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watchdog: coh901327: convert to use watchdog core
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This converts the COH901327 watchdog to use the watchdog core.
I followed Wolframs document, looked at some other drivers and
tested it on the U300.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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Linus Walleij authored and Wim Van Sebroeck committed Mar 27, 2012
1 parent fd7b673 commit 15b2570
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Showing 2 changed files with 56 additions and 137 deletions.
1 change: 1 addition & 0 deletions drivers/watchdog/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -287,6 +287,7 @@ config COH901327_WATCHDOG
bool "ST-Ericsson COH 901 327 watchdog"
depends on ARCH_U300
default y if MACH_U300
select WATCHDOG_CORE
help
Say Y here to include Watchdog timer support for the
watchdog embedded into the ST-Ericsson U300 series platforms.
Expand Down
192 changes: 55 additions & 137 deletions drivers/watchdog/coh901327_wdt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -8,17 +8,15 @@
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/interrupt.h>
#include <linux/pm.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/bitops.h>
#include <linux/uaccess.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/err.h>

#define DRV_NAME "WDOG COH 901 327"

Expand Down Expand Up @@ -74,8 +72,6 @@ static resource_size_t phybase;
static resource_size_t physize;
static int irq;
static void __iomem *virtbase;
static unsigned long coh901327_users;
static unsigned long boot_status;
static struct device *parent;

/*
Expand Down Expand Up @@ -155,30 +151,31 @@ static void coh901327_disable(void)
__func__, val);
}

static void coh901327_start(void)
static int coh901327_start(struct watchdog_device *wdt_dev)
{
coh901327_enable(margin * 100);
return 0;
}

static int coh901327_stop(struct watchdog_device *wdt_dev)
{
coh901327_disable();
return 0;
}

static void coh901327_keepalive(void)
static int coh901327_ping(struct watchdog_device *wdd)
{
clk_enable(clk);
/* Feed the watchdog */
writew(U300_WDOG_FR_FEED_RESTART_TIMER,
virtbase + U300_WDOG_FR);
clk_disable(clk);
return 0;
}

static int coh901327_settimeout(int time)
static int coh901327_settimeout(struct watchdog_device *wdt_dev,
unsigned int time)
{
/*
* Max margin is 327 since the 10ms
* timeout register is max
* 0x7FFF = 327670ms ~= 327s.
*/
if (time <= 0 || time > 327)
return -EINVAL;

margin = time;
clk_enable(clk);
/* Set new timeout value */
Expand All @@ -190,6 +187,23 @@ static int coh901327_settimeout(int time)
return 0;
}

static unsigned int coh901327_gettimeleft(struct watchdog_device *wdt_dev)
{
u16 val;

clk_enable(clk);
/* Read repeatedly until the value is stable! */
val = readw(virtbase + U300_WDOG_CR);
while (val & U300_WDOG_CR_VALID_IND)
val = readw(virtbase + U300_WDOG_CR);
val &= U300_WDOG_CR_COUNT_VALUE_MASK;
clk_disable(clk);
if (val != 0)
val /= 100;

return val;
}

/*
* This interrupt occurs 10 ms before the watchdog WILL bark.
*/
Expand Down Expand Up @@ -218,130 +232,35 @@ static irqreturn_t coh901327_interrupt(int irq, void *data)
return IRQ_HANDLED;
}

/*
* Allow only one user (daemon) to open the watchdog
*/
static int coh901327_open(struct inode *inode, struct file *file)
{
if (test_and_set_bit(1, &coh901327_users))
return -EBUSY;
coh901327_start();
return nonseekable_open(inode, file);
}

static int coh901327_release(struct inode *inode, struct file *file)
{
clear_bit(1, &coh901327_users);
coh901327_disable();
return 0;
}

static ssize_t coh901327_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
if (len)
coh901327_keepalive();
return len;
}

static long coh901327_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret = -ENOTTY;
u16 val;
int time;
int new_options;
union {
struct watchdog_info __user *ident;
int __user *i;
} uarg;
static const struct watchdog_info ident = {
.options = WDIOF_CARDRESET |
WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING,
.identity = "COH 901 327 Watchdog",
.firmware_version = 1,
};
uarg.i = (int __user *)arg;

