// // Created by MightyPork on 2018/03/31. // #include #include "debug.h" #include "msg_queue.h" #include "gex_gateway.h" #include "main.h" #include "minmax.h" #include "payload_parser.h" // USB RX enum URX_STATE { URXS_IDLE = 0, URXS_MSG4SLAVE = 1, }; #define MAX_FRAME_LEN 512 static enum URX_STATE urx_state = URXS_IDLE; static uint32_t msg4slave_len = 0; // total len to be collected static uint32_t msg4slave_already = 0; // already collected len static uint8_t msg4slave[MAX_FRAME_LEN]; // equal buffer size in GEX static uint8_t msg4slave_addr = 0; static uint8_t msg4slave_cksum = 0; #define MAGIC_GW_COMMAND 0x47U // 'G' enum GW_CMD { CMD_GET_ID = 'i', // 105 CMD_MSG4SLAVE = 'm', // 109 }; void respond_gw_id() {} // TODO impl void start_slave_cmd(uint8_t slave_addr, uint16_t frame_len, uint8_t cksum) { msg4slave_len = frame_len; msg4slave_already = 0; msg4slave_addr = slave_addr; msg4slave_cksum = cksum; } /** called from the main loop, periodically */ void gw_process(void) { static uint8_t buffer[MQ_SLOT_LEN]; while (mq_read(&usb_rxq, buffer)) { // greedy - handle as many as possible dbg("Handling frame."); if (urx_state == URXS_IDLE) { PayloadParser pp = pp_start(buffer, MQ_SLOT_LEN, NULL); // handle binary commands for the gateway // magic twice, one inverted - denotes a gateway command uint16_t magic1 = pp_u8(&pp); uint16_t magic2 = pp_u8(&pp); if (magic1 == MAGIC_GW_COMMAND && magic2 == (0xFFU & (~MAGIC_GW_COMMAND))) { // third byte is the command code switch (pp_u8(&pp)) { case CMD_GET_ID: respond_gw_id(); break; case CMD_MSG4SLAVE:; uint8_t slave_addr = pp_u8(&pp); uint16_t frame_len = pp_u16(&pp); uint8_t cksum = pp_u8(&pp); if (frame_len == 0 || frame_len > MAX_FRAME_LEN) { dbg("Frame too big!"); break; } start_slave_cmd(slave_addr, frame_len, cksum); dbg("Collecting frame for slave %02x: %d bytes", (int)slave_addr, (int)frame_len); urx_state = URXS_MSG4SLAVE; break; default: dbg("Bad cmd"); } } else { // Bad frame?? dbg("Bad USB frame, starts %x,%x", buffer[0],buffer[1]); } } else if (urx_state == URXS_MSG4SLAVE) { uint32_t wanted = MIN(msg4slave_len-msg4slave_already, MQ_SLOT_LEN); memcpy(&msg4slave[msg4slave_already], buffer, wanted); msg4slave_already += wanted; if (wanted < MQ_SLOT_LEN) { // this was the end uint8_t ck = 0; for (int i = 0; i < msg4slave_len; i++) { ck ^= msg4slave[i]; } ck = ~ck; if (ck != msg4slave_cksum) { dbg("Checksum mismatch!"); } else { dbg("Verified, sending a %d B frame to slave.", (int) msg4slave_len); // TODO send to slave } urx_state = URXS_IDLE; } } } }