xref: /freebsd/sys/dev/uart/uart_if.m (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
1#-
2# Copyright (c) 2003 Marcel Moolenaar
3# All rights reserved.
4#
5# Redistribution and use in source and binary forms, with or without
6# modification, are permitted provided that the following conditions
7# are met:
8#
9# 1. Redistributions of source code must retain the above copyright
10#    notice, this list of conditions and the following disclaimer.
11# 2. Redistributions in binary form must reproduce the above copyright
12#    notice, this list of conditions and the following disclaimer in the
13#    documentation and/or other materials provided with the distribution.
14#
15# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25#
26# $FreeBSD$
27
28#include <sys/param.h>
29#include <sys/lock.h>
30#include <sys/mutex.h>
31#include <sys/bus.h>
32#include <machine/bus.h>
33#include <dev/uart/uart.h>
34#include <dev/uart/uart_bus.h>
35
36# The UART hardware interface. The core UART code is hardware independent.
37# The details of the hardware are abstracted by the UART hardware interface.
38
39INTERFACE uart;
40
41# attach() - attach hardware.
42# This method is called when the device is being attached. All resources
43# have been allocated. The transmit and receive buffers exist, but no
44# high-level (ie tty) initialization has been done yet.
45# The intend of this method is to setup the hardware for normal operation.
46METHOD int attach {
47	struct uart_softc *this;
48};
49
50# detach() - detach hardware.
51# This method is called when a device is being detached from its bus. It
52# is the first action performed, so even the high-level (ie tty) interface
53# is still operational.
54# The intend of this method is to disable the hardware.
55METHOD int detach {
56	struct uart_softc *this;
57};
58
59# flush() - flush FIFOs.
60# This method is called to flush the transmitter and/or the receiver as
61# specified by the what argument. Characters are expected to be lost.
62METHOD int flush {
63	struct uart_softc *this;
64	int	what;
65};
66
67# getsig() - get line and modem signals.
68# This method retrieves the DTE and DCE signals and their corresponding
69# delta bits. The delta bits include those corresponding to DTE signals
70# when they were changed by a call to setsig. The delta bits maintained
71# by the hardware driver are cleared as a side-effect. A second call to
72# this function will not have any delta bits set, unless there was a
73# change in the signals in the mean time.
74METHOD int getsig {
75	struct uart_softc *this;
76};
77
78# ioctl() - get or set miscellaneous parameters.
79# This method is the bitbucket method. It can (and will) be used when there's
80# something we need to set or get for which a new method is overkill. It's
81# used for example to set HW or SW flow-control.
82METHOD int ioctl {
83	struct uart_softc *this;
84	int request;
85	intptr_t data;
86};
87
88# ipend() - query UART for pending interrupts.
89# When an interrupt is signalled, the handler will call this method to find
90# out which of the interrupt sources needs attention. The handler will use
91# this information to dispatch service routines that deal with each of the
92# interrupt sources. An advantage of this approach is that it allows multi-
93# port drivers (like puc(4)) to query multiple devices concurrently and
94# service them on an interrupt priority basis. If the hardware cannot provide
95# the information reliably, it is free to service the interrupt and return 0,
96# meaning that no attention is required.
97METHOD int ipend {
98	struct uart_softc *this;
99}
100
101# param() - set communication parameters.
102# This method is called to change the communication parameters.
103METHOD int param {
104	struct uart_softc *this;
105	int	baudrate;
106	int	databits;
107	int	stopbits;
108	int	parity;
109};
110
111# probe() - detect hardware.
112# This method is called as part of the bus probe to make sure the
113# hardware exists. This function should also set the device description
114# to something that represents the hardware.
115METHOD int probe {
116	struct uart_softc *this;
117};
118
119# receive() - move data from the receive FIFO to the receive buffer.
120# This method is called to move received data to the receive buffer and
121# additionally should make sure the receive interrupt should be cleared.
122METHOD int receive {
123	struct uart_softc *this;
124};
125
126# setsig() - set line and modem signals.
127# This method allows changing DTE signals. The DTE delta bits indicate which
128# signals are to be changed and the DTE bits themselves indicate whether to
129# set or clear the signals. A subsequent call to getsig will return with the
130# DTE delta bits set of those DTE signals that did change by this method.
131METHOD int setsig {
132	struct uart_softc *this;
133	int	sig;
134};
135
136# transmit() - move data from the transmit buffer to the transmit FIFO.
137# This method is responsible for writing the Tx buffer to the UART and
138# additionally should make sure that a transmit interrupt is generated
139# when transmission is complete.
140METHOD int transmit {
141	struct uart_softc *this;
142};
143