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 *
13 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
15 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
23 * POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include <sys/cdefs.h>
27__FBSDID("$FreeBSD$");
28
29#include <sys/param.h>
30#include <sys/systm.h>
31#include <sys/kernel.h>
32#include <sys/module.h>
33#include <sys/bus.h>
34#include <sys/uio.h>
35
36#include <arm/xscale/ixp425/ixp425reg.h>
37#include <arm/xscale/ixp425/ixp425var.h>
38#include <arm/xscale/ixp425/ixdp425reg.h>
39
40#include <dev/iicbus/iiconf.h>
41#include <dev/iicbus/iicbus.h>
42
43#include "iicbb_if.h"
44
45#define I2C_DELAY	10
46
47/* bit clr/set shorthands */
48#define	GPIO_CONF_CLR(sc, reg, mask)	\
49	GPIO_CONF_WRITE_4(sc, reg, GPIO_CONF_READ_4(sc, reg) &~ (mask))
50#define	GPIO_CONF_SET(sc, reg, mask)	\
51	GPIO_CONF_WRITE_4(sc, reg, GPIO_CONF_READ_4(sc, reg) | (mask))
52
53struct ixpiic_softc {
54	device_t		sc_dev;
55	bus_space_tag_t		sc_iot;
56	bus_space_handle_t	sc_gpio_ioh;
57
58	device_t		iicbb;
59};
60
61static struct ixpiic_softc *ixpiic_sc = NULL;
62
63static int
64ixpiic_probe(device_t dev)
65{
66	device_set_desc(dev, "IXP4XX GPIO-Based I2C Interface");
67	return (0);
68}
69
70static int
71ixpiic_attach(device_t dev)
72{
73	struct ixpiic_softc *sc = device_get_softc(dev);
74	struct ixp425_softc *sa = device_get_softc(device_get_parent(dev));
75
76	ixpiic_sc = sc;
77
78	sc->sc_dev = dev;
79	sc->sc_iot = sa->sc_iot;
80	sc->sc_gpio_ioh = sa->sc_gpio_ioh;
81
82	GPIO_CONF_SET(sc, IXP425_GPIO_GPOER,
83		GPIO_I2C_SCL_BIT | GPIO_I2C_SDA_BIT);
84	GPIO_CONF_CLR(sc, IXP425_GPIO_GPOUTR,
85		GPIO_I2C_SCL_BIT | GPIO_I2C_SDA_BIT);
86
87	/* add generic bit-banging code */
88	if ((sc->iicbb = device_add_child(dev, "iicbb", -1)) == NULL)
89		device_printf(dev, "could not add iicbb\n");
90
91	/* probe and attach the bit-banging code */
92	device_probe_and_attach(sc->iicbb);
93
94	return (0);
95}
96
97static int
98ixpiic_callback(device_t dev, int index, caddr_t data)
99{
100	return (0);
101}
102
103static int
104ixpiic_getscl(device_t dev)
105{
106	struct ixpiic_softc *sc = ixpiic_sc;
107	uint32_t reg;
108
109	IXP4XX_GPIO_LOCK();
110	GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SCL_BIT);
111
112	reg = GPIO_CONF_READ_4(sc, IXP425_GPIO_GPINR);
113	IXP4XX_GPIO_UNLOCK();
114	return (reg & GPIO_I2C_SCL_BIT);
115}
116
117static int
118ixpiic_getsda(device_t dev)
119{
120	struct ixpiic_softc *sc = ixpiic_sc;
121	uint32_t reg;
122
123	IXP4XX_GPIO_LOCK();
124	GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
125
126	reg = GPIO_CONF_READ_4(sc, IXP425_GPIO_GPINR);
127	IXP4XX_GPIO_UNLOCK();
128	return (reg & GPIO_I2C_SDA_BIT);
129}
130
131static void
132ixpiic_setsda(device_t dev, int val)
133{
134	struct ixpiic_softc *sc = ixpiic_sc;
135
136	IXP4XX_GPIO_LOCK();
137	GPIO_CONF_CLR(sc, IXP425_GPIO_GPOUTR, GPIO_I2C_SDA_BIT);
138	if (val)
139		GPIO_CONF_SET(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
140	else
141		GPIO_CONF_CLR(sc, IXP425_GPIO_GPOER, GPIO_I2C_SDA_BIT);
142	IXP4XX_GPIO_UNLOCK();
143	DELAY(I2C_DELAY);
144}
145
146static void
147ixpiic_setscl(device_t dev, int val)
148{
149	struct ixpiic_softc *sc = ixpiic_sc;
150
151	IXP4XX_GPIO_LOCK();
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	IXP4XX_GPIO_UNLOCK();
158	DELAY(I2C_DELAY);
159}
160
161static int
162ixpiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
163{
164	/* reset bus */
165	ixpiic_setsda(dev, 1);
166	ixpiic_setscl(dev, 1);
167
168	return (IIC_ENOADDR);
169}
170
171static device_method_t ixpiic_methods[] = {
172	/* device interface */
173	DEVMETHOD(device_probe,		ixpiic_probe),
174	DEVMETHOD(device_attach,	ixpiic_attach),
175
176	/* iicbb interface */
177	DEVMETHOD(iicbb_callback,	ixpiic_callback),
178	DEVMETHOD(iicbb_setsda,		ixpiic_setsda),
179	DEVMETHOD(iicbb_setscl,		ixpiic_setscl),
180	DEVMETHOD(iicbb_getsda,		ixpiic_getsda),
181	DEVMETHOD(iicbb_getscl,		ixpiic_getscl),
182	DEVMETHOD(iicbb_reset,		ixpiic_reset),
183
184	{ 0, 0 }
185};
186
187static driver_t ixpiic_driver = {
188	"ixpiic",
189	ixpiic_methods,
190	sizeof(struct ixpiic_softc),
191};
192static devclass_t ixpiic_devclass;
193
194DRIVER_MODULE(ixpiic, ixp, ixpiic_driver, ixpiic_devclass, 0, 0);
195DRIVER_MODULE(iicbb, ixpiic, iicbb_driver, iicbb_devclass, 0, 0);
196