riscv: cpu: fu540: Add support for cpu fu540

Add SiFive fu540 cpu to support RISC-V arch

Signed-off-by: Pragnesh Patel <pragnesh.patel@sifive.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com>

arch/riscv/Kconfig

@@ -56,6 +56,7 @@ source "board/sifive/fu540/Kconfig"
 
 # platform-specific options below
 source "arch/riscv/cpu/ax25/Kconfig"
+source "arch/riscv/cpu/fu540/Kconfig"
 source "arch/riscv/cpu/generic/Kconfig"
 
 # architecture-specific options below

arch/riscv/cpu/fu540/Kconfig

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+
+config SIFIVE_FU540
+	bool
+	select ARCH_EARLY_INIT_R
+	imply CPU
+	imply CPU_RISCV
+	imply RISCV_TIMER
+	imply SIFIVE_CLINT if (RISCV_MMODE || SPL_RISCV_MMODE)
+	imply CMD_CPU
+	imply SPL_CPU_SUPPORT
+	imply SPL_OPENSBI
+	imply SPL_LOAD_FIT

arch/riscv/cpu/fu540/Makefile

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2020 SiFive, Inc
+# Pragnesh Patel <pragnesh.patel@sifive.com>
+
+obj-y += dram.o
+obj-y += cpu.o

arch/riscv/cpu/fu540/cpu.c

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <irq_func.h>
+#include <asm/cache.h>
+
+/*
+ * cleanup_before_linux() is called just before we call linux
+ * it prepares the processor for linux
+ *
+ * we disable interrupt and caches.
+ */
+int cleanup_before_linux(void)
+{
+	disable_interrupts();
+
+	cache_flush();
+
+	return 0;
+}

arch/riscv/cpu/fu540/dram.c

@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <init.h>
+#include <linux/sizes.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();
+}
+
+ulong board_get_usable_ram_top(ulong total_size)
+{
+#ifdef CONFIG_64BIT
+	/*
+	 * Ensure that we run from first 4GB so that all
+	 * addresses used by U-Boot are 32bit addresses.
+	 *
+	 * This in-turn ensures that 32bit DMA capable
+	 * devices work fine because DMA mapping APIs will
+	 * provide 32bit DMA addresses only.
+	 */
+	if (gd->ram_top > SZ_4G)
+		return SZ_4G;
+#endif
+	return gd->ram_top;
+}

arch/riscv/include/asm/arch-fu540/clk.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2020 SiFive Inc
+ *
+ * Authors:
+ *   Pragnesh Patel <pragnesh.patel@sifive.com>
+ */
+
+#ifndef __CLK_SIFIVE_H
+#define __CLK_SIFIVE_H
+
+/* Note: This is a placeholder header for driver compilation. */
+
+#endif

arch/riscv/include/asm/arch-fu540/gpio.h

@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2019 SiFive, Inc.
+ */
+
+#ifndef _GPIO_SIFIVE_H
+#define _GPIO_SIFIVE_H
+
+#define GPIO_INPUT_VAL	0x00
+#define GPIO_INPUT_EN	0x04
+#define GPIO_OUTPUT_EN	0x08
+#define GPIO_OUTPUT_VAL	0x0C
+#define GPIO_RISE_IE	0x18
+#define GPIO_RISE_IP	0x1C
+#define GPIO_FALL_IE	0x20
+#define GPIO_FALL_IP	0x24
+#define GPIO_HIGH_IE	0x28
+#define GPIO_HIGH_IP	0x2C
+#define GPIO_LOW_IE	0x30
+#define GPIO_LOW_IP	0x34
+#define GPIO_OUTPUT_XOR	0x40
+
+#define NR_GPIOS	16
+
+enum gpio_state {
+	LOW,
+	HIGH
+};
+
+/* Details about a GPIO bank */
+struct sifive_gpio_platdata {
+	void *base;     /* address of registers in physical memory */
+};
+
+#define SIFIVE_GENERIC_GPIO_NR(port, index) \
+		(((port) * NR_GPIOS) + ((index) & (NR_GPIOS - 1)))
+
+#endif /* _GPIO_SIFIVE_H */

board/sifive/fu540/Kconfig

@@ -7,7 +7,7 @@ config SYS_VENDOR
 	default "sifive"
 
 config SYS_CPU
-	default "generic"
+	default "fu540"
 
 config SYS_CONFIG_NAME
 	default "sifive-fu540"