bmx280thpi2c.c revision 1.4
1 /* $NetBSD: bmx280thpi2c.c,v 1.4 2025/09/13 16:16:40 thorpej Exp $ */ 2 3 /* 4 * Copyright (c) 2022 Brad Spencer <brad (at) anduin.eldar.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 #include <sys/cdefs.h> 20 __KERNEL_RCSID(0, "$NetBSD: bmx280thpi2c.c,v 1.4 2025/09/13 16:16:40 thorpej Exp $"); 21 22 /* 23 * I2C driver for the Bosch BMP280 / BME280 sensor. 24 * Uses the common bmx280thp driver to do the real work. 25 */ 26 27 #include <sys/param.h> 28 #include <sys/systm.h> 29 #include <sys/kernel.h> 30 #include <sys/device.h> 31 #include <sys/module.h> 32 #include <sys/conf.h> 33 #include <sys/sysctl.h> 34 #include <sys/mutex.h> 35 #include <sys/condvar.h> 36 #include <sys/pool.h> 37 #include <sys/kmem.h> 38 39 #include <dev/sysmon/sysmonvar.h> 40 #include <dev/i2c/i2cvar.h> 41 #include <dev/spi/spivar.h> 42 #include <dev/ic/bmx280reg.h> 43 #include <dev/ic/bmx280var.h> 44 45 struct bmx280_i2c_softc { 46 struct bmx280_sc sc_bmx280; 47 i2c_tag_t sc_tag; 48 i2c_addr_t sc_addr; 49 }; 50 51 #define BMX280_TO_I2C(sc) \ 52 container_of((sc), struct bmx280_i2c_softc, sc_bmx280) 53 54 static int bmx280thpi2c_poke(i2c_tag_t, i2c_addr_t, bool); 55 static int bmx280thpi2c_match(device_t, cfdata_t, void *); 56 static void bmx280thpi2c_attach(device_t, device_t, void *); 57 static int bmx280thpi2c_detach(device_t, int); 58 59 CFATTACH_DECL_NEW(bmx280thpi2c, sizeof(struct bmx280_sc), 60 bmx280thpi2c_match, bmx280thpi2c_attach, bmx280thpi2c_detach, NULL); 61 62 /* For the BMX280, a read consists of writing on the I2C bus 63 * a I2C START, I2C SLAVE address, then the starting register. 64 * If that works, then following will be another I2C START, 65 * I2C SLAVE address, followed by as many I2C reads that is 66 * desired and then a I2C STOP 67 */ 68 69 static int 70 bmx280thpi2c_read_register_direct(i2c_tag_t tag, i2c_addr_t addr, uint8_t reg, 71 uint8_t *buf, size_t blen) 72 { 73 int error; 74 75 error = iic_exec(tag,I2C_OP_WRITE,addr,®,1,NULL,0,0); 76 77 if (error == 0) { 78 error = iic_exec(tag,I2C_OP_READ_WITH_STOP,addr,NULL,0, 79 buf,blen,0); 80 } 81 82 return error; 83 } 84 85 static int 86 bmx280thpi2c_read_register(struct bmx280_sc *sc, uint8_t reg, 87 uint8_t *buf, size_t blen) 88 { 89 struct bmx280_i2c_softc *isc = BMX280_TO_I2C(sc); 90 int error; 91 92 KASSERT(blen > 0); 93 94 error = bmx280thpi2c_read_register_direct(isc->sc_tag, isc->sc_addr, 95 reg, buf, blen); 96 97 return error; 98 } 99 100 /* For the BMX280, a write consists of sending a I2C START, I2C SLAVE 101 * address and then pairs of registers and data until a I2C STOP is 102 * sent. 103 */ 104 105 static int 106 bmx280thpi2c_write_register(struct bmx280_sc *sc, uint8_t *buf, size_t blen) 107 { 108 struct bmx280_i2c_softc *isc = BMX280_TO_I2C(sc); 109 int error; 110 111 KASSERT(blen > 0); 112 /* XXX - there should be a KASSERT for blen at least 113 being an even number */ 114 115 error = iic_exec(isc->sc_tag,I2C_OP_WRITE_WITH_STOP,isc->sc_addr,NULL,0, 116 buf,blen,0); 117 118 return error; 119 } 120 121 static int 122 bmx280thpi2c_acquire_bus(struct bmx280_sc *sc) 123 { 124 struct bmx280_i2c_softc *isc = BMX280_TO_I2C(sc); 125 126 return(iic_acquire_bus(isc->sc_tag, 