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betaflight/src/main/msp/msp_serial.c
2017-05-26 14:03:28 +01:00

326 lines
9.8 KiB
C

/*
* This file is part of Cleanflight.
*
* Cleanflight is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Cleanflight is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Cleanflight. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdbool.h>
#include <stdint.h>
#include <string.h>
#include "platform.h"
#include "common/streambuf.h"
#include "common/utils.h"
#include "build/debug.h"
#include "io/serial.h"
#include "msp/msp.h"
#include "msp/msp_serial.h"
static mspPort_t mspPorts[MAX_MSP_PORT_COUNT];
static void resetMspPort(mspPort_t *mspPortToReset, serialPort_t *serialPort)
{
memset(mspPortToReset, 0, sizeof(mspPort_t));
mspPortToReset->port = serialPort;
}
void mspSerialAllocatePorts(void)
{
uint8_t portIndex = 0;
serialPortConfig_t *portConfig = findSerialPortConfig(FUNCTION_MSP);
while (portConfig && portIndex < MAX_MSP_PORT_COUNT) {
mspPort_t *mspPort = &mspPorts[portIndex];
if (mspPort->port) {
portIndex++;
continue;
}
serialPort_t *serialPort = openSerialPort(portConfig->identifier, FUNCTION_MSP, NULL, baudRates[portConfig->msp_baudrateIndex], MODE_RXTX, SERIAL_NOT_INVERTED);
if (serialPort) {
resetMspPort(mspPort, serialPort);
portIndex++;
}
portConfig = findNextSerialPortConfig(FUNCTION_MSP);
}
}
void mspSerialReleasePortIfAllocated(serialPort_t *serialPort)
{
for (uint8_t portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
mspPort_t *candidateMspPort = &mspPorts[portIndex];
if (candidateMspPort->port == serialPort) {
closeSerialPort(serialPort);
memset(candidateMspPort, 0, sizeof(mspPort_t));
}
}
}
static bool mspSerialProcessReceivedData(mspPort_t *mspPort, uint8_t c)
{
if (mspPort->c_state == MSP_IDLE) {
if (c == '$') {
mspPort->c_state = MSP_HEADER_START;
} else {
return false;
}
} else if (mspPort->c_state == MSP_HEADER_START) {
mspPort->c_state = (c == 'M') ? MSP_HEADER_M : MSP_IDLE;
} else if (mspPort->c_state == MSP_HEADER_M) {
mspPort->c_state = MSP_IDLE;
switch(c) {
case '<': // COMMAND
mspPort->packetType = MSP_PACKET_COMMAND;
mspPort->c_state = MSP_HEADER_ARROW;
break;
case '>': // REPLY
mspPort->packetType = MSP_PACKET_REPLY;
mspPort->c_state = MSP_HEADER_ARROW;
break;
default:
break;
}
} else if (mspPort->c_state == MSP_HEADER_ARROW) {
if (c > MSP_PORT_INBUF_SIZE) {
mspPort->c_state = MSP_IDLE;
} else {
mspPort->dataSize = c;
mspPort->offset = 0;
mspPort->checksum = 0;
mspPort->checksum ^= c;
mspPort->c_state = MSP_HEADER_SIZE;
}
} else if (mspPort->c_state == MSP_HEADER_SIZE) {
mspPort->cmdMSP = c;
mspPort->checksum ^= c;
mspPort->c_state = MSP_HEADER_CMD;
} else if (mspPort->c_state == MSP_HEADER_CMD && mspPort->offset < mspPort->dataSize) {
mspPort->checksum ^= c;
mspPort->inBuf[mspPort->offset++] = c;
} else if (mspPort->c_state == MSP_HEADER_CMD && mspPort->offset >= mspPort->dataSize) {
if (mspPort->checksum == c) {
mspPort->c_state = MSP_COMMAND_RECEIVED;
} else {
mspPort->c_state = MSP_IDLE;
}
}
return true;
}
static uint8_t mspSerialChecksumBuf(uint8_t checksum, const uint8_t *data, int len)
{
while (len-- > 0) {
checksum ^= *data++;
}
return checksum;
}
#define JUMBO_FRAME_SIZE_LIMIT 255
static int mspSerialEncode(mspPort_t *msp, mspPacket_t *packet)
{
serialBeginWrite(msp->port);
const int len = sbufBytesRemaining(&packet->buf);
const int mspLen = len < JUMBO_FRAME_SIZE_LIMIT ? len : JUMBO_FRAME_SIZE_LIMIT;
uint8_t hdr[8] = {
'$',
'M',
packet->result == MSP_RESULT_ERROR ? '!' : packet->direction == MSP_DIRECTION_REPLY ? '>' : '<',
mspLen,
packet->cmd
};
int hdrLen = 5;
#define CHECKSUM_STARTPOS 3 // checksum starts from mspLen field
if (len >= JUMBO_FRAME_SIZE_LIMIT) {
hdrLen += 2;
hdr[5] = len & 0xff;
hdr[6] = (len >> 8) & 0xff;
}
serialWriteBuf(msp->port, hdr, hdrLen);
uint8_t checksum = mspSerialChecksumBuf(0, hdr + CHECKSUM_STARTPOS, hdrLen - CHECKSUM_STARTPOS);
if (len > 0) {
serialWriteBuf(msp->port, sbufPtr(&packet->buf), len);
