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watchdog: Convert twl4030_wdt to watchdog core
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Convert the twl4030_wdt watchdog driver to watchdog core.

While at there use devm_kzalloc and set the default timeout in order to be
able test this driver with a simple shell script.

Signed-off-by: Jarkko Nikula <jarkko.nikula@jollamobile.com>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
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Jarkko Nikula authored and Wim Van Sebroeck committed Dec 19, 2012
1 parent 5235f57 commit b2c4e4b
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Showing 2 changed files with 35 additions and 149 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 @@ -300,6 +300,7 @@ config COH901327_WATCHDOG
config TWL4030_WATCHDOG
tristate "TWL4030 Watchdog"
depends on TWL4030_CORE
select WATCHDOG_CORE
help
Support for TI TWL4030 watchdog. Say 'Y' here to enable the
watchdog timer support for TWL4030 chips.
Expand Down
183 changes: 34 additions & 149 deletions drivers/watchdog/twl4030_wdt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -22,26 +22,12 @@
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/watchdog.h>
#include <linux/platform_device.h>
#include <linux/miscdevice.h>
#include <linux/uaccess.h>
#include <linux/i2c/twl.h>

#define TWL4030_WATCHDOG_CFG_REG_OFFS 0x3

#define TWL4030_WDT_STATE_OPEN 0x1
#define TWL4030_WDT_STATE_ACTIVE 0x8

static struct platform_device *twl4030_wdt_dev;

struct twl4030_wdt {
struct miscdevice miscdev;
int timer_margin;
unsigned long state;
};

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
Expand All @@ -53,190 +39,90 @@ static int twl4030_wdt_write(unsigned char val)
TWL4030_WATCHDOG_CFG_REG_OFFS);
}

static int twl4030_wdt_enable(struct twl4030_wdt *wdt)
static int twl4030_wdt_start(struct watchdog_device *wdt)
{
return twl4030_wdt_write(wdt->timer_margin + 1);
return twl4030_wdt_write(wdt->timeout + 1);
}

static int twl4030_wdt_disable(struct twl4030_wdt *wdt)
static int twl4030_wdt_stop(struct watchdog_device *wdt)
{
return twl4030_wdt_write(0);
}

static int twl4030_wdt_set_timeout(struct twl4030_wdt *wdt, int timeout)
{
if (timeout < 0 || timeout > 30) {
dev_warn(wdt->miscdev.parent,
"Timeout can only be in the range [0-30] seconds");
return -EINVAL;
}
wdt->timer_margin = timeout;
return twl4030_wdt_enable(wdt);
}

static ssize_t twl4030_wdt_write_fop(struct file *file,
const char __user *data, size_t len, loff_t *ppos)
static int twl4030_wdt_set_timeout(struct watchdog_device *wdt,
unsigned int timeout)
{
struct twl4030_wdt *wdt = file->private_data;

if (len)
twl4030_wdt_enable(wdt);

return len;
}

static long twl4030_wdt_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
int __user *p = argp;
int new_margin;
struct twl4030_wdt *wdt = file->private_data;

static const struct watchdog_info twl4030_wd_ident = {
.identity = "TWL4030 Watchdog",
.options = WDIOF_SETTIMEOUT,
.firmware_version = 0,
};

switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp, &twl4030_wd_ident,
sizeof(twl4030_wd_ident)) ? -EFAULT : 0;

case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);

case WDIOC_KEEPALIVE:
twl4030_wdt_enable(wdt);
break;

case WDIOC_SETTIMEOUT:
if (get_user(new_margin, p))
return -EFAULT;
if (twl4030_wdt_set_timeout(wdt, new_margin))
return -EINVAL;
return put_user(wdt->timer_margin, p);

case WDIOC_GETTIMEOUT:
return put_user(wdt->timer_margin, p);

default:
return -ENOTTY;
}

wdt->timeout = timeout;
return 0;
}

static int twl4030_wdt_open(struct inode *inode, struct file *file)
{
struct twl4030_wdt *wdt = platform_get_drvdata(twl4030_wdt_dev);

