i2cm_sw.c

   1 /*
   2  *  Copyright Droids Corporation, Microb Technology, Eirbot (2005)
   3  *
   4  *  This program is free software; you can redistribute it and/or modify
   5  *  it under the terms of the GNU General Public License as published by
   6  *  the Free Software Foundation; either version 2 of the License, or
   7  *  (at your option) any later version.
   8  *
   9  *  This program is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *  GNU General Public License for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License
  15  *  along with this program; if not, write to the Free Software
  16  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  17  *
  18  *  Revision : $Id$
  19  *
  20  */
  21
  22
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <stdint.h>
  27 #include <aversive.h>
  28
  29 #include <aversive/wait.h>
  30
  31
  32 #include <util/delay.h>
  33
  34
  35 #include "i2cm_sw.h"
  36
  37
  38
  39
  40 volatile i2cm_state g_i2cm_NUM_state = NOT_INIT;
  41 volatile uint8_t g_i2cm_NUM_byte;
  42
  43 void (*g_i2cm_NUM_event)(i2cm_state state);
  44
  45 /*
  46   Mini Arduino
  47   I2C:
  48   A4 = PC4/SDA
  49   A5 = PC5/SCL
  50 */
  51
  52 #define I2CM_NUM_SCL_PORT  PORTC
  53 #define I2CM_NUM_SCL_BIT   5
  54
  55 #define  I2CM_NUM_SDA_PORT PORTC
  56 #define  I2CM_NUM_SDA_BIT  4
  57
  58 #define I2CM_NUM_SCL   I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT
  59 #define I2CM_NUM_SDA   I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT
  60
  61
  62
  63
  64 void i2cm_NUM_init(void)
  65 {
  66         /*
  67           - port SCL/SDA is set to 0
  68           - i2c is then driven using DDR 0 (Hi-Z) or 1 (For Low)
  69          */
  70
  71         // SCL high
  72         cbi(DDR(I2CM_NUM_SCL_PORT),I2CM_NUM_SCL_BIT);
  73         I2C_HIGH(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
  74
  75         // SDA high
  76         cbi(DDR(I2CM_NUM_SDA_PORT),I2CM_NUM_SDA_BIT);
  77         I2C_HIGH(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
  78         I2CM_NUM_DELAY();
  79
  80         g_i2cm_NUM_state = I2CM_READY;
  81 }
  82
  83
  84 void i2cm_NUM_manage(void)
  85 {
  86         if ( (g_i2cm_NUM_event  != NULL) && (g_i2cm_NUM_state  != I2CM_READY) ) {
  87                 g_i2cm_NUM_event( g_i2cm_NUM_state );
  88                 // reset notification
  89                 if (g_i2cm_NUM_state != I2CM_BUSY)
  90                         g_i2cm_NUM_state = I2CM_READY;
  91         }
  92 }
  93
  94 uint8_t i2cm_NUM_get_state(void)
  95 {
  96         return g_i2cm_NUM_state;
  97 }
  98
  99
 100 uint8_t i2cm_NUM_get_received_byte(void)
 101 {
 102         g_i2cm_NUM_state = I2CM_READY;
 103         return g_i2cm_NUM_byte;
 104 }
 105
 106 void i2cm_NUM_register_event(void (*func)(i2cm_state state))
 107 {
 108         uint8_t flags;
 109         IRQ_LOCK(flags);
 110         g_i2cm_NUM_event = func;
 111         IRQ_UNLOCK(flags);
 112 }
 113
 114
 115 uint8_t i2cm_NUM_send_byte(uint8_t byte)
 116 {
 117         uint8_t mask;
 118         uint8_t err = 0;
 119
 120
 121         g_i2cm_NUM_state = I2CM_BUSY;
 122
 123         // SCL should already be low
 124         //  I2C_LOW(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 125         //  I2CM_NUM_DELAY();
 126
 127         mask = 0x80;
 128         while (mask) {
 129
 130
 131                 // data out
 132                 if (mask & byte)
 133                         I2C_HIGH(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
 134                 else
 135                         I2C_LOW(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
 136                 I2CM_NUM_DELAY();
 137                 mask >>=1;
 138
 139                 // delay needed ?
