+++ /dev/null
-/*
- * drivers/watchdog/ar7_wdt.c
- *
- * Copyright (C) 2007 Nicolas Thill <nico@openwrt.org>
- * Copyright (c) 2005 Enrik Berkhan <Enrik.Berkhan@akk.org>
- *
- * Some code taken from:
- * National Semiconductor SCx200 Watchdog support
- * Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/errno.h>
-#include <linux/init.h>
-#include <linux/miscdevice.h>
-#include <linux/watchdog.h>
-#include <linux/notifier.h>
-#include <linux/reboot.h>
-#include <linux/fs.h>
-#include <linux/ioport.h>
-#include <linux/io.h>
-#include <linux/uaccess.h>
-
-#include <asm/addrspace.h>
-#include <asm/ar7/ar7.h>
-
-#define DRVNAME "ar7_wdt"
-#define LONGNAME "TI AR7 Watchdog Timer"
-
-MODULE_AUTHOR("Nicolas Thill <nico@openwrt.org>");
-MODULE_DESCRIPTION(LONGNAME);
-MODULE_LICENSE("GPL");
-MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
-
-static int margin = 60;
-module_param(margin, int, 0);
-MODULE_PARM_DESC(margin, "Watchdog margin in seconds");
-
-static int nowayout = WATCHDOG_NOWAYOUT;
-module_param(nowayout, int, 0);
-MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");
-
-#define READ_REG(x) readl((void __iomem *)&(x))
-#define WRITE_REG(x, v) writel((v), (void __iomem *)&(x))
-
-struct ar7_wdt {
- u32 kick_lock;
- u32 kick;
- u32 change_lock;
- u32 change;
- u32 disable_lock;
- u32 disable;
- u32 prescale_lock;
- u32 prescale;
-};
-
-static struct semaphore open_semaphore;
-static unsigned expect_close;
-
-/* XXX currently fixed, allows max margin ~68.72 secs */
-#define prescale_value 0xffff
-
-/* Offset of the WDT registers */
-static unsigned long ar7_regs_wdt;
-/* Pointer to the remapped WDT IO space */
-static struct ar7_wdt *ar7_wdt;
-static void ar7_wdt_get_regs(void)
-{
- u16 chip_id = ar7_chip_id();
- switch (chip_id) {
- case AR7_CHIP_7100:
- case AR7_CHIP_7200:
- ar7_regs_wdt = AR7_REGS_WDT;
- break;
- default:
- ar7_regs_wdt = UR8_REGS_WDT;
- break;
- }
-}
-
-
-static void ar7_wdt_kick(u32 value)
-{
- WRITE_REG(ar7_wdt->kick_lock, 0x5555);
- if ((READ_REG(ar7_wdt->kick_lock) & 3) == 1) {
- WRITE_REG(ar7_wdt->kick_lock, 0xaaaa);
- if ((READ_REG(ar7_wdt->kick_lock) & 3) == 3) {
- WRITE_REG(ar7_wdt->kick, value);
- return;
- }
- }
- printk(KERN_ERR DRVNAME ": failed to unlock WDT kick reg\n");
-}
-
-static void ar7_wdt_prescale(u32 value)
-{
- WRITE_REG(ar7_wdt->prescale_lock, 0x5a5a);
- if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 1) {
- WRITE_REG(ar7_wdt->prescale_lock, 0xa5a5);
- if ((READ_REG(ar7_wdt->prescale_lock) & 3) == 3) {
- WRITE_REG(ar7_wdt->prescale, value);
- return;
- }
- }
- printk(KERN_ERR DRVNAME ": failed to unlock WDT prescale reg\n");
-}
-
-static void ar7_wdt_change(u32 value)
-{
- WRITE_REG(ar7_wdt->change_lock, 0x6666);
- if ((READ_REG(ar7_wdt->change_lock) & 3) == 1) {
- WRITE_REG(ar7_wdt->change_lock, 0xbbbb);
- if ((READ_REG(ar7_wdt->change_lock) & 3) == 3) {
- WRITE_REG(ar7_wdt->change, value);
- return;
- }
- }
- printk(KERN_ERR DRVNAME ": failed to unlock WDT change reg\n");
-}
-
-static void ar7_wdt_disable(u32 value)
-{
- WRITE_REG(ar7_wdt->disable_lock, 0x7777);
- if ((READ_REG(ar7_wdt->disable_lock) & 3) == 1) {
- WRITE_REG(ar7_wdt->disable_lock, 0xcccc);
- if ((READ_REG(ar7_wdt->disable_lock) & 3) == 2) {
- WRITE_REG(ar7_wdt->disable_lock, 0xdddd);
- if ((READ_REG(ar7_wdt->disable_lock) & 3) == 3) {
- WRITE_REG(ar7_wdt->disable, value);
- return;
- }
- }
- }
- printk(KERN_ERR DRVNAME ": failed to unlock WDT disable reg\n");
-}
-
-static void ar7_wdt_update_margin(int new_margin)
-{
- u32 change;
-
- change = new_margin * (ar7_vbus_freq() / prescale_value);
- if (change < 1) change = 1;
- if (change > 0xffff) change = 0xffff;
- ar7_wdt_change(change);
- margin = change * prescale_value / ar7_vbus_freq();
- printk(KERN_INFO DRVNAME
- ": timer margin %d seconds (prescale %d, change %d, freq %d)\n",
