1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2006 Warner Losh. 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 WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 */ 26 27 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 /* 30 * Generic IIC eeprom support, modeled after the AT24C family of products. 31 */ 32 33 #include "opt_platform.h" 34 35 #include <sys/param.h> 36 #include <sys/systm.h> 37 #include <sys/bus.h> 38 #include <sys/conf.h> 39 #include <sys/kernel.h> 40 #include <sys/module.h> 41 #include <sys/resource.h> 42 #include <sys/sx.h> 43 #include <sys/uio.h> 44 #include <machine/bus.h> 45 46 #ifdef FDT 47 #include <dev/ofw/ofw_bus.h> 48 #include <dev/ofw/ofw_bus_subr.h> 49 #endif 50 51 #include <dev/iicbus/iiconf.h> 52 #include <dev/iicbus/iicbus.h> 53 54 #include "iicbus_if.h" 55 56 /* 57 * AT24 parts have a "write page size" that differs per-device, and a "read page 58 * size" that is always equal to the full device size. We define maximum values 59 * here to limit how long we occupy the bus with a single transfer, and because 60 * there are temporary buffers of these sizes allocated on the stack. 61 */ 62 #define MAX_RD_SZ 256 /* Largest read size we support */ 63 #define MAX_WR_SZ 256 /* Largest write size we support */ 64 65 struct icee_softc { 66 device_t dev; /* Myself */ 67 struct cdev *cdev; /* user interface */ 68 int addr; /* Slave address on the bus */ 69 int size; /* How big am I? */ 70 int type; /* What address type 8 or 16 bit? */ 71 int wr_sz; /* What's the write page size */ 72 }; 73 74 #ifdef FDT 75 struct eeprom_desc { 76 int type; 77 int size; 78 int wr_sz; 79 const char *name; 80 }; 81 82 static struct eeprom_desc type_desc[] = { 83 { 8, 128, 8, "AT24C01"}, 84 { 8, 256, 8, "AT24C02"}, 85 { 8, 512, 16, "AT24C04"}, 86 { 8, 1024, 16, "AT24C08"}, 87 { 8, 2 * 1024, 16, "AT24C16"}, 88 {16, 4 * 1024, 32, "AT24C32"}, 89 {16, 8 * 1024, 32, "AT24C64"}, 90 {16, 16 * 1024, 64, "AT24C128"}, 91 {16, 32 * 1024, 64, "AT24C256"}, 92 {16, 64 * 1024, 128, "AT24C512"}, 93 {16, 128 * 1024, 256, "AT24CM01"}, 94 }; 95 96 static struct ofw_compat_data compat_data[] = { 97 {"atmel,24c01", (uintptr_t)(&type_desc[0])}, 98 {"atmel,24c02", (uintptr_t)(&type_desc[1])}, 99 {"atmel,24c04", (uintptr_t)(&type_desc[2])}, 100 {"atmel,24c08", (uintptr_t)(&type_desc[3])}, 101 {"atmel,24c16", (uintptr_t)(&type_desc[4])}, 102 {"atmel,24c32", (uintptr_t)(&type_desc[5])}, 103 {"atmel,24c64", (uintptr_t)(&type_desc[6])}, 104 {"atmel,24c128", (uintptr_t)(&type_desc[7])}, 105 {"atmel,24c256", (uintptr_t)(&type_desc[8])}, 106 {"atmel,24c512", (uintptr_t)(&type_desc[9])}, 107 {"atmel,24c1024", (uintptr_t)(&type_desc[10])}, 108 {NULL, (uintptr_t)NULL}, 109 }; 110 #endif 111 112 #define CDEV2SOFTC(dev) ((dev)->si_drv1) 113 114 /* cdev routines */ 115 static d_open_t icee_open; 116 static d_close_t icee_close; 117 static d_read_t icee_read; 118 static d_write_t icee_write; 119 120 static struct cdevsw icee_cdevsw = 121 { 122 .d_version = D_VERSION, 123 .d_flags = D_TRACKCLOSE, 124 .d_open = icee_open, 125 .d_close = icee_close, 126 .d_read = icee_read, 127 .d_write = icee_write 