1 2 /* $NetBSD: scmdi2c.c,v 1.1 2021/12/07 17:39:54 brad Exp $ */ 3 4 /* 5 * Copyright (c) 2021 Brad Spencer <brad@anduin.eldar.org> 6 * 7 * Permission to use, copy, modify, and distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 #include <sys/cdefs.h> 21 __KERNEL_RCSID(0, "$NetBSD: scmdi2c.c,v 1.1 2021/12/07 17:39:54 brad Exp $"); 22 23 /* 24 * I2C driver for the Sparkfun Serial motor controller. 25 * Uses the common code to do the actual work. 26 */ 27 28 #include <sys/param.h> 29 #include <sys/systm.h> 30 #include <sys/kernel.h> 31 #include <sys/device.h> 32 #include <sys/module.h> 33 #include <sys/conf.h> 34 #include <sys/sysctl.h> 35 #include <sys/mutex.h> 36 #include <sys/condvar.h> 37 #include <sys/pool.h> 38 #include <sys/kmem.h> 39 40 #include <dev/i2c/i2cvar.h> 41 #include <dev/spi/spivar.h> 42 #include <dev/ic/scmdreg.h> 43 #include <dev/ic/scmdvar.h> 44 45 extern struct cdevsw scmd_cdevsw; 46 47 extern void scmd_attach(struct scmd_sc *); 48 49 static int scmdi2c_poke(i2c_tag_t, i2c_addr_t, bool); 50 static int scmdi2c_match(device_t, cfdata_t, void *); 51 static void scmdi2c_attach(device_t, device_t, void *); 52 static int scmdi2c_detach(device_t, int); 53 static int scmdi2c_activate(device_t, enum devact); 54 55 #define SCMD_DEBUG 56 #ifdef SCMD_DEBUG 57 #define DPRINTF(s, l, x) \ 58 do { \ 59 if (l <= s->sc_scmddebug) \ 60 printf x; \ 61 } while (/*CONSTCOND*/0) 62 #else 63 #define DPRINTF(s, l, x) 64 #endif 65 66 CFATTACH_DECL_NEW(scmdi2c, sizeof(struct scmd_sc), 67 scmdi2c_match, scmdi2c_attach, scmdi2c_detach, scmdi2c_activate); 68 69 static int 70 scmdi2c_read_reg_direct(i2c_tag_t tag, i2c_addr_t addr, uint8_t reg, 71 uint8_t *buf) 72 { 73 return iic_exec(tag, I2C_OP_READ_WITH_STOP, addr, ®, 1, buf, 74 1, 0); 75 } 76 77 static int 78 scmdi2c_read_reg(struct scmd_sc *sc, uint8_t reg, uint8_t *buf) 79 { 80 return scmdi2c_read_reg_direct(sc->sc_tag, sc->sc_addr, reg, buf); 81 } 82 83 static int 84 scmdi2c_write_reg_direct(i2c_tag_t tag, i2c_addr_t addr, uint8_t reg, 85 uint8_t buf) 86 { 87 return iic_exec(tag, I2C_OP_WRITE_WITH_STOP, addr, ®, 1, &buf, 88 1, 0); 89 } 90 91 static int 92 scmdi2c_write_reg(struct scmd_sc *sc, uint8_t reg, uint8_t buf) 93 { 94 return scmdi2c_write_reg_direct(sc->sc_tag, sc->sc_addr, reg, buf); 95 } 96 97 static int 98 scmdi2c_acquire_bus(struct scmd_sc *sc) 99 { 100 return(iic_acquire_bus(sc->sc_tag, 0)); 101 } 102 103 static void 104 scmdi2c_release_bus(struct scmd_sc *sc) 105 { 106 iic_release_bus(sc->sc_tag, 0); 107 } 108 109 static int 110 scmdi2c_poke(i2c_tag_t tag, i2c_addr_t addr, bool matchdebug) 111 { 112 uint8_t reg = SCMD_REG_ID; 113 uint8_t buf; 114 int error; 115 116 error = scmdi2c_read_reg_direct(tag, addr, reg, &buf); 117 if (matchdebug) { 118 printf("poke X 1: %d %02x %d\n", addr, buf, error); 119 } 120 return error; 121 } 122 123 static int 124 scmdi2c_match(device_t parent, cfdata_t match, void *aux) 125 { 126 struct i2c_attach_args *ia = aux; 127 int error, match_result; 128 const bool matchdebug = false; 129 130 if (iic_use_direct_match(ia, match, NULL, &match_result)) 131 return match_result; 132 133 if (matchdebug) { 134 printf("Looking at ia_addr: %x\n",ia->ia_addr); 135 } 136 137 /* indirect config - check for configured address */ 138 if (!(ia->ia_addr >= SCMD_LOW_I2C_ADDR && 139 ia->ia_addr <= SCMD_HIGH_I2C_ADDR)) 140 return 0; 141 142 /* 143 * Check to see if something is really at this i2c address. 