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rtc: ds1374: wdt: Use watchdog core for watchdog part
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Let ds1374 watchdog use watchdog core functions. It also includes
improving watchdog timer setting and nowayout, and just uses ioctl()
of watchdog core.

Signed-off-by: Johnson Chen <johnsonch.chen@moxa.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/HK2PR01MB328182D5A54BFAA8A22E448AFA640@HK2PR01MB3281.apcprd01.prod.exchangelabs.com
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Johnson CH Chen (陳昭勳) authored and Alexandre Belloni committed Jul 16, 2020
1 parent 3567d3d commit d3de4be
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Showing 2 changed files with 62 additions and 197 deletions.
1 change: 1 addition & 0 deletions drivers/rtc/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -282,6 +282,7 @@ config RTC_DRV_DS1374
config RTC_DRV_DS1374_WDT
bool "Dallas/Maxim DS1374 watchdog timer"
depends on RTC_DRV_DS1374
select WATCHDOG_CORE if WATCHDOG
help
If you say Y here you will get support for the
watchdog timer in the Dallas Semiconductor DS1374
Expand Down
258 changes: 61 additions & 197 deletions drivers/rtc/rtc-ds1374.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -46,6 +46,7 @@
#define DS1374_REG_WDALM2 0x06
#define DS1374_REG_CR 0x07 /* Control */
#define DS1374_REG_CR_AIE 0x01 /* Alarm Int. Enable */
#define DS1374_REG_CR_WDSTR 0x08 /* 1=INT, 0=RST */
#define DS1374_REG_CR_WDALM 0x20 /* 1=Watchdog, 0=Alarm */
#define DS1374_REG_CR_WACE 0x40 /* WD/Alarm counter enable */
#define DS1374_REG_SR 0x08 /* Status */
Expand All @@ -71,7 +72,9 @@ struct ds1374 {
struct i2c_client *client;
struct rtc_device *rtc;
struct work_struct work;

#ifdef CONFIG_RTC_DRV_DS1374_WDT
struct watchdog_device wdt;
#endif
/* The mutex protects alarm operations, and prevents a race
* between the enable_irq() in the workqueue and the free_irq()
* in the remove function.
Expand Down Expand Up @@ -369,238 +372,98 @@ static const struct rtc_class_ops ds1374_rtc_ops = {
*
*****************************************************************************
*/
static struct i2c_client *save_client;
/* Default margin */
#define WD_TIMO 131762
#define TIMER_MARGIN_DEFAULT 32
#define TIMER_MARGIN_MIN 1
#define TIMER_MARGIN_MAX 4095 /* 24-bit value */

#define DRV_NAME "DS1374 Watchdog"

static int wdt_margin = WD_TIMO;
static unsigned long wdt_is_open;
static int wdt_margin;
module_param(wdt_margin, int, 0);
MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)");

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default ="
__MODULE_STRING(WATCHDOG_NOWAYOUT)")");

static const struct watchdog_info ds1374_wdt_info = {
.identity = "DS1374 WTD",
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
};

static int ds1374_wdt_settimeout(unsigned int timeout)
static int ds1374_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout)
{
int ret = -ENOIOCTLCMD;
int cr;
struct ds1374 *ds1374 = watchdog_get_drvdata(wdt);
struct i2c_client *client = ds1374->client;
int ret, cr;

ret = cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
if (ret < 0)
goto out;
wdt->timeout = timeout;

cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
if (cr < 0)
return cr;

/* Disable any existing watchdog/alarm before setting the new one */
cr &= ~DS1374_REG_CR_WACE;

ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
if (ret < 0)
goto out;
return ret;

/* Set new watchdog time */
ret = ds1374_write_rtc(save_client, timeout, DS1374_REG_WDALM0, 3);
if (ret) {
pr_info("couldn't set new watchdog time\n");
goto out;
}
timeout = timeout * 4096;
ret = ds1374_write_rtc(client, timeout, DS1374_REG_WDALM0, 3);
if (ret)
return ret;

/* Enable watchdog timer */
cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_WDALM;
cr &= ~DS1374_REG_CR_WDSTR;/* for RST PIN */
cr &= ~DS1374_REG_CR_AIE;

ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
if (ret < 0)
goto out;
return ret;

return 0;
out:
return ret;
}


/*
* Reload the watchdog timer. (ie, pat the watchdog)
*/
static void ds1374_wdt_ping(void)
static int ds1374_wdt_start(struct watchdog_device *wdt)
{
struct ds1374 *ds1374 = watchdog_get_drvdata(wdt);
u32 val;
int ret = 0;

ret = ds1374_read_rtc(save_client, &val, DS1374_REG_WDALM0, 3);
if (ret)
pr_info("WD TICK FAIL!!!!!!!!!! %i\n", ret);
return ds1374_read_rtc(ds1374->client, &val, DS1374_REG_WDALM0, 3);
}

static void ds1374_wdt_disable(void)
static int ds1374_wdt_stop(struct watchdog_device *wdt)
{
struct ds1374 *ds1374 = watchdog_get_drvdata(wdt);
struct i2c_client *client = ds1374->client;
int cr;

cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR);
if (cr < 0)
return cr;

/* Disable watchdog timer */
cr &= ~DS1374_REG_CR_WACE;

i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
}

/*
* Watchdog device is opened, and watchdog starts running.
*/
static int ds1374_wdt_open(struct inode *inode, struct file *file)
{
struct ds1374 *ds1374 = i2c_get_clientdata(save_client);

if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
mutex_lock(&ds1374->mutex);
if (test_and_set_bit(0, &wdt_is_open)) {
mutex_unlock(&ds1374->mutex);
return -EBUSY;
}
/*
* Activate
*/
wdt_is_open = 1;
mutex_unlock(&ds1374->mutex);
return stream_open(inode, file);
}
return -ENODEV;
}

