xref: /freebsd/sys/dev/smbus/smbus.c (revision 3e5645b78f476816ca3b5acc28b29bbafbb9c444)
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 
41 #include "smbus_if.h"
42 #include "bus_if.h"
43 
44 
45 /*
46  * Autoconfiguration and support routines for System Management bus
47  */
48 
49 /*
50  * Device methods
51  */
52 static int smbus_probe(device_t);
53 static int smbus_attach(device_t);
54 static int smbus_detach(device_t);
55 
56 static int smbus_child_location_str(device_t parent, device_t child,
57 		    char *buf, size_t buflen);
58 static int smbus_print_child(device_t parent, device_t child);
59 static void smbus_probe_device(device_t dev, u_char* addr);
60 static int smbus_read_ivar(device_t parent, device_t child, int which,
61 		    uintptr_t *result);
62 
63 static device_method_t smbus_methods[] = {
64         /* device interface */
65         DEVMETHOD(device_probe,         smbus_probe),
66         DEVMETHOD(device_attach,        smbus_attach),
67         DEVMETHOD(device_detach,        smbus_detach),
68 
69 	/* bus interface */
70 	DEVMETHOD(bus_add_child,	bus_generic_add_child),
71 	DEVMETHOD(bus_child_location_str, smbus_child_location_str),
72 	DEVMETHOD(bus_driver_added,	bus_generic_driver_added),
73 	DEVMETHOD(bus_print_child,	smbus_print_child),
74 	DEVMETHOD(bus_read_ivar,	smbus_read_ivar),
75 
76 	DEVMETHOD_END
77 };
78 
79 driver_t smbus_driver = {
80         "smbus",
81         smbus_methods,
82         sizeof(struct smbus_softc),
83 };
84 
85 devclass_t smbus_devclass;
86 
87 /*
88  * At 'probe' time, we add all the devices which we know about to the
89  * bus.  The generic attach routine will probe and attach them if they
90  * are alive.
91  */
92 static int
93 smbus_probe(device_t dev)
94 {
95 
96 	device_set_desc(dev, "System Management Bus");
97 
98 	return (0);
99 }
100 
101 static int
102 smbus_attach(device_t dev)
103 {
104 	struct smbus_softc *sc = device_get_softc(dev);
105 	unsigned char addr;
106 
107 	mtx_init(&sc->lock, device_get_nameunit(dev), "smbus", MTX_DEF);
108 	bus_generic_probe(dev);
109 	for (addr = SMBUS_ADDR_MIN; addr < SMBUS_ADDR_MAX; ++addr) {
110 		sc->addrs[addr] = addr;
111 		smbus_probe_device(dev, &sc->addrs[addr]);
112 	}
113 	bus_generic_attach(dev);
114 
115 	return (0);
116 }
117 
118 static int
119 smbus_detach(device_t dev)
120 {
121 	struct smbus_softc *sc = device_get_softc(dev);
122 	int error;
123 
124 	error = bus_generic_detach(dev);
125 	if (error)
126 		return (error);
127 	mtx_destroy(&sc->lock);
128 
129 	return (0);
130 }
131 
132 void
133 smbus_generic_intr(device_t dev, u_char devaddr, char low, char high, int err)
134 {
135 }
136 
137 static void
138 smbus_probe_device(device_t dev, u_char* addr)
139 {
140 	device_t child;
141 	int error;
142 	u_char cmd;
143 	u_char buf[2];
144 
145 	cmd = 0x01;
146 	error = smbus_trans(dev, *addr, cmd,
147 			    SMB_TRANS_NOCNT | SMB_TRANS_NOREPORT,
148 			    NULL, 0, buf, 1, NULL);
149 	if (error == 0) {
150 		if (bootverbose)
151 			device_printf(dev, "Probed address 0x%02x\n", *addr);
152 		child = device_add_child(dev, NULL, -1);
153 		device_set_ivars(child, addr);
154 	}
155 }
156 
157 static int
158 smbus_child_location_str(device_t parent, device_t child, char *buf,
159     size_t buflen)
160 {
161 	unsigned char *addr;
162 
163 	addr = device_get_ivars(child);
164 	if (addr)
165 		snprintf(buf, buflen, "addr=0x%x", *addr);
166 	else if (buflen)
167 		buf[0] = 0;
168 	return (0);
169 }
170 
171 static int
172 smbus_print_child(device_t parent, device_t child)
173 {
174 	unsigned char *addr;
175 	int retval;
176 
177 	addr = device_get_ivars(child);
178 	retval = bus_print_child_header(parent, child);
179 	if (addr)
180 		retval += printf(" at addr 0x%x", *addr);
181 	retval += bus_print_child_footer(parent, child);
182 
183 	return (retval);
184 }
185 
186 static int
187 smbus_read_ivar(device_t parent, device_t child, int which,
188     uintptr_t *result)
189 {
190 	unsigned char *addr;
191 
192 	addr = device_get_ivars(child);
193 	switch (which) {
194 	case SMBUS_IVAR_ADDR:
195 		*result = (addr == NULL) ? -1 : *addr;
196 		break;
197 	default:
198 		return (ENOENT);
199 	}
200 	return (0);
201 }
202 
203 MODULE_VERSION(smbus, SMBUS_MODVER);
204