src/main/rx/fport.c

   1 /*
   2  * This file is part of Cleanflight and Betaflight.
   3  *
   4  * Cleanflight and Betaflight are free software. You can redistribute
   5  * this software and/or modify this software under the terms of the
   6  * GNU General Public License as published by the Free Software
   7  * Foundation, either version 3 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * Cleanflight and Betaflight are distributed in the hope that they
  11  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  12  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this software.
  17  *
  18  * If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <stdbool.h>
  22 #include <stdint.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include "platform.h"
  27
  28 #ifdef USE_SERIALRX_FPORT
  29
  30 #include "build/debug.h"
  31
  32 #include "common/maths.h"
  33 #include "common/utils.h"
  34
  35 #include "drivers/time.h"
  36
  37 #include "io/serial.h"
  38
  39 #ifdef USE_TELEMETRY
  40 #include "telemetry/telemetry.h"
  41 #include "telemetry/smartport.h"
  42 #endif
  43
  44 #include "pg/rx.h"
  45
  46 #include "rx/frsky_crc.h"
  47 #include "rx/rx.h"
  48 #include "rx/sbus_channels.h"
  49 #include "rx/fport.h"
  50
  51 #define FPORT_TIME_NEEDED_PER_FRAME_US 3000
  52 #define FPORT_MAX_TELEMETRY_RESPONSE_DELAY_US 2000
  53 #define FPORT_MIN_TELEMETRY_RESPONSE_DELAY_US 500
  54 #define FPORT_MAX_TELEMETRY_AGE_MS 500
  55
  56 #define FPORT_TELEMETRY_MAX_CONSECUTIVE_TELEMETRY_FRAMES 2
  57
  58 #define FPORT_FRAME_MARKER 0x7E
  59
  60 #define FPORT_ESCAPE_CHAR 0x7D
  61 #define FPORT_ESCAPE_MASK 0x20
  62
  63 #define FPORT_BAUDRATE 115200
  64
  65 #define FPORT_PORT_OPTIONS (SERIAL_STOPBITS_1 | SERIAL_PARITY_NO)
  66
  67 enum {
  68     DEBUG_FPORT_FRAME_INTERVAL = 0,
  69     DEBUG_FPORT_FRAME_ERRORS,
  70     DEBUG_FPORT_FRAME_LAST_ERROR,
  71     DEBUG_FPORT_TELEMETRY_INTERVAL,
  72 };
  73
  74 enum {
  75     DEBUG_FPORT_NO_ERROR = 0,
  76     DEBUG_FPORT_ERROR_TIMEOUT,
  77     DEBUG_FPORT_ERROR_OVERSIZE,
  78     DEBUG_FPORT_ERROR_SIZE,
  79     DEBUG_FPORT_ERROR_CHECKSUM,
  80     DEBUG_FPORT_ERROR_TYPE,
  81     DEBUG_FPORT_ERROR_TYPE_SIZE,
  82 };
  83
  84 enum {
  85     FPORT_FRAME_TYPE_CONTROL = 0x00,
  86     FPORT_FRAME_TYPE_TELEMETRY_REQUEST = 0x01,
  87     FPORT_FRAME_TYPE_TELEMETRY_RESPONSE = 0x81,
  88
  89 };
  90
  91 enum {
  92     FPORT_FRAME_ID_NULL = 0x00,     // (master/slave)
  93     FPORT_FRAME_ID_DATA = 0x10,     // (master/slave)
  94     FPORT_FRAME_ID_READ = 0x30,     // (master)
  95     FPORT_FRAME_ID_WRITE = 0x31,    // (master)
  96     FPORT_FRAME_ID_RESPONSE = 0x32, // (slave)
  97 };
  98
  99 typedef struct fportControlData_s {
 100     sbusChannels_t channels;
 101     uint8_t rssi;
 102 } fportControlData_t;
 103
 104 typedef union fportData_s {
 105     fportControlData_t controlData;
 106     smartPortPayload_t telemetryData;
 107 } fportData_t;
 108
 109 typedef struct fportFrame_s {
 110     uint8_t type;
 111     fportData_t data;
 112 } fportFrame_t;
 113
 114 #ifdef USE_TELEMETRY_SMARTPORT
 115 static const smartPortPayload_t emptySmartPortFrame = { .frameId = 0, .valueId = 0, .data = 0 };
 116 #endif
 117
 118 #define FPORT_REQUEST_FRAME_LENGTH sizeof(fportFrame_t)
 119 #define FPORT_RESPONSE_FRAME_LENGTH (sizeof(uint8_t) + sizeof(smartPortPayload_t))
 120
 121 #define FPORT_FRAME_PAYLOAD_LENGTH_CONTROL (sizeof(uint8_t) + sizeof(fportControlData_t))
 122 #define FPORT_FRAME_PAYLOAD_LENGTH_TELEMETRY_REQUEST (sizeof(uint8_t) + sizeof(smartPortPayload_t))
 123
 124 #define NUM_RX_BUFFERS 3
 125 #define BUFFER_SIZE (FPORT_REQUEST_FRAME_LENGTH + 2 * sizeof(uint8_t))
