icee.c revision 167857
1/*- 2 * Copyright (c) 2006 Warner Losh. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 15 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 16 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 19 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 20 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 23 */ 24 25#include <sys/cdefs.h> 26__FBSDID("$FreeBSD: head/sys/dev/iicbus/icee.c 167857 2007-03-23 23:10:35Z imp $"); 27/* 28 * Generic IIC eeprom support, modeled after the AT24C family of products. 29 */ 30#include <sys/param.h> 31#include <sys/systm.h> 32#include <sys/bus.h> 33#include <sys/conf.h> 34#include <sys/kernel.h> 35#include <sys/module.h> 36#include <sys/mutex.h> 37#include <sys/resource.h> 38#include <sys/uio.h> 39#include <machine/bus.h> 40#include <dev/iicbus/iiconf.h> 41#include <dev/iicbus/iicbus.h> 42 43#include "iicbus_if.h" 44 45#define IIC_M_WR 0 /* write operation */ 46#define MAX_RD_SZ 256 /* Largest read size we support */ 47#define MAX_WR_SZ 256 /* Largest write size we support */ 48 49struct icee_softc { 50 device_t sc_dev; /* Myself */ 51 struct mtx sc_mtx; /* basically a perimeter lock */ 52 struct cdev *cdev; /* user interface */ 53 int addr; 54 int flags; 55#define OPENED 1 56 int size; /* How big am I? */ 57 int type; /* What type 8 or 16 bit? */ 58 int rd_sz; /* What's the read page size */ 59 int wr_sz; /* What's the write page size */ 60}; 61 62#define ICEE_LOCK(_sc) mtx_lock_spin(&(_sc)->sc_mtx) 63#define ICEE_UNLOCK(_sc) mtx_unlock_spin(&(_sc)->sc_mtx) 64#define ICEE_LOCK_INIT(_sc) \ 65 mtx_init(&_sc->sc_mtx, device_get_nameunit(_sc->sc_dev), "icee", MTX_SPIN) 66#define ICEE_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx); 67#define ICEE_ASSERT_LOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_OWNED); 68#define ICEE_ASSERT_UNLOCKED(_sc) mtx_assert(&_sc->sc_mtx, MA_NOTOWNED); 69#define CDEV2SOFTC(dev) ((dev)->si_drv1) 70 71/* cdev routines */ 72static d_open_t icee_open; 73static d_close_t icee_close; 74static d_read_t icee_read; 75static d_write_t icee_write; 76 77static struct cdevsw icee_cdevsw = 78{ 79 .d_version = D_VERSION, 80 .d_open = icee_open, 81 .d_close = icee_close, 82 .d_read = icee_read, 83 .d_write = icee_write 84}; 85 86static int 87icee_probe(device_t dev) 88{ 89 /* XXX really probe? -- not until we know the size... */ 90 device_set_desc(dev, "I2C EEPROM"); 91 return (0); 92} 93 94static int 95icee_attach(device_t dev) 96{ 97 struct icee_softc *sc = device_get_softc(dev); 98 const char *dname; 99 int dunit, err; 100 101 sc->sc_dev = dev; 102 iicbus_get_addr(dev, &sc->addr); 103 err = 0; 104 dname = device_get_name(dev); 105 dunit = device_get_unit(dev); 106 resource_int_value(dname, dunit, "size", &sc->size); 107 resource_int_value(dname, dunit, "type", &sc->type); 108 resource_int_value(dname, dunit, "rd_sz", &sc->rd_sz); 109 if (sc->rd_sz > MAX_RD_SZ) 110 sc->rd_sz = MAX_RD_SZ; 111 resource_int_value(dname, dunit, "wr_sz", &sc->wr_sz); 112 if (bootverbose) 113 device_printf(dev, "size: %d bytes bus_width: %d-bits\n", 114 sc->size, sc->type); 115 sc->cdev = make_dev(&icee_cdevsw, device_get_unit(dev), UID_ROOT, 116 GID_WHEEL, 0600, "icee%d", device_get_unit(dev)); 117 if (sc->cdev == NULL) { 118 err = ENOMEM; 119 goto out; 120 } 121 sc->cdev->si_drv1 = sc; 122 ICEE_LOCK_INIT(sc); 123out:; 124 return (err); 125} 126 127static int 128icee_open(struct cdev *dev, int oflags, int devtype, struct thread *td) 129{ 130 struct icee_softc *sc; 131 132 sc = CDEV2SOFTC(dev); 133 ICEE_LOCK(sc); 134 if (!