[PATCH wireless-next] wifi: cfg80211: add fw_version device attribute for sysfs

[PATCH wireless-next] wifi: cfg80211: add fw_version device attribute for sysfs

[Rory Little]

The firmware version is already exposed via ethtool, but is not
accessible without an attached interface to create a netdev. Expose this
info in sysfs to allow users to query it without the use of ethtool.

Signed-off-by: Rory Little <roryl@candelatech.com>
---
 Documentation/ABI/testing/sysfs-class-ieee80211 |  7 +++++++
 MAINTAINERS                                     |  1 +
 net/wireless/sysfs.c                            | 14 ++++++++++++++
 3 files changed, 22 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-ieee80211

diff --git a/Documentation/ABI/testing/sysfs-class-ieee80211 b/Documentation/ABI/testing/sysfs-class-ieee80211
new file mode 100644
index 000000000000..caaf4f3fd4b4
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-ieee80211
@@ -0,0 +1,7 @@
+What:		/sys/class/ieee80211/<phyname>/fw_version
+Date:		July 2026
+Contact:	linux-wireless@vger.kernel.org
+Description:	Read-only firmware version string provided by the driver for
+		this wireless device. The read data will match the information
+		provided by ethtool get_drvinfo. As drivers are not required to
+		provide this information, reading may yield no data.
diff --git a/MAINTAINERS b/MAINTAINERS
index 2d420d40782e..56181edb718f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -117,6 +117,7 @@ W:	https://wireless.wiki.kernel.org/
 Q:	https://patchwork.kernel.org/project/linux-wireless/list/
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless.git
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless-next.git
+F:	Documentation/ABI/testing/sysfs-class-ieee80211
 F:	Documentation/driver-api/80211/cfg80211.rst
 F:	Documentation/networking/regulatory.rst
 F:	include/linux/ieee80211.h
diff --git a/net/wireless/sysfs.c b/net/wireless/sysfs.c
index 3ec25d3f004e..e63b6d1fa411 100644
--- a/net/wireless/sysfs.c
+++ b/net/wireless/sysfs.c
@@ -65,12 +65,26 @@ static ssize_t addresses_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(addresses);
 
+static ssize_t fw_version_show(struct device *dev,
+			       struct device_attribute *attr,
+			       char *buf)
+{
+	struct wiphy *wiphy = &dev_to_rdev(dev)->wiphy;
+
+	if (!wiphy->fw_version[0])
+		return 0;
+
+	return sysfs_emit(buf, "%s\n", wiphy->fw_version);
+}
+static DEVICE_ATTR_RO(fw_version);
+
 static struct attribute *ieee80211_attrs[] = {
 	&dev_attr_index.attr,
 	&dev_attr_macaddress.attr,
 	&dev_attr_address_mask.attr,
 	&dev_attr_addresses.attr,
 	&dev_attr_name.attr,
+	&dev_attr_fw_version.attr,
 	NULL,
 };
 ATTRIBUTE_GROUPS(ieee80211);
-- 
2.52.0

Re: [PATCH wireless-next] wifi: cfg80211: add fw_version device attribute for sysfs

[Jeff Johnson]

On 7/28/2026 4:47 PM, Rory Little wrote:
> The firmware version is already exposed via ethtool, but is not
> accessible without an attached interface to create a netdev. Expose this
> info in sysfs to allow users to query it without the use of ethtool.

Curious what is the value?

It looks like many drivers, including ath11k and ath12k, do not populate this.

And this attribute is pointless for Wi-Fi 7 drivers supporting MLO with
multiple underlying hardware running different firmware images. I suspect
there are a few wiphy attributes that have this issue.

You'd need to instantiate these attribute on a per-radio basis to properly
handle the new multi-radio wiphy model.

/jeff