 126
 127 typedef struct fportBuffer_s {
 128     uint8_t data[BUFFER_SIZE];
 129     uint8_t length;
 130     timeUs_t frameStartTimeUs;
 131 } fportBuffer_t;
 132
 133 static fportBuffer_t rxBuffer[NUM_RX_BUFFERS];
 134
 135 static volatile uint8_t rxBufferWriteIndex = 0;
 136 static volatile uint8_t rxBufferReadIndex = 0;
 137
 138 static volatile timeUs_t lastTelemetryFrameReceivedUs;
 139 static volatile bool clearToSend = false;
 140
 141 static volatile uint8_t framePosition = 0;
 142
 143 static smartPortPayload_t *mspPayload = NULL;
 144 static timeUs_t lastRcFrameReceivedMs = 0;
 145
 146 static serialPort_t *fportPort;
 147 #ifdef USE_TELEMETRY_SMARTPORT
 148 static bool telemetryEnabled = false;
 149 #endif
 150
 151 static void reportFrameError(uint8_t errorReason)
 152 {
 153     static volatile uint16_t frameErrors = 0;
 154
 155     frameErrors++;
 156
 157     DEBUG_SET(DEBUG_FPORT, DEBUG_FPORT_FRAME_ERRORS, frameErrors);
 158     DEBUG_SET(DEBUG_FPORT, DEBUG_FPORT_FRAME_LAST_ERROR, errorReason);
 159 }
 160
 161 // Receive ISR callback
 162 static void fportDataReceive(uint16_t c, void *data)
 163 {
 164     UNUSED(data);
 165
 166     static timeUs_t frameStartAt = 0;
 167     static bool escapedCharacter = false;
 168     static timeUs_t lastFrameReceivedUs = 0;
 169     static bool telemetryFrame = false;
 170
 171     const timeUs_t currentTimeUs = microsISR();
 172
 173     clearToSend = false;
 174
 175     if (framePosition > 1 && cmpTimeUs(currentTimeUs, frameStartAt) > FPORT_TIME_NEEDED_PER_FRAME_US + 500) {
 176         reportFrameError(DEBUG_FPORT_ERROR_TIMEOUT);
 177
 178         framePosition = 0;
 179      }
 180
 181     uint8_t val = (uint8_t)c;
 182
 183     if (val == FPORT_FRAME_MARKER) {
 184         if (framePosition > 1) {
 185             const uint8_t nextWriteIndex = (rxBufferWriteIndex + 1) % NUM_RX_BUFFERS;
 186             if (nextWriteIndex != rxBufferReadIndex) {
 187                 rxBuffer[rxBufferWriteIndex].length = framePosition - 1;
 188                 rxBufferWriteIndex = nextWriteIndex;
 189             }
 190
 191             if (telemetryFrame) {
 192                 clearToSend = true;
 193                 lastTelemetryFrameReceivedUs = currentTimeUs;
 194                 telemetryFrame = false;
 195             }
 196
 197             DEBUG_SET(DEBUG_FPORT, DEBUG_FPORT_FRAME_INTERVAL, currentTimeUs - lastFrameReceivedUs);
 198             lastFrameReceivedUs = currentTimeUs;
 199
 200             escapedCharacter = false;
 201         }
 202
 203         frameStartAt = currentTimeUs;
 204         framePosition = 1;
 205
 206         rxBuffer[rxBufferWriteIndex].frameStartTimeUs = currentTimeUs;
 207     } else if (framePosition > 0) {
 208         if (framePosition >= BUFFER_SIZE + 1) {
 209                 framePosition = 0;
 210
 211                 reportFrameError(DEBUG_FPORT_ERROR_OVERSIZE);
 212         } else {
 213             if (escapedCharacter) {
 214                 val = val ^ FPORT_ESCAPE_MASK;
 215                 escapedCharacter = false;
 216             } else if (val == FPORT_ESCAPE_CHAR) {
 217                 escapedCharacter = true;
 218
 219                 return;
 220             }
 221
 222             if (framePosition == 2 && val == FPORT_FRAME_TYPE_TELEMETRY_REQUEST) {
 223                 telemetryFrame = true;
 224             }
 225
 226             rxBuffer[rxBufferWriteIndex].data[framePosition - 1] = val;
 227             framePosition = framePosition + 1;
 228         }
 229     }
 230 }
 231
 232 #if defined(USE_TELEMETRY_SMARTPORT)
 233 static void smartPortWriteFrameFport(const smartPortPayload_t *payload)
 234 {
