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    SubjectRE: [PATCH v2] rtc: rtc-ds1374: wdt: Use watchdog core for watchdog part
    Date
    Hi,

    Thanks for your good suggestions!

    > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index
    > > b54d87d45c89..5e2444af5657 100644
    > > --- a/drivers/rtc/Kconfig
    > > +++ b/drivers/rtc/Kconfig
    > > @@ -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
    >
    > This has to be
    >
    > select WATCHDOG_CORE if WATCHDOG
    >
    > to fix the problem reported by 0-day.
    >
    > > help
    > > If you say Y here you will get support for the
    > > watchdog timer in the Dallas Semiconductor DS1374 diff --git
    > > a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c index
    > > 9c51a12cf70f..57a4e503b34a 100644
    > > --- a/drivers/rtc/rtc-ds1374.c
    > > +++ b/drivers/rtc/rtc-ds1374.c
    > > @@ -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 */
    > > @@ -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.
    > > @@ -371,72 +374,76 @@ static const struct rtc_class_ops ds1374_rtc_ops =
    > {
    > > */
    > > static struct i2c_client *save_client;
    >
    > This is no longer necessary. struct watchdog_device is part of struct ds1374, so
    > it is possible to derive the pointer to struct ds1374 from it and get the client
    > pointer from there.
    >
    > > /* 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 = TIMER_MARGIN_DEFAULT;
    >
    > Should be 0, not TIMER_MARGIN_DEFAULT.
    >
    > > 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;
    > > + 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(save_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);
    > > if (ret < 0)
    > > - goto out;
    > > + return ret;
    > >
    > > /* Set new watchdog time */
    > > + timeout = timeout * 4096;
    > > ret = ds1374_write_rtc(save_client, timeout, DS1374_REG_WDALM0, 3);
    > > if (ret) {
    > > pr_info("couldn't set new watchdog time\n");
    >
    > dev_info() can now be used since we have a device. _info seems to be wrong,
    > though, since this is an error.
    >
    > > - goto out;
    > > + 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);
    > > 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)
    > > {
    > > 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(save_client, &val, DS1374_REG_WDALM0, 3);
    > > }
    > >
    > > -static void ds1374_wdt_disable(void)
    > > +static int ds1374_wdt_stop(struct watchdog_device *wdt)
    > > {
    > > int cr;
    > >
    > > @@ -444,162 +451,16 @@ static void ds1374_wdt_disable(void)
    > > /* 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(save_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 const struct watchdog_ops ds1374_wdt_ops = {
    > > + .owner = THIS_MODULE,
    > > + .start = ds1374_wdt_start,
    > > + .stop = ds1374_wdt_stop,
    > > + .set_timeout = ds1374_wdt_settimeout,
    > > };
    > >
    > > -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,
    > > -};
    > >
    > > #endif /*CONFIG_RTC_DRV_DS1374_WDT*/
    > > /*
    > > @@ -653,15 +514,25 @@ static int ds1374_probe(struct i2c_client
    > > *client,
    > >
    > > #ifdef CONFIG_RTC_DRV_DS1374_WDT
    > > save_client = client;
    > > - ret = misc_register(&ds1374_miscdev);
    > > - if (ret)
    > > - return ret;
    > > - ret = register_reboot_notifier(&ds1374_wdt_notifier);
    > > + 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);
    > > + ds1374_wdt_settimeout(&ds1374->wdt, wdt_margin);
    > > +
    > > + ret = devm_watchdog_register_device(&client->dev, &ds1374->wdt);
    > > if (ret) {
    > > - misc_deregister(&ds1374_miscdev);
    > > + dev_err(&client->dev, "failed to register DS1374 watchdog
    > > +device\n");
    > > return ret;
    > > }
    > > - ds1374_wdt_settimeout(131072);
    > > +
    > > + dev_info(&client->dev, "DS1374 watchdog device enabled\n");
    >
    > Is that necessary ?
    >

    I think it's good to show watchdog initial timeout. I'll include above suggestions in v3, thanks!

    Best regards,
    Johnson
    > > #endif
    > >
    > > return 0;
    > > @@ -670,11 +541,6 @@ 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);
    > > --
    > > 2.20.1
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