1 /*- 2 * Copyright (c) 1998 Nicolas Souchu, Marc Bouget 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 * $FreeBSD$ 27 * 28 */ 29 30 /* 31 * I2C Bit-Banging over parallel port 32 * 33 * See the Official Philips interface description in lpbb(4) 34 */ 35 36 #include <sys/param.h> 37 #include <sys/kernel.h> 38 #include <sys/systm.h> 39 #include <sys/module.h> 40 #include <sys/bus.h> 41 #include <sys/conf.h> 42 #include <sys/buf.h> 43 #include <sys/uio.h> 44 #include <sys/malloc.h> 45 46 #include <machine/clock.h> 47 48 #include <dev/ppbus/ppbconf.h> 49 50 #include <dev/iicbus/iiconf.h> 51 #include <dev/iicbus/iicbus.h> 52 53 #include "iicbb_if.h" 54 55 /* iicbus softc */ 56 struct lpbb_softc { 57 58 struct ppb_device lpbb_dev; 59 }; 60 61 static int lpbb_detect(struct lpbb_softc *); 62 63 static int lpbb_probe(device_t); 64 static int lpbb_attach(device_t); 65 66 static int lpbb_callback(device_t, int, caddr_t *); 67 static void lpbb_setlines(device_t, int, int); 68 static int lpbb_getdataline(device_t); 69 static int lpbb_reset(device_t, u_char, u_char, u_char *); 70 71 static devclass_t lpbb_devclass; 72 73 static device_method_t lpbb_methods[] = { 74 /* device interface */ 75 DEVMETHOD(device_probe, lpbb_probe), 76 DEVMETHOD(device_attach, lpbb_attach), 77 78 /* bus interface */ 79 DEVMETHOD(bus_print_child, bus_generic_print_child), 80 81 /* iicbb interface */ 82 DEVMETHOD(iicbb_callback, lpbb_callback), 83 DEVMETHOD(iicbb_setlines, lpbb_setlines), 84 DEVMETHOD(iicbb_getdataline, lpbb_getdataline), 85 DEVMETHOD(iicbb_reset, lpbb_reset), 86 87 { 0, 0 } 88 }; 89 90 static driver_t lpbb_driver = { 91 "lpbb", 92 lpbb_methods, 93 sizeof(struct lpbb_softc), 94 }; 95 96 /* 97 * Make ourselves visible as a ppbus driver 98 */ 99 static struct ppb_device *lpbb_ppb_probe(struct ppb_data *ppb); 100 static int lpbb_ppb_attach(struct ppb_device *dev); 101 102 #define MAXLPBB 8 /* XXX not much better! */ 103 static struct lpbb_softc *lpbbdata[MAXLPBB]; 104 static int nlpbb = 0; 105 106 #ifdef KERNEL 107 108 static struct ppb_driver lpbbdriver = { 109 lpbb_ppb_probe, lpbb_ppb_attach, "lpbb" 110 }; 111 DATA_SET(ppbdriver_set, lpbbdriver); 112 113 #endif /* KERNEL */ 114 115 static int 116 lpbb_probe(device_t dev) 117 { 118 struct lpbb_softc *sc = lpbbdata[device_get_unit(dev)]; 119 struct lpbb_softc *scdst = (struct lpbb_softc *)device_get_softc(dev); 120 121 /* XXX copy softc. Yet, ppbus device is sc->lpbb_dev, but will be 122 * dev->parent when ppbus will be ported to the new bus architecture */ 123 bcopy(sc, scdst, sizeof(struct lpbb_softc)); 124 125 device_set_desc(dev, "parallel I2C bit-banging interface"); 126 127 /* probe done by ppbus initialization */ 128 return (0); 129 } 130 131 static int 132 lpbb_attach(device_t dev) 133 { 134 device_t bitbang, iicbus; 135 136 /* add generic bit-banging code */ 137 bitbang = device_add_child(dev, "iicbb", -1, NULL); 138 139 /* add the iicbus to the tree */ 140 iicbus = iicbus_alloc_bus(bitbang); 141 142 device_probe_and_attach(bitbang); 143 144 /* XXX should be in iicbb_attach! */ 145 device_probe_and_attach(iicbus); 146 147 return (0); 148 } 149 150 /* 151 * lppbb_ppb_probe() 152 */ 153 static struct ppb_device * 154 lpbb_ppb_probe(struct ppb_data *ppb) 155 { 156 struct lpbb_softc *sc; 157 158 sc = (struct lpbb_softc *) malloc(sizeof(struct lpbb_softc), 159 M_TEMP, M_NOWAIT); 160 if (!sc) { 161 printf("lpbb: cannot malloc!