[PATCH] usbnet: ax88179_178a: Add support for writing the EEPROM

[Alban Bedel]

Implement the .set_eeprom callback to allow setting the MAC address
as well as a few other parameters. Note that the EEPROM must have a
correct PID/VID checksum set otherwise the SROM is used and reads
return the SROM content.

Signed-off-by: Alban Bedel <alban.bedel@xxxxxxxxxxxxxxxxx>
---
 drivers/net/usb/ax88179_178a.c | 57 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index e6338c16081a..e6a986303dad 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -28,6 +28,7 @@
 
 #define AX88179_PHY_ID				0x03
 #define AX_EEPROM_LEN				0x100
+#define AX_EEPROM_BLOCK				0x40u
 #define AX88179_EEPROM_MAGIC			0x17900b95
 #define AX_MCAST_FLTSIZE			8
 #define AX_MAX_MCAST				64
@@ -43,6 +44,7 @@
 #define AX_ACCESS_PHY				0x02
 #define AX_ACCESS_EEPROM			0x04
 #define AX_ACCESS_EFUS				0x05
+#define AX_RELOAD_EEPROM			0x06
 #define AX_PAUSE_WATERLVL_HIGH			0x54
 #define AX_PAUSE_WATERLVL_LOW			0x55
 
@@ -620,6 +622,60 @@ ax88179_get_eeprom(struct net_device *net, struct ethtool_eeprom *eeprom,
 	return 0;
 }
 
+static int
+ax88179_set_eeprom(struct net_device *net, struct ethtool_eeprom *eeprom,
+		   u8 *data)
+{
+	struct usbnet *dev = netdev_priv(net);
+	unsigned int offset = eeprom->offset;
+	unsigned int len = eeprom->len;
+	int i, err = 0;
+	u8 *block;
+
+	/* The EEPROM data must be aligned on blocks of 64 bytes */
+	if ((offset % AX_EEPROM_BLOCK) || (len % AX_EEPROM_BLOCK)) {
+		offset = eeprom->offset / AX_EEPROM_BLOCK * AX_EEPROM_BLOCK;
+		len = eeprom->len + eeprom->offset - offset;
+		len = DIV_ROUND_UP(len, AX_EEPROM_BLOCK) * AX_EEPROM_BLOCK;
+
+		block = kmalloc(len, GFP_KERNEL);
+		if (!block)
+			return -ENOMEM;
+
+		/* Copy the current data, we could skip some but KISS */
+		for (i = 0; i < len; i += AX_EEPROM_BLOCK) {
+			err = __ax88179_read_cmd(dev, AX_ACCESS_EEPROM,
+						 (offset + i) >> 1,
+						 AX_EEPROM_BLOCK >> 1,
+						 AX_EEPROM_BLOCK,
+						 &block[i], 0);
+			if (err < 0) {
+				kfree(block);
+				return err;
+			}
+		}
+		memcpy(block + eeprom->offset - offset, data, eeprom->len);
+	} else {
+		block = data;
+	}
+
+	for (i = 0; err >= 0 && i < len; i += AX_EEPROM_BLOCK) {
+		err = ax88179_write_cmd(dev, AX_ACCESS_EEPROM,
+					(offset + i) >> 1,
+					AX_EEPROM_BLOCK >> 1,
+					AX_EEPROM_BLOCK, &block[i]);
+	}
+
+	if (block != data)
+		kfree(block);
+
+	/* Reload the EEPROM */
+	if (err >= 0)
+		err = ax88179_write_cmd(dev, AX_RELOAD_EEPROM, 0, 0, 0, NULL);
+
+	return err < 0 ? err : 0;
+}
+
 static int ax88179_get_settings(struct net_device *net, struct ethtool_cmd *cmd)
 {
 	struct usbnet *dev = netdev_priv(net);
@@ -826,6 +882,7 @@ static const struct ethtool_ops ax88179_ethtool_ops = {
 	.set_wol		= ax88179_set_wol,
 	.get_eeprom_len		= ax88179_get_eeprom_len,
 	.get_eeprom		= ax88179_get_eeprom,
+	.set_eeprom		= ax88179_set_eeprom,
 	.get_settings		= ax88179_get_settings,
 	.set_settings		= ax88179_set_settings,
 	.get_eee		= ax88179_get_eee,
-- 
2.9.3