jbus-i2c.c revision 1.8
1 /* $NetBSD: jbus-i2c.c,v 1.8 2025/09/15 13:23:02 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 1.8 2025/09/15 13:23:02 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 int sc_node; 83 }; 84 85 static void jbusi2c_setup_i2c(struct jbusi2c_softc *); 86 87 CFATTACH_DECL_NEW(jbusi2c, sizeof(struct jbusi2c_softc), 88 jbusi2c_match, jbusi2c_attach, NULL, NULL); 89 90 /* schizo GPIO registers */ 91 #define DATA 0 92 #define DIR 8 93 94 int 95 jbusi2c_match(device_t parent, cfdata_t match, void *aux) 96 { 97 struct mainbus_attach_args *ma = aux; 98 char *str; 99 100 if (strcmp(ma->ma_name, "i2c") != 0) 101 return (0); 102 103 str = prom_getpropstring(ma->ma_node, "compatible"); 104 if (strcmp(str, "jbus-i2c") == 0) 105 return (1); 106 107 return (0); 108 } 109 110 void 111 jbusi2c_attach(device_t parent, device_t self, void *aux) 112 { 113 struct jbusi2c_softc *sc = device_private(self); 114 struct mainbus_attach_args *ma = aux; 115 116 aprint_normal(": addr %" PRIx64 "\n", ma->ma_reg[0].ur_paddr); 117 118 sc->sc_dev = self; 119 sc->sc_node = ma->ma_node; 120 sc->sc_bustag = ma->ma_bustag; 121 122 if (bus_space_map(sc->sc_bustag, ma->ma_reg[0].ur_paddr, 16, 0, 123 &sc->sc_regh)) { 124 aprint_error(": failed to map registers\n"); 125 return; 126 } 127 128 jbusi2c_setup_i2c(sc); 129 } 130 131 132 133 static void 134 jbusi2c_setup_i2c(struct jbusi2c_softc *sc) 135 { 136 prop_array_t cfg; 137 prop_dictionary_t dev; 138 prop_dictionary_t dict = device_properties(sc->sc_dev); 139 int devs, regs[2], addr; 140 char name[64], compat[256]; 141 142 iic_tag_init(&sc->sc_i2c); 143 sc->sc_i2c.ic_cookie = sc; 144 sc->sc_i2c.ic_send_start = jbusi2c_i2c_send_start; 145 sc->sc_i2c.ic_send_stop = jbusi2c_i2c_send_stop; 146 sc->sc_i2c.ic_initiate_xfer = jbusi2c_i2c_initiate_xfer; 147 sc->sc_i2c.ic_read_byte = jbusi2c_i2c_read_byte; 148 sc->sc_i2c.ic_write_byte = jbusi2c_i2c_write_byte; 149 150 /* round up i2c devices */ 151 devs = OF_child(sc->sc_node); 152 cfg = prop_array_create(); 153 prop_dictionary_set(dict, "i2c-child-devices", cfg); 154 prop_object_release(cfg); 155 while (devs != 0) { 156 if (OF_getprop(devs, "name", name, 256) <= 0) 157 goto skip; 158 memset(compat, 0, sizeof(compat)); 159 if (OF_getprop(devs, "compatible", 160 compat, 255) <= 0) 161 goto skip; 162 if (OF_getprop(devs, "reg", regs, 8) <= 0) 163 goto skip; 164 if (regs[0] != 0) goto skip; 165 addr = (regs[1] & 0xff) >> 1; 166 DPRINTF("-> %s@%d,%x\n", name, regs[0], addr); 167 dev = prop_dictionary_create(); 168 prop_dictionary_set_string(dev, "name", name); 169 prop_dictionary_set_data(dev, "compatible", compat, 170 strlen(compat)+1); 171 prop_dictionary_set_uint32(dev, "addr", addr); 172 prop_dictionary_set_uint64(dev, "cookie", devs); 173 prop_array_add(cfg, dev); 174 prop_object_release(dev); 175 skip: 176 devs = OF_peer(devs); 177 } 178 iicbus_attach(sc->sc_dev, &sc->sc_i2c); 179 } 180 181 static inline void 182 jbusi2c_write(struct jbusi2c_softc *sc, int reg, uint64_t bits) 183 { 184 bus_space_write_8(sc->sc_bustag, sc->sc_regh, reg, bits); 185 } 186 187 static inline uint64_t 188 jbusi2c_read(struct jbusi2c_softc *sc, int reg) 189 { 190 return bus_space_read_8(sc->sc_bustag, sc->sc_regh, reg); 191 } 192 193 /* I2C bitbanging */ 194 static void 195 jbusi2c_i2cbb_set_bits(void *cookie, uint32_t bits) 196 { 197 struct jbusi2c_softc *sc = cookie; 198 199 jbusi2c_write(sc, DATA, bits); 200 } 201 202 static void 203 jbusi2c_i2cbb_set_dir(void *cookie, uint32_t dir) 204 { 205 struct jbusi2c_softc *sc = cookie; 206 207 jbusi2c_write(sc, DIR, dir); 208 } 209 210 static uint32_t 211 jbusi2c_i2cbb_read(void *cookie) 212 { 213 struct jbusi2c_softc *sc = cookie; 214 215 return jbusi2c_read(sc, DATA); 216 } 217 218 /* higher level I2C stuff */ 219 static int 220 jbusi2c_i2c_send_start(void *cookie, int flags) 221 { 222 223 return i2c_bitbang_send_start(cookie, flags, &jbusi2c_i2cbb_ops); 224 } 225 226 static int 227 jbusi2c_i2c_send_stop(void *cookie, int flags) 228 { 229 230 return i2c_bitbang_send_stop(cookie, flags, &jbusi2c_i2cbb_ops); 231 } 232 233 static int 234 jbusi2c_i2c_initiate_xfer(void *cookie, i2c_addr_t addr, int flags) 235 { 236 237 return i2c_bitbang_initiate_xfer(cookie, addr, flags, 238 &jbusi2c_i2cbb_ops); 239 } 240 241 static int 242 jbusi2c_i2c_read_byte(void *cookie, uint8_t *valp, int flags) 243 { 244 245 return i2c_bitbang_read_byte(cookie, valp, flags, &jbusi2c_i2cbb_ops); 246 } 247 248 static int 249 jbusi2c_i2c_write_byte(void *cookie, uint8_t val, int flags) 250 { 251 252 return i2c_bitbang_write_byte(cookie, val, flags, &jbusi2c_i2cbb_ops); 253 } 254
Indexes created Mon Sep 22 13:09:51 GMT 2025