openwrtv4/target/linux/danube/files/drivers/char/watchdog/danube_wdt.c
John Crispin 82f0d72664 initial merge of danube wdt code
SVN-Revision: 9727
2007-12-13 19:20:12 +00:00

361 lines
8.4 KiB
C

/*
* 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 (C) 2006 infineon
* 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-mips/danube/danube_wdt.h>
#include <asm-mips/danube/danube.h>
extern unsigned int danube_get_fpi_hz (void);
static int danube_wdt_inuse = 0;
static int danube_wdt_major = 0;
int
danube_wdt_enable (unsigned int timeout)
{
unsigned int wdt_cr = 0;
unsigned int wdt_reload = 0;
unsigned int wdt_clkdiv, clkdiv, wdt_pwl, pwl, ffpi;
/* clock divider & prewarning limit */
switch (clkdiv = DANUBE_BIU_WDT_CR_CLKDIV_GET(readl(DANUBE_BIU_WDT_CR)))
{
case 0:
wdt_clkdiv = 1;
break;
case 1:
wdt_clkdiv = 64;
break;
case 2:
wdt_clkdiv = 4096;
break;
case 3:
wdt_clkdiv = 262144;
break;
}
switch (pwl = DANUBE_BIU_WDT_CR_PWL_GET (readl(DANUBE_BIU_WDT_CR)))
{
case 0:
wdt_pwl = 0x8000;
break;
case 1:
wdt_pwl = 0x4000;
break;
case 2:
wdt_pwl = 0x2000;
break;
case 3:
wdt_pwl = 0x1000;
break;
}
//TODO
printk("WARNING FUNCTION CALL MISSING!!!");
//ffpi = cgu_get_io_region_clock();
printk("cpu clock = %d\n", ffpi);
/* caculate reload value */
wdt_reload = (timeout * (ffpi / wdt_clkdiv)) + wdt_pwl;
printk("wdt_pwl=0x%x, wdt_clkdiv=%d, ffpi=%d, wdt_reload = 0x%x\n",
wdt_pwl, wdt_clkdiv, ffpi, wdt_reload);
if (wdt_reload > 0xFFFF) {
printk ("timeout too large %d\n", timeout);
return -EINVAL;
}
/* Write first part of password access */
*DANUBE_BIU_WDT_CR = DANUBE_BIU_WDT_CR_PW_SET (DANUBE_WDT_PW1);
wdt_cr = *DANUBE_BIU_WDT_CR;
wdt_cr &= (!DANUBE_BIU_WDT_CR_PW_SET (0xff) &
!DANUBE_BIU_WDT_CR_PWL_SET (0x3) &
!DANUBE_BIU_WDT_CR_CLKDIV_SET (0x3) &
!DANUBE_BIU_WDT_CR_RELOAD_SET (0xffff));
wdt_cr |= (DANUBE_BIU_WDT_CR_PW_SET (DANUBE_WDT_PW2) |
DANUBE_BIU_WDT_CR_PWL_SET (pwl) |
DANUBE_BIU_WDT_CR_CLKDIV_SET (clkdiv) |
DANUBE_BIU_WDT_CR_RELOAD_SET (wdt_reload) |
DANUBE_BIU_WDT_CR_GEN);
/* Set reload value in second password access */
*DANUBE_BIU_WDT_CR = wdt_cr;
printk ("enabled\n");
return 0;
}
void
danube_wdt_disable (void)
{
/* Write first part of password access */
writel(DANUBE_BIU_WDT_CR_PW_SET(DANUBE_WDT_PW1), DANUBE_BIU_WDT_CR);
/* Disable the watchdog in second password access (GEN=0) */
writel(DANUBE_BIU_WDT_CR_PW_SET(DANUBE_WDT_PW2), DANUBE_BIU_WDT_CR);
}
void
danube_wdt_low_power (int en)
{
unsigned int wdt_cr = 0;
writel(DANUBE_BIU_WDT_CR_PW_SET(DANUBE_WDT_PW1), DANUBE_BIU_WDT_CR);
wdt_cr = readl(DANUBE_BIU_WDT_CR);
if (en)
{
wdt_cr &= (!DANUBE_BIU_WDT_CR_PW_SET(0xff));
wdt_cr |=
(DANUBE_BIU_WDT_CR_PW_SET (DANUBE_WDT_PW2) |
DANUBE_BIU_WDT_CR_LPEN);
}
else {
wdt_cr &= (!DANUBE_BIU_WDT_CR_PW_SET (0xff) &
!DANUBE_BIU_WDT_CR_LPEN);
wdt_cr |= DANUBE_BIU_WDT_CR_PW_SET (DANUBE_WDT_PW2);
}
/* Set reload value in second password access */
writel(wdt_cr, DANUBE_BIU_WDT_CR);
}
void
danube_wdt_debug_suspend (int en)
{
unsigned int wdt_cr = 0;
writel(DANUBE_BIU_WDT_CR_PW_SET(DANUBE_WDT_PW1), DANUBE_BIU_WDT_CR);
wdt_cr = readl(DANUBE_BIU_WDT_CR);
if (en)
{
wdt_cr &= (!DANUBE_BIU_WDT_CR_PW_SET (0xff));
wdt_cr |=
(DANUBE_BIU_WDT_CR_PW_SET (DANUBE_WDT_PW2) |
DANUBE_BIU_WDT_CR_DSEN);
}
else {
wdt_cr &= (!DANUBE_BIU_WDT_CR_PW_SET (0xff) &
!DANUBE_BIU_WDT_CR_DSEN);
wdt_cr |= DANUBE_BIU_WDT_CR_PW_SET (DANUBE_WDT_PW2);
}
/* Set reload value in second password access */
writel(wdt_cr, DANUBE_BIU_WDT_CR);
}
void
danube_wdt_prewarning_limit (int pwl)
{
unsigned int wdt_cr = 0;
wdt_cr = readl(DANUBE_BIU_WDT_CR);
writel(DANUBE_BIU_WDT_CR_PW_SET(DANUBE_WDT_PW1), DANUBE_BIU_WDT_CR);
