xref: /netbsd-src/sys/dev/i2c/spdmem_i2c.c (revision 95b39c65ca575fb40c6bb7083e0eb7ec28eabef1)
1 /* $NetBSD: spdmem_i2c.c,v 1.12 2016/01/05 11:49:32 msaitoh Exp $ */
2 
3 /*
4  * Copyright (c) 2007 Nicolas Joly
5  * Copyright (c) 2007 Paul Goyette
6  * Copyright (c) 2007 Tobias Nygren
7  * Copyright (c) 2015 Michael van Elst
8  * All rights reserved.
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. The name of the author may not be used to endorse or promote products
19  *    derived from this software without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  * POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 /*
35  * Serial Presence Detect (SPD) memory identification
36  *
37  * JEDEC standard No. 21-C
38  * JEDEC document 4_01_06R24
39  * - Definitions of the EE1004-v 4 Kbit Serial Presence Detect EEPROM [...]
40  */
41 
42 #include <sys/cdefs.h>
43 __KERNEL_RCSID(0, "$NetBSD: spdmem_i2c.c,v 1.12 2016/01/05 11:49:32 msaitoh Exp $");
44 
45 #include <sys/param.h>
46 #include <sys/device.h>
47 #include <sys/endian.h>
48 #include <sys/module.h>
49 #include <sys/sysctl.h>
50 #include <machine/bswap.h>
51 
52 #include <dev/i2c/i2cvar.h>
53 #include <dev/ic/spdmemreg.h>
54 #include <dev/ic/spdmemvar.h>
55 
56 /* Constants for matching i2c bus address */
57 #define SPDMEM_I2C_ADDRMASK 0xfff8
58 #define SPDMEM_I2C_ADDR     0x50
59 #define SPDCTL_I2C_ADDR     0x30
60 
61 /* set write protection */
62 #define SPDCTL_SWP0         (SPDCTL_I2C_ADDR + 1)
63 #define SPDCTL_SWP1         (SPDCTL_I2C_ADDR + 4)
64 #define SPDCTL_SWP2         (SPDCTL_I2C_ADDR + 5)
65 #define SPDCTL_SWP3         (SPDCTL_I2C_ADDR + 0)
66 
67 /* clear write protections */
68 #define SPDCTL_CWP          (SPDCTL_I2C_ADDR + 3)
69 
70 /* read protection status */
71 #define SPDCTL_RPS0         (SPDCTL_I2C_ADDR + 1)
72 #define SPDCTL_RPS1         (SPDCTL_I2C_ADDR + 4)
73 #define SPDCTL_RPS2         (SPDCTL_I2C_ADDR + 5)
74 #define SPDCTL_RPS3         (SPDCTL_I2C_ADDR + 0)
75 
76 /* select page address */
77 #define SPDCTL_SPA0         (SPDCTL_I2C_ADDR + 6)
78 #define SPDCTL_SPA1         (SPDCTL_I2C_ADDR + 7)
79 
80 /* read page address */
81 #define SPDCTL_RPA          (SPDCTL_I2C_ADDR + 6)
82 
83 struct spdmem_i2c_softc {
84 	struct spdmem_softc sc_base;
85 	i2c_tag_t sc_tag;
86 	i2c_addr_t sc_addr; /* EEPROM */
87 	i2c_addr_t sc_page0;
88 	i2c_addr_t sc_page1;
89 };
90 
91 static int  spdmem_i2c_match(device_t, cfdata_t, void *);
92 static void spdmem_i2c_attach(device_t, device_t, void *);
93 static int  spdmem_i2c_detach(device_t, int);
94 
95 CFATTACH_DECL_NEW(spdmem_iic, sizeof(struct spdmem_i2c_softc),
96     spdmem_i2c_match, spdmem_i2c_attach, spdmem_i2c_detach, NULL);
97 
98 static int spdmem_i2c_read(struct spdmem_softc *, uint16_t, uint8_t *);
99 
100 static int
101 spdmem_i2c_match(device_t parent, cfdata_t match, void *aux)
102 {
103 	struct i2c_attach_args *ia = aux;
104 	struct spdmem_i2c_softc sc;
105 
106 	if (ia->ia_name) {
107 		/* add other names as we find more firmware variations */
