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Diffstat (limited to 'quantum/serial_link/protocol/byte_stuffer.c')
| -rw-r--r-- | quantum/serial_link/protocol/byte_stuffer.c | 135 |
1 files changed, 0 insertions, 135 deletions
diff --git a/quantum/serial_link/protocol/byte_stuffer.c b/quantum/serial_link/protocol/byte_stuffer.c deleted file mode 100644 index d3a91d8286..0000000000 --- a/quantum/serial_link/protocol/byte_stuffer.c +++ /dev/null @@ -1,135 +0,0 @@ -/* -The MIT License (MIT) - -Copyright (c) 2016 Fred Sundvik - -Permission is hereby granted, free of charge, to any person obtaining a copy -of this software and associated documentation files (the "Software"), to deal -in the Software without restriction, including without limitation the rights -to use, copy, modify, merge, publish, distribute, sublicense, and/or sell -copies of the Software, and to permit persons to whom the Software is -furnished to do so, subject to the following conditions: - -The above copyright notice and this permission notice shall be included in all -copies or substantial portions of the Software. - -THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR -IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, -FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE -AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER -LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, -OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE -SOFTWARE. -*/ - -#include "serial_link/protocol/byte_stuffer.h" -#include "serial_link/protocol/frame_validator.h" -#include "serial_link/protocol/physical.h" -#include <stdbool.h> - -// This implements the "Consistent overhead byte stuffing protocol" -// https://en.wikipedia.org/wiki/Consistent_Overhead_Byte_Stuffing -// http://www.stuartcheshire.org/papers/COBSforToN.pdf - -typedef struct byte_stuffer_state { - uint16_t next_zero; - uint16_t data_pos; - bool long_frame; - uint8_t data[MAX_FRAME_SIZE]; -} byte_stuffer_state_t; - -static byte_stuffer_state_t states[NUM_LINKS]; - -void init_byte_stuffer_state(byte_stuffer_state_t* state) { - state->next_zero = 0; - state->data_pos = 0; - state->long_frame = false; -} - -void init_byte_stuffer(void) { - int i; - for (i = 0; i < NUM_LINKS; i++) { - init_byte_stuffer_state(&states[i]); - } -} - -void byte_stuffer_recv_byte(uint8_t link, uint8_t data) { - byte_stuffer_state_t* state = &states[link]; - // Start of a new frame - if (state->next_zero == 0) { - state->next_zero = data; - state->long_frame = data == 0xFF; - state->data_pos = 0; - return; - } - - state->next_zero--; - if (data == 0) { - if (state->next_zero == 0) { - // The frame is completed - if (state->data_pos > 0) { - validator_recv_frame(link, state->data, state->data_pos); - } - } else { - // The frame is invalid, so reset - init_byte_stuffer_state(state); - } - } else { - if (state->data_pos == MAX_FRAME_SIZE) { - // We exceeded our maximum frame size - // therefore there's nothing else to do than reset to a new frame - state->next_zero = data; - state->long_frame = data == 0xFF; - state->data_pos = 0; - } else if (state->next_zero == 0) { - if (state->long_frame) { - // This is part of a long frame, so continue - state->next_zero = data; - state->long_frame = data == 0xFF; - } else { - // Special case for zeroes - state->next_zero = data; - state->data[state->data_pos++] = 0; - } - } else { - state->data[state->data_pos++] = data; - } - } -} - -static void send_block(uint8_t link, uint8_t* start, uint8_t* end, uint8_t num_non_zero) { - send_data(link, &num_non_zero, 1); - if (end > start) { - send_data(link, start, end - start); - } -} - -void byte_stuffer_send_frame(uint8_t link, uint8_t* data, uint16_t size) { - const uint8_t zero = 0; - if (size > 0) { - uint16_t num_non_zero = 1; - uint8_t* end = data + size; - uint8_t* start = data; - while (data < end) { - if (num_non_zero == 0xFF) { - // There's more data after big non-zero block - // So send it, and start a new block - send_block(link, start, data, num_non_zero); - start = data; - num_non_zero = 1; - } else { - if (*data == 0) { - // A zero encountered, so send the block - send_block(link, start, data, num_non_zero); - start = data + 1; - num_non_zero = 1; - } else { - num_non_zero++; - } - ++data; - } - } - send_block(link, start, data, num_non_zero); - send_data(link, &zero, 1); - } -} |