net: usb: ax88179_178a: allow passing MAC via DTB

From: Peter Fink <redacted>

This is a resend of the following patch as net-next was closed before:

I adopted the feature to pass the MAC address through device tree
from asix_devices.c (introduced in 03fc5d4) to ax88179-based devices.
Please have a look if this patch can be accepted.

I introduced a new function to avoid code duplication, but I'm not perfectly
satisfied with the function name. Suggestions welcome.

I'm not totally sure if the use of net->dev_addr and net->perm_addr
was correct in the first place or if my understanding is lacking some bits.
But I kept the existing behavior as it is working as expected.

Patch tested with 4.19, but applies cleanly on net-next.

Best regards,
Peter

--

 drivers/net/usb/ax88179_178a.c | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

-- 
2.7.4

From: Peter Fink <redacted>

Adopt and integrate the feature to pass the MAC address via device tree
from asix_device.c (03fc5d4) also to other ax88179 based asix chips.
E.g. the bootloader fills in local-mac-address and the driver will then
pick up and use this MAC address.

Signed-off-by: Peter Fink <redacted>
---
 drivers/net/usb/ax88179_178a.c | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index daa5448..5a58766 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c

@@ -1214,6 +1214,29 @@ static int ax88179_led_setting(struct usbnet *dev)
 	return 0;
 }
 
+static void ax88179_get_mac_addr(struct usbnet *dev)
+{
+	u8 mac[ETH_ALEN];
+
+	/* Maybe the boot loader passed the MAC address via device tree */
+	if (!eth_platform_get_mac_address(&dev->udev->dev, mac)) {
+		netif_dbg(dev, ifup, dev->net,
+			  "MAC address read from device tree");
+	} else {
+		ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_NODE_ID, ETH_ALEN,
+				 ETH_ALEN, mac);
+		netif_dbg(dev, ifup, dev->net,
+			  "MAC address read from ASIX chip");
+	}
+
+	if (is_valid_ether_addr(mac)) {
+		memcpy(dev->net->dev_addr, mac, ETH_ALEN);
+	} else {
+		netdev_info(dev->net, "invalid MAC address, using random\n");
+		eth_hw_addr_random(dev->net);
+	}
+}
+
 static int ax88179_bind(struct usbnet *dev, struct usb_interface *intf)
 {
 	u8 buf[5];

@@ -1240,8 +1263,8 @@ static int ax88179_bind(struct usbnet *dev, struct usb_interface *intf)
 	ax88179_write_cmd(dev, AX_ACCESS_MAC, AX_CLK_SELECT, 1, 1, tmp);
 	msleep(100);
 
-	ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_NODE_ID, ETH_ALEN,
-			 ETH_ALEN, dev->net->dev_addr);
+	/* Read MAC address from DTB or asix chip */
+	ax88179_get_mac_addr(dev);
 	memcpy(dev->net->perm_addr, dev->net->dev_addr, ETH_ALEN);
 
 	/* RX bulk configuration */

@@ -1541,8 +1564,8 @@ static int ax88179_reset(struct usbnet *dev)
 	/* Ethernet PHY Auto Detach*/
 	ax88179_auto_detach(dev, 0);
 
-	ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_NODE_ID, ETH_ALEN, ETH_ALEN,
-			 dev->net->dev_addr);
+	/* Read MAC address from DTB or asix chip */
+	ax88179_get_mac_addr(dev);
 
 	/* RX bulk configuration */
 	memcpy(tmp, &AX88179_BULKIN_SIZE[0], 5);

-- 
2.7.4

On Mon, Sep 30, 2019 at 02:04:03PM +0200, Peter Fink wrote:

From: Peter Fink <redacted>

Adopt and integrate the feature to pass the MAC address via device tree
from asix_device.c (03fc5d4) also to other ax88179 based asix chips.
E.g. the bootloader fills in local-mac-address and the driver will then
pick up and use this MAC address.

Signed-off-by: Peter Fink <redacted>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

From: Peter Fink <redacted>
Date: Mon, 30 Sep 2019 14:04:03 +0200

From: Peter Fink <redacted>

Adopt and integrate the feature to pass the MAC address via device tree
from asix_device.c (03fc5d4) also to other ax88179 based asix chips.
E.g. the bootloader fills in local-mac-address and the driver will then
pick up and use this MAC address.

Signed-off-by: Peter Fink <redacted>

Applied.