]> err.no Git - linux-2.6/commitdiff
[PATCH] powerpc: Add support for the MPC83xx watchdog
authorKumar Gala <galak@gate.crashing.org>
Sat, 14 Jan 2006 21:20:50 +0000 (13:20 -0800)
committerLinus Torvalds <torvalds@g5.osdl.org>
Sun, 15 Jan 2006 02:27:07 +0000 (18:27 -0800)
Add support for the PowerPC MPC83xx watchdog.  The MPC83xx has a simple
watchdog that once enabled it can not be stopped, has some simple timeout
range selection, and the ability to either reset the processor or take a
machine check.

Signed-off-by: Dave Updegraff <dave@cray.org>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
drivers/char/watchdog/Kconfig
drivers/char/watchdog/Makefile
drivers/char/watchdog/mpc83xx_wdt.c [new file with mode: 0644]

index f68aaa60fa8ff9db80891ec5a9c77cebe0727bd9..c0dfcf273f0a5bd84e3be9dcd4f4a22835dcd198 100644 (file)
@@ -423,6 +423,10 @@ config 8xx_WDT
        tristate "MPC8xx Watchdog Timer"
        depends on WATCHDOG && 8xx
 
+config 83xx_WDT
+       tristate "MPC83xx Watchdog Timer"
+       depends on WATCHDOG && PPC_83xx
+
 config MV64X60_WDT
        tristate "MV64X60 (Marvell Discovery) Watchdog Timer"
        depends on WATCHDOG && MV64X60
index 4fa2ca8e943cce4efac3a83639308d2d581e059a..36c0b282b8ba30d3119325acd5fb844a65d1aa7f 100644 (file)
@@ -56,6 +56,7 @@ obj-$(CONFIG_SBC_EPX_C3_WATCHDOG) += sbc_epx_c3.o
 
 # PowerPC Architecture
 obj-$(CONFIG_8xx_WDT) += mpc8xx_wdt.o
+obj-$(CONFIG_83xx_WDT) += mpc83xx_wdt.o
 obj-$(CONFIG_MV64X60_WDT) += mv64x60_wdt.o
 obj-$(CONFIG_BOOKE_WDT) += booke_wdt.o
 
