1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2006 M. Warner Losh <imp@FreeBSD.org> 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/sysctl.h> 44 #include <sys/uio.h> 45 #include <machine/bus.h> 46 47 #ifdef FDT 48 #include <dev/ofw/ofw_bus.h> 49 #include <dev/ofw/ofw_bus_subr.h> 50 #endif 51 52 #include <dev/iicbus/iiconf.h> 53 #include <dev/iicbus/iicbus.h> 54 55 #include "iicbus_if.h" 56 57 /* 58 * AT24 parts have a "write page size" that differs per-device, and a "read page 59 * size" that is always equal to the full device size. We define maximum values 60 * here to limit how long we occupy the bus with a single transfer, and because 61 * there are temporary buffers of these sizes allocated on the stack. 62 */ 63 #define MAX_RD_SZ 256 /* Largest read size we support */ 64 #define MAX_WR_SZ 256 /* Largest write size we support */ 65 66 struct icee_softc { 67 device_t dev; /* Myself */ 68 struct cdev *cdev; /* user interface */ 69 int addr; /* Slave address on the bus */ 70 int size; /* How big am I? */ 71 int type; /* What address type 8 or 16 bit? */ 72 int wr_sz; /* What's the write page size */ 73 }; 74 75 #ifdef FDT 76 struct eeprom_desc { 77 int type; 78 int size; 79 int wr_sz; 80 const char *name; 81 }; 82 83 static struct eeprom_desc type_desc[] = { 84 { 8, 128, 8, "AT24C01"}, 85 { 8, 256, 8, "AT24C02"}, 86 { 8, 512, 16, "AT24C04"}, 87 { 8, 1024, 16, "AT24C08"}, 88 { 8, 2 * 1024, 16, "AT24C16"}, 89 {16, 4 * 1024, 32, "AT24C32"}, 90 {16, 8 * 1024, 32, "AT24C64"}, 91 {16, 16 * 1024, 64, "AT24C128"}, 92 {16, 32 * 1024, 64, "AT24C256"}, 93 {16, 64 * 1024, 128, "AT24C512"}, 94 {16, 128 * 1024, 256, "AT24CM01"}, 95 }; 96 97 static struct ofw_compat_data compat_data[] = { 98 {"atmel,24c01", (uintptr_t)(&type_desc[0])}, 99 {"atmel,24c02", (uintptr_t)(&type_desc[1])}, 100 {"atmel,24c04", (uintptr_t)(&type_desc[2])}, 101 {"atmel,24c08", (uintptr_t)(&type_desc[3])}, 102 {"atmel,24c16", (uintptr_t)(&type_desc[4])}, 103 {"atmel,24c32", (uintptr_t)(&type_desc[5])}, 104 {"atmel,24c64", (uintptr_t)(&type_desc[6])}, 105 {"atmel,24c128", (uintptr_t)(&type_desc[7])}, 106 {"atmel,24c256", (uintptr_t)(&type_desc[8])}, 107 {"atmel,24c512", (uintptr_t)(&type_desc[9])}, 108 {"atmel,24c1024", (uintptr_t)(&type_desc[10])}, 109 {NULL, (uintptr_t)NULL}, 110 }; 111 #endif 112 113 #define CDEV2SOFTC(dev) ((dev)->si_drv1) 114 115 /* cdev routines */ 116 static d_read_t icee_read; 117 static d_write_t icee_write; 118 119 static struct cdevsw icee_cdevsw = 120 { 121 .d_version = D_VERSION, 122 .d_read = icee_read, 123 .d_write = icee_write 124 }; 125 126 #ifdef FDT 127 static int 128 icee_probe(device_t dev) 129 { 130 struct eeprom_desc *d; 131 132 if (!ofw_bus_status_okay(dev)) 133 return (ENXIO); 134 135 d = (struct eeprom_desc *) 136 ofw_bus_search_compatible(dev, compat_data)->ocd_data; 137 if (d == NULL) 138 return (ENXIO); 139 140 device_set_desc(dev, d->name); 141 return (BUS_PROBE_DEFAULT); 142 } 143 144 static void 145 icee_init(struct icee_softc *sc) 