123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111 |
- #include <stddef.h>
- #include <avr/io.h>
- #include <util/twi.h>
- #include <avr/interrupt.h>
- #include <stdbool.h>
- #include "i2c_slave.h"
- #if defined(USE_I2C) && defined(SPLIT_COMMON_TRANSACTIONS)
- # include "transactions.h"
- static volatile bool is_callback_executor = false;
- #endif
- volatile uint8_t i2c_slave_reg[I2C_SLAVE_REG_COUNT];
- static volatile uint8_t buffer_address;
- static volatile bool slave_has_register_set = false;
- void i2c_slave_init(uint8_t address) {
-
- TWAR = address;
-
- TWCR = (1 << TWIE) | (1 << TWEA) | (1 << TWINT) | (1 << TWEN);
- }
- void i2c_slave_stop(void) {
-
- TWCR &= ~((1 << TWEA) | (1 << TWEN));
- }
- ISR(TWI_vect) {
- uint8_t ack = 1;
- switch (TW_STATUS) {
- case TW_SR_SLA_ACK:
-
- slave_has_register_set = false;
- #if defined(USE_I2C) && defined(SPLIT_COMMON_TRANSACTIONS)
- is_callback_executor = false;
- #endif
- break;
- case TW_SR_DATA_ACK:
-
-
- if (!slave_has_register_set) {
- buffer_address = TWDR;
- if (buffer_address >= I2C_SLAVE_REG_COUNT) {
- ack = 0;
- buffer_address = 0;
- }
- slave_has_register_set = true;
- #if defined(USE_I2C) && defined(SPLIT_COMMON_TRANSACTIONS)
-
- is_callback_executor = buffer_address == split_transaction_table[I2C_EXECUTE_CALLBACK].initiator2target_offset;
- #endif
- } else {
- i2c_slave_reg[buffer_address] = TWDR;
- buffer_address++;
- #if defined(USE_I2C) && defined(SPLIT_COMMON_TRANSACTIONS)
-
- if (is_callback_executor) {
- split_transaction_desc_t *trans = &split_transaction_table[split_shmem->transaction_id];
- if (trans->slave_callback) {
- trans->slave_callback(trans->initiator2target_buffer_size, split_trans_initiator2target_buffer(trans), trans->target2initiator_buffer_size, split_trans_target2initiator_buffer(trans));
- }
- }
- #endif
- }
- break;
- case TW_ST_SLA_ACK:
- case TW_ST_DATA_ACK:
-
- TWDR = i2c_slave_reg[buffer_address];
- buffer_address++;
- break;
- case TW_BUS_ERROR:
-
- TWCR = 0;
- default:
- break;
- }
-
- TWCR |= (1 << TWIE) | (1 << TWINT) | (ack << TWEA) | (1 << TWEN);
- }
|