144 * This will keep phantom devices from appearing 145 */ 146 if (iic_acquire_bus(ia->ia_tag, 0) != 0) { 147 if (matchdebug) 148 printf("in match acquire bus failed\n"); 149 return 0; 150 } 151 152 error = scmdi2c_poke(ia->ia_tag, ia->ia_addr, matchdebug); 153 iic_release_bus(ia->ia_tag, 0); 154 155 return error == 0 ? I2C_MATCH_ADDRESS_AND_PROBE : 0; 156 } 157 158 static void 159 scmdi2c_attach(device_t parent, device_t self, void *aux) 160 { 161 struct scmd_sc *sc; 162 struct i2c_attach_args *ia; 163 164 ia = aux; 165 sc = device_private(self); 166 167 sc->sc_dev = self; 168 sc->sc_tag = ia->ia_tag; 169 sc->sc_addr = ia->ia_addr; 170 sc->sc_scmddebug = 0; 171 sc->sc_topaddr = 0xff; 172 sc->sc_opened = false; 173 sc->sc_dying = false; 174 sc->sc_func_acquire_bus = &scmdi2c_acquire_bus; 175 sc->sc_func_release_bus = &scmdi2c_release_bus; 176 sc->sc_func_read_register = &scmdi2c_read_reg; 177 sc->sc_func_write_register = &scmdi2c_write_reg; 178 179 mutex_init(&sc->sc_mutex, MUTEX_DEFAULT, IPL_NONE); 180 mutex_init(&sc->sc_condmutex, MUTEX_DEFAULT, IPL_NONE); 181 mutex_init(&sc->sc_dying_mutex, MUTEX_DEFAULT, IPL_NONE); 182 cv_init(&sc->sc_condvar, "scmdi2ccv"); 183 cv_init(&sc->sc_cond_dying, "scmdi2cdc"); 184 185 scmd_attach(sc); 186 187 return; 188 } 189 190 static int 191 scmdi2c_detach(device_t self, int flags) 192 { 193 struct scmd_sc *sc; 194 195 sc = device_private(self); 196 197 mutex_enter(&sc->sc_mutex); 198 sc->sc_dying = true; 199 /* If this is true we are still open, destroy the condvar */ 200 if (sc->sc_opened) { 201 mutex_enter(&sc->sc_dying_mutex); 202 DPRINTF(sc, 2, ("%s: Will wait for anything to exit\n", 203 device_xname(sc->sc_dev))); 204 /* In the worst case this will time out after 5 seconds. 205 * It really should not take that long for the drain / whatever 206 * to happen 207 */ 208 cv_timedwait_sig(&sc->sc_cond_dying, 209 &sc->sc_dying_mutex, mstohz(5000)); 210 mutex_exit(&sc->sc_dying_mutex); 211 cv_destroy(&sc->sc_cond_dying); 212 } 213 cv_destroy(&sc->sc_condvar); 214 mutex_exit(&sc->sc_mutex); 215 216 mutex_destroy(&sc->sc_mutex); 217 mutex_destroy(&sc->sc_condmutex); 218 219 return 0; 220 } 221 222 int 223 scmdi2c_activate(device_t self, enum devact act) 224 { 225 struct scmd_sc *sc = device_private(self); 226 227 switch (act) { 228 case DVACT_DEACTIVATE: 229 sc->sc_dying = true; 230 return 0; 231 default: 232 return EOPNOTSUPP; 233 } 234 } 235 236 MODULE(MODULE_CLASS_DRIVER, scmdi2c, "i2cexec,scmd"); 237 238 #ifdef _MODULE 239 /* Like other drivers, we do this because the scmd common 240 * driver has the definitions already. 241 */ 242 #undef CFDRIVER_DECL 243 #define CFDRIVER_DECL(name, class, attr) 244 #include "ioconf.c" 245 #endif 246 247 static int 248 scmdi2c_modcmd(modcmd_t cmd, void *opaque) 249 { 250 #ifdef _MODULE 251 int error = 0; 252 static struct cfdriver * const no_cfdriver_vec[] = { NULL }; 253 #endif 254 255 switch (cmd) { 256 case MODULE_CMD_INIT: 257 #ifdef _MODULE 258 /* I really do not understand why I had to do this this way. 259 * If I did not then the module would either not install when 260 * the SPI driver and hence the scmd dependent driver was compiled 261 * into the kernel, or it would not install if it was not. 262 * I suspect something is still not set up correctly somewhere, but 263 * I am at a lose to see what. 264 * 265 * The first config_init_component will fail if the SPI driver and the 266 * scmd dependent is in the kernel already, but the second one will work. 267 * Otherwise the other way around. 268 * 269 * This all manages to get this module set up in any situation. 270 */ 271 error = config_init_component(cfdriver_ioconf_scmdi2c, 272 cfattach_ioconf_scmdi2c, cfdata_ioconf_scmdi2c); 273 if (error) { 274 aprint_error("%s: Trying no_cfdriver_vec method: %d\n", 275 scmd_cd.cd_name, error); 276 error = config_init_component(no_cfdriver_vec, 277 cfattach_ioconf_scmdi2c, cfdata_ioconf_scmdi2c); 278 } 279 280 return error; 281 #else 282 return 0; 283 #endif 284 case MODULE_CMD_FINI: 285 #ifdef _MODULE 286 /* See above.. same thing */ 287 error = config_fini_component(cfdriver_ioconf_scmdi2c, 288 cfattach_ioconf_scmdi2c, cfdata_ioconf_scmdi2c); 289 if (error) { 290 aprint_error("%s: Trying no_cfdriver_vec method: %d\n", 291 scmd_cd.cd_name, error); 292 error = config_fini_component(no_cfdriver_vec, 293 cfattach_ioconf_scmdi2c, cfdata_ioconf_scmdi2c); 294 } 295 296 return error; 297 #else 298 return 0; 299 #endif 300 default: 301 return ENOTTY; 302 } 303 } 304