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authornbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2007-12-24 22:47:27 +0000
committernbd <nbd@3c298f89-4303-0410-b956-a3cf2f4a3e73>2007-12-24 22:47:27 +0000
commit0d5a134b783b7743a7ec70b5f43da2eeda3850a1 (patch)
tree954f0828ba02cd2558391d4c40e1ac646f0383be /target/linux/rb532/files/drivers/char
parent54dcc5811d2a1728a6cc5cb468ac738e6ba5208a (diff)
watchdog driver for RB 532
Here is the driver for the hardware watchdog timer integrated in RB 532 (as part of the SoC IDT 79RC32434). File include/asm-mips/rc32434/integ.h is taken from Mikrotik RB 532 kernel patch. Signed-off-by: Ondrej Zajicek <santiago@crfreenet.org> git-svn-id: svn://svn.openwrt.org/openwrt/trunk@9896 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'target/linux/rb532/files/drivers/char')
-rw-r--r--target/linux/rb532/files/drivers/char/watchdog/rc32434_wdt.c240
1 files changed, 240 insertions, 0 deletions
diff --git a/target/linux/rb532/files/drivers/char/watchdog/rc32434_wdt.c b/target/linux/rb532/files/drivers/char/watchdog/rc32434_wdt.c
new file mode 100644
index 000000000..2266329de
--- /dev/null
+++ b/target/linux/rb532/files/drivers/char/watchdog/rc32434_wdt.c
@@ -0,0 +1,240 @@
+/*
+ * RC32434_WDT 0.01: IDT Interprise 79RC32434 watchdog driver
+ * Copyright (c) Ondrej Zajicek <santiago@crfreenet.org>, 2006
+ *
+ * based on
+ *
+ * SoftDog 0.05: A Software Watchdog Device
+ *
+ * (c) Copyright 1996 Alan Cox <alan@redhat.com>, All Rights Reserved.
+ *
+ * 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/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/reboot.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
+#include <asm/bootinfo.h>
+#include <asm/time.h>
+#include <asm/uaccess.h>
+#include <asm/rc32434/integ.h>
+
+#define DEFAULT_TIMEOUT 15 /* (secs) Default is 15 seconds */
+#define MAX_TIMEOUT 20
+/*
+ * (secs) Max is 20 seconds
+ * (max frequency of counter is ~200 MHz, counter is 32-bit unsigned int)
+ */
+
+#define NAME "rc32434_wdt"
+#define VERSION "0.1"
+
+static INTEG_t rc_wdt = (INTEG_t) INTEG_VirtualAddress;
+
+static int expect_close = 0;
+static int access = 0;
+static int timeout = 0;
+
+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) ")");
+MODULE_LICENSE("GPL");
+
+
+static inline void start_wdt(void)
+{
+ rc_wdt -> wtcount = 0;
+ rc_wdt -> errcs |= ERRCS_wre_m;
+ rc_wdt -> wtc |= WTC_en_m;
+}
+
+static inline void stop_wdt(void)
+{
+ rc_wdt -> wtc &= ~WTC_en_m;
+ rc_wdt -> errcs &= ~ERRCS_wre_m;
+}
+
+static inline void set_wdt(int new_timeout)
+{
+ u32 cmp = new_timeout * mips_hpt_frequency;
+ u32 state;
+
+ timeout = new_timeout;
+ /*
+ * store and disable WTC
+ */
+ state = rc_wdt -> wtc & WTC_en_m;
+ rc_wdt -> wtc &= ~WTC_en_m;
+
+ rc_wdt -> wtcount = 0;
+ rc_wdt -> wtcompare = cmp;
+
+ /*
+ * restore WTC
+ */
+ rc_wdt -> wtc |= state;
+}
+
+static inline void update_wdt(void)
+{
+ rc_wdt -> wtcount = 0;
+}
+
+/*
+ * Allow only one person to hold it open
+ */
+
+static int wdt_open(struct inode *inode, struct file *file)
+{
+ if (access)
+ return -EBUSY;
+ if (nowayout) {
+ __module_get(THIS_MODULE);
+ }
+ /*
+ * Activate timer
+ */
+ start_wdt();
+ printk(KERN_INFO NAME ": enabling watchdog timer\n");
+ access = 1;
+ return 0;
+}
+
+static int wdt_release(struct inode *inode, struct file *file)
+{
+ /*
+ * Shut off the timer.
+ * Lock it in if it's a module and we set nowayout
+ */
+ if (expect_close && nowayout == 0) {
+ stop_wdt ();
+ printk(KERN_INFO NAME ": disabling watchdog timer\n");
+ module_put(THIS_MODULE);
+ } else {
+ printk (KERN_CRIT NAME ": device closed unexpectedly. WDT will not stop!\n");
+ }
+ access = 0;
+ return 0;
+}
+
+static ssize_t wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+{
+ /*
+ * Refresh the timer.
+ */
+ if (len) {
+ if (!nowayout) {
+ size_t i;
+
+ /* In case it was set long ago */
+ expect_close = 0;
+
+ for (i = 0; i != len; i++) {
+ char c;
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == 'V')
+ expect_close = 1;
+ }
+ }
+ update_wdt ();
+ return len;
+ }
+ return 0;
+}
+
+static int wdt_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int new_timeout;
+ static struct watchdog_info ident = {
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+ .firmware_version = 0,
+ .identity = "RC32434_WDT Watchdog",
+ };
+ switch (cmd) {
+ default:
+ return -ENOTTY;
+ case WDIOC_GETSUPPORT:
+ if(copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident)))
+ return -EFAULT;
+ return 0;
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0,(int *)arg);
+ case WDIOC_KEEPALIVE:
+ update_wdt();
+ return 0;
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_timeout, (int *)arg))
+ return -EFAULT;
+ if (new_timeout < 1)
+ return -EINVAL;
+ if (new_timeout > MAX_TIMEOUT)
+ return -EINVAL;
+ set_wdt(new_timeout);
+ /* Fall */
+ case WDIOC_GETTIMEOUT:
+ return put_user(timeout, (int *)arg);
+ }
+}
+
+static struct file_operations wdt_fops = {
+ owner: THIS_MODULE,
+ llseek: no_llseek,
+ write: wdt_write,
+ ioctl: wdt_ioctl,
+ open: wdt_open,
+ release: wdt_release,
+};
+
+static struct miscdevice wdt_miscdev = {
+ minor: WATCHDOG_MINOR,
+ name: "watchdog",
+ fops: &wdt_fops,
+};
+
+static char banner[] __initdata = KERN_INFO NAME ": Watchdog Timer version " VERSION ", timer margin: %d sec\n";
+
+static int __init watchdog_init(void)
+{
+ int ret;
+
+ /*
+ * There should be check for RC32434 SoC
+ */
+ if (mips_machgroup != MACH_GROUP_MIKROTIK) return -1;
+
+ ret = misc_register(&wdt_miscdev);
+
+ if (ret)
+ return ret;
+
+ stop_wdt();
+ set_wdt(DEFAULT_TIMEOUT);
+
+ printk(banner, timeout);
+
+ return 0;
+}
+
+static void __exit watchdog_exit(void)
+{
+ misc_deregister(&wdt_miscdev);
+}
+
+module_init(watchdog_init);
+module_exit(watchdog_exit);