From 33b711269ade3f6bc9d9d15e4343e6fa922d999b Mon Sep 17 00:00:00 2001 From: Pratyush Anand Date: Thu, 17 Dec 2015 17:53:59 +0530 Subject: watchdog: Read device status through sysfs attributes This patch adds following attributes to watchdog device's sysfs interface to read its different status. * state - reads whether device is active or not * identity - reads Watchdog device's identity string. * timeout - reads current timeout. * timeleft - reads timeleft before watchdog generates a reset * bootstatus - reads status of the watchdog device at boot * status - reads watchdog device's internal status bits * nowayout - reads whether nowayout feature was set or not Testing with iTCO_wdt: # cd /sys/class/watchdog/watchdog1/ # ls bootstatus dev device identity nowayout power state subsystem timeleft timeout uevent # cat identity iTCO_wdt # cat timeout 30 # cat state inactive # echo > /dev/watchdog1 # cat timeleft 26 # cat state active # cat bootstatus 0 # cat nowayout 0 Signed-off-by: Pratyush Anand Reviewed-by: Guenter Roeck Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- Documentation/ABI/testing/sysfs-class-watchdog | 51 +++++++++++ drivers/watchdog/Kconfig | 7 ++ drivers/watchdog/watchdog_core.c | 2 +- drivers/watchdog/watchdog_dev.c | 114 +++++++++++++++++++++++++ 4 files changed, 173 insertions(+), 1 deletion(-) create mode 100644 Documentation/ABI/testing/sysfs-class-watchdog --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-watchdog @@ -0,0 +1,51 @@ +What: /sys/class/watchdog/watchdogn/bootstatus +Date: August 2015 +Contact: Wim Van Sebroeck +Description: + It is a read only file. It contains status of the watchdog + device at boot. It is equivalent to WDIOC_GETBOOTSTATUS of + ioctl interface. + +What: /sys/class/watchdog/watchdogn/identity +Date: August 2015 +Contact: Wim Van Sebroeck +Description: + It is a read only file. It contains identity string of + watchdog device. + +What: /sys/class/watchdog/watchdogn/nowayout +Date: August 2015 +Contact: Wim Van Sebroeck +Description: + It is a read only file. While reading, it gives '1' if that + device supports nowayout feature else, it gives '0'. + +What: /sys/class/watchdog/watchdogn/state +Date: August 2015 +Contact: Wim Van Sebroeck +Description: + It is a read only file. It gives active/inactive status of + watchdog device. + +What: /sys/class/watchdog/watchdogn/status +Date: August 2015 +Contact: Wim Van Sebroeck +Description: + It is a read only file. It contains watchdog device's + internal status bits. It is equivalent to WDIOC_GETSTATUS + of ioctl interface. + +What: /sys/class/watchdog/watchdogn/timeleft +Date: August 2015 +Contact: Wim Van Sebroeck +Description: + It is a read only file. It contains value of time left for + reset generation. It is equivalent to WDIOC_GETTIMELEFT of + ioctl interface. + +What: /sys/class/watchdog/watchdogn/timeout +Date: August 2015 +Contact: Wim Van Sebroeck +Description: + It is a read only file. It is read to know about current + value of timeout programmed. --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -46,6 +46,13 @@ config WATCHDOG_NOWAYOUT get killed. If you say Y here, the watchdog cannot be stopped once it has been started. +config WATCHDOG_SYSFS + bool "Read different watchdog information through sysfs" + default n + help + Say Y here if you want to enable watchdog device status read through + sysfs attributes. + # # General Watchdog drivers # --- a/drivers/watchdog/watchdog_core.c +++ b/drivers/watchdog/watchdog_core.c @@ -249,7 +249,7 @@ static int __watchdog_register_device(st devno = wdd->cdev.dev; wdd->dev = device_create(watchdog_class, wdd->parent, devno, - NULL, "watchdog%d", wdd->id); + wdd, "watchdog%d", wdd->id); if (IS_ERR(wdd->dev)) { watchdog_dev_unregister(wdd); ida_simple_remove(&watchdog_ida, id); --- a/drivers/watchdog/watchdog_dev.c +++ b/drivers/watchdog/watchdog_dev.c @@ -247,6 +247,119 @@ out_timeleft: return err; } +#ifdef CONFIG_WATCHDOG_SYSFS +static ssize_t nowayout_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sprintf(buf, "%d\n", !!test_bit(WDOG_NO_WAY_OUT, &wdd->status)); +} +static DEVICE_ATTR_RO(nowayout); + +static ssize_t status_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + ssize_t status; + unsigned int val; + + status = watchdog_get_status(wdd, &val); + if (!status) + status = sprintf(buf, "%u\n", val); + + return status; +} +static DEVICE_ATTR_RO(status); + +static ssize_t bootstatus_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", wdd->bootstatus); +} +static DEVICE_ATTR_RO(bootstatus); + +static ssize_t timeleft_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + ssize_t status; + unsigned int val; + + status = watchdog_get_timeleft(wdd, &val); + if (!status) + status = sprintf(buf, "%u\n", val); + + return status; +} +static DEVICE_ATTR_RO(timeleft); + +static ssize_t timeout_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sprintf(buf, "%u\n", wdd->timeout); +} +static DEVICE_ATTR_RO(timeout); + +static ssize_t identity_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + return sprintf(buf, "%s\n", wdd->info->identity); +} +static DEVICE_ATTR_RO(identity); + +static ssize_t state_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct watchdog_device *wdd = dev_get_drvdata(dev); + + if (watchdog_active(wdd)) + return sprintf(buf, "active\n"); + + return sprintf(buf, "inactive\n"); +} +static DEVICE_ATTR_RO(state); + +static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr, + int n) +{ + struct device *dev = container_of(kobj, struct device, kobj); + struct watchdog_device *wdd = dev_get_drvdata(dev); + umode_t mode = attr->mode; + + if (attr == &dev_attr_status.attr && !wdd->ops->status) + mode = 0; + else if (attr == &dev_attr_timeleft.attr && !wdd->ops->get_timeleft) + mode = 0; + + return mode; +} +static struct attribute *wdt_attrs[] = { + &dev_attr_state.attr, + &dev_attr_identity.attr, + &dev_attr_timeout.attr, + &dev_attr_timeleft.attr, + &dev_attr_bootstatus.attr, + &dev_attr_status.attr, + &dev_attr_nowayout.attr, + NULL, +}; + +static const struct attribute_group wdt_group = { + .attrs = wdt_attrs, + .is_visible = wdt_is_visible, +}; +__ATTRIBUTE_GROUPS(wdt); +#else +#define wdt_groups NULL +#endif + /* * watchdog_ioctl_op: call the watchdog drivers ioctl op if defined * @wdd: the watchdog device to do the ioctl on @@ -584,6 +697,7 @@ int watchdog_dev_unregister(struct watch static struct class watchdog_class = { .name = "watchdog", .owner = THIS_MODULE, + .dev_groups = wdt_groups, }; /*