Integrate generic net_selftest framework by wiring up
.get_strings, .get_sset_count, and .self_test ethtool ops.

This enables execution of standard self-tests using
`ethtool -t <dev>` on LAN78xx devices.

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
---
 drivers/net/usb/Kconfig   | 1 +
 drivers/net/usb/lan78xx.c | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
index 0a678e31cfaa..856e648d804e 100644
--- a/drivers/net/usb/Kconfig
+++ b/drivers/net/usb/Kconfig
@@ -116,6 +116,7 @@ config USB_LAN78XX
 	select PHYLINK
 	select MICROCHIP_PHY
 	select CRC32
+	imply NET_SELFTESTS
 	help
 	  This option adds support for Microchip LAN78XX based USB 2
 	  & USB 3 10/100/1000 Ethernet adapters.
diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index 1ff25f57329a..b56e2459ee3c 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -20,6 +20,7 @@
 #include <linux/mdio.h>
 #include <linux/phy.h>
 #include <net/ip6_checksum.h>
+#include <net/selftests.h>
 #include <net/vxlan.h>
 #include <linux/interrupt.h>
 #include <linux/irqdomain.h>
@@ -1702,12 +1703,16 @@ static void lan78xx_get_strings(struct net_device *netdev, u32 stringset,
 {
 	if (stringset == ETH_SS_STATS)
 		memcpy(data, lan78xx_gstrings, sizeof(lan78xx_gstrings));
+	else if (stringset == ETH_SS_TEST)
+		net_selftest_get_strings(data);
 }
 
 static int lan78xx_get_sset_count(struct net_device *netdev, int sset)
 {
 	if (sset == ETH_SS_STATS)
 		return ARRAY_SIZE(lan78xx_gstrings);
+	else if (sset == ETH_SS_TEST)
+		return net_selftest_get_count();
 	else
 		return -EOPNOTSUPP;
 }
@@ -1894,6 +1899,7 @@ static const struct ethtool_ops lan78xx_ethtool_ops = {
 	.set_eeprom	= lan78xx_ethtool_set_eeprom,
 	.get_ethtool_stats = lan78xx_get_stats,
 	.get_sset_count = lan78xx_get_sset_count,
+	.self_test	= net_selftest,
 	.get_strings	= lan78xx_get_strings,
 	.get_wol	= lan78xx_get_wol,
 	.set_wol	= lan78xx_set_wol,
-- 
2.39.5