[source] lantiq: simplify ath9k eeprom extraction script

[LEDE Commits]

mkresin pushed a commit to source.git, branch master:
https://git.lede-project.org/ee5a6c10410b25adc6d400780953388035135fed

commit ee5a6c10410b25adc6d400780953388035135fed
Author: Mathias Kresin <dev at kresin.me>
AuthorDate: Mon Dec 5 09:21:29 2016 +0100

    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 at kresin.me>
---
 .../etc/hotplug.d/firmware/12-ath9k-eeprom         | 27 +++++++++++++---------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/target/linux/lantiq/base-files/etc/hotplug.d/firmware/12-ath9k-eeprom b/target/linux/lantiq/base-files/etc/hotplug.d/firmware/12-ath9k-eeprom
index 28bde59..fa52dd5 100644
--- a/target/linux/lantiq/base-files/etc/hotplug.d/firmware/12-ath9k-eeprom
+++ b/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