(sc->flags & OPENED)) { 135 sc->flags |= OPENED; 136 } 137 ICEE_UNLOCK(sc); 138 return (0); 139} 140 141static int 142icee_close(struct cdev *dev, int fflag, int devtype, struct thread *td) 143{ 144 struct icee_softc *sc; 145 146 sc = CDEV2SOFTC(dev); 147 ICEE_LOCK(sc); 148 sc->flags &= ~OPENED; 149 ICEE_UNLOCK(sc); 150 return (0); 151} 152 153static int 154icee_read(struct cdev *dev, struct uio *uio, int ioflag) 155{ 156 struct icee_softc *sc; 157 uint8_t addr[2]; 158 uint8_t data[MAX_RD_SZ]; 159 int error, i, len, slave; 160 struct iic_msg msgs[2] = { 161 { 0, IIC_M_WR, 1, addr }, 162 { 0, IIC_M_RD, 0, data }, 163 }; 164 165 sc = CDEV2SOFTC(dev); 166 if (uio->uio_offset == sc->size) 167 return (0); 168 if (uio->uio_offset > sc->size) 169 return (EIO); 170 if (sc->type != 8 && sc->type != 16) 171 return (EINVAL); 172 ICEE_LOCK(sc); 173 slave = error = 0; 174 while (uio->uio_resid > 0) { 175 if (uio->uio_offset >= sc->size) 176 break; 177 len = MIN(sc->rd_sz - (uio->uio_offset & (sc->rd_sz - 1)), 178 uio->uio_resid); 179 switch (sc->type) { 180 case 8: 181 slave = (uio->uio_offset >> 7) | sc->addr; 182 msgs[0].len = 1; 183 msgs[1].len = len; 184 addr[0] = uio->uio_offset & 0xff; 185 break; 186 case 16: 187 slave = sc->addr | (uio->uio_offset >> 15); 188 msgs[0].len = 2; 189 msgs[1].len = len; 190 addr[0] = (uio->uio_offset >> 8) & 0xff; 191 addr[1] = uio->uio_offset & 0xff; 192 break; 193 } 194 for (i = 0; i < 2; i++) 195 msgs[i].slave = slave; 196 error = iicbus_transfer(sc->sc_dev, msgs, 2); 197 if (error) 198 break; 199 error = uiomove(data, len, uio); 200 if (error) 201 break; 202 } 203 ICEE_UNLOCK(sc); 204 return (error); 205} 206 207/* 208 * Write to the part. We use three transfers here since we're actually 209 * doing a write followed by a read to make sure that the write finished. 210 * It is easier to encode the dummy read here than to break things up 211 * into smaller chunks... 212 */ 213static int 214icee_write(struct cdev *dev, struct uio *uio, int ioflag) 215{ 216 struct icee_softc *sc; 217 int error, len, slave, waitlimit; 218 uint8_t data[MAX_WR_SZ + 2]; 219 struct iic_msg wr[1] = { 220 { 0, IIC_M_WR, 0, data }, 221 }; 222 struct iic_msg rd[1] = { 223 { 0, IIC_M_RD, 1, data }, 224 }; 225 226 sc = CDEV2SOFTC(dev); 227 if (uio->uio_offset >= sc->size) 228 return (EIO); 229 if (sc->type != 8 && sc->type != 16) 230 return (EINVAL); 231 ICEE_LOCK(sc); 232 slave = error = 0; 233 while (uio->uio_resid > 0) { 234 if (uio->uio_offset >= sc->size) 235 break; 236 len = MIN(sc->wr_sz - (uio->uio_offset & (sc->wr_sz - 1)), 237 uio->uio_resid); 238 switch (sc->type) { 239 case 8: 240 slave = (uio->uio_offset >> 7) | sc->addr; 241 wr[0].len = 1 + len; 242 data[0] = uio->uio_offset & 0xff; 243 break; 244 case 16: 245 slave = sc->addr | (uio->uio_offset >> 15); 246 wr[0].len = 2 + len; 247 data[0] = (uio->uio_offset >> 8) & 0xff; 248 data[1] = uio->uio_offset & 0xff; 249 break; 250 } 251 wr[0].slave = slave; 252 error = uiomove(data + sc->type / 8, len, uio); 253 if (error) 254 break; 255 error = iicbus_transfer(sc->sc_dev, wr, 1); 256 if (error) 257 break; 258 // Now wait for the write to be done by trying to read 259 // the part. 260 waitlimit = 10000; 261 rd[0].slave = slave; 262 do 263 { 264 error = iicbus_transfer(sc->sc_dev, rd, 1); 265 } while (waitlimit-- > 0 && error != 0); 266 if (error) { 267 printf("waiting for write failed %d\n", error); 268 break; 269 } 270 } 271 ICEE_UNLOCK(sc); 272 return error; 273} 274 275static device_method_t icee_methods[] = { 276 DEVMETHOD(device_probe, icee_probe), 277 DEVMETHOD(device_attach, icee_attach), 278 279 {0, 0}, 280}; 281 282static driver_t icee_driver = { 283 "icee", 284 icee_methods, 285 sizeof(struct icee_softc), 286}; 287static devclass_t icee_devclass; 288 289DRIVER_MODULE(icee, iicbus, icee_driver, icee_devclass, 0, 0); 290MODULE_VERSION(icee, 1); 291MODULE_DEPEND(icee, iicbus, 1, 1, 1); 292