Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Max Uvarov <muvarov@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     UNGLinuxDriver@microchip.com, steve.glendinning@shawell.net,
        Max Uvarov <muvarov@gmail.com>
Subject: [PATCH] usbnet: smsc95xx: allow to down ethernet link
Date:   Fri, 21 Dec 2018 12:45:53 +0300
Message-Id: <20181221094553.13137-1-muvarov@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

allow ifconfig ethX to down ethernet link. Ethernet
part of chip is switched to power down more and on
ifconfig up driver does soft reset and restores it's
state.

Signed-off-by: Max Uvarov <muvarov@gmail.com>
---
 drivers/net/usb/smsc95xx.c | 34 +++++++++++++++++++++++++++++++++-
 drivers/net/usb/smsc95xx.h |  5 +++++
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
index 41e283f3eeb9..e72b038cfb79 100644
--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -1142,9 +1142,41 @@ static int smsc95xx_reset(struct usbnet *dev)
 	return 0;
 }
 
+static int smsc95xx_lan_power_down(struct net_device *net)
+{
+	struct usbnet *dev = netdev_priv(net);
+	struct mii_if_info *mii = &dev->mii;
+	int ret;
+
+	ret = smsc95xx_mdio_read_nopm(net, mii->phy_id, SMSC95XX_PHY_BASIC);
+	if (ret < 0)
+		return ret;
+	ret &= ~SMSC95XX_PHY_BASIC_BIT_AUTONEG; /* disable autoneg */
+	smsc95xx_mdio_write_nopm(net, mii->phy_id, SMSC95XX_PHY_BASIC, ret);
+
+	ret = smsc95xx_mdio_read_nopm(net, mii->phy_id, SMSC95XX_PHY_BASIC);
+	if (ret < 0)
+		return ret;
+	ret |= SMSC95XX_PHY_BASIC_BIT_POWER_DOWN; /* enable power down */
+	smsc95xx_mdio_write_nopm(net, mii->phy_id, SMSC95XX_PHY_BASIC, ret);
+
+	return 0;
+}
+
+static int smsc95xx_stop(struct net_device *net)
+{
+	int ret;
+
+	ret = smsc95xx_lan_power_down(net);
+	if (ret)
+		netdev_err(net, "err switch to power down mode\n");
+
+	return usbnet_stop(net);
+}
+
 static const struct net_device_ops smsc95xx_netdev_ops = {
 	.ndo_open		= usbnet_open,
-	.ndo_stop		= usbnet_stop,
+	.ndo_stop		= smsc95xx_stop,
 	.ndo_start_xmit		= usbnet_start_xmit,
 	.ndo_tx_timeout		= usbnet_tx_timeout,
 	.ndo_change_mtu		= usbnet_change_mtu,
diff --git a/drivers/net/usb/smsc95xx.h b/drivers/net/usb/smsc95xx.h
index 526faa0c44e6..547e8053feba 100644
--- a/drivers/net/usb/smsc95xx.h
+++ b/drivers/net/usb/smsc95xx.h
@@ -47,6 +47,11 @@
 #define RX_STS_DB_			(0x00000004)	/* Dribbling */
 #define RX_STS_CRC_			(0x00000002)	/* CRC Error */
 
+/* Basic Control Register */
+#define SMSC95XX_PHY_BASIC		  (0x0)
+#define SMSC95XX_PHY_BASIC_BIT_AUTONEG	  BIT(12)
+#define SMSC95XX_PHY_BASIC_BIT_POWER_DOWN BIT(11)
+
 /* SCSRs */
 #define ID_REV				(0x00)
 #define ID_REV_CHIP_ID_MASK_		(0xFFFF0000)
-- 
2.17.1