146 { 147 struct eeprom_desc *d; 148 149 d = (struct eeprom_desc *) 150 ofw_bus_search_compatible(sc->dev, compat_data)->ocd_data; 151 if (d == NULL) 152 return; /* attach will see sc->size == 0 and return error */ 153 154 sc->size = d->size; 155 sc->type = d->type; 156 sc->wr_sz = d->wr_sz; 157 } 158 #else /* !FDT */ 159 static int 160 icee_probe(device_t dev) 161 { 162 163 device_set_desc(dev, "I2C EEPROM"); 164 return (BUS_PROBE_NOWILDCARD); 165 } 166 167 static void 168 icee_init(struct icee_softc *sc) 169 { 170 const char *dname; 171 int dunit; 172 173 dname = device_get_name(sc->dev); 174 dunit = device_get_unit(sc->dev); 175 resource_int_value(dname, dunit, "size", &sc->size); 176 resource_int_value(dname, dunit, "type", &sc->type); 177 resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz); 178 } 179 #endif /* FDT */ 180 181 static int 182 icee_attach(device_t dev) 183 { 184 struct icee_softc *sc = device_get_softc(dev); 185 struct sysctl_ctx_list *ctx; 186 struct sysctl_oid_list *tree; 187 188 sc->dev = dev; 189 sc->addr = iicbus_get_addr(dev); 190 icee_init(sc); 191 if (sc->size == 0 || sc->type == 0 || sc->wr_sz == 0) { 192 device_printf(sc->dev, "Missing config data, " 193 "these cannot be zero: size %d type %d wr_sz %d\n", 194 sc->size, sc->type, sc->wr_sz); 195 return (EINVAL); 196 } 197 if (bootverbose) 198 device_printf(dev, "size: %d bytes, addressing: %d-bits\n", 199 sc->size, sc->type); 200 sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT, 201 GID_WHEEL, 0600, "icee%d", device_get_unit(dev)); 202 if (sc->cdev == NULL) { 203 return (ENOMEM); 204 } 205 sc->cdev->si_drv1 = sc; 206 207 ctx = device_get_sysctl_ctx(dev); 208 tree = SYSCTL_CHILDREN(device_get_sysctl_tree(dev)); 209 SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "address_size", CTLFLAG_RD, 210 &sc->type, 0, "Memory array address size in bits"); 211 SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "device_size", CTLFLAG_RD, 212 &sc->size, 0, "Memory array capacity in bytes"); 213 SYSCTL_ADD_INT(ctx, tree, OID_AUTO, "write_size", CTLFLAG_RD, 214 &sc->wr_sz, 0, "Memory array page write size in bytes"); 215 216 return (0); 217 } 218 219 static int 220 icee_detach(device_t dev) 221 { 222 struct icee_softc *sc = device_get_softc(dev); 223 224 destroy_dev(sc->cdev); 225 return (0); 226 } 227 228 static int 229 icee_read(struct cdev *dev, struct uio *uio, int ioflag) 230 { 231 struct icee_softc *sc; 232 uint8_t addr[2]; 233 uint8_t data[MAX_RD_SZ]; 234 int error, i, len, slave; 235 struct iic_msg msgs[2] = { 236 { 0, IIC_M_WR, 1, addr }, 237 { 0, IIC_M_RD, 0, data }, 238 }; 239 240 sc = CDEV2SOFTC(dev); 241 if (uio->uio_offset == sc->size) 242 return (0); 243 if (uio->uio_offset > sc->size) 244 return (EIO); 245 if (sc->type != 8 && sc->type != 16) 246 return (EINVAL); 247 slave = error = 0; 248 while (uio->uio_resid > 0) { 249 if (uio->uio_offset >= sc->size) 250 break; 251 len = MIN(MAX_RD_SZ - (uio->uio_offset & (MAX_RD_SZ - 1)), 252 uio->uio_resid); 253 