lpbb.c revision 331722
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: stable/11/sys/dev/ppbus/lpbb.c 331722 2018-03-29 02:50:57Z eadler $"); 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/bus.h> 40#include <sys/lock.h> 41#include <sys/kernel.h> 42#include <sys/module.h> 43#include <sys/mutex.h> 44#include <sys/systm.h> 45#include <sys/uio.h> 46 47 48#include <dev/ppbus/ppbconf.h> 49#include "ppbus_if.h" 50#include <dev/ppbus/ppbio.h> 51 52#include <dev/iicbus/iiconf.h> 53#include <dev/iicbus/iicbus.h> 54 55#include "iicbb_if.h" 56 57static int lpbb_detect(device_t dev); 58 59static void 60lpbb_identify(driver_t *driver, device_t parent) 61{ 62 63 device_t dev; 64 65 dev = device_find_child(parent, "lpbb", -1); 66 if (!dev) 67 BUS_ADD_CHILD(parent, 0, "lpbb", -1); 68} 69 70static int 71lpbb_probe(device_t dev) 72{ 73 74 /* Perhaps call this during identify instead? */ 75 if (!lpbb_detect(dev)) 76 return (ENXIO); 77 78 device_set_desc(dev, "Parallel I2C bit-banging interface"); 79 80 return (0); 81} 82 83static int 84lpbb_attach(device_t dev) 85{ 86 device_t bitbang; 87 88 /* add generic bit-banging code */ 89 bitbang = device_add_child(dev, "iicbb", -1); 90 device_probe_and_attach(bitbang); 91 92 return (0); 93} 94 95static int 96lpbb_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 ppb_lock(ppbus); 107 error = ppb_request_bus(ppbus, dev, how); 108 ppb_unlock(ppbus); 109 break; 110 111 case IIC_RELEASE_BUS: 112 /* release the ppbus */ 113 ppb_lock(ppbus); 114 error = ppb_release_bus(ppbus, dev); 115 ppb_unlock(ppbus); 116 break; 117 118 default: 119 error = EINVAL; 120 } 121 122 return (error); 123} 124 125#define SDA_out 0x80 126#define SCL_out 0x08 127#define SDA_in 0x80 128#define SCL_in 0x08 129#define ALIM 0x20 130#define I2CKEY 0x50 131 132/* Reset bus by setting SDA first and then SCL. */ 133static void 134lpbb_reset_bus(device_t dev) 135{ 136 device_t ppbus = device_get_parent(dev); 137 138 ppb_assert_locked(ppbus); 139 ppb_wdtr(ppbus, (u_char)~SDA_out); 140 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus) | SCL_out)); 141} 142 143static int 144lpbb_getscl(device_t dev) 145{ 146 device_t ppbus = device_get_parent(dev); 147 int rval; 148 149 ppb_lock(ppbus); 150 rval = ((ppb_rstr(ppbus) & SCL_in) == SCL_in); 151 ppb_unlock(ppbus); 152 return (rval); 153} 154 155static int 156lpbb_getsda(device_t dev) 157{ 158 device_t ppbus = device_get_parent(dev); 159 int rval; 160 161 ppb_lock(ppbus); 162 rval = ((ppb_rstr(ppbus) & SDA_in) == SDA_in); 163 ppb_unlock(ppbus); 164 return (rval); 165} 166 167static void 168lpbb_setsda(device_t dev, int val) 169{ 170 device_t ppbus = device_get_parent(dev); 171 172 ppb_lock(ppbus); 173 if (val == 0) 174 ppb_wdtr(ppbus, (u_char)SDA_out); 175 else 176 ppb_wdtr(ppbus, (u_char)~SDA_out); 177 ppb_unlock(ppbus); 178} 179 180static void 181lpbb_setscl(device_t dev, int val) 182{ 183 device_t ppbus = device_get_parent(dev); 184 185 ppb_lock(ppbus); 186 if (val == 0) 187 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus) & ~SCL_out)); 188 else 189 ppb_wctr(ppbus, (u_char)(ppb_rctr(ppbus) | SCL_out)); 190 ppb_unlock(ppbus); 191} 192 193static int 194lpbb_detect(device_t dev) 195{ 196 device_t ppbus = device_get_parent(dev); 197 198 ppb_lock(ppbus); 199 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) { 200 ppb_unlock(ppbus); 201 device_printf(dev, "can't allocate ppbus\n"); 202 return (0); 203 } 204 205 lpbb_reset_bus(dev); 206 207 if ((ppb_rstr(ppbus) & I2CKEY) || 208 ((ppb_rstr(ppbus) & ALIM) != ALIM)) { 209 ppb_release_bus(ppbus, dev); 210 ppb_unlock(ppbus); 211 return (0); 212 } 213 214 ppb_release_bus(ppbus, dev); 215 ppb_unlock(ppbus); 216 217 return (1); 218} 219 220static int 221lpbb_reset(device_t dev, u_char speed, u_char addr, u_char * oldaddr) 222{ 223 device_t ppbus = device_get_parent(dev); 224 225 ppb_lock(ppbus); 226 if (ppb_request_bus(ppbus, dev, PPB_DONTWAIT)) { 227 ppb_unlock(ppbus); 228 device_printf(dev, "can't allocate ppbus\n"); 229 return (0); 230 } 231 232 lpbb_reset_bus(dev); 233 234 ppb_release_bus(ppbus, dev); 235 ppb_unlock(ppbus); 236 237 return (IIC_ENOADDR); 238} 239 240static devclass_t lpbb_devclass; 241 242static device_method_t lpbb_methods[] = { 243 /* device interface */ 244 DEVMETHOD(device_identify, lpbb_identify), 245 DEVMETHOD(device_probe, lpbb_probe), 246 DEVMETHOD(device_attach, lpbb_attach), 247 248 /* iicbb interface */ 249 DEVMETHOD(iicbb_callback, lpbb_callback), 250 DEVMETHOD(iicbb_setsda, lpbb_setsda), 251 DEVMETHOD(iicbb_setscl, lpbb_setscl), 252 DEVMETHOD(iicbb_getsda, lpbb_getsda), 253 DEVMETHOD(iicbb_getscl, lpbb_getscl), 254 DEVMETHOD(iicbb_reset, lpbb_reset), 255 256 DEVMETHOD_END 257}; 258 259static driver_t lpbb_driver = { 260 "lpbb", 261 lpbb_methods, 262 1, 263}; 264 265DRIVER_MODULE(lpbb, ppbus, lpbb_driver, lpbb_devclass, 0, 0); 266DRIVER_MODULE(iicbb, lpbb, iicbb_driver, iicbb_devclass, 0, 0); 267MODULE_DEPEND(lpbb, ppbus, 1, 1, 1); 268MODULE_DEPEND(lpbb, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER); 269MODULE_VERSION(lpbb, 1); 270