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
  52 #define FPORT_TIME_NEEDED_PER_FRAME_US 3000
  53 #define FPORT_MAX_TELEMETRY_RESPONSE_DELAY_US 2000
  54 #define FPORT_MIN_TELEMETRY_RESPONSE_DELAY_US 500
  55 #define FPORT_MAX_TELEMETRY_AGE_MS 500
  56
  57 #define FPORT_TELEMETRY_MAX_CONSECUTIVE_TELEMETRY_FRAMES 2
  58
  59
  60 #define FPORT_FRAME_MARKER 0x7E
  61
  62 #define FPORT_ESCAPE_CHAR 0x7D
  63 #define FPORT_ESCAPE_MASK 0x20
  64
  65 #define FPORT_BAUDRATE 115200
  66
  67 #define FPORT_PORT_OPTIONS (SERIAL_STOPBITS_1 | SERIAL_PARITY_NO)
  68
  69 enum {
  70     DEBUG_FPORT_FRAME_INTERVAL = 0,
  71     DEBUG_FPORT_FRAME_ERRORS,
  72     DEBUG_FPORT_FRAME_LAST_ERROR,
  73     DEBUG_FPORT_TELEMETRY_INTERVAL,
  74 };
  75
  76 enum {
  77     DEBUG_FPORT_NO_ERROR = 0,
  78     DEBUG_FPORT_ERROR_TIMEOUT,
  79     DEBUG_FPORT_ERROR_OVERSIZE,
  80     DEBUG_FPORT_ERROR_SIZE,
  81     DEBUG_FPORT_ERROR_CHECKSUM,
  82     DEBUG_FPORT_ERROR_TYPE,
  83     DEBUG_FPORT_ERROR_TYPE_SIZE,
  84 };
  85
  86 enum {
  87     FPORT_FRAME_TYPE_CONTROL = 0x00,
  88     FPORT_FRAME_TYPE_TELEMETRY_REQUEST = 0x01,
  89     FPORT_FRAME_TYPE_TELEMETRY_RESPONSE = 0x81,
  90
  91 };
  92
  93 enum {
  94     FPORT_FRAME_ID_NULL = 0x00,     // (master/slave)
  95     FPORT_FRAME_ID_DATA = 0x10,     // (master/slave)
  96     FPORT_FRAME_ID_READ = 0x30,     // (master)
  97     FPORT_FRAME_ID_WRITE = 0x31,    // (master)
  98     FPORT_FRAME_ID_RESPONSE = 0x32, // (slave)
  99 };
 100
 101 typedef struct fportControlData_s {
 102     sbusChannels_t channels;
 103     uint8_t rssi;
 104 } fportControlData_t;
 105
 106 typedef union fportData_s {
 107     fportControlData_t controlData;
 108     smartPortPayload_t telemetryData;
 109 } fportData_t;
 110
 111 typedef struct fportFrame_s {
 112     uint8_t type;
 113     fportData_t data;
 114 } fportFrame_t;
 115
 116 #ifdef USE_TELEMETRY_SMARTPORT
 117 static const smartPortPayload_t emptySmartPortFrame = { .frameId = 0, .valueId = 0, .data = 0 };
 118 #endif
 119
 120 #define FPORT_REQUEST_FRAME_LENGTH sizeof(fportFrame_t)
 121 #define FPORT_RESPONSE_FRAME_LENGTH (sizeof(uint8_t) + sizeof(smartPortPayload_t))
 122
 123 #define FPORT_FRAME_PAYLOAD_LENGTH_CONTROL (sizeof(uint8_t) + sizeof(fportControlData_t))
 124 #define FPORT_FRAME_PAYLOAD_LENGTH_TELEMETRY_REQUEST (sizeof(uint8_t) + sizeof(smartPortPayload_t))
 125
 126 #define NUM_RX_BUFFERS 3
 127 #define BUFFER_SIZE (FPORT_REQUEST_FRAME_LENGTH + 2 * sizeof(uint8_t))
 128
 129 typedef struct fportBuffer_s {
 130     uint8_t data[BUFFER_SIZE];
 131     uint8_t length;
 132     timeUs_t frameStartTimeUs;
 133 } fportBuffer_t;
 134
 135 static fportBuffer_t rxBuffer[NUM_RX_BUFFERS];
 136
 137 static volatile uint8_t rxBufferWriteIndex = 0;
 138 static volatile uint8_t rxBufferReadIndex = 0;
 139
 140 static volatile timeUs_t lastTelemetryFrameReceivedUs;
 141 static volatile bool clearToSend = false;
 142
 143 static volatile uint8_t framePosition = 0;
 144
 145 static smartPortPayload_t *mspPayload = NULL;
 146 static timeUs_t lastRcFrameReceivedMs = 0;
 147
 148 static serialPort_t *fportPort;
 149 #ifdef USE_TELEMETRY_SMARTPORT
 150 static bool telemetryEnabled = false;
 151 #endif
 152
 153 static void reportFrameError(uint8_t errorReason)
 154 {
 155     static volatile uint16_t frameErrors = 0;
 156
 157     frameErrors++;
 158
