| 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); |