 140                 //I2CM_NUM_DELAY();
 141
 142                 // clock High
 143                 I2C_HIGH(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 144                 I2CM_NUM_DELAY();
 145                 while ( bit_is_clear(PIN(I2CM_NUM_SCL_PORT), I2CM_NUM_SCL_BIT) );// slave handshake
 146
 147                 // clock low
 148                 I2C_LOW(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 149
 150         }
 151
 152         /* receive ack */
 153
 154         // release SDA
 155         I2C_HIGH(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
 156         I2CM_NUM_BIT_DELAY();
 157
 158         // clock HIGH
 159         I2C_HIGH(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 160         I2CM_NUM_DELAY();
 161         while ( bit_is_clear(PIN(I2CM_NUM_SCL_PORT), I2CM_NUM_SCL_BIT) );// slave handshake
 162
 163         // receive ACK
 164         if (bit_is_set(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT))
 165                 err = I2CM_SENT_NO_ACK;
 166
 167         // clock low
 168         I2C_LOW(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 169         I2CM_NUM_DELAY();
 170
 171         return err;
 172 }
 173
 174
 175 uint8_t i2cm_NUM_send_start(uint8_t sla_w)
 176 {
 177         uint8_t err;
 178         uint16_t i;
 179         g_i2cm_NUM_state = I2CM_BUSY;
 180
 181         I2C_HIGH(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 182         I2C_HIGH(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
 183
 184         I2CM_NUM_DELAY();
 185
 186         /* wait for bus realese */
 187         for (i=0;i<0x8000; i++){
 188                 if( bit_is_set(PIN(I2CM_NUM_SCL_PORT), I2CM_NUM_SCL_BIT) && \
 189                     bit_is_set(PIN(I2CM_NUM_SDA_PORT), I2CM_NUM_SDA_BIT) )
 190                         break;
 191         }
 192
 193         //      while ( bit_is_clear(PIN(I2CM_NUM_SCL_PORT), I2CM_NUM_SCL_BIT) );// slave handshake
 194
 195         // start condition
 196         I2C_LOW(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
 197         I2CM_NUM_DELAY();
 198         I2C_LOW(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 199         I2CM_NUM_DELAY();
 200
 201         err = i2cm_NUM_send_byte(sla_w);
 202         return err;
 203 }
 204
 205
 206
 207 uint8_t i2cm_NUM_send_stop(void)
 208 {
 209         g_i2cm_NUM_state = I2CM_BUSY;
 210
 211         // data down
 212         I2C_LOW(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 213         I2C_LOW(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
 214         I2CM_NUM_DELAY();
 215
 216         // stop condition
 217         I2C_HIGH(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 218         I2CM_NUM_DELAY();
 219         I2C_HIGH(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
 220         I2CM_NUM_DELAY();
 221
 222         g_i2cm_NUM_state = I2CM_SENT_STOP;
 223         return 0;
 224 }
 225
 226
 227 uint8_t i2cm_NUM_receive_byte(uint8_t last)
 228 {
 229         uint8_t mask,data;
 230
 231         g_i2cm_NUM_state = I2CM_BUSY;
 232
 233         I2C_HIGH(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
 234
 235
 236         data = 0;
 237         mask = 0x80;
 238         while (mask) {
 239
 240                 // clock High
 241                 I2C_HIGH(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 242                 I2CM_NUM_DELAY();
 243                 while ( bit_is_clear(PIN(I2CM_NUM_SCL_PORT), I2CM_NUM_SCL_BIT) );// slave handshake
 244
 245                 if (bit_is_set(PIN(I2CM_NUM_SDA_PORT),I2CM_NUM_SDA_BIT))
 246                         data |= mask;
 247
 248                 // clock low
 249                 I2C_LOW(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 250                 I2CM_NUM_DELAY();
 251
 252                 mask >>=1;
 253         }
 254
 255         if (!last){
 256                 /* send ack */
 257                 I2C_LOW(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
 258                 I2CM_NUM_BIT_DELAY();
 259         }
 260
 261         // clock HIGH
 262         I2C_HIGH(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 263         I2CM_NUM_DELAY();
 264         while ( bit_is_clear(PIN(I2CM_NUM_SCL_PORT), I2CM_NUM_SCL_BIT) );// slave handshake
 265
 266         // clock low
 267         I2C_LOW(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 268         I2CM_NUM_DELAY();
 269
 270         if (!last) {
 271                 // release DATA
 272                 I2C_HIGH(I2CM_NUM_SDA_PORT, I2CM_NUM_SDA_BIT);
 273                 I2CM_NUM_BIT_DELAY();
 274         }
 275
 276         g_i2cm_NUM_byte  = data;
 277         g_i2cm_NUM_state = I2CM_RECEIVED_BYTE;
 278
 279         I2C_HIGH(I2CM_NUM_SCL_PORT, I2CM_NUM_SCL_BIT);
 280
 281         return 0;
 282 }
 283
 284
 285
 286 uint8_t i2c_send(uint8_t addr, uint8_t* data, uint8_t len, uint8_t dummy)
 287 {
 288         uint8_t i;
 289         uint8_t err = 0;
 290
 291         err = i2cm_NUM_send_start((addr<<1) | 0);
 292         if (err)
 293                 return err;
 294
 295         for (i=0; i<len; i++) {
 296                 err = i2cm_NUM_send_byte(data[i]);
 297                 if (err)
 298                         break;
 299         }
 300
 301         i2cm_NUM_send_stop();
 302         return err;
 303 }
 304
 305
 306 uint8_t i2c_buf[0x20];
 307
 308 uint8_t i2c_recv(uint8_t addr, uint8_t len, uint8_t dummy)
 309 {
 310         uint8_t i;
 311         uint8_t err = 0;
 312
 313         err = i2cm_NUM_send_start((addr<<1) | 1);
 314         if (err)
 315                 return err;
 316
 317         I2CM_NUM_DELAY();
 318
 319         for (i=0; i<len; i++){
 320                 err =i2cm_NUM_receive_byte(i == len-1);
 321                 i2c_buf[i] = g_i2cm_NUM_byte;
 322                 if (err)
 323                         break;
 324         }
 325         i2cm_NUM_send_stop();
 326         return err;
 327 }
 328
 329
 330 uint8_t i2c_get_recv_buffer(uint8_t* buf, uint8_t len)
 331 {
 332         uint8_t i;
 333         for (i=0; i<len; i++)
 334                 buf[i] = i2c_buf[i];
 335         return len;
 336 }
 337
 338