xref: /freebsd/sys/dev/smbus/smbus.c (revision 90b5fc95832da64a5f56295e687379732c33718f)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1998, 2001 Nicolas Souchu
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  *
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/lock.h>
36 #include <sys/malloc.h>
37 #include <sys/module.h>
38 #include <sys/mutex.h>
39 #include <sys/bus.h>
40 
41 #include <dev/smbus/smbconf.h>
42 #include <dev/smbus/smbus.h>
43 
44 #include "smbus_if.h"
45 #include "bus_if.h"
46 
47 struct smbus_ivar
48 {
49 	uint8_t	addr;
50 };
51 
52 /*
53  * Autoconfiguration and support routines for System Management bus
54  */
55 
56 static int
57 smbus_probe(device_t dev)
58 {
59 
60 	device_set_desc(dev, "System Management Bus");
61 
62 	return (0);
63 }
64 
65 static int
66 smbus_attach(device_t dev)
67 {
68 	struct smbus_softc *sc = device_get_softc(dev);
69 
70 	mtx_init(&sc->lock, device_get_nameunit(dev), "smbus", MTX_DEF);
71 	bus_generic_probe(dev);
72 	bus_enumerate_hinted_children(dev);
73 	bus_generic_attach(dev);
74 
75 	return (0);
76 }
77 
78 static int
79 smbus_detach(device_t dev)
80 {
81 	struct smbus_softc *sc = device_get_softc(dev);
82 	int error;
83 
84 	error = bus_generic_detach(dev);
85 	if (error)
86 		return (error);
87 	device_delete_children(dev);
88 	mtx_destroy(&sc->lock);
89 
90 	return (0);
91 }
92 
93 void
94 smbus_generic_intr(device_t dev, u_char devaddr, char low, char high, int err)
95 {
96 }
97 
98 static device_t
99 smbus_add_child(device_t dev, u_int order, const char *name, int unit)
100 {
101 	struct smbus_ivar *devi;
102 	device_t child;
103 
104 	child = device_add_child_ordered(dev, order, name, unit);
105 	if (child == NULL)
106 		return (child);
107 	devi = malloc(sizeof(struct smbus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
108 	if (devi == NULL) {
109 		device_delete_child(dev, child);
110 		return (NULL);
111 	}
112 	device_set_ivars(child, devi);
113 	return (child);
114 }
115 
116 static void
117 smbus_hinted_child(device_t bus, const char *dname, int dunit)
118 {
119 	struct smbus_ivar *devi;
120 	device_t child;
121 	int addr;
122 
123 	addr = 0;
124 	resource_int_value(dname, dunit, "addr", &addr);
125 	if (addr > UINT8_MAX) {
126 		device_printf(bus, "ignored incorrect slave address hint 0x%x"
127 		    " for %s%d\n", addr, dname, dunit);
128 		return;
129 	}
130 	child = BUS_ADD_CHILD(bus, SMBUS_ORDER_HINTED, dname, dunit);
131 	if (child == NULL)
132 		return;
133 	devi = device_get_ivars(child);
134 	devi->addr = addr;
135 }
136 
137 static int
138 smbus_child_location_str(device_t parent, device_t child, char *buf,
139     size_t buflen)
140 {
141 	struct smbus_ivar *devi;
142 
143 	devi = device_get_ivars(child);
144 	if (devi->addr != 0)
145 		snprintf(buf, buflen, "addr=0x%x", devi->addr);
146 	else if (buflen)
147 		buf[0] = 0;
148 	return (0);
149 }
150 
151 static int
152 smbus_print_child(device_t parent, device_t child)
153 {
154 	struct smbus_ivar *devi;
155 	int retval;
156 
157 	devi = device_get_ivars(child);
158 	retval = bus_print_child_header(parent, child);
159 	if (devi->addr != 0)
160 		retval += printf(" at addr 0x%x", devi->addr);
161 	retval += bus_print_child_footer(parent, child);
162 
163 	return (retval);
164 }
165 
166 static int
167 smbus_read_ivar(device_t parent, device_t child, int which, uintptr_t *result)
168 {
169 	struct smbus_ivar *devi;
170 
171 	devi = device_get_ivars(child);
172 	switch (which) {
173 	case SMBUS_IVAR_ADDR:
174 		if (devi->addr != 0)
175 			*result = devi->addr;
176 		else
177 			*result = -1;
178 		break;
179 	default:
180 		return (ENOENT);
181 	}
182 	return (0);
183 }
184 
185 static int
186 smbus_write_ivar(device_t parent, device_t child, int which, uintptr_t value)
187 {
188 	struct smbus_ivar *devi;
189 
190 	devi = device_get_ivars(child);
191 	switch (which) {
192 	case SMBUS_IVAR_ADDR:
193 		/* Allow to set but no change the slave address. */
194 		if (devi->addr != 0)
195 			return (EINVAL);
196 		devi->addr = value;
197 		break;
198 	default:
199 		return (ENOENT);
200 	}
201 	return (0);
202 }
203 
204 static void
205 smbus_probe_nomatch(device_t bus, device_t child)
206 {
207 	struct smbus_ivar *devi = device_get_ivars(child);
208 
209 	/*
210 	 * Ignore (self-identified) devices without a slave address set.
211 	 * For example, smb(4).
212 	 */
213 	if (devi->addr != 0)
214 		device_printf(bus, "<unknown device> at addr %#x\n",
215 		    devi->addr);
216 }
217 
218 /*
219  * Device methods
220  */
221 static device_method_t smbus_methods[] = {
222         /* device interface */
223         DEVMETHOD(device_probe,         smbus_probe),
224         DEVMETHOD(device_attach,        smbus_attach),
225         DEVMETHOD(device_detach,        smbus_detach),
226 
227 	/* bus interface */
228 	DEVMETHOD(bus_add_child,	smbus_add_child),
229 	DEVMETHOD(bus_hinted_child,	smbus_hinted_child),
230 	DEVMETHOD(bus_probe_nomatch,	smbus_probe_nomatch),
231 	DEVMETHOD(bus_child_location_str, smbus_child_location_str),
232 	DEVMETHOD(bus_print_child,	smbus_print_child),
233 	DEVMETHOD(bus_read_ivar,	smbus_read_ivar),
234 	DEVMETHOD(bus_write_ivar,	smbus_write_ivar),
235 
236 	DEVMETHOD_END
237 };
238 
239 driver_t smbus_driver = {
240         "smbus",
241         smbus_methods,
242         sizeof(struct smbus_softc),
243 };
244 
245 devclass_t smbus_devclass;
246 
247 MODULE_VERSION(smbus, SMBUS_MODVER);
248