xref: /netbsd-src/sys/arch/mmeye/dev/rtciic.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
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