wdt_cr &= 0xff00ffff; //(!DANUBE_BIU_WDT_CR_PW_SET(0xff));
wdt_cr &= 0xf3ffffff; //(!DANUBE_BIU_WDT_CR_PWL_SET(3));
wdt_cr |= (DANUBE_BIU_WDT_CR_PW_SET (DANUBE_WDT_PW2) |
DANUBE_BIU_WDT_CR_PWL_SET (pwl));
/* Set reload value in second password access */
writel(wdt_cr, DANUBE_BIU_WDT_CR);
}
void
danube_wdt_set_clkdiv (int clkdiv)
{
unsigned int wdt_cr = 0;
wdt_cr = readl(DANUBE_BIU_WDT_CR);
writel(DANUBE_BIU_WDT_CR_PW_SET(DANUBE_WDT_PW1), DANUBE_BIU_WDT_CR);
wdt_cr &= 0xff00ffff; //(!DANUBE_BIU_WDT_CR_PW_SET(0xff));
wdt_cr &= 0xfcffffff; //(!DANUBE_BIU_WDT_CR_CLKDIV_SET(3));
wdt_cr |= (DANUBE_BIU_WDT_CR_PW_SET (DANUBE_WDT_PW2) |
DANUBE_BIU_WDT_CR_CLKDIV_SET (clkdiv));
/* Set reload value in second password access */
writel(wdt_cr, DANUBE_BIU_WDT_CR);
}
static int
danube_wdt_ioctl (struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
int result = 0;
int en = 0;
int istatus;
int pwl, clkdiv;
static int timeout = -1;
switch (cmd)
{
case DANUBE_WDT_IOC_START:
printk("enable watch dog timer!\n");
if (copy_from_user((void *) &timeout, (void *) arg, sizeof (int)))
{
printk ("invalid argument\n");
result = -EINVAL;
} else {
if ((result = danube_wdt_enable (timeout)) < 0)
timeout = -1;
}
break;
case DANUBE_WDT_IOC_STOP:
printk("disable watch dog timer\n");
timeout = -1;
danube_wdt_disable();
break;
case DANUBE_WDT_IOC_PING:
if (timeout < 0)
result = -EIO;
else
result = danube_wdt_enable(timeout);
break;
case DANUBE_WDT_IOC_SET_PWL:
if (copy_from_user((void *) &pwl, (void *) arg, sizeof (int)))
result = -EINVAL;
danube_wdt_prewarning_limit(pwl);
break;
case DANUBE_WDT_IOC_SET_DSEN:
if (copy_from_user((void *) &en, (void *) arg, sizeof (int)))
result = -EINVAL;
danube_wdt_debug_suspend (en);
break;
case DANUBE_WDT_IOC_SET_LPEN:
if (copy_from_user((void *) &en, (void *) arg, sizeof (int)))
result = -EINVAL;
danube_wdt_low_power(en);
break;
case DANUBE_WDT_IOC_SET_CLKDIV:
if (copy_from_user((void *) &clkdiv, (void *) arg, sizeof (int)))
result = -EINVAL;
danube_wdt_set_clkdiv (clkdiv);
break;
case DANUBE_WDT_IOC_GET_STATUS:
istatus = readl(DANUBE_BIU_WDT_SR);
copy_to_user((int *) arg, (int *) &istatus, sizeof (int));
break;
}
return result;
}
static int
danube_wdt_open (struct inode *inode, struct file *file)
{
if (danube_wdt_inuse)
return -EBUSY;
danube_wdt_inuse = 1;
return 0;
}
static int
danube_wdt_release (struct inode *inode, struct file *file)
{
danube_wdt_inuse = 0;
return 0;
}
int
danube_wdt_register_proc_read (char *buf, char **start, off_t offset, int count,
int *eof, void *data)
{
int len = 0;
len += sprintf (buf + len, "DANUBE_BIU_WDT_PROC_READ\n");
len += sprintf (buf + len, "DANUBE_BIU_WDT_CR(0x%08x) : 0x%08x\n",
(unsigned int)DANUBE_BIU_WDT_CR,
readl(DANUBE_BIU_WDT_CR));
len += sprintf (buf + len, "DANUBE_BIU_WDT_SR(0x%08x) : 0x%08x\n",
(unsigned int)DANUBE_BIU_WDT_SR,
readl(DANUBE_BIU_WDT_SR));
*eof = 1;
return len;
}
static struct file_operations wdt_fops = {
.owner = THIS_MODULE,
.ioctl = danube_wdt_ioctl,
.open = danube_wdt_open,
.release = danube_wdt_release,
};
int __init
danube_wdt_init_module (void)
{
danube_wdt_major = register_chrdev(0, "wdt", &wdt_fops);
if (danube_wdt_major < 0)
{
printk("cannot register watchdog device\n");
return -EINVAL;
}
create_proc_read_entry("danube_wdt", 0, NULL, danube_wdt_register_proc_read, NULL);
printk("danube watchdog loaded\n");
return 0;
}
void
danube_wdt_cleanup_module (void)
{
unregister_chrdev(danube_wdt_major, "wdt");
remove_proc_entry("danube_wdt", NULL);
}
module_init(danube_wdt_init_module);
module_exit(danube_wdt_cleanup_module);