/* /dev/watchdog can only be opened once */
if (test_and_set_bit(0, &wdt->state))
return -EBUSY;

wdt->state |= TWL4030_WDT_STATE_ACTIVE;
file->private_data = (void *) wdt;

twl4030_wdt_enable(wdt);
return nonseekable_open(inode, file);
}

static int twl4030_wdt_release(struct inode *inode, struct file *file)
{
struct twl4030_wdt *wdt = file->private_data;
if (nowayout) {
dev_alert(wdt->miscdev.parent,
"Unexpected close, watchdog still running!\n");
twl4030_wdt_enable(wdt);
} else {
if (twl4030_wdt_disable(wdt))
return -EFAULT;
wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
}

clear_bit(0, &wdt->state);
return 0;
}
static const struct watchdog_info twl4030_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "TWL4030 Watchdog",
};

static const struct file_operations twl4030_wdt_fops = {
static const struct watchdog_ops twl4030_wdt_ops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.open = twl4030_wdt_open,
.release = twl4030_wdt_release,
.unlocked_ioctl = twl4030_wdt_ioctl,
.write = twl4030_wdt_write_fop,
.start = twl4030_wdt_start,
.stop = twl4030_wdt_stop,
.set_timeout = twl4030_wdt_set_timeout,
};

static int twl4030_wdt_probe(struct platform_device *pdev)
{
int ret = 0;
struct twl4030_wdt *wdt;
struct watchdog_device *wdt;

wdt = kzalloc(sizeof(struct twl4030_wdt), GFP_KERNEL);
wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL);
if (!wdt)
return -ENOMEM;

wdt->state = 0;
wdt->timer_margin = 30;
wdt->miscdev.parent = &pdev->dev;
wdt->miscdev.fops = &twl4030_wdt_fops;
wdt->miscdev.minor = WATCHDOG_MINOR;
wdt->miscdev.name = "watchdog";
wdt->info = &twl4030_wdt_info;
wdt->ops = &twl4030_wdt_ops;
wdt->status = 0;
wdt->timeout = 30;
wdt->min_timeout = 1;
wdt->max_timeout = 30;

watchdog_set_nowayout(wdt, nowayout);
platform_set_drvdata(pdev, wdt);

twl4030_wdt_dev = pdev;
twl4030_wdt_stop(wdt);

twl4030_wdt_disable(wdt);

ret = misc_register(&wdt->miscdev);
ret = watchdog_register_device(wdt);
if (ret) {
dev_err(wdt->miscdev.parent,
"Failed to register misc device\n");
platform_set_drvdata(pdev, NULL);
kfree(wdt);
twl4030_wdt_dev = NULL;
return ret;
}

return 0;
}

static int twl4030_wdt_remove(struct platform_device *pdev)
{
struct twl4030_wdt *wdt = platform_get_drvdata(pdev);

if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
if (twl4030_wdt_disable(wdt))
return -EFAULT;

wdt->state &= ~TWL4030_WDT_STATE_ACTIVE;
misc_deregister(&wdt->miscdev);
struct watchdog_device *wdt = platform_get_drvdata(pdev);

watchdog_unregister_device(wdt);
platform_set_drvdata(pdev, NULL);
kfree(wdt);
twl4030_wdt_dev = NULL;

return 0;
}

#ifdef CONFIG_PM
static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
{
struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
return twl4030_wdt_disable(wdt);
struct watchdog_device *wdt = platform_get_drvdata(pdev);
if (watchdog_active(wdt))
return twl4030_wdt_stop(wdt);

return 0;
}

static int twl4030_wdt_resume(struct platform_device *pdev)
{
struct twl4030_wdt *wdt = platform_get_drvdata(pdev);
if (wdt->state & TWL4030_WDT_STATE_ACTIVE)
return twl4030_wdt_enable(wdt);
struct watchdog_device *wdt = platform_get_drvdata(pdev);
if (watchdog_active(wdt))
return twl4030_wdt_start(wdt);

return 0;
}
Expand All @@ -260,6 +146,5 @@ module_platform_driver(twl4030_wdt_driver);

MODULE_AUTHOR("Nokia Corporation");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
MODULE_ALIAS("platform:twl4030_wdt");

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