net: usb: qmi_wwan: add qmap id sysfs file for qmimux interfaces

Add qmimux interface sysfs file qmap/mux_id to show qmap id set
during the interface creation, in order to provide a method for
userspace to associate QMI control channels to network interfaces.

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Acked-by: Bjørn Mork <bjorn@mork.no>
Acked-by: Aleksander Morgado <aleksander@aleksander.es>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index b96a3dc775a4e276761a187c712e833ff934eeca..29568ea8a9f257b3a3390a670d8267ef417e602b 100644 (file)
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -218,6 +218,28 @@ skip:
        return 1;
 }
 
+static ssize_t mux_id_show(struct device *d, struct device_attribute *attr, char *buf)
+{
+       struct net_device *dev = to_net_dev(d);
+       struct qmimux_priv *priv;
+
+       priv = netdev_priv(dev);
+
+       return sysfs_emit(buf, "0x%02x\n", priv->mux_id);
+}
+
+static DEVICE_ATTR_RO(mux_id);
+
+static struct attribute *qmi_wwan_sysfs_qmimux_attrs[] = {
+       &dev_attr_mux_id.attr,
+       NULL,
+};
+
+static struct attribute_group qmi_wwan_sysfs_qmimux_attr_group = {
+       .name = "qmap",
+       .attrs = qmi_wwan_sysfs_qmimux_attrs,
+};
+
 static int qmimux_register_device(struct net_device *real_dev, u8 mux_id)
 {
        struct net_device *new_dev;
@@ -240,6 +262,8 @@ static int qmimux_register_device(struct net_device *real_dev, u8 mux_id)
                goto out_free_newdev;
        }
 
+       new_dev->sysfs_groups[0] = &qmi_wwan_sysfs_qmimux_attr_group;
+
        err = register_netdevice(new_dev);
        if (err < 0)
                goto out_free_newdev;