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red_rs485_extension.c
1221 lines (962 loc) · 38.4 KB
/
red_rs485_extension.c
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/*
* brickd
* Copyright (C) 2014, 2017 Ishraq Ibne Ashraf <ishraq@tinkerforge.com>
* Copyright (C) 2014, 2018 Olaf Lüke <olaf@tinkerforge.com>
* Copyright (C) 2014-2019 Matthias Bolte <matthias@tinkerforge.com>
*
* red_rs485_extension.c: RS485 extension support for RED Brick
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <errno.h>
#include <stdbool.h>
#include <stdint.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <linux/types.h>
#include <linux/serial.h>
#include <sys/eventfd.h>
#include <sys/timerfd.h>
#include <sys/ioctl.h>
#include <time.h>
#include <termios.h>
#include <daemonlib/base58.h>
#include <daemonlib/config.h>
#include <daemonlib/event.h>
#include <daemonlib/log.h>
#include <daemonlib/packet.h>
#include <daemonlib/pipe.h>
#include <daemonlib/gpio_red.h>
#include <daemonlib/red_i2c_eeprom.h>
#include <daemonlib/threads.h>
#include <daemonlib/timer.h>
#include <daemonlib/conf_file.h>
#include "red_rs485_extension.h"
#include "hardware.h"
#include "network.h"
#include "stack.h"
static LogSource _log_source = LOG_SOURCE_INITIALIZER;
#define CRC_ERROR_COUNT_UPDATE_INTERVAL 4000000 // 4 seconds in microseconds
#define RS485_EXTENSION_CRC_ERROR_COUNT_COMMENT "# This file is written by brickd's RS485 stack."
#define RS485_EXTENSION_CRC_ERROR_COUNT_FILE_PATH "/tmp/extension_rs485_crc_error_count.conf"
static ConfFile crc_error_count_file;
static uint64_t crc_error_count_value = 0;
static Timer crc_error_count_update_timer;
#define RS485_EXTENSION_FUNCTION_CODE 100 // Custom modbus function code
// Serial interface config stuffs
#define RECEIVE_BUFFER_SIZE 1024
#if BRICKD_WITH_RED_BRICK == 9
#define RS485_EXTENSION_SERIAL_DEVICE "/dev/ttyS0"
#else
#define RS485_EXTENSION_SERIAL_DEVICE "/dev/ttyS3"
#endif
// Time related constants
static uint64_t TIMEOUT = 0;
// delay between polls in nanoseconds. configurable with brickd.conf option poll_delay.rs485 in microseconds
static uint64_t MASTER_POLL_SLAVE_INTERVAL = 40000000;
static uint32_t TIMEOUT_BYTES = 86;
static uint64_t last_timer_enable_at_us = 0;
static uint64_t time_passed_from_last_timer_enable = 0;
// Frame related constants
#define RS485_FRAME_HEADER_LENGTH 3
#define RS485_FRAME_FOOTER_LENGTH 2
#define RS485_FRAME_TRIES_DATA 10
#define RS485_FRAME_TRIES_EMPTY 1
#define RS485_FRAME_OVERHEAD RS485_FRAME_HEADER_LENGTH + RS485_FRAME_FOOTER_LENGTH
#define RS485_FRAME_MAX_CONTENT_DUMP_LENGTH (((int)sizeof(Packet) + RS485_FRAME_OVERHEAD) * 3 + 1)
// Table of CRC values for high-order byte
static const uint8_t table_crc_hi[] = {
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40,
0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1,
0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
0x80, 0x41, 0x00, 0xC1, 0x81, 0x40
};
// Table of CRC values for low-order byte
static const uint8_t table_crc_lo[] = {
0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06,
0x07, 0xC7, 0x05, 0xC5, 0xC4, 0x04, 0xCC, 0x0C, 0x0D, 0xCD,
0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09,
0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A,
0x1E, 0xDE, 0xDF, 0x1F, 0xDD, 0x1D, 0x1C, 0xDC, 0x14, 0xD4,
0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3,
0xF2, 0x32, 0x36, 0xF6, 0xF7, 0x37, 0xF5, 0x35, 0x34, 0xF4,
0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A,
