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: src/sys/dev/ppbus/lpbb.c,v 1.11.2.1 2000/05/24 00:20:57 n_hibma Exp $ 27 * $DragonFly: src/sys/dev/misc/lpbb/lpbb.c,v 1.3 2003/08/07 21:16:56 dillon Exp $ 28 * 29 */ 30 31 /* 32 * I2C Bit-Banging over parallel port 33 * 34 * See the Official Philips interface description in lpbb(4) 35 */ 36 37 #include <sys/param.h> 38 #include <sys/kernel.h> 39 #include <sys/systm.h> 40 #include <sys/module.h> 41 #include <sys/bus.h> 42 #include <sys/uio.h> 43 44 #include <machine/clock.h> 45 46 #include <bus/ppbus/ppbconf.h> 47 #include "ppbus_if.h" 48 #include <bus/ppbus/ppbio.h> 49 50 #include <bus/iicbus/iiconf.h> 51 #include <bus/iicbus/iicbus.h> 52 53 #include "iicbb_if.h" 54 55 static int lpbb_detect(device_t dev); 56 57 static void 58 lpbb_identify(driver_t *driver, device_t parent) 59 { 60 61 BUS_ADD_CHILD(parent, 0, "lpbb", 0); 62 } 63 64 static int 65 lpbb_probe(device_t dev) 66 { 67 68 /* Perhaps call this during identify instead? */ 69 if (!lpbb_detect(dev)) 70 return (ENXIO); 71 72 device_set_desc(dev, "Parallel I2C bit-banging interface"); 73 74 return (0); 75 } 76 77 static int 78 lpbb_attach(device_t dev) 79 { 80 device_t bitbang, iicbus; 81 82 /* add generic bit-banging code */ 83 bitbang = device_add_child(dev, "iicbb", -1); 84 85 /* add the iicbus to the tree */ 86 iicbus = iicbus_alloc_bus(bitbang); 87 88 device_probe_and_attach(bitbang); 89 90 /* XXX should be in iicbb_attach! */ 91 device_probe_and_attach(iicbus); 92 93 return (0); 94 } 95 96 static int 97 lpbb_callback(device_t dev, int index, caddr_t *data) 98 { 99 device_t ppbus = device_get_parent(dev); 100 int error = 0; 101 int how; 102 103 switch (index) { 104 case IIC_REQUEST_BUS: 105 /* request the ppbus */ 106 how = *(int *)data; 107 error = ppb_request_bus(ppbus, dev, how); 108 break; 109 110 case IIC_RELEASE_BUS: 111 /* release the ppbus */ 112 error = ppb_release_bus(ppbus, dev); 113 break; 114 115 default: 116 error = EINVAL; 117 } 118 119 return (error); 120 } 121 122 #define SDA_out 0x80 123 #define SCL_out 0x08 124 #define SDA_in 0x80 125 #define SCL_in 0x08 126 #define ALIM 0x20 127 #define I2CKEY 0x50 128 129 static int getSDA(device_t ppbus) 130 { 131 if((ppb_rstr(ppbus)&SDA_in)==SDA_in) 132 return 1; 133 else 134 return 0; 135 } 136 137 static void setSDA(device_t ppbus, char val) 138 { 139 if(val==0) 140 ppb_wdtr(ppbus, (u_char)SDA_out); 141 else 142 ppb_wdtr(ppbus, (u_char)~SDA_out); 143 } 144 145 static void setSCL(device_t ppbus, unsigned char val) 146 { 147 if(val==0) 148 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)&~SCL_out)); 149 else 150 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)|SCL_out)); 151 } 152 153 static int lpbb_detect(device_t dev) 154 { 155 device_t ppbus = device_get_parent(dev); 156 157 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) { 158 device_printf(dev, "can't allocate ppbus\n"); 159 return (0); 160 } 161 162 /* reset bus */ 163 setSDA(ppbus, 1); 164 setSCL(ppbus, 1); 165 166 if ((ppb_rstr(ppbus) & I2CKEY) || 167 ((ppb_rstr(ppbus) & ALIM) != ALIM)) { 168 169 ppb_release_bus(ppbus, dev); 170 return (0); 171 } 172 173 ppb_release_bus(ppbus, dev); 174 175 return (1); 176 } 177 178 static int 179 lpbb_reset(device_t dev, u_char speed, u_char addr, u_char * oldaddr) 180 { 181 device_t ppbus = device_get_parent(dev); 182 183 /* reset bus */ 184 setSDA(ppbus, 1); 185 setSCL(ppbus, 1); 186 187 return (IIC_ENOADDR); 188 } 189 190 static void 191 lpbb_setlines(device_t dev, int ctrl, int data) 192 { 193 device_t ppbus = device_get_parent(dev); 194 195 setSCL(ppbus, ctrl); 196 setSDA(ppbus, data); 197 } 198 199 static int 200 lpbb_getdataline(device_t dev) 201 { 202 device_t ppbus = device_get_parent(dev); 203 204 return (getSDA(ppbus)); 205 } 206 207 static devclass_t lpbb_devclass; 208 209 static device_method_t lpbb_methods[] = { 210 /* device interface */ 211 DEVMETHOD(device_identify, lpbb_identify), 212 DEVMETHOD(device_probe, lpbb_probe), 213 DEVMETHOD(device_attach, lpbb_attach), 214 215 /* bus interface */ 216 DEVMETHOD(bus_print_child, bus_generic_print_child), 217 218 /* iicbb interface */ 219 DEVMETHOD(iicbb_callback, lpbb_callback), 220 DEVMETHOD(iicbb_setlines, lpbb_setlines), 221 DEVMETHOD(iicbb_getdataline, lpbb_getdataline), 222 DEVMETHOD(iicbb_reset, lpbb_reset), 223 224 { 0, 0 } 225 }; 226 227 static driver_t lpbb_driver = { 228 "lpbb", 229 lpbb_methods, 230 1, 231 }; 232 233 DRIVER_MODULE(lpbb, ppbus, lpbb_driver, lpbb_devclass, 0, 0); 234