1/*-
2 * Copyright (c) 1998, 2001 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 *
27 */
28
29#include <sys/cdefs.h>
30__FBSDID("$FreeBSD$");
31#include <sys/param.h>
32#include <sys/systm.h>
33#include <sys/lock.h>
34#include <sys/module.h>
35#include <sys/mutex.h>
36#include <sys/bus.h>
37
38#include <dev/smbus/smbconf.h>
39#include <dev/smbus/smbus.h>
40#include "smbus_if.h"
41
42/*
43 * smbus_intr()
44 */
45void
46smbus_intr(device_t bus, u_char devaddr, char low, char high, int error)
47{
48	struct smbus_softc *sc = device_get_softc(bus);
49
50	/* call owner's intr routine */
51	mtx_lock(&sc->lock);
52	if (sc->owner)
53		SMBUS_INTR(sc->owner, devaddr, low, high, error);
54	mtx_unlock(&sc->lock);
55}
56
57/*
58 * smbus_error()
59 *
60 * Converts an smbus error to a unix error.
61 */
62int
63smbus_error(int smb_error)
64{
65	int error = 0;
66
67	if (smb_error == SMB_ENOERR)
68		return (0);
69
70	if (smb_error & (SMB_ENOTSUPP))
71		error = ENODEV;
72	else if (smb_error & (SMB_ENOACK))
73		error = ENXIO;
74	else if (smb_error & (SMB_ETIMEOUT))
75		error = EWOULDBLOCK;
76	else if (smb_error & (SMB_EBUSY))
77		error = EBUSY;
78	else if (smb_error & (SMB_EABORT | SMB_EBUSERR | SMB_ECOLLI))
79		error = EIO;
80	else
81		error = EINVAL;
82
83	return (error);
84}
85
86static int
87smbus_poll(struct smbus_softc *sc, int how)
88{
89	int error;
90
91	switch (how) {
92	case SMB_WAIT | SMB_INTR:
93		error = msleep(sc, &sc->lock, SMBPRI|PCATCH, "smbreq", 0);
94		break;
95
96	case SMB_WAIT | SMB_NOINTR:
97		error = msleep(sc, &sc->lock, SMBPRI, "smbreq", 0);
98		break;
99
100	default:
101		error = EWOULDBLOCK;
102		break;
103	}
104
105	return (error);
106}
107
108/*
109 * smbus_request_bus()
110 *
111 * Allocate the device to perform transfers.
112 *
113 * how	: SMB_WAIT or SMB_DONTWAIT
114 */
115int
116smbus_request_bus(device_t bus, device_t dev, int how)
117{
118	struct smbus_softc *sc = device_get_softc(bus);
119	device_t parent;
120	int error;
121
122	/* first, ask the underlying layers if the request is ok */
123	parent = device_get_parent(bus);
124	mtx_lock(&sc->lock);
125	do {
126		mtx_unlock(&sc->lock);
127		error = SMBUS_CALLBACK(parent, SMB_REQUEST_BUS, &how);
128		mtx_lock(&sc->lock);
129
130		if (error)
131			error = smbus_poll(sc, how);
132	} while (error == EWOULDBLOCK);
133
134	while (error == 0) {
135		if (sc->owner && sc->owner != dev)
136			error = smbus_poll(sc, how);
137		else {
138			sc->owner = dev;
139			break;
140		}
141
142		/* free any allocated resource */
143		if (error) {
144			mtx_unlock(&sc->lock);
145			SMBUS_CALLBACK(parent, SMB_RELEASE_BUS, &how);
146			return (error);
147		}
148	}
149	mtx_unlock(&sc->lock);
150
151	return (error);
152}
153
154/*
155 * smbus_release_bus()
156 *
157 * Release the device allocated with smbus_request_dev()
158 */
159int
160smbus_release_bus(device_t bus, device_t dev)
161{
162	struct smbus_softc *sc = device_get_softc(bus);
163	int error;
164
165	/* first, ask the underlying layers if the release is ok */
166	error = SMBUS_CALLBACK(device_get_parent(bus), SMB_RELEASE_BUS, NULL);
167
168	if (error)
169		return (error);
170
171	mtx_lock(&sc->lock);
172	if (sc->owner == dev) {
173		sc->owner = NULL;
174
175		/* wakeup waiting processes */
176		wakeup(sc);
177	} else
178		error = EACCES;
179	mtx_unlock(&sc->lock);
180
181	return (error);
182}
183