checksum = mspSerialChecksumBuf(checksum, sbufPtr(&packet->buf), len);
}
serialWriteBuf(msp->port, &checksum, 1);
serialEndWrite(msp->port);
return sizeof(hdr) + len + 1; // header, data, and checksum
}
static mspPostProcessFnPtr mspSerialProcessReceivedCommand(mspPort_t *msp, mspProcessCommandFnPtr mspProcessCommandFn)
{
static uint8_t outBuf[MSP_PORT_OUTBUF_SIZE];
mspPacket_t reply = {
.buf = { .ptr = outBuf, .end = ARRAYEND(outBuf), },
.cmd = -1,
.result = 0,
.direction = MSP_DIRECTION_REPLY,
};
uint8_t *outBufHead = reply.buf.ptr;
mspPacket_t command = {
.buf = { .ptr = msp->inBuf, .end = msp->inBuf + msp->dataSize, },
.cmd = msp->cmdMSP,
.result = 0,
.direction = MSP_DIRECTION_REQUEST,
};
mspPostProcessFnPtr mspPostProcessFn = NULL;
const mspResult_e status = mspProcessCommandFn(&command, &reply, &mspPostProcessFn);
if (status != MSP_RESULT_NO_REPLY) {
sbufSwitchToReader(&reply.buf, outBufHead); // change streambuf direction
mspSerialEncode(msp, &reply);
}
return mspPostProcessFn;
}
static void mspSerialProcessReceivedReply(mspPort_t *msp, mspProcessReplyFnPtr mspProcessReplyFn)
{
mspPacket_t reply = {
.buf = {
.ptr = msp->inBuf,
.end = msp->inBuf + msp->dataSize,
},
.cmd = msp->cmdMSP,
.result = 0,
};
mspProcessReplyFn(&reply);
msp->c_state = MSP_IDLE;
}
/*
* Process MSP commands from serial ports configured as MSP ports.
*
* Called periodically by the scheduler.
*/
void mspSerialProcess(mspEvaluateNonMspData_e evaluateNonMspData, mspProcessCommandFnPtr mspProcessCommandFn, mspProcessReplyFnPtr mspProcessReplyFn)
{
for (uint8_t portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
mspPort_t * const mspPort = &mspPorts[portIndex];
if (!mspPort->port) {
continue;
}
mspPostProcessFnPtr mspPostProcessFn = NULL;
while (serialRxBytesWaiting(mspPort->port)) {
const uint8_t c = serialRead(mspPort->port);
const bool consumed = mspSerialProcessReceivedData(mspPort, c);
if (!consumed && evaluateNonMspData == MSP_EVALUATE_NON_MSP_DATA) {
serialEvaluateNonMspData(mspPort->port, c);
}
if (mspPort->c_state == MSP_COMMAND_RECEIVED) {
if (mspPort->packetType == MSP_PACKET_COMMAND) {
mspPostProcessFn = mspSerialProcessReceivedCommand(mspPort, mspProcessCommandFn);
} else if (mspPort->packetType == MSP_PACKET_REPLY) {
mspSerialProcessReceivedReply(mspPort, mspProcessReplyFn);
}
mspPort->c_state = MSP_IDLE;
break; // process one command at a time so as not to block.
}
}
if (mspPostProcessFn) {
waitForSerialPortToFinishTransmitting(mspPort->port);
mspPostProcessFn(mspPort->port);
}
}
}
bool mspSerialWaiting(void)
{
for (uint8_t portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
mspPort_t * const mspPort = &mspPorts[portIndex];
if (!mspPort->port) {
continue;
}
if (serialRxBytesWaiting(mspPort->port)) {
return true;
}
}
return false;
}
void mspSerialInit(void)
{
memset(mspPorts, 0, sizeof(mspPorts));
mspSerialAllocatePorts();
}
int mspSerialPush(uint8_t cmd, uint8_t *data, int datalen, mspDirection_e direction)
{
int ret = 0;
for (int portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
mspPort_t * const mspPort = &mspPorts[portIndex];
if (!mspPort->port) {
continue;
}
// XXX Kludge!!! Avoid zombie VCP port (avoid VCP entirely for now)
if (mspPort->port->identifier == SERIAL_PORT_USB_VCP) {
continue;
}
mspPacket_t push = {
.buf = { .ptr = data, .end = data + datalen, },
.cmd = cmd,
.result = 0,
.direction = direction,
};
ret = mspSerialEncode(mspPort, &push);
}
return ret; // return the number of bytes written
}
uint32_t mspSerialTxBytesFree()
{
uint32_t ret = UINT32_MAX;
for (int portIndex = 0; portIndex < MAX_MSP_PORT_COUNT; portIndex++) {
mspPort_t * const mspPort = &mspPorts[portIndex];
if (!mspPort->port) {
continue;
}
// XXX Kludge!!! Avoid zombie VCP port (avoid VCP entirely for now)
if (mspPort->port->identifier == SERIAL_PORT_USB_VCP) {
continue;
}
const uint32_t bytesFree = serialTxBytesFree(mspPort->port);
if (bytesFree < ret) {
ret = bytesFree;
}
}
return ret;
}