0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29,
0xEB, 0x2B, 0x2A, 0xEA, 0xEE, 0x2E, 0x2F, 0xEF, 0x2D, 0xED,
0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60,
0x61, 0xA1, 0x63, 0xA3, 0xA2, 0x62, 0x66, 0xA6, 0xA7, 0x67,
0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F,
0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68,
0x78, 0xB8, 0xB9, 0x79, 0xBB, 0x7B, 0x7A, 0xBA, 0xBE, 0x7E,
0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71,
0x70, 0xB0, 0x50, 0x90, 0x91, 0x51, 0x93, 0x53, 0x52, 0x92,
0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C,
0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B,
0x99, 0x59, 0x58, 0x98, 0x88, 0x48, 0x49, 0x89, 0x4B, 0x8B,
0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42,
0x43, 0x83, 0x41, 0x81, 0x80, 0x40
};
// Data structure definitions
typedef struct {
Packet packet;
uint8_t tries_left;
} RS485ExtensionPacket;
typedef struct {
uint8_t address;
uint8_t sequence;
Queue packet_queue;
} RS485Slave;
typedef struct {
Stack base;
RS485Slave slaves[EXTENSION_RS485_SLAVES_MAX];
int slave_num;
uint32_t baudrate;
uint8_t parity;
uint8_t stopbits;
uint32_t address;
} RS485Extension;
static RS485Extension _red_rs485_extension;
static char packet_signature[PACKET_MAX_SIGNATURE_LENGTH] = {0};
static int _red_rs485_serial_fd = -1; // Serial interface file descriptor
// Variables tracking current states
static char current_request_as_byte_array[sizeof(Packet) + RS485_FRAME_OVERHEAD] = {0};
static int master_current_slave_to_process = -1; // Only used used by master
// Receive buffer
#include <daemonlib/packed_begin.h>
static union {
struct {
struct {
uint8_t address;
uint8_t function_code;
uint8_t sequence_number;
} ATTRIBUTE_PACKED frame;
Packet packet;
} ATTRIBUTE_PACKED;
uint8_t buffer[RECEIVE_BUFFER_SIZE];
} ATTRIBUTE_PACKED _receive;
#include <daemonlib/packed_end.h>
static int _receive_buffer_used = 0;
// Events
static int _master_timer_event = 0;
// Timers
static struct itimerspec master_timer;
// Used as boolean
static bool _initialized = false;
static uint8_t sent_ack_of_data_packet = 0;
static uint8_t send_verify_flag = 0;
static bool master_poll_interval = false;
// RX GPIO pin definitions
static GPIOREDPin _rx_pin; // Active low
// Function prototypes
uint16_t crc16(uint8_t*, uint16_t);
int serial_interface_init(const char*);
void verify_buffer(void);
void send_packet(void);
void init_rxe_pin_state(int);
void serial_data_available_handler(void*);
void master_poll_slave(void);
void master_timeout_handler(void*);
int red_rs485_extension_dispatch_to_rs485(Stack*, Packet*, Recipient*);
void disable_master_timer(void);
void pop_packet_from_slave_queue(void);
bool is_current_request_empty(void);
void seq_pop_poll(void);
void arm_master_poll_slave_interval_timer(void);
bool init_crc_error_count_to_fs(void);
static void update_crc_error_count_to_fs(void *opaque);
// CRC16 function
uint16_t crc16(uint8_t *buffer, uint16_t buffer_length) {
uint8_t crc_hi = 0xFF; // High CRC byte initialized
uint8_t crc_lo = 0xFF; // Low CRC byte initialized
int i;
// Pass through message buffer
while (buffer_length--) {
i = crc_hi ^ *buffer++; // Calculate the CRC
crc_hi = crc_lo ^ table_crc_hi[i];
crc_lo = table_crc_lo[i];
}
return (crc_hi << 8 | crc_lo);
}
// Function for initializing the serial interface
int serial_interface_init(const char *serial_interface) {
// Device file opening flags
