[PATCH net-next v5 12/13] ax88179_178a: Add support for AX88179A/772D/279 EEPROM access

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 <[email protected]>
Reviewed-by: Andrew Lunn <[email protected]>
---
 drivers/net/usb/ax88179_178a.c | 19 +++++++++++++++
 drivers/net/usb/ax88179_lib.c  | 54 ++++++++++++++++++++++++++++++++----------
 2 files changed, 61 insertions(+), 12 deletions(-)

diff --git a/drivers/net/usb/ax88179_178a.c b/drivers/net/usb/ax88179_178a.c
index 6d6ee39b342e9b4e008bb2c1ee276dc27279a2f7..be72ed955b6b8b1700d5f3624c59d7dea1b3d1dd 100644
--- a/drivers/net/usb/ax88179_178a.c
+++ b/drivers/net/usb/ax88179_178a.c
@@ -687,6 +687,19 @@ static int ax88179_bind(struct usbnet *dev, struct usb_interface *intf)
 	ax179_data->resume = ax88179_resume;
 	ax179_data->suspend = ax88179_suspend;
 
+	ret = ax88179_read_cmd(dev, AX_ACCESS_MAC, AX_CHIP_STATUS,
+			       1, 1, &ax179_data->chip_version);
+	if (ret < 0)
+		goto err_nodev;
+
+	ax179_data->chip_version = (ax179_data->chip_version & 0xf0) >> 4;
+	ax179_data->is_ax88772d = 0;
+	ax179_data->ip_align = 1;
+	ax179_data->eeprom_read_cmd = AX_ACCESS_EEPROM;
+	ax179_data->eeprom_write_cmd = AX_ACCESS_EEPROM;
+	ax179_data->eeprom_block = 2;
+	ax179_data->eeprom_wen = 0;
+
 	dev->net->netdev_ops = &ax88179_netdev_ops;
 	dev->net->ethtool_ops = &ax88179_ethtool_ops;
 	dev->net->needed_headroom = 8;
@@ -711,6 +724,12 @@ 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 8aa5489d4bbc46faa1545cdfb85f65d8035c0c3c..22209640734c884a0c83d76ad72e4364dd29c653 100644
--- a/drivers/net/usb/ax88179_lib.c
+++ b/drivers/net/usb/ax88179_lib.c
@@ -203,36 +203,61 @@ 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]);
+	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 < 0) {
 			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;
 }
@@ -240,12 +265,17 @@ 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