smbconf.c revision 38776 
1/*-
2 * Copyright (c) 1998 Nicolas Souchu
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 *	$Id: smbconf.c,v 1.1.1.2 1998/08/13 15:16:57 son Exp $
27 *
28 */
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/kernel.h>
32#include <sys/malloc.h>
33#include <sys/module.h>
34#include <sys/bus.h>
35
36#include <dev/smbus/smbconf.h>
37#include <dev/smbus/smbus.h>
38#include "smbus_if.h"
39
40/*
41 * smbus_intr()
42 */
43void
44smbus_intr(device_t bus, u_char devaddr, char low, char high, int error)
45{
46	struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus);
47
48	/* call owner's intr routine */
49	if (sc->owner)
50		SMBUS_INTR(sc->owner, devaddr, low, high, error);
51
52	return;
53}
54
55/*
56 * smbus_alloc_bus()
57 *
58 * Allocate a new bus connected to the given parent device
59 */
60device_t
61smbus_alloc_bus(device_t parent)
62{
63	device_t child;
64
65	/* add the bus to the parent */
66	child = device_add_child(parent, "smbus", -1, NULL);
67
68	if (child)
69		device_set_desc(child, "System Management Bus");
70
71	return (child);
72}
73
74/*
75 * smbus_request_bus()
76 *
77 * Allocate the device to perform transfers.
78 *
79 * how	: SMB_WAIT or SMB_DONTWAIT
80 */
81int
82smbus_request_bus(device_t bus, device_t dev, int how)
83{
84	struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus);
85	int s, error = 0;
86
87	while (!error) {
88		s = splhigh();
89		if (sc->owner) {
90			splx(s);
91
92			switch (how) {
93			case (SMB_WAIT | SMB_INTR):
94				error = tsleep(sc, SMBPRI|PCATCH, "smbreq", 0);
95				break;
96
97			case (SMB_WAIT | SMB_NOINTR):
98				error = tsleep(sc, SMBPRI, "smbreq", 0);
99				break;
100
101			default:
102				return (EWOULDBLOCK);
103				break;
104			}
105
106		} else {
107			sc->owner = dev;
108
109			splx(s);
110			return (0);
111		}
112	}
113
114	return (error);
115}
116
117/*
118 * smbus_release_bus()
119 *
120 * Release the device allocated with smbus_request_dev()
121 */
122int
123smbus_release_bus(device_t bus, device_t dev)
124{
125	struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus);
126	int s;
127
128	s = splhigh();
129	if (sc->owner != dev) {
130		splx(s);
131		return (EACCES);
132	}
133
134	sc->owner = 0;
135	splx(s);
136
137	/* wakeup waiting processes */
138	wakeup(sc);
139
140	return (0);
141}
142
143/*
144 * smbus_get_addr()
145 *
146 * Get the I2C 7 bits address of the device
147 */
148u_char
149smbus_get_addr(device_t dev)
150{
151	u_long addr;
152	device_t parent = device_get_parent(dev);
153
154	BUS_READ_IVAR(parent, dev, SMBUS_IVAR_ADDR, &addr);
155
156	return ((u_char)addr);
157}
158