arm: zynqmp: Add ZynqMP minimal R5 support

Xilinx ZynqMP also contains dual Cortex R5 which can run U-Boot.
This patch is adding minimal support to get U-Boot boot.
U-Boot on R5 runs out of DDR with default configuration that's why
DDR needs to be partitioned if there is something else running on arm64.
Console is done via Cadence uart driver and the first Cadence Triple
Timer Counter is used for time.

This configuration with uart1 was tested on zcu100-revC.

U-Boot 2018.05-rc2-00021-gd058a08d907d (Apr 18 2018 - 14:11:27 +0200)

Model: Xilinx ZynqMP R5
DRAM:  512 MiB
WARNING: Caches not enabled
MMC:
In:    serial@ff010000
Out:   serial@ff010000
Err:   serial@ff010000
Net:   Net Initialization Skipped
No ethernet found.
ZynqMP r5>

There are two ways how to run this on ZynqMP.
1. Run from ZynqMP arm64
tftpb 20000000 u-boot-r5.elf
setenv autostart no && bootelf -p 20000000
cpu 4 disable && cpu 4 release 10000000 lockstep
or
cpu 4 disable && cpu 4 release 10000000 split

2. Load via jtag when directly to R5

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

7 files changed, 153 insertions, 0 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a7618f9ff2..c9d6e0a424 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -823,6 +823,14 @@ config ARCH_ZYNQ
 	imply CMD_SPL
 	imply ARCH_EARLY_INIT_R
 
+config ARCH_ZYNQMP_R5
+	bool "Xilinx ZynqMP R5 based platform"
+	select CPU_V7R
+	select OF_CONTROL
+	select DM
+	select DM_SERIAL
+	select CLK
+
 config ARCH_ZYNQMP
 	bool "Xilinx ZynqMP based platform"
 	select ARM64
@@ -1345,6 +1353,8 @@ source "arch/arm/cpu/armv7/vf610/Kconfig"
 
 source "arch/arm/mach-zynq/Kconfig"
 
+source "arch/arm/mach-zynqmp-r5/Kconfig"
+
 source "arch/arm/cpu/armv7/Kconfig"
 
 source "arch/arm/cpu/armv8/zynqmp/Kconfig"
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 3b1dd85716..4d6d276137 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -76,6 +76,7 @@ machine-$(CONFIG_ARCH_STM32MP)		+= stm32mp
 machine-$(CONFIG_TEGRA)			+= tegra
 machine-$(CONFIG_ARCH_UNIPHIER)		+= uniphier
 machine-$(CONFIG_ARCH_ZYNQ)		+= zynq
+machine-$(CONFIG_ARCH_ZYNQMP_R5)	+= zynqmp-r5
 
 machdirs := $(patsubst %,arch/arm/mach-%/,$(machine-y))
 
