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rtciic.c revision 1.3.10.1
      1 /*	$NetBSD: rtciic.c,v 1.3.10.1 2021/03/23 07:14:49 thorpej 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 1.3.10.1 2021/03/23 07:14:49 thorpej 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)	/* received 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_send_start(void *, int);
     76 static int rtciic_send_stop(void *, int);
     77 static int rtciic_initiate_xfer(void *, i2c_addr_t, int);
     78 static int rtciic_read_byte(void *, uint8_t *, int);
     79 static int rtciic_write_byte(void *, uint8_t, int);
     80 
     81 static void rtciic_set_dir(void *, uint32_t);
     82 static void rtciic_set_bits(void *, uint32_t);
     83 static uint32_t rtciic_read_bits(void *);
     84 
     85 CFATTACH_DECL_NEW(rtciic, sizeof(struct rtciic_softc),
     86     rtciic_match, rtciic_attach, NULL, NULL);
     87 
     88 static int
     89 rtciic_match(device_t parent, cfdata_t match, void *aux)
     90 {
     91 	struct mainbus_attach_args *ma = aux;
     92 
     93 	if (strcmp(ma->ma_name, match->cf_name) != 0)
     94 		return 0;
     95 
     96 	/* Disallow wildcarded values. */
     97 	if (ma->ma_addr1 == MAINBUSCF_ADDR1_DEFAULT)
     98 		return 0;
     99 
    100 	/* no irq */
    101 	if (ma->ma_irq1 != MAINBUSCF_IRQ1_DEFAULT)
    102 		return 0;
    103 
    104 	return 1;
    105 }
    106 
    107 void
    108 rtciic_attach(device_t parent, device_t self, void *aux)
    109 {
    110 	struct rtciic_softc *sc = device_private(self);
    111 	struct mainbus_attach_args *ma = aux;
    112 	struct i2cbus_attach_args iba;
    113 
    114 	sc->sc_dev = self;
    115 
    116 	aprint_normal("\n");
    117 	aprint_naive("\n");
    118 
    119 	/* Map I/O space(16bit). */
    120 	sc->sc_iot = 0;
    121 	if (bus_space_map(sc->sc_iot, ma->ma_addr1, 2, 0, &sc->sc_ioh)) {
    122 		aprint_error_dev(self, "can't map registers\n");
    123 		return;
    124 	}
    125 	sc->sc_rw = RTCIIC_READ(sc) & RTCIIC_RW;
    126 
    127 	/* register with iic */
    128 	iic_tag_init(&sc->sc_i2c);
    129 	sc->sc_i2c.ic_cookie = sc;
    130 	sc->sc_i2c.ic_send_start = rtciic_send_start;
    131 	sc->sc_i2c.ic_send_stop = rtciic_send_stop;
    132 	sc->sc_i2c.ic_initiate_xfer = rtciic_initiate_xfer;
    133 	sc->sc_i2c.ic_read_byte = rtciic_read_byte;
    134 	sc->sc_i2c.ic_write_byte = rtciic_write_byte;
    135 
    136 	sc->sc_bops.ibo_set_dir = rtciic_set_dir;
    137 	sc->sc_bops.ibo_set_bits = rtciic_set_bits;
    138 	sc->sc_bops.ibo_read_bits = rtciic_read_bits;
    139 	sc->sc_bops.ibo_bits[I2C_BIT_SDA] = RTCIIC_SDAW;
    140 	sc->sc_bops.ibo_bits[I2C_BIT_SCL] = RTCIIC_SCL;
    141 	sc->sc_bops.ibo_bits[I2C_BIT_OUTPUT] = 0;
    142 	sc->sc_bops.ibo_bits[I2C_BIT_INPUT] = RTCIIC_RW;
    143 
    144 	memset(&iba, 0, sizeof(iba));