128 }; 129 130 #ifdef FDT 131 static int 132 icee_probe(device_t dev) 133 { 134 struct eeprom_desc *d; 135 136 if (!ofw_bus_status_okay(dev)) 137 return (ENXIO); 138 139 d = (struct eeprom_desc *) 140 ofw_bus_search_compatible(dev, compat_data)->ocd_data; 141 if (d == NULL) 142 return (ENXIO); 143 144 device_set_desc(dev, d->name); 145 return (BUS_PROBE_DEFAULT); 146 } 147 148 static void 149 icee_init(struct icee_softc *sc) 150 { 151 struct eeprom_desc *d; 152 153 d = (struct eeprom_desc *) 154 ofw_bus_search_compatible(sc->dev, compat_data)->ocd_data; 155 if (d == NULL) 156 return; /* attach will see sc->size == 0 and return error */ 157 158 sc->size = d->size; 159 sc->type = d->type; 160 sc->wr_sz = d->wr_sz; 161 } 162 #else /* !FDT */ 163 static int 164 icee_probe(device_t dev) 165 { 166 167 device_set_desc(dev, "I2C EEPROM"); 168 return (BUS_PROBE_NOWILDCARD); 169 } 170 171 static void 172 icee_init(struct icee_softc *sc) 173 { 174 const char *dname; 175 int dunit; 176 177 dname = device_get_name(sc->dev); 178 dunit = device_get_unit(sc->dev); 179 resource_int_value(dname, dunit, "size", &sc->size); 180 resource_int_value(dname, dunit, "type", &sc->type); 181 resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz); 182 } 183 #endif /* FDT */ 184 185 static int 186 icee_attach(device_t dev) 187 { 188 struct icee_softc *sc = device_get_softc(dev); 189 190 sc->dev = dev; 191 sc->addr = iicbus_get_addr(dev); 192 icee_init(sc); 193 if (sc->size == 0 || sc->type == 0 || sc->wr_sz == 0) { 194 device_printf(sc->dev, "Missing config data, " 195 "these cannot be zero: size %d type %d wr_sz %d\n", 196 sc->size, sc->type, sc->wr_sz); 197 return (EINVAL); 198 } 199 if (bootverbose) 200 device_printf(dev, "size: %d bytes, addressing: %d-bits\n", 201 sc->size, sc->type); 202 sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT, 203 GID_WHEEL, 0600, "icee%d", device_get_unit(dev)); 204 if (sc->cdev == NULL) { 205 return (ENOMEM); 206 } 207 sc->cdev->si_drv1 = sc; 208 return (0); 209 } 210 211 static int 212 icee_detach(device_t dev) 213 { 214 struct icee_softc *sc = device_get_softc(dev); 215 216 destroy_dev(sc->cdev); 217 return (0); 218 } 219 220 static int 221 icee_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 222 { 223 struct icee_softc *sc; 224 225 sc = CDEV2SOFTC(dev); 226 if (device_get_state(sc->dev) < DS_BUSY) 227 device_busy(sc->dev); 228 229 return (0); 230 } 231 232 static int 233 icee_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 234 { 235 struct icee_softc *sc; 236 237 sc = CDEV2SOFTC(dev); 238 device_unbusy(sc->dev); 239 return (0); 240 } 241 242 static int 243 icee_read(struct cdev *dev, struct uio *uio, int ioflag) 244 { 245 struct icee_softc *sc; 246 uint8_t addr[2]; 247 uint8_t data[MAX_RD_SZ]; 248 int error, i, len, slave; 249 struct iic_msg msgs[2] = { 250 { 0, IIC_M_WR, 1, addr }, 251 { 0, IIC_M_RD, 0, data }, 252 }; 253 254 sc = CDEV2SOFTC(dev); 255 if (uio->uio_offset == sc->size) 256 return (0); 257 if (uio->uio_offset > sc->size) 258 return (EIO); 259 if (sc->type != 8 && sc->type != 16) 260 return (EINVAL); 261 slave = error = 0; 262 