xref: /freebsd/sys/dev/smbus/smbus.c (revision 076ad2f836d5f49dc1375f1677335a48fe0d4b82)
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/malloc.h>
35 #include <sys/module.h>
36 #include <sys/mutex.h>
37 #include <sys/bus.h>
38 
39 #include <dev/smbus/smbconf.h>
40 #include <dev/smbus/smbus.h>
41 
42 #include "smbus_if.h"
43 #include "bus_if.h"
44 
45 struct smbus_ivar
46 {
47 	uint8_t	addr;
48 };
49 
50 /*
51  * Autoconfiguration and support routines for System Management bus
52  */
53 
54 static int
55 smbus_probe(device_t dev)
56 {
57 
58 	device_set_desc(dev, "System Management Bus");
59 
60 	return (0);
61 }
62 
63 static int
64 smbus_attach(device_t dev)
65 {
66 	struct smbus_softc *sc = device_get_softc(dev);
67 
68 	mtx_init(&sc->lock, device_get_nameunit(dev), "smbus", MTX_DEF);
69 	bus_generic_probe(dev);
70 	bus_enumerate_hinted_children(dev);
71 	bus_generic_attach(dev);
72 
73 	return (0);
74 }
75 
76 static int
77 smbus_detach(device_t dev)
78 {
79 	struct smbus_softc *sc = device_get_softc(dev);
80 	int error;
81 
82 	error = bus_generic_detach(dev);
83 	if (error)
84 		return (error);
85 	device_delete_children(dev);
86 	mtx_destroy(&sc->lock);
87 
88 	return (0);
89 }
90 
91 void
92 smbus_generic_intr(device_t dev, u_char devaddr, char low, char high, int err)
93 {
94 }
95 
96 static device_t
97 smbus_add_child(device_t dev, u_int order, const char *name, int unit)
98 {
99 	struct smbus_ivar *devi;
100 	device_t child;
101 
102 	child = device_add_child_ordered(dev, order, name, unit);
103 	if (child == NULL)
104 		return (child);
105 	devi = malloc(sizeof(struct smbus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
106 	if (devi == NULL) {
107 		device_delete_child(dev, child);
108 		return (NULL);
109 	}
110 	device_set_ivars(child, devi);
111 	return (child);
112 }
113 
114 static void
115 smbus_hinted_child(device_t bus, const char *dname, int dunit)
116 {
117 	struct smbus_ivar *devi;
118 	device_t child;
119 	int addr;
120 
121 	addr = 0;
122 	resource_int_value(dname, dunit, "addr", &addr);
123 	if (addr > UINT8_MAX) {
124 		device_printf(bus, "ignored incorrect slave address hint 0x%x"
125 		    " for %s%d\n", addr, dname, dunit);
126 		return;
127 	}
128 	child = BUS_ADD_CHILD(bus, SMBUS_ORDER_HINTED, dname, dunit);
129 	if (child == NULL)
130 		return;
131 	devi = device_get_ivars(child);
132 	devi->addr = addr;
133 }
134 
135 
136 static int
137 smbus_child_location_str(device_t parent, device_t child, char *buf,
138     size_t buflen)
139 {
140 	struct smbus_ivar *devi;
141 
142 	devi = device_get_ivars(child);
143 	if (devi->addr != 0)
144 		snprintf(buf, buflen, "addr=0x%x", devi->addr);
145 	else if (buflen)
146 		buf[0] = 0;
147 	return (0);
148 }
149 
150 static int
151 smbus_print_child(device_t parent, device_t child)
152 {
153 	struct smbus_ivar *devi;
154 	int retval;
155 
156 	devi = device_get_ivars(child);
157 	retval = bus_print_child_header(parent, child);
158 	if (devi->addr != 0)
159 		retval += printf(" at addr 0x%x", devi->addr);
160 	retval += bus_print_child_footer(parent, child);
161 
162 	return (retval);
163 }
164 
165 static int
166 smbus_read_ivar(device_t parent, device_t child, int which, uintptr_t *result)
167 {
168 	struct smbus_ivar *devi;
169 
170 	devi = device_get_ivars(child);
171 	switch (which) {
172 	case SMBUS_IVAR_ADDR:
173 		if (devi->addr != 0)
174 			*result = devi->addr;
175 		else
176 			*result = -1;
177 		break;
178 	default:
179 		return (ENOENT);
180 	}
181 	return (0);
182 }
183 
184 static int
185 smbus_write_ivar(device_t parent, device_t child, int which, uintptr_t value)
186 {
187 	struct smbus_ivar *devi;
188 
189 	devi = device_get_ivars(child);
190 	switch (which) {
191 	case SMBUS_IVAR_ADDR:
192 		/* Allow to set but no change the slave address. */
193 		if (devi->addr != 0)
194 			return (EINVAL);
195 		devi->addr = value;
196 		break;
197 	default:
198 		return (ENOENT);
199 	}
200 	return (0);
201 }
202 
203 static void
204 smbus_probe_nomatch(device_t bus, device_t child)
205 {
206 	struct smbus_ivar *devi = device_get_ivars(child);
207 
208 	/*
209 	 * Ignore (self-identified) devices without a slave address set.
210 	 * For example, smb(4).
211 	 */
212 	if (devi->addr != 0)
213 		device_printf(bus, "<unknown device> at addr %#x\n",
214 		    devi->addr);
215 }
216 
217 /*
218  * Device methods
219  */
220 static device_method_t smbus_methods[] = {
221         /* device interface */
222         DEVMETHOD(device_probe,         smbus_probe),
223         DEVMETHOD(device_attach,        smbus_attach),
224         DEVMETHOD(device_detach,        smbus_detach),
225 
226 	/* bus interface */
227 	DEVMETHOD(bus_add_child,	smbus_add_child),
228 	DEVMETHOD(bus_hinted_child,	smbus_hinted_child),
229 	DEVMETHOD(bus_probe_nomatch,	smbus_probe_nomatch),
230 	DEVMETHOD(bus_child_location_str, smbus_child_location_str),
231 	DEVMETHOD(bus_print_child,	smbus_print_child),
232 	DEVMETHOD(bus_read_ivar,	smbus_read_ivar),
233 	DEVMETHOD(bus_write_ivar,	smbus_write_ivar),
234 
235 	DEVMETHOD_END
236 };
237 
238 driver_t smbus_driver = {
239         "smbus",
240         smbus_methods,
241         sizeof(struct smbus_softc),
242 };
243 
244 devclass_t smbus_devclass;
245 
246 MODULE_VERSION(smbus, SMBUS_MODVER);
247