iic.c revision 167856
1/*- 2 * Copyright (c) 1998, 2001 Nicolas Souchu 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: head/sys/dev/iicbus/iic.c 167856 2007-03-23 23:08:28Z imp $ 27 * 28 */ 29#include <sys/param.h> 30#include <sys/kernel.h> 31#include <sys/systm.h> 32#include <sys/malloc.h> 33#include <sys/module.h> 34#include <sys/bus.h> 35#include <sys/conf.h> 36#include <sys/uio.h> 37#include <sys/fcntl.h> 38 39#include <dev/iicbus/iiconf.h> 40#include <dev/iicbus/iicbus.h> 41#include <dev/iicbus/iic.h> 42 43#include "iicbus_if.h" 44 45#define BUFSIZE 1024 46 47struct iic_softc { 48 49 u_char sc_addr; /* 7 bit address on iicbus */ 50 int sc_count; /* >0 if device opened */ 51 52 char sc_buffer[BUFSIZE]; /* output buffer */ 53 char sc_inbuf[BUFSIZE]; /* input buffer */ 54 55 struct cdev *sc_devnode; 56}; 57 58#define IIC_SOFTC(unit) \ 59 ((struct iic_softc *)devclass_get_softc(iic_devclass, (unit))) 60 61#define IIC_DEVICE(unit) \ 62 (devclass_get_device(iic_devclass, (unit))) 63 64static int iic_probe(device_t); 65static int iic_attach(device_t); 66static int iic_detach(device_t); 67static void iic_identify(driver_t *driver, device_t parent); 68 69static devclass_t iic_devclass; 70 71static device_method_t iic_methods[] = { 72 /* device interface */ 73 DEVMETHOD(device_identify, iic_identify), 74 DEVMETHOD(device_probe, iic_probe), 75 DEVMETHOD(device_attach, iic_attach), 76 DEVMETHOD(device_detach, iic_detach), 77 78 /* iicbus interface */ 79 DEVMETHOD(iicbus_intr, iicbus_generic_intr), 80 81 { 0, 0 } 82}; 83 84static driver_t iic_driver = { 85 "iic", 86 iic_methods, 87 sizeof(struct iic_softc), 88}; 89 90static d_open_t iicopen; 91static d_close_t iicclose; 92static d_write_t iicwrite; 93static d_read_t iicread; 94static d_ioctl_t iicioctl; 95 96static struct cdevsw iic_cdevsw = { 97 .d_version = D_VERSION, 98 .d_flags = D_NEEDGIANT, 99 .d_open = iicopen, 100 .d_close = iicclose, 101 .d_read = iicread, 102 .d_write = iicwrite, 103 .d_ioctl = iicioctl, 104 .d_name = "iic", 105}; 106 107static void 108iic_identify(driver_t *driver, device_t parent) 109{ 110 BUS_ADD_CHILD(parent, 0, "iic", -1); 111} 112 113static int 114iic_probe(device_t dev) 115{ 116 device_set_desc(dev, "I2C generic I/O"); 117 return (0); 118} 119 120static int 121iic_attach(device_t dev) 122{ 123 struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev); 124 125 sc->sc_devnode = make_dev(&iic_cdevsw, device_get_unit(dev), 126 UID_ROOT, GID_WHEEL, 127 0600, "iic%d", device_get_unit(dev)); 128 return (0); 129} 130 131static int 132iic_detach(device_t dev) 133{ 134 struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev); 135 136 if (sc->sc_devnode) 137 destroy_dev(sc->sc_devnode); 138 139 return (0); 140} 141 142static int 143iicopen(struct cdev *dev, int flags, int fmt, struct thread *td) 144{ 145 struct iic_softc *sc = IIC_SOFTC(minor(dev)); 146 147 if (!sc) 148 return (EINVAL); 149 150 if (sc->sc_count > 0) 151 return (EBUSY); 152 153 sc->sc_count++; 154 155 return (0); 156} 157 158static int 159iicclose(struct cdev *dev, int flags, int fmt, struct thread *td) 160{ 161 struct iic_softc *sc = IIC_SOFTC(minor(dev)); 162 163 if (!sc) 164 return (EINVAL); 165 166 if (!sc->sc_count) 167 return (EINVAL); 168 169 sc->sc_count--; 170 171 if (sc->sc_count < 0) 172 panic("%s: iic_count < 0!", __func__); 173 174 return (0); 175} 176 177static int 178iicwrite(struct cdev *dev, struct uio * uio, int ioflag) 179{ 180 device_t iicdev = IIC_DEVICE(minor(dev)); 181 struct iic_softc *sc = IIC_SOFTC(minor(dev)); 182 int sent, error, count; 183 184 if (!sc || !iicdev || !sc->sc_addr) 185 return (EINVAL); 186 187 if (sc->sc_count == 0) 188 return (EINVAL); 189 190 if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev, IIC_DONTWAIT))) 191 return (error); 192 193 count = min(uio->uio_resid, BUFSIZE); 194 uiomove(sc->sc_buffer, count, uio); 195 196 error = iicbus_block_write(device_get_parent(iicdev), sc->sc_addr, 197 sc->sc_buffer, count, &sent); 198 199 iicbus_release_bus(device_get_parent(iicdev), iicdev); 200 201 return(error); 202} 203 204static int 205iicread(struct cdev *dev, struct uio * uio, int ioflag) 206{ 207 device_t iicdev = IIC_DEVICE(minor(dev)); 208 struct iic_softc *sc = IIC_SOFTC(minor(dev)); 209 int len, error = 0; 210 int bufsize; 211 212 if (!sc || !iicdev || !sc->sc_addr) 213 return (EINVAL); 214 215 if (sc->sc_count == 0) 216 return (EINVAL); 217 218 if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev, IIC_DONTWAIT))) 219 return (error); 220 221 /* max amount of data to read */ 222 len = min(uio->uio_resid, BUFSIZE); 223 224 if ((error = iicbus_block_read(device_get_parent(iicdev), sc->sc_addr, 225 sc->sc_inbuf, len, &bufsize))) 226 return (error); 227 228 if (bufsize > uio->uio_resid) 229 panic("%s: too much data read!", __func__); 230 231 iicbus_release_bus(device_get_parent(iicdev), iicdev); 232 233 return (uiomove(sc->sc_inbuf, bufsize, uio)); 234} 235 236static int 237iicioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td) 238{ 239 device_t iicdev = IIC_DEVICE(minor(dev)); 240 struct iic_softc *sc = IIC_SOFTC(minor(dev)); 241 device_t parent = device_get_parent(iicdev); 242 struct iiccmd *s = (struct iiccmd *)data; 243 struct iic_rdwr_data *d = (struct iic_rdwr_data *)data; 244 struct iic_msg *m; 245 int error, count, i; 246 char *buf = NULL; 247 void **usrbufs = NULL; 248 249 if (!sc) 250 return (EINVAL); 251 252 if ((error = iicbus_request_bus(parent, iicdev, 253 (flags & O_NONBLOCK) ? IIC_DONTWAIT : (IIC_WAIT | IIC_INTR)))) 254 return (error); 255 256 switch (cmd) { 257 case I2CSTART: 258 error = iicbus_start(parent, s->slave, 0); 259 260 /* 261 * Implicitly set the chip addr to the slave addr passed as 262 * parameter. Consequently, start/stop shall be called before 263 * the read or the write of a block. 264 */ 265 if (!error) 266 sc->sc_addr = s->slave; 267 268 break; 269 270 case I2CSTOP: 271 error = iicbus_stop(parent); 272 break; 273 274 case I2CRSTCARD: 275 error = iicbus_reset(parent, IIC_UNKNOWN, 0, NULL); 276 break; 277 278 case I2CWRITE: 279 if (s->count <= 0) { 280 error = EINVAL; 281 break; 282 } 283 buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK); 284 error = copyin(s->buf, buf, s->count); 285 if (error) 286 break; 287 error = iicbus_write(parent, buf, s->count, &count, 10); 288 break; 289 290 case I2CREAD: 291 if (s->count <= 0) { 292 error = EINVAL; 293 break; 294 } 295 buf = malloc((unsigned long)s->count, M_TEMP, M_WAITOK); 296 error = iicbus_read(parent, buf, s->count, &count, s->last, 10); 297 if (error) 298 break; 299 error = copyout(buf, s->buf, s->count); 300 break; 301 302 case I2CRDWR: 303 buf = malloc(sizeof(*d->msgs) * d->nmsgs, M_TEMP, M_WAITOK); 304 usrbufs = malloc(sizeof(void *) * d->nmsgs, M_TEMP, M_ZERO | M_WAITOK); 305 error = copyin(d->msgs, buf, sizeof(*d->msgs) * d->nmsgs); 306 if (error) 307 break; 308 /* Alloc kernel buffers for userland data, copyin write data */ 309 for (i = 0; i < d->nmsgs; i++) { 310 m = &((struct iic_msg *)buf)[i]; 311 usrbufs[i] = m->buf; 312 m->buf = malloc(m->len, M_TEMP, M_WAITOK); 313 if (!(m->flags & IIC_M_RD)) 314 copyin(usrbufs[i], m->buf, m->len); 315 } 316 error = iicbus_transfer(iicdev, (struct iic_msg *)buf, d->nmsgs); 317 /* Copyout all read segments, free up kernel buffers */ 318 for (i = 0; i < d->nmsgs; i++) { 319 m = &((struct iic_msg *)buf)[i]; 320 if (m->flags & IIC_M_RD) 321 copyout(m->buf, usrbufs[i], m->len); 322 free(m->buf, M_TEMP); 323 } 324 free(usrbufs, M_TEMP); 325 break; 326 default: 327 error = ENOTTY; 328 } 329 330 iicbus_release_bus(parent, iicdev); 331 332 if (buf != NULL) 333 free(buf, M_TEMP); 334 return (error); 335} 336 337DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, 0, 0); 338MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER); 339MODULE_VERSION(iic, 1); 340