    145 	iba.iba_tag = &sc->sc_i2c;
    146 	config_found(sc->sc_dev, &iba, iicbus_print, CFARG_EOL);
    147 }
    148 
    149 static int
    150 rtciic_send_start(void *arg, int flags)
    151 {
    152 	struct rtciic_softc *sc = arg;
    153 
    154 	return i2c_bitbang_send_start(sc, flags, &sc->sc_bops);
    155 }
    156 
    157 static int
    158 rtciic_send_stop(void *arg, int flags)
    159 {
    160 	struct rtciic_softc *sc = arg;
    161 
    162 	return i2c_bitbang_send_stop(sc, flags, &sc->sc_bops);
    163 }
    164 
    165 static int
    166 rtciic_initiate_xfer(void *arg, i2c_addr_t addr, int flags)
    167 {
    168 	struct rtciic_softc *sc = arg;
    169 
    170 	return i2c_bitbang_initiate_xfer(sc, addr, flags, &sc->sc_bops);
    171 }
    172 
    173 static int
    174 rtciic_read_byte(void *arg, uint8_t *vp, int flags)
    175 {
    176 	struct rtciic_softc *sc = arg;
    177 
    178 	return i2c_bitbang_read_byte(sc, vp, flags, &sc->sc_bops);
    179 }
    180 
    181 static int
    182 rtciic_write_byte(void *arg, uint8_t v, int flags)
    183 {
    184 	struct rtciic_softc *sc = arg;
    185 
    186 	return i2c_bitbang_write_byte(sc, v, flags, &sc->sc_bops);
    187 }
    188 
    189 
    190 static void
    191 rtciic_set_dir(void *arg, uint32_t bits)
    192 {
    193 	struct rtciic_softc *sc = arg;
    194 	uint16_t reg;
    195 
    196 	DPRINTF(("%s: set dir %s\n",
    197 	    device_xname(sc->sc_dev), (bits & RTCIIC_RW) ? "READ" : "WRITE"));
    198 
    199 	if (sc->sc_rw != (bits & RTCIIC_RW)) {
    200 		reg = RTCIIC_READ(sc);
    201 		reg &= ~RTCIIC_RW;
    202 		reg |= bits;
    203 		RTCIIC_WRITE(sc, reg);
    204 		delay(30);
    205 		sc->sc_rw = bits & RTCIIC_RW;
    206 	}
    207 }
    208 
    209 static void
    210 rtciic_set_bits(void *arg, uint32_t bits)
    211 {
    212 	struct rtciic_softc *sc = arg;
    213 
    214 	DPRINTF(("%s: %s\n",
    215 	    device_xname(sc->sc_dev),
    216 	    (bits == (RTCIIC_SDAW | RTCIIC_SCL)) ? "set SDA/SCL" :
    217 	    ((bits == RTCIIC_SDAW) ? "set SDA" :
    218 	    ((bits == RTCIIC_SCL) ? "set SCL" : "reset"))));
    219 
    220 	if (sc->sc_rw & RTCIIC_RW) {
    221 		bits &= RTCIIC_SCL;
    222 		bits |= RTCIIC_RW;
    223 	}
    224 	RTCIIC_WRITE(sc, bits);
    225 	delay(40);
    226 }
    227 
    228 static uint32_t
    229 rtciic_read_bits(void *arg)
    230 {
    231 	struct rtciic_softc *sc = arg;
    232 	uint8_t rv, v;
    233 
    234 	v = RTCIIC_READ(sc);
    235 	rv = v & RTCIIC_SCL;
    236 	if (v & RTCIIC_SDAR)
    237 		rv |= RTCIIC_SDAW;
    238 
    239 	DPRINTF(("%s: read %s\n",
    240 	    device_xname(sc->sc_dev),
    241 	    (rv == (RTCIIC_SDAW | RTCIIC_SCL)) ? "SDA/SCL" :
    242 	    ((rv == RTCIIC_SDAW) ? "SDA" :
    243 	    ((rv == RTCIIC_SCL) ? "SCL" : "no"))));
    244 
    245 	return (uint32_t)rv;
    246 }
    247