1 /*- 2 * Copyright (c) 1998, 2001 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/uio.h> 42 43 44 #include <dev/ppbus/ppbconf.h> 45 #include "ppbus_if.h" 46 #include <dev/ppbus/ppbio.h> 47 48 #include <dev/iicbus/iiconf.h> 49 #include <dev/iicbus/iicbus.h> 50 51 #include "iicbb_if.h" 52 53 static int lpbb_detect(device_t dev); 54 55 static void 56 lpbb_identify(driver_t *driver, device_t parent) 57 { 58 59 BUS_ADD_CHILD(parent, 0, "lpbb", -1); 60 } 61 62 static int 63 lpbb_probe(device_t dev) 64 { 65 66 /* Perhaps call this during identify instead? */ 67 if (!lpbb_detect(dev)) 68 return (ENXIO); 69 70 device_set_desc(dev, "Parallel I2C bit-banging interface"); 71 72 return (0); 73 } 74 75 static int 76 lpbb_attach(device_t dev) 77 { 78 device_t bitbang; 79 80 /* add generic bit-banging code */ 81 bitbang = device_add_child(dev, "iicbb", -1); 82 device_probe_and_attach(bitbang); 83 84 return (0); 85 } 86 87 static int 88 lpbb_callback(device_t dev, int index, caddr_t *data) 89 { 90 device_t ppbus = device_get_parent(dev); 91 int error = 0; 92 int how; 93 94 switch (index) { 95 case IIC_REQUEST_BUS: 96 /* request the ppbus */ 97 how = *(int *)data; 98 error = ppb_request_bus(ppbus, dev, how); 99 break; 100 101 case IIC_RELEASE_BUS: 102 /* release the ppbus */ 103 error = ppb_release_bus(ppbus, dev); 104 break; 105 106 default: 107 error = EINVAL; 108 } 109 110 return (error); 111 } 112 113 #define SDA_out 0x80 114 #define SCL_out 0x08 115 #define SDA_in 0x80 116 #define SCL_in 0x08 117 #define ALIM 0x20 118 #define I2CKEY 0x50 119 120 static int lpbb_getscl(device_t dev) 121 { 122 return ((ppb_rstr(device_get_parent(dev)) & SCL_in) == SCL_in); 123 } 124 125 static int lpbb_getsda(device_t dev) 126 { 127 return ((ppb_rstr(device_get_parent(dev)) & SDA_in) == SDA_in); 128 } 129 130 static void lpbb_setsda(device_t dev, char val) 131 { 132 device_t ppbus = device_get_parent(dev); 133 134 if(val==0) 135 ppb_wdtr(ppbus, (u_char)SDA_out); 136 else 137 ppb_wdtr(ppbus, (u_char)~SDA_out); 138 } 139 140 static void lpbb_setscl(device_t dev, unsigned char val) 141 { 142 device_t ppbus = device_get_parent(dev); 143 144 if(val==0) 145 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)&~SCL_out)); 146 else 147 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus)|SCL_out)); 148 } 149 150 static int lpbb_detect(device_t dev) 151 { 152 device_t ppbus = device_get_parent(dev); 153 154 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) { 155 device_printf(dev, "can't allocate ppbus\n"); 156 return (0); 157 } 158 159 /* reset bus */ 160 lpbb_setsda(dev, 1); 161 lpbb_setscl(dev, 1); 162 163 if ((ppb_rstr(ppbus) & I2CKEY) || 164 ((ppb_rstr(ppbus) & ALIM) != ALIM)) { 165 166 ppb_release_bus(ppbus, dev); 167 return (0); 168 } 169 170 ppb_release_bus(ppbus, dev); 171 172 return (1); 173 } 174 175 static int 176 lpbb_reset(device_t dev, u_char speed, u_char addr, u_char * oldaddr) 177 { 178 device_t ppbus = device_get_parent(dev); 179 180 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) { 181 device_printf(dev, "can't allocate ppbus\n"); 182 return (0); 183 } 184 185 /* reset bus */ 186 lpbb_setsda(dev, 1); 187 lpbb_setscl(dev, 1); 188 189 ppb_release_bus(ppbus, dev); 190 191 return (IIC_ENOADDR); 192 } 193 194 static devclass_t lpbb_devclass; 195 196 static device_method_t lpbb_methods[] = { 197 /* device interface */ 198 DEVMETHOD(device_identify, lpbb_identify), 199 DEVMETHOD(device_probe, lpbb_probe), 200 DEVMETHOD(device_attach, lpbb_attach), 201 202 /* bus interface */ 203 DEVMETHOD(bus_print_child, bus_generic_print_child), 204 205 /* iicbb interface */ 206 DEVMETHOD(iicbb_callback, lpbb_callback), 207 DEVMETHOD(iicbb_setsda, lpbb_setsda), 208 DEVMETHOD(iicbb_setscl, lpbb_setscl), 209 DEVMETHOD(iicbb_getsda, lpbb_getsda), 210 DEVMETHOD(iicbb_getscl, lpbb_getscl), 211 DEVMETHOD(iicbb_reset, lpbb_reset), 212 213 { 0, 0 } 214 }; 215 216 static driver_t lpbb_driver = { 217 "lpbb", 218 lpbb_methods, 219 1, 220 }; 221 222 DRIVER_MODULE(lpbb, ppbus, lpbb_driver, lpbb_devclass, 0, 0); 223 MODULE_DEPEND(lpbb, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER); 224 MODULE_VERSION(lpbb, 1); 225