[openwrt/openwrt] mvebu: Disable internal RTC on Linksys devices

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch master:
https://git.lede-project.org/8605ac87f822254af258bf8f20d24cd4186ff84a

commit 8605ac87f822254af258bf8f20d24cd4186ff84a
Author: Hauke Mehrtens <hauke at hauke-m.de>
AuthorDate: Sat Mar 17 15:52:47 2018 +0100

    mvebu: Disable internal RTC on Linksys devices
    
    The internal RTC does not work correctly on these Linksys boards based
    on Marvell SoCs. It is off by 3 minutes in 10 minutes running, this
    was reported by multiple users. On the Linksys Mamba device the device
    tree comment says that no crystal is connected to the internal RTC, this
    is probably also true for the other devices.
    
    Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
 ...s-armada-385-linksys-Disable-internal-RTC.patch | 28 ++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/target/linux/mvebu/patches-4.14/423-ARM-dts-armada-385-linksys-Disable-internal-RTC.patch b/target/linux/mvebu/patches-4.14/423-ARM-dts-armada-385-linksys-Disable-internal-RTC.patch
new file mode 100644
index 0000000..ea5ad5a
--- /dev/null
+++ b/target/linux/mvebu/patches-4.14/423-ARM-dts-armada-385-linksys-Disable-internal-RTC.patch
@@ -0,0 +1,28 @@
+From e1cac198fea08c31ec204bed84c279ab05d20389 Mon Sep 17 00:00:00 2001
+From: Hauke Mehrtens <hauke at hauke-m.de>
+Date: Sat, 17 Mar 2018 15:22:25 +0100
+Subject: ARM: dts: armada-385-linksys: Disable internal RTC
+
+The internal RTC does not work correctly on these Linksys boards based
+on Marvell SoCs. For me it only shows Wed Dec 31 23:59:59 1969 and for
+others it is off by 3 minutes in 10 minutes running, this was reported
+by multiple users. On the Linksys Mamba device the device tree comment
+says that no crystal is connected to the internal RTC, this is probably
+also true for the other devices.
+
+Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
+---
+ arch/arm/boot/dts/armada-385-linksys.dtsi | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+--- a/arch/arm/boot/dts/armada-385-linksys.dtsi
++++ b/arch/arm/boot/dts/armada-385-linksys.dtsi
+@@ -302,3 +302,8 @@
+ 	status = "okay";
+ 	usb-phy = <&usb3_1_phy>;
+ };
++
++&rtc {
++	/* No crystal connected to the internal RTC */
++	status = "disabled";
++};