add support for big endian eeprom partition to mt76 driver

Introduce the possibility to specify eeprom radio partition endianness since mt76x0e users reported some devices (e.g TP-Link Archer VR200v) have been flashed with big endian calibration data.

Changes since v1:
- Add bing-endian property documentation

Lorenzo Bianconi (2):
mt76: eeprom: add support for big endian eeprom partition
dt-bindings: net: wireless: mt76: introduce big-endian property

 .../devicetree/bindings/net/wireless/mediatek,mt76.txt |  3 +++
 drivers/net/wireless/mediatek/mt76/eeprom.c            | 10 ++++++++++
 2 files changed, 13 insertions(+)

2.21.0

mt76x0e users reported some devices (e.g TP-Link Archer VR200v) have been flashed with big endian radio partition. Add the possibility to specify eeprom endianness using big-endian dts property and in case covert eeprom data in little endian

---
 drivers/net/wireless/mediatek/mt76/eeprom.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

index 804224e81103..33d992d5662a 100644
@@ -64,6 +64,16 @@ mt76_get_of_eeprom(struct mt76_dev *dev, int len)
 		goto out_put_node;
 	}
 
+	if (of_property_read_bool(dev->dev->of_node, "big-endian")) {
+		u8 *data = (u8 *)dev->eeprom.data;
+		int i;
+
+		/* convert eeprom data in Little Endian */
+		for (i = 0; i < round_down(len, 2); i += 2)
+			put_unaligned_le16(get_unaligned_be16(&data[i]),
+					   &data[i]);
+	}
+
 out_put_node:
 	of_node_put(np);
 	return ret;

2.21.0

Introduce big-endian property to specify mtd radio partition endianness

---
 .../devicetree/bindings/net/wireless/mediatek,mt76.txt         | 3 +++
 1 file changed, 3 insertions(+)

index 7e675dafc256..d4d982f7ab37 100644
@@ -15,6 +15,8 @@ Optional properties:
 
 - ieee80211-freq-limit: See ieee80211.txt
 - mediatek,mtd-eeprom: Specify a MTD partition + offset containing EEPROM data
+- big-endian: if the radio eeprom partition is written in big-endian, specify
+  this property
 
 The MAC address can as well be set with corresponding optional properties
 defined in net/ethernet.txt.

@@ -31,6 +33,7 @@ Optional nodes:
 			reg = <0x0000 0 0 0 0>;
 			ieee80211-freq-limit = <5000000 6000000>;
 			mediatek,mtd-eeprom = <&factory 0x8000>;
+			big-endian;
 
 			led {
 				led-sources = <2>;

2.21.0