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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