int flags = O_RDWR | O_NOCTTY | O_NDELAY | O_EXCL | ASYNC_SPD_CUST | ASYNC_LOW_LATENCY;
// Opening device file
if ((_red_rs485_serial_fd = open(serial_interface, flags)) < 0) {
log_error("Serial device open failed");
return -1;
}
// Serial interface setup
// Serial interface config struct
struct termios serial_interface_config;
struct serial_struct serial_config;
tcgetattr(_red_rs485_serial_fd, &(serial_interface_config));
memset(&serial_interface_config, 0, sizeof(serial_interface_config));
memset(&serial_config, 0, sizeof(serial_config));
// Control options
serial_interface_config.c_cflag |= (CREAD | CLOCAL);
serial_interface_config.c_cflag &= ~CSIZE;
serial_interface_config.c_cflag |= CS8; // Setting data bits
if (_red_rs485_extension.stopbits == 1) {
serial_interface_config.c_cflag &= ~CSTOPB; // Setting one stop bits
} else if (_red_rs485_extension.stopbits == 2) {
serial_interface_config.c_cflag |= CSTOPB; // Setting two stop bits
} else {
robust_close(_red_rs485_serial_fd);
log_error("Error in serial stop bits config");
return -1;
}
if (_red_rs485_extension.parity == EXTENSION_RS485_PARITY_NONE) {
serial_interface_config.c_cflag &= ~PARENB; // parity disabled
} else if (_red_rs485_extension.parity == EXTENSION_RS485_PARITY_EVEN) {
/* Even */
serial_interface_config.c_cflag |= PARENB;
serial_interface_config.c_cflag &= ~PARODD;
} else if (_red_rs485_extension.parity == EXTENSION_RS485_PARITY_ODD) {
/* Odd */
serial_interface_config.c_cflag |= PARENB;
serial_interface_config.c_cflag |= PARODD;
} else {
robust_close(_red_rs485_serial_fd);
log_error("Error in serial parity config");
return -1;
}
// Setting the baudrate
serial_config.reserved_char[0] = 0;
if (ioctl(_red_rs485_serial_fd, TIOCGSERIAL, &serial_config) < 0) {
log_error("Error setting RS485 serial baudrate");
return -1;
}
serial_config.flags &= ~ASYNC_SPD_MASK;
serial_config.flags |= ASYNC_SPD_CUST;
serial_config.custom_divisor = (serial_config.baud_base + (_red_rs485_extension.baudrate / 2)) /
_red_rs485_extension.baudrate;
if (serial_config.custom_divisor < 1) {
serial_config.custom_divisor = 1;
}
if (ioctl(_red_rs485_serial_fd, TIOCSSERIAL, &serial_config) < 0) {
log_error("Error setting serial baudrate");
return -1;
}
log_info("Baudrate configured = %d, Effective baudrate = %f",
_red_rs485_extension.baudrate,
(float)serial_config.baud_base / serial_config.custom_divisor);
cfsetispeed(&serial_interface_config, B38400);
cfsetospeed(&serial_interface_config, B38400);
// Line options
serial_interface_config.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // Raw input
// Input options
if (_red_rs485_extension.parity == EXTENSION_RS485_PARITY_NONE) {
serial_interface_config.c_iflag &= ~INPCK; // Input check disabled
} else {
serial_interface_config.c_iflag |= INPCK; // Input check enabled
}
serial_interface_config.c_iflag &= ~(IXON | IXOFF | IXANY); // Software iflow control is disabled
// Output options
serial_interface_config.c_oflag &= ~OPOST;
// Control character options
serial_interface_config.c_cc[VMIN] = 0;
serial_interface_config.c_cc[VTIME] = 0;
tcsetattr(_red_rs485_serial_fd, TCSANOW, &serial_interface_config);
// Flushing the buffer
tcflush(_red_rs485_serial_fd, TCIOFLUSH);
log_info("Serial interface initialized");
return 0;
}
char *frame_get_content_dump(char *content_dump, uint8_t *frame, int length) {
int i;
if (length > (int)sizeof(Packet) + RS485_FRAME_OVERHEAD) {
length = (int)sizeof(Packet) + RS485_FRAME_OVERHEAD;
}
for (i = 0; i < length; ++i) {
