xref: /openbsd/sys/dev/i2c/i2c.c (revision 471aeecf)
1 /*	$OpenBSD: i2c.c,v 1.19 2022/04/06 18:59:28 naddy Exp $	*/
2 /*	$NetBSD: i2c.c,v 1.1 2003/09/30 00:35:31 thorpej Exp $	*/
3 
4 /*
5  * Copyright (c) 2003 Wasabi Systems, Inc.
6  * All rights reserved.
7  *
8  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *      This product includes software developed for the NetBSD Project by
21  *      Wasabi Systems, Inc.
22  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
23  *    or promote products derived from this software without specific prior
24  *    written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/device.h>
42 #include <sys/event.h>
43 
44 #define _I2C_PRIVATE
45 #include <dev/i2c/i2cvar.h>
46 
47 #define IICCF_ADDR	0
48 #define IICCF_SIZE	1
49 
50 struct iic_softc {
51 	struct device sc_dev;
52 	i2c_tag_t sc_tag;
53 };
54 
55 int	iic_match(struct device *, void *, void *);
56 void	iic_attach(struct device *, struct device *, void *);
57 int	iic_search(struct device *, void *, void *);
58 
59 const struct cfattach iic_ca = {
60 	sizeof (struct iic_softc),
61 	iic_match,
62 	iic_attach
63 };
64 
65 struct cfdriver iic_cd = {
66 	NULL, "iic", DV_DULL, CD_SKIPHIBERNATE
67 };
68 
69 int
iicbus_print(void * aux,const char * pnp)70 iicbus_print(void *aux, const char *pnp)
71 {
72 	struct i2cbus_attach_args *iba = aux;
73 
74 	if (pnp != NULL)
75 		printf("%s at %s", iba->iba_name, pnp);
76 
77 	return (UNCONF);
78 }
79 
80 int
iic_print(void * aux,const char * pnp)81 iic_print(void *aux, const char *pnp)
82 {
83 	struct i2c_attach_args *ia = aux;
84 
85 	if (pnp != NULL)
86 		printf("\"%s\" at %s", ia->ia_name, pnp);
87 	printf(" addr 0x%x", ia->ia_addr);
88 
89 	return (UNCONF);
90 }
91 
92 int
iic_search(struct device * parent,void * arg,void * aux)93 iic_search(struct device *parent, void *arg, void *aux)
94 {
95 	struct iic_softc *sc = (void *) parent;
96 	struct cfdata *cf = arg;
97 	struct i2c_attach_args ia;
98 
99 	if (cf->cf_loc[IICCF_ADDR] != -1) {
100 		memset(&ia, 0, sizeof(ia));
101 		ia.ia_tag = sc->sc_tag;
102 		ia.ia_addr = cf->cf_loc[IICCF_ADDR];
103 		ia.ia_size = cf->cf_loc[IICCF_SIZE];
104 		ia.ia_name = "unknown";
105 
106 		if (cf->cf_attach->ca_match(parent, cf, &ia) > 0)
107 			config_attach(parent, cf, &ia, iic_print);
108 	}
109 	return (0);
110 }
111 
112 int
iic_match(struct device * parent,void * arg,void * aux)113 iic_match(struct device *parent, void *arg, void *aux)
114 {
115 	struct cfdata *cf = arg;
116 	struct i2cbus_attach_args *iba = aux;
117 
118 	/* Just make sure we're looking for i2c. */
119 	return (strcmp(iba->iba_name, cf->cf_driver->cd_name) == 0);
120 }
121 
122 void
iic_attach(struct device * parent,struct device * self,void * aux)123 iic_attach(struct device *parent, struct device *self, void *aux)
124 {
125 	struct iic_softc *sc = (void *) self;
126 	struct i2cbus_attach_args *iba = aux;
127 
128 	sc->sc_tag = iba->iba_tag;
129 
130 	printf("\n");
131 
132 	/*
133 	 * Attach all i2c devices described in the kernel
134 	 * configuration file.
135 	 */
136 	config_search(iic_search, self, NULL);
137 
138 	/*
139 	 * Scan for known device signatures.
140 	 */
141 	if (iba->iba_bus_scan)
142 		(iba->iba_bus_scan)(self, aux, iba->iba_bus_scan_arg);
143 	else
144 		iic_scan(self, aux);
145 }
146 
147 int
iic_is_compatible(const struct i2c_attach_args * ia,const char * name)148 iic_is_compatible(const struct i2c_attach_args *ia, const char *name)
149 {
150 	const char *end, *entry;
151 
152 	if (ia->ia_namelen > 0) {
153 		/* ia_name points to a concatenation of strings. */
154 		entry = ia->ia_name;
155 		end = entry + ia->ia_namelen;
156 		while (entry < end) {
157 			if (strcmp(entry, name) == 0)
158 				return (1);
159 			entry += strlen(entry) + 1;
160 		}
161 	} else {
162 		/* ia_name points to a string. */
163 		if (strcmp(ia->ia_name, name) == 0)
164 			return (1);
165 	}
166 
167 	return (0);
168 }
169