i2c_protocol.c

   1 /*
   2  *  Copyright Droids Corporation (2009)
   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: i2c_protocol.c,v 1.8 2009-11-08 17:24:33 zer0 Exp $
  19  *
  20  */
  21
  22 #include <stdio.h>
  23 #include <string.h>
  24
  25 #include <aversive/pgmspace.h>
  26 #include <aversive/wait.h>
  27 #include <aversive/error.h>
  28
  29 #include <callout.h>
  30 #include <i2c.h>
  31
  32 #include "../fpv-common/i2c_commands.h"
  33 #include "main.h"
  34 #include "i2c_protocol.h"
  35
  36 #define I2C_STATE_MAX 2
  37 #define I2C_PERIOD_MS 50
  38
  39 #define I2C_TIMEOUT 100 /* ms */
  40 #define I2C_MAX_ERRORS 40
  41
  42 static volatile uint8_t i2c_poll_num = 0;
  43 static volatile uint8_t i2c_state = 0;
  44 static volatile uint16_t i2c_errors = 0;
  45
  46 #define OP_READY 0 /* no i2c op running */
  47 #define OP_POLL  1 /* a user command is running */
  48 #define OP_CMD   2 /* a polling (req / ans) is running */
  49
  50 static volatile uint8_t running_op = OP_READY;
  51
  52 #define I2C_MAX_LOG 3
  53 static uint8_t error_log = 0;
  54
  55 static struct callout i2c_timer;
  56
  57 static int8_t i2c_req_imuboard_status(void);
  58
  59 /* latest received imuboard_status */
  60 struct i2c_ans_imuboard_status imuboard_status;
  61
  62 /* used for commands */
  63 uint8_t command_buf[I2C_SEND_BUFFER_SIZE];
  64 volatile int8_t command_dest=-1;
  65 volatile uint8_t command_size=0;
  66
  67 #define I2C_ERROR(args...) do {                                         \
  68                 if (error_log < I2C_MAX_LOG) {                          \
  69                         ERROR(E_USER_I2C_PROTO, args);                  \
  70                         error_log ++;                                   \
  71                         if (error_log == I2C_MAX_LOG) {                 \
  72                                 ERROR(E_USER_I2C_PROTO,                 \
  73                                       "i2c logs are now warnings");     \
  74                         }                                               \
  75                 }                                                       \
  76                 else                                                    \
  77                         WARNING(E_USER_I2C_PROTO, args);                \
  78         } while(0)
  79
  80 void i2c_protocol_debug(void)
  81 {
  82         printf_P(PSTR("I2C protocol debug infos:\r\n"));
  83         printf_P(PSTR("  i2c_state=%d\r\n"), i2c_state);
  84         printf_P(PSTR("  i2c_errors=%d\r\n"), i2c_errors);
  85         printf_P(PSTR("  running_op=%d\r\n"), running_op);
  86         printf_P(PSTR("  command_size=%d\r\n"), command_size);
  87         printf_P(PSTR("  command_dest=%d\r\n"), command_dest);
  88         printf_P(PSTR("  i2c_status=%x\r\n"), i2c_status());
  89 }
  90
  91 static void i2cproto_next_state(uint8_t inc)
  92 {
  93         i2c_state += inc;
  94         if (i2c_state >= I2C_STATE_MAX) {
  95                 i2c_state = 0;
  96                 i2c_poll_num ++;
  97         }
  98 }
  99
 100 void i2cproto_wait_update(void)
 101 {
 102         uint8_t poll_num;
 103         poll_num = i2c_poll_num;
 104         (void)poll_num;
 105         //WAIT_COND_OR_TIMEOUT((i2c_poll_num-poll_num) > 1, 150); /* XXX todo */
 106 }
 107
 108 /* called periodically : the goal of this 'thread' is to send requests
 109  * and read answers on i2c slaves in the correct order. */
 110 static void i2c_poll_slaves(struct callout_mgr *cm, struct callout *tim, void *arg)
 111 {
 112         uint8_t flags;
 113         int8_t err;
 114
 115         (void)cm;
 116         (void)tim;
 117         (void)arg;
 118
 119 #if 0
 120         static uint8_t a = 0;
 121
 122         a++;
 123         if (a & 0x4)
 124                 LED2_TOGGLE();
 125 #endif
 126
 127         /* already running */
 128         IRQ_LOCK(flags);
 129         if (running_op != OP_READY) {
 130                 IRQ_UNLOCK(flags);
 131                 goto reschedule;
 132         }
 133
 134         /* if a command is ready to be sent, so send it */
 135         if (command_size) {
 136                 running_op = OP_CMD;
 137                 err = i2c_send(command_dest, command_buf, command_size,
 138                              I2C_CTRL_GENERIC);
 139                 if (err < 0)
 140                         goto error;
 141                 IRQ_UNLOCK(flags);
 142                 goto reschedule;
 143         }
 144
 145         /* no command, so do the polling */
 146         running_op = OP_POLL;
 147
 148         switch(i2c_state) {
 149
 150         /* poll status of imuboard */
 151 #define I2C_REQ_IMUBOARD 0
 152         case I2C_REQ_IMUBOARD:
 153                 if ((err = i2c_req_imuboard_status()))
 154                         goto error;
 155                 break;
 156
 157 #define I2C_ANS_IMUBOARD 1
 158         case I2C_ANS_IMUBOARD:
 159                 if ((err = i2c_recv(I2C_IMUBOARD_ADDR,
 160                                     sizeof(struct i2c_ans_imuboard_status),
 161                                     I2C_CTRL_GENERIC)))
 162                         goto error;
