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 <panand@redhat.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 1c427beffadd..71e47dde7d4a 100644
--- 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
 #