1 /*
2 * Copyright (c) 2006 Kevin Lo. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. All advertising materials mentioning features or use of this software
13 * must display the following acknowledgement:
14 * This product includes software developed for the NetBSD Project by
15 * Wasabi Systems, Inc.
16 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
17 * or promote products derived from this software without specific prior
18 * written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
21 * 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 WASABI SYSTEMS, INC
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 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD: releng/6.3/sys/arm/xscale/ixp425/ixp425_iic.c 167038 2007-02-26 23:13:09Z cognet $");
35
36 #include <sys/param.h>
37 #include <sys/systm.h>
38 #include <sys/kernel.h>
39 #include <sys/module.h>
40 #include <sys/bus.h>
41 #include <sys/uio.h>
42
43 #include <arm/xscale/ixp425/ixp425reg.h>
44 #include <arm/xscale/ixp425/ixp425var.h>
45 #include <arm/xscale/ixp425/ixdp425reg.h>
46
47 #include <dev/iicbus/iiconf.h>
48 #include <dev/iicbus/iicbus.h>
49
50 #include "iicbb_if.h"
51
52 #define I2C_DELAY 10
53
54 /* bit clr/set shorthands */
55 #define GPIO_CONF_CLR(sc, reg, mask) \
56 GPIO_CONF_WRITE_4(sc, reg, GPIO_CONF_READ_4(sc, reg) &~ (mask))
57 #define GPIO_CONF_SET(sc, reg, mask) \
58 GPIO_CONF_WRITE_4(sc, reg, GPIO_CONF_READ_4(sc, reg) | (mask))
59
60 struct ixpiic_softc {
61 device_t sc_dev;
62 bus_space_tag_t sc_iot;
63 bus_space_handle_t sc_gpio_ioh;
64
65 device_t iicbb;
66 };
67
68 static struct ixpiic_softc *ixpiic_sc = NULL;
69
70 static int
71 ixpiic_probe(device_t dev)
72 {
73 device_set_desc(dev, "IXP425 GPIO-Based I2C Interface");
74 return (0);
75 }
76
77 static int
78 ixpiic_attach(device_t dev)
79 {
80 struct ixpiic_softc *sc = device_get_softc(dev);
81 struct ixp425_softc *sa = device_get_softc(device_get_parent(dev));
82
83 ixpiic_sc = sc;
84
85 sc->sc_dev = dev;
86 sc->sc_iot = sa->sc_iot;
87 sc->sc_gpio_ioh = sa->sc_gpio_ioh;
88
89 GPIO_CONF_SET(sc, IXP425_GPIO_GPOER,
90 GPIO_I2C_SCL_BIT | GPIO_I2C_SDA_BIT);
91 GPIO_CONF_CLR(sc, IXP425_GPIO_GPOUTR,
92 GPIO_I2C_SCL_BIT | GPIO_I2C_SDA_BIT);
93
94 /* add generic bit-banging code */
95 if ((sc->iicbb = device_add_child(dev, "iicbb", -1)) == NULL)
96 device_printf(dev, "could not add iicbb\n");
97
98 /* probe and attach the bit-banging code */
99 device_probe_and_attach(sc->iicbb);
100
101 return (0);
102 }
103
104 static int
105 ixpiic_callback(device_t dev, int index, caddr_t *data)
106 {
107 return (0);
108 }
109
110 static int
111 ixpiic_getscl(device_t dev)
112 {
113 struct ixpiic_softc *sc = ixpiic_sc;
114 uint32_t reg;
115
116 GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SCL_BIT);
117
118 reg = GPIO_CONF_READ_4(sc, IXP425_GPIO_GPINR);
119 return (reg & GPIO_I2C_SCL_BIT);
120 }
121
122 static int
123 ixpiic_getsda(device_t dev)
124 {
125 struct ixpiic_softc *sc = ixpiic_sc;
126 uint32_t reg;
127
128 GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
129
130 reg = GPIO_CONF_READ_4(sc, IXP425_GPIO_GPINR);
131 return (reg & GPIO_I2C_SDA_BIT);
132 }
133
134 static void
135 ixpiic_setsda(device_t dev, char val)
136 {
137 struct ixpiic_softc *sc = ixpiic_sc;
138
139 GPIO_CONF_CLR(sc, IXP425_GPIO_GPOUTR, GPIO_I2C_SDA_BIT);
140 if (val)
141 GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
142 else
143 GPIO_CONF_CLR(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
144 DELAY(I2C_DELAY);
145 }
146
147 static void
148 ixpiic_setscl(device_t dev, char val)
149 {
150 struct ixpiic_softc *sc = ixpiic_sc;
151
152 GPIO_CONF_CLR(sc, IXP425_GPIO_GPOUTR, GPIO_I2C_SCL_BIT);
153 if (val)
154 GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SCL_BIT);
155 else
156 GPIO_CONF_CLR(sc, IXP425_GPIO_GPOER, GPIO_I2C_SCL_BIT);
157 DELAY(I2C_DELAY);
158 }
159
160 static int
161 ixpiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
162 {
163 /* reset bus */
164 ixpiic_setsda(dev, 1);
165 ixpiic_setscl(dev, 1);
166
167 return (IIC_ENOADDR);
168 }
169
170 static device_method_t ixpiic_methods[] = {
171 /* device interface */
172 DEVMETHOD(device_probe, ixpiic_probe),
173 DEVMETHOD(device_attach, ixpiic_attach),
174
175 /* iicbb interface */
176 DEVMETHOD(iicbb_callback, ixpiic_callback),
177 DEVMETHOD(iicbb_setsda, ixpiic_setsda),
178 DEVMETHOD(iicbb_setscl, ixpiic_setscl),
179 DEVMETHOD(iicbb_getsda, ixpiic_getsda),
180 DEVMETHOD(iicbb_getscl, ixpiic_getscl),
181 DEVMETHOD(iicbb_reset, ixpiic_reset),
182
183 { 0, 0 }
184 };
185
186 static driver_t ixpiic_driver = {
187 "ixpiic",
188 ixpiic_methods,
189 sizeof(struct ixpiic_softc),
190 };
191 static devclass_t ixpiic_devclass;
192
193 DRIVER_MODULE(ixpiic, ixp, ixpiic_driver, ixpiic_devclass, 0, 0);
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