--- /dev/null
+/*
+ * WARNING: be careful changing this code, it is very timing dependent
+ */
+
+#ifndef F_CPU
+#define F_CPU 16000000
+#endif
+
+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <util/delay.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include "serial.h"
+//#include <pro_micro.h>
+
+#ifdef USE_SERIAL
+//#ifndef USE_SERIAL_PD2
+
+#ifndef SERIAL_USE_MULTI_TRANSACTION
+/* --- USE Simple API (OLD API, compatible with let's split serial.c) */
+ #if SERIAL_SLAVE_BUFFER_LENGTH > 0
+ uint8_t volatile serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH] = {0};
+ #endif
+ #if SERIAL_MASTER_BUFFER_LENGTH > 0
+ uint8_t volatile serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH] = {0};
+ #endif
+ uint8_t volatile status0 = 0;
+
+SSTD_t transactions[] = {
+ { (uint8_t *)&status0,
+ #if SERIAL_MASTER_BUFFER_LENGTH > 0
+ sizeof(serial_master_buffer), (uint8_t *)serial_master_buffer,
+ #else
+ 0, (uint8_t *)NULL,
+ #endif
+ #if SERIAL_SLAVE_BUFFER_LENGTH > 0
+ sizeof(serial_slave_buffer), (uint8_t *)serial_slave_buffer
+ #else
+ 0, (uint8_t *)NULL,
+ #endif
+ }
+};
+
+void serial_master_init(void)
+{ soft_serial_initiator_init(transactions); }
+
+void serial_slave_init(void)
+{ soft_serial_target_init(transactions); }
+
+// 0 => no error
+// 1 => slave did not respond
+// 2 => checksum error
+int serial_update_buffers()
+{ return soft_serial_transaction(); }
+
+#endif // Simple API (OLD API, compatible with let's split serial.c)
+
+#define ALWAYS_INLINE __attribute__((always_inline))
+#define NO_INLINE __attribute__((noinline))
+#define _delay_sub_us(x) __builtin_avr_delay_cycles(x)
+
+// Serial pulse period in microseconds.
+#define TID_SEND_ADJUST 14
+
+#define SELECT_SERIAL_SPEED 1
+#if SELECT_SERIAL_SPEED == 0
+ // Very High speed
+ #define SERIAL_DELAY 4 // micro sec
+ #define READ_WRITE_START_ADJUST 33 // cycles
+ #define READ_WRITE_WIDTH_ADJUST 3 // cycles
+#elif SELECT_SERIAL_SPEED == 1
+ // High speed
+ #define SERIAL_DELAY 6 // micro sec
+ #define READ_WRITE_START_ADJUST 30 // cycles
+ #define READ_WRITE_WIDTH_ADJUST 3 // cycles
+#elif SELECT_SERIAL_SPEED == 2
+ // Middle speed
+ #define SERIAL_DELAY 12 // micro sec
+ #define READ_WRITE_START_ADJUST 30 // cycles
+ #define READ_WRITE_WIDTH_ADJUST 3 // cycles
+#elif SELECT_SERIAL_SPEED == 3
+ // Low speed
+ #define SERIAL_DELAY 24 // micro sec
+ #define READ_WRITE_START_ADJUST 30 // cycles
+ #define READ_WRITE_WIDTH_ADJUST 3 // cycles
+#elif SELECT_SERIAL_SPEED == 4
+ // Very Low speed
+ #define SERIAL_DELAY 50 // micro sec
