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authorAnton Vorontsov <avorontsov@ru.mvista.com>2008-07-03 23:51:34 -0700
committerWim Van Sebroeck <wim@iguana.be>2008-08-06 13:06:25 +0000
commit28acd02f9f9efe44718de3bbe8be22d6dfb7e47f (patch)
treea9afe194d2d4cee5d3356f25c790b4486dd2b77a /drivers/watchdog/mpc8xxx_wdt.c
parent500c919e3d699644cc9d6c1e93022481baafd8e1 (diff)
downloadlinux-28acd02f9f9efe44718de3bbe8be22d6dfb7e47f.tar.gz
[WATCHDOG] mpc83xx_wdt: rename to mpc8xxx_wdt
Rename the driver because now we support some MPC86xx processors. There are no changes to the mpc83xx_wdt.c file, yet. When possible, we do file renames and changes separately (because Linus once asked so, because it helps git to track the renamed files). Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Wim Van Sebroeck <wim@iguana.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers/watchdog/mpc8xxx_wdt.c')
-rw-r--r--drivers/watchdog/mpc8xxx_wdt.c294
1 files changed, 294 insertions, 0 deletions
diff --git a/drivers/watchdog/mpc8xxx_wdt.c b/drivers/watchdog/mpc8xxx_wdt.c
new file mode 100644
index 00000000000..fa82ec99ba8
--- /dev/null
+++ b/drivers/watchdog/mpc8xxx_wdt.c
@@ -0,0 +1,294 @@
+/*
+ * mpc83xx_wdt.c - MPC83xx/MPC86xx 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
+ * Copyright (c) 2008 MontaVista Software, Inc.
+ * Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * 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/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/miscdevice.h>
+#include <linux/of_platform.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <sysdev/fsl_soc.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];
+};
+
+struct mpc83xx_wdt_type {
+ int prescaler;
+ bool hw_enabled;
+};
+
+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");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+ "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+/*
+ * 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 DEFINE_SPINLOCK(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 void mpc83xx_wdt_timer_ping(unsigned long arg);
+static DEFINE_TIMER(wdt_timer, mpc83xx_wdt_timer_ping, 0, 0);
+
+static void mpc83xx_wdt_timer_ping(unsigned long arg)
+{
+ mpc83xx_wdt_keepalive();
+ /* We're pinging it twice faster than needed, just to be sure. */
+ mod_timer(&wdt_timer, jiffies + HZ * timeout_sec / 2);
+}
+
+static void mpc83xx_wdt_pr_warn(const char *msg)
+{
+ pr_crit("mpc83xx_wdt: %s, expect the %s soon!\n", msg,
+ reset ? "reset" : "machine check exception");
+}
+
+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 */
+ if (nowayout)
+ __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);
+
+ del_timer_sync(&wdt_timer);
+
+ return nonseekable_open(inode, file);
+}
+
+static int mpc83xx_wdt_release(struct inode *inode, struct file *file)
+{
+ if (!nowayout)
+ mpc83xx_wdt_timer_ping(0);
+ else
+ mpc83xx_wdt_pr_warn("watchdog closed");
+ clear_bit(0, &wdt_is_open);
+ return 0;
+}
+
+static long mpc83xx_wdt_ioctl(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_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+ case WDIOC_KEEPALIVE:
+ mpc83xx_wdt_keepalive();
+ return 0;
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout_sec, p);
+ default:
+ return -ENOTTY;
+ }
+}
+
+static const struct file_operations mpc83xx_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = mpc83xx_wdt_write,
+ .unlocked_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 of_device *ofdev,
+ const struct of_device_id *match)
+{
+ int ret;
+ struct device_node *np = ofdev->node;
+ struct mpc83xx_wdt_type *wdt_type = match->data;
+ u32 freq = fsl_get_sys_freq();
+ bool enabled;
+
+ if (!freq || freq == -1)
+ return -EINVAL;
+
+ wd_base = of_iomap(np, 0);
+ if (!wd_base)
+ return -ENOMEM;
+
+ enabled = in_be32(&wd_base->swcrr) & SWCRR_SWEN;
+ if (!enabled && wdt_type->hw_enabled) {
+ pr_info("mpc83xx_wdt: could not be enabled in software\n");
+ ret = -ENOSYS;
+ goto err_unmap;
+ }
+
+ ret = misc_register(&mpc83xx_wdt_miscdev);
+ if (ret) {
+ pr_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 * wdt_type->prescaler) / freq;
+ else
+ timeout_sec = timeout / freq;
+
+ pr_info("WDT driver for MPC83xx initialized. mode:%s timeout=%d "
+ "(%d seconds)\n", reset ? "reset" : "interrupt", timeout,
+ timeout_sec);
+
+ /*
+ * If the watchdog was previously enabled or we're running on
+ * MPC86xx, we should ping the wdt from the kernel until the
+ * userspace handles it.
+ */
+ if (enabled)
+ mpc83xx_wdt_timer_ping(0);
+ return 0;
+err_unmap:
+ iounmap(wd_base);
+ return ret;
+}
+
+static int __devexit mpc83xx_wdt_remove(struct of_device *ofdev)
+{
+ mpc83xx_wdt_pr_warn("watchdog removed");
+ del_timer_sync(&wdt_timer);
+ misc_deregister(&mpc83xx_wdt_miscdev);
+ iounmap(wd_base);
+
+ return 0;
+}
+
+static const struct of_device_id mpc83xx_wdt_match[] = {
+ {
+ .compatible = "mpc83xx_wdt",
+ .data = &(struct mpc83xx_wdt_type) {
+ .prescaler = 0x10000,
+ },
+ },
+ {
+ .compatible = "fsl,mpc8610-wdt",
+ .data = &(struct mpc83xx_wdt_type) {
+ .prescaler = 0x10000,
+ .hw_enabled = true,
+ },
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, mpc83xx_wdt_match);
+
+static struct of_platform_driver mpc83xx_wdt_driver = {
+ .match_table = mpc83xx_wdt_match,
+ .probe = mpc83xx_wdt_probe,
+ .remove = __devexit_p(mpc83xx_wdt_remove),
+ .driver = {
+ .name = "mpc83xx_wdt",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init mpc83xx_wdt_init(void)
+{
+ return of_register_platform_driver(&mpc83xx_wdt_driver);
+}
+
+static void __exit mpc83xx_wdt_exit(void)
+{
+ of_unregister_platform_driver(&mpc83xx_wdt_driver);
+}
+
+subsys_initcall(mpc83xx_wdt_init);
+module_exit(mpc83xx_wdt_exit);
+
+MODULE_AUTHOR("Dave Updegraff, Kumar Gala");
+MODULE_DESCRIPTION("Driver for watchdog timer in MPC83xx/MPC86xx uProcessors");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);