[PATCH 1/4] board: spacemit: add SpacemiT K3 Pico-ITX

[Yixun Lan <dlan@kernel.org>]

Add initial support for K3 Pico-ITX board, in this version, the DRAM
information is parsed from DTS "/memory" node. And with UART enabled,
the U-Boot serial console works fine now.

Signed-off-by: Yixun Lan <dlan@kernel.org>
---
 arch/riscv/Kconfig            |  5 +++++
 arch/riscv/cpu/k3/Kconfig     | 18 ++++++++++++++++++
 arch/riscv/cpu/k3/Makefile    |  5 +++++
 arch/riscv/cpu/k3/dram.c      | 29 +++++++++++++++++++++++++++++
 board/spacemit/k3/Kconfig     | 30 ++++++++++++++++++++++++++++++
 board/spacemit/k3/MAINTAINERS |  8 ++++++++
 board/spacemit/k3/Makefile    |  5 +++++
 board/spacemit/k3/board.c     |  4 ++++
 include/configs/k3.h          | 13 +++++++++++++
 9 files changed, 117 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index c1b2890f1f3..386241efd4a 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -53,6 +53,9 @@ config TARGET_SIPEED_MAIX
 config TARGET_SPACEMIT_K1
 	bool "Support Spacemit K1 SoC"
 
+config TARGET_SPACEMIT_K3
+	bool "Support SpacemiT K3 SoC"
+
 config TARGET_STARFIVE_VISIONFIVE2
 	bool "Support StarFive VisionFive2 Board"
 	select BOARD_LATE_INIT
@@ -124,6 +127,7 @@ source "board/sophgo/milkv_duo/Kconfig"
 source "board/sophgo/milkv_duo_256m/Kconfig"
 source "board/sophgo/licheerv_nano/Kconfig"
 source "board/spacemit/k1/Kconfig"
+source "board/spacemit/k3/Kconfig"
 source "board/starfive/visionfive2/Kconfig"
 source "board/thead/th1520_lpi4a/Kconfig"
 source "board/xilinx/mbv/Kconfig"
@@ -138,6 +142,7 @@ source "arch/riscv/cpu/mpfs/Kconfig"
 source "arch/riscv/cpu/generic/Kconfig"
 source "arch/riscv/cpu/jh7110/Kconfig"
 source "arch/riscv/cpu/k1/Kconfig"
+source "arch/riscv/cpu/k3/Kconfig"
 source "arch/riscv/cpu/k230/Kconfig"
 source "arch/riscv/cpu/th1520/Kconfig"
 
diff --git a/arch/riscv/cpu/k3/Kconfig b/arch/riscv/cpu/k3/Kconfig
new file mode 100644
index 00000000000..5474ac11243
--- /dev/null
+++ b/arch/riscv/cpu/k3/Kconfig
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2026 Yixun Lan <dlan@kernel.org>
+
+if TARGET_SPACEMIT_K3
+
+config SPACEMIT_K3
+	bool
+	select BINMAN
+	select ARCH_EARLY_INIT_R
+	select SYS_CACHE_SHIFT_6
+	imply CPU
+	imply CPU_RISCV
+	imply RISCV_TIMER if RISCV_SMODE
+	imply CMD_CPU
+	imply OF_UPSTREAM
+
+endif
diff --git a/arch/riscv/cpu/k3/Makefile b/arch/riscv/cpu/k3/Makefile
new file mode 100644
index 00000000000..fba4e4b0a3f
--- /dev/null
+++ b/arch/riscv/cpu/k3/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2026 Yixun Lan <dlan@kernel.org>
+
+obj-y += dram.o
diff --git a/arch/riscv/cpu/k3/dram.c b/arch/riscv/cpu/k3/dram.c
new file mode 100644
index 00000000000..203d72a5da1
--- /dev/null
+++ b/arch/riscv/cpu/k3/dram.c
@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2026 Yixun Lan <dlan@kernel.org>
+ */
+
+#include <fdtdec.h>
+#include <init.h>
+#include <linux/sizes.h>
+#include <asm/global_data.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int dram_init(void)
+{
+	return fdtdec_setup_mem_size_base();
+}
+
+int dram_init_banksize(void)
+{
+	return fdtdec_setup_memory_banksize();
+}
+
+phys_addr_t board_get_usable_ram_top(phys_size_t total_size)
+{
+	if (gd->ram_size > SZ_2G)
+		return gd->ram_base + SZ_2G;
+
+	return gd->ram_base + gd->ram_size;
+}
diff --git a/board/spacemit/k3/Kconfig b/board/spacemit/k3/Kconfig
new file mode 100644
index 00000000000..b0e423d829c
--- /dev/null
+++ b/board/spacemit/k3/Kconfig
@@ -0,0 +1,30 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2026 Yixun Lan <dlan@kernel.org>
+
+if TARGET_SPACEMIT_K3
+
+config SYS_BOARD
+	default "k3"
+
+config SYS_VENDOR
+	default "spacemit"
+
+config SYS_CPU
+	default "k3"
+
+config SYS_CONFIG_NAME
+	default "k3"
+
+config TEXT_BASE
+	default 0x102000000
+
+config SPL_OPENSBI_LOAD_ADDR
+	hex
+	default 0x100000000
+
+config BOARD_SPECIFIC_OPTIONS
+	def_bool y
+	select SPACEMIT_K3
+
+endif
diff --git a/board/spacemit/k3/MAINTAINERS b/board/spacemit/k3/MAINTAINERS
new file mode 100644
index 00000000000..34cf1ed4453
--- /dev/null
+++ b/board/spacemit/k3/MAINTAINERS
@@ -0,0 +1,8 @@
+SPACEMIT K3
+M:	Yixun Lan <dlan@kernel.org>
+S:	Maintained
+F:	arch/riscv/cpu/k3/
+F:	board/spacemit/k3/
+F:	configs/spacemit_k3_defconfig
+F:	include/configs/k3.h
+F:	arch/riscv/dts/k3-u-boot.dtsi
diff --git a/board/spacemit/k3/Makefile b/board/spacemit/k3/Makefile
new file mode 100644
index 00000000000..bd5343be789
--- /dev/null
+++ b/board/spacemit/k3/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright (C) 2026 Yixun Lan <dlan@kernel.org>
+
+obj-y := board.o
diff --git a/board/spacemit/k3/board.c b/board/spacemit/k3/board.c
new file mode 100644
index 00000000000..29994e49ce8
--- /dev/null
+++ b/board/spacemit/k3/board.c
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2026 Yixun Lan <dlan@kernel.org>
+ */
diff --git a/include/configs/k3.h b/include/configs/k3.h
new file mode 100644
index 00000000000..83e4945d2b3
--- /dev/null
+++ b/include/configs/k3.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2026 Yixun Lan <dlan@kernel.org>
+ */
+
+#ifndef __CONFIG_H
+#define __CONFIG_H
+
+#define CFG_SYS_NS16550_IER	0x40
+
+#define RISCV_SMODE_TIMER_FREQ	24000000
+
+#endif /* __CONFIG_H */

-- 
2.55.0