spdmem_i2c.c revision 1.9 
1/* $NetBSD: spdmem_i2c.c,v 1.9 2014/04/14 14:30:24 pooka Exp $ */
2
3/*
4 * Copyright (c) 2007 Nicolas Joly
5 * Copyright (c) 2007 Paul Goyette
6 * Copyright (c) 2007 Tobias Nygren
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. The name of the author may not be used to endorse or promote products
18 *    derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33/*
34 * Serial Presence Detect (SPD) memory identification
35 */
36
37#include <sys/cdefs.h>
38__KERNEL_RCSID(0, "$NetBSD: spdmem_i2c.c,v 1.9 2014/04/14 14:30:24 pooka Exp $");
39
40#include <sys/param.h>
41#include <sys/device.h>
42#include <sys/endian.h>
43#include <sys/module.h>
44#include <sys/sysctl.h>
45#include <machine/bswap.h>
46
47#include <dev/i2c/i2cvar.h>
48#include <dev/ic/spdmemreg.h>
49#include <dev/ic/spdmemvar.h>
50
51/* Constants for matching i2c bus address */
52#define SPDMEM_I2C_ADDRMASK 0x3f8
53#define SPDMEM_I2C_ADDR     0x50
54
55struct spdmem_i2c_softc {
56	struct spdmem_softc sc_base;
57	i2c_tag_t sc_tag;
58	i2c_addr_t sc_addr;
59};
60
61static int  spdmem_i2c_match(device_t, cfdata_t, void *);
62static void spdmem_i2c_attach(device_t, device_t, void *);
63static int  spdmem_i2c_detach(device_t, int);
64
65CFATTACH_DECL_NEW(spdmem_iic, sizeof(struct spdmem_i2c_softc),
66    spdmem_i2c_match, spdmem_i2c_attach, spdmem_i2c_detach, NULL);
67
68static uint8_t spdmem_i2c_read(struct spdmem_softc *, uint8_t);
69
70static int
71spdmem_i2c_match(device_t parent, cfdata_t match, void *aux)
72{
73	struct i2c_attach_args *ia = aux;
74	struct spdmem_i2c_softc sc;
75
76	if (ia->ia_name) {
77		/* add other names as we find more firmware variations */
78		if (strcmp(ia->ia_name, "dimm-spd") &&
79		    strcmp(ia->ia_name, "dimm"))
80			return 0;
81	}
82
83	/* only do this lame test when not using direct config */
84	if (ia->ia_name == NULL) {
85		if ((ia->ia_addr & SPDMEM_I2C_ADDRMASK) != SPDMEM_I2C_ADDR)
86			return 0;
87	}
88
89	sc.sc_tag = ia->ia_tag;
90	sc.sc_addr = ia->ia_addr;
91	sc.sc_base.sc_read = spdmem_i2c_read;
92
93	return spdmem_common_probe(&sc.sc_base);
94}
95
96static void
97spdmem_i2c_attach(device_t parent, device_t self, void *aux)
98{
99	struct spdmem_i2c_softc *sc = device_private(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_i2c_read;
105
106	if (!pmf_device_register(self, NULL, NULL))
107		aprint_error_dev(self, "couldn't establish power handler\n");
108
109	spdmem_common_attach(&sc->sc_base, self);
110}
111
112static int
113spdmem_i2c_detach(device_t self, int flags)
114{
115	struct spdmem_i2c_softc *sc = device_private(self);
116
117	pmf_device_deregister(self);
118
119	return spdmem_common_detach(&sc->sc_base, self);
120}
121
122static uint8_t
123spdmem_i2c_read(struct spdmem_softc *softc, uint8_t reg)
124{
125	uint8_t val;
126	struct spdmem_i2c_softc *sc = (struct spdmem_i2c_softc *)softc;
127
128	iic_acquire_bus(sc->sc_tag, 0);
129	iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr, &reg, 1,
130		 &val, 1, I2C_F_POLL);
131	iic_release_bus(sc->sc_tag, 0);
132
133	return val;
134}
135
136MODULE(MODULE_CLASS_DRIVER, spdmem, "iic");
137
138#ifdef _MODULE
139#include "ioconf.c"
140#endif
141
142static int
143spdmem_modcmd(modcmd_t cmd, void *opaque)
144{
145	int error = 0;
146#ifdef _MODULE
147	static struct sysctllog *spdmem_sysctl_clog;
148#endif
149
150	switch (cmd) {
151	case MODULE_CMD_INIT:
152#ifdef _MODULE
153		error = config_init_component(cfdriver_ioconf_spdmem,
154		    cfattach_ioconf_spdmem, cfdata_ioconf_spdmem);
155#endif
156		return error;
157	case MODULE_CMD_FINI:
158#ifdef _MODULE
159		error = config_fini_component(cfdriver_ioconf_spdmem,
160		    cfattach_ioconf_spdmem, cfdata_ioconf_spdmem);
161		sysctl_teardown(&spdmem_sysctl_clog);
162#endif
163		return error;
164	default:
165		return ENOTTY;
166	}
167}
168