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