snprintf(content_dump + i * 3, 4, "%02X ", frame[i]);
}
if (length > 0) {
content_dump[length * 3 - 1] = '\0';
} else {
content_dump[0] = '\0';
}
return content_dump;
}
// Verify packet
void verify_buffer(void) {
int frame_length;
uint16_t crc16_calculated;
uint16_t crc16_on_packet;
RS485ExtensionPacket* queue_packet;
int i;
char frame_content_dump[RS485_FRAME_MAX_CONTENT_DUMP_LENGTH];
char base58[BASE58_MAX_LENGTH];
// Check if length byte is available
if (_receive_buffer_used < 8) {
return;
}
// Calculate packet end index
frame_length = RS485_FRAME_HEADER_LENGTH + _receive.packet.header.length + RS485_FRAME_FOOTER_LENGTH;
// Check if complete packet is available
if (_receive_buffer_used < frame_length) {
return;
}
// If send verify flag was set
if (send_verify_flag) {
for (i = 0; i < frame_length; i++) {
if (_receive.buffer[i] != current_request_as_byte_array[i]) {
// Move on to next slave
disable_master_timer();
log_error("Send verification failed (offset: %d, actual: %u != expected: %u)",
i, _receive.buffer[i], current_request_as_byte_array[i]);
seq_pop_poll();
return;
}
}
// Send verify successful. Reset flag
send_verify_flag = 0;
log_packet_debug("Send verification done");
if (sent_ack_of_data_packet > 0) {
// Request processing done. Move on to next slave
disable_master_timer();
if (sent_ack_of_data_packet == 1) {
log_packet_debug("Processed current request");
++_red_rs485_extension.slaves[master_current_slave_to_process].sequence;
queue_pop(&_red_rs485_extension.slaves[master_current_slave_to_process].packet_queue, NULL);
}
// Poll next slave after the configured timeout
arm_master_poll_slave_interval_timer();
return;
} else if (_receive_buffer_used == frame_length) {
// Everything OK. Wait for response now
log_packet_debug("No more Data. Waiting for response");
_receive_buffer_used = 0;
memset(_receive.buffer, 0, RECEIVE_BUFFER_SIZE);
return;
} else if (_receive_buffer_used > frame_length) {
// More data in the receive buffer
log_packet_debug("Potential partial data in the buffer. Verifying");
memmove(_receive.buffer, _receive.buffer + frame_length,
_receive_buffer_used - frame_length);
_receive_buffer_used -= frame_length;
// A recursive call to handle the remaining bytes in the buffer
if (_receive_buffer_used >= 8) {
verify_buffer(); // FIXME: turn this into an external loop
}
return;
} else {
// Undefined state
disable_master_timer();
log_error("Undefined receive buffer state");
seq_pop_poll();
return;
}
}
// Checking the CRC16 checksum
crc16_calculated = crc16(_receive.buffer, frame_length - RS485_FRAME_FOOTER_LENGTH);
crc16_on_packet = (_receive.buffer[frame_length - 2] << 8) | _receive.buffer[frame_length - 1];
if (crc16_calculated != crc16_on_packet) {
// Increase CRC error count
crc_error_count_value++;
// Move on to next slave
disable_master_timer();
log_error("Received response (frame: %s) with CRC-16 mismatch (actual: %04X != expected: %04X)",
frame_get_content_dump(frame_content_dump, _receive.buffer, frame_length),
crc16_calculated, crc16_on_packet);
seq_pop_poll();
return;
}
// Checking address
if (_receive.frame.address != current_request_as_byte_array[0]) {
// Move on to next slave
disable_master_timer();
log_error("Received response (frame: %s) with address mismatch (actual: %u != expected: %u)",
frame_get_content_dump(frame_content_dump, _receive.buffer, frame_length),
_receive.frame.address, current_request_as_byte_array[0]);
seq_pop_poll();
return;
}
