xref: /freebsd/sys/kern/serdev_if.m (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1#-
2# Copyright (c) 2006 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# 1. Redistributions of source code must retain the above copyright
9#    notice, this list of conditions and the following disclaimer.
10# 2. Redistributions in binary form must reproduce the above copyright
11#    notice, this list of conditions and the following disclaimer in the
12#    documentation and/or other materials provided with the distribution.
13#
14# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24# SUCH DAMAGE.
25#
26# $FreeBSD$
27#
28
29#include <sys/bus.h>
30#include <sys/serial.h>
31
32# The serdev interface is used by umbrella drivers and children thereof to
33# establish a more intimate relationship, necessary for efficient handling
34# of multiple (concurrent) serial communication channels.  Examples include
35# serial communications controller (SCC) drivers, multi-I/O adapter drivers
36# and intelligent multi-port serial drivers.  Methods specifically deal
37# with interrupt handling and configuration.  Conceptually, the umbrella
38# driver is responsible for the overall operation of the hardware and uses
39# child drivers to handle each individual channel.
40# The serdev interface is intended to inherit the device interface.
41
42INTERFACE serdev;
43
44# Default implementations of some methods.
45CODE {
46	static serdev_intr_t *
47	default_ihand(device_t dev, int ipend)
48	{
49		return (NULL);
50	}
51
52	static int
53	default_ipend(device_t dev)
54	{
55		return (-1);
56	}
57
58	static int
59	default_sysdev(device_t dev)
60	{
61		return (0);
62	}
63};
64
65# ihand() - Query serial device interrupt handler.
66# This method is called by the umbrella driver to obtain function pointers
67# to interrupt handlers for each individual interrupt source. This allows
68# the umbralla driver to control the servicing of interrupts between the
69# different channels in the most flexible way.
70METHOD serdev_intr_t* ihand {
71	device_t dev;
72	int ipend;
73} DEFAULT default_ihand;
74
75# ipend() - Query pending interrupt status.
76# This method is called by the umbrella driver to obtain interrupt status
77# for the UART in question. This allows the umbrella driver to build a
78# matrix and service the interrupts in the most flexible way by calling
79# interrupt handlers collected with the ihand() method.
80METHOD int ipend {
81	device_t dev;
82} DEFAULT default_ipend;
83
84# sysdev() - Query system device status
85# This method may be called by the umbrella driver for each child driver
86# to establish if a particular channel and mode is currently being used
87# for system specific usage. If this is the case, the hardware is not
88# reset and the channel will not change its operation mode.
89# The return value is !0 if the channel and mode are used for a system
90# device and 0 otherwise.
91METHOD int sysdev {
92	device_t dev;
93} DEFAULT default_sysdev;
94
95