 159     DEBUG_SET(DEBUG_FPORT, DEBUG_FPORT_FRAME_ERRORS, frameErrors);
 160     DEBUG_SET(DEBUG_FPORT, DEBUG_FPORT_FRAME_LAST_ERROR, errorReason);
 161 }
 162
 163 // Receive ISR callback
 164 static void fportDataReceive(uint16_t c, void *data)
 165 {
 166     UNUSED(data);
 167
 168     static timeUs_t frameStartAt = 0;
 169     static bool escapedCharacter = false;
 170     static timeUs_t lastFrameReceivedUs = 0;
 171     static bool telemetryFrame = false;
 172
 173     const timeUs_t currentTimeUs = microsISR();
 174
 175     clearToSend = false;
 176
 177     if (framePosition > 1 && cmpTimeUs(currentTimeUs, frameStartAt) > FPORT_TIME_NEEDED_PER_FRAME_US + 500) {
 178         reportFrameError(DEBUG_FPORT_ERROR_TIMEOUT);
 179
 180         framePosition = 0;
 181      }
 182
 183     uint8_t val = (uint8_t)c;
 184
 185     if (val == FPORT_FRAME_MARKER) {
 186         if (framePosition > 1) {
 187             const uint8_t nextWriteIndex = (rxBufferWriteIndex + 1) % NUM_RX_BUFFERS;
 188             if (nextWriteIndex != rxBufferReadIndex) {
 189                 rxBuffer[rxBufferWriteIndex].length = framePosition - 1;
 190                 rxBufferWriteIndex = nextWriteIndex;
 191             }
 192
 193             if (telemetryFrame) {
 194                 clearToSend = true;
 195                 lastTelemetryFrameReceivedUs = currentTimeUs;
 196                 telemetryFrame = false;
 197             }
 198
 199             DEBUG_SET(DEBUG_FPORT, DEBUG_FPORT_FRAME_INTERVAL, currentTimeUs - lastFrameReceivedUs);
 200             lastFrameReceivedUs = currentTimeUs;
 201
 202             escapedCharacter = false;
 203         }
 204
 205         frameStartAt = currentTimeUs;
 206         framePosition = 1;
 207
 208         rxBuffer[rxBufferWriteIndex].frameStartTimeUs = currentTimeUs;
 209     } else if (framePosition > 0) {
 210         if (framePosition >= BUFFER_SIZE + 1) {
 211                 framePosition = 0;
 212
 213                 reportFrameError(DEBUG_FPORT_ERROR_OVERSIZE);
 214         } else {
 215             if (escapedCharacter) {
 216                 val = val ^ FPORT_ESCAPE_MASK;
 217                 escapedCharacter = false;
 218             } else if (val == FPORT_ESCAPE_CHAR) {
 219                 escapedCharacter = true;
 220
 221                 return;
 222             }
 223
 224             if (framePosition == 2 && val == FPORT_FRAME_TYPE_TELEMETRY_REQUEST) {
 225                 telemetryFrame = true;
 226             }
 227
 228             rxBuffer[rxBufferWriteIndex].data[framePosition - 1] = val;
 229             framePosition = framePosition + 1;
 230         }
 231     }
 232 }
 233
 234 #if defined(USE_TELEMETRY_SMARTPORT)
 235 static void smartPortWriteFrameFport(const smartPortPayload_t *payload)
 236 {
 237     framePosition = 0;
 238
 239     uint16_t checksum = 0;
 240     smartPortSendByte(FPORT_RESPONSE_FRAME_LENGTH, &checksum, fportPort);
 241     smartPortSendByte(FPORT_FRAME_TYPE_TELEMETRY_RESPONSE, &checksum, fportPort);
 242     smartPortWriteFrameSerial(payload, fportPort, checksum);
 243 }
 244 #endif
 245
 246 static uint8_t fportFrameStatus(rxRuntimeState_t *rxRuntimeState)
 247 {
 248     static bool hasTelemetryRequest = false;
 249
 250 #ifdef USE_TELEMETRY_SMARTPORT
 251     static smartPortPayload_t payloadBuffer;
 252     static bool rxDrivenFrameRate = false;
 253     static uint8_t consecutiveTelemetryFrameCount = 0;
