diff options
Diffstat (limited to 'target/linux/amazon-2.6/files/drivers/char/amazon_wdt.c')
| -rw-r--r-- | target/linux/amazon-2.6/files/drivers/char/amazon_wdt.c | 261 |
1 files changed, 261 insertions, 0 deletions
diff --git a/target/linux/amazon-2.6/files/drivers/char/amazon_wdt.c b/target/linux/amazon-2.6/files/drivers/char/amazon_wdt.c new file mode 100644 index 0000000000..c6a90f07b2 --- /dev/null +++ b/target/linux/amazon-2.6/files/drivers/char/amazon_wdt.c @@ -0,0 +1,261 @@ +/* + * Infineon AP DC COM Amazon WDT driver + * Copyright 2004 Wu Qi Ming <gokimi@msn.com> + * All rights reserved + */ +#if defined(MODVERSIONS) +#include <linux/modversions.h> +#endif + +#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 AMAZON_WDT_EMSG(fmt, args...) printk( "%s: " fmt, __FUNCTION__ , ##args) + +extern unsigned int amazon_get_fpi_hz(void); + +/* forward declarations for _fops */ +static ssize_t wdt_read(struct file *file, char *buf, size_t count, loff_t *offset); +static ssize_t wdt_write(struct file *file, const char *buf, size_t count, loff_t *offset); +static int wdt_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg); +static int wdt_open(struct inode *inode, struct file *file); +static int wdt_release(struct inode *inode, struct file *file); +static int wdt_proc_read(char *buf, char **start, off_t offset,int count, int *eof, void *data); + + +static struct file_operations wdt_fops = { + read:wdt_read, + write:wdt_write, + ioctl:wdt_ioctl, + open:wdt_open, + release:wdt_release, +}; + +/* data */ +static struct wdt_dev *amazon_wdt_dev; +static struct proc_dir_entry* amazon_wdt_dir; +static int occupied=0; + + +/* Brief: enable WDT + * Parameter: + timeout: time interval for WDT + * Return: + 0 OK + EINVAL + * Describes: + 1. Password Access + 2. Modify Access (change ENDINIT => 0) + 3. Change WDT_CON1 (enable WDT) + 4. Password Access again + 5. Modify Access (change ENDINIT => 1) + */ +int wdt_enable(int timeout) +{ + u32 hard_psw,ffpi; + int reload_value, divider=0; + + ffpi = amazon_get_fpi_hz(); + + divider = 1; + if((reload_value=65536-timeout*ffpi/256)<0){ + divider = 0; + reload_value=65536-timeout*ffpi/16384; + } + if (reload_value < 0){ + AMAZON_WDT_EMSG("timeout too large %d\n", timeout); + return -EINVAL; + } + + AMAZON_WDT_EMSG("timeout:%d reload_value: %8x\n", timeout, reload_value); + + hard_psw=(AMAZON_WDT_REG32(AMAZON_WDT_CON0)&0xffffff01)+(AMAZON_WDT_REG32(AMAZON_WDT_CON1)&0xc)+ 0xf0; + AMAZON_WDT_REG32(AMAZON_WDT_CON0)=hard_psw; + wmb(); + + AMAZON_WDT_REG32(AMAZON_WDT_CON0)=(hard_psw&0xff00)+(reload_value<<16)+0xf2; + wmb(); + + AMAZON_WDT_REG32(AMAZON_WDT_CON1)=divider<<2; + wmb(); + + hard_psw=(AMAZON_WDT_REG32(AMAZON_WDT_CON0)&0xffffff01)+(AMAZON_WDT_REG32(AMAZON_WDT_CON1)&0xc)+ 