+ #define READ_WRITE_START_ADJUST 30 // cycles
+ #define READ_WRITE_WIDTH_ADJUST 3 // cycles
+#else
+#error Illegal Serial Speed
+#endif
+
+
+#define SERIAL_DELAY_HALF1 (SERIAL_DELAY/2)
+#define SERIAL_DELAY_HALF2 (SERIAL_DELAY - SERIAL_DELAY/2)
+
+#define SLAVE_INT_WIDTH_US 1
+#ifndef SERIAL_USE_MULTI_TRANSACTION
+ #define SLAVE_INT_RESPONSE_TIME SERIAL_DELAY
+#else
+ #define SLAVE_INT_ACK_WIDTH_UNIT 2
+ #define SLAVE_INT_ACK_WIDTH 4
+#endif
+
+static SSTD_t *Transaction_table = NULL;
+
+inline static
+void serial_delay(void) {
+ _delay_us(SERIAL_DELAY);
+}
+
+inline static
+void serial_delay_half1(void) {
+ _delay_us(SERIAL_DELAY_HALF1);
+}
+
+inline static
+void serial_delay_half2(void) {
+ _delay_us(SERIAL_DELAY_HALF2);
+}
+
+inline static void serial_output(void) ALWAYS_INLINE;
+inline static
+void serial_output(void) {
+ SERIAL_PIN_DDR |= SERIAL_PIN_MASK;
+}
+
+// make the serial pin an input with pull-up resistor
+inline static void serial_input_with_pullup(void) ALWAYS_INLINE;
+inline static
+void serial_input_with_pullup(void) {
+ SERIAL_PIN_DDR &= ~SERIAL_PIN_MASK;
+ SERIAL_PIN_PORT |= SERIAL_PIN_MASK;
+}
+
+inline static
+uint8_t serial_read_pin(void) {
+ return !!(SERIAL_PIN_INPUT & SERIAL_PIN_MASK);
+}
+
+inline static void serial_low(void) ALWAYS_INLINE;
+inline static
+void serial_low(void) {
+ SERIAL_PIN_PORT &= ~SERIAL_PIN_MASK;
+}
+
+inline static void serial_high(void) ALWAYS_INLINE;
+inline static
+void serial_high(void) {
+ SERIAL_PIN_PORT |= SERIAL_PIN_MASK;
+}
+
+void soft_serial_initiator_init(SSTD_t *sstd_table)
+{
+ Transaction_table = sstd_table;
+ serial_output();
+ serial_high();
+}
+
+void soft_serial_target_init(SSTD_t *sstd_table)
+{
+ Transaction_table = sstd_table;
+ serial_input_with_pullup();
+
+#if SERIAL_PIN_MASK == _BV(PD0)
+ // Enable INT0
+ EIMSK |= _BV(INT0);
+ // Trigger on falling edge of INT0
+ EICRA &= ~(_BV(ISC00) | _BV(ISC01));
+#elif SERIAL_PIN_MASK == _BV(PD2)
+ // Enable INT2
+ EIMSK |= _BV(INT2);
+ // Trigger on falling edge of INT2
+ EICRA &= ~(_BV(ISC20) | _BV(ISC21));
+#else
+ #error unknown SERIAL_PIN_MASK value
+#endif
+}
+
+// Used by the sender to synchronize timing with the reciver.
+static void sync_recv(void) NO_INLINE;
+static
+void sync_recv(void) {
+ for (uint8_t i = 0; i < SERIAL_DELAY*5 && serial_read_pin(); i++ ) {
+ }
+ // This shouldn't hang if the target disconnects because the
+ // serial line will float to high if the target does disconnect.
+ while (!serial_read_pin());
+}
+
+// Used by the reciver to send a synchronization signal to the sender.