// Checking function code
if (_receive.frame.function_code != current_request_as_byte_array[1]) {
// Move on to next slave
disable_master_timer();
log_error("Received response (frame: %s) with function code mismatch (actual: %u != expected: %u)",
frame_get_content_dump(frame_content_dump, _receive.buffer, frame_length),
_receive.frame.function_code, current_request_as_byte_array[1]);
seq_pop_poll();
return;
}
// Received empty packet from the other side (UID=0, FID=0)
if (_receive.packet.header.uid == 0 && _receive.packet.header.function_id == 0) {
// Checking current sequence number
if (_receive.frame.sequence_number != current_request_as_byte_array[2]) {
// Move on to next slave
disable_master_timer();
log_error("Received empty response (frame: %s) with sequence number mismatch (actual: %u != expected: %u)",
frame_get_content_dump(frame_content_dump, _receive.buffer, frame_length),
_receive.frame.sequence_number, current_request_as_byte_array[2]);
seq_pop_poll();
return;
}
disable_master_timer();
log_packet_debug("Received empty response");
// Updating sequence number
++_red_rs485_extension.slaves[master_current_slave_to_process].sequence;
// Popping slave's packet queue
queue_pop(&_red_rs485_extension.slaves[master_current_slave_to_process].packet_queue, NULL);
// Poll next slave after the configured timeout
arm_master_poll_slave_interval_timer();
}
// Received data packet from the other side
else if (_receive.packet.header.uid != 0 && _receive.packet.header.function_id != 0) {
// Checking current sequence number
if (_receive.frame.sequence_number != current_request_as_byte_array[2]) {
log_warn("Received data response (frame: %s) with sequence number mismatch (actual: %u != expected: %u)",
frame_get_content_dump(frame_content_dump, _receive.buffer, frame_length),
_receive.frame.sequence_number, current_request_as_byte_array[2]);
} else {
log_packet_debug("Received data response");
stack_add_recipient(&_red_rs485_extension.base, _receive.packet.header.uid, _receive.frame.address); // FIXME: check return value
// Send message into brickd dispatcher
network_dispatch_response(&_receive.packet);
}
queue_packet = queue_peek(&_red_rs485_extension.slaves[master_current_slave_to_process].packet_queue);
if (queue_packet == NULL) {
log_warn("Sending ACK for unexpected data response");
queue_packet = queue_push(&_red_rs485_extension.slaves[master_current_slave_to_process].packet_queue);
if (queue_packet == NULL) {
log_error("Could not push empty request to packet queue for slave %d: %s (%d)",
_red_rs485_extension.slaves[master_current_slave_to_process].address,
get_errno_name(errno), errno);
return; // FIXME
}
sent_ack_of_data_packet = 2;
} else {
sent_ack_of_data_packet = 1;
}
// Replace head of slave queue with an ACK
memset(queue_packet, 0, sizeof(RS485ExtensionPacket));
queue_packet->tries_left = RS485_FRAME_TRIES_EMPTY;
queue_packet->packet.header.length = 8;
_receive_buffer_used = 0;
memset(_receive.buffer, 0, RECEIVE_BUFFER_SIZE);
log_packet_debug("Sending ACK of the data response");
send_packet();
} else {
// Undefined packet
disable_master_timer();
log_error("Undefined response (frame: %s, U: %s, L: %u, F: %u)",
frame_get_content_dump(frame_content_dump, _receive.buffer, frame_length),
base58_encode(base58, uint32_from_le(_receive.packet.header.uid)),
_receive.packet.header.length,
_receive.packet.header.function_id);
seq_pop_poll();
}
}
// Send packet
void send_packet(void) {
uint16_t packet_crc16 = 0;
