322 lines
6.8 KiB
C
322 lines
6.8 KiB
C
/*
|
|
* drivers/watchdog/orion_wdt.c
|
|
*
|
|
* Watchdog driver for Orion/Kirkwood processors
|
|
*
|
|
* Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
|
|
*
|
|
* This file is licensed under the terms of the GNU General Public
|
|
* License version 2. This program is licensed "as is" without any
|
|
* warranty of any kind, whether express or implied.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/init.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/io.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/clk.h>
|
|
#include <mach/bridge-regs.h>
|
|
|
|
/*
|
|
* Watchdog timer block registers.
|
|
*/
|
|
#define TIMER_CTRL 0x0000
|
|
#define WDT_EN 0x0010
|
|
#define WDT_VAL 0x0024
|
|
|
|
#define WDT_MAX_CYCLE_COUNT 0xffffffff
|
|
#define WDT_IN_USE 0
|
|
#define WDT_OK_TO_CLOSE 1
|
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
static int heartbeat = -1; /* module parameter (seconds) */
|
|
static unsigned int wdt_max_duration; /* (seconds) */
|
|
static struct clk *clk;
|
|
static unsigned int wdt_tclk;
|
|
static void __iomem *wdt_reg;
|
|
static unsigned long wdt_status;
|
|
static DEFINE_SPINLOCK(wdt_lock);
|
|
|
|
static void orion_wdt_ping(void)
|
|
{
|
|
spin_lock(&wdt_lock);
|
|
|
|
/* Reload watchdog duration */
|
|
writel(wdt_tclk * heartbeat, wdt_reg + WDT_VAL);
|
|
|
|
spin_unlock(&wdt_lock);
|
|
}
|
|
|
|
static void orion_wdt_enable(void)
|
|
{
|
|
u32 reg;
|
|
|
|
spin_lock(&wdt_lock);
|
|
|
|
/* Set watchdog duration */
|
|
writel(wdt_tclk * heartbeat, wdt_reg + WDT_VAL);
|
|
|
|
/* Clear watchdog timer interrupt */
|
|
reg = readl(BRIDGE_CAUSE);
|
|
reg &= ~WDT_INT_REQ;
|
|
writel(reg, BRIDGE_CAUSE);
|
|
|
|
/* Enable watchdog timer */
|
|
reg = readl(wdt_reg + TIMER_CTRL);
|
|
reg |= WDT_EN;
|
|
writel(reg, wdt_reg + TIMER_CTRL);
|
|
|
|
/* Enable reset on watchdog */
|
|
reg = readl(RSTOUTn_MASK);
|
|
reg |= WDT_RESET_OUT_EN;
|
|
writel(reg, RSTOUTn_MASK);
|
|
|
|
spin_unlock(&wdt_lock);
|
|
}
|
|
|
|
static void orion_wdt_disable(void)
|
|
{
|
|
u32 reg;
|
|
|
|
spin_lock(&wdt_lock);
|
|
|
|
/* Disable reset on watchdog */
|
|
reg = readl(RSTOUTn_MASK);
|
|
reg &= ~WDT_RESET_OUT_EN;
|
|
writel(reg, RSTOUTn_MASK);
|
|
|
|
/* Disable watchdog timer */
|
|
reg = readl(wdt_reg + TIMER_CTRL);
|
|
reg &= ~WDT_EN;
|
|
writel(reg, wdt_reg + TIMER_CTRL);
|
|
|
|
spin_unlock(&wdt_lock);
|
|
}
|
|
|
|
static int orion_wdt_get_timeleft(int *time_left)
|
|
{
|
|
spin_lock(&wdt_lock);
|
|
*time_left = readl(wdt_reg + WDT_VAL) / wdt_tclk;
|
|
spin_unlock(&wdt_lock);
|
|
return 0;
|
|
}
|
|
|
|
static int orion_wdt_open(struct inode *inode, struct file *file)
|
|
{
|
|
if (test_and_set_bit(WDT_IN_USE, &wdt_status))
|
|
return -EBUSY;
|
|
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
|
|
orion_wdt_enable();
|
|
return nonseekable_open(inode, file);
|
|
}
|
|
|
|
static ssize_t orion_wdt_write(struct file *file, const char *data,
|
|
size_t len, loff_t *ppos)
|
|
{
|
|
if (len) {
|
|
if (!nowayout) {
|
|
size_t i;
|
|
|
|
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
|
|
for (i = 0; i != len; i++) {
|
|
char c;
|
|
|
|
if (get_user(c, data + i))
|
|
return -EFAULT;
|
|
if (c == 'V')
|
|
set_bit(WDT_OK_TO_CLOSE, &wdt_status);
|
|
}
|
|
}
|
|
orion_wdt_ping();
|
|
}
|
|
return len;
|
|
}
|
|
|
|
static int orion_wdt_settimeout(int new_time)
|
|
{
|
|
if ((new_time <= 0) || (new_time > wdt_max_duration))
|
|
return -EINVAL;
|
|
|
|
/* Set new watchdog time to be used when
|
|
* orion_wdt_enable() or orion_wdt_ping() is called. */
|
|
heartbeat = new_time;
|
|
return 0;
|
|
}
|
|
|
|
static const struct watchdog_info ident = {
|
|
.options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT |
|
|
