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// 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);
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