1 /* $NetBSD: iomdiic.c,v 1.12 2022/03/28 12:38:57 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 2003 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
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. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
23 * written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #include <sys/param.h>
39 #include <sys/device.h>
40 #include <sys/device_impl.h> /* XXX autoconf abuse */
41 #include <sys/kernel.h>
42 #include <sys/systm.h>
43 #include <sys/mutex.h>
44 #include <sys/bus.h>
45 #include <sys/cpu.h>
46
47 #include <arm/iomd/iomdreg.h>
48 #include <arm/iomd/iomdvar.h>
49
50 #include <dev/i2c/i2cvar.h>
51 #include <dev/i2c/i2c_bitbang.h>
52
53 #include <arm/iomd/iomdiicvar.h>
54
55 struct iomdiic_softc {
56 device_t sc_dev;
57 bus_space_tag_t sc_st;
58 bus_space_handle_t sc_sh;
59
60 struct i2c_controller sc_i2c;
61
62 /*
63 * The SDA pin is open-drain, so we make it an input by
64 * writing a 1 to it.
65 */
66 uint8_t sc_iomd_iocr;
67 };
68
69 static int iomdiic_send_start(void *, int);
70 static int iomdiic_send_stop(void *, int);
71 static int iomdiic_initiate_xfer(void *, i2c_addr_t, int);
72 static int iomdiic_read_byte(void *, uint8_t *, int);
73 static int iomdiic_write_byte(void *, uint8_t, int);
74
75 #define IOMDIIC_READ *(volatile uint8_t *)(IOMD_ADDRESS(IOMD_IOCR))
76 #define IOMDIIC_WRITE(x) *(volatile uint8_t *)(IOMD_ADDRESS(IOMD_IOCR)) = (x)
77
78 #define IOMD_IOCR_SDA 0x01
79 #define IOMD_IOCR_SCL 0x02
80
81 static void
iomdiic_bb_set_bits(void * cookie,uint32_t bits)82 iomdiic_bb_set_bits(void *cookie, uint32_t bits)
83 {
84 struct iomdiic_softc *sc = cookie;
85
86 IOMDIIC_WRITE((IOMDIIC_READ & ~(IOMD_IOCR_SDA|IOMD_IOCR_SCL)) |
87 sc->sc_iomd_iocr | bits);
88 }
89
90 static void
iomdiic_bb_set_dir(void * cookie,uint32_t bits)91 iomdiic_bb_set_dir(void *cookie, uint32_t bits)
92 {
93 struct iomdiic_softc *sc = cookie;
94
95 sc->sc_iomd_iocr = bits;
96 }
97
98 static uint32_t
iomdiic_bb_read_bits(void * cookie)99 iomdiic_bb_read_bits(void *cookie)
100 {
101
102 return (IOMDIIC_READ);
103 }
104
105 static const struct i2c_bitbang_ops iomdiic_bbops = {
106 iomdiic_bb_set_bits,
107 iomdiic_bb_set_dir,
108 iomdiic_bb_read_bits,
109 {
110 IOMD_IOCR_SDA, /* SDA */
111 IOMD_IOCR_SCL, /* SCL */
112 0, /* SDA is output */
113 IOMD_IOCR_SDA, /* SDA is input */
114 }
115 };
116
117 static int
iomdiic_match(device_t parent,cfdata_t cf,void * aux)118 iomdiic_match(device_t parent, cfdata_t cf, void *aux)
119 {
120 struct iic_attach_args *ia = aux;
121
122 if (strcmp(ia->ia_name, "iic") == 0) return 1;
123 return 0;
124 }
125
126 static void
iomdiic_attach(device_t parent,device_t self,void * aux)127 iomdiic_attach(device_t parent, device_t self, void *aux)
128 {
129 struct iomdiic_softc *sc = device_private(self);
130 struct i2cbus_attach_args iba;
131
132 aprint_normal("\n");
133
134 sc->sc_dev = self;
135
136 iic_tag_init(&sc->sc_i2c);
137 sc->sc_i2c.ic_cookie = sc;
138 sc->sc_i2c.ic_send_start = iomdiic_send_start;
139 sc->sc_i2c.ic_send_stop = iomdiic_send_stop;
140 sc->sc_i2c.ic_initiate_xfer = iomdiic_initiate_xfer;
141 sc->sc_i2c.ic_read_byte = iomdiic_read_byte;
142 sc->sc_i2c.ic_write_byte = iomdiic_write_byte;
143
144 memset(&iba, 0, sizeof(iba));
145 iba.iba_tag = &sc->sc_i2c;
146 config_found(sc->sc_dev, &iba, iicbus_print, CFARGS_NONE);
147 }
148
149 CFATTACH_DECL_NEW(iomdiic, sizeof(struct iomdiic_softc),
150 iomdiic_match, iomdiic_attach, NULL, NULL);
151
152 i2c_tag_t
iomdiic_bootstrap_cookie(void)153 iomdiic_bootstrap_cookie(void)
154 {
155 static struct iomdiic_softc sc;
156 static struct device dev;
157
158 /* XXX Yuck. */
159 strcpy(dev.dv_xname, "iomdiicboot");
160
161 sc.sc_dev = &dev;
162
163 iic_tag_init(&sc.sc_i2c);
164 sc.sc_i2c.ic_cookie = ≻
165 sc.sc_i2c.ic_send_start = iomdiic_send_start;
166 sc.sc_i2c.ic_send_stop = iomdiic_send_stop;
167 sc.sc_i2c.ic_initiate_xfer = iomdiic_initiate_xfer;
168 sc.sc_i2c.ic_read_byte = iomdiic_read_byte;
169 sc.sc_i2c.ic_write_byte = iomdiic_write_byte;
170
171 return ((void *) &sc.sc_i2c);
172 }
173
174 static int
iomdiic_send_start(void * cookie,int flags)175 iomdiic_send_start(void *cookie, int flags)
176 {
177
178 return (i2c_bitbang_send_start(cookie, flags, &iomdiic_bbops));
179 }
180
181 static int
iomdiic_send_stop(void * cookie,int flags)182 iomdiic_send_stop(void *cookie, int flags)
183 {
184
185 return (i2c_bitbang_send_stop(cookie, flags, &iomdiic_bbops));
186 }
187
188 static int
iomdiic_initiate_xfer(void * cookie,i2c_addr_t addr,int flags)189 iomdiic_initiate_xfer(void *cookie, i2c_addr_t addr, int flags)
190 {
191
192 return (i2c_bitbang_initiate_xfer(cookie, addr, flags, &iomdiic_bbops));
193 }
194
195 static int
iomdiic_read_byte(void * cookie,uint8_t * bytep,int flags)196 iomdiic_read_byte(void *cookie, uint8_t *bytep, int flags)
197 {
198
199 return (i2c_bitbang_read_byte(cookie, bytep, flags, &iomdiic_bbops));
200 }
201
202 static int
iomdiic_write_byte(void * cookie,uint8_t byte,int flags)203 iomdiic_write_byte(void *cookie, uint8_t byte, int flags)
204 {
205
206 return (i2c_bitbang_write_byte(cookie, byte, flags, &iomdiic_bbops));
207 }
208