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Diffstat (limited to 'drivers/avr/i2c_master.c')
| -rw-r--r-- | drivers/avr/i2c_master.c | 224 |
1 files changed, 0 insertions, 224 deletions
diff --git a/drivers/avr/i2c_master.c b/drivers/avr/i2c_master.c deleted file mode 100644 index b1e4885298..0000000000 --- a/drivers/avr/i2c_master.c +++ /dev/null @@ -1,224 +0,0 @@ -/* Copyright (C) 2019 Elia Ritterbusch - + - * 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 3 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, see <https://www.gnu.org/licenses/>. - */ -/* Library made by: g4lvanix - * GitHub repository: https://github.com/g4lvanix/I2C-master-lib - */ - -#include <avr/io.h> -#include <util/twi.h> - -#include "i2c_master.h" -#include "timer.h" -#include "wait.h" - -#ifndef F_SCL -# define F_SCL 400000UL // SCL frequency -#endif - -#define TWBR_val (((F_CPU / F_SCL) - 16) / 2) - -void i2c_init(void) { - TWSR = 0; /* no prescaler */ - TWBR = (uint8_t)TWBR_val; - -#ifdef __AVR_ATmega32A__ - // set pull-up resistors on I2C bus pins - PORTC |= 0b11; - - // enable TWI (two-wire interface) - TWCR |= (1 << TWEN); - - // enable TWI interrupt and slave address ACK - TWCR |= (1 << TWIE); - TWCR |= (1 << TWEA); -#endif -} - -i2c_status_t i2c_start(uint8_t address, uint16_t timeout) { - // reset TWI control register - TWCR = 0; - // transmit START condition - TWCR = (1 << TWINT) | (1 << TWSTA) | (1 << TWEN); - - uint16_t timeout_timer = timer_read(); - while (!(TWCR & (1 << TWINT))) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { - return I2C_STATUS_TIMEOUT; - } - } - - // check if the start condition was successfully transmitted - if (((TW_STATUS & 0xF8) != TW_START) && ((TW_STATUS & 0xF8) != TW_REP_START)) { - return I2C_STATUS_ERROR; - } - - // load slave address into data register - TWDR = address; - // start transmission of address - TWCR = (1 << TWINT) | (1 << TWEN); - - timeout_timer = timer_read(); - while (!(TWCR & (1 << TWINT))) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { - return I2C_STATUS_TIMEOUT; - } - } - - // check if the device has acknowledged the READ / WRITE mode - uint8_t twst = TW_STATUS & 0xF8; - if ((twst != TW_MT_SLA_ACK) && (twst != TW_MR_SLA_ACK)) { - return I2C_STATUS_ERROR; - } - - return I2C_STATUS_SUCCESS; -} - -i2c_status_t i2c_write(uint8_t data, uint16_t timeout) { - // load data into data register - TWDR = data; - // start transmission of data - TWCR = (1 << TWINT) | (1 << TWEN); - - uint16_t timeout_timer = timer_read(); - while (!(TWCR & (1 << TWINT))) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { - return I2C_STATUS_TIMEOUT; - } - } - - if ((TW_STATUS & 0xF8) != TW_MT_DATA_ACK) { - return I2C_STATUS_ERROR; - } - - return I2C_STATUS_SUCCESS; -} - -int16_t i2c_read_ack(uint16_t timeout) { - // start TWI module and acknowledge data after reception - TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWEA); - - uint16_t timeout_timer = timer_read(); - while (!(TWCR & (1 << TWINT))) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { - return I2C_STATUS_TIMEOUT; - } - } - - // return received data from TWDR - return TWDR; -} - -int16_t i2c_read_nack(uint16_t timeout) { - // start receiving without acknowledging reception - TWCR = (1 << TWINT) | (1 << TWEN); - - uint16_t timeout_timer = timer_read(); - while (!(TWCR & (1 << TWINT))) { - if ((timeout != I2C_TIMEOUT_INFINITE) && ((timer_read() - timeout_timer) >= timeout)) { - return I2C_STATUS_TIMEOUT; - } - } - - // return received data from TWDR - return TWDR; -} - -i2c_status_t i2c_transmit(uint8_t address, const uint8_t* data, uint16_t length, uint16_t timeout) { - i2c_status_t status = i2c_start(address | I2C_WRITE, timeout); - - for (uint16_t i = 0; i < length && status >= 0; i++) { - status = i2c_write(data[i], timeout); - } - - i2c_stop(); - - return status; -} - -i2c_status_t i2c_receive(uint8_t address, uint8_t* data, uint16_t length, uint16_t timeout) { - i2c_status_t status = i2c_start(address | I2C_READ, timeout); - - for (uint16_t i = 0; i < (length - 1) && status >= 0; i++) { - status = i2c_read_ack(timeout); - if (status >= 0) { - data[i] = status; - } - } - - if (status >= 0) { - status = i2c_read_nack(timeout); - if (status >= 0) { - data[(length - 1)] = status; - } - } - - i2c_stop(); - - return (status < 0) ? status : I2C_STATUS_SUCCESS; -} - -i2c_status_t i2c_writeReg(uint8_t devaddr, uint8_t regaddr, const uint8_t* data, uint16_t length, uint16_t timeout) { - i2c_status_t status = i2c_start(devaddr | 0x00, timeout); - if (status >= 0) { - status = i2c_write(regaddr, timeout); - - for (uint16_t i = 0; i < length && status >= 0; i++) { - status = i2c_write(data[i], timeout); - } - } - - i2c_stop(); - - return status; -} - -i2c_status_t i2c_readReg(uint8_t devaddr, uint8_t regaddr, uint8_t* data, uint16_t length, uint16_t timeout) { - i2c_status_t status = i2c_start(devaddr, timeout); - if (status < 0) { - goto error; - } - - status = i2c_write(regaddr, timeout); - if (status < 0) { - goto error; - } - - status = i2c_start(devaddr | 0x01, timeout); - - for (uint16_t i = 0; i < (length - 1) && status >= 0; i++) { - status = i2c_read_ack(timeout); - if (status >= 0) { - data[i] = status; - } - } - - if (status >= 0) { - status = i2c_read_nack(timeout); - if (status >= 0) { - data[(length - 1)] = status; - } - } - -error: - i2c_stop(); - - return (status < 0) ? status : I2C_STATUS_SUCCESS; -} - -void i2c_stop(void) { - // transmit STOP condition - TWCR = (1 << TWINT) | (1 << TWEN) | (1 << TWSTO); -} |