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 #include "ppbus_if.h" 50 #include <dev/ppbus/ppbio.h> 51 52 #include <dev/iicbus/iiconf.h> 53 #include <dev/iicbus/iicbus.h> 54 55 #include "iicbb_if.h" 56 57 struct lpbb_softc { 58 int dummy; 59 }; 60 61 static int lpbb_detect(device_t dev); 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 static int 97 lpbb_probe(device_t dev) 98 { 99 device_set_desc(dev, "Parallel I2C bit-banging interface"); 100 101 if (!lpbb_detect(dev)) 102 return (ENXIO); 103 104 return (0); 105 } 106 107 static int 108 lpbb_attach(device_t dev) 109 { 110 device_t bitbang, iicbus; 111 112 /* add generic bit-banging code */ 113 bitbang = device_add_child(dev, "iicbb", -1); 114 115 /* add the iicbus to the tree */ 116 iicbus = iicbus_alloc_bus(bitbang); 117 118 device_probe_and_attach(bitbang); 119 120 /* XXX should be in iicbb_attach! */ 121 device_probe_and_attach(iicbus); 122 123 return (0); 124 } 125 126 static int 127 lpbb_callback(device_t dev, int index, caddr_t *data) 128 { 129 device_t ppbus = device_get_parent(dev); 130 int error = 0; 131 int how; 132 133 switch (index) { 134 case IIC_REQUEST_BUS: 135 /* request the ppbus */ 136 how = *(int *)data; 137 error = ppb_request_bus(ppbus, dev, how); 138 break; 139 140 case IIC_RELEASE_BUS: 141 /* release the ppbus */ 142 error = ppb_release_bus(ppbus, dev); 143 break; 144 145 default: 146 error = EINVAL; 147 } 148 149 return (error); 150 } 151 152 #define SDA_out 0x80 153 #define SCL_out 0x08 154 #define SDA_in 0x80 155 #define SCL_in 0x08 156 #define ALIM 0x20 157 #define I2CKEY 0x50 158 159 static int getSDA(device_t ppbus) 160 { 161 if((ppb_rstr(ppbus)&SDA_in)==SDA_in) 162 return 1; 163 else 164 return 0; 165 } 166 167 static void setSDA(device_t ppbus, char val) 168 { 169 if(val==0) 170 ppb_wdtr(ppbus, (u_char)SDA_out); 171 else 172 ppb_wdtr(ppbus, (u_char)~SDA_out); 173 } 174 175 static void setSCL(device_t ppbus, unsigned char val) 176 { 177 if(val==0) 178 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)&~SCL_out)); 179 else 180 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)|SCL_out)); 181 } 182 183 static int lpbb_detect(device_t dev) 184 { 185 device_t ppbus = device_get_parent(dev); 186 187 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) { 188 device_printf(dev, "can't allocate ppbus\n"); 189 return (0); 190 } 191 192 /* reset bus */ 193 setSDA(ppbus, 1); 194 setSCL(ppbus, 1); 195 196 if ((ppb_rstr(ppbus) & I2CKEY) || 197 ((ppb_rstr(ppbus) & ALIM) != ALIM)) { 198 199 ppb_release_bus(ppbus, dev); 200 return (0); 201 } 202 203 ppb_release_bus(ppbus, dev); 204 205 return (1); 206 } 207 208 static int 209 lpbb_reset(device_t dev, u_char speed, u_char addr, u_char * oldaddr) 210 { 211 device_t ppbus = device_get_parent(dev); 212 213 /* reset bus */ 214 setSDA(ppbus, 1); 215 setSCL(ppbus, 1); 216 217 return (IIC_ENOADDR); 218 } 219 220 static void 221 lpbb_setlines(device_t dev, int ctrl, int data) 222 { 223 device_t ppbus = device_get_parent(dev); 224 225 setSCL(ppbus, ctrl); 226 setSDA(ppbus, data); 227 } 228 229 static int 230 lpbb_getdataline(device_t dev) 231 { 232 device_t ppbus = device_get_parent(dev); 233 234 return (getSDA(ppbus)); 235 } 236 237 DRIVER_MODULE(lpbb, ppbus, lpbb_driver, lpbb_devclass, 0, 0); 238