xref: /openbsd-src/sys/dev/i2c/spdmem_i2c.c (revision 471aeecfc619bc9b69519928152daf993376c2a1)
1 /*	$OpenBSD: spdmem_i2c.c,v 1.2 2022/04/06 18:59:28 naddy Exp $	*/
2 /* $NetBSD: spdmem.c,v 1.3 2007/09/20 23:09:59 xtraeme Exp $ */
3 
4 /*
5  * Copyright (c) 2007 Jonathan Gray <jsg@openbsd.org>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 /*
21  * Copyright (c) 2007 Nicolas Joly
22  * Copyright (c) 2007 Paul Goyette
23  * Copyright (c) 2007 Tobias Nygren
24  * All rights reserved.
25  *
26  * Redistribution and use in source and binary forms, with or without
27  * modification, are permitted provided that the following conditions
28  * are met:
29  * 1. Redistributions of source code must retain the above copyright
30  *    notice, this list of conditions and the following disclaimer.
31  * 2. Redistributions in binary form must reproduce the above copyright
32  *    notice, this list of conditions and the following disclaimer in the
33  *    documentation and/or other materials provided with the distribution.
34  * 3. The name of the author may not be used to endorse or promote products
35  *    derived from this software without specific prior written permission.
36  *
37  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS
38  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
39  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
40  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
41  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
42  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
43  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
44  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
45  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
47  * POSSIBILITY OF SUCH DAMAGE.
48  */
49 
50 /*
51  * Serial Presence Detect (SPD) memory identification
52  */
53 
54 #include <sys/param.h>
55 #include <sys/systm.h>
56 #include <sys/device.h>
57 
58 #include <dev/spdmemvar.h>
59 #include <dev/i2c/i2cvar.h>
60 
61 struct spdmem_iic_softc {
62 	struct spdmem_softc	sc_base;
63 	i2c_tag_t		sc_tag;
64 	i2c_addr_t		sc_addr;
65 };
66 
67 int	spdmem_iic_match(struct device *, void *, void *);
68 void	spdmem_iic_attach(struct device *, struct device *, void *);
69 uint8_t	spdmem_iic_read(struct spdmem_softc *, uint8_t);
70 
71 const struct cfattach spdmem_iic_ca = {
72 	sizeof(struct spdmem_iic_softc), spdmem_iic_match, spdmem_iic_attach
73 };
74 
75 int
spdmem_iic_match(struct device * parent,void * match,void * aux)76 spdmem_iic_match(struct device *parent, void *match, void *aux)
77 {
78 	struct i2c_attach_args *ia = aux;
79 	struct spdmem_iic_softc sc;
80 
81 	/* clever attachments like openfirmware informed macppc */
82 	if (strcmp(ia->ia_name, "spd") == 0)
83 		return (1);
84 
85 	/* dumb, need sanity checks */
86 	if (strcmp(ia->ia_name, "eeprom") != 0)
87 		return (0);
88 
89 	sc.sc_tag = ia->ia_tag;
90 	sc.sc_addr = ia->ia_addr;
91 	sc.sc_base.sc_read = spdmem_iic_read;
92 
93 	return spdmem_probe(&sc.sc_base);
94 }
95 
96 void
spdmem_iic_attach(struct device * parent,struct device * self,void * aux)97 spdmem_iic_attach(struct device *parent, struct device *self, void *aux)
98 {
99 	struct spdmem_iic_softc *sc = (struct spdmem_iic_softc *)self;
100 	struct i2c_attach_args *ia = aux;
101 
102 	sc->sc_tag = ia->ia_tag;
103 	sc->sc_addr = ia->ia_addr;
104 	sc->sc_base.sc_read = spdmem_iic_read;
105 
106 	printf(":");
107 
108 	spdmem_attach_common(&sc->sc_base);
109 }
110 
111 uint8_t
spdmem_iic_read(struct spdmem_softc * v,uint8_t reg)112 spdmem_iic_read(struct spdmem_softc *v, uint8_t reg)
113 {
114 	struct spdmem_iic_softc *sc = (struct spdmem_iic_softc *)v;
115 	uint8_t val = 0xff;
116 
117 	iic_acquire_bus(sc->sc_tag,0);
118 	iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
119 	    &reg, sizeof reg, &val, sizeof val, 0);
120 	iic_release_bus(sc->sc_tag, 0);
121 
122 	return val;
123 }
124