diff --git a/drivers/char/watchdog/mpc83xx_wdt.c b/drivers/char/watchdog/mpc83xx_wdt.c
new file mode 100644 (file)
index 0000000..5d6f506
--- /dev/null
@@ -0,0 +1,229 @@
+/*
+ * mpc83xx_wdt.c - MPC83xx watchdog userspace interface
+ *
+ * Authors: Dave Updegraff <dave@cray.org>
+ *         Kumar Gala <galak@kernel.crashing.org>
+ *             Attribution: from 83xx_wst: Florian Schirmer <jolt@tuxbox.org>
+ *                             ..and from sc520_wdt
+ *
+ * Note: it appears that you can only actually ENABLE or DISABLE the thing
+ * once after POR. Once enabled, you cannot disable, and vice versa.
+ *
+ * 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/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+struct mpc83xx_wdt {
+       __be32 res0;
+       __be32 swcrr; /* System watchdog control register */
+#define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */
+#define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */
+#define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/
+#define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */
+       __be32 swcnr; /* System watchdog count register */
+       u8 res1[2];
+       __be16 swsrr; /* System watchdog service register */
+       u8 res2[0xF0];
+};
+
+static struct mpc83xx_wdt __iomem *wd_base;
+
+static u16 timeout = 0xffff;
+module_param(timeout, ushort, 0);
+MODULE_PARM_DESC(timeout, "Watchdog timeout in ticks. (0<timeout<65536, default=65535");
+
+static int reset = 1;
+module_param(reset, bool, 0);
+MODULE_PARM_DESC(reset, "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset");
+
+/*
+ * We always prescale, but if someone really doesn't want to they can set this
+ * to 0
+ */
+static int prescale = 1;
+static unsigned int timeout_sec;
+
+static unsigned long wdt_is_open;
+static spinlock_t wdt_spinlock;
+
+static void mpc83xx_wdt_keepalive(void)
+{
+       /* Ping the WDT */
+       spin_lock(&wdt_spinlock);
+       out_be16(&wd_base->swsrr, 0x556c);
+       out_be16(&wd_base->swsrr, 0xaa39);
+       spin_unlock(&wdt_spinlock);
+}
+
+static ssize_t mpc83xx_wdt_write(struct file *file, const char __user *buf,
+                                size_t count, loff_t *ppos)
+{
+       if (count)
+               mpc83xx_wdt_keepalive();
+       return count;
+}
+
+static int mpc83xx_wdt_open(struct inode *inode, struct file *file)
+{
+       u32 tmp = SWCRR_SWEN;
+       if (test_and_set_bit(0, &wdt_is_open))
+               return -EBUSY;
+
+       /* Once we start the watchdog we can't stop it */
+       __module_get(THIS_MODULE);
+
+       /* Good, fire up the show */
+       if (prescale)
+               tmp |= SWCRR_SWPR;
+       if (reset)
+               tmp |= SWCRR_SWRI;
+
+       tmp |= timeout << 16;
+
+       out_be32(&wd_base->swcrr, tmp);
+
+       return nonseekable_open(inode, file);
+}
+
+static int mpc83xx_wdt_release(struct inode *inode, struct file *file)
+{
+       printk(KERN_CRIT "Unexpected close, not stopping watchdog!\n");
+       mpc83xx_wdt_keepalive();
+       clear_bit(0, &wdt_is_open);
+       return 0;
+}
+
+static int mpc83xx_wdt_ioctl(struct inode *inode, struct file *file,
+                               unsigned int cmd, unsigned long arg)
+{
+       void __user *argp = (void __user *)arg;
+       int __user *p = argp;
+       static struct watchdog_info ident = {
+               .options = WDIOF_KEEPALIVEPING,
+               .firmware_version = 1,
+               .identity = "MPC83xx",
+       };
+
+       switch (cmd) {
+       case WDIOC_GETSUPPORT:
+               return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+       case WDIOC_KEEPALIVE:
+               mpc83xx_wdt_keepalive();
+               return 0;
+       case WDIOC_GETTIMEOUT:
+               return put_user(timeout_sec, p);
+       default:
+               return -ENOIOCTLCMD;
+       }
+}
+
+static struct file_operations mpc83xx_wdt_fops = {
+       .owner          = THIS_MODULE,
+       .llseek         = no_llseek,
+       .write          = mpc83xx_wdt_write,
+       .ioctl          = mpc83xx_wdt_ioctl,
+       .open           = mpc83xx_wdt_open,
+       .release        = mpc83xx_wdt_release,
+};
+
+static struct miscdevice mpc83xx_wdt_miscdev = {
+       .minor  = WATCHDOG_MINOR,
+       .name   = "watchdog",
+       .fops   = &mpc83xx_wdt_fops,
+};
+
+static int __devinit mpc83xx_wdt_probe(struct platform_device *dev)
+{
+       struct resource *r;
+       int ret;
+       unsigned int *freq = dev->dev.platform_data;
+
+       /* get a pointer to the register memory */
+       r = platform_get_resource(dev, IORESOURCE_MEM, 0);
+
+       if (!r) {
+               ret = -ENODEV;
+               goto err_out;
+       }
+
+       wd_base = ioremap(r->start, sizeof (struct mpc83xx_wdt));
+
+       if (wd_base == NULL) {
+               ret = -ENOMEM;
+               goto err_out;
+       }
+
+       ret = misc_register(&mpc83xx_wdt_miscdev);
+       if (ret) {
+               printk(KERN_ERR "cannot register miscdev on minor=%d "
+                               "(err=%d)\n",
+                               WATCHDOG_MINOR, ret);
+               goto err_unmap;
+       }
+
+       /* Calculate the timeout in seconds */
+       if (prescale)
+               timeout_sec = (timeout * 0x10000) / (*freq);
+       else
+               timeout_sec = timeout / (*freq);
+
+       printk(KERN_INFO "WDT driver for MPC83xx initialized. "
+               "mode:%s timeout=%d (%d seconds)\n",
+               reset ? "reset":"interrupt", timeout, timeout_sec);
+
+       spin_lock_init(&wdt_spinlock);
+
+       return 0;
+
+err_unmap:
+       iounmap(wd_base);
+err_out:
+       return ret;
+}
+
+static int __devexit mpc83xx_wdt_remove(struct platform_device *dev)
+{
+       misc_deregister(&mpc83xx_wdt_miscdev);
+       iounmap(wd_base);
+
+       return 0;
+}
+
+static struct platform_driver mpc83xx_wdt_driver = {
+       .probe          = mpc83xx_wdt_probe,
+       .remove         = __devexit_p(mpc83xx_wdt_remove),
+       .driver         = {
+               .name   = "mpc83xx_wdt",
+       },
+};
+
+static int __init mpc83xx_wdt_init(void)
+{
+       return platform_driver_register(&mpc83xx_wdt_driver);
+}
+
+static void __exit mpc83xx_wdt_exit(void)
+{
+       platform_driver_unregister(&mpc83xx_wdt_driver);
+}
+
+module_init(mpc83xx_wdt_init);
+module_exit(mpc83xx_wdt_exit);
+
+MODULE_AUTHOR("Dave Updegraff, Kumar Gala");
+MODULE_DESCRIPTION("Driver for watchdog timer in MPC83xx uProcessor");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);