\n"); 162 return (0); 163 } 164 bzero(sc, sizeof(struct lpbb_softc)); 165 166 lpbbdata[nlpbb] = sc; 167 168 /* 169 * ppbus dependent initialisation. 170 */ 171 sc->lpbb_dev.id_unit = nlpbb; 172 sc->lpbb_dev.name = lpbbdriver.name; 173 sc->lpbb_dev.ppb = ppb; 174 sc->lpbb_dev.intr = 0; 175 176 if (!lpbb_detect(sc)) { 177 free(sc, M_TEMP); 178 return (NULL); 179 } 180 181 /* Ok, go to next device on next probe */ 182 nlpbb ++; 183 184 /* XXX wrong according to new bus architecture. ppbus needs to be 185 * ported 186 */ 187 return (&sc->lpbb_dev); 188 } 189 190 static int 191 lpbb_ppb_attach(struct ppb_device *dev) 192 { 193 /* add the parallel port I2C interface to the bus tree */ 194 if (!device_add_child(root_bus, "lpbb", dev->id_unit, NULL)) 195 return (0); 196 197 return (1); 198 } 199 200 static int 201 lpbb_callback(device_t dev, int index, caddr_t *data) 202 { 203 struct lpbb_softc *sc = (struct lpbb_softc *)device_get_softc(dev); 204 int error = 0; 205 int how; 206 207 switch (index) { 208 case IIC_REQUEST_BUS: 209 /* request the ppbus */ 210 how = *(int *)data; 211 error = ppb_request_bus(&sc->lpbb_dev, how); 212 break; 213 214 case IIC_RELEASE_BUS: 215 /* release the ppbus */ 216 error = ppb_release_bus(&sc->lpbb_dev); 217 break; 218 219 default: 220 error = EINVAL; 221 } 222 223 return (error); 224 } 225 226 #define SDA_out 0x80 227 #define SCL_out 0x08 228 #define SDA_in 0x80 229 #define SCL_in 0x08 230 #define ALIM 0x20 231 #define I2CKEY 0x50 232 233 static int getSDA(struct lpbb_softc *sc) 234 { 235 if((ppb_rstr(&sc->lpbb_dev)&SDA_in)==SDA_in) 236 return 1; 237 else 238 return 0; 239 } 240 241 static void setSDA(struct lpbb_softc *sc, char val) 242 { 243 if(val==0) 244 ppb_wdtr(&sc->lpbb_dev, (u_char)SDA_out); 245 else 246 ppb_wdtr(&sc->lpbb_dev, (u_char)~SDA_out); 247 } 248 249 static void setSCL(struct lpbb_softc *sc, unsigned char val) 250 { 251 if(val==0) 252 ppb_wctr(&sc->lpbb_dev, (u_char)(ppb_rctr(&sc->lpbb_dev)&~SCL_out)); 253 else 254 ppb_wctr(&sc->lpbb_dev, (u_char)(ppb_rctr(&sc->lpbb_dev)|SCL_out)); 255 } 256 257 static int lpbb_detect(struct lpbb_softc *sc) 258 { 259 if (ppb_request_bus(&sc->lpbb_dev, PPB_DONTWAIT)) { 260 printf("lpbb: can't allocate ppbus\n"); 261 return (0); 262 } 263 264 /* reset bus */ 265 setSDA(sc, 1); 266 setSCL(sc, 1); 267 268 if ((ppb_rstr(&sc->lpbb_dev) & I2CKEY) || 269 ((ppb_rstr(&sc->lpbb_dev) & ALIM) != ALIM)) { 270 271 ppb_release_bus(&sc->lpbb_dev); 272 return (0); 273 } 274 275 ppb_release_bus(&sc->lpbb_dev); 276 277 return (1); 278 } 279 280 static int 281 lpbb_reset(device_t dev, u_char speed, u_char addr, u_char * oldaddr) 282 { 283 struct lpbb_softc *sc = (struct lpbb_softc *)device_get_softc(dev); 284 285 /* reset bus */ 286 setSDA(sc, 1); 287 setSCL(sc, 1); 288 289 return (IIC_ENOADDR); 290 } 291 292 static void 293 lpbb_setlines(device_t dev, int ctrl, int data) 294 { 295 struct lpbb_softc *sc = (struct lpbb_softc *)device_get_softc(dev); 296 297 setSCL(sc, ctrl); 298 setSDA(sc, data); 299 } 300 301 static int 302 lpbb_getdataline(device_t dev) 303 { 304 struct lpbb_softc *sc = (struct lpbb_softc *)device_get_softc(dev); 305 306 return (getSDA(sc)); 307 } 308 309 DRIVER_MODULE(lpbb, root, lpbb_driver, lpbb_devclass, 0, 0); 310