uint8_t crc16_first_byte_index = 0;
RS485Slave* current_slave = NULL;
RS485ExtensionPacket* packet_to_send = NULL;
current_slave = &_red_rs485_extension.slaves[master_current_slave_to_process];
packet_to_send = queue_peek(¤t_slave->packet_queue);
if (packet_to_send == NULL) {
// Slave's packet queue is empty. Move on to next slave
log_packet_debug("Slave packet queue empty. Moving on");
// Poll next slave after the configured timeout
arm_master_poll_slave_interval_timer();
return;
}
uint8_t rs485_packet[packet_to_send->packet.header.length + RS485_FRAME_OVERHEAD];
// Assemble packet header
rs485_packet[0] = current_slave->address;
rs485_packet[1] = RS485_EXTENSION_FUNCTION_CODE;
rs485_packet[2] = current_slave->sequence;
// Assemble Tinkerforge packet
memcpy(&rs485_packet[3], packet_to_send, packet_to_send->packet.header.length);
// Calculating CRC16
packet_crc16 = crc16(rs485_packet, packet_to_send->packet.header.length + RS485_FRAME_HEADER_LENGTH);
// Assemble the calculated CRC16
crc16_first_byte_index = packet_to_send->packet.header.length +
RS485_FRAME_HEADER_LENGTH;
rs485_packet[crc16_first_byte_index] = packet_crc16 >> 8;
rs485_packet[++crc16_first_byte_index] = packet_crc16 & 0x00FF;
// Sending packet
if (robust_write(_red_rs485_serial_fd, &rs485_packet, sizeof(rs485_packet)) <= 0) {
log_error("Error sending packet on interface, %s (%d)",
get_errno_name(errno), errno);
// Poll next slave after the configured timeout
arm_master_poll_slave_interval_timer();
return;
}
// Save the packet as byte array
memcpy(¤t_request_as_byte_array, &rs485_packet, sizeof(rs485_packet));
// Set send verify flag
send_verify_flag = 1;
log_packet_debug("Sent packet");
// Start the master timer
master_timer.it_interval.tv_sec = 0;
master_timer.it_interval.tv_nsec = 0;
master_timer.it_value.tv_sec = 0;
master_timer.it_value.tv_nsec = TIMEOUT;
timerfd_settime(_master_timer_event, 0, &master_timer, NULL);
last_timer_enable_at_us = microtime();
}
// Initialize RX state
void init_rxe_pin_state(int extension) {
switch (extension) {
case 0:
_rx_pin.port_index = GPIO_RED_PORT_B;
_rx_pin.pin_index = GPIO_RED_PIN_13;
break;
case 1:
_rx_pin.port_index = GPIO_RED_PORT_G;
#if BRICKD_WITH_RED_BRICK == 9
_rx_pin.pin_index = GPIO_RED_PIN_2;
#else
_rx_pin.pin_index = GPIO_RED_PIN_5;
#endif
break;
}
gpio_red_mux_configure(_rx_pin, GPIO_RED_MUX_OUTPUT);
gpio_red_output_clear(_rx_pin);
log_info("Initialized RS485 RXE state");
}
void disable_master_timer(void) {
uint64_t dummy_read_buffer = 0;
if (robust_read(_master_timer_event, &dummy_read_buffer, sizeof(uint64_t)) < 0) {}
master_timer.it_interval.tv_sec = 0;
master_timer.it_interval.tv_nsec = 0;
master_timer.it_value.tv_sec = 0;
master_timer.it_value.tv_nsec = 0;
timerfd_settime(_master_timer_event, 0, &master_timer, NULL);
log_debug("Disabled master timer");
}
// New data available event handler
void serial_data_available_handler(void* opaque) {
(void)opaque;
// Check if there is space in the receive buffer
if (_receive_buffer_used >= RECEIVE_BUFFER_SIZE) {
log_warn("No more space in the receive buffer. Aborting current request");
// Poll next slave after the configured timeout
arm_master_poll_slave_interval_timer();
return;
}
// Put newly received bytes on the specific index in receive buffer
int bytes_received = robust_read(_red_rs485_serial_fd,
_receive.buffer + _receive_buffer_used,
RECEIVE_BUFFER_SIZE - _receive_buffer_used);
if (bytes_received < 0) {
// FIXME: log error?
