rtciic.c revision 1.1 1 /* $NetBSD: rtciic.c,v 1.1 2011/02/19 10:46:28 kiyohara Exp $ */
2 /*
3 * Copyright (c) 2011 KIYOHARA Takashi
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
19 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
24 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 *
27 */
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: rtciic.c,v 1.1 2011/02/19 10:46:28 kiyohara Exp $");
30
31 #include <sys/param.h>
32 #include <sys/bus.h>
33 #include <sys/device.h>
34 #include <sys/errno.h>
35
36 #include <machine/autoconf.h>
37
38 #include <dev/i2c/i2cvar.h>
39 #include <dev/i2c/i2c_bitbang.h>
40
41 #include "locators.h"
42
43 #ifdef RTCIIC_DEBUG
44 #define DPRINTF(x) printf x
45 #else
46 #define DPRINTF(x)
47 #endif
48
49 #define RTCIIC_SDAR (1 << 3) /* recived serial data */
50 #define RTCIIC_SDAW (1 << 2) /* sended serial data */
51 #define RTCIIC_SCL (1 << 1) /* serial clock */
52 #define RTCIIC_RW (1 << 0) /* data direction (0:write, 1:read) */
53
54 /* This device is Big Endian */
55 #define RTCIIC_READ(sc) \
56 bswap16(bus_space_read_2((sc)->sc_iot, (sc)->sc_ioh, 0))
57 #define RTCIIC_WRITE(sc, val) \
58 bus_space_write_2((sc)->sc_iot, (sc)->sc_ioh, 0, bswap16(val))
59
60 struct rtciic_softc {
61 device_t sc_dev;
62
63 bus_space_tag_t sc_iot;
64 bus_space_handle_t sc_ioh;
65
66 struct i2c_controller sc_i2c;
67 struct i2c_bitbang_ops sc_bops;
68
69 int sc_rw;
70 };
71
72 static int rtciic_match(device_t, cfdata_t , void *);
73 static void rtciic_attach(device_t, device_t, void *);
74
75 static int rtciic_acquire_bus(void *, int);
76 static void rtciic_release_bus(void *, int);
77 static int rtciic_send_start(void *, int);
78 static int rtciic_send_stop(void *, int);
79 static int rtciic_initiate_xfer(void *, i2c_addr_t, int);
80 static int rtciic_read_byte(void *, uint8_t *, int);
81 static int rtciic_write_byte(void *, uint8_t, int);
82
83 static void rtciic_set_dir(void *, uint32_t);
84 static void rtciic_set_bits(void *, uint32_t);
85 static uint32_t rtciic_read_bits(void *);
86
87 CFATTACH_DECL_NEW(rtciic, sizeof(struct rtciic_softc),
88 rtciic_match, rtciic_attach, NULL, NULL);
89
90 static int
91 rtciic_match(device_t parent, cfdata_t match, void *aux)
92 {
93 struct mainbus_attach_args *ma = aux;
94
95 if (strcmp(ma->ma_name, match->cf_name) != 0)
96 return 0;
97
98 /* Disallow wildcarded values. */
99 if (ma->ma_addr1 == MAINBUSCF_ADDR1_DEFAULT)
100 return 0;
101
102 /* no irq */
103 if (ma->ma_irq1 != MAINBUSCF_IRQ1_DEFAULT)
104 return 0;
105
106 return 1;
107 }
108
109 void
110 rtciic_attach(device_t parent, device_t self, void *aux)
111 {
112 struct rtciic_softc *sc = device_private(self);
113 struct mainbus_attach_args *ma = aux;
114 struct i2cbus_attach_args iba;
115
116 sc->sc_dev = self;
117
118 aprint_normal("\n");
119 aprint_naive("\n");
120
121 /* Map I/O space(16bit). */
122 sc->sc_iot = 0;
123 if (bus_space_map(sc->sc_iot, ma->ma_addr1, 2, 0, &sc->sc_ioh)) {
124 aprint_error_dev(self, "can't map registers\n");
125 return;
126 }
127 sc->sc_rw = RTCIIC_READ(sc) & RTCIIC_RW;
128
129 /* register with iic */
130 sc->sc_i2c.ic_cookie = sc;
131 sc->sc_i2c.ic_acquire_bus = rtciic_acquire_bus;
132 sc->sc_i2c.ic_release_bus = rtciic_release_bus;