switch (cmd) {
case WDIOC_GETSUPPORT:
ret = copy_to_user(uarg.ident, &ident,
sizeof(ident)) ? -EFAULT : 0;
break;

case WDIOC_GETSTATUS:
ret = put_user(0, uarg.i);
break;

case WDIOC_GETBOOTSTATUS:
ret = put_user(boot_status, uarg.i);
break;

case WDIOC_SETOPTIONS:
ret = get_user(new_options, uarg.i);
if (ret)
break;
if (new_options & WDIOS_DISABLECARD)
coh901327_disable();
if (new_options & WDIOS_ENABLECARD)
coh901327_start();
ret = 0;
break;

case WDIOC_KEEPALIVE:
coh901327_keepalive();
ret = 0;
break;

case WDIOC_SETTIMEOUT:
ret = get_user(time, uarg.i);
if (ret)
break;

ret = coh901327_settimeout(time);
if (ret)
break;
/* Then fall through to return set value */

case WDIOC_GETTIMEOUT:
ret = put_user(margin, uarg.i);
break;

case WDIOC_GETTIMELEFT:
clk_enable(clk);
/* Read repeatedly until the value is stable! */
val = readw(virtbase + U300_WDOG_CR);
while (val & U300_WDOG_CR_VALID_IND)
val = readw(virtbase + U300_WDOG_CR);
val &= U300_WDOG_CR_COUNT_VALUE_MASK;
clk_disable(clk);
if (val != 0)
val /= 100;
ret = put_user(val, uarg.i);
break;
}
return ret;
}
static const struct watchdog_info coh901327_ident = {
.options = WDIOF_CARDRESET | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = DRV_NAME,
};

static const struct file_operations coh901327_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = coh901327_write,
.unlocked_ioctl = coh901327_ioctl,
.open = coh901327_open,
.release = coh901327_release,
static struct watchdog_ops coh901327_ops = {
.owner = THIS_MODULE,
.start = coh901327_start,
.stop = coh901327_stop,
.ping = coh901327_ping,
.set_timeout = coh901327_settimeout,
.get_timeleft = coh901327_gettimeleft,
};

static struct miscdevice coh901327_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &coh901327_fops,
static struct watchdog_device coh901327_wdt = {
.info = &coh901327_ident,
.ops = &coh901327_ops,
/*
* Max margin is 327 since the 10ms
* timeout register is max
* 0x7FFF = 327670ms ~= 327s.
*/
.min_timeout = 0,
.max_timeout = 327,
};

static int __exit coh901327_remove(struct platform_device *pdev)
{
misc_deregister(&coh901327_miscdev);
watchdog_unregister_device(&coh901327_wdt);
coh901327_disable();
free_irq(irq, pdev);
clk_put(clk);
Expand All @@ -350,7 +269,6 @@ static int __exit coh901327_remove(struct platform_device *pdev)
return 0;
}


static int __init coh901327_probe(struct platform_device *pdev)
{
int ret;
Expand Down Expand Up @@ -393,7 +311,7 @@ static int __init coh901327_probe(struct platform_device *pdev)
case U300_WDOG_SR_STATUS_TIMED_OUT:
dev_info(&pdev->dev,
"watchdog timed out since last chip reset!\n");
boot_status = WDIOF_CARDRESET;
coh901327_wdt.bootstatus |= WDIOF_CARDRESET;
/* Status will be cleared below */
break;
case U300_WDOG_SR_STATUS_NORMAL:
Expand Down Expand Up @@ -435,7 +353,7 @@ static int __init coh901327_probe(struct platform_device *pdev)

clk_disable(clk);

ret = misc_register(&coh901327_miscdev);
ret = watchdog_register_device(&coh901327_wdt);
if (ret == 0)
dev_info(&pdev->dev,
"initialized. timer margin=%d sec\n", margin);
Expand Down Expand Up @@ -547,4 +465,4 @@ module_param(margin, int, 0);
MODULE_PARM_DESC(margin, "Watchdog margin in seconds (default 60s)");

MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("platform:coh901327-watchdog");

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