 235     framePosition = 0;
 236
 237     uint16_t checksum = 0;
 238     smartPortSendByte(FPORT_RESPONSE_FRAME_LENGTH, &checksum, fportPort);
 239     smartPortSendByte(FPORT_FRAME_TYPE_TELEMETRY_RESPONSE, &checksum, fportPort);
 240     smartPortWriteFrameSerial(payload, fportPort, checksum);
 241 }
 242 #endif
 243
 244 static uint8_t fportFrameStatus(rxRuntimeState_t *rxRuntimeState)
 245 {
 246     static bool hasTelemetryRequest = false;
 247
 248 #ifdef USE_TELEMETRY_SMARTPORT
 249     static smartPortPayload_t payloadBuffer;
 250     static bool rxDrivenFrameRate = false;
 251     static uint8_t consecutiveTelemetryFrameCount = 0;
 252 #endif
 253
 254     uint8_t result = RX_FRAME_PENDING;
 255
 256     if (rxBufferReadIndex != rxBufferWriteIndex) {
 257         uint8_t bufferLength = rxBuffer[rxBufferReadIndex].length;
 258         uint8_t frameLength = rxBuffer[rxBufferReadIndex].data[0];
 259         if (frameLength != bufferLength - 2) {
 260             reportFrameError(DEBUG_FPORT_ERROR_SIZE);
 261         } else {
 262             if (!frskyCheckSumIsGood(&rxBuffer[rxBufferReadIndex].data[0], bufferLength)) {
 263                 reportFrameError(DEBUG_FPORT_ERROR_CHECKSUM);
 264             } else {
 265                 fportFrame_t *frame = (fportFrame_t *)&rxBuffer[rxBufferReadIndex].data[1];
 266
 267                 switch (frame->type) {
 268                 case FPORT_FRAME_TYPE_CONTROL:
 269                     if (frameLength != FPORT_FRAME_PAYLOAD_LENGTH_CONTROL) {
 270                         reportFrameError(DEBUG_FPORT_ERROR_TYPE_SIZE);
 271                     } else {
 272                         result = sbusChannelsDecode(rxRuntimeState, &frame->data.controlData.channels);
 273
 274                         setRssi(scaleRange(frame->data.controlData.rssi, 0, 100, 0, RSSI_MAX_VALUE), RSSI_SOURCE_RX_PROTOCOL);
 275
 276                         lastRcFrameReceivedMs = millis();
 277
 278                         if (!(result & (RX_FRAME_FAILSAFE | RX_FRAME_DROPPED))) {
 279                             rxRuntimeState->lastRcFrameTimeUs = rxBuffer[rxBufferReadIndex].frameStartTimeUs;
 280                         }
 281                     }
 282
 283                     break;
 284                 case FPORT_FRAME_TYPE_TELEMETRY_REQUEST:
 285                     if (frameLength != FPORT_FRAME_PAYLOAD_LENGTH_TELEMETRY_REQUEST) {
 286                         reportFrameError(DEBUG_FPORT_ERROR_TYPE_SIZE);
 287                     } else {
 288 #if defined(USE_TELEMETRY_SMARTPORT)
 289                         if (!telemetryEnabled) {
 290                             break;
 291                         }
 292
 293                         switch(frame->data.telemetryData.frameId) {
 294                         case FPORT_FRAME_ID_DATA:
 295                             if (!rxDrivenFrameRate) {
 296                                 rxDrivenFrameRate = true;
 297                             }
 298
 299                             hasTelemetryRequest = true;
 300
 301                             break;
 302                         case FPORT_FRAME_ID_NULL:
 303                             if (!rxDrivenFrameRate) {
 304                                 if (consecutiveTelemetryFrameCount >= FPORT_TELEMETRY_MAX_CONSECUTIVE_TELEMETRY_FRAMES && !(mspPayload && smartPortPayloadContainsMSP(mspPayload))) {
 305                                     consecutiveTelemetryFrameCount = 0;
 306                                 } else {
 307                                     hasTelemetryRequest = true;
 308
 309                                     consecutiveTelemetryFrameCount++;
 310                                 }
 311                             }
