1const std = @import("../../std.zig");
 2
 3const bits = switch (@import("builtin").cpu.arch) {
 4    .mips,
 5    .mipsel,
 6    .mips64,
 7    .mips64el,
 8    .powerpc,
 9    .powerpcle,
10    .powerpc64,
11    .powerpc64le,
12    .sparc,
13    .sparc64,
14    => .{ .size = 13, .dir = 3, .none = 1, .read = 2, .write = 4 },
15    else => .{ .size = 14, .dir = 2, .none = 0, .read = 2, .write = 1 },
16};
17
18const Direction = std.meta.Int(.unsigned, bits.dir);
19
20pub const Request = packed struct {
21    nr: u8,
22    io_type: u8,
23    size: std.meta.Int(.unsigned, bits.size),
24    dir: Direction,
25};
26
27fn io_impl(dir: Direction, io_type: u8, nr: u8, comptime T: type) u32 {
28    const request = Request{
29        .dir = dir,
30        .size = @sizeOf(T),
31        .io_type = io_type,
32        .nr = nr,
33    };
34    return @as(u32, @bitCast(request));
35}
36
37pub fn IO(io_type: u8, nr: u8) u32 {
38    return io_impl(bits.none, io_type, nr, void);
39}
40
41pub fn IOR(io_type: u8, nr: u8, comptime T: type) u32 {
42    return io_impl(bits.read, io_type, nr, T);
43}
44
45pub fn IOW(io_type: u8, nr: u8, comptime T: type) u32 {
46    return io_impl(bits.write, io_type, nr, T);
47}
48
49pub fn IOWR(io_type: u8, nr: u8, comptime T: type) u32 {
50    return io_impl(bits.read | bits.write, io_type, nr, T);
51}
52
53comptime {
54    std.debug.assert(@bitSizeOf(Request) == 32);
55}