- margin, prescale_value, change, ar7_vbus_freq());
-}
-
-static void ar7_wdt_enable_wdt(void)
-{
- printk(KERN_DEBUG DRVNAME ": enabling watchdog timer\n");
- ar7_wdt_disable(1);
- ar7_wdt_kick(1);
-}
-
-static void ar7_wdt_disable_wdt(void)
-{
- printk(KERN_DEBUG DRVNAME ": disabling watchdog timer\n");
- ar7_wdt_disable(0);
-}
-
-static int ar7_wdt_open(struct inode *inode, struct file *file)
-{
- /* only allow one at a time */
- if (down_trylock(&open_semaphore))
- return -EBUSY;
- ar7_wdt_enable_wdt();
- expect_close = 0;
-
- return nonseekable_open(inode, file);
-}
-
-static int ar7_wdt_release(struct inode *inode, struct file *file)
-{
- if (!expect_close)
- printk(KERN_WARNING DRVNAME
- ": watchdog device closed unexpectedly,"
- "will not disable the watchdog timer\n");
- else if (!nowayout)
- ar7_wdt_disable_wdt();
-
- up(&open_semaphore);
-
- return 0;
-}
-
-static int ar7_wdt_notify_sys(struct notifier_block *this,
- unsigned long code, void *unused)
-{
- if (code == SYS_HALT || code == SYS_POWER_OFF)
- if (!nowayout)
- ar7_wdt_disable_wdt();
-
- return NOTIFY_DONE;
-}
-
-static struct notifier_block ar7_wdt_notifier = {
- .notifier_call = ar7_wdt_notify_sys
-};
-
-static ssize_t ar7_wdt_write(struct file *file, const char *data,
- size_t len, loff_t *ppos)
-{
- /* check for a magic close character */
- if (len) {
- size_t i;
-
- ar7_wdt_kick(1);
-
- 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;
- }
-
- }
- return len;
-}
-
-static int ar7_wdt_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd, unsigned long arg)
-{
- static struct watchdog_info ident = {
- .identity = LONGNAME,
- .firmware_version = 1,
- .options = (WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING),
- };
- int new_margin;
-
- 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:
- if (put_user(0, (int *)arg))
- return -EFAULT;
- return 0;
- case WDIOC_KEEPALIVE:
- ar7_wdt_kick(1);
- return 0;
- case WDIOC_SETTIMEOUT:
- if (get_user(new_margin, (int *)arg))
- return -EFAULT;
- if (new_margin < 1)
- return -EINVAL;
-
- ar7_wdt_update_margin(new_margin);
- ar7_wdt_kick(1);
-
- case WDIOC_GETTIMEOUT:
- if (put_user(margin, (int *)arg))
- return -EFAULT;
- return 0;
- }
-}
-
-static struct file_operations ar7_wdt_fops = {
- .owner = THIS_MODULE,
- .write = ar7_wdt_write,
- .ioctl = ar7_wdt_ioctl,
- .open = ar7_wdt_open,
- .release = ar7_wdt_release,
-};
-
-static struct miscdevice ar7_wdt_miscdev = {
- .minor = WATCHDOG_MINOR,
- .name = "watchdog",
- .fops = &ar7_wdt_fops,
-};
-
-static int __init ar7_wdt_init(void)
-{
- int rc;
-
- ar7_wdt_get_regs();
-
- if (!request_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt),
- LONGNAME)) {
- printk(KERN_WARNING DRVNAME ": watchdog I/O region busy\n");
- return -EBUSY;
- }
-
- ar7_wdt = (struct ar7_wdt *)
- ioremap(ar7_regs_wdt, sizeof(struct ar7_wdt));
-
- ar7_wdt_disable_wdt();
- ar7_wdt_prescale(prescale_value);
- ar7_wdt_update_margin(margin);
-
- sema_init(&open_semaphore, 1);
-
- rc = register_reboot_notifier(&ar7_wdt_notifier);
- if (rc) {
- printk(KERN_ERR DRVNAME
- ": unable to register reboot notifier\n");
- goto out_alloc;
- }
-
- rc = misc_register(&ar7_wdt_miscdev);
- if (rc) {
- printk(KERN_ERR DRVNAME ": unable to register misc device\n");
- goto out_register;
- }
- goto out;
-
-out_register:
- unregister_reboot_notifier(&ar7_wdt_notifier);
-out_alloc:
- iounmap(ar7_wdt);
- release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
-out:
- return rc;
-}
-
-static void __exit ar7_wdt_cleanup(void)
-{
- misc_deregister(&ar7_wdt_miscdev);
- unregister_reboot_notifier(&ar7_wdt_notifier);
- iounmap(ar7_wdt);
- release_mem_region(ar7_regs_wdt, sizeof(struct ar7_wdt));
-}
-
-module_init(ar7_wdt_init);
-module_exit(ar7_wdt_cleanup);
projects / openwrt / svn-archive / archive.git / blobdiff