rtc: ds1374: wdt: Use watchdog core for watchdog part
authorJohnson CH Chen (陳昭勳) <JohnsonCH.Chen@moxa.com>
Thu, 9 Jul 2020 06:34:06 +0000 (06:34 +0000)
committerAlexandre Belloni <alexandre.belloni@bootlin.com>
Thu, 16 Jul 2020 09:24:06 +0000 (11:24 +0200)
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
drivers/rtc/Kconfig
drivers/rtc/rtc-ds1374.c

index b54d87d..c25d51f 100644 (file)
@@ -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
index 9c51a12..c71065d 100644 (file)
@@ -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.
@@ -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*/
 /*
  *****************************************************************************
@@ -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;
@@ -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);