[PATCH net-next v18 12/13] ax88179_178a: Add support for AX88179A/772D/279 EEPROM access

[Birger Koblitz]

The AX88179A/772D devices have 32 efuses with 20 bytes each,
which can be randomly programmed. The AX88279 has 16K FLASH.

Provide ethtool read capability for these devices. However,
no write access is provided.

Signed-off-by: Birger Koblitz <mail@xxxxxxxxxxxxxxxxx>
Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
---
 drivers/net/usb/ax88179_178a.c |  6 +++++
 drivers/net/usb/ax88179_lib.c  | 56 ++++++++++++++++++++++++++++++++----------
 2 files changed, 49 insertions(+), 13 deletions(-)

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index ff68454667b08237252ccb57b0aae229f017e8e2..56fb2e5efeeae3bb1fca26e04b8bee1971f8011a 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -725,6 +725,12 @@ static int ax88179_bind(struct usbnet *dev, struct usb_interface *intf)
 	ax88179_reset(dev);
 
 	return 0;
+
+err_nodev:
+	kfree(ax179_data);
+	ax179_data = NULL;
+
+	return ret;
 }
 
 static void ax88179_unbind(struct usbnet *dev, struct usb_interface *intf)
diff --git a/drivers/net/usb/ax88179_lib.c b/drivers/net/usb/ax88179_lib.c
index 6ccfd8c1c93ffcab7ede6cc00ce0bbd0d5fb30ba..32787b02d7889b1c82b829a55f1f1ede91ae684a 100644
--- a/drivers/net/usb/ax88179_lib.c
+++ b/drivers/net/usb/ax88179_lib.c
@@ -210,36 +210,61 @@ int ax88179_set_wol(struct net_device *net, struct ethtool_wolinfo *wolinfo)
 	return 0;
 }
 
+static void
+ax88179_eeprom_access_params(struct ax88179_data *ax179_data, int i, u16 *value, u16 *idx)
+{
+	/* AX88179 has a word-addressable EEPROM
+	 * AX88179A uses EFUSES with 20 bytes length
+	 * AX88279 has an EEPROM addressable in 256 byte blocks
+	 */
+	if (ax179_data->chip_version < AX_VERSION_AX88179A) {
+		*value = i;
+		*idx = 1;
+	} else if (ax179_data->chip_version == AX_VERSION_AX88279) {
+		*value = (i * ax179_data->eeprom_block) >> 16;
+		*idx = (i * ax179_data->eeprom_block) & 0xffff;
+	} else {
+		*value = i << 4;
+		*idx = 0;
+	}
+}
+
 int ax88179_get_eeprom(struct net_device *net, struct ethtool_eeprom *eeprom, u8 *data)
 {
 	struct usbnet *dev = netdev_priv(net);
-	u16 *eeprom_buff;
-	int first_word, last_word;
-	int i, ret;
+	struct ax88179_data *ax179_data;
+	int first, last, i, ret;
+	u8 *eeprom_buff;
+
+	ax179_data = dev->driver_priv;
 
 	if (eeprom->len == 0)
 		return -EINVAL;
 
 	eeprom->magic = AX88179_EEPROM_MAGIC;
 
-	first_word = eeprom->offset >> 1;
-	last_word = (eeprom->offset + eeprom->len - 1) >> 1;
-	eeprom_buff = kmalloc_array(last_word - first_word + 1, sizeof(u16),
-				    GFP_KERNEL);
+	first = eeprom->offset / ax179_data->eeprom_block;
+	last = (eeprom->offset + eeprom->len - 1) / ax179_data->eeprom_block;
+
+	eeprom_buff = kzalloc((last - first + 1) * ax179_data->eeprom_block, GFP_KERNEL);
 	if (!eeprom_buff)
 		return -ENOMEM;
 
-	/* ax88179/178A returns 2 bytes from eeprom on read */
-	for (i = first_word; i <= last_word; i++) {
-		ret = __ax88179_read_cmd(dev, AX_ACCESS_EEPROM, i, 1, 2,
-					 &eeprom_buff[i - first_word]);
-		if (ret < 0) {
+	for (i = first; i <= last; i++) {
+		u16 value, idx;
+
+		ax88179_eeprom_access_params(ax179_data, i, &value, &idx);
+		ret = __ax88179_read_cmd(dev, ax179_data->eeprom_read_cmd,
+					 value, idx, ax179_data->eeprom_block,
+					 eeprom_buff + (i - first) * ax179_data->eeprom_block);
+
+		if (ret != ax179_data->eeprom_block) {
 			kfree(eeprom_buff);
 			return -EIO;
 		}
 	}
 
-	memcpy(data, (u8 *)eeprom_buff + (eeprom->offset & 1), eeprom->len);
+	memcpy(data, eeprom_buff + eeprom->offset % ax179_data->eeprom_block, eeprom->len);
 	kfree(eeprom_buff);
 	return 0;
 }
@@ -247,12 +272,17 @@ int ax88179_get_eeprom(struct net_device *net, struct ethtool_eeprom *eeprom, u8
 int ax88179_set_eeprom(struct net_device *net, struct ethtool_eeprom *eeprom, u8 *data)
 {
 	struct usbnet *dev = netdev_priv(net);
+	struct ax88179_data *ax179_data;
 	u16 *eeprom_buff;
 	int first_word;
 	int last_word;
 	int ret;
 	int i;
 
+	ax179_data = dev->driver_priv;
+	if (ax179_data->chip_version >= AX_VERSION_AX88179A)
+		return -EOPNOTSUPP;
+
 	netdev_dbg(net, "write EEPROM len %d, offset %d, magic 0x%x\n",
 		   eeprom->len, eeprom->offset, eeprom->magic);
 

-- 
2.47.3