xref: /freebsd/sys/dev/smbus/smbus.c (revision dd21556857e8d40f66bf5ad54754d9d52669ebf7)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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/param.h>
32 #include <sys/systm.h>
33 #include <sys/bus.h>
34 #include <sys/lock.h>
35 #include <sys/malloc.h>
36 #include <sys/module.h>
37 #include <sys/mutex.h>
38 #include <sys/sbuf.h>
39 
40 #include <dev/smbus/smbconf.h>
41 #include <dev/smbus/smbus.h>
42 
43 #include "smbus_if.h"
44 #include "bus_if.h"
45 
46 struct smbus_ivar
47 {
48 	uint8_t	addr;
49 };
50 
51 /*
52  * Autoconfiguration and support routines for System Management bus
53  */
54 
55 static int
56 smbus_probe(device_t dev)
57 {
58 
59 	device_set_desc(dev, "System Management Bus");
60 
61 	return (0);
62 }
63 
64 static int
65 smbus_attach(device_t dev)
66 {
67 	struct smbus_softc *sc = device_get_softc(dev);
68 
69 	mtx_init(&sc->lock, device_get_nameunit(dev), "smbus", MTX_DEF);
70 	bus_identify_children(dev);
71 	bus_enumerate_hinted_children(dev);
72 	bus_attach_children(dev);
73 
74 	return (0);
75 }
76 
77 static int
78 smbus_detach(device_t dev)
79 {
80 	struct smbus_softc *sc = device_get_softc(dev);
81 	int error;
82 
83 	error = bus_generic_detach(dev);
84 	if (error)
85 		return (error);
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_child_deleted(device_t dev, device_t child)
116 {
117 	free(device_get_ivars(child), M_DEVBUF);
118 }
119 
120 static void
121 smbus_hinted_child(device_t bus, const char *dname, int dunit)
122 {
123 	struct smbus_ivar *devi;
124 	device_t child;
125 	int addr;
126 
127 	addr = 0;
128 	resource_int_value(dname, dunit, "addr", &addr);
129 	if (addr > UINT8_MAX) {
130 		device_printf(bus, "ignored incorrect slave address hint 0x%x"
131 		    " for %s%d\n", addr, dname, dunit);
132 		return;
133 	}
134 	child = BUS_ADD_CHILD(bus, SMBUS_ORDER_HINTED, dname, dunit);
135 	if (child == NULL)
136 		return;
137 	devi = device_get_ivars(child);
138 	devi->addr = addr;
139 }
140 
141 static int
142 smbus_child_location(device_t parent, device_t child, struct sbuf *sb)
143 {
144 	struct smbus_ivar *devi;
145 
146 	devi = device_get_ivars(child);
147 	if (devi->addr != 0)
148 		sbuf_printf(sb, "addr=0x%x", devi->addr);
149 	return (0);
150 }
151 
152 static int
153 smbus_print_child(device_t parent, device_t child)
154 {
155 	struct smbus_ivar *devi;
156 	int retval;
157 
158 	devi = device_get_ivars(child);
159 	retval = bus_print_child_header(parent, child);
160 	if (devi->addr != 0)
161 		retval += printf(" at addr 0x%x", devi->addr);
162 	retval += bus_print_child_footer(parent, child);
163 
164 	return (retval);
165 }
166 
167 static int
168 smbus_read_ivar(device_t parent, device_t child, int which, uintptr_t *result)
169 {
170 	struct smbus_ivar *devi;
171 
172 	devi = device_get_ivars(child);
173 	switch (which) {
174 	case SMBUS_IVAR_ADDR:
175 		if (devi->addr != 0)
176 			*result = devi->addr;
177 		else
178 			*result = -1;
179 		break;
180 	default:
181 		return (ENOENT);
182 	}
183 	return (0);
184 }
185 
186 static int
187 smbus_write_ivar(device_t parent, device_t child, int which, uintptr_t value)
188 {
189 	struct smbus_ivar *devi;
190 
191 	devi = device_get_ivars(child);
192 	switch (which) {
193 	case SMBUS_IVAR_ADDR:
194 		/* Allow to set but no change the slave address. */
195 		if (devi->addr != 0)
196 			return (EINVAL);
197 		devi->addr = value;
198 		break;
199 	default:
200 		return (ENOENT);
201 	}
202 	return (0);
203 }
204 
205 static void
206 smbus_probe_nomatch(device_t bus, device_t child)
207 {
208 	struct smbus_ivar *devi = device_get_ivars(child);
209 
210 	/*
211 	 * Ignore (self-identified) devices without a slave address set.
212 	 * For example, smb(4).
213 	 */
214 	if (devi->addr != 0)
215 		device_printf(bus, "<unknown device> at addr %#x\n",
216 		    devi->addr);
217 }
218 
219 /*
220  * Device methods
221  */
222 static device_method_t smbus_methods[] = {
223         /* device interface */
224         DEVMETHOD(device_probe,         smbus_probe),
225         DEVMETHOD(device_attach,        smbus_attach),
226         DEVMETHOD(device_detach,        smbus_detach),
227 
228 	/* bus interface */
229 	DEVMETHOD(bus_add_child,	smbus_add_child),
230 	DEVMETHOD(bus_child_deleted,	smbus_child_deleted),
231 	DEVMETHOD(bus_hinted_child,	smbus_hinted_child),
232 	DEVMETHOD(bus_probe_nomatch,	smbus_probe_nomatch),
233 	DEVMETHOD(bus_child_location,	smbus_child_location),
234 	DEVMETHOD(bus_print_child,	smbus_print_child),
235 	DEVMETHOD(bus_read_ivar,	smbus_read_ivar),
236 	DEVMETHOD(bus_write_ivar,	smbus_write_ivar),
237 
238 	DEVMETHOD_END
239 };
240 
241 driver_t smbus_driver = {
242         "smbus",
243         smbus_methods,
244         sizeof(struct smbus_softc),
245 };
246 
247 MODULE_VERSION(smbus, SMBUS_MODVER);
248