0xf0; + AMAZON_WDT_REG32(AMAZON_WDT_CON0)=hard_psw; + + wmb(); + AMAZON_WDT_REG32(AMAZON_WDT_CON0)=(AMAZON_WDT_REG32(AMAZON_WDT_CON0)&0xffffff00)+0xf3; + wmb(); + return 0; +} + +/* Brief: Disable/stop WDT + */ +void wdt_disable(void) +{ + u32 hard_psw=0; + + hard_psw=(AMAZON_WDT_REG32(AMAZON_WDT_CON0)&0xffffff01)+(AMAZON_WDT_REG32(AMAZON_WDT_CON1)&0xc)+ 0xf0; + AMAZON_WDT_REG32(AMAZON_WDT_CON0)=hard_psw; + wmb(); + + AMAZON_WDT_REG32(AMAZON_WDT_CON0)=(AMAZON_WDT_REG32(AMAZON_WDT_CON0)&0xffffff00)+0xf2; + wmb(); + + AMAZON_WDT_REG32(AMAZON_WDT_CON1)|=8; + wmb(); + + hard_psw=(AMAZON_WDT_REG32(AMAZON_WDT_CON0)&0xffffff01)+(AMAZON_WDT_REG32(AMAZON_WDT_CON1)&0xc)+ 0xf0; + AMAZON_WDT_REG32(AMAZON_WDT_CON0)=hard_psw; + wmb(); + + AMAZON_WDT_REG32(AMAZON_WDT_CON0)=(AMAZON_WDT_REG32(AMAZON_WDT_CON0)&0xffffff00)+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: + AMAZON_WDT_DMSG("enable watch dog timer!\n"); + if ( copy_from_user((void*)&timeout, (void*)arg, sizeof (int)) ){ + AMAZON_WDT_EMSG("invalid argument\n"); + result=-EINVAL; + }else{ + if ((result = wdt_enable(timeout)) < 0){ + timeout = -1; + } + } + break; + case AMAZON_WDT_IOC_STOP: + AMAZON_WDT_DMSG("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); + } + } + 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) +{ + AMAZON_WDT_DMSG("wdt_open\n"); + + if (occupied == 1) return -EBUSY; + occupied = 1; + + return 0; +} + +static int wdt_release(struct inode *inode, struct file *file) +{ + AMAZON_WDT_DMSG("wdt_release\n"); + + occupied = 0; + return 0; +} + + +int wdt_register_proc_read(char *buf, char **start, off_t offset, + int count, int *eof, void *data) +{ + int len=0; + printk("wdt_registers:\n"); + 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; +} + + +int __init amazon_wdt_init_module(void) +{ + int result=0; + + amazon_wdt_dev = (wdt_dev*)kmalloc(sizeof(wdt_dev),GFP_KERNEL); + if (amazon_wdt_dev == NULL){ + return -ENOMEM; + } + memset(amazon_wdt_dev,0,sizeof(wdt_dev)); + + amazon_wdt_dev->major=result; + strcpy(amazon_wdt_dev->name,"wdt"); + + result = register_chrdev(0,amazon_wdt_dev->name,&wdt_fops); + if (result < 0) { + AMAZON_WDT_EMSG("cannot register device\n"); + kfree(amazon_wdt_dev); + return result; + } + + amazon_wdt_dir=proc_mkdir("amazon_wdt",NULL); + create_proc_read_entry("wdt_register", + 0, + amazon_wdt_dir, + wdt_register_proc_read, + NULL); + + occupied=0; + return 0; +} + +void amazon_wdt_cleanup_module(void) +{ + unregister_chrdev(amazon_wdt_dev->major,amazon_wdt_dev->name); + kfree(amazon_wdt_dev); + remove_proc_entry("wdt_register",amazon_wdt_dir); + remove_proc_entry("amazon_wdt",NULL); + AMAZON_WDT_DMSG("unloaded\n"); + return; +} + +MODULE_LICENSE ("GPL"); +MODULE_AUTHOR("Infineon IFAP DC COM"); +MODULE_DESCRIPTION("AMAZON WDT driver"); + +module_init(amazon_wdt_init_module); +module_exit(amazon_wdt_cleanup_module); + |