WDIOF_KEEPALIVEPING,
|
|
.identity = "Orion Watchdog",
|
|
};
|
|
|
|
static long orion_wdt_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
int ret = -ENOTTY;
|
|
int time;
|
|
|
|
switch (cmd) {
|
|
case WDIOC_GETSUPPORT:
|
|
ret = copy_to_user((struct watchdog_info *)arg, &ident,
|
|
sizeof(ident)) ? -EFAULT : 0;
|
|
break;
|
|
|
|
case WDIOC_GETSTATUS:
|
|
case WDIOC_GETBOOTSTATUS:
|
|
ret = put_user(0, (int *)arg);
|
|
break;
|
|
|
|
case WDIOC_KEEPALIVE:
|
|
orion_wdt_ping();
|
|
ret = 0;
|
|
break;
|
|
|
|
case WDIOC_SETTIMEOUT:
|
|
ret = get_user(time, (int *)arg);
|
|
if (ret)
|
|
break;
|
|
|
|
if (orion_wdt_settimeout(time)) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
orion_wdt_ping();
|
|
/* Fall through */
|
|
|
|
case WDIOC_GETTIMEOUT:
|
|
ret = put_user(heartbeat, (int *)arg);
|
|
break;
|
|
|
|
case WDIOC_GETTIMELEFT:
|
|
if (orion_wdt_get_timeleft(&time)) {
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
ret = put_user(time, (int *)arg);
|
|
break;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
static int orion_wdt_release(struct inode *inode, struct file *file)
|
|
{
|
|
if (test_bit(WDT_OK_TO_CLOSE, &wdt_status))
|
|
orion_wdt_disable();
|
|
else
|
|
pr_crit("Device closed unexpectedly - timer will not stop\n");
|
|
clear_bit(WDT_IN_USE, &wdt_status);
|
|
clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
static const struct file_operations orion_wdt_fops = {
|
|
.owner = THIS_MODULE,
|
|
.llseek = no_llseek,
|
|
.write = orion_wdt_write,
|
|
.unlocked_ioctl = orion_wdt_ioctl,
|
|
.open = orion_wdt_open,
|
|
.release = orion_wdt_release,
|
|
};
|
|
|
|
static struct miscdevice orion_wdt_miscdev = {
|
|
.minor = WATCHDOG_MINOR,
|
|
.name = "watchdog",
|
|
.fops = &orion_wdt_fops,
|
|
};
|
|
|
|
static int __devinit orion_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
struct resource *res;
|
|
int ret;
|
|
|
|
clk = clk_get(&pdev->dev, NULL);
|
|
if (IS_ERR(clk)) {
|
|
printk(KERN_ERR "Orion Watchdog missing clock\n");
|
|
return -ENODEV;
|
|
}
|
|
clk_prepare_enable(clk);
|
|
wdt_tclk = clk_get_rate(clk);
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
|
|
wdt_reg = ioremap(res->start, resource_size(res));
|
|
|
|
if (orion_wdt_miscdev.parent)
|
|
return -EBUSY;
|
|
orion_wdt_miscdev.parent = &pdev->dev;
|
|
|
|
wdt_max_duration = WDT_MAX_CYCLE_COUNT / wdt_tclk;
|
|
if (orion_wdt_settimeout(heartbeat))
|
|
heartbeat = wdt_max_duration;
|
|
|
|
ret = misc_register(&orion_wdt_miscdev);
|
|
if (ret)
|
|
return ret;
|
|
|
|
pr_info("Initial timeout %d sec%s\n",
|
|
heartbeat, nowayout ? ", nowayout" : "");
|
|
return 0;
|
|
}
|
|
|
|
static int __devexit orion_wdt_remove(struct platform_device *pdev)
|
|
{
|
|
int ret;
|
|
|
|
if (test_bit(WDT_IN_USE, &wdt_status)) {
|
|
orion_wdt_disable();
|
|
clear_bit(WDT_IN_USE, &wdt_status);
|
|
}
|
|
|
|
ret = misc_deregister(&orion_wdt_miscdev);
|
|
if (!ret)
|
|
orion_wdt_miscdev.parent = NULL;
|
|
|
|
clk_disable_unprepare(clk);
|
|
clk_put(clk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void orion_wdt_shutdown(struct platform_device *pdev)
|
|
{
|
|
if (test_bit(WDT_IN_USE, &wdt_status))
|
|
orion_wdt_disable();
|
|
}
|
|
|
|
static struct platform_driver orion_wdt_driver = {
|
|
.probe = orion_wdt_probe,
|
|
.remove = __devexit_p(orion_wdt_remove),
|
|
.shutdown = orion_wdt_shutdown,
|
|
.driver = {
|
|
.owner = THIS_MODULE,
|
|
.name = "orion_wdt",
|
|
},
|
|
};
|
|
|
|
module_platform_driver(orion_wdt_driver);
|
|
|
|
MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
|
|
MODULE_DESCRIPTION("Orion Processor Watchdog");
|
|
|
|
module_param(heartbeat, int, 0);
|
|
MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
|
|
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
|