Skip to content

Commit

Permalink
feat: Linux revert termios config on close
Browse files Browse the repository at this point in the history
  • Loading branch information
@mochalins
mochalins committed Sep 23, 2024
1 parent cb422fe commit 7c06560
Showing 1 changed file with 47 additions and 35 deletions.
82 changes: 47 additions & 35 deletions src/backend/linux.zig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,7 +4,7 @@ const serialport = @import("../serialport.zig");
const linux = std.os.linux;

pub const BaudRate = b: {
const ti = @typeInfo(std.os.linux.speed_t).@"enum";
const ti = @typeInfo(linux.speed_t).@"enum";
var baud_rate_ti: std.builtin.Type.Enum = .{
.tag_type = ti.tag_type,
.fields = undefined,
Expand All @@ -27,26 +27,36 @@ pub const BaudRate = b: {
break :b @Type(std.builtin.Type{ .@"enum" = baud_rate_ti });
};

pub const PortImpl = std.fs.File;
pub const PortImpl = struct {
file: std.fs.File,
orig_termios: ?linux.termios = null,
};

pub const ReadError = std.fs.File.ReadError;
pub const Reader = std.fs.File.Reader;
pub const WriteError = std.fs.File.WriteError;
pub const Writer = std.fs.File.Writer;

pub fn open(path: []const u8) !PortImpl {
return try std.fs.cwd().openFile(path, .{
.mode = .read_write,
.allow_ctty = false,
});
return .{
.file = try std.fs.cwd().openFile(path, .{
.mode = .read_write,
.allow_ctty = false,
}),
};
}

pub fn close(port: PortImpl) void {
port.close();
pub fn close(port: *PortImpl) void {
if (port.orig_termios) |orig_termios| {
std.posix.tcsetattr(port.file.handle, .NOW, orig_termios) catch {};
}
port.orig_termios = null;
port.file.close();
port.* = undefined;
}

fn configureParity(
termios: *std.os.linux.termios,
termios: *linux.termios,
parity: serialport.Config.Parity,
) void {
termios.cflag.PARENB = parity != .none;
Expand All @@ -58,7 +68,7 @@ fn configureParity(
}

fn configureFlowControl(
termios: *std.os.linux.termios,
termios: *linux.termios,
flow_control: serialport.Config.FlowControl,
) void {
termios.cflag.CLOCAL = flow_control == .none;
Expand All @@ -69,7 +79,7 @@ fn configureFlowControl(
termios.iflag.IXOFF = flow_control == .software;
}

pub fn configure(port: PortImpl, config: serialport.Config) !void {
pub fn configure(port: *PortImpl, config: serialport.Config) !void {
const CBAUD: u32 = switch (comptime builtin.target.cpu.arch) {
.powerpc, .powerpcle, .powerpc64, .powerpc64le => 0x000000FF,
else => 0x0000100F,
Expand Down Expand Up @@ -101,15 +111,16 @@ pub fn configure(port: PortImpl, config: serialport.Config) !void {
inline for (@typeInfo(serialport.Config.BaudRate).@"enum".fields) |field| {
if (output_baud_bits == field.value) {
output_baud_bits =
@intFromEnum(@field(std.os.linux.speed_t, field.name));
@intFromEnum(@field(linux.speed_t, field.name));
}
if (input_baud_bits == field.value) {
input_baud_bits =
@intFromEnum(@field(std.os.linux.speed_t, field.name));
@intFromEnum(@field(linux.speed_t, field.name));
}
}

var settings = try std.posix.tcgetattr(port.handle);
var settings = try std.posix.tcgetattr(port.file.handle);
const orig_termios = settings;

