1 /* $NetBSD: gpiic_opb.c,v 1.12 2021/08/07 16:19:03 thorpej Exp $ */
2
3 /*
4 * Copyright 2002, 2003 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Steve C. Woodford 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 "locators.h"
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/device.h>
43 #include <sys/errno.h>
44 #include <sys/mutex.h>
45 #include <sys/cpu.h>
46
47 #include <dev/i2c/i2cvar.h>
48 #include <dev/i2c/i2c_bitbang.h>
49
50 #include <powerpc/ibm4xx/cpu.h>
51 #include <powerpc/ibm4xx/dev/opbvar.h>
52 #include <powerpc/ibm4xx/dev/gpiicreg.h>
53
54 struct gpiic_softc {
55 device_t sc_dev;
56 bus_space_tag_t sc_bust;
57 bus_space_handle_t sc_bush;
58 uint8_t sc_txen;
59 uint8_t sc_tx;
60 struct i2c_controller sc_i2c;
61 struct i2c_bitbang_ops sc_bops;
62 };
63
64 static int gpiic_match(device_t, cfdata_t, void *);
65 static void gpiic_attach(device_t, device_t, void *);
66
67 CFATTACH_DECL_NEW(gpiic, sizeof(struct gpiic_softc),
68 gpiic_match, gpiic_attach, NULL, NULL);
69
70 static int gpiic_send_start(void *, int);
71 static int gpiic_send_stop(void *, int);
72 static int gpiic_initiate_xfer(void *, i2c_addr_t, int);
73 static int gpiic_read_byte(void *, uint8_t *, int);
74 static int gpiic_write_byte(void *, uint8_t, int);
75 static void gpiic_set_dir(void *, uint32_t);
76 static void gpiic_set_bits(void *, uint32_t);
77 static uint32_t gpiic_read_bits(void *);
78
79 static int
gpiic_match(device_t parent,cfdata_t cf,void * args)80 gpiic_match(device_t parent, cfdata_t cf, void *args)
81 {
82 struct opb_attach_args * const oaa = args;
83
84 if (strcmp(oaa->opb_name, cf->cf_name) != 0)
85 return 0;
86
87 return (1);
88 }
89
90 static void
gpiic_attach(device_t parent,device_t self,void * args)91 gpiic_attach(device_t parent, device_t self, void *args)
92 {
93 struct gpiic_softc * const sc = device_private(self);
94 struct opb_attach_args * const oaa = args;
95 struct i2cbus_attach_args iba;
96
97 aprint_naive(": IIC controller\n");
98 aprint_normal(": On-Chip IIC controller\n");
99
100 sc->sc_dev = self;
101 sc->sc_bust = oaa->opb_bt;
102
103 bus_space_map(sc->sc_bust, oaa->opb_addr, IIC_NREG, 0, &sc->sc_bush);
104
105 sc->sc_txen = 0;
106 sc->sc_tx = IIC_DIRECTCNTL_SCC | IIC_DIRECTCNTL_SDAC;
107 iic_tag_init(&sc->sc_i2c);
108 sc->sc_i2c.ic_cookie = sc;
109 sc->sc_i2c.ic_send_start = gpiic_send_start;
110 sc->sc_i2c.ic_send_stop = gpiic_send_stop;
111 sc->sc_i2c.ic_initiate_xfer = gpiic_initiate_xfer;
112 sc->sc_i2c.ic_read_byte = gpiic_read_byte;
113 sc->sc_i2c.ic_write_byte = gpiic_write_byte;
114
115 sc->sc_bops.ibo_set_dir = gpiic_set_dir;
116 sc->sc_bops.ibo_set_bits = gpiic_set_bits;
117 sc->sc_bops.ibo_read_bits = gpiic_read_bits;
118 sc->sc_bops.ibo_bits[I2C_BIT_SDA] = IIC_DIRECTCNTL_SDAC;
119 sc->sc_bops.ibo_bits[I2C_BIT_SCL] = IIC_DIRECTCNTL_SCC;
120 sc->sc_bops.ibo_bits[I2C_BIT_OUTPUT] = 1;
121 sc->sc_bops.ibo_bits[I2C_BIT_INPUT] = 0;
122
123 /*
124 * Put the controller into Soft Reset. This allows us to
125 * manually bit-bang the I2C clock/data lines.
