jbus-i2c.c revision 1.7.2.1
1 /* $NetBSD: jbus-i2c.c,v 1.7.2.1 2021/08/09 00:30:08 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 2018 Michael Lorenz 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 25 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: jbus-i2c.c,v 1.7.2.1 2021/08/09 00:30:08 thorpej Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/device.h> 34 #include <sys/errno.h> 35 36 #include <sys/bus.h> 37 #include <machine/autoconf.h> 38 39 #include <dev/i2c/i2cvar.h> 40 #include <dev/i2c/i2c_bitbang.h> 41 42 #include <machine/openfirm.h> 43 44 #ifdef JBUSI2C_DEBUG 45 #define DPRINTF printf 46 #else 47 #define DPRINTF if (0) printf 48 #endif 49 50 /* I2C glue */ 51 static int jbusi2c_i2c_send_start(void *, int); 52 static int jbusi2c_i2c_send_stop(void *, int); 53 static int jbusi2c_i2c_initiate_xfer(void *, i2c_addr_t, int); 54 static int jbusi2c_i2c_read_byte(void *, uint8_t *, int); 55 static int jbusi2c_i2c_write_byte(void *, uint8_t, int); 56 57 /* I2C bitbang glue */ 58 static void jbusi2c_i2cbb_set_bits(void *, uint32_t); 59 static void jbusi2c_i2cbb_set_dir(void *, uint32_t); 60 static uint32_t jbusi2c_i2cbb_read(void *); 61 62 static const struct i2c_bitbang_ops jbusi2c_i2cbb_ops = { 63 jbusi2c_i2cbb_set_bits, 64 jbusi2c_i2cbb_set_dir, 65 jbusi2c_i2cbb_read, 66 { 67 2, /* bit 1 is data */ 68 1, /* bit 0 is clock */ 69 3, /* direction register for both out */ 70 1 /* data in, clock out */ 71 } 72 }; 73 74 static int jbusi2c_match(device_t, cfdata_t, void *); 75 static void jbusi2c_attach(device_t, device_t, void *); 76 77 struct jbusi2c_softc { 78 device_t sc_dev; 79 struct i2c_controller sc_i2c; 80 bus_space_tag_t sc_bustag; 81 bus_space_handle_t sc_regh; 82 }; 83 84 CFATTACH_DECL_NEW(jbusi2c, sizeof(struct jbusi2c_softc), 85 jbusi2c_match, jbusi2c_attach, NULL, NULL); 86 87 /* schizo GPIO registers */ 88 #define DATA 0 89 #define DIR 8 90 91 int 92 jbusi2c_match(device_t parent, cfdata_t match, void *aux) 93 { 94 struct mainbus_attach_args *ma = aux; 95 char *str; 96 97 if (strcmp(ma->ma_name, "i2c") != 0) 98 return (0); 99 100 str = prom_getpropstring(ma->ma_node, "compatible"); 101 if (strcmp(str, "jbus-i2c") == 0) 102 return (1); 103 104 return (0); 105 } 106 107 void 108 jbusi2c_attach(device_t parent, device_t self, void *aux) 109 { 110 struct jbusi2c_softc *sc = device_private(self); 111 struct mainbus_attach_args *ma = aux; 112 struct i2cbus_attach_args iba; 113 114 aprint_normal(": addr %" PRIx64 "\n", ma->ma_reg[0].ur_paddr); 115 116 sc->sc_dev = self; 117 sc->sc_bustag = ma->ma_bustag; 118 119 if (bus_space_map(sc->sc_bustag, ma->ma_reg[0].ur_paddr, 16, 0, 120 &sc->sc_regh)) { 121 aprint_error(": failed to map registers\n"); 122 return; 123 } 124 125 iic_tag_init(&sc->sc_i2c); 126 sc->sc_i2c.ic_cookie = sc; 127 sc->sc_i2c.ic_send_start = jbusi2c_i2c_send_start; 128 sc->sc_i2c.ic_send_stop = jbusi2c_i2c_send_stop; 129 sc->sc_i2c.ic_initiate_xfer = jbusi2c_i2c_initiate_xfer; 130 sc->sc_i2c.ic_read_byte = jbusi2c_i2c_read_byte; 131 sc->sc_i2c.ic_write_byte = jbusi2c_i2c_write_byte; 132 133 memset(&iba, 0, sizeof(iba)); 134 iba.iba_tag = &sc->sc_i2c; 135 config_found(sc->sc_dev, &iba, iicbus_print, 136 CFARGS(.devhandle = device_handle(self))); 137 } 138 139 static inline void 140 jbusi2c_write(struct jbusi2c_softc *sc, int reg, uint64_t bits) 141 { 142 bus_space_write_8(sc->sc_bustag, sc->sc_regh, reg, bits); 143 } 144 145 static inline uint64_t 146 jbusi2c_read(struct jbusi2c_softc *sc, int reg) 147 { 148 return bus_space_read_8(sc->sc_bustag, sc->sc_regh, reg); 149 } 150 151 /* I2C bitbanging */ 152 static void 153 jbusi2c_i2cbb_set_bits(void *cookie, uint32_t bits) 154 { 155 struct jbusi2c_softc *sc = cookie; 156 157 jbusi2c_write(sc, DATA, bits); 158 } 159 160 static void 161 jbusi2c_i2cbb_set_dir(void *cookie, uint32_t dir) 162 { 163 struct jbusi2c_softc *sc = cookie; 164 165 jbusi2c_write(sc, DIR, dir); 166 } 167 168 static uint32_t 169 jbusi2c_i2cbb_read(void *cookie) 170 { 171 struct jbusi2c_softc *sc = cookie; 172 173 return jbusi2c_read(sc, DATA); 174 } 175 176 /* higher level I2C stuff */ 177 static int 178 jbusi2c_i2c_send_start(void *cookie, int flags) 179 { 180 181 return i2c_bitbang_send_start(cookie, flags, &jbusi2c_i2cbb_ops); 182 } 183 184 static int 185 jbusi2c_i2c_send_stop(void *cookie, int flags) 186 { 187 188 return i2c_bitbang_send_stop(cookie, flags, &jbusi2c_i2cbb_ops); 189 } 190 191 static int 192 jbusi2c_i2c_initiate_xfer(void *cookie, i2c_addr_t addr, int flags) 193 { 194 195 return i2c_bitbang_initiate_xfer(cookie, addr, flags, 196 &jbusi2c_i2cbb_ops); 197 } 198 199 static int 200 jbusi2c_i2c_read_byte(void *cookie, uint8_t *valp, int flags) 201 { 202 203 return i2c_bitbang_read_byte(cookie, valp, flags, &jbusi2c_i2cbb_ops); 204 } 205 206 static int 207 jbusi2c_i2c_write_byte(void *cookie, uint8_t val, int flags) 208 { 209 210 return i2c_bitbang_write_byte(cookie, val, flags, &jbusi2c_i2cbb_ops); 211 } 212
Indexes created Tue Sep 30 07:10:03 GMT 2025