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 1.4 2005/10/28 03:25:45 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 int 58 lpbb_probe(device_t dev) 59 { 60 61 /* Perhaps call this during identify instead? */ 62 if (!lpbb_detect(dev)) 63 return (ENXIO); 64 65 device_set_desc(dev, "Parallel I2C bit-banging interface"); 66 67 return (0); 68 } 69 70 static int 71 lpbb_attach(device_t dev) 72 { 73 device_t bitbang, iicbus; 74 75 /* add generic bit-banging code */ 76 bitbang = device_add_child(dev, "iicbb", -1); 77 78 /* add the iicbus to the tree */ 79 iicbus = iicbus_alloc_bus(bitbang); 80 81 device_probe_and_attach(bitbang); 82 83 /* XXX should be in iicbb_attach! */ 84 device_probe_and_attach(iicbus); 85 86 return (0); 87 } 88 89 static int 90 lpbb_callback(device_t dev, int index, caddr_t *data) 91 { 92 device_t ppbus = device_get_parent(dev); 93 int error = 0; 94 int how; 95 96 switch (index) { 97 case IIC_REQUEST_BUS: 98 /* request the ppbus */ 99 how = *(int *)data; 100 error = ppb_request_bus(ppbus, dev, how); 101 break; 102 103 case IIC_RELEASE_BUS: 104 /* release the ppbus */ 105 error = ppb_release_bus(ppbus, dev); 106 break; 107 108 default: 109 error = EINVAL; 110 } 111 112 return (error); 113 } 114 115 #define SDA_out 0x80 116 #define SCL_out 0x08 117 #define SDA_in 0x80 118 #define SCL_in 0x08 119 #define ALIM 0x20 120 #define I2CKEY 0x50 121 122 static int getSDA(device_t ppbus) 123 { 124 if((ppb_rstr(ppbus)&SDA_in)==SDA_in) 125 return 1; 126 else 127 return 0; 128 } 129 130 static void setSDA(device_t ppbus, char val) 131 { 132 if(val==0) 133 ppb_wdtr(ppbus, (u_char)SDA_out); 134 else 135 ppb_wdtr(ppbus, (u_char)~SDA_out); 136 } 137 138 static void setSCL(device_t ppbus, unsigned char val) 139 { 140 if(val==0) 141 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)&~SCL_out)); 142 else 143 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)|SCL_out)); 144 } 145 146 static int lpbb_detect(device_t dev) 147 { 148 device_t ppbus = device_get_parent(dev); 149 150 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) { 151 device_printf(dev, "can't allocate ppbus\n"); 152 return (0); 153 } 154 155 /* reset bus */ 156 setSDA(ppbus, 1); 157 setSCL(ppbus, 1); 158 159 if ((ppb_rstr(ppbus) & I2CKEY) || 160 ((ppb_rstr(ppbus) & ALIM) != ALIM)) { 161 162 ppb_release_bus(ppbus, dev); 163 return (0); 164 } 165 166 ppb_release_bus(ppbus, dev); 167 168 return (1); 169 } 170 171 static int 172 lpbb_reset(device_t dev, u_char speed, u_char addr, u_char * oldaddr) 173 { 174 device_t ppbus = device_get_parent(dev); 175 176 /* reset bus */ 177 setSDA(ppbus, 1); 178 setSCL(ppbus, 1); 179 180 return (IIC_ENOADDR); 181 } 182 183 static void 184 lpbb_setlines(device_t dev, int ctrl, int data) 185 { 186 device_t ppbus = device_get_parent(dev); 187 188 setSCL(ppbus, ctrl); 189 setSDA(ppbus, data); 190 } 191 192 static int 193 lpbb_getdataline(device_t dev) 194 { 195 device_t ppbus = device_get_parent(dev); 196 197 return (getSDA(ppbus)); 198 } 199 200 /* 201 * Because lpbb is a static device that always exists under any attached 202 * ppbus device, and not scanned by the ppbus device, we need an identify 203 * function to install the device. 204 */ 205 static devclass_t lpbb_devclass; 206 207 static device_method_t lpbb_methods[] = { 208 /* device interface */ 209 DEVMETHOD(device_identify, bus_generic_identify), 210 DEVMETHOD(device_probe, lpbb_probe), 211 DEVMETHOD(device_attach, lpbb_attach), 212 213 /* bus interface */ 214 DEVMETHOD(bus_print_child, bus_generic_print_child), 215 216 /* iicbb interface */ 217 DEVMETHOD(iicbb_callback, lpbb_callback), 218 DEVMETHOD(iicbb_setlines, lpbb_setlines), 219 DEVMETHOD(iicbb_getdataline, lpbb_getdataline), 220 DEVMETHOD(iicbb_reset, lpbb_reset), 221 222 { 0, 0 } 223 }; 224 225 static driver_t lpbb_driver = { 226 "lpbb", 227 lpbb_methods, 228 1, 229 }; 230 231 DRIVER_MODULE(lpbb, ppbus, lpbb_driver, lpbb_devclass, 0, 0); 232