 163                 break;
 164
 165         /* sync with I2C_STATE_MAX */
 166
 167         /* nothing, go to the first request */
 168         default:
 169                 i2c_state = 0;
 170                 running_op = OP_READY;
 171         }
 172         IRQ_UNLOCK(flags);
 173
 174         goto reschedule;
 175
 176  error:
 177         running_op = OP_READY;
 178         IRQ_UNLOCK(flags);
 179         i2c_errors++;
 180         if (i2c_errors > I2C_MAX_ERRORS) {
 181                 I2C_ERROR("I2C send is_cmd=%d proto_state=%d "
 182                       "err=%d i2c_status=%x", !!command_size, i2c_state, err, i2c_status());
 183                 i2c_reset();
 184                 i2c_errors = 0;
 185         }
 186
 187  reschedule:
 188         /* reschedule */
 189         callout_reschedule(cm, tim, I2C_PERIOD_MS);
 190 }
 191
 192 /* called when the xmit is finished */
 193 void i2c_sendevent(int8_t size)
 194 {
 195         if (size > 0) {
 196                 if (running_op == OP_POLL) {
 197                         i2cproto_next_state(1);
 198                 }
 199                 else
 200                         command_size = 0;
 201         }
 202         else {
 203                 i2c_errors++;
 204                 NOTICE(E_USER_I2C_PROTO, "send error state=%d size=%d "
 205                         "op=%d", i2c_state, size, running_op);
 206                 if (i2c_errors > I2C_MAX_ERRORS) {
 207                         I2C_ERROR("I2C error, slave not ready");
 208                         i2c_reset();
 209                         i2c_errors = 0;
 210                 }
 211
 212                 if (running_op == OP_POLL) {
 213                         /* skip associated answer */
 214                         i2cproto_next_state(2);
 215                 }
 216         }
 217         running_op = OP_READY;
 218 }
 219
 220 /* called rx event */
 221 void i2c_recvevent(uint8_t * buf, int8_t size)
 222 {
 223         if (running_op == OP_POLL)
 224                 i2cproto_next_state(1);
 225
 226         /* recv is only trigged after a poll */
 227         running_op = OP_READY;
 228
 229         if (size < 0) {
 230                 goto error;
 231         }
 232
 233         switch (buf[0]) {
 234
 235         case I2C_ANS_IMUBOARD_STATUS: {
 236                 struct i2c_ans_imuboard_status *ans =
 237                         (struct i2c_ans_imuboard_status *)buf;
 238
 239                 if (size != sizeof (*ans))
 240                         goto error;
 241
 242                 /* copy status in a global struct */
 243                 memcpy(&imuboard_status, ans, sizeof(imuboard_status));
 244
 245                 break;
 246         }
 247
 248         default:
 249                 break;
 250         }
 251
 252         return;
 253  error:
 254         i2c_errors++;
 255         NOTICE(E_USER_I2C_PROTO, "recv error state=%d op=%d",
 256                i2c_state, running_op);
 257         if (i2c_errors > I2C_MAX_ERRORS) {
 258                 I2C_ERROR("I2C error, slave not ready");
 259                 i2c_reset();
 260                 i2c_errors = 0;
 261         }
 262 }
 263
 264 void i2c_recvbyteevent(uint8_t hwstatus, uint8_t i, uint8_t c)
 265 {
 266         (void)hwstatus;
 267         (void)i;
 268         (void)c;
 269 }
 270
 271 /* ******** ******** ******** ******** */
 272 /* commands */
 273 /* ******** ******** ******** ******** */
 274
 275
 276 static int8_t
 277 i2c_send_command(uint8_t addr, uint8_t * buf, uint8_t size)
 278 {
 279         uint8_t flags;
 280         uint16_t ms = get_time_ms();
 281
 282         while ((get_time_ms() - ms) < I2C_TIMEOUT) {
 283                 IRQ_LOCK(flags);
 284                 if (command_size == 0) {
 285                         memcpy(command_buf, buf, size);
 286                         command_size = size;
 287                         command_dest = addr;
 288                         IRQ_UNLOCK(flags);
 289                         return 0;
 290                 }
 291                 IRQ_UNLOCK(flags);
 292         }
 293         /* this should not happen... except if we are called from an
 294          * interrupt context, but it's forbidden */
 295         I2C_ERROR("I2C command send failed");
 296         return -EBUSY;
 297 }
 298
 299 static int8_t i2c_req_imuboard_status(void)
 300 {
 301         struct i2c_req_imuboard_status buf;
 302         int8_t err;
 303
 304         buf.hdr.cmd = I2C_REQ_IMUBOARD_STATUS;
 305         err = i2c_send(I2C_IMUBOARD_ADDR, (uint8_t*)&buf,
 306                         sizeof(buf), I2C_CTRL_GENERIC);
 307
 308         return err;
 309 }
 310
 311 int8_t i2c_led_control(uint8_t addr, uint8_t led, uint8_t state)
 312 {
 313         struct i2c_cmd_led_control buf;
 314         buf.hdr.cmd = I2C_CMD_GENERIC_LED_CONTROL;
 315         buf.led_num = led;
 316         buf.state = state;
 317         return i2c_send_command(addr, (uint8_t*)&buf, sizeof(buf));
 318 }
 319
 320 void i2c_protocol_init(void)
 321 {
 322         callout_init(&i2c_timer, i2c_poll_slaves, NULL, I2C_PRIO);
 323         callout_schedule(&xbeeboard.intr_cm, &i2c_timer, I2C_PERIOD_MS);
 324 }