/* * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Copyright 2004 Wu Qi Ming <gokimi@msn.com> * Copyright (C) 2007 John Crispin <blogic@openwrt.org> */ #include <linux/module.h> #include <linux/init.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/slab.h> #include <linux/string.h> #include <linux/timer.h> #include <linux/fs.h> #include <linux/errno.h> #include <linux/proc_fs.h> #include <linux/stat.h> #include <linux/tty.h> #include <linux/selection.h> #include <linux/kmod.h> #include <linux/vmalloc.h> #include <linux/kdev_t.h> #include <linux/ioctl.h> #include <asm/uaccess.h> #include <asm/system.h> #include <asm/amazon/amazon.h> #include <asm/amazon/amazon_wdt.h> #define DRV_NAME "AMAZON WDT:" #undef AMAZON_WDT_DEBUG extern unsigned int amazon_get_fpi_hz(void); static int amazon_wdt_isopen = 0; #ifdef AMAZON_WDT_DEBUG static struct proc_dir_entry* amazon_wdt_dir; #endif int wdt_enable(int timeout) { u32 hard_psw, ffpi; int reload_value, divider = 1; ffpi = amazon_get_fpi_hz(); reload_value = 65536 - timeout * ffpi / 256; if (reload_value < 0) { divider = 0; reload_value = 65536 - timeout * ffpi / 16384; } if (reload_value < 0){ printk(KERN_INFO DRV_NAME "timeout too large %d\n", timeout); return -EINVAL; } printk(KERN_INFO DRV_NAME "timeout:%d reload_value: %8x\n", timeout, reload_value); hard_psw = (amazon_readl(AMAZON_WDT_CON0) & 0xffffff01) + (amazon_readl(AMAZON_WDT_CON1) & 0xc) + 0xf0; amazon_writel(hard_psw, AMAZON_WDT_CON0); wmb(); amazon_writel((hard_psw & 0xff00) + (reload_value << 16) + 0xf2, AMAZON_WDT_CON0); wmb(); amazon_writel(divider << 2, AMAZON_WDT_CON1); wmb(); hard_psw = (amazon_readl(AMAZON_WDT_CON0) & 0xffffff01) + (amazon_readl(AMAZON_WDT_CON1) & 0xc) + 0xf0; amazon_writel(hard_psw, AMAZON_WDT_CON0); wmb(); amazon_writel_masked(AMAZON_WDT_CON0, 0xff, 0xf3); wmb(); return 0; } void wdt_disable(void) { u32 hard_psw = 0; hard_psw = (amazon_readl(AMAZON_WDT_CON0) & 0xffffff01) + (amazon_readl(AMAZON_WDT_CON1) & 0xc) + 0xf0; amazon_writel(hard_psw, AMAZON_WDT_CON0); wmb(); amazon_writel_masked(AMAZON_WDT_CON0, 0xff, 0xf2); wmb(); amazon_writel_masked(AMAZON_WDT_CON1, 0x8, 0x8); wmb(); hard_psw=(amazon_readl(AMAZON_WDT_CON0) & 0xffffff01) + (amazon_readl(AMAZON_WDT_CON1) & 0xc) + 0xf0; amazon_writel(hard_psw, AMAZON_WDT_CON0); wmb(); amazon_writel_masked(AMAZON_WDT_CON0, 0xff, 0xf3); wmb(); return; } static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { int result=0; static int timeout=-1; switch(cmd){ case AMAZON_WDT_IOC_START: printk(KERN_INFO DRV_NAME "enable watch dog timer!\n"); if (copy_from_user((void*)&timeout, (void*)arg, sizeof (int))) { printk(KERN_INFO DRV_NAME "invalid argument\n"); result=-EINVAL; } else if ((result = wdt_enable(timeout)) < 0) { timeout = -1; } break; case AMAZON_WDT_IOC_STOP: printk(KERN_INFO DRV_NAME "disable watch dog timer\n"); timeout = -1; wdt_disable(); break; case AMAZON_WDT_IOC_PING: if (timeout < 0) { result = -EIO; } else { result = wdt_enable(timeout); } break; default: result=-EINVAL; break; } return result; } static ssize_t wdt_read(struct file *file, char *buf, size_t count, loff_t *offset) { return 0; } static ssize_t wdt_write(struct file *file, const char *buf, size_t count, loff_t *offset) { return count; } static int wdt_open(struct inode *inode, struct file *file) { if (amazon_wdt_isopen == 1) return -EBUSY; amazon_wdt_isopen = 1; printk(KERN_INFO DRV_NAME "opened\n"); return 0; } static int wdt_release(struct inode *inode, struct file *file) { amazon_wdt_isopen = 0; printk(KERN_INFO DRV_NAME "closed\n"); return 0; } #ifdef AMAZON_WDT_DEBUG int wdt_register_proc_read(char *buf, char **start, off_t offset, int count, int *eof, void *data) { int len=0; len+=sprintf(buf+len,"NMISR: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_WDT_NMISR)); len+=sprintf(buf+len,"RST_REQ: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_RST_REQ)); len+=sprintf(buf+len,"RST_SR: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_RST_SR)); len+=sprintf(buf+len,"WDT_CON0: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_WDT_CON0)); len+=sprintf(buf+len,"WDT_CON1: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_WDT_CON1)); len+=sprintf(buf+len,"WDT_SR: 0x%08x\n",AMAZON_WDT_REG32(AMAZON_WDT_SR)); *eof = 1; return len; } #endif static struct file_operations wdt_fops = { read: wdt_read, write: wdt_write, ioctl: wdt_ioctl, open: wdt_open, release: wdt_release, }; int __init amazon_wdt_init_module(void) { int result = result = register_chrdev(0, "watchdog", &wdt_fops); if (result < 0) { printk(KERN_INFO DRV_NAME "cannot register device\n"); return result; } #ifdef AMAZON_WDT_DEBUG amazon_wdt_dir=proc_mkdir("amazon_wdt",NULL); create_proc_read_entry("wdt_register", 0, amazon_wdt_dir, wdt_register_proc_read, NULL); #endif amazon_wdt_isopen=0; printk(KERN_INFO DRV_NAME "driver loaded but inactive"); return 0; } void amazon_wdt_cleanup_module(void) { unregister_chrdev(0, "watchdog"); #ifdef AMAZON_WDT_DEBUG remove_proc_entry("wdt_register", amazon_wdt_dir); remove_proc_entry("amazon_wdt", NULL); #endif printk(KERN_INFO DRV_NAME "unregistered"); return; } MODULE_LICENSE ("GPL"); MODULE_AUTHOR("Infineon / John Crispin <blogic@openwrt.org>"); MODULE_DESCRIPTION("AMAZON WDT driver"); module_init(amazon_wdt_init_module); module_exit(amazon_wdt_cleanup_module);