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index f7f24365bb..f94940a7dd 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -163,6 +163,8 @@ dtb-$(CONFIG_ARCH_ZYNQMP) += \
 	zynqmp-zc1751-xm017-dc3.dtb		\
 	zynqmp-zc1751-xm018-dc4.dtb		\
 	zynqmp-zc1751-xm019-dc5.dtb
+dtb-$(CONFIG_ARCH_ZYNQMP_R5) += \
+	zynqmp-r5.dtb
 dtb-$(CONFIG_AM33XX) += am335x-boneblack.dtb am335x-bone.dtb \
 	am335x-draco.dtb \
 	am335x-evm.dtb \
diff --git a/arch/arm/dts/zynqmp-r5.dts b/arch/arm/dts/zynqmp-r5.dts
new file mode 100644
index 0000000000..a72172ef2e
--- /dev/null
+++ b/arch/arm/dts/zynqmp-r5.dts
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * dts file for Xilinx ZynqMP R5
+ *
+ * (C) Copyright 2018, Xilinx, Inc.
+ *
+ * Michal Simek <michal.simek@xilinx.com>
+ */
+
+/dts-v1/;
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+	compatible = "xlnx,zynqmp-r5";
+	model = "Xilinx ZynqMP R5";
+
+	cpus {
+		#address-cells = <0x1>;
+		#size-cells = <0x0>;
+
+		cpu@0 {
+			compatible = "arm,cortex-r5";
+			device_type = "cpu";
+			reg = <0>;
+		};
+	};
+
+	aliases {
+		serial0 = &uart1;
+	};
+
+	memory@0 {
+		device_type = "memory";
+		reg = <0x00000000 0x20000000>;
+	};
+
+	chosen {
+		bootargs = "";
+		stdout-path = "serial0:115200n8";
+	};
+
+	clk100: clk100 {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+		clock-frequency = <100000000>;
+		u-boot,dm-pre-reloc;
+	};
+
+	amba {
+		u-boot,dm-pre-reloc;
+		compatible = "simple-bus";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+
+		ttc0: timer@ff110000 {
+			compatible = "cdns,ttc";
+			status = "okay";
+			reg = <0xff110000 0x1000>;
+			timer-width = <32>;
+			clocks = <&clk100>;
+		};
+
+		uart1: serial@ff010000 {
+			u-boot,dm-pre-reloc;
+			compatible = "cdns,uart-r1p12", "xlnx,xuartps";
+			reg = <0xff010000 0x1000>;
+			clock-names = "uart_clk", "pclk";
+			clocks = <&clk100 &clk100>;
+		};
+	};
+};
diff --git a/arch/arm/mach-zynqmp-r5/Kconfig b/arch/arm/mach-zynqmp-r5/Kconfig
new file mode 100644
index 0000000000..5e01754133
--- /dev/null
+++ b/arch/arm/mach-zynqmp-r5/Kconfig
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0
+
+if ARCH_ZYNQMP_R5
+
+config SYS_BOARD
+	string "Board name"
+	default "zynqmp_r5"
+
+config SYS_VENDOR
+	string "Vendor name"
+	default "xilinx"
+
+config SYS_SOC
+	default "zynqmp-r5"
+
+config SYS_CONFIG_NAME
+	string "Board configuration name"
+	default "xilinx_zynqmp_r5"
+	help
+	  This option contains information about board configuration name.
+	  Based on this option include/configs/<CONFIG_SYS_CONFIG_NAME>.h header
+	  will be used for board configuration.
+
+config SYS_MALLOC_F_LEN
+	default 0x600
+
+endif
diff --git a/arch/arm/mach-zynqmp-r5/Makefile b/arch/arm/mach-zynqmp-r5/Makefile
new file mode 100644
index 0000000000..0d39e97dd3
--- /dev/null
+++ b/arch/arm/mach-zynqmp-r5/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-y	+= cpu.o
diff --git a/arch/arm/mach-zynqmp-r5/cpu.c b/arch/arm/mach-zynqmp-r5/cpu.c
new file mode 100644
index 0000000000..98f63e3427
--- /dev/null
+++ b/arch/arm/mach-zynqmp-r5/cpu.c
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Xilinx, Inc. (Michal Simek)
+ */
+
+#include <common.h>
+#include <asm/armv7_mpu.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct mpu_region_config region_config[] = {
+	{ 0x00000000, REGION_0, XN_DIS, PRIV_RW_USR_RW,
+	  O_I_WB_RD_WR_ALLOC, REGION_1GB },
+	{ 0x20000000, REGION_1, XN_EN, PRIV_RO_USR_RO,
+	  O_I_WB_RD_WR_ALLOC, REGION_512MB },
+	{ 0x40000000, REGION_2, XN_EN, PRIV_RO_USR_RO,
+	  O_I_WB_RD_WR_ALLOC, REGION_1GB },
+};
+
+int arch_cpu_init(void)
+{
+	gd->cpu_clk = CONFIG_CPU_FREQ_HZ;
+
+	setup_mpu_regions(region_config, sizeof(region_config) /
+			  sizeof(struct mpu_region_config));
+
+	return 0;
+}
+
+/*
+ * Perform the low-level reset.
+ */
+void reset_cpu(ulong addr)
+{
+	while (1)
+		;
+}