smbconf.c revision 40785 
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 1.1.1.1 1998/09/03 20:52:54 nsouch 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
74static int
75smbus_poll(struct smbus_softc *sc, int how)
76{
77	int error;
78
79	switch (how) {
80	case (SMB_WAIT | SMB_INTR):
81		error = tsleep(sc, SMBPRI|PCATCH, "smbreq", 0);
82		break;
83
84	case (SMB_WAIT | SMB_NOINTR):
85		error = tsleep(sc, SMBPRI, "smbreq", 0);
86		break;
87
88	default:
89		return (EWOULDBLOCK);
90		break;
91	}
92
93	return (error);
94}
95
96/*
97 * smbus_request_bus()
98 *
99 * Allocate the device to perform transfers.
100 *
101 * how	: SMB_WAIT or SMB_DONTWAIT
102 */
103int
104smbus_request_bus(device_t bus, device_t dev, int how)
105{
106	struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus);
107	int s, error = 0;
108
109	/* first, ask the underlying layers if the request is ok */
110	do {
111		error = SMBUS_CALLBACK(device_get_parent(bus),
112						SMB_REQUEST_BUS, (caddr_t)&how);
113		if (error)
114			error = smbus_poll(sc, how);
115	} while (error);
116
117	while (!error) {
118		s = splhigh();
119		if (sc->owner) {
120			splx(s);
121
122			error = smbus_poll(sc, how);
123		} else {
124			sc->owner = dev;
125
126			splx(s);
127			return (0);
128		}
129	}
130
131	return (error);
132}
133
134/*
135 * smbus_release_bus()
136 *
137 * Release the device allocated with smbus_request_dev()
138 */
139int
140smbus_release_bus(device_t bus, device_t dev)
141{
142	struct smbus_softc *sc = (struct smbus_softc *)device_get_softc(bus);
143	int s, error;
144
145	/* first, ask the underlying layers if the release is ok */
146	error = SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, NULL);
147
148	if (error)
149		return (error);
150
151	s = splhigh();
152	if (sc->owner != dev) {
153		splx(s);
154		return (EACCES);
155	}
156
157	sc->owner = 0;
158	splx(s);
159
160	/* wakeup waiting processes */
161	wakeup(sc);
162
163	return (0);
164}
165
166/*
167 * smbus_get_addr()
168 *
169 * Get the I2C 7 bits address of the device
170 */
171u_char
172smbus_get_addr(device_t dev)
173{
174	u_long addr;
175	device_t parent = device_get_parent(dev);
176
177	BUS_READ_IVAR(parent, dev, SMBUS_IVAR_ADDR, &addr);
178
179	return ((u_char)addr);
180}
181