diff options
Diffstat (limited to 'arch/riscv/boards/riscvemu/board.c')
-rw-r--r-- | arch/riscv/boards/riscvemu/board.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/arch/riscv/boards/riscvemu/board.c b/arch/riscv/boards/riscvemu/board.c new file mode 100644 index 0000000000..7dbf9afe4c --- /dev/null +++ b/arch/riscv/boards/riscvemu/board.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2021 Ahmad Fatoum, Pengutronix + */ + +#include <common.h> +#include <driver.h> +#include <poweroff.h> +#include <restart.h> +#include <asm/system.h> +#include <asm/barebox-riscv.h> + +struct riscvemu_priv { + struct restart_handler rst; + void __noreturn (*restart)(unsigned long, void *); + +}; + +#define HTIF_BASE_ADDR IOMEM(0x40008000) +#define HTIF_TOHOST_LOW (HTIF_BASE_ADDR + 0) +#define HTIF_TOHOST_HIGH (HTIF_BASE_ADDR + 4) + +static void __noreturn riscvemu_poweroff(struct poweroff_handler *pwr) +{ + writel(1, HTIF_TOHOST_LOW); + writel(0, HTIF_TOHOST_HIGH); + + __builtin_unreachable(); +} + +static void __noreturn riscvemu_restart(struct restart_handler *rst) +{ + struct riscvemu_priv *priv = container_of(rst, struct riscvemu_priv, rst); + + /* + * barebox PBL relocates itself to end of RAM early on, so unless + * something explicitly scrubbed the initial PBL, we can jump back to + * the reset vector to "reset". + */ + priv->restart(riscv_hartid(), barebox_riscv_boot_dtb()); +} + +static int riscvemu_probe(struct device_d *dev) +{ + struct device_node *of_chosen; + struct riscvemu_priv *priv; + u64 start; + + if (of_find_compatible_node(NULL, NULL, "ucb,htif0")) + poweroff_handler_register_fn(riscvemu_poweroff); + + of_chosen = of_find_node_by_path("/chosen"); + + if (of_property_read_u64(of_chosen, "riscv,kernel-start", &start)) + return 0; + + priv = xzalloc(sizeof(*priv)); + + priv->restart = (void *)(uintptr_t)start; + priv->rst.restart = riscvemu_restart; + priv->rst.name = "vector"; + + return restart_handler_register(&priv->rst); +} + +static const struct of_device_id riscvemu_of_match[] = { + { .compatible = "ucbbar,riscvemu-bar_dev" }, + { /* sentinel */ }, +}; + +static struct driver_d riscvemu_board_driver = { + .name = "board-riscvemu", + .probe = riscvemu_probe, + .of_compatible = riscvemu_of_match, +}; +device_platform_driver(riscvemu_board_driver); |