 254 #endif
 255
 256     uint8_t result = RX_FRAME_PENDING;
 257
 258
 259     if (rxBufferReadIndex != rxBufferWriteIndex) {
 260         uint8_t bufferLength = rxBuffer[rxBufferReadIndex].length;
 261         uint8_t frameLength = rxBuffer[rxBufferReadIndex].data[0];
 262         if (frameLength != bufferLength - 2) {
 263             reportFrameError(DEBUG_FPORT_ERROR_SIZE);
 264         } else {
 265             if (!frskyCheckSumIsGood(&rxBuffer[rxBufferReadIndex].data[0], bufferLength)) {
 266                 reportFrameError(DEBUG_FPORT_ERROR_CHECKSUM);
 267             } else {
 268                 fportFrame_t *frame = (fportFrame_t *)&rxBuffer[rxBufferReadIndex].data[1];
 269
 270                 switch (frame->type) {
 271                 case FPORT_FRAME_TYPE_CONTROL:
 272                     if (frameLength != FPORT_FRAME_PAYLOAD_LENGTH_CONTROL) {
 273                         reportFrameError(DEBUG_FPORT_ERROR_TYPE_SIZE);
 274                     } else {
 275                         result = sbusChannelsDecode(rxRuntimeState, &frame->data.controlData.channels);
 276
 277                         setRssi(scaleRange(frame->data.controlData.rssi, 0, 100, 0, RSSI_MAX_VALUE), RSSI_SOURCE_RX_PROTOCOL);
 278
 279                         lastRcFrameReceivedMs = millis();
 280
 281                         if (!(result & (RX_FRAME_FAILSAFE | RX_FRAME_DROPPED))) {
 282                             rxRuntimeState->lastRcFrameTimeUs = rxBuffer[rxBufferReadIndex].frameStartTimeUs;
 283                         }
 284                     }
 285
 286                     break;
 287                 case FPORT_FRAME_TYPE_TELEMETRY_REQUEST:
 288                     if (frameLength != FPORT_FRAME_PAYLOAD_LENGTH_TELEMETRY_REQUEST) {
 289                         reportFrameError(DEBUG_FPORT_ERROR_TYPE_SIZE);
 290                     } else {
 291 #if defined(USE_TELEMETRY_SMARTPORT)
 292                         if (!telemetryEnabled) {
 293                             break;
 294                         }
 295
 296                         switch(frame->data.telemetryData.frameId) {
 297                         case FPORT_FRAME_ID_DATA:
 298                             if (!rxDrivenFrameRate) {
 299                                 rxDrivenFrameRate = true;
 300                             }
 301
 302                             hasTelemetryRequest = true;
 303
 304                             break;
 305                         case FPORT_FRAME_ID_NULL:
 306                             if (!rxDrivenFrameRate) {
 307                                 if (consecutiveTelemetryFrameCount >= FPORT_TELEMETRY_MAX_CONSECUTIVE_TELEMETRY_FRAMES && !(mspPayload && smartPortPayloadContainsMSP(mspPayload))) {
 308                                     consecutiveTelemetryFrameCount = 0;
 309                                 } else {
 310                                     hasTelemetryRequest = true;
 311
 312                                     consecutiveTelemetryFrameCount++;
 313                                 }
 314                             }
 315
 316                             break;
 317                         case FPORT_FRAME_ID_READ:
 318                         case FPORT_FRAME_ID_WRITE: // never used
 319                             memcpy(&payloadBuffer, &frame->data.telemetryData, sizeof(smartPortPayload_t));
 320                             mspPayload = &payloadBuffer;
