riscv_platform.c revision 1.2 
1/* $NetBSD: riscv_platform.c,v 1.2 2023/06/12 19:04:13 skrll Exp $ */
2
3/*-
4 * Copyright (c) 2023 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Nick Hudson
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32/*
33 * This is the default RISC-V FDT platform implementation. It assumes the
34 * following:
35 *
36 *  - Console UART is pre-configured by firmware
37 */
38
39#include <sys/cdefs.h>
40__KERNEL_RCSID(0, "$NetBSD: riscv_platform.c,v 1.2 2023/06/12 19:04:13 skrll Exp $");
41
42#include <sys/param.h>
43#include <sys/bus.h>
44
45#include <dev/fdt/fdtvar.h>
46
47#include <uvm/uvm_extern.h>
48#include <uvm/pmap/pmap_devmap.h>
49
50#include <riscv/fdt/riscv_fdtvar.h>
51
52static const struct pmap_devmap *
53riscv_platform_devmap(void)
54{
55	static const struct pmap_devmap devmap_empty[] = {
56		DEVMAP_ENTRY_END
57	};
58
59	static struct pmap_devmap devmap_uart[] = {
60		DEVMAP_ENTRY(VM_KERNEL_IO_BASE, 0, PAGE_SIZE),
61		DEVMAP_ENTRY_END
62	};
63	bus_addr_t uart_base;
64
65	const int phandle = fdtbus_get_stdout_phandle();
66	if (phandle <= 0)
67		return devmap_empty;
68
69	if (fdtbus_get_reg(phandle, 0, &uart_base, NULL) != 0)
70		return devmap_empty;
71
72	devmap_uart[0].pd_pa = DEVMAP_ALIGN(uart_base);
73
74	return devmap_uart;
75}
76
77
78static u_int
79riscv_platform_uart_freq(void)
80{
81	return 0;
82}
83
84static const struct fdt_platform riscv_platform = {
85	.fp_devmap = riscv_platform_devmap,
86	.fp_bootstrap = riscv_fdt_cpu_bootstrap,
87	.fp_uart_freq = riscv_platform_uart_freq,
88	.fp_mpstart = riscv_fdt_cpu_mpstart,
89};
90
91FDT_PLATFORM(rv, FDT_PLATFORM_DEFAULT, &riscv_platform);
92