+static void sync_send(void)NO_INLINE;
+static
+void sync_send(void) {
+ serial_low();
+ serial_delay();
+ serial_high();
+}
+
+// Reads a byte from the serial line
+static uint8_t serial_read_chunk(uint8_t *pterrcount, uint8_t bit) NO_INLINE;
+static uint8_t serial_read_chunk(uint8_t *pterrcount, uint8_t bit) {
+ uint8_t byte, i, p, pb;
+
+ _delay_sub_us(READ_WRITE_START_ADJUST);
+ for( i = 0, byte = 0, p = 0; i < bit; i++ ) {
+ serial_delay_half1(); // read the middle of pulses
+ if( serial_read_pin() ) {
+ byte = (byte << 1) | 1; p ^= 1;
+ } else {
+ byte = (byte << 1) | 0; p ^= 0;
+ }
+ _delay_sub_us(READ_WRITE_WIDTH_ADJUST);
+ serial_delay_half2();
+ }
+ /* recive parity bit */
+ serial_delay_half1(); // read the middle of pulses
+ pb = serial_read_pin();
+ _delay_sub_us(READ_WRITE_WIDTH_ADJUST);
+ serial_delay_half2();
+
+ *pterrcount += (p != pb)? 1 : 0;
+
+ return byte;
+}
+
+// Sends a byte with MSB ordering
+void serial_write_chunk(uint8_t data, uint8_t bit) NO_INLINE;
+void serial_write_chunk(uint8_t data, uint8_t bit) {
+ uint8_t b, p;
+ for( p = 0, b = 1<<(bit-1); b ; b >>= 1) {
+ if(data & b) {
+ serial_high(); p ^= 1;
+ } else {
+ serial_low(); p ^= 0;
+ }
+ serial_delay();
+ }
+ /* send parity bit */
+ if(p & 1) { serial_high(); }
+ else { serial_low(); }
+ serial_delay();
+
+ serial_low(); // sync_send() / senc_recv() need raise edge
+}
+
+static void serial_send_packet(uint8_t *buffer, uint8_t size) NO_INLINE;
+static
+void serial_send_packet(uint8_t *buffer, uint8_t size) {
+ for (uint8_t i = 0; i < size; ++i) {
+ uint8_t data;
+ data = buffer[i];
+ sync_send();
+ serial_write_chunk(data,8);
+ }
+}
+
+static uint8_t serial_recive_packet(uint8_t *buffer, uint8_t size) NO_INLINE;
+static
+uint8_t serial_recive_packet(uint8_t *buffer, uint8_t size) {
+ uint8_t pecount = 0;
+ for (uint8_t i = 0; i < size; ++i) {
+ uint8_t data;
+ sync_recv();
+ data = serial_read_chunk(&pecount, 8);
+ buffer[i] = data;
+ }
+ return pecount == 0;
+}
+
+inline static
+void change_sender2reciver(void) {
+ sync_send(); //0
+ serial_delay_half1(); //1
+ serial_low(); //2
+ serial_input_with_pullup(); //2
+ serial_delay_half1(); //3
+}
+
+inline static
+void change_reciver2sender(void) {
+ sync_recv(); //0
+ serial_delay(); //1
+ serial_low(); //3
+ serial_output(); //3
+ serial_delay_half1(); //4
+}
+
+// interrupt handle to be used by the target device
+ISR(SERIAL_PIN_INTERRUPT) {
+
+#ifndef SERIAL_USE_MULTI_TRANSACTION
+ serial_low();
+ serial_output();
+ SSTD_t *trans = Transaction_table;
+#else
+ // recive transaction table index
+ uint8_t tid;
+ uint8_t pecount = 0;
+ sync_recv();
+ tid = serial_read_chunk(&pecount,4);
+ if(pecount> 0)
+ return;
+ serial_delay_half1();
+
+ serial_high(); // response step1 low->high
+ serial_output();
+ _delay_sub_us(SLAVE_INT_ACK_WIDTH_UNIT*SLAVE_INT_ACK_WIDTH);
+ SSTD_t *trans = &Transaction_table[tid];
+ serial_low(); // response step2 ack high->low
+#endif
+
+ // target send phase
+ if( trans->target2initiator_buffer_size > 0 )
+ serial_send_packet((uint8_t *)trans->target2initiator_buffer,
+ trans->target2initiator_buffer_size);
+ // target switch to input