 321
 322                             break;
 323                         default:
 324
 325                            break;
 326                         }
 327 #endif
 328                     }
 329
 330                     break;
 331                 default:
 332                     reportFrameError(DEBUG_FPORT_ERROR_TYPE);
 333
 334                     break;
 335                 }
 336             }
 337
 338         }
 339
 340         rxBufferReadIndex = (rxBufferReadIndex + 1) % NUM_RX_BUFFERS;
 341     }
 342
 343     if ((mspPayload || hasTelemetryRequest) && cmpTimeUs(micros(), lastTelemetryFrameReceivedUs) >= FPORT_MIN_TELEMETRY_RESPONSE_DELAY_US) {
 344         hasTelemetryRequest = false;
 345
 346         result = (result & ~RX_FRAME_PENDING) | RX_FRAME_PROCESSING_REQUIRED;
 347     }
 348
 349     if (lastRcFrameReceivedMs && ((millis() - lastRcFrameReceivedMs) > FPORT_MAX_TELEMETRY_AGE_MS)) {
 350         setRssiDirect(0, RSSI_SOURCE_RX_PROTOCOL);
 351         lastRcFrameReceivedMs = 0;
 352     }
 353
 354     return result;
 355 }
 356
 357 static bool fportProcessFrame(const rxRuntimeState_t *rxRuntimeState)
 358 {
 359     UNUSED(rxRuntimeState);
 360
 361 #if defined(USE_TELEMETRY_SMARTPORT)
 362     static timeUs_t lastTelemetryFrameSentUs;
 363
 364     timeUs_t currentTimeUs = micros();
 365     if (cmpTimeUs(currentTimeUs, lastTelemetryFrameReceivedUs) > FPORT_MAX_TELEMETRY_RESPONSE_DELAY_US) {
 366        clearToSend = false;
 367     }
 368
 369     if (clearToSend) {
 370         processSmartPortTelemetry(mspPayload, &clearToSend, NULL);
 371
 372         if (clearToSend) {
 373             smartPortWriteFrameFport(&emptySmartPortFrame);
 374
 375             clearToSend = false;
 376         }
 377
 378         DEBUG_SET(DEBUG_FPORT, DEBUG_FPORT_TELEMETRY_INTERVAL, currentTimeUs - lastTelemetryFrameSentUs);
 379         lastTelemetryFrameSentUs = currentTimeUs;
 380     }
 381
 382     mspPayload = NULL;
 383 #endif
 384
 385     return true;
 386 }
 387
 388 bool fportRxInit(const rxConfig_t *rxConfig, rxRuntimeState_t *rxRuntimeState)
 389 {
 390     static uint16_t sbusChannelData[SBUS_MAX_CHANNEL];
 391     rxRuntimeState->channelData = sbusChannelData;
 392     sbusChannelsInit(rxConfig, rxRuntimeState);
 393
 394     rxRuntimeState->channelCount = SBUS_MAX_CHANNEL;
 395     rxRuntimeState->rcFrameStatusFn = fportFrameStatus;
 396     rxRuntimeState->rcProcessFrameFn = fportProcessFrame;
 397     rxRuntimeState->rcFrameTimeUsFn = rxFrameTimeUs;
 398
 399     const serialPortConfig_t *portConfig = findSerialPortConfig(FUNCTION_RX_SERIAL);
 400     if (!portConfig) {
 401         return false;
 402     }
 403
 404     fportPort = openSerialPort(portConfig->identifier,
 405         FUNCTION_RX_SERIAL,
 406         fportDataReceive,
 407         NULL,
 408         FPORT_BAUDRATE,
 409         MODE_RXTX,
 410         FPORT_PORT_OPTIONS | (rxConfig->serialrx_inverted ? SERIAL_INVERTED : 0) | (rxConfig->halfDuplex ? SERIAL_BIDIR : 0)
 411     );
 412
 413     if (fportPort) {
 414 #if defined(USE_TELEMETRY_SMARTPORT)
 415         telemetryEnabled = initSmartPortTelemetryExternal(smartPortWriteFrameFport);
 416 #endif
 417
 418         if (rssiSource == RSSI_SOURCE_NONE) {
 419             rssiSource = RSSI_SOURCE_RX_PROTOCOL;
 420         }
 421     }
 422
 423     return fportPort != NULL;
 424 }
 425 #endif