt_init);