108 		if (strcmp(ia->ia_name, "dimm-spd") &&
109 		    strcmp(ia->ia_name, "dimm"))
110 			return 0;
111 	}
112 
113 	/* only do this lame test when not using direct config */
114 	if (ia->ia_name == NULL) {
115 		if ((ia->ia_addr & SPDMEM_I2C_ADDRMASK) != SPDMEM_I2C_ADDR)
116 			return 0;
117 	}
118 
119 	sc.sc_tag = ia->ia_tag;
120 	sc.sc_addr = ia->ia_addr;
121 	sc.sc_page0 = SPDCTL_SPA0;
122 	sc.sc_page1 = SPDCTL_SPA1;
123 	sc.sc_base.sc_read = spdmem_i2c_read;
124 
125 	return spdmem_common_probe(&sc.sc_base);
126 }
127 
128 static void
129 spdmem_i2c_attach(device_t parent, device_t self, void *aux)
130 {
131 	struct spdmem_i2c_softc *sc = device_private(self);
132 	struct i2c_attach_args *ia = aux;
133 
134 	sc->sc_tag = ia->ia_tag;
135 	sc->sc_addr = ia->ia_addr;
136 	sc->sc_page0 = SPDCTL_SPA0;
137 	sc->sc_page1 = SPDCTL_SPA1;
138 	sc->sc_base.sc_read = spdmem_i2c_read;
139 
140 	if (!pmf_device_register(self, NULL, NULL))
141 		aprint_error_dev(self, "couldn't establish power handler\n");
142 
143 	spdmem_common_attach(&sc->sc_base, self);
144 }
145 
146 static int
147 spdmem_i2c_detach(device_t self, int flags)
148 {
149 	struct spdmem_i2c_softc *sc = device_private(self);
150 
151 	pmf_device_deregister(self);
152 
153 	return spdmem_common_detach(&sc->sc_base, self);
154 }
155 
156 static int
157 spdmem_i2c_read(struct spdmem_softc *softc, uint16_t addr, uint8_t *val)
158 {
159 	uint8_t reg;
160 	struct spdmem_i2c_softc *sc = (struct spdmem_i2c_softc *)softc;
161 	static uint8_t dummy = 0;
162 	int rv;
163 
164 	reg = addr & 0xff;
165 
166 	iic_acquire_bus(sc->sc_tag, 0);
167 
168 	if (addr & 0x100) {
169 		rv = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_page1,
170 		    &dummy, 1, NULL, 0, I2C_F_POLL);
171 		rv |= iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
172 		    &reg, 1, val, 1, I2C_F_POLL);
173 		rv |= iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
174 		    sc->sc_page0, &dummy, 1, NULL, 0, I2C_F_POLL);
175 	} else {
176 		rv = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
177 		    &reg, 1, val, 1, I2C_F_POLL);
178 	}
179 
180 	iic_release_bus(sc->sc_tag, 0);
181 
182 	return rv;
183 }
184 
185 MODULE(MODULE_CLASS_DRIVER, spdmem, "i2cexec");
186 
187 #ifdef _MODULE
188 #include "ioconf.c"
189 #endif
190 
191 static int
192 spdmem_modcmd(modcmd_t cmd, void *opaque)
193 {
194 	int error = 0;
195 #ifdef _MODULE
196 	static struct sysctllog *spdmem_sysctl_clog;
197 #endif
198 
199 	switch (cmd) {
200 	case MODULE_CMD_INIT:
201 #ifdef _MODULE
202 		error = config_init_component(cfdriver_ioconf_spdmem,
203 		    cfattach_ioconf_spdmem, cfdata_ioconf_spdmem);
204 #endif
205 		return error;
206 	case MODULE_CMD_FINI:
207 #ifdef _MODULE
208 		error = config_fini_component(cfdriver_ioconf_spdmem,
209 		    cfattach_ioconf_spdmem, cfdata_ioconf_spdmem);
210 		sysctl_teardown(&spdmem_sysctl_clog);
211 #endif
212 		return error;
213 	default:
214 		return ENOTTY;
215 	}
216 }
217