[PATCH v2 1/2] watchdog: report fw_version in sysfs

[Thomas Weißschuh]

This synchronizes the information reported by ioctl and sysfs.
The mismatch is confusing because "wdctl" from util-linux uses the ioctl
when used with root privileges and sysfs without.

The file is called "fw_version" instead of "firmware_version" as
"firmware_version" is already used as custom attribute by single drivers.

Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
 Documentation/ABI/testing/sysfs-class-watchdog |  7 +++++++
 drivers/watchdog/watchdog_dev.c                | 10 ++++++++++
 2 files changed, 17 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-class-watchdog b/Documentation/ABI/testing/sysfs-class-watchdog
index 585caecda3a5..27c000238fe4 100644
--- a/Documentation/ABI/testing/sysfs-class-watchdog
+++ b/Documentation/ABI/testing/sysfs-class-watchdog
@@ -6,6 +6,13 @@ Description:
 		device at boot. It is equivalent to WDIOC_GETBOOTSTATUS of
 		ioctl interface.
 
+What:		/sys/class/watchdog/watchdogn/fw_version
+Date:		April 2023
+Contact:	Thomas Weißschuh
+Description:
+		It is a read only file. It contains firmware version of
+		watchdog device.
+
 What:		/sys/class/watchdog/watchdogn/identity
 Date:		August 2015
 Contact:	Wim Van Sebroeck <wim@xxxxxxxxx>
diff --git a/drivers/watchdog/watchdog_dev.c b/drivers/watchdog/watchdog_dev.c
index 55574ed42504..7feeda02a531 100644
--- a/drivers/watchdog/watchdog_dev.c
+++ b/drivers/watchdog/watchdog_dev.c
@@ -546,6 +546,15 @@ static ssize_t pretimeout_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(pretimeout);
 
+static ssize_t fw_version_show(struct device *dev, struct device_attribute *attr,
+			       char *buf)
+{
+	struct watchdog_device *wdd = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", wdd->info->firmware_version);
+}
+static DEVICE_ATTR_RO(fw_version);
+
 static ssize_t identity_show(struct device *dev, struct device_attribute *attr,
 				char *buf)
 {
@@ -617,6 +626,7 @@ static umode_t wdt_is_visible(struct kobject *kobj, struct attribute *attr,
 }
 static struct attribute *wdt_attrs[] = {
 	&dev_attr_state.attr,
+	&dev_attr_fw_version.attr,
 	&dev_attr_identity.attr,
 	&dev_attr_timeout.attr,
 	&dev_attr_min_timeout.attr,

-- 
2.39.0