133 sc->sc_i2c.ic_exec = NULL;
134 sc->sc_i2c.ic_send_start = rtciic_send_start;
135 sc->sc_i2c.ic_send_stop = rtciic_send_stop;
136 sc->sc_i2c.ic_initiate_xfer = rtciic_initiate_xfer;
137 sc->sc_i2c.ic_read_byte = rtciic_read_byte;
138 sc->sc_i2c.ic_write_byte = rtciic_write_byte;
139
140 sc->sc_bops.ibo_set_dir = rtciic_set_dir;
141 sc->sc_bops.ibo_set_bits = rtciic_set_bits;
142 sc->sc_bops.ibo_read_bits = rtciic_read_bits;
143 sc->sc_bops.ibo_bits[I2C_BIT_SDA] = RTCIIC_SDAW;
144 sc->sc_bops.ibo_bits[I2C_BIT_SCL] = RTCIIC_SCL;
145 sc->sc_bops.ibo_bits[I2C_BIT_OUTPUT] = 0;
146 sc->sc_bops.ibo_bits[I2C_BIT_INPUT] = RTCIIC_RW;
147
148 memset(&iba, 0, sizeof(iba));
149 iba.iba_tag = &sc->sc_i2c;
150 (void) config_found_ia(sc->sc_dev, "i2cbus", &iba, iicbus_print);
151 }
152
153
154 static int
155 rtciic_acquire_bus(void *cookie, int flags)
156 {
157
158 return 0;
159 }
160
161 static void
162 rtciic_release_bus(void *cookie, int flags)
163 {
164 /* nothing */
165 }
166
167 static int
168 rtciic_send_start(void *arg, int flags)
169 {
170 struct rtciic_softc *sc = arg;
171
172 return i2c_bitbang_send_start(sc, flags, &sc->sc_bops);
173 }
174
175 static int
176 rtciic_send_stop(void *arg, int flags)
177 {
178 struct rtciic_softc *sc = arg;
179
180 return i2c_bitbang_send_stop(sc, flags, &sc->sc_bops);
181 }
182
183 static int
184 rtciic_initiate_xfer(void *arg, i2c_addr_t addr, int flags)
185 {
186 struct rtciic_softc *sc = arg;
187
188 return i2c_bitbang_initiate_xfer(sc, addr, flags, &sc->sc_bops);
189 }
190
191 static int
192 rtciic_read_byte(void *arg, uint8_t *vp, int flags)
193 {
194 struct rtciic_softc *sc = arg;
195
196 return i2c_bitbang_read_byte(sc, vp, flags, &sc->sc_bops);
197 }
198
199 static int
200 rtciic_write_byte(void *arg, uint8_t v, int flags)
201 {
202 struct rtciic_softc *sc = arg;
203
204 return i2c_bitbang_write_byte(sc, v, flags, &sc->sc_bops);
205 }
206
207
208 static void
209 rtciic_set_dir(void *arg, uint32_t bits)
210 {
211 struct rtciic_softc *sc = arg;
212 uint16_t reg;
213
214 DPRINTF(("%s: set dir %s\n",
215 device_xname(sc->sc_dev), (bits & RTCIIC_RW) ? "READ" : "WRITE"));
216
217 if (sc->sc_rw != (bits & RTCIIC_RW)) {
218 reg = RTCIIC_READ(sc);
219 reg &= ~RTCIIC_RW;
220 reg |= bits;
221 RTCIIC_WRITE(sc, reg);
222 delay(30);
223 sc->sc_rw = bits & RTCIIC_RW;
224 }
225 }
226
227 static void
228 rtciic_set_bits(void *arg, uint32_t bits)
229 {
230 struct rtciic_softc *sc = arg;
231
232 DPRINTF(("%s: %s\n",
233 device_xname(sc->sc_dev),
234 (bits == (RTCIIC_SDAW | RTCIIC_SCL)) ? "set SDA/SCL" :
235 ((bits == RTCIIC_SDAW) ? "set SDA" :
236 ((bits == RTCIIC_SCL) ? "set SCL" : "reset"))));
237
238 if (sc->sc_rw & RTCIIC_RW) {
239 bits &= RTCIIC_SCL;
240 bits |= RTCIIC_RW;
241 }
242 RTCIIC_WRITE(sc, bits);
243 delay(40);
244 }
245
246 static uint32_t
247 rtciic_read_bits(void *arg)
248 {
249 struct rtciic_softc *sc = arg;
250 uint8_t rv, v;
251
252 v = RTCIIC_READ(sc);
253 rv = v & RTCIIC_SCL;
254 if (v & RTCIIC_SDAR)
255 rv |= RTCIIC_SDAW;
256
257 DPRINTF(("%s: read %s\n",
258 device_xname(sc->sc_dev),
259 (rv == (RTCIIC_SDAW | RTCIIC_SCL)) ? "SDA/SCL" :
260 ((rv == RTCIIC_SDAW) ? "SDA" :
261 ((rv == RTCIIC_SCL) ? "SCL" : "no"))));
262
263 return (uint32_t)rv;
264 }
265