lantiq: simplify ath9k eeprom extraction script

Add an extra function to patch the mac and fixup the checksum
afterwards. Calculate the checksum position automatically. The offset
to the mac address is the same for all checksum protected EEPROMs.

No EEPROM requires a byte swapped mac address. The mac byte swap code
was required due to an bug in the script that is now fixed.

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/lantiq/base-files/etc/hotplug.d/firmware/12-ath9k-eeprom

@@ -75,19 +75,24 @@ ath9k_ubi_eeprom_extract() {
 	ath9k_eeprom_extract_raw /dev/$ubi $offset $swap
 }
 
-ath9k_patch_firmware_mac() {
+ath9k_patch_fw_mac_crc() {
 	local mac=$1
 	local mac_offset=$2
-	local swap=$3
-	local chksum_offset=$4
+	local chksum_offset=$((mac_offset - 10))
+
+	ath9k_patch_fw_mac "${mac}" "${mac_offset}" "${chksum_offset}"
+}
+
+ath9k_patch_fw_mac() {
+	local mac=$1
+	local mac_offset=$2
+	local chksum_offset=$3
 	local xor_mac
 	local xor_fw_mac
 	local xor_fw_chksum
 
 	[ -z "$mac" -o -z "$mac_offset" ] && return
 
-	[ $swap -gt 0 ] && mac="${mac:3:2}:${mac:0:2}:${mac:9:2}:${mac:6:2}:${mac:15:2}:${mac:12:2}"
-
 	[ -n "$chksum_offset" ] && {
 		xor_mac=${mac//:/}
 		xor_mac="${xor_mac:0:4} ${xor_mac:4:4} ${xor_mac:8:4}"
@@ -120,27 +125,27 @@ case "$FIRMWARE" in
 				;;
 			BTHOMEHUBV2B)
 				ath9k_eeprom_extract "art" 0 1
-				ath9k_patch_firmware_mac "00:00:00:00:00:00" 524 0 514
+				ath9k_patch_fw_mac_crc "00:00:00:00:00:00" 524
 				;;
 			BTHOMEHUBV3A)
 				ath9k_eeprom_extract "art-copy" 0 1
-				ath9k_patch_firmware_mac $(macaddr_add $(mtd_get_mac_ascii uboot-env ethaddr) +2) 268 0 258
+				ath9k_patch_fw_mac_crc $(macaddr_add $(mtd_get_mac_ascii uboot-env ethaddr) +2) 268
 				;;
 			BTHOMEHUBV5A)
 				ath9k_ubi_eeprom_extract "caldata" 4096 0
-				ath9k_patch_firmware_mac $(macaddr_add $(mtd_get_mac_binary_ubi caldata 4364) +2) 268 0 258
+				ath9k_patch_fw_mac_crc $(macaddr_add $(mtd_get_mac_binary_ubi caldata 4364) +2) 268
 				;;
 			DGN3500*)
 				ath9k_eeprom_extract "calibration" 61440 0
-				ath9k_patch_firmware_mac $(macaddr_add $(mtd_get_mac_ascii uboot-env ethaddr) +2) 524 0 514
+				ath9k_patch_fw_mac_crc $(macaddr_add $(mtd_get_mac_ascii uboot-env ethaddr) +2) 524
 				;;
 			FRITZ3370)
 				ath9k_eeprom_extract "urlader" 2437 0
-				ath9k_patch_firmware_mac "00:00:00:00:00:00" 2 0
+				ath9k_patch_fw_mac "00:00:00:00:00:00" 2
 				;;
 			FRITZ7320|FRITZ7360SL)
 				ath9k_eeprom_extract "urlader" 2437 0
-				ath9k_patch_firmware_mac "00:00:00:00:00:00" 268 0 258
+				ath9k_patch_fw_mac_crc "00:00:00:00:00:00" 268
 				;;
 			TDW8970|TDW8980)
 				ath9k_eeprom_extract "boardconfig" 135168 0