while (uio->uio_resid > 0) { 263 if (uio->uio_offset >= sc->size) 264 break; 265 len = MIN(MAX_RD_SZ - (uio->uio_offset & (MAX_RD_SZ - 1)), 266 uio->uio_resid); 267 switch (sc->type) { 268 case 8: 269 slave = (uio->uio_offset >> 7) | sc->addr; 270 msgs[0].len = 1; 271 msgs[1].len = len; 272 addr[0] = uio->uio_offset & 0xff; 273 break; 274 case 16: 275 slave = sc->addr | (uio->uio_offset >> 15); 276 msgs[0].len = 2; 277 msgs[1].len = len; 278 addr[0] = (uio->uio_offset >> 8) & 0xff; 279 addr[1] = uio->uio_offset & 0xff; 280 break; 281 } 282 for (i = 0; i < 2; i++) 283 msgs[i].slave = slave; 284 error = iicbus_transfer_excl(sc->dev, msgs, 2, IIC_INTRWAIT); 285 if (error) { 286 error = iic2errno(error); 287 break; 288 } 289 error = uiomove(data, len, uio); 290 if (error) 291 break; 292 } 293 return (error); 294 } 295 296 /* 297 * Write to the part. We use three transfers here since we're actually 298 * doing a write followed by a read to make sure that the write finished. 299 * It is easier to encode the dummy read here than to break things up 300 * into smaller chunks... 301 */ 302 static int 303 icee_write(struct cdev *dev, struct uio *uio, int ioflag) 304 { 305 struct icee_softc *sc; 306 int error, len, slave, waitlimit; 307 uint8_t data[MAX_WR_SZ + 2]; 308 struct iic_msg wr[1] = { 309 { 0, IIC_M_WR, 0, data }, 310 }; 311 struct iic_msg rd[1] = { 312 { 0, IIC_M_RD, 1, data }, 313 }; 314 315 sc = CDEV2SOFTC(dev); 316 if (uio->uio_offset >= sc->size) 317 return (EIO); 318 if (sc->type != 8 && sc->type != 16) 319 return (EINVAL); 320 321 slave = error = 0; 322 while (uio->uio_resid > 0) { 323 if (uio->uio_offset >= sc->size) 324 break; 325 len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)), 326 uio->uio_resid); 327 switch (sc->type) { 328 case 8: 329 slave = (uio->uio_offset >> 7) | sc->addr; 330 wr[0].len = 1 + len; 331 data[0] = uio->uio_offset & 0xff; 332 break; 333 case 16: 334 slave = sc->addr | (uio->uio_offset >> 15); 335 wr[0].len = 2 + len; 336 data[0] = (uio->uio_offset >> 8) & 0xff; 337 data[1] = uio->uio_offset & 0xff; 338 break; 339 } 340 wr[0].slave = slave; 341 error = uiomove(data + sc->type / 8, len, uio); 342 if (error) 343 break; 344 error = iicbus_transfer_excl(sc->dev, wr, 1, IIC_INTRWAIT); 345 if (error) { 346 error = iic2errno(error); 347 break; 348 } 349 /* Read after write to wait for write-done. */ 350 waitlimit = 10000; 351 rd[0].slave = slave; 352 do { 353 error = iicbus_transfer_excl(sc->dev, rd, 1, 354 IIC_INTRWAIT); 355 } while (waitlimit-- > 0 && error != 0); 356 if (error) { 357 error = iic2errno(error); 358 break; 359 } 360 } 361 return error; 362 } 363 364 static device_method_t icee_methods[] = { 365 DEVMETHOD(device_probe, icee_probe), 366 DEVMETHOD(device_attach, icee_attach), 367 DEVMETHOD(device_detach, icee_detach), 368 369 DEVMETHOD_END 370 }; 371 372 static driver_t icee_driver = { 373 "icee", 374 icee_methods, 375 sizeof(struct icee_softc), 376 }; 377 static devclass_t icee_devclass; 378 379 DRIVER_MODULE(icee, iicbus, icee_driver, icee_devclass, 0, 0); 380 MODULE_VERSION(icee, 1); 381 MODULE_DEPEND(icee, iicbus, 1, 1, 1); 382