mvebu: new subtarget cortex A53

This commit introduces new subtarget for Marvell EBU Armada Cortex A53
processor based devices.

The first device is Globalscale ESPRESSObin. Some hardware specs:

SoC: Marvell Armada 3700LP (88F3720) dual core ARM Cortex A53
     processor up to 1.2GHz
RAM: 512MB, 1GB or 2GB DDR3
Storage: SATA interface
         µSD card slot with footprint for an optional 4GB EMMC
         4MB SPI NOR flash for bootloader
Ethernet: Topaz Networking Switch (88E6341) with 3x GbE ports
Connectors: USB 3.0
            USB 2.0
            µUSB port connected to PL2303SA (USB to serial bridge
            controller) for UART access
Expansion: 2x 46-pin GPIO headers for accessories and shields with
           I2C, GPIOs, PWM, UART, SPI, MMC, etc
           MiniPCIe slot
Misc: Reset button, JTAG interface

Currently booting only from µSD card is supported.
The boards depending on date of dispatch can come with various U-Boot
versions. For the newest version 2017.03-armada-17.10 no manual
intervention should be needed to boot OpenWrt image. For the older ones
it's necessary to modify default U-Boot environment:

 1. Interrupt boot process to run U-Boot command line,

 2. Run following commands:
    (for version 2017.03-armada-17.06 and 2017.03-armada-17.08)
     setenv bootcmd "load mmc 0:1 0x4d00000 boot.scr; source 0x4d00000"
     saveenv

    (for version 2015.01-armada-17.02 and 2015.01-armada-17.04)
     setenv bootargs "console=ttyMV0,115200 root=/dev/mmcblk0p2 rw rootwait"
     setenv bootcmd "ext4load mmc 0:1 ${fdt_addr} armada-3720-espressobin.dtb; ext4load mmc 0:1 ${kernel_addr} Image; booti ${kernel_addr} - ${fdt_addr}"
     saveenv

 3. Poweroff, insert SD card with OpenWrt image, boot and enjoy.

Signed-off-by: Tomasz Maciej Nowak <tomek_n@o2.pl>

1 files changed, 27 insertions, 0 deletions

diff --git a/target/linux/mvebu/patches-4.14/506-arm64-dts-marvell-armada-37xx-add-UART-clock.patch b/target/linux/mvebu/patches-4.14/506-arm64-dts-marvell-armada-37xx-add-UART-clock.patch
new file mode 100644
index 0000000000..47e0751c5f
--- /dev/null
+++ b/target/linux/mvebu/patches-4.14/506-arm64-dts-marvell-armada-37xx-add-UART-clock.patch
@@ -0,0 +1,27 @@
+From 2ff0d0b5bb397c3dc5c9b97bd0f20948f0b77740 Mon Sep 17 00:00:00 2001
+From: Miquel Raynal <miquel.raynal@free-electrons.com>
+Date: Fri, 13 Oct 2017 11:01:57 +0200
+Subject: arm64: dts: marvell: armada-37xx: add UART clock
+
+Add the missing clock property to armada-3700 UART node.
+
+This clock will be used to derive the prescaler value to comply with
+the requested baudrate.
+
+Signed-off-by: Miquel Raynal <miquel.raynal@free-electrons.com>
+Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
+Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
+---
+ arch/arm64/boot/dts/marvell/armada-37xx.dtsi | 1 +
+ 1 file changed, 1 insertion(+)
+
+--- a/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
++++ b/arch/arm64/boot/dts/marvell/armada-37xx.dtsi
+@@ -135,6 +135,7 @@
+ 			uart0: serial@12000 {
+ 				compatible = "marvell,armada-3700-uart";
+ 				reg = <0x12000 0x200>;
++				clocks = <&xtalclk>;
+ 				interrupts = <GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>;
+ 				status = "disabled";
+ 			};