126 */
127 bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_XTCNTLSS,
128 IIC_XTCNTLSS_SRST);
129 delay(10);
130 bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL,
131 IIC_DIRECTCNTL_SCC | IIC_DIRECTCNTL_SDAC);
132
133 memset(&iba, 0, sizeof(iba));
134 iba.iba_tag = &sc->sc_i2c;
135 config_found(self, &iba, iicbus_print, CFARGS_NONE);
136 }
137
138 static int
gpiic_send_start(void * arg,int flags)139 gpiic_send_start(void *arg, int flags)
140 {
141 struct gpiic_softc * const sc = arg;
142
143 return (i2c_bitbang_send_start(sc, flags, &sc->sc_bops));
144 }
145
146 static int
gpiic_send_stop(void * arg,int flags)147 gpiic_send_stop(void *arg, int flags)
148 {
149 struct gpiic_softc * const sc = arg;
150
151 return (i2c_bitbang_send_stop(sc, flags, &sc->sc_bops));
152 }
153
154 static int
gpiic_initiate_xfer(void * arg,i2c_addr_t addr,int flags)155 gpiic_initiate_xfer(void *arg, i2c_addr_t addr, int flags)
156 {
157 struct gpiic_softc * const sc = arg;
158
159 return (i2c_bitbang_initiate_xfer(sc, addr, flags, &sc->sc_bops));
160 }
161
162 static int
gpiic_read_byte(void * arg,uint8_t * vp,int flags)163 gpiic_read_byte(void *arg, uint8_t *vp, int flags)
164 {
165 struct gpiic_softc * const sc = arg;
166
167 return (i2c_bitbang_read_byte(sc, vp, flags, &sc->sc_bops));
168 }
169
170 static int
gpiic_write_byte(void * arg,uint8_t v,int flags)171 gpiic_write_byte(void *arg, uint8_t v, int flags)
172 {
173 struct gpiic_softc * const sc = arg;
174
175 return (i2c_bitbang_write_byte(sc, v, flags, &sc->sc_bops));
176 }
177
178 static void
gpiic_set_dir(void * arg,uint32_t bits)179 gpiic_set_dir(void *arg, uint32_t bits)
180 {
181 struct gpiic_softc * const sc = arg;
182 uint8_t tx, txen;
183
184 txen = (uint8_t)bits;
185 if (sc->sc_txen == txen)
186 return;
187
188 sc->sc_txen = txen;
189
190 tx = sc->sc_tx;
191 if (sc->sc_txen == 0)
192 tx |= IIC_DIRECTCNTL_SDAC;
193 bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL, tx);
194 }
195
196 static void
gpiic_set_bits(void * arg,uint32_t bits)197 gpiic_set_bits(void *arg, uint32_t bits)
198 {
199 struct gpiic_softc * const sc = arg;
200
201 sc->sc_tx = (uint8_t)bits;
202 if (sc->sc_txen == 0)
203 bits |= IIC_DIRECTCNTL_SDAC;
204
205 bus_space_write_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL, bits);
206 }
207
208 static uint32_t
gpiic_read_bits(void * arg)209 gpiic_read_bits(void *arg)
210 {
211 struct gpiic_softc * const sc = arg;
212 uint8_t rv;
213
214 rv = bus_space_read_1(sc->sc_bust, sc->sc_bush, IIC_DIRECTCNTL) << 2;
215 rv &= (IIC_DIRECTCNTL_SCC | IIC_DIRECTCNTL_SDAC);
216
217 return ((uint32_t)rv);
218 }
219