 312
 313                             break;
 314                         case FPORT_FRAME_ID_READ:
 315                         case FPORT_FRAME_ID_WRITE: // never used
 316                             memcpy(&payloadBuffer, &frame->data.telemetryData, sizeof(smartPortPayload_t));
 317                             mspPayload = &payloadBuffer;
 318
 319                             break;
 320                         default:
 321
 322                            break;
 323                         }
 324 #endif
 325                     }
 326
 327                     break;
 328                 default:
 329                     reportFrameError(DEBUG_FPORT_ERROR_TYPE);
 330
 331                     break;
 332                 }
 333             }
 334
 335         }
 336
 337         rxBufferReadIndex = (rxBufferReadIndex + 1) % NUM_RX_BUFFERS;
 338     }
 339
 340     if ((mspPayload || hasTelemetryRequest) && cmpTimeUs(micros(), lastTelemetryFrameReceivedUs) >= FPORT_MIN_TELEMETRY_RESPONSE_DELAY_US) {
 341         hasTelemetryRequest = false;
 342
 343         result = (result & ~RX_FRAME_PENDING) | RX_FRAME_PROCESSING_REQUIRED;
 344     }
 345
 346     if (lastRcFrameReceivedMs && ((millis() - lastRcFrameReceivedMs) > FPORT_MAX_TELEMETRY_AGE_MS)) {
 347         setRssiDirect(0, RSSI_SOURCE_RX_PROTOCOL);
 348         lastRcFrameReceivedMs = 0;
 349     }
 350
 351     return result;
 352 }
 353
 354 static bool fportProcessFrame(const rxRuntimeState_t *rxRuntimeState)
 355 {
 356     UNUSED(rxRuntimeState);
 357
 358 #if defined(USE_TELEMETRY_SMARTPORT)
 359     static timeUs_t lastTelemetryFrameSentUs;
 360
 361     timeUs_t currentTimeUs = micros();
 362     if (cmpTimeUs(currentTimeUs, lastTelemetryFrameReceivedUs) > FPORT_MAX_TELEMETRY_RESPONSE_DELAY_US) {
 363        clearToSend = false;
 364     }
 365
 366     if (clearToSend) {
 367         processSmartPortTelemetry(mspPayload, &clearToSend, NULL);
 368
 369         if (clearToSend) {
 370             smartPortWriteFrameFport(&emptySmartPortFrame);
 371
 372             clearToSend = false;
 373         }
 374
 375         DEBUG_SET(DEBUG_FPORT, DEBUG_FPORT_TELEMETRY_INTERVAL, currentTimeUs - lastTelemetryFrameSentUs);
 376         lastTelemetryFrameSentUs = currentTimeUs;
 377     }
 378
 379     mspPayload = NULL;
 380 #endif
 381
 382     return true;
 383 }
 384
 385 bool fportRxInit(const rxConfig_t *rxConfig, rxRuntimeState_t *rxRuntimeState)
 386 {
 387     static uint16_t sbusChannelData[SBUS_MAX_CHANNEL];
 388     rxRuntimeState->channelData = sbusChannelData;
 389     sbusChannelsInit(rxConfig, rxRuntimeState);
 390
 391     rxRuntimeState->channelCount = SBUS_MAX_CHANNEL;
 392     rxRuntimeState->rcFrameStatusFn = fportFrameStatus;
 393     rxRuntimeState->rcProcessFrameFn = fportProcessFrame;
 394
 395     const serialPortConfig_t *portConfig = findSerialPortConfig(FUNCTION_RX_SERIAL);
 396     if (!portConfig) {
 397         return false;
 398     }
 399
 400     fportPort = openSerialPort(portConfig->identifier,
 401         FUNCTION_RX_SERIAL,
 402         fportDataReceive,
 403         NULL,
 404         FPORT_BAUDRATE,
 405         MODE_RXTX,
 406         FPORT_PORT_OPTIONS | (rxConfig->serialrx_inverted ? SERIAL_INVERTED : 0) | (rxConfig->halfDuplex ? SERIAL_BIDIR : 0)
 407     );
 408
 409     if (fportPort) {
 410 #if defined(USE_TELEMETRY_SMARTPORT)
 411         telemetryEnabled = initSmartPortTelemetryExternal(smartPortWriteFrameFport);
 412 #endif
 413
 414         if (rssiSource == RSSI_SOURCE_NONE) {
 415             rssiSource = RSSI_SOURCE_RX_PROTOCOL;
 416         }
 417     }
 418
 419     return fportPort != NULL;
 420 }
 421 #endif