0)); 127 } 128 129 static void 130 bmx280thpi2c_release_bus(struct bmx280_sc *sc) 131 { 132 struct bmx280_i2c_softc *isc = BMX280_TO_I2C(sc); 133 134 iic_release_bus(isc->sc_tag, 0); 135 } 136 137 static const struct bmx280_accessfuncs bmx280_i2c_accessfuncs = { 138 .acquire_bus = bmx280thpi2c_acquire_bus, 139 .release_bus = bmx280thpi2c_release_bus, 140 .read_reg = bmx280thpi2c_read_register, 141 .write_reg = bmx280thpi2c_write_register, 142 }; 143 144 static int 145 bmx280thpi2c_poke(i2c_tag_t tag, i2c_addr_t addr, bool matchdebug) 146 { 147 uint8_t reg = BMX280_REGISTER_ID; 148 uint8_t buf[1]; 149 int error; 150 151 error = bmx280thpi2c_read_register_direct(tag, addr, reg, buf, 1); 152 if (matchdebug) { 153 printf("poke X 1: %d\n", error); 154 } 155 return error; 156 } 157 158 static int 159 bmx280thpi2c_match(device_t parent, cfdata_t cf, void *aux) 160 { 161 struct i2c_attach_args *ia = aux; 162 int error, match_result; 163 const bool matchdebug = false; 164 165 if (iic_use_direct_match(ia, cf, bmx280_compat_data, &match_result)) { 166 return match_result; 167 } 168 169 /* indirect config - check for configured address */ 170 if (ia->ia_addr != BMX280_TYPICAL_ADDR_1 && 171 ia->ia_addr != BMX280_TYPICAL_ADDR_2) 172 return 0; 173 174 /* 175 * Check to see if something is really at this i2c address. This will 176 * keep phantom devices from appearing 177 */ 178 if (iic_acquire_bus(ia->ia_tag, 0) != 0) { 179 if (matchdebug) 180 printf("in match acquire bus failed\n"); 181 return 0; 182 } 183 184 error = bmx280thpi2c_poke(ia->ia_tag, ia->ia_addr, matchdebug); 185 iic_release_bus(ia->ia_tag, 0); 186 187 return error == 0 ? I2C_MATCH_ADDRESS_AND_PROBE : 0; 188 } 189 190 static void 191 bmx280thpi2c_attach(device_t parent, device_t self, void *aux) 192 { 193 struct bmx280_i2c_softc *isc = device_private(self); 194 struct bmx280_sc *sc = &isc->sc_bmx280; 195 struct i2c_attach_args *ia = aux; 196 197 sc->sc_dev = self; 198 sc->sc_funcs = &bmx280_i2c_accessfuncs; 199 200 isc->sc_tag = ia->ia_tag; 201 isc->sc_addr = ia->ia_addr; 202 203 bmx280_attach(sc); 204 } 205 206 static int 207 bmx280thpi2c_detach(device_t self, int flags) 208 { 209 struct bmx280_i2c_softc *isc = device_private(self); 210 211 return bmx280_detach(&isc->sc_bmx280, flags); 212 } 213 214 MODULE(MODULE_CLASS_DRIVER, bmx280thpi2c, "iic,bmx280thp"); 215 216 #ifdef _MODULE 217 /* Like other drivers, we do this because the bmx280 common 218 * driver has the definitions already. 219 */ 220 #undef CFDRIVER_DECL 221 #define CFDRIVER_DECL(name, class, attr) 222 #include "ioconf.c" 223 #endif 224 225 static int 226 bmx280thpi2c_modcmd(modcmd_t cmd, void *opaque) 227 { 228 229 switch (cmd) { 230 case MODULE_CMD_INIT: 231 #ifdef _MODULE 232 return config_init_component(cfdriver_ioconf_bmx280thpi2c, 233 cfattach_ioconf_bmx280thpi2c, cfdata_ioconf_bmx280thpi2c); 234 #else 235 return 0; 236 #endif 237 case MODULE_CMD_FINI: 238 #ifdef _MODULE 239 return config_fini_component(cfdriver_ioconf_bmx280thpi2c, 240 cfattach_ioconf_bmx280thpi2c, cfdata_ioconf_bmx280thpi2c); 241 #else 242 return 0; 243 #endif 244 default: 245 return ENOTTY; 246 } 247 } 248
Indexes created Sun Oct 19 02:09:48 GMT 2025