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 * 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 /* 33 * I2C Bit-Banging over parallel port 34 * 35 * See the Official Philips interface description in lpbb(4) 36 */ 37 38 #include <sys/param.h> 39 #include <sys/kernel.h> 40 #include <sys/systm.h> 41 #include <sys/module.h> 42 #include <sys/bus.h> 43 #include <sys/uio.h> 44 45 46 #include <dev/ppbus/ppbconf.h> 47 #include "ppbus_if.h" 48 #include <dev/ppbus/ppbio.h> 49 50 #include <dev/iicbus/iiconf.h> 51 #include <dev/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", -1); 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; 81 82 /* add generic bit-banging code */ 83 bitbang = device_add_child(dev, "iicbb", -1); 84 device_probe_and_attach(bitbang); 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 lpbb_getscl(device_t dev) 123 { 124 return ((ppb_rstr(device_get_parent(dev)) & SCL_in) == SCL_in); 125 } 126 127 static int lpbb_getsda(device_t dev) 128 { 129 return ((ppb_rstr(device_get_parent(dev)) & SDA_in) == SDA_in); 130 } 131 132 static void lpbb_setsda(device_t dev, char val) 133 { 134 device_t ppbus = device_get_parent(dev); 135 136 if(val==0) 137 ppb_wdtr(ppbus, (u_char)SDA_out); 138 else 139 ppb_wdtr(ppbus, (u_char)~SDA_out); 140 } 141 142 static void lpbb_setscl(device_t dev, unsigned char val) 143 { 144 device_t ppbus = device_get_parent(dev); 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 lpbb_setsda(dev, 1); 163 lpbb_setscl(dev, 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 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) { 183 device_printf(dev, "can't allocate ppbus\n"); 184 return (0); 185 } 186 187 /* reset bus */ 188 lpbb_setsda(dev, 1); 189 lpbb_setscl(dev, 1); 190 191 ppb_release_bus(ppbus, dev); 192 193 return (IIC_ENOADDR); 194 } 195 196 static devclass_t lpbb_devclass; 197 198 static device_method_t lpbb_methods[] = { 199 /* device interface */ 200 DEVMETHOD(device_identify, lpbb_identify), 201 DEVMETHOD(device_probe, lpbb_probe), 202 DEVMETHOD(device_attach, lpbb_attach), 203 204 /* bus interface */ 205 DEVMETHOD(bus_print_child, bus_generic_print_child), 206 207 /* iicbb interface */ 208 DEVMETHOD(iicbb_callback, lpbb_callback), 209 DEVMETHOD(iicbb_setsda, lpbb_setsda), 210 DEVMETHOD(iicbb_setscl, lpbb_setscl), 211 DEVMETHOD(iicbb_getsda, lpbb_getsda), 212 DEVMETHOD(iicbb_getscl, lpbb_getscl), 213 DEVMETHOD(iicbb_reset, lpbb_reset), 214 215 { 0, 0 } 216 }; 217 218 static driver_t lpbb_driver = { 219 "lpbb", 220 lpbb_methods, 221 1, 222 }; 223 224 DRIVER_MODULE(lpbb, ppbus, lpbb_driver, lpbb_devclass, 0, 0); 225 MODULE_DEPEND(lpbb, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER); 226 MODULE_VERSION(lpbb, 1); 227