/*
* Close the watchdog device.
*/
static int ds1374_wdt_release(struct inode *inode, struct file *file)
{
if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
clear_bit(0, &wdt_is_open);

return 0;
return i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr);
}

/*
* Pat the watchdog whenever device is written to.
*/
static ssize_t ds1374_wdt_write(struct file *file, const char __user *data,
size_t len, loff_t *ppos)
{
if (len) {
ds1374_wdt_ping();
return 1;
}
return 0;
}

static ssize_t ds1374_wdt_read(struct file *file, char __user *data,
size_t len, loff_t *ppos)
{
return 0;
}

/*
* Handle commands from user-space.
*/
static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int new_margin, options;

switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user((struct watchdog_info __user *)arg,
&ds1374_wdt_info, sizeof(ds1374_wdt_info)) ? -EFAULT : 0;

case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, (int __user *)arg);
case WDIOC_KEEPALIVE:
ds1374_wdt_ping();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_margin, (int __user *)arg))
return -EFAULT;

/* the hardware's tick rate is 4096 Hz, so
* the counter value needs to be scaled accordingly
*/
new_margin <<= 12;
if (new_margin < 1 || new_margin > 16777216)
return -EINVAL;

wdt_margin = new_margin;
ds1374_wdt_settimeout(new_margin);
ds1374_wdt_ping();
/* fallthrough */
case WDIOC_GETTIMEOUT:
/* when returning ... inverse is true */
return put_user((wdt_margin >> 12), (int __user *)arg);
case WDIOC_SETOPTIONS:
if (copy_from_user(&options, (int __user *)arg, sizeof(int)))
return -EFAULT;

if (options & WDIOS_DISABLECARD) {
pr_info("disable watchdog\n");
ds1374_wdt_disable();
return 0;
}

if (options & WDIOS_ENABLECARD) {
pr_info("enable watchdog\n");
ds1374_wdt_settimeout(wdt_margin);
ds1374_wdt_ping();
return 0;
}
return -EINVAL;
}
return -ENOTTY;
}

static long ds1374_wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
int ret;
struct ds1374 *ds1374 = i2c_get_clientdata(save_client);

mutex_lock(&ds1374->mutex);
ret = ds1374_wdt_ioctl(file, cmd, arg);
mutex_unlock(&ds1374->mutex);

return ret;
}

static int ds1374_wdt_notify_sys(struct notifier_block *this,
unsigned long code, void *unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
/* Disable Watchdog */
ds1374_wdt_disable();
return NOTIFY_DONE;
}

static const struct file_operations ds1374_wdt_fops = {
.owner = THIS_MODULE,
.read = ds1374_wdt_read,
.unlocked_ioctl = ds1374_wdt_unlocked_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.write = ds1374_wdt_write,
.open = ds1374_wdt_open,
.release = ds1374_wdt_release,
.llseek = no_llseek,
};

static struct miscdevice ds1374_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &ds1374_wdt_fops,
};

static struct notifier_block ds1374_wdt_notifier = {
.notifier_call = ds1374_wdt_notify_sys,
static const struct watchdog_ops ds1374_wdt_ops = {
.owner = THIS_MODULE,
.start = ds1374_wdt_start,
.stop = ds1374_wdt_stop,
.set_timeout = ds1374_wdt_settimeout,
};

#endif /*CONFIG_RTC_DRV_DS1374_WDT*/
/*
*****************************************************************************
Expand Down Expand Up @@ -652,16 +515,22 @@ static int ds1374_probe(struct i2c_client *client,
return ret;

#ifdef CONFIG_RTC_DRV_DS1374_WDT
save_client = client;
ret = misc_register(&ds1374_miscdev);
ds1374->wdt.info = &ds1374_wdt_info;
ds1374->wdt.ops = &ds1374_wdt_ops;
ds1374->wdt.timeout = TIMER_MARGIN_DEFAULT;
ds1374->wdt.min_timeout = TIMER_MARGIN_MIN;
ds1374->wdt.max_timeout = TIMER_MARGIN_MAX;

watchdog_init_timeout(&ds1374->wdt, wdt_margin, &client->dev);
watchdog_set_nowayout(&ds1374->wdt, nowayout);
watchdog_stop_on_reboot(&ds1374->wdt);
watchdog_stop_on_unregister(&ds1374->wdt);
watchdog_set_drvdata(&ds1374->wdt, ds1374);
ds1374_wdt_settimeout(&ds1374->wdt, ds1374->wdt.timeout);

ret = devm_watchdog_register_device(&client->dev, &ds1374->wdt);
if (ret)
return ret;
ret = register_reboot_notifier(&ds1374_wdt_notifier);
if (ret) {
misc_deregister(&ds1374_miscdev);
return ret;
}
ds1374_wdt_settimeout(131072);
#endif

return 0;
Expand All @@ -670,11 +539,6 @@ static int ds1374_probe(struct i2c_client *client,
static int ds1374_remove(struct i2c_client *client)
{
struct ds1374 *ds1374 = i2c_get_clientdata(client);
#ifdef CONFIG_RTC_DRV_DS1374_WDT
misc_deregister(&ds1374_miscdev);
ds1374_miscdev.parent = NULL;
unregister_reboot_notifier(&ds1374_wdt_notifier);
#endif

if (client->irq > 0) {
mutex_lock(&ds1374->mutex);
Expand Down

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