riscv_platform.c revision 1.1 
1/* $NetBSD: riscv_platform.c,v 1.1 2023/05/07 12:41:48 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 1.1 2023/05/07 12:41:48 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
51static const struct pmap_devmap *
52riscv_platform_devmap(void)
53{
54	static const struct pmap_devmap devmap_empty[] = {
55		DEVMAP_ENTRY_END
56	};
57
58	static struct pmap_devmap devmap_uart[] = {
59		DEVMAP_ENTRY(VM_KERNEL_IO_BASE, 0, PAGE_SIZE),
60		DEVMAP_ENTRY_END
61	};
62	bus_addr_t uart_base;
63
64	const int phandle = fdtbus_get_stdout_phandle();
65	if (phandle <= 0)
66		return devmap_empty;
67
68	if (fdtbus_get_reg(phandle, 0, &uart_base, NULL) != 0)
69		return devmap_empty;
70
71	devmap_uart[0].pd_pa = DEVMAP_ALIGN(uart_base);
72
73	return devmap_uart;
74}
75
76
77static void
78riscv_platform_bootstrap(void)
79{
80}
81
82
83static u_int
84riscv_platform_uart_freq(void)
85{
86	return 0;
87}
88
89static const struct fdt_platform riscv_platform = {
90	.fp_devmap = riscv_platform_devmap,
91	.fp_bootstrap = riscv_platform_bootstrap,
92	.fp_uart_freq = riscv_platform_uart_freq,
93};
94
95FDT_PLATFORM(rv, FDT_PLATFORM_DEFAULT, &riscv_platform);
96