[PATCH] ramips: increase SPI frequency for MT7620 Archer

[David Bauer]

Increase the SPI frequency for the MT7620 based TP-Link Archer
series to 30MHz.

TP-Link uses different SPI flash chips for the same board
revision, so be conservative to not break boards with a
different chip. 30MHz should be well supported by all chips.

Tested on Archer C2 v1 (GD25Q64B) and Archer C20i (W25Q64FV).

Archer C20i (before)
====================
root at OpenWrt:~# time dd if=/dev/mtd1 of=/tmp/test.bin bs=64k
122+0 records in
122+0 records out
real	0m 15.30s
user	0m 0.00s
sys	0m 15.29s

Archer C20i (after)
===================
root at OpenWrt:~# time dd if=/dev/mtd1 of=/tmp/test.bin bs=64k
122+0 records in
122+0 records out
real	0m 5.99s
user	0m 0.00s
sys	0m 5.98s

Signed-off-by: David Bauer <mail at david-bauer.net>
---
 target/linux/ramips/dts/mt7620a_tplink_archer-c2-v1.dts | 2 +-
 target/linux/ramips/dts/mt7620a_tplink_archer-mr200.dts | 2 +-
 target/linux/ramips/dts/mt7620a_tplink_archer.dtsi      | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/target/linux/ramips/dts/mt7620a_tplink_archer-c2-v1.dts b/target/linux/ramips/dts/mt7620a_tplink_archer-c2-v1.dts
index c0b2c1ae92..75ddc5fb5d 100644
--- a/target/linux/ramips/dts/mt7620a_tplink_archer-c2-v1.dts
+++ b/target/linux/ramips/dts/mt7620a_tplink_archer-c2-v1.dts
@@ -82,7 +82,7 @@
 	flash at 0 {
 		compatible = "jedec,spi-nor";
 		reg = <0>;
-		spi-max-frequency = <10000000>;
+		spi-max-frequency = <30000000>;
 
 		partitions {
 			compatible = "fixed-partitions";
diff --git a/target/linux/ramips/dts/mt7620a_tplink_archer-mr200.dts b/target/linux/ramips/dts/mt7620a_tplink_archer-mr200.dts
index c3c0efdfe6..0c0f4bb8e9 100644
--- a/target/linux/ramips/dts/mt7620a_tplink_archer-mr200.dts
+++ b/target/linux/ramips/dts/mt7620a_tplink_archer-mr200.dts
@@ -121,7 +121,7 @@
 	flash at 0 {
 		compatible = "jedec,spi-nor";
 		reg = <0>;
-		spi-max-frequency = <10000000>;
+		spi-max-frequency = <30000000>;
 
 		partitions {
 			compatible = "fixed-partitions";
diff --git a/target/linux/ramips/dts/mt7620a_tplink_archer.dtsi b/target/linux/ramips/dts/mt7620a_tplink_archer.dtsi
index 184627b9f4..670bad615d 100644
--- a/target/linux/ramips/dts/mt7620a_tplink_archer.dtsi
+++ b/target/linux/ramips/dts/mt7620a_tplink_archer.dtsi
@@ -43,7 +43,7 @@
 	flash at 0 {
 		compatible = "jedec,spi-nor";
 		reg = <0>;
-		spi-max-frequency = <10000000>;
+		spi-max-frequency = <30000000>;
 
 		partitions {
 			compatible = "fixed-partitions";
-- 
2.27.0