+ change_sender2reciver();
+
+ // target recive phase
+ if( trans->initiator2target_buffer_size > 0 ) {
+ if (serial_recive_packet((uint8_t *)trans->initiator2target_buffer,
+ trans->initiator2target_buffer_size) ) {
+ *trans->status = TRANSACTION_ACCEPTED;
+ } else {
+ *trans->status = TRANSACTION_DATA_ERROR;
+ }
+ } else {
+ *trans->status = TRANSACTION_ACCEPTED;
+ }
+
+ sync_recv(); //weit initiator output to high
+}
+
+/////////
+// start transaction by initiator
+//
+// int soft_serial_transaction(int sstd_index)
+//
+// Returns:
+// TRANSACTION_END
+// TRANSACTION_NO_RESPONSE
+// TRANSACTION_DATA_ERROR
+// this code is very time dependent, so we need to disable interrupts
+#ifndef SERIAL_USE_MULTI_TRANSACTION
+int soft_serial_transaction(void) {
+ SSTD_t *trans = Transaction_table;
+#else
+int soft_serial_transaction(int sstd_index) {
+ SSTD_t *trans = &Transaction_table[sstd_index];
+#endif
+ cli();
+
+ // signal to the target that we want to start a transaction
+ serial_output();
+ serial_low();
+ _delay_us(SLAVE_INT_WIDTH_US);
+
+#ifndef SERIAL_USE_MULTI_TRANSACTION
+ // wait for the target response
+ serial_input_with_pullup();
+ _delay_us(SLAVE_INT_RESPONSE_TIME);
+
+ // check if the target is present
+ if (serial_read_pin()) {
+ // target failed to pull the line low, assume not present
+ serial_output();
+ serial_high();
+ *trans->status = TRANSACTION_NO_RESPONSE;
+ sei();
+ return TRANSACTION_NO_RESPONSE;
+ }
+
+#else
+ // send transaction table index
+ sync_send();
+ _delay_sub_us(TID_SEND_ADJUST);
+ serial_write_chunk(sstd_index, 4);
+ serial_delay_half1();
+
+ // wait for the target response (step1 low->high)
+ serial_input_with_pullup();
+ while( !serial_read_pin() ) {
+ _delay_sub_us(2);
+ }
+
+ // check if the target is present (step2 high->low)
+ for( int i = 0; serial_read_pin(); i++ ) {
+ if (i > SLAVE_INT_ACK_WIDTH + 1) {
+ // slave failed to pull the line low, assume not present
+ serial_output();
+ serial_high();
+ *trans->status = TRANSACTION_NO_RESPONSE;
+ sei();
+ return TRANSACTION_NO_RESPONSE;
+ }
+ _delay_sub_us(SLAVE_INT_ACK_WIDTH_UNIT);
+ }
+#endif
+
+ // initiator recive phase
+ // if the target is present syncronize with it
+ if( trans->target2initiator_buffer_size > 0 ) {
+ if (!serial_recive_packet((uint8_t *)trans->target2initiator_buffer,
+ trans->target2initiator_buffer_size) ) {
+ serial_output();
+ serial_high();
+ *trans->status = TRANSACTION_DATA_ERROR;
+ sei();
+ return TRANSACTION_DATA_ERROR;
+ }
+ }
+
+ // initiator switch to output
+ change_reciver2sender();
+
+ // initiator send phase
+ if( trans->initiator2target_buffer_size > 0 ) {
+ serial_send_packet((uint8_t *)trans->initiator2target_buffer,
+ trans->initiator2target_buffer_size);
+ }
+
+ // always, release the line when not in use
+ sync_send();
+
+ *trans->status = TRANSACTION_END;
+ sei();
+ return TRANSACTION_END;
+}
+
+#ifdef SERIAL_USE_MULTI_TRANSACTION
+int soft_serial_get_and_clean_status(int sstd_index) {
+ SSTD_t *trans = &Transaction_table[sstd_index];
+ cli();
+ int retval = *trans->status;
+ *trans->status = 0;;
+ sei();
+ return retval;
+}
+#endif
+
+#endif
projects / qmk_firmware.git / blobdiff