switch (sc->type) { 254 case 8: 255 slave = (uio->uio_offset >> 7) | sc->addr; 256 msgs[0].len = 1; 257 msgs[1].len = len; 258 addr[0] = uio->uio_offset & 0xff; 259 break; 260 case 16: 261 slave = sc->addr | (uio->uio_offset >> 15); 262 msgs[0].len = 2; 263 msgs[1].len = len; 264 addr[0] = (uio->uio_offset >> 8) & 0xff; 265 addr[1] = uio->uio_offset & 0xff; 266 break; 267 } 268 for (i = 0; i < 2; i++) 269 msgs[i].slave = slave; 270 error = iicbus_transfer_excl(sc->dev, msgs, 2, IIC_INTRWAIT); 271 if (error) { 272 error = iic2errno(error); 273 break; 274 } 275 error = uiomove(data, len, uio); 276 if (error) 277 break; 278 } 279 return (error); 280 } 281 282 /* 283 * Write to the part. We use three transfers here since we're actually 284 * doing a write followed by a read to make sure that the write finished. 285 * It is easier to encode the dummy read here than to break things up 286 * into smaller chunks... 287 */ 288 static int 289 icee_write(struct cdev *dev, struct uio *uio, int ioflag) 290 { 291 struct icee_softc *sc; 292 int error, len, slave, waitlimit; 293 uint8_t data[MAX_WR_SZ + 2]; 294 struct iic_msg wr[1] = { 295 { 0, IIC_M_WR, 0, data }, 296 }; 297 struct iic_msg rd[1] = { 298 { 0, IIC_M_RD, 1, data }, 299 }; 300 301 sc = CDEV2SOFTC(dev); 302 if (uio->uio_offset >= sc->size) 303 return (EIO); 304 if (sc->type != 8 && sc->type != 16) 305 return (EINVAL); 306 307 slave = error = 0; 308 while (uio->uio_resid > 0) { 309 if (uio->uio_offset >= sc->size) 310 break; 311 len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)), 312 uio->uio_resid); 313 switch (sc->type) { 314 case 8: 315 slave = (uio->uio_offset >> 7) | sc->addr; 316 wr[0].len = 1 + len; 317 data[0] = uio->uio_offset & 0xff; 318 break; 319 case 16: 320 slave = sc->addr | (uio->uio_offset >> 15); 321 wr[0].len = 2 + len; 322 data[0] = (uio->uio_offset >> 8) & 0xff; 323 data[1] = uio->uio_offset & 0xff; 324 break; 325 } 326 wr[0].slave = slave; 327 error = uiomove(data + sc->type / 8, len, uio); 328 if (error) 329 break; 330 error = iicbus_transfer_excl(sc->dev, wr, 1, IIC_INTRWAIT); 331 if (error) { 332 error = iic2errno(error); 333 break; 334 } 335 /* Read after write to wait for write-done. */ 336 waitlimit = 10000; 337 rd[0].slave = slave; 338 do { 339 error = iicbus_transfer_excl(sc->dev, rd, 1, 340 IIC_INTRWAIT); 341 } while (waitlimit-- > 0 && error != 0); 342 if (error) { 343 error = iic2errno(error); 344 break; 345 } 346 } 347 return error; 348 } 349 350 static device_method_t icee_methods[] = { 351 DEVMETHOD(device_probe, icee_probe), 352 DEVMETHOD(device_attach, icee_attach), 353 DEVMETHOD(device_detach, icee_detach), 354 355 DEVMETHOD_END 356 }; 357 358 static driver_t icee_driver = { 359 "icee", 360 icee_methods, 361 sizeof(struct icee_softc), 362 }; 363 static devclass_t icee_devclass; 364 365 DRIVER_MODULE(icee, iicbus, icee_driver, icee_devclass, 0, 0); 366 MODULE_VERSION(icee, 1); 367 MODULE_DEPEND(icee, iicbus, 1, 1, 1); 368 IICBUS_FDT_PNP_INFO(compat_data); 369