return;
}
_receive_buffer_used += bytes_received;
verify_buffer();
}
// Master polling slave event handler
void master_poll_slave(void) {
RS485ExtensionPacket* slave_queue_packet;
sent_ack_of_data_packet = 0;
_receive_buffer_used = 0;
memset(_receive.buffer, 0, RECEIVE_BUFFER_SIZE);
// Updating current slave to process
if (++master_current_slave_to_process >= _red_rs485_extension.slave_num) {
master_current_slave_to_process = 0;
}
log_debug("Updated current RS485 slave's index");
if (_red_rs485_extension.slaves[master_current_slave_to_process].packet_queue.count == 0) {
// Nothing to send in the slave's queue. So send a poll packet
slave_queue_packet = queue_push(&_red_rs485_extension.slaves[master_current_slave_to_process].packet_queue);
if (slave_queue_packet == NULL) {
log_error("Could not push empty request to packet queue for slave %d: %s (%d)",
_red_rs485_extension.slaves[master_current_slave_to_process].address,
get_errno_name(errno), errno);
return;
}
slave_queue_packet->tries_left = RS485_FRAME_TRIES_EMPTY;
slave_queue_packet->packet.header.length = 8;
log_packet_debug("Sending empty packet to slave ID = %d, Sequence number = %d",
_red_rs485_extension.slaves[master_current_slave_to_process].address,
_red_rs485_extension.slaves[master_current_slave_to_process].sequence);
// The timer will be fired by the send function
send_packet();
} else {
log_packet_debug("Sending packet from queue to slave ID = %d, Sequence number = %d",
_red_rs485_extension.slaves[master_current_slave_to_process].address,
_red_rs485_extension.slaves[master_current_slave_to_process].sequence);
// Slave's packet queue if not empty. Send the packet that is at the head of the queue
// The timer will be fired by the send function
send_packet();
}
}
// Master timer event handler
void master_timeout_handler(void* opaque) {
(void)opaque;
disable_master_timer();
if (master_poll_interval) {
// For some unknown reason the timer randomly times out or this timeout function is called
// much long before the actual timeout. This is a fix to this problem
// until we find the real problem
time_passed_from_last_timer_enable = (microtime() - last_timer_enable_at_us) * 1000;
if (time_passed_from_last_timer_enable < MASTER_POLL_SLAVE_INTERVAL) {
master_timer.it_interval.tv_sec = 0;
master_timer.it_interval.tv_nsec = 0;
master_timer.it_value.tv_sec = 0;
master_timer.it_value.tv_nsec = MASTER_POLL_SLAVE_INTERVAL;
timerfd_settime(_master_timer_event, 0, &master_timer, NULL);
last_timer_enable_at_us = microtime();
return;
}
log_debug("Master poll slave interval timed out... time to poll next slave");
master_poll_interval = false;
master_poll_slave();
return;
}
// For some unknown reason the timer randomly times out or this timeout function is called
// much long before the actual timeout. This is a fix to this problem
// until we find the real problem
time_passed_from_last_timer_enable = (microtime() - last_timer_enable_at_us) * 1000;
if (time_passed_from_last_timer_enable < TIMEOUT) {
master_timer.it_interval.tv_sec = 0;
master_timer.it_interval.tv_nsec = 0;
master_timer.it_value.tv_sec = 0;
master_timer.it_value.tv_nsec = TIMEOUT;
timerfd_settime(_master_timer_event, 0, &master_timer, NULL);
last_timer_enable_at_us = microtime();
return;
}
log_debug("Current request timed out. Moving on");
// Current request timedout. Move on to next slave
if (is_current_request_empty()) {
++_red_rs485_extension.slaves[master_current_slave_to_process].sequence;
}
pop_packet_from_slave_queue();
// Poll next slave after the configured timeout
arm_master_poll_slave_interval_timer();
}
void pop_packet_from_slave_queue(void) {
RS485ExtensionPacket* current_slave_queue_packet;
current_slave_queue_packet = queue_peek(&_red_rs485_extension.slaves[master_current_slave_to_process].packet_queue);
if (current_slave_queue_packet != NULL && --current_slave_queue_packet->tries_left == 0) {
queue_pop(&_red_rs485_extension.slaves[master_current_slave_to_process].packet_queue, NULL);
}
}
bool is_current_request_empty(void) {
uint32_t uid;
memcpy(&uid, ¤t_request_as_byte_array[3], sizeof(uint32_t));
if (uid == 0 && current_request_as_byte_array[7] == 8 &&
current_request_as_byte_array[8] == 0) {
return true;
} else {
return false;
}
}
void seq_pop_poll(void) {
if (is_current_request_empty()) {