// `cfmakeraw`
settings.iflag.IGNBRK = false;
Expand Down Expand Up @@ -165,7 +176,8 @@ pub fn configure(port: PortImpl, config: serialport.Config) !void {
settings.cc[@intFromEnum(linux.V.START)] = 0x11;
settings.cc[@intFromEnum(linux.V.STOP)] = 0x13;

try std.posix.tcsetattr(port.handle, .NOW, settings);
try std.posix.tcsetattr(port.file.handle, .NOW, settings);
port.orig_termios = orig_termios;
}

pub fn flush(port: PortImpl, options: serialport.Port.FlushOptions) !void {
Expand All @@ -178,7 +190,7 @@ pub fn flush(port: PortImpl, options: serialport.Port.FlushOptions) !void {

const result = linux.syscall3(
.ioctl,
@bitCast(@as(isize, @intCast(port.handle))),
@bitCast(@as(isize, @intCast(port.file.handle))),
TCFLSH,
if (options.input and options.output)
TCIOFLUSH
Expand All @@ -198,7 +210,7 @@ pub fn flush(port: PortImpl, options: serialport.Port.FlushOptions) !void {
pub fn poll(port: PortImpl) !bool {
var pollfds: [1]linux.pollfd = .{
.{
.fd = port.handle,
.fd = port.file.handle,
.events = linux.POLL.IN,
.revents = undefined,
},
Expand All @@ -214,11 +226,11 @@ pub fn poll(port: PortImpl) !bool {
}

pub fn reader(port: PortImpl) Reader {
return port.reader();
return port.file.reader();
}

pub fn writer(port: PortImpl) Writer {
return port.writer();
return port.file.writer();
}

pub fn iterate() !IteratorImpl {
Expand Down Expand Up @@ -281,13 +293,13 @@ fn openVirtualPorts(master_port: *PortImpl, slave_port: *PortImpl) !void {
});

master_port.* = try open("/dev/ptmx");
errdefer close(master_port.*);
errdefer close(master_port);

if (c.grantpt(master_port.handle) < 0 or
c.unlockpt(master_port.handle) < 0)
if (c.grantpt(master_port.file.handle) < 0 or
c.unlockpt(master_port.file.handle) < 0)
return error.MasterPseudoTerminalSetupError;

const slave_name = c.ptsname(master_port.handle) orelse
const slave_name = c.ptsname(master_port.file.handle) orelse
return error.SlavePseudoTerminalSetupError;
const slave_name_len = std.mem.len(slave_name);
if (slave_name_len == 0)
Expand All @@ -300,16 +312,16 @@ test "software flow control" {
var master: PortImpl = undefined;
var slave: PortImpl = undefined;
try openVirtualPorts(&master, &slave);
defer close(master);
defer close(slave);
defer close(&master);
defer close(&slave);

const config: serialport.Config = .{
.baud_rate = .B230400,
.flow_control = .software,
};

try configure(master, config);
try configure(slave, config);
try configure(&master, config);
try configure(&slave, config);

const writer_m = writer(master);
const reader_s = reader(slave);
Expand Down Expand Up @@ -344,12 +356,12 @@ test {
var master: PortImpl = undefined;
var slave: PortImpl = undefined;
try openVirtualPorts(&master, &slave);
defer close(master);
defer close(slave);
defer close(&master);
defer close(&slave);

const config: serialport.Config = .{ .baud_rate = .B115200 };
try configure(master, config);
try configure(slave, config);
try configure(&master, config);
try configure(&slave, config);

const writer_m = writer(master);
const reader_s = reader(slave);
Expand Down Expand Up @@ -384,12 +396,12 @@ test "custom baud rate" {
var master: PortImpl = undefined;
var slave: PortImpl = undefined;
try openVirtualPorts(&master, &slave);
defer close(master);
defer close(slave);
defer close(&master);
defer close(&slave);

const config: serialport.Config = .{ .baud_rate = @enumFromInt(7667) };
try configure(master, config);
try configure(slave, config);
try configure(&master, config);
try configure(&slave, config);

const writer_m = writer(master);
const reader_s = reader(slave);
Expand Down

0 comments on commit 7c06560

Please sign in to comment.