log_debug("Updating sequence");
++_red_rs485_extension.slaves[master_current_slave_to_process].sequence;
}
pop_packet_from_slave_queue();
// Poll next slave after the configured timeout
arm_master_poll_slave_interval_timer();
}
void arm_master_poll_slave_interval_timer(void) {
log_debug("Waiting before polling next slave");
master_poll_interval = true;
master_timer.it_interval.tv_sec = 0;
master_timer.it_interval.tv_nsec = 0;
master_timer.it_value.tv_sec = 0;
master_timer.it_value.tv_nsec = MASTER_POLL_SLAVE_INTERVAL;
timerfd_settime(_master_timer_event, 0, &master_timer, NULL);
last_timer_enable_at_us = microtime();
}
// New packet from brickd event loop is queued to be sent via RS485 interface
int red_rs485_extension_dispatch_to_rs485(Stack *stack, Packet *request, Recipient *recipient) {
RS485ExtensionPacket* queued_request;
int i;
(void)stack;
if (request->header.uid == 0 || recipient == NULL) {
log_packet_debug("Broadcasting to all available slaves");
for (i = 0; i < _red_rs485_extension.slave_num; i++) {
queued_request = queue_push(&_red_rs485_extension.slaves[i].packet_queue);
if (queued_request == NULL) {
log_error("Could not push request (%s) to packet queue for slave %d, dropping request: %s (%d)",
packet_get_request_signature(packet_signature, request),
_red_rs485_extension.slaves[i].address,
get_errno_name(errno), errno);
return -1;
}
queued_request->tries_left = RS485_FRAME_TRIES_DATA;
memcpy(&queued_request->packet, request, request->header.length);
log_packet_debug("Broadcast... Packet is queued to be sent to slave %d. Function signature = (%s)",
_red_rs485_extension.slaves[i].address,
packet_get_request_signature(packet_signature, request));
}
} else if (recipient != NULL) {
for (i = 0; i < _red_rs485_extension.slave_num; i++) {
if (_red_rs485_extension.slaves[i].address == recipient->opaque) {
queued_request = queue_push(&_red_rs485_extension.slaves[i].packet_queue);
if (queued_request == NULL) {
log_error("Could not push request (%s) to packet queue for slave %d, dropping request: %s (%d)",
packet_get_request_signature(packet_signature, request),
_red_rs485_extension.slaves[i].address,
get_errno_name(errno), errno);
return -1;
}
queued_request->tries_left = RS485_FRAME_TRIES_DATA;
memcpy(&queued_request->packet, request, request->header.length);
log_packet_debug("Packet is queued to be sent to slave %d over. Function signature = (%s)",
_red_rs485_extension.slaves[i].address,
packet_get_request_signature(packet_signature, request));
break;
}
}
}
return 0;
}
// Init function called from central brickd code
int red_rs485_extension_init(ExtensionRS485Config *rs485_config) {
int phase = 0;
bool cleanup_return_zero = false;
int i;
bool init_crc_error_count = false;
log_info("Initializing extension subsystem");
MASTER_POLL_SLAVE_INTERVAL = (uint64_t)config_get_option_value("poll_delay.rs485")->integer * 1000;
// Create base stack
if (stack_create(&_red_rs485_extension.base, "red_rs485_extension",
red_rs485_extension_dispatch_to_rs485) < 0) {
log_error("Could not create base stack for extension, %s (%d)",
get_errno_name(errno), errno);
goto cleanup;
}
phase = 1;
// Add to stacks array
if (hardware_add_stack(&_red_rs485_extension.base) < 0) {
goto cleanup;
}
phase = 2;
// Saving eeprom config
_red_rs485_extension.address = rs485_config->address;
_red_rs485_extension.baudrate = rs485_config->baudrate;
_red_rs485_extension.parity = rs485_config->parity;
_red_rs485_extension.stopbits = rs485_config->stopbits;
if (rs485_config->address == 0) {
_red_rs485_extension.slave_num = rs485_config->slave_num;
for (i = 0; i < _red_rs485_extension.slave_num; i++) {
_red_rs485_extension.slaves[i].address = rs485_config->slave_address[i];
_red_rs485_extension.slaves[i].sequence = 0;
if (queue_create(&_red_rs485_extension.slaves[i].packet_queue, sizeof(RS485ExtensionPacket)) < 0) {
log_error("Could not create slave queue, %s (%d)",
get_errno_name(errno), errno);
goto cleanup;
}
}
} else {
log_error("Only master mode supported");
cleanup_return_zero = true;
goto cleanup;
}
// Calculate time to send number of bytes of max packet length and to receive the same amount
TIMEOUT = (((double)(TIMEOUT_BYTES / (double)(_red_rs485_extension.baudrate / 8)) *
(double)1000000000) * (double)2) + (double)8000000;